23920 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

DEPARTMENT OF ENERGY 

10 CFR Parts 429 and 431 

[EERE–2017–BT–TP–0010] 

RIN 1904–AD78 

Energy Conservation Program: Test 

Procedures for Walk-In Coolers and 

Walk-In Freezers 

AGENCY: Office of Energy Efficiency and 

Renewable Energy, Department of 

Energy. 

ACTION: Notice of proposed rulemaking 

and announcement of public webinar. 

SUMMARY: The U.S. Department of 

Energy (‘‘DOE’’) proposes to amend the 

test procedures for walk-in coolers and 

walk-in freezers to harmonize with 

updated industry standards, revise the 

test methods to more fully represent 

field energy use, and better account for 

the range of walk-in cooler and walk-in 

freezer component equipment designs. 

DOE also proposes to revise certain 

definitions applicable to walk-ins. DOE 

is seeking comment from interested 

parties on the proposal and announcing 

a public meeting to collect comments 

and data on its proposal. 

DATES: DOE will accept comments, data, 

and information regarding this proposal 

no later than June 21, 2022. See section 

V, ‘‘Public Participation,’’ for details. 

DOE will hold a webinar on Monday, 

May 9, from 1:00 p.m. to 5:00 p.m. See 

section V, ‘‘Public Participation,’’ for 

webinar registration information, 

participant instructions, and 

information about the capabilities 

available to webinar participants. 

ADDRESSES: Interested persons are 

encouraged to submit comments using 

the Federal eRulemaking Portal at 

www.regulations.gov, under docket 

number EERE–2017–BT–TP–0010. 

Follow the instructions for submitting 

comments. Alternatively, interested 

persons may submit comments by email 

to WICF2017TP0010@ee.doe.gov. 

Include docket number EERE–2017–BT– 

TP–0010 in the subject line of the 

message. 

No telefacsimiles (‘‘faxes’’) will be 

accepted. For detailed instructions on 

submitting comments and additional 

information on this process, See section 

V of this document. 

Although DOE has routinely accepted 

public comment submissions through a 

variety of mechanisms, including postal 

mail and hand delivery/courier, the 

Department has found it necessary to 

make temporary modifications to the 

comment submission process in light of 

the ongoing coronavirus 2019 (‘‘COVID– 

19 pandemic’’). DOE is currently 

suspending receipt of public comments 

via postal mail and hand delivery/ 

courier. If a commenter finds that this 

change poses an undue hardship, please 

contact Appliance Standards Program 

staff at (202) 586–1445 to discuss the 

need for alternative arrangements. Once 

the COVID–19 pandemic health 

emergency is resolved, DOE anticipates 

resuming all of its regular options for 

public comment submission, including 

postal mail and hand delivery/courier. 

Docket: The docket, which includes 

Federal Register notices, public meeting 

attendee lists and transcripts (if a public 

meeting is held), comments, and other 

supporting documents/materials, is 

available for review at 

www.regulations.gov. All documents in 

the docket are listed in the 

www.regulations.gov index. However, 

some documents listed in the index, 

such as those containing information 

that is exempt from public disclosure, 

may not be publicly available. 

The docket web page can be found at 

www.regulations.gov/docket/EERE2017-BT-TP-0010. The docket web page 

contains instructions on how to access 

all documents, including public 

comments, in the docket. See section V 

for information on how to submit 

comments through 

www.regulations.gov. 

FOR FURTHER INFORMATION CONTACT:

Dr. Stephanie Johnson, U.S. 

Department of Energy, Office of Energy 

Efficiency and Renewable Energy, 

Building Technologies Office, EE–2J, 

1000 Independence Avenue SW, 

Washington, DC 20585–0121. 

Telephone: (202) 287–1943. Email 

ApplianceStandardsQuestions@

ee.doe.gov. 

Mr. Michael Kido, U.S. Department of 

Energy, Office of the General Counsel, 

GC–33, 1000 Independence Avenue SW, 

Washington, DC 20585–0121. 

Telephone: (202) 586–8145. Email: 

Michael.Kido@hq.doe.gov. 

For further information on how to 

submit a comment, review other public 

comments and the docket, or participate 

in a public meeting (if one is held), 

contact the Appliance and Equipment 

Standards Program staff at (202) 287– 

1445 or by email: 

ApplianceStandardsQuestions@

ee.doe.gov. 

SUPPLEMENTARY INFORMATION: DOE 

proposes to maintain previously 

approved incorporations by reference 

and to incorporate by reference the 

following industry standards into part 

431: 

ANSI/AHRI Standard 420–2008, 

‘‘Performance Rating of ForcedCirculation Free-Delivery Unit Coolers 

for Refrigeration,’’ copyright 2008. 

AHRI Standard 1250 (I–P)–2009, 

‘‘Standard for Performance Rating of 

Walk-in Coolers and Freezers,’’ 

(including Errata sheet dated December 

2015), copyright 2009, except Table 15 

and Table 16. 

AHRI Standard 1250–2020, ‘‘Standard 

for Performane Rating of Walk-in 

Coolers and Freezers,’’ copyright 2020. 

Copies of AHRI 420–2008, AHRI 

1250–2009, and AHRI 1250–2020 can be 

obtained from the Air-Conditioning, 

Heating, and Refrigeration Institute, 

2111 Wilson Boulevard, Suite 500, 

Arlington, VA 22201, or by going to 

www.ahrinet.org. 

ANSI/ASHRAE Standard 16–2016, 

‘‘Method of Testing for Rating Room Air 

Conditioners, Packaged Terminal Air 

Conditioners, and Packaged Terminal 

Heat Pumps for Cooling and Heating 

Capacity,’’ approved October 31, 2016. 

ANSI/ASHRAE Standard 23.1–2010, 

‘‘Methods of Testing for Rating the 

Performance of Positive Displacement 

Refrigerant Compressors and 

Condensing Units that Operate at 

Subcritical Temperatures of the 

Refrigerant,’’ ANSI approved January 

28, 2010. 

ANSI/ASHRAE Standard 37–2009, 

‘‘Methods of Testing for Rating 

Electrically Driven Unitary AirConditioning and Heat Pump 

Equipment,’’ approved June 24, 2009. 

Copies of ANSI/ASHRAE 16, 

ASHRAE 23.1–2010, and ANSI/ 

ASHRAE 37 can be obtained from the 

American Society of Heating, 

Refrigerating and Air-Conditioning 

Engineers, 180 Technology Parkway, 

Peachtree Corners, GA 30092, or by 

going to: www.ashrae.org. 

ASTM C518–17, ‘‘Standard Test 

Method for Steady state Thermal 

Transmission Properties by Means of 

the Heat Flow Meter Apparatus,’’ ASTM 

approved May 1, 2017. 

ASTM C1199–14, ‘‘Standard Test 

Method for Measuring the Steady state 

Thermal Transmittance of Fenestration 

Systems Using Hot Box Methods,’’ 

ASTM approved February 1, 2014. 

Copies of ASTM C518–17 and ASTM 

C1199–14 can be obtained from the 

American Society for Testing and 

Materials, 100 Barr Harbor Drive, West 

Conshohocken, PA 19428–2959, or by 

going to www.astm.org. 

NFRC 102–2020 [E0A0], ‘‘Procedure 

for Measuring the Stready-State Thermal 

Transmittance of Fenestration Systems.’’ 

Copies of NFRC 102–2020 can be 

obtained from the National Fenestration 

Rating Council, 6305 Ivy Lane, Ste. 140, 

Greenbelt, MD 20770, or by going to 

www.nfrc.org/. 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23921 

1All references to EPCA in this document refer 

to the statute as amended through the Energy Act 

of 2020, Public Law 116–260 (Dec. 27, 2020). 

See section IV.M of this document for 

a further discussion of these standards. 

Table of Contents 

I. Authority and Background 

A. Authority 

B. Background 

II. Synopsis of the Notice of Proposed 

Rulemaking 

III. Discussion 

A. Scope and Definitions 

1. Scope 

a. Liquid-Cooled Refrigeration Systems 

b. Carbon Dioxide Systems 

c. Multi-Circuit Single-Packaged 

Refrigeration Systems 

d. Ducted Units 

2. Definitions 

a. Walk-In Cooler and Walk-in Freezer 

b. Doors 

c. High-Temperature Refrigeration Systems 

d. Ducted Fan Coil Units 

e. Multi-Circuit Single-Packaged 

Refrigeration Systems 

f. Attached Split Systems 

g. Detachable Single-Packaged System 

h. CO2 Unit Coolers 

i. Hot Gas Defrost 

B. Industry Standards 

1. Standards for Determining Thermal 

Transmittance (U-factor) 

2. Standard for Determining R-Value 

3. Standards for Determining AWEF 

a. Changes Consistent With Subpart R, 

Appendix C 

b. CFR Language Not Adopted in AHRI 

1250–2020 

c. Changes That May Impact the 

Determination of AWEF 

d. Additional Amendments 

C. Proposed Amendments to the Test 

Procedure in Appendix A for Measuring 

the Energy Consumption of Walk-In 

Doors 

1. Procedure for Determining Thermal 

Transmittance (U-Factor) 

a. Reference to NFRC 102 in Place of NFRC 

100 

b. Exceptions to Industry Test Method for 

Determining U-Factor 

c. Calibration of Hot Box for Measuring UFactor 

2. Additional Definitions 

a. Surface Area for Determining 

Compliance With Standards 

b. Surface Area for Determining U-Factor 

3. Electrical Door Components 

4. Percent Time Off Values 

5. EER Values 

6. Air Infiltration Reduction 

D. Proposed Amendments to the Test 

Procedure in Appendix A for Display 

Panels 

E. Proposed Amendments to the Test 

Procedure in Appendix B for Panels and 

Non-Display Doors 

1. Specimen Conditioning 

2. Total Insulation and Test Specimen 

Thickness 

3. Parallelism and Flatness 

4. Insulation Aging 

5. Determining Energy Consumption of 

Panels That Are Not Display Panels 

F. Proposed Amendments to Subpart R, 

Appendix C, To Determine Compliance 

With the Current Energy Conservation 

Standards 

1. Refrigeration Test Room Conditioning 

2. Temperature Measurement 

Requirements 

3. Hierarchy of Installation Instructions 

and Specified Refrigerant Conditions for 

Refrigerant Charging and Setting 

Refrigerant Conditions 

a. Dedicated Condensing Unit Charging 

Instructions 

b. Unit Cooler Charging Instructions 

c. Single-Packaged Dedicated System Setup 

and Charging Instructions 

d. Hierarchy of Setup Conditions if 

Manufacturer-Specified Setup 

Conditions Cannot Be Met 

4. Subcooling Requirement for Mass Flow 

Meters 

5. Instrument Accuracy and Test 

Tolerances 

6. CO2 Unit Coolers 

7. High-Temperature Unit Coolers 

G. Proposal To Establish Appendix C1 

1. Off-Cycle Power Consumption 

a. Off-Cycle Test Duration and Repetition 

b. Off-Cycle Operating Tolerances and Data 

Collection Rates 

c. Off-Cycle Load Points 

d. Modification to AWEF Calculations 

2. Single-Packaged Dedicated Systems 

a. AHRI 1250–2020 Methods for Testing 

b. Waivers 

c. Suitability of the Single-Packaged Test 

Methods in AHRI 1250–2020 

d. Single-Packaged Refrigerant Enthalpy 

Method 

e. Multi-Circuit Single-Packaged Dedicated 

Systems 

f. CO2 Single-Packaged Dedicated Systems 

3. Detachable Single-Packaged Dedicated 

Systems 

4. Attached Split Systems 

5. Systems for High-Temperature Freezer 

Applications 

6. Systems for High-Temperature 

Applications 

7. Variable-, Two-, and Multiple-Capacity 

Systems 

a. Dedicated Condensing Units 

b. Indoor Matched Pair and SinglePackaged Units 

c. Revision to EER Calculation for Outdoor 

Variable-Capacity and Multiple-Capacity 

Refrigeration Systems 

d. Digital Compressors 

8. Defrost 

a. Adaptive Defrost 

b. Hot Gas Defrost 

9. Refrigerant Glide 

10. Refrigerant Temperature and Pressure 

Instrumentation Locations 

11. Updates to Default Values for Unit 

Cooler Parameters 

12. Calculations and Rounding 

H. Alternative Efficiency Determination 

Methods 

1. Doors 

2. Refrigeration Systems 

I. Sampling Plan for Enforcement Testing 

J. Test Procedure Costs and Impact 

1. Doors 

2. Panels 

3. Refrigeration Systems 

K. Compliance Date and Waivers 

L. Organizational Changes 

IV. Procedural Issues and Regulatory Review 

A. Review Under Executive Order 12866 

and 13563 

B. Review Under the Regulatory Flexibility 

Act 

1. Description of Why Action Is Being 

Considered 

2. Objective of, and Legal Basis for, Rule 

3. Description and Estimate of Small 

Entities Regulated 

4. Description and Estimate of Compliance 

Requirements 

a. Doors 

b. Panels 

c. Refrigeration Systems 

5. Duplication, Overlap, and Conflict With 

Other Rules and Regulations 

6. Significant Alternatives to the Rule 

C. Review Under the Paperwork Reduction 

Act of 1995 

D. Review Under the National 

Environmental Policy Act of 1969 

E. Review Under Executive Order 13132 

F. Review Under Executive Order 12988 

G. Review Under the Unfunded Mandates 

Reform Act of 1995 

H. Review Under the Treasury and General 

Government Appropriations Act, 1999 

I. Review Under Executive Order 12630 

J. Review Under Treasury and General 

Government Appropriations Act, 2001 

K. Review Under Executive Order 13211 

L. Review Under Section 32 of the Federal 

Energy Administration Act of 1974 

M. Description of Materials Incorporated 

by Reference 

V. Public Participation 

A. Participation in the Webinar 

B. Procedure for Submitting Prepared 

General Statements for Distribution 

C. Conduct of the Webinar 

D. Submission of Comments 

E. Issues on Which DOE Seeks Comment 

VI. Approval of the Office of the Secretary 

I. Authority and Background 

Walk-in coolers and freezers 

(collectively, ‘‘WICFs’’ or ‘‘walk-ins’’) 

are included in the list of ‘‘covered 

equipment’’ for which DOE is 

authorized to establish and amend 

energy conservation standards and test 

procedures. (42 U.S.C. 6311(1)(G)) 

DOE’s energy conservation standards 

and test procedures for WICFs are 

currently prescribed at subpart R of part 

431 of title 10 of the Code of Federal 

Regulations (‘‘CFR’’). The following 

sections discuss DOE’s authority to 

establish test procedures for WICFs and 

relevant background information 

regarding DOE’s consideration of test 

procedures for this equipment. 

A. Authority 

The Energy Policy and Conservation 

Act, as amended (‘‘EPCA’’),1 authorizes 

DOE to regulate the energy efficiency of 

a number of consumer products and 

certain industrial equipment. (42 U.S.C. 


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23922 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

2For editorial reasons, upon codification in the 

U.S. Code, Part C was redesignated Part A–1. 

3The R-value is the thermal resistance, or the 

capacity of an insulated material to resist heat-flow. 

See Section 3.3.3 of ASTM C518. See 42 U.S.C. 

6313(f)(1)(C) for the EPCA R-value requirements for 

non-display panels and doors. 

4These symbols represent the following units of 

measurement—h: hour; ft2: square foot; °F: degrees 

Fahrenheit; Btu: British thermal unit. 

5The K-factor represents the thermal conductivity 

of a material, or its ability to conduct heat, in units 

of Btu-in/(h-ft2-°F). See Section 3.3.1 of ASTM 

C518. 

6291–6317) Title III, Part C2 of EPCA, 

added by Public Law 95–619, Title IV, 

section 441(a), established the Energy 

Conservation Program for Certain 

Industrial Equipment, which sets forth a 

variety of provisions designed to 

improve energy efficiency. This covered 

equipment includes walk-in coolers and 

walk-in freezers, the subject of this 

document. (42 U.S.C. 6311(1)(G)) 

Under EPCA, the energy conservation 

program consists essentially of four 

parts: (1) Testing, (2) labeling, (3) 

Federal energy conservation standards 

(‘‘ECS’’), and (4) certification and 

enforcement procedures. Relevant 

provisions of EPCA include definitions 

(42 U.S.C. 6311), test procedures (42 

U.S.C. 6314), labeling provisions (42 

U.S.C. 6315), energy conservation 

standards (42 U.S.C. 6313), and the 

authority to require information and 

reports from manufacturers (42 U.S.C. 

6316). 

The Federal testing requirements 

consist of test procedures that 

manufacturers of covered equipment 

must use as the basis for: (1) Certifying 

to DOE that their equipment complies 

with the applicable energy conservation 

standards adopted pursuant to EPCA (42 

U.S.C. 6316(a); 42 U.S.C. 6295(s)), and 

(2) making representations about the 

efficiency of that equipment (42 U.S.C. 

6314(d)). Similarly, DOE must use these 

test procedures to determine whether 

the equipment complies with relevant 

standards promulgated under EPCA. (42 

U.S.C. 6316(a); 42 U.S.C. 6295(s)) 

Federal energy efficiency 

requirements for covered equipment 

established under EPCA generally 

supersede State laws and regulations 

concerning energy conservation testing, 

labeling, and standards. (42 U.S.C. 

6316(a) and 42 U.S.C. 6316(b); 42 U.S.C. 

6297) DOE may, however, grant waivers 

of Federal pre-emption for particular 

State laws or regulations, in accordance 

with the procedures and other 

provisions of EPCA. (42 U.S.C. 6316(a)) 

Under 42 U.S.C. 6314, EPCA sets forth 

the criteria and procedures DOE must 

follow when prescribing or amending 

test procedures for covered equipment. 

EPCA requires that any test procedures 

prescribed or amended under this 

section must be reasonably designed to 

produce test results that reflect the 

energy efficiency, energy use or 

estimated annual operating cost of a 

given type of covered equipment during 

a representative average use cycle and 

requires that test procedures not be 

unduly burdensome to conduct. (42 

U.S.C. 6314(a)(2)) 

EPCA also requires that, at least once 

every 7 years, DOE evaluate test 

procedures for each type of covered 

equipment, including walk-ins, to 

determine whether amended test 

procedures would more accurately or 

fully comply with the requirements for 

the test procedures to not be unduly 

burdensome to conduct and be 

reasonably designed to produce test 

results that reflect the energy efficiency, 

energy use, and estimated operating 

costs during a representative average 

use cycle. (42 U.S.C. 6314(a)(1)) 

In addition, if the Secretary 

determines that a test procedure 

amendment is warranted, the Secretary 

must publish proposed test procedures 

in the Federal Register and afford 

interested persons an opportunity (of 

not less than 45 days’ duration) to 

present oral and written data, views, 

and arguments on the proposed test 

procedures. (42 U.S.C. 6314(b)) If DOE 

determines that test procedure revisions 

are not appropriate, DOE must publish 

its determination not to amend the test 

procedures. (42 U.S.C. 6314(a)(1)(A)(ii)) 

DOE is publishing this notice of 

proposed rulemaking (‘‘NOPR’’) in 

satisfaction of the 7-year review 

requirement specified in EPCA. 

B. Background 

For measuring walk-in energy use, 

DOE has established separate test 

procedures for the principal 

components that make up a walk-in (i.e., 

doors, panels, and refrigeration 

systems), with separate test metrics for 

each component. 10 CFR 431.304(b). For 

walk-in doors and display panels, the 

efficiency metric is daily energy 

consumption, measured in kilowatthours per day (‘‘kWh/day’’), which 

accounts for the thermal conduction 

through the door or display panel and 

the direct and indirect electricity use of 

any electrical components associated 

with the door. 10 CFR 431.304(b)(1)–(2) 

and 10 CFR part 431, subpart R, 

appendix A, ‘‘Uniform Test Method for 

the Measurement of Energy 

Consumption of the Components of 

Envelopes of Walk-In Coolers and WalkIn Freezers’’ (‘‘appendix A’’). The 

thermal transmittance through the door, 

which inputs into the calculation of 

thermal conduction, is determined 

using National Fenestration Rating 

Council (‘‘NFRC’’) 100–2010, 

‘‘Procedure for Determining 

Fenestration U-factors’’ (‘‘NFRC 100’’). 

For walk-in non-display panels and 

non-display doors, DOE codified in the 

CFR standards established in EPCA 

based on the R-value metric,3 expressed 

in units of (h-ft2-°F/Btu),4 which is 

calculated as the thickness of the panel 

in inches (‘‘in.’’) divided by the Kfactor.5 See 10 CFR 431.304(b)(3) and 10 

CFR part 431, subpart R, appendix B, 

titled ‘‘Uniform Test Method for the 

Measurement of R-Value for Envelope 

Components of Walk-In Coolers and 

Walk-In Freezers’’ (‘‘appendix B’’). (See 

also, 42 U.S.C. 6314(a)(9)(A)) The Kfactor is calculated based on American 

Society for Testing and Materials 

(‘‘ASTM’’) C518, ‘‘Standard Test 

Method for Steady-State Thermal 

Transmission Properties by Means of 

the Heat Flow Meter Apparatus’’ 

(‘‘ASTM C518’’), which is incorporated 

by reference at 10 CFR 431.303. Id. 

For walk-in refrigeration systems, the 

efficiency metric is Annual Walk-in 

Energy Factor (‘‘AWEF’’), which is the 

ratio of the total heat, not including the 

heat generated by the operation of 

refrigeration systems, removed, in Btu, 

from a walk-in box during one-year 

period of usage for refrigeration to the 

total energy input of refrigeration 

systems, in watt-hours, during the same 

period. AWEF is determined by 

conducting the test procedure set forth 

in American National Standards 

Institute (‘‘ANSI’’)/Air-Conditioning, 

Heating, and Refrigeration Institute 

(‘‘AHRI’’) Standard 1250P (I–P), ‘‘2009 

Standard for Performance Rating of 

Walk-In Coolers and Freezers,’’ (‘‘AHRI 

1250–2009’’), with certain adjustments 

specified in the CFR. See 10 CFR 

431.304(b)(4) and 10 CFR part 431 

subpart R, appendix C, ‘‘Uniform Test 

Method for the Measurement of Net 

Capacity and AWEF of Walk-In Cooler 

and Walk-In Freezer Refrigeration 

Systems’’ (‘‘subpart R, appendix C’’). A 

manufacturer may also determine 

AWEF using an alternative efficiency 

determination method (‘‘AEDM’’). 10 

CFR 429.53(a)(2)(iii). An AEDM enables 

a manufacturer to utilize computerbased or mathematical models for 

purposes of determining an equipment’s 

energy use or energy efficiency 

performance in lieu of testing, provided 

certain prerequisites have been met. 10 

CFR 429.70(f). 

On August 5, 2015, DOE published its 

intention to establish a working group 


jspears on DSK121TN23PROD with PROPOSALS2
Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23923 

6Appliance Standards and Rulemaking Federal 

Advisory Committee Refrigeration Systems Walk-in 

Coolers and Freezers Term Sheet, available at https://www.regulations.gov/document/EERE-2015- 

BT-STD-0016-0056. 

under the Appliance Standards and 

Rulemaking Federal Advisory 

Committee (‘‘ASRAC’’) to negotiate 

energy conservation standards to 

replace the standards established in the 

final rule published on June 3, 2014 (79 

FR 32050; ‘‘June 2014 ECS final rule’’). 

80 FR 46521. The established working 

group (‘‘ASRAC Working Group’’) 

assembled its recommendations into a 

Term Sheet 6 (Docket EERE–2015–BT– 

STD–0016, No. 56) that was presented 

to, and approved by, ASRAC on 

December 18, 2015 (‘‘ASRAC Term 

Sheet’’). 

The ASRAC Term Sheet provided 

recommendations for energy 

conservation standards to replace 

standards that had been vacated by the 

United States Court of Appeals for the 

Fifth Circuit in a controlling order 

issued August 10, 2015. It also included 

recommendations regarding definitions 

for a number of terms related to the 

WICF regulations, as well as 

recommendations to amend the test 

procedure that the ASRAC Working 

Group viewed as necessary to properly 

implement the energy conservation 

standards recommendations. 

Consequently, DOE initiated both an 

energy conservation standards 

rulemaking and a test procedure 

rulemaking in 2016 to implement these 

recommendations. The ASRAC Term 

Sheet also included recommendations 

for future amendments to the test 

procedures intended to make DOE’s test 

procedure more fully representative of 

walk-in energy use. 

On December 28, 2016, DOE 

published a final rule amending the 

WICF test procedures (‘‘December 2016 

final rule’’), consistent with the ASRAC 

Term Sheet recommendations and 

including provisions to facilitate 

implementation of energy conservation 

standards for walk-in components. 81 

FR 95758. Subsequently, on July 10, 

2017, DOE published a final rule 

amending the energy conservation 

standards for WICF refrigeration 

systems (‘‘July 2017 ECS final rule’’). 82 

FR 31808. 

AHRI published an updated industry 

test standard for walk-in refrigeration 

systems in 2020, ‘‘2020 Standard for 

Performance Rating of Walk-in Coolers 

and Freezers,’’ (‘‘AHRI 1250–2020’’). 

This test procedure included updated 

calculations for the determination of 

default values for equipment with 

electric defrost and hot gas defrost. DOE 

published a final rule for hot gas defrost 

unit coolers on March 26, 2021 (‘‘March 

2021 final rule’’) that amended the test 

procedure to rate hot gas defrost unit 

coolers using the modified default 

values for energy use and heat load 

contributions in AHRI 1250–2020. 

These amendments ensure that ratings 

for hot gas defrost unit coolers are 

consistent with those of electric defrost 

unit coolers. 86 FR 16027. 

Under 10 CFR 431.401, any interested 

person may submit a petition for waiver 

from DOE’s test procedure 

requirements. DOE will grant a waiver 

from the test procedure requirements if 

DOE determines either that the basic 

model for which the waiver was 

requested contains a design 

characteristic that prevents testing of the 

basic model according to the prescribed 

test procedures, or that the prescribed 

test procedures evaluate the basic model 

in a manner so unrepresentative of its 

true energy consumption characteristics 

as to provide materially inaccurate 

comparative data. 10 CFR 431.401(f)(2). 

DOE may grant the waiver subject to 

conditions, including adherence to 

alternate test procedures specified by 

DOE. Id. DOE has granted interim 

waivers and/or waivers to the 

manufacturers listed in Table I.1 from 

either appendix A or subpart R, 

appendix C. 

TABLE I.1: MANUFACTURERS WHO RECEIVED A TEST PROCEDURE WAIVER/INTERIM WAIVER FROM DOE 

Manufacturer Subject Case No. Waiver from 

appendix 

Jamison Door Company ............................................... PTO for Door Motors .................................................... 2017–009 A 

HH Technologies .......................................................... PTO for Door Motors .................................................... 2018–001 A 

Senneca Holdings ........................................................ PTO for Door Motors .................................................... 2020–002 A 

Hercules ........................................................................ PTO for Door Motors .................................................... 2020–013 A 

HTPG ............................................................................ CO2 Unit Coolers .......................................................... 2020–009 C 

Hussmann ..................................................................... CO2 Unit Coolers .......................................................... 2020–010 C 

Keeprite ........................................................................ CO2 Unit Coolers .......................................................... 2020–014 C 

RefPlus, Inc. ................................................................. CO2 Unit Coolers .......................................................... 2021–006 C 

RSG .............................................................................. Multi-Circuit Single-Package Dedicated Systems ........ 2022–004 C 

Store It Cold ................................................................. Single-Package Dedicated Systems ............................ 2018–002 C 

CellarPro ....................................................................... Wine Cellar Refrigeration Systems .............................. 2019–009 C 

Air Innovations .............................................................. Wine Cellar Refrigeration Systems .............................. 2019–010 C 

Vinotheque .................................................................... Wine Cellar Refrigeration Systems .............................. 2019–011 C 

Vinotemp ....................................................................... Wine Cellar Refrigeration Systems .............................. 2020–005 C 

LRC Coil ....................................................................... Wine Cellar Refrigeration Systems .............................. 2020–024 C 

On June 17, 2021, DOE published a 

request for information (‘‘RFI’’) to 

collect information and data to consider 

amendments to DOE’s test procedures 

for walk-ins (‘‘June 2021 RFI’’). 86 FR 

32332. DOE received comments in 

response to the June 2021 RFI from the 

interested parties listed in Table I.2. 

TABLE I.2 LIST OF COMMENTERS WITH WRITTEN SUBMISSIONS IN RESPONSE TO THE JUNE 2021 RFI 

Commenter(s) Reference in this NOPR Commenter type 

Air-Conditioning, Heating, & Refrigeration Institute ................................ AHRI .............................................. Industry Association 

Anthony International .............................................................................. Anthony .......................................... Manufacturer 

Appliance Standards Awareness Project ................................................ ASAP ............................................. Efficiency Organization 


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23924 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

7The parenthetical reference provides a reference 

for information located in the docket of DOE’s 

rulemaking to develop test procedures for walk-ins. 

(Docket No. EERE–2017–BT–TP–0010, which is 

maintained at www.regulations.gov). The references 

are arranged as follows: Commenter name, 

comment docket ID number, page of that document. 

TABLE I.2 LIST OF COMMENTERS WITH WRITTEN SUBMISSIONS IN RESPONSE TO THE JUNE 2021 RFI—Continued 

Commenter(s) Reference in this NOPR Commenter type 

Pacific Gas and Electric Company, San Diego Gas and Electric, and 

Southern California Edison; collectively, the California InvestorOwned Utilities.

CA IOUs ........................................ Utility Association 

Daikin US Corporation ............................................................................ Daikin ............................................. Manufacturer 

Hussmann Corporation ........................................................................... Hussmann ...................................... Manufacturer 

Imperial Brown, Inc ................................................................................. Imperial Brown ............................... Manufacturer 

Keeprite Refrigeration, Inc. ..................................................................... Keeprite ......................................... Manufacturer 

Lennox International ................................................................................ Lennox ........................................... Manufacturer 

National Refrigeration & Air Conditioning Canada Corp. ....................... National Refrigeration .................... Manufacturer 

Northwest Energy Efficiency Alliance ..................................................... NEEA ............................................. Efficiency Organization 

National Fenestration Rating Council ..................................................... NFRC ............................................. Industry Association 

In response to the June 2021 RFI, DOE 

also received comments specific to 

energy conservation standards (‘‘ECS’’), 

which it will address in a future walkin ECS rulemaking notice. 

A parenthetical reference at the end of 

a comment quotation or paraphrase 

provides the location of the item in the 

public record.7

II. Synopsis of the Notice of Proposed 

Rulemaking 

In this NOPR, DOE is proposing to 

expand the scope of its walk-in coolers 

and freezers test procedure to include 

carbon dioxide (‘‘CO2’’) unit coolers, 

multi-circuit single-packaged dedicated 

systems, and ducted fan coil units. DOE 

has also tentatively determined that 

liquid-cooled refrigeration systems are 

within the scope of DOE coverage 

authority for walk-ins but is not 

proposing to add an applicable test 

procedure at this time. 

In this NOPR, DOE is proposing to 

alter the definitions of walk-in cooler 

and walk-in freezer, door, door surface 

area, and single-packaged dedicated 

systems. DOE is also proposing new 

definitions for door leaf, hinged vertical 

door, non-display door, roll-up door, 

sliding door, high-temperature 

refrigeration systems, ducted fan coil 

units, multi-circuit single-packaged 

dedicated systems, attached split 

systems, detachable single-packaged 

dedicated systems, CO2 unit coolers, 

and hot gas defrost. 

In this NOPR, DOE is proposing to 

make the following revisions to 

appendix A: (1) Reference NFRC 102– 

2020 as the applicable test procedure to 

determine door ‘‘U-factor’’ in place of 

NFRC 100 (DOE proposes to adopt 

AEDM provisions for doors in 10 CFR 

429.53 to allow calculation of door 

energy use representations); (2) provide 

further detail on and distinguish the 

area to be used for determining 

compliance with standards and the area 

used to calculate a thermal load from Ufactor; (3) establish a percent time off 

(‘‘PTO’’) specific to door motors; and (4) 

reorganize appendix A so that it is 

easier to follow. 

Additionally, DOE is proposing to 

modify appendix B to improve test 

representativeness and repeatability. 

Specifically, DOE is proposing to make 

the following revisions to appendix B: 

(1) Reference the updated industry 

standard ASTM C518–17; (2) include 

more detailed provisions for 

determining measuring insulation 

thickness and test specimen thickness; 

(3) provide additional guidance on 

determining parallelism and flatness of 

a test specimen; and (4) reorganize 

appendix B as a step-by-step procedure 

so it is easier to follow. 

DOE is also proposing to include 

walk-in doors and walk-in panels in the 

list of covered equipment in the same 

sampling plan for enforcement testing 

that is used for walk-in refrigeration 

systems. See 10 CFR 429.110(e)(2). 

DOE is proposing two sets of changes 

for the refrigeration system test 

procedure. One set of changes would be 

grouped into proposed revisions to 

subpart R, appendix C, and the other set 

of changes is being proposed through 

the establishment of a new appendix C1 

to subpart R of part 431 (‘‘appendix 

C1’’). DOE has tentatively determined 

that the changes to subpart R, appendix 

C, would not affect AWEF ratings and 

therefore would not require any 

retesting or recertification. These 

proposed changes, if adopted, would be 

required starting 180 days after the test 

procedure final rule is published. DOE 

has tentatively determined, however, 

that the proposed appendix C1 would 

affect the measurement of energy use; 

therefore, DOE is proposing to establish 

a new metric, AWEF2, in appendix C1 

which would require retesting and 

recertification. The requirements 

proposed in appendix C1, if adopted, 

would take place on the compliance 

date of amended energy conservation 

standards that DOE may ultimately 

decide to adopt as part of a separate 

rulemaking assessing the technological 

feasibility and economic justification for 

such standards. 

DOE is proposing to make the 

following revisions to subpart R, 

appendix C: 

(1) Specify refrigeration test room 

conditions; 

(2) provide for a temperature probe 

exception for small diameter refrigerant 

lines; 

(3) incorporate a test setup hierarchy 

for installation instructions for 

laboratories to follow when setting up a 

unit for test; 

(4) allow active cooling of the liquid 

line in order to achieve the required 3 

ßF subcooling at a refrigerant mass flow 

meter; 

(5) modify instrument accuracy and 

test tolerances; and 

(6) address current test procedure 

waivers for CO2 unit coolers tested 

alone and high-temperature unit coolers 

tested alone by incorporating 

amendments appropriate for this 

equipment. 

Additionally, DOE is proposing a new 

metric, AWEF2, associated with a new 

appendix C1, which would include the 

proposed changes to subpart R, 

appendix C. DOE is proposing the 

following provisions be included in 

appendix C1, which would be required 

to demonstrate compliance coincident 

with the compliance date of any 

amended energy conservation 

standards, should such standards be 

established: 

(1) Adoption of AHRI 1250–2020; 

(2) provide for testing single-packaged 

dedicated systems, detachable singlepackaged dedicated systems, attached 

split systems, CO2, variable-, two-, and 

multiple-capacity dedicated condensing 

units, indoor variable-, two- and 

multiple-capacity matched pairs, 


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matched refrigeration systems for hightemperature applications, and multicircuit single-packaged dedicated 

systems; 

(3) add a single-packaged dedicated 

system refrigerant enthalpy test 

procedure; and 

(4) add a new energy metric, AWEF2, 

to reflect the proposed changes in the 

test procedure that would result in a 

significant change to energy use values. 

Table II.1 summarizes the current 

DOE test procedure, DOE’s proposed 

changes to the test procedure, the 

attribution for each proposed change, 

and the location of the proposed test 

procedure. 

TABLE II.1—SUMMARY OF CHANGES IN PROPOSED TEST PROCEDURE RELATIVE TO CURRENT TEST PROCEDURE

WICF component(s) Current DOE test procedure Proposed test procedure(s) Attribution Proposed 

in appendix 

Doors and Display Panels.Incorporates by reference NFRC 

100–2010 for determining U-factor as part of determining energy 

consumption.

Incorporates by reference NFRC 

102–2020 for determining U-factor and allows for AEDMs to be 

used for determining energy consumption.

Reduce test burden ..... A 

Doors and Display Panels.Uses surface area of the door or 

display panel external to the 

walk-in to convert U-factor into a 

conduction load.

Requires that area of the aperture 

or surface area used to determine the U-factor be used to convert U-factor into a conduction 

load.

Improve representative 

values.

A 

Doors ............................. Uses a percent time off value of 25 

percent for door motors (as they 

are considered ‘‘other electricityconsuming devices’’).

Establishes a percent time off value 

of 97 percent specific to door motors.

Improve representative 

values and addresses inconsistent values across waivers 

granted.

A 

Non-display Doors and 

Panels.

Incorporates by reference ASTM 

C518–04.

Incorporates by reference ASTM 

C518–17.

Updates to the applicable industry test procedures.B 

Non-display Doors and 

Panels.

Does not include detailed provisions for determining and measuring total insulation thickness 

and test specimen thickness.

Includes detailed provisions for determining and measuring total insulation thickness and test specimen thickness.Ensure test repeatability.B 

Non-display Doors and 

Panels.

Requires that the test specimen 

meet a parallelism and flatness 

tolerance of ±0.03 inches but provides no guidance on measurement.

Provides guidance on determining 

parallelism and flatness of the 

test specimen.

Ensure test repeatability.B 

Refrigeration Systems ... Does not include guidance on test 

room conditioning.

Includes guidance on test room 

conditioning.

Ensure test repeatability.C 

Refrigeration Systems ... Does not include an allowance for 

measuring refrigerant temperatures with surface-mounted 

measuring instruments.

Includes an allowance for measuring refrigerant temperatures 

with surface-mounted measuring 

instruments for small diameter 

tubes.

Reduce test burden ..... C 

Refrigeration Systems ... Does not include guidance for unit 

charging or a setup condition hierarchy.

Includes guidance for unit charging 

and a setup condition hierarchy.

Ensure test repeatability.C 

Refrigeration Systems ... Does not include provisions for testing CO2 unit coolers.Includes provisions for testing CO2

unit coolers.

Improve representative 

values.

C 

Refrigeration Systems ... Does not include provisions for testing high-temperature unit coolers 

alone.

Includes provisions for testing hightemperature unit coolers alone.Improve representative 

values.

C 

Refrigeration Systems ... Incorporates by reference AHRI 

1250–2009, ASHRAE 23.1–2010, 

and AHRI 420–2008.

Incorporates by reference AHRI 

1250–2020, ASHRAE 37, and 

ASHRAE 16.

Updates to the applicable industry test procedures.C1 

Refrigeration Systems ... Single-packaged dedicated systems 

are tested using the refrigerant 

enthalpy method for matched 

pairs.

Includes multiple methods for testing single-packaged dedicated 

systems.

Improve representative 

values.

C1 

Refrigeration Systems ... Does not include provisions for testing attached split systems or detachable single-packaged dedicated systems.Includes provisions for testing attached split systems or detachable single-packaged dedicated 

systems.

Improve representative 

values.

C1 

Refrigeration Systems ... Does not include provisions for testing multi-circuit single-packaged 

dedicated systems.

Includes provisions for testing multicircuit single-packaged dedicated 

systems.

Improve representative 

values.

C1 

Refrigeration Systems ... Does not include provisions for testing ducted fan coil units.Includes provisions for testing 

ducted fan coil units.

Improve representative 

values.

C1 

Refrigeration Systems ... Does not include provisions for testing high-temperature matchedpair and single-packaged dedicated systems.Includes provisions for testing hightemperature matched-pair and 

single-packaged dedicated systems.

Improve representative 

values.

C1 


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8See Docket No. EERE–2017–BT–TP–0010–0001, 

Docket No. EERE–2017–BT–TP–0010–0002, and 

Docket No. EERE–2017–BT–TP–0010–0003. 

TABLE II.1—SUMMARY OF CHANGES IN PROPOSED TEST PROCEDURE RELATIVE TO CURRENT TEST PROCEDURE— 

Continued 

WICF component(s) Current DOE test procedure Proposed test procedure(s) Attribution Proposed 

in appendix 

Refrigeration Systems ... Does not include provisions for testing of variable- and multiple-capacity dedicated condensing units 

nor variable- and multiple-capacity outdoor matched pairs.

Includes provisions for testing of 

variable, two-, and multiple-capacity dedicated condensing units 

and variable, two-, and multiplecapacity outdoor matched pairs.

Improve representative 

values.

C1 

DOE has tentatively determined that 

the proposed amendments described in 

section III of this NOPR would not alter 

the measured energy consumption of 

walk-in doors without motors or the Rvalue of walk-in non-display doors and 

non-display panels or require retesting 

or recertification solely as a result of 

DOE’s adoption of the proposed 

amendments to the test procedures, if 

made final. Additionally, DOE has 

tentatively determined that the 

proposed amendments, if made final, 

would not increase the cost of testing. 

Further, DOE has tentatively 

determined that the proposed 

amendments described in section III of 

this NOPR would alter the measured 

energy consumption or efficiency of 

walk-in doors with motors and would 

only require retesting or recertification 

because of DOE’s adoption of the 

proposed amendments to the test 

procedures, if made final. Additionally, 

DOE has tentatively determined that the 

proposed amendments, if made final, 

would not increase the cost of testing for 

doors with motors. 

DOE has also tentatively determined 

that the proposed amendments to 

subpart R, appendix C, described in 

section III.F of this NOPR would not 

alter the measured efficiency of walk-in 

refrigeration systems and would not 

require retesting or recertification as a 

result of DOE’s adoption of the 

proposed amendments to the test 

procedures, if made final. Additionally, 

DOE has tentatively determined that the 

proposed amendments, if made final, 

would not increase the cost of testing. 

Finally, DOE has tentatively 

determined that the proposed 

provisions of appendix C1 described in 

section III.G of this NOPR would alter 

the measured efficiency of walk-in 

refrigeration systems. However, the 

proposed procedure in appendix C1 

would only require retesting or 

recertification when a future energy 

conservation standard would take effect. 

Additionally, DOE has tentatively 

determined that the proposed 

provisions in appendix C1, if made 

final, would increase the cost of testing. 

Tentative cost estimates are discussed in 

section III.J of this document. 

Discussion of DOE’s proposed actions 

are addressed in detail in section III of 

this NOPR. 

III. Discussion 

In the following sections, DOE 

proposes certain amendments to its test 

procedures for walk-in doors, panels, 

and refrigeration systems. For each 

proposed amendment, DOE provides 

relevant background information, 

explains why the amendment merits 

consideration, discusses relevant public 

comments, and proposes a potential 

approach. 

Many of the refrigeration system test 

procedure proposals under 

consideration in this NOPR stem from 

recommendations made by the ASRAC 

Working Group (see ASRAC Term Sheet 

Recommendation #6, EERE–2015–BT– 

STD–0016, No. 56). The remainder of 

the refrigeration system, door, and panel 

test procedure amendments proposed in 

this NOPR are in response to issues 

identified by DOE and stakeholders in 

the time since the publication of the 

December 2016 final rule, including 

through petitions for test procedure 

waivers. 

A. Scope and Definitions 

This NOPR applies to the test 

procedures for ‘‘walk-in coolers and 

walk-in freezers.’’ DOE defines ‘‘walk-in 

cooler and walk-in freezer’’ as: An 

enclosed storage space refrigerated to 

temperatures (1) above 32 °F for walk-in 

coolers and (2) at or below 32 °F for 

walk-in freezers, that can be walked 

into, and has a total chilled storage area 

of less than 3,000 square feet, but 

excluding equipment designed and 

marketed exclusively for medical, 

scientific, or research purposes. 10 CFR 

431.302. (See also 42 U.S.C. 6311(20)) 

1. Scope 

The following sections discuss 

considerations and proposals regarding 

the scope of equipment covered by 

DOE’s test procedures for walk-ins. As 

discussed, the DOE test procedures and 

standards apply to walk-in refrigeration 

systems, doors, and panels. 

a. Liquid-Cooled Refrigeration Systems 

A -liquid-cooled refrigeration system 

rejects heat during the condensing 

process to a liquid that transports the 

heat to a remote location. This is in 

contrast to an air-cooled system, which 

rejects heat to ambient air during the 

condensing process. DOE understands 

that liquid-cooled refrigeration systems 

are typically used in facilities where 

either cooling water or glycol is 

plumbed throughout the building prior 

to installation of the refrigeration unit, 

although it is possible that some such 

systems use potable water for condenser 

cooling and dispose the water in a drain 

after it passes through the condenser. As 

discussed in the June 2021 RFI, liquidcooled dedicated condensing units for 

walk-ins are readily available for a wide 

range of capacities and refrigerants from 

major walk-in refrigeration system 

manufacturers (see for example, 

Airdyne W-series indoor units (watercooled), and Russell (water-cooled, 

glycol-cooled) 8 86 FR 32332, 32334. 

DOE notes that the EPCA definition 

for walk-ins makes no distinction on 

how the condenser is cooled. (42 U.S.C. 

6311(20)(A)) However, the current DOE 

test procedure for walk-in refrigeration 

systems, which incorporates by 

reference AHRI 1250–2009, does not 

address how to test liquid-cooled 

systems. Additionally, liquid-cooled 

dedicated condensing units are outside 

the scope of AHRI 1250–2020, being 

specifically excluded in section 2.2.4. 

In the June 2021 RFI, DOE requested 

comment on whether it should consider 

establishing a test procedure for liquidcooled walk-in equipment. 86 FR 32332, 

32334. Lennox, AHRI, Keeprite, 

National Refrigeration, and Hussmann 

recommended against establishing a 

separate test procedure for liquid-cooled 

refrigeration systems due to the small 

market size for such systems. (Lennox, 

No. 9 at p. 2; AHRI, No. 11 at p. 2; 

Keeprite, No. 12 at p. 1; National 


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9CO2 refrigeration systems are transcritical 

because the high-temperature refrigerant that is 

cooled by ambient air is in a supercritical state, 

above the 87.8 °F critical point temperature, above 

which the refrigerant cannot exist as separate vapor 

and liquid phases. 

Refrigeration, No 17 at p. 1; Hussmann, 

No. 18 at p. 2) Lennox, AHRI, Keeprite, 

and Hussmann also explained that the 

type of coolant used has the most 

impact on efficiency for liquid-cooled 

systems; however, coolants are not 

specified by the WICF system 

manufacturer. These stakeholders 

asserted that liquid-cooled systems do 

not have a large potential for energy 

savings since purchasers, rather than 

WICF manufacturers, specify the 

coolant system. (Lennox, No. 9 at p. 2; 

AHRI, No. 11 at p. 2; Keeprite, No. 12 

at p. 1; Hussmann, No. 18 at p. 2) 

Keeprite also stated that liquid-cooled 

systems are generally more efficient 

than air cooled models. (Keeprite, No. 

12 at p. 1) 

ASAP recommended developing a test 

procedure for liquid-cooled systems 

since the systems are currently available 

in the market and there are no 

applicable test procedures. (ASAP, No. 

13 at p. 1) ASAP stated that adopting 

test methods for liquid-cooled systems 

would provide purchasers with 

comparable ratings regardless of cooling 

type. Id. Daikin recommended 

considering EN 17432, ‘‘Packaged 

refrigerating units for walk-in cold 

rooms—Classification, performance and 

energy consumption testing’’ (‘‘EN 

17432’’), which addresses water-cooled 

and liquid-cooled refrigeration systems. 

(Daikin, No. 17 at p. 1) 

DOE reiterates that the scope of the 

walk-in definition includes liquidcooled equipment. DOE recognizes the 

potential benefit of a test procedure for 

liquid-cooled walk-ins and the value 

that a reliable test procedure can 

provide to facilitate comparable 

representations of energy use for 

consumers. DOE has tentatively 

determined that liquid-cooled 

refrigeration systems may represent a 

small portion of the walk-in market and 

the potential for energy savings is likely 

limited. Therefore, although liquidcooled refrigeration systems are 

considered to be covered equipment, 

DOE is not proposing to amend its 

procedures to include liquid-cooled 

refrigeration systems at this time. 

b. Carbon Dioxide Systems 

Currently, the DOE test procedure for 

walk-in refrigeration systems does not 

explicitly define scope based on 

refrigerant. See 10 CFR 431.301, 10 CFR 

431.304, and appendix A. DOE 

understands that the current test 

procedure, which is based on AHRI 

1250–2009 (incorporated by reference, 

10 CFR 431.303(b)), specifies test 

conditions that may not be consistent 

with the design and operation of carbon 

dioxide (‘‘CO2’’) refrigeration systems; 

i.e., although AHRI 1250–2009 does not 

specifically exclude CO2 systems, the 

test method is not designed to 

accommodate such systems. 

The DOE test procedure for unit 

coolers requires testing with a liquid 

inlet saturation temperature of 105 °F 

and a liquid inlet subcooling 

temperature of 9 °F, as specified by 

Tables 15 and 16 of AHRI 1250–2009. 

However, CO2 has a critical temperature 

of 87.8 °F; therefore, it does not coexist 

as saturated liquid and gas above this 

temperature. The liquid inlet saturation 

temperature of 105 °F and the liquid 

inlet subcooling temperature of 9 °F 

specified in subpart R, appendix C, are 

not achievable by CO2 unit coolers. DOE 

has granted waivers or interim waivers 

from subpart R, appendix C, for specific 

basic models of CO2 unit coolers to the 

manufacturers listed in Table III.1 of 

this document. The alternate test 

procedure specified in these waivers 

modified the liquid inlet saturation 

temperature to 38 °F and the liquid inlet 

subcooling temperature to 5 °F. Pursuant 

to its waiver regulations, as soon as 

practicable after the granting of any 

waiver, DOE will publish in the Federal 

Register a notice of proposed 

rulemaking to amend its regulations so 

as to eliminate any need for the 

continuation of such waiver. 10 CFR 

431.401(l). As soon thereafter as 

practicable, DOE will publish in the 

Federal Register a final rule to that 

effect. Id. 

TABLE III.1—WAIVERS GRANTED TO MANUFACTURERS OF CO2 WALK-IN REFRIGERATION SYSTEMS

Manufacturer Interim waiver Federal Register citation Waiver decision and order Federal Register 

citation 

Heat Transfer Products Group (‘‘HTPG’’) ......... 85 FR 83927 (Dec. 23, 2020) .......................... 86 FR 14887 (Mar. 19, 2021). 

Hussmann Corporation (‘‘Hussmann’’) .............. 86 FR 10046 (Feb. 18, 2021) .......................... 86 FR 24606 (May 7, 2021). 

Keeprite Refrigeration (‘‘Keeprite’’) ................... 86 FR 12433 (Mar. 3, 2021) ............................ 86 FR 24603 (May 7, 2021). 

RefPlus Inc. (‘‘RefPlus’’) .................................... 86 FR 43633 (Aug. 10, 2021).

The alternate test procedure granted 

in the CO2 waivers and DOE’s proposal 

with respect to refrigeration systems 

utilizing CO2 as a refrigerant are further 

discussed in section III.F.6 of this 

document. 

As discussed in the June 2021 RFI, all 

CO2 refrigerant waiver petitions DOE 

has thus far received address unit 

coolers. 86 FR 32332, 32346. However, 

it is possible that other CO2 refrigeration 

system configurations may be relevant 

in the future, e.g. dedicated condensing 

units, matched pairs, or single-packaged 

dedicated systems. DOE reviewed 

product literature and other information 

for CO2 systems having some of these 

alternative configurations. Most of the 

information identified by DOE pertains 

to manufacturers operating in Europe. 

In the June 2021 RFI, DOE requested 

comment on the future expected use of 

walk-in refrigeration systems using CO2. 

86 FR 32332, 32346. Lennox, AHRI, 

National Refrigeration, and Hussmann 

stated that they are not aware of any 

transcritical 9 CO2 dedicated condensing 

units available in North America. 

(Lennox, No. 9 at p. 7; AHRI, No. 11 at 

p. 12; National Refrigeration, No 17 at 

p. 1; Hussmann, No. 18 at p. 14) 

National Refrigeration asserted that CO2

tends to be used in large, complex 

multi-compressor systems and therefore, 

would not be used in smaller systems 

with just one dedicated condensing unit 

(National Refrigeration, No. 17 at p. 1) 

The CA IOUs stated that CO2 unit 

coolers cannot be tested and rated at the 

temperatures and pressures used in the 

current test procedure for more 

traditional hydrofluorocarbon (‘‘HFC’’) 

refrigerants; however, single-packaged 

dedicated CO2 refrigeration systems 

should be able to use the test methods 

established in AHRI 1250–2020 for 

single-packaged dedicated systems, 

because these test methods do not use 

refrigerant flow or refrigerant conditions 

for energy calculations. (CA IOUs, No. 

14 at p. 4) Additionally, the CA IOUs 

urged DOE to ensure that the WICF test 

procedures and metrics continue to 

provide consumers with the information 

necessary to easily compare the 


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performance of products with the same 

utility. Id. 

DOE preliminarily finds that, in the 

North American market, CO2 is 

primarily used in large rack systems, 

and that there do not appear to be any 

CO2 dedicated condensing units 

available. Hence, DOE tentatively finds 

that adopting a test procedure for CO2

dedicated condensing units is currently 

not warranted. However, DOE has also 

tentatively determined that the test 

methods in AHRI 1250–2020 for singlepackaged dedicated systems do not need 

to be modified for CO2 refrigerant as 

long as these units are tested using air 

enthalpy or calorimeter test methods, 

rather than a refrigerant enthalpy 

method. DOE further discusses its 

proposals for testing single-packaged 

dedicated systems in section III.G.2 of 

this document. 

In this NOPR, DOE is proposing that 

walk-in refrigeration equipment 

utilizing CO2 as a refrigerant meet the 

definition of a walk-in refrigeration 

system, but that the DOE test procedure, 

as proposed in this document, would 

apply only to (1) single-packaged 

dedicated systems and (2) unit cooler 

variants of CO2 refrigeration systems. 

This proposal would exclude CO2

dedicated condensing units from the 

proposed test procedure. The test 

procedures for CO2 unit coolers and 

single-packaged refrigeration systems 

which use CO2 as a refrigerant are 

outlined in more detail in sections 

III.F.6 and III.G.2.f of this document, 

respectively. 

c. Multi-Circuit Single-Packaged 

Refrigeration Systems 

DOE has received a request for waiver 

and interim waiver from Refrigerated 

Solutions Group (‘‘RSG’’) from the test 

procedure in subpart R, appendix C, for 

basic models of single-packaged 

dedicated systems having multiple 

refrigerant circuits within a single unit 

that share a single evaporator and a 

single condenser. (Docket EERE–2022– 

BT–WAV–0010, No. 1) In its petition, 

RSG stated that the current walk-in test 

procedure does not address multiple 

refrigeration circuits that are enclosed in 

a single unit. Id. Therefore, in this test 

procedure NOPR, DOE has initially 

determined that refrigeration systems 

with multiple refrigeration circuits that 

share a single evaporator and a single 

condenser and are used in walk-in 

applications meet the definition of 

‘‘walk-in cooler and walk-in freezer.’’ 

Thus, DOE proposes to define ‘‘multicircuit single-packaged dedicated 

system’’ in section III.A.2.e of this 

document. Additionally, DOE is 

proposing a test procedure for such 

systems. 

d. Ducted Units 

DOE is aware that some walk-in 

evaporators and/or dedicated 

condensing units are sold with 

provisions to be installed with duct(s) to 

circulate air between the walk-in and 

the refrigeration system. The current 

definition of ‘‘single-packaged dedicated 

system’’ specifies that such systems do 

not have ‘‘any element external to the 

system imposing resistance to flow of 

the refrigerated air;’’ and the definition 

of ‘‘unit cooler’’ specifies that such 

equipment does not have ‘‘any element 

external to the cooler imposing air 

resistance.’’ (10 CFR 431.302) As such, 

unit coolers and single-packaged 

dedicated systems sold for ducted 

installation are not addressed by either 

definition—also, the current test 

procedure does not include provisions 

for setup of ductwork. While the 

definition for condensing unit does not 

exclude systems intended for ducted 

installation, the current test procedure 

does not include provisions for setup of 

ductwork for these components either. 

DOE has granted waivers from the test 

procedure in subpart R, appendix C, to 

Air Innovations, Vinotheque, Cellar Pro, 

and Vinotemp, and an interim waiver to 

LRC Coil, for walk-ins marketed for use 

as wine cellar refrigeration systems (see 

Table III.2). The waivers are discussed 

in more detail in sections III.A.2.c and 

III.G.6 of this document. Relevant to the 

present discussion of scope, the specific 

basic models for which waivers have 

been granted include equipment sold as 

ducted units. As a result of the test 

procedure waivers granted by DOE, DOE 

proposes to revise the single-packaged 

dedicated system definition to clarify 

that such systems may have provisions 

for ducted installation. DOE proposes to 

add a definition for ‘‘ducted fan coil 

unit,’’ the ducted equivalent of a unit 

cooler. In doing so, DOE preserves the 

standard industry definition of a unit 

cooler while expanding the scope of the 

test procedure to ducted units. DOE also 

proposes to add provisions in the test 

procedures to address setup of ductwork 

and the external static pressure that it 

imposes on refrigeration system fans— 

all in order to improve 

representativeness of the test procedure. 

These test procedure revisions are 

addressed in section III.G.6 of this 

document. 

TABLE III.2—INTERIM WAIVERS AND

WAIVERS GRANTED TO MANUFACTURERS OF WALK-INS MARKETED AS

WINE CELLAR REFRIGERATION SYSTEMS

Manufacturer 

Interim waiver 

Federal 

Register 

citation 

Waiver decision 

and order 

Federal 

Register 

citation 

Air Innovations.86 FR 2403 

(Jan. 12, 

2021).

86 FR 23702 

(May 4, 

2021). 

Vinotheque.86 FR 11961 

(Mar. 1, 2021).

86 FR 26504 

(May 14, 

2021). 

CellarPro.86 FR 11972 

(Mar. 1, 2021).

86 FR 26496 

(May 14, 

2021). 

Vinotemp.86 FR 23692 

(May 4, 2021).

86 FR 36732 

(July 

13,2021). 

LRC 

Coil.

86 FR 47631 

(Aug. 26, 

2021).

2. Definitions 

a. Walk-in Cooler and Walk-in Freezer 

The term ‘‘walk-in cooler and walk-in 

freezer’’ means an enclosed storage 

space refrigerated to temperatures, 

respectively, above, and at or below 

32 °F, that can be walked into, and has 

a total chilled storage area of less than 

3,000 square feet; however, the term 

does not include products designed and 

marketed exclusively for medical, 

scientific, or research purposes. 10 CFR 

431.302. (See also 42 U.S.C. 6311(20)) 

In this notice, DOE proposes to amend 

the definition of walk-in cooler and 

freezer to specify that a walk-in may be 

comprised of doors, panels, and 

refrigeration systems. As explained in 

section I.B of this document, DOE 

established separate test procedures and 

energy conservation standards for the 

principal components that make up a 

walk-in: panels, doors, and refrigeration 

systems. 76 FR 21580, 21582 and 79 FR 

32050, 32051–32052. DOE noted in a 

final rule published March 7, 2011 

(‘‘March 2011 Compliance, Certification, 

and Enforcement (‘‘CCE’’) final rule’’) 

that the legislative design standards set 

forth in EPCA provide the framework 

for a component-based approach since 

each design standard is based on the 

performance of a given component of 

the walk-in. 76 FR 12422, 12444. In 

order to align the definition with the 

regulatory scheme adopted by DOE, 

DOE proposes to revise the definition to 

mean an enclosed storage space, 

including but not limited to panels, 

doors, and refrigeration systems, 

refrigerated to temperatures, 

respectively, above, and at or below 32 


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degrees Fahrenheit that can be walked 

into, and has a total chilled storage area 

of less than 3,000 square feet; however, 

the terms do not include products 

designed and marketed exclusively for 

medical, scientific, or research 

purposes. DOE does not intend for this 

amended definition to expand the scope 

of the definition for walk-in coolers and 

freezers nor does it intend for this 

amended definition to expand the 

certification and compliance 

responsibilities of entities involved in 

manufacturing or assembling walk-ins 

or walk-in components. Instead, DOE’s 

proposed revision to the definition of 

walk-in cooler and walk-in freezer 

clarifies that DOE has the authority to 

separately regulate walk-in components 

as well as a full walk-in system 

(including but not limited to panels, 

doors, and refrigeration systems). The 

March 2011 CCE final rule adopted a 

definition for a walk-in manufacturer to 

specify the entities responsible for 

certification and/or compliance of walkins or walk-in components. 76 FR 

12422, 12442–12444. DOE emphasizes 

that both the component manufacturer 

and the assembler bear the 

responsibility of standards compliance, 

even though the component 

manufacturer is the entity responsible 

for certification. An assembler may rely 

on the certification from the component 

manufacturer regarding whether the 

component being used is certified as 

compliant with DOE standards. 

Issue 1: DOE requests comment on its 

proposed changes to the definition for 

walk-in cooler and walk-in freezer. 

b. Doors 

With respect to walk-ins, DOE defines 

a ‘‘door’’ as an assembly installed in an 

opening on an interior or exterior wall 

that is used to allow access or close off 

the opening and that is movable in a 

sliding, pivoting, hinged, or revolving 

manner of movement. For walk-in 

coolers and walk-in freezers, a door 

includes the door panel, glass, framing 

materials, door plug, mullion, and any 

other elements that form the door or 

part of its connection to the wall. 10 

CFR 431.302. In the June 2021 RFI, DOE 

requested feedback on the current 

definition of ‘‘door.’’ 86 FR 32332, 

32335. 

Hussmann stated that the current 

definition of door is sufficient. 

(Hussmann, No. 18 at p. 3) Anthony and 

AHRI stated that ‘‘door’’ is unclear and 

inadequately defined. (Anthony, No. 8 

at p. 1; AHRI, No. 11 at p. 2) AHRI 

commented that the current definition 

seems to describe an individual ‘‘door’’ 

opening, but that the requirement for 

testing uses the opening space in the 

walk-in regardless of whether it 

contains more than one ‘‘door’’ opening. 

AHRI suggested that the definition of 

‘‘door’’ should contain the door frame 

and all door components, and that DOE 

should differentiate between the 

number of openings for a specific door 

assembly inserted into the opening 

space, especially for display doors. 

(AHRI, No. 11 at pp. 2–3) Anthony 

asserted that any component that is part 

of the door assembly (e.g., door, frame, 

wiring) is within the definition of a 

WICF door. (Anthony, No. 8 at pp. 1– 

2) 

In the June 2021 RFI, DOE also 

requested comment specifically on the 

use of the term ‘‘door plug’’ within the 

definition of ‘‘door.’’ 86 FR 32332, 

32335. Anthony and AHRI stated that 

they were unfamiliar with the term 

‘‘door plug.’’ (Anthony, No. 8 at pp. 1– 

2; AHRI, No. 11 at pp. 2–3) Imperial 

Brown stated that the door plug is the 

moving part of the door that can swing 

or slide and comes attached to the 

frame. (Imperial Brown, No. 15 at p. 1) 

Hussmann stated that the term ‘‘door 

plug’’ is in reference to a regular door 

plug (i.e., plugging heaters from a door 

to a frame system), and that Hussmann 

does not use the term ‘‘door plug’’ 

interchangeably with a ‘‘door.’’ 

(Hussmann, No. 18 at p. 3) 

DOE recognizes that the current 

definition of ‘‘door’’ does not explicitly 

address that walk-in door assemblies 

may contain multiple door openings 

within one frame. DOE also notes that 

NFRC 100 includes several defined 

terms relating to door components (e.g., 

door leaf), which differ from the terms 

used in DOE’s definition of ‘‘door.’’ 

Additionally, certain stakeholders 

commented that they are unfamiliar 

with the term ‘‘door plug,’’ whereas 

others use it to describe different 

components of the door assembly. 

DOE proposes to amend the definition 

of ‘‘door’’ to address doors with 

multiple openings within one frame; to 

include terminology that generally 

aligns with terminology used by the 

industry; and to remove use of the term 

‘‘door plug,’’ which is being interpreted 

inconsistently by stakeholders. 

Specifically, DOE proposes to amend 

the definition of ‘‘door’’ to mean an 

assembly installed in an opening of an 

interior or exterior wall that is used to 

allow access or close off the opening 

and that is movable in a sliding, 

pivoting, hinged or revolving manner of 

movement. For walk-in coolers and 

walk-in freezers, a door includes the 

frame (including mullions), the door 

leaf or multiple door leaves (including 

glass) within the frame, and any other 

elements that form the assembly or part 

of its connection to the wall. DOE also 

proposes to define the term ‘‘door leaf’’ 

to mean the pivoting, rolling, sliding, or 

swinging portion of a door. DOE 

tentatively concludes that the proposed 

revision of ‘‘door’’ and proposed 

definition of ‘‘door leaf’’ better align 

with industry terminology and address 

doors with multiple openings within 

one frame. DOE does not intend for the 

proposed changes to the definition of 

‘‘door’’ and the newly defined term for 

‘‘door leaf’’ to change the scope of 

applicability of the DOE test procedures 

or the applicability of standards for 

walk-in doors. 

As discussed in the June 2021 RFI, 

DOE differentiates WICF doors by 

whether such doors are ‘‘display doors’’ 

or not display doors (i.e., ‘‘passage 

doors’’ or ‘‘freight doors’’). 86 FR 32332, 

32335. A ‘‘freight door’’ is a door that 

is not a display door and is equal to or 

larger than 4 feet wide and 8 feet tall. 

10 CFR 431.302. A ‘‘passage door’’ is a 

door that is not a freight or display door. 

Id. The use of dimensions in the 

definition of freight door conveys that 

these doors typically allow large 

machines (e.g., forklifts) to pass through 

carrying freight. However, the definition 

does not address instances where one 

dimension exceeds the height or width 

requirement per the definition, but the 

other dimension is smaller than the 

other dimension requirement per the 

definition. In some cases, the surface 

area for such doors could be larger than 

32 square feet, the area of a 4-foot by 8- 

foot door provided in the definition 

(e.g., a door 5 feet wide and 7 feet tall, 

with a surface area of 35 square feet); in 

other cases, the surface area could be 

smaller than 32 square feet (e.g., a door 

5 feet wide and 6 feet tall, with a surface 

area of 30 square feet). As part of the 

June 2021 RFI, DOE reviewed the 

certified surface areas of freight and 

passage doors in DOE’s Compliance 

Certification Management System 

(‘‘CCMS’’) Database. DOE found that 

many models certified as passage doors 

had rated surface areas greater than or 

equal to 32 square feet while some 

models certified as freight doors had 

rated surface areas less than 32 square 

feet. 86 FR 32332, 32335. 

In the June 2021 RFI, DOE requested 

comment on whether height and width 

or surface area effectively distinguish 

between passage and freight doors and 

whether there are any building codes, 

standards, or industry practices to 

support or refute maintaining 

dimensions of a door as the defining 

characteristics separating freight and 

passage doors. Additionally, DOE 

sought comment on any other attributes 

other than size which would 


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10 Imperial Brown defined WIC as the clear 

opening width, typically from left frame jamb to 

right frame jamb. (Imperial Brown, No. 15 at p. 1) 

11 Imperial Brown defined HIC as the clear 

opening height, typically from door sill to frame 

header. (Imperial Brown, No. 15 at p. 1) 

appropriately distinguish passage and 

freight doors. Lastly, DOE sought 

comment on how to classify non-display 

doors with multiple openings where the 

individual door openings do not meet 

the definition of freight door, but the 

overall door assembly would meet the 

definition of a freight door per the 

dimension requirements in the freight 

door definition. Id. 

The CA IOUs generally supported 

DOE updating its definitions related to 

walk-in doors to prevent miscategorization. Specifically, the CA 

IOUs suggested that DOE align with 

industry definitions for freight doors, 

such as vertical or sectional overhead 

doors, and consider differentiating 

doors based on opening characteristics 

(e.g., swing, horizontal slide, vertical 

slide, rollup) rather than size. (CA IOUs, 

No. 14 at p. 5) 

Imperial Brown stated that the door 

width-in-clear 10 (or ‘‘WIC’’) should be 

the determining factor for distinguishing 

passage and freight doors. Imperial 

Brown recommended that a freight door 

be identified as a door with a WIC of 48 

inches or more and a height-in-clear 11

(‘‘HIC’’) of 78 inches or more, allowing 

for pallet and forklift traffic. (Imperial 

Brown, No. 15 at p. 1) 

AHRI stated that the current area cutoff of 4 feet by 8 feet is sufficient for 

distinguishing between passage and 

freight doors. AHRI stated that there are 

no specific dimensions that distinguish 

freight from passage doors and that the 

dimensions tend to be application 

specific. AHRI also commented that 

generally the height of passage and 

freight doors are similar, but that the 

width varies. (AHRI, No. 11 at p. 3) 

Regarding other characteristics that 

may distinguish passage and freight 

doors, both Anthony and Hussmann 

stated that they define passage doors 

and freight doors by whether the door 

is provided for personnel access to the 

WICF (i.e., passage doors) or provided 

for stocking of product with the use of 

equipment (i.e., freight doors). 

(Anthony, No. 8 at p. 2; Hussmann, No. 

18 at pp. 3–4) Hussmann stated that 

passage doors must be large enough for 

individuals to pass through and meet 

requirements established by the 

Americans with Disabilities Act 

(‘‘ADA’’). (Hussmann, No. 18 at pp. 3– 

4) 

Regarding non-display doors that 

contain multiple openings, AHRI and 

Hussmann commented that it is not 

necessary to change how non-display 

doors with multiple openings are 

classified. (AHRI, No. 11 at p. 3; 

Hussmann, No. 10 at p. 4) Imperial 

Brown stated that non-display doors 

with multiple openings should be 

considered freight doors only if they 

have an unobstructed WIC by HIC (i.e., 

there are no mullions in the opening) 

that meets the freight door dimensional 

requirements. (Imperial Brown, No. 15 

at p. 1) 

Considering the comments received, 

DOE is not proposing to revise the 

definition of ‘‘freight door’’ at this time. 

DOE is proposing to define the term 

‘‘non-display door.’’ Although the test 

procedures outlined in 10 CFR 431.304 

and appendices A and B use the term 

‘‘non-display door,’’ it is not currently 

defined. The proposed definition would 

provide that a ‘‘non-display door’’ 

would mean a door that is not a display 

door. 

Based on the input it has received, 

DOE has tentatively determined that 

differentiating walk-in doors based on 

opening characteristics would better 

align with industry terminology. 

Therefore, DOE is proposing to define 

three terms, which include some 

industry terminology identified in 

NFRC 100, to further differentiate 

among both display and non-display 

doors: ‘‘Hinged vertical door,’’ ‘‘roll-up 

door,’’ and ‘‘sliding door’’ (see proposed 

definitions set out in the regulatory text 

at the end of the document, proposed 

§ 431.302). 

Issue 2: DOE requests feedback on the 

proposed changes to the definition of 

‘‘door’’ and the newly proposed 

definition for ‘‘door leaf.’’ DOE also 

seeks comment on the newly proposed 

definitions for certain door opening 

characteristics: ‘‘Hinged vertical door,’’ 

‘‘roll-up door,’’ and ‘‘sliding door.’’ 

c. High-Temperature Refrigeration 

Systems 

As discussed previously, DOE has 

granted several manufacturers waivers 

and interim waivers from the test 

procedure in subpart R, appendix C, for 

basic models of refrigeration systems 

marketed as wine cellar refrigeration 

systems (see section III.A.1.d). These 

manufacturers stated that walk-ins used 

for wine storage are intended to operate 

at a temperature range of 45 to 65 °F and 

50–70 percent relative humidity, rather 

than the 35 °F and less than 50 percent 

relative humidity test condition 

prescribed in subpart R, appendix C. 

In the June 2021 RFI, DOE requested 

comment on how refrigeration systems 

marketed as wine cellar refrigeration 

systems should be defined to best 

represent the conditions under which 

these systems are designed to operate. 

86 FR 32332, 32334–32335. AHRI, 

Lennox, and the CA IOUs recommended 

that DOE adequately define refrigeration 

systems marketed as wine cellar 

refrigeration systems and evaluate them 

as a separate efficiency class. (Lennox, 

No. 9 at p. 6; AHRI, No. 11 at p. 11; CA 

IOUs, No. 14 at pp. 3–4) AHRI and 

Hussmann suggested that refrigeration 

systems marketed as wine cellar 

refrigeration systems be defined as an 

enclosed storage space designed to be 

cooled to between 45 °F and 65 °F with 

a relative humidity range of 50 percent 

to 70 percent, and typically kept at 55 

°F and 55% RH. (AHRI, No. 11 at p. 2; 

Hussmann, No. 18 at p. 3) Daikin stated 

that refrigeration systems marketed as 

wine cellar refrigeration systems operate 

between 37.4 °F and 68 °F, and between 

70% and 85% relative humidity. 

(Daikin, No. 17 at p. 2) 

In the June 2021 RFI, DOE also 

requested feedback on walk-in 

applications other than wine cellar 

cooling that may have a target room 

temperature of 35 °F and higher. 86 FR 

32332, 32334–32335. Lennox, AHRI and 

Hussmann each stated that wine cellars 

are the only walk-in applications with a 

temperature range between 45 °F and 65 

°F and with a relative humidity between 

50 percent and 70 percent. (Lennox, No. 

9 at p. 2; AHRI, No. 11 at p. 2; 

Hussmann, No. 18 at pp. 2–3) Daikin 

stated by way of example that florist 

coolers operate at 68 °F and between 

90% to 95% humidity. (Daikin, No. 17 

at p. 2) 

DOE understands from these 

comments that there are walk-in 

applications other than wine cellars that 

require cooling to temperatures higher 

than 35 °F. To provide for testing of 

such walk-ins using test conditions that 

result in measurements of energy use in 

a representative average-use cycle DOE 

proposes to define walk-ins designed to 

operate at cooling temperatures above 

45 °F as employing a ‘‘high-temperature 

refrigeration system’’—which would 

mean a walk-in refrigeration system 

which is not designed to operate below 

45 °F.’’ The proposed definition would 

provide for the testing of such units 

using specified conditions 

representative of their average use, i.e., 

cooling the refrigerated space to a 

temperature above 45 °F. See the 

corresponding test procedure provisions 

proposed in section III.G.6 for further 

details. 

d. Ducted Fan Coil Units 

DOE has granted waivers to Air 

Innovations, Vinotheque, Cellar Pro, 

and Vinotemp, and an interim waiver to 

LRC Coil for walk-ins that are marketed 


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12The American Society of Heating, Refrigerating 

and Air-Conditioning Engineers (‘‘ASHRAE’’) has 

formed the ASHRAE Standard Project Committee 

210 (‘‘ASHRAE 210P’’) to evaluate and revise its 

‘‘Method of Testing and Rating Commercial Walkin Refrigerators and Freezers.’’ See 

spc210.ashraepcs.org/. 

as wine cellar refrigeration systems that 

are designed and marketed as ducted 

units. (See Table III.2) The definitions 

for single-packaged units and unit 

coolers currently exclude ducted units, 

resulting in the lack of a test procedure 

for such units. 10 CFR 431.302. 

Specifically, the current single-packaged 

unit definition excludes units with ‘‘any 

element external to the system imposing 

resistance to flow of the refrigerated 

air.’’ Similarly, the current unit cooler 

definition specifically excludes units 

with ‘‘element[s] external to the cooler 

imposing air resistance.’’ Id. 

In the June 2021 RFI, DOE requested 

comment on changing the ‘‘singlepackaged dedicated system’’ and ‘‘unit 

cooler’’ definitions to address units that 

are designed to be installed with ducts. 

86 FR 32332, 32346. Lennox and AHRI 

both stated that the ASHRAE 210P 

committee 12 is working to define a 

‘‘ducted unit cooler’’ and is currently 

considering defining it as ‘‘an assembly, 

including means for forced air 

circulation, capable of moving air 

against both internal and non-zero 

external flow resistance, and elements 

by which heat is transferred from air to 

refrigerant to cool the air, with 

provision for ducted installation.’’ 

(Lennox, No. 9 at p. 6; AHRI, No. 11 at 

p. 11) Lennox and AHRI both urged 

DOE to work with the ASHRAE 210P 

committee to find an appropriate 

solution. (Lennox, No. 9 at p. 7; AHRI, 

No. 11 at p. 12) 

To clarify that refrigeration systems 

that have provision for ducted 

installation are indeed included in the 

DOE test procedure, DOE is proposing 

an appropriate term and a definition for 

the term ‘‘ducted unit cooler’’ 

mentioned by commenters and is also 

proposing to revise the definition for 

single-packaged dedicated system to 

clarify that such a system can have 

provision for ducted installation. DOE 

proposes to adopt the new term, 

‘‘ducted fan-coil unit,’’ which would be 

defined as an assembly including means 

for forced air circulation capable of 

moving air against both internal and 

non-zero external flow resistance, and 

elements by which heat is transferred 

from air to refrigerant to cool the air, 

with provision for ducted installation. 

DOE is also proposing to revise the 

current single-packaged dedicated 

system definition to mean a refrigeration 

system (as defined in 10 CFR 431.302) 

that is a single-packaged assembly that 

includes one or more compressors, a 

condenser, a means for forced 

circulation of refrigerated air, and 

elements by which heat is transferred 

from air to refrigerant. 

Issue 3: DOE requests comment on the 

proposed definition of ‘‘ducted fan coil 

unit’’ and on the proposed modification 

to the ‘‘single-packaged dedicated 

system’’ definition. 

e. Multi-Circuit Single-Packaged 

Refrigeration Systems 

As discussed in section III.A.1.c, DOE 

is proposing to include a test procedure 

for evaluating the energy consumption 

of single-packaged units that contain 

multiple refrigeration circuits. As 

discussed, these units differ from larger 

multi-circuit refrigeration systems in 

that the refrigeration circuits are housed 

within an assembly and share a single 

condenser and a single evaporator. DOE 

proposes to define a ‘‘multi-circuit 

single-packaged refrigeration system’’ as 

a single-packaged dedicated system (as 

defined in 10 CFR 431.302) that 

contains two or more refrigeration 

circuits that refrigerate a single stream 

of circulated air. 

Issue 4: DOE requests comment on the 

proposed definition for multi-circuit 

single-packaged dedicated refrigeration 

systems. 

f. Attached Split Systems 

DOE is aware of some refrigeration 

systems that are sold as matched pairs 

in which the dedicated condensing unit 

and unit cooler are permanently 

attached to each other with structural 

beams. When these units are mounted to 

the refrigerated box, these beams extend 

through the wall of the walk-in, 

connecting the unit cooler inside the 

refrigerated box with the dedicated 

condensing unit outside the refrigerated 

box. The functionality of an attached 

split system may be similar to that of a 

matched pair system but may also have 

similarities to a single-packaged 

dedicated system, since they are single 

assemblies. The DOE test procedure 

does not currently define such systems, 

nor does it provide any unique test 

provisions for them—thereby affecting 

the ability of manufacturers to provide 

test results reflecting the energy 

efficiency of this equipment during a 

representative average use cycle. DOE 

discusses its proposal for testing such 

units in section III.G.4 of this document. 

DOE has initially determined that 

attached split systems are a type of 

matched pair system and proposes to 

define these systems as matched pair 

refrigeration systems designed to be 

installed with the evaporator entirely 

inside the walk-in enclosure and the 

condenser entirely outside the walk-in 

enclosure, and the evaporator and 

condenser are permanently connected 

with structural members extending 

through the walk-in wall. 

Issue 5: DOE requests comment on the 

proposed definition for attached split 

system. 

g. Detachable Single-Packaged System 

DOE is aware of some refrigeration 

systems that are designed to be installed 

with the evaporator unit exchanging air 

through the wall or ceiling of the walkin as would be the case in a singlepackaged system, but with the 

condensing unit installed either next to 

the evaporator unit or installed remotely 

and connected to the evaporator with 

refrigerant lines as is done in split 

systems. The current DOE test 

procedure does not define such systems 

or provide testing provisions specific to 

this configuration. DOE discusses its 

proposal for testing such units in 

section III.G.3 of this document. DOE 

has initially determined that these units 

are a type of single-packaged dedicated 

system, and proposes to define a 

detachable single-packaged system as a 

system consisting of a dedicated 

condensing unit and an insulated 

evaporator section in which the 

evaporator section is designed to be 

installed external to the walk-in 

enclosure and circulating air through 

the enclosure wall, and the condensing 

unit is designed to be installed either 

attached to the evaporator section or 

mounted remotely with a set of 

refrigerant lines connecting the two 

components. 

Issue 6: DOE requests comment on the 

proposed definition for detachable 

single-packaged dedicated system. 

h. CO2 Unit Coolers 

As discussed in section III.A.1.b, DOE 

is proposing to adopt test procedures for 

unit coolers designed for use in CO2

refrigeration systems, these proposals 

are discussed in detail in section III.F.6 

of this document. CO2 systems are 

designed and built to operate using CO2

as a refrigerant, which has the potential 

to reach pressures much higher than 

conventional refrigerants. With the air 

enthalpy test method, CO2 singlepackaged refrigeration systems would 

use the same test methods as 

conventional-refrigerant singlepackaged dedicated systems (see DOE’s 

proposal discussed in section III.G.2.f). 

However, the proposed test procedure 

for CO2 unit coolers would alter the 

inlet refrigerant test conditions as 

compared to conventional refrigerants 

(see section III.F.6). To clarify the scope 


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13AHRI 420–2008, ‘‘Performance Rating of 

Forced-Circulation Free-Delivery Unit Coolers for 

Refrigeration’’ (‘‘AHRI 420–2008’’). 

14ANSI/ASHRAE 23.1–2010, ‘‘Methods of 

Testing for Rating the Performance of Positive 

Displacement Refrigerant Compressors and 

Condensing Units that Operate at Subcritical 

Temperatures of the Refrigerant’’ (‘‘ASHRAE 23.1– 

2010’’). 

15Section 4.7.1 of NFRC 100 requires that the 

accepted difference between the tested U-factor and 

the simulated U-factor be (a) 0.03 Btu/(h-ft2-°F) for 

simulated U-factors that are 0.3 Btu/(h-ft2-°F) or 

less, or (b) 10 percent of the simulated U-factor for 

simulated U-factors greater than 0.3 Btu/(h-ft2-°F). 

This agreement must match for the baseline product 

in a product line. Per NFRC 100, the baseline 

product is the individual product selected for 

validation; it is not synonymous with ‘‘basic 

model’’ as defined in 10 CFR 431.302. 

of the proposed unit cooler test 

procedure, DOE is proposing to define 

a CO2 unit cooler as one that includes 

a nameplate listing only CO2 as an 

approved refrigerant. 

Issue 7: DOE requests comment on the 

proposed definition of CO2 unit coolers. 

DOE also requests comment on whether 

any distinguishing features of CO2 unit 

coolers exist that could reliably be used 

as an alternative approach that can 

differentiate them from those unit 

coolers intended for use with 

conventional refrigerants. 

i. Hot Gas Defrost 

As discussed previously, DOE 

published a final rule that amended the 

test procedure to rate hot gas defrost 

unit coolers using the modified default 

values for energy use and heat load 

contributions in AHRI 1250–2020. 86 

FR 16027. At that time, DOE did not 

adopt a definition for ‘‘hot gas defrost.’’ 

However, as discussed in more detail in 

section III.G.8.b, DOE is proposing that 

equipment with hot gas defrost installed 

at the factory may be marketed using 

representations of performance with hot 

gas defrost activated. This would be a 

voluntary representation by the 

manufacturer. To ensure that the scope 

of this voluntary representation is clear, 

DOE is proposing to define ‘‘hot gas 

defrost’’ as a factory-installed system 

where refrigerant is used to transfer heat 

from ambient outside air, the 

compressor, and/or a thermal storage 

component that stores heat when the 

compressor is running and uses this 

stored heat to defrost the evaporator 

coils. 

Issue 8: DOE requests comment on the 

proposed definition for hot gas defrost. 

Specifically, DOE requests comment on 

if this proposed definition is sufficient 

to identify which equipment is sold 

with hot gas defrost capability installed 

and which is not. 

B. Industry Standards 

The current DOE test procedure for 

walk-in coolers and freezers 

incorporates the following industry test 

standards: NFRC 100–2010 into 

appendix A; ASTM C518 into appendix 

B; and AHRI 1250–2009, AHRI 420– 

2008,13 and ASHRAE 23.1–2010 14 into 

subpart R, appendix C. The following 

sections detail the industry standards 

DOE is proposing to incorporate by 

reference in the NOPR and the relevant 

provisions of those industry standards 

that DOE is proposing to adopt. 

1. Standards for Determining Thermal 

Transmittance (U-Factor) 

Appendix A references NFRC 100 as 

the method for determining the U-factor 

of doors and display panels. NFRC 100 

allows for computational determination 

of U-factor by simulating U-factor using 

Lawrence Berkeley National Lab’s 

(‘‘LBNL’’) WINDOW and THERM 

software, provided that the simulated 

value for the baseline product in a 

product line is validated with a physical 

test of that baseline product and the 

simulated value is within the accepted 

agreement with the physical test value 

as specified in section 4.7.1 of NFRC 

100.15 Section 4.3.2.1 of NFRC 100 

references NFRC 102–2010, ‘‘Procedure 

for Measuring the Steady state Thermal 

Transmittance of Fenestration Systems’’ 

(‘‘NFRC 102–2010’’), as the physical test 

procedure for determining U-factor. 

NFRC 102–2010 is based on ASTM 

C1199–09, ‘‘Standard Test Method for 

Measuring the Steady state Thermal 

Transmittance of Fenestration Systems 

Using Hot Box Methods’’ (‘‘ASTM 

C1199–09’’) with some modifications. 

Since DOE adopted this test 

procedure for determining U-factor of 

doors and display panels in 2011, NFRC 

has published updates to NFRC 102, the 

most recent being NFRC 102–2020, 

which supersedes all previous versions 

of NFRC 102. The following are the 

identified substantive changes and 

additions in NFRC 102–2020 as 

compared to NFRC 102–2010, which is 

referenced in the current Federal test 

procedure via NFRC 100–2010: 

1. Added a list of required 

calibrations for primary measurement 

equipment, including metering box wall 

transducer and surround panel flanking 

loss characterization and annual 

verification procedure, and incorporated 

a calibration transfer standard (‘‘CTS’’) 

calibration continuous characterization 

procedure; and 

2. The provisions regarding air 

velocity distribution were revised to be 

more specific to the type of fans used. 

Additionally, NFRC 102–2020 

references the updated version of ASTM 

C1199 (ASTM C1199–14) instead of 

ASTM C1199–09. Based on a review of 

ASTM C1199–14, DOE has tentatively 

determined that the differences between 

editions are editorial. 

DOE is proposing to adopt by 

reference in appendix A, the following 

sections of NFRC 102–2020 for 

determining U-factor: 

• 2. Referenced Documents, 

• 3. Terminology, 

• 5. Apparatus, 

• 6. Calibration, 

• 7. Experimental Procedure 

(excluding 7.3. Test Conditions), 

• 8. Calculation of Thermal 

Transmittance, 

• 9. Calculation of Standardized 

Thermal Transmittance, 

• Annex A1. Calibration Transfer 

Standard Design, 

• Annex A2. Radiation Heat Transfer 

Calculation Procedure, and 

• Annex A4. Garage Panel and 

Rolling Door Installation. 

DOE is also proposing to incorporate 

by reference ASTM C1199–14, as it is 

referenced in NFRC 102–2020. 

Specifically, in the proposed test 

procedure in appendix A, DOE is 

proposing to reference the following 

sections of ASTM C1199–14 as 

referenced through NFRC 102–2020: 

Sections 2, 3, 5, 6, 7 (excluding 7.3), 8, 

9, and Annexes A1 and A2. DOE is not 

proposing to reference any other 

sections of NFRC 102–2020 or ASTM 

C1199–14 as they either do not apply or 

they are in direct conflict with other test 

procedure provisions included in the 

subpart R. 

2. Standard for Determining R-Value 

As mentioned previously, section 4.2 

of appendix B references ASTM C518 to 

determine the thermal conductivity, or 

K-factor, of panel insulation. EPCA 

requires that the measurement of the Kfactor used to calculate the R-value be 

based on ASTM C518–2004 (‘‘ASTM 

C518–04’’). (42 U.S.C. 6314(a)(9)(A)(ii)) 

In December 2015, ASTM published a 

revision of this standard (‘‘ASTM C518– 

15’’). ASTM C518–15 removed 

references to ASTM Standard C1363, 

‘‘Test Method for Thermal Performance 

of Building Materials and Envelope 

Assemblies by Means of a Hot Box 

Apparatus’’ (‘‘ASTM C1363’’), and 

added references to ASTM Standard 

E456, ‘‘Terminology Relating to Quality 

and Statistics.’’ Additionally, ASTM 

C518–15 relies solely on the 

International System of Units (‘‘SI 

units’’), with paragraph 1.13 clarifying 

that these SI unit values are to be 

regarded as standard. In July 2017, 

ASTM published another revision of 

ASTM C518 (‘‘ASTM C518–17’’). ASTM 


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16Available at www.ahrinet.org. AHRI 1250–2009 

incorporates by reference AHRI 420–2008 for 

testing of unit coolers and ASHRAE 23–2005 for 

testing of dedicated condensing units. DOE has 

updated the reference for the latter test standard to 

ASHRAE 23.1–2010. 

C518–17 added a summary of precision 

statistics from an interlaboratory study 

from 2002–2004 in section 10 

‘‘Precision and Bias.’’ 

As part of the June 2021 RFI, DOE 

requested comment on what issues, if 

any, would be present if DOE were to 

adopt the most current version of the 

standard, ASTM C518–17, for 

measuring panel K-factor. 86 FR 32332, 

32336. NFRC stated that the updates to 

ASTM C518–17 as compared to what is 

in ASTM C518–04 would have no 

substantial impact on the results of 

testing and no impact on test burden. 

NFRC also stated that adopting ASTM 

C518–17 would bring DOE test 

procedures in line with current industry 

methods and practice. (NFRC, No. 10 at 

p. 2) DOE did not receive any additional 

comments on potentially adopting 

ASTM C518–17 for measuring panel Kfactor. 

DOE has tentatively determined that 

the updates to ASTM C518–2004 (the 

version of the industry test procedure 

specified by EPCA as the basis for 

calculating the K-factor) made in 2015 

and 2017 do not substantively change 

the test method nor would adoption of 

the latest version in the DOE test 

procedure increase test burden. 

Therefore, DOE is proposing to amend 

its test procedure for determining Rvalue of insulation for non-display 

doors and panels by incorporating by 

reference ASTM C518–17. Specifically, 

in the proposed test procedure in 

appendix B, DOE is proposing to 

reference the following sections of 

ASTM C518–17: 

• 2. Referenced Documents, 

• 3. Terminology, 

• 5. Apparatus, 

• 6. Calibration, 

• 7. Test Procedures (excluding 7.3. 

Specimen Conditioning), 

• 8. Calculation, and 

• Annex A1. Equipment Design. 

DOE is not proposing to reference any 

other sections of ASTM C518–17 as they 

either do not apply or they are in direct 

conflict with other test procedure 

provisions included in subpart R. As 

ASTM C518–17 is an updated version of 

ASTM C518–2004, the DOE test 

procedure for determining the K-value 

remains based on ASTM C518–2004. 

3. Standards for Determining AWEF 

DOE’s current test procedure for 

WICF refrigeration systems is codified 

in appendix C to subpart R of part 431 

and incorporates by reference AHRI 

1250–2009, AHRI 420–2008, and 

ASHRAE 23.1–2010. AHRI 1250–2009 is 

the industry test standard for 

refrigeration systems for walk-in coolers 

and freezers, including unit coolers and 

dedicated condensing units sold 

separately, as well as matched pairs. 81 

FR 95758, 95798.16 The procedure 

describes the method for measuring the 

refrigeration capacity and the electrical 

energy consumption for a condensing 

unit and a unit cooler, including offcycle fan and defrost subsystem 

contributions. Using the refrigeration 

capacity and electrical energy 

consumption, AHRI 1250–2009 

provides a calculation methodology to 

compute AWEF, the applicable energyperformance metric for refrigeration 

systems. 

The DOE test procedure for walk-in 

refrigeration systems adopts by 

reference the test procedure in AHRI 

1250–2009 (excluding Tables 15 and 

16), with certain enumerated 

modifications. Generally, DOE’s 

modifications to AHRI 1250–2009 

address specific test conditions, 

tolerances, and instrumentation 

requirements, as well as specific 

instructions for how to address defrost 

energy use, unit coolers tested alone, 

and dedicated condensing units tested 

alone. See appendix C to subpart R of 

part 431. 

In 2014, AHRI published an update to 

AHRI Standard 1250 (‘‘AHRI 1250– 

2014’’) which supersedes AHRI 1250– 

2009. After publication of AHRI 1250– 

2014, DOE and other stakeholders 

supported the AHRI 1250 committee in 

its update of AHRI Standard 1250. 

Subsequently, in April 2020, AHRI 

published AHRI 1250–2020, which 

supersedes AHRI 1250–2014. AHRI 

1250–2020 incorporates many of the 

modifications and additions to AHRI 

1250–2009 that DOE currently 

prescribes in its test procedure. It also 

includes test methods for unit coolers 

and dedicated condensing units tested 

alone, rather than incorporating by 

reference updated versions of AHRI 

420–2008 and/or ASHRAE 23.1–2010, 

and also includes test methods for 

single-packaged dedicated systems. 

Sections III.B.3.a to III.B.3.d detail the 

changes made to AHRI 1250–2020 as 

compared to AHRI 1250–2009. 

In the June 2021 RFI, DOE requested 

comment on what issues, if any, would 

be present if DOE were to adopt AHRI 

1250–2020 into the DOE test procedure. 

86 FR 32332, 32336. The CA IOUs and 

NEEA stated their general support for 

the adoption of AHRI 1250–2020. (CA 

IOUs, No. 14 at p. 1; NEEA, No. 16 at 

pp. 1–2) Lennox, AHRI, and Hussmann 

supported the adoption of AHRI 1250– 

2020 with some reservations associated 

with the retest burden it may create. 

(Lennox, No. 9 at p. 2; AHRI, No. 11 at 

p. 4; Hussmann, No. 18 at p. 6) Lennox, 

AHRI, and Hussmann asked DOE to 

evaluate if a full revision of the test 

standards was appropriate at this time. 

(Lennox, No. 9 at p. 2; AHRI, No. 11 at 

p. 4; Hussmann, No. 18 at p. 6) DOE 

acknowledges the potential burden of a 

new test procedure and notes that a full 

cost evaluation of the proposed test 

procedure changes has been conducted 

and is discussed in section III.J. 

Therefore, DOE is proposing two sets of 

changes for the refrigeration system test 

procedure. One set of changes would be 

included as proposed revisions to 

subpart R, appendix C, and the other 

group would be proposed through the 

establishment of an appendix C1. DOE 

has tentatively determined that the 

changes to subpart R, appendix C, 

would not affect AWEF ratings and 

therefore not require retesting or 

recertification. These proposed changes, 

if adopted, would be required 180 days 

after the test procedure final rule is 

published. DOE has also tentatively 

determined that the proposed 

provisions included in appendix C1 

would affect the determination of 

energy use and would therefore require 

retesting and recertification of the 

proposed AWEF2. The provisions 

proposed in appendix C1, if adopted, 

would be required to be followed in 

conjunction with the compliance date of 

any amended energy conservation 

standards that DOE may end up 

adopting as part of a separate standards 

rulemaking. 

In this test procedure NOPR DOE is 

proposing to reference AHRI 1250–2020 

for use in appendix C1, but excluding: 

• Section 1 Purpose, 

• Section 2 Scope, 

• Section 9 Minimum Data 

Requirements for Published Ratings, 

• Section 10 Marking and Nameplate 

Data, 

• Section 11 Conformance 

Conditions, and 

• Section C10.2.1.1 Test Room 

Conditioning Equipment under section 

C10—Defrost Calculation and Test 

Methods. 

DOE is not proposing to reference 

these sections of AHRI 1250–2020 since 

they either do not apply or conflict with 

other test procedure provisions 

included in the proposed appendix C1. 

Additionally, DOE is not proposing to 

reference ASHRAE 23.1–2010 or AHRI 

420–2008 in the proposed appendix C1, 

as the materials referenced in these 

standards by AHRI 1250–2009 are now 

included within AHRI 1250–2020. 


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Further, DOE is proposing to 

reference ASHRAE 16–2016 in the 

proposed appendix C1, as it is 

referenced in AHRI 1250–2020, but 

excluding: 

• Section 1 Purpose 

• Section 2 Scope 

• Section 4 Classifications 

• Normative Appendices E–M 

• Informative Appendices N–R 

DOE is not proposing to reference 

these sections of ASHRAE 16–2016 as 

they either do not apply or conflict with 

other test procedure provisions that 

would be included as part of the newly 

proposed appendix C1. 

Similarly, DOE is proposing to 

reference ASHRAE 37–2009 in the 

proposed appendix C1, as it is 

referenced in AHRI 1250–2020, but 

excluding: 

• Section 1 Purpose, 

• Section 2 Scope, 

• Section 4 Classifications, 

• Informative appendix A 

Classifications of Unitary Airconditioners and Heat Pumps. 

DOE is not proposing to reference 

these sections of ASHRAE 37–2009 as 

they either do not apply or conflict with 

other test procedure provisions that 

would be included as part of the newly 

proposed appendix C1. 

a. Changes Consistent With Subpart R, 

Appendix C 

As mentioned previously, AHRI 

1250–2020 incorporates many of the 

modifications and additions to AHRI 

1250–2009 that DOE currently 

prescribes in its test procedure. The 

modifications in the following sections 

of subpart R, appendix C, were 

incorporated into AHRI 1250–2020. 

Thus, if DOE were to adopt AHRI 1250– 

2020, DOE would remove the following 

sections from subpart R, appendix C: 

• Section 3.1.1, which modifies Table 

1 (Instrumentation Accuracy) in AHRI 

1250–2009; 

• Section 3.1.2, which provides 

guidance on electrical power frequency 

tolerances; 

• Section 3.1.3, which states that in 

Table 2 of AHRI 1250–2009, the test 

operating tolerances and test condition 

tolerances for air leaving temperatures 

shall be deleted; 

• Section 3.1.4, which states that in 

Tables 2 through 14 in AHRI–1250– 

2009, the test condition outdoor wet 

bulb temperature requirement and its 

associated tolerance apply only to units 

with evaporative cooling; 

• Section 3.1.5, which provides tables 

to use in place of AHRI 1250–2009 

Tables 15 and 16, which are excluded 

from the IBR in 10 CFR 431.303. The 

update in AHRI 1250–2020 to Tables 15 

and 16 would allow DOE to incorporate 

the AHRI 1250–2020 tables by reference 

if DOE were to adopt AHRI 1250–2020; 

• Section 3.2.1, which provides 

specific guidance on how to measure 

refrigerant temperature; 

• Section 3.2.2, which removes the 

requirement to perform a refrigerant 

composition and oil concentration 

analysis; 

• Section 3.2.4, which provides 

voltage requirements for unit cooler fan 

power measurements; 

• Section 3.2.5, which provides 

insulation and configuration 

requirements for liquid and suction 

lines used for testing; 

• Section 3.3.1, which gives direction 

for how to test and rate unit coolers 

tested alone; 

• Section 3.3.2, which clarifies that 

the 2008 version of AHRI Standard 420 

should be used for unit coolers tested 

alone; 

• Section 3.3.3, which modifies the 

allowable reduction in fan speed for offcycle evaporator testing; 

• Section 3.4.1, which specifies that 

the 2010 version of ASHRAE 23.1 

should be used and that ‘‘suction A’’ 

condition test points should be used 

when testing dedicated condensing 

units and, 

• Section 3.5, which provides 

guidance on how to rate refrigeration 

systems with hot gas defrost. 

The entirety of section 3.4.2 of 

subpart R, appendix C, which provides 

instruction on how to calculate AWEF 

and net capacity for dedicated 

condensing units, would also be 

removed if AHRI 1250–2020 were to be 

adopted, but the text in AHRI 1250– 

2020 that would replace it alters the text 

currently in section 3.4.2, which would 

result in a change to the current test 

procedure. 

b. CFR Language Not Adopted in AHRI 

1250–2020 

As mentioned previously, AHRI 

1250–2020 incorporates many, but not 

all, of the modifications and additions 

to AHRI 1250–2009 that DOE currently 

prescribes in its test procedure. For 

example, section 3.2.3, which modifies 

the requirements in Section C3.4.5 of 

AHRI 1250–2009 to require only a sight 

glass and a temperature sensor located 

on the tube surface under the insulation 

to verify sub-cooling downstream of 

mass flow meters, was not incorporated 

into AHRI 1250–2020. DOE is 

proposing, however, to carry over this 

section into the newly proposed 

appendix C1. 

With respect to other current sections 

in subpart R, appendix C, sections that 

were not adopted by AHRI 1250–2020, 

DOE is proposing to revise those 

sections as part of this NOPR in the 

following manner: 

• Sections 3.3.4 and 3.3.5, which 

modify the defrost test procedure in 

AHRI 1250–2009, would not be carried 

over into the newly proposed appendix 

C1. This NOPR proposes a revised 

approach to account for defrost heat 

load and energy use. This topic and 

DOE’s proposals are discussed in 

sections III.G.8.a and III.G.8.b; and 

• Section 3.3.7, which provides 

guidance on how to rate refrigeration 

systems with variable-speed evaporator 

fans would also not be carried over into 

the newly proposed appendix C1. 

c. Changes That May Impact the 

Determination of AWEF 

Several changes in AHRI 1250–2020 

may impact the AWEF calculation. 

These changes can be grouped into five 

categories, discussed in the following 

paragraphs: Off-cycle tests, singlepackaged dedicated systems, defrost 

calculations, variable capacity, and unit 

coolers. 

Off-Cycle Tests 

AHRI 1250–2020 updated the offcycle tests in Sections C3.5 and C4.2 

such that the total input wattage of the 

test unit is measured during the off 

cycle, rather than just the unit cooler fan 

input wattage. This change accounts for 

ancillary power from components such 

as crank case heaters and would deliver 

more representative off-cycle power 

results. As a result, if DOE were to 

incorporate this provision into its test 

procedure, it would affect the AWEF 

measurement for dedicated condensing 

units, matched pairs, and singlepackaged dedicated systems by 

accounting for additional energy usage 

in the measured off-cycle power 

consumption value. In addition, updates 

made in AHRI 1250–2020 require that 

the measurement of unit cooler off-cycle 

power include the total electric power 

input to pan heaters and controls as 

well as the fan motors. AHRI 1250–2020 

requires that off-cycle fan speed be at 

least 50% of full speed or that duty 

cycle for cycling fans be at least 50%, 

consistent with the current 

requirements of section 3.3.3 of subpart 

appendix C. 

Single-Packaged Units 

AHRI 1250–2020 added Section C9.1, 

which includes test methods for singlepackaged refrigeration units. These 

methods allow for testing of singlepackaged units with indoor and outdoor 

air enthalpy methods as specified in 

ASHRAE 37 and ASHRAE 16. These 

methods account for the heat leakage 


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17The defrost challenge tests included in AHRI 

1250–2020 are informative test methods that 

provide validation that defrost is occurring as 

would be expected in Appendix E for adaptive 

defrost control systems and in Appendix F for hot 

gas defrost systems. Neither challenge test is 

designed to quantify the energy use of the defrost 

system, but are intended to validate defrost system 

functionality. 

18 DOE is proposing to incorporate Section C3.5 

of AHRI 1250–2020 appendix C as a part of the new 

appendix C1. 

that single-packaged dedicated systems 

are prone to experience by design. The 

inclusion of this heat leakage would 

lower single-packaged dedicated 

systems’ net capacities and therefore 

lower their AWEFs. It would also make 

their net capacities more representative 

of field performance. 

Defrost Calculations 

AHRI 1250–2020 combined the 

defrost calculations and test methods 

into Section C10 to AHRI 1250–2020. 

For systems using electric defrost, the 

defrost calculations for defrost heat 

contributed to the box load (QDF) have 

been changed to three different 

equations depending on the system’s 

gross capacity. In addition, new 

calculation methods for estimating the 

defrost energy of units with hot gas 

defrost have been added. The new 

default equations for electric and hot gas 

defrost heat and energy contributions 

are based on testing and analysis work 

conducted by AHRI and DOE, and 

therefore these values are expected to be 

more representative than previous 

equations for the default values. 

AHRI 1250–2020 also added two 

optional challenge 17 tests for adaptive 

and hot gas defrost in appendices E and 

F, respectively. Both tests evaluate 

whether a unit has a system that 

functions as either an adaptive or hot 

gas defrost system. For compliance 

purposes, DOE requires that units are 

tested without activating adaptive 

defrost or hot gas defrost; therefore, 

neither challenge test included in AHRI 

1250–2020 would affect the calculation 

of AWEF. The defrost challenge tests 

and calculations are discussed in detail 

in sections III.G.8.a, and III.G.8.b of this 

document. 

d. Additional Amendments 

In addition to those changes 

enumerated in sections III.B.3.a through 

III.B.3.c of this document, AHRI 1250– 

2020 includes additional amendments 

that are inconsistent with the current 

DOE test procedure and would not be 

expected to impact calculated AWEF. 

This section discusses those changes. 

AHRI 1250–2020 added exclusions for 

liquid-cooled condensing systems in 

section 2.2.4. and excludes systems that 

use carbon dioxide, glycol, or ammonia 

as refrigerants in section 2.2.5. The 

current DOE test procedure is neutral 

with respect to refrigerant, and DOE 

considers all walk-in refrigeration 

systems to be covered equipment 

regardless of the refrigerant used. 

However, DOE recognizes that 

modifications may be necessary to the 

test method for different refrigerants (for 

example, see discussion in section 

III.F.6 for CO2). 

As discussed in section III.B.3.a, 

AHRI 1250–2020 updated many of the 

tolerances in Table 2 of section 4. Some 

of these updates are not included in the 

current CFR language. DOE proposes to 

adopt the tolerances in AHRI 1250– 

2020, Table 2 of section 4 in subpart R, 

appendix C. As discussed later, DOE 

expects that the updated tolerance 

values would improve the repeatability 

of the test procedure with no impact on 

test cost. 

AHRI 1250–2020 includes an updated 

list of references and the applicable 

versions of certain test standards in 

appendix A, ‘‘References—Normative.’’ 

DOE proposes to reference AHRI 1250– 

2020 appendix A in subpart R, appendix 

C. DOE expects that this modification 

would have no impact on test cost, 

while ensuring that more recent test 

standards are referenced. 

Both AHRI 1250–2009 appendix C 

and AHRI 1250–2020 appendix C 

provide specific test methods for testing 

walk-in cooler and freezer systems, 

whereas the body of the standard 

specifies test requirements and 

calculations for walk-in box load and for 

determining AWEF. Additionally, AHRI 

1250–2020 includes the following 

updated provisions: Section C3 of AHRI 

1250–2009 lists requirements for 

measuring temperature (Section C3.1), 

measuring pressure (Section C3.2), 

measuring refrigerant properties 

(Section C3.3), determining refrigerant 

flow (Section C3.4), determining unit 

cooler fan power (Section C3.5), and 

specifies measurement and recording 

intervals (Section C3.6). In AHRI 1250– 

2020, Section C3 has been expanded to 

include requirements for measuring offcycle power (Section C3.5) and 

determining steady state refrigeration 

capacity and energy consumption 

(Section C3.6), which are applicable to 

all tests unless otherwise specified. 

Aside from single-packaged dedicated 

system tests and the off-cycle power 

tests discussed in the previous section 

and in Sections III.G.2 and III.G.1, 

respectively, of this document, DOE 

does not expect that the revisions made 

to Section C3 in AHRI 1250–2020 would 

impact test duration and is therefore 

proposing to incorporate these sections 

(except for Section C3.5) 18 into subpart 

R, appendix C. 

Sections C3.1.3.1, C3.1.3.2, and 

C3.1.3.3 of AHRI 1250–2020 specified 

refrigerant temperature measurement 

locations for unit coolers tested alone, 

matched pairs, and dedicated 

condensing systems tested alone. 

Specific changes include: 

• For unit coolers tested alone: 

Refrigerant entering temperature is 

measured within six pipe diameters 

upstream of the control device (Section 

C3.1.3.1). 

• For matched pairs, but not singlepackaged dedicated systems: Refrigerant 

entering temperature is measured 

within the first six inches of the 

refrigerant pipe entering the unit cooler 

conditioned space, and the leaving 

temperature is measured within the last 

six inches of the refrigerant pipe leaving 

the unit cooler conditioned space 

(Section C3.1.3.2); and 

• For dedicated condensing units 

tested alone: Entering and leaving 

refrigerant temperatures are measured at 

the inlet and outlet of the unit using two 

independent measuring systems 

(Section C3.1.3.3). 

The modifications for measuring 

refrigerant temperature in AHRI 1250– 

2020 are expected to improve the 

repeatability and reproducibility of the 

test procedure, but do not impact test 

setup or test duration; therefore, DOE is 

proposing to reference these sections in 

subpart R, appendix C. 

AHRI 1250–2020 added Section 

C7.5.1.1 to provide more detailed 

instructions for calculating system 

capacity beginning with measured 

temperatures instead of calculated 

enthalpies, which is what was done in 

AHRI 1250–2009. Section C7.5.1 also 

includes the determination of enthalpy 

from capacity test results. 

AHRI 1250–2020 added Section C9.2, 

which specifies an allowable heat 

balance of ± 6 percent for singlepackaged refrigeration capacity testing. 

AHRI 1250–2009 required a heat 

balance of ± 5 percent for all systems. 

This change was made to align with 

ASHRAE 37, which AHRI 1250–2020 

incorporates by reference for singlepackaged testing. 

AHRI 1250–2009 included Section 

C12 ‘‘Method of Testing Condensing 

Units for Walk-In Cooler and Freezer 

Systems for Use in Mix-Match System 

Ratings,’’ which referenced AHRAE 

23.1–2010. AHRI 1250–2020 now 

provides specific test methods for 

testing dedicated condensing units 


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tested alone. DOE has tentatively 

determined that the test procedure 

incorporated into AHRI 1250–2020 is 

the same as that in ASHRAE 23.1–2010 

and therefore does not impact test setup 

or burden. As a result, DOE proposes to 

no longer incorporate ASHRAE 23.1– 

2010 by reference. 

Section C13 of AHRI 1250–2009, 

‘‘Method of Testing Unit Coolers for 

Walk-In Cooler and Freezer Systems for 

Use in Mix-Match System Ratings,’’ 

referenced AHRI 420–2008. AHRI 1250– 

2020 no longer references AHRI 420– 

2008 and instead outlines a method for 

unit coolers tested alone. As a result, 

DOE proposes to no longer incorporate 

AHRI 420–2008 by reference. DOE has 

tentatively determined that the test 

procedure incorporated into AHRI 

1250–2020 is the same as that in 

ASHRAE AHRI 420–2008 and therefore 

does not impact test setup or burden. As 

a result, DOE proposes to no longer 

incorporate AHRI 420–2008 by 

reference. 

C. Proposed Amendments to the Test 

Procedure in Appendix A for Measuring 

the Energy Consumption of Walk-in 

Doors 

Appendix A provides the test 

procedures to measure the energy 

consumption of the components of 

envelopes of walk-ins. Specifically, 

appendix A provides the test procedures 

to determine the U-factor, conduction 

load, and energy use of walk-in display 

panels and to determine the energy use 

of walk-in display doors and nondisplay doors. DOE notes that display 

panels are also subject to the energy 

consumption test procedure in 

appendix A. Display panels are 

discussed in section III.D of this 

document. 

In this NOPR, DOE is proposing to 

make the following revisions to 

appendix A, specific to display doors 

and non-display doors: (1) Reference 

NFRC 102–2020 in place of NFRC 100 

and adopt AEDM provisions; (2) provide 

further detail on and distinguish the 

area to be used for determining 

compliance with standards and the area 

used to calculate a thermal load from Ufactor; (3) establish a percent time off 

value specific to door motors; and (4) 

reorganize the test method so that it is 

easier to follow. The organizational 

changes include moving the test 

methods and measurement provisions 

for determining U-factor up before the 

provisions for calculating energy 

consumption and moving the percent 

time off values for all electrical 

components into a table. DOE has 

preliminarily determined that these 

changes would improve test 

representativeness and repeatability. 

DOE does not expect that the changes 

it is proposing in this section would 

have a substantive impact on energy 

consumption calculations for display 

doors or non-display doors, except in 

the case of testing doors with motors as 

described in the following paragraphs. 

The following sections describe the 

modifications that DOE is proposing to 

appendix A with respect to walk-in 

display doors and walk-in non-display 

doors. 

1. Procedure for Determining Thermal 

Transmittance (U-Factor) 

a. Reference to NFRC 102 in Place of 

NFRC 100 

As discussed in section III.B.1 of this 

document, section 5.3 of appendix A 

requires manufacturers to determine 

thermal transmittance, or ‘‘U-factor,’’ 

according to NFRC 100. As also 

mentioned previously, NFRC 100 

includes a computational method for 

determining U-factor, which involves 

simulating the U-factor using LBNL’s 

WINDOW and THERM software. 

Section 4.1.1 of NFRC 100 provides 

validation requirements so that 

simulation, rather than a physical test, 

can be used for rating U-factor for a 

product line. This approach may be less 

costly but can result in a different, and 

potentially less accurate, thermal 

transmittance value than the thermal 

transmittance value determined by 

physical test using NFRC 102. NFRC 

100 defines a ‘‘product line’’ as a series 

of individual products of the same 

product type, and a ‘‘product type’’ as 

a designation used to differentiate 

between fenestration products based on 

fixed and operable sash and frame 

members. Section 4.2.1 of NFRC 100 

lists the allowable changes from product 

to product within a product line. DOE 

notes that ‘‘product line’’ is not 

synonymous with ‘‘basic model’’ as 

defined in 10 CFR 431.302. DOE 

understands that simulated U-factors of 

non-display doors using NFRC 100 have 

generally not been accurately 

determined when compared to a 

physical test. 

In the June 2021 RFI, DOE noted it 

was considering incorporating by 

reference NFRC 102 as the test method 

for determining U-factor of walk-in 

doors in place of NFRC 100 and 

adopting AEDM provisions for walk-in 

doors to replace the computational 

methodology in NFRC 100. 86 FR 

32332, 32336. As part of the June 2021 

RFI, DOE requested comment on the 

accuracy of the computational method 

in NFRC 100 to predict U-factor for 

display and non-display doors, the 

magnitude of the difference in U-factor 

determined using the computational 

method and using the physical test 

method, and whether the computational 

method could be modified to more 

closely match the results obtained from 

physical testing. DOE also sought 

comment on whether manufacturers are 

using the computational method in 

NFRC 100 to rate U-factors, whether 

there are other alternative methods for 

computationally determining U-factor, 

and the costs associated with NFRC 100 

or other computational methods 

compared to physical testing. 86 FR 

32332, 32336. 

NFRC stated that the NFRC 100 

computational method has been used to 

accurately simulate U-factors for display 

doors because the physical 

characteristics of a display door are 

similar to the windows and glass doors 

for which the NFRC 100 computational 

method was developed. NFRC also 

stated, however, that there has been 

limited success validating NFRC 100 

simulations with physical tests for nondisplay doors because non-display 

doors, unlike windows and glass doors, 

have high amounts of insulation and 

significant thermal bypasses along the 

door perimeter. (NFRC, No. 10 at p. 1) 

Similarly, AHRI commented that while 

NFRC 100 is appropriate and accurate 

for display doors, it was not designed 

for non-display doors, but it is not 

aware of an industry test method better 

suited for non-display doors. (AHRI, No. 

11 at p. 4) NFRC stated that while 

refinements to the computational 

method in NFRC 100 may be possible 

for more accurately determining Ufactor of non-display doors, they have 

not yet been addressed due to limited 

usage of this method for specimens like 

non-display doors. NFRC also stated 

that the computational method does not 

always result in higher or more 

conservative U-factors than the Ufactors determined through physical 

test, and that the test and simulation 

agreement vary in either direction. 

(NFRC, No. 10 at p. 1) 

Anthony and Hussmann stated that in 

their experience, the U-factors generated 

using the computational method in 

NFRC 100 generally align with the Ufactors obtained from the physical test 

method, NFRC 102. (Anthony, No. 8 at 

p. 2; Hussmann, No. 18 at p. 5) Imperial 

Brown stated that it is possible to 

simulate U-factor of non-display doors if 

the door frame is included in the 

simulation and provided example 

simulation cross-sections. (Imperial 

Brown, No. 15 at p. 2) 

The CA IOUs recommended that the 

physical test method ASTM C1199 be 


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19Solar irradiance is the power per unit area 

received from the sun in the form of 

electromagnetic radiation. 

used for doors and window assemblies 

to provide a measured approach that 

can be compared to the current 

calculated method. (CA IOUs, No. 14 at 

p. 5) Hussmann recommended using the 

computational method exclusively, 

except for the physical testing of one 

model per product line required for 

validation, stating that physical testing 

imposes an unnecessary burden on a 

manufacturer. (Hussmann, No. 18 at p. 

5) Imperial Brown asserted that NFRC 

102 is costly and time consuming to 

conduct, and that it is unrealistic to test 

all of the models they offer since the 

walk-in door market is highly 

customizable. Imperial Brown 

supported continuing to use NFRC 100 

and recommended a ‘‘safety factor’’ be 

included to make up for potential 

inaccuracies of the computational 

method. (Imperial Brown, No. 15 at pp. 

1–2) 

Anthony urged DOE to eliminate the 

requirement for a physical test, stating 

that there is no added value for it and 

that physical testing is more than two 

times the cost of the computational 

method. Anthony also stated, however, 

that if NFRC 100 remains the referenced 

industry test method, the test procedure 

should specify a course of action if the 

computational method results fall 

outside the 10 percent acceptance 

criteria. (Anthony, No. 8 at p. 2) 

NFRC stated that developing an 

AEDM would be inefficient as the 

computational method described in 

NFRC 100 has been shown to be 

accurate. (NFRC, No. 10 at p. 1) 

Additionally, NFRC estimated a cost of 

$2,000 for simulating U-factors for a 

typical product line of display doors 

(about 35–50 U-factor values). NFRC 

emphasized that there is no economy of 

scale in performing more physical tests 

because each sample must be tested on 

its own and requires its own specific 

setup and time to run. NFRC suggested 

that given the U-factors of non-display 

doors cannot typically be simulated 

within the agreement specified by NFRC 

100, the most economical way to 

determine U-factor for a product line 

would be to pick a few sizes within the 

range of offerings and use the worst-case 

U-factors to represent a range of sizes. 

(Id. At p. 2) 

In response to comments received on 

the accuracy of the computational 

method, DOE understands that there has 

been limited success in accurately 

simulating the U-factor of non-display 

doors using NFRC 100. Although 

stakeholders asserted that NFRC 100 can 

accurately simulate display door Ufactors, the recommendation by one 

stakeholder that instruction be provided 

when the simulated value and tested 

value do not agree within the limits 

specified by NFRC 100 suggests there 

may be instances when the 

computational method does not provide 

sufficiently accurate results. DOE 

recognizes that if display or non-display 

door manufacturers are unable to 

simulate U-factor using NFRC 100, they 

are currently required to physically test 

every door basic model, which may be 

unduly burdensome given the highly 

customizable nature of the market and 

thus high number of basic models to 

test. 

In this NOPR, DOE is proposing to 

remove reference to NFRC 100 from its 

test procedure and instead reference 

NFRC 102 and adopt provisions 

allowing manufacturers to use an 

AEDM. DOE emphasizes that allowing 

use of an AEDM would provide 

manufacturers with the flexibility to use 

an alternative method that yields the 

best agreement with a physical test for 

their doors. If manufacturers have had 

success using the computational method 

in NFRC 100, inclusion of AEDM 

provisions would enable manufacturers 

to continue using NFRC 100, provided 

that manufacturers meet the proposed 

AEDM requirements in 10 CFR 429.53 

and 10 CFR 429.70(f). Particularly, 

under the proposals, manufacturers 

would need to ensure that the output 

result of energy consumption from the 

AEDM is within the proposed 5 percent 

tolerance of an energy consumption 

result that includes a physical U-factor 

test. The proposed adoption of an 

AEDM is discussed in more detail in 

section III.H.1. 

b. Exceptions to Industry Test Method 

for Determining U-Factor 

Section 5.3 of appendix A references 

NFRC 100 for determining U-factor with 

the specific modifications to the 

industry standard listed in section 

5.3(a). The first modification specifies 

that the average surface heat transfer 

coefficients during a test must be within 

± 5 percent of the values specified 

through NFRC 100 in ASTM C1199. The 

second and third items modify the cold 

and warm side conditions from the 

standard conditions prescribed in NFRC 

100. The final provision listed specifies 

the direct solar irradiance 19 be 0 Btu/(hft2). 

As discussed in the June 2021 RFI, 

DOE has found that obtaining the 

standardized heat transfer values within 

the tolerances specified in section 

5.3(a)(1) of appendix A on the warmside and cold-side may not be 

achievable depending on the thermal 

transmittance through the door. 86 FR 

32332, 32340. Specifically, the warmside heat transfer is dominated by 

natural convection and radiation and 

the heat transfer coefficient varies as a 

function of surface temperature. When 

testing doors with higher thermal 

resistance, less heat is transferred across 

the door from the warm-side to the coldside, so the warm-side surface 

temperature is closer to the warm-side 

air temperature. 

Sections 6.2.3 and 6.2.4 of ASTM 

C1199 specify the standardized heat 

transfer coefficients and their tolerances 

as part of the procedure to set the 

surface heat transfer conditions of the 

test facility using the Calibration 

Transfer Standard (‘‘CTS’’) test. The 

warm-side surface heat transfer 

coefficient must be within ± 5 percent 

of the standardized warm-side value of 

1.36 Btu/(h-ft2-°F), and the cold-side 

surface heat transfer coefficient must be 

within ± 10 percent of the standardized 

cold-side value of 5.3 Btu/(h-ft2-°F) 

during the CTS test (ASTM C1199, 

Sections 6.2.3 and 6.2.4). ASTM C1199 

does not require that the measured 

surface heat transfer coefficients match 

or be within a certain tolerance of 

standardized values during the official 

sample test—although test facility 

operational (e.g., cold side fan settings) 

conditions would remain identical to 

those set during the CTS test. ASTM 

C1199 also does not require 

measurement of the warm-side surface 

temperature of the door. Rather, this 

value is calculated based on the 

radiative and convective heat flows 

from the test specimen’s surface to the 

surroundings, which are driven by 

values determined from the calibration 

of the hot box using the CTS test (e.g., 

the convection coefficient). See ASTM 

C1199, Section 9.2.1. When testing 

doors with extremely high- or lowthermal resistance, the resulting change 

in warm-side surface temperature can 

shift the warm-side heat transfer 

coefficient out of the tolerance specified 

in the DOE test procedure. To ensure 

that these coefficients are within 

tolerance during the test would require 

recalibration of the hot box for each 

specific door. 

As part of the June 2021 RFI, DOE 

requested feedback on the tolerances 

currently specified in section 5.3(a)(1) of 

appendix A applied to the surface heat 

transfer coefficients used to measure 

thermal transmittance and whether they 

should be increased or omitted. 86 FR 

32332, 32340. 

In response, NFRC asserted that 

applying the surface heat transfer 

coefficient tolerances to the surface heat 


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transfer coefficients determined in the 

actual U-factor test is not a correct 

application of the NFRC 102 test 

method and recommended that the 

tolerances be removed from section 

5.3(a)(1) of appendix A. NFRC 

additionally stated that the idea behind 

the CTS calibration tests is to set up a 

consistent set of fan speeds on both 

sides of the chamber or to create 

consistent cold and warm side 

environments for testing of all products. 

NFRC further stated that the convection 

currents will be influenced during 

sample testing by the surface 

temperatures of the test sample and that 

this is an expected and natural 

occurrence. (NFRC, No. 10 at pp. 3–4) 

Given DOE’s experience with testing 

walk-in doors and the comments 

provided by NFRC, DOE is proposing to 

remove the requirement listed in section 

5.3(a)(1) regarding the surface heat 

transfer coefficients and the tolerances 

on them during testing. 

Additionally, while DOE did not 

request specific comment on the surface 

heat transfer coefficients themselves 

(i.e., the warm side value of 1.36 Btu/ 

(h-ft2-°F) and cold side value of 5.3 Btu/ 

(h-ft2-°F)), Anthony commented that the 

heat transfer coefficient applied to the 

cold side of the test specimen correlates 

to a wind speed roughly equivalent to 

12.3 miles per hour (‘‘mph’’). Anthony 

stated that their field testing has 

demonstrated that the wind speed 

interior to the walk-in is below 5 mph. 

(Anthony, No. 8 at pp. 3–4) 

DOE is not proposing to deviate from 

the surface heat transfer coefficients 

specified in NFRC 102–2020 for 

calibration because additional 

investigation is needed. Deviating from 

these surface heat transfer coefficients 

would require test labs to change their 

test chamber calibration procedures and 

would require manufacturers to retest 

and re-rate all envelope components 

subject to the energy consumption test 

procedure in appendix A. DOE may 

consider changes to the surface heat 

transfer coefficients specified in NFRC 

102–2020 for calibration in the future if 

more data became available regarding 

the internal and external conditions of 

walk-ins in various installations. At this 

time however, more data and 

Departmental analysis would need to be 

conducted to support any changes to the 

surface heat transfer coefficients 

specified in NFRC 102–2020. 

DOE also received comment on the 

direct solar irradiance requirement. 

NFRC stated that direct solar irradiance 

of 0 Btu/(h-ft2) listed in section 5.3(a)(4) 

of appendix A is not an exception to 

NFRC 100 and should be removed from 

appendix A. (NFRC, No. 10 at p. 4) 

Consistent with DOE’s proposal to 

remove reference to NFRC 100, DOE 

proposes to remove this requirement in 

section 5.3(a)(4) of appendix A. 

c. Calibration of Hot Box for Measuring 

U-Factor 

As stated previously, NFRC 100 

references NFRC 102 as the physical test 

method for measuring U-factor, which 

in turn incorporates by reference ASTM 

C1199. ASTM C1199 references ASTM 

C1363–05, ‘‘Standard Test Method for 

Thermal Performance of Building 

Materials and Envelope Assemblies by 

Means of a Hot Box Apparatus’’ 

(‘‘ASTM C1363’’). Section 6.1 of ASTM 

C1199 and Annexes 5 and 6 of ASTM 

C1363 include calibration requirements 

to characterize metering box wall loss 

and surround panel flanking loss, but 

the frequency at which these 

calibrations should occur is not 

specified in these test standards. As part 

of the June 2021 RFI, DOE sought 

comment on the frequency at which test 

laboratories perform each of the 

calibration procedures referenced in 

ASTM C1199 and ASTM C1363, e.g., 

those used to determine the calibration 

coefficients for calculating metering box 

wall loss and surround panel flanking 

loss. 86 FR 32332, 32340. DOE also 

requested comment on the magnitude of 

variation in the calibration coefficients 

measured during successive 

calibrations. Id. 

NFRC stated that because the 

referenced ASTM standards (i.e., ASTM 

C1199 and ASTM C1363) do not specify 

frequency of calibration, NFRC 102 

includes calibration frequency 

requirements in section 6.1. NFRC 

stated that section 6.1 requires that 

metering box wall loss and surround 

panel flanking loss be determined once 

and verified annually as these values 

would not inherently change over time. 

It noted that the verification of the 

metering box wall loss and surround 

panel flanking loss requires results to be 

within 2 Watts of previous 

characterization results. NFRC added 

that their experience shows that these 

results repeat well over time and that an 

increase in calibration frequency is 

unnecessary. (NFRC, No. 10 at p. 3) 

As NFRC stated, the most recent 

version of NFRC 102, NFRC 102–2020, 

includes calibration frequencies and 

requirements in section 6.1(A). The 

currently referenced version of NFRC 

102, NFRC 102–2010, does not include 

these calibration requirements. For this 

reason and because of the comments 

provided by NFRC, DOE is proposing to 

adopt the calibration requirements in 

Section 6.1(A) of NFRC 102–2020. 

2. Additional Definitions 

a. Surface Area for Determining 

Compliance With Standards 

The surface area of display doors and 

non-display doors (designated as Add

and And, respectively) are used to 

determine maximum energy 

consumption (‘‘MEC’’) in kWh/day of a 

walk-in door. 10 CFR 431.306(c)–(d). 

Surface area is currently defined in 

section 3.4 of appendix A as ‘‘the area 

of the surface of the walk-in component 

that would be external to the walk-in 

cooler or walk-in freezer as 

appropriate.’’ As currently written, the 

definition does not provide further 

detail on how to determine the 

boundaries of the walk-in door from 

which height and width are determined 

to calculate surface area. Additionally, 

the definition does not specify if these 

measurements are to be strictly in-plane 

with the surface of the wall or panel that 

the walk-in door would be affixed to, or 

if troughs and other design features on 

the exterior surface of the walk-in door 

should be included in the measured 

surface area. Inconsistent determination 

of surface area, specifically with respect 

to the measurement boundaries, may 

result in unrepresentative and 

inconsistent MEC values. Additionally, 

walk-in doors with antisweat heaters are 

subject to prescriptive standards for 

power use of antisweat heaters per 

square foot of door opening. 10 CFR 

431.306(b)(3)–(4). DOE considers the 

area of the ‘‘door opening’’ to be 

consistent with the surface area used to 

determine MEC. 

Display doors are fundamentally 

different from non-display doors in 

terms of their overall construction. For 

example, display door assemblies 

contain a larger frame that can 

encompass multiple door openings or 

leaves, and the entire assembly fits into 

an opening within a walk-in wall. Nondisplay doors differ in that they often 

are affixed to a panel-like structure that 

more closely resembles a walk-in wall 

rather than a traditional door frame. 

In the June 2021 RFI, DOE described 

how it applies the current test 

procedure definition for surface area 

when determining compliance with 

standards. 86 FR 32332, 32337. As part 

of the June 2021 RFI, DOE requested 

comment on how manufacturers 

determine surface area for the purpose 

of evaluating compliance with the MEC 

performance standards and with the 

prescriptive standards pertaining to 

antisweat heaters for both display and 

non-display doors. Id. 

AHRI and Hussmann stated that they 

determine surface area consistent with 

DOE, and that they do not see any 


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distinctions between display doors and 

non-display doors that warrant 

determining surface area differently. 

(AHRI, No. 11 at p. 7; Hussmann, No. 

18 at p. 9) Anthony stated that they 

include the frame and frame flange as 

part of the door assembly when 

determining door surface area. Anthony 

also stated that, contrary to how they 

determine surface area, Figure 4–2 of 

NFRC 100–2017 excludes frame flanges. 

(Anthony, No. 8 at pp. 2–3) Imperial 

Brown stated that the area for nondisplay doors, And, should be the clear 

opening area, or WIC by HIC, which 

excludes the door frame portion of the 

door assembly. They also stated that the 

clear opening area may be smaller than 

the swinging or sliding portion of the 

door, which typically overlaps a portion 

of the door frame. (Imperial Brown, No. 

15 at p. 2) 

With regard to the prescriptive antisweat heater standards, Anthony agreed 

that the power use of anti-sweat heat per 

square foot is consistent with the 

surface area used to determine MEC. 

(Anthony, No. 8 at pp. 2–3) AHRI and 

Hussmann stated that they do not see a 

need to change requirements for the 

prescriptive standards pertaining to 

anti-sweat heaters. (AHRI, No. 11 at p. 

7; Hussmann, No. 18 at p. 9) 

In response to comments received, 

DOE notes that the description of 

surface area for determining MEC in the 

June 2021 RFI considers the structural 

differences between display and nondisplay doors and assumes different 

bounds for determining the surface area 

of display doors and non-display doors. 

As described previously, DOE includes 

the frame in the surface area calculation 

for display doors, whereas the panellike frame of non-display doors has not 

been included in the surface area 

calculation. However, DOE has observed 

that many electrical components of nondisplay doors are sited on or within the 

frame to which the door is attached. If 

the non-display door frame is not 

considered as part of the non-display 

door, the frame would fall under the 

category of a walk-in panel. However, 

the current test procedure for panels 

does not account for electrical energy 

consumption. Many of the electrical 

components sited on the non-display 

door frame serve a function for 

operation of the door itself. For 

example, to keep non-display doors 

from freezing shut, anti-sweat heaters 

are used to prevent condensation from 

accumulating around the edge of the 

door. 

Comments received regarding surface 

area determination suggest that the 

approach provided in appendix A may 

result in inconsistent interpretations as 

to how to determine this measurement. 

To clarify this issue, DOE is proposing 

additional specification on how the 

surface area is measured. DOE is 

proposing that the surface area bounds 

of both display doors and non-display 

doors be the outer edge of the frame. 

Specifically, DOE proposes to revise the 

term ‘‘surface area’’ to ‘‘door surface 

area,’’ and to define the new term as 

meaning the product of the height and 

width of a walk-in door measured 

external to the walk-in. Under this 

definition, the height and width 

dimensions would be perpendicular to 

each other and parallel to the wall or 

panel of the walk-in to which the door 

is affixed, the height and width 

measurements would extend to the edge 

of the frame and frame flange (as 

applicable) to which the door is affixed, 

and the surface area of a display door 

and non-display door would be 

represented as Add and And, respectively. 

In addition, DOE proposes to move the 

defined term from the test procedure in 

appendix A because, as revised and in 

light of the following proposal in 

section III.C.2.b, this term does not 

apply to the proposed test procedure 

and is only relevant for determining 

compliance with the standards. Instead, 

DOE proposes to include the amended 

term and revised definition with the 

other definitions that are broadly 

applicable to subpart R in 10 CFR 

431.302. 

b. Surface Area for Determining UFactor 

As stated previously, appendix A 

currently references NFRC 100, which 

in turn references NFRC 102 for the 

determination of U-factor through a 

physical test. When conducting a 

simulation, the U-factor is calculated 

using the projected fenestration product 

area (Apt), or the area of the rough 

opening in the wall or roof, for the 

fenestration product, less installation 

clearances. See NFRC 100, section 3. 

When conducting physical testing, the 

U-factor (Us) is calculated using 

projected surface area (As) and is then 

converted to the final standardized Ufactor (UST). See ASTM C1199, sections 

8.1.3 and 9.2.7 as referenced through 

NFRC 102. Projected surface area (As) is 

defined as ‘‘the projected area of test 

specimen (same as test specimen 

aperture in surround panel).’’ See 

ASTM C1199, section 3.3 as referenced 

through NFRC 102. 

Currently, equations 4–19 and 4–28 of 

appendix A specify that surface area of 

display doors (Add) and non-display 

doors (And), respectively, are used to 

convert a door’s U-factor into a 

conduction load. This conduction load 

represents the amount of heat that is 

transferred from the exterior to the 

interior of the walk-in. 

As discussed in section III.C.2.a, DOE 

is proposing to amend the definitions of 

And and Add to be specific to the exterior 

plane of the door, including the frame 

and frame flange as appropriate. 

Defining the area in this manner is 

inconsistent with the area (As) used to 

calculate U-factor in NFRC 102–2020. 

As part of the June 2021 RFI, DOE 

sought comment on this inconsistency 

and feedback on specifying additional 

detail for the surface area used to 

determine thermal conduction through a 

walk-in door to differentiate it from the 

surface area used to determine the 

maximum energy consumption of a 

walk-in door. 86 FR 32332, 32337. 

NFRC stated that the area used to 

convert U-factor into energy use and the 

area used to determine U-factor must be 

consistent when calculating conduction 

load from thermal transmittance. 

(NFRC, No. 10 at pp. 2–3) NFRC also 

observed that NFRC 100, NFRC 102, 

ASTM C1199 and ASTM C1363 all 

define the area for U-factor based ‘‘n 

‘‘projec’’ed’’ specimen ‘‘r ‘‘open’’ng’’ 

area in the wall through which the door 

is installed. Id. NFRC further asserted 

that since the surface area as defined by 

Add and And are different from the 

projected area, heat flow is 

miscalculated when the tested U-factor 

is inserted into equations 4–19 and 4– 

28. Id. AHRI and Hussmann declared 

that they determine surface area in a 

manner consistent with the DOE 

regulations in 10 CFR parts 429 and 431 

and that they do not see a distinction 

that warrants determining surface area 

differently in these instances. (AHRI, 

No. 11 at p. 7; Hussmann, No. 18 at p. 

9) 

Imperial Brown stated that for a nondisplay door, the outer frame is 

equivalent to a walk-in panel and 

therefore the frame would have a 

limited impact on the U-factor 

calculation of the swinging or sliding 

portion of the door. (Imperial Brown, 

No. 15 at p. 2) Imperial Brown 

separately defined the two types of nondisplay doors they manufacture, 

defining a ‘‘panel frame’’ as a frame that 

is connected in-line with other walk-in 

panels and a ‘‘flat frame’’ as a frame that 

is typically used in retrofit applications 

or by door-only manufacturers which 

are non-insulating and mount over and 

are fastened to walk-in panels. (Id. at p. 

1) Imperial Brown suggested that 

manufacturers not be required to 

separately test basic models for U-factor 

which differ in their frame type because 

they believe ‘‘panel’’ frames and ‘‘flat’’ 

frames to be equivalent in performance 


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once mounted. Imperial Brown 

recommended that the same U-factor 

determined for a door with a ‘‘panel 

frame’’ be used for an otherwise the 

same door with a ‘‘flat frame.’’ (Id. at p. 

2) 

Based on this feedback, DOE has 

preliminarily determined that using the 

same area that is used to determine Ufactor (As in NFRC 102 and ASTM 

C1199 as referenced) to convert U-factor 

into a conduction load, rather than the 

proposed revised term for door surface 

area in section III.C.2.a (Add or And) 

results in a more representative 

conduction load and provides for 

improved consistency in application of 

the test procedure across all walk-in 

doors. As such, DOE proposes to specify 

that the projected area of the test 

specimen, As, as defined in ASTM 

C1199, or the area used to determine Ufactor is the area used for converting the 

tested U-factor, UST, into a conduction 

load in appendix A. DOE recognizes 

that this may not change ratings for 

some doors, where As is equivalent to 

And or Add, but it may result in slightly 

lower ratings of energy consumption for 

other doors, where As is less than And or 

Add. DOE expects that since this 

proposed detail would either result in a 

reduced energy consumption or have no 

impact, there would be no need for 

manufacturers to retest or re-rate. 

Additional details on how this proposed 

detail impacts retesting and re-rating are 

further discussed in section III.J.1. 

In response to Imperial Brown’s 

assertion that the frame has a limited 

impact on the thermal performance of 

the door, DOE testing of non-display 

doors found that inclusion of the frame 

in the U-factor test (which resulted in a 

34 to 52 percent increase in total door 

area) increased the heat transferred 

through the door assembly by 23 to 139 

percent compared to heat transfer 

through the door leaf alone. This 

implies that including the frame in the 

U-factor test does have a measurable 

impact on the thermal performance of 

the door assembly. Therefore, DOE also 

proposes to specify in appendix A that 

the U-factor test includes the frame of 

the door to improve consistency in 

application of the test procedure across 

all walk-in doors. 

3. Electrical Door Components 

Sections 4.4.2 and 4.5.2 of appendix 

A include provisions for calculating the 

direct energy consumption of electrical 

components of display doors and nondisplay doors, respectively. For 

example, electrical components 

associated with doors could include, but 

are not limited to: Heater wire (for antisweat or anti-freeze application); lights 

(including display door lighting 

systems); control system units; and 

sensors. See appendix A, sections 4.4.2 

and 4.5.2. For each electricityconsuming component, the calculation 

of energy consumption is based on the 

component’s ‘‘rated power’’ rather than 

a measurement of its power draw. 

Section 3.5 of appendix A defines 

‘‘rated power’’ as the electricity 

consuming device’s power as specified 

(1) on the device’s nameplate or (2) from 

the device’s product data sheet if the 

device does not have a nameplate or 

such nameplate does not list the 

device’s power. 

DOE has observed that walk-in doors 

often provide a single nameplate for the 

door, rather than providing individual 

nameplates for each electricityconsuming device. In many cases, the 

nameplate does not provide separate 

power information for the different 

electrical components. Also, the 

nameplate often specifies voltage and 

amperage (a measure of current) ratings 

without providing wattage (a measure of 

power) ratings, as is referenced by the 

definition of ‘‘rated power.’’ While the 

wattage is equal to voltage multiplied by 

the current for many components, this 

may not be true for all components that 

may be part of a walk-in door assembly. 

Furthermore, nameplate labels typically 

do not specify whether any listed values 

of rated power or amperage represent 

the maximum operation conditions or 

continuous steady state operating 

conditions, which could differ for 

components such as motors that 

experience an initial surge in power 

before power use levels off. These issues 

make calculating a door’s total energy 

consumption a challenge for a test 

facility that does not have in-depth 

knowledge of the electrical 

characteristics of the door components. 

As part of the June 2021 RFI, DOE 

requested comment on whether, and if 

so how, an option for direct component 

power measurement could be included 

in the test procedure or DOE’s CCE 

provisions to allow for a more accurate 

accounting of the direct electrical 

energy consumption of WICF doors. 86 

FR 32332, 32338. 

ASAP supported adding an option for 

direct measurement of power consumed 

by door electrical components. (ASAP, 

No. 13 at p. 1) The CA IOUs also 

supported direct measurement of power 

used by door components, but more 

specifically for components designed to 

operate at partial nameplate power such 

as door motors or powered door closers. 

The CA IOUs stated that, in their 

experience, power measurement for 

resistance components like lighting and 

door heaters are not necessary if these 

components are designed to operate at 

full nameplate power. They 

recommended that the electrical energy 

consumption of door motors be reported 

per door opening and that the electrical 

energy consumption be calculated as the 

actual power consumption of the motor 

multiplied by the duration of the door 

opening and closing. (CA IOUs, No. 14 

at p. 4) Hussmann and Imperial Brown 

supported maintaining the current 

approach of using rated power for 

calculating direct electrical energy 

consumption and did not see a need for 

the measurement option. (Hussmann, 

No. 18 at p. 10; Imperial Brown, No. 15 

at pp. 2–3) Imperial Brown also stated 

that control components are typically 

rated at 5 Watts or less and that they 

should be excluded from the calculation 

of direct electrical energy consumption. 

(Imperial Brown, No. 15 at pp. 2–3) 

DOE is not proposing to include 

provisions requiring measurement of 

power consumption of electrical door 

components in the test procedure in 

appendix A because additional 

investigation is needed. However, DOE 

has observed that some manufacturers 

may be certifying door motor power as 

the output power rating of the motor, 

rather than the input power of the 

motor. Thus, DOE is proposing to 

specify in appendix A that the rated 

power of each electrical component, 

Prated,u,t, would be the rated input power 

of each component because the input 

power represents power consumption. 

Additionally, DOE has observed 

through testing that the measured power 

of some walk-in door electrical 

components exceeds either the certified 

or nameplate power values of these 

electrical components. For the purposes 

of enforcement testing, DOE is 

proposing in 10 CFR 429.134(q) that 

DOE may validate the certified or 

nameplate power values of an electrical 

component by measuring the power 

when the device is energized using a 

power supply that provides power 

within the allowable voltage range listed 

on the nameplate. If the measured input 

power is more than 10 percent higher 

than the power listed on the nameplate 

or the rated input power in a 

manufacturer’s certification, then the 

measured input power would be used in 

the energy consumption calculation. For 

electrical components with controls, the 

maximum input wattage observed while 

energizing the device and activating the 

control would be considered the 

measured input power. 

4. Percent Time Off Values 

The test procedure also assigns 

percent time off (‘‘PTO’’) values to 

various walk-in door components. PTO 


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20 DOE’s previously estimated door openings per 

day were relevant for a proposal to address door 

opening infiltration in the test procedure 

introduced in a supplemental notice of proposed 

rulemaking from September 9, 2010. Ultimately, 

DOE did not adopt test procedure provisions 

addressing door opening infiltration, having 

determined that a typical door manufacturer has 

very few direct means for reducing the door 

Continued 

values are applied to reflect the hours in 

a day that an electricity-consuming 

device operates at its full-rated or 

certified power (i.e., daily component 

energy use is calculated assuming that 

the component operates at its rated 

power for a number of hours equal to 24 

multiplied by ¥1 - PTO)). PTO values 

are not incorporated in the rated or 

certified power of an electricityconsuming device. Table III.3 lists the 

PTO values in the current DOE test 

procedure for walk-in doors. 

TABLE III.3—ASSIGNED PTO VALUES FOR WALK-IN DOOR COMPONENTS

Component type 

Percent 

time off 

(PTO) 

(%) 

Lights without timers, control system or other demand-based control ............................................................................................... 25 

Lights with timers, control system or other demand-based control .................................................................................................... 50 

Anti-sweat heaters without timers, control system or other demand-based control ........................................................................... 0 

Anti-sweat heaters on walk-in cooler doors with timers, control system or other demand-based control ......................................... 75 

Anti-sweat heaters on walk-in freezer doors with timers, control system or other demand-based control ........................................ 50 

All other electricity consuming devices without timers, control systems, or other auto-shut-off systems .......................................... 0 

All other electricity consuming devices for which it can be demonstrated that the device is controlled by a preinstalled timer,

control system or other auto- shut-off system ................................................................................................................................. 25 

As discussed in the June 2021 RFI, 

DOE has granted waivers to several 

manufacturers of doors with motorized 

door openers, allowing for the use of a 

different PTO for motors. 86 FR 32332, 

32338–32339. The manufacturers who 

requested and were granted waivers and 

the PTO defined in their alternate test 

procedure are shown in Table III.4. 

TABLE III.4—PTO VALUES GRANTED IN DECISION AND ORDERS FOR MANUFACTURERS OF DOORS WITH MOTORIZED

DOOR OPENERS

Manufacturer 

Percent 

time off 

(PTO) 

(%) 

Decision and order Federal Register citation 

HH Technologies ........................................................................ 96 83 FR 53457. (Oct. 23, 2018). 

Jamison Door Company ............................................................. 93.5 83 FR 53460. (Oct. 23, 2018). 

Senneca Holdings ...................................................................... 97 86 FR 75. (Jan. 4, 2021). 

Hercules ...................................................................................... 92 86 FR 17801. (Apr. 6, 2021). 

In the June 2021 RFI, DOE requested 

comment on the current PTO values for 

all electricity-consuming devices, 

whether these values should be 

amended, and whether specific values 

should be added for certain electrical 

components, such as motors. 86 FR 

32332, 32339. 

In response, Hussmann stated that 

they determine energy consumption 

consistent with DOE’s regulations in 

parts 429 and 431 and do not see a need 

to change the current PTO values. 

(Hussmann, No. 18 at p. 10) ASAP 

supported adding specific PTO values 

for motorized door openers because they 

believe it will provide similar treatment 

for these components as for other 

electrical components and eliminate the 

need for ongoing test procedure waivers. 

(ASAP, No. at p. 1) The CA IOUs 

recommended that DOE reduce the 

usage factor of door opening motors 

from 75 percent to 5 percent or less (i.e., 

implement a PTO of 95 percent or 

greater). In their comments, the CA 

IOUs provided anecdotal data for two 

food service sites where doors were 

open an average of 20 and 40 minutes 

per day. The CA IOUs observed that if 

these doors had motors, the motor on 

time would be even less than the time 

recorded in the open position. 

Additionally, the CA IOUs 

recommended that DOE explore the 

differences in opening patterns among 

passage, freight, and display doors and 

potentially adjust the door motor PTO 

based on door opening pattern for each 

corresponding class. (CA IOUs, No. 14 

at pp. 5–6) 

As shown in Table III.4, each 

manufacturer requested a PTO value 

specific to their door and motor 

characteristics, resulting in four 

different PTO values. For this proposal, 

DOE evaluated a PTO that could be used 

to consistently evaluate energy 

consumption of doors with motors and 

would be sufficiently representative. 

Recognizing that the PTO values 

requested in the waivers are relatively 

close to one another, DOE calculated an 

average PTO value based on the 

information received in the waivers and 

is proposing to specify one PTO value 

for all basic models of doors with 

motors to use. This approach results in 

a more representative test procedure for 

doors with motors as compared to the 

current value specified for other 

electricity-consuming devices in 

appendix A. The intent of the PTO 

value is not to reflect behaviorallyrelated energy consumption of each 

individual installation of a door with a 

motor, but to provide a more 

representative means for comparison of 

walk-in door performance. 

DOE calculated an average PTO value, 

as follows. For each motorized door 

offering from manufacturers that were 

granted waivers, DOE used the cycle 

rating as specified in the product 

literature. When a cycle rating was not 

provided in the product literature, DOE 

used its previously estimated number of 

door openings per day of 60 for passage 

doors and 120 for freight doors, 

respectively.20 75 FR 55068, 55085. 


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infiltration on its own. 76 FR 21580, 21595 (Apr. 

15, 2011). 

21The difference in EER values between coolers 

and freezers reflects the relative efficiency of the 

refrigeration equipment for the associated 

application. 75 FR 186, 197. As the temperature of 

the air surrounding the evaporator coil drops (that 

is, when considering a freezer relative to a cooler), 

thermodynamics dictates that the system 

effectiveness at removing heat per unit of electrical 

input energy decreases. Id. 

22The dewpoint temperature to be used for 

testing unit coolers alone is defined in section 3.3.1 

of appendix C to be the Suction A saturation 

condition provided in Tables 15 or 16 of appendix 

C (for refrigerator unit coolers and freezer unit 

coolers, respectively). Table 15 for refrigerator unit 

coolers defines the Suction A saturation condition 

(i.e., dewpoint temperature) as 25 °F. Table 16 for 

freezer unit coolers defines the Suction A dewpoint 

temperature as –20 °F. Furthermore, section 7.9.1 of 

AHRI 1250–2009 specifies that for unit coolers 

rated at a suction dewpoint other than 19 °F for a 

coolers and –26 °F for a freezer, the Adjusted 

Dewpoint Value shall be 2 °F less than the unit 

cooler rating suction dewpoint—resulting in 

adjusted dewpoint values of 23 °F and ¥22 °F for 

refrigerator unit coolers and freezer unit coolers, 

respectively. 

DOE then calculated the PTO range for 

each motor offering using the cycle 

rating or DOE’s cycle assumption, the 

maximum opening size offered by the 

manufacturer, and the minimum and 

maximum operating speeds of the 

motor. DOE averaged these PTO ranges 

across each motor offering and then 

averaged them across all manufacturers. 

This yielded an average PTO of 97 

percent. 

Considering the waivers granted, 

DOE’s own calculations, and comments 

received, DOE is proposing to adopt a 

door motor PTO value of 97 percent for 

display doors with motors and nondisplay doors with motors. 

As discussed in the June 2021 RFI, 

DOE is aware that some manufacturers 

design and market walk-in cooler 

display doors for high humidity 

applications. Ratings from the CCMS 

database show these doors have more 

anti-sweat heater power per door 

opening area than standard cooler 

display doors. 86 FR 32332, 32339. 

Section 4.4.2(a)(2) of appendix A 

requires a PTO value of 50 percent be 

used when determining the direct 

energy consumption for anti-sweat 

heaters with timers, control systems, or 

other demand-based controls situated 

within a walk-in cooler door (which 

would include walk-in cooler doors 

marketed for high humidity 

applications). This approach assumes 

that the anti-sweat heaters are not 

operating for 50 percent of the time. 

DOE recognizes that anti-sweat heaters 

may be in operation for a different 

amount of time in high humidity 

installations than in standard 

installations. In the June 2021 RFI, DOE 

requested comment on whether the 

current PTO of 50 percent is appropriate 

for evaluating direct energy 

consumption of anti-sweat heaters with 

controls for walk-in cooler doors 

marketed for high humidity applications 

and the amount of time per day or per 

year that anti-sweat heaters with 

controls are off for high humidity doors. 

Id. 

In response, DOE received comments 

from Anthony, AHRI, and Hussmann 

regarding the maximum energy 

consumption of high humidity doors. 

(Anthony, No. 8 at p. 3; AHRI, No. 11 

at pp. 7–8; Hussmann, No. 18 at p. 10) 

However, as the responses of these 

comments were more focused on the 

standards, DOE plans to address these 

comments as part of a separate 

standards rulemaking for this 

equipment. DOE did not receive any 

comments regarding whether the PTO in 

the test procedure for anti-sweat heaters 

with controls sited on high humidity 

doors should be modified nor any data 

on the amount of time the anti-sweat 

heaters operate on high-humidity doors 

as compared to standard doors (i.e., 

cooler display doors). DOE is not 

proposing any changes to the PTO 

values for anti-sweat heaters sited on 

high humidity doors at this time. 

5. EER Values 

To calculate the daily energy 

consumption associated with heat loss 

through a walk-in door, appendix A 

requires dividing the calculated heat 

loss rate by specified energy efficiency 

ratio (‘‘EER’’) values of 12.4 Btu per 

Watt-hour (‘‘Btu/W-h’’) for coolers and 

6.3 Btu/(W-h) for freezers. Appendix A, 

sections 4.4.4(a) and 4.5.4(a). DOE 

selected EER values of 12.4 Btu/(W-h) 

for coolers and 6.3 Btu/(W-h) for 

freezers because these are typical EER 

values of walk-in cooler and walk-in 

freezer refrigeration systems, 

respectively.21 75 FR 186, 209 (Jan. 4, 

2010); 76 FR 21580, 21593–21594 (Apr. 

15, 2011). The DOE test procedure in 

subpart R, appendix C, also assigns 

nominal EER values, which correspond 

to the appropriate adjusted dew point 

temperature in Table 17 of AHRI 1250– 

2009,22 when testing the refrigeration 

systems of walk-in unit coolers alone. 

The resulting EER values for unit 

coolers tested alone are 13.3 Btu/(W-h) 

for coolers and 6.6 Btu/(W-h) for 

freezers, which are different than the 

EER values of 12.4 Btu/(W-h) and 6.3 

Btu/(W-h), respectively, applied to 

walk-in doors, as described previously. 

In the June 2021 RFI, DOE sought 

feedback on the EER values specified in 

appendix A used to calculate daily 

energy consumption for walk-in doors 

and the values used to test unit coolers 

as specified in subpart R, appendix C. 

Specifically, DOE requested comment 

on whether the EER values used for 

door testing and unit cooler testing 

consistent with each other, and if so, 

which values are more representative. 

86 FR 32332, 32339. 

Anthony responded that the EER 

values referenced in subpart R, 

appendix C (i.e., 13.3 Btu/(W-h) for 

coolers and 6.6 Btu/(W-h) for freezers), 

better reflect current compressor 

efficiency for walk-in refrigeration 

systems. (Anthony, No. 8 at p. 3) 

National Refrigeration encouraged DOE 

to keep the current EER values, stating 

that they believe the values are accurate, 

but did not specify if they were referring 

to walk-in door or refrigeration system 

EER values. (National Refrigeration, No. 

17 at p. 1) Keeprite, Lennox, and AHRI 

all supported maintaining the EER 

values applicable to unit coolers in 

subpart R, appendix C. (Keeprite, No. 12 

at p. 2; Lennox, No. 9 at p. 4; AHRI, No. 

11 at p. 8) 

Based on the comments received, it is 

not clear that there is an advantage to 

harmonizing the EER values between 

appendix A and subpart R, appendix C. 

Therefore, DOE is not proposing to 

change the subpart R, appendix C, EER 

values pertaining to walk-in 

refrigeration systems. 

Additionally, with respect to 

envelope components, DOE is not 

proposing to align the EER values in 

appendix A for calculating the energy 

consumption of envelope components 

with the EER values used for testing 

unit coolers alone in subpart R, 

appendix C, at this time. DOE originally 

defined nominal EER values in 

appendix A because an envelope 

component manufacturer generally 

cannot control what refrigeration 

equipment is installed, and the defined 

EER value is intended to provide a 

nominal means of comparison rather 

than reflecting an actual walk-in 

installation. 76 FR 21580, 21593 (Apr. 

15, 2011). In other words, the EER 

values used to estimate energy 

consumption of the envelope 

components is a constant. DOE notes 

that the difference between the EER 

values used in appendix A for doors and 

those used in subpart R, appendix C, for 

unit coolers is seven percent for coolers 

and five percent for freezers, which 

would have minimal impact on rated 

values but would require manufacturers 

to retest and re-rate energy consumption 

without necessarily providing a more 

representative test procedure. 


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6. Air Infiltration Reduction 

EPCA includes prescriptive 

requirements for doors used in walk-in 

applications which are intended to 

reduce air infiltration. Specifically, 

walk-ins must have (A) automatic door 

closers that firmly close all walk-in 

doors that have been closed to within 1 

inch of full closure (excluding doors 

wider than 3 feet 9 inches or taller than 

7 feet), and (B) strip doors, springhinged doors, or other method of 

minimizing infiltration when doors are 

open. (42 U.S.C. 6313(f)(1)(A)–(B)) DOE 

previously proposed methods for 

determining the thermal energy leakage 

due to steady state infiltration through 

the seals of a closed door and door 

opening infiltration. DOE did not 

ultimately adopt these methods as part 

of the test procedure because DOE 

concluded that steady state infiltration 

was primarily influenced by on-site 

assembly practices rather than the 

performance of individual components. 

76 FR 21580, 21594–21595 (April 15, 

2011) (‘‘April 2011 final rule’’). 

Similarly, DOE stated that, based on its 

experience with the door manufacturing 

industry, door opening infiltration is 

primarily reduced by incorporating a 

separate infiltration reduction device at 

the assembly stage of the complete 

walk-in. Id. In the June 2021 RFI, DOE 

invited comment on whether it should 

account for steady state and/or door 

opening infiltration in its test 

procedure. 86 FR 32332, 32340–32341. 

DOE also requested test methods and 

calculations to quantify heat load, the 

associated costs of any suggested 

methods, and supporting data on door 

usage patterns. Id. 

ASAP encouraged DOE to incorporate 

a measurement of air infiltration into 

the test procedure for walk-in doors 

because it would improve 

representativeness and encourage the 

development and deployment of 

technologies that could reduce 

infiltration and save energy. (ASAP, No. 

13 at p. 2) The CA IOUs recommended 

that DOE consider specifically 

incorporating door opening infiltration 

energy into the test procedure. They 

also suggested that DOE validate the 

actual savings of devices such as air 

curtains to determine if the test method 

should be refined to more accurately 

represent these features in the 

determination of walk-in performance. 

(CA IOUs, No. 14 at p. 6) In contrast, 

Imperial Brown stated that including air 

infiltration in the test procedure would 

be burdensome and cost prohibitive 

because most WICF doors are custommade. (Imperial Brown, No. 15 at p. 3) 

DOE is not proposing to include air 

infiltration in the test procedure for 

determining energy consumption of 

walk-in envelope components at this 

time because additional investigation is 

needed. DOE intends to consider data 

on the magnitude of air infiltration for 

walk-ins as it becomes available for 

appropriate evaluation of the 

representativeness of including it in the 

test procedure for walk-in doors. 

However, as previously mentioned, 

EPCA requires air infiltration limiting 

devices on all doors. (42 U.S.C. 

6313(f)(1)(A)–(B)) Even though air 

infiltration is not currently evaluated as 

part of the current test procedure and is 

thus not part of the performance 

standard, all walk-in doors are subject to 

the prescriptive requirements pertaining 

to air infiltration limiting devices. 

D. Proposed Amendments to the Test 

Procedure in Appendix A for Display 

Panels 

Appendix A specifies the test 

procedure to determine energy 

consumption of walk-in display panels, 

which are not currently subject to any 

performance standards in terms of daily 

energy consumption, but are subject to 

the prescriptive requirements at 10 CFR 

431.306. 

In the June 2021 RFI, DOE requested 

specific comment on the current test 

procedure for determining energy 

consumption for display panels and 

whether any amendments to this 

procedure were warranted. 86 FR 32332, 

32342. In response, Anthony and NFRC 

commented that the test procedure for 

display panels should be identical to the 

test procedure for display doors. 

(Anthony, No. 8 at p. 4; NFRC, No. 10 

at p. 4) 

DOE is proposing that the changes 

proposed throughout section III.C for 

determining conduction load and 

energy consumption of display doors 

would also be applicable to determining 

display panel conduction load and 

energy consumption, except for the 

provisions applicable to electrical 

components and percent time off values. 

E. Proposed Amendments to the Test 

Procedure in Appendix B for Panels and 

Non-Display Doors 

The insulation R-value of walk-in 

non-display panels and non-display 

doors is determined using appendix B. 

In this NOPR, DOE is proposing to 

modify appendix B to improve test 

representativeness and repeatability. 

Specifically, DOE is proposing to make 

the following revisions to appendix B: 

(1) Reference the updated industry 

standard ASTM C518–17; (2) include 

more detailed provisions on measuring 

insulation thickness and test sample 

thickness; (3) provide additional 

guidance on determining parallelism 

and flatness of test specimen; and (4) 

reorganize appendix B so it is easier for 

stakeholders to follow as a step-by-step 

test procedure. 

DOE does not expect that the changes 

it is proposing in this section would 

have a significant impact on measured 

R-value of insulation. Rather, the 

revisions proposed for appendix B 

address repeatability issues that DOE 

has observed through its testing of the 

insulation of walk-in panels. 

The following sections describe the 

modifications that DOE is proposing to 

appendix B, the test procedure for 

determining the R-value of walk-in 

envelope component insulation. DOE 

discusses the proposed changes 

specifically in the context of walk-in 

panels; however, DOE notes that nondisplay doors are also subject to the 

prescriptive R-value requirement at 10 

CFR 431.306(a)(3) and that the R-value 

for walk-in door insulation is 

determined using appendix B. 

1. Specimen Conditioning 

In the June 2021 RFI, DOE noted that 

the test specimen conditioning 

instruction and example given in 

section 7.3 of ASTM C518 conflict with 

the provision in section 4.5 of the DOE 

test procedure at appendix B that 

requires testing per ASTM C518 be 

completed within 24 hours of 

specimens being cut for the purpose of 

testing. 86 FR 32332, 32341–32342. 

Section 7.3 of ASTM C518 directs that 

a test specimen be conditioned prior to 

testing and states that this be done per 

material specifications. If material 

specifications for conditioning are not 

provided, the specimen preparation 

shall be conducted so as not to expose 

the specimen to conditions which 

would change the specimen in an 

irreversible manner. Section 7.3 of 

ASTM C518 provides an example of a 

material specification that requires test 

specimen conditioning at 72 °F and 50 

percent relative humidity until less than 

a one percent change in mass is 

observed over a 24-hour period. As part 

of the June 2021 RFI, DOE sought 

comment on whether manufacturers of 

insulation specify conditioning for 

insulation materials that differ from the 

typical approach described in ASTM 

C518. DOE also requested feedback on 

whether more than one 24-hour 

conditioning period is ever needed to 

complete specimen conditioning given 

ASTM’s requirement regarding change 

in mass. Lastly, DOE requested data on 

panel performance for conditioning 

times less than 24 hours, specifically, 


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23944 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

23Edge region means a region of the panel that 

is wide enough to encompass any framing members. 

If the panel contains framing members (e.g., a wood 

frame) then the width of the edge region must be 

as wide as any framing member plus an additional 

2 in. ± 0.25 in. See section 3.1 of appendix B. 

24Maintaining a flatness tolerance means that no 

part of a given surface is more distant than the 

tolerance from the ‘‘best-fit perfectly flat plane’’ 

representing the surface. Maintaining parallelism 

tolerance means that the range of distances between 

the best-fit perfectly flat planes representing the two 

surfaces is no more than twice the tolerance (e.g., 

for square surfaces, the distance between the most 

distant corners of the perfectly flat planes minus the 

distance between the closest corners is no more 

than twice the tolerance). 

how conditioning time impacts the 

accuracy, repeatability, and 

representativeness of the test. 86 FR 

32332, 32342. 

Imperial Brown stated that the panel 

should cure for 30 days before a test 

specimen is cut and that the test 

specimen should be tested within 24 

hours of being cut. Imperial Brown 

asserted that conditioning for longer 

than 24 hours would create an issue 

with outgassing, particularly on a small 

test specimen. Additionally, Imperial 

Brown observed that the 180-day 

conditioning period specified in ASTM 

C1029–2015, ‘‘Standard Specification 

for Spray-Applied Rigid Cellular 

Polyurethane Thermal Insulation’’ 

would be unrealistic and a significant 

test burden. (Imperial Brown, No. 15 at 

p. 3) 

In response to the suggestion by 

Imperial Brown that a panel should cure 

for 30 days before a test, DOE notes that 

section 4.5 of the current test procedure 

in appendix B already specifies that 

foam insulation be tested after it is 

produced in its final chemical form. For 

foam-in-place insulation, this means the 

foam has cured as intended and is ready 

for use in a finished panel. In response 

to the comments received regarding 

outgassing of the test specimen for 

conditioning times beyond 24 hours, 

preliminary tests conducted by DOE 

demonstrate negligible change in mass 

of the test specimen within 24 to 48 

hours and negligible difference in Rvalue when compared to a test specimen 

from the same foam that was tested 

within 24 hours. Regarding the 180-day 

conditioning period specified in ASTM 

C1029–2015, DOE has tentatively 

concluded that this timeframe for 

testing is unrealistic and burdensome. 

Considering all the information at hand, 

DOE is not proposing any changes to the 

current requirement that testing be 

completed with 24 hours of the test 

specimen being cut from the envelope 

component. Correspondingly, DOE is 

not proposing to reference Section 7.3 of 

ASTM C518–17 regarding specimen 

conditioning. 

2. Total Insulation and Test Specimen 

Thickness 

Section 4.5 of appendix B currently 

requires that K-factor of a 1 ± 0.1-inch 

sample of insulation be determined 

according to ASTM C518–04. The walkin envelope component insulation Rvalue is determined by dividing the 

envelope component insulation 

thickness by the K-factor. As mentioned 

in the June 2021 RFI, the measurement 

of total insulation thickness is important 

in determining the envelope 

component’s insulation R-value. 86 FR 

32332, 32341. As part of the June 2021 

RFI, DOE requested comment on how 

panel thickness is typically measured. 

Id. DOE did not receive any comments 

in response to this request. 

In order to make the test procedure in 

appendix B more repeatable, DOE is 

proposing to include instructions for 

determining both the total insulation 

thickness as well as the test specimen 

insulation thickness prior to conducting 

the test to determine K-factor using 

ASTM C518–17. DOE is also proposing 

step-by-step instructions for specimen 

preparation, including detailed 

instructions of the number and locations 

of thickness and area measurements and 

from where the test specimen should be 

removed from the overall envelope 

component. DOE proposes to require the 

following steps for determining the total 

thickness of the foam, tfoam, from which 

the final R-value would be calculated: 

• The thickness around the perimeter 

of the envelope component is 

determined as the average of at least 8 

measurements taken around the 

perimeter, but avoiding the edge 

region; 23

• The area of the entire envelope 

component is calculated as the width by 

the height of the envelope component; 

• A sample is cut from the center of 

the envelope component relative to the 

envelope component’s width and 

height. The specimen to be tested using 

ASTM C518–17 would be cut from the 

center sample; 

• The thickness of the sample cut and 

removed from the center of the envelope 

component is determined as the average 

of at least 8 measurements, with 2 

measurements taken in each quadrant; 

• The area of the sample cut and 

removed from the center of the envelope 

component is determined as the width 

by the height of the cut sample; 

• Any facers on the sample cut from 

the envelope component shall be 

removed while minimally disturbing the 

foam and the thickness of each facer 

shall be the average of at least 4 

measurements; 

• The average total thickness of the 

foam shall then be determined by 

calculating an area-weighted average 

thickness of the complete envelope 

component less the thickness of the 

facers. 

For preparing and determining the 

thickness of the 1-inch test specimen, 

DOE proposes to include the following 

steps: 

• A 1 ± 0.1-inch-thick specimen shall 

be cut from the center of the cut 

envelope sample removed from the 

center of the envelope component; 

• Prior to testing, the average of at 

least nine thickness measurements at 

evenly-spaced intervals around the test 

specimen shall be the thickness of the 

test specimen, L. 

Issue 9: DOE requests feedback on the 

proposed provisions relating to test 

specimen and total insulation thickness 

and test specimen preparation prior to 

conducting the ASTM C518–17 test. 

3. Parallelism and Flatness 

The test procedure for determining Rvalue also requires that the two surfaces 

of the tested sample that contact the hot 

plate assemblies (as defined in ASTM 

C518) maintain ± 0.03 inches flatness 

tolerance and maintain parallelism with 

respect to one another within a 

tolerance of ± 0.03 inches.24 See 

appendix B, section 4.5. As mentioned 

in the June 2021 RFI, the current test 

procedure does not provide direction on 

how flatness and parallelism should be 

measured or calculated. 86 FR 32332, 

32341. As part of the June 2021 RFI, 

DOE sought comment on how flatness 

and parallelism are determined by test 

laboratories and whether the DOE test 

procedure should include instruction on 

how to determine these parameters. Id. 

While DOE received no comments in 

response to this request for comment, 

DOE believes that accurate and 

repeatable determination of a 

specimen’s R-value requires the 

specimen under test to be both flat and 

parallel. Therefore, DOE proposes to 

include the following steps for 

determining the parallelism and flatness 

of the tested specimen in appendix B: 

• Prior to determining the specimen 

thickness, the specimen would be 

placed on a flat surface and gravity will 

determine the specimen’s position on 

the surface. As specified previously, a 

minimum of nine thickness 

measurements would be taken at 

equidistant positions on the specimen. 

These measurements would be 

associated with side 1 of the specimen. 

• The least squares plane of side 1 is 

determined based on the height 

measurements taken. The theoretical 

height of the least squares plane is 


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25 DOE referenced DIN EN 13164:2009–02, 

‘‘Thermal insulation products for buildings— 

Factory made products of extruded polystyrene 

foam (XPS)—Specification’’ and DIN EN 

13165:2009–02, ‘‘Thermal insulation products for 

buildings—Factory made rigid polyurethane foam 

(PUR) products—Specification.’’ 

26A presentation on ORNL’s study can be found 

online at https://www.osti.gov/biblio/1844325- 

impact-thermal-bridging-imperfections-agingeffective-value-walk-cooler-freezer-panels. DOE 

acknowledges that panels are shipped for assembly 

in walk-ins with the foam already in final chemical 

form between facers. Thus, the most applicable 

evaluation of change in insulation R-value over 

time is demonstrated by the red data points (labeled 

‘‘2’’) for the foam that remained intact with the 

facers on slides 26 through 30 of ORNL’s 

presentation. 

determined at each measurement 

location in the x and y (length and 

width) direction of the specimen. 

• The difference at each measurement 

location between actual height 

measurement and theoretical height 

measurement based on the least squares 

plane is calculated. The maximum value 

minus the minimum value is the 

flatness associated with this side (side 

1). In order for each side of the 

specimen to be considered flat, this 

value would need to be less than or 

equal to 0.03 inches. 

• Flip the specimen so that side 1 is 

now on the flat surface and let gravity 

determine the specimen position on the 

surface. Repeat the above steps for side 

2 of the specimen. 

• To determine if each side of the 

specimen is parallel, the theoretical 

height at the four corners (i.e., at points 

(0,0), (0,12), (12,0), and (12,12)) of the 

specimen must be calculated using the 

least squares plane. The difference in 

the maximum and minimum heights 

would represent the parallelism of one 

side and would need to be less than or 

equal to 0.03 inches for the specimen to 

be considered parallel. 

Issue 10: DOE requests feedback on 

the proposed provisions relating to 

determining parallelism and flatness of 

the test specimen. 

4. Insulation Aging 

In the April 2011 final rule, DOE 

adopted a test procedure that referenced 

two industry test standards 25 that 

considered aging of insulation for foams 

that experience aging. 76 FR 21580, 

21588–21592. However, after receiving 

comments concerning test burden and 

the availability of labs to conduct the 

test procedure, DOE re-evaluated its 

earlier decision and removed this 

portion of the walk-in panel test 

procedure in the final rule published 

May 13, 2014 (‘‘May 2014 final rule’’). 

79 FR 27388, 27405–27406. Although 

the current test procedure for 

determining panel R-value does not 

account for aging, manufacturers have 

raised concern regarding insulation 

aging and its potential effect on testing 

results. 

‘‘Aging’’ of foam insulation refers to 

how diffusion of blowing agents out of 

the foam and diffusion of air into the 

foam impacts thermal resistance of 

insulation materials. The gaseous 

blowing agents contained in the foam 

provide the foam with much of its 

insulating performance, represented by 

the R-value of the foam material. 

Because air has a lower insulating value 

than the blowing agents used in foam 

insulation, the increased ratio of air to 

blowing agent reduces the foam 

insulation performance, which reduces 

the R-value of the foam material. The 

building industry uses long-term 

thermal resistance (‘‘LTTR’’) to 

represent the R-value of foam material 

over its lifetime by describing the 

insulating performance changes due to 

diffusion over time. The presence of 

impermeable facers on a foam structure 

may delay the rate of aging or reduce the 

decrease in R-value when compared to 

a foam structure that is unfaced or has 

permeable facers. Blowing agents and 

temperature and humidity conditions 

may also affect the amount or rate of 

aging that occurs in a foam structure. 

Since the May 2014 final rule, DOE 

worked with the Oak Ridge National 

Laboratory (‘‘ORNL’’) to conduct a study 

on performance aging and thermal 

bridging of walk-in cooler and freezer 

panels.26 In this study, multiple panels 

from five manufacturers were allowed to 

age intact (i.e., with facers attached) at 

room temperature, with 1-inch samples 

taken from the middle of a given panel 

for testing according to the test 

procedure in appendix B. These 

samples were tested upon receipt of the 

panels and extracted at various times 

throughout 5 years from intact panels 

(i.e., with facers attached). Aging panels 

with their facers attached is 

representative of how panels are stored 

and, ultimately, installed for use in a 

walk-in box. Appendix B does not test 

with facers because, as previously 

stated, the DOE test procedure evaluates 

only the R-value of the foam 

insulation—not the R-value of the entire 

panel. 

Based on DOE evaluation of product 

literature, there are two common ways 

to manufacture walk-in panels: (1) 

Foaming metal skins in place using 

closed cell polyurethane foam (‘‘PUF’’) 

or (2) gluing layers of previouslyhardened foam to metal skins. DOE 

research suggests that PUF is the most 

common insulation used in walk-ins. To 

manufacture PUF panels, the PUF is 

injected and hardened using jigs that 

firmly maintain exterior panel 

dimensions until the foam has cooled 

and hardened. This process encourages 

standardization of panel dimensions as 

jigs are expensive and typically have 

limited adjustability. Extruded 

polystyrene (‘‘XPS’’) is used by some 

manufacturers to construct walk-in 

panels. XPS-based walk-ins are built in 

layers of XPS, a previously-hardened 

foam material that is shipped in sheets 

to the original equipment manufacturer 

(‘‘OEM’’), where it is cut to the desired 

shape and assembled. Customization is 

more common with XPS panels. XPS 

strongly resists water absorption, 

preventing panels from losing their 

insulative properties should water or 

condensation leaks develop. Other 

layered panel assembly materials 

include polyisocyanurate and expanded 

polystyrene (‘‘EPS’’) which are used less 

but are still offered by some 

manufacturers. Polyisocyanurate has 

similar advantages to XPS, but generally 

has lower thermal resistivity at lower 

temperature conditions. EPS also has 

similar advantages to XPS in terms of 

moisture absorption, but generally has a 

lower R-value. The study conducted at 

ORNL evaluated four panel brands 

manufactured with PUF and one panel 

brand manufactured using XPS. The Rvalue of insulation measured by ORNL 

at the initial test date and most recent 

test date are summarized in Table III.5. 

TABLE III.5—SUMMARY OF R-VALUE TEST RESULTS AT INITIAL TEST DATE AND MOST RECENT TEST DATE FROM ORNL 

STUDY

Label Foam type Temperature condition Number of years after initial test R-value 

F1 ................ PUF ............. Freezer .............................................................. 0 (initial test) ..................................................... 31.2 

2.3 ..................................................................... 30.9 

F2 ................ PUF ............. Freezer .............................................................. 0 (initial test) ..................................................... 31.8 

4.2 ..................................................................... 30.3 


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27Thermal bridging occurs when a more 

conductive material allows an easy pathway for 

heat flow across a thermal barrier. 

TABLE III.5—SUMMARY OF R-VALUE TEST RESULTS AT INITIAL TEST DATE AND MOST RECENT TEST DATE FROM ORNL 

STUDY—Continued 

Label Foam type Temperature condition Number of years after initial test R-value 

C1 ................ PUF ............. Cooler ............................................................... 0 (initial test) ..................................................... 28.2 

4.8 ..................................................................... 26.8 

C2 ................ XPS ............. Cooler ............................................................... 0 (initial test) ..................................................... 25.0 

4.7 ..................................................................... 23.1 

C3 ................ PUF ............. Cooler ............................................................... 0 (initial test) ..................................................... 28.0 

0.5 ..................................................................... 27.8 

Based on ORNL’s study, DOE 

considers the effects of foam insulation 

aging for walk-in refrigeration panels 

sold with facers to be minimal when 

panel facers remain attached to the foam 

(i.e., when the panel remains intact.). 

DOE understands that for the purposes 

of certification and represented Rvalues, manufacturers are determining 

their represented R-value by testing 

specimens from panels at the point of 

manufacture (i.e., R-value without 

aging). For assessment and enforcement 

testing conducted to support the 

enforcement of DOE’s energy 

conservation standards, DOE is 

generally able to test samples within 

one to three months after receipt. The 

time lag from when the panel is 

manufactured and when testing is 

conducted at a lab is typically 

significantly shorter than that evaluated 

in the ORNL study; therefore, DOE 

expects any reduction in R-value to be 

even less during the period from date of 

manufacture to assessment or 

enforcement test date. Additionally, 

walk-in panels received by DOE for 

assessment and enforcement testing are 

evaluated upon arrival to ensure that 

they are received intact (i.e., with facers) 

and undamaged and testing of the 

specimen is completed within 24 hours 

of sample removal from the panel, as 

specified in section 4.5 of the DOE test 

procedure in appendix B. DOE does not 

expect any reduction in R-value within 

24 hours of the sample being cut from 

the panel. 

Issue 11: DOE seeks comment on 

other comparable data or studies of 

aging of foam panels that are 

representative of the foam insulation, 

blowing agents, and panel construction 

currently used in the manufacture of 

walk-in panels. DOE also requests 

comment on whether manufacturers 

have been certifying R-value at time of 

manufacture or after a period of aging. 

5. Determining Energy Consumption of 

Panels That Are Not Display Panels 

When DOE initially established the 

test procedures for components of a 

WICF in its April 2011 final rule, DOE 

adopted a test method for measuring the 

overall thermal transmittance of a walkin panel, including the impacts of 

thermal bridges 27 and edge effects (e.g., 

due to framing materials and fixtures 

used to mount cam locks). 76 FR 21580, 

21605–21612. This method was based 

on an existing industry test method, 

incorporating by reference ASTM 

C1363. Id. However, after receiving 

comments concerning test and cost 

burden and the lack of availability of 

labs to conduct the test procedure, DOE 

re-evaluated its earlier decision and 

removed this portion of the walk-in 

panel test procedure in the May 2014 

final rule. 79 FR 27388, 27405–27406. 

As previously stated, the current test 

procedure in appendix B for nondisplay panels evaluates insulation Rvalue according to ASTM C518–04. In 

the June 2021 RFI, DOE requested 

information regarding panel 

construction factors that would affect 

overall thermal transmission and the 

magnitude of these effects. 86 FR 32332, 

32342. DOE also requested comment on 

alternative test methods to measure 

overall thermal transmittance of a panel 

assembly along with the number of labs 

that are qualified to run ASTM C1363. 

Id. 

ASAP and the CA IOUs encouraged 

DOE to consider a test method that 

captures overall thermal transmittance 

of walk-in panels. (ASAP, No. 13 at p. 

2; CA IOUs, No. 14 at p. 5) The CA IOUs 

specifically recommended that the 

ASTM C1363 test be conducted on a 

wall panel assembly that includes the 

panel joint to ensure the joint locking 

mechanism does not significantly affect 

the thermal conductance of the 

assembly. The CA IOUs also suggested 

that the tested joint assembly use a 

manufacturer-recommended sealant 

representative of field installation. (CA 

IOUs, No. 14 at p. 5) 

Imperial Brown urged DOE to 

maintain the current test procedure for 

non-display panels based on insulation 

R-values determined using ASTM C518. 

Imperial Brown stated that ASTM 

C1363 is unduly burdensome given the 

custom nature of the walk-ins they 

manufacture and that this would 

substantially increase their testing 

requirements. Imperial Brown also 

remarked that the effect of panel edges 

or accessories is of little value to the 

overall energy consumption of a walkin and that considering these effects 

would be equivalent to considering one 

opening of the walk-in door per day. 

Specifically, Imperial Brown stated that 

the panel edges and accessories are not 

considered when calculating box loads 

and sizing refrigeration equipment 

because they do not consider them to be 

an important factor in heat loss. 

Imperial Brown also stressed that 

retesting will be required every few 

years as they switch to different 

insulation chemicals to comply with 

other regulations coming into effect 

(e.g., the Environmental Protection 

Agency (‘‘EPA’’) phasedown of HFCs. 

(Imperial Brown, No. 15 at p. 3) 

NFRC stated that all labs qualified to 

run NFRC 102 are qualified to run 

ASTM C1363 and that there are 

currently ten labs accredited by NFRC to 

run NFRC 102, and thus ASTM C1363. 

(NFRC, No. 10 at p. 4) 

While commenters indicated that 

there are more laboratory facilities now 

able to conduct an overall U-factor test 

procedure, the concerns previously 

expressed regarding cost and test 

burden, which led to the removal of this 

test procedure in the May 2014 AEDM 

final rule (79 FR 27388, 27405–27406), 

remain. At this time, DOE is not 

proposing to include a test procedure 

for determining energy consumption of 

non-display panels and is proposing to 

maintain the R-value of insulation test 

procedure in appendix B with the 

proposed amendments as described 

previously in sections III.E.1 through 

III.E.4. 

F. Proposed Amendments to Subpart R, 

Appendix C, to Determine Compliance 

With the Current Energy Conservation 

Standards 

Subpart R, appendix C, provides the 

test procedures to determine the AWEF 

and net capacity of walk-in refrigeration 


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systems. DOE is proposing to modify 

subpart R, appendix C, to improve test 

representativeness and repeatability. 

Specifically, DOE is proposing to make 

the following revisions to subpart R, 

appendix C: (1) Specify refrigeration test 

room conditions; (2) provide for a 

temperature probe exception for small 

diameter refrigerant lines; (3) 

incorporate a test setup hierarchy for 

laboratories to follow when setting up a 

unit for test; (4) allow active cooling of 

the liquid line in order to achieve the 

required 3 °F subcooling at a refrigerant 

mass flow meter; and (5) modify 

instrument accuracy and test tolerances. 

DOE does not expect that the changes 

it is proposing in this section would 

alter measured capacity values or 

AWEF—which means that no retesting 

or recertification would be required. 

Rather, the revisions proposed for 

subpart R, appendix C, address 

repeatability issues that DOE has 

observed through its testing of walk-in 

refrigeration systems. 

The following sections describe the 

modifications that DOE is proposing to 

subpart R, appendix C. 

1. Refrigeration Test Room Conditioning 

The DOE test procedure for walk-in 

refrigeration systems has requirements 

for test chambers to be at specific 

temperature and/or humidity 

conditions. (See, e.g., Tables 3 through 

16 of AHRI 1250–2009, which is 

incorporated by reference in the DOE 

test procedure) Section C6.2 of AHRI 

1250–2009 appendix C requires that the 

environmental chambers ‘‘be equipped 

with essential air handling units and 

controllers to process and maintain the 

enclosed air to any required test 

conditions.’’ This same requirement is 

in Section C5.2.2 of AHRI 1250–2020. 

However, DOE is aware that some test 

facilities rely on the test unit to cool and 

dehumidify the test room, in some cases 

without support from additional 

chamber conditioning systems. When 

unit coolers with hot gas defrost are 

tested and certified alone, these unit 

coolers may be paired with a 

condensing unit at a test facility that 

lacks hot gas capability and would be 

unable to remove the frost accumulated 

during pretest conditioning. Such frost 

would affect the results of the capacity 

test. 

DOE proposes to specify that for 

applicable system configurations 

(matched pairs, single-packaged 

systems, and unit coolers tested alone), 

the unit under test may be used to aid 

in achieving the required test chamber 

conditions prior to beginning any steady 

state test. However, the unit under test 

must be inspected and confirmed to be 

free from frost before initiating steady 

state testing. This additional instruction 

reflects DOE’s understanding of the 

existing practice followed by 

manufacturers and third-party 

laboratories who use the unit under test 

to establish the required chamber 

conditions. The proposed inspection 

requirement would ensure that a steady 

state test is not started with frost on the 

coil. Starting a test with a frosted coil 

would likely lead to reduced-efficiency 

and non-representative test results, and 

DOE expects that test laboratories would 

have no incentive to conduct tests with 

a frosted coil. 

Issue 12: DOE requests comment on 

the proposed pretest coil inspection 

requirement. DOE requests comment on 

whether the proposed approach is 

inconsistent in any way with the way 

units under test are used to assist in 

chamber conditioning by testing 

facilities, and if so, in what way are the 

proposals inconsistent, and how could 

they be changed to align with this 

practice. 

2. Temperature Measurement 

Requirements 

The current DOE test procedure 

requires all refrigerant temperature 

measurements entering or leaving the 

unit cooler be measured by a 

‘‘temperature measuring instrument 

placed in a thermometer well and 

inserted into the refrigerant stream. 

These wells shall be filled with nonsolidifying, thermal conducting liquid 

or paste to ensure the temperature 

sensing instrument is exposed to a 

representative temperature.’’ AHRI 

1250–2009 appendix C, Section C3.1.6. 

These temperature measurements are 

used to determine refrigerant enthalpy 

as part of the capacity measurement for 

matched pairs and unit coolers tested 

alone (see AHRI 1250–2009, Section 

C8.5.1, Equations C1 and C2). However, 

the capacity determination for dedicated 

condensing units tested alone is based 

on the refrigerant conditions leaving the 

condensing unit and standardized 

conditions leaving the unit cooler, as 

specified in section 3.4.2.1 of subpart R, 

appendix C. DOE believes that the 

added accuracy provided by immersing 

the temperature sensor in the refrigerant 

or by the thermometer wells should be 

applied for the temperature 

measurement used in the capacity 

calculation. Hence, DOE proposes that 

the test procedure provide clarification 

that when testing dedicated condensing 

units, the use of thermometer wells or 

immersed sensors be used only at the 

condensing unit liquid outlet. DOE 

believes this may reduce testing burden 

in cases where labs have been using two 

sets of refrigerant-immersed temperature 

measurements when testing dedicated 

condensing units alone. 

Issue 13: DOE requests comment on 

its proposal to require use of 

thermometer wells or sheathed sensors 

immersed in the refrigerant when 

measuring temperature at the liquid 

outlet of the condensing unit and to 

forego the requirement for this 

measurement technique for the suction 

line when testing a dedicated 

condensing unit alone. 

DOE has found that implementing the 

current thermometer well requirement 

for refrigerant lines with outer diameter 

1⁄2-inch or less can restrict the 

refrigerant flow and thus affect the 

measurements. To rectify this issue and 

to ensure that all walk-in refrigeration 

systems can be tested according to the 

DOE test procedure, DOE proposes 

allowing an alternative approach when 

the refrigerant line tubing diameter is 

1⁄2-inch or less in which the temperature 

measurement would be made using two 

surface-mounted measuring instruments 

with a minimum accuracy of ±0.5 °F, 

which would be averaged to obtain the 

reading. DOE notes that when using the 

Dual Instrumentation method described 

in Section C8 of AHRI 1250–2009 

appendix C, the two surface 

measurements described would 

constitute one temperature 

measurement, rather than the two 

measurements required for the test 

method. Additionally, DOE proposes 

that the two measuring instruments 

must be mounted on the pipe separated 

by 180-degrees around the refrigerant 

tube circumference. To ensure 

measurements are not affected by 

changes in ambient temperature, DOE 

proposes requiring use of 1-inch-thick 

insulation around the measuring 

instruments that extends 6-inches upand down-stream of the measurement 

locations. Where this technique is used 

to measure temperature at the expansion 

valve inlet, i.e., where Section C3.16 of 

AHRI 1250–2009 requires the 

measurement to be within 6 pipe 

diameters of the control device, DOE 

proposes to relax this requirement and 

require instead that the measurement be 

within 6 inches of the device. 

Issue 14: DOE requests comment on 

its proposal to allow the use of two 

temperature measuring instruments, 

placed on the outside of refrigerant 

tubing that is less than or equal to 1⁄2- 

inch, for the measurement of refrigerant 

temperature where the current test 

procedure requirement is to use 

thermometer wells or a sheathed sensor 

immersed in the refrigerant. 


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28Superheat is the difference between vaporphase refrigerant temperature and the dew point 

corresponding to the pressure level. 

29A zeotropic refrigerant is a blend of two or 

more refrigerants that have different boiling points. 

Each refrigerant will evaporate and condense at 

different temperatures. 

3. Hierarchy of Installation Instructions 

and Specified Refrigerant Conditions for 

Refrigerant Charging and Setting 

Refrigerant Conditions 

During testing, DOE has found that 

some refrigeration systems cannot be set 

up fully consistent with the refrigerant 

conditions specified in installation 

instructions. In some cases, there may 

be multiple installation instructions 

(e.g., instructions on labels affixed to the 

unit and instructions shipped with the 

unit), and different results could be 

obtained depending on which 

instructions are followed. To address 

this issue, DOE has developed a setup 

hierarchy for installation instructions 

and setup of refrigerant conditions to 

improve repeatability in testing by 

indicating which manufacturerspecified conditions would be 

prioritized during test setup. DOE’s 

proposed setup hierarchy is discussed 

in more detail in the following 

paragraphs. 

Setup conditions or instructions may 

be stamped on the unit nameplate or 

otherwise affixed to the unit, shipped 

with the unit, or available online. DOE 

has encountered walk-in refrigeration 

units for which these three sources of 

instruction provide different values or 

conflicting directions. To ensure 

consistent setup during testing, DOE 

proposes that instructions or conditions 

stamped on or adhered to a test unit 

take precedence, followed by 

instructions shipped with the unit. 

Additionally, since online instructions 

can be easily revised, DOE proposes that 

instructions or other setup information 

found online would not be used to set 

up the unit for test. 

Setting of refrigerant charge level or 

refrigerant conditions is a key aspect of 

setup of refrigeration systems, whether 

for field use or testing. DOE proposes 

that units be charged and set up at 

operating conditions specified in the 

test procedure (for outdoor refrigeration 

systems, DOE proposes use of operating 

condition A) based on the installation 

instructions, using the proposed 

hierarchy (i.e., prioritize instructions 

stamped or adhered to unit over 

instructions included in a manual 

shipped with the unit). In the case 

where instructions for refrigerant 

charging or refrigerant conditions are 

provided only in online instructions or 

not at all, DOE is proposing that a 

generic charging approach be used 

instead. If the installation instructions 

specify operating conditions to use to 

set up the refrigerant charge or 

refrigerant conditions, that operating 

condition would be used rather than the 

conditions specified in the test 

procedure. 

DOE often finds that in some cases, 

the manufacturer specifies a range of 

conditions for superheat,28 subcooling, 

and/or refrigerant pressure. If this is the 

case, DOE proposes to treat the 

midpoint of that range as the target 

temperature/pressure, and that a test 

condition tolerance would be applied to 

the parameter that is equal to half the 

range. For example, if a manufacturer 

specifies a target superheat of 5 to 10 °F, 

the target for test would be 7.5 °F and 

that the average value during operation 

at the setup operating conditions would 

have to be 7.5 °F ± 2.5 °F. Alternatively, 

installation instructions may specify a 

refrigerant condition value without a 

range or without indicated tolerances. In 

such cases, DOE proposes that 

standardized tolerances be applied as 

indicated in Table III.6. These 

tolerances depend on the kind of 

refrigerant expansion device used. 

DOE also notes that zeotropic 29

refrigerants have become more common. 

When charging with such refrigerants 

(i.e., any 400 series refrigerant), DOE 

proposes that the refrigerant charged 

into the system must be in liquid form. 

This is standard practice for charging of 

such refrigerants since the 

concentrations of the components of the 

blend present in the vapor phase of the 

charging cylinder are often skewed from 

the intended concentrations of the 

refrigerant blend. 

If the installation instructions on the 

label affixed to (or shipped with) the 

unit do not provide instructions for 

setting subcooling or otherwise how to 

charge it with refrigerant for a 

condensing unit tested alone, or tested 

as part of a matched pair, DOE proposes 

requiring that the unit be tested in a way 

that is consistent with the DOE test 

procedure and the installation 

instructions and also does not cause the 

unit to stop operating during testing, 

e.g., by shutoff by the high pressure 

switch. DOE believes that such 

installation would be most 

representative of the way a technician 

would set up a system in the field if 

there were no refrigerant charge or 

subcooling instructions. 

a. Dedicated Condensing Unit Charging 

Instructions 

For dedicated condensing units tested 

alone, subcooling is the primary setup 

condition. DOE is proposing that if the 

dedicated condensing unit includes a 

receiver and the subcooling target 

leaving the condensing unit provided in 

the installation instructions cannot be 

met without fully filling the receiver, 

the subcooling target would be ignored. 

Likewise, if the dedicated condensing 

unit does not include a receiver and the 

subcooling target leaving the 

condensing unit cannot be met without 

the unit cycling off on high pressure, the 

subcooling target would be ignored. 

Also, if no instructions for charging or 

for setting subcooling leaving the 

condensing unit are provided in the 

installation instructions, DOE is 

proposing that the refrigeration system 

would be set up with a charge quantity 

and/or exit subcooling such that the 

unit operates during testing without 

shutdown (e.g., on a high-pressure 

switch) and operation of the unit is 

otherwise consistent with the 

requirements of the test procedure and 

the installation instructions. 

b. Unit Cooler Charging Instructions 

For unit coolers tested alone, 

superheat is the primary setup 

condition. Most WICF refrigeration 

systems use either thermostatic or 

electronic expansion valves that 

respond either mechanically or through 

a controller to adjust valve position to 

control for superheat leaving the unit 

cooler. If the unit under test is shipped 

with an adjustable expansion device, 

DOE proposes that this would be the 

primary method to adjust superheat. 

However, DOE has encountered units 

with expansion devices that are not 

adjustable or where the expansion 

device does not provide a sufficient 

range of adjustment to achieve the 

superheat target. If the expansion valve 

associated with the unit under test 

reaches its limit before the superheat 

target is met, the specified superheat 

may not be met within the specified 

tolerance. In this case, DOE proposes 

that the expansion valve should be left 

at the adjustment limit achieving the 

closest match to the superheat target. 

DOE has also encountered mismatched expansion devices and unit 

coolers. In this situation, DOE proposes 

that any expansion device specified for 

use with the unit cooler in manufacturer 

literature may be used for the purposes 

of DOE testing. 

Also, DOE proposes that an operating 

tolerance would not apply to superheat. 

Hence, in the event that the expansion 

valve control of the systems is not 

steady, i.e., if so-called ‘‘hunting’’ 

occurs, in which the valve position, 

temperatures, and/or pressures are 

unsteady, this fluctuation would not 


jspears on DSK121TN23PROD with PROPOSALS2
Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23949 

30Evaporator Temperature Difference (TD) is the 

difference in temperature between the entering air 

and the refrigerant dew point of the exiting 

refrigerant. 

31 ‘‘Split refrigeration systems’’ refer to systems 

made up of a condensing unit and a unit cooler that 

are connected by refrigerant lines and are not 

contained in a single housing. Split refrigeration 

systems could be field-matched condensing units 

and unit coolers or condensing units and unit 

coolers sold as matched pairs. 

invalidate a test. However, if the 

fluctuations are so great that a valid test 

cannot be performed (i.e., any 

individual measurement of superheat 

during the test is zero or less, or if the 

operating tolerances for measurements 

that would be affected by expansion 

device hunting are exceeded (mass flow, 

pressure at the unit cooler exit, 

evaporator temperature difference),30

the test procedure would call for 

remedial action allowing deviation from 

the installation instructions. The 

remedial action would be, at the 

discretion of the test laboratory, 

replacing the expansion device with a 

different expansion device that does not 

need to be listed in installation 

instructions, adjusting the expansion 

device to provide an average superheat 

that is greater than the target superheat, 

or both. 

If the installation instructions on the 

label affixed to the unit or shipped with 

the unit do not provide instructions for 

setting superheat for a unit cooler tested 

alone or tested as part of a matched pair, 

DOE proposes that the target superheat 

would be 6.5 °F, the same value required 

in such circumstances in AHRI 1250– 

2020 (see footnotes to Tables 16 and 17 

of AHRI 1250–2020). 

c. Single-Packaged Dedicated System 

Setup and Charging Instructions 

DOE has identified multiple setup 

issues while testing single-packaged 

dedicated systems. Compared to split 

refrigeration systems,31 single-packaged 

dedicated systems have less adjustment 

flexibility due to lack of controls. 

Additionally, many single-packaged 

dedicated systems are marketed as 

‘‘fully charged’’; therefore, it could be 

assumed that the charge would not need 

to be adjusted. 

DOE proposes that one or more 

pressure gauges, depending on the 

number of conditions which require a 

pressure measurement for validation, 

should be installed during the setup 

according to installation instructions to 

evaluate the charge of the unit under 

test and to accurately measure setup 

conditions. The location of the pressure 

gauge(s) would depend on the test setup 

conditions given in the installation 

instructions. If charging is based on 

subcooling or liquid pressure, DOE 

proposes that the pressure gauge would 

be installed at the service valve of the 

liquid line. If charging is based on 

superheat, low side pressure, or a 

corresponding saturation temperature/ 

dew point temperature, DOE proposes 

that the pressure gauge(s) would be 

placed in the suction line. 

DOE is aware that installation 

instructions for some single-packaged 

dedicated systems recommend against 

installing charging ports; however, DOE 

has observed through testing that some 

of these units do not operate once 

installed due to high- or low-pressure 

compressor cut off, which is often a 

symptom of under- or over-charging or 

refrigerant loss. These units are 

representative of what a contractor 

would encounter when installing a 

walk-in single-packaged unit in the 

field. Therefore, in cases where a unit 

under test is not operating due to highor low-pressure compressor cut off, DOE 

proposes a charging port should be 

installed, the unit should be evacuated, 

and the nameplate charge should be 

added. This approach would eliminate 

under- or over-charging of the unit 

which would address compressor cut 

off. 

d. Hierarchy of Setup Conditions if 

Manufacturer-Specified Setup 

Conditions Cannot be Met 

In DOE’s experience, even when all 

the previously discussed measures are 

implemented during test setup, some 

manufacturer specified setup conditions 

may not be met. If this is the case, DOE 

is proposing that the unit under test be 

set up according to a hierarchy of 

conditions similar to those used for 

central air-conditioning systems and 

heat pumps. First, the installation 

instruction hierarchy previously 

discussed would be applied. 

Specifically, if a refrigerant-related 

setup instruction in the installation 

instructions affixed to the unit and a 

different instruction in the installation 

instructions shipped with the unit 

cannot both be achieved within 

tolerance, the instruction on the label 

takes precedence. Further, if multiple 

instructions within the relevant 

installation instructions cannot be met, 

the proposed hierarchy outlined in 

Table III.6 would be applied. The 

highest priority condition that can be 

satisfied, based on Table III.6, would 

need to be met, depending on what kind 

of expansion device the system uses. 

This approach would ensure that units 

are set up consistently across testing 

facilities, ensuring more consistent 

results. 

TABLE III.6—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF

REFRIGERANT CONDITIONS

Fixed orifice or capillary tube Expansion valve 

Priority Method Tolerance Priority Method Tolerance 

1 Superheat ........................... ±2.0 °F .................... 1 Subcooling .......................... 10% of the Target Value; 

No less than ±0.5 °F, No 

more than ±2.0 °F. 

2 High Side Pressure or Saturation Temperature.±4.0 psi or ±1.0 °F 2 High Side Pressure or Saturation Temperature.±4.0 psi or ±1.0 °F. 

3 Low Side Pressure or Saturation Temperature.±2.0 psi or ±0.8 °F 3 Superheat ........................... ±2.0 °F. 

4 Low Side Temperature ....... ±2.0 °F .................... 4 Low Side Pressure or Saturation Temperature.±2.0 psi or ±0.8 °F. 

5 High Side Temperature ...... ±2.0 °F .................... 5 Approach Temperature ....... ±1.0 °F. 

6 Charge Weight .................... ±2.0 oz ................... 6 Charge Weight .................... 0.5% or 1.0 oz, whichever 

is greater. 


jspears on DSK121TN23PROD with PROPOSALS2
23950 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

32For example, when testing a matched pair 

refrigerator system under test condition A, the 

condensing unit chamber air temperature is at 95 °F 

and the unit cooler chamber air is at 35 °F. The 

liquid refrigerant generally is warmer than the 

condensing unit ambient temperature. Hence, there 

is at least a 60 °F temperature difference between 

the unit cooler inlet air temperature and the liquid 

refrigerant temperature. 

33For the same example, the liquid temperature 

may be in the range roughly from 95 °F to 105 °F, 

at most about 10 °F warmer than the surrounding 

air. 

Issue 15: DOE requests comment on 

its proposals discussed in this section 

regarding set up of walk-in refrigeration 

systems for testing to achieve 

manufacturer-specified conditions for 

superheat, subcooling, high-side 

temperature, pressure or saturation 

temperature, low-side temperature, 

pressure or saturation temperature, and 

refrigerant charge weight. Additionally, 

DOE requests comment on the proposed 

hierarchy presented in Table III.6, if a 

laboratory has confirmed that the unit is 

properly charged. 

4. Subcooling Requirement for Mass 

Flow Meters 

DOE has found that for testing 

dedicated condensing units alone an 

appropriate subcooling temperature 

ensures that the refrigerant is fully 

liquid at the mass flow meter, providing 

an accurate measurement. A mass flow 

meter may provide an inaccurate flow 

rate if the refrigerant is a mixture of 

vapor and liquid at the point of 

measurement. Section C3.4.5 of AHRI 

1250–2009 appendix C requires that 

refrigerant be subcooled to at least 3 °F 

and that bubbles not be visible in a sight 

glass immediately downstream of the 

mass flow meter. Section 3.2.3 of 

subpart R, appendix C, allows use of the 

sight glass and a temperature sensor 

located on the tube surface under the 

insulation to verify sufficient 

subcooling. DOE testing has also shown 

that even when the subcooling 

requirement is met downstream of the 

mass flow meters, the subcooling can be 

significantly lower upstream of the mass 

flow meters, resulting in questionable 

mass flow measurements that do not 

provide capacity determinations within 

the required tolerances, e.g., with 5 

percent of each other as required by 

Section C8.5.3 of AHRI 1250–2009 (see 

EERE–2017–BT–TP–0010–0021, 

‘‘Development of Test Rating Conditions 

for Two-Capacity, Multiple-Capacity, 

and Variable-Capacity Condensing 

Units’’). DOE proposes to add further 

instruction to section 3.2.3 of subpart R, 

appendix C. 

First, DOE proposes that the 3 °F 

subcooling requirement be applied at a 

location depending on location of the 

liquid-line mass flow meters. 

Specifically, the requirement would 

apply downstream of any mass flow 

meter located in the chamber in which 

the condensing unit under test is 

located, consistent with AHRI 1250– 

2009. However, for mass flow meters 

located in the chamber in which the 

unit cooler under test is located, the 

subcooling would have to be verified 

upstream of the mass flow meter. The 

latter requirement addresses observation 

in DOE testing that the upstream 

subcooling is less than the downstream 

subcooling when the mass flow meter is 

in the same chamber as the unit cooler. 

Id. This occurs because the unit cooler 

chamber is generally much cooler than 

the liquid refrigerant.32 Since mass flow 

meters are rarely insulated, the liquid 

refrigerant is cooled as it passes through 

the mass flow meter, which increases 

the refrigerant’s subcooling. However, as 

the liquid refrigerant passes through the 

mass flow meter it also experiences a 

pressure drop which decreases the 

subcooling. The increase in subcooling 

that occurs across the mass flow meter 

is nearly always larger than the decrease 

in subcooling that occurs because of the 

pressure drop across the mass flow 

meter. Therefore, subcooling will nearly 

always be less at the inlet of a mass flow 

meter than at the outlet. This is in 

contrast to a mass flow meter located in 

the same chamber as the condensing 

unit, for which the air surrounding the 

mass flow meter, while typically cooler 

than the liquid, would be much closer 

in temperature to the liquid 

temperature.33 DOE also notes that the 

requirement for subcooling specified in 

ASHRAE 23.1–2010, which is 

incorporated by reference by the DOE 

test procedure for testing of condensing 

units alone, indicates in section 7.1.2 

(‘‘Adequate subcooling shall be 

provided upstream of a liquid 

refrigerant flowmeter . . .’’) suggesting 

that there is a lack of clarity regarding 

the best location for ensuring adequate 

subcooling. Based on DOE’s experience 

and the prevailing air-liquid 

temperature differences during testing, 

DOE proposes to include the 

clarification above regarding the 

location of the subcooling verification. 

Second, DOE proposes to indicate that 

active cooling of the liquid line may be 

used to achieve the required subcooling, 

since the subcooling at the mass flow 

meter outlet may not meet the 3 °F 

requirement when the subcooling at the 

condensing unit exit is within tolerance 

of its target. However, DOE also 

proposes requiring that if this is done 

when testing a matched pair (not 

including single-packaged dedicated 

systems), that the temperature also must 

be measured upstream of the location 

where cooling is provided, and that the 

temperature used to calculate the 

enthalpy of the refrigerant entering the 

unit cooler be increased by the 

difference between the upstream and 

downstream measurements. DOE is 

proposing this adjustment so that active 

cooling of the liquid to obtain a mass 

flow measurement does not provide a 

non-representative boost in calculated 

cooling capacity. 

DOE proposes to add these 

requirements to subpart R, appendix C, 

which would also carry over to the 

newly proposed subpart R, appendix 

C1. 

Issue 16: DOE requests comments on 

its proposal to clarify the location where 

the 3 °F subcooling requirement would 

apply and to require active cooling of 

the liquid line in order to achieve the 

required 3 °F subcooling at a refrigerant 

mass flow meter. DOE also seeks 

comment on its proposal to require, for 

matched pairs, adjustment of the 

measured unit cooler inlet temperature 

by the difference in temperatures 

measured upstream and downstream of 

the active cooling in order to calculate 

the inlet enthalpy in the capacity 

calculation. 

5. Instrument Accuracy and Test 

Tolerances 

As discussed in section III.B.3.a, 

AHRI 1250–2020 has adopted language 

from the current DOE test procedure 

covering test tolerances and 

instrumentation accuracy. Additionally, 

as discussed in section III.B.3.d, some 

tolerances and instrumentation accuracy 

requirements in AHRI 1250–2020 are 

not consistent with the current DOE test 

procedure. DOE is proposing to adopt 

these changes from AHRI 1250–2020 

into subpart R, appendix C, as DOE has 

tentatively determined these changes 

would not have an effect on measured 

values. 

AHRI 1250–2020 changes the 

measurement accuracy for the 

temperature of air entering or leaving 

either the evaporator or condenser to ± 

0.25 °F from ± 0.2 °F in AHRI 1250– 

2009. DOE notes that ± 0.25 °F is the 

standard minimum accuracy across 

many Heating, Ventilation and AirConditioning (‘‘HVAC’’) testing 

standards. Since AHRI 1250–2020 

references AHSRAE 37–2009 for singlepackaged testing, it simplifies the test 

procedure to have the same instrument 

accuracy requirements across both 

standards. In addition, providing a 

consistent minimum accuracy across 

test procedures reduces laboratory test 

burden and DOE expects it may benefit 

a laboratory’s quality control. DOE is 


jspears on DSK121TN23PROD with PROPOSALS2
Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23951 

34Absolute pressure is the pressure measured 

relative to a complete vacuum; ‘‘psia’’ represents 

the absolute pressure in pounds per square inch. 

proposing that the temperature 

measurement of air entering or leaving 

either the compressor or evaporator 

would have a minimum accuracy of ± 

0.25 °F. DOE does not expect this 

modification to have a significant 

impact on measured values. 

Additionally, the proposed tolerance is 

greater than the current tolerance and 

therefore if adopted it would not require 

manufacturers to retest. DOE does not 

expect that the changed tolerance would 

impact the representativeness of the 

results. As noted, the proposed 

tolerance is that generally used for 

HVAC systems. 

As discussed in section III.B.3.d, 

AHRI 1250–2020 does not reference 

ASHRAE 23 or AHRI 420 for the testing 

of dedicated condensing units and unit 

coolers, respectively. As such, the 

ASHRAE 23 refrigerant mass flow 

operating tolerance of ± one percent of 

the quantity measured has been 

replaced in Table 2 of AHRI 1250–2020 

by an operating tolerance of 3 pounds 

per hour (‘‘lb/h’’) or 2 percent of the 

reading (whichever is greater). DOE 

notes that the requirement for a one 

percent mass flow tolerance posed 

challenges for test labs when at very low 

flow rates (near 0 lb/h). Specifically, as 

mass flow approaches 0 lb/h, the 

acceptable deviation from the average 

also approaches zero resulting in an 

unrealistic accuracy target. This issue 

would not occur with the minimum 

accuracy provided in AHRI 1250–2020 

because the acceptable deviation from 

the average must be within ± 3 lb/h if 

the variation is less than 2 percent of the 

mass flow reading. As such, DOE is 

proposing to adopt the mass flow 

tolerance specified in Table 2 of AHRI 

1250–2020 into subpart R, appendix C. 

DOE does not expect that this 

modification would have a significant 

impact on capacity and AWEF values, 

and therefore would not require 

retesting or recertification. 

6. CO2 Unit Coolers 

All refrigerants have a ‘‘critical 

pressure’’ and an associated ‘‘critical 

temperature’’ above which liquid and 

vapor phases cannot coexist. Above this 

critical point, the refrigerant will be a 

gas and its temperature will increase or 

decrease as heat is added or removed. 

For all conventional refrigerants, the 

critical pressure is so high that it is 

never exceeded in typical refrigeration 

cycles. For example, R404A is a 

common refrigerant used in refrigeration 

systems that has a critical pressure of 

540.8 psia 34 with an associated critical 

temperature of 161.7 °F. However, CO2

behaves differently, with a critical 

pressure of 1,072 psia associated with a 

lower critical temperature of 87.8 °F. 

The refrigerant temperature must be 

somewhat higher than the ambient 

temperature in order to reject 

refrigeration cycle heat to the ambient 

environment. Ambient temperatures 

greater than 87.8 °F are common and the 

performance of many refrigeration and 

air conditioning systems are tested 

using a 95 °F ambient temperature, as 

indicated by the A test condition in 

Section 5 of AHRI 1250–2009 (and 

AHRI 1250–2020). At temperatures 

greater than the critical temperature, the 

CO2 refrigerant is in a supercritical state 

(i.e., a condition with pressure above the 

critical temperature). Since useful 

cooling is provided below the critical 

temperature, CO2 cycles are said to be 

transcritical. 

DOE has granted test procedure 

waivers to the manufacturers listed in 

Table III.1 for certain basic models of 

walk-in refrigeration systems that use 

CO2 as a refrigerant. Manufacturers 

requesting a waiver from the DOE test 

procedure for CO2 unit coolers stated 

that the test conditions described in 

Tables 15 and 16 of AHRI 1250–2009, as 

incorporated by subpart R, appendix C, 

with modification, cannot be achieved 

by, and are not consistent with the 

operation of, CO2 direct expansion unit 

coolers. These manufacturers also 

specified that CO2 has a critical 

temperature of 87.8 °F, and therefore the 

required liquid inlet saturation 

temperature of 105 °F and the required 

liquid inlet subcooling temperature of 

9 °F as specified in the DOE test 

procedure are not achievable. The 

alternate test procedure provided in 

these waivers modifies the test 

condition values to reflect typical 

operating conditions for a transcritical 

CO2 booster system. Specifically, the 

waiver test procedures require that CO2

unit cooler testing is conducted at a 

liquid inlet saturation temperature of 

38 °F and a liquid inlet subcooling 

temperature of 5 °F. CO2 that is cooled 

in the gas cooler of a transcritical 

booster system expands through a highpressure control valve that delivers CO2

to a subcritical-pressure flash tank, 

where liquid and vapor phases of the 

refrigerant are separated. The liquid is 

then split, and the unit cooler, 

regardless of refrigerated storage space 

temperature, receives the refrigerant at 

the same condition. This applies to both 

medium- and low-temperature systems. 

In the June 2021 RFI, DOE requested 

comment on whether the test conditions 

provided in the waivers are appropriate 

and if there are additional modifications 

that could more accurately evaluate the 

energy use of these systems while 

minimizing test burden. 86 FR 32332, 

32346. Lennox, AHRI, National 

Refrigeration, and Hussmann 

recommended that DOE use the 

conditions provided in the waivers for 

CO2 unit coolers. (Lennox, No. 9 at p. 

7; AHRI, No. 11 at p. 12; National 

Refrigeration, No. 17 at p. 1; Hussmann, 

No. 18 at p. 14) 

In the June 2021 RFI, DOE also 

requested comment on the present and 

future expected use of CO2 systems and 

information about such systems that 

would suggest a need to modify the DOE 

test procedure. 86 FR 32332, 32346. 

Lennox, AHRI, and Hussmann stated 

that some CO2 units, not available in the 

U.S., may supply subcritical liquid or 

supercritical gas at the expansion valve, 

while some condensing units with 

integrated expansion valves supply twophase CO2 to evaporators. (Lennox, No. 

9 at pp. 7–8; AHRI, No. 11 at pp. 12– 

13; Hussmann, No. 18 at p. 14) For units 

where the CO2 leaving the condensing 

unit is supercritical or two-phase, 

Lennox, AHRI, and Hussmann 

recommended setting temperature and 

pressure conditions; for condensing 

units providing subcritical liquid to unit 

cooler expansion devices, these 

stakeholders suggested that the test 

method provided in the waivers should 

be used. (Lennox, No. 9 at p. 8; AHRI, 

No. 11 at p. 13; Hussmann, No. 18 at p. 

14) Lennox, AHRI, and Hussmann 

additionally stated that while CO2

condensing units with a single 

compression stage and conventional 

HFC units can be tested using the same 

method, an intermediate pressure that is 

the same as the liquid supply conditions 

in the waiver test procedures must be 

specified for units with two stages of 

compression. Id. Lennox recommended 

evaluating the potential energy savings 

of CO2 units to see if additional changes 

are warranted. (Lennox, No. 9 at p. 7) 

The CA IOUs suggested that DOE 

differentiate AWEF ratings of units 

using CO2 and units using traditional 

refrigerants. (CA IOUs, No. 14 at p. 4) 

Additionally, the CA IOUs urged DOE to 

ensure that the walk-in test procedures 

and metrics continue to provide 

consumers with the information 

necessary to easily compare the 

performance of products with the same 

utility. Id. 

DOE acknowledges that a goal of its 

test procedures is to provide purchasers 


jspears on DSK121TN23PROD with PROPOSALS2
23952 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

35LRC Coil Company submitted a petition for 

waiver and interim waiver for specific basic models 

of unit cooler only walk-in wine cellar refrigeration 

systems. (LRC Coil, EERE–2020–BT–WAV–0040, 

No. 1) In reviewing another petition for waiver and 

interim waiver from Vinotheque for single-packaged 

system and matched pair system basic models 

(Vinotheque, EERE–2019–BT–WAV–0038, No. 6), 

DOE noted that the manufacturer also offered unit 

cooler-only systems distributed without a paired 

condensing system. 

36AHRI 1250–2009 Table 11 prescribes a return 

gas temperature (measured at the condensing unit 

inlet location) equal to 41 °F for testing medium 

temperature dedicated condensing units. Also, 

Table 15 and section 3.3.1 of appendix C prescribe 

testing medium-temperature unit coolers using 

25 °F saturated suction temperature (this is the same 

with an energy use metric that is 

consistent across products that provide 

similar utility. In response to the 

comment by Lennox, DOE would 

evaluate the potential energy savings of 

CO2 units as part of a separate, future 

energy conservation standards 

rulemaking. DOE investigation confirms 

that there are no known sales of CO2

dedicated condensing units in the U.S. 

The only relevant CO2 system 

architecture in the U.S. appears to be 

CO2 booster systems using unit coolers 

operating with conditions consistent 

with the waivers. 

DOE also evaluated if the current 

AWEF calculation for unit coolers tested 

alone could be applied to CO2 unit 

coolers. The current calculation uses an 

EER to determine the representative 

compressor power consumption. The 

EER values used are in Table 18 of AHRI 

1250–2020 and are based on typical 

traditional refrigerant compressor 

efficiency. DOE has tentatively 

determined that the EER values used for 

the AWEF calculations of traditional 

unit coolers can also be used for CO2

unit coolers. DOE research into the 

performance of different configurations 

of CO2 booster systems shows that 

enhanced CO2 cycles can match 

conventional refrigerants in average 

annual efficiency. These data and 

studies help to justify the use of the EER 

values in Table 18 of AHRI 1250–2020 

for determining the power consumption 

of CO2 booster system unit coolers, even 

though these EER values were initially 

established for conventional 

refrigerants. 

In this NOPR, DOE is proposing to 

adopt in subpart R, appendix C (and 

also appendix C1), the alternate test 

conditions specified in the waivers that 

DOE granted for CO2 transcritical unit 

coolers for all CO2 unit coolers. Also, 

consistent with the waiver alternate test 

procedures, DOE proposes that the 

established EER values be used to 

determine compressor power found in 

Table 17 of AHRI 1250–2009 (or Table 

18 of AHRI 1250–2020 for appendix C1) 

would be used to determine the AWEF 

of all CO2 unit coolers. 

Issue 17: DOE requests comment on 

the appropriateness of traditional 

refrigerant compressor EER values for 

use in CO2 unit cooler AWEF 

calculations. 

7. High-Temperature Unit Coolers 

As discussed in the June 2021 RFI, 

DOE is aware of wine cellar (hightemperature) refrigeration systems that 

fall within the walk-in definition but 

that may be incapable of being tested in 

a manner that would yield 

representative performance results 

during a representative average use 

cycle under the current version of the 

walk-in test procedure. 86 FR 32332, 

32344. For example, wine cellar 

refrigeration systems that may be 

installed in some commercial settings 

are designed to operate at a temperature 

range of 45 °F to 65 °F. 

High-temperature refrigeration 

systems are discussed generally in 

section III.G.6. Most of these 

refrigeration systems are either a singlepackaged dedicated system or a 

matched pair. However, DOE has also 

received a petition for waiver for hightemperature unit coolers that are 

distributed into commerce without a 

paired condensing system.35 These unit 

cooler-only models would be tested 

according to the provisions in the test 

procedure for unit coolers tested alone, 

for which calculation of AWEF requires 

use of an appropriate EER based on the 

suction dew point temperature. Table 17 

in AHRI 1250–2009 provides EER 

values for medium- and lowtemperature unit coolers tested alone. 

However, DOE has tentatively 

determined that these values are not 

appropriate for calculating AWEF for 

high-temperature unit coolers because 

this equipment operates with a different 

suction dew point temperature and the 

counterpart dedicated condensing units 

likely use different compressor designs 

than those considered when developing 

the EER values included in AHRI 1250– 

2020. 

In the June 2021 RFI, DOE requested 

data on appropriate EER values for use 

with high-temperature unit coolers and 

questioned how these values might 

depend on refrigerant or capacity. 86 FR 

32332, 32345. AHRI stated that they did 

not have data to support EER values for 

use in determining AWEF for wine 

cellar unit coolers since most systems 

are sold as a matched pair. (AHRI, No. 

11 at p. 11) In the June 2021 RFI, DOE 

also requested information on dedicated 

condensing units that would typically 

be paired with high-temperature unit 

coolers. 86 FR 32332, 32345–32346. 

Lennox and AHRI stated that there are 

no definitive characteristics for unit 

coolers that are sold for use in wine 

cellar refrigeration applications, and 

that many units are sold to users as 

pairs matched by contractors. (Lennox, 

No. 9 at pp. 6–7; AHRI, No. 11 at pp. 

11–12) 

In its market evaluation, DOE has 

observed that a majority of hightemperature refrigeration systems are 

sold as matched pairs or singlepackaged systems. While unit coolers 

sold for high-temperature walk-in cooler 

applications are sold separately, DOE 

was unable to find any dedicated 

condensing units marketed specifically 

for high-temperature walk-in 

applications. Thus, DOE could not use 

the performance data of such dedicated 

condensing unit models to provide an 

indication of the appropriate EER for 

dedicated condensing units paired with 

such high-temperature unit coolers. 

Rather, consistent with the interim 

waiver granted to LRC, DOE is 

proposing EER values developed using 

compressor performance data from 

Emerson and Tecumseh product 

websites (EERE–2020–BT–WAV–0040, 

No. 2 and No. 8, respectively) for hightemperature refrigeration compressor 

models within the applicable capacity 

range (2,900 Btu/h to 36,000 Btu/h). 

DOE expects that the dedicated 

condensing units paired with hightemperature walk-in unit coolers would 

use hermetic reciprocating compressors 

at lower capacities and hermetic scroll 

compressors at higher capacities. Also, 

DOE developed the EER values based on 

compressors rated for use with HFC– 

134a, R404A, or R407C refrigerants. 

Based on these compressor performance 

data, DOE calculated representative 

compressor EER levels for wine cellar 

walk-in unit coolers using the following 

parameters: 

• 38 °F unit cooler exit dew point 

condition, as suggested by LRC (EERE– 

2020–BT–WAV–0040, No. 1 at p. 3). 

• 2 °F equivalent suction line dew 

point pressure drop, consistent with 

AHRI 1250–2009 section 7.9.1. 

• 7 °F evaporator exit superheat, 

rounding to whole number values of the 

6.5 °F superheat test condition 

prescribed in the footnote to Table 15 of 

subpart R, appendix C, in case a value 

is not provided in an installation 

manual. 

• 55 °F refrigerant temperature 

entering the compressor, representing a 

10 °F refrigerant vapor temperature rise 

in the suction line, consistent with the 

temperature rise implied for mediumtemperature refrigeration system test 

conditions.36


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as unit cooler exit dew point temperature), and 

6.5 °F superheat (in case the installation manual 

doesn’t provide superheat requirements). Thus, the 

unit cooler exit temperature would be 25 °F + 6.5 °F 

= 31.5 °F, and the implied suction line temperature 

rise is 41 °F¥ 31.5 °F = 9.5 °F. The analysis 

conducted for wine cellars rounds this to 10 °F. 

37 ‘‘Head pressure control’’ refers to the reduction 

of condenser heat transfer performance using fan 

cycling or other means when it is cold outside in 

order to avoid unusually low condensing 

temperature. Such low condensing temperatures are 

undesirable because they can reduce refrigeration 

system performance and/or increase risk of 

compressor damage. A typical minimum 

condensing temperature is 70 °F, which may apply 

whenever outdoor temperature is lower than 50 °F. 

DOE selected the 90 °F annual average to be 

representative of operation that would involve 

condensing temperature ranging from 70 °F to 

120 °F, since outdoor temperature varies. 

38A crankcase heater prevents refrigerant 

migration and mixing with the crankcase oil when 

the compressor is off by heating the crankcase of the 

compressor. A receiver heater warms refrigerant in 

the receiver to prevent flooded starts of the 

compressor and cycling on low pressure to reduce 

the potential for compressor damage. They are used 

for outdoor dedicated condensing units in colder 

climates. 

39Fans using periodic stir cycles are tested at the 

greater of a 50% duty cycle or the manufacturer 

default. Fans with two, multi-, or adjustable-speed 

controls are tested at the greater of 50% fan speed 

or the manufacturer’s default fan speed. Fans with 

no controls are tested at their single operating point. 

(See 10 CFR part 431, subpart R, appendix C, 

section 3.3.3). 

40Appliance Standards and Rulemaking Federal 

Advisory Committee Refrigeration Systems Walk-in 

Coolers and Freezers Term Sheet, available at 

www.regulations.gov/document?D=EERE-2015-BTSTD-0016-0056. 

• 90 °F annual average condensing

temperature. This assumes that the 

condensing unit serving the unit cooler 

would be located outdoors and that 

head pressure control would prevent 

excessively cold condensing operation 

at cold outdoor temperatures.37

DOE plotted the calculated 

compressor EER values versus 

calculated unit cooler capacity and 

noted that the EER can significantly 

vary with capacity. (EERE–2020–BT– 

WAV–0040, No. 9) EER is generally 

lower for low-capacity compressors and 

higher for high-capacity compressors, 

with a transition region in between. 

Based on the plotted calculations, DOE 

determined for the purpose of the 

interim waiver that a representative 

value for EER should depend on 

capacity. As such, DOE developed 

different functions of EER for three 

distinct capacity ranges. Table III.7 

summarizes these capacity ranges and 

EER functions for high-temperature 

compressors. 

TABLE III.7—EER VALUES FOR HIGH

TEMPERATURE COMPRESSORS AS A

FUNCTION OF CAPACITY FOR HIGHTEMPERATURE REFRIGERATION SYSTEMS

Capacity 

(Btu/hr) 

EER 

(Btu/Wh) 

<10,000 ..................... 11 

10,000–19,999 .......... (0.0007 × Capacity) + 

4 

20,000–36,000 .......... 18 

The LRC interim waiver includes 

additional test procedure provisions to 

obtain representations that are 

representative for high-temperature unit 

coolers, including both testing 

requirements and AWEF calculation 

requirements. These include provisions 

for setting ducted fan-coil unit 

evaporator systems. 

DOE proposes to include provisions 

for testing high-temperature unit coolers 

in subpart R, appendix C. These 

provisions, consistent with the LRC 

interim waiver, would include test 

conditions for testing these unit coolers 

at high-temperature refrigeration 

conditions, as well as EER values 

described previously for calculation of 

AWEF. DOE also proposes to include 

these provisions in appendix C1. 

Issue 18: DOE requests comment on 

its proposals to adopt test procedure 

provisions for high-temperature unit 

coolers in appendices C and C1 of 10 

CFR part 431, subpart R. 

G. Proposal To Establish Appendix C1

In this NOPR, DOE is proposing to

establish a new appendix C1 to subpart 

R of part 431, which would be required 

to demonstrate compliance coincident 

with the compliance date of any 

amended energy conservation standards 

that DOE may promulgate as part of a 

separate standards rulemaking. Certain 

proposed modifications to the test 

procedure are expected to alter 

measured values, and such changes are 

contained in the proposed appendix C1. 

DOE has tentatively determined that 

AHRI 1250–2020 improves 

representativeness of the walk-in 

refrigeration system test procedure by 

incorporating off-cycle measurement for 

components in addition to off-cycle fan 

power and providing test options for 

single-packaged dedicated systems, in 

addition to other changes. Therefore, 

DOE is proposing to incorporate AHRI 

1250–2020 by reference into its 

proposed test procedure at appendix C1 

for walk-in refrigeration systems. 

Lennox, AHRI, Keeprite, National 

Refrigeration, and Hussmann 

commented in response to the June 2021 

RFI, that adopting the changes to AHRI 

1250–2020 in the DOE test procedure 

would result in different energy 

consumption measurements. (Lennox, 

No. 9 at p. 2; AHRI, No. 11 at p. 4; 

Keeprite, No. 12 at p. 1; National 

Refrigeration, No 17 at p. 1; Hussmann, 

No. 18 at p. 6) DOE has tentatively 

determined that certain changes in 

AHRI 1250–2020, if adopted in DOE’s 

test procedure, would impact measured 

values as compared to the current DOE 

test procedure. As discussed in the 

following paragraphs, DOE proposes to 

adopt such provisions in the newly 

proposed appendix C1 through refence 

to AHRI 1250–2020 and proposes that 

appendix C1 would not be required for 

testing until such time as compliance is 

required with amended energy 

conservation standards for walk-ins that 

are based on testing according to 

appendix C1, should DOE adopt such 

standards. 

The test procedure changes that DOE 

proposes to include in a newly 

proposed appendix C1 are discussed in 

the following sections. DOE expects 

these changes to improve the 

representativeness and applicability of 

the test procedure for walk-in 

refrigeration systems. 

1. Off-Cycle Power Consumption

For walk-in refrigeration systems, the

term off-cycle refers to the period when 

the compressor is not running and 

defrost (if applicable) is not active. 

During off-cycle, unit cooler fans and 

other auxiliary equipment (i.e., 

crankcase heater, receiver heater, etc.) 38

may typically run or cycle on and off, 

consuming energy. The DOE test 

procedure currently accounts for only 

unit cooler fan energy use during the 

off-cycle period. 10 CFR part 431, 

subpart R, appendix C, section 3.3.3. 

Specifically, the current test procedure 

requires manufacturers to measure the 

integrated average off-cycle fan 

wattage 39 for matched pair and unit 

coolers tested alone. Dedicated 

condensing units tested alone use 

default fan energy values rather than 

tested values. 10 CFR part 431, subpart 

R, appendix C, section 3.4.2.2. When 

calculating AWEF, the unit cooler fans 

are assumed to run at this average 

integrated wattage throughout the entire 

off-cycle duration. Id. 

In the June 2021 RFI, DOE discussed 

the recommendations of the ASRAC 

Working Group (See Docket No. EERE– 

2015–BT–STD–0016, No. 56,40

Recommendation #6) to revise the offcycle test procedure to account for all 

other components that consume energy 

during the off-cycle, such as pan 

heaters, crankcase heaters, and controls. 

86 FR 32332, 32348. DOE noted that 

AHRI 1250–2020 includes a method for 

determining energy consumption during 


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41Off-cycle load points are discussed later in this 

section. 

off-cycle for many of these components 

and DOE discussed the possibility of 

incorporating the updated industry test 

method into a test procedure. In 

response to the June 2021 RFI, the CA 

IOUs supported the prioritization of 

ASRAC Term Sheet recommendation 

#6. (CA IOUs, No. 14 at p. 1–2) 

DOE requested comment on the 

representativeness and repeatability of 

the off-cycle test procedure in AHRI 

1250–2020. 86 FR 32332, 32348. 

Keeprite and National Refrigeration both 

stated that the off-cycle power 

measurement in AHRI 1250–2020 is 

accurate. (Keeprite, No. 12 at p. 2; 

National Refrigeration, No. 17 at p. 2) 

Lennox, AHRI, ASAP, and Hussmann 

supported using the off-cycle power 

measurements in AHRI 1250–2020. 

(Lennox, No. 9 at p. 9; AHRI, No. 11 at 

p. 14; ASAP, No. 13 at p. 2; Hussmann, 

No. 18 at p. 17) Keeprite and National 

Refrigeration asserted that adopting the 

off-cycle power measurements in AHRI 

1250–2020 would increase test burden 

without significant efficiency gains. 

(Keeprite, No. 12 at p. 3; National 

Refrigeration, No 17 at p. 2) NEEA 

commented that AHRI 1250–2020 

captures off cycle energy consumption 

more fully but does not appear to 

account for start up or shutdown 

variation. (NEEA, No. 16 at p. 2) 

Also, in the June 2021 RFI, DOE 

sought feedback on whether there were 

additional walk-in refrigeration system 

components that consume energy while 

the unit is in off-cycle mode, which 

AHRI 1250–2020 does not address. 86 

FR 32332, 32348. DOE did not receive 

comments on this topic. 

In the June 2021 RFI, DOE 

additionally requested comment on the 

magnitude of off-cycle energy use for 

each component. Id. DOE did not 

receive comments on this topic. 

DOE acknowledges that adopting the 

off-cycle power measurements in AHRI 

1250–2020 may incrementally increase 

test time; however, obtaining off-cycle 

power measurements would account for 

less than 10 percent of the overall setup 

and test duration for walk-in 

refrigeration systems. In its testing, DOE 

has found that the additional energy use 

measured using the off-cycle power 

measurements in AHRI 1250–2020 can 

be up to 60% more than the off-cycle 

power measurements in the current test 

procedure, indicating that the current 

test procedure does not fully represent 

off-cycle power use for walk-in 

refrigeration systems. Therefore, DOE 

proposes adopting the off-cycle 

procedure in sections C3.5, C4.2, and 

Table C3 in AHRI 1250–2020. 

In the following sections (III.F.1.a 

through III.F.1.d), DOE presents in more 

detail its proposals to modify the offcycle test method and metric. 

a. Off-Cycle Test Duration and 

Repetition 

DOE proposes revising the off-cycle 

test procedure to account for all other 

components (beyond evaporator fans) 

that consume energy during the offcycle, including, but not limited to pan 

heaters, crankcase heaters, and controls 

(collectively, ‘‘ancillary equipment’’). 

To account for this energy, DOE 

proposes adopting the off-cycle power 

measurements in sections C3.5, C4.2, 

and Table C3 in AHRI 1250–2020. This 

method is generally consistent with the 

current DOE test method used to 

account for off-cycle evaporator fan 

power; however, DOE proposes 

adopting AHRI 1250–2020 in order to 

properly account for the energy use of 

ancillary equipment. 

Specifically, AHRI 1250–2020 

includes two off-cycle test durations: 

One for evaporator fans and ancillary 

equipment with controls that are timevarying or respond to ambient or 

refrigerant temperatures (e.g., a 

crankcase heater or fan cycling control), 

and one for evaporator fans and 

ancillary equipment without such 

controls. For the former, AHRI 1250– 

2020 requires a 30-minute test. DOE 

expects that 30 minutes is the shortest 

duration that can effectively capture the 

cyclic and time-varying energy use that 

may occur for equipment with 

controls—thus, this duration balances 

the need to minimize test burden with 

the need for an accurate and 

representative test method. For units 

lacking such controls, AHRI 1250–2020 

requires a test cycle duration of 5 

minutes. In the absence of controls, DOE 

expects the off-cycle integrated power to 

be constant over time; consequently, 

DOE is proposing the shorter 5-minute 

duration, which would minimize test 

burden, while still providing results 

representative of off-mode energy 

consumption. 

AHRI 1250–2020 also has two sets of 

test repetition requirements: One for 

evaporator fans and ancillary equipment 

with controls that are time-varying or 

respond to ambient or refrigerant 

temperatures (e.g., a crankcase heater or 

fan cycling control), and one for 

evaporator fans and ancillary equipment 

without such controls. For the former, 

AHRI 1250–2020 requires that the offcycle test for each applicable load 

point 41 would consist of three initial 

test cycles, with the potential for three 

supplemental cycles. DOE anticipates 

that at least three cycles are needed to 

determine if the measured integrated 

off-cycle power is representative of 

typical operation because the cyclic 

operation of evaporator fan and 

ancillary equipment controls has the 

potential to introduce a significant level 

of test-to-test variability. Specifically, 

AHRI 1250–2020 states that if the 

integrated power for each of the first 

three cycles is within 2 percent of the 

average of the first three cycles, then offcycle power would be calculated as the 

average of the first three cycles. This 

requirement reduces test burden if the 

unit under test shows repeatable 

performance. If the 2 percent 

requirement is not met, DOE proposes 

running three supplemental cycles to 

provide an opportunity for the unit’s 

controls to exhibit repeatable behavior. 

Specifically, AHRI 1250–2020 states 

that if the integrated power for each of 

the three supplemental cycles is within 

2 percent of the average of the three 

supplemental cycles, then off-cycle 

power would be calculated as the 

average of the three supplemental 

cycles—this follows the same rationale 

as the three initial test cycles. DOE 

expects that continuing to test the unit 

beyond a total of six cycles would be 

ineffectual and overly burdensome, as 

the previous two rounds of testing 

would show that stable test-to-test 

integrated power readings are unlikely. 

In the absence of stability, AHRI 1250– 

2020 requires off-cycle power to be 

calculated as the maximum of all six 

integrated power readings. This 

requirement is appropriate since it 

provides a conservative estimate of 

integrated off-cycle. 

Alternatively, for equipment lacking 

evaporator fans and ancillary equipment 

controls, AHRI 1250–2020 requires a 

single cycle to measure integrated 

power. In the absence of controls, DOE 

expects the off-cycle integrated power to 

be constant from cycle-to-cycle; 

consequently, DOE is proposing the 

single-cycle test for units without 

ancillary power controls. DOE has 

preliminarily determined that this 

approach would minimize test burden, 

while providing results representative of 

off-mode energy consumption. A 

summary of test durations and fan 

settings based on fan control 

configuration and ancillary equipment 

control configuration is listed in Table 

III.8. 


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42 DOE notes that under this proposal, condensing 

unit off-cycle power is not explicitly accounted for 

unit coolers; rather, the total energy contribution 

from the condensing unit is based on a defined EER 

lookup table, which is currently found in Table 17 

of AHRI 1250–2009 (incorporated by reference, 10 

CFR 431.303(b)). This NOPR proposes changing that 

to Table 18 of AHRI 1250–2020. This aspect of the 

proposed unit cooler test method is consistent with 

the current method specified in appendix C to 

subpart R of 10 CFR part 431. 

TABLE III.8—PROPOSED OFF-CYCLE TEST SETTINGS AND DURATIONS

Fan control 

configuration 

Ancillary equipment 

control configuration 

Fan setting 

for test 

Test 

duration 

No Control ................................ No Control .............................. Default setting, as shipped ............................. 5 minutes. 

No Control ................................ With Control ............................ Default setting, as shipped ............................. 30 minutes. 

User-Adjustable Speed Controls.No Control .............................. The greater of 50% fan speed or the manufacturer’s default fan speed.5 minutes. 

User-Adjustable Speed Controls.With Control ............................ The greater of 50% fan speed or the manufacturer’s default fan speed.30 minutes. 

User-Adjustable Stir Cycles ..... With or Without Control .......... The greater of a 50% duty cycle or the manufacturer default.The greater of 30 minutes or 

three full ‘‘stir cycles.’’ 

Non-User Adjustable Controls With or Without Control .......... Default setting, as shipped ............................. 30 minutes. 

b. Off-Cycle Operating Tolerances and 

Data Collection Rates 

DOE proposes to adopt the off-cycle 

power measurements in Section C3.5 of 

AHRI 1250–2020 to establish off-cyclespecific operating test tolerances. AHRI 

1250–2020 excludes the first 10 minutes 

that follow the termination of the 

compressor on-cycle interval from the 

general operating tolerances (indoor/ 

outdoor temperatures and power 

readings) established for the on-cycle 

steady state test. During this time 

period, the test room conditioning 

equipment is transitioning from steady 

state on-cycle operation into off-cycle 

operation and the evaporator coil will 

continue to remove heat from the inside 

room air until temperature equilibrium 

between the coil and the air is reached. 

This non-steady state operation 

following the on-cycle creates an 

environment that is temporarily difficult 

to control; consequently, DOE expects 

that the suspension of steady state 

tolerances during the transition period 

would not impact the representativeness 

of the test, since this non-steady state 

operation is representative of real-world 

performance during the transition 

period. 

DOE also proposes to establish offcycle-specific data collection rates by 

adopting the off-cycle power 

measurements approach provided in 

Section C3.6 of AHRI 1250–2020. 

Specifically, AHRI 1250–2020 requires 

that the minimum data collection rate 

be increased (with respect to steadystate requirements) from 30 to 60 test 

readings per hour for temperature 

measurements and condensing unit 

electric power measurements, and from 

3 to 60 test readings per hour for unit 

cooler electric power measurements. 

See Table C3 in Section C3.6.2 of AHRI 

1250–2020. DOE anticipates that the 

increased data collection rate is 

necessary since the off-cycle test time 

interval can be as low as five minutes 

whereas the steady-state test will 

typically run for at least 60 minutes. 

AHRI 1250–2020 also requires that offcycle power measurements be integrated 

and averaged over the recording interval 

with a sampling rate of no less than 1 

second unless an integrating watt/hour 

meter is used. This requirement is 

necessary since power is anticipated to 

fluctuate during the off-cycle test. 

Increasing to a 1 second sampling rate 

allows for an accurate software 

integration of power that would be 

comparable to an integrating watt/hour 

meter. 

c. Off-Cycle Load Points 

Currently, the DOE test procedure 

specifies that off-cycle evaporator fan 

power is measured once with no 

specifications for ambient conditions. 

The current test procedure uses this 

approach because off-cycle fan power is 

not expected to vary significantly with 

ambient conditions. However, DOE 

expects the integrated power of 

ancillary equipment to potentially vary 

with ambient conditions, depending on 

the refrigeration system design. 

Consequently, DOE proposes that the 

off-cycle power test described in section 

III.G.1.a be run at each steady-state 

ambient test conditions as specified in 

Tables 4 through 17 of AHRI 1250–2020. 

Accordingly, refrigeration systems with 

dedicated condensing units located 

indoors would evaluate off-cycle power 

at a single outdoor ambient condition 

(90 °F dry-bulb), while systems with 

dedicated condensing units located 

outdoors would determine off-cycle 

power at three ambient conditions 

(95 °F, 59 °F, and 35 °F dry-bulb). The 

measured integrated off-cycle power 

results would then be used to calculate 

a revised AWEF metric, as described in 

the following section. 

d. Modification to AWEF Calculations 

Walk-in cooler AWEF is calculated as 

a function of steady state capacity, 

steady state on-cycle power, and offcycle unit cooler fan power in the 

current test procedure (see Section 7 of 

AHRI 1250–2009). 10 CFR part 431, 

subpart R, appendix C, sections 3.3 and 

3.4. AWEF for walk-in freezers 

considers defrost electrical energy 

consumption in addition to steady state 

gross capacity, steady state on-cycle 

power, and off-cycle fan power. Id. As 

discussed earlier, DOE proposes to 

update the AWEF calculation for 

refrigeration systems to account for offcycle power more fully, not just offcycle evaporator fan power. To do so, 

DOE proposes adopting the off-cycle 

calculations in AHRI 1250–2020, which 

replace integrated off-cycle evaporator 

fan power with the combined integrated 

off-cycle power from the unit cooler and 

condensing unit in each equation. 

Additionally, for unit coolers tested 

alone, DOE proposes to update the 

AWEF calculation to account for all unit 

cooler off-cycle power—not just the 

evaporator fan power.42 To do so, DOE 

proposes adopting the off-cycle 

calculations in AHRI 1250–2020, which 

replace integrated off-cycle fan power 

with integrated off-cycle power in the 

unit cooler equation. 

DOE, however, proposes deviating 

from the AHRI 1250–2020 calculations 

for off-cycle energy use for outdoor 

refrigeration systems. DOE notes that 

the AHRI 1250–2020 equations for 

average refrigeration system total power 

input for bin temperature Tj, e.g., 

Equation 13, do not appear to use offcycle power values for the unit cooler 

and/or the condensing unit that vary 

with Tj. In fact, there are no equations 

providing the off-cycle power for either 

component as a function of Tj in Section 

7 of AHRI 1250–2020, such as there are 

for net capacity and on-cycle power 

input (e.g., Equations 14 through 17). 

Since the off-cycle power may vary as 

a function of outdoor temperature as 

discussed previously, DOE proposes to 


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43As described in section III.G.2.f, this does not 

apply to CO2 single-packaged units. 

44Table III.2 lists the manufacturers that have 

received a test procedure waiver or interim waiver 

for walk-in refrigeration systems designed for wine 

cellar applications. 

provide instructions for calculating offcycle power as a function of outdoor 

temperature based on the measurements 

made at the three outdoor test condition 

temperatures. 

For condensing unit off-cycle power, 

DOE proposes to require that off-cycle 

power for Tj less than or equal to 35 °F 

would be equal to the power measured 

for the test condition C off-cycle power 

test. For Tj higher than 95 °F, DOE 

proposes that off-cycle power would be 

equal to the power measured for the test 

condition A off-cycle power test. 

Between these two temperatures, DOE 

proposes that condensing unit off-cycle 

power would be determined based on 

the test condition B and C 

measurements when Tj is below 59 °F, 

and based on the A and B measurements 

when it is above 59 °F, similar to 

equations 14 through 17 for on-cycle 

capacity and power. 

For unit cooler off-cycle power, it is 

unclear whether to apply a specific 

trend correlated to condensing unit 

outdoor air temperature. DOE notes that 

AHRI 1250–2020 did not establish tests 

for unit coolers tested alone for different 

condensing unit outdoor air 

temperatures, which supports the 

suggestion that there is no such trend. 

Hence, DOE is not proposing any 

equations for unit cooler off-cycle power 

that are based on the different bin 

temperatures, Tj. Instead, DOE proposes 

that the three-unit cooler off-cycle 

power measurements that would be 

made when testing a matched pair or 

single-packaged dedicated system 

would be averaged, and that the 

resulting average, with no dependence 

on Tj, would be used in the AWEF 

calculations. 

Issue 19: DOE requests comments on 

its proposals to align the test procedures 

for appendix C1 with AHRI 1250–2020, 

except for the use of off-cycle power 

measurements in the AWEF calculations 

for dedicated condensing units, 

matched pairs, or single-packaged 

dedicated systems intended for outdoor 

installation. DOE requests comments on 

its proposals for use in the AWEF 

calculations of the three sets of unit 

cooler and condensing unit off-cycle 

measurements made for outdoor 

refrigeration systems. 

2. Single-Packaged Dedicated Systems 

a. AHRI 1250–2020 Methods for Testing 

As discussed in section III.B.3.c, 

AHRI 1250–2020 expanded methods of 

test for single-packaged units to include 

air enthalpy, calorimetry, and 

compressor calibration. Specifically, 

AHRI 1250–2020 incorporates the 

following tests procedures by reference: 

(1) Air enthalpy method: ASHRAE 37 

and ANSI/ASHRAE 41.6–2014 

(‘‘ASHRAE 41.6’’), ‘‘Standard Method 

for Humidity Measurement’’; 

(2) calorimeter methods: ASHRAE 16, 

‘‘Method of Testing for Rating Room Air 

Conditioners, Packaged Terminal Air 

Conditioners, and Packaged Terminal 

Heat Pumps for Cooling and Heating 

Capacity’’; 

(3) compressor calibration methods: 

ASHRAE 37 and ANSI/ASHRAE 23.1– 

2010. 

AHRI 1250–2020 requires two 

simultaneous measurements of system 

capacity (i.e., a primary and a secondary 

method) for single-packaged dedicated 

systems, and Section C9.2.1 of AHRI 

1250–2020 requires that the 

measurements agree within 6 percent. 

Table C4 in AHRI 1250–2020 specifies 

which of the test methods (calorimeter, 

air enthalpy, and compressor 

calibration) qualify as primary and/or 

secondary methods. However, as 

summarized in Table III.9, DOE is 

proposing to modify the method of test 

and test hierarchy table in AHRI 1250– 

2020 to include a single-packaged 

refrigerant enthalpy method—the 

addition of the Single-Packaged 

Refrigerant Enthalpy method is the only 

change to the hierarchy of test methods 

that DOE is proposing. The reasoning 

behind this addition is discussed in 

section III.G.2.d of this document. 

TABLE III.9—SINGLE-PACKAGED SYSTEM TEST METHODS AND TEST HIERARCHY

Method of test Allowable use 

Balanced Ambient Indoor Calorimeter ....................................................................................................................... Primary. 

Balanced Ambient Outdoor Calorimeter .................................................................................................................... Primary or Secondary. 

Indoor Air Enthalpy .................................................................................................................................................... Primary or Secondary. 

Indoor Room Calorimeter ........................................................................................................................................... Primary or Secondary. 

Single-packaged Refrigerant Enthalpy 43 ................................................................................................................... Secondary. 

Outdoor Room Calorimeter ........................................................................................................................................ Secondary. 

Outdoor Air Enthalpy .................................................................................................................................................. Secondary. 

Compressor Calibration ............................................................................................................................................. Secondary. 

b. Waivers 

DOE granted a waiver to Store It Cold 

for single-packaged units on August 9, 

2019. 84 FR 39286. Store It Cold 

petitioned for a waiver after determining 

that the refrigerant enthalpy method 

specified in AHRI 1250–2009 was not 

providing consistent capacity 

measurements for its single-packaged 

dedicated systems. 84 FR 39286, 39287. 

The alternate test procedure associated 

with this waiver requires that the 

specified single-packaged basic models 

shall be tested using the Indoor Air 

Enthalpy Method and the Outdoor Air 

Enthalpy Method in accordance with 

ASHRAE 37. 84 FR 39286, 39292. DOE 

also granted waivers to Air Innovations, 

CellarPro, Vinotemp, and Vinotheque 

for walk-in refrigeration systems used in 

wine cellar applications, where some of 

the basic models included in these 

waivers were single-packaged dedicated 

systems.44 Similar to the Store It Cold 

waiver, the alternate test methods 

included in these other waivers require 

the specified basic models to be tested 

in accordance with the air enthalpy 

methods specified in ASHRAE 37 for 

testing single-packaged dedicated 

systems, which is now referenced by 

AHRI 1250–2020. Use of air enthalpy 

methods for testing a single-packaged 

dedicated system captures the impact of 

thermal loss and the infiltration of warm 

air into the evaporator portion of these 

systems. As discussed, DOE proposes to 

reference in appendix C1 the methods of 

test for single-packaged dedicated 

systems in Section C9 of AHRI 1250– 

2020, with some modifications. Since 

DOE is proposing that appendix C1 

would be required on the compliance 

date of any amended energy 

conservation standards, were such 

standards to be adopted, the current test 

procedure waivers for specified singlepackaged basic models would expire on 

the compliance date of proposed 

appendix C1 if it should be adopted. 


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c. Suitability of the Single-Packaged 

Test Methods in AHRI 1250–2020 

In the June 2021 RFI, DOE requested 

data or comment on the additional 

thermal losses associated with singlepackaged dedicated systems, and 

whether AHRI 1250–2020 fully accounts 

for these losses. 86 FR 32332, 32344. 

Lennox, AHRI, and Hussmann stated 

that the AHRI 1250–2020 singlepackaged formulas account for 

additional thermal losses. (Lennox, No. 

9 at p. 5; AHRI, No. 11 at p. 10; 

Hussmann, No. 18 at p. 12) These 

stakeholders also asserted that the 

calorimeter test method should measure 

any minimal leakage. Id. 

In response to the June 2021 RFI, the 

CA IOUs commented that the room 

calorimeter and air enthalpy test 

methods in AHRI 1250–2020 would 

address single-packaged dedicated 

system test challenges that led to the 

Store It Cold waiver petition and 

subsequent granting of the waiver. (CA 

IOUs, No. 14 at p. 2) However, the 

comment did not specifically address 

the single-packaged heat loss or its 

magnitude. 

DOE requested comment on the 

representativeness of the singlepackaged dedicated test and calculation 

methods in AHRI 1250–2020 in the June 

2021 RFI. DOE additionally invited 

comment on whether DOE should 

update its test procedure to incorporate 

AHRI 1250–2020 by reference. 86 FR 

32332, 32343–32344. While Lennox, 

AHRI, and Hussmann each supported 

the AHRI 1250–2020 test methods for 

single-packaged dedicated systems, 

these stakeholders stated that these test 

procedures have not yet been fully 

evaluated and recommended against 

DOE updating its test procedure to 

incorporate single-packaged systemspecific sections of AHRI 1250–2020. 

(Lennox, No. 9 at p. 5; AHRI, No. 11 at 

p. 9; Hussmann, No. 18 at p. 12) 

The calorimeter tests mentioned 

previously were originally developed in 

ASHRAE 16 for testing room air 

conditioning units. In the June 2021 

RFI, DOE noted that precise 

determination of the calorimeter 

chamber cooling fluid heat capacity is 

necessary for an accurate test. 86 FR 

32332, 32344. Since air conditioning 

units do not cool below 32 °F, the 

freezing temperature of pure water, 

ASHRAE 16 would not have 

encountered problems with this issue, 

as water can be used as the calorimetry 

fluid and the heat capacity of pure water 

is known. When testing walk-in 

refrigeration systems using this method, 

the fluid may have to be at a 

temperature lower than 32 °F, which 

means that pure water would not be 

used. Precise determination of the heat 

capacity of glycol-water mixtures may 

present a challenge, since the 

concentration of the mixture must be 

determined. Therefore, in the June 2021 

RFI, DOE requested feedback on what 

heat transfer liquids might be used to 

maintain test chamber temperature 

when testing single-packaged dedicated 

systems using the calorimeter method 

included in AHRI 1250–2020. DOE 

additionally requested comment on 

whether the calorimetric procedure in 

AHRI 1250–2020 for testing singlepackaged dedicated systems could be 

modified to enhance test accuracy or 

repeatability. 86 FR 32332, 32344. 

Lennox, AHRI, and Hussmann stated 

that additional testing is necessary to 

fully evaluate each test method outlined 

for single-packaged units in AHRI 1250– 

2020. (Lennox, No. 9 at p. 5; AHRI, No. 

11 at p. 10; Hussmann, No. 18 at p. 12) 

Daikin commented that standard EN 

17432 uses a room calorimetry test for 

single-packaged units, with test 

conditions and a setup figure provided 

in the comment. (Daikin, No. 17 at p. 3) 

DOE notes the calorimetry room method 

suggested by Daikin does not appear to 

have a glycol loop and therefore does 

not provide a solution for heat transfer 

liquids that could be used when testing 

single-packaged dedicated systems 

using the calorimeter method included 

in AHRI 1250–2020. After 

consideration, DOE has tentatively 

determined that the comments provided 

do not conclusively indicate one way or 

the other that the AHSRAE 16 test 

method is unsuitable for walk-in 

refrigeration systems. Therefore, DOE is 

proposing to adopt the ASHRAE 16 

calorimetry methods of test for singlepackaged dedicated systems as 

referenced in AHRI 1250–2020. This 

approach would provide flexibility in 

selecting from one of the discussed 

testing methods even if these methods 

may be more challenging to implement 

for walk-in refrigeration systems than 

for room air conditioners. As the 

comments have not provided sufficient 

quantitative information, DOE will 

continue to consider this question and 

may take action at a later date. 

DOE also discussed the requirement 

for a pressure equalizer device for 

calorimetry chambers in ASHRAE 16 in 

the June 2021 RFI. DOE noted that since 

the calibrated box method (established 

in the current DOE test procedure) does 

not require such a device, this may 

increase testing burden. 86 FR 32332, 

32344. DOE discussed two potential 

alternatives to this requirement; 

specifically, (1) no requirement to 

address transfer air or pressure 

equalization, or (2) require leak-free test 

facility chambers with no equalization 

requirement. Id. DOE requested 

comment on the requirement for a 

pressure equalizing device in ASHRAE 

16 and solicited feedback on the 

expected cost and resource burdens 

associated with employing such a 

device. Id. Lennox, AHRI, and 

Hussmann stated that an equalizer 

device would not be necessary if the 

chamber were leak-free, that the 

addition of an equalizer device has not 

been fully evaluated and is expected to 

increase test burden. (Lennox, No. 9 at 

p. 5; AHRI, No. 11 at p. 10; Hussmann, 

No. 18 at p. 13) Based on the singlepackaged system testing conducted by 

DOE, DOE is not planning to propose an 

equalizer device for calorimeter room 

testing. DOE notes that a pressure 

equalizer is typically used when 

comfort cooling devices have a damper 

to bring fresh air into the cooled 

environment. Single-packaged 

dedicated systems do not include this 

functionality and therefore a pressure 

equalizing device is not necessary. 

Finally, DOE requested comment on 

any alternative test methods to measure 

single-packaged dedicated system 

capacity in the June 2021 RFI. 86 FR 

32332, 32344. Lennox, AHRI, and 

Hussmann confirmed that the test 

methods included in AHRI 1250–2020 

for testing single-packaged dedicated 

systems are sufficient. (Lennox, No. 9 at 

p. 6; AHRI, No. 11 at p. 10; Hussmann, 

No. 18 at p. 13) 

Testing conducted by DOE on singlepackaged units using the room 

calorimeter and air enthalpy methods as 

described in AHRI 1250–2020 suggest 

that these test methods appropriately 

account for the thermal losses 

experienced by this equipment. 

Therefore, DOE has tentatively 

determined that these methods are 

representative of single-packaged 

system energy use. As such, DOE 

proposes to adopt the single-packaged 

system test procedure in AHRI 1250– 

2020 with the modifications outlined in 

sections III.G.2.d and III.G.2.e of this 

document. DOE notes that while there 

may not be extensive experience 

applying these test methods to walk-in 

refrigeration systems, all the proposed 

test methods have been evaluated and 

are used extensively for testing other 

HVAC equipment. Additionally, DOE is 

required, as soon as practicable after the 

granting of any waiver, to publish in the 

Federal Register a notice of proposed 

rulemaking to amend its regulations so 

as to eliminate any need for the 

continuation of such a waiver. 10 CFR 

431.401(l). Finally, DOE emphasizes 


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45These issues were the primary motivation for 

and are described in the Store-it-Cold petition for 

waiver—see the discussion in section III.G.2.b of 

this document. 

46The RSG petition for waiver and interim waiver 

can be found at www.regulations.gov/docket/EERE2022-BT-WAV-0010. 

47 Global warming potential is a measure of a 

substance’s ability to warm the planet relative to 

CO2. CO2 has a GWP of 1 while a traditional HFC 

refrigerant like R134a has a GWP of 3400, meaning 

a ton of R134a warms the planet 3400 times more 

than a ton of CO2. 

that testing according to proposed 

appendix C1 would not be required 

until such time as compliance is 

required with any amended energy 

conservation standards, should such 

standards be adopted. As such, were 

appendix C1 adopted, the existing 

waivers would remain in effect until 

such time as compliance would be 

required with appendix C1. 

d. Single-Packaged Refrigerant Enthalpy 

Method 

As previously discussed, AHRI 1250– 

2020 includes 4 potential primary, and 

6 potential secondary test methods for 

testing single-packaged dedicated 

systems (see Table III.9). The refrigerant 

enthalpy method is not included in this 

list. Although the dual instrumentation 

test (i.e., two separate measurements 

using the refrigerant enthalpy method) 

is routinely used to evaluate the 

capacity of matched pair, dedicated 

condensing, and unit cooler systems, 

the DX dual instrumentation method is 

generally considered to be impractical 

for testing single-packaged dedicated 

systems. This is primarily because it 

requires breaking into the liquid 

refrigerant line within the packaged 

unit, routing the line outside of the unit 

to pass through two mass flow meters, 

and then routing the line back into the 

unit and through dual pressure and 

temperature measurements before it 

rejoins the original liquid line at the 

expansion device inlet. This is generally 

inappropriate for a single-packaged unit 

because the internal volume of the 

added liquid line and mass flow meters 

adds substantially to the required 

refrigerant charge, and the entire 

assembly adds substantial pressure 

drop.45 As discussed in section III.A.2.e, 

RSG submitted a request for waiver and 

interim waiver to use the refrigerant 

enthalpy method to test single-packaged 

dedicated systems with multiple 

refrigeration circuits, using only one 

mass flow meter per circuit and using 

added refrigerant liquid line no longer 

than 5 feet in length.46 DOE is proposing 

to adopt a single-packaged refrigerant 

enthalpy method that is similar to the 

alternate test procedure outlined in 

RSG’s waiver request. 

The single-packaged refrigerant 

enthalpy method would be based using 

the refrigerant-side measurements of the 

DX Calibrated Box method in section C8 

of AHRI 1250–2020 while 

simultaneously using one of the 

‘‘Primary’’ methods listed in the table 

for single-packaged methods of test as 

an air-side measurement. These primary 

test methods all measure the capacity 

delivered to the air passing through the 

evaporator section of the system, or to 

the air that is refrigerated by the system. 

Before disassembling the refrigeration 

system to set up the refrigerant-side 

mass flow measurement, a preliminary 

test at Condition A would be conducted 

using only the primary air-side 

measurement. For this test, surfacemounted temperature sensors would be 

installed on the evaporator and 

condenser coils, tubing entering and 

leaving the compressor, and tubing 

entering the expansion device. This 

preliminary test would be compared to 

the later test at Condition A using both 

airside and refrigerant-side 

measurements. To ensure that the 

refrigerant circuit modifications did not 

materially alter the system operation, 

the later test would be performed to 

confirm that (1) each on-coil 

temperature sensor indicates a reading 

that is within ±1.0 °F of its initial-test 

measurement, (2) the temperatures of 

the refrigerant entering and leaving the 

compressor are within ±4 °F, and (3) the 

refrigerant temperature entering the 

expansion device is within ±1 °F. To 

limit the alteration of the refrigerant 

circuit, only 5 feet of tubing shall be 

added to the liquid refrigerant lines (not 

including the flow length associated 

with the mass flow meter). 

The heat balance applied to singlepackaged dedicated systems using this 

method would involve comparison of 

the air-side net capacity to a net 

capacity determined based on the gross 

refrigerant-side capacity measurement 

that would include adjustment for the 

evaporator fan heat in addition to 

adjustment for the single-packaged 

dedicated system thermal loss. The 

thermal loss would be calculated 

similarly to the duct loss calculation of 

Section 7.3.3.3 of ASHRAE 37–2009, in 

which the heat losses associated with 

the insulated surface areas subject to 

heat transfer are summed based on their 

surface area, thermal resistance (which 

is based on known insulating material 

and insulation thickness), and the 

temperatures on either side of the 

surface. 

Issue 20: DOE requests comment on 

the proposed single-packaged refrigerant 

enthalpy test procedure for evaluating 

the performance of single-packaged 

dedicated systems. 

e. Multi-Circuit Single-Packaged 

Dedicated Systems 

Multi-circuit single-packaged 

refrigeration systems provide a solution 

for flammable refrigerants, where safety 

standards limit the amount of refrigerant 

in a refrigeration circuit. Some 

flammable refrigerants, like propane, are 

efficient and have a very low global 

warming potential (‘‘GWP’’),47 making 

them advantageous design options for 

future refrigeration systems. Neither the 

current DOE test procedure nor AHRI 

1250–2020, which DOE is proposing 

generally to adopt through reference in 

its updated test procedure for walk-in 

refrigeration systems, provides a method 

for testing single-packaged dedicated 

systems with multiple refrigeration 

circuits. 

In its request for waiver and interim 

waiver, RSG provided an alternate test 

method for testing multi-circuit singlepackaged dedicated systems. (EERE– 

2022–BT–WAV–0010–0001) This test 

procedure is based on the singlepackaged refrigerant enthalpy method 

for single-packaged units described in 

section III.G.2.d of this document. The 

procedure is duplicated for each 

refrigeration circuit contained in the 

unit such that each circuit returns mass 

flow, enthalpy in, and enthalpy out 

values. The resultant mass flow and 

enthalpy values are used to calculate the 

gross refrigeration capacity for each 

circuit. Each circuit’s gross capacity is 

then summed to determine the total 

capacity of the system. 

DOE has tentatively determined that 

the alternate approach would generally 

provide a reasonable method for 

determining the capacity of multicircuit single-packaged dedicated 

systems. However, this approach may 

not adequately capture the heat loss 

associated with single-packaged 

dedicated systems; therefore, an indoor 

air refrigeration capacity test would 

need to be used to confirm the multiple 

refrigeration circuit capacity test. In 

sum, DOE proposes to adopt the 

previously described method for 

determining the capacity of singlepackaged dedicated systems with 

multiple refrigeration circuits, with the 

additional requirement that the primary 

test would be an indoor air refrigeration 

capacity test where the allowable 

refrigeration capacity heat balance is 6 

percent. 


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48Lennox commented that the industry was 

moving to low-GWP refrigerants in response to the 

Environmental Protection Agency final rule under 

the Significant New Alternatives Policy (‘‘SNAP’’) 

program that prohibited the use of R–404A in 

certain retail food refrigeration applications, 

including WICF refrigeration systems starting July 

20, 2016. (Docket EERE–2016–BT–TP–0030, 

Lennox, No. 13 at p. 2) For further discussion of the 

SNAP rule, see section III.G.9 of this document. 

49Available at www.regulations.gov/ 

document?D=EERE-2015-BT-STD-0016-0089. 

In summary, DOE is proposing to 

adopt the test procedures in section C8 

of AHRI 1250–2020 for testing singlepackaged dedicated systems with 

modifications to allow for secondary 

refrigerant enthalpy tests, and to 

accommodate multi-circuit singlepackaged dedicated systems. The 

proposed test methods and their 

designation as primary or secondary 

tests are outlined in Table III.9 of this 

document. 

f. CO2 Single-Packaged Dedicated 

Systems 

The current DOE test procedure for 

single-packaged dedicated systems uses 

dual instrumentation refrigerant 

enthalpy methods. Using these methods, 

the current test procedure does not 

provide representative values for singlepackaged dedicated systems that use 

CO2 as a refrigerant because CO2

remains in a gaseous state in those areas 

where mass flow meters are placed. The 

typical mass flow meters do not deliver 

accurate readings unless the medium 

being measured is in liquid form. 

However, the single-packaged dedicated 

system test methods in AHRI 1250–2020 

use air enthalpy measurements and 

would not require any refrigerant mass 

flow measurements. This means singlepackaged refrigeration systems that use 

CO2 as a refrigerant can be tested using 

these methods with no issues. 

Therefore, DOE proposes that singlepackaged refrigeration systems that use 

CO2 as a refrigerant be tested using the 

test methods for single-packaged 

dedicated systems outlined in AHRI 

1250–2020. 

3. Detachable Single-Packaged 

Dedicated Systems 

As discussed in section III.A.2.g DOE 

is aware of refrigeration systems that are 

installed with the evaporator unit 

through the wall of the walk-in, but 

with the condensing unit installed 

remotely and connected to the 

evaporator with refrigerant lines—DOE 

has defined this equipment as 

‘‘detachable single-packaged dedicated 

systems.’’ Neither subpart R, appendix 

C, nor AHRI 1250–2020 contain 

provisions for testing these walk-in 

refrigeration systems. Detachable singlepackaged dedicated systems may be 

tested as either systems with the 

condensing unit and unit cooler in 

separate housings or as single-packaged 

dedicated systems. Testing as the former 

is more typical of the walk-in industry 

and therefore may be less burdensome. 

However, testing as a single-packaged 

system using the indoor air enthalpy 

test would account for the heat loss of 

the evaporator installation. Since the 

single-packaged indoor air enthalpy 

method would be more representative of 

these separable single-packaged 

dedicated systems, DOE is proposing as 

part of new appendix C1 and 10 CFR 

429.53(a)(2)(i)(C) that detachable singlepackaged dedicated systems would be 

tested using the test procedure for 

single-packaged dedicated systems. 

Issue 21: DOE requests comment on 

testing detachable single-packaged 

dedicated systems using the test 

procedure for single-packaged dedicated 

systems. 

4. Attached Split Systems 

As discussed in section III.A.2.f., DOE 

is aware of refrigeration systems that are 

sold as matched systems and 

permanently attached to each other with 

beams. These systems are mounted to 

the cooler box with the beams piercing 

the interior wall of the walk-in. As 

discussed in section III.A.2.f, DOE is 

proposing to classify these systems as 

‘‘attached split systems.’’ While thermal 

losses are expected to be lower for an 

attached split system than a singlepackaged system since attached split 

systems have comparatively more 

insulation between the condenser and 

evaporator sides, DOE has preliminarily 

confirmed through testing that these 

systems still experience some heat 

leakage when compared to traditionallyinstalled systems that have the 

dedicated condensing unit and the unit 

cooler in separate housings. However, 

this heat leakage has not been studied 

extensively and DOE is aware that it 

may be difficult to calculate. Because of 

this issue, DOE is proposing in new 

appendix C1 and 10 CFR 

429.53(a)(2)(i)(D) that attached split 

systems would be tested as a matched 

pair using refrigerant enthalpy methods. 

Issue 22: DOE requests comment on 

its proposal that attached split systems 

be tested using refrigerant enthalpy 

methods. 

5. Systems for High-Temperature 

Freezer Applications 

As discussed in the December 2016 

final rule, stakeholders commented that 

high-temperature freezer walk-ins, 

which have an enclosed storage (i.e., 

room) temperature range of 10 °F to 

32 °F, are typically refrigerated with 

medium-temperature dedicated 

condensing units. 81 FR 95758, 95790. 

Under the statutory definitions of 

‘‘walk-in cooler’’ and ‘‘walk-in freezer,’’ 

this equipment would be considered a 

walk-in freezer because its room 

temperature is less than or equal to 

32 °F. (42 U.S.C. 6311(20)) 

Accordingly, these refrigeration 

systems would be tested using a room 

temperature of ¥10 °F, as specified in 

subpart R, appendix C. However, 

stakeholders commented that it is 

difficult for these medium-temperature 

refrigeration systems to meet this 

temperature condition when using 

lower GWP refrigerants.48 81 FR 95758, 

95790. Lennox offered data suggesting 

that medium-temperature units 

generally perform more efficiently at the 

10 °F operating condition (i.e., the low 

end of the cited ‘‘high-temperature 

freezer’’ temperature range) than lowtemperature systems. (Docket EERE– 

2015–BT–STD–0016, Lennox, No. 89 49

at pp. 2–5) Lennox suggested that this 

‘‘high-temperature freezer’’ application 

may justifiably represent a third class of 

walk-in refrigeration systems, but also 

noted the reporting and testing burden 

that establishing an additional set of 

classes would incur. Id. In response, 

DOE noted that manufacturers of 

equipment that cannot be tested in a 

way that properly represents their 

performance characteristics may 

petition DOE for a test procedure 

waiver, as detailed in 10 CFR 431.401. 

DOE also indicated that it may consider 

amending its regulations by establishing 

new equipment classes and applicable 

test methods. 81 FR 95758, 95791. 

In the June 2021 RFI, DOE presented 

three potential approaches for testing 

and certifying high-temperature 

freezers. One approach would provide 

for testing and certification based on the 

standardized 35 °F walk-in cooler 

temperature (or corresponding 

refrigerant suction conditions), if the 

walk-in refrigeration system is marketed 

at or above 10 °F. By extension, the 

approach would also allow 

representations of performance (e.g., 

capacity, power input) of such mediumtemperature refrigeration systems for 

walk-in temperatures at 10 °F and higher 

without requiring them to be tested and 

certified based on the –10 °F lowtemperature walk-in test condition. 86 

FR 32332, 32350. 

DOE could establish new definitions 

for the terms ‘‘high-temperature freezer 

system’’ and ‘‘medium-temperature 

refrigeration system,’’ that implement 

this potential structure. For example, 

‘‘high-temperature freezer system’’ 

could be defined as ‘‘a refrigeration 


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system used to cool the interior of walkin freezers and maintain a room 

temperature of between 10 °F and 

32 °F,’’ while ‘‘medium-temperature 

refrigeration system’’ could be defined 

as ‘‘a refrigeration system used to cool 

the interior of a walk-in cooler or a 

walk-in freezer operating above 32 °F.’’ 

A second alternative presented in the 

June 2021 RFI would be to require walkin cooler refrigeration systems to be 

tested and certified at their lowest 

application temperature conditions. 86 

FR 32332, 32350. This approach would 

be similar to that taken for commercial 

refrigerators, freezers, and refrigeratorfreezers, where manufacturers report the 

lowest application product temperature, 

i.e., the lowest average compartment 

temperature at which the equipment can 

operate during testing (section 2.2 of 

appendix B to part 431, subpart C). For 

walk-ins, this concept could be based on 

the lowest evaporator return air 

temperature for matched pair 

refrigeration systems and the lowest 

saturated suction temperature (and a 

suitable corresponding return gas 

temperature) for dedicated condensing 

units tested alone. This approach would 

result in ratings for units used in hightemperature freezer applications that are 

representative of field performance, 

since the refrigeration system would be 

tested at a representative box 

temperature for such an application. 

Further, this approach would not 

presuppose what the optimal hightemperature freezer operating condition 

would be since it avoids selecting a 

standardized condition that may be 

unachievable by some units. However, 

AWEF ratings obtained from the lowest 

application temperature for different 

units, which would be rated for 

different box temperatures, would not 

be directly comparable. This approach 

would also add testing and reporting 

burden associated with the additional 

test condition. 

Finally, DOE presented a third 

approach in the June 2021 RFI, that 

would establish a single standardized 

test condition at which walk-in cooler 

refrigeration equipment would be 

tested. 86 FR 32332, 32350. This 

approach would result in AWEF ratings 

that are not as reflective of the expected 

field performance as compared with the 

lowest application temperature 

approach. Under a standardized test 

condition approach, all walk-in cooler 

refrigeration systems would be rated at 

the same condition, providing more 

directly comparable ratings for models 

that serve similar applications. 

In the June 2021 RFI, DOE requested 

comment on the three potential 

approaches for addressing hightemperature freezer walk-ins as well as 

any other potential approaches that DOE 

did not discuss. 86 FR 32332, 32350. 

Lennox, AHRI, Keeprite, National 

Refrigeration, and Hussmann supported 

the first option presented by DOE, 

specifically, testing and rating hightemperature freezer systems at 35 °F. 

(Lennox, No. 9 at p. 10; AHRI, No. 11 

at p. 15; Keeprite, No. 12 at p. 3; 

National Refrigeration, No. 17 at p. 2; 

Hussmann, No. 18 at pp. 17–18) 

Keeprite and National Refrigeration both 

stated that this approach would 

eliminate the need to create a new class 

of equipment, and thus avoid additional 

testing. (Keeprite, No. 12 at p. 3; 

National Refrigeration, No. 17 at p. 2) 

Additionally, Keeprite stated that 

medium-temperature equipment design 

is no different from high-temperature 

freezer equipment design and therefore 

concluded that testing the same 

equipment twice would have no 

tangible benefit. (Keeprite, No. 12 at p. 

3) ASAP and the CA IOUs 

recommended the third option 

presented by DOE, which suggested 

establishing new, representative test 

conditions for high-temperature freezers 

irrespective of their lowest operating 

temperature. (ASAP, No. 13 at p. 3; CA 

IOUs, No. 14 at p. 4) Specifically, the 

CA IOUs stated that they support 

establishing additional equipment 

classes for refrigeration systems that are 

not well represented by the 35 °F indoor 

test conditions in DOE’s current test 

procedure. (CA IOUs, No. 14 at pp. 3– 

4) DOE understands the CA IOUs 

comment to infer that for systems not 

well represented by the 35 °F indoor test 

conditions, this equipment should be 

included in a separate equipment class 

and energy use determined at a more 

representative temperature, with 

definitions and labelling that clearly 

identify that these units have different 

test conditions than ‘standard’ walk-in 

refrigeration systems. 

In the June 2021 RFI, DOE also 

requested information to inform the 

development of test procedures for hightemperature freezer systems. 86 FR 

32332, 32350. Specifically, DOE sought 

comment on the test procedure 

parameters or calculations that would 

need to be modified to test mediumtemperature refrigeration systems in the 

high-temperature freezer range. Id. 

Lennox, AHRI, Keeprite, National 

Refrigeration, and Hussmann stated that 

no new test procedures would be 

necessary if the DOE test procedure 

were to require testing and rating hightemperature freezers at 35 °F. (Lennox, 

No. 9 at pp. 10–11; AHRI, No. 11 at pp. 

15–16; Keeprite, No. 12 at p. 3; National 

Refrigeration, No. 17 at p. 2; Hussmann, 

No. 18 at pp. 18–19) 

As also discussed in the June 2021 

RFI, if DOE were to pursue the lowest 

application temperature approach or the 

standardized high-temperature freezer 

test condition approach, DOE would 

need to establish certain new default 

values to calculate the AWEF and net 

capacity of stand-alone hightemperature freezer dedicated 

condensing units. 86 FR 32332, 32350. 

Currently, the test procedure provides 

equations for determining evaporator 

fan power, defrost energy, and defrost 

heat load, all of which are used in lieu 

of matched unit cooler test data (section 

3.4.2 of subpart R, appendix C). 

The current test procedure offers two 

separate equations that relate the 

cooling capacity to the evaporator fan 

power for medium- and lowtemperature unit coolers (section 3.4.2.2 

of subpart R, appendix C). Based on the 

condensing unit capacity at the 

medium-temperature test condition 

(35 °F box temperature), using the 

medium-temperature equation seems to 

be the most appropriate approach since 

the dedicated condensing units in 

question would also be certified as 

medium-temperature dedicated 

condensing units. This approach also 

assumes that fan energy use at hightemperature freezer conditions would be 

the same as fan energy use at mediumtemperature conditions since it makes 

no adjustment in the calculated fan 

power for the high-temperature freezer 

application. DOE requested comment on 

the appropriateness of using the current 

medium-temperature refrigeration 

system default fan input power 

equations (found at section 3.4.2.2 of 

subpart R, appendix C) to represent the 

fan input power of high-temperature 

freezer refrigeration systems. 86 FR 

32332, 32350. In response, Lennox, 

AHRI, and Hussmann recommended 

using the current low-temperature 

default fan input power equation since 

medium-temperature dedicated 

condensing units are typically paired 

with low-temperature unit coolers for 

use in high-temperature freezer 

applications and low-temperature unit 

coolers operate at higher suction 

temperatures than medium-temperature 

unit coolers. (Lennox, No. 9 at p. 11; 

AHRI, No. 11 at p. 16; Hussmann, No. 

18 at p. 19) 

In the current test procedure, defrost 

energy and defrost heat load for standalone dedicated condensing units are 

estimated based on the condenser 

capacity using an equation in section 

3.4.2 of subpart R, appendix C. The 

calculations apply only to freezer 

models, since they assume that 


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50Memorandum from AHRI, ‘‘Department of 

Energy (DOE) Wine Cellar Cooling Systems Test 

Procedure Waiver Industry Comments from AHRI 

Membership,’’ August 18, 2020. (EERE–2019–BT– 

WAV–0028, No. 5 (CellarPro); EERE–2019–BT– 

WAV–0029, No. 5 (Air Innovations); EERE–2019– 

BT–WAV–0038, No. 5(Vinotheque); EERE–2019– 

BT–WAV–022, No. 2 (Vinotemp)) 

51A ‘‘matched refrigeration system’’ is also called 

a ‘‘matched pair’’ and is a refrigeration system 

where the condensing system is distributed into 

commerce with a specific unit cooler(s). See 10 CFR 

431.302. 

52 Inches of water column (‘‘in. wc’’) is a unit of 

pressure conventionally used for measurement of 

pressure differentials. 

refrigeration systems serving walk-in 

coolers are not equipped for defrost 

capability and thus have no defrost 

energy or heat load. However, mediumtemperature refrigeration systems used 

for high-temperature freezer 

applications require defrost capability 

because frost that collects on the 

evaporator during the compressor offcycle will not melt in sub-freezing walkin temperature conditions. The energy 

and heat load of these high-temperature 

freezer defrost systems may differ 

significantly from those of –10 °F 

freezers. Therefore, proper accounting 

for defrost of high-temperature freezer 

refrigeration systems requires 

developing a modified calculation. The 

equation found in section 3.4.2.4 of 

subpart R, appendix C, calculates 

freezer equipment daily defrost energy 

use (‘‘DF’’) using the condenser capacity 

(‘‘qmix,cd’’) and the number of defrost 

cycles per day (‘‘NDF’’). The daily 

defrost heat load (‘‘QDF’’) is directly 

dependent on DF (see relevant equation 

in section 3.4.2.5 of subpart R, appendix 

C). DOE anticipates calculating defrost 

impacts for high-temperature freezers, if 

adopted, would use similar equations 

with different magnitudes. In the June 

2021 RFI, DOE requested information or 

data to inform the use of potential 

modifications to the defrost equations 

for high-temperature freezers, and 

whether frost loads and/or defrost 

frequency are different for hightemperature freezers when compared to 

walk-in freezers that operate at a 

temperature of –10 °F. 86 FR 32332, 

32350. Lennox, AHRI, and Hussmann 

responded that modifications to defrost 

energy equations are unnecessary for 

high-temperature freezer applications 

since calculations for a freezer operating 

at –10 °F, 0 °F, and 10 °F would result in 

a negligible difference in defrost energy 

use. (Lennox, No. 9 at p. 11; AHRI, No. 

11 at p. 16; Hussmann, No. 18 at pp. 19– 

20) 

DOE recognizes that testing hightemperature freezer refrigeration 

systems at a consistent test condition is 

important to ensure test procedure 

consistency and to provide comparable 

performance values in the market. 

Additionally, DOE acknowledges that 

testing high-temperature freezer 

refrigeration systems at a temperature 

less than 35 °F would be more 

representative of their actual energy use; 

however, it is not clear if the potential 

additional test burden justifies 

including an additional test condition 

for walk-in cooler refrigeration systems. 

Therefore, DOE has tentatively 

determined that medium-temperature 

dedicated condensing units used in 

high-temperature freezer applications 

would continue to be tested according 

to subpart R, appendix C; however, DOE 

may revisit its approach for this 

equipment in a future rulemaking. 

6. Systems for High-Temperature 

Applications 

As discussed in the June 2021 RFI, 

DOE is aware of wine cellar (hightemperature) refrigeration systems that 

fall within the walk-in definition but 

that may be incapable of being tested in 

a manner that would yield 

representative performance results 

during a representative average use 

cycle under the current version of the 

walk-in test procedure. 86 FR 32332, 

32344. For example, wine cellar 

refrigeration systems that may be 

installed in some commercial settings 

are designed to operate at a temperature 

range of 45 °F to 65 °F. Under the 

current walk-in test procedure, walk-in 

coolers must be tested while operating 

at 35 °F—see Section 3.1.1 of subpart R, 

appendix C. To the extent that a wine 

cellar refrigeration system does not 

operate at 35 °F, applying the required 

35 °F testing temperature condition 

when evaluating the energy usage of this 

equipment would not produce results 

representative of an average use cycle. 

As discussed in section III.A.2.c, DOE 

has received requests for waiver and 

interim waiver from several 

manufacturers from the test procedure 

in subpart R, appendix C, for basic 

models of wine cellar refrigeration 

systems. DOE engaged with AHRI, the 

industry trade association, to discuss 

how to develop a consistent alternate 

testing approach for high-temperature 

refrigeration systems that would apply 

to all impacted manufacturers. 

Ultimately, AHRI submitted a 

memorandum on behalf of its wine 

cellar members supporting (1) a 45 °F 

minimum operating temperature for 

high-temperature refrigeration systems, 

and (2) testing at 50 percent of 

maximum external static pressure, with 

manufacturers providing maximum 

external static pressure values to DOE.50

DOE has granted interim waivers or 

waivers to the manufacturers listed in 

Table III.2 for specified basic models of 

wine cellar refrigeration systems. These 

waivers provide an alternate test 

procedure for specific basic models of 

single-packaged dedicated systems, 

matched pair, and unit-cooler-only 

high-temperature refrigeration systems. 

In the June 2021 RFI, DOE requested 

comment on the alternative test 

procedure for high-temperature 

refrigeration systems, and if the 

procedure would be appropriate for 

basic models other than those specified 

in the waivers. 86 FR 32332, 32345. 

AHRI and Lennox both recommended 

that DOE adopt the test procedures 

outlined in the waivers. (Lennox, No. 9 

at p. 6; AHRI, No. 11 at p. 11) AHRI and 

Lennox also stated that the ASHRAE 

210P subcommittee is evaluating the 

inclusion of the waiver revisions into 

their test standard. Id. 

DOE is proposing to include a test 

procedure for testing and rating hightemperature matched-pair 51 systems. 

The proposed test procedure specifies 

an air entering dry-bulb temperature of 

55 °F. DOE proposes that testing hightemperature refrigeration systems that 

are single-packaged systems be 

conducted using one of the following: 

The indoor air enthalpy method; the 

outdoor air enthalpy method; the 

compressor calibration method; the 

indoor room calorimeter method; the 

outdoor room calorimeter method; or 

the balanced ambient room calorimeter 

method as specified in AHRI 1250– 

2020. 

As discussed in the June 2021 RFI, 

many refrigeration systems for wine 

cellars are designed for both ducted and 

non-ducted air delivery. 86 FR 32332, 

32345. The current DOE test procedure 

does not address the testing of ducted 

systems. In section III.A.1.d, DOE 

proposed including ducted singlepackaged units in the scope of the walkin test procedure. In section III.A.2.d, 

DOE proposed a definition for a ducted 

fan coil unit and proposed removing the 

restriction of ducts from the definition 

of a single-packaged unit. The alternate 

test approach in the waivers requires 

that testing of ducted units be 

conducted at 50 percent of the 

maximum external static pressure 

(‘‘ESP’’), subject to a tolerance of –0.00/ 

+0.05 in. wc.52 DOE requested feedback 

on its approach for testing ducted units, 

if testing at 50 percent of maximum ESP 

is representative, if there are other 

industry test methods that include 

testing of ducted. 86 FR 32332, 32345. 

Lennox and AHRI supported testing at 

50 percent of the maximum ESP, stating 


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53Multiple-capacity product information from 

one manufacturer can be found at 

www.regulations.gov under Docket EERE–2017–BT– 

TP–0010, No. 4. 

that it will provide representative 

performance values. (Lennox, No. 9 at p. 

6; AHRI, No. 11 at p. 11) The CA IOUs 

recommended that DOE require 

manufacturers to publish the maximum 

ESP to ensure that consumers do not 

exceed the maximum static pressure 

when they install these units so that the 

efficiency and operating capacity 

measured by the test procedure are 

representative of average use. (CA IOUs, 

No. 14 at p. 4) 

Consistent with the waivers that DOE 

has granted for high-temperature 

refrigeration systems, DOE proposes to 

require that testing for ducted systems 

would be conducted with ducts fitted 

and at 50 percent of the unit’s maximum 

ESP, subject to a tolerance of –0.00/ 

+0.05 in. wc. DOE would include this 

provision to apply to any ducted units, 

not strictly high-temperature 

refrigeration systems. DOE proposes 

adding clarification on how to set ESP 

as follows. If testing using either the 

indoor or outdoor air enthalpy method, 

which includes a measurement of the 

air volume rate, the airflow 

measurement apparatus fan would be 

adjusted to set the external static 

pressure—otherwise, the external static 

pressure could be set by symmetrically 

restricting the outlet of the test duct. 

DOE has tentatively determined that 

requiring manufacturers to publish the 

maximum ESP could further ensure that 

the test conditions are representative of 

installation conditions. DOE intends to 

address in a future certification 

rulemaking the certification of the 

maximum ESP for each ducted unit. 

However, DOE proposes at this time to 

include a contingency in the test 

procedure for those cases where the 

maximum ESP is not listed in the 

installation instructions. DOE proposes 

that if the ESP is not provided, it would 

be set such that the air volume rate for 

the test is equal to two-thirds of the 

value that is measured for zero ESP 

operation. Making the measurements 

and adjustments required for this setup 

step would require use of an airflow 

measurement apparatus. 

Issue 23: DOE requests comment on 

provisions for setting ESP when testing 

ducted units. 

Finally, in the June 2021 RFI, DOE 

requested comment on any other issues 

regarding the testing of wine cellar 

(high-temperature) refrigeration 

systems. 86 FR 32332, 32346. Lennox 

and AHRI suggested that DOE work 

with wine cellar manufacturers to 

incorporate high-temperature 

refrigeration systems adequately as a 

separate category. (Lennox, No. 9 at p. 

7; AHRI, No. 11 at p. 12) Lennox and 

AHRI also both suggested that there may 

need to be a high medium temperature 

category of ducted indoor and outdoor 

units. Id. The same commenters noted 

the impact of HFC regulations on wine 

cellar refrigeration and recommended 

alternative refrigerants be evaluated. Id. 

DOE may evaluate equipment categories 

and refrigerant requirements for hightemperature refrigeration systems in a 

future energy conservation standards 

rulemaking. The CA IOUs 

recommended that definitions and 

labeling be developed to clearly 

differentiate high-temperature 

refrigeration units from medium 

temperature units. (CA IOUs, No. 14 at 

pp. 3–4) In response to the comment 

from the CA IOUs, DOE has proposed a 

high-temperature refrigeration system 

definition that differentiates these units 

from other refrigeration systems. 

7. Variable-, Two-, and MultipleCapacity Systems 

As discussed in the June 2021 RFI, 

DOE expected the majority of 

refrigeration equipment within the 

dedicated condensing class to be 

certified as dedicated condensing units 

tested alone, with a much smaller 

number of systems certified as matched 

pairs. 86 FR 32332, 32348–32349. DOE’s 

review of CCMS data has confirmed that 

most certified dedicated condensing 

unit basic models are dedicated 

condensing units tested and rated alone 

rather than matched pairs. This is 

consistent with comments made during 

the 2014 and 2016 rulemakings. 

However, the current DOE test 

procedure does not include a method 

for assessing stand-alone multiple- and 

variable-capacity systems. Similarly, 

AHRI 1250–2020 does not include test 

procedures or conditions for indoor 

variable- or two-capacity units. To 

address this gap, the ASRAC Working 

Group recommended that DOE amend 

its test procedure to allow for separate 

ratings of stand-alone variable-capacity 

dedicated condensing units. (ASRAC 

Term Sheet Recommendation #6) 

Historically, refrigeration systems 

have been designed using a single-speed 

compressor, which operates at full 

cooling capacity while the compressor 

is on. To match the cooling load of the 

refrigerated space, which in most cases 

is less than the full cooling capacity of 

the compressor, a single-speed 

compressor cycles on and off. In 

contrast, variable-speed systems employ 

an inverter-driven compressor that can 

reduce its speed to match the cooling 

load. Accordingly, a variable-speed 

compressor can deliver cooling that 

more closely matches the load. This can 

reduce energy use by unloading the 

system’s heat exchangers, allowing them 

to operate more effectively, and may 

also allow reduction of fan speeds, 

which can further enhance savings 

potential. Emerson’s digital technology, 

used in scroll compressors, can also 

vary the average refrigerant flow by 

cycling the engagement of the scroll 

elements that make up the compressor— 

the duty cycle of this engagement 

within a cycle time on the order of 15 

to 20 seconds can be varied to adjust 

average capacity. Similarly, a two- or 

multiple-capacity compressor can 

reduce its displacement (volume intake 

per revolution), for example in a 

multiple-cylinder reciprocating 

compressor by ‘‘unloading’’ individual 

cylinders within the compressor. This 

allows the compressor to more closely 

match the required cooling load. Other 

staging technologies have been used, 

including multiple compressors and 

scroll compressors with a closable port 

that deactivates the outermost scroll 

wraps when open, thus reducing 

effective displacement. DOE is aware of 

some multiple- or variable-capacity 

dedicated condensing units that are 

currently available on the market using 

such compressor technologies.53

The current DOE test procedure 

measures the performance of a walk-in 

condensing unit while operating under 

a full cooling load at a fixed capacity; 

i.e., the compressor is operated 

continuously in its ‘‘on’’ state. See 

Tables 11 through 14 of AHRI 1250– 

2009, and section 3 of subpart R, 

appendix C, for further details. While 

AHRI 1250–2009 and AHRI 1250–2020 

both include test methods for two-, 

multiple-, and variable-capacity 

matched pair refrigeration systems with 

outdoor dedicated condensing units, 

there is no test method for such 

dedicated condensing units when tested 

alone. 

In the June 2021 RFI DOE requested 

information on the development of test 

standards for, the efficiency gains of, 

and the market availability of multiple 

and variable-capacity systems. 86 FR 

32332, 32349. Lennox, AHRI, Keeprite, 

National Refrigeration, and Hussmann 

all stated that the market for variable 

capacity units is low and does not 

warrant test procedure changes. 

(Lennox, No. 9 at pp. 9–10; AHRI, No. 

11 at p. 14; Keeprite, No. 12 at p. 2; 

National Refrigeration, No 17 at p. 2; 

Hussmann, No. 18 at p. 17) Keeprite 

stated that variable capacity units are 

most often designed in tandem with the 

evaporator unit, and that AHRI 1250– 


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54Although the compressor would operate during 

hot gas defrost, the DOE test procedure calls for 

testing hot gas defrost dedicated condensing units 

using the electric defrost default parameters. 

Section 3.5 of appendix C to subpart R of 10 CFR 

part 431. 

2020 tests were acceptable for all 

systems on the market. (Keeprite, No. 12 

at p. 2) ASAP and NEEA recommended 

DOE develop a test method for 

dedicated condensing units tested 

alone. (ASAP, No. 13 at p. 2; NEEA, No. 

16 at p. 2) NEEA notes that no matched 

systems are certified in CCMS 

indicating that the lack of test procedure 

may be limiting market adoption. 

(NEEA, No. 16 at p. 2) Similarly the CA 

IOUs stated that accurately measuring 

the field performance of variable 

capacity units is key for market 

adoption. (CA IOUs, No. 14 at p. 2) 

ASAP noted the ASRAC Working 

Group’s recommendation to develop a 

test procedure for dedicated condensing 

units tested alone. (ASAP, No. 13 at pp. 

2–3) ASAP, the CA IOUs, and NEEA all 

recommended that DOE evaluate 

whether AHRI 1250–2020 has the 

capability to measure real world cycling 

conditions of refrigeration systems. 

(ASAP, No. 13 at p. 2; CA IOUs, No. 14 

at pp. 2–3; NEEA, No. 16 at p. 2) The 

CA IOUs note that this is important for 

more widespread adoption of variable 

capacity technology. (CA IOUs, No. 14 

at p. 2) The CA IOUs recommended a 

potential alternative of testing variable 

capacity systems only as matched 

systems and having matching 

guidelines, similar to ASHRAE 29 or 

AHRI 810. (CA IOUs, No. 14 at p. 3) 

DOE acknowledges the small market 

share of variable- and multiple-capacity 

units but notes that the ASRAC Working 

Group agreed to the need for such test 

procedures for dedicated condensing 

units tested alone. Because of this, DOE 

proposes adding test procedures and 

conditions for variable-, two-, and 

multiple-capacity dedicated condensing 

units. DOE also proposes test methods 

for variable-, two-, and multiplecapacity matched pairs with indoor 

dedicated condensing units. To support 

these proposed additions, DOE also 

proposes to add a definition specifying 

that a ‘‘multiple-capacity’’ refrigeration 

system is one having three or more 

stages. 

a. Dedicated Condensing Units 

As discussed, AHRI 1250–2020 

specifies test conditions for matched 

variable- and multi-capacity 

refrigeration systems. Because matched 

pairs are complete refrigeration systems, 

the test conditions do not address 

refrigerant conditions in the refrigerant 

lines connecting the condensing unit 

and the unit cooler. Instead, the test 

specifies conditions for the air entering 

the unit cooler and the air entering the 

condensing unit. Test procedures for 

dedicated condensing units tested alone 

must address refrigerant conditions in 

the lines that would connect the 

condensing unit to a unit cooler. For 

example, Table 12 of AHRI 1250–2020 

provides test conditions for fixed 

capacity refrigerated indoor dedicated 

condensing units. The table specifies 

the refrigerant suction dew point return 

gas temperature at the condensing unit 

suction inlet—these conditions reflect 

the operation of a representative unit 

cooler as well as the temperature rise of 

refrigerant as it returns to the 

condensing unit in the suction line. In 

addition, the test procedure calculations 

also address the direct energy use of the 

unit cooler, specifically the unit cooler 

fan and (for freezer dedicated 

condensing units) the defrost heater 

energy input and heat impact. Section 

7.9 of AHRI 1250–2020 includes 

equations providing representative 

values for some of these parameters— 

see, e.g., Equation 130 for on-cycle unit 

cooler power and Equation 118 for offcycle unit cooler power. Section C10.2.2 

in AHRI 1250–2020 includes equations 

providing representative values for the 

defrost parameters. 

To extend the test procedure to 

variable- and multiple-capacity 

dedicated condensing units, the test 

would need to specify how the 

parameters representing the unit cooler 

would change at part-load as compared 

to full-load. DOE is proposing new test 

conditions for such models, including 

values representing the unit cooler and 

suction line influence on operation at 

part-load. The proposed test conditions 

address condensing unit suction inlet 

refrigerant pressure (represented as dew 

point temperature) and temperature for 

the part-load conditions. The condenser 

air inlet conditions would be the same 

as for existing tests of dedicated 

condensing units: Tests only with 90 °F 

dry bulb entering air temperature for 

indoor dedicated condensing units, and 

tests at 95 °F, 59 °F, and 35 °F for 

outdoor dedicated condensing units. 

Also, the maximum-capacity test 

conditions would be the same as the test 

conditions for a single-capacity 

condensing unit since maximumcapacity operation of a multiple- or 

variable-capacity unit should match 

operation of a single-capacity unit. 

Specifically, for cooler dedicated 

condensing units the maximumcapacity suction connection dew point 

temperature would be 23 °F and the 

refrigerant temperature would be 

41 °F—for freezers, these conditions 

would be –22 °F and 5 °F. These 

parameters would need to be defined for 

the part-load test conditions for 

variable-, multiple-, and two-capacity 

dedicated condensing units. In addition, 

the unit cooler power levels at part-load 

would have to be specified, if they 

would be different than for full-load. 

Defrost parameters would not be 

expected to be changed for variable-, 

multiple-, or two-capacity dedicated 

condensing units as compared with 

single-capacity condensing units, 

because the defrost would occur when 

the dedicated condensing unit 

compressor is off, and the defrost energy 

and heat contribution depend primarily 

on the representative unit cooler.54

DOE developed representative values 

for the part-load refrigerant conditions 

at the condensing unit suction inlet 

based on testing of two variable-capacity 

systems. The testing and the 

development of the parameters is 

discussed in greater detail in document 

EERE–2017–BT–TP–0010–0021, 

‘‘Development of Test Rating Conditions 

for Two-Capacity, Multiple-Capacity, 

and Variable-Capacity Condensing 

Units.’’ The development is based on 

the expectation that the unit coolers 

with which such dedicated condensing 

units are paired in the field would have 

two-speed fans, either already installed 

or retrofitted as part of the condensing 

unit installation. The test work shows 

that this inclusion of two-speed fans 

would be necessary in order to achieve 

efficiency gains with part-load capacity 

near or lower than half of the full-load 

capacity. 

(1) Dew Point Target Values for PartLoad Operation: Unit Cooler Exit 

As unit cooler-part-load capacity 

decreases, the suction dew point rises, 

approaching the temperature of the air 

entering the unit cooler (‘‘air-entering 

temperature’’). However, when a unit 

cooler fan switches to reduced speed, 

the suction dew point falls, in this case 

from the reduction in unit cooler 

evaporator effectiveness when operating 

with less airflow. Note that the unit 

cooler fan power reduces significantly at 

reduced speed, and this fan heat 

reduction can significantly increase net 

capacity and efficiency at part-load. 

DOE developed representative 

trendlines for approach of unit cooler 

exit evaporating (dew point) 

temperature to the unit cooler airentering temperature for both full- and 

half-speed fan operation. 

However, in its development, DOE 

limited its approach to air-entering 

temperature to account for the expected 

exit of superheat. Refrigerant flow 


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through unit coolers is controlled by 

expansion devices controlling for the 

presence of a certain refrigerant 

superheat level at the unit cooler exit. 

The test procedure for unit coolers calls 

for this value to be set at 6.5 °F in case 

there is no manufacturer-specified level. 

For such operation, the temperature of 

the refrigerant leaving the unit cooler is 

6.5 °F warmer than the dew point 

temperature. However, the refrigerant 

leaving the unit cooler can be no 

warmer than the entering air. Thus, the 

approach of dew point temperature to 

entering air temperature can be no more 

than 6.5 °F for a unit cooler operating 

with this level of superheat. Thus, in its 

development, DOE limited the approach 

to 7 °F to account for this issue and to 

provide a 0.5 °F margin. 

The selection of dew point 

temperature at the unit cooler exit for a 

given part-load operating condition thus 

depends on the capacity level and the 

unit cooler fan speed (full or half 

speed). While different compressor partload technologies can provide different 

levels of capacity turndown, DOE 

developed representative dew point 

levels based on expectations of likely 

part-load capacity levels. Specifically, 

for variable- or multiple-stage dedicated 

condensing units, the expected 

minimum level is roughly 1⁄3 of full 

capacity, and the expected intermediate 

level is roughly 2⁄3 of full capacity. For 

two-capacity dedicated condensing 

units, DOE used a representative lowcapacity level of roughly half the fullcapacity level. 

As for unit cooler fan speed, DOE’s 

testing showed that the optimum 

capacity level for switching between 

speeds is near 2⁄3—this means that lower 

than this capacity level, the higher fan 

heat and power input associated with 

full fan operation outweighs the benefit 

of higher evaporator effectiveness. 

Hence, in determining the appropriate 

unit cooler exit condition, DOE assumed 

that low fan speed would be used if the 

compressor or compressors run at an 

operating level less than 65 percent. As 

mentioned, there are different ways that 

compressors can achieve part-load 

conditions. The operating level 

determination would be based on the 

compressor technology. Specifically, 

this would involve the speed ratio for a 

variable-speed compressor, scroll 

engagement duty cycle for a digital 

scroll compressor, or displacement ratio 

for a staged compressor system that 

changes displacement at part-load. 

Hence, for those part-load conditions 

where the operating level (determined 

as appropriate for the compressor 

technology) is less than or equal to 65 

percent, the unit cooler exit condition 

would be based on the low fan trend 

measured in DOE’s test series, and 

where the operating level is greater than 

65 percent, it would be based on the full 

fan trend. Correspondingly, the fan 

power used in calculating AWEF would 

be based on the operating level as well. 

(2) Compressor Operating Levels During 

Testing 

In order to clarify the compressor 

operating level, DOE proposes to define 

specific terms appropriate for the 

compressor technologies expected to be 

used to achieve part-load operation. 

These terms would be ‘‘duty cycle’’ for 

digital scroll compressors, ‘‘speed ratio’’ 

for variable-speed compressors, and 

‘‘displacement ratio’’ for compressors or 

compressor systems that vary the 

compressor inlet displacement volume 

to achieve capacity modulation. 

DOE proposes the following 

definitions: 

• Displacement Ratio, applicable for a 

staged positive displacement 

compressor system, means the swept 

volume rate, e.g., in cubic centimeters 

per second, of a given stage, divided by 

the swept volume rate at full capacity. 

• Duty Cycle, applicable for a digital 

compressor, means the fraction of time 

that the compressor is engaged and 

actively compressing refrigerant. 

• Speed Ratio, applicable for a 

variable-speed compressor, means the 

ratio of operating speed to the maximum 

speed. 

DOE is proposing to specify use of 

compressor operating levels during partload testing that are consistent with the 

development of the representative unit 

cooler exit dew point targets. For twocapacity compressors, this is 

straightforward since there is only one 

part-load operating level. For variablecapacity and multiple-capacity 

compressors, DOE proposes that the 

part-load operating levels be the lowest 

level (e.g., speed, duty cycle, or stage) 

available for the compressor, and that 

the intermediate level be the nearest 

available level to the mean of the fullcapacity and minimum-capacity levels. 

To clarify this proposal, DOE is 

proposing to define ‘‘Minimum Speed’’ 

and ‘‘Maximum Speed’’ as set out in the 

regulatory text at the end of this 

document, proposed appendix C1 to 

subpart R of part 431. 

(3) Dew Point Target Values for PartLoad Operation: Condensing Unit Inlet 

The previous section discussed the 

approach for development of 

appropriate unit representative cooler 

exit conditions for part-load operation 

of a condensing unit tested alone. 

However, performance depends on 

conditions at the condensing unit inlet. 

For full-load operation, the test 

procedure operating conditions are 

based on assuming that the pressure 

drop in the suction line is equivalent to 

a 2 °F reduction in dew point 

temperature. 81 FR 95758, 95792 

(December 28, 2016). For part-load 

operation, the suction line pressure 

drop would be lower, due to the 

reduced refrigerant flow rate. In its 

development of condensing unit test 

conditions, DOE assumed that the 

suction line pressure drop would be 

equivalent to a dew point reduction of 

1 °F when the part-load capacity is 50 

percent of the full-load capacity or more 

and would be 0.5 °F when the capacity 

is lower (see discussion in EERE–2017– 

BT–TP–0010–0021, ‘‘Development of 

Test Rating Conditions for TwoCapacity, Multiple-Capacity, and 

Variable-Capacity Condensing Units’’). 

The suction dew point levels at the 

condensing unit inlet would then be as 

indicated in Table III.10 and Table 

III.11. 

TABLE III.10—TWO-CAPACITY DEDICATED CONDENSING UNIT SUCTION DEW POINTS

Application 

High-capacity 

suction dew 

point, °F 

Low capacity, 

high unit 

cooler fan 

speed, suction 

dew point, °F 

Low capacity, 

low unit cooler 

fan speed, 

suction dew 

point, °F 

Cooler .......................................................................................................................................... 23 25.5 23 

Freezer ......................................................................................................................................... ¥22 ¥19.5 ¥22 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23965 

TABLE III.11—VARIABLE-CAPACITY OR MULTIPLE-CAPACITY DEDICATED CONDENSING UNIT SUCTION DEW POINTS

Application 

Maximumcapacity 

suction dew 

point, °F 

Intermediate 

capacity, high 

unit cooler fan 

speed, suction 

dew point, °F 

Intermediate 

capacity, low 

unit cooler fan 

speed, suction 

dew point, °F 

Minimumcapacity 

suction dew 

point, °F 

Cooler .............................................................................................................. 23 25.5 22 26 

Freezer ............................................................................................................. ¥22 ¥19.5 ¥23 ¥19 

(4) Target Refrigerant Temperature at 

Condensing Unit Inlet 

As discussed previously, the 

refrigerant temperature at the exit of the 

representative unit cooler is equal to the 

unit cooler exit dew point temperature 

plus the superheat, assumed to be 6.5 °F. 

The refrigerant warms up in the suction 

line as it returns to the condensing unit. 

For full-load operation, the test 

procedure specifies condensing unit 

inlet temperature conditions, i.e., 41 °F 

for cooler dedicated condensing units 

and 5 °F for freezer condensing units. In 

a cooler system operating at full-load in 

a 95 °F outdoor condition, this means 

that the refrigerant is warmed from 

31.5 °F at the unit cooler exit to 41 °F at 

the condensing unit inlet. Most of this 

warmup would be expected to occur 

where the suction line is exposed to 

95 °F outdoor conditions, since the 

cooler interior temperature at 35 °F is 

only a few degrees warmer than the 

refrigerant exiting the unit cooler. The 

suction line exposed to outdoor air 

conditions can be seen as a heat 

exchanger with low effectiveness. For 

the purposes of determining the trend of 

suction line refrigerant temperature 

increase at part-load, DOE assumed that 

the suction line thermal resistance 

would remain the same as the capacity 

level changes. This means that when 

refrigerant flow is lower at part-load, the 

heat transfer effectiveness would be 

higher, and the refrigerant temperature 

rise would be greater. (See the more 

detailed discussion in EERE–2017–BT– 

TP–0010–0021, ‘‘Development of Test 

Rating Conditions for Two-Capacity, 

Multiple-Capacity, and VariableCapacity Condensing Units’’) The 

document discusses in more detail how 

the suction line temperature rise was 

calculated for different operating 

conditions and related to the operating 

capacity level of the condensing unit. 

Note that for refrigerated outdoor 

dedicated condensing units using test 

condition C, no change in the 

condensing unit inlet temperature is 

assumed for different capacity levels, 

because the 41 °F specified for singlecapacity systems already suggests a 

suction line heat transfer effectiveness 

greater than 100 percent. Hence, DOE 

proposes no change in condensing unit 

inlet temperature for cooler dedicated 

condensing units for condition C. 

TABLE III.12—TWO-CAPACITY DEDICATED CONDENSING UNIT RETURN GAS CONDITIONS

Test title 

Unit cooler fan level 

corresponding to compressor 

operating level 

Freezer return 

gas, °F 

Cooler return 

gas, °F 

Capacity, Condition A, Low Capacity ........................................................ Low ..................................................

High .................................................

13.5 

12.0 

45.0 

42.5 

Capacity, Condition A, High Capacity ....................................................... High ................................................. 5 41 

Capacity, Condition B, Low Capacity ........................................................ Low ..................................................

High .................................................

13.0 

11.5 

41.0 

41.5 

Capacity, Condition B, High Capacity ....................................................... High ................................................. 5 41 

Capacity, Condition C, Low Capacity ........................................................ Low ..................................................

High .................................................

12.0 

10.5 

42.5 

41.0 

Capacity, Condition C, High Capacity ....................................................... High ................................................. 5 41 

TABLE III.13—VARIABLE-CAPACITY DEDICATED CONDENSING UNIT RETURN GAS CONDITIONS

Test title Unit cooler fan level corresponding 

to compressor operating level 

Freezer return 

gas, °F 

Cooler return 

gas, °F 

Capacity, Condition A, Minimum Capacity ................................................ Low .................................................. 26.5 53.0 

Capacity, Condition A, Intermediate Capacity ........................................... Low .................................................. 10.5 43.0 

High ................................................. 12.0 45.5 

Capacity, Condition A, Maximum Capacity ............................................... High ................................................. 5 41 

Capacity, Condition B, Minimum Capacity ................................................ Low .................................................. 24.0 46.0 

Capacity, Condition B, Intermediate Capacity ........................................... Low .................................................. 10.0 40.0 

High ................................................. 11.5 41.5 

Capacity, Condition B, Maximum Capacity ............................................... High ................................................. 5 41 

Capacity, Condition C, Minimum Capacity ................................................ Low .................................................. 20.0 41.0 

Capacity, Condition C, Intermediate Capacity .......................................... Low .................................................. 10.0 41.0 

High ................................................. 10.5 41.0 

Capacity, Condition C, Maximum Capacity ............................................... High ................................................. 5 41 


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23966 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

(5) Unit Cooler Power To Use for AWEF 

Calculations 

As discussed previously, the 

proposed test for dedicated condensing 

units with more than one compressor 

capacity is based on the expectation that 

a representative unit cooler with which 

the condensing unit would be paired in 

the field will have or be fitted with 

during installation a two-speed or 

variable-speed fan, and that the fan 

would operate at half-speed as 

appropriate for part-load operation. Also 

discussed previously, the unit cooler 

dew point target for the test depends on 

the assumption for unit cooler fan 

operating condition, and DOE is 

proposing that half-speed would be 

used for compressor operating levels up 

to 65 percent. AHRI 1250–2020 already 

provides power input levels for a 

representative unit cooler with fans 

operating at full- and half-speed levels 

(for example, see Equations 118 and 130 

of the test standard, providing 

representative wattages for off-cycle and 

on-cycle wattages). DOE proposes that 

the half-speed off-cycle wattage would 

also be used for half-speed on-cycle 

operation when calculating AWEF. 

(6) Other Aspects of AWEF Calculations 

DOE proposes that the calculations 

used to determine AWEF for dedicated 

condensing units with more than one 

capacity level would be essentially 

identical to the calculations for matched 

pair or single-packaged dedicated 

systems once capacity and power input 

are determined for each standard 

operating condition at the different 

capacity levels. However, this proposal 

would adjust the calculation methods 

for variable- and multiple-capacity 

systems, consistent with the direction 

taken for calculating efficiency metrics 

for variable-capacity central air 

conditioners and heat pumps in the test 

procedure final rule published in 2016 

for those products. These changes are 

described in section III.G.7.c of this 

document. 

Issue 24: DOE requests comments on 

its proposals for testing multiple-, 

variable-, and two-capacity dedicated 

condensing units tested alone. DOE 

specifically requests comments on (a) 

the expectation that a unit cooler with 

which such a condensing unit is paired 

in the field would have two-speed (or 

variable-speed) fans or be fitted with 

such fans during installation, (b) the 

proposed compressor operating levels to 

use for testing, (c) the proposed 

compressor operating level at which the 

unit cooler fan would be assumed to 

switch to half-speed, (d) the proposed 

targets for unit cooler exit and 

condensing unit inlet refrigerant 

temperatures and dew point target 

temperatures, and (e) the unit cooler 

half-fan-speed input wattage. 

(7) Information Required for Testing 

Testing of dedicated condensing units 

with multiple capacity levels requires 

setting operating conditions for testing 

that are not required when testing 

single-capacity dedicated condensing 

units. DOE expects that some of this 

information may not be readily available 

in installation instructions and may 

consider whether certification of some 

of the required information may be 

needed in a separate rulemaking 

addressing certification. 

(8) Potential Use of Equations Rather 

Than Tabulated Values for Target Test 

Conditions 

The proposed tabulated target values 

for suction dew point and suction 

temperature for part-load operation of 

dedicated condensing units shown in 

Table III.10 through Table III.13 were 

using correlations for the trends of unit 

cooler operation and suction line 

pressure drop and heat transfer 

developed based on test data (See the 

discussion in EERE–2017–BT–TP– 

0010–0021, ‘‘Development of Test 

Rating Conditions for Two-Capacity, 

Multiple-Capacity, and VariableCapacity Condensing Units’’) The target 

values also consider likely compressor 

minimum operating levels and 

decisions regarding the unit cooler fan 

operating level corresponding to each 

compressor operating level. Rather than 

use a tabular approach to specifying 

target operating conditions, DOE could 

consider direct use of the correlations 

for determination of target test 

conditions. The approach would 

involve, for each part-load test, using (1) 

two correlations to calculate the target 

condensing unit suction inlet dew 

point, and (2) two equations to calculate 

target condensing unit suction inlet 

temperature. This approach would 

provide more flexibility in manufacturer 

decisions regarding the unit cooler fan 

level corresponding to any given 

compressor staging level and slightly 

better alignment of the test conditions to 

the compressor operating levels. 

However, it would require 

manufacturers to provide more 

information regarding selection of test 

conditions to clarify how models were 

tested and could be considered more 

burdensome by requiring calculation of 

test conditions. Depending on 

comments provided on this topic, DOE 

may consider adopting this approach of 

using the correlations for unit cooler 

and suction line trends instead of the 

tabulated values for setting target test 

conditions. 

Issue 25: DOE requests comment on 

whether DOE should set the target test 

conditions using correlations for unit 

cooler and suction line response to partload operation rather than the proposed 

tabular approach. 

b. Indoor Matched Pair and SinglePackaged Units 

As discussed previously, AHRI 1250– 

2020 does not include test procedures or 

conditions for indoor variable or 

multiple-capacity units. As with 

dedicated condensing units, DOE 

proposes to adopt test methods for 

indoor matched pair and singlepackaged dedicated systems. Testing of 

these systems and calculating AWEF for 

them would require parallel testing and 

AWEF calculations for outdoor matched 

systems, except that there is only one 

test condition and the AWEF 

calculation would be based only on that 

one condition. The details for required 

test conditions and calculations are 

presented in section 4.5.6 and Table 17 

and Table 18 of this document showing 

the proposed regulatory text revisions. 

Issue 26: DOE requests comment on 

its proposal to include in its test 

procedures instructions for testing and 

determining representations for indoor 

matched pair and single-packaged 

dedicated systems. 

c. Revision to EER Calculation for 

Outdoor Variable-Capacity and 

Multiple-Capacity Refrigeration Systems 

AHRI 1250–2020 includes test 

conditions and calculations to 

determine representations, specifically 

AWEF, for refrigeration systems having 

variable-capacity capability. The 

calculations use a quadratic equation for 

determining system EER for 

intermediate-capacity operation (see, 

e.g., Equations 76 through 84 of AHRI 

1250–2020). DOE moved from the same 

quadratic approach for central air 

conditioners and heat pumps (‘‘CAC/ 

HP’’) to a linear interpolation method 

due to concerns about potential 

inaccuracies of this method. 82 FR 1426, 

1440–1441 (January 5, 2017). DOE 

proposes to make the same change when 

testing WICF refrigeration systems. 

Issue 27: DOE requests comment on 

its proposal to modify the approach for 

calculating intermediate-capacity EER 

for variable-speed refrigeration systems. 

d. Digital Compressors 

Dedicated condensing units with 

digital compressors have been 

commercialized (see, e.g., EERE–2017– 

BT–TP–0010–0020). Digital compressor 

operation is discussed in the 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23967 

55 In a ‘‘hot gas’’ defrost system, high-temperature, 

high-pressure hot refrigerant gas from the discharge 

side of the compressor is introduced into the 

evaporator, where it condenses, thereby releasing 

latent heat into the evaporator. This heat is used to 

melt the frost that has accumulated on the outside 

of the evaporator coil. 

introduction to section III.G.7 of this 

document. To clarify the proposed test 

procedure for digital compressors, DOE 

proposes to define the term ‘‘digital 

compressor’’ as a compressor that uses 

mechanical means for disengaging 

active compression on a cyclic basis to 

provide a reduced average refrigerant 

flow rate in response to an input signal. 

DOE testing has shown that operating 

tolerances specified in AHRI 1250–2020 

for certain parameters such as 

refrigerant pressure and mass flow can 

be exceeded when a digital compressor 

operates at part-load. Nevertheless, DOE 

testing has shown that the refrigerant 

enthalpy method for measuring capacity 

may still be quite accurate, as long as 

the liquid subcooling at the mass flow 

meter is sufficiently low, as required in 

Section C3.4.5 of AHRI 1250–2020. 

When conducting these tests, DOE used 

an integrating mass flow meter and 

measurement of temperature and 

pressure at a frequency of one 

measurement per second. DOE 

calculated capacity using refrigerant 

enthalpies determined based on testperiod-average values of refrigerant 

temperature and pressure. When 

meeting the mass flow meter subcooling 

requirements, capacity balance with a 

separate calorimetric capacity 

measurement ranged from 0.2 to 4.1 

percent. 

Thus, DOE proposes that testing of 

refrigeration equipment with digital 

compressors operating at part-load may 

use the refrigerant enthalpy method as 

a secondary test method, with the 

following provisions and adjustments: 

(1) Pressure and temperature 

measurement would be at a frequency of 

once per second or faster, (2) the 

operating tolerances for pressure and 

temperature at both the inlet and outlet 

connections, and for mass flow would 

not apply, and (3) enthalpies 

determined for the capacity calculation 

would be based on test-period-average 

pressure and temperature values. 

DOE proposes that the selection of the 

primary test method for measuring 

capacity would depend on the 

refrigeration system configuration. For 

single-packaged dedicated systems, the 

test methods proposed to be used as 

primary methods for any singlepackaged dedicated system would be 

used (see discussion in section III.G.2of 

this document). For matched pairs, the 

same test methods allowed as primary 

methods for single-packaged dedicated 

systems would be used. For dedicated 

condensing units, the primary methods 

that would be used would include 

outdoor air enthalpy method, balanced 

ambient outdoor calorimeter, and 

outdoor room calorimeter 

measurements. 

Issue 28: DOE requests comments on 

its proposals to address part-load testing 

for refrigeration systems with digital 

compressors. 

8. Defrost 

The April 2011 final rule referenced 

AHRI 1250–2009 as DOE’s WICF 

refrigeration system test procedure, 

including that standard’s requirement 

that both frosted and dry coil defrost 

tests be conducted. 81 FR 21580, 21597. 

DOE later noted in a supplemental 

notice of proposed rulemaking 

published on February 20, 2014 

(‘‘February 2014 SNOPR’’) that these 

tests may be overly burdensome for 

manufacturers to conduct due to the 

difficulty of maintaining the moist air 

infiltration conditions for the frosted 

coil test in a repeatable manner. 79 FR 

9818, 9831. Accordingly, in the May 

2014 final rule, DOE adopted a set of 

nominal values for calculating defrost 

energy use for a frosted coil, number of 

defrosts per day if the unit has an 

adaptive defrost system, and daily 

contribution of heat load. 79 FR 27388, 

27401. To address testing lowtemperature dedicated condensing units 

alone, the May 2014 final rule 

established nominal values for the 

defrost energy use and thermal load. In 

addressing refrigeration systems with 

hot gas defrost, the May 2014 final rule 

established nominal values for 

calculating hot gas defrost energy use 

and heat load.55 Id. 

The December 2016 final rule 

removed the method for calculating the 

defrost energy and defrost heat load of 

systems with hot gas defrost and 

established a new method to evaluate 

hot gas defrost refrigeration systems. 

That new method treated hot gas defrost 

refrigeration systems as if they used 

electric defrost rather than hot gas 

defrost. This method relied on the same 

nominal values for defrost energy use 

and thermal load that the test procedure 

prescribes for electric-defrost dedicated 

condensing units that are tested alone. 

81 FR 95758, 95774–95777. This 

approach was modified in the March 

2021 final rule, which amended the 

DOE test procedure by rating hot gas 

defrost unit coolers using modified 

default values for energy use and heat 

load contributions that would make 

their ratings more consistent with those 

of electric defrost unit coolers. 86 FR 

16027. The scope of the March 2021 

final rule is limited to unit coolers only. 

86 FR 16027, 16030. 

In the June 2021 test procedure (‘‘TP’’) 

RFI, DOE stated that it was considering 

whether to include a test method for 

determining the energy use associated 

with defrost and/or a test method to 

assess and confirm defrost adequacy. 86 

FR 32332, 32347. DOE observed that 

any test method for determining defrost 

energy use and adequacy would have to 

provide consistent, repeatable methods 

for (1) delivering a frost load to the test 

coil and (2) measuring the thermal load 

released into the refrigerated space 

during the defrost cycle, regardless of 

the method of defrost (e.g., electric or 

hot gas defrost), all while ensuring that 

the procedure provides results reflecting 

energy usage during a representative 

average use cycle and not be unduly 

burdensome to conduct. Id. DOE 

requested information on methods that 

might provide a measurable frost load 

and frost type to ensure repeatable 

defrost testing. Additionally, DOE 

requested data on typical frost loads and 

frost type, or information on the type 

and amount of testing that would be 

necessary to validate a method for 

evaluating frost loads and frost types 

during defrost testing. Id. 

In response to DOE’s request for 

comment, Lennox, AHRI, National 

Refrigeration, and Hussmann recognized 

that although the injector system 

included in appendix E of AHRI 1250– 

2020 is an improvement, it remains a 

challenge to consistently build frost on 

an evaporator coil while minimizing 

interference with calorimeter systems. 

(Lennox No. 9 at p. 8; AHRI No. 11 at 

p. 13; National Refrigeration No. 17 at 

p. 2; Hussmann No. 18 at p. 15 Keeprite 

reiterated the technical difficulties 

associated with a moist-air loading 

approach. (Keeprite No. 12 at p. 2) Each 

of these stakeholders urged DOE to wait 

for the completion of ASHRAE research 

project WS 1831, ‘‘Validation of a Test 

Method for Applying a Standardized 

Frost Load on a Test Evaporator in a 

Test Chamber with an Operating 

Conditioning System’’ (‘‘WS 1831’’), 

before modifying its defrost test 

procedure. (Lennox No. 9 at p. 8; AHRI 

No. 11 at p. 13; National Refrigeration 

No. 17 at p. 2; Hussmann No. 18 at p. 

15) ASAP also recognized the challenge 

associated with developing a test 

method to measure defrost energy 

(ASAP No. 13 at p. 2), while the CA 

IOUs agreed that AHRI 1250–2020 

appendix E provides a good starting 

point for a universal defrost test but 

urged DOE to work with stakeholders to 

develop a test procedure for defrost that 


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23968 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

56Sherif, S.A., P.J. Mago, and R.S. Theen. A Study 

to Determine Heat Loads Due to Coil Defrosting. 

1997. University of Florida: Gainesville, FL. 

ASHRAE Project No. 622–RP. Report No. UFME/ 

SEECLSEE–9701 (‘‘622–RP’’) and Sherif, 

S.A., P.J. Mago, and R.S. Theen. A Study to 

Determine Heat Loads Due to Coil Defrosting-Phase 

II. 2003. University of Florida: Gainesville, FL. 

ASHRAE Project No. 1094–RP. Report No. UFME/ 

SEECLSEE–200201 (‘‘1094–RP’’). 

57AHRI 1250–2020 includes an adaptive defrost 

challenge test in appendix E (‘‘Appendix E’’) and 

a hot gas defrost challenge test in appendix F 

(‘‘Appendix F’’) that require a frosted coil. The tests 

in both of these appendices are labelled as 

‘‘informative,’’ and were designed to evaluate 

adaptive defrost or hot gas defrost functionality, 

respectively, rather than to quantify defrost energy 

use. 

could be used for all walk-in equipment. 

(CA IOUs No. 14 at p. 3) More 

specifically, the CA IOUs suggested that 

a test procedure for determining defrost 

energy consumption would vary the 

length and intensity of moisture 

injections to better represent field 

conditions. Id. Similarly, ASAP stressed 

that the ASRAC Working Group 

recommended incorporating a test 

method for measurement of defrost 

energy consumption and encouraged 

DOE to develop a future test method 

that better captures defrost energy use 

and performance for all defrost systems. 

(ASAP No. 13 at p. 2) 

DOE recognizes that it is challenging 

to consistently build frost on an 

evaporator coil to assess a unit’s defrost 

performance. In Section C11 of AHRI 

1250–2009, the moisture to provide a 

frost load is introduced through the 

infiltration of air at a 75.2 °F dry-bulb 

temperature and a 64.4 °F wet-bulb 

temperature into the walk-in freezer at 

a constant airflow rate that depends on 

the refrigeration capacity of the tested 

freezer unit (equations C11 and C12 in 

Section C11.1.1 of AHRI 1250–2009). A 

key issue with this approach is the 

difficulty in ensuring repeatable frost 

development on the unit under test, 

despite specifying the infiltration air 

dry-bulb and wet-bulb temperatures. For 

example, in addition to frost 

accumulating on the evaporator of the 

unit under test, frost may also 

accumulate on the evaporator of other 

cooling equipment used to condition the 

room, which could subsequently affect 

the rate of frost accumulation on the 

unit under test (by affecting the amount 

of moisture remaining in the air). 

In past ASHRAE-supported research, 

researchers created a frost load by 

introducing steam directly into the 

refrigerated space.56 However, as 

discussed in 1094–RP, this approach 

can result in the suspension of ice 

crystals in the saturated room air and 

the formation of snow-like frost on the 

test coils. The researchers found that 

this snow-like frost degrades 

refrigeration system performance more, 

and is more difficult to defrost, than the 

ice-like frost that forms in sub-saturated 

air conditions. Both 622–RP and 1094– 

RP observed that a significant portion of 

the coil frost was converted to water 

vapor rather than melted during the 

defrost cycle. This finding suggests that 

measuring the quantity of frost melt 

water mass may be a poor indicator of 

the frost load, since a significant portion 

of the frost would not be captured as 

melt water.61

DOE is aware that ASHRAE initiated 

project WS 1831 on September 2, 2021. 

The purpose of this research is to 

examine different approaches for 

applying a standardized, repeatable, 

full-frost accumulation (i.e., 

accumulation of a frost quantity that 

would typically accumulate between 

defrosts during system operation in 

moist conditions) on evaporator coils so 

that the subsequent defrost test provides 

a representative indication of energy use 

associated with defrosting a frosted coil. 

Indirect methods for determining full 

frost load might include air side 

temperature, humidity, or pressure 

drop, refrigerant-side evaporation 

temperature or pressure, compressor or 

unit cooler fan power consumption, or 

the refrigerant-to-air or air-side inlet-tooutlet temperature difference. 

Since the defrost test procedure in 

AHRI 1250–2009, section C11 has 

limitations, AHRI 1250–2020 does not 

include a frosted-coil test but does 

include provisions for a dry-coil defrost 

test.57 Industry is currently evaluating 

how to create and validate consistent 

evaporator coil frost loads; therefore, 

DOE proposes to maintain the current 

calculation-based approach for 

estimating defrost energy consumption. 

Specifically, DOE proposes to 

incorporate by reference Section C10 of 

AHRI 1250–2020 for unit coolers with 

either electric or hot gas defrost. 

In the June 2021 RFI, DOE requested 

comment on whether these and other 

updates to AHRI 1250–2020 would, if 

incorporated by DOE, result in 

additional testing burden. 86 FR 32332, 

32336. Lennox, AHRI, Keeprite, and 

Hussmann recommended that DOE omit 

Section C10.2.1.1 of AHRI 1250–2020 

from its test procedure since it does 

little to make the test procedure more 

representative but introduces technical 

challenges associated with air 

conditions during the dry coil defrost 

test. (Lennox No. 9 at p. 3; AHRI No. 11 

at p. 5; Keeprite No. 12 at p. 1–3; 

Hussmann No. 18 at p. 6–7) Section 

C10.2.1.1 of AHRI 1250–2020 specifies 

that the general test condition tolerances 

are not applicable but does require that 

the indoor entering dry-blub 

temperature must be less than or equal 

to 4 °F and that air velocity in the 

vicinity of the test unit must not exceed 

500 feet per minute. At this time, DOE 

does not have sufficient data to fully 

evaluate how these test room condition 

requirements during the dry coil defrost 

test would impact the 

representativeness of the test procedure 

relative to any potential additional test 

burden. DOE has tentatively decided not 

to incorporate Section C10.2.1.1 of 

AHRI 1250-but will instead continue to 

investigate this issue and may decide to 

include dry coil defrost operating 

tolerances in a later rulemaking. While 

DOE will continue to evaluate the dry 

coil defrost test room conditions, DOE 

emphasizes that it is proposing to 

incorporate the entirety of Section C10 

of AHRI 1250–2020, ‘‘Defrost 

Calculation and Test Methods,’’ by 

reference, except for Section C10.2.1.1, 

‘‘Test Room Conditioning Equipment.’’ 

In the following sections, DOE 

discusses relevant stakeholder 

comments and additional proposals for 

adaptive defrost and hot gas defrost. 

a. Adaptive Defrost 

Adaptive defrost refers to a factoryinstalled defrost control system that 

reduces defrost frequency by initiating 

defrosts or adjusting the number of 

defrosts per day in response to operating 

conditions rather than initiating defrost 

strictly based on compressor run time or 

clock time. 10 CFR 431.303. In the 

December 2016 final rule, DOE 

established an approach to address 

systems with adaptive defrost. 81 FR 

95758, 95777. This approach requires 

that adaptive defrost features are 

deactivated during certification testing; 

i.e., for certification, units are tested as 

if they do not have adaptive defrost. See 

subpart R, appendix C, section 3.3.5. 

However, DOE’s current approach also 

allows the energy saving benefits of 

adaptive defrost to be displayed in 

public representations and marketing 

material (but not for certification 

purposes). Id. To represent the benefits 

of adaptive defrost, a calculation 

method is provided that allows the unit 

under test to reduce its number of 

defrosts per day (‘‘NDF’’) to the average 

of its daily dry coil and frosted coil 

defrosts (typically 1 and 4, respectively, 

for an average of 2.5), rather than basing 

NDF on the number of frosted coil 

defrosts per day (typically 4). Id. DOE’s 

current approach applies to all 

refrigeration system configurations (i.e., 

matched pairs, unit coolers tested alone, 

and dedicated condensing units tested 

alone). 


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In the June 2021 TP RFI, DOE 

observed that a test method to evaluate 

the impact of adaptive defrost must 

evaluate (1) whether a system waits too 

long to defrost (i.e., too much frost 

builds up on the coils, which impacts 

on-cycle performance) and (2) if the 

system defrosts more than four times 

per day, which is typical for a 

conventional timed defrost. 86 FR 

32332, 32348. DOE requested comment 

on how the performance of adaptive 

defrost systems should be accounted for 

in the walk-in test procedure and which 

refrigeration systems (i.e., matched 

pairs, unit coolers tested alone, and 

dedicated condensing units tested 

alone) should be eligible for a potential 

adaptive defrost test procedure. Lennox, 

AHRI, Keeprite, National Refrigeration, 

and Hussmann stated that adaptive 

defrost is most prevalent in matched 

pairs and that it would be necessary to 

match unit coolers and dedicated 

condensing units to realize adaptive 

defrost. (Lennox, No. 9 at p. 9; AHRI, 

No. 11 at p. 14; Keeprite, No. 12 at p. 

2; National Refrigeration, No. 17 at p. 2; 

Hussmann, No. 18 at p. 16) The CA 

IOUs encouraged DOE to develop a test 

to measure the performance benefits of 

adaptive defrost. (CA IOUs, No. 14 at p. 

3) While the CA IOUs stated that 

Appendix E of AHRI 1250–2020 

provides a good starting point for a 

defrost test, they suggested that the 

addition of moisture as a static load of 

0.5 pounds per hour per 1,000 Btu per 

hour in Appendix E does not evaluate 

the full capability of most adaptive 

defrost systems and does not 

sufficiently differentiate between 

adaptive control strategies. (CA IOUs, 

No. 14 at p. 3) 

DOE also requested data showing the 

performance of adaptive defrost systems 

relative to non-controlled defrost 

systems, data showing the impact of 

adaptive defrost to on-cycle operation, 

and data demonstrating seasonal or 

daily frosting patterns for walk-in 

applications. 86 FR 32332, 32348. In 

response, the CA IOUs shared test 

results from adaptive defrost control 

systems installed in the field which 

show between 0 and 30 percent energy 

savings compared to baseline systems 

with no adaptive defrost control. (CA 

IOUs, No. 14 at p. 3) Accordingly, the 

CA IOUs encouraged DOE to consider 

varying the length and intensity of 

moisture injections to better represent 

in-field frost load and differentiate 

between control strategies. Id. 

DOE recognizes the need to develop a 

representative and repeatable test 

method for evaluating adaptive defrost 

performance, and notes that appendix E 

may be an appropriate starting point. 

DOE also acknowledges that industry is 

invested in developing an adaptive 

defrost test procedure and that the 

ASHRAE WS 1831 research project 

must be completed in order to 

understand how to best form a 

representative and uniform layer of frost 

on the defrost coil. DOE appreciates the 

information provided by the CA IOUs 

and will consider it in its development 

and/or evaluation of any newly 

developed test procedure for 

quantifying the energy use of adaptive 

defrost. After considering the 

stakeholder comments received, DOE 

proposes to maintain the current 

regulatory approach that reduces the 

number of defrosts per day in the AWEF 

calculation from 4.0 to 2.5, for adaptive 

defrost systems. DOE also proposes to 

maintain its approach where AWEF 

calculated using the adaptive defrost 

credit (i.e., using 2.5 defrosts per day, 

rather than 4.0) may be used for 

representation purposes only, and may 

not be used when calculating AWEF for 

compliance with DOE energy 

conservation standards. DOE also 

proposes to maintain its current 

approach, in which the adaptive defrost 

calculation method is applicable to all 

refrigeration system configurations (i.e., 

matched pairs, unit coolers tested alone, 

and dedicated condensing units tested 

alone). Finally, DOE notes that use of 

the adaptive defrost credit for 

representation purposes only would 

continue to apply only to factoryinstalled defrost control systems. 

Overall, the optional adaptive defrost 

strategy that DOE is proposing for 

representation purposes can be 

summarized as follows: 

• The adaptive defrost calculation 

method (i.e., the adaptive defrost 

‘‘credit’’) may be used only for 

representation purposes, and may not be 

used to calculate AWEF for compliance 

purposes. 

• All refrigeration system 

configurations (i.e., matched pairs, unit 

coolers tested alone, and dedicated 

condensing units tested alone) may use 

the adaptive defrost calculation method 

for representation purposes. 

• Refrigeration systems may use the 

adaptive defrost calculation method for 

representation purposes only if the 

adaptive defrost controller is distributed 

in commerce with the refrigeration 

system. 

b. Hot Gas Defrost 

As discussed previously, the March 

2021 final rule amended the test 

procedure to rate hot gas defrost unit 

coolers using modified default values 

for energy use and heat load 

contributions that would make their 

ratings more consistent with those of 

electric defrost unit coolers but is 

limited to unit coolers only. 86 FR 

16027, 16030. 

In the June 2021 TP RFI, DOE 

discussed that it was interested in 

obtaining feedback on the most 

practicable method for measuring hot 

gas defrost performance. 86 FR 32332, 

32347. DOE recognized that in order to 

assess the energy performance of a 

defrost cycle, the test procedure must 

measure both the energy consumed and 

the heat released into the refrigerated 

space by the defrost system. Id. DOE 

further discussed that for hot gas defrost 

systems, unlike electric resistance 

heating systems, the energy consumed 

and the heat released are not equivalent, 

which makes the current electric defrost 

test procedure outlined in AHRI 1250– 

2009 inappropriate for hot gas defrost 

systems. Id. 

DOE stated that it is not aware of a 

test method that can reliably be used to 

directly measure the thermal impact of 

hot gas defrost without a substantial 

increase in test burden and mentioned 

that it was therefore considering the use 

of a calculation method. Id. Rather than 

measure the energy used and heat 

released into the refrigerated space for 

the unit-under-test, the energy use and 

heat load could be calculated as a 

function of the refrigeration system’s 

steady state capacity. Id. DOE further 

discussed that the energy use and heat 

load to capacity relationships could be 

defined based on test data from actual 

hot gas defrost systems. Id. DOE 

recognized that AHRI has developed a 

calculation method to represent hot gas 

defrost heat load and energy use 

contributions. Id. This method is 

provided in Section C10.1 of AHRI 

1250–2020 and prescribes equations to 

represent energy use and heat addition 

associated with defrost for different 

system configurations (matched pair, 

single-packaged dedicated, unit cooler, 

condensing unit) and considers whether 

hot gas is used only to defrost the 

evaporator or whether it also maintains 

warm temperatures in the drip pan. 

Finally, DOE discussed that if it were 

to amend its walk-in refrigeration 

systems test procedure to account for 

hot gas defrost energy consumption and 

heat load, DOE would need to decide if 

all refrigeration system configurations 

(i.e., matched pairs, unit coolers tested 

alone, and dedicated condensing units 

tested alone) would be subject to a hot 

gas defrost-specific test procedure. Id. 

In their comments, AHRI, Lennox, 

Keeprite, Hussmann, and National 

Refrigeration each recommended that 

DOE utilize the AHRI 1250–2020 hot gas 

defrost calculations for all equipment 


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58As noted in the June 2021 RFI, on July 20, 

2015, the U.S. Environmental Protection Agency 

(‘‘EPA’’) published a final rule under the Significant 

New Alternatives Policy (‘‘SNAP’’) program listing 

the use of certain hydrofluorocarbons (‘‘HFCs’’) as 

unacceptable, including the use of R–404A in WICF 

refrigeration systems. 80 FR 42870 (‘‘July 2015 EPA 

SNAP Rule’’). On December 1, 2016, EPA published 

a final rule (‘‘December 2016 EPA SNAP Rule’’) 

which listed a number of refrigerants, included R– 

407A, for use in certain refrigerant applications as 

unacceptable starting January 1, 2023 for cold 

storage warehouse application, and January 1, 2021, 

for retail food refrigerant applications. 81 FR 86778. 

In August 2017, the U.S. Court of Appeals for the 

District of Columbia Circuit vacated and remanded 

the July 2015 EPA SNAP Rule to the extent that it 

required manufacturers to replace HFCs with a 

substitute substance. (Mexichem Fluor, Inc. v. EPA, 

Case No. 15–1328 (D.C. Cir. August 8, 2017)) A 

petition for rehearing has been filed by a number 

of parties. (D.C. Cir., Consolidated Case Nos. 15– 

1328, 15–1329). That petition for rehearing was 

denied on January 26, 2018. 

Additionally, in October 2016, the 28th Meeting 

of the Parties to the Montreal Protocol adopted the 

Kigali Amendment on HFCs. The Kigali 

Amendment enters into force on January 1, 2019, 

and it requires parties to the protocol to reduce 

consumption and production of HFCs. DOE 

understands that, while the United States has not 

yet ratified the Kigali Amendment, a significant 

portion of WICFs currently use HFC-based 

refrigerants and may become affected by this 

Amendment to the Montreal Protocol. 

DOE plans to consider the potential impact of the 

court’s decision and the Amendment to the 

Montreal Protocol in this rulemaking as 

appropriate. 

types, since matched pairs, unit coolers, 

and dedicated condensing units may be 

associated with hot gas defrost. (AHRI, 

No. 11 at pp. 13–14; Lennox, No. 9 at 

pp. 8–9; Keeprite, No. 12 at p. 2; 

Hussmann, No. 18 at pp. 15–16; 

National Refrigeration, No. 17 at p. 2) 

ASAP also supported the adoption of 

the hot gas defrost calculations in AHRI 

1250–2020 but did not specify for which 

equipment systems. (ASAP, No. 13 at p. 

2) NEEA observed that AHRI 1250–2020 

provides both a calculation approach 

and a test method to account for hot gas 

defrost energy and recommended that 

DOE proceed with the hot gas defrost 

calculations in AHRI 1250–2020 in 

addition to including the hot gas defrost 

challenge test in Appendix F of AHRI 

1250–2020. (NEEA, No. 16 at p. 3) In 

spite of its inability to capture frost load 

conditions, the CA IOUs nevertheless 

supported the use of AHRI 1250–2020 

Appendix F since it captures hot gas 

defrost energy use. (CA IOUs, No. 14 at 

p. 2) Both NEEA and the CA IOUs 

observed that additional work is needed 

to develop a robust test method to 

evaluate how hot gas defrost impacts 

equipment energy consumption and 

NEEA recommended that DOE continue 

to work with industry groups to develop 

such a procedure. (NEEA, No. 16 at p. 

3; CA IOUs, No. 14 at p. 2) 

After reviewing the comments 

submitted by AHRI, Lennox, Keeprite, 

Hussmann and National Refrigeration, 

DOE has tentatively determined that all 

refrigeration system configurations (i.e., 

matched pairs, unit coolers tested alone, 

and dedicated condensing units tested 

alone) can benefit from hot gas defrost. 

For this reason, DOE proposes that all 

system configurations (when equipped 

with hot gas defrost) should be eligible 

for a hot gas defrost ‘‘credit,’’ which will 

be discussed in more detail in the 

following paragraphs. 

As discussed previously, there is 

currently no industry-accepted test 

method that can measure the heat load 

addition coming from hot gas defrost 

operation. In the absence of such a 

method, DOE is not able to propose a 

hot gas defrost testing-based method at 

this time. However, if the walk-in 

industry develops such a method in the 

future, DOE may evaluate that method’s 

appropriateness in a future rulemaking. 

While all stakeholders support a 

calculation-based approach using the 

hot gas defrost equations in AHRI 1250– 

2020, DOE’s goal in the December 2016 

final rule was to provide calculations for 

rating hot gas defrost unit coolers using 

modified default values for energy use 

and heat load contributions that would 

make their ratings more consistent with 

those of electric defrost unit coolers. 81 

FR 95758, 95776. The March 2021 final 

rule sought to maintain this consistency 

between units configured with hot gas 

defrost or electric defrost and ultimately 

included the equations in Section C10.2 

of AHRI 1250–2020 for representing the 

defrost energy use and thermal load 

associated with hot gas defrost systems. 

86 FR 16027, 16032. DOE proposes to 

maintain this calculation equivalence 

between hot gas defrost and electric 

defrost systems. Specifically, for rating 

and certification, all walk-in 

refrigeration systems would utilize the 

default values for energy use and heat 

load for dedicated condensing units 

tested alone with electric defrost 

systems. AHRI 1250–2020, Section 

10.2.2. 

However, like the approach discussed 

previously for adaptive defrost systems, 

DOE is proposing that manufacturers 

may account for a unit’s potential 

improved performance with hot gas 

defrost in its market representations. In 

other words, DOE proposes that 

manufacturers may apply a hot gas 

defrost ‘‘credit’’ in their market 

representations but must certify hot gas 

defrost units using the default electric 

defrost equations. As mentioned 

previously, AHRI has developed 

specific equations for determining the 

defrost energy and heat load associated 

with hot gas defrost. AHRI 1250–2020, 

Section C10.1. DOE proposes that the 

hot gas defrost ‘‘credit’’ may be used in 

marketing materials for all refrigeration 

system configurations sold with hot gas 

defrost (i.e., matched pairs, unit coolers 

tested alone, and dedicated condensing 

units tested alone). 

9. Refrigerant Glide 

In the June 2021 RFI, DOE discussed 

that it was considering changing its test 

procedure to a more refrigerant-neutral 

approach—specifically, DOE discussed 

that it was considering approaches that 

would more accurately represent the 

performance of zero-, low-, and highglide refrigerants. 86 FR 32332, 32351. 

Refrigerant glide refers to the increase in 

temperature at a fixed pressure as liquid 

refrigerant vaporizes during its 

conversion from saturated liquid (at its 

bubble point) to saturated vapor (at its 

dew point). R–404A—a common walkin refrigerant—has very little glide, 

while R–407A—another common walkin refrigerant—can exhibit glide of up to 

8 °F.58

The current DOE test procedure 

specifies unit cooler test conditions 

based on the dew point at the 

evaporator exit. For zero-glide 

refrigerants, the average evaporator 

temperature will typically be equivalent 

to the specified dew point. However, for 

high-glide refrigerants, the average 

evaporator temperature will be 

significantly lower than the dew point 

since the refrigerant temperature will 

increase (up to the dew point) as it 

travels through the evaporator. As a 

result, two identical unit coolers, one 

charged with R–404A and one with R– 

407A, will be tested at different 

evaporator-to-air temperature 

differences (‘‘TD’’), but with the same 

evaporator airflow. Measured capacity is 

directly correlated with the product of 

TD and airflow; therefore, the high-glide 

R–407A unit cooler would achieve a 

higher rated capacity than the R–404A 

unit cooler. However, this capacity 

difference is an artifact of the test 

procedure, which requires that unit 

coolers and dedicated condensing units 

be tested alone. In the field, a unit 

cooler will be paired with a dedicated 

condensing unit and R–407A unit 

coolers will not actually provide 

additional capacity when compared to 

their R–404A counterparts. 

For these reasons, the current test 

procedure is not refrigerant-neutral. In 

the June 2021 RFI, DOE discussed the 

possibility of pursuing a modified 

midpoint approach, which DOE 

believed may be more refrigerantneutral. 86 FR 32332, 32355. The 

modified midpoint approach attempts to 

standardize the average evaporator 


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59For example, for coolers, Tables 12 and 13 of 

AHRI 1250–2020 require that CDU suction dew 

point be 23 °F, while section C7.5.2 indicates that 

the enthalpy to use in the calculation of capacity 

shall be for a pressure corresponding to dew point 

2 °F higher than for the recorded pressure at the 

inlet of the dedicated condensing unit. 

temperature, rather than standardizing 

the evaporator dew point. In doing so, 

identical unit coolers using zero- and 

high-glide refrigerants would exhibit 

identical TDs, thus alleviating concerns 

of overstated capacity. DOE requested 

comment on the appropriateness of a 

modified midpoint approach and how 

such a method could be implemented in 

the June 2021 RFI. 86 FR 32332, 32355. 

Lennox, AHRI, Keeprite, National 

Refrigeration, and Hussmann 

recommended maintaining the current 

dew point approach since dewpoint is 

measurable and the approach is 

accepted in the industry. (Lennox, No. 

9 at p. 11; AHRI, No. 11 at p. 16; 

Keeprite, No. 12 at p. 3; National 

Refrigeration, No. 17 at p. 2; Hussmann, 

No. 18 at p. 20) Lennox, AHRI, and 

Hussmann also stated that dew point is 

a required reference for dual 

instrumentation evaporator superheat 

calculations and can be measured 

during installation and service. (Lennox, 

No. 9 at p. 11; AHRI, No. 11 at p. 16; 

Hussmann, No. 18 at p. 20) Keeprite 

claimed that a midpoint or corrected 

midpoint approach is unproven and is 

not measurable. (Keeprite, No. 12 at p. 

3) Keeprite additionally added that a 

change from dewpoint to midpoint may 

have large effects on unit cooler AWEF 

values. Id. Daikin stated that engineers 

use the mean value between dew point 

and bubble point when designing 

refrigeration systems since this 

approach simplifies energy calculations. 

(Daikin, No. 17 at p. 4) 

DOE acknowledges the potential 

increased testing burden highlighted by 

manufacturers if a modified midpoint 

were to be adopted. In response to these 

comments DOE proposes to continue to 

use dewpoint throughout the test 

procedure but will continue to evaluate 

the potential for using a midpoint in 

testing. 

10. Refrigerant Temperature and 

Pressure Instrumentation Locations 

In the June 2021 RFI, DOE requested 

comment on changes between AHRI 

1250–2020 and AHRI 1250–2009 which 

may impact the determination of AWEF 

or increase the testing burden. 86 FR 

32332, 32336. In response to this 

request AHRI, Lennox, and Hussmann 

stated that the test set-up for DX Dual 

instrumentation method for testing 

dedicated condensing units alone has 

changed, represented by Figure C1 in 

AHRI 1250–2009, and the new Figure 

C2 in AHRI 1250–2020. The 

commenters stated that this changes the 

location of the instrumentation for 

pressure and temperature measurement. 

Additionally, they stated that the new 

method removes the alternative location 

of the second mass flow meter and 

claim that both sets of changes 

necessitate changes in lab test stands. 

Further, the commenters claimed that 

AHRI 1250–2020 added a change to the 

refrigeration capacity calculation for 

dedicated condensing units, whereby 

the enthalpy representing the refrigerant 

at the evaporator exit condition has 

changed such that it is based on a 

pressure corresponding to a dew point 

2 °F higher than at the condensing unit 

inlet and a superheat of 6.5 °F. (Lennox, 

No. 9 at p. 3; AHRI, No. 11 at p. 5; 

Hussmann, No. 18 at p. 7) The same 

group of commentors stated these 

locations are now different than those 

specified for matched pair testing, and 

the DX Calibrated Box method. Id. 

DOE notes first that AHRI 1250–2009 

does not provide a test method for 

dedicated condensing units tested 

alone, other than incorporating by 

reference ASHRAE 23–2005 (see Section 

C12 of AHRI 1250–2009 appendix C). 

ASHRAE 23 calls for calculating 

capacity by multiplying the refrigerant 

mass flow rate by the difference in 

enthalpies. However, the current DOE 

test procedure clarifies which values of 

pressure and temperature are used to 

determine the enthalpies to use for this 

capacity calculation—this is specified in 

section 3.4.2.1 of subpart R, appendix C. 

The section indicates that, for enthalpy 

leaving the unit cooler, the calculation 

uses a pressure corresponding to a dew 

point temperature of 25 °F and a 

temperature of 35 °F for coolers, and a 

dew point of –20 °F and temperature of 

–14 °F for freezers. These dew points are 

identical to the dew points specified in 

AHRI 1250–2020.59 The temperatures 

represent superheat levels equal to 10 °F 

for coolers and 6 °F for freezers, which 

are different than the 6.5 °F specified in 

Section C7.5.2 of AHRI 1250–2020. 

Section 3.4.2.1 of subpart R, appendix 

C, also indicates that in the current DOE 

test procedure, the measured enthalpy 

at the condensing unit exit shall be used 

as the enthalpy entering the unit cooler. 

This is consistent with Figure C2 and 

Section C7.5.1.1.2 of AHRI 1250–2020. 

Thus, the only difference in AHRI 1250– 

2020 affecting the dedicated condensing 

unit efficiency calculations is the 

change in specified superheat, and there 

is no effective difference in the location 

of required pressure and temperature 

measurements. DOE will address the 

calculation change and other test 

procedure changes that can alter the 

measurement in an energy conservation 

standards rulemaking. 

The comments of AHRI, Lennox, and 

Hussmann also address the test burden 

of not allowing the use of the alternative 

second location of the mass flow meter. 

(AHRI, No. 11 at pp. 5–6; Lennox, No. 

9 at p. 3; Hussmann, No. 18 at p. 7 The 

comments provided no indication that 

use of a mass flow meter in the suction 

line should not be allowed. Hence, DOE 

proposes to clarify that the location of 

the second mass flow meter in the 

suction line would still be allowed. This 

proposal would eliminate the potential 

costs associated with Figure C2’s 

suggestion that use of a suction line 

mass flow meter is not allowed. 

Issue 29: DOE requests comment on 

its proposal to clarify that the second 

mass flow measurement for the DX Dual 

Instrumentation method may be in the 

suction line upstream of the inlet to the 

condensing unit, as shown in Figure C1 

of AHRI 1250–2009. 

11. Updates to Default Values for Unit 

Cooler Parameters 

For dedicated condensing units tested 

alone, the current DOE test procedure 

calculates on-cycle evaporator fan 

power based on the cooling capacity of 

the condensing unit. This is necessary 

as a dedicated condensing unit tested 

alone will have no measured value for 

evaporator fan power. The on-cycle 

evaporator fan power is set equal to a 

fraction of the gross cooling capacity. 

The fraction is specified by a coefficient 

of .013 for medium temperature coolers 

and a coefficient of .016 for low 

temperature coolers. These coefficients 

were a product of the 2016 rulemaking 

negotiations. As discussed in section 

III.B.3.c, Sections 7.9.1 and 7.9.2 of 

AHRI 1250–2020 add new equations to 

calculate on-cycle evaporator fan power 

when testing a dedicated condensing 

unit alone. These equations are different 

from those in the current test procedure 

at subpart R, appendix C. The equations 

in AHRI 1250–2020 are split based on 

low versus medium temperature 

dedicated condensing units, and the 

capacity of the dedicated condensing 

units. Those units over 50,000 Btu/h 

have one equation and those under 

50,000 Btu/h that capacity have another, 

resulting in 4 equations total. These 

equations are based on more test data 

and analysis than those currently in 

subpart R, appendix C. DOE has 

tentatively determined that these 

equations would be more representative, 

and do not pose a greater test burden. 

Therefore, DOE proposes to adopt the 

calculations for on-cycle evaporator fan 


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23972 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

60A version of Table III.9 can be found in AHRI 

Standard 390 I–P (2021) ‘‘Performance Rating of 

Single-packaged Vertical Air-Conditioners and Heat 

Pumps.’’ 

power for dedicated condensing units 

tested alone in AHRI 1250–2020. 

Issue 30: DOE requests comment on 

its proposal to adopt the calculations for 

evaporator fan power in AHRI 1250– 

2020. 

12. Calculations and Rounding 

To ensure greater test procedure 

consistency, DOE is proposing to 

include rounding requirements for 

AWEF and capacity in the newly 

proposed appendix C1. DOE notes that 

AHRI 1250–2020 does not include 

requirements for rounding these values. 

DOE recognizes that the manner in 

which values are rounded can affect the 

resulting capacity and AWEF values. To 

ensure consistency in the manner in 

which capacity and AWEF values are 

calculated, DOE is proposing that raw 

measured data would be used in all 

capacity and AWEF calculations. DOE’s 

current standards specify a minimum 

AWEF value in Btu/(W–h) to the 

hundredths place; therefore, DOE is 

proposing that AWEF values would be 

rounded to the nearest 0.05 Btu/(W–h). 

To round capacity, DOE is proposing to 

round to the nearest multiple as 

specified in Table III.14. The proposed 

capacity bins and multiples are 

consistent with other HVAC test 

procedures.60

TABLE III.14—REFRIGERATION CAPACITY RATING RANGES AND THEIR

ROUNDING MULTIPLES

Refrigeration capacity 

ratings, 1,000 Btu/h 

Multiples, 

Btu/h 

<20 ........................................ 100 

≥20 and <38 ......................... 200 

≥38 and <65 ......................... 500 

≥65 ........................................ 1,000 

Issue 31: DOE requests comment on 

its proposal for rounding AWEF to the 

nearest 0.05 Btu/(W-h) and rounding 

capacity values to the nearest multiple 

as presented in Table III.14. 

H. Alternative Efficiency Determination 

Methods 

Pursuant to the requirements of 10 

CFR 429.70, DOE may permit use of an 

alternative efficiency determination 

method (‘‘AEDM’’) in lieu of testing 

equipment for which testing burden 

may be considerable and for which that 

equipment’s energy efficiency 

performance may be well predicted by 

such alternative methods. Although 

specific requirements vary by product or 

equipment, use of an AEDM entails 

development of a mathematical model 

that estimates energy efficiency or 

energy consumption characteristics of 

the basic model, as would be measured 

by the applicable DOE test procedure. 

The AEDM must be based on 

engineering or statistical analysis, 

computer simulation or modeling, or 

other analytic evaluation of performance 

data. A manufacturer must perform 

validation of an AEDM by 

demonstrating that the performance, as 

predicted by the AEDM, is in agreement 

with the performance as measured by 

actual testing in accordance with the 

applicable DOE test procedure. The 

validation procedure and requirements, 

including the statistical tolerance, 

number of basic models, and number of 

units tested vary by product or 

equipment. 

Once developed, an AEDM may be 

used to rate and certify the performance 

of untested basic models in lieu of 

physical testing. However, use of an 

AEDM for any basic model is always at 

the option of the manufacturer. One 

potential advantage of AEDM use is that 

it may free a manufacturer from the 

burden of physical testing. One 

potential risk is that the AEDM may not 

perfectly predict performance, and the 

manufacturer could be found 

responsible for having an invalid rating 

for the equipment in question or for 

having distributed a noncompliant basic 

model. The manufacturer, by using an 

AEDM, bears the responsibility and risk 

of the validity of the ratings. For walkins, DOE currently permits the use of 

AEDMs for refrigeration systems only. 

10 CFR 429.70(f). 

The following sections discuss DOE’s 

proposal to allow walk-in door 

manufacturers to use AEDMs to rate 

both display and non-display doors, as 

well as proposed updates to the current 

AEDM provisions for refrigeration 

systems. 

1. Doors 

DOE did not adopt provisions 

allowing for the use of AEDMs for walkin doors in the May 2014 rule because 

DOE found that the modeling 

techniques approved for use in the 

NFRC 100 test procedure (incorporated 

by reference at 10 CFR 431.303) made a 

parallel AEDM provision for walk-in 

doors unnecessary. 79 FR 27388, 27394. 

Consistent with DOE’s proposal to 

remove reference to NFRC 100 (and thus 

the computational method) for 

determining U-factor of doors, DOE is 

proposing to allow the use of AEDMs to 

determine the represented value of 

energy consumption of walk-in doors at 

10 CFR 429.53(a)(3). Correspondingly, 

DOE is proposing to expand the AEDM 

provisions in 10 CFR 429.70(f) to apply 

to walk-in doors. DOE is proposing to 

include a 5 percent individual model 

tolerance, which aligns with the 

individual model tolerance applicable 

to walk-in refrigeration systems, to 

validate the energy consumption result 

of an AEDM with the appendix A test 

result at 10 CFR 429.70(f)(2)(ii). DOE 

also proposes that an AEDM for doors 

may not simulate or model components 

of the door that are not required to be 

tested by the DOE test procedure. If the 

test results used to validate the AEDM 

are for the U-factor test of the door, the 

AEDM must estimate the daily energy 

consumption—specifically, the 

conduction thermal load, and the direct 

and indirect electrical energy 

consumption, by using the nominal 

values (e.g., EER values used for coolers 

and freezers, PTO values) and 

calculation procedure specified in the 

DOE test procedure. Additionally, DOE 

is proposing to include walk-in door 

validation classes at 10 CFR 

429.70(f)(2)(iv) and to require that two 

basic models per validation class be 

tested using the proposed test procedure 

in appendix A, which is consistent with 

the number of basic models required to 

be tested per validation class for walkin refrigeration systems. Lastly, DOE is 

proposing to include a 5 percent 

tolerance applicable to the maximum 

daily energy consumption metric for 

AEDM verification testing at 10 CFR 

429.70(f)(5)(vi), which aligns with the 

tolerance applicable to AWEF of walkin refrigeration systems. 

Issue 32: DOE seeks comment on its 

proposal to allow for the use of AEDMs 

to determine the energy consumption 

rating of walk-in doors. DOE requests 

specific feedback on the proposed 5 

percent model tolerance for validating 

an AEDM, the proposed validation 

classes and number of basic models 

required to be tested per validation 

class, and the proposed 5 percent 

tolerance on the result from a DOE 

AEDM verification test. 

2. Refrigeration Systems 

In the May 2014 final rule, DOE 

established that AEDMs can be used by 

manufacturers of refrigeration systems, 

once certain qualifications are met, to 

certify compliance and report ratings. 79 

FR 27388, 27389. That rule established 

a uniform, systematic, and fair approach 

to the use of these types of modeling 

techniques that has enabled DOE to 

ensure that products in the marketplace 

are correctly rated—irrespective of 

whether they are subject to actual 

physical testing or are rated using 


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modeling—without unnecessarily 

burdening regulated entities. Id. 

A minimum of two distinct models 

must be tested to validate an AEDM for 

each validation class. The May 2014 

final rule established the following 

AEDM validation classes for walk-ins: 

• Dedicated condensing units, 

medium temperature, indoor system; 

• Dedicated condensing units, 

medium temperature, outdoor system; 

• Dedicated condensing units, low 

temperature, indoor system; 

• Dedicated condensing units, low 

temperature, outdoor system; 

• Unit cooler connected to a muliplex 

condensing unit, medium temperature; 

• Unit cooler connected to a 

multiplex condensing unit, low 

temperature; 

• Medium temperature, indoor 

condensing unit; 

• Medium temperature, outdoor 

condensing unit; 

• Low temperature, indoor 

condensing unit; 

• Low temperature, outdoor 

condensing unit. 

See 79 FR 27388, 27411 (codified at 

10 CFR 429.70(f)(5)(iv)). 

In this NOPR, DOE is proposing new 

test procedures for single-packaged 

refrigeration systems, high-temperature 

refrigeration systems, and CO2 unit 

coolers. Temperature has a significant 

impact on equipment performance; 

therefore, DOE is proposing to 

incorporate new AEDM validation 

classes for all high-temperature 

refrigeration systems (dedicated 

condensing units, single-packaged 

dedicated systems, and matched pair 

systems). Additionally, single-packaged 

units are expected to perform differently 

than dedicated condensing units under 

the proposed test procedure which 

incorporates thermal losses. Therefore, 

DOE proposes to create new validation 

classes for low-temperature, mediumtemperature, and high-temperature 

single-packaged dedicated systems. To 

ensure that walk-in validation classes 

are consistent with DOE’s current walkin terminology, DOE proposes to rename 

the ‘‘unit cooler connected to a 

multiplex condensing unit’’ validation 

classes to ‘‘unit cooler’’ at either 

medium- or low-temperature; however, 

the AEDM requirements for theses 

classes remain the same. Finally, DOE 

proposes to remove the medium/low 

temperature indoor/outdoor condensing 

unit validation classes, as these are 

redundant with the medium/low 

temperature indoor/outdoor dedicated 

condensing unit validation classes. 

As discussed, DOE proposes to 

reference in appendix C1 the methods of 

test for single-packaged dedicated 

systems in Section C9 of AHRI 1250– 

2020, with some modifications. 

Implementation of appendix C1, if 

finalized, would require that all AEDMs 

for single-packaged dedicated systems 

are amended to be consistent with the 

test procedure proposed in appendix 

C1. 

In summary, DOE is proposing the 

following AEDM validation classes for 

walk-in refrigeration equipment: 

• Dedicated Condensing Unit, 

Medium Temperature, Indoor System 

• Dedicated Condensing Unit, 

Medium Temperature, Outdoor System 

• Dedicated Condensing Unit, Low 

Temperature, Indoor System 

• Dedicated Condensing Unit, Low 

Temperature, Outdoor System 

• Single-packaged Dedicated System, 

High-temperature, Indoor System 

• Single-packaged Dedicated System, 

High-temperature, Outdoor System 

• Single-packaged Dedicated System, 

Medium Temperature, Indoor System 

• Single-packaged Dedicated System, 

Medium Temperature, Outdoor System 

• Single-packaged Dedicated System, 

Low Temperature, Indoor System 

• Single-packaged Dedicated System, 

Low Temperature, Outdoor System 

• Matched Pair, High-temperature, 

Indoor Condensing Unit 

• Matched Pair, High-temperature, 

Outdoor Condensing Unit 

• Matched Pair, Medium 

Temperature, Indoor Condensing Unit 

• Matched Pair, Medium 

Temperature, Outdoor Condensing Unit 

• Matched Pair, Low Temperature, 

Indoor Condensing Unit 

• Matched Pair, Low Temperature, 

Outdoor Condensing Unit 

• Unit Cooler, High-temperature 

• Unit Cooler, Medium Temperature 

• Unit Cooler, Low Temperature 

DOE would maintain its provision 

that outdoor models that are within a 

given validation class may be used to 

determine represented values for the 

corresponding indoor class, and 

additional validation testing is not 

required. For example, two dedicated 

condensing unit, medium temperature, 

outdoor systems may be used to validate 

an AEDM for both the ‘‘Dedicated 

Condensing Unit, Medium Temperature, 

Outdoor System’’ class and the 

‘‘Dedicated Condensing Units, Medium 

Temperature, Indoor System’’ class. If 

indoor models that fall within a given 

validation class are tested and used to 

validate an indoor AEDM, they may 

only be used for that validation class. 

DOE is proposing no additional 

modifications to the provisions within 

10 CFR 429.70(f). 

Issue 33: DOE seeks comment on its 

proposal to modify and extend its 

AEDM validation classes for 

refrigeration systems, consistent with 

the test procedure revisions discussed 

in this document. 

I. Sampling Plan for Enforcement 

Testing 

When DOE conducts enforcement 

testing of equipment, DOE uses one of 

the enforcement sampling plans in 

appendix A or B to subpart C of 10 CFR 

part 429 to calculate upper control 

limits and lower control limits around 

the standard value based on the 

standard deviation of the test sample. 

These statistics are applied to the test 

results in the sample to determine 

compliance or non-compliance. DOE 

uses appendix B to subpart C of 10 CFR 

part 429 to assess compliance for walkin refrigeration systems, which is 

specifically intended for use for covered 

equipment and certain low-volume 

covered products. 10 CFR 429.110(e)(2). 

DOE does not specifically call out 

which appendix in subpart C of 10 CFR 

part 429 it uses for determination of 

compliance for walk-in doors or walk-in 

panels. In an Enforcement NOPR 

published on August 31, 2020 (‘‘August 

2020 Enforcement NOPR’’), DOE 

proposed to add walk-in cooler and 

freezer doors and panels to the list of 

equipment subject to the low-volume 

enforcement sampling procedures in 

appendix B to subpart C of 10 CFR part 

429. 85 FR 53691, 53696. DOE noted 

that this equipment is not currently 

included within DOE’s list because 

when the current regulations were 

drafted, walk-in doors and walk-in 

panels did not have applicable 

performance standards, only design 

standards, and therefore sampling 

provisions were not necessary at the 

time. Id. DOE did not receive any 

comments in response to this proposal 

in the August 2020 Enforcement NOPR. 

DOE is therefore proposing in this 

document to include walk-in doors and 

walk-in panels in the list of low-volume 

products 10 CFR 429.110(e)(2). 

Issue 34: DOE requests comment on 

its proposal to apply the low-volume 

sampling procedures in appendix B of 

subpart C of 10 CFR part 429 to walkin doors and panels. 

J. Test Procedure Costs and Impact 

EPCA requires that test procedures 

proposed by DOE be reasonably 

designed to produce test results which 

reflect energy efficiency and energy use 

of a type of industrial equipment during 

a representative average use cycle and 

not be unduly burdensome to conduct. 

(42 U.S.C. 6314(a)(2)) The following 

sections discuss DOE’s evaluation of the 

estimated costs and savings associated 


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61As already noted elsewhere in this document, 

an AEDM is a computer modeling or mathematical 

tool that predicts the performance of non-tested 

basic models. These computer modeling and 

mathematical tools, when properly developed, can 

provide a means to predict the energy usage or 

efficiency characteristics of a basic model of a given 

covered product or equipment and reduce the 

burden and cost associated with testing. 

62 DOE estimates the cost of one test to determine 

energy consumption of a walk-in door, including 

one physical U-factor test per NFRC 102–2020 to be 

$5,000. Per the sampling requirements specified at 

10 CFR 429.53(a)(3)(ii) and 10 CFR 429.11(b), 

manufacturers are required to test at least two units 

to determine the rating for a basic model, except 

where only one unit of the basic model is produced. 

63Section 4.7.1 of NFRC 100 requires that the 

accepted difference between the tested U-factor and 

the simulated U-factor be (a) 0.03 Btu/(h-ft2 °F) for 

simulated U-factors that are 0.3 Btu/(h-ft2-°F) or 

less, or (b) 10 percent of the simulated U-factor for 

simulated U-factors greater than 0.3 Btu/(h-ft2-°F). 

This agreement must match for the baseline product 

in a product line. Per NFRC 100, the baseline 

product is the individual product selected for 

validation; it is not synonymous with ‘‘basic 

model’’ as defined in 10 CFR 431.302. 

64 DOE estimated initial costs to validate an 

AEDM assuming 24 hours of general time to 

develop and validate an AEDM based on existing 

simulation tools. DOE estimated the cost of an 

engineering calibration technician fully burdened 

wage of $46 per hour plus the cost of third-party 

physical testing of two basic models per proposed 

validation class. DOE estimated the additional per 

basic model cost to determine efficiency using an 

AEDM assuming 1 hour per basic model at the cost 

of an engineering calibration technician wage of $46 

per hour. 65See guidance issued by DOE at: 

www1.eere.energy.gov/buildings/appliance_

standards/pdfs/cert_faq_2012-04-17.pdf. 

with the amendments proposed in this 

NOPR. The following sections outline 

the potential costs and savings 

differentiated by WICF component: 

Doors, panels, and refrigeration systems. 

1. Doors 

In this NOPR, DOE proposes the 

following amendments to the test 

procedures for walk-in cooler and 

freezer doors: 

1. Referencing NFRC 102–2020 for the 

determination of U-factor; 

2. Including AEDM 61 provisions for 

manufacturers to alternately determine the 

total energy consumption of display and nondisplay doors; 

3. Providing additional detail for 

determining the area used to convert U-factor 

into conduction load, As, to differentiate it 

from the area used to determine compliance 

with the standards, Add or And; and 

4. Specifying a PTO value of 97 percent for 

door motors. 

Items 1 and 3, referencing NFRC 102– 

2020 and additional detail on the area 

used to convert U-factor into a 

conduction load, improves the 

consistency, reproducibility, and 

representativeness of test procedure 

results. Item 2, including AEDM 

provisions, intends to provide 

manufacturers with the flexibility to use 

an alternative method that gives the best 

agreement for their doors. Item 4, by 

proposing to include a PTO value of 97 

percent, intends to provide a more 

representative and consistent means for 

comparison of walk-in door 

performance for doors with motors. 

DOE has tentatively determined that 

these proposed amendments would 

improve the representativeness, 

accuracy, and reproducibility of the test 

results, and would not be unduly 

burdensome for door manufacturers to 

conduct. DOE has also tentatively 

determined that these proposed 

amendments would not increase testing 

costs per basic model relative to the 

current DOE test procedure in appendix 

A, which DOE estimates to be $10,000 

for third-party labs to determine energy 

consumption of a walk-in door, 

including physical U-factor testing per 

NFRC 102–2020.62 DOE has tentatively 

determined that manufacturers would 

not be required to redesign any of the 

covered equipment or change how the 

equipment is manufactured, solely as 

result of the proposed amendments, if 

finalized. 

The cost impact to manufacturers as 

a result of the reference to NFRC 102– 

2020 and inclusion of AEDM provisions 

is dependent on the agreement between 

tested and simulated values as specified 

in Section 4.7.1 of NFRC 100 63 as 

referenced in the current test procedure. 

For manufacturers of doors that have 

been able to achieve the specified 

agreement between U-factors simulated 

using the method in NFRC 100 and Ufactors tested using NFRC 102, 

manufacturers would be able to 

continue using the simulation method 

in NFRC 100, provided that the 

simulation method also meets the basic 

requirements proposed for an AEDM in 

10 CFR 429.53 and 10 CFR 429.70(f). 

For manufacturers of doors that have 

not been able to achieve the specified 

agreement between U-factors simulated 

using the method in NFRC 100 and Ufactors tested using NFRC 102, DOE 

estimates that the test burden would 

decrease. Under the current 

requirements, manufacturers may be 

required to determine U-factor through 

physical testing of every basic model. If 

the proposed test procedure were to be 

adopted, manufacturers who would 

have otherwise been required to 

physically test every walk-in door basic 

model could develop an AEDM for 

rating their basic models of walk-in 

doors consistent with the proposed 

provisions in 10 CFR 429.53 and 10 CFR 

429.70(f). DOE estimates the permanufacturer cost to develop and 

validate an AEDM for a single validation 

class of walk-in doors to be $11,100. 

DOE estimates an additional cost to 

determine energy consumption of a 

walk-in door using an AEDM to be $46 

per basic model.64

DOE expects that the additional detail 

provided for determining the area used 

to convert U-factor into conduction 

load, As, would either result in a 

reduced energy consumption or have no 

impact. To the extent that this change to 

the test procedure would amend the 

energy consumption attributable to a 

door, such changes would either not 

change the calculated energy 

consumption or result in a lower energy 

consumption value as compared to how 

manufacturers may currently be rating 

given that the current test procedure 

does not provide specific details on 

measurement of Add or And. As such, 

DOE expects that manufacturers would 

be able to rely on data generated under 

the current test procedure. While 

manufacturers must submit a report 

annually to certify a basic model’s 

represented values, basic models do not 

need to be retested annually. The initial 

test results used to generate a certified 

rating for a basic model remain valid as 

long as the basic model has not been 

modified from the tested design in a 

way that makes it less efficient or more 

consumptive, which would require a 

change to the certified rating. If a 

manufacturer has modified a basic 

model in a way that makes it more 

efficient or less consumptive, new 

testing is only required if the 

manufacturer wishes to make claims of 

the new, more efficient rating.65

For doors without motors, DOE has 

tentatively concluded that the proposed 

test procedure would not change energy 

consumption ratings, and therefore 

would not require re-rating solely as 

result of DOE’s adoption of this 

proposed amendment to the test 

procedure. Therefore, DOE has 

determined the proposed amendments 

either decrease or result in no additional 

testing costs to manufacturers of walkin doors. 

To the extent that changes to the test 

procedure would amend the energy 

consumption attributable to a door 

motor, such changes would either not 

change the calculated energy 

consumption or result in a lower energy 

consumption value as compared to the 

currently granted waivers addressing 

door motors. As such, DOE expects that 

manufacturers would be able to rely on 

data generated under the current test 

procedure and current waivers. While 

manufacturers must submit a report 

annually to certify a basic model’s 

represented values, basic models do not 


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66See guidance issued by DOE at: 

www1.eere.energy.gov/buildings/appliance_

standards/pdfs/cert_faq_2012-04-17.pdf. 

67 DOE estimates the cost of one test to determine 

R-value to be $600. Per the sampling requirements 

specified at 10 CFR 429.53(a)(3)(ii) and 10 CFR 

429.11(b), manufacturers are required to test at least 

two units to determine the rating for a basic model, 

except where only one unit of the basic model is 

produced. 

68Outdoor single-packaged systems are also 

impacted by the proposed adoption of AHRI 1250– 

2020 single-packaged test procedure for walk-in 

cooler and freezer refrigeration systems. The 

combined potential cost increase for outdoor singlepackaged systems is presented in the next 

paragraph. 

need to be retested annually. The initial 

test results used to generate a certified 

rating for a basic model remain valid as 

long as the basic model has not been 

modified from the tested design in a 

way that makes it less efficient or more 

consumptive, which would require a 

change to the certified rating. If a 

manufacturer has modified a basic 

model in a way that makes it more 

efficient or less consumptive, new 

testing is only required if the 

manufacturer wishes to make claims of 

the new, more efficient rating.66

Issue 35: DOE requests comment on 

its tentative understanding of the impact 

of the test procedure proposals for 

appendix A in this NOPR—specifically, 

whether the proposed test procedure 

amendments, if finalized, would either 

not impact or decrease the testing 

burden for walk-in door manufacturers 

when compared to the current DOE test 

procedure in appendix A. 

2. Panels 

In this NOPR, DOE proposes to amend 

the existing test procedure in appendix 

B for measuring the R-value of 

insulation of panels by: 

1. Incorporating by reference the 

updated version of the applicable 

industry test method, ASTM C518–17; 

2. Including provisions specific to 

measurement of test specimen and total 

insulation thickness; and 

3. Providing guidance on determining 

the parallelism and flatness of the test 

specimen. 

Item 1 incorporates by reference the 

most up to date version of the industry 

standards currently referenced in the 

DOE test procedure. Items 2 and 3 

include additional instructions intended 

to improve consistency and 

reproducibility of test procedure results. 

DOE has tentatively determined that 

these proposed amendments would 

improve the accuracy and 

reproducibility of the test results and 

would not be unduly burdensome for 

manufacturers to conduct, nor would 

they be expected to increase the testing 

burden. 

DOE expects that the proposed test 

procedure in appendix B for measuring 

the R-value of insulation would not 

increase testing costs per basic model 

relative to the current DOE test 

procedure, which DOE estimates to be 

$1,200 for third-party lab testing.67

Additionally, DOE has tentatively 

determined that the proposed test 

procedure in appendix B would not 

result in manufacturers having to 

redesign any of the covered equipment 

or change how the equipment is 

manufactured. Further DOE has 

tentatively determined that, if finalized, 

the proposed amendments would not 

impact the utility of the equipment. 

Issue 36: DOE requests comment on 

its tentative understanding of the impact 

of the test procedure proposals for 

appendix B in this NOPR—specifically, 

that the proposed test procedure 

amendments, if finalized, would not 

increase testing burden on panel 

manufacturers when compared to the 

current DOE test procedure in appendix 

B. 

3. Refrigeration Systems 

In this NOPR, DOE proposes certain 

changes to subpart R, appendix C, that 

DOE has tentatively determined would 

improve the accuracy and 

reproducibility of the test results and 

would not be unduly burdensome for 

manufacturers to conduct. DOE has 

tentatively determined that these 

proposed changes would not impact 

testing cost. Additionally, the proposed 

amended subpart R, appendix C, 

measuring AWEF per AHRI 1250–2009, 

does not contain any changes that 

would require retesting or rerating if it 

were to be adopted. DOE’s tentative 

assessment of the impacts of the 

proposed amendments of subpart R, 

appendix C, to include new test 

procedures for high-temperature 

refrigeration systems and CO2 unit 

coolers are discussed in more detail 

below. 

DOE also proposes to adopt certain 

changes in the newly proposed 

appendix C1 that would amend the 

existing test procedure for walk-in 

coolers and freezers by: 

1. Expanding the off-cycle 

refrigeration system power 

measurements; 

2. Adding methods of test for singlepackaged dedicated systems; and 

3. Including a method for testing 

ducted systems. 

DOE has tentatively determined that 

these proposed amendments would 

improve the representativeness, 

accuracy, and reproducibility of the test 

results, and would not be unduly 

burdensome for manufacturers to 

conduct. DOE has also tentatively 

determined that these proposed 

amendments would impact testing costs 

by equipment type. DOE does not 

anticipate that the remainder of the 

amendments proposed in this NOPR 

would impact test costs or test burden. 

DOE estimates third-party test costs 

for testing to the current DOE test 

procedure to be: 

• $10,000 for outdoor lowtemperature and medium-temperature 

dedicated condensing units tested alone 

• $6,500 for indoor low temperature 

and medium temperature dedicated 

condensing units tested alone 

• $6,500 for low-temperature unit 

coolers tested alone 

• $6,000 for medium-temperature 

unit coolers tested alone 

• $10,000 for single-packaged 

dedicated systems 

• $10,000 for high-temperature 

matched pairs 

As discussed previously in section 

III.G.1 of this document, DOE is 

proposing to adopt off-cycle test 

provisions in AHRI 1250–2020 for walkin cooler and freezer refrigeration 

systems. The current test procedure 

requires off-cycle power to be measured 

at the 95 °F ambient condition. The 

proposed test procedure requires offcycle to be measured at 95 °F, 59 °F, and 

35 °F ambient conditions for outdoor 

dedicated condensing units, outdoor 

matched pair systems, and outdoor 

dedicated systems. The matched pair 

and single-packaged dedicated systems 

include high-temperature refrigeration 

systems. When the waivers for these 

high-temperature refrigeration systems 

were granted, only one off-cycle test was 

required; therefore, manufacturers with 

waivers would be required to conduct 

additional testing as compared to the 

alternate test procedure currently 

required. DOE estimates that measuring 

off-cycle power at these additional 

ambient conditions may increase perunit third-party lab test cost by $1,000 

per unit to a total cost of $11,000 per 

unit for outdoor dedicated condensing 

units, outdoor matched pair systems, 

and outdoor single-packaged dedicated 

systems. 

Manufacturers are not required to 

perform laboratory testing on all basic 

models. In accordance with 10 CFR 

429.53, WICF refrigeration system 

manufacturers may elect to use AEDMs. 

DOE estimates the per-manufacturer 

cost to develop and validate an AEDM 

for outdoor dedicated condensing units 

and outdoor matched pair systems to be 

$24,580.68 DOE estimates an additional 


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69 DOE estimated initial costs to validate an 

AEDM assuming 40 hours of general time to 

develop an AEDM based on existing simulation 

tools and 16 hours to validate two basic models 

within that AEDM at the cost of an engineering 

calibration technician fully burdened wage of $46 

per hour plus the cost of third-party physical testing 

of two units per validation class (as required in 10 

CFR 429.70(c)(2)(iv)). DOE estimated the additional 

per basic model cost to determine efficiency using 

an AEDM assuming 1 hour per basic model at the 

cost of an engineering calibration technician wage 

of $46 per hour. 70 DOE estimated initial costs to validate an 

AEDM assuming 40 hours of general time to 

develop an AEDM based on existing simulation 

tools and 16 hours to validate two basic models 

within that AEDM at the cost of an engineering 

calibration technician fully burdened wage of $46 

per hour plus the cost of third-party physical testing 

of two units per validation class (as required in 10 

CFR 429.70(c)(2)(iv)). DOE estimated the additional 

per basic model cost to determine efficiency using 

an AEDM assuming 1 hour per basic model at the 

cost of an engineering calibration technician wage 

of $46 per hour. 

71The RSG waiver docket can be found at 

www.regulations.gov/docket/EERE-2022-BT-WAV0010. 

cost of approximately $46 per basic 

model 69 for determining energy 

efficiency of a given basic model using 

the validated AEDM. 

As discussed previously in section 

III.G.2, DOE is proposing to adopt the 

single-packaged dedicated system test 

procedure for walk-ins in AHRI 1250– 

2020. The proposed procedure requires 

air enthalpy tests to be used as the 

primary test method. In the current test 

procedure, single-packaged dedicated 

systems use refrigerant enthalpy as the 

primary test method. DOE does not 

estimate a difference in physical testing 

costs between air and refrigerant 

enthalpy testing of single-packaged 

units. DOE estimates the per-unit thirdparty lab test cost to be $11,000 for 

outdoor single-packaged units and 

$6,500 for indoor single-packaged units. 

However, should a manufacturer choose 

to use an AEDM, they may incur 

additional costs regarding the 

development and validation of new 

AEDMs for single-packaged dedicated 

systems. DOE estimates the permanufacturer cost to develop and 

validate an AEDM to be $24,580 for 

outdoor single-packaged units and 

$15,580 for indoor single-packaged 

units. DOE estimates an additional cost 

of approximately $46 per basic model 70

for determining energy efficiency using 

the validated AEDM. 

As discussed in sections III.F.6 and 

III.G.6, DOE is proposing test 

procedures for CO2 unit coolers and 

high-temperature refrigeration systems. 

DOE tentatively estimates that the 

average third-party lab per unit test cost 

would be $11,000 for a hightemperature matched pair or singlepackaged system, $6,000 for a hightemperature unit cooler tested alone, 

$6,500 for a low temperature CO2 unit 

cooler, and $6,000 for a medium 

temperature CO2 unit cooler. As 

discussed previously, DOE has granted 

waivers to certain manufacturers for 

both high-temperature refrigeration 

systems and CO2 unit coolers. The test 

procedures proposed in this NOPR are 

consistent with the alternate test 

procedures included in the granted 

waivers. For those manufacturers who 

have been granted a test procedure 

waiver for this equipment, DOE expects 

that there would be no additional test 

burden. However, DOE expects that 

there would be additional testing costs 

for any manufacturers of these products 

who have not submitted or been granted 

a test procedure waiver at the time this 

proposed test procedure is finalized. 

Such companies may incur an 

additional per unit test cost of: 

• $11,000 for a high-temperature 

matched pair or single-packaged system; 

• $6,000 for a high-temperature unit 

cooler tested alone; 

• $6,500 for a low temperature CO2

unit cooler tested alone; and 

• $6,000 for a medium temperature 

CO2 unit cooler tested alone. 

Issue 37: DOE requests comment on 

its tentative understanding of the impact 

of the test procedure proposals for 

refrigeration systems—specifically, 

whether DOE’s initial conclusion that 

the proposed DOE test procedure 

amendments, if finalized, would 

increase testing burden. 

K. Compliance Date and Waivers 

EPCA prescribes that, if DOE amends 

a test procedure, all representations of 

energy efficiency and energy use, 

including those made on marketing 

materials and product labels, must be 

made in accordance with that amended 

test procedure, beginning 180 days after 

publication of such a test procedure 

final rule in the Federal Register. (42 

U.S.C. 6314(d)(1)) To the extent the 

modified test procedure proposed in 

this document is required only for the 

evaluation and issuance of updated 

efficiency standards, use of the modified 

test procedure, if finalized, would not 

be required until the implementation 

date of updated standards. 10 CFR 

431.4; section 8(e) of appendix A 10 

CFR part 430 subpart C. 

If DOE were to publish an amended 

test procedure, EPCA provides an 

allowance for individual manufacturers 

to petition DOE for an extension of the 

180-day period if the manufacturer may 

experience undue hardship in meeting 

the deadline. (42 U.S.C. 6314(d)(2)) To 

receive such an extension, petitions 

must be filed with DOE no later than 60 

days before the end of the 180-day 

period and must detail how the 

manufacturer will experience undue 

hardship. Id. 

Upon the compliance date of any 

provisions of an amended test 

procedure, any waivers that are 

currently in effect pertaining to issues 

addressed by such provisions are 

terminated. 10 CFR 431.401(h)(3). 

Recipients of any such waivers would 

be required to test the products subject 

to the waiver according to the amended 

test procedure as of the compliance date 

of the amended test procedure. The 

amendments proposed in this document 

pertain to issues addressed by waivers 

and interim waivers granted to the 

manufacturers listed in Table III.15. The 

proposed amendments also address 

issues identified in a pending waiver for 

RSG (Case No. 2022–004).71

TABLE III.15—MANUFACTURERS GRANTED WAIVERS AND INTERIM WAIVERS

Manufacturer Subject Case No. Relevant test 

procedure Proposed test procedure compliance date 

Jamison Door Company ........ PTO for Door Motors ............. 2017–009 Appendix A .... 180 days after test procedure final rule publication. 

HH Technologies .................... PTO for Door Motors ............. 2018–001 Appendix A .... 180 days after test procedure final rule publication. 

Senneca Holdings .................. PTO for Door Motors ............. 2020–002 Appendix A .... 180 days after test procedure final rule publication. 

Hercules ................................. PTO for Door Motors ............. 2020–013 Appendix A .... 180 days after test procedure final rule publication. 


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TABLE III.15—MANUFACTURERS GRANTED WAIVERS AND INTERIM WAIVERS—Continued 

Manufacturer Subject Case No. Relevant test 

procedure Proposed test procedure compliance date 

HTPG ..................................... CO2 Unit Coolers ................... 2020–009 Appendix C .... 180 days after test procedure final rule publication. 

Hussmann .............................. CO2 Unit Coolers ................... 2020–010 Appendix C .... 180 days after test procedure final rule publication. 

Keeprite .................................. CO2 Unit Coolers ................... 2020–014 Appendix C .... 180 days after test procedure final rule publication. 

RefPlus, Inc ............................ CO2 Unit Coolers ................... 2021–006 Appendix C .... 180 days after test procedure final rule publication. 

RSG ........................................ Multi-Circuit Single-Package 

Dedicated Systems.

2022–004 Appendix C .... 180 days after test procedure final rule publication. 

Store It Cold ........................... Single-Package Dedicated 

Systems.

2018–002 Appendix C1 .. Compliance date of updated standards. 

CellarPro ................................ Wine Cellar Refrigeration 

Systems.

2019–009 Appendix C1 .. Compliance date of updated standards. 

Air Innovations ....................... Wine Cellar Refrigeration 

Systems.

2019–010 Appendix C1 .. Compliance date of updated standards. 

Vinotheque ............................. Wine Cellar Refrigeration 

Systems.

2019–011 Appendix C1 .. Compliance date of updated standards. 

Vinotemp ................................ Wine Cellar Refrigeration 

Systems.

2020–005 Appendix C1 .. Compliance date of updated standards. 

LRC Coil ................................. Wine Cellar Refrigeration 

Systems.

2020–024 Appendix C1 .. Compliance date of updated standards. 

L. Organizational Changes 

DOE is also proposing a number of 

non-substantive organizational changes. 

As discussed previously, DOE is 

proposing to reorganize appendices A 

and B so that they are easier for 

stakeholders to follow as a step-by-step 

test procedure. Additionally, DOE is 

proposing to remove the specifications 

at 10 CFR 429.53(a)(2)(i) regarding 

specific test procedure provisions and 

instead include these provisions in the 

uniform test method section at 10 CFR 

431.304. The intent of this proposed 

change is to move provisions of the 

applicable test procedure to the 

appropriate place in subpart R, rather 

than keeping them under the provisions 

for determining represented values for 

certification. However, DOE is 

proposing to keep the additional detail 

regarding the represented values of 

various configurations of refrigeration 

systems (e.g., outdoor and indoor 

dedicated condensing units, matched 

refrigeration systems, etc.) at 10 CFR 

429.53(a)(2)(i). 

IV. Procedural Issues and Regulatory 

Review 

A. Review Under Executive Order 12866 

and 13563 

Executive Order (‘‘E.O.’’) 12866, 

‘‘Regulatory Planning and Review,’’ as 

supplemented and reaffirmed by E.O. 

13563, ‘‘Improving Regulation and 

Regulatory Review,’’ 76 FR 3821 (Jan. 

21, 2011), requires agencies, to the 

extent permitted by law, to (1) propose 

or adopt a regulation only upon a 

reasoned determination that its benefits 

justify its costs (recognizing that some 

benefits and costs are difficult to 

quantify); (2) tailor regulations to 

impose the least burden on society, 

consistent with obtaining regulatory 

objectives, taking into account, among 

other things, and to the extent 

practicable, the costs of cumulative 

regulations; (3) select, in choosing 

among alternative regulatory 

approaches, those approaches that 

maximize net benefits (including 

potential economic, environmental, 

public health and safety, and other 

advantages; distributive impacts; and 

equity); (4) to the extent feasible, specify 

performance objectives, rather than 

specifying the behavior or manner of 

compliance that regulated entities must 

adopt; and (5) identify and assess 

available alternatives to direct 

regulation, including providing 

economic incentives to encourage the 

desired behavior, such as user fees or 

marketable permits, or providing 

information upon which choices can be 

made by the public. DOE emphasizes as 

well that E.O. 13563 requires agencies to 

use the best available techniques to 

quantify anticipated present and future 

benefits and costs as accurately as 

possible. In its guidance, the Office of 

Information and Regulatory Affairs 

(‘‘OIRA’’) has emphasized that such 

techniques may include identifying 

changing future compliance costs that 

might result from technological 

innovation or anticipated behavioral 

changes. For the reasons stated in the 

preamble, this proposed regulatory 

action is consistent with these 

principles. 

Section 6(a) of E.O. 12866 also 

requires agencies to submit ‘‘significant 

regulatory actions’’ to OIRA for review. 

OIRA has determined that this proposed 

regulatory action does not constitute a 

‘‘significant regulatory action’’ under 

section 3(f) of E.O. 12866. Accordingly, 

this action was not submitted to OIRA 

for review under E.O. 12866. 

B. Review Under the Regulatory 

Flexibility Act 

The Regulatory Flexibility Act (5 

U.S.C. 601 et seq.) requires preparation 

of an initial regulatory flexibility 

analysis (‘‘IRFA’’) for any rule that by 

law must be proposed for public 

comment, unless the agency certifies 

that the rule, if promulgated, will not 

have a significant economic impact on 

a substantial number of small entities. 

As required by Executive Order 13272, 

‘‘Proper Consideration of Small Entities 

in Agency Rulemaking,’’ 67 FR 53461 

(Aug. 16, 2002), DOE published 

procedures and policies on February 19, 

2003, to ensure that the potential 

impacts of its rules on small entities are 

properly considered during the DOE 

rulemaking process. 68 FR 7990. DOE 

has made its procedures and policies 

available on the Office of the General 

Counsel’s website: www.energy.gov/gc/ 

office-general-counsel. 

The following sections detail DOE’s 

IRFA for this test procedure proposed 

rulemaking. 


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72All references to EPCA in this document refer 

to the statute as amended through the Energy Act 

of 2020, Public Law 116–260 (Dec. 27, 2020). 

73For editorial reasons, upon codification in the 

U.S. Code, Part C was redesignated Part A–1. 

74All references to EPCA in this document refer 

to the statute as amended through the Energy Act 

of 2020, Public Law 116–260 (Dec. 27, 2020). 

75For editorial reasons, upon codification in the 

U.S. Code, Part C was redesignated Part A–1. 

76The size standards are listed by NAICS code 

and industry description and are available at: 

www.sba.gov/document/support--table-sizestandards (Last accessed on November 1, 2021). 

77Certified equipment in the CCD are listed by 

product class and can be accessed at 

www.regulations.doe.gov/certification-data/ 

#q=Product_Group_s%3A* (Last accessed July 15th, 

2021). 

78MAEDbS can be accessed at 

www.cacertappliances.energy.ca.gov/Pages/Search/ 

AdvancedSearch.aspx (Last accessed Nov. 1, 2021). 

79An AEDM is a computer modeling or 

mathematical tool that predicts the performance of 

non-tested basic models. These computer modeling 

and mathematical tools, when properly developed, 

can provide a means to predict the energy usage or 

efficiency characteristics of a basic model of a given 

covered product or equipment and reduce the 

burden and cost associated with testing. 

1. Description of Why Action Is Being 

Considered 

The Energy Policy and Conservation 

Act, as amended (‘‘EPCA’’),72 authorizes 

DOE to regulate the energy efficiency of 

a number of consumer products and 

certain industrial equipment. (42 U.S.C. 

6291–6317) Title III, Part C73 of EPCA, 

added by Public Law 95–619, Title IV, 

section 441(a), established the Energy 

Conservation Program for Certain 

Industrial Equipment, which sets forth a 

variety of provisions designed to 

improve energy efficiency. This covered 

equipment includes walk-in coolers and 

walk-in freezers, the subject of this 

document. (42 U.S.C. 6311(1)(G)) DOE is 

publishing this NOPR in satisfaction of 

the 7-year review requirement specified 

in EPCA. (42 U.S.C. 6314(a)(1)) 

2. Objective of, and Legal Basis for, Rule 

The Energy Policy and Conservation 

Act, as amended (‘‘EPCA’’),74 authorizes 

DOE to regulate the energy efficiency of 

a number of consumer products and 

certain industrial equipment. (42 U.S.C. 

6291–6317) Title III, Part C75 of EPCA, 

added by Public Law 95–619, Title IV, 

section 441(a), established the Energy 

Conservation Program for Certain 

Industrial Equipment, which sets forth a 

variety of provisions designed to 

improve energy efficiency. This covered 

equipment includes walk-in coolers and 

walk-in freezers, the subject of this 

document. (42 U.S.C. 6311(1)(G)) 

Under 42 U.S.C. 6314, EPCA sets forth 

the criteria and procedures DOE must 

follow when prescribing or amending 

test procedures for covered equipment. 

EPCA requires that any test procedures 

prescribed or amended under this 

section must be reasonably designed to 

produce test results which reflect energy 

efficiency, energy use or estimated 

annual operating cost of a given type of 

covered equipment during a 

representative average use cycle and 

requires that test procedures not be 

unduly burdensome to conduct. (42 

U.S.C. 6314(a)(2)) 

EPCA also requires that, at least once 

every 7 years, DOE evaluate test 

procedures for each type of covered 

equipment including WICFs, to 

determine whether amended test 

procedures would more accurately or 

fully comply with the requirements for 

the test procedures to not be unduly 

burdensome to conduct and be 

reasonably designed to produce test 

results that reflect energy efficiency, 

energy use, and estimated operating 

costs during a representative average 

use cycle. (42 U.S.C. 614(a)(1)(A)) 

3. Description and Estimate of Small 

Entities Regulated 

For manufacturers of WICFs, the 

Small Business Administration (‘‘SBA’’) 

has set a size threshold, which defines 

those entities classified as ‘‘small 

businesses’’ for the purposes of the 

statute. DOE used the SBA’s small 

business size standards to determine 

whether any small entities would be 

subject to the requirements of the rule. 

See 13 CFR part 121. The equipment 

covered by this rule are classified under 

North American Industry Classification 

System (‘‘NAICS’’) code 333415,76 ‘‘AirConditioning and Warm Air Heating 

Equipment and Commercial and 

Industrial Refrigeration Equipment 

Manufacturing.’’ In 13 CFR 121.201, the 

SBA sets a threshold of 1,250 employees 

or fewer for an entity to be considered 

as a small business for this category. 

DOE reviewed the test procedures 

proposed in this NOPR under the 

provisions of the Regulatory Flexibility 

Act and the procedures and policies 

published on February 19, 2003. DOE 

used publicly available information to 

identify potential small businesses that 

manufacture WICFs covered in this 

rulemaking. DOE’s analysis relied on 

publicly available databases to identify 

potential small businesses that 

manufacture equipment covered in this 

rulemaking. DOE utilized the DOE’s 

Certification Compliance Database 

(‘‘CCD’’) 77 and the California Energy 

Commission’s Modernized Appliance 

Efficiency Database System 

(‘‘MAEDbS’’) 78 in identifying 

manufacturers. DOE also used 

subscription-based business information 

tools to determine headcount and 

revenue of the small businesses. 

Using these data sources, DOE 

identified 79 original equipment 

manufacturers (‘‘OEMs’’) of WICFs that 

could be potentially affected by this 

rulemaking. DOE screened out 

companies that do not meet the 

definition of a ‘‘small business’’ or are 

foreign-owned and operated. Of these 79 

OEMs, 60 are small, domestic 

manufacturers. DOE notes that some 

manufacturers may produce more than 

one of the principal components of 

WICFs: Panels, doors, and refrigeration 

systems. Eighteen of the small, domestic 

OEMs manufacture refrigeration 

systems; 38 of the small, domestic 

OEMs manufacture panels; and 43 of the 

small, domestic OEMs manufacture 

doors. To better reflect the impact on 

manufacturers, DOE evaluated the 

impacts of test procedure changes to 

panels, doors, and refrigeration systems 

separately. 

Of these small businesses, not all 

were impacted by the proposed changes. 

The following section further details the 

impact to manufacturers by principal 

component and proposed test procedure 

amendment. 

Issue 38: DOE invites comment on the 

number of small, domestic OEMs 

producing the three principal 

components of WICFs: Panels, doors, 

and refrigeration systems. 

4. Description and Estimate of 

Compliance Requirements 

The potential regulatory costs of the 

proposed test procedure are 

differentiated by WICF component: 

Panels, doors, and refrigeration systems. 

The following sub-sections outline these 

changes and potential burden. 

a. Doors 

In this NOPR, DOE proposes the 

following amendments to the test 

procedures for walk-in cooler and 

freezer doors: 

1. Referencing NFRC 102–2020 for the 

determination of U-factor; 

2. Including AEDM 79 provisions for 

manufacturers to alternately determine 

the total energy consumption of display 

and non-display doors; 

3. Providing additional detail for 

determining the area used to convert Ufactor into conduction load, As, to 

differentiate it from the area used to 

determine compliance with the 

standards, Add or And; and 

4. Specifying a percent time off 

(‘‘PTO’’) value of 97 percent for door 

motors. 

Items 1 and 3, referencing NFRC 102– 

2020 and additional detail on the area 

used to convert U-factor into a 


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80 DOE estimates the cost of one test to determine 

energy consumption of a walk-in door, including 

one physical U-factor test per NFRC 102–2020, to 

be $5,000. Per the sampling requirements specified 

at 10 CFR 429.53(a)(3)(ii) and 10 CFR 429.11(b), 

manufacturers are required to test at least two units 

to determine the rating for a basic model, except 

where only one unit of the basic model is produced. 

81Section 4.7.1 of NFRC 100 requires that the 

accepted difference between the tested U-factor and 

the simulated U-factor be (a) 0.03 Btu/(h-ft2-°F) for 

simulated U-factors that are 0.3 Btu/(h-ft2-°F) or 

less, or 10 percent of the simulated U-factor for 

simulated U-factors greater than 0.3 Btu/(h-ft2-°F). 

This agreement must match for the baseline product 

in a product line. Per NFRC 100, the baseline 

product is the individual product selected for 

validation; it is not synonymous with ‘‘basic 

model’’ as defined in 10 CFR 431.302. 

82See guidance issued by DOE at: 

www1.eere.energy.gov/buildings/appliance_

standards/pdfs/cert_faq_2012-04-17.pdf. 

83See guidance issued by DOE at: 

www1.eere.energy.gov/buildings/appliance_

standards/pdfs/cert_faq_2012-04-17.pdf. 

conduction load, would improve the 

consistency, reproducibility, and 

representativeness of test procedure 

results. Item 2, including AEDM 

provisions, would provide 

manufacturers with the flexibility to use 

an alternative method that gives the best 

agreement for their doors. Item 4, 

specifying a PTO value of 97 percent for 

door motors, would provide a more 

representative and consistent means for 

comparison of walk-in door 

performance for doors with motors. DOE 

has tentatively determined that these 

proposed amendments as a whole 

would improve the representativeness, 

accuracy, and reproducibility of the test 

results, and would not be unduly 

burdensome for door manufacturers to 

conduct. DOE has also tentatively 

determined that these proposed 

amendments would not increase 

physical testing costs per basic model 

relative to the current DOE test 

procedure in appendix A, which DOE 

estimates to be $10,000 for third-party 

labs to determine energy consumption 

of a walk-in door, including physical Ufactor testing per NFRC 102–2020.80

DOE has tentatively determined that 

manufacturers would not be required 

redesign any of the covered equipment 

or change how the equipment is 

manufactured, solely as result of the 

proposed amendments. 

DOE is also proposing to permit 

manufacturers to use AEDMs. Using 

AEDMs when evaluating the energy 

efficiency of their equipment may 

enable some manufacturers to reduce 

costs to rate models. AEDMs can require 

an upfront investment but lower overall 

testing costs. The cost impact to 

manufacturers as result of the reference 

to NFRC 102–2020 and inclusion of 

AEDM provisions is dependent on the 

agreement specified in Section 4.7.1 of 

NFRC 100 81 between U-factors 

simulated using the method in NFRC 

100 and U-factors tested using NFRC 

102. For manufacturers of doors that 

have been able to achieve the specified 

agreement between U-factors simulated 

using the method in NFRC 100 and Ufactors tested using NFRC 102, 

manufacturers would be able to 

continue using the simulation method 

in NFRC 100, provided that the 

simulation method also meets the basic 

requirements proposed for an AEDM in 

10 CFR 429.53 and 10 CFR 429.70(f). 

For manufacturers of doors that have 

not been able to achieve the specified 

agreement between U-factors simulated 

using the method in NFRC 100 and Ufactors tested using NFRC 102, DOE 

estimates that the test burden could 

decrease. Under the current 

requirements, manufacturers may be 

required to physically test every model 

to meet the basic model definition since 

these models are highly customizable. If 

the proposed test procedure is adopted, 

manufacturers who would otherwise 

physically test every walk-in door basic 

model could develop an AEDM for 

rating. DOE estimates the permanufacturer cost to develop and 

validate an AEDM for a single validation 

class of walk-in doors to be $11,100. 

DOE estimates the cost to determine 

energy consumption of a walk-in door 

using an AEDM to be $46 per basic 

model. 

DOE expects that the additional detail 

provided for determining the area used 

to convert U-factor into conduction 

load, As, would either result in a 

reduced energy consumption or have no 

impact. To the extent that this change to 

the test procedure would amend the 

energy consumption attributable to a 

door, such changes would either not 

change the calculated energy 

consumption or result in a lower energy 

consumption value as compared to how 

manufacturers may currently be rating. 

As such, DOE expects that 

manufacturers would be able to rely on 

data generated under the current test 

procedure. While manufacturers must 

submit a report annually to certify a 

basic model’s represented values, basic 

models do not need to be retested 

annually. The initial test results used to 

generate a certified rating for a basic 

model remain valid as long as the basic 

model has not been modified from the 

tested design in a way that makes it less 

efficient or more consumptive, which 

would require a change to the certified 

rating. If a manufacturer has modified a 

basic model in a way that makes it more 

efficient or less consumptive, new 

testing is only required if the 

manufacturer wishes to make claims of 

the new, more efficient rating.82

For doors without motors, DOE has 

tentatively concluded that the proposed 

test procedure would not change energy 

consumption ratings, and therefore 

would not require re-rating as a result 

this proposed test procedure. Therefore, 

DOE has determined the proposed 

amendments would either decrease or 

result in no additional testing costs to 

small business manufacturers of walk-in 

doors. 

To the extent that changes to the test 

procedure would amend the energy 

consumption attributable to a door 

motor, such changes would either not 

change the calculated energy 

consumption or result in a lower energy 

consumption value as compared to the 

currently granted waivers addressing 

door motors. As such, DOE expects that 

manufacturers would be able to rely on 

data generated under the current test 

procedure and current waivers. While 

manufacturers must submit a report 

annually to certify a basic model’s 

represented values, basic models would 

not need to be retested annually. The 

initial test results used to generate a 

certified rating for a basic model would 

remain valid as long as the basic model 

has not been modified from the tested 

design in a way that makes it less 

efficient or more consumptive, which 

would require a change to the certified 

rating. If a manufacturer has modified a 

basic model in a way that makes it more 

efficient or less consumptive, new 

testing would be required only if the 

manufacturer wishes to make claims of 

the new, more efficient rating.83

Issue 39: DOE requests comment on 

its cost estimate of impacts on small, 

domestic OEMs of doors. 

b. Panels 

DOE proposes to amend the existing 

test procedure in appendix B for 

measuring the R-value of insulation of 

walk-in panels by: 

1. Incorporating by reference the 

updated version of the applicable 

industry test method, ASTM C518–17; 

2. Including provisions specific to the 

measurement of test specimen and total 

insulation thickness; and 

3. Providing guidance on determining 

the parallelism and flatness of the test 

specimen. 

Item 1 incorporates by reference the 

most up to date version of the industry 

standards currently referenced in the 

DOE test procedure. Items 2 and 3 

includes additional instructions that 

would improve the consistency and 

reproducibility of test procedure results. 


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84 DOE estimates the cost of one test to determine 

R-value to be $600. Per the sampling requirements 

specified at 10 CFR 429.53(a)(3)(ii) and 10 CFR 

429.11(b), manufacturers are required to test at least 

two units to determine the rating for a basic model, 

except where only one unit of the basic model is 

produced. 

85Outdoor single-packaged systems are also 

impacted by the proposed adoption of AHRI 1250– 

2020 single-packaged test procedure for walk-in 

cooler and freezer refrigeration systems. The 

combined potential cost increase for outdoor singlepackaged systems is presented in the following 

section. 

86The cost to test one unit is $11,000. Per the 

sampling requirements specified at 10 CFR 

429.53(a)(2)(ii) and 10 CFR 429.11(b), 

manufacturers are required to test at least two units 

to determine the rating for a basic model, except 

where only one unit of the basic model is produced. 

87 DOE estimated initial costs to validate an 

AEDM assuming 40 hours of general time to 

develop an AEDM based on existing simulation 

tools and 16 hours to validate two basic models 

within that AEDM at the cost of an engineering 

calibration technician fully burdened wage of $46 

per hour plus the cost of third-party physical testing 

of two units per validation class (as required in 10 

CFR 429.70(c)(2)(iv)). DOE estimated the additional 

per basic model cost to determine efficiency using 

an AEDM assuming 1 hour per basic model at the 

cost of an engineering calibration technician wage 

of $46 per hour. 

DOE has tentatively determined that 

these proposed amendments would 

improve the accuracy and 

reproducibility of the test results and 

would not be unduly burdensome for 

manufacturers to conduct, nor would 

they be expected to increase the testing 

burden. 

DOE expects that the proposed test 

procedure in appendix B for the 

measuring R-value of insulation would 

not increase testing costs per basic 

model relative to the current DOE test 

procedure, which DOE estimates to be 

$1,200 for third-party lab testing.84

Additionally, DOE has tentatively 

determined that manufacturers would 

not be required to redesign any of the 

covered equipment or change how the 

equipment is manufactured, solely as 

result of the proposed amendments. 

Further, DOE has tentatively determined 

that the proposed amendments would 

not impact the utility of the equipment. 

DOE has tentatively concluded that 

the proposed test procedure would not 

change efficiency ratings for walk-in 

panels, and therefore would not require 

re-rating as result of DOE’s adoption of 

this proposed amendment to the test 

procedure. Therefore, DOE has 

determined the proposed amendments 

would not add any additional testing 

costs to small business manufacturers of 

walk-in doors. 

Issue 40: DOE requests comment on 

its cost estimate of impacts on small, 

domestic OEMs of panels. 

c. Refrigeration Systems 

In this NOPR, DOE proposes certain 

changes to subpart R, appendix C, that 

DOE has tentatively determined would 

improve the accuracy and 

reproducibility of the test results and 

would not be unduly burdensome for 

manufacturers to conduct. DOE has 

tentatively determined that these 

proposed changes would not impact 

testing cost. Additionally, the proposed 

amended subpart R, appendix C, 

measuring AWEF per AHRI 1250–2009, 

does not contain any changes that 

would require retesting or rerating if it 

were to be adopted. 

DOE also proposes to adopt through 

incorporations by reference certain 

provisions of AHRI 1250–2020 in 

appendix C1 that would amend the 

existing test procedure for walk-in 

cooler and freezer refrigeration systems. 

Additionally, DOE proposes 

amendments to the current DOE test 

procedure to accommodate hightemperature refrigeration systems and 

CO2 unit coolers. A summary of the 

proposed changes are as follows: 

1. Expanding the off-cycle 

refrigeration system power 

measurements; 

2. Adding air enthalpy methods for 

single-packaged dedicated systems; 

3. Including new test procedures for 

high-temperature refrigeration systems; 

and 

4. Including new test procedures for 

CO2 unit coolers. 

DOE has tentatively determined that 

these proposed amendments would 

improve the representativeness, 

accuracy, and reproducibility of the test 

results, and would not be unduly 

burdensome for manufacturers to 

conduct. DOE has also tentatively 

determined that these proposed 

amendments may impact testing costs. 

The following paragraphs outline the 

proposed changes and the potential 

costs to manufacturers. Because DOE’s 

proposal of off-cycle refrigeration power 

measurements and single-packaged 

dedicated system air enthalpy test 

methods requirements impact both 

high-temperature and CO2 units, all 

potential cost impacts to hightemperature and CO2 units are 

discussed separately in the third and 

fourth sections. 

(1) Small Business Impacts as a Result 

of Off-Cycle Refrigeration System Power 

Requirements 

DOE is proposing to adopt the offcycle testing for walk-ins in AHRI 1250– 

2020. The current test procedure 

requires off-cycle power to be measured 

at the 95 °F ambient condition. The 

proposed test procedure requires offcycle to be measured at 95 °F, 59 °F, and 

35 °F ambient conditions for outdoor 

dedicated condensing units, outdoor 

matched pair systems, and outdoor 

single-packaged dedicated systems. 

These proposed amendments would not 

increase testing costs or require 

manufacturers to re-rate models, as DOE 

energy conservation standards do not 

currently require off-cycle requirements 

to be measured at 95 °F, 59 °F, and 35 

°F ambient conditions for outdoor 

dedicated condensing units, outdoor 

matched pair systems, and outdoor 

single-packaged systems. However, 

should DOE adopt energy conservation 

standards that require these off-cycle 

requirements, DOE estimates that 

measuring off-cycle power at these 

additional ambient conditions may 

increase per-unit third-party lab test 

cost by $1,000 per unit to a total cost of 

$11,000 per unit for outdoor dedicated 

condensing units and outdoor matched 

pair systems.85 The physical testing 

cost, according to the proposed 

amendments, would be $22,000 per 

basic model for outdoor dedicated 

condensing units and outdoor matched 

pair systems.86

However, manufacturers are not 

required to perform laboratory testing 

on all basic models. In accordance with 

10 CFR 429.53, WICF refrigeration 

system manufacturers may elect to use 

AEDMs. DOE estimates the permanufacturer cost to develop and 

validate an AEDM for outdoor dedicated 

condensing units and outdoor matched 

pair systems to be $24,580 per 

validation class. DOE estimates an 

additional cost of approximately $46 per 

basic model 87 for determining energy 

efficiency using the validated AEDM. 

DOE estimates the range of potential 

costs for the five small OEMs that 

manufacture outdoor dedicated 

condensing units and outdoor matched 

pair systems. When developing cost 

estimates for the small OEMs, DOE 

considers the cost to update the existing 

AEDM simulation tool, the costs to 

validate the AEDM through physical 

testing, and the cost to rate basic models 

using the AEDM. DOE assumes a highcost scenario where manufacturers 

would be required to develop AEDMs 

for six validation classes. 

DOE estimates the impacts based on 

basic model counts and company 

revenue. Table IV.1 summarizes DOE’s 

estimates for the five identified small 

businesses. On average, testing costs 

represent less than 1 percent of annual 

revenue for a typical small business. 


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88Per the sampling requirements specified at 10 

CFR 429.53(a)(2)(ii) and 10 CFR 429.11(b), 

manufacturers are required to test at least two units 

to determine the rating for a basic model, except 

where only one unit of the basic model is produced. 

89 DOE estimated initial costs to validate an 

AEDM assuming 40 hours of general time to 

develop an AEDM based on existing simulation 

tools and 16 hours to validate two basic models 

within that AEDM at the cost of an engineering 

calibration technician fully burdened wage of $46 

per hour plus the cost of third-party physical testing 

of two units per validation class (as required in 10 

CFR 429.70(c)(2)(iv)). DOE estimated the additional 

per basic model cost to determine efficiency using 

an AEDM assuming 1 hour per basic model at the 

cost of an engineering calibration technician wage 

of $46 per hour. 

90Per the sampling requirements specified at 10 

CFR 429.53(a)(2)(ii) and 10 CFR 429.11(b), 

manufacturers are required to test at least two units 

to determine the rating for a basic model, except 

where only one unit of the basic model is produced. 

91 DOE estimated initial costs to validate an 

AEDM assuming 40 hours of general time to 

develop an AEDM based on existing simulation 

tools and 16 hours to validate two basic models 

within that AEDM at the cost of an engineering 

calibration technician fully burdened wage of $46 

per hour plus the cost of third-party physical testing 

of two units per validation class (as required in 10 

CFR 429.70(c)(2)(iv)). DOE estimated the additional 

per basic model cost to determine efficiency using 

an AEDM assuming 1 hour per basic model at the 

cost of an engineering calibration technician wage 

of $46 per hour. 

TABLE IV.1—ESTIMATED SMALL BUSINESS RE-RATING COSTS (2022$) AS A RESULT OF OFF-CYCLE REFRIGERATION

SYSTEM POWER REQUIREMENTS

Manufacturer 

Re-rating 

estimate 

($mm) 

Annual 

revenue 

estimate 

($mm) 

Percent of 

revenue 

(%) 

Manufacturer A ............................................................................................................................ 0.151 12 1.25 

Manufacturer B ............................................................................................................................ 0.148 19 0.78 

Manufacturer C ............................................................................................................................ 0.214 77 0.28 

Manufacturer D ............................................................................................................................ 0.148 86 0.17 

Manufacturer E ............................................................................................................................ 0.159 147 0.10 

(2) Small Business Impacts as a Result 

of Requiring Single-Packaged Dedicated 

Systems To Test Using Air Enthalpy 

Methods 

DOE is also proposing to adopt the 

single-packaged dedicated system test 

procedure in AHRI 1250–2020 for walkin cooler and freezer refrigeration 

systems. The proposed procedure 

requires air enthalpy tests to be used as 

the primary test method. In the current 

test procedure, single-packaged 

dedicated systems use refrigerant 

enthalpy as the primary test method. 

DOE estimates no difference in costs 

between air and refrigerant enthalpy 

testing of single-packaged dedicated 

systems. DOE estimates the per-unit 

third-party lab test cost to be $11,000 for 

outdoor single-packaged dedicated 

systems and $6,500 for indoor singlepackaged dedicated systems. The 

physical testing cost, according to the 

proposed amendments, would be 

$22,000 per basic model for outdoor 

single-packaged dedicated systems and 

$13,000 per basic model for indoor 

package systems.88 However, 

manufacturers of single-packaged 

dedicated systems may elect to use 

AEDMs. DOE estimates the permanufacturer cost to develop and 

validate an AEDM per validation class 

to be $24,580 for outdoor singlepackaged dedicated systems and 

$15,580 for indoor single-packaged 

dedicated systems. DOE estimates an 

additional cost of approximately $46 per 

basic model 89 for determining energy 

efficiency using the validated AEDM. 

DOE estimated the range of potential 

costs for the two domestic, small OEMs 

that manufacture single-packaged 

dedicated systems. When developing 

cost estimates for the small OEMs, DOE 

considered the cost to update the 

existing AEDM simulation tool, the 

costs to validate the AEDM through 

physical testing, and the cost to rate 

basic models using the AEDM. 

Both small businesses manufacture 

indoor and outdoor, low and medium 

temperature, single-packaged dedicated 

systems. One small business 

manufactures 28 basic models of singlepackaged dedicated systems with an 

estimated annual revenue of $19 

million. Therefore, DOE estimates that 

the associated re-rating costs for this 

manufacturer to be approximately 

$81,650 when making use of AEDMs. 

The cost for this manufacturer 

represents less than 1 percent of annual 

revenue. 

The second small business 

manufactures 38 basic models of singlepackaged dedicated systems with an 

estimated annual revenue of $147 

million. Therefore, DOE estimates that 

the associated re-rating costs for this 

manufacturer to be approximately 

$82,100 when making use of AEDMs. 

The cost for this manufacturer 

represents less than 1 percent of annual 

revenue. 

(3) Small Business Impacts as a Result 

of New Test Procedures for HighTemperature Refrigeration Systems 

DOE is proposing test procedures for 

high-temperature refrigeration systems. 

DOE has granted waivers to certain 

manufacturers for high-temperature 

refrigeration systems. The test 

procedures proposed in this NOPR are 

consistent with the alternate test 

procedures included in the granted 

waivers, excluding the changes 

discussed previously about off-cycle 

power measurements. For those 

manufacturers who have been granted a 

test procedure waiver for this 

equipment, DOE expects the only test 

burden incurred would be that related 

to off-cycle requirements. However, 

DOE expects that there would be 

additional testing costs for any 

manufacturers of these products who 

have not submitted or been granted a 

test procedure waiver at the time this 

proposed test procedure is finalized. 

For manufacturers that have been 

granted waivers, DOE estimates that 

measuring off-cycle power at these 

additional ambient conditions may 

increase per-unit third-party lab test 

cost by $1,000 to a total per-unit cost of 

$11,000 for high-temperature outdoor 

dedicated condensing units, outdoor 

matched pair systems, and outdoor 

single-packaged dedicated systems. The 

physical testing cost, according to the 

proposed amendments, would be 

$22,000 per basic model for outdoor 

dedicated condensing units and outdoor 

matched pair systems.90

However, manufacturers are not 

required to perform laboratory testing 

on all basic models. In accordance with 

10 CFR 429.53, WICF refrigeration 

system manufacturers may elect to use 

AEDMs. DOE estimates the permanufacturer cost to develop and 

validate an AEDM for outdoor dedicated 

condensing units and outdoor matched 

pair systems to be $24,580 per 

validation class. DOE estimates an 

additional cost of approximately $46 per 

basic model 91 for determining energy 

efficiency using the validated AEDM. 


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23982 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

92Per the sampling requirements specified at 10 

CFR 429.53(a)(2)(ii) and 10 CFR 429.11(b), 

manufacturers are required to test at least two units 

to determine the rating for a basic model, except 

where only one unit of the basic model is produced. 

93Per the sampling requirements specified at 10 

CFR 429.53(a)(2)(ii) and 10 CFR 429.11(b), 

manufacturers are required to test at least two units 

to determine the rating for a basic model, except 

where only one unit of the basic model is produced. 

DOE estimated the potential costs to 

manufacturers of high-temperature units 

as a result of off-cycle requirements 

using an AEDM. Specifically, DOE 

estimated the range of potential costs for 

the five identified domestic, small 

OEMs that manufacture hightemperature units. When developing 

cost estimates for the small OEMs, DOE 

considers the cost to develop the AEDM 

simulation tool, the costs to validate the 

AEDM through physical testing, and the 

cost to rate basic models using the 

AEDM. DOE assumes a scenario where 

manufacturers would be required to 

develop AEDMs for three validation 

classes. 

DOE estimated the impacts based on 

basic model counts and company 

revenue. Table IV.2 summarizes DOE’s 

estimates for the five identified small 

businesses. On average, testing costs 

represent approximately 1.5 percent of 

annual revenue for a typical small 

business. 

TABLE IV.2—ESTIMATED SMALL BUSINESS RE-RATING COSTS (2022$) FOR HIGH-TEMPERATURE REFRIGERATION

SYSTEMS

Manufacturer 

Re-rating 

estimate 

($mm) 

Annual 

revenue 

estimate 

($mm) 

Percent of 

revenue 

(%) 

Manufacturer A ............................................................................................................................ 0.075 2.1 3.57 

Manufacturer B ............................................................................................................................ 0.074 3.6 2.06 

Manufacturer C ............................................................................................................................ 0.074 8.9 0.84 

Manufacturer D ............................................................................................................................ 0.076 11 0.70 

Manufacturer E ............................................................................................................................ 0.075 14 0.53 

For manufacturers that have not been 

granted waivers, manufacturers of hightemperature equipment may incur firsttime rating expenses. DOE estimates 

these manufacturers may incur rating 

expenses up to $22,000 per basic model 

for a high-temperature matched pair, 

$22,000 per basic model for a singlepackaged dedicated system, and $12,000 

per basic model for a high-temperature 

unit cooler.92

(4) Small Business Impacts as a Result 

of New Test Procedures for CO2 Unit 

Coolers 

Lastly, DOE is proposing test 

procedures for CO2 unit coolers. DOE 

has granted waivers to certain 

manufacturers for CO2 unit coolers. In 

this proposal, DOE is proposing that 

CO2 refrigeration systems, as DOE 

proposed to define in section III.A.2.h of 

this NOPR, meet the definition of a 

walk-in, but that the DOE test procedure 

is applicable only to single-packaged 

dedicated and to unit cooler variants of 

CO2 refrigeration systems. All CO2

refrigerant waiver petitions DOE has 

thus far received address unit coolers. 

86 FR 32332, 32346. 

The test procedures proposed in this 

NOPR are consistent with the alternate 

test procedures included in the granted 

waivers. For those manufacturers who 

have been granted a test procedure 

waiver for this equipment, DOE expects 

no change in test burden. However, DOE 

expects that there would be additional 

testing costs for any manufacturers of 

these products who have not submitted 

or been granted a test procedure waiver 

at the time this proposed test procedure 

is finalized. This additional cost is 

partially offset because, without a 

method of test, manufacturers of these 

products would not be able to sell them 

in the U.S. since there would be no way 

of certifying their energy use as required 

EPCA. 

For manufacturers that have not been 

granted waivers, manufacturers of CO2

equipment may incur first-time rating 

expenses. DOE estimates these 

manufacturers may incur rating 

expenses up to $13,000 per-unit for a 

low temperature CO2 unit cooler and 

$12,000 per-unit for a medium 

temperature CO2 unit cooler.93

However, manufacturers of CO2 unit 

coolers may choose to utilize an AEDM. 

Furthermore, AEDM unit cooler 

validation classes do not distinguish 

between CO2 unit coolers and non-CO2

unit coolers. Therefore, manufacturers 

of CO2 unit coolers may use the same 

validation classes as non-CO2 unit 

coolers. 

Issue 41: DOE requests comment on 

its cost estimate of impacts on small, 

domestic OEMs of refrigeration systems. 

5. Duplication, Overlap, and Conflict 

With Other Rules and Regulations 

DOE is not aware of any rules or 

regulations that duplicate, overlap, or 

conflict with the rule being considered 

in this document. 

6. Significant Alternatives to the Rule 

DOE proposes to reduce burden on 

manufacturers, including small 

businesses, by allowing AEDMs in lieu 

of physically testing all basic models. 

The use of an AEDM is less costly than 

physical testing WICF components. For 

doors, DOE’s proposed inclusion of 

AEDM provisions would allow 

manufacturers to develop an AEDM for 

rating their models. Without an AEDM, 

DOE estimates physical testing would 

cost door manufacturers $10,000 per 

basic model. With the use of an AEDM, 

DOE estimates the costs of $11,100 to 

develop and validate a single validation 

class plus an additional $46 per basic 

model yielding savings to manufacturers 

that produce more than one basic model 

of door. For refrigeration systems, DOE 

estimates $24,580 at the high-end of the 

range to develop and validate an AEDM 

with an additional cost of $46 per basic 

model. With a high-end cost of 

approximately $22,000 per basic model 

to physically test refrigeration models, 

manufacturers of three or more basic 

models could yield cost savings. 

Additional compliance flexibilities 

may be available through other means. 

For example, manufacturers subject to 

DOE’s energy efficiency standards may 

apply to DOE’s Office of Hearings and 

Appeals for exception relief under 

certain circumstances. Manufacturers 

should refer to 10 CFR part 1003 for 

additional details. 

C. Review Under the Paperwork 

Reduction Act of 1995 

Manufacturers of walk-ins must 

certify to DOE that their products 

comply with any applicable energy 

conservation standards. To certify 


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compliance, manufacturers must first 

obtain test data for their products 

according to the DOE test procedures, 

including any amendments adopted for 

those test procedures. DOE has 

established regulations for the 

certification and recordkeeping 

requirements for all covered consumer 

products and commercial equipment, 

including walk-ins. See generally 10 

CFR part 429. The collection-ofinformation requirement for the 

certification and recordkeeping is 

subject to review and approval by the 

Office of Management and Budget 

(‘‘OMB’’) under the Paperwork 

Reduction Act (‘‘PRA’’). This 

requirement has been approved by OMB 

under OMB control number 1910–1400. 

Public reporting burden for the 

certification is estimated to average 35 

hours per response, including the time 

for reviewing instructions, searching 

existing data sources, gathering and 

maintaining the data needed, and 

completing and reviewing the collection 

of information. 

DOE is not proposing to amend the 

certification or reporting requirements 

for walk-ins in this NOPR. Instead, DOE 

may consider proposals to amend the 

certification requirements and reporting 

for walk-ins under a separate 

rulemaking regarding appliance and 

equipment certification. DOE will 

address changes to OMB Control 

Number 1910–1400 at that time, as 

necessary. 

Notwithstanding any other provision 

of the law, no person is required to 

respond to, nor shall any person be 

subject to a penalty for failure to comply 

with, a collection of information subject 

to the requirements of the PRA, unless 

that collection of information displays a 

currently valid OMB Control Number. 

D. Review Under the National 

Environmental Policy Act of 1969 

In this NOPR, DOE proposes test 

procedure amendments that it expects 

would be used to develop and 

implement future energy conservation 

standards for walk-in coolers and 

freezers. DOE has determined that this 

rule falls into a class of actions that are 

categorically excluded from review 

under the National Environmental 

Policy Act of 1969 (42 U.S.C. 4321 et 

seq.) and DOE’s implementing 

regulations at 10 CFR part 1021. 

Specifically, DOE has tentatively 

determined that adopting test 

procedures for measuring energy 

efficiency of consumer products and 

industrial equipment is consistent with 

activities identified in 10 CFR part 1021, 

appendix A to subpart D, A5 and A6. 

See also 10 CFR 1021.410. DOE will 

complete its NEPA review before 

issuing the final rule. 

E. Review Under Executive Order 13132 

Executive Order 13132, ‘‘Federalism,’’ 

64 FR 43255 (Aug. 4, 1999), imposes 

certain requirements on agencies 

formulating and implementing policies 

or regulations that preempt State law or 

that have federalism implications. The 

Executive order requires agencies to 

examine the constitutional and statutory 

authority supporting any action that 

would limit the policymaking discretion 

of the States and to carefully assess the 

necessity for such actions. The 

Executive order also requires agencies to 

have an accountable process to ensure 

meaningful and timely input by State 

and local officials in the development of 

regulatory policies that have federalism 

implications. On March 14, 2000, DOE 

published a statement of policy 

describing the intergovernmental 

consultation process it will follow in the 

development of such regulations. 65 FR 

13735. DOE has examined this proposed 

rule and has tentatively determined that 

it would not have a substantial direct 

effect on the States, on the relationship 

between the National Government and 

the States, or on the distribution of 

power and responsibilities among the 

various levels of government. EPCA 

governs and prescribes Federal 

preemption of State regulations as to 

energy conservation for the products 

that are the subject of this proposed 

rule. States can petition DOE for 

exemption from such preemption to the 

extent, and based on criteria, set forth in 

EPCA. (42 U.S.C. 6297(d)) No further 

action is required by Executive Order 

13132. 

F. Review Under Executive Order 12988 

Regarding the review of existing 

regulations and the promulgation of 

new regulations, section 3(a) of 

Executive Order 12988, ‘‘Civil Justice 

Reform,’’ 61 FR 4729 (Feb. 7, 1996), 

imposes on Federal agencies the general 

duty to adhere to the following 

requirements: (1) Eliminate drafting 

errors and ambiguity, (2) write 

regulations to minimize litigation, (3) 

provide a clear legal standard for 

affected conduct rather than a general 

standard, and (4) promote simplification 

and burden reduction. Section 3(b) of 

Executive Order 12988 specifically 

requires that executive agencies make 

every reasonable effort to ensure that the 

regulation (1) clearly specifies the 

preemptive effect, if any, (2) clearly 

specifies any effect on existing Federal 

law or regulation, (3) provides a clear 

legal standard for affected conduct 

while promoting simplification and 

burden reduction, (4) specifies the 

retroactive effect, if any, (5) adequately 

defines key terms, and (6) addresses 

other important issues affecting clarity 

and general draftsmanship under any 

guidelines issued by the Attorney 

General. Section 3(c) of Executive Order 

12988 requires executive agencies to 

review regulations in light of applicable 

standards in sections 3(a) and 3(b) to 

determine whether they are met, or it is 

unreasonable to meet one or more of 

them. DOE has completed the required 

review and determined that, to the 

extent permitted by law, the proposed 

rule meets the relevant standards of 

Executive Order 12988. 

G. Review Under the Unfunded 

Mandates Reform Act of 1995 

Title II of the Unfunded Mandates 

Reform Act of 1995 (‘‘UMRA’’) requires 

each Federal agency to assess the effects 

of Federal regulatory actions on State, 

local, and Tribal governments, and the 

private sector. Public Law 104–4, sec. 

201 (codified at 2 U.S.C. 1531). For a 

proposed regulatory action likely to 

result in a rule that may cause the 

expenditure by State, local, and Tribal 

governments, in the aggregate, or by the 

private sector of $100 million or more 

in any one year (adjusted annually for 

inflation), section 202 of UMRA requires 

a Federal agency to publish a written 

statement that estimates the resulting 

costs, benefits, and other effects on the 

national economy. (2 U.S.C. 1532(a), (b)) 

The UMRA also requires a Federal 

agency to develop an effective process 

to permit timely input by elected 

officers of State, local, and Tribal 

governments on a proposed ‘‘significant 

intergovernmental mandate,’’ and 

requires an agency plan for giving notice 

and opportunity for timely input to 

potentially affected small governments 

before establishing any requirements 

that might significantly or uniquely 

affect small governments. On March 18, 

1997, DOE published a statement of 

policy on its process for 

intergovernmental consultation under 

UMRA. 62 FR 12820; also available at 

energy.gov/gc/office-general-counsel. 

DOE examined this proposed rule 

according to UMRA and its statement of 

policy and determined that the rule 

contains neither an intergovernmental 

mandate, nor a mandate that may result 

in the expenditure of $100 million or 

more in any year, so these requirements 

do not apply. 

H. Review Under the Treasury and 

General Government Appropriations 

Act, 1999 

Section 654 of the Treasury and 

General Government Appropriations 


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Act, 1999 (Pub. L. 105–277), requires 

Federal agencies to issue a Family 

Policymaking Assessment for any rule 

that may affect family well-being. This 

proposed rule would not have any 

impact on the autonomy or integrity of 

the family as an institution. 

Accordingly, DOE has concluded that it 

is not necessary to prepare a Family 

Policymaking Assessment. 

I. Review Under Executive Order 12630 

DOE has determined, under Executive 

Order 12630, ‘‘Governmental Actions 

and Interference with Constitutionally 

Protected Property Rights,’’ 53 FR 8859 

(March 18, 1988), that this proposed 

regulation would not result in any 

takings that might require compensation 

under the Fifth Amendment to the U.S. 

Constitution. 

J. Review Under Treasury and General 

Government Appropriations Act, 2001 

Section 515 of the Treasury and 

General Government Appropriations 

Act, 2001 (44 U.S.C. 3516 note), 

provides for agencies to review most 

disseminations of information to the 

public under guidelines established by 

each agency pursuant to general 

guidelines issued by OMB. OMB’s 

guidelines were published at 67 FR 

8452 (Feb. 22, 2002), and DOE’s 

guidelines were published at 67 FR 

62446 (Oct. 7, 2002). Pursuant to OMB 

Memorandum M–19–15, Improving 

Implementation of the Information 

Quality Act (April 24, 2019), DOE 

published updated guidelines which are 

available at www.energy.gov/sites/prod/ 

files/2019/12/f70/DOE%20Final

%20Updated%20IQA%20Guidelines

%20Dec%202019.pdf. DOE has 

reviewed this proposed rule under the 

OMB and DOE guidelines and has 

concluded that it is consistent with 

applicable policies in those guidelines. 

K. Review Under Executive Order 13211 

Executive Order 13211, ‘‘Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use,’’ 66 FR 28355 (May 

22, 2001), requires Federal agencies to 

prepare and submit to OMB, a 

Statement of Energy Effects for any 

proposed significant energy action. A 

‘‘significant energy action’’ is defined as 

any action by an agency that 

promulgated or is expected to lead to 

promulgation of a final rule, and that (1) 

is a significant regulatory action under 

Executive Order 12866, or any successor 

order; and (2) is likely to have a 

significant adverse effect on the supply, 

distribution, or use of energy; or (3) is 

designated by the Administrator of 

OIRA as a significant energy action. For 

any proposed significant energy action, 

the agency must give a detailed 

statement of any adverse effects on 

energy supply, distribution, or use 

should the proposal be implemented, 

and of reasonable alternatives to the 

action and their expected benefits on 

energy supply, distribution, and use. 

The proposed regulatory action to 

amend the test procedure for measuring 

the energy efficiency of walk-ins is not 

a significant regulatory action under 

Executive Order 12866. Moreover, it 

would not have a significant adverse 

effect on the supply, distribution, or use 

of energy, nor has it been designated as 

a significant energy action by the 

Administrator of OIRA. Therefore, it is 

not a significant energy action, and, 

accordingly, DOE has not prepared a 

Statement of Energy Effects. 

L. Review Under Section 32 of the 

Federal Energy Administration Act of 

1974 

Under section 301 of the Department 

of Energy Organization Act (Pub. L. 95– 

91; 42 U.S.C. 7101), DOE must comply 

with section 32 of the Federal Energy 

Administration Act of 1974, as amended 

by the Federal Energy Administration 

Authorization Act of 1977. (15 U.S.C. 

788; ‘‘FEAA’’) Section 32 essentially 

provides in relevant part that, where a 

proposed rule authorizes or requires use 

of commercial standards, the notice of 

proposed rulemaking must inform the 

public of the use and background of 

such standards. In addition, section 

32(c) requires DOE to consult with the 

Attorney General and the Chairman of 

the Federal Trade Commission (‘‘FTC’’) 

concerning the impact of the 

commercial or industry standards on 

competition. 

The proposed modifications to the 

test procedure for walk-ins would 

incorporate testing methods contained 

in certain sections of the following 

commercial standards: NFRC 102–2020, 

ASTM C1199–14, ASTM C518–17, 

AHRI 1250–2020, ASHRAE 37–2009, 

AHRI 1250–2020, ANSI/ASHRAE 37– 

2009, and ANSI/ASHRAE 16–2016. 

DOE has evaluated these standards and 

is unable to conclude whether they fully 

comply with the requirements of section 

32(b) of the FEAA (i.e., whether they 

were developed in a manner that fully 

provides for public participation, 

comment, and review). DOE will 

consult with both the Attorney General 

and the Chairman of the FTC 

concerning the impact of these test 

procedures on competition, prior to 

prescribing a final rule. 

M. Description of Materials 

Incorporated by Reference 

In this NOPR, DOE proposes to 

incorporate by reference the following 

industry test standards into 10 CFR part 

431: 

(1) AHRI Standard 1250–2020, 

‘‘Standard for Performane Rating of 

Walk-in Coolers and Freezers,’’ 

copyright 2020. 

AHRI 1250–2020 is an industryaccepted test procedure for measuring 

the performance of walk-in cooler and 

walk-in freezer refrigeration systems. 

AHRI 1250–2020 is available on AHRI’s 

website at www.ahrinet.org/searchstandards. 

(2) ANSI/ASHRAE Standard 16–2016, 

‘‘Method of Testing for Rating Room Air 

Conditioners, Packaged Terminal Air 

Conditioners, and Packaged Terminal 

Heat Pumps for Cooling and Heating 

Capacity,’’ approved October 31, 2016. 

ANSI/ASHRAE 16 is an industryaccepted test procedure for measuring 

cooling and heating capacity of room air 

conditioners, packaged terminal air 

conditioners, and packaged terminal 

heat pumps referenced by AHRI 1250– 

2020. ANSI/ASHRAE 16 includes test 

provisions related to the measuring of 

the capacity of single-packaged 

dedicated systems for the proposed 

appendix C1 test procedure. ANSI/ 

ASHRAE 16 is available on ASHRAE’s 

website at www.ashrae.org. 

(3) ANSI/ASHRAE Standard 37–2009, 

‘‘Methods of Testing for Rating 

Electrically Driven Unitary AirConditioning and Heat Pump 

Equipment,’’ approved June 24, 2009. 

ANSI/ASHRAE 37 is an industryaccepted test procedure for testing and 

rating air-conditioning and heat pump 

equipment referenced by AHRI 1250– 

2020. ANSI/ASHRAE 37 includes test 

provisions related to the measuring of 

the capacity of single-packaged 

dedicated systems for the proposed 

appendix C1 test procedure. ANSI/ 

ASHRAE 37 is available on ASHRAE’s 

website at www.ashrae.org. 

(4) ASTM C518–17, ‘‘Standard Test 

Method for Steady state Thermal 

Transmission Properties by Means of 

the Heat Flow Meter Apparatus,’’ 

approved May 1, 2017. 

ASTM C518–17 is an industryaccepted test procedure for measuring 

thermal transmission properties using a 

heat flow meter apparatus. ASTM C518– 

17 is available on ASTM’s website at 

www.astm.org. 

(5) ASTM C1199–14, ‘‘Standard Test 

Method for Measuring the Steady state 

Thermal Transmittance of Fenestration 

Systems Using Hot Box Methods,’’ 

approved February 1, 2014. 


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94 DOE has historically provided a 75-day 

comment period for test procedure NOPRs pursuant 

to the North American Free Trade Agreement, U.S.- 

Canada-Mexico (‘‘NAFTA’’), Dec. 17, 1992, 32 

I.L.M. 289 (1993); the North American Free Trade 

Agreement Implementation Act, Public Law 103– 

182, 107 Stat. 2057 (1993) (codified as amended at 

10 U.S.C.A. 2576) (1993) (‘‘NAFTA Implementation 

Act’’); and Executive Order 12889, ‘‘Implementation 

of the North American Free Trade Agreement,’’ 58 

FR 69681 (Dec. 30, 1993). However, on July 1, 2020, 

the Agreement between the United States of 

America, the United Mexican States, and the United 

Canadian States (‘‘USMCA’’), Nov. 30, 2018, 134 

Stat. 11 (i.e., the successor to NAFTA), went into 

effect, and Congress’s action in replacing NAFTA 

through the USMCA Implementation Act, 19 U.S.C. 

4501 et seq. (2020), implies the repeal of E.O. 12889 

and its 75-day comment period requirement for 

technical regulations. Thus, the controlling laws are 

EPCA and the USMCA Implementation Act. 

Consistent with EPCA’s public comment period 

requirements for consumer products, the USMCA 

only requires a minimum comment period of 60 

days. Consequently, DOE now provides a 60-day 

public comment period for test procedure NOPRs. 

ASTM C1199–14 is an industryaccepted test procedure for measuring 

the steady state thermal transmittance of 

fenestration systems referenced by 

NFRC 102–2020. ASTM C1199–14 is 

available on ASTM’s website at 

www.astm.org. 

(6) NFRC 102–2020 [E0A0], 

‘‘Procedure for Measuring the SteadyState Thermal Transmittance of 

Fenestration Systems.’’ 

NFRC 102–2020 is an industryaccepted test procedure for measuring 

the steady state thermal transmittance of 

fenestration systems. NFRC 102–2020 is 

available on NFRC’s website at 

www.nfrc.org/. 

The following standards were 

approved on December 28, 2016, for IBR 

into the provisions where they appear in 

this document and no change in use is 

proposed: ANSI/AHRI Standard 420– 

2008, AHRI Standard 1250 (I–P)–2009, 

and ANSI/ASHRAE Standard 23.1– 

2010. 

V. Public Participation 

A. Participation in the Webinar 

The time and date of the webinar are 

listed in the DATES section at the 

beginning of this document. Webinar 

registration information, participant 

instructions, and information about the 

capabilities available to webinar 

participants will be published on DOE’s 

website: www.energy.gov/eere/ 

buildings/public-meetings-andcomment-deadlines. Participants are 

responsible for ensuring their systems 

are compatible with the webinar 

software. 

B. Procedure for Submitting Prepared 

General Statements for Distribution 

Any person who has an interest in the 

topics addressed in this document, or 

who is representative of a group or class 

of persons that has an interest in these 

issues, may request an opportunity to 

make an oral presentation at the 

webinar. Such persons may submit to 

ApplianceStandardsQuestions@

ee.doe.gov. Persons who wish to speak 

should include with their request a 

computer file in WordPerfect, Microsoft 

Word, PDF, or text (ASCII) file format 

that briefly describes the nature of their 

interest in this proposed rulemaking 

and the topics they wish to discuss. 

Such persons should also provide a 

daytime telephone number where they 

can be reached. 

Persons requesting to speak should 

briefly describe the nature of their 

interest in this rulemaking and provide 

a telephone number for contact. DOE 

requests persons selected to make an 

oral presentation to submit an advance 

copy of their statements at least two 

weeks before the webinar. At its 

discretion, DOE may permit persons 

who cannot supply an advance copy of 

their statement to participate, if those 

persons have made advance alternative 

arrangements with the Building 

Technologies Office. As necessary, 

requests to give an oral presentation 

should ask for such alternative 

arrangements. 

C. Conduct of the Webinar 

DOE will designate a DOE official to 

preside at the webinar/public meeting 

and may also use a professional 

facilitator to aid discussion. The 

meeting will not be a judicial or 

evidentiary-type public hearing, but 

DOE will conduct it in accordance with 

section 336 of EPCA (42 U.S.C. 6306). A 

court reporter will be present to record 

the proceedings and prepare a 

transcript. DOE reserves the right to 

schedule the order of presentations and 

to establish the procedures governing 

the conduct of the webinar/public 

meeting. There shall not be discussion 

of proprietary information, costs or 

prices, market share, or other 

commercial matters regulated by U.S. 

anti-trust laws. After the webinar/public 

meeting and until the end of the 

comment period, interested parties may 

submit further comments on the 

proceedings and any aspect of the 

proposed rulemaking. 

The webinar/public meeting will be 

conducted in an informal, conference 

style. DOE will present a general 

overview of the topics addressed in this 

proposed rulemaking, allow time for 

prepared general statements by 

participants, and encourage all 

interested parties to share their views on 

issues affecting this proposed 

rulemaking. Each participant will be 

allowed to make a general statement 

(within time limits determined by DOE), 

before the discussion of specific topics. 

DOE will permit, as time permits, other 

participants to comment briefly on any 

general statements. 

At the end of all prepared statements 

on a topic, DOE will permit participants 

to clarify their statements briefly. 

Participants should be prepared to 

answer questions by DOE and by other 

participants concerning these issues. 

DOE representatives may also ask 

questions of participants concerning 

other matters relevant to this proposed 

rulemaking. The official conducting the 

webinar/public meeting will accept 

additional comments or questions from 

those attending, as time permits. The 

presiding official will announce any 

further procedural rules or modification 

of the procedures that may be needed 

for the proper conduct of the webinar/ 

public meeting. 

A transcript of the webinar/public 

meeting will be included in the docket, 

which can be viewed as described in the 

Docket section at the beginning of this 

proposed rule. In addition, any person 

may buy a copy of the transcript from 

the transcribing reporter. 

D. Submission of Comments 

DOE will accept comments, data, and 

information regarding this proposed 

rule no later than the date provided in 

the DATES section at the beginning of 

this proposed rule.94 Interested parties 

may submit comments using any of the 

methods described in the ADDRESSES

section at the beginning of this 

document. 

Submitting comments via 

www.regulations.gov. The 

www.regulations.gov web page will 

require you to provide your name and 

contact information. Your contact 

information will be viewable to DOE 

Building Technologies staff only. Your 

contact information will not be publicly 

viewable except for your first and last 

names, organization name (if any), and 

submitter representative name (if any). 

If your comment is not processed 

properly because of technical 

difficulties, DOE will use this 

information to contact you. If DOE 

cannot read your comment due to 

technical difficulties and cannot contact 

you for clarification, DOE may not be 

able to consider your comment. 

However, your contact information 

will be publicly viewable if you include 

it in the comment or in any documents 

attached to your comment. Any 

information that you do not want to be 

publicly viewable should not be 

included in your comment, nor in any 

document attached to your comment. 


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23986 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

Persons viewing comments will see only 

first and last names, organization 

names, correspondence containing 

comments, and any documents 

submitted with the comments. 

Do not submit to www.regulations.gov 

information for which disclosure is 

restricted by statute, such as trade 

secrets and commercial or financial 

information (hereinafter referred to as 

Confidential Business Information 

(‘‘CBI’’)). Comments submitted through 

www.regulations.gov cannot be claimed 

as CBI. Comments received through the 

website will waive any CBI claims for 

the information submitted. For 

information on submitting CBI, see the 

Confidential Business Information 

section. 

DOE processes submissions made 

through www.regulations.gov before 

posting. Normally, comments will be 

posted within a few days of being 

submitted. However, if large volumes of 

comments are being processed 

simultaneously, your comment may not 

be viewable for up to several weeks. 

Please keep the comment tracking 

number that www.regulations.gov 

provides after you have successfully 

uploaded your comment. 

Submitting comments via email. 

Comments and documents submitted 

via email also will be posted to 

www.regulations.gov. If you do not want 

your personal contact information to be 

publicly viewable, do not include it in 

your comment or any accompanying 

documents. Instead, provide your 

contact information on a cover letter. 

Include your first and last names, email 

address, telephone number, and 

optional mailing address. The cover 

letter will not be publicly viewable as 

long as it does not include any 

comments. 

Include contact information each time 

you submit comments, data, documents, 

and other information to DOE. No faxes 

will be accepted. 

Comments, data, and other 

information submitted to DOE 

electronically should be provided in 

PDF (preferred), Microsoft Word or 

Excel, WordPerfect, or text (ASCII) file 

format. Provide documents that are not 

secured, written in English and free of 

any defects or viruses. Documents 

should not contain special characters or 

any form of encryption and, if possible, 

they should carry the electronic 

signature of the author. 

Campaign form letters. Please submit 

campaign form letters by the originating 

organization in batches of between 50 to 

500 form letters per PDF or as one form 

letter with a list of supporters’ names 

compiled into one or more PDFs. This 

reduces comment processing and 

posting time. 

Confidential Business Information. 

Pursuant to 10 CFR 1004.11, any person 

submitting information that he or she 

believes to be confidential and exempt 

by law from public disclosure should 

submit via email two well-marked 

copies: One copy of the document 

marked confidential including all the 

information believed to be confidential, 

and one copy of the document marked 

non-confidential with the information 

believed to be confidential deleted. DOE 

will make its own determination about 

the confidential status of the 

information and treat it according to its 

determination. 

It is DOE’s policy that all comments 

may be included in the public docket, 

without change and as received, 

including any personal information 

provided in the comments (except 

information deemed to be exempt from 

public disclosure). 

E. Issues on Which DOE Seeks Comment 

Although DOE welcomes comments 

on any aspect of this proposal, DOE is 

particularly interested in receiving 

comments and views of interested 

parties concerning the following issues: 

Issue 1: DOE requests comment on its 

proposed changes to the definition for 

walk-in cooler and walk-in freezer. 

Issue 2: DOE requests feedback on the 

proposed changes to the definition of 

‘‘door’’ and the newly proposed 

definition for ‘‘door leaf.’’ DOE also 

seeks comment on the newly proposed 

definitions for certain door opening 

characteristics: ‘‘hinged vertical door,’’ 

‘‘roll-up door,’’ and ‘‘sliding door.’’ 

Issue 3: DOE requests comment on the 

proposed definition of ‘‘ducted fan coil 

unit’’ and on the proposed modification 

to the ‘‘single-packaged dedicated 

system’’ definition. 

Issue 4: DOE requests comment on the 

proposed definition for multi-circuit 

single-packaged dedicated refrigeration 

systems. 

Issue 5: DOE requests comment on the 

proposed definition for attached split 

system. 

Issue 6: DOE requests comment on the 

proposed definition for detachable 

single-packaged dedicated system. 

Issue 7: DOE requests comment on the 

proposed definition of CO2 unit coolers. 

DOE also requests comment on whether 

any distinguishing features of CO2 unit 

coolers exist that could reliably be used 

as an alternative approach that can 

differentiate them from those unit 

coolers intended for use with 

conventional refrigerants. 

Issue 8: DOE requests comment on the 

proposed definition for hot gas defrost. 

Specifically, DOE requests comment on 

if this proposed definition is sufficient 

to identify which equipment is sold 

with hot gas defrost capability installed 

and which is not. 

Issue 9: DOE requests feedback on the 

proposed provisions relating to test 

specimen and total insulation thickness 

and test specimen preparation prior to 

conducting the ASTM C518–17 test. 

Issue 10: DOE requests feedback on 

the proposed provisions relating to 

determining parallelism and flatness of 

the test specimen. 

Issue 11: DOE seeks comment on 

other comparable data or studies of 

aging of foam panels that are 

representative of the foam insulation, 

blowing agents, and panel construction 

currently used in the manufacture of 

walk-in panels. DOE also requests 

comment on whether manufacturers 

have been certifying R-value at time of 

manufacture or after a period of aging. 

Issue 12: DOE requests comment on 

the proposed pretest coil inspection 

requirement. DOE requests comment on 

whether the proposed approach is 

inconsistent in any way with the way 

units under test are used to assist in 

chamber conditioning by testing 

facilities, and if so, in what way are the 

proposals inconsistent, and how could 

they be changed to align with this 

practice. 

Issue 13: DOE requests comment on 

its proposal to require use of 

thermometer wells or sheathed sensors 

immersed in the refrigerant when 

measuring temperature at the liquid 

outlet of the condensing unit and to 

forego the requirement for this 

measurement technique for the suction 

line when testing a dedicated 

condensing unit alone. 

Issue 14: DOE requests comment on 

its proposal to allow the use of two 

temperature measuring instruments, 

placed on the outside of refrigerant 

tubing that is less than or equal to 1⁄2- 

inch, for the measurement of refrigerant 

temperature where the current test 

procedure requirement is to use 

thermometer wells or a sheathed sensor 

immersed in the refrigerant. 

Issue 15: DOE requests comment on 

its proposals discussed in this section 

regarding set up of walk-in refrigeration 

systems for testing to achieve 

manufacturer-specified conditions for 

superheat, subcooling, high-side 

temperature, pressure or saturation 

temperature, low-side temperature, 

pressure or saturation temperature, and 

refrigerant charge weight. Additionally, 

DOE requests comment on the proposed 

hierarchy presented in Table III.6, if a 

laboratory has confirmed that the unit is 

properly charged. 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23987 

Issue 16: DOE requests comments on 

its proposal to clarify the location where 

the 3 °F subcooling requirement would 

apply and to require active cooling of 

the liquid line in order to achieve the 

required 3 °F subcooling at a refrigerant 

mass flow meter. DOE also seeks 

comment on its proposal to require, for 

matched pairs, adjustment of the 

measured unit cooler inlet temperature 

by the difference in temperatures 

measured upstream and downstream of 

the active cooling in order to calculate 

the inlet enthalpy in the capacity 

calculation. 

Issue 17: DOE requests comment on 

the appropriateness of traditional 

refrigerant compressor EER values for 

use in CO2 unit cooler AWEF 

calculations. 

Issue 18: DOE requests comment on 

its proposals to adopt test procedure 

provisions for high-temperature unit 

coolers in appendices C and C1 of 10 

CFR part 431, subpart R. 

Issue 19: DOE requests comments on 

its proposals to align the test procedures 

for appendix C1 with AHRI 1250–2020, 

except for the use of off-cycle power 

measurements in the AWEF calculations 

for dedicated condensing units, 

matched pairs, or single-packaged 

dedicated systems intended for outdoor 

installation. DOE requests comments on 

its proposals for use in the AWEF 

calculations of the three sets of unit 

cooler and condensing unit off-cycle 

measurements made for outdoor 

refrigeration systems. 

Issue 20: DOE requests comment on 

the proposed single-packaged refrigerant 

enthalpy test procedure for evaluating 

the performance of single-packaged 

dedicated systems. 

Issue 21: DOE requests comment on 

testing detachable single-packaged 

dedicated systems using the test 

procedure for single-packaged dedicated 

systems. 

Issue 22: DOE requests comment on 

its proposal that attached split systems 

be tested using refrigerant enthalpy 

methods. 

Issue 23: DOE requests comment on 

provisions for setting ESP when testing 

ducted units. 

Issue 24: DOE requests comments on 

its proposals for testing multiple-, 

variable-, and two-capacity dedicated 

condensing units tested alone. DOE 

specifically requests comments on (a) 

the expectation that a unit cooler with 

which such a condensing unit is paired 

in the field would have two-speed (or 

variable-speed) fans or be fitted with 

such fans during installation, (b) the 

proposed compressor operating levels to 

use for testing, (c) the proposed 

compressor operating level at which the 

unit cooler fan would be assumed to 

switch to half-speed, (d) the proposed 

targets for unit cooler exit and 

condensing unit inlet refrigerant 

temperatures and dew point target 

temperatures, and (e) the unit cooler 

half-fan-speed input wattage. 

Issue 25: DOE requests comment on 

whether DOE should set the target test 

conditions using correlations for unit 

cooler and suction line response to partload operation rather than the proposed 

tabular approach. 

Issue 26: DOE requests comment on 

its proposal to include in its test 

procedures instructions for testing and 

determining representations for indoor 

matched pair and single-packaged 

dedicated systems. 

Issue 27: DOE requests comment on 

its proposal to modify the approach for 

calculating intermediate-capacity EER 

for variable-speed refrigeration systems. 

Issue 28: DOE requests comments on 

its proposals to address part-load testing 

for refrigeration systems with digital 

compressors. 

Issue 29: DOE requests comment on 

its proposal to clarify that the second 

mass flow measurement for the DX Dual 

Instrumentation method may be in the 

suction line upstream of the inlet to the 

condensing unit, as shown in Figure C1 

of AHRI 1250–2009. 

Issue 30: DOE requests comment on 

its proposal to adopt the calculations for 

evaporator fan power in AHRI 1250– 

2020. 

Issue 31: DOE requests comment on 

its proposal for rounding AWEF to the 

nearest 0.05 Btu/(W-h) and rounding 

capacity values to the nearest multiple 

as presented in Table III.14. 

Issue 32: DOE seeks comment on its 

proposal to allow for the use of AEDMs 

to determine the energy consumption 

rating of walk-in doors. DOE requests 

specific feedback on the proposed 5 

percent model tolerance for validating 

an AEDM, the proposed validation 

classes and number of basic models 

required to be tested per validation 

class, and the proposed 5 percent 

tolerance on the result from a DOE 

AEDM verification test. 

Issue 33: DOE seeks comment on its 

proposal to modify and extend its 

AEDM validation classes for 

refrigeration systems, consistent with 

the test procedure revisions discussed 

in this document. 

Issue 34: DOE requests comment on 

its proposal to apply the low-volume 

sampling procedures in appendix B of 

subpart C of 10 CFR part 429 to walkin doors and panels. 

Issue 35: DOE requests comment on 

its tentative understanding of the impact 

of the test procedure proposals for 

appendix A in this NOPR—specifically, 

whether the proposed test procedure 

amendments, if finalized, would either 

not impact or decrease the testing 

burden for walk-in door manufacturers 

when compared to the current DOE test 

procedure in appendix A. 

Issue 36: DOE requests comment on 

its tentative understanding of the impact 

of the test procedure proposals for 

appendix B in this NOPR—specifically, 

that the proposed test procedure 

amendments, if finalized, would not 

increase testing burden on panel 

manufacturers when compared to the 

current DOE test procedure in appendix 

B. 

Issue 37: DOE requests comment on 

its tentative understanding of the impact 

of the test procedure proposals for 

refrigeration systems—specifically, 

whether DOE’s initial conclusion that 

the proposed DOE test procedure 

amendments, if finalized, would 

increase testing burden. 

Issue 38: DOE invites comment on the 

number of small, domestic OEMs 

producing the three principal 

components of WICFs: Panels, doors, 

and refrigeration systems. 

Issue 39: DOE requests comment on 

its cost estimate of impacts on small, 

domestic OEMs of doors. 

Issue 40: DOE requests comment on 

its cost estimate of impacts on small, 

domestic OEMs of panels. 

Issue 41: DOE requests comment on 

its cost estimate of impacts on small, 

domestic OEMs of refrigeration systems. 

VI. Approval of the Office of the 

Secretary 

The Secretary of Energy has approved 

publication of this notice of proposed 

rulemaking and announcement of 

public webinar. 

List of Subjects 

10 CFR Part 429 

Administrative practice and 

procedure, Confidential business 

information, Energy conservation, 

Household appliances, Reporting and 

recordkeeping requirements. 

10 CFR Part 431 

Administrative practice and 

procedure, Confidential business 

information, Energy conservation test 

procedures, Incorporation by reference, 

and Reporting and recordkeeping 

requirements. 

Signing Authority 

This document of the Department of 

Energy was signed on March 18, 2022, 

by Kelly J. Speakes-Backman, Principal 

Deputy Assistant Secretary for Energy 

Efficiency and Renewable Energy, 


jspears on DSK121TN23PROD with PROPOSALS2
23988 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

pursuant to delegated authority from the 

Secretary of Energy. That document 

with the original signature and date is 

maintained by DOE. For administrative 

purposes only, and in compliance with 

requirements of the Office of the Federal 

Register, the undersigned DOE Federal 

Register Liaison Officer has been 

authorized to sign and submit the 

document in electronic format for 

publication, as an official document of 

the Department of Energy. This 

administrative process in no way alters 

the legal effect of this document upon 

publication in the Federal Register. 

Signed in Washington, DC, on March 23, 

2022. 

Treena V. Garrett, 

Federal Register Liaison Officer, U.S. 

Department of Energy. 

For the reasons stated in the 

preamble, DOE is proposing to amend 

parts 429 and 431 of chapter II of title 

10, Code of Federal Regulations as set 

forth below: 

PART 429—CERTIFICATION, 

COMPLIANCE, AND ENFORCEMENT 

FOR CONSUMER PRODUCTS AND 

COMMERCIAL AND INDUSTRIAL 

EQUIPMENT 

■ 1. The authority citation for part 429 

continues to read as follows: 

Authority: 42 U.S.C. 6291–6317; 28 U.S.C. 

2461 note. 

■ 2. Amend § 429.53 by: 

■ a. Revising paragraphs (a)(2)(i) and 

(a)(3); and 

■ b. Adding paragraph (a)(4). 

The revisions and addition read as 

follows: 

§ 429.53 Walk-in coolers and walk-in 

freezers. 

(a) * * * 

(2) * * * 

(i) Applicable test procedure. If the 

AWEF is determined by testing, test 

according to the applicable provisions 

of § 431.304(b) of this chapter with the 

equipment specific provisions in 

paragraphs (a)(2)(i)(A) through (D) of 

this section. 

(A) Dedicated condensing units. 

Outdoor dedicated condensing 

refrigeration systems that are also 

designated for use in indoor 

applications must be tested and rated as 

both an outdoor dedicated condensing 

refrigeration system and an indoor 

dedicated refrigeration system. 

(B) Matched refrigeration systems. A 

matched refrigeration system is not 

required to be rated if the constituent 

unit cooler(s) and dedicated condensing 

unit have been tested as specified in 

§ 431.304(b)(4) of this chapter. However, 

if a manufacturer wishes to represent 

the efficiency of the matched 

refrigeration system as distinct from the 

efficiency of either constituent 

component, or if the manufacturer 

cannot rate one or both of the 

constituent components using the 

specified method, the manufacturer 

must test and rate the matched 

refrigeration system as specified in 

§ 431.304(b)(4) of this chapter. 

(C) Detachable single-packaged 

dedicated systems. Detachable singlepackaged dedicated systems must be 

tested and rated as a single-packaged 

dedicated systems using the test 

procedure in § 431.304(b)(4) of this 

chapter. 

(D) Attached split systems. Attached 

split systems must be tested and rated 

as dedicated condensing units and unit 

coolers using the test procedure in 

§ 431.304(b)(4) of this chapter. 

* * * * * 

(3) For each basic model of walk-in 

cooler and walk-in freezer display and 

non-display door, the daily energy 

consumption must be determined by 

testing, in accordance with § 431.304 of 

this chapter and the provisions of this 

section, or by application of an 

alternative efficiency determination 

method (AEDM) that meets the 

requirements of § 429.70 and the 

provisions of this section. 

(i) Applicable test procedure. Prior to 

[180 days after publication of final rule], 

use the test procedure for walk-ins as it 

appeared in 10 CFR part 431, subpart R, 

appendix A, revised as of January 1, 

2021, to determine daily energy 

consumption. Beginning [180 days after 

publication of final rule], use the test 

procedure in part 431, subpart R, 

appendix A, of this chapter to determine 

daily energy consumption. 

(ii) Units to be tested. For each basic 

model, a sample of sufficient size shall 

be randomly selected and tested to 

ensure that any represented value of 

daily energy consumption of a basic 

model or other measure of energy use 

for which consumers would favor lower 

values shall be greater than or equal to 

the higher of: 

(A) The mean of the sample, where: 

And x ̄ is the sample mean, n is the 

number of samples, and xi is the ith

sample; or, 

(B) The upper 95 percent confidence 

limit (UCL) of the true mean divided by 

1.05, where: 

And x ̄ is the sample mean, s is the 

sample standard deviation; n is the 

number of samples, and t0.95 is the 

statistic for a 95% one-tailed confidence 

interval with n-1 degrees of freedom 

(from appendix A to this subpart). 

(4) For each basic model of walk-in 

cooler and walk-in freezer panel and 

non-display door, the R-value must be 

determined by testing, in accordance 

with § 431.304 of this chapter and the 

provisions of this section. 

(i) Applicable test procedure. Prior to 

[date 180 days after publication of final 

rule], use the test procedure for walk-ins 

as it appeared in 10 CFR part 431, 

subpart R, appendix B, revised as of 

January 1, 2021, to determine R-value. 

Beginning [date 180 days after 

publication of final rule], use the test 

procedure in part 431, subpart R, 

appendix B, of this chapter to determine 

R-value. 

(ii) Units to be tested. For each basic 

model, a sample of sufficient size shall 

be randomly selected and tested to 

ensure that any represented value of Rvalue or other measure of efficiency of 

a basic model for which consumers 

would favor higher values shall be less 

than or equal to the lower of: 

(A) The mean of the sample, where: 

And x ̄ is the sample mean, n is the 

number of samples, and xi is the ith

sample; or, 

(B) The lower 95 percent confidence 

limit (LCL) of the true mean divided by 

0.95, where: 

And x ̄ is the sample mean, s is the 

sample standard deviation; n is the 

number of samples, and t0.95 is the 

statistic for a 95% one-tailed confidence 

interval with n-1 degree of freedom 

(from appendix A to this subpart). 

* * * * * 

■ 3. Amend § 429.70 by: 

■ a. Revising paragraphs (f) heading and 

(f)(2)(ii)(A) and (B); 

■ b. Adding paragraph (f)(2)(ii)(C); 

■ c. Removing the word ‘‘and’’ at the 

end of paragraphs (f)(2)(iii)(A) and (C); 

■ d. Removing the period at the end of 

paragraph (f)(2)(iii)(D) and adding ‘‘; 

and’’ in its place; 

■ e. Adding paragraph (f)(2)(iii)(E); and 

■ f. Revising paragraphs (f)(2)(iv) and 

(f)(5)(vi). 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23989 

The revisions and additions read as 

follows: 

§ 429.70 Alternative methods for 

determining energy efficiency and energy 

use. 

* * * * * 

(f) Alternative efficiency 

determination method (AEDM) for walkin refrigeration systems and doors— 

* * * 

(2) * * * 

(ii) * * * 

(A) For refrigeration systems, which 

are subject to an energy efficiency 

metric, the predicted efficiency for each 

model calculated by applying the AEDM 

may not be more than five percent 

greater than the efficiency determined 

from the corresponding test of the 

model. 

(B) For doors, which are subject to an 

energy consumption metric the 

predicted daily energy consumption for 

each model calculated by applying the 

AEDM may not be more than five 

percent less than the daily energy 

consumption determined from the 

corresponding test of the model. 

(C) The predicted energy efficiency or 

energy consumption for each model 

calculated by applying the AEDM must 

meet or exceed the applicable Federal 

energy conservation standard. 

(iii) * * * 

(E) For rating doors, an AEDM may 

not simulate or model components of 

the door that are not required to be 

tested by the DOE test procedure. That 

is, if the test results used to validate the 

AEDM are for the U-factor test of the 

door, the AEDM must estimate the daily 

energy consumption, specifically the 

conduction thermal load, and the direct 

and indirect electrical energy 

consumption, using the nominal values 

and calculation procedure specified in 

the DOE test procedure. 

(iv) Walk-in coolers and freezers 

(WICF) validation classes—(A) Doors. 

TABLE 1 TO PARAGRAPH (f)(2)(iv)(A) 

Validation class 

Minimum number 

of distinct models 

that must be 

tested 

Display Doors, Medium Temperature ............................................................................................................................................ 2 Basic Models. 

Display Doors, Low Temperature ................................................................................................................................................... 2 Basic Models. 

Non-display Doors, Medium Temperature ..................................................................................................................................... 2 Basic Models. 

Non-display Doors, Low Temperature ........................................................................................................................................... 2 Basic Models. 

(B) Refrigeration systems. (1) For 

representations made prior to the 

compliance date of revised energy 

conservation standards for walk-in 

cooler and walk-in freezer refrigeration 

systems, use the following validation 

classes. 

TABLE 2 TO PARAGRAPH (f)(2)(iv)(B)(1) 

Validation class 

Minimum number 

of distinct models 

that must be 

tested 

Dedicated Condensing, Medium Temperature, Matched Pair Indoor System .............................................................................. 2 Basic Models. 

Dedicated Condensing, Medium Temperature, Matched Pair Outdoor System.1 2 Basic Models. 

Dedicated Condensing, Low Temperature, Matched Pair Indoor System .................................................................................... 2 Basic Models. 

Dedicated Condensing, Low Temperature, Matched Pair Outdoor System.1 2 Basic Models. 

Unit Cooler, High-temperature ....................................................................................................................................................... 2 Basic Models. 

Unit Cooler, Medium Temperature ................................................................................................................................................. 2 Basic Models. 

Unit Cooler, Low Temperature ....................................................................................................................................................... 2 Basic Models. 

Medium Temperature, Indoor Condensing Unit ............................................................................................................................. 2 Basic Models. 

Medium Temperature, Outdoor Condensing Unit.1 2 Basic Models. 

Low Temperature, Indoor Condensing Unit ................................................................................................................................... 2 Basic Models. 

Low Temperature, Outdoor Condensing Unit.1 2 Basic Models. 

1AEDMs validated for an outdoor class by testing only outdoor models of that class may be used to determine representative values for the 

corresponding indoor class, and additional validation testing is not required. AEDMs validated only for a given indoor class by testing indoor 

models or a mix of indoor and outdoor models may not be used to determine representative values for the corresponding outdoor class. 

(2) For representations made on or 

after the compliance date of revised 

energy conservation standards for walkin cooler and walk-in freezer refrigeration systems, use the following 

validation classes. 

TABLE 3 TO PARAGRAPH (f)(2)(iv)(B)(2) 

Validation class 

Minimum number 

of distinct models 

that must be 

tested 

Dedicated Condensing Unit, Medium Temperature, Indoor System ............................................................................................. 2 Basic Models. 

Dedicated Condensing Unit, Medium Temperature, Outdoor System.1 2 Basic Models. 

Dedicated Condensing Unit, Low Temperature, Indoor System ................................................................................................... 2 Basic Models. 

Dedicated Condensing Unit, Low Temperature, Outdoor System.1 2 Basic Models. 

Single-packaged Dedicated Condensing, High-temperature, Indoor System ............................................................................... 2 Basic Models. 


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TABLE 3 TO PARAGRAPH (f)(2)(iv)(B)(2)—Continued 

Validation class 

Minimum number 

of distinct models 

that must be 

tested 

Single-packaged Dedicated Condensing, High-temperature, Outdoor System.1 2 Basic Models. 

Single-packaged Dedicated Condensing, Medium Temperature, Indoor System ......................................................................... 2 Basic Models. 

Single-packaged Dedicated Condensing, Medium Temperature, Outdoor System.1 2 Basic Models. 

Single-packaged Dedicated Condensing, Low Temperature, Indoor System ............................................................................... 2 Basic Models. 

Single-packaged Dedicated Condensing, Low Temperature, Indoor System.1 2 Basic Models. 

Matched Pair, High-temperature, Indoor Condensing Unit ............................................................................................................ 2 Basic Models. 

Matched Pair, High-temperature, Outdoor Condensing Unit.1 2 Basic Models. 

Matched Pair, Medium Temperature, Indoor Condensing Unit ..................................................................................................... 2 Basic Models. 

Matched Pair, Medium Temperature, Outdoor Condensing Unit.1 2 Basic Models. 

Matched Pair, Low Temperature, Indoor Condensing Unit ........................................................................................................... 2 Basic Models. 

Matched Pair, Low Temperature, Outdoor Condensing Unit.1 2 Basic Models. 

Unit Cooler, High-temperature ....................................................................................................................................................... 2 Basic Models. 

Unit Cooler, Medium Temperature ................................................................................................................................................. 2 Basic Models. 

Unit Cooler, Low Temperature ....................................................................................................................................................... 2 Basic Models. 

1AEDMs validated for an outdoor class by testing only outdoor models of that class may be used to determine representative values for the 

corresponding indoor class, and additional validation testing is not required. AEDMs validated only for a given indoor class by testing indoor 

models or a mix of indoor and outdoor models may not be used to determine representative values for the corresponding outdoor class. 

* * * * * 

(5) * * * 

(vi) Tolerances. For efficiency 

metrics, the result from a DOE 

verification test must be greater than or 

equal to the certified rating × (1 ¥ the 

applicable tolerance). For energy 

consumption metrics, the result from a 

DOE verification test must be less than 

or equal to the certified rating × (1 + the 

applicable tolerance). 

TABLE 4 TO PARAGRAPH (f)(5)(vi) 

Equipment Metric Applicable 

tolerance 

Refrigeration systems (including components) ............................................................ AWEF ........................................................ 5% 

Doors ............................................................................................................................ Daily Energy Consumption ....................... 5% 

* * * * * 

■ 4. Amend § 429.110 by revising 

paragraph (e)(2) to read as follows: 

§ 429.110 Enforcement testing. 

* * * * * 

(e) * * * 

(2) For automatic commercial ice 

makers; commercial refrigerators, 

freezers, and refrigerator-freezers; 

refrigerated bottled or canned vending 

machines; commercial air conditioners 

and heat pumps; commercial packaged 

boilers; commercial warm air furnaces; 

commercial water heating equipment; 

and walk-in cooler and walk-in freezer 

doors, panels, and refrigeration systems, 

DOE will use an initial sample size of 

not more than four units and follow the 

sampling plans in appendix B of this 

subpart (Sampling Plan for Enforcement 

Testing of Covered Equipment and 

Certain Low-Volume Covered Products). 

* * * * * 

■ 5. Amend § 429.134 by: 

■ a. Adding paragraph (q) introductory 

text; and 

■ b. Revising paragraphs (q)(2) and (4). 

The addition and revisions read as 

follows: 

§ 429.134 Product-specific enforcement 

provisions. 

* * * * * 

(q) * * * Prior to [date 180 days after 

final rule publication], the provisions in 

10 CFR 429.134, revised as of January 1, 

2021, are applicable. On and after [date 

180 days after final rule publication], 

the provisions in paragraphs (q)(1) 

through (4) of this section apply. 

* * * * * 

(2) Verification of refrigeration system 

net capacity. The net capacity of the 

refrigeration system basic model will be 

measured pursuant to the test 

requirements of part 431, subpart R, 

appendix C, of this chapter for each unit 

tested on and after [date 180 days after 

final rule publication] but before the 

compliance date of revised energy 

conservation standards for walk-in 

cooler and walk-in freezer refrigeration 

systems. The net capacity of the 

refrigeration system basic model will be 

measured pursuant to the test 

requirements of part 431, subpart R, 

appendix C1, of this chapter for each 

unit tested on and after the compliance 

date of revised energy conservation 

standards for walk-in cooler and walkin freezer refrigeration systems. The 

results of the measurement(s) will be 

averaged and compared to the value of 

net capacity certified by the 

manufacturer. The certified net capacity 

will be considered valid only if the 

average measured net capacity is within 

plus or minus five percent of the 

certified net capacity. 

* * * * * 

(4) Verification of door electricityconsuming device power. For each basic 

model of walk-in cooler and walk-in 

freezer door, DOE will calculate the 

door’s energy consumption using the 

input power listed on the nameplate of 

each electricity-consuming device 

shipped with the door. If an electricityconsuming device shipped with a walkin door does not have a nameplate or 

the nameplate does not list the device’s 

input power, then DOE will use the 

device’s rated input power included in 

the door’s certification report. If the 

door is not certified or if the 

certification does not include a rated 

input power for an electricityconsuming device shipped with a walkin door, DOE will use the measured 

input power. DOE also may validate the 

power listed on the nameplate or the 

rated input power by measuring it when 


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energized using a power supply that 

provides power within the allowable 

voltage range listed on the component 

nameplate or the door nameplate, 

whichever is available. If the measured 

input power is more than 10 percent 

higher than the input power listed on 

the nameplate or the rated input power, 

as appropriate, then the measured input 

power shall be used in the door’s energy 

consumption calculation. 

(i) For electricity-consuming devices 

with controls, the maximum input 

wattage observed while energizing the 

device and activating the control shall 

be considered the measured input 

power. For anti-sweat heaters that are 

controlled based on humidity levels, the 

control may be activated by increasing 

relative humidity in the region of the 

controls without damaging the sensor. 

For lighting fixtures that are controlled 

with motion sensors, the control may be 

activated by simulating motion in the 

vicinity of the sensor. Other kinds of 

controls may be activated based on the 

functions of their sensor. 

(ii) [Reserved] 

* * * * * 

PART 431—ENERGY EFFICIENCY 

PROGRAM FOR CERTAIN 

COMMERCIAL AND INDUSTRIAL 

EQUIPMENT 

■ 6. The authority citation for part 431 

continues to read as follows: 

Authority: 42 U.S.C. 6291–6317; 28 U.S.C. 

2461 note. 

■ 7. Amend § 431.302 by: 

■ a. Adding, in alphabetical order, 

definitions for ‘‘Attached split system,’’ 

‘‘CO2 unit cooler,’’ and ‘‘Detachable 

single-packaged dedicated system’’; 

■ b. Revising the definition for ‘‘Door’’; 

■ c. Adding, in alphabetical order, 

definitions for ‘‘Door leaf,’’ ‘‘Door 

surface area,’’ ‘‘Ducted fan coil unit,’’ 

‘‘High-temperature refrigeration 

system,’’ ‘‘Hinged vertical door,’’ ‘‘Hot 

gas defrost,’’ ‘‘Multi-circuit singlepackaged dedicated system,’’ ‘‘Nondisplay door,’’ and ‘‘Roll-up door’’; 

■ d. Revising the definition of ‘‘Singlepackaged dedicated system’’; 

■ e. Adding, in alphabetical order, the 

definition for ‘‘Sliding door’’; and 

■ f. Revising the definition of ‘‘Walk-in 

cooler and walk-in freezer’’; 

The additions and revisions read as 

follows: 

§ 431.302 Definitions concerning walk-in 

coolers and walk-in freezers. 

* * * * * 

Attached split system means a 

matched pair refrigeration system which 

is designed to be installed with the 

evaporator entirely inside the walk-in 

enclosure and the condenser entirely 

outside the walk-in enclosure, and the 

evaporator and condenser are 

permanently connected with structural 

members extending through the walk-in 

wall. 

* * * * * 

CO2 unit cooler means a unit cooler 

that includes a nameplate listing only 

CO2 as an approved refrigerant. 

* * * * * 

Detachable single-packaged dedicated 

system means a system consisting of a 

dedicated condensing unit and an 

insulated evaporator section in which 

the evaporator section is designed to be 

installed external to the walk-in 

enclosure and circulating air through 

the enclosure wall, and the condensing 

unit is designed to be installed either 

attached to the evaporator section or 

mounted remotely with a set of 

refrigerant lines connecting the two 

components. 

* * * * * 

Door means an assembly installed in 

an opening of an interior or exterior 

wall that is used to allow access or close 

off the opening and that is movable in 

a sliding, pivoting, hinged, or revolving 

manner of movement. For walk-in 

coolers and walk-in freezers, a door 

includes the frame (including mullions), 

the door leaf or multiple leaves 

(including glass) within the frame, and 

any other elements that form the 

assembly or part of its connection to the 

wall. 

Door leaf means the pivoting, rolling, 

sliding, or swinging portion of a door. 

Door surface area means the product 

of the height and width of a walk-in 

door measured external to the walk-in. 

The height and width dimensions shall 

be perpendicular to each other and 

parallel to the wall or panel of the walkin to which the door is affixed. The 

height and width measurements extend 

to the edge of the frame and frame 

flange (as applicable) to which the door 

is affixed. The surface area of a display 

door is represented as Add and the 

surface area of a non-display door is 

represented as And. 

Ducted fan coil unit means an 

assembly, including means for forced air 

circulation capable of moving air against 

both internal and non-zero external flow 

resistance, and elements by which heat 

is transferred from air to refrigerant to 

cool the air, with provision for ducted 

installation. 

* * * * * 

High-temperature refrigeration system 

means a refrigeration system which is 

not designed to operate below 45 °F. 

Hinged vertical door means a door 

with a leaf (or leaves) with a hinge (or 

hinges) connecting one vertical edge of 

the leaf (or leaves) to a frame or mullion 

of the door. This includes doors that 

swing open in one direction (i.e., into or 

out of the walk-in) and free-swinging 

doors that open both into and out of the 

walk-in. 

Hot gas defrost means a factoryinstalled system where refrigerant is 

used to transfer heat from ambient 

outside air, to the compressor, and/or a 

thermal storage component that stores 

heat when the compressor is running 

and uses this stored heat to defrost the 

evaporator coils. 

* * * * * 

Multi-circuit single-packaged 

dedicated system means a singlepackaged dedicated system (as defined 

in this section) that contains two or 

more refrigeration circuits that 

refrigerate a single stream of circulated 

air. 

Non-display door means a door that is 

not a display door. 

* * * * * 

Roll-up door means a door that bidirectionally rolls open and closed in a 

vertical and horizontal manner and 

includes vertical jamb tracks. 

Single-packaged dedicated system 

means a refrigeration system (as defined 

in this section) that is a single-packaged 

assembly that includes one or more 

compressors, a condenser, a means for 

forced circulation of refrigerated air, and 

elements by which heat is transferred 

from air to refrigerant. 

Sliding door means a door having one 

or more manually-operated or motorized 

leaves within a common frame that slide 

horizontally or vertically. 

* * * * * 

Walk-in cooler and walk-in freezer 

means an enclosed storage space 

including, but not limited to, panels, 

doors, and refrigeration system, 

refrigerated to temperatures, 

respectively, above, and at or below 32 

degrees Fahrenheit that can be walked 

into, and has a total chilled storage area 

of less than 3,000 square feet; however, 

the terms do not include products 

designed and marketed exclusively for 

medical, scientific, or research 

purposes. 

* * * * * 

■ 8. Amend § 431.303 by: 

■ a. Revising paragraph (a); 

■ b. Adding paragraph (b)(3); 

■ c. Revising paragraphs (c), (d), and 

(e)(1). 

The revisions and additions read as 

follows: 

§ 431.303 Materials incorporated by 

reference. 

(a) Certain material is incorporated by 

reference into this subpart with the 


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approval of the Director of the Federal 

Register in accordance with 5 U.S.C. 

552(a) and 1 CFR part 51. To enforce 

any edition other than that specified in 

this section, DOE must publish a 

document in the Federal Register and 

the material must be available to the 

public. All approved material is 

available for inspection at DOE, and at 

the National Archives and Records 

Administration (‘‘NARA’’). Contact DOE 

at the U.S. Department of Energy, Office 

of Energy Efficiency and Renewable 

Energy, Building Technologies Program, 

Sixth Floor, 950 L’Enfant Plaza SW, 

Washington, DC 20024, (202) 586–9127, 

Buildings@ee.doe.gov, www.energy.gov/ 

eere/buildings/building-technologiesoffice. For information on the 

availability of this material at NARA, 

email: fr.inspection@nara.gov, or go to: 

www.archives.gov/federal-register/cfr/ 

ibr-locations.html. The material may be 

obtained from the sources in the 

following paragraphs of this section. 

(b) * * * 

(3) AHRI Standard 1250–2020 (‘‘AHRI 

1250–2020’’), ‘‘Standard for 

Performance Rating of Walk-in Coolers 

and Freezers,’’ copyright 2020. IBR 

approved for appendix C1 to subpart R. 

(c) ASHRAE. American Society of 

Heating, Refrigerating and AirConditioning Engineers, 180 

Technology Parkway, Peachtree 

Corners, GA 30092; (404) 636–8400; 

www.ashrae.org. 

(1) ANSI/ASHRAE Standard 16–2016, 

(‘‘ANSI/ASHRAE 16’’), ‘‘Method of 

Testing for Rating Room Air 

Conditioners, Packaged Terminal Air 

Conditioners, and Packaged Terminal 

Heat Pumps for Cooling and Heating 

Capacity,’’ approved October 31, 2016, 

IBR approved for appendix C1 to 

subpart R. 

(2) ANSI/ASHRAE Standard 23.1– 

2010, (‘‘ASHRAE 23.1–2010’’), 

‘‘Methods of Testing for Rating the 

Performance of Positive Displacement 

Refrigerant Compressors and 

Condensing Units that Operate at 

Subcritical Temperatures of the 

Refrigerant,’’ ANSI approved January 

28, 2010, IBR approved for appendix C 

to subpart R of part 431. 

(3) ANSI/ASHRAE Standard 37–2009, 

(‘‘ANSI/ASHRAE 37’’), ‘‘Methods of 

Testing for Rating Electrically Driven 

Unitary Air-Conditioning and Heat 

Pump Equipment,’’ ASHRAE approved 

June 24, 2009, IBR approved for 

appendices C and C1 to subpart R. 

(d) ASTM. ASTM, International, 100 

Barr Harbor Drive, West Conshohocken, 

PA 19428–2959; (610) 832–9500; 

www.astm.org. 

(1) ASTM C518–17, (‘‘ASTM C518– 

17’’), ‘‘Standard Test Method for SteadyState Thermal Transmission Properties 

by Means of the Heat Flow Meter 

Apparatus,’’ approved May 1, 2017, IBR 

approved for appendix B to subpart R. 

(2) ASTM C1199–14, (‘‘ASTM C1199– 

14’’), ‘‘Standard Test Method for 

Measuring the Steady-State Thermal 

Transmittance of Fenestration Systems 

Using Hot Box Methods,’’ approved 

February 1, 2014, IBR approved for 

appendix A to subpart R. 

(e) * * * 

(1) NFRC 102–2020 [E0A0], (‘‘NFRC 

102–2020’’), ‘‘Procedure for Measuring 

the Steady-State Thermal Transmittance 

of Fenestration Systems,’’ IBR approved 

for appendix A to subpart R. 

* * * * * 

■ 9. Amend § 431.304 by revising 

paragraph (b) to read as follows: 

§ 431.304 Uniform test method for the 

measurement of energy consumption of 

walk-in coolers and walk-in freezers. 

* * * * * 

(b) Testing and Calculations. 

Determine the energy efficiency and/or 

energy consumption of the specified 

walk-in cooler and walk-in freezer 

components by conducting the 

appropriate test procedure as follows: 

(1) Display panels. Determine the 

energy use of walk-in cooler and walkin freezer display panels by conducting 

the test procedure set forth in appendix 

A to this subpart. 

(2) Display doors and non-display 

doors. Determine the energy use of 

walk-in cooler and walk-in freezer 

display doors and non-display doors by 

conducting the test procedure set forth 

in appendix A to this subpart. 

(3) Non-display panels and nondisplay doors. Determine the R-value of 

insulation of walk-in cooler and walk-in 

freezer non-display panels and nondisplay doors by conducting the test 

procedure set forth in appendix B to this 

subpart. 

(4) Refrigeration systems. Determine 

the Annual Walk-in Energy Factor 

(AWEF) and net capacity of walk-in 

cooler and walk-in freezer refrigeration 

systems by conducting the test 

procedures set forth in appendix C or C1 

to this subpart, as applicable. Refer to 

the notes at the beginning of those 

appendices to determine the applicable 

appendix to use for testing. 

(i) For unit coolers: Follow the general 

testing provisions in sections 3.1 and 

3.2 of appendices C or C1 to this 

subpart, and the equipment-specific 

provisions in section 3.3 of appendix C 

or sections 4.5 through 4.8 of appendix 

C1. 

(ii) For dedicated condensing units: 

Follow the general testing provisions in 

sections 3.1 and 3.2 of appendices C or 

C1 to this subpart, and the productspecific provisions in section 3.4 of 

appendix C or sections 4.5 through 4.8 

of appendix C1. 

(iii) For single-packaged dedicated 

systems: Follow the general testing 

provisions in sections 3.1 and 3.2 of 

appendices C or C1 to this subpart, and 

the product-specific provisions in 

section 3.3 of appendix C or sections 4.5 

through 4.8 of appendix C1. 

■ 10. Revise appendix A to subpart R of 

part 431 to read as follows: 

Appendix A to Subpart R of Part 431— 

Uniform Test Method for the 

Measurement of Energy Consumption of 

the Components of Envelopes of Walkin Coolers and Walk-in Freezers 

Note: Prior to [date 180 days after 

publication of final rule], representations 

with respect to the energy use of envelope 

components of walk-in coolers and walk-in 

freezers, including compliance certifications, 

must be based on testing conducted in 

accordance with the applicable provisions of 

10 CFR part 431, subpart R, appendix A, 

revised as of January 1, 2022. Beginning [date 

180 days after publication of final rule], 

representations with respect to energy use of 

envelope components of walk-in coolers and 

walk-in freezers, including compliance 

certifications, must be based on testing 

conducted in accordance with this appendix. 

Incorporation by Reference 

DOE incorporated by reference in § 431.303 

the entire standards for NFRC 102–2020, and 

ASTM C1199–14. However, certain 

enumerated provisions of these standards, as 

set forth in sections 0.1 and 0.2 of this 

appendix are inapplicable. To the extent that 

there is a conflict between the terms or 

provisions of a referenced industry standard 

and the CFR, the CFR provisions control. 

0.1 NFRC 102–2020 

0.1.1 Section 1 Scope, is inapplicable as 

specified in section 5.1.1.1 of this appendix, 

0.1.2 Section 4 Significance and Use, is 

inapplicable as specified in section 5.1.1.2 of 

this appendix, 

0.1.3 Section 7.3 Test Conditions, is 

inapplicable as specified in section 5.1.1.3 of 

this appendix, 

0.1.4 Section 10 Report, is inapplicable as 

specified in section 5.1.1.4 of this appendix, 

0.1.5 Section 11 Precision and Bias, is 

inapplicable as specified in section 5.1.1.5 of 

this appendix, 

0.1.6 Annex A3 Standard Test Method for 

Determining the Thermal Transmittance of 

Tubular Daylighting Devices, is inapplicable 

as specified in section 5.1.1.6 of this 

appendix, and 

0.1.7 Annex A5 Tables and Figures, is 

inapplicable as specified in section 5.1.1.7 of 

this appendix. 

0.2 ASTM C1199–14 

0.2.1 Section 1 Scope, is inapplicable as 

specified in section 5.1.2.1 of this appendix, 

0.2.2 Section 4 Significance and Use is 

inapplicable as specified in section 5.1.2.2 of 

this appendix, 


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0.2.3 Section 7.3 Test Conditions, is 

inapplicable as specified in section 5.1.2.3 of 

this appendix, 

0.2.4 Section 10 Report, is inapplicable as 

specified in section 5.1.2.4 of this appendix, 

and 

0.2.5 Section 11 Precision and Bias, is 

inapplicable as specified in section 5.1.2.5 of 

this appendix. 

1. General. The following sections of this 

appendix provide additional instructions for 

testing. In cases where there is a conflict, the 

language of this appendix takes highest 

precedence, followed by NFRC 102–2020, 

followed by ASTM C1199–14. Any 

subsequent amendment to a referenced 

document by the standard-setting 

organization will not affect the test procedure 

in this appendix, unless and until the test 

procedure is amended by DOE. Material is 

incorporated as it exists on the date of the 

approval, and a notification of any change in 

the incorporation will be published in the 

Federal Register. 

2. Scope. 

This appendix covers the test requirements 

used to measure the energy consumption of 

the components that make up the envelope 

of a walk-in cooler or walk-in freezer. 

3. Definitions. 

The definitions contained in § 431.302 are 

applicable to this appendix. 

4. Additional Definitions. 

4.1 Automatic door opener/closer means 

a device or control system that 

‘‘automatically’’ opens and closes doors 

without direct user contact, such as a motion 

sensor that senses when a forklift is 

approaching the entrance to a door and opens 

it, and then closes the door after the forklift 

has passed. 

4.2 Percent time off (PTO) means the 

percent of time that an electrical device is 

assumed to be off. 

4.3 Rated power means the input power 

of an electricity-consuming device as 

specified on the device’s nameplate. If the 

device does not have a nameplate or such 

nameplate does not list the device’s input 

power, then the rated power must be 

determined from the device’s product data 

sheet, literature, or installation instructions 

that come with the device or are available 

online. 

4.4 Rating conditions means, unless 

explicitly stated otherwise, all conditions 

shown in Table A.1 of this appendix. 

TABLE A.1—TEMPERATURE

CONDITIONS

Internal Temperatures (cooled space within 

the envelope) 

Cooler Dry Bulb Temperature ........ 35 °F. 

Freezer Dry Bulb Temperature ...... ¥10 °F. 

External Temperatures (space external to 

the envelope) 

Freezer and Cooler Dry Bulb Temperatures.75 °F. 

5. Test Methods and Measurements. 

5.1 U-factor Test of Doors and Display 

Panels. 

Determine the U-factor of the entire door 

or display panel, including the frame, in 

accordance with the specified sections of 

NFRC 1022020 and ASTM C1199–14 at the 

temperature conditions listed in Table A.1 of 

this appendix; however, the following 

enumerated provisions of NFRC 102–2020 

and ASTM C1199–14 are not applicable, as 

set forth in sections 5.1.1 and 5.1.2 of this 

appendix. 

5.1.1 Excepted sections of NFRC 102– 

2020. 

5.1.1.1 Section 1 Scope, 

5.1.1.2 Section 4 Significance and Use, 

5.1.1.3 Section 7.3 Test Conditions, 

5.1.1.4 Section 10 Report, 

5.1.1.5 Section 11 Precision and Bias, 

5.1.1.6 Annex A3 Standard Test Method 

for Determining the Thermal Transmittance 

of Tubular Daylighting Devices, and 

5.1.1.7 Annex A5 Tables and Figures. 

5.1.2 Excepted sections of ASTM C1199– 

14. 

5.1.2.1 Section 1 Scope, 

5.1.2.2 Section 4 Significance and Use, 

5.1.2.3 Section 7.3 Test Conditions, 

5.1.2.4 Section 10 Report, and 

5.1.2.5 Section 11 Precision and Bias. 

5.2 Required Test Measurements. 

5.2.1 For display doors and display 

panels, thermal transmittance, Udd or Udp, 

respectively, shall be the standardized 

thermal transmittance, UST, determined per 

section 5.1.1 of this appendix. 

5.2.2 For non-display doors, thermal 

transmittance, Und, shall be the standardized 

thermal transmittance, UST, determined per 

section 5.1 of this appendix. 

5.2.3 Projected area of the test specimen, 

As, in ft2, as referenced in ASTM C1199–14. 

6. Calculations. 

6.1 Display Panels. 

6.1.1 Determine the U-factor of the 

display panel in accordance with section 5.1 

of this appendix, in units of Btu/(h-ft2-°F). 

6.1.2 Calculate the temperature 

differential, DTdp, °F, for the display panel, as 

follows: 

Where: 

TDB,ext,dp = dry-bulb air external temperature, 

°F, as prescribed in Table A.1 of this 

appendix; and 

TDB,int,dp = dry-bulb air temperature internal 

to the cooler or freezer, °F, as prescribed 

in Table A.1 of this appendix. 

6.1.3 Calculate the conduction load 

through the display panel, Qcond-dp, Btu/h, as 

follows: 

Where: 

As = projected area of the test specimen 

(same as the test specimen aperture in 

the surround panel) or the area used to 

determine the U-factor in section 5.1 of 

this appendix, ft2; 

DTdp = temperature differential between 

refrigerated and adjacent zones, °F; and 

Udp = thermal transmittance, U-factor, of the 

display panel in accordance with section 

5.1 of this appendix, Btu/(h-ft2-°F). 

6.1.4 Calculate the total daily energy 

consumption, Edp, kWh/day, as follows: 

Where: 

Qcond,dp = the conduction load through the 

display panel, Btu/h; and 

EER = Energy Efficiency Ratio of walk-in 

(cooler or freezer), Btu/W-h. For coolers, 

use EER = 12.4 Btu/W-h. For freezers, 

use EER = 6.3 Btu/W-h. 

6.2 Display Doors. 

6.2.1 Conduction Through Display Doors. 

6.2.1.1 Determine the U-factor of the 

display door in accordance with section 5.1 

of this appendix, in units of Btu/(h-ft2-°F). 

6.2.1.2 Calculate the temperature 

differential, DTdd, °F, for the display door as 

follows: 


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23994 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

Where: 

TDB,ext,dd = dry-bulb air temperature external 

to the display door, °F, as prescribed in 

Table A.1 of this appendix; and 

TDB,int,dd = dry-bulb air temperature internal 

to the display door, °F, as prescribed in 

Table A.1 of this appendix. 

6.2.1.3 Calculate the conduction load 

through the display doors, Qcond,dd, Btu/h, as 

follows: 

Where: 

As = projected area of the test specimen 

(same as the test specimen aperture in 

the surround panel) or the area used to 

determine the U-factor in section 5.1 of 

this appendix, ft2; 

DTdd = temperature differential between 

refrigerated and adjacent zones, °F; and 

Udd = thermal transmittance, U-factor of the 

door, in accordance with section 5.1 of 

this appendix, Btu/(h-ft2-°F). 

6.2.1.4 Calculate the total daily energy 

consumption due to conduction thermal 

load, Edd,thermal, kWh/day, as follows: 

Where: 

Qcond,dd = the conduction load through the 

display door, Btu/h; and 

EER = EER of walk-in (cooler or freezer), Btu/ 

W-h. For coolers, use EER = 12.4 Btu/(Wh). For freezers, use EER = 6.3 Btu/(Wh). 

6.2.2 Direct Energy Consumption of 

Electrical Component(s) of Display Doors. 

Electrical components associated with 

display doors could include but are not 

limited to: Heater wire (for anti-sweat or antifreeze application); lights; door motors; 

control system units; and sensors. 

6.2.2.1 Select the required value for 

percent time off (PTO) for each type of 

electricity-consuming device per Table A.2 of 

this appendix, PTOt (%). 

TABLE A.2—PERCENT TIME OFF VALUES

Device Temperature 

condition Controls 

Percent time 

off value 

(%) 

Lights ........................................................................................ All ............................................ Without .................................... 25 

With ......................................... 50 

Anti-sweat heaters .................................................................... All ............................................ Without .................................... 0 

Coolers .................................... With ......................................... 75 

Freezers .................................. With ......................................... 50 

Door motors .............................................................................. All ............................................ ................................................. 97 

All other electricity-consuming devices ..................................... All ............................................ Without .................................... 0 

With ......................................... 25 

6.2.2.2 Calculate the power usage for each 

type of electricity-consuming device, 

Pdd,comp,u,t, kWh/day, as follows: 

Where: 

u = the index for each of type of electricityconsuming device located on either (1) 

the interior facing side of the display 

door or within the inside portion of the 

display door, (2) the exterior facing side 

of the display door, or (3) any 

combination of (1) and (2). For purposes 

of this calculation, the interior index is 

represented by u = int and the exterior 

index is represented by u = ext. If the 

electrical component is both on the 

interior and exterior side of the display 

door then use u = int. For anti-sweat 

heaters sited anywhere in the display 

door, 75 percent of the total power is be 

attributed to u = int and 25 percent of the 

total power is attributed to u = ext; 

t = index for each type of electricityconsuming device with identical rated 

power; 

Prated,u,t = rated input power of each 

component, of type t, kW; 

PTOu,t = percent time off, for device of type 

t, %; and 

nu,t = number of devices at the rated input 

power of type t, unitless. 

6.2.2.3 Calculate the total electrical 

energy consumption for interior and exterior 

power, Pdd,tot,int (kWh/day) and Pdd,tot,ext (kWh/ 

day), respectively, as follows: 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23995 

Where: 

t = index for each type of electricityconsuming device with identical rated 

input power; 

Pdd,comp,int,t = the energy usage for an 

electricity-consuming device sited on the 

interior facing side of or in the display 

door, of type t, kWh/day; and 

Pdd,comp,ext,t = the energy usage for an 

electricity-consuming device sited on the 

external facing side of the display door, 

of type t, kWh/day. 

6.2.2.4 Calculate the total electrical 

energy consumption, Pdd,tot, (kWh/day), as 

follows: 

Where: 

Pdd,tot,int = the total interior electrical energy 

usage for the display door, kWh/day; and 

Pdd,tot,ext = the total exterior electrical energy 

usage for the display door, kWh/day. 

6.2.3 Total Indirect Electricity 

Consumption Due to Electrical Devices. 

Calculate the additional refrigeration 

energy consumption due to thermal output 

from electrical components sited inside the 

display door, Cdd,load, kWh/day, as follows: 

Where: 

Pdd,tot,int = The total internal electrical energy 

consumption due for the display door, 

kWh/day; and 

EER = EER of walk-in cooler or walk-in 

freezer, Btu/W-h. For coolers, use EER = 

12.4 Btu/(W-h). For freezers, use EER = 

6.3 Btu/(W-h). 

6.2.4 Total Display Door Energy 

Consumption. 

Calculate the total energy, Edd,tot, kWh/day, 

Where: 

Edd,thermal = the total daily energy 

consumption due to thermal load for the 

display door, kWh/day; 

Pdd,tot = the total electrical load, kWh/day; 

and 

Cdd,load = additional refrigeration load due to 

thermal output from electrical 

components contained within the 

display door, kWh/day. 

6.3 Non-Display Doors. 

6.3.1 Conduction Through Non-Display 

Doors. 

6.3.1.1 Determine the U-factor of the nondisplay door in accordance with section 5.1 

of this appendix, in units of Btu/(h-ft2-°F). 

6.3.1.2 Calculate the temperature 

differential of the non-display door, DTnd, °F, 

as follows: 

Where: 

TDB,ext,nd = dry-bulb air external temperature, 

°F, as prescribed by Table A.1 of this 

appendix; and 

TDB,int,nd = dry-bulb air internal temperature, 

°F, as prescribed by Table A.1 of this 

appendix. If the component spans both 

cooler and freezer spaces, the freezer 

temperature must be used. 

6.3.1.3 Calculate the conduction load 

through the non-display door: Qcond,nd, Btu/h, 

Where: 

As = projected area of the test specimen 

(same as the test specimen aperture in 

the surround panel) or the area used to 

determine the U-factor in section 5.1 of 

this appendix, ft2; 

DTnd = temperature differential across the 

non-display door, °F; and 

Und = thermal transmittance, U-factor of the 

door, in accordance with section 5.1 of 

this appendix, Btu/(h-ft2-°F). 

6.3.1.4 Calculate the total daily energy 

consumption due to thermal load, End,thermal, 

kWh/day, as follows: 


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23996 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

Where: 

Qcond,nd = the conduction load through the 

non-display door, Btu/h; and 

EER = EER of walk-in (cooler or freezer), Btu/ 

W-h. For coolers, use EER = 12.4 Btu/(Wh). For freezers, use EER = 6.3 Btu/(Wh). 

6.3.2 Direct Energy Consumption of 

Electrical Components of Non-Display Doors. 

Electrical components associated with nondisplay doors comprise could include, but 

are not limited to: Heater wire (for anti-sweat 

or anti-freeze application), lights, door 

motors, control system units, and sensors. 

6.3.2.1 Select the required value for 

percent time off for each type of electricityconsuming device per Table A.2 of this 

appendix, PTOt (%). 

6.3.2.2 Calculate the power usage for each 

type of electricity-consuming device, 

Pnd,comp,u,t, kWh/day, as follows: 

Where: 

u = the index for each of type of electricityconsuming device located on either (1) 

the interior facing side of the nondisplay door or within the inside portion 

of the non-display door, (2) the exterior 

facing side of the non-display door, or (3) 

any combination of (1) and (2). For 

purposes of this calculation, the interior 

index is represented by u = int and the 

exterior index is represented by u = ext. 

If the electrical component is both on the 

interior and exterior side of the nondisplay door then use u = int. For antisweat heaters sited anywhere in the nondisplay door, 75 percent of the total 

power is be attributed to u = int and 25 

percent of the total power is attributed to 

u = ext; 

t = index for each type of electricityconsuming device with identical rated 

input power; 

Prated,u,t = rated input power of each 

component, of type t, kW; 

PTOu,t = percent time off, for device of type 

t, %; and 

nu,t = number of devices at the rated input 

power of type t, unitless. 

6.3.2.3 Calculate the total electrical 

energy consumption for interior and exterior 

power, Pnd,tot,int, kWh/day, and Pnd,tot,ext, kWh/ 

day, respectively, as follows: 

Where: 

t = index for each type of electricityconsuming device with identical rated 

input power; 

Pnd,comp,int,t = the energy usage for an 

electricity-consuming device sited on the 

internal facing side or internal to the 

non-display door, of type t, kWh/day; 

and 

Pnd,comp,ext,t = the energy usage for an 

electricity-consuming device sited on the 

external facing side of the non-display 

door, of type t, kWh/day. For anti-sweat 

heaters, 

6.3.2.4 Calculate the total electrical 

energy consumption, Pnd,tot, kWh/day, as 

follows: 

Where: 

Pnd,tot,int = the total interior electrical energy 

usage for the non-display door, of type 

t, kWh/day; and 

Pnd,tot,ext = the total exterior electrical energy 

usage for the non-display door, of type 

t, kWh/day. 

6.3.3 Total Indirect Electricity 

Consumption Due to Electrical Devices. 

Calculate the additional refrigeration 

energy consumption due to thermal output 

from electrical components associated with 

the non-display door, Cnd,load, kWh/day, as 

follows: 

Where: 

Pnd,tot,int = the total interior electrical energy 

consumption for the non-display door, 

kWh/day; and 

EER = EER of walk-in cooler or freezer, Btu/ 

W-h. For coolers, use EER = 12.4 Btu/(Wh). For freezers, use EER = 6.3 Btu/(Wh). 

6.3.4 Total Non-Display Door Energy 

Consumption. 

Calculate the total energy, End,tot, kWh/day, 

as follows: 

Where: 

End,thermal = the total daily energy 

consumption due to thermal load for the 

non-display door, kWh/day; 

Pnd,tot = the total electrical energy 

consumption, kWh/day; and 

Cnd,load = additional refrigeration load due to 

thermal output from electrical 

components contained on the inside face 

of the non-display door, kWh/day. 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 23997 

■ 11. Revise appendix B to subpart R of 

part 431 to read as follows: 

Appendix B to Subpart R of Part 431— 

Uniform Test Method for the 

Measurement of R-Value of Insulation 

for Envelope Components of Walk-In 

Coolers and Walk-In Freezers 

Note: Prior to [date 180 days after 

publication of final rule], representations 

with respect to the R-value for insulation of 

envelope components of walk-in coolers and 

walk-in freezers, including compliance 

certifications, must be based on testing 

conducted in accordance with the applicable 

provisions of 10 CFR part 431, subpart R, 

appendix B, revised as of January 1, 2022. 

Beginning [date 180 days after publication of 

final rule], representations with respect to Rvalue for insulation of envelope components 

of walk-in coolers and walk-in freezers, 

including compliance certifications, must be 

based on testing conducted in accordance 

with this appendix. 

0. Incorporation by Reference. 

DOE incorporated by reference in 

§ 431.303 the entire standard for ASTM 

C518–17. However, certain enumerated 

provisions of ASTM C518–17, as set forth in 

section 0.1 of this appendix, are inapplicable. 

To the extent there is a conflict between the 

terms or provisions of a referenced industry 

standard and the CFR, the CFR provisions 

control. 

0.1 ASTM C518–17 

0.1.1 Section 1 Scope, is inapplicable as 

specified in section 5.3.1.1 of this appendix, 

0.1.2 Section 4 Significance and Use, is 

inapplicable as specified in section 5.3.1.2 of 

this appendix, 

0.1.3 Section 7.3 Specimen 

Conditioning, is inapplicable as specified in 

section 5.3.1.3 of this appendix, 

0.1.4 Section 9 Report, is inapplicable 

as specified in section 5.3.1.4 of this 

appendix, 

0.1.5 Section 10 Precision and Bias, is 

inapplicable as specified in section 5.3.1.5 of 

this appendix, 

0.1.6 Section 11 Keywords, is 

inapplicable as specified in section 5.3.1.6 of 

this appendix, 

0.1.7 Annex A2 Equipment Error 

Analysis, is inapplicable as specified in 

section 5.3.1.7 of this appendix, 

0.1.8 Appendix X1 is inapplicable as 

specified in section 5.3.1.8 of this appendix, 

0.1.9 Appendix X2 Response of Heat 

Flux Transducers, is inapplicable as 

specified in section 5.3.1.9 of this appendix, 

and 

0.1.10 Appendix X3 Proven 

Performance of a Heat Flow Apparatus, is 

inapplicable as specified in section 5.3.1.10 

of this appendix. 

1. General. 

The following sections of this appendix 

provide additional instructions for testing. In 

cases where there is a conflict, the language 

of this appendix takes highest precedence, 

followed by ASTM C518–17. Any subsequent 

amendment to a referenced document by the 

standard-setting organization will not affect 

the test procedure in this appendix, unless 

and until the test procedure is amended by 

DOE. Material is incorporated as it exists on 

the date of the approval, and a notification 

of any change in the incorporation will be 

published in the Federal Register. 

2. Scope. 

This appendix covers the test requirements 

used to measure the R-value of non-display 

panels and non-display doors of a walk-in 

cooler or walk-in freezer. 

3. Definitions. 

The definitions contained in § 431.302 

apply to this appendix. 

4. Additional Definitions. 

4.1 Edge region means a region of the 

envelope component that is wide enough to 

encompass any framing members. If the 

envelope component contains framing 

members (e.g., a wood frame) then the width 

of the edge region must be as wide as any 

framing member plus an additional 2 in. 

±0.25 in. 

5. Test Methods, Measurements, and 

Calculations. 

5.1 General. Foam shall be tested after it 

is produced in its final chemical form. For 

foam produced inside of an envelope 

component (‘‘foam-in-place’’), ‘‘final 

chemical form’’ means the foam is cured as 

intended and ready for use as a finished 

envelope component. For foam produced as 

board stock (e.g., polystyrene), ‘‘final 

chemical form’’ means after extrusion and 

ready for assembly into an envelope 

component or after assembly into an 

envelope component. Foam must not include 

any structural members or non-foam 

materials during testing in accordance with 

ASTM C518–17. When preparing the 

specimen for test, a high-speed bandsaw or 

a meat slicer are two types of recommended 

cutting tools. Hot wire cutters or other heated 

tools shall not be used for cutting foam test 

specimens. 

5.2 Specimen Preparation. 

5.2.1 Determining the thickness around 

the perimeter of the envelope component, tp. 

The full thickness of an envelope component 

around the perimeter, which may include 

facers on one or both sides, shall be 

determined as follows: 

5.2.1.1 At least 8 thickness measurements 

shall be taken around the perimeter of the 

envelope component, at least 2 inches from 

the edge region, and avoiding any regions 

with hardware or fixtures. 

5.2.1.2 The average of the thickness 

measurements taken around the perimeter of 

the envelope component shall be the 

thickness around the perimeter of the 

envelope component, tp. 

5.2.1.3 Measure and record the width, wp, 

and height, hp, of the envelope component. 

The surface area of the envelope component, 

Ap, shall be determined as follows: 

Where: 

wp = width of the envelope component, in.; 

and 

hp = height of the envelope component, in. 

5.2.2. Removing the sample from the 

envelope component. 

5.2.2.1. Determine the center of the 

envelope component relative to its height 

and its width. 

5.2.2.2. Cut a sample from the envelope 

component that is at least the length and 

width dimensions of the heat flow meter, and 

where the marked center of the sample is at 

least 3 inches from any cut edge. 

5.2.2.3. If the center of the envelope 

component contains any non-foam 

components (excluding facers), additional 

samples may be cut adjacent to the previous 

cut that is at least the length and width 

dimensions of the heat flow meter and is 

greater than 12 inches from the edge region. 

5.2.3. Determining the thickness at the 

center of the envelope component, tc. The full 

thickness of an envelope component at the 

center, which may include facers on one or 

both sides, shall be determined as follows: 

5.2.3.1. At least 2 thickness 

measurements shall be taken in each 

quadrant of the cut sample removed from the 

envelope component per section 5.2.2 of this 

appendix, for a total of at least 8 

measurements. 

5.2.3.2. The average of the thickness 

measurements of the cut sample removed 

from the envelope component shall be the 

overall thickness of the cut sample, tc. 

5.2.3.3. Measure and record the width 

and height of the cut sample removed from 

the envelope component. The surface area of 

the cut sample removed from the envelope 

component, Ac., shall be determined as 

follows: 

Where: 

wc = width of the cut sample removed from 

the envelope component, in.; and 

hc = height of the cut sample removed from 

the envelope component, in. 

5.2.4. Determining the total thickness of 

the foam within the envelope component, 

tfoam. The average total thickness of the foam 


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23998 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

sample, without facers, shall be determined 

as follows: 

5.2.4.1. Remove the facers on the 

envelope component sample, while 

minimally disturbing the foam. 

5.2.4.2. Measure the thickness of each 

facer in 4 locations for a total of 4 

measurements if 1 facer is removed, and a 

total of 8 measurements if 2 facers are 

removed. The average of all facer 

measurements shall be the thickness of the 

facers, tfacers, in. 

5.2.4.3. The average total thickness of the 

foam, tfoam, in., shall be determined as 

follows: 

Where: 

tc = the average thickness of the center of the 

envelope component, in., as determined 

per sections 5.2.3.1 and 5.2.3.2 of this 

appendix; 

Ac = the surface area of the center of the 

envelope component, in2., as determined 

per section 5.2.3.3 of this appendix; 

tp = the average thickness of the perimeter of 

the envelope component, in., as 

determined per sections 5.2.1.1 and 

5.2.1.2 of this appendix; 

Ap = the average thickness of the center of the 

envelope component, in2, as determined 

per section 5.2.1.3 of this appendix; 

tfacers = the average thickness of the facers of 

the envelope component, in., as 

determined per section 5.2.4.2 of this 

appendix. 

5.2.5 Cutting, measuring, and 

determining parallelism and flatness of a 1- 

inch-thick specimen for test from the center 

of the cut envelope component sample. 

5.2.5.1 Cut a 1 ±0.1-inch-thick specimen 

from the center of the cut envelope sample. 

The 1-inch-thick test specimen shall be cut 

from the point that is equidistant from both 

edges of the sample (i.e., shall be cut from the 

center point that would be directly between 

the interior and exterior space of the walkin). 

5.2.5.2 Document through measurement 

or photographs with measurement indicators 

that the specimen was taken from the center 

of the sample. 

5.2.5.3 After the 1-inch specimen has 

been cut, and prior to testing, place the 

specimen on a flat surface and allow gravity 

to determine the specimen’s position on the 

surface. This will be side 1. 

5.2.5.4 To determine the flatness of side 

1, take at least nine height measurements at 

equidistant positions on the specimen (i.e., 

the specimen would be divided into 9 

regions and height measurements taken at the 

center of each of these nine regions). Contact 

with the measurement indicator shall not 

indent the foam surface. From the height 

measurements taken, determine the least 

squares plane for side 1. For each 

measurement location, calculate the 

theoretical height from the least squares 

plane for side 1. Then, calculate the 

difference between the measured height and 

the theoretical least squares plane height at 

each location. The maximum difference 

minus the minimum difference out of the 

nine measurement locations is the flatness of 

side 1. For side 1 of the specimen to be 

considered flat, this shall be less than or 

equal to 0.03 inches. 

5.2.5.5 To determine the flatness of side 

2, turn the specimen over and allow gravity 

to determine the specimen’s position on the 

surface. Repeat section 5.2.5.4 to determine 

the flatness of side 2. 

5.2.5.6 To determine the parallelism of 

the specimen for side 1, calculate the 

theoretical height of the least squares plane 

at the furthest corners (i.e., at points (0,0), 

(0,12), (12,0), and (12,12)) of the 12-inch by 

12-inch test specimen. The difference 

between the maximum theoretical height and 

the minimum theoretical height shall be less 

than or equal to 0.03 inches for each side in 

order for side 1 to be considered parallel. 

5.2.5.7 To determine the parallelism of 

the specimen for side 2, repeat section 

5.2.5.8 The average thickness of the test 

specimen, L, shall be 1 ±0.1-inches 

determined using a minimum of 18 thickness 

measurements (i.e., a minimum of 9 

measurements on side 1 of the specimen and 

a minimum of 9 on side 2 of the specimen). 

This average thickness shall be used to 

determine the thermal conductivity, or 

K-factor. 

5.3 K-factor Test. Determine the thermal 

conductivity, or K-factor, of the 1-inch-thick 

specimen in accordance with the specified 

sections of ASTM C518–17; however, the 

following enumerated provisions of ASTM 

C518–17 are not applicable, as set forth in 

section 5.3.1 of this appendix. Testing must 

be completed within 24 hours of the 

specimen being cut for testing per section 

5.2.5 of this appendix. 

5.3.1 Excepted sections of ASTM C518– 

17. 

5.3.1.1 Section 1 Scope, 

5.3.1.2 Section 4 Significance and Use, 

5.3.1.3 Section 7.3 Specimen 

Conditioning, 

5.3.1.4 Section 9 Report, 

5.3.1.5 Section 10 Precision and Bias, 

5.3.1.6 Section 11 Keywords, 

5.3.1.7 Annex A2 Equipment Error 

Analysis, 

5.3.1.8 Appendix X1, 

5.3.1.9 Appendix X2 Response of Heat 

Flux Transducers, and 

5.3.1.10 Appendix X3 Proven 

Performance of a Heat Flow Apparatus. 

5.3.2 Test Conditions. 

5.3.2.1 For freezer envelope components, 

the K-factor of the specimen shall be 

determined at an average specimen 

temperature of 20 ±1 degrees Fahrenheit. 

5.3.2.2 For cooler envelope components, 

the K-factor of the specimen shall be 

determined at an average specimen 

temperature of 55 ±1 degrees Fahrenheit. 

5.4 R-value Calculation. 

5.4.1 For envelope components 

consisting of one homogeneous layer of 

insulation, calculate the R-value, h-ft2-°F/ 

Btu, as follows: 

Where: 

tfoam = the total thickness of the foam, in., as 

determined in section 5.2.4 of this 

appendix; and 

l = K-factor, Btu-in/(h-ft2-°F), as determined 

in section 5.3 of this appendix. 

5.4.2 For envelope components 

consisting of two or more layers of dissimilar 

insulating materials (excluding facers or 

protective skins), determine the K-factor of 

each material as described in sections 5.1 

through 5.3 of this appendix. For an envelope 

component with N layers of insulating 

material, the overall R-value shall be 

calculated as follows: 

Where: 

ti is the thickness of the ith material that 

appears in the envelope component, 

inches, as determined in section 5.2.4 of 

this appendix; 

li is the k factor of the ith material, Btu-in/ 

(h-ft2-°F), as determined in section 5.3 of 

this appendix; and 


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N is the total number of material layers that 

appears in the envelope component. 

5.4.3 K-factor test results from a test 

sample 1 ±0.1-inches in thickness may be 

used to determine the R-value of envelope 

components with various foam thicknesses as 

long as the foam throughout the panel depth 

is of the same final chemical form and the 

test was completed at the same test 

conditions that the other envelope 

components would be used at. For example, 

a K-factor test result conducted at cooler 

conditions cannot be used to determine 

R-value of a freezer envelope component. 

■ 12. Amend appendix C to subpart R of 

part 431 by: 

■ a. Adding a note to the beginning of 

the appendix; 

■ b. Revising sections 2.0 and 3.1.1; 

■ c. Adding sections 3.1.6 and 3.1.7; 

■ d. Revising sections 3.2.1 and 3.2.3; 

■ e. Adding sections 3.2.6, 3.2.7, 3.2.7.1, 

3.2.7.2, 3.2.7.3, and 3.2.8; 

■ f. Revising sections 3.3.1 and 3.3.3; 

■ g. Adding sections 3.3.3.1, 3.3.3.2, 

3.3.3.3, 3.3.3.3.1, and 3.3.3.3.2; 

■ h. Revising sections 3.3.7, 3.3.7.1, and 

3.3.7.2; 

■ i. Adding sections 3.3.7.3, 3.3.7.3.1, 

and 3.3.7.3.2; and 

■ j. Revising section 3.4.2.1. 

The additions and revisions read as 

follows: 

Appendix C to Subpart R of Part 431— 

Uniform Test Method for the 

Measurement of Net Capacity and 

AWEF of Walk-In Cooler and Walk-In 

Freezer Refrigeration Systems 

Note: Prior to [date 180 days after 

publication of final rule], representations 

with respect to the energy use of refrigeration 

components of walk-in coolers and walk-in 

freezers, including compliance certifications, 

must be based on testing conducted in 

accordance with the applicable provisions of 

this appendix as they appeared in 10 CFR 

part 431, subpart R, appendix C, revised as 

of January 1, 2022. Beginning [date 180 days 

after publication of final rule], 

representations with respect to energy use of 

refrigeration components of walk-in coolers 

and walk-in freezers, including compliance 

certifications, must be based on testing 

conducted in accordance with this appendix. 

For any amended standards for walk-in 

coolers and freezers published after January 

1, 2022, manufacturers must use the results 

of testing under appendix C1 of this part to 

determine compliance. Representations 

related to energy consumption must be made 

in accordance with appendix C1 of this part 

when determining compliance with the 

relevant standard. Manufacturers may also 

use appendix C1 of this part to certify 

compliance with any amended standards 

prior to the applicable compliance date for 

those standards. 

* * * * * 

2.0 Definitions. 

The definitions contained in § 431.302 and 

AHRI 1250–2009 (incorporated by reference; 

see § 431.303) apply to this appendix. When 

definitions contained in the standards DOE 

has incorporated by reference are in conflict 

or when they conflict with this section, the 

hierarchy of precedence shall be in the 

following order: § 431.302, AHRI 1250–2009, 

and then either AHRI 420–2008 

(incorporated by reference; see § 431.303) for 

unit coolers or ASHRAE 23.1–2010 

(incorporated by reference; see § 431.303) for 

dedicated condensing units. 

The term ‘‘unit cooler’’ used in AHRI 

1250–2009, AHRI 420–2008, and this subpart 

shall be considered to address both ‘‘unit 

coolers’’ and ‘‘ducted fan-coil units,’’ as 

appropriate. 

3.0 * * * 

3.1. * * * 

3.1.1. In Table 1, Instrumentation 

Accuracy, refrigerant temperature 

measurements shall have an accuracy of +/ 

¥0.5 °F for unit cooler in/out. When testing 

high-temperature refrigeration systems, 

measurements used to determine temperature 

or water vapor content of the air (i.e. wet bulb 

or dew point) shall be accurate to within +/ 

¥0.25 °F; all other temperature 

measurements shall be accurate to within +/ 

¥1.0 °F. 

* * * * * 

3.1.6. Test Operating Conditions for CO2

Unit Coolers. 

For medium-temperature CO2 unit coolers, 

conduct tests using the test conditions 

specified in Table 17 of this appendix. For 

low-temperature CO2 unit coolers, conduct 

tests using the test conditions specified in 

Table 18 of this appendix. 

TABLE 17—TEST OPERATING CONDITIONS FOR MEDIUM-TEMPERATURE CO2 UNIT COOLERS

Test description 

Unit cooler air 

entering 

dry-bulb, °F 

Unit cooler air 

entering 

relative 

humidity, 

% 

Suction dew 

point temp, °F 

Liquid inlet 

bubble point 

temperature, °F 

Liquid inlet 

subcooling, °F 

Compressor 

capacity Test objective 

Off-Cycle Power ................. 35 <50 ........................ ........................ ........................ Compressor On .... Measure fan input power 

during compressor off 

cycle. 

Refrigeration Capacity, Ambient Condition A.35 <50 25 38 5 Compressor Off .... Determine Net Refrigeration Capacity of Unit 

Cooler. 

Notes: 

1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used. 

TABLE 18—TEST OPERATING CONDITIONS FOR LOW-TEMPERATURE CO2 UNIT COOLERS

Test description 

Unit cooler air 

entering 

dry-bulb, 

°F 

Unit cooler air 

entering relative humidity, 

% 

Suction dew 

point temp, 

°F 

Liquid inlet 

bubble point 

temperature 

°F 

Liquid inlet 

subcooling, 

°F 

Compressor 

capacity Test objective 

Off-Cycle Power ................... ¥10 <50 ........................ ........................ ........................ Compressor Off .... Measure fan input power 

during compressor off 

cycle. 

Refrigeration Capacity, Ambient Condition A.¥10 <50 ¥20 38 5 Compressor On .... Determine Net Refrigeration Capacity of Unit 

Cooler. 

Defrost .................................. ¥10 <50 ........................ ........................ ........................ Compressor Off .... Test according to Appendix C Section C11 of 

AHRI 1250–2009. 

Notes: 

1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used. 


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3.1.7. Test Operating Conditions for HighTemperature Unit Coolers. For high temperature cooler unit coolers, 

conduct tests using the test conditions 

specified in Table 19 of this appendix. 

TABLE 19—TEST OPERATING CONDITIONS FOR HIGH-TEMPERATURE UNIT COOLERS

Test description 

Unit cooler air 

entering 

dry-bulb, 

°F 

Unit cooler air 

entering relative humidity, 

% 1

Suction dew 

point temp, °F 2 3

Liquid inlet 

bubble point 

temperature, °F 

Liquid inlet 

subcooling, °F 

Compressor 

capacity Test objective 

Off-Cycle ............................ 55 55 ........................ 105 9 Compressor Off .... Measure fan input power. 

Refrigeration Capacity Suction A.55 55 38 105 9 Compressor On .... Determine Net Refrigeration Capacity of Unit 

Cooler. 

Notes: 

1. The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 

3%. 

2. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used. 

3. Suction Dew Point shall be measured at the Unit Cooler Exit. 

3.2. * * * 

3.2.1. Refrigerant Temperature 

Measurements. 

In AHRI 1250–2009 appendix C, section 

C3.1.6, any refrigerant temperature 

measurements entering and leaving the unit 

cooler may use sheathed sensors immersed in 

the flowing refrigerant instead of 

thermometer wells. When testing a 

condensing unit alone, measure refrigerant 

liquid temperature leaving the condensing 

unit using thermometer wells as described in 

AHRI 1250–2009 appendix C, section C3.1.6 

or sheathed sensors immersed in the flowing 

refrigerant. For all of these cases, if the 

refrigerant tube outer diameter is less than 1⁄2

inch, the refrigerant temperature may be 

measured using the average of two 

temperature measuring instruments with a 

minimum accuracy of ±0.5 °F placed on 

opposite sides of the refrigerant tube 

surface—resulting in a total of up to 8 

temperature measurement devices used for 

the DX Dual Instrumentation method. In this 

case, the refrigerant tube shall be insulated 

with 1-inch thick insulation from a point 6 

inches upstream of the measurement location 

to a point 6 inches downstream of the 

measurement location. Also, to comply with 

this requirement, the unit cooler entering 

measurement location may be moved to a 

location 6 inches upstream of the expansion 

device and, when testing a condensing unit 

alone, the entering and leaving measurement 

locations may be moved to locations 6 inches 

from the respective service valves. 

* * * * * 

3.2.3. Subcooling at Refrigerant Mass Flow 

Meter. 

In appendix C, Section C3.4.5 of AHRI 

1250–2009 (incorporated by reference; see 

§ 431.303), and in Section 7.1.2 of ASHRAE 

23.1–2010 (incorporated by reference; see 

§ 431.303) when verifying sub-cooling at the 

mass flow meters, only the sight glass and a 

temperature sensor located on the tube 

surface under the insulation are required. 

Subcooling shall be verified to be within the 

3 ßF requirement downstream of flow meters 

located in the same chamber as a condensing 

unit under test and upstream of flow meters 

located in the same chamber as a unit cooler 

under test, rather than always downstream as 

indicated in AHRI 1250–2009, Section C3.4.5 

or always upstream as indicated in Section 

7.1.2 of ASHRAE 23.1–2010. If the 

subcooling is less than 3 ßF, cool the line 

between the condensing unit outlet and this 

location to achieve the required subcooling. 

When providing such cooling while testing a 

matched pair, also measure the refrigerant 

temperature upstream of the location at 

which the line is being cooled, and increase 

the temperature used to calculate unit cooler 

entering enthalpy by the difference between 

the upstream and downstream temperatures. 

* * * * * 

3.2.6. Installation Instructions. 

Manufacturer installation instructions or 

installation instructions described in this 

section refer to the instructions that come 

packaged with or appear on the labels 

applied to the unit. This does not include 

online manuals or materials. 

Installation Instruction Hierarchy: If a 

given installation instruction provided on the 

label(s) applied to the unit conflicts with the 

installation instructions that are shipped 

with the unit, the label takes precedence. For 

testing of matched pairs, the installation 

instructions for the dedicated condensing 

unit shall take precedence. Setup shall be in 

accordance with the field installation 

instructions (laboratory installation 

instructions shall not be used). Achieving 

test conditions shall always take precedence 

over installation instructions. 

3.2.7. Refrigerant Charging and Adjustment 

of Superheat and Subcooling. 

All test samples shall be charged, and 

superheat and/or subcooling shall be set, at 

Refrigeration A test conditions unless 

otherwise specified in the installation 

instructions. If the installation instructions 

give a specified range for superheat, subcooling, or refrigerant pressure, the average of 

the range shall be used as the refrigerant 

charging parameter target and the test 

condition tolerance shall be ±50 percent of 

the range. Perform charging of nearazeotropic and zeotropic refrigerants only 

with refrigerant in the liquid state. Once the 

correct refrigerant charge is determined, all 

tests shall run until completion without 

further modification. 

3.2.7.1. When charging or adjusting 

superheat/subcooling, use all pertinent 

instructions contained in the installation 

instructions to achieve charging parameters 

within the tolerances. However, in the event 

of conflicting charging information between 

installation instructions, follow the 

installation instruction hierarchy listed in 

section 3.2.6. of this appendix. Conflicting 

information is defined as multiple conditions 

given for charge adjustment where all 

conditions specified cannot be met. In the 

event of conflicting information within the 

same set of charging instructions (e.g., the 

installation instructions shipped with the 

dedicated condensing unit), follow the 

hierarchy in Table 1 of this section for 

priority. Unless the installation instructions 

specify a different charging tolerance, the 

tolerances identified in Table 1 of this 

section shall be used. 

TABLE 1—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF REFRIGERANT

CONDITIONS

Priority 

Fixed orifice Expansion valve 

Parameter with installation instruction 

target Tolerance 

Parameter with 

installation 

instruction target 

Tolerance 

1 ............... Super-heat ................................................ ± 2.0 °F ................... Sub-cooling ........... 10% of the Target Value; No less than 

±0.5 °F, No more than ±2.0 °F. 


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TABLE 1—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF REFRIGERANT

CONDITIONS—Continued 

Priority 

Fixed orifice Expansion valve 

Parameter with installation instruction 

target Tolerance 

Parameter with 

installation 

instruction target 

Tolerance 

2 ............... High Side Pressure or Saturation Temperature.±4.0 psi or ±1.0 °F .. High Side Pressure 

or Saturation 

Temperature.

±4.0 psi or ±1.0 °F. 

3 ............... Low Side Pressure or Saturation Temperature.±2.0 psi or ±0.8 °F .. Super-heat ............ ±2.0 °F. 

4 ............... Low Side Temperature ............................. ±2.0 °F .................... Low Side Pressure 

or Saturation 

Temperature.

±2.0 psi or ±0.8 °F. 

5 ............... High Side Temperature ............................ ±2.0 °F .................... Approach Temperature.±1.0 °F. 

6 ............... Charge Weight .......................................... ±2.0 oz .................... Charge Weight ...... 0.5% or 1.0 oz, whichever is greater. 

3.2.7.2. Dedicated Condensing Unit. If the 

Dedicated Condensing Unit includes a 

receiver and the subcooling target leaving the 

condensing unit provided in installation 

instructions cannot be met without fully 

filling the receiver, the subcooling target 

shall be ignored. Likewise, if the Dedicated 

Condensing unit does not include a receiver 

and the subcooling target leaving the 

condensing unit cannot be met without the 

unit cycling off on high pressure, the 

subcooling target can be ignored. Also, if no 

instructions for charging or for setting 

subcooling leaving the condensing unit are 

provided in the installation instructions, the 

refrigeration system shall be set up with a 

charge quantity and/or exit subcooling such 

that the unit operates during testing without 

shutdown (e.g., on a high-pressure switch) 

and operation of the unit is otherwise 

consistent with the requirements of the test 

procedure of this appendix and the 

installation instructions. 

3.2.7.3. Unit Cooler. Use the shipped 

expansion device for testing. Otherwise, use 

the expansion device specified in the 

installation instructions. If the installation 

instructions specify multiple options for the 

expansion device, any specified expansion 

device may be used. The supplied expansion 

device shall be adjusted until either the 

superheat target is met, or the device reaches 

the end of its adjustable range. In the event 

the device reaches the end of its adjustable 

range and the super heat target is not met, 

test with the adjustment at the end of its 

range providing the closest match to the 

superheat target, and the test condition 

tolerance for super heat target shall be 

ignored. The measured superheat is not 

subject to a test operating tolerance. 

However, if the evaporator exit condition is 

used to determine capacity using the DX 

dual-instrumentation method or the 

refrigerant enthalpy method, individual 

superheat value measurements may not be 

equal to or less than zero. If this occurs, or 

if the operating tolerances of measurements 

affected by expansion device fluctuation are 

exceeded, the expansion device shall be 

replaced, operated at an average superheat 

value higher than the target, or both, in order 

to avoid individual superheat value 

measurements less than zero and/or to meet 

the required operating tolerances. 

3.2.8. Chamber Conditioning using the Unit 

Under Test. 

In appendix C, Section C6.2 of AHRI 1250– 

2009, for applicable system configurations 

(matched pairs, single-packaged refrigeration 

systems, and standalone unit coolers), the 

unit under test may be used to aid in 

achieving the required test chamber 

conditions prior to beginning any steady state 

test. However, the unit under test must be 

inspected and confirmed to be free from frost 

before initiating steady state testing. 

3.3. * * * 

3.3.1. For unit coolers tested alone, use test 

procedures described in AHRI 1250–2009 for 

testing unit coolers for use in mix-match 

system ratings, except that for the test 

conditions in Tables 15 and 16 of this 

appendix, use the Suction A saturation 

condition test points only. Also for unit 

coolers tested alone, other than hightemperature unit coolers, use the calculations 

in section 7.9 to determine AWEF and net 

capacity described in AHRI 1250–2009 for 

unit coolers matched to parallel rack systems. 

* * * * * 

3.3.3. Evaporator Fan Power. 

3.3.3.1. Ducted Evaporator Air. 

For ducted fan-coil units with ducted 

evaporator air, or that can be installed with 

or without ducted evaporator air: Connect 

ductwork on both the inlet and outlet 

connections and determine external static 

pressure as described in ASHRAE 37–2009 

(incorporated by reference; see § 431.303), 

Sections 6.4 and 6.5. Use pressure 

measurement instrumentation as described in 

ASHRAE 37–2009, Section 5.3.2. Test at the 

fan speed specified in manufacturer 

installation instructions—if there is more 

than one fan speed setting and the 

installation instructions do not specify which 

speed to use, test at the highest speed. 

Conduct tests with the external static 

pressure equal to 50 percent of the maximum 

external static pressure allowed by the 

manufacturer for system installation within a 

tolerance of ¥0.00/+0.05 in. wc. Set the 

external static pressure by symmetrically 

restricting the outlet of the test duct. 

Alternatively, if using the indoor air enthalpy 

method to measure capacity, set external 

static pressure by adjusting the fan of the 

airflow measurement apparatus. In case of 

conflict, these requirements for setting 

evaporator airflow take precedence over 

airflow values specified in manufacturer 

installation instructions or product literature. 

3.3.3.2. Unit Coolers or Single-Packaged 

Systems that are not High-Temperature 

Refrigeration Systems. 

Use appendix C, Section C10 of AHRI 

1250–2009 for off-cycle evaporator fan 

testing, with the exception that evaporator 

fan controls using periodic stir cycles shall 

be adjusted so that the greater of a 50% duty 

cycle (rather than a 25% duty cycle) or the 

manufacturer default is used for measuring 

off-cycle fan energy. For adjustable-speed 

controls, the greater of 50% fan speed (rather 

than 25% fan speed) or the manufacturer’s 

default fan speed shall be used for measuring 

off-cycle fan energy. Also, a two-speed or 

multi-speed fan control may be used as the 

qualifying evaporator fan control. For such a 

control, a fan speed no less than 50% of the 

speed used in the maximum capacity tests 

shall be used for measuring off-cycle fan 

energy. 

3.3.3.3. High-Temperature Refrigeration 

Systems. 

3.3.3.3.1. The evaporator fan power 

consumption shall be measured in 

accordance with the requirements in Section 

C3.5 of AHRI 1250–2009. This measurement 

shall be made with the fan operating at full 

speed, either measuring unit cooler or total 

system power input upon the completion of 

the steady state test when the compressor 

and the condenser fan of the walk-in system 

are turned off, or by submetered 

measurement of the evaporator fan power 

during the steady state test. 

Section C3.5 of AHRI 1250–2009 is revised 

to read: 

Evaporator Fan Power Measurement. 

The following shall be measured and 

recorded during a fan power test. 

EFcomp,on Total electrical power input to fan 

motor(s) of Unit Cooler, W 

FS Fan speed(s), rpm 

N Number of motors 

Pb Barometric pressure, in. Hg 

Tdb Dry-bulb temperature of air at inlet, °F 


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Twb Wet-bulb temperature of air at inlet, °F 

V Voltage of each phase 

For a given motor winding configuration, 

the total power input shall be measured at 

the highest nameplate voltage. For threephase power, voltage imbalance shall be no 

more than 2%. 

3.3.3.3.2. Evaporator fan power for the offcycle is equal to the on-cycle evaporator fan 

power with a run time of ten percent of the 

off-cycle time. 

EFcomp,off = 0.1 × EFcomp,on

* * * * * 

3.3.7. Calculations for Unit Coolers Tested 

Alone. 

3.3.7.1. Unit Coolers that are not HighTemperature Unit Coolers. 

Calculate the AWEF and net capacity using 

the calculations in AHRI 1250–2009, Section 

7.9. 

3.3.7.2. High-Temperature Unit Coolers. 

Calculate AWEF on the basis that walk-in 

box load is equal to half of the system net 

capacity, without variation according to high 

and low load periods, and with EER set 

according to tested evaporator capacity, as 

follows: 

The net capacity, q ̇ mix,evap, is determined 

from the test data for the unit cooler at the 

38 °F suction dewpoint. 

Where: 

B ̇ L is the non-equipment-related box load; 

LF is the load factor; and 

Other symbols are as defined in Section 8 of 

AHRI 1250–2009. 

3.3.7.3. If the unit cooler has variablespeed evaporator fans that vary fan speed in 

response to load, then: 

3.3.7.3.1. When testing to certify 

compliance with the energy conservation 

standards in § 431.306, fans shall operate at 

full speed during on-cycle operation. Do not 

conduct the calculations in AHRI 1250–2009, 

Section 7.9.3. Instead, use AHRI 1250–2009, 

Section 7.9.2 to determine the system’s 

AWEF. 

3.3.7.3.2. When calculating the benefit for 

the inclusion of variable-speed evaporator 

fans that modulate fan speed in response to 

load for the purpose of making 

representations of efficiency, use AHRI 1250– 

2009, Section 7.9.3 to determine the system 

A WEF. 

3.4. * * * 

3.4.2. * * * 

3.4.2.1. For calculating enthalpy leaving 

the unit cooler to calculate gross capacity, (a) 

the saturated refrigerant temperature (dew 

point) at the unit cooler coil exit, Tevap, shall 

be 25 °F for medium-temperature systems 

(coolers) and ¥20 °F for low-temperature 

systems (freezers), and (b) the refrigerant 

temperature at the unit cooler exit shall be 

35 °F for medium-temperature systems 

(coolers) and ¥14 °F for low-temperature 

systems (freezers). For calculating gross 

capacity, the measured enthalpy at the 

condensing unit exit shall be used as the 

enthalpy entering the unit cooler. The 

temperature measurement requirements of 

appendix C, Section C3.1.6 of AHRI 1250– 

2009 and modified by section 3.2.1 of this 

appendix shall apply only to the condensing 

unit exit rather than to the unit cooler inlet 

and outlet, and they shall be applied for two 

measurements when using the DX Dual 

Instrumentation test method. 

* * * * * 

■ 13. Add appendix C1 to subpart R of 

part 431 to read as follows: 

Appendix C1 to Subpart R of Part 431— 

Uniform Test Method for the 

Measurement of Net Capacity and 

AWEF of Walk-In Cooler and Walk-In 

Freezer Refrigeration Systems 

Note: Prior to [date 180 days after 

publication of final rule], representations 

with respect to the energy use of refrigeration 

components of walk-in coolers and walk-in 

freezers, including compliance certifications, 

must be based on testing conducted in 

accordance with the applicable provisions for 

10 CFR part 431, subpart R, appendix C, 


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revised as of January 1, 2022. Beginning [date 

180 days after publication of final rule], 

representations with respect to energy use of 

refrigeration components of walk-in coolers 

and walk-in freezers, including compliance 

certifications, must be based on testing 

conducted in accordance with appendix C of 

this subpart. 

For any amended standards for walk-in 

coolers and walk-in freezers published after 

January 1, 2022, manufacturers must use the 

results of testing under this appendix to 

determine compliance. Representations 

related to energy consumption must be made 

in accordance with this appendix when 

determining compliance with the relevant 

standard. Manufacturers may also use this 

appendix to certify compliance with any 

amended standards prior to the applicable 

compliance date for those standards. 

1. Incorporation by Reference 

DOE incorporated by reference in 

§ 431.303, the entire standards for AHRI 

1250–2020, ANSI/ASHRAE 16, and ANSI/ 

ASHRAE 37. However, certain enumerated 

provisions of these standards, as set forth in 

sections 1.1, 1.2, and 1.3 of this appendix are 

inapplicable. To the extent there is a conflict 

between the terms or provisions of a 

referenced industry standard and the CFR, 

the CFR provisions control. To the extent 

there is a conflict between the terms or 

provisions of AHRI 1250–2020, ANSI/ 

ASHRAE 16, and ANSI/ASHRAE 37, the 

AHRI 1250–2020 provisions control. 

1.1 AHRI 1250–2020 

1.1.1 Section 1 Purpose, is inapplicable 

as specified in section 4.1.1 of this appendix. 

1.1.2 Section 2 Scope, is inapplicable as 

specified in section 4.1.2 of this appendix. 

1.1.3 Section 9 Minimum Data 

Requirements for Published Rating, is 

inapplicable as specified in section 4.1.3 of 

this appendix. 

1.1.4 Section 10 Marking and 

Nameplate Data, is inapplicable as specified 

in section 4.1.4 of this appendix. 

1.1.5 Section 11 Conformance 

Conditions, is inapplicable as specified in 

section 4.1.5 of this appendix. 

1.2 ANSI/ASHRAE 16 

1.2.1 Section 1 Purpose, is inapplicable 

as specified in section 4.2.1 of this appendix. 

1.2.2 Section 2 Scope, is inapplicable as 

specified in section 4.2.2 of this appendix. 

1.2.3 Section 4 Classifications, is 

inapplicable as specified in section 4.2.3 of 

this appendix. 

1.2.4 Normative Appendices E–M, are 

inapplicable as specified in section 4.2.4 of 

this appendix. 

1.2.5 Informative Appendices N–R, are 

inapplicable as specified in section 4.2.5 of 

this appendix. 

1.3 ANSI/ASHRAE 37 

1.3.1 Section 1 Purpose, is inapplicable 

as specified in section 4.3.1 of this appendix. 

1.3.2 Section 2 Scope, is inapplicable as 

specified in section 4.3.2 of this appendix. 

1.3.3 Section 4 Classifications, is 

inapplicable as specified in section 4.3.3 of 

this appendix. 

1.3.4 Informative Appendix A

Classifications of Unitary Air-conditioners 

and Heat Pumps, is inapplicable as specified 

in section 4.3.4 of this appendix. 

2. Scope. 

This appendix covers the test requirements 

used to determine the net capacity and the 

AWEF of the refrigeration system of a walkin cooler or walk-in freezer. 

3. Definitions. 

3.1. Applicable Definitions. 

The definitions contained in § 431.302, 

AHRI 1250–2020, ANSI/ASHRAE 37, and 

ANSI/ASHRAE 16 apply to this appendix. 

When definitions in standards incorporated 

by reference are in conflict or when they 

conflict with this section, the hierarchy of 

precedence shall be in the following order: 

§ 431.302, AHRI 1250–2020, and then either 

ANSI/ASHRAE 37 or ANSI/ASHRAE 16. 

The term ‘‘unit cooler’’ used in AHRI 

1250–2020 and this subpart shall be 

considered to address both ‘‘unit coolers’’ 

and ‘‘ducted fan-coil units,’’ as appropriate. 

3.2. Additional Definitions. 

3.2.1. Digital Compressor means a 

compressor that uses mechanical means for 

disengaging active compression on a cyclic 

basis to provide a reduced average refrigerant 

flow rate in response to a control system 

input signal. 

3.2.2. Displacement Ratio, applicable to 

staged positive displacement compressor 

systems, means the swept volume rate, e.g., 

in cubic centimeters per second, of a given 

stage, divided by the swept volume rate at 

full capacity. 

3.2.3. Duty Cycle, applicable to digital 

compressors, means the fraction of time that 

the compressor is engaged and actively 

compressing refrigerant. 

3.2.4. Maximum Speed, applicable to 

variable-speed compressors, means the 

maximum speed at which the compressor 

will operate under the control of the 

dedicated condensing system control system 

for extended periods of time, i.e., not 

including short-duration boost-mode 

operation. 

3.2.5. Minimum Speed, applicable to 

variable-speed compressors, means the 

minimum compressor speed at which the 

compressor will operate under the control of 

the dedicated condensing system control 

system. 

3.2.6. Multiple-Capacity, applicable for 

describing a refrigeration system, indicates 

that it has three or more stages (levels) of 

capacity. 

3.2.7. Speed Ratio, applicable to variablespeed compressors, means the ratio of 

operating speed to the maximum speed. 

4. Test Methods, Measurements, and 

Calculations. 

Determine the Annual Walk-in Energy 

Factor (AWEF) and net capacity of walk-in 

cooler and walk-in freezer refrigeration 

systems by conducting the test procedure set 

forth in AHRI 1250–2020, with the 

modifications to that test procedure provided 

in this section. However, certain sections of 

AHRI 1250–2020, ANSI/ASHRAE 37, and 

ANSI/ASHRAE 16 are not applicable, as set 

forth in sections 4.1, 4.2, and 4.3 of this 

appendix. Round AWEF measurements to the 

nearest 0.05 Btu/Wh. Round net capacity 

measurements as indicated in Table 1 of this 

appendix. 

TABLE 1—ROUNDING OF REFRIGERATION SYSTEM NET CAPACITY

Net capacity range, Btu/h Rounding multiple, Btu/h 

<20,000 ................................. 100 

≥20,000 and <38,000 ........... 200 

≥38,000 and <65,000 ........... 500 

≥65,000 ................................. 1,000 

The following sections of this appendix 

provide additional instructions for testing. In 

cases where there is a conflict, the language 

of this appendix takes highest precedence, 

followed by AHRI 1250–2020, then ANSI/ 

ASHRAE 37 or ANSI/ASHRAE 16. Any 

subsequent amendment to a referenced 

document by the standard-setting 

organization will not affect the test procedure 

in this appendix, unless and until the test 

procedure is amended by DOE. Material is 

incorporated as it exists on the date of the 

approval, and a notice of any change in the 

incorporation will be published in the 

Federal Register. 

4.1 Excepted sections of AHRI 1250– 

2020. 

(a) Section 1 Purpose, 

(b) Section 2 Scope, 

(c) Section 9 Minimum Data 

Requirements for Published Ratings, 

(d) Section 10 Marking and Nameplate 

Data, and 

(e) Section 11 Conformance Conditions. 

4.2 Excepted sections of ANSI/ASHRAE 

16. 

(a) Section 1 Purpose, 

(b) Section 2 Scope, 

(c) Section 4 Classifications, 

(d) Normative Appendices E–M, 

(e) Informative Appendices N–R. 

4.3 Excepted sections of ANSI/ASHRAE 

37. 

(a) Section 1 Purpose, 

(b) Section 2 Scope, 

(c) Section 4 Classifications, 

(d) Informative Appendix A Classifications 

of Unitary Air-conditioners and Heat Pumps. 

4.4. Instrumentation Accuracy and Test 

Tolerances. 

Use measuring instruments as described in 

Section 4.1 of AHRI 1250–2020, with the 

following additional requirement. 

4.4.1. Electrical Energy Input measured in 

Wh with a minimum accuracy of ±0.5% of 

reading (for Off-Cycle tests per footnote 5 of 

Table C3 in Section C3.6.2 of AHRI 1250– 

2020). 

4.5. Test Operating Conditions. 

Test conditions used to determine AWEF 

shall be as specified in Tables 4 through 17 

of AHRI 1250–2020. Tables 7 and 11 of AHRI 

1250–2020, labeled to apply to variablespeed outdoor matched-pair refrigeration 

systems, shall also be used for testing 

variable-capacity single-packaged outdoor 

refrigeration systems, and also for testing 

multiple-capacity matched-pair or singlepackaged outdoor refrigeration systems. Test 

conditions used to determine AWEF for 

refrigeration systems not specifically 

identified in AHRI 1250–2020 are as 

enumerated in sections 4.5.1 through 4.5.6 of 

this appendix. 


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4.5.1 Test Operating Conditions for HighTemperature Refrigeration Systems. 

For fixed-capacity high-temperature 

matched-pair or single-packaged refrigeration 

systems with indoor condensing units, 

conduct tests using the test conditions 

specified in Table 2 of this appendix. For 

fixed-capacity high-temperature matchedpair or single-packaged refrigeration systems 

with outdoor condensing units, conduct tests 

using the test conditions specified in Table 

3 of this appendix. For high-temperature unit 

coolers tested alone, conduct tests using the 

test conditions specified in Table 4 of this 

appendix. 

TABLE 2—TEST OPERATING CONDITIONS FOR FIXED-CAPACITY HIGH-TEMPERATURE INDOOR MATCHED PAIR OR SINGLEPACKAGED REFRIGERATION SYSTEMS

Test description 

Unit cooler air 

entering 

dry-bulb, °F 

Unit cooler air 

entering 

relative 

humidity, % 1

Condenser air 

entering 

dry-bulb, °F 

Condenser air 

entering 

wet-bulb, °F 

Compressor status Test objective 

Off-Cycle Power ................... 55 55 ........................ ........................ Compressor Off .... Measure total input wattage during compressor off cycle, (E ̇ cu,off + E ̇ Fcomp,off) 2. 

Refrigeration Capacity A ...... 55 55 90 75,3 65 4 Compressor On .... Determine Net Refrigeration Capacity of 

Unit Cooler, input power, and EER at 

Test Condition. 

Notes: 

1The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%. 

2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250–2020. 

3 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 4 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is located in 

the outdoor room. 

TABLE 3—TEST OPERATING CONDITIONS FOR FIXED-CAPACITY HIGH-TEMPERATURE OUTDOOR MATCHED-PAIR OR

SINGLE-PACKAGED REFRIGERATION SYSTEMS

Test description 

Unit cooler air 

entering 

dry-bulb, °F 

Unit cooler air 

entering 

relative 

humidity, % 1

Condenser air 

entering 

dry-bulb, °F 

Condenser air 

entering 

wet-bulb, °F 

Compressor status Test objective 

Refrigeration Capacity A ...... 55 55 95 75,3 68 4 Compressor On .... Determine Net Refrigeration Capacity of 

Unit Cooler, input power, and EER at 

Test Condition. 

Off-Cycle Power, Capacity A 55 55 95 75,3 68 4 Compressor Off .... Measure total input wattage during compressor off cycle, (E ̇ cu,off + E ̇ Fcomp,off) 2. 

Refrigeration Capacity B ...... 55 55 59 54,3 46 4 Compressor On .... Determine Net Refrigeration Capacity of 

Unit Cooler and system input power at 

moderate condition. 

Off-Cycle Power, Capacity B 55 55 59 54,3 46 4 Compressor Off .... Measure total input wattage during compressor off cycle, (E ̇ cu,off + E ̇ Fcomp,off) 2. 

Refrigeration Capacity C ...... 55 55 35 34,3 29 4 Compressor On .... Determine Net Refrigeration Capacity of 

Unit Cooler and system input power at 

cold condition. 

Off-Cycle Power, Capacity C 55 55 35 34,3 29 4 Compressor Off .... Measure total input wattage during compressor off cycle, (E ̇ cu,off + E ̇ Fcomp,off) 2

Notes: 

1The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%. 

2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250–2020. 

3 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 

4 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is located in 

the outdoor room. 

TABLE 4—TEST OPERATING CONDITIONS FOR HIGH-TEMPERATURE UNIT COOLERS

Test description 

Unit cooler air 

entering 

dry-bulb, °F 

Unit cooler air 

entering 

relative 

humidity, % 1

Suction dew 

point temp, °F 3 4

Liquid inlet 

bubble point 

temperature, °F 

Liquid inlet 

subcooling, °F Compressor status Test objective 

Off-Cycle .......................... 55 55 ........................ 105 9 Compressor Off .... Measure unit cooler input 

wattage during compressor off cycle, 

E ̇ Fcomp,off 2. 

Refrigeration Capacity ..... 55 55 38 105 9 Compressor On .... Determine Net Refrigeration 

Capacity of Unit Cooler, 

input power, and EER at 

Test Condition. 

Notes: 

1The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%. 

2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250–2020. 

3Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used. 4Suction Dew Point shall be measured at the Unit Cooler Exit. 

4.5.2 Test Operating Conditions for CO2

Unit Coolers. 

For medium-temperature CO2 Unit Coolers, 

conduct tests using the test conditions 

specified in Table 5 of this appendix. For 

low-temperature CO2 Unit Coolers, conduct 

tests using the test conditions specified in 

Table 6 of this appendix. 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 24005 

TABLE 5—TEST OPERATING CONDITIONS FOR MEDIUM-TEMPERATURE CO2 UNIT COOLERS 1

Test title 

Unit cooler air 

entering 

dry-bulb, 

°F 

Unit cooler air 

entering 

relative 

humidity, % 

Suction dew 

point temp,3

°F 

Liquid inlet 

bubble point 

temperature, °F 

Liquid inlet 

subcooling, °F 

Compressor 

operating mode Test objective 

Off-Cycle Power ................. 35 <50 ........................ ........................ ........................ Compressor On .... Measure unit cooler input 

wattage during compressor off cycle, 

E ̇ Fcomp,off.2

Refrigeration Capacity, Ambient Condition A.35 <50 25 38 5 Compressor Off .... Determine Net Refrigeration Capacity of Unit 

Cooler, q ̇mix,rack. 

Notes: 

1Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used. 2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250–2020. 

3Suction Dew Point shall be measured at the Unit Cooler Exit conditions. 

TABLE 6—TEST OPERATING CONDITIONS FOR LOW-TEMPERATURE CO2 UNIT COOLERS 1

Test Title 

Unit cooler air 

entering 

dry-bulb, °F 

Unit cooler air 

entering 

relative 

humidity, 

% 

Suction dew 

point temp,3

°F 

Liquid inlet 

bubble point 

temperature, °F 

Liquid inlet 

subcooling, °F 

Compressor 

operating mode Test objective 

Off-Cycle Power ................. ¥10 <50 ........................ ........................ ........................ Compressor Off .... Measure unit cooler input 

wattage during compressor off cycle, 

E ̇ Fcomp,off.2

Refrigeration Capacity, Ambient Condition A.¥10 <50 ¥20 38 5 Compressor On .... Determine Net Refrigeration Capacity of Unit 

Cooler, q ̇mix,rack. 

Defrost ................................ ¥10 <50 ........................ ........................ ........................ Compressor Off .... Test according to Appendix 

C Section C10 of AHRI 

1250–2020, D ̇ F,Q ̇ DF. 

Notes: 

1Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 °F shall be used. 2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250–2020. 

3Suction Dew Point shall be measured at the Unit Cooler Exit conditions. 

4.5.3 Test Operating Conditions for TwoCapacity Condensing Units Tested Alone. 

For two-capacity medium-temperature 

outdoor condensing units tested alone, 

conduct tests using the test conditions 

specified in Table 7 of this appendix. For 

two-capacity medium-temperature indoor 

condensing units tested alone, conduct tests 

using the test conditions specified in Table 

8 of this appendix. For two-capacity lowtemperature outdoor condensing units tested 

alone, conduct tests using the test conditions 

specified in Table 9 of this appendix. For 

two-capacity low-temperature indoor 

condensing units tested alone, conduct tests 

using the test conditions specified in Table 

10 of this appendix. 

TABLE 7—TEST OPERATING CONDITIONS FOR TWO-CAPACITY MEDIUM-TEMPERATURE OUTDOOR DEDICATED CONDENSING

UNITS

Test description Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 1

Compressor status 

Capacity, Condition A, Low Capacity.Unit Cooler Low Fan: 2 24.5 .....

Unit Cooler High Fan: 2 25.5 ....

49 

46 

95 75 Low Capacity, k=1. 

Capacity, Condition A, High 

Capacity.

23 ............................................. 41 95 75 High Capacity, k=2. 

Off Cycle, Condition A .............. ................................................... ........................ 95 75 Off. 

Capacity, Condition B, Low Capacity.Unit Cooler Low Fan: 2 24.5 .....

Unit Cooler High Fan: 2 25.5 ....

47 

45 

59 54 Low Capacity, k=1. 

Capacity, Condition B, High 

Capacity.

23 ............................................. ........................ 59 54 High Capacity, k=2. 

Off Cycle, Condition B .............. ................................................... ........................ 59 54 Off. 

Capacity, Condition C, Low Capacity.Unit Cooler Low Fan: 2 22.5 .....

Unit Cooler High Fan: 2 25.5 ....

41 

41 

35 34 Low Capacity, k=1. 

Capacity, Condition C, High 

Capacity.

23 ............................................. 41 35 34 High Capacity, k=2. 

Off Cycle, Condition C .............. ................................................... ........................ 35 34 Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When Staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit 

cooler High Fan condition. 


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24006 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

TABLE 8—TEST OPERATING CONDITIONS FOR TWO-CAPACITY MEDIUM-TEMPERATURE INDOOR DEDICATED CONDENSING

UNITS

Test description Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 1

Compressor status 

Capacity, Condition A, Low Capacity.Unit Cooler Low Fan: 2 24.5 .....

Unit Cooler High Fan: 2 25.5 ....

49 

46 

90 75 Low Capacity, k=1. 

Capacity, Condition A, High 

Capacity.

23 ............................................. 41 90 75 High Capacity, k=2. 

Off Cycle, Condition A .............. ................................................... ........................ 90 75 Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit 

cooler High Fan condition. 

TABLE 9—TEST OPERATING CONDITIONS FOR TWO-CAPACITY LOW-TEMPERATURE OUTDOOR DEDICATED CONDENSING

UNITS

Test title Suction dew point, °F Return gas, °F 

Condenser air 

entering 

dry-bulb, °F 

Condenser air 

entering 

wet-bulb, °F 1

Compressor 

operating 

mode 

Capacity, Condition A, 

Low Capacity.

Unit Cooler Low Fan: 2 ¥20.5 .....................

Unit Cooler High Fan: 2 ¥19.5 ....................

21 

13 

95 75 Low Capacity, k=1. 

Capacity, Condition A, 

High Capacity.

¥22 .............................................................. 5 95 75 High Capacity, k=2. 

Off Cycle, Condition A ....................................................................... ........................ 95 75 Compressor Off. 

Capacity, Condition B, 

Low Capacity.

Unit Cooler Low Fan: 2 ¥20.5 .....................

Unit Cooler High Fan: 2 ¥19.5 ....................

19 

13 

59 54 Low Capacity, k=1. 

Capacity, Condition B, 

High Capacity.

¥22 .............................................................. 5 59 54 High Capacity, k=2. 

Off Cycle, Condition B ....................................................................... ........................ 59 54 Compressor Off. 

Capacity, Condition C, 

Low Capacity.

Unit Cooler Low Fan: 2 ¥20.5 .....................

Unit Cooler High Fan: 2 ¥19.5 ....................

17 

12 

35 34 Low Capacity, k=1. 

Capacity, Condition C, 

High Capacity.

¥22 .............................................................. 5 35 34 Maximum Capacity, 

k=2. 

Off Cycle, Condition C ....................................................................... ........................ 35 34 Compressor Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit 

cooler High Fan condition. 

TABLE 10—TEST OPERATING CONDITIONS FOR TWO-CAPACITY LOW-TEMPERATURE INDOOR DEDICATED CONDENSING

UNITS

Test title Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 1

Compressor 

operating 

mode 

Capacity, Condition A, Low Capacity.Unit Cooler Low Fan: 2 ¥20.5

Unit Cooler High Fan: 2¥19.5

21 

13 

90 75 Low Capacity, k=1. 

Capacity, Condition A, High 

Capacity.

¥22 .......................................... 5 90 75 High Capacity, k=2. 

Off Cycle, Condition A .............. ................................................... ........................ 90 75 Compressor Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit 

cooler High Fan condition. 

4.5.4 Test Operating Conditions for 

Variable- or Multiple-Capacity Condensing 

Units Tested Alone. 

For variable-capacity or multiple-capacity 

outdoor medium-temperature condensing 

units tested alone, conduct tests using the 

test conditions specified in Table 11 of this 

appendix. For variable-capacity or multiplecapacity indoor medium-temperature 

condensing units tested alone, conduct tests 

using the test conditions specified in Table 

12 of this appendix. For variable-capacity or 

multiple-capacity outdoor low-temperature 

condensing units tested alone, conduct tests 

using the test conditions specified in Table 

13 of this appendix. For variable-capacity or 

multiple-capacity indoor low-temperature 

condensing units tested alone, conduct tests 

using the test conditions specified in Table 

14 of this appendix. 


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TABLE 11—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY MEDIUM-TEMPERATURE OUTDOOR

DEDICATED CONDENSING UNITS

Test description Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 1

Compressor status 

Capacity, Condition A, Minimum Capacity.26 ............................................. 56 95 75 Minimum Capacity, k=1. 

Capacity, Condition A, Intermediate Capacity.Unit Cooler Low Fan: 2 22.5 .....

Unit Cooler High Fan: 2 25.5 ....

44 

46 

95 75 Intermediate Capacity, 

k=i. 

Capacity, Condition A, Maximum Capacity.23 ............................................. 41 95 75 Maximum Capacity, k=2. 

Off Cycle, Condition A .............. ................................................... ........................ 95 75 Off. 

Capacity, Condition B, Minimum Capacity.26 ............................................. 51 59 54 Minimum Capacity, k=1. 

Capacity, Condition B, Intermediate Capacity.Unit Cooler Low Fan: 2 22.5 .....

Unit Cooler High Fan: 2 25.5 ....

44 

45 

59 54 Intermediate Capacity, 

k=i. 

Capacity, Condition B, Maximum Capacity.23 ............................................. 41 59 54 Maximum Capacity, k=2. 

Off Cycle, Condition B .............. ................................................... ........................ 59 54 Off. 

Capacity, Condition C, Minimum Capacity.26 ............................................. 41 35 34 Minimum Capacity, k=1. 

Capacity, Condition C, Intermediate Capacity.Unit Cooler Low Fan: 2 22.5 .....

Unit Cooler High Fan: 2 25.5 ....

41 

41 

35 34 Intermediate Capacity, 

k=i. 

Capacity, Condition C, Maximum Capacity.23 ............................................. 41 35 34 Maximum Capacity, k=2. 

Off Cycle, Condition C .............. ................................................... ........................ 35 34 Off 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or 

less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition. 

TABLE 12—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY MEDIUM-TEMPERATURE INDOOR

DEDICATED CONDENSING UNITS

Test description Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 1

Compressor status 

Capacity, Condition A, Minimum Capacity.26 ............................................. 56 90 75 Minimum Capacity, k=1. 

Capacity, Condition A, Intermediate Capacity.Unit Cooler Low Fan: 2 22.5 .....

Unit Cooler High Fan: 2 25.5 ....

44 

46 

90 75 Intermediate Capacity, 

k=i, 

Capacity, Condition A, Maximum Capacity.23 ............................................. 41 90 75 Maximum Capacity, k=2. 

Off Cycle, Condition A .............. ................................................... ........................ 90 75 Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or 

less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition. 

TABLE 13—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE OUTDOOR

DEDICATED CONDENSING UNITS

Test title Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, °F 

Condenser air 

entering 

wet-bulb, °F 1

Compressor operating 

mode 

Capacity, Condition A, Minimum Capacity.¥19 .......................................... 32 95 75 Minimum Capacity, k=1. 

Capacity, Condition A, Intermediate Capacity.Unit Cooler Low Fan: 2 ¥22.5

Unit Cooler High Fan: 2 ¥19.5 

13 

13 

95 75 Minimum Capacity, k=i. 

Capacity, Condition A, Maximum Capacity.¥22 .......................................... 5 95 75 Maximum Capacity, k=2. 

Off Cycle, Condition A .............. ................................................... ........................ 95 75 Compressor Off. 


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24008 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

TABLE 13—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE OUTDOOR

DEDICATED CONDENSING UNITS—Continued 

Test title Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, °F 

Condenser air 

entering 

wet-bulb, °F 1

Compressor operating 

mode 

Capacity, Condition B, Minimum Capacity.¥19 .......................................... 28 59 54 Minimum Capacity, k=1. 

Capacity, Condition B, Intermediate Capacity.Unit Cooler Low Fan: 2 ¥22.5

Unit Cooler High Fan: 2 ¥19.5 

12 

13 

59 54 Minimum Capacity, k=i. 

Capacity, Condition B, Maximum Capacity.¥22 .......................................... 5 59 54 Maximum Capacity, k=2. 

Off Cycle, Condition B .............. ................................................... ........................ 59 54 Compressor Off. 

Capacity, Condition C, Minimum Capacity.¥19 .......................................... 23 35 34 Minimum Capacity, k=1. 

Capacity, Condition C, Intermediate Capacity.Unit Cooler Low Fan: 2 ¥22.5

Unit Cooler High Fan: 2 ¥19.5 

11 

12 

35 34 Minimum Capacity, k=i. 

Capacity, Condition C, Maximum Capacity.¥22 .......................................... 5 35 34 Maximum Capacity, k=2. 

Off Cycle, Condition C .............. ................................................... ........................ 35 34 Compressor Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or 

less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition. 

TABLE 14—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE INDOOR

DEDICATED CONDENSING UNITS

Test title Suction dew point, °F Return gas, 

°F 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 1

Compressor 

operating mode 

Capacity, Condition A, Minimum Capacity.¥19 .......................................... 32 90 75 Minimum Capacity, k=1. 

Capacity, Condition A, Intermediate Capacity.Unit Cooler Low Fan: 2 ¥22.5

Unit Cooler High Fan: 2 ¥19.5 

13 

13 

90 75 Minimum Capacity, k=i. 

Capacity, Condition A, Maximum Capacity.¥22 .......................................... 5 90 75 Maximum Capacity, k=2. 

Off Cycle, Condition A .............. ................................................... ........................ 90 75 Compressor Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or 

less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition. 

4.5.5 Test Operating Conditions for TwoCapacity Indoor Matched-Pair or SinglePackaged Refrigeration Systems. 

For two-capacity indoor mediumtemperature matched-pair or single-packaged 

refrigeration systems, conduct tests using the 

test conditions specified in Table 15 of this 

appendix. For two-capacity indoor lowtemperature matched-pair or single-packaged 

refrigeration systems, conduct tests using the 

test conditions specified in Table 16 of this 

appendix. 

TABLE 15—TEST OPERATING CONDITIONS FOR TWO-CAPACITY MEDIUM-TEMPERATURE INDOOR MATCHED-PAIR OR

SINGLE-PACKAGED REFRIGERATION SYSTEMS

Test description 

Unit cooler air 

entering 

dry-bulb, 

°F 

Unit cooler air 

entering 

relative 

humidity, 

% 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 

Compressor status 

Capacity, Condition A, Low Capacity ................. 35 <50 90 75,1 65 2 ......... Low Capacity. 

Capacity, Condition A, High Capacity ................. 35 <50 90 75,1 65 2 ......... High Capacity. 

Off Cycle, ............................................................

Condition A ..........................................................

35 <50 90 75,1 65 2 ......... Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the 

equipment is located in the outdoor room. 


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TABLE 16—TEST OPERATING CONDITIONS FOR TWO CAPACITY LOW-TEMPERATURE INDOOR MATCHED-PAIR OR SINGLEPACKAGED REFRIGERATION SYSTEMS

Test description 

Unit cooler air 

entering 

dry-bulb, 

°F 

Unit cooler air 

entering 

relative 

humidity, 

% 

Condenser air 

entering 

dry-bulb, 

°F 

Maximum 

condenser air 

entering 

wet-bulb, 

°F 

Compressor status 

Capacity, Condition A, Low Capacity ................. ¥10 <50 90 75,1 65 2 ......... Low Capacity. 

Capacity, Condition A, High Capacity ................. ¥10 <50 90 75,1 65 2 ......... High Capacity. 

Off Cycle, Condition A ........................................ ¥10 <50 90 75,1 65 2 ......... Off. 

Defrost ................................................................. ¥10 <50 ........................ ........................ System Dependent. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the 

equipment is located in the outdoor room. 

4.5.6 Test Conditions for Variable- or 

Multiple-Capacity Indoor Matched Pair or 

Single-Packaged Refrigeration Systems. 

For variable- or multiple-capacity indoor 

medium-temperature matched-pair or singlepackaged refrigeration systems, conduct tests 

using the test conditions specified in Table 

17 of this appendix. For variable- or 

multiple-capacity indoor low-temperature 

matched-pair or single-packaged refrigeration 

systems, conduct tests using the test 

conditions specified in Table 18 of this 

appendix. 

TABLE 17—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY MEDIUM-TEMPERATURE INDOOR

MATCHED-PAIR OR SINGLE-PACKAGED REFRIGERATION SYSTEMS

Test description 

Unit cooler air 

entering 

dry-bulb, 

°F 

Unit cooler air 

entering 

relative 

humidity, 

% 

Condenser air 

entering 

dry-bulb, 

°F 

Condenser air 

entering 

wet-bulb, 

°F 

Compressor status 

Capacity, Condition A, Minimum Capacity ......... 35 <50 90 75,1 65 2 ......... Minimum Capacity. 

Capacity, Condition A, Intermediate Capacity .... 35 <50 90 75,1 65 2 ......... Intermediate Capacity. 

Capacity, Condition A, High Capacity ................. 35 <50 90 75,1 65 2 ......... Maximum Capacity. 

Off Cycle, Condition A ........................................ 35 <50 90 75,1 65 2 ......... Off. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the 

equipment is located in the outdoor room. 

TABLE 18—TEST OPERATING CONDITIONS FOR VARIABLE- OR MULTIPLE-CAPACITY LOW-TEMPERATURE INDOOR

MATCHED-PAIR OR SINGLE-PACKAGED REFRIGERATION SYSTEMS

Test description 

Unit cooler air 

entering 

dry-bulb, 

°F 

Unit cooler air 

entering 

relative 

humidity, 

% 

Condenser air 

entering 

dry-bulb, 

°F 

Maximum 

condenser air 

entering 

wet-bulb, 

°F 

Compressor status 

Capacity, Condition A, Minimum Capacity ......... ¥10 <50 90 75,1 65 2 ......... Minimum Capacity. 

Capacity, Condition A, Intermediate Capacity .... ¥10 <50 90 75,1 65 2 ......... Intermediate Capacity. 

Capacity, Condition A, Maximum Capacity ........ ¥10 <50 90 75,1 65 2 ......... Maximum Capacity. 

Off Cycle, Condition A ........................................ ¥10 <50 90 75,1 65 2 ......... Off. 

Defrost ................................................................. ¥10 <50 ........................ ........................ System Dependent. 

Notes: 

1 Required only for evaporative condensing units (e.g., incorporates a slinger ring). 2 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the 

equipment is located in the outdoor room. 


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24010 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

4.6. Calculation for Walk-in Box Load. 

4.6.1 For medium- and low-temperature 

refrigeration systems with indoor condensing 

units, calculate walk-in box loads for high 

and low load periods as a function of net 

capacity as described in Section 6.2.1 of 

AHRI 1250–2020. 

4.6.2 For medium- and low-temperature 

refrigeration systems with outdoor 

condensing units, calculate walk-in box loads 

for high and low load periods as a function 

of net capacity and outdoor temperature as 

described in Section 6.2.2 of AHRI 1250– 

2020. 

4.6.3 For high-temperature refrigeration 

systems, calculate walk-in box load as 

follows. 

B ̇ L = · q ̇ss,A

Where q ̇ ss,A is the measured net capacity for 

Test Condition A. 

4.7. Calculation for Annual Walk-in Energy 

Factor (AWEF). 

Calculations used to determine AWEF 

based on performance data obtained for 

testing shall be as specified in Section 7 of 

AHRI 1250–2020 with modifications as 

indicated in sections 4.7.7 through 4.7.10 of 

this appendix. Calculations used to 

determine AWEF for refrigeration systems 

not specifically identified in Sections 7.1.1 

through 7.1.6 of AHRI 1250–2020 are 

enumerated in sections 4.7.1 through 4.7.6 

and sections 4.7.11 through 4.7.14 of this 

appendix. 

4.7.1 Two-Capacity Condensing Units 

Tested Alone, Indoor. 

4.7.1.1 Unit Cooler Power. 

Calculate maximum-capacity unit cooler 

power during the compressor on period 

E ̇ Fcomp,on, in Watts, using Equation 130 of 

AHRI 1250–2020 for medium-temperature 

refrigeration systems and using Equation 173 

of AHRI 1250–2020 for low-temperature 

refrigeration systems. 

Calculate unit cooler power during the 

compressor off period E ̇ Fcomp,off, in Watts, as 

20 percent of the maximum-capacity unit 

cooler power during the compressor on 

period. 

4.7.1.2 Defrost. 

For freezer refrigeration systems, calculate 

defrost heat contribution Q ̇ DF in Btu/h and 

the defrost average power consumption D ̇ F in 

W as a function of steady-state maximum 

gross refrigeration capacity Q ̇ , as specified 

in Section C10.2.2 of Appendix C of AHRI 

1250–2020. 

4.7.1.3 Net Capacity. 

Calculate steady-state maximum net 

capacity, q ̇ , and minimum net capacity, q ̇

as follows: 

q ̇ = Q ̇ ¥3.412 · E ̇ Fcomp,on

q ̇ = Q ̇ ¥3.412 · 0.2 · E ̇ Fcomp,on

Where: 

Q ̇ , and Q ̇ , represent gross refrigeration 

capacity at maximum and minimum 

capacity, respectively. 

4.7.1.4 Calculate average power input 

during the low load period as follows. 

If the low load period box load, BL ̇L, plus 

defrost heat contribution, Q ̇ DF (only 

applicable for freezers), is less than the 

minimum net capacity q ̇ : 

Where: 

E ̇ is the steady state condensing unit power 

input for minimum-capacity operation. 

E ̇ cu,off is the condensing unit off-cycle power 

input, measured as described in Section 

C3.5 of AHRI 1250–2020. 

If the low load period box load, BL ̇L, plus 

defrost heat contribution, Q ̇ DF , (only 

applicable for freezers) is greater than the 

minimum net capacity q ̇ : 

4.1.7.5 Calculate average power input 

during the high load period as follows. 


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4.1.7.6 Calculate the AWEF as follows: 

4.7.2 Variable-Capacity or Multistage 

Condensing Units Tested Alone, Indoor. 

4.7.2.1 Unit Cooler Power. 

Calculate maximum-capacity unit cooler 

power during the compressor on period 

E ̇ Fcomp,on as described in section 4.7.1.1 of 

this appendix. 

Calculate unit cooler power during the 

compressor off period E ̇ Fcomp,off, in Watts, as 

20 percent of the maximum-capacity unit 

cooler power during the compressor on 

period. 

4.7.2.2 Defrost. 

Calculate Defrost parameters as described 

in section 4.7.1.2 of this appendix. 

4.7.2.3 Net Capacity. 

Calculate steady-state maximum net 

capacity, q ̇ , intermediate net capacity, q ̇ , 

and minimum net capacity, q ̇ , as follows: 

q ̇ = Q ̇ ¥ 3.412 · E ̇Fcomp,on

q ̇ = Q ̇ ¥ 3.412 · Kf E ̇Fcomp,on

q ̇ = Q ̇ ¥ 3.412 · 0.2 · E ̇Fcomp,on

Where: 

Q ̇ , Q ̇ , Q ̇ , and represent gross 

refrigeration capacity at maximum, 

intermediate, and minimum capacity, 

respectively. 

Kf is the unit cooler power coefficient for 

intermediate capacity operation, set equal to 

0.2 to represent low-speed fan operation if 

the Duty Cycle for a Digital Compressor, the 

Speed Ratio for a Variable-Speed 

Compressor, or the Displacement Ratio for a 

Multi-Stage Compressor at Intermediate 

Capacity is 65% or less, and otherwise set 

equal to 1.0. 

4.7.2.4 Calculate average power input 

during the low load period as follows. 

If the low load period box load, BL ̇L, plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is less than the 

minimum net capacity: 

Where E ̇ cu,off, in W, is the condensing unit 

off-mode power consumption, measured as 

described in Section C3.5 of AHRI 1250– 

2020. 

If the low load period box load BL ̇L plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is greater than the 

minimum net capacity and less than the 

intermediate net capacity q ̇ : 

Where: 

EERk=1 is the minimum-capacity energy 

efficiency ratio, equal to q ̇ divided by 

E ̇ + E ̇Fcomp,on; and 

EERk=i is the intermediate-capacity energy 

efficiency ratio, equal to q ̇ divided by 

E ̇ + E ̇Fcomp,on. 

4.7.2.5 Calculate average power input 

during the high load period as follows: 

If the high load period box load, BL ̇H, plus 

defrost heat contribution, Q ̇ DF (only 

applicable for freezers), is greater than the 

minimum net capacity q ̇ and less than the 

intermediate net capacity q ̇ : 


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24012 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

If the high load period box load, BL ̇H, plus 

defrost heat contribution, Q ̇ DF (only 

applicable for freezers), is greater than the 

intermediate net capacity q ̇ and less than 

the maximum net capacity, q ̇ : 

Where: EERk=2 is the maximum-capacity energy 

efficiency ratio, equal to q ̇ divided by 

E ̇ + E ̇Fcomp,on

4.7.2.6 Calculate the AWEF as follows. 

4.7.3 Two-Capacity Condensing Units 

Tested Alone, Outdoor. 

4.7.3.1 Unit Cooler Power. 

Calculate maximum-capacity unit cooler 

power during the compressor on period 

E ̇ Fcomp,on, in Watts, using Equation 153 of 

AHRI 1250–2020 for medium-temperature 

refrigeration systems and using Equation 196 

of AHRI 1250–2020 for low-temperature 

refrigeration systems. 

Calculate unit cooler power during the 

compressor off period E ̇ Fcomp,off, in Watts, as 

20 percent of the maximum-capacity unit 

cooler power during the compressor on 

period. 

4.7.3.2 Defrost. 

Calculate Defrost parameters as described 

in section 4.7.1.2. 

4.7.3.3 Condensing Unit Off-Cycle Power. 

Calculate Condensing Unit Off-Cycle 

Power for temperature tj as follows. 

Where E ̇ cu,off,A and E ̇ cu,off,C are the 

Condensing Unit off-cycle power 

measurements for test conditions A and C, 

respectively, measured as described in 

Section C3.5 of AHRI 1250–2020. If tj is 

greater than 35 °F and less than 59 °F, use 

Equation 157 of AHRI 1250–2020, and if tj is 

greater than or equal to 59 °F and less than 

95 °F, use Equation 159. 

4.7.3.4 Net Capacity and Condensing Unit 

Power Input. 

Calculate steady-state maximum net 

capacity, q ̇ (tj), and minimum net capacity, 

q ̇ (tj), and corresponding condensing unit 

power input levels E ̇ (tj) and E ̇ (tj) as a 

function of outdoor temperature tj as follows: 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 24013 

Where: 

The capacity level k can equal 1 or 2; 

Q ̇ and Q ̇ represent gross refrigeration 

capacity at maximum and minimum 

capacity, respectively, for test condition 

X, which can take on values A, B, or C; 

E ̇ and E ̇ represent condensing unit 

power input at maximum and minimum 

capacity, respectively for test condition 

X. 

4.7.3.5 Calculate average power input 

during the low load period as follows. 

Calculate the temperature, tIL, below which 

the low load period box load, BL ̇L(tj), plus 

defrost heat contribution, Q ̇ DF (only 

applicable for freezers), is less than the 

minimum net capacity, q ̇ (tj), by solving the 

following equation for tIL: 

BL ̇L(tIL) + Q ̇ DF = q ̇ (tIL) 

For tj < tIL: 

Where E ̇ cu,off(tj), in W, is the condensing 

unit off-mode power consumption for 

temperature tj, determined as indicated in 

section 4.7.3.3 of this appendix. 

For tj ≥ tIL: 

4.7.3.6 Calculate average power input 

during the high load period as follows. 

Calculate the temperature, tIH, below 

which the high load period box load, BL ̇H(tj), 

plus defrost heat contribution, Q ̇ DF (only 

applicable for freezers), is less than the 


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24014 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

minimum net capacity, q ̇ (tj), by solving the 

following equation for tIH: 

BL ̇H(tIH) + Q ̇ DF = q ̇ (tIH) 

Calculate the temperature, tIIH, below 

which the high load period box load BL ̇H(tj) 

plus defrost heat contribution Q ̇ DF (only 

applicable for freezers) is less than the 

maximum net capacity q ̇ (tj), by solving the 

following equation for tIIH: 

BL ̇H(tIH) + Q ̇ DF = q ̇ (tIIH) 

For tj < tIH: 

For tIH ≤ tj < tIIH: 

For tIIH ≤ tj: 

E ̇ H(tj) + (E ̇ (tj) + E ̇ Fcomp,on

4.7.3.7 Calculate the AWEF as follows: 

4.7.4 Variable-Capacity or Multistage 

Condensing Units Tested Alone, Outdoor. 

4.7.4.1 Unit Cooler Power. 

Calculate maximum-capacity unit cooler 

power during the compressor on period 

E ̇ Fcomp,on as described in section 4.7.1.1 of 

this appendix. 

Calculate unit cooler power during the 

compressor off period E ̇ Fcomp,off, in Watts, as 

20 percent of the maximum-capacity unit 

cooler power during the compressor on 

period. 

4.7.4.2 Defrost. 

Calculate Defrost parameters as described 

in section 4.7.1.2. 

4.7.4.3 Condensing Unit Off-Cycle Power. 

Calculate Condensing Unit Off-Cycle 

Power for temperature, tj, as described in 

section 4.7.3.3 of this appendix. 

4.7.4.4 Net Capacity and Condensing Unit 

Power Input. 

Calculate steady-state maximum net 

capacity, q ̇ (tj), intermediate net capacity, 

q ̇ (tj), and minimum net capacity, q ̇ (tj), 

and corresponding condensing unit power 

input levels E ̇ (tj), E ̇ (tj), and E ̇ (tj) as a 

function of outdoor temperature, tj, as 

follows: 

If 35 °F > tj ≥ 59 °F: 

If 59 °F ≥ tj > 95 °F: 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 24015 

Where: 

The capacity level k can equal 1, i, or 2; 

Q ̇ , Q ̇ and Q ̇ represent gross 

refrigeration capacity at maximum, 

intermediate, and minimum capacity, 

respectively, for test condition X, which 

can take on values A, B, or C; 

E ̇ and E ̇ represent condensing unit 

power input at maximum and minimum 

capacity, respectively for test condition 

X; and 

Kf is the unit cooler power coefficient for 

intermediate capacity operation, set 

equal to 0.2 to represent low-speed fan 

operation if the Duty Cycle for a Digital 

Compressor, the Speed Ratio for a 

Variable-Speed Compressor, or the 

Displacement Ratio for a Multi-Stage 

Compressor at Intermediate Capacity is 

65% or less, and otherwise set equal to 

1.0. 

4.7.4.5 Calculate average power input 

during the low load period as follows. 

Calculate the temperature, tIL, below which 

the low load period box load BL ̇L(tj) plus 

defrost heat contribution, Q ̇ DF (only 

applicable for freezers), is less than the 

minimum net capacity, q ̇ (tj), by solving the 

following equation for tIL: 

BL ̇L(tIL) + q ̇ (tIL) 

Calculate the temperature, tVL, below 

which the low load period box load, BL ̇ L(tj), 

plus defrost heat contribution, Q ̇ DF (only 

applicable for freezers), is less than the 

intermediate net capacity, q ̇ (tj), by solving 

the following equation for tVL: 

BL ̇L(tVL) + Q ̇ DF = q ̇ (tVL) 

For tj < tIL: 

Where E ̇ cu,off(tj), in W, is the condensing 

unit off-mode power consumption for 

temperature, tj, determined as indicated in 

section 4.7.3.3 of this appendix. 

For tIL ≤ tj < tVL: 

For tVL ≤ tj: 


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24016 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

Where: 

EERk=1(tj) is the minimum-capacity energy 

efficiency ratio, equal to q ̇ (tj) divided 

by E ̇ (tj) + 0.2 · E ̇ Fcomp,on; 

EERk=i(tj) is the intermediate-capacity energy 

efficiency ratio, equal to q ̇ (tj) divided 

by E ̇ ssk=i(tj) + Kf · E ̇ Fcomp,on; and 

EERk=2(tj) is the maximum-capacity energy 

efficiency ratio, equal to q ̇ (tj) divided 

by E ̇ (tj) + E ̇ Fcomp,on

4.7.4.6 Calculate average power input 

during the high load period as follows. 

Calculate the temperature tVH below which 

the high load period box load BL ̇H(tj) plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is less than the 

intermediate net capacity q ̇ (tj), by solving 

the following equation for tVH: 

BL ̇H(tVH) + Q ̇ DF = q ̇ ssk=i(tVH) 

Calculate the temperature tIIH below which 

the high load period box load BL ̇H(tj) plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is less than the 

maximum net capacity q ̇ (tj), by solving the 

following equation for tIIH: 

BL ̇H(tIIH) + Q ̇ DF = q ̇ (tIIH) 

For tj < tVH: 

For tVH ≤ tj < tIIH: 

For tIIH ≤ tj: 

E ̇ H(tj) = (E ̇ (tj) + E ̇ Fcomp,on) 

4.7.4.7 Calculate the AWEF as follows: 

4.7.5 Two-Capacity Indoor Matched Pairs 

or Single-Packaged Refrigeration Systems 

Other than High-Temperature. 

4.7.5.1 Defrost. 

For freezer refrigeration systems, defrost 

heat contribution Q ̇ DF in Btu/h and the 

defrost average power consumption D ̇ F in W 

shall be as measured in accordance with 

Section C10.2.1 of Appendix C of AHRI 

1250–2020. 

4.7.5.2 Calculate average power input 

during the low load period as follows. 

If the low load period box load BL ̇L plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is less than the 

minimum net capacity q ̇ : 

Where: 

q ̇ and E ̇ ≤ are the steady state refrigeration 

system minimum net capacity, in Btu/h, 

and associated refrigeration system 

power input, in W, respectively, for 

minimum-capacity operation, measured 

as described in AHRI 1250–2020. 

E ̇ Fcomp,off and E ̇ cu,off, both in W, are the unit 

cooler and condensing unit, respectively, 

off-mode power consumption, measured 

as described in Section C3.5 of AHRI 

1250–2020. 

If the low load period box load BL ̇L plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is greater than the 

minimum net capacity q ̇ : 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 24017 

Where q ̇ and E ̇ are the steady state 

refrigeration system maximum net capacity, 

in Btu/h, and associated refrigeration system 

power input, in W, respectively, for 

maximum-capacity operation, measured as 

described in AHRI 1250–2020. 

4.7.5.3 Calculate average power input 

during the high load period as follows. 

4.7.5.4 Calculate the AWEF as follows: 

4.7.6 Variable-Capacity or Multistage 

Indoor Matched Pairs or Single-Packaged 

Refrigeration Systems Other than HighTemperature. 

4.7.6.1 Defrost. 

For freezer refrigeration systems, defrost 

heat contribution in Btu/h and the defrost 

average power consumption in W shall be as 

measured in accordance with Section C10.2.1 

of Appendix C of AHRI 1250–2020. 

4.7.6.2 Calculate average power input 

during the low load period as follows. 

If the low load period box load BL ̇ L plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is less than the 

minimum net capacity q ̇

Where: 

q ̇ and E ̇ are the steady state refrigeration 

system minimum net capacity, in Btu/h, 

and associated refrigeration system 

power input, in W, respectively, for 

minimum-capacity operation, measured 

as described in AHRI 1250–2020; and 

E ̇ Fcomp,off and E ̇ cu,off, both in W, are the unit 

cooler and condensing unit, respectively, 

off-mode power consumption, measured 

as described in Section C3.5 of AHRI 

1250–2020. 

If the low load period box load BL ̇L plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is greater than the 

minimum net capacity q ̇ and less than the 

intermediate net capacity q ̇ : 


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24018 Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 

Where: 

EERk=1 is the minimum-capacity energy 

efficiency ratio, equal to q ̇ divided by 

E ̇ ; 

q ̇ and E ̇ are the steady state refrigeration 

system intermediate net capacity, in Btu/ 

h, and associated refrigeration system 

power input, in W, respectively, for 

intermediate-capacity operation, 

measured as described in AHRI 1250– 

2020. 

EERk=i is the intermediate-capacity energy 

efficiency ratio, equal to q ̇ divided by 

E ̇ . 

4.7.6.3 Calculate average power input 

during the high load period as follows. 

If the high load period box load BL ̇H plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is greater than the 

minimum net capacity q ̇ and less than the 

intermediate net capacity q ̇ : 

If the high load period box load BL ̇H plus 

defrost heat contribution Q ̇ DF (only 

applicable for freezers) is greater than the 

intermediate net capacity q ̇ and less than 

the maximum net capacity q ̇ : 

Where: 

q ̇ and E ̇ are the steady state refrigeration 

system maximum net capacity, in Btu/h, 

and associated refrigeration system 

power input, in W, respectively, for 

maximum-capacity operation, measured 

as described in AHRI 1250–2020; and 

EERk=2 is the maximum-capacity energy 

efficiency ratio, equal toq ̇ divided by 

E ̇ . 

4.7.6.4 Calculate the AWEF as follows. 

4.7.7 Variable-Capacity or Multistage 

Outdoor Matched Pairs or Single-Packaged 

Refrigeration Systems Other than HighTemperature. 

Calculate AWEF as described in Section 

7.6 of AHRI 1250–2020, with the following 

revisions. 

4.7.7.1 Condensing Unit Off-Cycle Power. 

Calculate condensing unit off-cycle power 

for temperature tj as indicated in section 

4.7.3.3 of this appendix. Replace the constant 

value E ̇ CU,off in Equations 55 and 70 of AHRI 

1250–2020 with the values E ̇ CU,off(tj), which 

vary with outdoor temperature tj. 

4.7.7.2 Unit Cooler Off-Cycle Power. 

Set unit cooler Off-Cycle power E ̇ Fcomp,off

equal to the average of the unit cooler offcycle power measurements made for test 

conditions A, B, and C. 

4.7.7.3 Average Power During the Low 

Load Period. 

Calculate average power for intermediatecapacity compressor operation during the 

low load period E ̇ ss,Lk=v(tj) as described in 

Section 7.6 of AHRI 1250–2020, except that, 

instead of calculating intermediate-capacity 

compressor EER using Equation 77, calculate 

EER as follows. 

For tj < tVL: 

For tVL ≤ tj: 


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Federal Register / Vol. 87, No. 77 / Thursday, April 21, 2022 / Proposed Rules 24019 

Where: 

EERk=1(tj) is the minimum-capacity energy 

efficiency ratio, equal to q ̇ (tj) divided 

by E ̇ k=1(tj); 

EERk=i(tj) is the intermediate-capacity energy 

efficiency ratio, equal to q ̇ (tj) divided 

by E ̇ (tj); and 

EERk=2(tj) is the maximum-capacity energy 

efficiency ratio, equal to q ̇ (tj) divided 

by E ̇ (tj) 

4.7.7.4 Average Power During the High 

Load Period. 

Calculate average power for intermediatecapacity compressor operation during the 

high load period E ̇ (tj) as described in 

Section 7.6 of AHRI 1250–2020, except that, 

instead of calculating intermediate-capacity 

compressor EER using Equation 61, calculate 

EER as follows: 

For tj < tVH: 

For tVH ≤ tj: 

4.7.8 Two-Capacity Outdoor Matched Pairs 

or Single-Packaged Refrigeration Systems 

Other than High-Temperature. 

Calculate AWEF as described in Section 

7.5 of AHRI 1250–2020, with the following 

revisions for Condensing Unit Off-Cycle 

Power and Unit Cooler Off-Cycle Power. 

Calculate condensing unit off-cycle power for 

temperature tj as indicated in section 4.7.3.3 

of this appendix. Replace the constant value 

E ̇ CU,off in Equations 13 and 29 of AHRI 1250– 

2020 with the values E ̇ CU,off(tj), which vary 

with outdoor temperature (tj. Set unit cooler 

Off-Cycle power E ̇ Fcomp,off equal to the 

average of the unit cooler off-cycle power 

measurements made for test conditions A, B, 

and C. 

4.7.9 Single-capacity Outdoor Matched 

Pairs or Single-Packaged Refrigeration 

Systems Other than High-Temperature. 

Calculate AWEF as described in Section 

7.4 of AHRI 1250–2020, with the following 

revision for Condensing Unit Off-Cycle 

Power and Unit Cooler Off-cycle Power. 

Calculate condensing unit off-cycle power for 

temperature tj as indicated in section 4.7.3.3 

of this appendix. Replace the constant value 

E ̇ CU,off in Equations 13 of AHRI 1250–2020 

with the values E ̇ CU,off(tj), which vary with 

outdoor temperature tj. Set unit cooler OffCycle power E ̇ Fcomp,off equal to the average of 

the unit cooler off-cycle power measurements 

made for test conditions A, B, and C. 

4.7.10 Single-capacity Condensing Units, 

Outdoor. 

Calculate AWEF as described in Section 

7.9 of AHRI 1250–2020, with the following 

revision for Condensing Unit Off-Cycle 

Power. Calculate condensing unit off-cycle 

power for temperature tj as indicated in 

section 4.7.3.3 of this appendix rather than 

as indicated in equations 157, 159, 202, and 

204 of AHRI 1250–2020. 

4.7.11 High-Temperature Matched Pairs 

or Single-Packaged Refrigeration Systems, 

Indoor. 

4.7.11.1 Calculate Load Factor LF as 

follows: 

Where: 

B ̇ L, in Btu/h is the non-equipment-related 

box load calculated as described in 

section 4.6.3 of this appendix; 

E ̇ Fcomp,off, in W, is the unit cooler off-cycle 

power consumption, equal to 0.1 times 

the unit cooler on-cycle power 

consumption; and 

q ̇ss,A, in Btu/h is the measured net capacity 

for test condition A. 

4.7.11.2 Calculate the AWEF as follows: 

Where: 

E ̇ ss,A, in W, is the measured system power 

input for test condition A; and 

E ̇ cu,off, in W, is the condensing unit off-cycle 

power consumption, measured as 

described in Section C3.5 of AHRI 1250– 

2020. 

4.7.12 High-Temperature Matched Pairs 

or Single-Packaged Refrigeration Systems, 

Outdoor. 

4.7.12.1 Calculate Load Factor LF(tj) for 

outdoor temperature tj as follows: 

Where: 

B ̇ L, in Btu/h, is the non-equipment-related 

box load calculated as described in 

section 4.6.3 of this appendix; 

E ̇ Fcomp,off, in W, is the unit cooler off-cycle 

power consumption, equal to 0.1 times 

the unit cooler on-cycle power 

consumption; and 

q ̇ss(tj), in Btu/h, is the net capacity for 

outdoor temperature tj, calculated as 

described in Section 7.4.2 of AHRI 1250– 

2020. 

4.7.12.2 Calculate the AWEF as follows: 


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Where: 

E ̇ ss(tj), in W, is the system power input for 

temperature tj, calculated as described in 

Section 7.4.2 of AHRI 1250–2020; 

E ̇ cu,off in W, is the condensing unit off-cycle 

power consumption, measured as 

described in Section C3.5 of AHRI 1250– 

2020; and 

nj are the hours for temperature bin j. 

4.7.13 High-Temperature Unit Coolers 

Tested Alone. 

4.7.13.1 Calculate Refrigeration System 

Power Input as follows: 

Where: q ̇ mix,evap, in W, is the net evaporator capacity, 

measured as described in AHRI 1250– 

2020; 

E ̇ Fcomp,on, in W, is the unit cooler on-cycle 

power consumption; and EER, in W, 

equals 

4.7.13.2 Calculate the load factor LF as 

follows: 

Where: 

B ̇ L, in Btu/h, is the non-equipment-related 

box load calculated as described in 

section 4.6.3 of this appendix; and 

E ̇ Fcomp,off, in W, is the unit cooler off-cycle 

power consumption, equal to 0.1 times 

the unit cooler on-cycle power 

consumption. 

4.7.13.3 Calculate AWEF as follows: 

4.7.14 CO2 Unit Coolers Tested Alone. 

Calculate AWEF for CO2 Unit Coolers 

Tested Alone using the calculations specified 

in in Section 7.8 of AHRI 1250–2020 for 

calculation of AWEF for Unit Cooler Tested 

Alone. 

4.8. Test Method. 

Test the Refrigeration System in 

accordance with AHRI 1250–2020 to 

determine refrigeration capacity and power 

input for the specified test conditions, with 

revisions and additions as described in this 

section. 

4.8.1 Chamber Conditioning Using the 

Unit Under Test. 

In Appendix C, Section C5.2.2 of AHRI 

1250–2020, for applicable system 

configurations (matched pairs, singlepackaged refrigeration systems, and 

standalone unit coolers), the unit under test 

may be used to aid in achieving the required 

test chamber conditions prior to beginning 

any steady state test. However, the unit under 

test must be inspected and confirmed to be 

free from frost before initiating steady state 

testing. 

4.8.2 General Modification: Methods of 

Testing. 

4.8.2.1 Refrigerant Temperature 

Measurements. 

When testing a condensing unit alone, 

measure refrigerant liquid temperature 

leaving the condensing unit as required in 

Section C7.5.1.1.2 of Appendix C of AHRI 

1250–2020 using the same measurement 

approach specified for the unit cooler in 

Section C3.1.3 of Appendix C of AHRI 1250– 

2020. In all cases in which thermometer 

wells or immersed sheathed sensors are 

prescribed, if the refrigerant tube outer 

diameter is less than 1⁄2 inch, the refrigerant 

temperature may be measured using the 

average of two temperature measuring 

instruments with a minimum accuracy of 

±0.5 °F placed on opposite sides of the 

refrigerant tube surface—resulting in a total 

of up to 8 temperature measurement devices 

used for the DX Dual Instrumentation 

method. In this case, the refrigerant tube 

shall be insulated with 1-inch thick 

insulation from a point 6 inches upstream of 

the measurement location to a point 6 inches 

downstream of the measurement location. 

Also, to comply with this requirement, the 

unit cooler/evaporator entering measurement 

location may be moved to a location 6 inches 

upstream of the expansion device and, when 

testing a condensing unit alone, the entering 

and leaving measurement locations may be 

moved to locations 6 inches from the 

respective service valves. 

4.8.2.2 Mass Flow Meter Location. 


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When using the DX Dual Instrumentation 

test method of AHRI 1250–2020, applicable 

for unit coolers, dedicated condensing units, 

and matched pairs, the second mass flow 

meter may be installed in the suction line as 

shown in Figure C1 of AHRI 1250–2020. 

4.8.2.3 Subcooling at Refrigerant Mass 

Flow Meter. 

In Section C3.4.5 of Appendix C of AHRI 

1250–2020, when verifying sub-cooling at the 

mass flow meters, only the sight glass and a 

temperature sensor located on the tube 

surface under the insulation are required. 

Subcooling shall be verified to be within the 

3 °F requirement downstream of flow meters 

located in the same chamber as a condensing 

unit under test and upstream of flow meters 

located in the same chamber as a unit cooler 

under test, rather than always downstream as 

indicated in AHRI 1250–2009, Section 

C3.4.5. If the subcooling is less than 3 °F 

when testing a unit cooler, dedicated 

condensing unit, or matched pair (not a 

single-packaged system), cool the line 

between the condensing unit outlet and this 

location to achieve the required subcooling. 

When providing such cooling while testing a 

matched pair, also measure the refrigerant 

temperature upstream of the location that the 

line is being cooled, and increase the 

temperature used to calculate unit cooler 

entering enthalpy by the difference between 

the upstream and downstream temperatures. 

4.8.2.4 Installation Instructions. 

Manufacturer installation instructions or 

installation instructions described in this 

section refer to the instructions that come 

packaged with or appear on the labels 

applied to the unit. This does not include 

online manuals. 

Installation Instruction Hierarchy: If a 

given installation instruction provided on the 

label(s) applied to the unit conflicts with the 

installation instructions that are shipped 

with the unit, the label takes precedence. For 

testing of matched pairs, the installation 

instructions for the dedicated condensing 

unit shall take precedence. Setup shall be in 

accordance with the field installation 

instructions (laboratory installation 

instructions shall not be used). Achieving 

test conditions shall always take precedence 

over installation instructions. 

4.8.2.5 Refrigerant Charging and 

Adjustment of Superheat and Subcooling. 

All test samples shall be charged, and 

superheat and/or subcooling shall be set, at 

Refrigeration A test conditions unless 

otherwise specified in the installation 

instructions. If the installation instructions 

give a specified range for superheat, subcooling, or refrigerant pressure, the average of 

the range shall be used as the refrigerant 

charging parameter target and the test 

condition tolerance shall be ±50 percent of 

the range. Perform charging of nearazeotropic and zeotropic refrigerants only 

with refrigerant in the liquid state. Once the 

correct refrigerant charge is determined, all 

tests shall run until completion without 

further modification. 

4.8.2.5.1. When charging or adjusting 

superheat/subcooling, use all pertinent 

instructions contained in the installation 

instructions to achieve charging parameters 

within the tolerances. However, in the event 

of conflicting charging information between 

installation instructions, follow the 

installation instruction hierarchy listed in 

section 4.8.2.4. Conflicting information is 

defined as multiple conditions given for 

charge adjustment where all conditions 

specified cannot be met. In the event of 

conflicting information within the same set 

of charging instructions (e.g., the installation 

instructions shipped with the dedicated 

condensing unit), follow the hierarchy in 

Table 19 of this appendix for priority. Unless 

the installation instructions specify a 

different charging tolerance, the tolerances 

identified in Table 19 shall be used. 

TABLE 19—TEST CONDITION TOLERANCES AND HIERARCHY FOR REFRIGERANT CHARGING AND SETTING OF REFRIGERANT

CONDITIONS

Priority 

Fixed orifice Expansion valve 

Parameter with installation 

instruction target Tolerance Parameter with installation instruction target Tolerance 

1 ............. Super-heat ............................... ±2.0 °F ..................................... Sub-cooling .............................. 10% of the Target Value; No 

less than ±0.5 °F, No more 

than ±2.0 °F. 

2 ............. High Side Pressure or Saturation Temperature.±4.0 psi or ±1.0 °F ................... High Side Pressure or Saturation Temperature.±4.0 psi or 

±1.0 °F. 

3 ............. Low Side Pressure or Saturation Temperature.±2.0 psi or ±0.8 °F ................... Super-heat ............................... ±2.0 °F. 

4 ............. Low Side Temperature ............ ±2.0 °F ..................................... Low Side Pressure or Saturation Temperature.±2.0 psi or 

±0.8 °F. 

5 ............. High Side Temperature ........... ±2.0 °F ..................................... Approach Temperature ............ ±1.0 °F. 

6 ............. Charge Weight ......................... ±2.0 oz ..................................... Charge Weight ......................... 0.5% or 1.0 oz, whichever is 

greater. 

4.8.2.5.2. Dedicated Condensing Unit. 

If the Dedicated Condensing Unit includes 

a receiver and the subcooling target leaving 

the condensing unit provided in installation 

instructions cannot be met without fully 

filling the receiver, the subcooling target 

shall be ignored. Likewise, if the Dedicated 

Condensing unit does not include a receiver 

and the subcooling target leaving the 

condensing unit cannot be met without the 

unit cycling off on high pressure, the 

subcooling target can be ignored. Also, if no 

instructions for charging or for setting 

subcooling leaving the condensing unit are 

provided in the installation instructions, the 

refrigeration system shall be set up with a 

charge quantity and/or exit subcooling such 

that the unit operates during testing without 

shutdown (e.g., on a high-pressure switch) 

and operation of the unit is otherwise 

consistent with the requirements of the test 

procedure of this appendix and the 

installation instructions. 

4.8.2.5.3. Unit Cooler. Use the shipped 

expansion device for testing. Otherwise, use 

the expansion device specified in the 

installation instructions. If the installation 

instructions specify multiple options for the 

expansion device, any specified expansion 

device may be used. The supplied expansion 

device shall be adjusted until either the 

superheat target is met, or the device reaches 

the end of its adjustable range. In the event 

the device reaches the end of its adjustable 

range and the super heat target is not met, 

test with the adjustment at the end of its 

range providing the closest match to the 

superheat target, and the test condition 

tolerance for super heat target shall be 

ignored. The measured superheat is not 

subject to a test operating tolerance. 

However, if the evaporator exit condition is 

used to determine capacity using the DX 

dual-instrumentation method or the 

refrigerant enthalpy method, individual 

superheat value measurements may not be 

equal to or less than zero. If this occurs, or 

if the operating tolerances of measurements 

affected by expansion device fluctuation are 

exceeded, the expansion device shall be 

replaced, operated at an average superheat 

value higher than the target, or both, in order 

to avoid individual superheat value 

measurements less than zero and/or to meet 

the required operating tolerances. 

4.8.2.5.4. Single-Packaged Unit. Unless 

otherwise directed by the installation 

instructions, install one or more refrigerant 

line pressure gauges during the setup of the 

unit, located depending on the parameters 

used to verify or set charge, as described in 

this section: 

4.8.2.5.4.1. Install a pressure gauge in the 

liquid line if charging is on the basis of 

subcooling, or high side pressure or 


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corresponding saturation or dew point 

temperature. 

4.8.2.5.4.2. Install a pressure gauge in the 

suction line if charging is on the basis of 

superheat, or low side pressure or 

corresponding saturation or dew point 

temperature. Install this gauge as close to the 

evaporator as allowable by the installation 

instructions and the physical constraints of 

the unit. Use methods for installing pressure 

gauge(s) at the required location(s) as 

indicated in the installation instructions if 

specified. 

4.8.2.5.4.3. If the installation instructions 

indicate that refrigerant line pressure gauges 

should not be installed and the unit fails to 

operate due to high pressure or low pressure 

compressor cut off, then a charging port shall 

be installed, and the unit shall be evacuated 

of refrigerant and charged to the nameplate 

charge. 

4.8.2.6 Ducted Units. 

For systems with ducted evaporator air, or 

that can be installed with or without ducted 

evaporator air: Connect ductwork on both the 

inlet and outlet connections and determine 

external static pressure (ESP) as described in 

Sections 6.4 and 6.5 of ANSI/ASHRAE 37. 

Use pressure measurement instrumentation 

as described in Section 5.3.2 of ANSI/ 

ASHRAE 37. Test at the fan speed specified 

in the installation instructions—if there is 

more than one fan speed setting and the 

installation instructions do not specify which 

speed to use, test at the highest speed. 

Conduct tests with the ESP equal to 50% of 

the maximum ESP allowed in the installation 

instructions, within a tolerance of ¥0.00/ 

+0.05 inches of water column. If the 

installation instructions do not provide the 

maximum ESP, the ESP shall be set for 

testing such that the air volume rate is 2⁄3 of 

the air volume rate measured when the ESP 

is 0.00 inches of water column within a 

tolerance of ¥0.00/+0.05 inches of water 

column. 

If testing using either the indoor or outdoor 

air enthalpy method to measure the air 

volume rate, adjust the airflow measurement 

apparatus fan to set the external static 

pressure—otherwise, set the external static 

pressure by symmetrically restricting the 

outlet of the test duct. In case of conflict, 

these requirements for setting airflow take 

precedence over airflow values specified in 

manufacturer installation instructions or 

product literature. 

4.8.2.7 Two-Speed or Multiple-Speed 

Evaporator Fans. Two-Speed or MultipleSpeed evaporator fans shall be considered to 

meet the qualifying control requirements of 

Section C4.2 of Appendix C of AHRI 1250– 

2020 for measuring off-cycle fan energy if 

they use a fan speed no less than 50% of the 

speed used in the maximum capacity tests. 

4.8.2.8 Defrost. 

Use Section C10.2.1 of Appendix C of 

AHRI 1250–2020 for defrost testing. The Test 

Room Conditioning Equipment requirement 

of Section C10.2.1.1 of Appendix C of AHRI 

1250–2020 does not apply. 

4.8.2.8.1 Adaptive Defrost. 

When testing to certify compliance to the 

energy conservation standards, use NDF = 4, 

as instructed in Section C10.2.1.7 or 

C10.2.2.1 of AHRI 1250–2020. When 

determining the represented value of the 

calculated benefit for the inclusion of 

adaptive defrost, use NDF = 2.5, as instructed 

in Section C10.2.1.7 or C10.2.2.1 of AHRI 

1250–2020. 

4.8.2.8.2 Hot Gas Defrost. 

When testing to certify compliance to the 

energy conservation standards, remove the 

hot gas defrost mechanical components and 

disconnect all such components from 

electrical power. Test the units as if they are 

electric defrost units, but do not conduct the 

defrost tests described in Section C10.2.1 of 

AHRI 1250–2020. Use the defrost heat and 

power consumption values as described in 

Section C10.2.2 of AHRI 1250–2020 for the 

AWEF calculations. 

When determining the represented value of 

the calculated benefit for the inclusion of hot 

gas defrost, test with hot gas mechanical 

components installed, but do not conduct the 

defrost tests. Use the defrost heat and power 

consumption values as described in Section 

C10.1.1 of AHRI 1250–2020 for the AWEF 

calculations. 

4.8.2.9 Dedicated condensing units that 

are not matched for testing and are not 

single-packaged dedicated systems. 

The temperature measurement 

requirements of sections C3.1.3 and C4.1.3.1 

Appendix C of AHRI 1250–2020 shall apply 

only to the condensing unit exit rather than 

to the unit cooler inlet and outlet, and they 

shall be applied for two measurements when 

using the DX Dual Instrumentation test 

method. 

4.8.2.10 Single-packaged dedicated 

systems. 

Use the test method in section C9 of 

Appendix C of AHRI 1250–2020 as the 

method of test for single-packaged dedicated 

systems, with modifications as described in 

this section. Use two test methods listed in 

Table 20 of this appendix to calculate the net 

capacity and power consumption. The test 

method listed with a lower ‘‘Hierarchy 

Number’’ and that has ‘‘Primary’’ as an 

allowable use in Table 20 shall be considered 

the primary measurement and used as the net 

capacity. 

TABLE 20—SINGLE-PACKAGED METHODS OF TEST AND HIERARCHY

Hierarchy No. Method of test Allowable use 

1 .................................. Balanced Ambient Indoor Calorimeter ...................................................................................... Primary. 

2 .................................. Indoor Air Enthalpy .................................................................................................................... Primary or Secondary. 

3 .................................. Indoor Room Calorimeter .......................................................................................................... Primary or Secondary. 

4 .................................. Balanced Ambient Outdoor Calorimeter .................................................................................... Secondary. 

5 .................................. Outdoor Air Enthalpy ................................................................................................................. Secondary. 

6 .................................. Outdoor Room Calorimeter ....................................................................................................... Secondary. 

7 .................................. Single-Packaged Refrigerant Enthalpy1 .................................................................................... Secondary. 

8 .................................. Compressor Calibration ............................................................................................................. Secondary. 

Notes: 

1See description of the single-packaged refrigerant enthalpy method in section 4.8.2.10.1 of this appendix. 

4.8.2.10.1 Single-Packaged Refrigerant 

Enthalpy Method. 

The single-packaged refrigerant enthalpy 

method shall follow the test procedure of the 

DX Calibrated Box method in AHRI 1250– 

2020, Appendix C, section C8 for refrigerantside measurements with the following 

modifications. 

4.8.2.10.1.1 Air-side measurements shall 

follow the requirements of the primary 

single-packaged method listed in Table 20 of 

this appendix. The air-side measurements 

and refrigerant-side measurements shall be 

collected over the same intervals. 

4.8.2.10.1.2 A preliminary test at Test 

Rating Condition A is required using the 

primary method prior to any modification 

necessary to install the refrigerant-side 

measuring instruments. Install surface mount 

temperature sensors on the evaporator and 

condenser coils at locations not affected by 

liquid subcooling or vapor superheat (i.e., 

near the midpoint of the coil at a return 

bend), entering and leaving the compressor, 

and entering the expansion device. These 

temperature sensors shall be included in the 

regularly recorded data. 

4.8.2.10.1.3 After the preliminary test is 

completed, the refrigerant shall be removed 

from the equipment and the refrigerant-side 

measuring instruments shall be installed. The 

equipment shall then be evacuated and 

recharged with refrigerant. Once the 

equipment is operating at Test Condition A, 

the refrigerant charge shall be adjusted until, 

as compared to the average values from the 

preliminary test, the following conditions are 

achieved: 

(1) Each on-coil temperature sensor 

indicates a reading that is within ±1.0 °F of 

the measurement in the initial test, 

(2) The temperatures of the refrigerant 

entering and leaving the compressor are 

within ±4 °F, and 

(3) The refrigerant temperature entering the 

expansion device is within ±1 °F. Once these 

conditions have been achieved over an 

interval of at least ten minutes, refrigerant 


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charging equipment shall be removed and the 

official tests shall be conducted. 

4.8.2.10.1.4 The lengths of liquid line to 

be added shall be 5 feet maximum, not 

including the requisite flow meter. This 

maximum length applies to each circuit 

separately. 

4.8.2.10.1.5 Use section C9.2 of Appendix 

C of AHRI 1250–2020 for allowable 

refrigeration capacity heat balance. Calculate 

the single-packaged refrigerant enthalpy 

(secondary) method test net capacity 

Q ̇ net,secondary as follows: 

Q ̇ net,secondary = Q ̇ ref¥3.412.E ̇ Fcomp,on¥Q ̇ sploss

Where: 

Q ̇ ref is the gross capacity; 

E ̇ Fcomp,on is the evaporator compartment oncycle power, including evaporator fan 

power; and 

Q ̇ sploss is a duct loss calculation applied to the 

evaporator compartment of the singlepackaged systems, which is calculated as 

indicated below. 

Q ̇ sploss = UAcond × (Tevapside¥Tcondside) + UAamb

× (Tevapside¥Tamb) 

Where: 

UAcond and UAamb are, for the condenser/ 

evaporator partition and the evaporator 

compartment walls exposed to ambient 

air, respectively, the product of the 

overall heat transfer coefficient and 

surface area of the unit as manufactured, 

i.e., without external insulation that 

might have been added during the test. 

The areas shall be calculated based on 

measurements, and the thermal 

resistance values shall be based on 

insulation thickness and insulation 

material; 

Tevapside is the air temperature in the 

evaporator compartment—the measured 

evaporator air inlet temperature may be 

used; 

Tcondside is the air temperature in the 

condenser compartment—the measured 

chamber ambient temperature may be 

used, or a measurement may be made 

using a temperature sensor placed inside 

the condenser box at least 6 inches 

distant from any part of the refrigeration 

system; and 

Tamb is the air temperature outside the singlepackaged system. 

4.8.2.10.1.6 For multi-circuit singlepackaged systems utilizing the singlepackaged refrigerant enthalpy method, apply 

the test method separately for each circuit 

and sum the separately-calculated 

refrigerant-side gross refrigeration capacities. 

4.8.2.10.2 Detachable single-packaged 

systems shall be tested as single-packaged 

dedicated refrigeration systems. 

4.8.2.11 Variable-Capacity and MultipleCapacity Dedicated Condensing Refrigeration 

Systems. 

4.8.2.11.1 Manufacturer-Provided 

Equipment Overrides. 

Where needed, the manufacturer must 

provide a means for overriding the controls 

of the test unit so that the compressor(s) 

operates at the specified speed or capacity 

and the indoor blower operates at the speed 

consistent with the compressor operating 

level as would occur without override. 

4.8.2.11.2 Compressor Operating Levels. 

For variable-capacity and multiplecapacity compressor systems, the minimum 

capacity for testing shall be the minimum 

capacity that the system control would 

operate the compressor in normal operation. 

Likewise, the maximum capacity for testing 

shall be the maximum capacity that the 

system control would operate the compressor 

in normal operation. For variable-speed 

compressor systems, the intermediate speed 

for testing shall be the average of the 

minimum and maximum speeds. For digital 

compressor systems, the intermediate duty 

cycle shall be the average of the minimum 

and maximum duty cycles. For multiplecapacity compressor systems with three 

capacity levels, the intermediate operating 

level for testing shall be the middle capacity 

level. For multiple-capacity compressor 

systems with more than three capacity levels, 

the intermediate operating level for testing 

shall be the level whose displacement ratio 

is closest to the average of the maximum and 

minimum displacement ratios. 

4.8.2.11.3 Refrigeration Systems with 

Digital Compressor(s). 

Use the test methods described in section 

4.8.2.10.1 of this appendix as the secondary 

method of test for refrigeration systems with 

digital compressor(s) with modifications as 

described in this section. The Test Operating 

tolerance for refrigerant mass flow rate and 

suction pressure in Table 2 of AHRI 1250– 

2020 shall be ignored. Temperature and 

pressure measurements used to calculate Q ̇ ref

shall be recorded at a frequency of once per 

second or faster and based on average values 

measured over the 30-minute test period. 

4.8.2.11.3.1 For Matched pair (not 

including single-packaged systems) and 

Dedicated Condensing Unit refrigeration 

systems, the preliminary test in sections 

4.8.2.10.1.2 and 4.8.2.10.1.3 of this appendix 

is not required. The liquid line and suction 

line shall be 25 feet ± 3 inches, not including 

the requisite flow meters. Also, the term 

Q ̇ sploss in the equation to calculate net 

capacity shall be set equal to zero. 

4.8.2.11.3.2 For Dedicated Condensing 

Unit refrigeration systems, the primary 

capacity measurement method shall be 

balanced ambient outdoor calorimeter, 

outdoor air enthalpy, or outdoor room 

calorimeter. 

[FR Doc. 2022–06423 Filed 4–20–22; 8:45 am] 

BILLING CODE 6450–01–P 


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