1224 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

DEPARTMENT OF ENERGY 

10 CFR Parts 429 and 430 

[EERE–2022–BT–TP–0028] 

RIN 1904–AF49 

Energy Conservation Program: Test 

Procedure for Central Air Conditioners 

and Heat Pumps 

AGENCY: Office of Energy Efficiency and 

Renewable Energy, Department of 

Energy. 

ACTION: Final rule. 

SUMMARY: This final rule amends the 

Federal test procedure for central air 

conditioners and heat pumps (‘‘CAC/ 

HPs’’) to incorporate by reference the 

latest versions of the applicable industry 

standards. Specifically, DOE is 

incorporating by reference the latest 

version of the relevant industry 

consensus test standard, AHRI 210/240– 

2024 (I–P) for the current test procedure 

for CAC/HPs (‘‘appendix M1’’) for 

measuring the current cooling and 

heating metrics—seasonal energy 

efficiency ratio 2 (‘‘SEER2’’) and heating 

seasonal performance factor 2 

(‘‘HSPF2’’). DOE is incorporating by 

reference the new industry consensus 

test standard, AHRI 1600–2024 (I–P), for 

a new test procedure (‘‘appendix M2’’) 

for CAC/HPs that adopts two new 

metrics—seasonal cooling and off-mode 

rating efficiency (‘‘SCORE’’) and 

seasonal heating and off-mode rating 

efficiency (‘‘SHORE’’). Testing to the 

SCORE and SHORE metrics would not 

be required until such time as 

compliance is required with any 

amended energy conservation standard 

based on the new metrics. Additionally, 

DOE is amending certain provisions of 

DOE’s regulations related to 

representations and enforcement for 

CAC/HPs. 

DATES: The effective date of this rule is 

February 6, 2025. The amendments will 

be mandatory for product testing 

starting July 7, 2025. Manufacturers will 

be required to use the amended test 

procedure until the compliance date of 

any final rule establishing amended 

energy conservation standards based on 

the newly established test procedure. At 

such time, manufacturers will be 

required to begin using the newly 

established test procedure. 

The incorporation by reference of 

certain publications listed in this rule is 

approved by the Director of the Federal 

Register on February 6, 2025. 

ADDRESSES: The docket, which includes 

Federal Register notices, public meeting 

attendee lists and transcripts, 

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, not all documents listed in 

the index may be publicly available, 

such as those containing information 

that is exempt from public disclosure. 

A link to the docket web page can be 

found at www.regulations.gov/docket/ 

EERE-2022-BT-TP-0028. The docket 

web page contains instructions on how 

to access all documents, including 

public comments, in the docket. 

For further information on how to 

review the docket contact the Appliance 

and Equipment Standards Program staff 

at (202) 287–1445 or by email: 

ApplianceStandardsQuestions@

ee.doe.gov. 

FOR FURTHER INFORMATION CONTACT: 

Dr. Pradeep Prathibha, U.S. 

Department of Energy, Office of Energy 

Efficiency and Renewable Energy, 

Building Technologies Office, EE–5B, 

1000 Independence Avenue SW, 

Washington, DC 20585–0121. 

Telephone: (240) 255–0630. Email: 

ApplianceStandardsQuestions@

ee.doe.gov. 

Mr. Pete Cochran, U.S. Department of 

Energy, Office of the General Counsel, 

GC–33, 1000 Independence Avenue SW, 

Washington, DC 20585–0121. 

Telephone: (202) 586–4798. Email: 

peter.cochran@hq.doe.gov. 

SUPPLEMENTARY INFORMATION: DOE 

maintains previously approved 

incorporations by reference and 

incorporates by reference the following 

industry standards into 10 CFR parts 

429 and 430: 

AHRI Standard 210/240–2024 (I–P), 

Performance Rating of Unitary Airconditioning and Air-source Heat Pump 

Equipment, copyright 2024 (‘‘AHRI 210/ 

240–2024’’). 

AHRI Standard 1600–2024 (I–P), 

Performance Rating of Unitary Airconditioning and Air-source Heat Pump 

Equipment, copyright 2024 (‘‘AHRI 

1600–2024’’). 

Copies of AHRI 210/240–2024 and 

AHRI 1600–2024 can be obtained from 

the Air-Conditioning, Heating, and 

Refrigeration Institute (AHRI), 2311 

Wilson Blvd., Suite 400, Arlington, VA 

22201, (703) 524–8800, or online at: 

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, ANSI approved November 1, 

2016 (‘‘ANSI/ASHRAE 16’’). 

ANSI/ASHRAE Standard 37–2009, 

Methods of Testing for Rating 

Electrically Driven Unitary AirConditioning and Heat Pump 

Equipment, ANSI-approved June 25, 

2009 (‘‘ASHRAE 37–2009’’). 

ANSI/ASHRAE Standard 116–2010, 

Methods of Testing for Rating Seasonal 

Efficiency of Unitary Air Conditioners 

and Heat Pumps, ANSI approved 

February 24, 2010 (‘‘ANSI/ASHRAE 

116–2010’’). 

Copies of ANSI/ASHRAE 16, 

ASHRAE 37–2009, and ANSI/ASHRAE 

116–2010 can be purchased from the 

American Society of Heating, 

Refrigerating, and Air-Conditioning 

Engineers (‘‘ASHRAE’’) website at 

www.ashrae.org/resources— 

publications. 

See section IV.N of this document for 

further discussion of these standards. 

Table of Contents 

I. Authority and Background 

A. Authority 

B. Background 

II. Synopsis of the Final Rule 

III. Discussion 

A. Scope of Applicability 

B. Updates to Industry Standards 

1. AHRI 210/240–2024 

2. AHRI 1600–2024 

3. ANSI/ASHRAE 37–2009 

4. ANSI/ASHRAE 16–2016 

5. ANSI/ASHRAE 116–2010 

C. Revised CAC/HP Test Procedure 

D. Efficiency Metrics 

1. Metrics Applicable to Appendix M1 

2. Metrics Applicable to Appendix M2 

E. Near-Term Changes in the CAC/HP Test 

Procedure 

1. Controls Verification Procedure for 

Variable Speed Systems 

2. Low-Temperature Heating Performance 

3. Cut-Out and Cut-In Temperature 

Verification 

4. Low-Static Single-Split Blower-Coil 

System Definition and Testing 

Provisions 

5. Mandatory Constant Circulation Systems 

6. Provisions for Outdoor Units With No 

Match 

7. Inlet and Outlet Duct Configurations 

8. Heat Comfort Controllers 

F. Long-Term Changes in the CAC Test 

Procedure 

1. Power Consumption of Auxiliary 

Components 

2. Impact of Defrost on Performance 

3. Updates to Building Load Lines and 

Temperature Bin Hours 

4. Default Fan Power Coefficients for CoilOnly Systems 

5. Air Flow Limits To Address Inadequate 

Dehumidification 

G. General Comments Received in 

Response to the April 2024 NOPR 

H. Represented Values 

1. Represented Values for the Federal 

Trade Commission 

2. Off-Mode Power 

3. AEDM Tolerance for SCORE and SHORE 

4. Removal of the AEDM Exception for 

Split-System CAC/HPs 

I. Enforcement Provisions 


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Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1225 

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), which 

reflects the last statutory amendments that impact 

Parts A and A–1 of EPCA. 

2For editorial reasons, upon codification in the 

U.S. Code, Part B was redesignated Part A. 

1. Verifying Cut-Out and Cut-In 

Temperatures 

2. Controls Verification Procedure 

J. Test Procedure Costs and Impacts 

1. Appendix M1 

2. Appendix M2 

K. Effective and Compliance Dates 

IV. Procedural Issues and Regulatory Review 

A. Review Under Executive Orders 12866, 

13563, and 14094 

B. Review Under the Regulatory Flexibility 

Act 

1. Descriptions of Reasons for Action 

2. Objectives of, and Legal Basis for, Rule 

3. Description and Estimate of Small 

Entities Regulated 

4. Description and Estimate of Compliance 

Requirements 

5. Duplication, Overlap, and Conflict With 

Other Rules and Regulations 

1. Certification Statement 

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. Congressional Notification 

N. Description of Materials Incorporated by 

Reference 

V. Approval of the Office of the Secretary 

I. Authority and Background 

Central air conditioners (‘‘CACs’’) and 

central air conditioning heat pumps 

(‘‘HPs’’) (collectively, ‘‘CAC/HPs’’) are 

included in the list of ‘‘covered 

products’’ for which the U.S. 

Department of Energy (‘‘DOE’’) is 

authorized to establish and amend 

energy conservation standards and test 

procedures. (42 U.S.C. 6292 (a)(3)) 

DOE’s test procedure for CAC/HPs is 

currently prescribed at 10 CFR part 430, 

subpart B, appendix M1 (‘‘appendix 

M1’’). The following sections discuss 

DOE’s authority to establish and amend 

the test procedure for CAC/HPs and 

relevant background information 

regarding DOE’s consideration of the 

test procedure for this product. 

A. Authority 

The Energy Policy and Conservation 

Act, Pub. L. 94–163, 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. 6291– 

6317, as codified) Title III, Part B of 

EPCA 2 established the Energy 

Conservation Program for Consumer 

Products Other Than Automobiles, 

which sets forth a variety of provisions 

designed to improve energy efficiency. 

These products include CAC/HPs, the 

subject of this document. (42 U.S.C. 

6292(a)(3)) 

The energy conservation program 

under EPCA consists essentially of four 

parts: (1) testing, (2) labeling, (3) Federal 

energy conservation standards, and (4) 

certification and enforcement 

procedures. Relevant provisions of 

EPCA specifically include definitions 

(42 U.S.C. 6291), test procedures (42 

U.S.C. 6293), labeling provisions (42 

U.S.C. 6294), energy conservation 

standards (42 U.S.C. 6295), and the 

authority to require information and 

reports from manufacturers (42 U.S.C. 

6296). 

The Federal testing requirements 

consist of test procedures that 

manufacturers of covered products must 

use as the basis for: (1) certifying to DOE 

that their products comply with the 

applicable energy conservation 

standards adopted under EPCA (42 

U.S.C. 6295(s)), and (2) making other 

representations about the efficiency of 

those products (42 U.S.C. 6293(c)). 

Similarly, DOE must use these test 

procedures to determine whether the 

products comply with any relevant 

standards promulgated under EPCA. (42 

U.S.C. 6295(s)) 

Federal energy efficiency 

requirements for covered products 

established under EPCA generally 

supersede State laws and regulations 

concerning energy conservation testing, 

labeling, and standards. (42 U.S.C. 6297) 

DOE may, however, grant waivers of 

Federal preemption for particular State 

laws or regulations, in accordance with 

the procedures and other provisions of 

EPCA. (42 U.S.C. 6297(d)) 

Under 42 U.S.C. 6293, EPCA sets forth 

the criteria and procedures DOE must 

follow when prescribing or amending 

test procedures for covered products. 

EPCA requires that any test procedures 

prescribed or amended under this 

section shall be reasonably designed to 

produce test results which measure 

energy efficiency, energy use or 

estimated annual operating cost of a 

covered product during a representative 

average use cycle (as determined by the 

Secretary) or period of use and shall not 

be unduly burdensome to conduct. (42 

U.S.C. 6293(b)(3)) 

EPCA also requires that, at least once 

every seven years, DOE evaluate test 

procedures for each type of covered 

product, including CAC/HPs, 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 or period of use. (42 U.S.C. 

6293(b)(1)(A)) 

If the Secretary determines, on her 

own behalf or in response to a petition 

by any interested person, that a test 

procedure should be prescribed or 

amended, the Secretary shall promptly 

publish in the Federal Register 

proposed test procedures and afford 

interested persons an opportunity to 

present oral and written data, views, 

and arguments with respect to such 

procedures. The comment period on a 

proposed rule to amend a test procedure 

shall be at least 60 days and may not 

exceed 270 days. In prescribing or 

amending a test procedure, the 

Secretary shall take into account such 

information as the Secretary determines 

relevant to such procedure, including 

technological developments relating to 

energy use or energy efficiency of the 

type (or class) of covered products 

involved. (42 U.S.C. 6293(b)(2)). If DOE 

determines that test procedure revisions 

are not appropriate, DOE must publish 

its determination not to amend the test 

procedures. 

DOE’s regulations at 10 CFR 430.27 

provide that any interested person may 

seek a waiver from the test procedure 

requirements if certain conditions are 

met. A waiver requires manufacturers to 

use an alternate test procedure in 

situations in which the DOE test 

procedure cannot be used to test the 

product or equipment, or use of the DOE 

test procedure would generate 

unrepresentative results. 10 CFR 

430.27(a)(1). DOE’s regulations at 10 

CFR 430.27(l) require that as soon as 

practicable after the granting of any 

waiver, DOE will publish in the Federal 

Register a notice of proposed 

rulemaking (‘‘NOPR’’) to amend its 

regulations so as to eliminate any need 

for the continuation of such waiver. As 

soon thereafter as practicable, DOE will 

publish in the Federal Register a final 

rule. 10 CFR 430.27(l). 

In addition, EPCA requires that DOE 

amend its test procedures for all covered 

products to integrate measures of 

standby mode and off-mode energy 

consumption into the overall energy 

efficiency, energy consumption, or other 


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1226 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

3 IEC 62301, Household electrical appliances— 

Measurement of standby power (Edition 2.0, 2011– 

01). 

4 IEC 62087, Audio, video and related 

equipment—Methods of measurement for power 

consumption (Edition 1.0, Parts 1–6: 2015, Part 7: 

2018). 

5The AHRI 210/240–202X Draft test procedure is 

available in the docket for this rulemaking at: 

www.regulations.gov/document/EERE-2022-BT-TP0028-0017. 

6The AHRI 1600–202X Draft test procedure is 

available in the docket for this rulemaking at: 

www.regulations.gov/document/EERE-2022-BT-TP0028-0018. 

7The parenthetical reference provides a reference 

for information located in the docket of DOE’s 

rulemaking to develop test procedures for CAC/ 

HPs. (Docket No. EERE–2022–BT–TP–0028, which 

is maintained at: www.regulations.gov). The 

references are arranged as follows: (commenter 

name, comment docket ID number at page of that 

document). 

energy descriptor, unless the current 

test procedure already incorporates the 

standby mode and off-mode energy 

consumption, or if such integration is 

technically infeasible. (42 U.S.C. 

6295(gg)(2)(A)(i)–(ii)) If an integrated 

test procedure is technically infeasible, 

DOE must prescribe separate standby 

mode and off-mode energy use test 

procedures for the covered product, if a 

separate test is technically feasible. (42 

U.S.C. 6295(gg)(2)(A)(ii)) Any such 

amendment must consider the most 

current versions of the International 

Electrotechnical Commission (IEC) 

Standard 62301 3 and IEC Standard 

62087 4 as applicable. (42 U.S.C. 

6295(gg)(2)(A)) DOE is publishing this 

final rule in satisfaction of the sevenyear review requirement specified in 

EPCA. (42 U.S.C. 6293(b)(1)(A)) 

B. Background 

On April 5, 2024, DOE published in 

the Federal Register a notice of 

proposed rulemaking (‘‘NOPR’’) (‘‘April 

2024 NOPR’’) proposing to update the 

Federal test procedure for CAC/HPs by: 

(1) incorporating by reference at 

appendix M1 the most recent draft 

version of the AHRI Standard 210/240 

industry test procedure, AHRI 210/240– 

202X Draft, for measuring SEER2 and 

HSPF2; and (2) establishing a new test 

procedure at 10 CFR part 430, subpart 

B, appendix M2 (‘‘appendix M2’’) that 

references the draft new industry test 

procedure, AHRI 1600–202X Draft, for 

measuring new efficiency metrics, 

seasonal cooling and off mode rating 

efficiency (‘‘SCORE’’), and seasonal 

heating and off mode rating efficiency 

(‘‘SHORE’’). 89 FR 24206. Copies of the 

AHRI drafts were added to the docket 

for this rulemaking for review by 

interested parties.5 6 As stated in the 

April 2024 NOPR, if AHRI 210/240– 

202X Draft and AHRI 1600–202X Draft 

were to be finalized and formally 

adopted, DOE’s intention would be to 

reference the final published version of 

AHRI 210/240 and AHRI 1600 in DOE’s 

subsequent test procedure final rule. 89 

FR 24206, 24209. DOE held a public 

meeting webinar on April 25, 2024 to 

discuss the proposed amendments to 

the CAC/HP test procedure presented in 

the April 2024 NOPR. 

DOE received comments in response 

to the April 2024 NOPR from the 

interested parties listed in table I.1. 

TABLE I–1—LIST OF COMMENTERS WITH WRITTEN SUBMISSIONS IN RESPONSE TO THE APRIL 2024 NOPR 

Commenter(s) Reference in this final 

rule 

Comment No. 

in the docket Commenter type 

Air-Conditioning, Heating, and Refrigeration Institute .................................. AHRI ............................. 25 ................... Trade Association. 

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

Southern California Edison; collectively, the California Investor-Owned 

Utilities.

CA IOUs ........................ 32 ................... Utilities. 

Carrier Global Corporation ........................................................................... Carrier ........................... 29 ................... Manufacturer. 

Copeland LP ................................................................................................. Copeland ....................... 31 ................... Manufacturer. 

Daikin Comfort Technologies North America Inc ......................................... Daikin ............................ 36 and 40 ...... Manufacturer. 

GE Appliances .............................................................................................. GE Appliances .............. 37 ................... Manufacturer. 

Heating, Air-conditioning & Refrigeration Distributors International ............ HARDI ........................... 26 ................... Trade Association. 

Johnson Controls ......................................................................................... JCI ................................. 35 ................... Manufacturer. 

Appliance Standards Awareness Project, National Consumer Law Center, 

and New York State Energy Research and Development Authority.

Joint Advocates ............ 30 ................... Efficiency Organization, 

Consumer Advocacy 

Organization, and 

State Agency. 

Keith Rice ..................................................................................................... Keith Rice ..................... 33 ................... HVAC R&D Engineer. 

Lennox International Inc ............................................................................... Lennox .......................... 24 ................... Manufacturer. 

LG Electronics U.S.A., Inc ........................................................................... LG ................................. 38 ................... Manufacturer. 

Mitsubishi Electric US .................................................................................. Mitsubishi ...................... 28 ................... Manufacturer. 

National Comfort Products ........................................................................... NCP .............................. 27 ................... Manufacturer. 

Northwest Energy Efficiency Alliance .......................................................... NEEA ............................ 39 ................... Efficiency Organization. 

Rheem Manufacturing Company ................................................................. Rheem .......................... 34 ................... Manufacturer. 

A parenthetical reference at the end of 

a comment quotation or paraphrase 

provides the location of the item in the 

public record.7 To the extent that 

interested parties have provided written 

comments that are substantively 

consistent with any oral comments 

provided during the April 25, 2024 

public meeting, DOE cites the written 

comments throughout this final rule. 

DOE did not identify any oral comments 

provided during the April 25, 2024, 

public meeting that are not 

substantively addressed by written 

comments. 

In May 2024, AHRI finalized AHRI 

210/240–202X Draft and AHRI 1600– 

202X Draft without substantial change, 

and published AHRI Standard 210/240– 

2024, ‘‘Performance Rating of Unitary 

Air-conditioning and Air-source Heat 

Pump Equipment’’ (‘‘AHRI 210/240– 

2024’’), and AHRI Standard 1600–2024, 

‘‘Performance Rating of Unitary Airconditioning and Air-source Heat Pump 

Equipment’’ (‘‘AHRI 1600–2024’’), 

respectively. 

II. Synopsis of the Final Rule 

In this final rule, DOE is updating its 

regulations for CAC/HPs by: (1) 

amending appendix M1 to incorporate 

by reference the latest industry 

standard, AHRI 210/240–2024, while 

maintaining the current efficiency 

metrics EER2, SEER2 and HSPF2; and 

(2) establishing a new appendix M2 that 

references the new industry test 


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Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1227 

procedure, AHRI 1600–2024, for 

measuring new efficiency metrics, EER, 

SCORE and SHORE. Appendix M2 

would be the applicable test method for 

CAC/HPs for any standards 

denominated in terms of SCORE and 

SHORE. Use of appendix M2 would not 

be required until such time as 

compliance is required with any 

amended energy conservation standard 

based on the new metrics, should DOE 

adopt such standards. After the date on 

which compliance with appendix M2 

would be required, appendix M1 would 

no longer be required as part of the 

Federal test procedure. DOE is also 

amending certain provisions within 

DOE’s regulations for representation and 

enforcement consistent with the 

proposed test procedure amendments. 

Table II.1 summarizes the adopted 

changes to the amended appendix M1 

and the new appendix M2 test 

procedures, as well as the reason for the 

adopted change. 

TABLE II–1—SUMMARY OF CHANGES IN AMENDED APPENDIX M1 AND NEW APPENDIX M2 TEST PROCEDURES RELATIVE

TO CURRENT TEST PROCEDURE

DOE test procedure 

prior to amendment 

Appendix M1 

test procedure 

Appendix M2 

test procedure Attribution 

Incorporates by reference AHRI 

210/240–2008.

Incorporates by reference AHRI 

210/240–2024.

Incorporates by reference AHRI 

1600–2024.

Updates to the applicable industry 

test procedures. 

Includes provisions for determining 

SEER2, HSPF2, EER2, and 

PW,OFF.

Maintains provisions for determining SEER2, HPSF2, EER2, 

and PW,OFF.

Includes provisions for determining SCORE and SHORE 

and maintains provisions for determining EER (same as EER2).

Updates to the applicable industry 

test procedures. 

Includes certain CAC/HP provisions regarding determination of 

represented values in 10 CFR 

429.16.

Includes provisions to remove the 

alternative efficiency determination method (‘‘AEDM’’) exception for split-systems in 10 CFR 

429.16.

Includes provisions to remove the 

AEDM exception for split-systems, to extend the AEDM tolerance requirement to SCORE 

and SHORE, and to no longer 

require representations of the 

PW,OFF metric in 10 CFR 

429.16.

Improve representativeness of 

test procedure. 

Does not include certain CAC/HPspecific enforcement provisions 

in 10 CFR 429.134(k).

Includes CAC/HP-specific enforcement provisions regarding 

verification of cut-out and cut-in 

temperatures and a controls 

verification procedure.

Includes CAC/HP-specific enforcement provisions regarding 

verification of cut-out and cut-in 

temperatures and a controls 

verification procedure.

Clarify how DOE will conduct enforcement testing. 

DOE has determined that the 

amendments to the CAC/HP test 

procedures in appendix M1 and newly 

established appendix M2 would not be 

unduly burdensome to conduct. 

Furthermore, DOE has determined that 

the amendments to appendix M1 would 

not alter the measured efficiency of 

CAC/HPs or require retesting or 

recertification solely as a result of DOE’s 

adoption of the amendments to the test 

procedure. Additionally, DOE has 

determined that the amendments to 

appendix M1 would not increase the 

cost of testing. Representations of 

energy use or energy efficiency would 

be required to be based on testing in 

accordance with the amended test 

procedure in appendix M1 beginning 

180 days after the date of publication of 

the test procedure final rule in the 

Federal Register. 

DOE has determined, however, that 

new appendix M2 would alter the 

measured efficiency of CAC/HPs, in part 

because the amended test procedure 

would adopt different energy efficiency 

metrics than in the current test 

procedure. Additionally, DOE has 

determined that testing according to the 

new appendix M2 would not increase 

the cost of testing as compared to 

appendix M1. Cost estimates are 

discussed in section III.J of this 

document. As discussed, use of 

appendix M2 would not be required 

until the compliance date of amended 

energy conservation standards 

denominated in terms of SCORE and 

SHORE, should DOE adopt such 

standards. 

The amendments to representation 

requirements in 10 CFR 429.16 would 

not be required until 180 days after 

publication in the Federal Register of 

this final rule. 

Discussion of DOE’s proposed actions 

are addressed in further detail in section 

III of this final rule. 

III. Discussion 

A. Scope of Applicability 

This rulemaking applies to CAC/HPs. 

DOE defines the term central air 

conditioner or central air conditioner 

heat pump to mean a product, other 

than a packaged terminal air conditioner 

or packaged terminal heat pump, singlephase single-package vertical air 

conditioner with cooling capacity less 

than 65,000 British thermal units 

(‘‘Btu’’) per hour (‘‘Btu/h’’), single-phase 

single-package vertical heat pump with 

cooling capacity less than 65,000 Btu/h, 

computer room air conditioner, or 

unitary dedicated outdoor air system, as 

these equipment categories are defined 

at 10 CFR 431.92, which is powered by 

single-phase electric current, air-cooled, 

rated below 65,000 Btu/h, not contained 

within the same cabinet as a furnace, 

the rated capacity of which is above 

225,000 Btu/h, and is a heat pump or a 

cooling unit only. A central air 

conditioner or central air conditioning 

heat pump may consist of: a singlepackage unit; an outdoor unit and one 

or more indoor units; an indoor unit 

only; or an outdoor unit with no match. 

In the case of an indoor unit only or an 

outdoor unit with no match, the unit 

must be tested and rated as a system 

(combination of both an indoor and an 

outdoor unit). For all central air 

conditioner and central air conditioning 

heat pump-related definitions, see 

appendix M or M1 of subpart B of this 

part. 10 CFR 430.2. 

Consistent with the April 2024 NOPR, 

DOE is not proposing any changes to the 

CAC/HP definition. However, DOE 

notes that the last sentence in the CAC/ 

HP definition includes references to see 

additional definitions in appendices M 

and M1. As noted in section II, in this 

final rule, DOE is incorporating by 

reference the latest industry standards, 

AHRI 210/240–2024 and AHRI 1600– 

2024, including the relevant definitions 


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8ANSI/ASHRAE 37–2009 provides a method of 

test for many categories of air-conditioning and 

heating products and equipment, including CAC/ 

HPs. 

9ANS/ASHRAE 16–2016 provides a method of 

test for rating room air conditioners, packaged 

terminal air conditioners, and packaged terminal 

heat pumps. 

10Currently, all full-speed cooling and heating 

mode tests in appendix M1 are identified with ‘‘2’’ 

in the subscript of the relevant test, whereas AHRI 

210/240–202X and AHRI 1600–202X identify them 

with the ‘‘Full’’ subscript. Similarly, all minimumspeed cooling and heating mode tests in appendix 

M1 are identified with ‘‘1’’ in the subscript of the 

relevant test, whereas AHRI 210/240–202X and 

AHRI 1600–202X identify them with the ‘‘Low’’ 

subscript. 

in these standards. Therefore, references 

to appendices M and M1 are no longer 

relevant in the CAC/HP definition. To 

prevent confusion, DOE is removing the 

last sentence in the definition that 

contains these references. 10 CFR 430.2. 

The current scope of the CACs/HP test 

procedure includes: 

(a) Split-system air conditioners, 

including single-split, multi-head minisplit, multi-split (including variable 

refrigerant flow (‘‘VRF’’)), and multicircuit systems; 

(b) Split-system heat pumps, 

including single-split, multi-head minisplit, multi-split (including VRF), and 

multi-circuit systems; 

(c) Single-package air conditioners; 

(d) Single-package heat pumps; 

(e) Small-duct, high-velocity systems 

(including VRF); 

(f) Space-constrained products—air 

conditioners; and 

(g) Space-constrained products—heat 

pumps. 

See section 1.1 of appendix M1. 

DOE is not amending the scope of 

CACs/HPs covered by the test procedure 

in appendix M1 or appendix M2. 

B. Updates to Industry Standards 

DOE is incorporating by reference 

AHRI 210/240–2024 and the relevant 

standards it references as the basis for 

the updated appendix M1 test 

procedure. Similarly, DOE is 

incorporating by reference AHRI 1600– 

2024 and the relevant standards it 

references as the basis for the new 

appendix M2 test procedure. 

Incorporating each industry standard in 

full as the basis for each respective 

appendix would enable DOE to better 

harmonize with the industry standard 

and eliminate manufacturer burden in 

certifying with separate test procedures. 

The following sections discuss the 

referenced standards for appendices M1 

and M2. 

1. AHRI 210/240–2024 

In the April 2024 NOPR, DOE noted 

that AHRI and other relevant 

stakeholders, including DOE, worked to 

develop a revised AHRI 210/240 

standard, AHRI 210/240–202X Draft, 

that included updates to address issues 

pertaining to the CAC/HP test procedure 

with broad stakeholder consensus. 89 

FR 24206, 24211–24212. DOE proposed 

to amend its test procedure for CAC/HPs 

at appendix M1 by incorporating by 

reference AHRI 210/240–202X Draft. Id. 

Because AHRI 210/240–202X Draft was 

in draft form at the time of the 

publication of the April 2024 NOPR, 

DOE noted that it intended to update its 

incorporation by reference to the final 

published version of AHRI 210/240– 

202X Draft in the final rule, unless the 

draft version is not finalized before the 

final rule or there are substantive 

changes between the draft and 

published versions, in which case DOE 

may adopt the substance of the AHRI 

210/240–202X Draft or provide 

additional opportunity for comment on 

the substantive changes to the updated 

industry consensus standard. Id. In May 

2024, AHRI published the finalized 

AHRI 210/240 standard, AHRI 210/240– 

2024, which did not include any 

significant deviations from AHRI 210/ 

240–202X Draft. 

AHRI, the CA IOUs, Carrier, Daikin, 

GE Appliances, JCI, Lennox, and NEEA 

were generally supportive of DOE‘s 

proposal on updating appendix M1 by 

adopting the finalized AHRI 210/240 

standard. (AHRI, No. 25 at p. 3; Carrier, 

No. 29 at p. 4; CA IOUs, No. 32 at p. 

1; Daikin, No. 36 at p. 1; GE Appliances, 

No. 37 at pp. 4–5; JCI, No. 35 at p. 1; 

Lennox, No. 24 at p. 3; NEEA, No. 39 

at p. 2) AHRI commented that it 

supports the adoption of AHRI 210/240– 

2024 as a revised appendix M1, but with 

minimal additions and some exclusions, 

and will be publishing an addendum to 

AHRI 210/240–2024 that will include 

the aforementioned minimal additions 

that DOE established in the April 2024 

NOPR, including revision to the 

definition of outdoor unit with no 

match. (AHRI, No. 25 at p. 3) 

The Joint Advocates and CA IOUs 

encouraged DOE to adopt AHRI 210/ 

240–2024 in the new CAC/HP test 

procedure final rule as soon as possible. 

(Joint Advocates, No. 30 at p. 1; CA 

IOUs, No. 32 at p. 1) Carrier stated that 

it supports the incorporation by 

reference of AHRI 210/240–2024 into a 

revised appendix M1, but with some 

recommendations. (Carrier, No. 29 at p. 

4) Rheem commented that even though 

it supported the adoption of the 

consensus AHRI 210/240–2024 in the 

updated Appendix M1, it was 

concerned that the new versions of 

ANSI/ASHRAE Standard 37–2009 8 and 

ANSI/ASHRAE Standard 16–2016 9

with major changes, which are to be 

published in the near future, are not 

currently referenced in AHRI 210/240– 

2024. (Rheem, No. 34 at p. 3) 

Specifically, Rheem pointed out that 

once the new versions of the 

aforementioned ASHRAE standards are 

published, AHRI 210/240–2024 should 

be revised to incorporate references to 

the revised standards, and subsequently, 

DOE should update appendix M1 to 

incorporate the revised AHRI 210/240– 

2024 by reference. (Id. at pp. 3–4) 

Rheem further commented that since 

AHRI 210/240–2024 cites sections of 10 

CFR 429.16, and of appendix M1 to 

subpart B of 10 CFR part 430, it should 

be revised to ensure that these 

references to CFR are still appropriate, 

since DOE has proposed major revisions 

to these sections from the CFR. (Id.) 

Rheem pointed to the newly introduced 

enforcement provisions in 10 CFR 

429.134(k), which require calculation of 

average capacity (10 CFR 

429.134(k)(4)(iii)(A)(1) and (2)) or timeaveraged integrated (10 CFR 

429.134(k)(4)(iii)(A)(3)) capacity and 

power consumption, and Rheem 

suggested updates to appendix I of 

AHRI 210/240–2024 to state that average 

capacity, average power consumption, 

time-averaged integrated capacity, and 

time-integrated power consumption 

should be calculated according to the 

appropriate sections of AHRI 210/240– 

2024 and ANSI/ASHRAE 16, as 

applicable. (Id.) Rheem pointed out that 

table 8 of AHRI 210/240–2024, which 

lists the test conditions for CAC/HPs 

under test, does not include the details 

on how to measure the compressor 

speed for cooling full-speed tests (A2 

and B2), and cooling minimum-speed 

tests (B1, F1, G1, and I1) for variablespeed compressor units, as currently 

specified in section 3.2.4(a) of appendix 

M1. (Id. at p. 4) Rheem commented that 

the aforementioned details should be 

added as notes under table 8 of AHRI 

210/240–2024, after appropriate 

translations of the test nomenclature.10

Id. 

In response to Rheem’s comment, 

DOE notes that in the April 2024 NOPR, 

DOE proposed to incorporate by 

reference AHRI 210/240–202X draft and 

the AHRI 1600–202X draft, at revised 

appendix M1 and new appendix M2, 

respectively, while this final rule is 

updating these references to the final 

drafts, AHRI 210/240–2024 and AHRI 

1600–2024. DOE has reviewed the 

finalized standards, AHRI 210/240–2024 

and AHRI 1600–2024, and has 

concluded that all current references to 

10 CFR 429.16 in the standards would 


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11 DOE notes that the substance of these 

provisions remains the same as those proposed in 

the April 2024 NOPR, but AHRI did some 

reorganization in moving from AHRI 210/240–202X 

Draft to AHRI 210/240–2024. Consequently, the 

adopted section numbers cited here differ from 

those presented in DOE’s proposed rule. See 89 FR 

24206, 24212. 

12ANSI/AMCA 210–2007, ANSI/ASHRAE 51– 

2007, (‘‘AMCA 210–2007’’) Laboratory Methods of 

Testing Fans for Certified Aerodynamic 

Performance Rating, ANSI approved Aug. 17, 2007. 

A copy of AMCA 210–2007 can be purchased from 

the Air Movement and Control Association 

International Inc. (‘‘AMCA’’) website at 

www.amca.org/store/index.php. 

13ANSI/AHRI 1230–2010 with Addendum 2, 

(‘‘AHRI 1230–2010’’): 2010 Standard for 

Performance Rating of Variable Refrigerant Flow 

(‘‘VRF’’) Multi-Split Air-Conditioning and Heat 

Pump Equipment, ANSI approved Aug. 2, 2010. A 

copy of AHRI 1230–2010 can be obtained from 

AHRI, 2111 Wilson Boulevard, Suite 500, 

Arlington, VA 22201, USA, 703–524–8800, or by 

going to www.ahrinet.org. 

14ANSI/ASHRAE 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 Jan. 28, 2010. A copy of ASHRAE 23.1– 

2010 can be obtained from the ASHRAE website at 

www.ashrae.org/resources--publications. 

15While AHRI‘s comment noted support for the 

adoption of the AHRI 1600 standard at appendix 

M1, DOE surmises that this is a typographical error, 

and AHRI intended to express support for adoption 

at appendix M2 instead. As proposed in the April 

2024 NOPR, appendix M1 references the draft AHRI 

210/240 standard. 

not require revision. Additionally, DOE 

clarifies that any further updates to 

appendix I of the AHRI 210/240 and 

AHRI 1600 standards to add the 

definitions of average capacity, average 

power consumption, time-averaged 

integrated capacity, and time-integrated 

power consumption will have to be 

initiated by AHRI, as part of an 

addendum. DOE has determined that 

additional definitions are not necessary 

at this time and notes that an updated 

appendix I to AHRI 210/240 and AHRI 

1600 is not yet available for review; 

therefore, DOE is not adopting 

additional definitions as recommended 

by Rheem at this time. Regarding 

Rheem’s comment on table 8 of AHRI 

210/240–2024 lacking language from 

section 3.2.4 (a) of the current appendix 

M1 for maintaining the same full 

compressor speed for all full-speed 

cooling tests, and the same minimum 

compressor speed for all minimumspeed cooling tests, DOE is adding 

provisions in section 2 of the revised 

appendix M1 and section 2 of the new 

appendix M2, consistent with the 

existing requirement in appendix M1, as 

follows: 

For cooling mode tests of variable 

capacity systems, the compressor shall 

operate at the same cooling full speed, 

measured by RPM of power input 

frequency (Hz), for both AFull and BFull

tests. Additionally, the compressor shall 

operate at the same cooling minimum 

speed, measured by RPM or power 

input frequency (Hz), for the BLow, FLow, 

GLow, and ILow tests. 

As noted, in May 2024, AHRI 

published AHRI 210/240–2024, which 

does not include any significant 

deviations from AHRI 210/240–202X 

Draft. As such, the adoption of AHRI 

210/240–2024 in this final rule is 

consistent with the proposal to 

reference AHRI 210/240–202X Draft in 

the April 2024 NOPR. 

Therefore, DOE is amending its test 

procedure for CAC/HPs by 

incorporating by reference AHRI 210/ 

240–2024 for use in the new appendix 

M1. Specifically, in the new test 

procedure for CAC/HPs at appendix M1, 

DOE is adopting sections 3 (excluding 

3.2.16, 3.2.20, 3.2.46, 3.2.51, 3.2.63, 

3.2.78 and 3.2.79), 5 (excluding 5.1.6.2), 

6.1–6.3, and 6.6, and Appendices D, E, 

G, and K of AHRI 210/240–2024.11

Additionally, as proposed in the April 

2024 NOPR, DOE is making additions 

and deletions to the incorporations by 

reference for the CAC/HP Federal test 

procedure (see 10 CFR 430.3) to align 

with the references made within AHRI 

210/240–2024. 89 FR 24206, 24212. 

Currently, appendix M1 incorporates 

by reference: AMCA 210–2007,12 AHRI 

210/240–2008, AHRI 1230–2010,13

ASHRAE 23.1–2010,14 ANSI/ASHRAE 

37–2009, and ASHRAE 116–2010. 10 

CFR 430.3. 

In the amended test procedure at 

appendix M1, DOE is adding an 

incorporation by reference to ANSI/ 

ASHRAE 16–2016 and removing 

incorporations by reference to AMCA 

210–2007, AHRI 210/240–2008, AHRI 

1230–2010, and ASHRAE 23.1–2010. 

Therefore, DOE is incorporating by 

reference AHRI 210/240–2024, ANSI/ 

ASHRAE 16–2016, ANSI/ASHRAE 37– 

2009, and ANSI/ASHRAE 116–2010, at 

appendix M1. 

2. AHRI 1600–2024 

In parallel to the AHRI 210/240–202X 

Draft, AHRI and other relevant 

stakeholders, including DOE, worked to 

develop a forward-looking AHRI test 

procedure that would act as the 

successor to the AHRI 210/240–202X 

Draft and be effective in the long term 

(i.e., AHRI 1600–202X Draft). 

In the April 2024 NOPR, DOE 

proposed to establish a new test 

procedure for CAC/HPs at appendix M2 

by incorporating by reference AHRI 

1600–202X Draft (in its entirety). 89 FR 

24206, 24212. DOE noted that it 

intended to update its incorporation by 

reference to the final published version 

of AHRI 1600–202X Draft in the final 

rule, unless the draft version is not 

finalized before the final rule or there 

are substantive changes between the 

draft and published versions, in which 

case DOE may adopt the substance of 

the AHRI 1600–202X Draft or provide 

additional opportunity for comment on 

the substantive changes to the updated 

industry consensus standard. Id. In May 

2024, AHRI published the finalized 

AHRI 1600 standard, AHRI 1600–2024, 

which did not include any significant 

deviations from AHRI 1600–202X Draft. 

Several stakeholders, namely Lennox, 

AHRI, Mitsubishi, Copeland, the CA 

IOUs, Rheem, Daikin, NEEA, and 

Carrier, appreciated DOE’s efforts of 

collaborating with the stakeholders to 

develop the AHRI 1600 standard, and 

supported its adoption at appendix M2. 

(Lennox, No. 24 at p. 4; AHRI, No. 25 

at p. 3; 15 Mitsubishi, No. 28 at p. 1; 

Copeland, No. 31 at p. 1; CA IOUs, No. 

32 at p. 2; Rheem, No. 34 at p. 4; Daikin, 

No. 36 at p. 1; NEEA, No. 39 at p. 2; 

Carrier, No. 29 at p. 4) Rheem 

commented that in a similar vein to its 

comment made on AHRI 210/240–2024 

(see section III.B.1 of this document), 

DOE should be aware that the revised 

editions of ANSI/ASHRAE Standard 37 

and ANSI/ASHRAE Standard 16 are 

currently not referenced in AHRI 

Standard 1600–2024. (Rheem, No. 34 at 

p. 4) Rheem further pointed to DOE‘s 

inclusion of the energy efficiency metric 

energy efficiency ratio 2 (‘‘EER2) in 10 

CFR 430.23(m)(2); several sections of 10 

CFR 429.16 and 10 CFR 429.134(k)(4); 

and sections 2, 4.1, and 4.2 of appendix 

M2 to subpart B of 10 CFR part 430, 

which in turn incorporate AHRI 1600– 

2024 by reference, which only includes 

energy efficiency ratio (‘‘EER’’) as the 

efficiency metric, and not EER2. (Id. at 

p. 5) Rheem stated that this mismatch 

should be resolved by either DOE 

revising its relevant references from 

EER2 to EER, or that AHRI 1600–2024 

should be revised to replace all 

instances of EER with EER2. (Id.) 

Further, Rheem pointed out that section 

4.1 of the new appendix M2 references 

10 CFR 431.97, in relation to 

certification to the energy conservation 

standards SCORE and SHORE, and 

suggested this citation should be 

changed to 10 CFR 430.32(c), which will 

be amended to prescribe energy 

conservation standards for CAC/HPs. 

(Id.) Additionally, as noted in section 

III.B.1 for AHRI 210/240–2024, Rheem 

commented that table 8 of AHRI 1600– 

2024 should contain sentences similar 

to section 3.2.4(a) of appendix M1, to 


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specify that for variable-speed 

compressor systems, the cooling full 

compressor speed for both A2 and B2 

tests should be same, and the cooling 

minimum compressor speed for the B1, 

F1, G1, and I1 tests should remain the 

same. (Id. at p. 4) 

In response to Rheem’s comment 

regarding AHRI 210/240–2024 retaining 

the EER2 metric while AHRI 1600–2024 

using the EER metric, DOE agrees with 

Rheem that this mismatch has potential 

to confuse users of the test procedure. 

DOE notes that the EER2 metric in AHRI 

210/240–2024 is identical to the EER 

metric in AHRI 1600–2024. Both metrics 

are evaluated at the same test conditions 

and convey the same full-load efficiency 

information. Therefore, for appendix 

M1, which references AHRI 210/240– 

2024, DOE is retaining the EER2 metric. 

For appendix M2, which references 

AHRI 1600–2024, DOE is including EER 

as the full-load metric, with EER 

evaluated the same way as EER2 per 

appendix M1. DOE is making 

appropriates changes in the regulatory 

text at 10 CFR parts 429 and 430, and 

appendix M2, to reflect this 

clarification. In response to Rheem’s 

comment for the citation of the SCORE 

and SHORE energy conservation 

standards in the April 2024 NOPR, DOE 

agrees that the correct citation is to 10 

CFR 430.32(c), and not 10 CFR 431.97. 

Finally, as mentioned in section III.B.1 

of this document, DOE is adding 

language to section 2 of appendix M2 to 

explicitly state that for variable-capacity 

compressor systems, the cooling full 

compressor speeds for both AFull and 

BFull tests should be identical, and the 

cooling minimum compressor speed for 

the BLow, FLow, GLow, and ILow tests 

should be identical. 

As discussed, AHRI 1600–2024 does 

not include any significant deviations 

from AHRI 1600–202X Draft. As such, 

the adoption of AHRI 1600–2024 in this 

final rule is consistent with the proposal 

to reference AHRI 1600–202X Draft in 

the April 2024 NOPR. 

DOE is amending its test procedure 

for CAC/HPs by incorporating by 

reference AHRI 1600–2024 for use in the 

new appendix M2. Specifically, in the 

new test procedure for CAC/HPs at 

appendix M2, DOE is adopting sections 

3 (excluding 3.2.16, 3.2.20, 3.2.45, 

3.2.50, 3.2.63, 3.2.78, and 3.2.79), 5 

(excluding 5.1.6.2), 6 (excluding 6.1.8, 

6.2, 6.3, 6.4, and 6.5), 11, and 12 and 

appendices D, E, G, K, and L of the 

AHRI 1600–202X Draft in the Federal 

test procedure for CAC/HPs at appendix 

M2. 

Additionally, consistent with the 

April 2024 NOPR, DOE is also 

incorporating by reference ANSI/ 

ASHRAE 16–2016, ANSI/ASHRAE 37– 

2009, and ANSI/ASHRAE 116–2010, 

which are referenced within AHRI 

1600–2024. Therefore, in total, DOE is 

proposing to incorporate by reference 

AHRI 1600–2024, ANSI/ASHRAE 16– 

2016, ANSI/ASHRAE 37–2009, and 

ANSI/ASHRAE 116–2010, at appendix 

M2. 

3. ANSI/ASHRAE 37–2009 

ANSI/ASHRAE 37–2009 provides a 

method of test for electrically driven 

unitary air-conditioning and heat pump 

equipment, which includes CAC/HPs. 

In the April 2024 NOPR, DOE proposed 

to incorporate by reference ANSI/ 

ASHRAE 37–2009 at both appendix M1 

and appendix M2, since AHRI 210/240– 

202X Draft and AHRI 1600–202X Draft 

both reference test instructions in ANSI/ 

ASHRAE 37–2009. 89 FR 24206, 24212. 

The finalized versions of these draft 

standards, AHRI 210/240–2024 and the 

AHRI 1600–2024, also reference ANSI/ 

ASHRAE 37–2009. More specifically, 

sections 5, 6, 8, and 11 and appendices 

C, D, E, I, and J of AHRI 210/240–2024 

and AHRI 1600–2024 refer to methods 

of test in ANSI/ASHRAE 37–2009. 

DOE currently incorporates by 

reference ANSI/ASHRAE 37–2009 in 10 

CFR part 430, subpart B, and the current 

incorporation by reference applies to the 

current Federal test procedure for CAC/ 

HPs specified at appendix M1. Given 

that AHRI 210/240–2024 Draft 

references ANSI/ASHRAE 37–2009 for 

several test instructions, DOE has 

concluded, consistent with the April 

2024 NOPR, that it is appropriate to 

maintain the existing incorporation by 

reference of ANSI/ASHRAE 37–2009 in 

appendix M1. Additionally, given that 

AHRI 1600–2024 references ANSI/ 

ASHRAE 37–2009 for several test 

instructions, DOE has concluded, 

consistent with the April 2024 NOPR, 

that it is appropriate to incorporate by 

reference ANSI/ASHRAE 37–2009 for 

use with appendix M2. 

4. ANSI/ASHRAE 16–2016 

ANSI/ASHRAE 16–2016, which 

provides a method of test for rating 

room air conditioners, packaged 

terminal air conditioners, and packaged 

terminal heat pumps, is referenced for 

testing CAC/HPs by both the AHRI 210/ 

240–202X Draft and the AHRI 1600– 

202X Draft. Consequently, in the April 

2024 NOPR, DOE proposed to 

incorporate by reference ANSI/ASHRAE 

16–2016 at both appendix M1 and 

appendix M2. 89 FR 24206, 24213. The 

finalized versions of the AHRI draft 

standards, AHRI 210/240–2024 and 

AHRI 1600–2024, also reference ANSI/ 

ASHRAE 16–2016. More specifically, 

section 5.1.1 of AHRI 210/240–2024 and 

AHRI 1600–2024 refer to testing of nonducted CAC/HPs from provisions in 

ANSI/ASHRAE 16–2016, or by using a 

combination of provisions in ANSI/ 

ASHRAE 37–2009 and ANSI/ASHRAE 

116–2016. 

Currently, ANSI/ASHRAE 16–2016 is 

not incorporated by reference in 

appendix M1. DOE has concluded that 

testing conducted per ANSI/ASHRAE 

16–2016 for non-ducted CAC/HPs will 

not impact ratings in comparison to 

testing conducted per provisions in 

ANSI/ASHRAE 37–2009 and ANSI/ 

ASHRAE 116–2010. Thus, given that 

AHRI 210/240–2024 and AHRI 1600– 

2024 refer to ANSI/ASHRAE 16–2016 as 

an option for testing of non-ducted 

CAC/HPs, and it does not impact 

ratings, DOE has concluded, consistent 

with the April 2024 NOPR, that it is 

appropriate to incorporate by reference 

ANSI/ASHRAE 16–2016 for appendices 

M1 and M2. 

5. ANSI/ASHRAE 116–2010 

ANSI/ASHRAE 116–2010, which 

provides a method of test for unitary air 

conditioners and heat pumps with a 

cooling capacity of 65,000 Btu/h and 

less, is referenced for testing CAC/HPs 

by both AHRI 210/240–202X Draft and 

AHRI 1600–202X Draft. Consequently, 

in the April 2024 NOPR, DOE proposed 

to incorporate by reference ANSI/ 

ASHRAE 116–2010 at both appendix 

M1 and appendix M2. 89 FR 24206, 

24213. The finalized versions of the 

AHRI draft standards, AHRI 210/240– 

2024 and AHRI 1600–2024, also 

reference ANSI/ASHRAE 116–2010. 

More specifically, sections 5, 6, 8, and 

11 and appendices D and E of AHRI 

210/240–2024 and AHRI 1600–2024 

refer to methods of test in ANSI/ 

ASHRAE 116–2010. 

Given that AHRI 210/240–2024 

references ANSI/ASHRAE 116–2010 for 

several test instructions, DOE has 

concluded, consistent with the April 

2024 NOPR, that it is appropriate to 

maintain the incorporation by reference 

of ANSI/ASHRAE 116–2010 in 

appendix M1. Additionally, given that 

the AHRI 1600–2024 Draft references 

ANSI/ASHRAE 116–2010 for several 

test instructions, DOE has concluded, 

consistent with the April 2024 NOPR, 

that it is appropriate to incorporate by 

reference ANSI/ASHRAE 116–2010 for 

use with appendix M2. 

C. Revised CAC/HP Test Procedure 

As discussed, EPCA requires that test 

procedures for each type of covered 

product, including CAC/HPs, not be 

unduly burdensome to conduct and be 

reasonably designed to produce test 


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16 DOE is not incorporating by reference the 

following provisions in section 3 of AHRI 210/240– 

2024 because the terms are either defined in 

appendix M1, or are not needed for the DOE test 

procedure: 3.2.16 (Double-duct System), 3.2.20 

(Gross Capacity), 3.2.46 (Oil Recovery Mode), 3.2.51 

(Published Rating), 3.2.63 (Standard Filter), 3.2.78 

(Unitary Air-conditioner), and 3.2.79 (Unitary Heat 

Pump). 

17 DOE is not incorporating by reference the 

following provision in section 5 of AHRI 210/240– 

2024 because the term is defined in appendix M1: 

5.1.6.2 (Outdoor Unit with No Match (OUWNM)). 

18 DOE is not incorporating by reference the 

following provisions in section 6 of AHRI 210/240– 

2024 because the provisions are either defined in 

10 CFR 429.16, or are not needed for the DOE test 

procedure: 6.1.8 (Tested Combinations or Tested 

Units), 6.2 (Application Ratings), 6.3 (Publication of 

Ratings), 6.4 (Ratings), and 6.5 (Uncertainty and 

Variability). 

19As explained in Section III.B.2, DOE will 

replace EER2 in appendix M1 with EER in 

appendix M2. However, EER will be calculated in 

a manner identical to EER2, and both convey the 

same full load test information. 

20 DOE is not incorporating by reference the 

following provisions in section 3 of AHRI 1600– 

2024 because the terms are either defined in 

appendix M1, or are not needed for the DOE test 

procedure: 3.2.16 (Double-duct System), 3.2.20 

(Gross Capacity), 3.2.45 (Oil Recovery Mode), 3.2.50 

(Published Rating), 3.2.63 (Standard Filter), 3.2.78 

(Unitary Air-conditioner), and 3.2.79 (Unitary Heat 

Pump). 

21 DOE is not incorporating by reference the 

following provision in section 5 of AHRI 1600–2024 

because the term is defined in appendix M2: 5.1.6.2 

(Outdoor Unit with No Match (OUWNM)). 

22 DOE is not incorporating by reference the 

following provisions in section 6 of AHRI 1600– 

2024 D because the provisions are either defined in 

10 CFR 429.16, or are not needed for the DOE test 

procedure: 6.1.8 (Tested Combinations or Tested 

Units), 6.2 (Application Ratings), 6.3 (Publication of 

Ratings), 6.4 (Ratings), and 6.5 (Uncertainty and 

Variability). 

23AHRI 1600–2024 replaced the EER2 and COP2 

metrics from AHRI 210/240–2024 with EER and 

COP. For consistency, appendix M2 will follow the 

nomenclature in AHRI 1600–2024 and will hence 

use EER as the full-load metric, while appendix M1 

will use the EER2 metric. 

24A load-based test method differs from the 

steady-state test method currently used in DOE test 

procedures for air-conditioning and heat pump 

equipment. In a steady-state test method, the indoor 

room is maintained at a constant temperature 

Continued 

results that reflect energy efficiency, 

energy use, and estimated operating 

costs during a representative average 

use cycle or period of use. (42 U.S.C. 

6293(b)(3)) 

In this final rule, DOE is maintaining 

the current efficiency metrics, EER2, 

SEER2 and HSPF2, at appendix M1 and 

is referencing AHRI 210/240–2024 for 

measuring the existing metrics. DOE has 

determined that the amendments to 

appendix M1 would not affect the 

measured efficiency of CAC/HPs or 

require retesting solely because of DOE’s 

adoption of the amendments to the 

appendix M1 test procedure. At 

appendix M1, DOE is incorporating by 

reference the following sections of the 

AHRI 210/240–2024: sections 3 (with 

certain exclusions 16), 5 (with one 

exclusion 17), 6 (with certain 

exclusions 18), 11, and 12, as well as 

appendices D, E, G, K, and L. 

Additionally, DOE is establishing a 

new test procedure at appendix M2 that 

adopts AHRI 1600–2024, including the 

new SCORE and SHORE metrics.19 Use 

of appendix M2 is not required until the 

compliance date of any amended 

standards denominated in terms of the 

new metrics for appendix M2, should 

such standards be adopted. At appendix 

M2, DOE is referencing the following 

sections of AHRI 1600–2024: sections 3 

(with certain exclusions 20), 5 (with one 

exclusion 21), 6 (with certain 

exclusions 22), 11, and 12 and 

appendices D, E, G, K and L. 

Further, at both appendix M1 and 

appendix M2, DOE is incorporating by 

reference the following: ANSI/ASHRAE 

37–2009, except sections 1 (Purpose), 2 

(Scope), and 4 (Classifications); ANSI/ 

ASHRAE 16–2016 except sections 1 

(Purpose), 2 (Scope), and 4 

(Classifications); and ANSI/ASHRAE 

116–2010 except sections 1 (Purpose), 2 

(Scope), 4 (Classifications), and 7 

(Methods of Test). 

D. Efficiency Metrics 

As discussed, DOE is updating the 

current Federal test procedure for CAC/ 

HPs at appendix M1 consistent with the 

most recent draft version of the relevant 

industry consensus test procedure, 

AHRI 210/240–2024. DOE is also 

establishing a new Federal test 

procedure at 10 CFR part 430, subpart 

B, appendix M2, consistent with the 

new industry consensus test procedure, 

AHRI 1600–2024. Sections III.D.1 and 

III.D.2 of this document discuss which 

metrics are applicable for appendices 

M1 and M2, respectively. 

1. Metrics Applicable to Appendix M1 

Consistent with the April 2024 NOPR, 

appendix M1 maintains the current 

energy efficiency metrics (i.e., EER2, 

SEER2, and HSPF2), and includes a new 

optional metric: the peak load 

coefficient of performance (‘‘COPpeak’’), 

applicable to central heat pumps 

(‘‘CHPs’’). The amendments to appendix 

M1 to align with AHRI 210/240–2024 

maintain the existing energy efficiency 

metrics, and DOE has determined that 

testing under appendix M1 would be 

consistent with the existing test 

procedure and there would be no 

impact on measured efficiencies. 

2. Metrics Applicable to Appendix M2 

The newly established appendix M2 

introduces new integrated cooling and 

integrated heating efficiency metrics, 

namely SCORE and SHORE, 

respectively. Unlike SEER2 and HSPF2, 

which are seasonal energy efficiency 

descriptors, SCORE and SHORE are 

integrated metrics that include off mode 

power, PW,OFF. Hence, appendix M2 will 

not require separate representations for 

off mode power. Appendix M2 will 

retain the full-load EER metric, with 

EER evaluated in the same way as 

appendix M1.23 Appendix M2 also 

includes the optional metric COPpeak. 

E. Near-Term Changes in the CAC/HP 

Test Procedure 

The following sections discuss issues 

that affect the CAC/HP test procedure in 

the near term—i.e., they will be required 

180 days after publication of the final 

rule. As previously explained, these 

near-term revisions are implemented at 

appendix M1 via incorporation by 

reference of the relevant industry 

consensus test procedure, AHRI 210/ 

240–2024. DOE has reviewed AHRI 210/ 

240–2024 and has concluded that it 

satisfies the EPCA requirement that test 

procedures should not be unduly 

burdensome to conduct and should be 

representative of an average use cycle. 

(42 U.S.C. 6293(b)(3)) These near-term 

amendments in appendix M1 do not 

alter the measured efficiency of CAC/ 

HPs in terms of the current cooling and 

heating test metrics, SEER2 and HSPF2, 

or the current off mode metric, PW,OFF. 

DOE clarifies that while all issues 

discussed subsequently within this 

section are near-term, they are also part 

of the long-term CAC/HP test 

procedure—i.e., these revisions are also 

included in AHRI 1600–2024, which 

DOE is incorporating by reference at 

appendix M2. As such, when discussing 

these near-term changes, DOE makes 

references to both AHRI 210/240–2024 

and AHRI 1600–2024. 

1. Controls Verification Procedure for 

Variable-Speed Systems 

Appendix M1 uses a steady-state test 

concept for variable-speed systems 

where test room conditions are kept 

within narrow operating tolerances for 

each test point, and the CAC/HP system 

is manually controlled to operate at a 

fixed specified compressor speed and 

airflow rate for each test point. As part 

of the previous rulemaking, several 

stakeholders encouraged DOE to review 

ways to improve the representativeness 

of the test procedures for CAC/HPs 

(especially variable-speed systems), 

particularly to consider test procedures 

where the unit operates under its own 

native controls in responding to 

conditioning loads (i.e., load-based 

testing).24


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throughout the test. In this type of test, any 

variable-speed or variable-position components of 

air conditioners and heat pumps are set in a fixed 

position, which is typically specified by the 

manufacturer. In contrast, a load-based test has the 

conditioning load applied to the indoor room using 

a load profile that approximates how the load varies 

for units installed in the field. In this type of test, 

an air-conditioning system or heat pump is allowed 

to automatically determine and vary its control 

settings in response to the imposed conditioning 

loads rather than relying on manufacturer-specified 

settings. 

25 In several instances of the April 2024 NOPR, 

DOE incorrectly referred to appendix L of the 

To review this topic in detail as part 

of the current rulemaking, in an RFI 

published on January 24, 2023, (the 

‘‘January 2023 RFI’’), DOE requested 

comments, information, and data 

pertaining to the consideration of loadbased testing methodologies under 

development by various organizations 

and whether certain aspects of these 

methodologies might be adopted into 

the DOE test procedure. 88 FR 4091, 

4098–4101. 

In the April 2024 NOPR, based on 

review of the stakeholder comments 

received in response to the January 2023 

RFI—specifically, that it has not yet 

been conclusively demonstrated that 

load-based testing methods have 

sufficient repeatability and 

reproducibility to be the basis of direct 

measurement of system performance— 

DOE tentatively concluded that use for 

direct measurement of performance for 

regulatory purposes would not be 

suitable at this time. 89 FR 24206, 

24220. Instead, DOE tentatively 

concluded that it would be appropriate 

to continue to allow regulatory tests to 

use fixed-speed settings for testing 

variable-speed systems, while 

developing a controls verification 

procedure (‘‘CVP’’) that could be used 

for audit, assessment, and enforcement 

testing to ensure that the fixed-speed 

settings are representative of native 

(unfixed) control, in which the control 

system may vary compressor speed and/ 

or indoor airflow. Id. 

DOE noted that AHRI and other 

relevant stakeholders, including DOE, 

participated in the development of 

revised AHRI test standards to address 

several issues raised in the January 2023 

RFI, including the representativeness of 

fixed-speed testing for variable-speed 

systems. 89 FR 24206, 24220. From 

these discussions on the revised AHRI 

test standards, consensus was 

developed on using a CVP approach. Id. 

In section III.F.1.e of the April 2024 

NOPR, DOE provided a summary of the 

CVP approach in Appendix I of AHRI 

210/240–202X Draft and AHRI 1600– 

202X Draft. 89 FR 24206, 24220–24222. 

DOE acknowledged that the CVP 

approach outlined in appendix I of the 

relevant AHRI drafts represented 

industry consensus regarding: (1) the 

verification of compliance of systems 

with the variable capacity system 

definition, and (2) verification of the 

consistency of fixed-speed settings of 

compressor and indoor fans with native 

control operation as part of 

enforcement. 89 FR 24206, 24222. DOE 

considered that the CVP approach 

presented a more representative test 

procedure for variable-speed systems 

operating in the field, because it 

provided a tool to verify that the fixed 

compressor speed settings and indoor 

air fan settings used in regulatory tests 

are representative of native control 

operation as the unit operates to 

maintain the thermostat set point, i.e., 

indoor dry-bulb temperature. Id. For 

these reasons, DOE proposed to 

incorporate by reference appendix I of 

AHRI 210/240–202X Draft to support 

enforcement associated with testing 

conducted in accordance with appendix 

M1, and to incorporate by reference 

appendix I of AHRI 1600–202X Draft to 

support enforcement associated with 

testing conducted in accordance with 

appendix M2. Id. 

In response to DOE’s proposal, several 

stakeholders, namely Lennox, the CA 

IOUs, Rheem, Daikin, GE Appliances, 

and Carrier, generally showed support 

for DOE’s proposal on implementing the 

CVP approach for certification of 

variable-speed products. (Lennox, No. 

24 at p. 2; CA IOUs, No. 32 at p. 2; 

Rheem, No. 34 at p. 5; Daikin, No. 36 

at p. 3; GE Appliances, No. 37 at p. 4; 

Carrier, No. 29 at p. 5) 

The Joint Advocates commented that 

even though it is not appropriate to 

adopt load-based testing for measuring 

the direct regulatory test performance of 

CAC/HPs due to insufficient 

information on repeatability and 

reproducibility of load-based testing 

methods, DOE should consider adopting 

them as an integral part of the test 

procedure in a future update to the 

CAC/HP test procedure. (Joint 

Advocates, No. 30 at pp. 3–4) Further, 

the Joint Advocates commented that test 

data that will better inform repeatability 

and reproducibility of load-based tests 

will be coming out in the near future. 

(Id.) The Joint Advocates expressed 

concern that since the CVP is only an 

enforcement provision, manufacturers 

are not required to conduct it while 

rating their product, and hence, 

adopting some version of load-based 

testing will ensure that all certified 

ratings are more representative of unit 

performance in the field. (Id.) 

In response to the Joint Advocates’ 

comment, DOE reiterates that it 

explored the potential of adopting a 

load-based method for direct 

measurement of performance in the 

April 2024 NOPR. However, as 

discussed in the April 2024 NOPR, the 

consensus of affected stakeholders was 

to adopt a CVP approach instead of a 

wholesale load-based method test 

procedure. 89 FR 24206, 24222. DOE is 

not aware of additional information, 

such as new load-based test data, 

available for review to assess the 

feasibility of adopting load-based testing 

as a mandatory part of the CAC/HP test 

procedure. Even though the CVP is 

primarily intended for use by DOE for 

assessment and enforcement purposes, 

it is expected that manufacturers will 

preemptively utilize the CVP to evaluate 

the fixed-speed settings used for 

certification tests of their variable-speed 

products to ensure consistency with 

native-control operation. 

AHRI 210/240–2024 and AHRI 1600– 

2024, the industry standards DOE is 

referencing in this final rule, finalized 

the relevant test method for the CVP at 

appendix I without any substantial 

change as compared to their 

corresponding drafts. Therefore, 

consistent with the April 2024 NOPR, 

DOE is incorporating by reference 

appendix I of AHRI 210/240–2024 to 

support enforcement associated with 

testing conducted in accordance with 

appendix M1, and to incorporate by 

reference appendix I of AHRI 1600– 

2024 to support enforcement associated 

with testing conducted in accordance 

with appendix M2. The enforcement 

provisions are discussed in more detail 

in section III.I.2 of this document. 

2. Low-Temperature Heating 

Performance 

In the April 2024 NOPR, DOE 

proposed to incorporate by reference 

AHRI 210/240–202X and AHRI 1600– 

202X Drafts and adopt several test 

procedure provisions that pertained to 

low-temperature heating performance. 

89 FR 24206, 24222–24225. Specifically, 

DOE proposed to (1) reference the 

definition of ‘‘cold climate heat pump’’ 

(‘‘CCHP’’) contained in the AHRI drafts, 

(2) reference the requirement for 

products certified as a CCHP to conduct 

the H4 heating test (either the H4, H4Full, 

or H4Boost heating test, as applicable), (3) 

retain the current size-for-cooling 

approach, and (4) include COPpeak as an 

optional representation for combined 

heat pump and electric resistance heat 

efficiency at 5 °F outdoor temperature 

for CHPs, as outlined in appendix K of 

AHRI 210/240–202X and AHRI 1600– 

202X Drafts,25 at appendix M1 and 

appendix M2, respectively. 


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respective AHRI 210/240–202X and AHRI 1600– 

202X Drafts as the appendices regarding COPpeak. 

(See 89 FR 24206, 24225). These were typographical 

errors, since the appendices regarding COPpeak are 

at appendix K of the respective AHRI 210/240– 

202X and AHRI 1600–202X Drafts. 

26 In several instances of the April 2024 NOPR, 

DOE incorrectly referred to appendix K of the 

respective AHRI 210/240–202X and AHRI 1600– 

202X Drafts as the appendices regarding cut-out and 

cut-in temperature verification. (See 89 FR 24206, 

24226 and 89 FR 24206, 24243). These were 

typographical errors, since the appendices 

regarding cut-out and cut-in temperature 

verification are at appendix J of the respective AHRI 

210/240–202X and AHRI 1600–202X Drafts. 

27See Samsung’s petition at www.regulations.gov/ 

docket/EERE-2023-BT-WAV-0010. 

28See Mitsubishi’s petition at 

www.regulations.gov/docket/EERE-2023-BT-WAV0015. 

29See Hisense’s petition at www.regulations.gov/ 

docket/EERE-2023-BT-WAV-0011. 

DOE did not receive any comments 

regarding the aforementioned proposals 

in the April 2024 NOPR. AHRI 210/240– 

2024 and AHRI 1600–2024, the final 

versions of the draft AHRI standards, 

finalized the same low-temperature 

heating performance provisions without 

change. Therefore, consistent with the 

April 2024 NOPR proposal, DOE is 

incorporating by reference AHRI 210/ 

240–2024 and AHRI 1600–2024 and 

adopting the low-temperature heating 

performance provisions discussed in the 

aforementioned paragraphs. 

3. Cut-Out and Cut-In Temperature 

Verification 

Appendix J of AHRI 210/240–202X 

Draft and also of AHRI 1600–202X Draft 

includes a test applicable to all CHPs to 

determine cut-out and cut-in 

temperatures (i.e., Toff and Ton

respectively).26 In the April 2024 NOPR, 

DOE proposed that during assessment 

and enforcement testing of CHPs, DOE 

may verify the cut-out and cut-in 

temperatures using the test specified in 

appendix J of AHRI 210/240–202X 

Draft, when conducting assessment and 

enforcement testing associated with 

appendix M1, and the test specified in 

appendix J of AHRI 1600–202X Draft, 

when conducting assessment and 

enforcement testing associated with 

appendix M2. The proposal indicated 

that, if conducting the appendix J cutout/cut-in verification, the tested values 

determined for these temperatures 

would be used as the Toff and Ton values 

for the unit. 89 FR 24206, 24226. 

AHRI 210/240–2024 and AHRI 1600– 

2024, the industry standards DOE is 

referencing in this final rule, finalized 

the relevant test method for determining 

cut-out and cut-in temperatures at 

appendix J without any substantial 

change as compared to their respective 

drafts. Therefore, consistent with the 

April 2024 NOPR, DOE is incorporating 

by reference appendix J of AHRI 210/ 

240–2024 and AHRI 1600–2024 at 

appendix M1 and appendix M2, 

respectively. 

As further discussed in section III.I.1 

of this document, DOE may verify 

certified cut-out and cut-in temperatures 

using the test methods in appendix J of 

the relevant AHRI drafts for the 

purposes of assessment and 

enforcement testing. 

4. Low-Static Single-Split Blower-Coil 

System Definition and Testing 

Provisions 

Section 3.1.4.1.1 of appendix M1 

defines the minimum external static 

pressure (‘‘ESP’’) for ducted blower-coil 

systems in table 4. For conventional 

blower-coil systems (i.e., all CAC/HPs 

that are not classified as ceiling-mount, 

wall-mount, mobile home, low-static, 

mid-static, small-duct high-velocity 

(‘‘SDHV’’), or space-constrained), the 

minimum ESP is specified as 0.5 inches 

of water column (‘‘in. wc.’’). The 

definition for low-static blower-coil 

systems includes only multi-split and 

multi-head mini-split systems—it does 

not include single-split systems. 

AHRI 210/240–202X Draft and AHRI 

1600–202X Draft include a new 

definition specific for low-static singlesplit blower-coil systems, as shown 

below. 

‘‘Low-static single-split blower-coil 

system’’ means a ducted single-split 

system air conditioner or heat pump for 

which all of the following apply: 

(1) The Outdoor Unit has a Specified 

cooling capacity less than or equal to 

24,000 Btu/h; 

(2) If the Outdoor Unit is a heat pump 

or a variable capacity air conditioner, it 

is separately Specified with a blowercoil indoor unit tested with a minimum 

0.5 in H2O ESP, otherwise it is 

separately Specified with a coil-only 

indoor unit; and 

(3) The Indoor Unit is marketed for 

and produces a maximum ESP less than 

0.5 in H2O when operated at the 

Specified cooling full-load airflow not 

exceeding 400 scfm per Specified ton of 

cooling. 

Both drafts also include provisions 

requiring low-static single-split blowercoil systems to be tested at their 

specified airflow (not to exceed 400 

standardized cubic feet per minute 

(‘‘scfm’’) per specified ton of cooling 

capacity) at their maximum airflow 

setting. If the ESP achieved at the 

specified airflow is less than 0.1 in. wc., 

the provisions require adjustment of the 

airflow measurement apparatus fan to 

reduce airflow and increase ESP until a 

minimum of 0.1 in. wc. is achieved. 

In the April 2024 NOPR, DOE 

proposed to incorporate by reference the 

new definition of low-static single-split 

blower-coil system and associated 

testing provisions, which would include 

single-split systems that cannot 

accommodate the 0.5 in. wc. required 

for testing single-split blower-coil 

systems in accordance with the current 

DOE test procedure in appendix M1. 89 

FR 24206, 24227. 

DOE did not receive any comments 

regarding the aforementioned proposals 

in the April 2024 NOPR. AHRI 210/240– 

2024 and AHRI 1600–2024 finalized the 

definition and testing provisions for 

low-static single-split blower-coil 

systems without substantial change as 

compared with their respective drafts. 

Therefore, consistent with the April 

2024 NOPR proposals, DOE is 

incorporating by reference AHRI 210/ 

240–2024 and AHRI 1600–2024, and 

adopting the definition and testing 

provisions for low-static single-split 

blower-coil systems. 

In advance of adopting these changes, 

multiple manufacturers, including 

Samsung HVAC America LLC 

(‘‘Samsung’’),27 Mitsubishi,28 and 

Hisense (Guangdong) Air Conditioning 

Co. Ltd. (‘‘Hisense’’),29 petitioned DOE 

for test procedure waivers pertaining to 

low-static single-split blower-coil 

systems. All petitions asserted nearly 

identical circumstances and model 

limitations—that it was impossible to 

test certain basic models according to 

appendix M1 because the models could 

not operate at the conventional 

minimum ESP requirement of 0.5 in. 

wc. found in table 4 of appendix M1. 

Subsequently, manufacturers could not 

certify compliance for or sell these 

products. 

On June 5, 2023, DOE published a 

notification of petition for waiver and 

grant of an interim waiver that permits 

Samsung to use an alternative test 

procedure for the basic models subject 

to its petition. 88 FR 36558. The 

alternative test procedure allows 

Samsung to test its basic models that are 

designed for low-static, short-duct 

applications at 0.1 in. wc. ESP and to 

make proportional adjustments to fan 

power and capacity such that the results 

are equivalent to performance measured 

at 0.5 in. wc. ESP. 88 FR 36558, 36561– 

36563. DOE initially determined that 

this alternate test procedure was 

appropriate and allowed for the accurate 

measurement of the energy efficiency of 

the specified basic models, while 

alleviating the testing problems cited in 

implementing the DOE test procedure 

for the models. Id. 

In the April 2024 NOPR, DOE noted 

that, should the new definition of lowVerDate Sep<11>2014 19:54 Jan 06, 2025 Jkt 265001 PO 00000 Frm 00011 Fmt 4701 Sfmt 4700 E:\FR\FM\07JAR2.SGM 07JAR2

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30EPA published an interim final rule on 

December 26, 2023 (‘‘EPA Technology Transition 

Interim Final Rule’’) that allows 1 additional year, 

until January 1, 2026, solely for the installation of 

new CAC/HPs using components manufactured or 

imported prior to January 1, 2025. 88 FR 88825. 

31Additional information regarding EPA’s SNAP 

Program is available online at www.epa.gov/ozone/ 

snap/. 

32A list of EPA SNAP Program-approved 

refrigerant substitutes is available at www.epa.gov/ 

snap/substitutes-residential-and-light-commercialair-conditioning-and-heat-pumps. 33ASHRAE assigns safety classification to 

refrigerants based on toxicity and flammability data. 

The capital letter designates a toxicity class based 

on allowable exposure, and the numeral denotes 

flammability. For toxicity, class A denotes 

refrigerants of lower toxicity, and class B denotes 

refrigerants of higher toxicity. For flammability, 

class 1 denotes refrigerants that do not propagate a 

flame when tested as per the standard; classes 2 and 

2L denote refrigerants of lower flammability; and 

class 3 denotes highly flammable refrigerants (such 

as hydrocarbons). 

34 DOE is aware that a refrigerant leakage 

detection system may also draw power, which 

would also be addressed in the AHRI 210/240 and 

AHRI 1600 test standards. However it is DOE’s 

understanding that the impact of this power is 

much less than operation of the fan in constant 

circulation mode. 

35UL 60335–2–40 fourth edition defines charge 

quantities m1 and m2 based on the type of 

refrigerant. 

static single-split blower-coil system 

and the associated testing provisions be 

adopted, DOE would terminate 

Samsung’s interim waiver pending final 

determination. 89 FR 24206, 24227. The 

interim waiver was granted with the 

understanding that it was impossible to 

test the manufacturer’s specific basic 

models according to the prescribed test 

procedures in appendix M1. Given that 

DOE is adopting provisions for lowstatic single-split blower-coil systems, 

DOE concludes that this alternate test 

procedure is no longer necessary. 

Therefore, DOE is terminating the 

aforementioned waiver for Samsung. 

DOE notes that the ratings for the 

subject Samsung basic models may 

change when moving to the amended 

appendix M1 test procedure outlined in 

this final rule. 

DOE has not published a notification 

of petition for waiver or granted interim 

waivers for either the Mitsubishi or 

Hisense petitions. However, for the 

same reasons that DOE is terminating 

Samsung’s aforementioned waiver, DOE 

concludes that an alternate test 

procedure is no longer necessary. DOE 

considers the petitions submitted by 

Mitsubishi and Hisense to be addressed 

sufficiently by the low-static single-split 

blower-coil system definition and 

testing provisions adopted in this final 

rule. 

5. Mandatory Constant Circulation 

Systems 

Currently, nearly all CAC/HP 

products are designed with R–410A as 

the refrigerant. However, under global 

warming potential (‘‘GWP’’) restrictions 

enacted by an Environmental Protection 

Agency (‘‘EPA’’) final rule published on 

October 24, 2023 (‘‘October 2023 EPA 

final rule’’), the use of R–410A is 

scheduled to be phased out for CAC/HP 

products.30 88 FR 73098. The EPA 

Significant New Alternatives Policy 

(‘‘SNAP’’) Program evaluates and 

regulates substitutes for ozone-depleting 

chemicals (such as CAC/HP refrigerants) 

that are being phased out under the 

stratospheric ozone protection 

provisions of the Clean Air Act. (42 

U.S.C. 7401 et seq.) 31 Of interest to 

CAC/HPs, the EPA SNAP Program’s list 

of viable substitutes 32 includes a group 

of refrigerants classified as A2L 

refrigerants. While these refrigerants 

have GWP levels meeting the 

requirements of the October 2023 EPA 

Final Rule, they face stricter safety 

requirements than R–410A due to the 

moderate flammability associated with 

their ‘‘2L’’ ASHRAE safety 

classification.33 Many of the safety 

requirements specifically address 

mitigation of ignition risk in case of 

refrigerant leakage. One mitigation 

option for refrigerant leakage is air 

circulation, which can be initiated when 

a leak is detected, or the system can use 

‘‘constant circulation,’’ running the fan, 

typically at a reduced speed, at all 

times. This latter approach has energy 

use implications, which are addressed 

in the AHRI 210/240 and AHRI 1600 

standards.34

AHRI 210/240–202X Draft and AHRI 

1600–202X Draft include a new 

definition for ‘‘mandatory constant 

circulation system’’ (‘‘MCCS’’). The 

updated industry standard drafts also 

include testing provisions for such 

systems, specifically requiring that 

CAC/HPs meeting the mandatory 

constant circulation system definition 

not use the default cooling and heating 

degradation coefficients, but rather 

evaluate these degradation coefficients 

using the respective cyclic tests 

specified by table 7 of AHRI 210/240– 

202X Draft and AHRI 1600–202X Draft, 

conducted in accordance with section 

E12 of appendix E of AHRI 210/240– 

202X Draft and AHRI 1600–202X Draft. 

In the April 2024 NOPR, DOE proposed 

to incorporate by reference the new 

definition of MCCS and the 

aforementioned testing provisions 

outlined in AHRI 210/240–202X Draft 

and AHRI 1600–202X Draft, at appendix 

M1 and appendix M2, respectively. 89 

FR 24206, 24228. 

In response to DOE’s proposal, Carrier 

expressed support for the MCCS testing 

approach, but it commented that there 

is ambiguity regarding the specific 

products to which the MCCS testing 

approach applies. (Carrier, No. 29 at pp. 

2–3) Carrier stated that for a CAC/HP 

system with a charge quantity between 

m1 and m2,35 the room size in which 

the UL 60335–2–40 4th edition 

refrigerant safety standard allows the 

system to be installed (or the effective 

volume into which refrigerant would be 

dispersed in case of leakage) is limited. 

Further, this limitation can be stricter if 

the system does not employ air 

circulation, either continuously or 

initiated by a refrigerant leak detection 

system (‘‘LDS’’). (Id.) Carrier requested 

that DOE provide further specificity on 

the testing approach for products that 

might require air circulation as 

mitigation in some installations but not 

necessarily all installations. (Id.) Carrier 

recommended that DOE require all 

systems with a charge level greater than 

m1 and less than or equal to m2 that do 

not contain an LDS be tested as an 

MCCS since how and where these 

products are installed in the field are 

outside the manufacturer’s control 

(besides a label specifying the required 

area). (Id.) 

In a rebuttal, Daikin opposed Carrier’s 

aforementioned recommendation, for 

several reasons. (Daikin, No. 40 at p. 1) 

First, Daikin commented that UL 

60335–2–40 4th edition is clear in its 

requirements for information that must 

be provided in installation instructions, 

including instructions regarding how to 

install the product in accordance with 

refrigerant safety codes, including how 

to meet the minimum floor area 

requirements. (Id.) Daikin specifically 

pointed to Annex DD of UL 60335–2–40 

4th edition, which specifies that an 

original equipment manufacturer 

(‘‘OEM’’) must include details of 

minimum installation height, minimum 

floor area, and other appropriate 

information in installation instructions 

to ensure safety requirements are met. 

(Id.) Daikin also commented that CAC/ 

HPs using A2L refrigerant, in addition 

to providing information in installation 

instructions, must have adequate 

warning labels (per Clause 7 of UL 

60335–2–40 4th edition, Annex 

101.DVF of UL 60335–2–40 4th edition, 

and EPA SNAP Rule 25), such that the 

installer will be well aware the product 

being installed needs special attention. 

(Id.) 

Second, Daikin commented that the 

minimum floor area required by 

ASHRAE 15.2 (with which UL 60335– 

2–40 requires compliance), for some 

situations, does not depend on whether 


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the system employs circulation 

(whether continuous or LDS initiated) to 

meet mitigation requirements. (Daikin, 

No. 40 at p. 2) 

Third, Daikin commented that, if a 

manufacturer chooses to use continuous 

circulation airflow as the method of leak 

mitigation, the manufacturer must 

conduct additional safety verification of 

that function, per Annex GG of UL 

60335–2–40 4th edition (specifically, 

Clause GG.2.2.2DV). (Daikin, No. 40 at 

pp. 2–3) Annex GG of UL 60335–2–40 

4th edition states that a product using 

continuous circulation shall (1) run the 

indoor fan continuously, except for 

short periods of maintenance and 

service; (2) detect or monitor 

continuously if the airflow rate drops 

below a specific level (Qmin); and (3) if 

the airflow drops below the specified 

level, provide an output signal that 

airflow is reduced and disable 

compressor operation unless the 

compressor operation reduces the leak 

rate or the total amount of refrigerant 

released to the indoor space. 

Consequently, Daikin commented that, 

if the manufacturer chooses to rely on 

continuous circulation as the mitigation 

method, the OSHA-certified Nationally 

Recognized Testing Laboratory 

(‘‘NRTL’’) that certifies the product to 

meet the safety standard UL 60335–2–40 

must check by inspection that the 

manufacturer runs the fan continuously. 

(Id.) 

Fourth, Daikin commented on the 

DOE test procedure emphasis on 

installation instructions. (Daikin, No. 40 

at p. 3) The DOE test procedure 

requirement to follow the OEM 

installation instructions when installing 

a system for testing is based on the 

premise that the installation 

instructions provide a setup 

representative of field installation. 

Thus, Daikin asserted it would be 

logical for DOE to be consistent and also 

assume that the installing contractor 

would follow requirements related to 

refrigerant safety that are laid out in 

installation instructions. (Id.) 

In response to the Carrier and Daikin 

comments, it is DOE’s understanding (as 

noted in Daikin’s comment) that use of 

constant circulation as the method of 

refrigerant leakage risk mitigation 

requires that the CAC/HP product must 

be inherently designed with this 

feature—a contractor cannot be in 

compliance with UL 60335–2–40 4th 

edition requirements if the feature is 

selected in the field for a system that 

does not inherently already have it. 

Specifically, an NRTL must certify upon 

inspection that a product using constant 

circulation for safety code compliance 

indeed runs its indoor fan continuously. 

Thus, the circumstances ‘‘outside the 

manufacturer’s control’’ involving 

installation by a contractor using 

constant circulation as the means of 

mitigation of systems without LDS and 

without MCCS that Carrier mentioned 

in its comment are violations of 

refrigerant safety codes. While such 

violations may occur in the future, DOE 

concludes that the seriousness of the 

potential consequences would make 

them infrequent, i.e., such 

circumstances could not be considered 

representative of the installation of such 

systems. Therefore, DOE determines 

that, for testing according to the DOE 

test procedure, it is not appropriate to 

require testing using constant 

circulation for products with charge 

between m1 and m2 that don’t have an 

LDS and are not inherently an MCCS. 

However, any product using constant 

circulation to comply with refrigerant 

safety codes that would meet the MCCS 

definition in AHRI 210/240–202X Draft 

and AHRI 1600–202X Draft could be 

verified to have this status by powering 

up the unit, and consequently will be 

required to test as an MCCS. 

AHRI 210/240–2024 and AHRI 1600– 

2024 finalized the definition and testing 

provisions for MCCS without 

substantial change. DOE has determined 

that the definition and approach 

included in the finalized versions 

provide a more representative measure 

of CAC/HP efficiency for systems 

utilizing mandatory constant circulation 

as a means of refrigerant leakage 

mitigation. Therefore, consistent with 

the April 2024 NOPR proposals, DOE is 

incorporating by reference AHRI 210/ 

240–2024 and AHRI 1600–2024 and 

adopting the definition and testing 

provisions for MCCS. 

Daikin noted in its comment that the 

certification aspects of the MCCS test 

procedure changes were not included in 

the April 2024 NOPR. (Daikin, No. 40 at 

p. 3) Daikin recommended that DOE 

include as mandatory certification a 

declaration from the manufacturer 

regarding whether the CAC/HP product 

relies upon mandatory continuous 

circulation or not. (Id.) Further, Daikin 

suggested that whether a product uses 

continuous circulation or not could be 

validated by operation of the product 

when it is powered up, as well as 

validated by the safety agency (i.e., 

NRTL) certification report. (Id.) 

In response to Daikin’s 

recommendation, DOE notes that it will 

consider certification requirements for 

CAC/HPs, including a requirement to 

certify whether the CAC/HP product 

relies upon mandatory constant 

circulation or not, in a separate 

rulemaking. However, DOE may 

validate whether a system utilizes 

constant circulation when powered up 

for the purposes of assessment or 

enforcement testing. 

6. Dual-Fuel Heat Pumps 

Heat pumps generally have reduced 

capacity and perform less efficiently at 

low ambient outdoor temperatures than 

they do at moderate ambient outdoor 

temperatures. Most heat pumps require 

some form of auxiliary heat when 

outdoor temperature is low to satisfy 

building load in excess of heat pump 

capacity. DOE is aware of HPs that 

combine the operation of a conventional 

electric HP with back-up heat provided 

by fuel, such as a gas fuel-fired furnace 

or boiler. These are referred to as ‘‘dualfuel’’ systems or hybrid heat pumps 

(‘‘HHPs’’) and provide an alternative to 

heat pumps specifically designed to 

perform in cold climates (i.e., cold 

climate heat pumps). Dual-fuel systems 

rely on heat pump operation at milder 

ambient temperatures, but switch to the 

back-up heating source at low ambient 

temperatures. 

The AHRI 210/240–202X Draft and 

AHRI 1600–202X Draft included a new 

definition for dual-fuel heat pump 

systems. Additionally, the two AHRI 

drafts introduced a new seasonal 

efficiency metric, Dual Fuel Utilization 

Efficiency (‘‘DFUE’’), meant to capture 

the heating efficiency of such dual-fuel 

heat pump systems. Calculation of 

DFUE according to the draft standards is 

optional, requires no additional testing, 

and is outlined in appendix L of both 

standards. 

In the April 2024 NOPR, DOE 

tentatively determined that while the 

definition and optional test approach 

included in the draft industry standards 

may provide a representative test 

approach for dual-fuel heat pump 

systems, DOE was at that time 

continuing to evaluate whether to 

include such provisions in its CAC/HP 

test procedures. 89 FR 24206, 24229. 

Therefore, DOE proposed to not 

incorporate by reference the new 

definition of dual-fuel heat pump and 

the optional seasonal efficiency metric, 

DFUE, outlined in the AHRI 210/240– 

202X and AHRI 1600–202X Drafts. Id. 

AHRI 210/240–2024 and AHRI 1600– 

2024 finalized the definition and 

optional seasonal efficiency metric, 

DFUE, for dual-fuel heat pump without 

substantial change. Based on DOE’s 

continued evaluation of the dual-fuel 

provisions in the two AHRI drafts, DOE 

has concluded that such provisions are 

not necessary in the CAC/HP test 

procedures. Therefore, DOE is not 

incorporating by reference the new 

definition of dual-fuel heat pump and 


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the optional seasonal efficiency metric, 

DFUE, outlined in the AHRI 210/240– 

2024 and AHRI 1600–2024. However, 

DOE recognizes that representations of 

dual-fuel heat pump performance may 

be useful to consumers. Therefore, 

while DOE is not proposing provisions 

for dual-fuel heat pumps, DOE would 

allow manufacturers to make optional 

representations of dual-fuel heat pump 

performance consistent with available 

AHRI industry test standards. 

DOE notes that since dual-fuel heat 

pump systems are comprised of two 

covered products currently subject to 

energy conservations standards (i.e., a 

heat pump and a furnace), DOE would 

continue to require reporting of the 

relevant CAC/HP and consumer furnace 

heating metrics—EER2, SEER2, HSPF2, 

EER, SCORE and SHORE for CAC/HP, 

and AFUE for consumer furnaces; 

regardless of whether a manufacturer 

chooses to rate their dual-fuel heat 

pumps with the DFUE metric. DOE also 

notes that the current representation 

requirements at 10 CFR 429.16 require 

representation of every individual heat 

pump combination distributed in 

commerce. As such, installing an 

outdoor HP unit and an indoor coil with 

an existing furnace (or other air mover) 

that is not being replaced would 

constitute distribution in commerce of a 

coil-only heat pump combination for 

which DOE requires a coil-only 

representation. 

7. Rating Individual Components of 

Split Systems 

(a) Background 

DOE’s test procedure in appendix M1 

and its rating and certification 

requirements for central air conditioners 

and heat pumps in 10 CFR 429.16 have 

provisions that apply based on the 

configurations in which these products 

are distributed in commerce. This 

includes provisions for outdoor units of 

a split system that are not distributed in 

commerce with any indoor units, which 

DOE’s regulations refer to as an outdoor 

unit with no match (‘‘OUWNM’’). 

Specifically, 10 CFR 429.16(b)(2) 

requires that the ratings for basic models 

of split-system central air conditioners 

or heat pumps distributed in commerce 

as an OUWNM be based on the testing 

of a model of coil-only indoor unit 

meeting the requirements of section 2.2e 

of appendix M1. Section 2.2.e of 

appendix M1 requires that an OUWNM 

be tested using a coil-only indoor unit 

with a single cooling air volume rate 

whose coil has round tubes of outer 

diameter no less than 0.375 inches, and 

normalized gross indoor fin surface 

(‘‘NGIFS,’’ gross indoor fin surface 

divided by the measured cooling 

capacity) no greater than 1.0 square inch 

per British thermal unit per hour (sq in/ 

Btu/hr). (10 CFR 429.16 (b)(2)(i) and 

appendix M1, section 2.2.e) These 

provisions were introduced in a final 

rule regarding CAC/HP test procedures 

published on June 8, 2016 (‘‘June 2016 

Final Rule’’), to address outdoor-unitonly replacements of old R–22 outdoor 

units. 81 FR 36992, 37008–37012. 

Effective January 1, 2010, EPA banned 

sales and distribution of CAC/HPs 

designed to use R–22, a 

hydrochlorofluorocarbon (‘‘HCFC’’) 

refrigerant that causes ozone depletion. 

74 FR 66450 (Dec. 15, 2009). However, 

EPA continued to allow sale and 

distribution of ‘‘components’’ of CAC/ 

HP systems for repair purposes, such as 

outdoor units. Id. at 74 FR 66452. In the 

June 2016 Final Rule, DOE introduced 

the testing provisions for OUWNMs to 

ensure that performance ratings for such 

installations would be representative of 

the replacement of outdoor units 

originally designed for R–22 and using 

the original indoor units. See 81 FR 

36992, 37008–37011. 

In a final rule published on October 

24, 2023 (‘‘October 2023 EPA final 

rule’’), pursuant to provisions of the 

American Innovation and 

Manufacturing Act (‘‘AIM Act’’), 

enacted on December 17, 2020 (42 

U.S.C. 7675), EPA restricted the 

installation of residential and light 

commercial systems that are designed 

for hydrofluorocarbon (‘‘HFC’’) 

refrigerants having a GWP greater than 

700, starting January 1, 2025. 88 FR 

73098. On December 26, 2023, EPA 

published an amendment to the October 

2023 EPA Final Rule that extended the 

installation deadline to January 1, 2026, 

as long as the ‘‘specified components’’ 

being installed were manufactured or 

imported prior to January 1, 2025 

(‘‘December 2023 EPA interim final 

rule’’). 88 FR 88825. 

Split-system CAC/HPs are included in 

the scope of residential and light 

commercial systems As such, new splitsystem CAC/HPs designed for use with 

R–410A and sold as a combination of an 

outdoor and indoor unit would be 

banned for installation, per the October 

2023 EPA Final Rule. However, EPA 

provides an exemption, permitting the 

sales of specified components, to allow 

consumers to service and repair existing 

systems that are over the GWP limits 

defined in the October 2023 EPA Final 

Rule, provided the specified 

components are used only to service 

existing systems and are subject to 

labeling and reporting requirements. 88 

FR 73098, 73124–73125. This provides 

an exemption for individual specified 

components of R–410A based splitsystem CAC/HPs to be sold as 

replacements, including condensing 

units and evaporator units, similar to 

the component exemption adopted by 

the EPA when R–22 was phased out. 74 

FR 66450, 66459–66460. 

(b) NOPR Proposal 

In the April 2024 NOPR, DOE noted 

that while the current OUWNM 

provisions were precipitated by EPA’s 

ruling on R–22 units, DOE’s intention 

was to apply them more broadly to any 

case where an outdoor unit is sold 

without an indoor unit. 89 FR 24206, 

24230. DOE noted that the current 

OUWNM provisions apply for any 

outdoor units that are distributed in 

commerce without an indoor matching 

pair, regardless of the refrigerant the 

outdoor unit employs. Id. DOE clarified 

that per the October 2023 EPA Final 

Rule, any outdoor unit designed for R– 

410A or any banned refrigerant as per 

EPA regulations, when distributed in 

commerce without an indoor unit on or 

after January 1, 2026, would be deemed 

an outdoor unit with no match. Id. DOE 

further noted that, similar to EPA 

requirements for the R–22 ban, EPA is 

allowing such an outdoor unit to be 

installed as a replacement specified 

component for an existing system but 

not to be installed with indoor units for 

installation as a complete split CAC/HP 

system. Id. 

DOE noted that appendix M1 

currently does not explicitly define 

outdoor units with no match and that 

while AHRI 210/240–202X Draft and 

AHRI 1600–202X Draft define outdoor 

units with no match, the definition 

applies explicitly only to R–22 

replacement outdoor units and outdoor 

units using refrigerants with properties 

similar to R–22. Id. Because the 

definition of outdoor unit with no 

match in AHRI 210/240–202X Draft and 

AHRI 1600–202X Draft is specifically 

focused on R–22 outdoor units, DOE 

proposed not to incorporate the 

definition by reference, and instead 

proposed a clarifying definition that is 

consistent with DOE’s intention in the 

June 2016 Final Rule. Id. 

DOE proposed the following 

definition for OUWNM in the April 

2024 NOPR for appendix M1: 

Outdoor Unit with No Match 

(OUWNM). An Outdoor Unit that is not 

distributed in commerce with any 

indoor units, and that meets any of the 

following criteria: 

(a) Is designed for use with a 

refrigerant that makes the unit banned 

for installation when paired with an 

Indoor Unit as a system, according to 

EPA regulations, 


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(b) Is designed for use with a 

refrigerant that has a 95 °F midpoint 

saturation absolute pressure that is ± 18 

percent of the 95 °F saturation absolute 

pressure for R–22, or 

(c) Is shipped without a specified 

refrigerant from the point of 

manufacture or is shipped such that 

more than 2 pounds of refrigerant are 

required to meet the charge per section 

5.1.8 of AHRI 210/240–202X Draft. This 

shall not apply if either (a) the factory 

charge is equal to or greater than 70 

percent of the outdoor unit internal 

volume times the liquid density of 

refrigerant at 95 °F, or (b) an A2L 

refrigerant is approved for use and listed 

in the certification report. 

DOE noted that the proposed 

definition of OUWNM for appendix M2 

is the same as that for appendix M1, 

except that the reference in part (c) of 

the definition is to section 5.1.8 of AHRI 

1600–202X Draft. Id. 

DOE tentatively concluded that the 

proposed definition would further help 

clarify that the existing test procedure 

and rating requirements for outdoor 

units with no match are applicable to R– 

410A-based systems and any other 

refrigerants banned by EPA regulations 

from January 1, 2026, as they have been 

previously, for R–22 and any other 

ozone-depleting refrigerants. Id. As 

proposed, the definition would apply to 

all types of outdoor units (i.e., heat 

pump, air conditioner, single-speed, 

two-speed, variable-speed, etc.) and 

outdoor units with no match would 

continue to be tested with an indoor coil 

having a nominal tube diameter of 0.375 

in and an NGIFS of 1.0 or less (as 

determined in section 5.1.6.3 of AHRI 

210/240–202X Draft and AHRI 1600– 

202X Draft). Id. DOE clarified that the 

determination of represented values, 

alternative efficiency determination 

method (‘‘AEDM’’) requirements, 

combinations selected for testing, and 

certification report requirements 

applicable to outdoor units with no 

match would remain the same as those 

specified in table 1 to paragraph (a)(1), 

paragraph (c)(2), table 2 to paragraph 

(b)(2)(i), and paragraph (e)(3), 

respectively, in 10 CFR 429.16. Id. DOE 

noted that existing outdoor models 

currently distributed in commerce as 

part of a split-system basic model that 

transition to a replacement outdoor unit 

only would need to be tested, rated, and 

recertified under the provisions in 10 

CFR 429.16 for an outdoor unit with no 

match. Id. DOE noted that the basic 

model number would need to change to 

reflect that the outdoor unit is no longer 

part of a combination as previously 

certified, but rather as an outdoor unit 

with no match; however, the outdoor 

unit model could still be assigned the 

same individual model number. Id. 

(c) Interaction With EPA Regulations 

In response to its April 2024 NOPR, 

DOE received comments from 

stakeholders on a variety of issues 

related to compliance with DOE’s 

regulations in the context of the October 

2023 EPA Final Rule. These specific 

comments are addressed in the next 

section, but to ensure clarity this section 

first summarizes the key elements of 

compliance with DOE testing, rating, 

and certification requirements for these 

products during the period of 

implementation of the EPA rules. 

As specified in the October 2023 EPA 

Final Rule, and modified in the 

December 2023 EPA interim final rule, 

installation of central air conditioner 

and heat pump systems manufactured 

or imported on or after January 1, 2025, 

that use a refrigerant with a GWP higher 

than 700 would be prohibited from 

being installed beginning on January 1, 

2025. A system comprised of ‘‘specified 

components’’ manufactured or imported 

prior to January 1, 2025, can still be 

installed until January 1, 2026. The 

EPA’s rule permits the continued 

manufacture, distribution, and 

installation of individual specified 

components that use higher GWP 

refrigerants on or after January 1, 2026, 

only as replacements for components in 

existing systems provided they are 

labeled for this use as specified in the 

EPA rule. 

The DOE definition of the term 

‘‘central air conditioner or central air 

conditioning heat pump’’ in 10 CFR 

430.2 specifies that a central air 

conditioner or central air conditioning 

heat pump may consist of: A singlepackage unit; an outdoor unit and one 

or more indoor units; an indoor unit 

only; or an outdoor unit with no match. 

Further, the DOE definition specifies 

that in the case of an indoor unit only 

or an outdoor unit with no match, the 

unit must be tested and rated as a 

system (combination of both an indoor 

and an outdoor unit). In addition, DOE’s 

requirements in 10 CFR 429.16(a) 

specify required representations based 

on how the model is distributed in 

commerce (i.e., as part of a matched 

system, as an indoor unit only, or as an 

outdoor unit with no match). 

DOE’s rules for testing and rating 

covered products to establish 

compliance with energy conservation 

standards apply to basic models as 

distributed in commerce by the 

manufacturer (or importer). Although 

the deadlines for installation of 

specified components under EPA’s rule 

apply to certain products based on their 

date of manufacture or import (i.e., 

depending on whether they were 

manufactured prior to January 1, 2025), 

DOE’s rules for how the manufacturer 

must test, rate, and certify their 

products apply based on the date of 

manufacture (or importation) and on 

how each basic model is distributed in 

commerce (i.e., as part of a matched 

system or as an OUWNM), with the 

purpose being to ensure that each basic 

model complies with the energy 

conservation standard that applies to 

that basic model. A manufacturer or 

importer is not required to retest and/or 

recertify a basic model unless the 

manufacturer either makes a change to 

that basic model that would make it a 

new basic model under DOE’s definition 

of that term in 10 CFR 430.2 or makes 

a change to the configuration in which 

it is being distributed in commerce such 

that a different tested combination 

requirement applies to it under 10 CFR 

429.16. Stated within the context of the 

EPA’s rule, a basic model of condensing 

unit that previously had been rated and 

certified to DOE in one or more 

combinations would not have to be retested and rated under the OUWNM 

provisions until such a time as the 

manufacturer ceases distribution of that 

basic model as part of a matched pair 

and begins distributing it as an 

OUWNM. At that point, the 

manufacturer must test, rate, and certify 

that condensing unit under the 

OUWNM as a new basic model, as 

under the basic model definition in 10 

CFR 430.2 the model as an OUWNM 

cannot be the same basic model as it 

would have been in a combination. 

For R–410A (or other refrigerant with 

GWP above 700) outdoor units 

manufactured (or imported) prior to 

January 1, 2025, which under the EPA’s 

rule can still be installed as a system 

until January 1, 2026, the certifications 

of those models based on their tested 

combinations remain valid under DOE 

regulations as long as manufacturers 

continue to distribute them in 

commerce as a system. However, if at 

some point the manufacturer chooses to 

distribute in commerce the unit alone 

and not as a combination with any 

indoor units (either before January 1, 

2026 or after that date as a service-only 

replacement component to comply with 

EPA’s rule), the outdoor unit would 

have to be tested, rated, and certified in 

accordance with the OUWNM 

provisions. This also applies for R–410A 

(or other refrigerant with GWP above 

700) outdoor units manufactured or 

imported on or after January 1, 2025, as 

DOE expects that manufacturers would 

cease distribution of the outdoor units 


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as part of a combination, as these 

systems could no longer be installed 

anywhere in the U.S. This certification 

as a new basic model must be made 

prior to the date at which the 

manufacturer begins distributing those 

outdoor units as an OUWMN and would 

be indicated to DOE in its certification 

reports via a discontinued model filing 

for the model as distributed in a 

combination and certification as a new 

basic model of OUWNM. 

For an indoor unit intended only for 

replacement in an existing system and 

which is no longer distributed in 

commerce for installation as a 

combination, as would be the case for 

an existing system that uses a refrigerant 

banned by EPA, the requirement in 10 

CFR 430.2 and table 1 of 10 CFR 

429.16(a) for the indoor unit to be rated 

as part of a system would still apply 

even though the indoor unit is no longer 

being distributed in commerce as part of 

a combination. This rating requirement 

would apply regardless of whether the 

manufacturer of the indoor unit is an 

ICM. If the indoor unit uses a refrigerant 

allowed by EPA only for component 

replacement (e.g., R–410A), the rating 

for such a unit would be based on a 

combination using that refrigerant, and 

per EPA regulations could not be 

distributed in commerce as a 

combination. However, this does not 

imply that the indoor unit cannot be 

rated, nor that the entire system would 

have to be replaced. DOE notes further 

that any such rating for the indoor unit 

must be compliant with current 

standards, and that any indoor units 

distributed in commerce for use in a 

system that uses a refrigerant subject to 

the EPA ban would need to have been 

certified to DOE as compliant with the 

applicable standards as part of a 

combination before January 1, 2025 and 

must have been tested and rated in 

every combination with an outdoor unit 

with which it has been previously 

distributed in commerce. 

(d) Comments Received 

In their response to the NOPR, the 

Joint Advocates and Lennox fully 

supported the proposed provisions for 

OUWNMs. The Joint Advocates agreed 

that DOE’s clarifying definition for 

OUWNM will help ensure 

representative ratings and that the 

proposed definition is consistent with 

DOE’s intent in the June 2016 Final 

Rule. (Joint Advocates, No. 30 at p. 3) 

Lennox strongly supported the DOE 

proposal that any outdoor unit designed 

for R–410A or any banned refrigerant as 

per EPA regulations, when distributed 

in commerce without an indoor unit on 

or after January 1, 2026, would be 

deemed an outdoor unit with no match. 

(Lennox, No. 24 at p. 2). 

Several commenters requested more 

clarity or expressed concerns on DOE’s 

OUWNM provisions. These are 

discussed in the following subsections. 

(1) OUWNM Definition 

An Outdoor Unit that is not 

distributed in commerce by the 

manufacturer with any indoor units, 

and that meets any of the following 

criteria: 

(a) is designed for use with a 

refrigerant that makes the unit banned 

for installation when paired with a new 

Indoor Unit as a system, according to 

EPA regulations in 40 CFR chapter I, 

subchapter C, 

[provisions (b) and (c) unchanged] 

Rheem requested that DOE consider 

simplifying the proposed definition for 

OUWNMs because some of the bullet 

points may overlap or conflict with each 

other. (Rheem, No. 34 at p. 3) Rheem 

noted that in SNAP Final Rule 237, EPA 

has approved R–32, R–452B, R–454A, 

R–454B, R–454C, and R–457A for use in 

residential and light commercial airconditioning and heat pump end use, 

which also includes CAC/HPs. (Id.) 

Rheem commented that among these 

substitutes, R–454C and R–457A have a 

95 °F midpoint saturation absolute 

pressure within 18 percent of the 95 °F 

saturation absolute pressure for R–22, 

thus meeting the provisions in 4.1(b) 

and 3.1(b) of the proposed OUWNM 

definition at appendix M1 and appendix 

M2, respectively. (Id.) Rheem suggested 

that DOE simplify the definition of 

OUWNM to avoid confusion. (Id.) 

DOE appreciates that AHRI is taking 

steps to update AHRI 210/240–2024 and 

AHRI 1600–2024 standards to broaden 

the OUWNM provisions beyond R–22 

outdoor units and make them applicable 

to any outdoor units that are distributed 

in commerce without an indoor 

matching pair, regardless of the 

refrigerant the outdoor unit employs. 

Such an implementation would be 

consistent with DOE’s proposed 

definition of OUWNMs in the April 


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AHRI commented that while the definition of"OUWNM" in AHRI 210/240-2024 

and AHRI 1600-2024 is specifically focused on R-22 outdoor units, in line with the 

current regulations in the DOE test procedure, AHRI is taking steps to update the 

standards to ensure that OUWNM provisions are applicable to any outdoor units that are 

distributed in commerce without an indoor matching pair, regardless of the refrigerant the 

outdoor unit employs. (AHRI, No. 25 at p. 4) AHRI noted that it intends to expedite 

revisions to AHRI 210/240-2024 and AHRI 1600-2024 to reflect OUWNM definitions 

adopted in the final rule. (Id.) AHRI suggested modification to part of the proposed 

definition of OUWNMs (proposed additions italics and deletions in strikeout) as follows: 
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1239 

36For Appendix M2, the definition references 

section 5.1.8 of AHRI 1600–2024. 

2024 NOPR. DOE disagrees with the 

addition of ‘‘by the manufacturer’’ in the 

OUWNM definition to qualify 

distribution in commerce, since under 

EPCA the term ‘‘distribution in 

commerce’’ also applies to subsequent 

distribution after the initial offering by 

the manufacturer. The proposed 

addition would undercut the general 

applicability of that term across the 

distribution chain as established in 

EPCA. As explained in DOE’s March 7, 

2011, final rule that established the 

certification provisions in Part 429, 

application of the term ‘‘distribution in 

commerce’’ would depend on a 

particular manufacturer’s production 

practices, business decisions, and the 

facts and circumstances of a particular 

case. 76 FR 12422, 12426. . However, 

DOE agrees with the inclusion of the 

term ‘‘new’’ to clarify that the EPA ban 

specifically pertains to new system 

installations, and for further 

clarification is including the term 

‘‘new’’ to describe both the indoor unit 

with which the outdoor unit is paired 

and the newly created system. In 

addition, notwithstanding the broad 

applicability of the term ‘‘distribute in 

commerce,’’ DOE notes that under 10 

CFR 429.102(a)(6) it is a prohibited act 

for a manufacturer or private labeler to 

distribute in commerce any new 

covered product or covered equipment 

that is not in compliance with an 

applicable energy conservation standard 

prescribed under the Act, and therefore 

the obligation to certify that basic 

models are in compliance with the 

standards lies with the manufacturer 

and importer. This is also the basis for 

the requirement in 10 CFR 429.12(a) 

that each manufacturer, before 

distributing in commerce any basic 

model of a covered product or covered 

equipment subject to an applicable 

energy conservation standard, certify 

that the model meets the applicable 

energy conservation standard. 

DOE agrees with Rheem that certain 

SNAP-approved refrigerants, for 

example R–454C and R–457A, have 

pressure-temperature relationship 

characteristics similar to R–22 and 

would meet provision (b) of the 

proposed OUWNM definition. DOE 

notes that both these refrigerants have 

GWPs equal to or less than 150, and 

thus could potentially be under 

consideration for future reductions in 

GWP as compared with refrigerants R– 

454B and R–32, the primary near-term 

candidates for transition from R–410A. 

To ensure that these SNAP-approved 

refrigerants would not be subject to 

provision (b) of the proposed OUWNM 

definition, DOE is qualifying provision 

(b) with a GWP limit—specifically, only 

refrigerants with GWP greater than 150 

(per EPA’s measure) would be subject to 

provision (b). 

In summary, DOE is making minor 

modifications to the OUWNM definition 

as follows: 

An Outdoor Unit that is not 

distributed in commerce with any 

indoor units, and that meets any of the 

following criteria: 

(a) Is designed for use with a 

refrigerant that makes the unit banned 

for installation when paired with a new 

Indoor Unit as a system, according to 

EPA regulations in 40 CFR chapter I, 

subchapter C; 

(b) Is designed for use with a 

refrigerant that has a 95 °F midpoint 

saturation absolute pressure that is ±18 

percent of the 95 °F saturation absolute 

pressure for R–22 and a global warming 

potential greater than 150 per EPA 

regulations in 40 CFR 84.64; or 

(c) Is shipped without a specified 

refrigerant from the point of 

manufacture or is shipped such that 

more than 2 pounds of refrigerant are 

required to meet the charge per section 

5.1.8 of AHRI 210/240–2024.36 This 

shall not apply if either (a) the factory 

charge is equal to or greater than 70 

percent of the outdoor unit internal 

volume times the liquid density of 

refrigerant at 95 °F, or (b) an A2L 

refrigerant is approved for use and listed 

in the certification report. 

(2) Clarity on Interaction With EPA Rule 

AHRI and Carrier requested further 

clarity on how DOE’s OUWNM 

provisions will interface with the 

October 2023 EPA final rule, 

particularly in terms of timing and 

scope. (AHRI, No. 25 at pp. 2–4; Carrier, 

No. 29 at p. 3) 

AHRI appreciated DOE’s proposal to 

expand the OUWNM definition to 

include HFC refrigerants having a GWP 

greater than 700, in line with EPA’s ban, 

but noted that the interaction between 

the EPA and DOE regulations are 

complex and implementation questions 

remain. (AHRI, No. 25 at p. 2) AHRI 

cautioned that care must be taken to 

ensure industry and downstream 

distribution partners understand and 

can remain compliant with applicable 

regulations and that consumers who 

recently installed products with R–410A 

refrigerant have meaningful access to 

service parts for the useful life of their 

equipment. (Id.) AHRI noted that while 

no date has been included with the 

DOE-proposed OUWNM definition, the 

NOPR preamble presents the proposed 

date of 2026. (AHRI, No. 25 at p. 3) 

AHRI sought clarification that OUWNM 

ratings would only be required for splitsystem outdoor units using HFC 

refrigerants having a GWP greater than 

700 manufactured after January 1, 2025. 

(Id.) AHRI attached a spreadsheet 

(Exhibit 1) that contained requests for 

clarification from DOE on questions 

regarding the prohibitions for 

manufacture, distribution, and 

installation of various product types. 

(AHRI, No. 25 at pp. 5–6). Specifically, 

AHRI requested clarification on whether 

DOE’s proposal applies to split-system 

CAC/HP products imported into the 

United States, but which are not for sale 

in the United States. (Id.) 

Carrier appreciated DOE’s intent to 

further clarify the OUWNM 

requirements and noted that it is clear 

that the OUWNM category is the 

equivalent of EPA’s service-only 

condenser allowance in the market. 

(Carrier, No. 29 at p. 3) Carrier 

commented that it supports DOE stating 

the application of OUWNM 

requirements to a service-only R–410A 

condensing unit, but requested that DOE 

provide additional clarity in the final 

rule on certain aspects, including 

effective date, which unit types 

OUWNM applies to, and the indoor 

airflow requirements. (Id.) In particular, 

Carrier requested that DOE make the 

following clarifications to better help 

the regulated community in complying 

with applicable efficiency and 

refrigerant regulations: (1) R–410A 

condensing units manufactured or 

imported on or after January 1, 2025 

would need to be tested and rated as an 

OUWNM because EPA prohibits the 

installation of those outdoor units with 

a new indoor unit; (2) any R–410A 

outdoor and indoor units manufactured 

before January 1, 2025 could be sold and 

installed utilizing the existing DOEcertified system rating, because EPA is 

allowing installation; (3) since EPA 

prohibits the sale and installation of any 

R–410A outdoor and indoor units in 

2026 regardless of production date, any 

remaining pre-2025 inventory held by a 

manufacturer would be required to be 

recertified using the OUWNM 

procedure when distributed in 

commerce on or after January 1, 2026; 

and (4) any pre-2025 R–410A air 

conditioners in the Southeast or 

Southwest regions could not be 

installed without being recertified as an 

OUWNM. (Carrier, No. 29 at p. 3) 

In response to AHRI, DOE clarifies 

that OUWNM ratings for split-system 

outdoor units employing refrigerants 

with GWP greater than 700 would be 

required for units distributed in 

commerce as service-only placement 


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37 42 U.S.C. 6295(o)(6)(E). 

components (i.e., not as a combination) 

from the point of manufacture and thus 

subject to DOE’s testing and rating 

requirements for outdoor units with no 

match in Appendix M1 and 10 CFR 

429.16. As discussed in the previous 

section of this notice, DOE expects that 

manufacturers would need to make this 

transition for units manufactured after 

January 1, 2025, which it intends to 

make available as service-only 

replacement components for existing 

systems. Regarding units that are 

imported into the United States but not 

distributed and sold for installation 

within the United States, DOE notes that 

its requirements specified in 10 CFR 

parts 429, 430, and 431 shall not apply 

to any covered product or covered 

equipment if: (a) such covered product 

or covered equipment is manufactured, 

sold, or held for sale for export from the 

United States or is imported for export; 

(b) such covered product or covered 

equipment or any container in which it 

is enclosed, when distributed in 

commerce, bears a stamp or label stating 

‘‘NOT FOR SALE FOR USE IN THE 

UNITED STATES’’; and (c) such 

product is, in fact, not distributed in 

commerce for use in the United States. 

10 CFR 429.6. 

DOE notes that the additional detail 

provided in the preceding section of this 

notice, and in the preceding paragraphs, 

is largely consistent with Carrier’s 

suggestions. However, DOE wishes to 

correct two of Carrier’s clarifications: (1) 

the recertification of remaining pre-2025 

inventory would not be required 

provided those basic models were 

correctly certified based on how they 

were distributed at the time of their 

manufacture; and (2) the applicability of 

these provisions for units to be installed 

in the Southeast or Southwest do not 

differ from products subject to 

nationwide standards. The only 

difference for installation in the 

Southeast or Southwest is that the 

regional energy conservation standards 

would apply for such installations, as 

would otherwise be the case per 10 CFR 

430.32(c)(6), and the efficiency rating as 

certified by the manufacturer must 

indicate those basic models comply 

with the applicable regional standards 

and may be installed in the Southeast 

and/or Southwest regions. 

(3) Recertification of Units Already 

Distributed in Commerce 

Several commenters expressed 

concern with the recertification as 

OUWNMs of units already distributed 

in commerce, when installed after 

January 1, 2026. 

AHRI sought clarification on the 

intended meaning of the phrase 

‘‘distributed in commerce.’’ (AHRI, No. 

25 at p. 3) AHRI noted that the current 

DOE regulation places no restrictions on 

distribution of products if the product 

was initially certified and regional 

standards are not an issue for the 

product and location. (AHRI, No. 25 at 

p. 6) AHRI noted that DOE’s NOPR 

proposal requires existing outdoor 

models currently distributed in 

commerce as part of a split-system basic 

model that transition to a replacement 

outdoor unit only to be tested, rated, 

and recertified under the provisions in 

10 CFR 429.16 for an outdoor unit with 

no match. (Id.) AHRI noted that per 

EPCA, ‘‘distribution in commerce’’ 

means ‘‘to sell in commerce, to import, 

to introduce or deliver for introduction 

into commerce, or to hold for sale or 

distribution after introduction into 

commerce,’’ and that ‘‘distribution in 

commerce’’ applies to both the initial 

offering for sale by the manufacturer 

and the subsequent distribution by 

downstream partners (i.e., sale by the 

distributor to the contractor, or the 

contractor to the homeowner). (Id.) 

AHRI cautioned that without linking the 

requirements to a manufacture/import 

date, DOE’s proposal complicates the 

distribution of outdoor units 

manufactured pre-2025 that are no 

longer in possession of the manufacturer 

or private labeler. (Id.) AHRI questioned 

how DOE will enforce the proposal on 

products subject to national energy 

efficiency standards. (Id.) 

AHRI contended that for products 

subject to national standards, DOE is 

constrained by the application of the 

base national standard, which ‘‘applies 

to all products manufactured or 

imported into the United States on and 

after the effective date of the 

standard.’’ 37 (AHRI, No. 25 at p. 6) 

Therefore, AHRI asserted that spaceconstrained products; small-duct highvelocity, air conditioners in the North; 

and heat pumps manufactured or 

imported prior to January 1, 2025 that 

were certified as compliant with the 

base national standard can still be 

installed in the United States until the 

inventory is depleted. (Id.) AHRI 

questioned how DOE could require 

manufacturers, distributors, or 

contractors to retroactively apply 

testing, rating, or certification 

requirements on outdoor units subject to 

national standards that were distributed 

in commerce and are no longer in the 

manufacturer’s possession. (AHRI, No. 

25 at pp. 6–7) AHRI requested for DOE 

to link the OUWNM definition to a 

manufacture/import date, as DOE’s 

proposal complicates the distribution of 

outdoor units manufactured prior to 

January 1, 2025 that are no longer in 

possession of the manufacturer (or 

private labeler). (AHRI, No. 25 at p. 7) 

Similarly, for products subject to 

regional standards, AHRI questioned 

how DOE could require manufacturers, 

distributors, or contractors to 

retroactively apply testing, rating, or 

certification for outdoor units 

manufactured/imported in 2024 and no 

longer in possession of the 

manufacturer. (Id.) AHRI requested 

clarification on whether DOE intended 

that air conditioners slated for the 

Southeast and Southwest regions, 

manufactured/imported in 2024, and 

still in possession of the manufacturer 

be recertified as OUWNMs on January 1, 

2025. (Id.) 

AHRI noted that while the NOPR 

preamble states that ‘‘the basic model 

number would need to change to reflect 

that the outdoor unit is no longer part 

of a combination as previously certified, 

but rather as an outdoor unit with no 

match, but the outdoor unit model 

could still be assigned the same 

individual model number,’’ DOE has not 

described in the proposed regulatory 

text how the testing, rating, and 

recertification for outdoor units 

distributed in commerce by outdoor 

unit manufacturers (‘‘OUMs’’) for a 

former certified combination that 

transitions to OUWNMs for replacement 

will be completed. (AHRI, No. 25 at p. 

6) AHRI expressed concern that this 

may create logistical complications, 

given that ‘‘distributed in commerce’’ 

applies to both the initial sale and the 

subsequent sale of products that have 

already entered commerce and are no 

longer in the possession of the 

manufacturer to be recertified. (Id.) 

AHRI contended that certification of a 

condensing unit as an OUWNM should 

apply to products manufactured after 

January 1, 2025. (Id.) 

HARDI strongly opposed any 

restriction on the ability of its members 

to sell products already in inventory, 

including install date regulations, such 

as EPA’s transitions program and the 

statutorily required install date in DOE’s 

regional standards for split-system 

central air conditioners. (HARDI, No. 26 

at pp. 1–2) HARDI commented that it 

believed install date requirements 

hinder the ability of the heating, 

ventilation, air-conditioning, and 

refrigeration industry to move to more 

energy-efficient or environmentally 

friendly products and that install date 

regulations that cause dead inventory 

are ineffective because they create 

waste, increase costs, and constitute a 


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38HARDI notes that a regulatory taking is a 

‘‘taking of property under the Fifth Amendment by 

way of regulation that seriously restricts a property 

owner’s rights,’’ Blacks Law Dictionary, 11th 

Edition. (HARDI, No. 26 at p. 1). 

regulatory taking.38 (Id.) HARDI 

commented that it was its 

understanding that the phrase 

‘‘currently distributed in commerce’’ 

does not intend to include CAC/HP 

equipment already in distributors’ 

warehouses, but it asserted that, just like 

with the confusing compliance regime 

caused by the install date associated 

with regional standards for split-system 

central air conditioners, if this phrase is 

used in the final regulation, local 

compliance officials will prevent repairs 

to existing systems if the outdoor unit 

does not have proof of meeting the 

minimum efficiency standard. (HARDI, 

No. 26 at p. 2) HARDI suggested that the 

best course of action is to apply the 

OUWNM testing and certification 

requirements at the same date of 

manufacture timeline as the EPA 

requirement for outdoor condensing 

units to be marked ‘‘For servicing 

existing equipment only.’’ (Id.) HARDI 

noted that for split-system CAC/HPs, 

EPA requires anything manufactured 

after January 1, 2025 to be marked ‘‘For 

servicing existing equipment only.’’ (Id.) 

HARDI further noted that while new 

split-system CAC/HPs can be installed 

until January 1, 2026 using R–410A or 

other high-GWP refrigerants, EPA 

requires those systems to be 

manufactured before January 1, 2025, 

and outdoor units manufactured after 

January 1, 2025 can only be used as 

components, thereby meeting the 

proposed definition of OUWNMs. (Id.) 

HARDI recommended that DOE limit 

the need to test, rate, and recertify 

equipment to only outdoor units 

manufactured after January 1, 2025, as 

this will ensure that equipment 

intended to be installed as an OUWNM 

does meet the minimum efficiency 

requirements while not affecting 

equipment originally sold for 

installation as a matched system. (Id.) 

JCI expressed concerns with DOE’s 

proposal to require recertification of 

units ‘‘currently distributed in 

commerce’’ to meet the OUWNM 

requirements, contending that requiring 

recertification of a component as part of 

a system that was previously certified as 

compliant and has already entered 

commerce, i.e., is no longer in the 

possession of the original manufacturer, 

is overly burdensome for manufacturers, 

distributors, and contractors, and will 

be problematic for DOE to enforce 

without tying enforcement to the 

manufacture/import date. (JCI, No. 35 at 

p. 2) JCI recommended that for outdoor 

units that have entered commerce, the 

‘‘date of manufacture’’ be used as the 

enforcement mechanism. (Id.) JCI 

commented that it was its 

understanding that outdoor units 

manufactured on or after January 1, 

2025 would be required to meet DOE’s 

OUWNM criteria if they were still in the 

possession of the original manufacturer. 

(Id.) JCI stated that clarifying that the 

OUWNM requirements would take 

effect on January 1, 2025, versus the 

NOPR date of January 1, 2026, reduces 

the amount of inventory in the channel 

that would require recertification. (Id.) 

Rheem also expressed concern about 

language for OUWNMs applicable to 

‘‘existing outdoor models currently 

distributed in commerce,’’ where these 

products would need to be recertified 

and given a new basic model number in 

the event that they are only eligible for 

component replacement per EPA’s 

Technology Transitions rule. (Rheem, 

No. 34 at p. 3) Rheem asserted that the 

notion of obtaining proof of new rating 

and a different model number is 

unreasonable to require once the 

equipment has left manufacturer 

warehouses, as the application of new 

labels and rating certifications is 

impractical to carry out at the 

distributor and installer levels. (Id.) 

Rheem commented that EPA appears to 

recognize this impracticality and does 

not require relabeling of equipment 

made prior to January 1, 2025 to 

indicate ‘‘for service only.’’ (Id.) Rheem 

contended that a change in the test 

procedure should not render obsolete a 

product currently in commerce that was 

compliant at the time of manufacture. 

(Id.) 

As indicated by AHRI, DOE notes that 

per EPCA, the terms ‘‘to distribute in 

commerce’’ and ‘‘distribution in 

commerce’’ mean to ‘‘sell in commerce, 

to import, to introduce or deliver for 

introduction into commerce, or to hold 

for sale or distribution after introduction 

into commerce.’’ (42 U.S.C. 6291(16)) 

Under the statutory definition, this term 

can apply to the initial offering of sale 

by a manufacturer or by subsequent 

distribution by downstream partners. As 

was discussed in the previous section, 

the December 2023 EPA Interim Final 

Rule allows for a 1-year sell-through 

period (until January 1, 2026) for any 

CAC/HP system employing a refrigerant 

with a GWP of 700 or greater, provided 

the specified component is 

manufactured or imported prior to 

January 1, 2025 (see 40 CFR 84.54(c)(1)). 

Since EPA prohibits the installation of 

any specified CAC/HP components to 

create a new system employing a 

refrigerant with a GWP of 700 or greater 

on or after January 1, 2026, irrespective 

of the manufacturing date, any 

remaining pre-2025 inventory (i.e., 

imported or manufactured before 

January 1, 2025) held by any channel of 

distribution (manufacturer or 

distributor) could not be installed as a 

system after January 1, 2026. 

DOE’s rating and certification 

requirements in 10 CFR 429.16 for 

central air conditioners and heat pumps 

apply based on how a manufacturer 

distributes the models in commerce. If 

the manufacturer ceases distribution in 

commerce of a model of outdoor unit 

that was previously part of a 

combination and begins distributing it 

only as an OUWNM to allow for use as 

a service-only replacement under the 

EPA’s rules for components of an R– 

410A system, that model of outdoor unit 

would need to be recertified under the 

OUWNM requirements regardless of 

when that transition occurs, since the 

manufacturer (or private labeler) has an 

obligation to ensure that any basic 

model it distributes is compliant with 

the applicable energy conservation 

standard for the configuration (or 

configurations) in which the 

manufacturer distributes it. However, 

the requirement to recertify those basic 

models does not apply retroactively to 

units of a basic model that were already 

distributed in commerce as part of a 

combination and had been correctly 

certified according to DOE’s regulations. 

Regarding AHRI’s concern about 

enforcement of national standards, DOE 

notes that no changes were proposed to 

national standards in the April 2024 

NOPR, and none are being finalized in 

this rulemaking. The purpose of the 

clarification provided in this 

rulemaking is to ensure that 

manufacturers have a clear 

understanding of how to comply with 

DOE’s certification requirements for 

products that will be subject to EPA 

regulations. DOE’s certification 

provisions in 10 CFR 429.12(a) specify 

that each manufacturer, before 

distributing in commerce any basic 

model of a covered product or covered 

equipment subject to an applicable 

energy conservation standard set forth 

in parts 430 or 431, and annually 

thereafter . . . shall submit a 

certification report to DOE certifying 

that each basic model meets the 

applicable energy conservation 

standard(s). To the extent that outdoor 

units that were previously certified as 

compliant as part of a matched system 

begin being distributed in commerce as 

outdoor units with no match, they are 

being distributed as a new basic model, 

and therefore, must certify compliance 

with the applicable energy conservation 


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1242 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

39The reference is to paragraph (c) but should be 

to paragraph (d), which specifies label design (e.g., 

English language, durable and printed/affixed to the 

product exterior surface, readily visible and legible, 

etc.). Paragraph (c) addresses products in the foam 

or aerosol sector and is not relevant for the 

refrigeration, air-conditioning, and heat pump 

sector addressed in paragraph (b). 

standards. The application of the base 

national standard, as referenced by 

AHRI, still applies to the outdoor unit 

based on its manufacture date, but 

compliance with that standard must be 

determined for the basic model 

distributed in commerce (i.e., the 

OUWNM). 

DOE notes that the EPA regulations 

include a 1-year sell-through period to 

reduce inventory of units that may be in 

danger of not complying with the EPA 

rule. DOE’s rationale also applies to 

AHRI’s concern on regional standards. 

However, DOE notes that there is 

confusion on the applicability of the 

EPA dates on the regional level. DOE 

clarifies, consistent with the national 

application, that air conditioners 

certified as able to be installed in the 

Southeast and Southwest regions 

manufactured or imported before 

January 1, 2025, and that have already 

been distributed in commerce, would 

not need to be certified as OUWNMs on 

January 1, 2025, provided the 

manufacturer had already certified 

compliance with the applicable energy 

conservation standards. For units 

intended for installation in the 

Southeast or Southwest regions, this 

would include a certification that they 

comply with those applicable standards. 

As previously explained in this notice, 

the only distinction from CAC/HP 

products that are not subject to regional 

efficiency standards is that split-system 

AC outdoor units certified as OUWNM 

would have to meet the applicable 

standards for the Southeast or 

Southwest regions to be installed in 

those regions. 

DOE notes there may be confusion 

regarding the applicability of the 

compliance dates in the EPA rule and 

how these dates affect DOE regional 

standards requirements. To be clear, the 

EPA rule has no effect on DOE 

requirements. For certain split-system 

central air conditioning systems or 

certain OUWNMs to be installed in the 

Southeast or Southwest region 

consistent with DOE regional standards 

requirements, the system/OUWNM 

must be certified to DOE as compliant 

with the applicable regional standard(s), 

and the certification must indicate that 

the model/combination can be installed 

in the Southeast and/or Southwest 

region. While the EPA rule may change 

the approach a manufacture may take 

with respect to testing and certifying a 

particular model, it does not change 

DOE requirements. 

In response to AHRI’s concern that 

DOE has not described in the proposed 

regulatory text how the testing, rating, 

and recertification for OUWNMs will be 

completed, DOE notes that the testing 

requirements are laid out in section 4.2 

of revised appendix M1 and section 3.2 

of new appendix M2. Additionally, as 

noted in the April 2024 NOPR, and 

explained in the preceding section of 

this notice, existing outdoor models 

currently distributed in commerce as 

part of a split-system basic model that 

the manufacturer transitions to a 

replacement outdoor unit only would 

need to be tested, rated, and certified 

under the provisions in 10 CFR 429.16 

for an outdoor unit with no match. 89 

FR 24206, 24231. As described 

previously in this section, distribution 

of such a model as an OUWNM 

represents distribution in commerce of 

a new basic model, and accordingly, the 

basic model must be certified as 

compliant with the applicable energy 

conservation standards. DOE may 

consider additional certification 

requirements under a separate 

rulemaking regarding appliance and 

equipment certification. 

In response to HARDI, DOE clarifies 

that the reporting obligations apply to 

manufacturers, and importers, and thus 

basic models previously distributed in 

commerce by the manufacturer that 

were certified by the manufacturer in 

accordance with 10 CFR 429.12 do not 

need to be recertified. Regarding 

HARDI’s criticism of regulation based 

on install date requirements, DOE 

clarifies that, whereas the EPA rule is 

based on the date of installation, the 

application of the OUWNM provisions 

are based on the configuration in which 

the manufacturer (or importer) 

distributed the basic model from the 

point of manufacture (or import). It does 

not depend upon distributor or retail 

sales and offerings. DOE notes that the 

EPA regulations include a 1-year sellthrough period for pre-2025 inventory to 

provide time to reduce inventory. The 

OUWNM provisions in this rulemaking 

simply align with the EPA action 

undertaken in the October 2023 EPA 

rule. In response to HARDI’s 

recommendation to limit the need to 

test, rate, and recertify equipment to 

only outdoor units manufactured after 

January 1, 2025, DOE agrees that most 

inventory manufactured prior to January 

1, 2025, will likely be distributed in 

commerce with indoor units and be 

installed prior to January 1, 2026; 

however, to the extent that any outdoor 

units manufactured prior to January 1, 

2025, continue to be distributed in 

commerce by the manufacturer after 

January 1, 2026, as OUWNM, the 

manufacturer must test consistent with 

the requirements applicable to 

OUWNMs and certify the compliance of 

such models with the applicable energy 

conservation standard. 

In response to JCI, DOE again stresses 

that the timing for implementation of 

the OUWNM provisions is tied to the 

EPA rule. Specifically, an outdoor unit 

no longer has a match when EPA 

requirements no longer allow 

installation with an indoor unit to create 

a new system, and thus must be 

certified to DOE as an OUWNM as it 

continues to be distributed in 

commerce. As discussed in III.E.7.c(2), 

DOE clarifies that any outdoor CAC/HP 

units manufactured or imported on or 

after January 1, 2025 and employing 

refrigerants with GWP greater than 700 

(for example, R–410A), would need to 

be tested and rated as an OUWNM, 

consistent with the EPA requirement 

that such models be used ‘‘for servicing 

existing equipment only.’’ For units 

manufactured or imported before 

January 1, 2025 the existing DOEcertified system rating can be used, 

provided the manufacturer does not 

continue distribution of the outdoor 

units alone, because the EPA regulations 

permit installations of such systems 

until January 1, 2026. However, if the 

unit is distributed in commerce alone 

and not as a combination with any 

indoor units, as likely would be the case 

for products intended for installation as 

an individual replacement component 

of an existing system, the outdoor unit 

would have to be certified in accordance 

with the OUWNM provisions prior to 

the date at which the manufacturer 

begins distributing those outdoor units 

as an OUWMN, as indicated to DOE in 

its certification reports via a 

discontinued model filing for the model 

as distributed in a combination and 

certification as an OUWNM. 

In response to Rheem’s claim that 

EPA does not require relabeling of 

equipment made prior to January 1, 

2025 to indicate ‘‘for service only,’’ DOE 

notes that the EPA labeling requirement 

at 40 CFR 84.58(b) states, ‘‘Effective 

upon the date listed for each subsector 

in § 84.54(c) . . . any specified 

component . . . that uses or is intended 

to use any regulated substance, or blend 

containing any regulated substance . . . 

must have a permanent label compliant 

with paragraph (c) 39 of this section 

containing the information in paragraph 

(a)(1) of this section. For specified 

components that are intended for use 


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Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1243 

with a regulated substance or blends 

containing a regulated substance that 

exceed the applicable GWP limit or HFC 

restriction, the label must state ‘‘For 

servicing existing equipment only’’ in 

addition to the other required labeling 

elements.’’ (See 40 CFR 84.58(b)) 40 

CFR 84.58(c) requires the label to list, at 

a minimum, the refrigerant and the date 

of manufacture. DOE is aware that there 

are two dates listed in the relevant 

paragraph for split-system CAC/HPs 

under section § 84.54(c)—January 1, 

2025 and January 1, 2026. As discussed 

above and in the preceding section of 

this notice the December 2023 EPA 

Interim Final Rule pushed back the 

restriction on R–410A and similar 

refrigerants such that components 

manufactured prior to January 1, 2025 

could be installed as part of systems 

prior to January 1, 2026, and thereafter 

would be installable only for servicing 

existing equipment. Thus, unless EPA 

intended for the ‘‘for servicing existing 

equipment only’’ words to be on 

specified components starting January 1, 

2025, when they would still be allowed 

to be used for system installations, EPA 

regulations effectively state that the 

required label would have to be applied 

or changed while the component is in 

distribution, i.e., after leaving the 

manufacturer but before installation. 

However, DOE notes that these labeling 

provisions are separate from its own 

regulatory requirements and that 

manufacturers seeking more specific 

guidance on the implementation of 

these provisions should consult EPA. 

Regarding Rheem’s contention that a 

change in the test procedure should not 

render a currently compliant product 

obsolete, DOE notes that it is the EPA 

action, and not a change to the DOE test 

procedure, that would prevent the 

installation of a previously certified 

CAC/HP system. In accordance with this 

EPA action, DOE’s OUWNM provisions 

in the test procedure provide a means 

for manufacturers to assign an energy 

efficiency rating to split-system outdoor 

units after the EPA has banned them for 

full-system installations. As discussed 

earlier in this section and in the 

preceding section, to the extent that the 

manufacturer of the outdoor unit of a 

previously certified CAC/HP system 

begins distributing it in commerce as an 

OUWNM, it would become a new basic 

model and the manufacturer would 

need to certify that it complies with the 

applicable energy conservation 

standard. 

In a comment related to concerns 

regarding recertification as OUWNM of 

outdoor units already distributed in 

commerce, GE Appliances indicated 

that products currently in production 

would need redesign to comply with 

cut-out/cut-in temperature and CVP 

enforcement testing. (GE Appliances, 

No. 37 at p. 6) They commented that 

since import and production of legacy 

R–410A equipment will cease after 

January 1, 2025, there will be no need 

to redesign existing inventory, in order 

to comply with the cut-out/cut-in 

temperature and CVP enforcement test. 

Id. They pointed out that most of DOE‘s 

energy efficiency enforcements are 

based on date of import or manufacture, 

so exclusion of R–410A legacy 

equipment from CVP and cut-out/cut-in 

enforcement testing would be consistent 

with this practice, and that failing to 

exclude these products from such 

enforcement would lead to stranded 

inventory, resulting in the loss of 

embodied carbon in the inventory, with 

little/no energy efficiency saving. Id. 

In response to the comment by GE 

Appliances, certifications required to be 

made by a manufacturer for the 

compressor and indoor blower speed of 

any variable capacity system at specific 

test conditions must represent normal 

operation. The CVP provisions 

established in this final rule describe 

how DOE would verify that certified 

values are appropriate for the purposes 

of DOE enforcement testing. Hence, 

DOE would expect existing properlycertified variable speed CAC/HPs and 

CHPs to pass the CVP enforcement with 

minimal or no adjustment to existing 

performance representations. Further, 

DOE certainly would not expect changes 

sufficient to call into question the 

compliance of such models with DOE 

efficiency standards. Similarly, although 

cut-out and cut-in temperatures are not 

currently required to be certified, DOE 

would expect manufacturers to have 

certified HSPF2 values that are 

consistent with the actual cut-out/cut-in 

characteristics of certified models. 

Manufacturers are not required 

themselves to conduct CVP testing. To 

the extent that manufacturers are 

correctly certifying performance of 

existing models, there would be no need 

to recertify or redesign such models in 

response to DOE implementing CVP 

testing for enforcement purposes. 

Therefore, DOE disagrees with the 

suggestion of GE Appliances, that there 

should be specific exclusions for legacy 

R–410A CAC/HPs from the CVP and 

cut-out/cut-in temperature enforcement 

provisions. 

(4) Applicability to Multi-Head MiniSplits, Multi-Splits, and Multi-Circuit 

Systems 

AHRI and Carrier requested clarity on 

whether the OUWNM provisions are 

applicable to multi-head mini-split, 

multi-split, or multi-circuit systems. 

(AHRI, No. 25 at pp. 4–5; Carrier, No. 

29 at pp. 3–4). 

Carrier requested that DOE confirm 

that the OUWNM certification 

requirement is applicable to all splitsystem condensing units within the 

scope of appendix M1, which includes 

single-split, multi-head mini-split, 

multi-split (including VRF), and multicircuit air conditioner and heat pump 

systems. (Carrier, No. 29 at pp. 3–4) 

Specifically, Carrier commented that it 

believes multi-head mini-split and 

multi-split systems should also require 

the OUWNM certification. (Id.) Carrier 

noted that while these systems are 

generally intended to be installed with 

multiple indoor units, they can be 

installed with a single indoor unit, 

which could be ducted or ductless, and 

that multiple manufacturers have 

combinations that utilize a mini-split 

(traditionally known as a ‘‘ductless 

outdoor unit’’) with a conventional 

‘‘ducted’’ indoor unit and coil 

combination. (Id.) Carrier further noted 

that multi-split and mini-VRF outdoor 

units are able to be rated, certified, and 

used in combination with a single 

indoor unit as well as the typical 

multiple indoor units. (Id.) Carrier 

expressed concern that if OUWNM 

provisions are not required for these 

systems that can be installed with a 

single indoor unit, they could be used 

to replace the condenser on a system 

with an indoor unit that was never a 

certified combination, yielding poor 

system efficiencies. (Id.) Carrier 

commented that it was its 

understanding that EPA’s reasoning to 

allow a service-only condenser was to 

address the customer concern of 

replacing their entire system upon a part 

failure in the condenser. (Id.) Carrier 

stated that in its experience, this does 

not happen regularly in the market, and 

if there is a premature part failure in the 

condenser, the part (i.e., compressor, 

expansion valve, motor, control board, 

or coil) is replaced or repaired, 

especially in the case of complex 

outdoor units such as multi-split 

condensers. (Id.) Carrier noted that in 

the situation the condenser fails at end 

of life, it is common practice to replace 

the entire system. (Id.) For these 

reasons, Carrier requested that DOE 

clarify that all split-system condensing 

units within the scope of appendix M1 

that are manufactured beginning 

January 1, 2025 with R–410A or any 

banned refrigerant must be certified as 

an OUWNM. (Id.). 

AHRI noted that appendix M1 defines 

the tested combination of a multi-head 

mini-split, multi-split, or multi-circuit 

system to consist of one outdoor unit 


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1244 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

40These instructions are also included in sections 

5.1.6.2 and 5.1.6.3 of AHRI 210/240–2024 and AHRI 

1600–2024. 

41While the term used by commenters to refer to 

such systems is ‘‘communicating,’’ DOE notes that 

the current test procedure uses this term differently. 

Specifically, ‘‘communicating,’’ per the current test 

procedure, refers to the ability of the system to 

communicate in-space temperature with both the 

outdoor and indoor units, instead of 

communication between the indoor and outdoor 

units. DOE also notes that neither the AHRI test 

standards (210/240 and 1600) nor the test procedure 

being finalized in this rule use the term 

‘‘communicating.’’ To prevent confusion, DOE is 

referring to these systems as ‘‘pairing confirming 

systems.’’ 

with one or more compressors matched 

with between two and five indoor units. 

(AHRI, No. 25 at p. 4) AHRI further 

noted that appendix M1 requires that 

these indoor units must collectively 

have a nominal cooling capacity greater 

than or equal to 95 percent and less than 

or equal to 105 percent of the nominal 

cooling capacity of the outdoor unit. 

(Id.) AHRI requested that DOE confirm 

(1) if multi-head systems would test as 

OUWNM with one or two indoor units 

per appendix M1, section 2.2(e); and (2) 

if the preference is for testing multihead systems with two (or more) indoor 

units, whether the coil-only indoor unit 

coil shall be split evenly between the 

two, or in another configuration. (AHRI, 

No. 25 at pp. 4–5). 

DOE agrees with the reasons 

presented by Carrier and clarifies that 

the OUWNM provisions are applicable 

to all split-system CAC/HPs within the 

scope of appendix M1—including 

single-split, multi-head mini-split, 

multi-split (including VRF), and multicircuit air conditioner and heat pump 

systems. As noted by AHRI, per 

appendix M1, the tested combination of 

a multi-head mini-split, multi-split, or 

multi-circuit system requires between 

two and five indoor units. However, the 

indoor unit requirements (which are 

based on the highest sales volume 

family) are not explicitly applicable for 

OUWNM testing. As indicated by 

Carrier, multi-head systems can be 

installed and are able to be rated with 

either a single indoor unit or multiple 

indoor units. To provide maximum 

flexibility to manufacturers and to limit 

test burden, DOE clarifies that, for 

multi-head systems being certified 

under the outdoor unit with no match 

provisions, (1) multi-head systems 

capable of being paired with a single 

indoor coil shall be tested with a single 

indoor coil; and (2) multi-head systems 

incapable of being paired with a single 

indoor coil shall be tested with the least 

amount (between two to five) of 

identical indoor coils. If testing with 

two or more indoor coils, all coils shall 

have the same dimensions. The current 

testing instructions in section 2.2(e) of 

appendix M1 40 are written for a single 

indoor coil, but the same concept of the 

NGIFS can be extended to two or more 

identical indoor coils. Specifically, 

when evaluating NGIFS with two or 

more indoor coils, the total summation 

of the fin surface area would include all 

coils. DOE may consider certification 

requirements to include whether one or 

more indoor coils were used to evaluate 

an OUWNM rating in a separate 

rulemaking. 

(5) Control Type and Communicating 

System 

Carrier also requested that DOE clarify 

that OUWNM certification is required 

for all condensing units, regardless of 

the control type being used to generate 

the system rating. (Carrier, No. 29 at p. 

4) Carrier noted that many of the 

communicating variable-speed 

condensers on the market today also 

have the capability to operate with a 

conventional 24–V non-communicating 

thermostat and that it would be 

extremely difficult to exclude these 

units from the OUWNM certification 

and ensure they were actually being 

matched with a certified communicating 

indoor unit that was previously 

installed. (Id.) 

Conversely, GE Appliances 

commented that multi-head ductless 

split systems and VRF systems under 

65k BTU, which are almost always 

variable-speed communicating systems, 

are unable to complete the existing test 

procedure for an OUWNM listing, as 

existing software does not support or 

allow a coil-only match without 

connection to a matched indoor unit. 

(GE Appliances, No. 37 at p. 4) GE 

asserted that the inability to provide 

replacement outdoor units to service 

existing communicating systems will 

lead to significant harm for consumers, 

the environment, and DOE’s goals for 

heat pumps and variable-speed systems. 

(Id.) GE Appliances requested that DOE 

allow outdoor-unit-only listings for 

variable-speed communicating systems 

capable of supporting multiple indoor 

coils based on the lowest-performing 

system performance for the outdoor coil 

for any previously listed system or 

currently produced, compatible 

communicating coil. (Id.) GE 

Appliances asserted that because 

outdoor units for communicating 

systems can generally only work with 

matched indoor units using the same 

communications protocol, there is little 

risk of improper combinations to create 

systems that perform worse than 

efficiency levels required by DOE. (Id.) 

GE Appliances further commented that 

listing OUWNM units for these systems 

in this manner ensures accurate 

consumer information about expected 

product performance and also ensures 

service components’ availability where 

they would otherwise be restricted. (Id.) 

Mitsubishi also asserted that while it 

understands the broad industry support 

for DOE to extend the definition of 

OUWNM to R–410A outdoor units, the 

proposed language does not take into 

account the emergence and expansion of 

communicating variable-speed 

equipment. (Mitsubishi, No. 28 at p. 2) 

Mitsubishi contended that like every 

other inverter-driven variable-capacity 

ductless OEM, Mitsubishi systems and 

components are unable to test or operate 

with any coil in a lab or in the field that 

is not equipped with proprietary 

communication protocol and firmware, 

and that evaluating their outdoor units 

as OUWNMs renders these controls and 

advancements completely useless. (Id.) 

Mitsubishi requested that either 

communicating variable-speed systems 

be exempted from the OUWNM 

provisions, or that specific allowances 

be considered to enable communicating 

variable-capacity outdoor units to be 

tested in a way that demonstrates 

compliance with Federal efficiency 

minimum standards. (Id.) 

DOE clarifies that the OUWNM 

requirements will apply to all splitsystem CAC/HPs units, whether they 

use proprietary controls to communicate 

conditioned-space temperature and/or 

humidity, use a generic thermostat, or 

allow either installation approach. Also, 

DOE understands that many ductless 

multi-split systems and VRF systems are 

variable-speed systems that employ 

software that requires the outdoor unit 

to be paired with a recognized indoor 

unit (i.e., a pairing confirming 

system).41 Manufacturers of ductless 

multi-split systems and VRF systems 

may already have the means to test 

these systems with a generic indoor unit 

or may need to reprogram their outdoor 

units to allow operation with a generic 

indoor unit, for units using a refrigerant 

with GWP greater than 700 that are 

manufactured after January 1, 2025. 

While the latter option may require 

additional software rework, this 

reprogramming would require limited 

engineering hours to implement, such 

that DOE does not consider it to be 

burdensome to manufacturers. In 

response to GE’s proposal to allow 

outdoor-unit-only listings for such 

systems based on the lowest-performing 

system combination for the outdoor coil, 

and Mitsubishi’s request for such 

systems to be exempted from the 

OUWNM provisions or given special 


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Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1245 

allowances, DOE notes that neither 

approach provides confirmation that a 

given outdoor unit could not be field 

paired with a nonproprietary indoor 

unit(s). Therefore, to maintain 

consistency across all split-system CAC/ 

HPs, irrespective of the control type, 

DOE is exempting neither pairing 

confirming variable-speed systems nor 

variable-speed communicating systems 

from the OUWNM provisions, nor 

allowing either category of outdoor 

units to be rated based on its lowestperforming combination. 

(6) Service Coil Definition 

GE Appliances and Mitsubishi 

requested revision to the ‘‘service coil’’ 

definition (see 10 CFR appendix M1, 

section 1.2) to also include integrated 

indoor blowers within the definition’s 

scope. (GE Appliances, No. 37 at pp. 1– 

3; Mitsubishi, No. 28 at p. 2) 


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GE Appliances commented that mini-split, multi-split, and light VRF systems 

("DFS systems") have become increasingly popular in the residential air-conditioning 

market and that these products are significantly different from traditional ducted systems. 

(GE Appliances, No. 37 at p. 2) GE Appliances noted that indoor units of such systems 

typically focus on using the smallest space possible and are composed of a tightly 

integrated blower fan, evaporator coil, and electronics package. (Id.) GE Appliances 

contended that when the coils on these indoor units fail, by far the most cost-effective 

means of repairing the system is to replace the entire indoor unit, which includes both the 

coil and the fan. (Id.) GE Appliances noted that DOE currently allows for replacement 

of indoor coils to repair an existing system without a listing of that indoor coil as a part of 

a system through the service coil provisions of 10 CFR 430 appendix Ml, and that these 

provisions allow service of existing systems using a legacy refrigerant where the system 

as a whole has been delisted under OUWNM requirements of 10 CFR 429.16(a)(3). (GE 

Appliances, No. 37 at pp. 1-2) However, GE Appliances noted that the service coil 

definition explicitly excludes integrated indoor blowers (Id.) To account for more recent 

prevalence of DFS systems in the market since the last refrigerant transition, GE 

Appliances suggested that DOE amend the definition of "service coil" to include units 

with integrated fans from the factory. (GE Appliances, No. 37 at p. 3) GE Appliances 

proposed the following definition for service coil (proposed additions italicized and 

deletions in strikeout): 
1246 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

GE Appliances contended that 

revising the definition of service coil to 

account for DFS systems is essential to 

protect consumers who have recently 

installed DFS systems using R–410A 

refrigerant and that without these 

revisions, indoor replacement units to 

repair DFS systems during their 

expected useful life may be limited, and 

consumers may be required to replace 

entire systems instead of merely 

components. (Id.) GE further 

commented that if DFS systems are not 

able to have indoor coil replacements, 

there is a risk of significant negative 

consumer sentiment toward DFS 

systems. (Id.) 

Mitsubishi asserted that 

circumstances where full replacement of 

ductless indoor units would be 

significantly less costly than field 

replacement of individual parts would 

needlessly impact the pocketbooks of 

homeowners and consume scarce 

technician labor hours. (Mitsubishi, No. 

28 at p. 2) Mitsubishi recommended a 

carve out or alteration of the current 

definition of service coil to allow 

ductless indoor units to be sold for 

purposes of service, as it would remedy 

this concern and be better aligned with 

the EPA Technology Transitions rule 

and guidance. (Id.) 

DOE concurs with GE Appliances that 

mini-split, multi-split, and VRF systems 

have become more prevalent in the 

residential air-conditioning market. As 

noted by GE Appliances, the current 

service coil definition does not include 

indoor units that have integrated indoor 

blowers. DOE also notes that the service 

coil definition in AHRI 210/240–2024 

and AHRI 1600–2024, the industry 

standards DOE is referencing in this 

final rule, also do not include integrated 

indoor blowers within the service coil 

definition. Both appendix M1 (see 

section 1.2 of appendix M1) and the 

AHRI standards define ‘‘indoor unit’’, 

which includes integrated blowers 

within the definition’s scope. The 

indoor unit definition in Appendix M1 

also explicitly notes that a service coil 

is not an indoor unit. In relevance to the 

EPA rule, the labelling requirements at 

40 CFR 84.58(b) clarify the installation 

allowances of indoor units. Specifically, 

40 CFR 84.58(b) notes that, after January 

1, 2025, specified components intended 

for use with banned refrigerants shall 

have the label ‘‘For servicing existing 

equipment only’’ attached. Any indoor 

units that are intended to be used with 

banned refrigerants (such as R–410A) 

fall within the scope of specified 

components and under the 

aforementioned regulatory provisions 

under the EPA’s rule would need to 

have this label attached. 

As was noted in the previous section 

of this notice, the CAC/HP definition in 

10 CFR 430.2 includes a requirement 

that indoor units sold alone be rated as 

part of a combination. Specifically, the 

definition states ‘‘A central air 

conditioner or central air conditioning 

heat pump may consist of: A singlepackage unit; an outdoor unit and one 

or more indoor units; an indoor unit 

only; or an outdoor unit with no match. 

In the case of an indoor unit only or an 

outdoor unit with no match, the unit 

must be tested and rated as a system 

(combination of both an indoor and an 

outdoor unit).’’ Such indoor units may 

be distributed by indoor coil 

manufacturers (‘‘ICMs’’) which, as 

defined in Appendix M1, manufacture 

indoor units but do not manufacture 

single-package units or outdoor units. 

They may also be distributed in 

commerce alone and not as part of a 

combination by non-ICMs for the 

replacement market. For an indoor unit 

intended only for replacement in an 

existing system and which is no longer 

distributed in commerce for installation 

as a combination, as would be the case 

for an existing system that uses a 

refrigerant banned by EPA, the 

requirement in table 1 of 10 CFR 

429.16(a) for the indoor unit to be rated 

as part of a system would still apply 

even though the indoor unit is no longer 

being distributed in commerce as part of 

a combination. This rating requirement 

would apply regardless of whether the 

manufacturer of the indoor unit is an 

ICM. If the indoor unit uses a refrigerant 

allowed by EPA only for component 

replacement (e.g., R–410A), the rating 

for such a unit would be based on a 

combination using that refrigerant, and 

per EPA regulations could not be 

distributed in commerce as a 

combination. However, this does not 

imply that the indoor unit cannot be 

rated, nor that the entire system would 

have to be replaced, as suggested by GE. 

DOE notes further that any such rating 


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Service coil means an arrangement ofrefrigerant-to-air heat transfer coil(s), 

condensate drain pan, sheet metal or plastic parts to direct/route airflow over the coil( s ), 

which may or may not include external cabinetry and/or a cooling mode expansion 

device.,_, A service coil may also include a fan if that fan is integrated into the service coil 

assembly at the factory. A service coil may be distributed in commerce solely for 

replacing an uncased coil or cased coil that has already been placed into service, and that 

has been must be labeled "for indoor coil replacement only" on the nameplate and in 

manufacturer technical and product literature. The model number for any service coil 

must include some mechanism (e.g., an additional letter or number) for differentiating a 

service coil from a coil intended for an indoor unit. (GE Appliances, No. 37 at p. 3) 
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1247 

42NCP shared results of its analysis in 

confidential exhibits A and B. 

for the indoor unit must be compliant 

with current standards, and that any 

indoor units distributed in commerce 

for use in a system that uses a 

refrigerant subject to the EPA ban would 

need to have been certified to DOE as 

compliant with the applicable standards 

as part of a combination before January 

1, 2025. 

(7) Space-Constrained Systems 

NCP commented that it performed 

analysis, testing, and simulations of 

through-the-wall space-constrained R– 

410A systems to evaluate available 

options to meet the proposed OUWNM 

requirement for applicable outdoor 

condensing units. (NCP, No. 27 at p. 2) 

NCP contended that the results of this 

testing 42 indicated that its spaceconstrained outdoor condensing units 

would not meet applicable minimum 

efficiency requirements when rated 

using a generic indoor coil as specified 

by the OUWNM requirements. (Id.) NCP 

asserted that it was not aware of any 

space-constrained outdoor condensing 

units from other manufacturers that 

could meet efficiency requirements 

when rated as an OUWNM. (Id.) NCP 

asserted that the OUWNM requirements 

in DOE’s proposed rule would 

effectively prohibit any spaceconstrained R–410A outdoor 

condensing unit after January 1, 2026, 

and leave manufacturers with stranded 

inventory. (NCP, No. 27 at p. 2) NCP 

contended that occupants of 

multifamily housing units with recently 

installed space-constrained R–410A 

split systems would be left without 

options for service replacement of their 

outdoor condensing unit section, 

beyond installation of the entire indoor 

and outdoor split system. (Id.) To 

provide relief from excessive cost 

burdens, NCP suggested that DOE 

should include language in the final 

rule that coil-only ratings for spaceconstrained split-system outdoor units 

with R–410A are permissible until 

January 1, 2028, for units manufactured 

before January 1, 2025. (Id.) 

Alternatively, NCP suggested that DOE 

should use its enforcement discretion to 

provide additional 2-year sell through 

before OUWNM ratings are required for 

through-the-wall space-constrained R– 

410A outdoor condensing units. (Id.) 

DOE reviewed the confidential data 

provided by NCP for select outdoor unit 

models and agrees that the data suggests 

that these models cannot meet 

applicable minimum efficiency 

requirements when tested as OUWNMs. 

However, DOE notes that the data 

provided does not include performance 

data or estimates for designs with any 

technology improvements, e.g., twostage or variable-speed compressors. 

Thus it is not clear that compliance with 

Federal standards is impossible for 

space-constrained OUWNMs. 

DOE further notes that NCP suggests 

a delay of the OUWNM requirement 

until January 1, 2028, but the need for 

replacement outdoor units would still 

exist after January 1, 2028, only 3 years 

after EPA’s transition date for R–410A. 

This would suggest that NCP believes 

that space-constrained outdoor unit 

designs can be developed to be 

compliant with standards using the 

OUWNM test requirements starting on 

that date. Regarding stranded inventory, 

as clarified earlier in section III.E.6.c.1, 

DOE notes that the EPA rule includes a 

1-year sell-through period that would 

enable any accumulated inventory to be 

distributed, beyond which any spaceconstrained CAC/HP outdoor units 

using R–410A would need to certify as 

OUWNMs. As discussed elsewhere in 

this final rule, to the extent that units 

are distributed in commerce as 

OUWNMs, they would be distributed as 

a different basic model as compared to 

distribution in commerce when paired 

with an indoor unit. 

For these reasons, DOE has 

determined that there is not sufficient 

justification for delaying the OUWNM 

requirements for R–410A spaceconstrained CAC/HP products. 

Additionally, as discussed previously in 

this section, the timing of permitted 

installations of R–410A systems and 

components is based on EPA’s 

refrigerant regulations. DOE is clarifying 

the applicability of the test procedure 

requirements in this final rule to allow 

for component installations consistent 

with EPA’s requirements. 

(8) Representativeness of Paired Indoor 

Coil 

Rheem questioned the 

appropriateness of the indoor coil 

specifications currently required for 

OUWNM testing. (Rheem, No. 34 at pp. 

2–3) Rheem provided historical 

background of DOE’s OUWNM 

provisions by citing language from past 

rulemaking notices, noting some of the 

following key points: 

(1) DOE first proposed an NGIFS for 

rating and certifying the performance of 

outdoor units designed for R–22 in the 

November 9, 2015 SNOPR, where DOE 

proposed an upper limit on NGIFS 

equal to 1.15. 80 FR 69278, 69404. 

(2) DOE indicated that its analysis 

supporting NGIFS values for OUWNM 

testing was based on reverse-engineered 

SEER 13 split systems (blower-coil 

combinations) designed for R–22. 81 FR 

36992, 37010. 

(3) However, DOE set the upper limit 

on NGIFS at 1.0 in the June 08, 2016 

Final Rule, arguing that a lower NGIFS 

better reflected the installed base of 

indoor units, since the installed base 

also included 10 SEER split systems. 81 

FR 36992, 37010. 

(4) In the August 24, 2016 SNOPR, 

DOE acknowledged that legacy 

(existing) indoor units matched with nomatch outdoor units would not always 

be indoor units designed for R–22, and 

that the NGIFS 1.0 upper limit did not 

provide a good representation of the 

heat transfer performance of indoor 

coils with newer designs. 81 FR 58164. 

Rheem also commented on the DOE 

proposal in the August 8, 2016 SNOPR 

to adopt a maximum NGIFS 

requirement generally for testing of 

single-split coil-only systems. Because 

this proposal did not address OUWNM 

outdoor units and because DOE did not 

adopt the proposal, Rheem stated that it 

is not relevant to the OUWNM 

discussion. Based on the historical 

context provided from prior rules, 

Rheem requested DOE review the test 

provisions for OUWNMs, the definition 

of NGIFS, and its upper limit to 

accurately represent the current 

installed base of indoor coils with 

which such condensing units would be 

matched in the field. (Rheem, No. 34 at 

p. 3) 

DOE appreciates Rheem’s comment 

charting the historical development of 

the OUWNM testing provisions. As 

noted earlier in section III.E.7 and 

indicated by Rheem’s comment, the 

current instruction at section 2.2.e of 

appendix M1 requires that an OUWNM 

be tested using a coil-only indoor unit 

coil that has round tubes of outer 

diameter no less than 0.375 inches and 

NGIFS of no greater than 1.0 sq in/Btu/ 

hr. These indoor coil specifications 

were initially finalized for appendix M 

in the June 8, 2016 Final Rule and 

extended to appendix M1 in the January 

2017 Final Rule. 81 FR 36992, 82 FR 

1426. DOE did not propose revision of 

the requirements in the April 2024 

NOPR. 

In response to Rheem’s comment, 

DOE reviewed historical data, starting 

with shipments analysis supporting the 

energy conservation standards direct 

final rule published on January 6, 2017 

(‘‘January 2017 DFR’’). 82 FR 1786. DOE 

conducted analysis to determine 

whether a substantial percentage of CAC 

system replacements in 2025 would 

occur in residences in which the indoor 

unit would have been installed prior to 

2010, i.e., when the representative 

indoor unit would have been part of a 


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13 SEER R–22 system, consistent with 

DOE’s initial analysis to establish the 

NGIFS requirements. To conduct this 

analysis, DOE used national impact 

analysis results provided in the January 

2017 DFR and its supporting documents 

and spreadsheets. (See 82 FR 1786, 

1822–1824) In this assessment, DOE 

considered that a portion of system 

replacements have been outdoor-unitonly installations, consistent with the 

January 2017 DFR assumptions for the 

percentage of installations involving just 

an outdoor unit. This factor increases 

the average age of an existing indoor 

unit, since, for some portion of the 

existing residences, the indoor unit 

would not have been replaced during 

the last outdoor unit replacement. 

The results of this analysis indicate 

that more than 60 percent of system 

replacements in 2025 would involve a 

residence where the indoor unit was 

installed before 2010. DOE also 

considered sensitivity of this analysis to 

differences between shipment 

projections made to support the January 

2017 DFR and actual recent-year 

shipments and found that an analysis 

updated for recent shipment data would 

suggest a slightly higher percentage for 

pre-2010 indoor units. Thus, DOE 

concludes that the NGIFS limit initially 

established in the June 8, 2016 Final 

Rule is still representative, and DOE is 

not revising it in this final rule. 

(9) Single Cooling Air Volume Rate 

AHRI, the CA IOUs, Carrier, and 

Daikin recommended that DOE retain 

the requirement to test OUWNMs with 

a single cooling air volume rate. (AHRI, 

No. 25 at p. 5; CA IOUs, No. 32 at pp. 

2–3; Carrier, No. 29 at p. 4; Daikin, No. 

36 at p. 2) 

AHRI recommended that the testing 

instructions proposed for OUWNMs at 

section 4.2 of appendix M1 also include 

the current regulatory requirement that 

the coil-only indoor unit has a ‘‘single 

cooling air volume rate.’’ (AHRI, No. 25 

at p. 5) The CA IOUs also recommended 

that DOE retain the requirement for 

testing OUWNMs with a ‘‘single cooling 

air volume rate’’ in section 4.2 of the 

proposed revision to appendix M1 and 

include an identical requirement in 

section 3.2 of appendix M2. (CA IOUs, 

No. 32 at p. 2) The CA IOUs commented 

that they believe this specific 

requirement of a single cooling air 

volume rate was inadvertently left out of 

the new AHRI standards. (Id.) The CA 

IOUs reasoned that because OUWNMs 

are compatible with any existing air 

handler that continues to remain as the 

primary air-moving system after the 

originally paired outdoor unit is 

replaced, DOE cannot guarantee that 

such systems will have controls capable 

of varying airflow during operation and 

should, therefore, continue to require a 

single air volume rate. (Id.) Carrier also 

noted that the current appendix M1 

requirements for OUWNM testing 

require a single cooling air volume rate, 

and it recommended that DOE continue 

to require a single cooling air volume 

rate. (Carrier, No. 29 at p. 4) Daikin 

strongly suggested that DOE maintain 

the single airflow rate requirement for 

all OUWNMs, reasoning that OUWNMs 

do not include an indoor unit change 

and would, therefore, not have any 

enhancements, such as non-bleed 

expansion valves or blower delays, to 

improve cyclic performance. (Daikin, 

No. 36 at p. 2) 

The current requirements at section 

2.2e of appendix M1 require that an 

OUWNM be tested using a coil-only 

indoor unit at a single cooling air 

volume rate. DOE notes that this 

requirement was inadvertently left out 

of the April 2024 NOPR. DOE agrees 

with the reasoning presented by 

commenters advocating that this 

requirement be retained. Therefore, DOE 

is including language at section 4.2 of 

revised appendix M1 and section 3.2 of 

new appendix M2, requiring the use of 

a single cooling air volume rate when 

testing OUWNMs. 

(10) Use of Default Degradation 

Coefficient for OUWNM Testing 

AHRI, the CA IOUs, and Daikin 

recommended that DOE use the default 

degradation coefficient of 0.25 for all 

OUWNMs, for both heating and cooling 

modes. (AHRI, No. 25 at p. 5; CA IOUs, 

No. 32 at p. 3; Daikin, No. 36 at p. 2) 

AHRI noted that the existing 

provisions for OUWNMs for degradation 

coefficient in enforcement is to use the 

default value (0.25), whereas the 

published versions of AHRI 210/240– 

2024 and AHRI 1600–2024 allow for 

testing of CD for OUWNMs. (AHRI, No. 

25 at p. 5) AHRI strongly recommended 

that DOE adopt the default degradation 

coefficient of 0.25 for all OUWNMs, for 

both heating and cooling modes. (Id.) 

AHRI reasoned that a significant portion 

of OUWNM units are applied in 

multifamily apartment dwelling 

situations, where the probability of 

being properly paired with an indoor 

product that can be retrofitted to have 

a time delay, or having an indoor 

product that is retrofitted with a nonbleed thermal expansion valve or an 

electronic expansion valve is relatively 

low (since many multifamily apartment 

dwelling indoor systems are ceilingmount blower coil systems or wallmount blower coil systems). (Id.) 

Therefore, AHRI contended that a 

substantial portion of OUWNMs 

installed in multifamily applications 

would not have the lower CD in the real 

world, as experienced in testing. (Id.) 

The CA IOUs also suggested that the 

cyclic degradation default values in 

proposed appendices M1 and M2 align 

with the current requirement in 10 CFR 

part 429 for OUWNMs. (CA IOUs, No. 

32 at p. 3) The CA IOUs noted that they 

supported the use of default values 

because the metering device, which is 

unknown for an OUWNM, significantly 

affects cyclic degradation. (Id.) Daikin 

also suggested that the default value of 

0.25 be used for both cooling and 

heating degradation coefficients for 

OUWNMs. (Daikin, No. 36 at p. 2) 

As noted by commenters, the current 

enforcement requirement at 10 CFR 

429.134(k)(2)(ii) states that DOE will use 

the default cooling and heating 

degradation coefficients when testing 

models of OUWNMs. DOE agrees with 

the reasoning presented by commenters 

and notes that this enforcement 

requirement was put in place on the 

basis of the same rationale. 

Additionally, the requirement was 

intended to be adopted broadly for 

testing, not just for enforcement, as 

indicated in the June 2016 Test 

Procedure Final Rule. 81 FR 36992, 

37011. To clarify that this requirement 

also applies to testing, DOE is including 

provisions at section 4.2 of revised 

appendix M1 and section 3.2 of new 

appendix M2 to require that testing of 

OUWNMs only use the default 

degradation coefficients (0.25) for both 

cooling and heating modes. 

8. Inlet and Outlet Duct Configurations 

Both appendix D of the AHRI 210/ 

240–202X Draft and appendix D of the 

AHRI 1600–202X Draft define lists of 

clarifications/exceptions to their 

referenced version of ASHRAE Test 

Standard 37 (ANSI/ASHRAE 37–2009). 

These clarifications/exceptions have 

been revised repeatedly throughout the 

version history of the AHRI 210/240 

standard. In the April 2024 NOPR, DOE 

noted that both appendix D of AHRI 

210/240–202X Draft and appendix D of 

AHRI 1600–202X Draft contain updates 

regarding inlet and outlet duct 

configurations, including the duct 

revisions investigated in RP 1581 and 

RP 1743 to accommodate smaller 

environmental chambers. These updates 

are consistent with the draft of an 

update of ANSI/ASHRAE Standard 37 

(‘‘May 2023 ASHRAE 37 Draft’’). DOE 

surmised that the inclusion of these 

May 2023 ASHRAE 37 Draft updates in 

appendix D of the relevant AHRI drafts 

represented industry consensus, and 

DOE tentatively determined that the 


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43 In the April 2024 NOPR, DOE incorrectly 

referred to appendix H of AHRI 1600–202X Draft as 

the appendix regarding the determination of 

average power of auxiliary components (see 89 FR 

24206, 24236). This was a typographical error, since 

the appendix regarding the determination of 

average power of auxiliary components is at 

appendix G of AHRI 1600–202X Draft. 

updates are appropriate for CAC/HP 

testing. 89 FR 24206, 24231. 

Consequently, DOE proposed to 

incorporate by reference appendix D of 

AHRI 210/240–202X Draft at appendix 

M1 and to incorporate by reference 

appendix D of AHRI 1600–202X Draft at 

appendix M2. Id. 

DOE noted that AHRI 210/240–202X 

Draft and AHRI 1600–202X Draft 

reference the current version of 

ASHRAE Test Standard 37, ANSI/ 

ASHRAE 37–2009, because the May 

2023 ASHRAE 37 Draft had not yet been 

finalized and published. Id. DOE further 

noted that it may choose to update its 

incorporation by reference to the final 

published version of the May 2023 

ASHRAE 37 Draft in a future 

rulemaking. Id. 

DOE did not receive any comments 

regarding the aforementioned proposals 

in the April 2024 NOPR. AHRI 210/240– 

2024 and AHRI 1600–2024 finalized the 

updates regarding inlet and outlet duct 

configurations without substantial 

change. Both standards continue to 

reference ANSI/ASHRAE 37–2009 since 

the May 2023 ASHRAE 37 Draft has not 

yet been finalized. Therefore, consistent 

with the April 2024 NOPR proposal, 

DOE is incorporating by reference 

Appendix D of AHRI 210/240–2024 and 

AHRI 1600–2024, at appendix M1 and 

appendix M2, respectively. DOE is also 

continuing to maintain reference to 

ANSI/ASHRAE 37–2009 since the May 

2023 ASHRAE 37 Draft has not yet been 

finalized. 

9. Heat Comfort Controllers 

A heat comfort controller enables a 

heat pump to regulate the operation of 

the electric resistance elements such 

that the air temperature leaving the 

indoor section does not fall below a 

specified temperature (see section 1.2 of 

appendix M1). 

In the April 2024 NOPR, DOE noted 

that appendix M1 does not currently 

specify additional steps for calculating 

the HSPF2 of heat pumps having a heat 

comfort controller and having a 

variable-speed compressor. 89 FR 

24206, 24231. DOE noted that AHRI 

210/240–202X Draft and AHRI 1600– 

202X Draft specify additional steps for 

calculating the HSPF2 and SHORE of 

heat pumps having a variable-capacity 

compressor and a heat comfort 

controller and that these additional 

steps are similar to the additional steps 

for calculating the HSPF2 and SHORE of 

other system types having a heat 

comfort controller. Id. DOE tentatively 

determined that the inclusion of these 

additional steps for calculating HSPF2 

and SHORE is appropriate for heat 

pumps having a variable-capacity 

compressor and a heat comfort 

controller, because these provisions 

provide representative measures of unit 

operation when installed with heat 

comfort controllers. Id. Therefore, DOE 

proposed to incorporate by reference the 

additional steps for calculating the 

HSPF2 of heat pumps having a variablecapacity compressor and a heat comfort 

controller outlined in section 11.2.2.5 of 

AHRI 210/240–202X Draft, at appendix 

M1. Id. Likewise, DOE proposed to 

incorporate by reference the additional 

steps for calculating the SHORE of heat 

pumps having a variable-capacity 

compressor and a heat comfort 

controller outlined in section 11.2.2.5 of 

AHRI 1600–202X Draft, at appendix M2. 

Id. 

DOE did not receive any comments 

regarding these proposals. AHRI 210/ 

240–2024 and AHRI 1600–2024 

finalized the updates to the heat comfort 

controller calculations without 

substantial change. Therefore, 

consistent with the April 2024 NOPR 

proposals, DOE is incorporating by 

reference section 11.2.2.5 of AHRI 210/ 

240–2024 and AHRI 1600–2024, at 

appendix M1 and appendix M2, 

respectively. 

F. Long-Term Changes in the CAC Test 

Procedure 

The following sections discuss issues 

that affect the CAC/HP test procedure in 

the long term—i.e., they will be effective 

when new CAC/HP standards are 

established in terms of the efficiency 

metrics SCORE and SHORE in appendix 

M2. As previously explained, these 

long-term revisions would be 

implemented at the new appendix M2 

via incorporation by reference of the 

relevant industry consensus test 

procedure, AHRI 1600–2024. DOE has 

reviewed AHRI 1600–2024 and has 

concluded that it satisfies the EPCA 

requirement that test procedures should 

not be unduly burdensome to conduct 

and should be representative of an 

average use cycle. (42 U.S.C. 6293(b)(3)) 

These long-term amendments in 

appendix M2 would alter the measured 

efficiency of CAC/HPs and would 

require representations in terms of new 

cooling and heating test metrics, SCORE 

and SHORE, respectively. 

1. Power Consumption of Auxiliary 

Components 

AHRI 1600–202X Draft introduces 

SCORE and SHORE as replacements for 

the current cooling and heating 

performance metrics, SEER2 and 

HSPF2, used to determine the measured 

efficiency of CAC/HPs. Unlike SEER2 

and HSPF2, which are seasonal 

efficiency metrics that don’t include all 

energy consumed by the systems, these 

new metrics do address energy use of all 

components and operational modes, 

specifically including the standby and 

off mode power consumption of 

auxiliary components. These include 

those components discussed previously 

(i.e., crankcase heaters and indoor fans 

utilizing constant circulation) for both 

SCORE and SHORE, and, additionally, 

base pan heaters for SHORE. 

SEER2 and HSPF2 are both ratio 

metrics that include all calculated space 

conditioning in the numerator and all 

energy use associated with space 

conditioning in the denominator. In 

contrast, AHRI 1600–202X Draft 

includes two new quantities—Es,c

(measured in watt-hours), added to the 

denominator of the calculation for 

SCORE, meant to represent all auxiliary 

component energy usage during cooling 

mode (i.e., during both cooling 

conditioning hours and cooling-season 

shoulder hours, as applicable), and Es,h

(also measured in watt-hours), added to 

the denominator of the calculation for 

SHORE, that is meant to represent all 

auxiliary component energy usage 

during heating mode (i.e., during both 

heating conditioning hours and heatingseason shoulder hours, as applicable). 

Table 14 and table 16 of AHRI 1600– 

202X Draft outline instructions for 

determining each component’s number 

of standby power operating hours in 

cooling mode and heating modes, and 

appendix G of AHRI 1600–202X Draft 43

outlines instructions for determining the 

average power of all auxiliary 

components considered in the 

calculations of either Es,c or Es,h. 

In the April 2024 NOPR, DOE 

tentatively concluded that the 

respective inclusions of Es,c and Es,h into 

the calculations of the new cooling and 

heating performance metrics, SCORE 

and SHORE, represent industry 

consensus regarding whether to reflect 

the power consumption of auxiliary 

components in the efficiency metrics for 

CAC/HPs. 89 FR 24206, 24236. DOE 

tentatively determined that inclusion of 

the energy consumed by auxiliary 

components in the efficiency metrics for 

CAC/HPs would result in more 

representative measures of efficiency. 

Id. Therefore, DOE proposed to 

incorporate by reference the new 

cooling and heating performance 

metrics, SCORE and SHORE, as 


ddrumheller on DSK120RN23PROD with RULES2
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44 In the relevant April 2024 NOPR preamble 

discussion, there were instances where DOE 

mistakenly referred to section table 13 of AHRI 

1600–202X Draft. This has been corrected to table 

15 of AHRI 1600–202X Draft in this final rule 

preamble discussion. 

45 In the relevant April 2024 NOPR preamble 

discussion, there were instances where DOE 

mistakenly referred to table 15 of AHRI 1600–202X 

Draft. This has been corrected to table 18 of AHRI 

1600–202X Draft in this final rule preamble 

discussion. 

46To access the normative section of the third 

edition of the ACCA Manual S, see www.acca.org/ 

standards/technical-manuals/manual-s. 

47See www.regulations.gov/document/EERE2016-BT-TP-0029-0002. 

included in AHRI 1600–202X Draft, and 

the associated provisions regarding the 

standby and off mode power 

consumption of auxiliary components, 

in appendix M2. Id. 

DOE did not receive any comments 

regarding this proposal. AHRI 1600– 

2024 finalized the new cooling and 

heating performance metrics, SCORE 

and SHORE, and the associated 

provisions regarding the standby and off 

mode power consumption of auxiliary 

components, without substantial 

change. Therefore, consistent with the 

April 2024 NOPR proposal, DOE is 

incorporating by reference AHRI 1600– 

2024, and adopting the SCORE and 

SHORE metrics, and the associated 

provisions regarding the standby and off 

mode power consumption of auxiliary 

components, at appendix M2. 

2. Impact of Defrost on Performance 

In order for HPs to undergo a defrost 

cycle, which aims to remove the 

moisture collected as frost on the 

outdoor coil, an HP temporarily 

switches to cooling mode operation. 

This enables an HP to transfer heat from 

the indoor coil to the outdoor coil, thus 

providing the heat needed to warm the 

coil above freezing temperature and 

melt the frost. 

In the April 2024 NOPR, DOE 

explained how AHRI 1600–202X Draft 

introduces two changes to the treatment 

of defrost performance of CAC/HPs: (1) 

it simplifies the demand defrost credit 

by uniformly applying a 3-percent 

increase to the SHORE rating for all HPs 

equipped with demand defrost, and (2) 

it accounts for the use of supplementary 

heat during defrost using a new defrost 

heat and defrost overrun debits. 89 FR 

24206, 24236–24238. DOE surmised that 

AHRI 1600–202X Draft’s introduction of 

the simplified demand defrost credit in 

AHRI 1600–202X Draft represented 

industry consensus regarding 

improvements to the accuracy of the 

credit, incentives for more efficient 

defrost control strategies, and more 

accurate representations of modern 

defrost control technologies in the test 

procedure. 89 FR 24206, 24237. DOE 

tentatively determined that a simplified 

demand defrost credit would 

disincentivize unnecessary early 

defrosts (90 minutes after the 

termination of the prior defrost cycle), 

accurately represent defrost energy use 

while limiting test burden, and 

consequently allow for more advanced 

and efficient defrost control strategies. 

Similarly, DOE tentatively determined 

that the defrost heat and defrost overrun 

debits associated with accounting for 

use of supplementary heat during 

defrost represented industry consensus 

and that these debits result in more 

representative CAC/HP efficiencies for 

models with supplementary heat during 

defrost. Therefore, DOE proposed to 

incorporate by reference at appendix M2 

the defrost-related provisions from 

AHRI 1600–202X Draft. 

In response to DOE’s proposal, the 

Joint Advocates stated that they 

acknowledge the improvements made to 

the treatment of defrost in the proposed 

appendix M2. (Joint Advocates, No. 30 

at p. 4) However, the Joint Advocates 

also commented that, by assigning the 

defrost credit and debits based on a yes 

or no framework, the proposed 

appendix M2 does not capture the true 

differentiation that exists between 

defrost controls. (Id.) The Joint 

Advocates encouraged DOE to collect 

information about defrost mechanisms 

and consider how defrost impact may be 

better represented in a future update to 

the CAC/HP Federal test procedures. 

(Id.) 

In response to the Joint Advocates, 

DOE notes that it will continue to 

review the defrost credit and debits and 

may propose changes once more 

information is made available. However, 

since little or no information is 

currently available and the defrost 

credit and debits represent industry 

consensus, DOE is adopting the defrost 

credit and debits without modification, 

as proposed. 

DOE did not receive any other 

comments regarding this proposal. 

AHRI 1600–2024 finalized the defrost 

related provisions discussed in the 

aforementioned paragraphs, without 

substantial change. Therefore, 

consistent with the April 2024 NOPR 

proposal, DOE is incorporating by 

reference AHRI 1600–2024 and adopting 

the defrost-related provisions at 

appendix M2. 

3. Updates to Building Load Lines and 

Temperature Bin Hours 

In the April 2024 NOPR, DOE 

discussed several changes introduced in 

AHRI 1600–202X Draft with regard to 

the building load lines and temperature 

bin hours used when determining the 

new seasonal metrics, SCORE and 

SHORE. 89 FR 24206, 24238–24239. 

Specifically, DOE noted that (1) the new 

metrics use total hours instead of 

fractional hours; (2) total hours are split 

into conditioning hours and shoulder 

hours, with the cooling conditioning 

hours and cooling-season shoulder 

hours for each bin listed in table 15 of 

AHRI 1600–202X Draft 44 and the 

heating conditioning hours and heatingseason shoulder hours for each bin 

listed in table 18 of AHRI 1600–202X 

Draft; 45 and (3) the cooling and heating 

building load lines were revised based 

on PNNL EnergyPlus simulations. Id. 

DOE surmised that the switch from 

fractional hours to total hours, the 

associated values of the conditioning 

hours and shoulder hours, and changes 

in the building load line equations 

represented industry consensus for 

calculations of the new cooling and 

heating performance metrics, SCORE 

and SHORE. 89 FR 24206, 24239. DOE 

proposed to incorporate by reference the 

new cooling conditioning hours, 

cooling-season shoulder hours, heating 

conditioning hours, heating-season 

shoulder hours, and the updated 

building load line equations in AHRI 

1600–202X Draft, at appendix M2. Id. 

In response to DOE’s proposal, 

Copeland asserted that, while a 

differentiated load line for variablespeed systems is indeed consistent with 

AHRI 1600–2024, it may no longer be 

representative of how various 

compressor-staging technologies are 

sized and installed in the field by the 

time ratings in terms of SCORE and 

SHORE take effect. (Copeland, No. 31 at 

pp. 2–3) Copeland pointed to a recent 

(February 2024) revision of the capacity 

range sizing recommendations for twostage systems in the third edition of Air 

Conditioning Contractors of America’s 

(‘‘ACCA’s’’) Manual S® 46 as the source 

of its concern, remarking that these 

revisions were not available when the 

AHRI Standards Technical Committee 

discussions regarding AHRI 210/240– 

2024 and AHRI 1600–2024 took place. 

(Id.) 

Copeland also noted that the slope 

factors used to differentiate the heating 

building load line for variable-speed 

HPs from single-stage and two-stage HPs 

in the current appendix M1 (i.e., C and 

CVS) were derived from an Oak Ridge 

National Laboratory (‘‘ORNL’’) 

analysis 47 and influenced by the 

capacity range sizing recommendations 

in the second edition of ACCA’s Manual 

S. (Copeland, No. 31 at pp. 2–3) 

Copeland commented that the second 


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48See table N1.16.2.4 in the normative section of 

the third edition of ACCA’s Manual S, available 

here: www.acca.org/standards/technical-manuals/ 

manual-s. 

49The different default fan power and default fan 

heat coefficients for mobile-home and spaceconstrained systems as compared to conventional 

systems reflect the lower duct pressure drop 

expected for such systems in field operation—the 

lower values are consistent with the lower ESP 

levels required in testing of blower-coil systems 

intended for mobile home and spaced-constrained 

applications (see table 4 of appendix M1). 

edition of ACCA’s Manual S allowed a 

range of capacity from 0.9 to 1.15 for 

single-stage and two-stage HPs and 0.9 

to 1.3 for variable-speed HPs, which, if 

used to calculate a size adjustment 

factor for variable-speed HPs, equals 

1.07 (by dividing (0.9 + 1.3) by (0.9 + 

1.15)). (Id.) Taking this same approach 

with the third edition of ACCA’s 

Manual S, which allows oversizing for 

two-stage HPs up to 1.25 and up to 1.3 

for variable-speed HPs, Copeland stated 

that the size adjustment factor for 

variable-speed HPs would be 1.02 (by 

dividing (0.9 + 1.3) by (0.9 + 1.25)) 

instead of 1.07. (Id.) 

Rather than adjusting the values of C 

and CVS, however, Copeland encouraged 

DOE to consider eliminating the 

differentiated load line altogether, since 

a building’s load calculation is not 

dependent on the compression 

technology of a heating and/or cooling 

system. (Copeland, No. 31 at pp. 2–3) 

Copeland also commented that it could 

not find any field data to support the 

idea that technicians vary oversizing 

practices based on compression 

technologies. Copeland asserted it is 

more likely that technicians calculate 

the load of the building and then select 

the next-larger capacity an OEM has 

available in a good, better, best offering 

when presenting quotes to homeowners. 

(Id.) 

In response to Copeland’s comment 

encouraging DOE to consider 

eliminating the differentiated load line 

altogether, DOE notes that similar 

concerns were raised and addressed in 

the previous CAC/HP final rule, 

published by DOE on January 5, 2017 

(‘‘January 2017 Final Rule’’). 82 FR 

1426. In the January 2017 Final Rule, 

DOE noted that the incorporation of 

differentiated slope factors does not 

suggest any difference in building load 

when using different technology. 82 FR 

1426, 1456. Rather, the slope factor 

simply represents the ratio of building 

load to heat pump capacity. Id. DOE 

acknowledged that variable-speed 

products are slightly more oversized in 

comparison to the building heating load 

than are single-speed and two-stage 

products. Id. Keeping the building load 

constant and increasing the variablespeed HP capacity reduces the building 

load/capacity ratio; hence DOE selected 

a lower slope factor (i.e., CVS, equal to 

1.07) for variable-speed HPs as 

compared to the slope factor for singlestage and two-stage HPs (i.e., C, equal to 

1.15). Id. In the absence of robust data 

showing average load/capacity ratios for 

different products, DOE based its 

building load factors on ACCA’s Manual 

S recommendations, at the time using 

the second edition. The topic of a 

differentiated building load line for 

variable-speed units was also discussed 

during the development of the AHRI 

210/240 and 1600 standards, and 

consensus was formed that it was 

appropriate to retain the differentiated 

line. Notably, both AHRI 210/240–2024 

and AHRI 1600–2024 include a 

differentiated building load line for 

variable-speed units. 

In response to Copeland’s comment, 

DOE notes that additional changes to 

the capacity range sizing 

recommendations were made in the 

third edition of ACCA’s Manual S that 

were not mentioned in Copeland’s 

comment. Specifically, the minimum 

capacity factor recommended for 

variable-speed heat pumps was 

increased from 0.9 in the second edition 

of ACCA’s Manual S to 1.0 in the third 

edition of ACCA’s Manual S.48

Incorporating this change into the 

approach taken by Copeland (as 

described in the preceding paragraphs), 

the size adjustment factor for variablespeed HPs as compared with two-stage 

heat pumps would remain 1.07 (by 

dividing (1 + 1.3) by (0.9 + 1.25)). DOE 

agrees that a future revisit of these 

issues, taking into consideration the 

revision to Manual S and any new data 

that could be collected to shed light on 

potential sizing differences, and 

allowing for a robust discussion of the 

issues among relevant stakeholders, may 

be appropriate when the AHRI test 

standards and DOE test procedure 

undergo amendments in future. 

However, DOE notes the committee 

consensus for retaining the 1.07 factor 

in the test standards, as reflected in 

AHRI 1600–2024, and is finalizing the 

DOE test procedure with this factor in 

this document. 

AHRI 1600–2024 finalized the 

updates to the building load lines and 

temperature bin hours, without 

substantial change from AHRI 1600– 

202X Draft. Therefore, consistent with 

the April 2024 NOPR proposal, DOE is 

incorporating by reference AHRI 1600– 

2024 and adopting the associated 

building load lines and temperature bin 

hours, at appendix M2. DOE is also 

clarifying that representations of SHORE 

made using the ‘‘Cold Climate Average’’ 

heating conditioning hours and 

shoulder season hours in table 18 of 

AHRI 1600–2024 are optional. 

4. Default Fan Power Coefficients for 

Coil-Only Systems 

Coil-only air conditioners are 

matched split systems consisting of a 

condensing unit and indoor coil that are 

distributed in commerce without an 

indoor blower or separate designated air 

mover. Such systems installed in the 

field rely on a separately installed 

furnace or a modular blower for indoor 

air movement. Because coil-only CAC/ 

HP combinations do not include a 

designated air mover to circulate air, the 

DOE test procedures prescribe default 

values for power input and heat output 

to represent the furnace fan with which 

the indoor coil would be paired in a 

field installation. The default values are 

equal to the measured airflow rate (in 

scfm) multiplied by a defined 

coefficient (expressed in Watts (‘‘W’’) 

per 1,000 scfm (‘‘W/1,000 scfm’’) for fan 

power, and Btu/h per 1,000 scfm (‘‘Btu/ 

h/1,000 scfm’’) for fan heat), hereafter 

referred to as the ‘‘default fan power 

coefficient’’ and ‘‘default fan heat 

coefficient.’’ The resulting fan power 

input value is added to the electrical 

power consumption measured during 

testing. The resulting fan heat output 

value is subtracted from the measured 

cooling capacity of the CAC/HP for 

cooling mode tests and added to the 

measured heating capacity for heating 

mode tests. 

In appendix M1, separate fan power 

and fan heat equations are provided for 

different types of coil-only systems (e.g., 

the equations for mobile home or spaceconstrained are different than for 

‘‘conventional’’ non-mobile home and 

non-space-constrained, and the 

equations for single-stage are different 

than for two-stage and variable speed).49

See, e.g., appendix M1, section 3.3. For 

single-stage coil-only units installed in 

mobile homes and for single-stage 

space-constrained systems, appendix 

M1 defines a default fan power 

coefficient of 406 W/1,000 scfm and a 

default fan heat coefficient of 1,385 Btu/ 

h/1,000 scfm. See, e.g., appendix M1, 

section 3.3.d. For single-stage coil-only 

units installed in ‘‘conventional’’ (i.e., 

non-mobile-home and non-spaceconstrained) systems, appendix M1 

defines a default fan power coefficient 

of 441 W/1,000 scfm and a default fan 

heat coefficient of 1,505 Btu/h/1,000 


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scfm. See, e.g., appendix M1, section 

3.3.e. 

In addition to the aforementioned 

default fan powers for single-stage coilonly systems, which reflect full-load 

operation, appendix M1 defines lowerload default fan powers at a reduced air 

volume rate of 75 percent for two-stage 

and variable-speed coil-only systems. 

Appendix M1 then uses these full-load 

and lower-load default fan powers to 

interpolate default fan power 

coefficients and default fan heat 

coefficients for the full-load and partload tests, depending on the air volume 

rate used for each test expressed as a 

percentage of the cooling full-load air 

volume rate (‘‘%FLAVR’’). See, e.g., 

appendix M1, section 3.3, equations for 

DFPCMHSC and DFPCC. Appendix M1 

interpolates the default fan power 

coefficient for two-stage and variable 

speed coil-only units installed in mobile 

homes and for two-stage and variablespeed space-constrained coil-only 

systems (‘‘DFPCMHSC’’), using 

assumptions for full-load default fan 

power at 406 W (i.e., the same as for 

single-stage systems) and a lower-load 

default fan power at a reduced air 

volume rate of 75 percent, at 308 W. For 

‘‘conventional’’ non-mobile-home and 

non-space-constrained two-stage and 

variable-speed systems, appendix M1 

interpolates the default fan power 

coefficient (‘‘DFPCC’’) using 

assumptions for full-load default fan 

power at 441 W (i.e., the same as for 

single-stage systems) and a lower-load 

default fan power at a reduced air 

volume rate of 75 percent, at 335 W. The 

default fan power values used in the 

determination of the default fan power 

coefficients were a result of empirical 

analysis presented by DOE in the 

October 2022 Final Rule. (See 87 FR 

64550, 64555–64559). 

In the April 2024 NOPR, DOE noted 

that AHRI 1600–202X Draft defines 

revised lower-load default fan powers at 

a reduced air volume rate of 65 percent 

(rather than 75 percent) for two-stage 

and variable-speed coil-only systems 

and updates the default fan power 

values used in each interpolation to 

better reflect the fan power values used 

by coil-only systems today (on average). 

89 FR 24206, 24239–24240. AHRI 1600– 

202X Draft also moves mobile home 

systems from the default fan power 

coefficient equation for spaceconstrained systems to the equation for 

‘‘conventional’’ non-space-constrained 

systems, because insufficient evidence 

was presented to the AHRI Standards 

Technical Committee to justify that 

default fan power coefficients for mobile 

home systems should be different from 

‘‘conventional’’ systems. Therefore, 

solely for space-constrained coil-only 

systems, AHRI 1600–202X Draft uses a 

full-load default fan power of 293 W 

and a lower-load default fan power of 

135 W in the default fan power 

coefficient interpolation (‘‘DFPCSC’’). 89 

FR 24206, 24239–24240. For non-spaceconstrained coil-only systems, AHRI 

1600–202X Draft uses a full-load default 

fan power of 346 W and a lower-load 

default fan power of 159 W in the 

default fan power coefficient 

interpolation (‘‘DFPCNSC’’). Id. All 

default fan powers are lower than those 

used in the calculation of DFPCMHSC

and DFPCC in appendix M1. 

DOE surmised that the new equations 

for default fan power coefficients and 

default fan heat coefficients (and their 

reduced full-load default fan powers 

and their reduced lower-load default fan 

powers at a reduced air volume rate of 

65 percent) in AHRI 1600–202X Draft 

represented industry consensus 

regarding the assumed power input and 

heat output of an average furnace fan or 

modular blower with which the test 

procedure assumes the indoor coil is 

paired in a field installation. Id. DOE 

tentatively determined that the reduced 

full-load and low-load default fan 

powers more accurately reflected the 

average design of the current installed 

base for blowers paired with coil-only 

CAC/HP installations, which 

increasingly use more efficient fan 

motors (with lower wattages). Id. DOE 

also tentatively determined that the 

reduced air volume rate more accurately 

reflected the average low-load air 

volume rate of the currently installed 

base for blowers paired with coil-only 

CAC/HP installations. Id. Therefore, 

DOE proposed to incorporate by 

reference the default fan power 

coefficient equations and default fan 

heat coefficient equations, and 

associated default fan powers used to 

interpolate such coefficients, in AHRI 

1600–202X Draft, at appendix M2. Id. 

DOE did not receive any comments 

regarding this proposal. AHRI 1600– 

2024 finalized the changes to the default 

fan power coefficients for coil-only 

systems, without change. Therefore, 

consistent with the April 2024 NOPR 

proposal, DOE is incorporating by 

reference AHRI 1600–2024 and the 

associated provisions for default fan 

power coefficients, at appendix M2. 

5. Airflow Limits To Address 

Inadequate Dehumidification 

In the April 2024 NOPR, DOE 

explained that, to address adequate 

dehumidification in hot and warm, 

humid climates, AHRI 1600–202X Draft 

established new airflow limits for the 

cooling mode tests to avoid high 

sensible heat ratios. 89 FR 24206, 24240. 

Specifically, section 6.1.5.2 of AHRI 

1600–202X Draft sets a maximum 

airflow limit at 37.5 scfm per 1000 Btu/ 

h (i.e., 450 cubic feet per minute (‘‘cfm’’) 

per ton of capacity) for cooling full 

airflow. Id. Additionally, section 6.1.5.3 

of AHRI 1600–202X Draft sets a 

maximum airflow limit at 50 scfm per 

1,000 Btu/h (i.e., 600 cfm per ton of 

capacity) for cooling low airflow. Id. 

Should the cooling full airflow or 

cooling low airflow specified by the 

manufacturer exceed these limits, AHRI 

1600–202X Draft requires that airflows 

be reduced to meet these limits for 

testing. Id. 

In the April 2024 NOPR, DOE 

surmised that the addition and selection 

of specific cooling airflow limits in 

AHRI 1600–202X Draft represented 

industry consensus regarding the issue 

of inadequate dehumidification. 89 FR 

24206, 24240. DOE tentatively 

determined that such airflow limits 

were appropriate to ensure that CAC/ 

HPs provide adequate dehumidification 

during cooling mode operation and, 

therefore, DOE proposed to incorporate 

by reference the cooling full airflow and 

cooling low airflow limits specified in 

the AHRI 1600–202X Draft, at appendix 

M2. Id. 

DOE did not receive any comments 

regarding this proposal. AHRI 1600– 

2024 finalized the cooling full airflow 

and cooling low airflow limits without 

change. Therefore, consistent with the 

April 2024 NOPR, DOE is incorporating 

by reference AHRI 1600–2024 and the 

associated airflow limits at appendix 

M2. 

G. General Comments Received in 

Response to the April 2024 NOPR 

In response to the April 2024 NOPR, 

DOE received several general comments 

not specific to any one test procedure 

provision. This section discusses those 

general comments received. 

The Joint Advocates commented that 

before appendix M2 is enforced, DOE 

should encourage manufacturers to 

optionally rate their systems using 

SCORE and SHORE, i.e., the appendix 

M2 energy efficiency metrics. (Joint 

Advocates, No. 30 at p. 1) The Joint 

Advocates commented that such ratings 

would allow DOE to do an appropriate 

crosswalk from SEER2 to SCORE, and 

HSPF2 to SHORE, to support the next 

round of CAC/HP standards rulemaking. 

(Id.) As discussed in section II of this 

document, use of appendix M2 would 

not be required until the compliance 

date of amended energy conservation 

standards denominated in terms of 

SCORE and SHORE, should DOE adopt 

such standards. However, 


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50See table 21 of appendix M1 for the current 

CLH and HLH estimates used for rating values. 

51See Docket No. EERE–2022–BT–TP–0028– 

0019. 

manufacturers may choose to make 

optional representations based on the 

metrics in appendix M2 and are 

encouraged to provide any test data to 

DOE to help support an analysis of the 

crosswalk of the energy efficiency 

metrics from appendix M1 to appendix 

M2. 

Additionally, the Joint Advocates 

commented that the bin method used to 

calculate HSPF2 and SHORE assumes 

that an HP will provide as much 

capacity as possible and resistance heat 

will meet the remaining building load. 

(Joint Advocates, No. 30 at p. 4) 

However, the Joint Advocates asserted 

that control logic will ultimately 

determine the relative operation of these 

heat sources, which may not fit with the 

bin calculation method assumption 

described. (Id.) The Joint Advocates 

stated that, in the case that an HP uses 

more resistance heat than assumed by 

the bin calculation method, a lower 

efficiency would be observed in the 

field than the efficiency rated for an HP; 

subsequently, the Joint Advocates 

encouraged DOE to consider this aspect 

of the CAC/HP Federal test procedure in 

a future rulemaking. (Id.) 

In response to the Joint Advocates’ 

comment, at this time DOE has not 

determined an approach to account for 

the controls of the heat pump working 

in tandem with electric resistance heat, 

and is not adopting such an approach in 

this final rule. DOE notes that it may 

consider such an approach in the future. 

H. Represented Values 

In the following sections, DOE 

discusses requirements regarding 

represented values. To the extent that 

DOE is amending the requirements 

specified in 10 CFR part 429 regarding 

representations of CAC/HPs, such 

amendments to 10 CFR part 429, if 

made final, would be required starting 

180 days after publication in the 

Federal Register of this final rule. Prior 

to 180 days after publication in the 

Federal Register of this final rule, the 

current requirements would apply. 

However, manufacturers would be 

permitted to choose between using the 

current or new requirements for a 

period between 30 days and 180 days 

after publication in the Federal Register 

of this test procedure final rule. 

1. Represented Values for the Federal 

Trade Commission 

As described in a final rule regarding 

EnergyGuide labels published on 

October 12, 2022, the Federal Trade 

Commission (‘‘FTC’’) is responsible for 

periodical updates to energy labeling for 

major home appliances and other 

consumer products, including CAC/ 

HPs, to help consumers compare 

competing models. 87 FR 61465, 61466. 

Among other disclosures, EnergyGuide 

labels for CAC/HPs include estimated 

annual energy costs for both cooling and 

heating, which are based on the 

represented values for each basic 

model’s efficiencies (SEER2 and HSPF2, 

as applicable), cooling capacities, and 

estimates for cooling load hours 

(‘‘CLH’’) and heating load hours 

(‘‘HLH’’) in a year. CLH and HLH can be 

thought of as the hours of run time at 

full capacity required to provide 

seasonal conditioning (in Btu) as 

calculated in the test procedure to 

determine seasonal efficiencies. 

Currently, the FTC uses 1,000 and 1,572 

hours as estimates for CLH and HLH, 

respectively, for all ratings of CAC/HP 

basic models.50

In the April 2024 NOPR, DOE 

proposed to retain the current CLH and 

HLH estimates in appendix M1, for use 

in conjunction with SEER2 and HSPF2 

representations. 89 FR 24206, 24242– 

24243. 

For appendix M2, DOE proposed new 

estimates for CLH and HLH for use in 

conjunction with the proposed 

appendix M2 efficiency metrics, SCORE 

and SHORE. 89 FR 24206, 24243. DOE 

noted that unlike SEER2 and HSPF2, 

SCORE and SHORE are integrated 

metrics (that include off mode and 

standby power) and use updated 

weather data for the United States’ 

average number of conditioning and 

shoulder-season hours per temperature 

bin. Id. Therefore, DOE tentatively 

determined that the proposed appendix 

M2 required new CLH and HLH values 

for use by the FTC. Id. Specifically, DOE 

proposed to use 1,457 and 972 hours as 

estimates for CLH and HLH, 

respectively, for use in conjunction with 

SCORE and SHORE representations. Id. 

DOE presented step-by-step derivations 

of proposed appendix M2 CLH and HLH 

values in a docketed white paper titled 

‘‘Derivation of Proposed Appendix M2 

Cooling Load Hours and Heating Load 

Hours for the Federal Trade 

Commission.’’ 51 Id. 

In response to DOE’s proposal, Keith 

Rice requested that the basis for these 

revised cooling and heating load hours 

(and the revised building load lines and 

temperature bin hours, discussed in 

section III.F.3 of this final rule) be well 

documented in a published report. 

(Keith Rice, No. 33 at p. 1) Keith Rice 

commented that this is important 

considering that the proposed CLH and 

HLH values for appendix M2 give a 

much higher weighting to cooling 

energy use performance relative to 

heating. (Id.) 

In response to Keith Rice, DOE notes 

that the CLH and HLH values presented 

in its docketed white paper were 

derived from the building load lines and 

temperature bin hours presented in 

AHRI 1600–202X Draft. Therefore, the 

report requested by Keith Rice (i.e., a 

report detailing the basis for the revised 

building load lines and temperature bin 

hours in AHRI 1600–2024) would need 

to be provided by AHRI. DOE 

understands the value of publicizing the 

weather analysis that forms the basis of 

the building load lines and temperature 

bin hours under appendix M2. 

Subsequently, DOE is willing to support 

AHRI in the process of publicizing a 

weather analysis report, as requested by 

Keith Rice. 

DOE did not receive any other 

comments regarding the proposal for 

new CLH and HLH values under 

appendix M2. Therefore, for the reasons 

discussed in the preceding paragraphs 

and the April 2024 NOPR, DOE is 

adopting different CLH and HLH values 

under appendix M2 than under the 

current appendix M1, as proposed. 

In response to DOE’s proposals for 

CLH and HLH, Keith Rice also 

commented on the proposed 

calculations of annual operating costs in 

the April 2024 NOPR. (Keith Rice, No. 

33 at p. 1) Keith Rice noted that the 

calculations of annual operating costs 

for single- versus variable-speed HPs in 

the current appendix M1 and proposed 

appendix M2 give a 7-percent additional 

energy savings benefit to variable-speed 

systems when compared on an equal 

rated capacity basis. (Id.) Keith Rice 

recommended, reasoning that 

consumers would expect that operating 

cost comparisons would be on the basis 

of equal house loads, that the existing 

appendix M1 and proposed appendix 

M2 operating cost calculation 

approaches be modified to remove the 

extra 7-percent benefit. (Id.) Keith Rice 

commented that, in the current 

appendix M1 and proposed appendix 

M2, the seasonal energy performance 

factors (i.e., SEER2 and HSPF2 for 

appendix M1 and SCORE and SHORE 

for appendix M2) for variable-speed 

systems have already been boosted by 

the assumption of lower cooling and 

heating building loads for a given 

cooling capacity. (Id. at pp. 1–2) 

Subsequently, Keith Rice suggested that 

the V-factor of 0.93 in cooling mode and 

the lower 1.07 Cx factor in heating mode 

be removed from the operating cost 

calculations for energy labeling so as to 

not result in a type of double counting 


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52 In the April 2024 NOPR preamble discussion, 

there were instances where DOE mistakenly 

referred to section 11.2.3 and appendix H of AHRI 

210/240–202X Draft. This has been corrected to 

section 11.3 and appendix G of AHRI 210/240– 

202X Draft in this final rule preamble discussion. 

of energy savings benefits for variablespeed units. (Id.) 

DOE appreciates Keith Rice’s 

comments regarding the calculations of 

annual operating costs and understands 

that, if a variable-speed product is 

compared with a single- or two-stage 

product on an apples-to-apples basis 

(i.e., if both products hypothetically had 

the same represented cooling capacity 

and same represented SEER2 or HSPF2 

under appendix M1 or SCORE or 

SHORE under appendix M2), the 

calculations of annual operating costs 

for a variable-speed product would 

yield 7-percent lower results. However, 

DOE notes that this 7-percent difference 

has been used by FTC for some time— 

since it was adopted in the January 2017 

Final Rule. 82 FR 1426, 1473–1475. 

Additionally, DOE notes that this 7- 

percent difference in annual operating 

costs is relatively marginal compared to 

other factors of variability, such as 

electricity rates, consumer usage 

patterns, etc. For these reasons, DOE is 

adopting the calculations of annual 

operating costs as proposed in the April 

2024 NOPR, which are unchanged from 

the existing calculations of annual 

operating costs. 

2. Off Mode Power 

Off mode power, PW,OFF, is a required 

represented value for all CAC/HPs, as 

specified in 10 CFR 429.16(a)(1). 

Currently, section 3.13 of appendix M1 

includes testing instructions to 

determine off-mode power ratings for 

CAC/HPs. In the April 2024 NOPR, DOE 

proposed to incorporate by reference 

AHRI 210/240–202X Draft at appendix 

M1, and it noted that section 11.3 and 

appendix G of AHRI 210/240–202X 

Draft 52 include the same test 

instructions to determine PW,OFF as are 

present in the current appendix M1. 89 

FR 24206, 24243. Therefore, DOE 

proposed no changes in representation 

requirement for off mode testing when 

testing per appendix M1. Id. 

For appendix M2, DOE noted that the 

applicable metrics, SCORE and SHORE, 

directly incorporate off mode power 

consumption and as such, requiring 

representation of PW,OFF would be 

redundant for appendix M2. 89 FR 

24206, 24243. Therefore, DOE proposed 

to clarify at 10 CFR 429.16(a)(2) that 

represented values of PW,OFF are only 

required when testing in accordance 

with appendix M1. Id. 

Additionally, 10 CFR 429.16(b)(2)(ii) 

currently allows flexibility for 

manufacturers to not test each 

individual model/combination (or 

tested combination) for PW,OFF, but at a 

minimum, test at least one individual 

model/combination for PW,OFF among 

individual models/combinations with 

similar off mode construction. In the 

April 2024 NOPR, DOE proposed to 

retain this flexibility for testing to 

appendix M1. 89 FR 24206, 24243. 

For appendix M2, DOE extended 

similar flexibility for determining off 

mode power values P1 (off mode power 

in shoulder season) and P2 (off mode 

power in heating season), which are 

used to calculate the SCORE and 

SHORE metrics when testing to 

appendix M2. 89 FR 24206, 24243. 

Specifically, DOE proposed at 10 CFR 

429.16(b)(2)(iii) that when testing in 

accordance with appendix M2 and 

determining SCORE and SHORE, each 

individual model/combination is not 

required to be tested for values of P1 (off 

mode power in shoulder season) and P2

(off mode power in heating season). Id. 

Instead, at a minimum, among 

individual models/combinations with 

similar off mode construction (even 

spanning different models of outdoor 

units), a manufacturer must test at least 

one individual model/combination, for 

which P1 and P2 are the most 

consumptive. Id. 

In response to the April 2024 NOPR, 

Carrier, Lennox, and Rheem all 

commented in support of DOE’s 

proposal pertaining to off mode power. 

(Carrier, No. 29 at p. 5; Lennox, No. 24 

at p. 4; Rheem, No. 34 at p. 5) Therefore, 

for the reasons discussed in the 

preceding paragraph and the April 2024 

NOPR, DOE is adopting these changes 

as proposed. 

3. AEDM Tolerance for SCORE and 

SHORE 

DOE’s existing regulations allow the 

use of an AEDM, in lieu of testing, to 

simulate the efficiency of CAC/HPs. 10 

CFR 429.16(d). For models certified 

with an AEDM, results from DOE 

verification tests are subject to certain 

tolerances when compared to certified 

ratings. 10 CFR 429.70(e)(5)(v). The 

current tolerance specified for efficiency 

metrics for CAC/HPs (i.e., SEER2, 

HSPF2, and EER2) requires that the 

result from the DOE verification test 

must be greater than or equal to 0.95 

multiplied by the certified represented 

value. 

In the April 2024 NOPR, to maintain 

consistency with the existing efficiency 

metrics, DOE proposed to extend the 

same tolerance requirement to the new 

efficiency metrics measured per 

appendix M2—EER, SCORE and 

SHORE. 89 FR 24206, 24243. 

DOE did not receive any comments 

regarding this proposal pertaining to 

AEDM tolerances on the new metrics 

and, therefore, DOE is adopting the 

change as proposed. 

4. Removal of the AEDM Exception for 

Split-System CAC/HPs 

Currently, the AEDM requirements at 

10 CFR 429.70(e) allow that, until July 

1, 2024, non-space-constrained singlesplit-system CAC/HPs rated based on 

testing in accordance with appendix M1 

are allowed to test a single-unit sample 

from 20 percent of the basic models 

distributed in commerce to validate the 

AEDM. On or after July 1, 2024, 

validation of the AEDM has to be based 

on complete testing of each basic model. 

See 10 CFR 429.70(e)(2)(i)(A). 

Corresponding provisions are also 

included at 10 CFR 429.16, paragraphs 

(b)(2)(i) and (c)(1)(i)(B). 

In the April 2024 NOPR, DOE noted 

that since amendments proposed in the 

NOPR are not expected to be finalized 

and made effective before July 1, 2024, 

the AEDM exception for non-spaceconstrained single-split-system CAC/ 

HPs would no longer apply at the time 

this rulemaking finalizes. 89 FR 24206, 

24243. As such, DOE proposed to 

remove the date-based application of the 

AEDM requirement and instead clarify 

that AEDM validation for all CAC/HPs, 

including non-space-constrained singlesplit-system CAC/HPs, must be based on 

complete testing of each basic model. Id. 

DOE did not receive any comments 

regarding this proposal and is adopting 

the change as proposed. 

I. Enforcement Provisions 

1. Verifying Cut-Out and Cut-In 

Temperatures 

In the April 2024 NOPR, DOE 

proposed that for assessment and 

enforcement testing of HP models, the 

cut-out and cut-in temperatures may be 

verified using the test method in 

appendix J of AHRI 210/240–202X Draft 

and AHRI 1600–202X Draft, and that if 

this method is conducted, the cut-in and 

cut-out temperatures determined using 

this method will be used to calculate the 

relevant heating metric for purposes of 

compliance. 89 FR 24206, 24243. 

AHRI 210/240–2024 and AHRI 1600– 

2024, the industry standards DOE is 

referencing in this final rule, finalized 

the relevant test method for determining 

cut-out and cut-in temperatures in 

appendix J without any substantial 

change. Therefore, consistent with the 

April 2024 NOPR, DOE is adding 

product-specific provisions at 10 CFR 


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53See 89 FR 24206, 24243. 

54EER2 and COP2 for cooling load intervals and 

heating load intervals, respectively, when tested in 

accordance with appendix M1, and EER and COP, 

for cooling load intervals and heating load intervals, 

respectively, when tested in accordance with 

appendix M2. 

55For the purpose of the CVP, ‘‘adjustment’’ 

means that the control device has the ability to 

make discrete adjustments, as required, to the 

compressor and indoor blower speeds without the 

need of any additional hardware or non-publicly 

available software. 

56For tests that do not correspond to any load 

intervals of the CVP, DOE proposed to adjust the 

compressor speed as follows: the compressor 

speeds for tests BFull, BLow, H3,low, and H0Low will 

be set at the same speeds observed in the CVP load 

intervals associated with the AFull, FLow, H3Full, 

H4Full, and H1Low tests, respectively. 

57As an example per the proposal, the capacity 

at BFull condition, QB,Full, will be calculated by the 

following equation: QB,Full = QB,Full,Certification × 

QCVP,A,Full QA,Full,Certification, where QB,Full,Certification is 

the capacity at BFull condition, QCVP,A,Full is the fullload interval capacity in cooling mode, and 

QA,Full,Certification is the capacity at Afull condition. 58As an example, the capacity at HOLow

condition, QH0,Low, will be calculated by the 

following equation: QH0,Low = QH0,Low,Certification × 

QCVP,H1,Low/QH1,Low,Certification. 

429.134(k)—specifically, DOE is adding 

provisions that for assessment and 

enforcement testing of HP models, the 

cut-out and cut-in temperatures may be 

verified using the method in appendix 

J of AHRI 210/240–2024 or AHRI 1600– 

2024, and that if this method is 

conducted, the cut-in and cut-out 

temperatures determined using this 

method will be used to calculate the 

relevant heating metric for purposes of 

compliance. 

In response to the April 2024 NOPR, 

the Joint Advocates encouraged DOE to 

adopt a requirement for manufacturers 

to report and certify cut-out and cut-in 

temperatures for all HPs as part of a 

separate rulemaking. (Joint Advocates, 

No. 30 at p. 2) DOE maintains that it 

will consider certification requirements 

for CAC/HPs, including the potential 

requirement for certification of cut-out 

and cut-in temperatures, in a separate 

rulemaking, as noted in the April 2024 

NOPR. 89 FR 24206, 24243. 

Additionally, the Joint Advocates 

expressed uncertainty regarding 

whether DOE intended to limit cut-out 

and cut-in temperature verification to 

CCHPs, specifically pointing to the 

following sentence 53 of the April 2024 

NOPR preamble: ‘‘DOE is proposing that 

for assessment and enforcement testing 

of CHP models, the cut-out and cut-in 

temperatures may be verified using the 

method in appendix J and that if this 

method is conducted, the cut-in and 

cut-out temperatures determined using 

this method will be used to calculate the 

relevant heating metric for purposes of 

compliance.’’ (Joint Advocates, No. 30 at 

p. 2) DOE surmises that the Joint 

Advocates’ uncertainty stems from the 

use of the acronym ‘‘CHP’’ in this 

sentence. DOE clarifies that ‘‘CHP’’ 

stands for ‘‘central heat pump,’’ not 

‘‘cold climate heat pump,’’ and that the 

cut-out and cut-in temperature 

verification test in appendix J of the 

respective AHRI Drafts applies to all 

central heat pumps. 

2. Controls Verification Procedure 

(a) DOE’s Proposal 

In the April 2024 NOPR, DOE 

proposed to establish requirements for 

DOE’s use of the CVP per appendix I of 

AHRI 210/240–202X Draft and AHRI 

1600–202X Draft for the purposes of 

assessment and enforcement testing. 89 

FR 24206, 24243–24244. 

DOE proposed that if after conducting 

the CVP a unit is determined to be 

either a variable-capacity compressor 

system; variable-capacity certified, 

single-capacity system; or variablecapacity certified, two-capacity system, 

and meets the tolerances on capacity 

measurement (6 percent) and 

efficiency 54 (10 percent) for the 

applicable CVP load intervals, the 

efficiency metrics for the unit will be 

evaluated by conducting the prescribed 

DOE rating tests per appendix M1 or 

appendix M2 applicable to that system. 

89 FR 24206, 24244. DOE clarified that 

these tests will be conducted based on 

the override instructions from the 

manufacturer for setting the appropriate 

compressor and fan speeds for each test. 

Id. 

However, if either of the full- or 

minimum-load CVP intervals fail to 

meet the required tolerances, and the 

control device allows monitoring and 

adjustment of the compressor and 

indoor blower speeds, and is the same 

control device used for certification and 

CVP tests,55 DOE proposed that it will 

conduct certification tests by setting the 

speeds for the tests to the average values 

observed during the corresponding 

failed CVP interval.56 89 FR 24206, 

24244. Alternatively, if either of the fullor minimum-load CVP intervals fail to 

meet the required tolerances, and the 

control device does not allow 

adjustment of the compressor and 

indoor blower speeds or is not the same 

control device used for certification 

tests, DOE proposed to use the average 

capacity and power(s) or, for CVP 

intervals that do not meet the operating 

tolerances and condition tolerances, 

time-averaged integrated capacity and 

time-averaged integrated power(s), 

measured during the CVP, in order to 

calculate SEER2, HSPF2, and EER2 for 

appendix M1, and SCORE, SHORE, and 

EER, for appendix M2. Id. For 

certification tests that do not have a 

corresponding CVP interval, DOE 

proposed to calculate the corresponding 

efficiency by adjusting the capacity and 

power, by application of a ratio to the 

corresponding CVP interval.57 Id. 

For CHPs determined to be a variablecapacity certified, single-capacity 

system or variable-capacity certified, 

two-capacity system that are certified/ 

marketed for use with only a proprietary 

control device, DOE proposed to utilize 

two options: (1) contact the 

manufacturer to provide override 

control instructions consistent with the 

full- and, if applicable, minimum-speed 

operation observed during the CVP, to 

enable tests without a corresponding 

CVP interval to be conducted at the 

appropriate speeds; or (2) conduct the 

tests for H1Nom, H2Full, H2Low, and 

H3Low, as applicable, using the certified 

instructions, and for other certification 

tests, calculate the corresponding 

efficiency by adjusting the capacity and 

efficiency, by application of a ratio to 

the corresponding CVP interval.58 89 FR 

24206, 24244. Otherwise, DOE proposed 

that the same simulated thermostat lowvoltage signal that resulted in full-speed 

compressor operation for the full-load 

intervals shall be used for all 

certification full-load tests (for variablecapacity certified, single-capacity 

system or variable-capacity certified, 

two-capacity systems), and the same 

simulated thermostat low-voltage signal 

that resulted in low-speed compressor 

operation for the low-load intervals 

shall be used for all certification lowload tests (for variable-capacity 

certified, two-capacity system). Id. 

(b) Comments Received 

In response to these proposals, DOE 

received several comments related to 

various aspects of the CVP’s adoption 

for enforcement and assessment testing. 

The comments are summarized in the 

following subsections. 

(1) General Feedback 

Lennox, the CA IOUs, Rheem, and GE 

Appliances all supported DOE’s 

proposed CVP enforcement provisions 

utilizing the methods in the AHRI 210/ 

240 and AHRI 1600 standards. (Lennox, 

No. 24 at p. 5; CA IOUs, No. 32 at p. 

2; Rheem, No. 34 at p. 5; GE Appliances, 

No. 37 at p. 4) The CA IOUs commented 

that the new provisions in AHRI 210/ 

240 will help consumers realize that 

heat pumps are an efficient means for 

space heating and cooling. (CA IOUs, 

No. 32 at p. 2) 

AHRI pointed out the differences 

between the CVP outlined in AHRI 210/ 


ddrumheller on DSK120RN23PROD with RULES2
1256 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

59See: www.energystar.gov/sites/default/files/ 

asset/document/ENERGY%20STAR%20

Version%206.1%20Central%20Air%20

Conditioner%20and%20

Heat%20Pump%20Final%20Specification%20%28

Rev.%20January%20%202022%29.pdf. 60On May 19, 2021, DOE, in conjunction with 

EPA and NRCan, announced the DOE CCHP Tech 

Challenge as part of the Energy, Emissions, and 

Equity (‘‘E3’’) Initiative. The specification of the 

DOE CCHP Tech Challenge is available at https:// 

www.energy.gov/eere/buildings/cchp-technologychallenge-specifications. 61The ‘‘Min/Mild’’ test is a load-based test 

conducted at outdoor conditions of 47 °F dry bulb 

temperature, and 43 °F wet bulb temperature, and 

indoor conditions of 70 °F dry bulb temperature and 

60 °F wet bulb temperature, in order to validate the 

minimum capacity (at 47 °F outdoor dry bulb 

temperature) of CCHPs participating in the DOE 

CCHP Tech Challenge. 

240 and AHRI 1600, and the CVP 

outlined in the ENERGY STAR® Version 

6.1 (‘‘EPA Energy Star CVP’’) 

Specifications for CACs and Air-Source 

Heat Pumps (‘‘ASHPs’’),59 which are 

shown in table III.1. (AHRI, No. 25 at 

pp. 8–9) 

TABLE III—1 SUMMARY OF CVP IN AHRI 210/240 AND THE EPA ENERGY STAR CVP 

[AHRI, No. 25 at pp. 8–9] 

Test type Test 

segments CAC 

Test 

segments 

CHP 

Test 

duration 

for CAC 

Test 

duration 

for CHP 

AHRI 210/240 and AHRI 1600—Appendix I ............................................... 3 ..................... 6 9–19 hours ..... 18–38 hours. 

EPA Energy Star CVP ................................................................................ None .............. 1 None .............. Up to 2 hours. 

Similarly, LG commented that even 

though the Energy Star CVP is used to 

certify ENERGY STAR CCHPs, DOE’s 

Cold Climate Heat Pump Technology 

Challenge (‘‘DOE CCHP Tech 

Challenge’’) 60 implemented a ‘‘Min/ 

Mild’’ CVP test.61 (LG, No. 38 at p. 3) 

LG suggested that the presence of 

multiple CVPs to certify identical 

products would place undue test burden 

on manufacturers, and DOE should 

incorporate the ‘‘Min/Mild’’ CVP in 

their CVP enforcement provisions, 

rather than going with the CVP outlined 

in the AHRI 210/240 and 1600 

standards. (Id.) 

In response to AHRI’s comment, DOE 

notes that the scope of the ENERGY 

STAR CVP only includes ENERGY 

STAR CCHPs, specifically performance 

at the 5 °F test condition. In contrast, the 

CVP outlined in AHRI 210/240–202X 

Draft and AHRI 1600–202X Draft is 

applicable more broadly to all variablecapacity CAC/HPs. Because of the 

increased scope of the latter CVP, more 

heating test conditions are included, 

resulting in increased heating tests, both 

in number and duration. The CVP 

outlined in appendix I of AHRI 210/ 

240–202X Draft and AHRI 1600–202X 

Draft also includes a 5 °F test for all 

CHPs that report performance at the H4 

conditions, and is functionally the same 

test as the ENERGY STAR CVP. 

In response to LG, DOE notes that 

although the ‘‘Min/Mild’’ CVP is a loadbased method, it has a different method 

of inducing the conditioning load on the 

indoor psychrometric chamber as 

opposed to the CVP outlined in AHRI 

210/240–202X Draft and AHRI 1600– 

202X Draft. As DOE detailed in the 

January 2023 RFI, the ‘‘Min/Mild’’ CVP 

uses the test chamber-induced load 

application scheme, where a fixed 

cooling or heating load is applied to the 

psychrometric chamber, and the unit 

under test responds to the test chamberinduced load to maintain the desired set 

point temperature. 88 FR 4091, 4094– 

4095. In contrast, the CVP in AHRI 210/ 

240–202X Draft and AHRI 1600–202X 

Draft uses the virtual load approach, 

where the load is varied to simulate the 

building response if the capacity of the 

unit under test does not match the 

imposed load. Id. DOE notes that the 

CVP outlined in appendix I of AHRI 

210/240–202X Draft and AHRI 1600– 

202X Draft represents industry 

consensus to ensure that fixed-speed 

settings of variable-speed systems 

would be achieved using native 

(unfixed) control. 89 FR 24206, 24222. 

Therefore, DOE considers that the CVP 

in appendix I of AHRI 210/240–202X 

Draft and AHRI 1600–202X Draft is the 

most suitable option to support 

enforcement associated with testing 

conducted in accordance with 

appendices M1 and M2. 

(2) Delaying CVP Compliance Due to 

Uncertain CVP Tolerances 

As noted in section III.E.1 of this 

document, DOE proposed in the April 

2024 NOPR that systems determined to 

be variable-capacity compressor 

systems; variable-capacity certified, 

single-capacity systems; or variablecapacity certified, two-capacity systems 

after conducting the CVP, must meet 

tolerances of 6 percent and 10 percent 

on capacity and energy efficiency, 

respectively. 89 FR 24206, 24244. 

Lennox commented that the proposed 

tolerances appeared to be reasonable 

from Lennox’s testing, but it noted that 

DOE should ensure that the proposed 

tolerances are not very stringent and 

expressed its openness to talk with DOE 

on the matter. (Lennox, No. 24 at p. 5) 

The Joint Advocates also supported the 

proposed tolerance values and 

requested that DOE continue evaluating 

appropriate values for the tolerances. 

(Joint Advocates, No. 30 at p. 1). 

AHRI, Carrier, Daikin, GE Appliances, 

JCI, LG, and Rheem had several issues 

with the aforementioned tolerances on 

capacity and energy efficiency for the 

CVP enforcement proposed by DOE, and 

they requested that DOE delay the 

compliance date CVP enforcement 

testing. (AHRI, No. 25 at p. 8; Carrier, 

No. 29 at p. 2; Daikin, No. 36 at pp. 3– 

4; GE Appliances, No. 37 at p. 4; JCI, No. 

35 at pp. 2–3; LG, No. 38 at p. 1; Rheem, 

No. 34 at p. 5) 

AHRI commented that even though 

the tolerances proposed by DOE were 

discussed with all stakeholders during 

development of the AHRI 210/240 and 

AHRI 1600 standards, AHRI is aiming to 

conduct CVP testing during 2025, 

analyze the proposed tolerances, and 

provide the relevant information to DOE 

by spring 2026, which will determine if 

the proposed tolerances are supported 

by test data. (AHRI, No. 25 at p. 8) 

Therefore, AHRI requested that DOE 

defer the effective date of CVP 

enforcement provisions to July 2026 at 

the earliest. (Id. at p. 9) 

Carrier recommended that DOE delay 

the compliance date of the CVP 

enforcement to be 360 days after the 

publication of the final rule and revisit 

the proposed tolerances on capacity and 

efficiency once the industry has test 

data available to confirm appropriate 

tolerance values. (Carrier, No. 29 at p. 2) 

Carrier further commented that even 

though the tolerances proposed by DOE 

were discussed with stakeholders 

during the Unitary Small Equipment 

Standards Technical Committee (‘‘USE 

STC’’) negotiations, the consensus was 


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Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1257 

62 GE Appliances, in its example, pointed out that 

the target sensible load for the full-load and lowload tests were set at 97 percent and 103 percent respectively, which may lead to unbalanced bilateral tolerance. 

to not specify any tolerances at that time 

due to a lack of lab test data and 

uncertainty in the CVP. (Id.) Carrier 

expressed concern that the proposed 

tolerances would result in inappropriate 

characterization of system performance 

and may require manufacturers to retest 

and recertify products, thereby 

increasing the cost of testing. (Id.) 

Daikin commented that it does not 

have sufficient test data from Daikin’s 

own test laboratories to agree or disagree 

with the tolerances proposed by DOE. 

(Daikin, No. 36 at pp. 3–4) Daikin 

requested that DOE be open to delay 

CVP enforcement dates and changes to 

the tolerances once stakeholders can 

provide test data to either validate or 

modify the current tolerances. (Id.) 

GE Appliances commented that it 

agrees with AHRI’s recommendation on 

delaying CVP enforcement to no sooner 

than July 2026. (GE Appliances, No. 37 

at p. 4) GE Appliances further 

commented that this will allow time for 

lab testing to validate DOE’s proposed 

tolerances, and for building additional 

lab capacity for CVP testing, which 

takes longer than some existing CVP 

procedures, such as the ENERGY STAR 

CVP. (Id. at pp. 4–5) GE Appliances 

expressed concern that there are some 

items 62 in the CVP in AHRI 210/240 

that may require changes to the 

tolerances proposed by DOE. (Id.) GE 

Appliances pointed to a mismatch 

between the text and the equations in 10 

CFR 429.134(k)(4)(iii)(B), stating that the 

language regarding capacity and 

efficiency tolerances provide for a twosided tolerance, while the formulas only 

allow for one side of the range. (Id. at 

p. 5) GE Appliances recommended that 

the capacity equations should be 

modified to show a two-sided tolerance 

(ensuring consistency with the text), but 

since a one-sided tolerance seems 

appropriate for efficiency, the text in 

429.134(k)(4)(iii)(D) should be updated 

to note that the equations are not 

‘‘within’’ the specified tolerance and are 

one sided. (Id.) 

JCI commented that since the CVP 

tests proposed in AHRI 210/240 are 

complex and time consuming, it is 

crucial for laboratories under the AHRI 

audit program to put in place tolerances 

that are achievable. (JCI, No. 35 at p. 3) 

JCI requested that DOE delay CVP 

enforcement testing until sufficient CVP 

test data has been collected by labs to 

establish such tolerances. (Id.) 

LG commented that since the CVP is 

a new and untried procedure, the 

capacity and efficiency tolerances 

proposed by DOE, of 6 percent and 10 

percent respectively, should be 

reevaluated before finalizing the CVP 

enforcement. (LG, No. 38 at p. 1) LG 

asserted that the proposed tolerances 

may not be sufficient to compare a 

certification test with the CVP test, 

noting that the certification tests utilize 

fixed compressor speed and airflow rate 

while the CVP tests modulate 

compressor speed and airflow rate to 

optimize thermal comfort and system 

performance. (Id.) Additionally, LG 

commented that even though the CVP 

would only be utilized during 

enforcement testing, manufacturers 

would need to verify CVP test values in 

order to internally assess the products, 

for which third-party testing may also 

be required to obtain reliable test data. 

(Id. at p. 3) LG asserted that while selfverification in the manufacturer’s 

internal lab may be available, this 

option also requires additional testing 

time and cost. (Id.) Therefore, LG 

requested that DOE align the 

compliance date of the CVP 

enforcement with appendix M2’s 

effective date, since manufacturers will 

have to do some retesting and 

recertification with the advent of 

appendix M2, and this would help 

reduce their overall test burden. (Id.) 

Similarly, Rheem questioned if there 

was adequate test data available to 

justify the tolerances on capacity and 

energy efficiency proposed by DOE for 

the full- and minimum-load intervals. 

(Rheem, No. 34 at p. 5) Rheem requested 

delaying the compliance data of the CVP 

to July 2026 so that the CVP test data 

collected by AHRI in 2025 may be 

analyzed and help validate the proposed 

tolerances. (Id.) Rheem referred to a 

residential furnace fans final rule 

published by DOE in the Federal 

Register on July 3, 2014 (‘‘July 2014 

Furnace Fan Final Rule’’), in which the 

fan energy rating (‘‘FER’’) metric’s 

enforcement was delayed by DOE. (Id. at 

p. 6) Rheem commented that DOE 

should utilize the aforementioned 

flexibility in delaying enforcement 

provisions, in order to delay 

enforcement of the CVP. (Id.) Rheem 

noted that section I5.1.5 from appendix 

I of AHRI 210/240–2024 and AHRI 

1600–2024—which prescribes a 

maximum allowable variation in EER/ 

COP equal to 5 percent—is redundant, 

given that all condition and operating 

tolerances have already been prescribed 

in section I5 and in the CVP 

enforcement provisions by DOE at 10 

CFR 429.134(k). (Id. at p. 7) 

As noted by AHRI, the CVP tolerances 

on capacity and efficiency, 6 percent 

and 10 percent, respectively, were 

discussed with the stakeholders during 

the development of the AHRI standards. 

During these discussions, DOE 

presented unit capacity, compressor 

speed, and efficiency data on 10 

different variable-speed CHPs—five (5) 

ducted split CHPs and five (5) ductless 

mini-split CHPs. The CHP units were 

from seven (7) different manufacturers 

and had capacities ranging from 1.5 tons 

to 3 tons. Regulatory cooling and 

heating tests were conducted on these 

units as per the existing appendix M1 

procedure, and CVP tests were 

conducted using the test chamberinduced load application scheme, as 

explained in section III.I.2.b.(1) of this 

document. The SEER2 and HSPF2 

metrics were evaluated for the units 

using both the regulatory test values and 

those obtained from the CVP. Table III– 

2 shows the comparison of the 

regulatory and CVP capacities and 

energy efficiency for each of the 10 

units, for cooling full load, cooling low 

load, heating full load, and heating low 

load. The following can be observed, if 

10% is the allowable tolerance for 

capacity and efficiency, when 

comparing the regulatory and CVP 

values: (1) unit 1 was out of tolerance 

on the cooling full load, and heating low 

load capacity and efficiency, (2) unit 3 

was out of tolerance on the cooling low 

load capacity, and heating low load 

capacity and efficiency, (3) unit 6 was 

out of tolerance on the heating full load 

and heating low load capacity and 

efficiency, (4) unit 9 was out of 

tolerance on the cooling low load and 

heating low load efficiency, and (5) unit 

10 was out of tolerance on the cooling 

low load and heating low load capacity 

and efficiency. For the aforementioned 

units, the SEER2 values were 

recalculated by use of the tested out of 

tolerance CVP load intervals and 

adjustment of the applicable load 

intervals without a CVP for full load or 

low load efficiencies and capacities, 

using the following equations: 


ddrumheller on DSK120RN23PROD with RULES2
1258 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

TABLE III–2—REGULATORY AND CVP CAPACITY AND ENERGY EFFICIENCY OF 10 VARIABLE SPEED CHPS

Unit No. Test 

Certification 

capacity 

(Btu/hr) 

CVP 

capacity 

(Btu/hr) 

Certification 

efficiency * 

CVP 

efficiency * 

%age 

difference 

in capacity 

%age 

difference 

in efficiency 

1 ................................... Cooling Full ........................................... 22,515 25,343 13.2 11.6 ¥13 12 

Cooling Low .......................................... 6,521 6,870 23.6 22.5 2 5 

Heating Full .......................................... 18,853 18,659 2.0 2.0 1 0 

Heating Low .......................................... 10,138 15,309 4.4 3.8 27 14 

2 ................................... Cooling Full ........................................... 18,614 17,423 15.0 15.2 6 ¥2 

Cooling Low .......................................... 11,444 12,325 17.6 15.8 5 10 

Heating Full .......................................... 10,787 15,961 2.3 2.1 ¥48 11 

Heating Low .......................................... 9,837 10,591 3.7 2.5 7 32 

3 ................................... Cooling Full ........................................... 33,062 32,397 12.7 12.7 2 0 

Cooling Low .......................................... 16,969 23,183 19.1 18.2 19 5 

Heating Full .......................................... 19,038 19,120 2.0 2.1 0 ¥3 

Heating Low .......................................... 16,373 20,290 4.9 4.3 21 13 

4 ................................... Cooling Full ........................................... 34,439 33,290 13.0 12.7 3 3 

Cooling Low .......................................... 13,196 13,660 24.2 24.5 1 ¥1 

Heating Full .......................................... 18,707 25,224 2.1 1.9 ¥35 11 

Heating Low .......................................... 9,880 10,081 4.1 4.1 1 1 

5 ................................... Cooling Full ........................................... 22,655 21,477 13.5 13.8 5 ¥2 

Cooling Low .......................................... 6,373 7,031 24.0 23.3 3 3 

Heating Full .......................................... 19,415 18,423 2.1 2.0 5 3 

Heating Low .......................................... 10,092 10,011 4.5 3.8 0 16 

6 ................................... Cooling Full ........................................... 21,668 22,734 12.7 12.1 ¥5 5 

Cooling Low .......................................... 11,124 11,018 20.8 18.8 0 9 

Heating Full .......................................... 12,992 22,441 2.6 1.9 ¥73 26 

Heating Low .......................................... 9,197 10,934 5.2 4.5 13 13 

7 ................................... Cooling Full ........................................... 33,470 33,290 12.7 12.7 1 0 

Cooling Low .......................................... 12,503 13,660 23.9 24.5 3 ¥2 

Heating Full .......................................... 17,430 17,217 2.0 2.0 1 ¥1 

Heating Low .......................................... 9,871 9,915 4.4 4.3 0 2 

8 ................................... Cooling Full ........................................... 35,324 38,800 13.7 13.4 ¥10 3 

Cooling Low .......................................... 20,254 20,824 19.9 19.1 2 4 

Heating Full .......................................... 37,690 37,498 2.4 2.4 1 0 

Heating Low .......................................... 20,128 19,479 4.5 4.4 ¥2 2 

9 ................................... Cooling Full ........................................... 22,515 22,455 13.2 13.4 0 ¥2 

Cooling Low .......................................... 6,521 6,602 23.6 18.3 0 22 

Heating Full .......................................... 18,853 18,890 2.0 2.0 0 1 

Heating Low .......................................... 10,138 10,199 4.4 3.9 0 12 

10 ................................. Cooling Full ........................................... 15215 14969 14.1 13.3 2 6 

Cooling Low .......................................... 4,752 5,497 30.3 27.3 5 10 

Heating Full .......................................... 20,509 18,824 2.2 2.1 8 6 

Heating Low .......................................... 3,644 4,998 6.1 5.1 7 17 

* EER2 for cooling tests (in Btu/hr/W), COP2 for heating tests. 

The recalculated SEER2 for units 1, 3, 

6, 9 and 10, are shown in table III–3, 

indicating that the highest difference 

between the recalculated (or adjusted) 

SEER2 was no greater than 9.7%. Unit 

6 was in tolerance for both the full and 

low load intervals and the reduction in 

SEER2 using the adjusted values was 

6.3%. Therefore, it was concluded that 

a maximum energy efficiency tolerance 

of 10% would be appropriate for CVP 

enforcement of variable capacity 

compressor systems. 


ddrumheller on DSK120RN23PROD with RULES2ER07JA25.003</GPH> ER07JA25.004</GPH> ER07JA25.005</GPH> ER07JA25.006</GPH>

C/.cvP,A,Full 

C/.B,Full = C/.B,Full,Certification X Cf.A,Full,Certification 

PcvP,A,Full 

PB,Full = PB,Full,Certification X PA,Full,Certification 

C/.cvP,F,Low 

C/.B,Low = C/.B,Low,Certification X C/.F,Low,Certification 

PcvP,F,Low 

PB,Low = PB,Low,Certification X PF,Low,Certification 
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1259 

TABLE III–3—COMPARISON OF RECALCULATED SEER2 WITH THE CERTIFIED SEER2 FOR UNITS THAT WERE OUT OF

TOLERANCE ON CAPACITY AND/OR EFFICIENCY

Unit No. Certified SEER2 Adjusted SEER2 

%age difference 

between adjusted 

and certified SEER2 

1 ........................................................................................................................... 17.50 16.66 ¥4.9 

3 ........................................................................................................................... 17.02 16.22 ¥4.7 

6 ........................................................................................................................... 18.88 17.69 ¥6.3 

9 ........................................................................................................................... 17.51 15.81 ¥9.7 

10 ......................................................................................................................... 23.84 22.64 ¥5.0 

For capacity, the tolerance of 6% was 

proposed in the April 2024 NOPR, as a 

result of discussions with stakeholders 

during development of appendix I of the 

AHRI 210/240–202X Draft and AHRI 

1600–202X Draft. 89 FR 24206, 24243– 

24244. In appendix I of the AHRI 210/ 

240–202X Draft and AHRI 1600–202X 

Draft, equations I2 and I3 show the 

calculation of the cooling virtual 

sensible load at outdoor conditions of 

95 °F and 67 °F, respectively, and 

equations I9, I10, and I11 show the 

calculation of the heating virtual load at 

outdoor conditions of 5 °F, 17 °F, and 

47 °F, respectively. Each of these 

equations provide a 3% factor on the 

cooling and heating full load and low 

load target virtual loads. Based on the 

data presented above in table III–2 and 

the discussions with relevant 

stakeholders during the development of 

appendix I of the AHRI 210/240–202X 

Draft, DOE has determined 6% as an 

appropriate tolerance for capacity 

measurements during the CVP test. 

During development of the AHRI 

Standards, no counter data was 

presented by any of the stakeholders to 

suggest revising the tolerances of 6% on 

unit capacity, and 10% on unit 

efficiency, for CVP enforcement. DOE 

has also not received any CVP test data 

in response to the April 2024 NOPR to 

indicate that the proposed tolerances are 

not appropriate. Therefore, DOE is 

finalizing the aforementioned tolerances 

as part of the CVP enforcement 

provisions at 10 CFR 429.134(k). 

Regarding delaying the CVP 

enforcement date so that stakeholders 

have sufficient time to conduct CVP 

testing and for DOE to wait for AHRI’s 

CVP testing in 2025 to help inform the 

proposed capacity and efficiency 

tolerances, DOE notes that the CVP is 

not required as part of testing, and a 

manufacturer is currently required to 

certify the compressor and indoor 

blower speed at settings that represent 

normal operation for any variable 

capacity system. Therefore, some form 

of validation to determine the settings 

for normal operation should already be 

in place to allow the manufacturers to 

properly certify these settings. The CVP 

outlined in appendix I of AHRI 210/ 

240–202X Draft and AHRI 1600–202X 

Draft is intended to standardize such a 

procedure. Hence, even if manufacturers 

wanted to prepare to conduct the CVP 

on their products to prepare for 

potential enforcement by DOE, the test 

burden is limited. 

Regarding Rheem’s comment on DOE 

delaying the enforcement of the FER 

metric for furnace fans, DOE clarifies 

that the FER metric was established as 

a regulatory metric, and is hence not 

comparable to the CVP procedure in 

appendix I of AHRI 210/240–202X Draft 

and AHRI 1600–202X Draft, which DOE 

intends to utilize only for the purposes 

of assessment and enforcement testing 

of variable-capacity compressor 

systems. As discussed, the enforcement 

provisions explain what DOE may do in 

the case of enforcement testing for CAC/ 

HPs and are not a requirement for 

manufacturer testing. As such, DOE 

does not see reason to delay the CVP 

enforcement provisions from their 

current effective date, i.e., 180 days after 

publication of this final rule in the 

Federal Register. 

DOE considers that the proposed 

tolerances on capacity and energy 

efficiency, of 6 percent and 10 percent, 

respectively, are currently the most 

appropriate values based on the 

variable-speed test data analyzed by 

DOE. At this time, no additional data is 

available nor has been provided by 

stakeholders and, therefore, DOE is 

finalizing its proposals on the tolerances 

and is not establishing a delayed 

effective date for the CVP. DOE 

welcomes any additional CVP test data 

as it becomes available. 


ddrumheller on DSK120RN23PROD with RULES2
1260 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

In response to Rheem’s comment 

(Rheem, No. 34 at p. 5) regarding the 

tolerances specified in section I5 in 

appendix I of AHRI 210/240–202X Draft 

and AHRI 1600–202X Draft being 

redundant, DOE clarifies that this 

tolerance was incorporated in order to 

determine if the variable-capacity 

compressor system under test met the 

stability requirements and subsequently 

determines the appropriate CVP test 

interval to be evaluated. Therefore, DOE 

disagrees with Rheem that this tolerance 

is redundant in the AHRI drafts. 


ddrumheller on DSK120RN23PROD with RULES2ER07JA25.007</GPH>

DOE agrees with GE Appliances' comment on the mismatch between the text and 

the equations in 10 CFR 429.134(k)(4)(iii)(B). (GE Appliances, No. 37 at p. 5) DOE's 

intent was to maintain a one-sided tolerance on capacity and efficiency since the unit 

under enforcement should not be penalized for better performance during the CVP load 

interval, when compared to the corresponding certification test. Therefore, DOE is 

maintaining the equations on capacity tolerance evaluation, but it is making corrections to 

the text in 10 CFR 429.134(k)( 4)(iii)(B) and 10 CFR 429.134(k)( 4)(iii)(C) as follows 

(additions shown in italics, deletions shown in strikethrough): 

The measured capacity for each full-load interval, as evaluated per the CVP 

conducted in paragraph (k)(4)(i)(A) or paragraph (k)(4)(i)(B) of this section, shall agree 

vritli tlie corresponding certification test 1.vitliin 6 percent be no more than 6 percent less 

than the corresponding certification test capacity, as follows: 

The measured capacity for each minimum-load interval, as evaluated per the CVP 

conducted in paragraph (k)(4)(i)(A) or paragraph (k)(4)(i)(B) of this section, shall agree 
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1261 

63 In the October 2022 VRF Final Rule, DOE 

specifies that if a manufacturer becomes aware that 

any of the certified operational settings for the 

critical parameters are determined to be invalid 

according to the results of a CVP, whether that CVP 

be performed by the manufacturer or another party, 

the manufacturer would be required to recertify the 

operational settings of those critical parameters for 

all affected basic models, as well as rerate and 

recertify the affected basic models. 

(3) Clarification on Enforcement 

Provisions 

Several commenters requested more 

clarity on the CVP enforcement 

provisions and made their own 

recommendations for some of the 

calculations and provisions proposed by 

DOE. 

The Joint Advocates pointed to DOE’s 

proposal for evaluation of CVP results 

when tolerances on capacity and energy 

efficiency are not met, and the control 

used for conducting CVP does not 

provide means for overriding 

compressor and indoor blower speeds 

(10 CFR 429.134(k)(4)(v)(B)) to adjust 

power measurements. (Joint Advocates, 

No. 30 at p. 2) In this case, the Joint 

Advocates commented that DOE 

proposed that power adjustment should 

be done by multiplication with the ratio 

of the efficiency measured during the 

CVP test interval divided by efficiency 

measured during the certification test 

(for the corresponding CVP interval). 

(Id.) The Joint Advocates noted that 

because of the 6-percent tolerance 

allowed for the full-load CVP intervalcapacity measurements, the capacity 

ratio may not be equal to 1, and hence 

it may not be appropriate to use the 

ratio of efficiencies (EER2 or COP2, as 

applicable). (Id.) The Joint Advocates 

suggested that DOE consider adjusting 

power by multiplying the ratio of 

powers, as follows: 

Additionally, the Joint Advocates 

pointed to the provisions in 10 CFR 

429.134(k)(4)(v)(A) and (B)—where DOE 

proposed that for CVP tests for which 

capacity and efficiency tolerances are 

not met, the certification tests must be 

conducted by using the compressor 

speeds determined in the corresponding 

CVP test (or certification test results 

must be adjusted) and the certification 

tests will be used for calculating the 

unit’s efficiency metrics. (Id. at p. 3) The 

Joint Advocates expressed concern that 

if the recalculated efficiency metric is 

compliant, but is lower than the value 

certified to DOE, this will result in a 

misleading efficiency rating and average 

energy cost printed on the FTC label. 

(Id.) The Joint Advocates pointed 

toward the rerate and recertify 

provision 63 for VRF multi-split air 

conditioners and heat pumps (‘‘VRF 


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·.vith the eorrespmidiHg eertifiea-tioH test •.vithiH 6 pereeHt of the eooliHg or hea-tiHg mode 

full load eertifiea-tioH test eapaeity be no more than 6 percent less than the corresponding 

certification test capacity, as follows: 

Similarly, DOE agrees with GE Appliances that a one-sided tolerance on 

efficiency will be appropriate. Therefore, DOE is maintaining the equations on 

efficiency tolerance evaluation, but it is making corrections to the text in 10 CFR 

429.134(k)(4)(iii)(D), as follows (additions shown in italics, deletions shown in 

strik:ethrough): 

The measured efficiency for the full- and minimum-load interval, as evaluated per 

the CVP conducted in paragraph (k)(4)(i)(A) or paragraph (k)(4)(i)(B) of this section, 

shall agree vrith the eorrespoHdiHg eertifieatioH test withiH 10 pereeHt be no more than 10 

percent less than the corresponding certification test efficiency, as follows: 

PcvP,A,Full 

PB,Full, = PB,Full,Certification X p 

A,Full,Certification 
1262 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

multi-split systems’’), which was 

specified by DOE in a final rule on 

October 20, 2022, suggesting that a 

similar provision should be adopted for 

CAC/HPs (‘‘October 2022 VRF Final 

Rule’’). 87 FR 63894. 

In response to the Joint Advocates’ 

comment on adjustment of power of 

certification tests for which a 

corresponding CVP interval did not 

exist, DOE did an analysis on an 

example case for a variable-capacity 

CAC unit. DOE assumed that for a 

hypothetical variable-capacity 

compressor 3-ton CAC unit, with a 

certified EER2A,Full of 12, the capacity at 

BFull condition was 40,000 Btu/hr, and 

the EER2B,Full was 15. It was assumed 

that after conducting the CVP on the 

unit, the value of the EER2 measured 

using the full-load CVP test dropped to 

11.28, as shown in table III.4. DOE then 

evaluated the capacity and power at the 

BFull condition—the power was adjusted 

by using the energy efficiency ratios 

first, as proposed by DOE in the April 

2022 CAC NOPR, and was separately 

adjusted by using the power ratios, as 

suggested by the Joint Advocates. 

BILLING CODE 6450–01–P 

BILLING CODE 6450–01–C 

DOE observed that adjusting the 

power using the energy efficiency ratios 

resulted in the certification and CVP 

values for energy efficiency being out of 

tolerance, i.e., ¥11.6 percent, whereas 

adjusting the power using the power 

ratios resulted in this difference being 

¥6 percent. Additionally, DOE revisited 

its analysis of the regulatory and CVP 

test data of the 10 variable-speed CHPs 

that was used to develop the 6-percent 

tolerance on capacity and 10-percent 

tolerance on efficiency, as explained in 

section III.I.2.b.(2) of this document. 

DOE observed that for one of the units, 

the power ratio adjusted EER2B,Low

value was only 5.9 percent lower than 

the actual EER2 for the Blow CVP test, , 

but the efficiency ratio adjusted 

EER2B,Low was 26 percent higher than 


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Table 111-4 Evaluating the Capacity and Power Measurement Adjustments for 

Certifications Tests with No CVP Interval, in the Event that CVP Tolerances Are 

Not Met 

Certification test values 

<J.A,Full,Certification 36,000 Btu/h 

PA,Full,Certification 3,000 W 

EER2A,Full,Certification 12.0 Btu/Wh 

iJ. B,Full,Certification 40,000 Btu/h 

PB,Full,Certification 2,667 W 

EER2B,Full.Certification 15.0 Btu/Wh 

CVP test values 

<J.cvPAFull 33,840 Btu/h 

PcvPAFull 3,000 W 

EER2cvPAFull 11.28 Btu/Wh 

Ad_justments of power and enernv efficiency using energy efficiency ratios 

. . <J.cvP.A,Full 3,7600 <J.B,Full - <J.B.Full,Certification X 100 qB.Full = qB.Full.Certification X q· Btu/hr A,Full.Certification iJ. B .Full,Certification 

PB.Full = PB,Full,Certification 2,837 PB,Full - PB,Full,Certification X 100 

EER2cvP,A.Full w PB,Full,Certification X 

EE R 2 A,Full.Certi fication 

EER2 - <JR.Full 13.25 EER2B.Full - EER2B,Full.Certification 

B.Full - p 

B.Full EER2B.Full.Certification 

X 100 

Adjustments of power and energy efficiency using power ratios 

. . <J.cvP.A,Full 3,7600 <J.B,Full - <J.B.Full,Certification 

qB.Full = qB.Full.Certification X q· Btu/hr iJ. B .Full,Certification 

X 100 

A,Full.Certification 

PB,Full = PB,Full.Certification X p 

PcvP,A,Full 2,667 PB,Full - PB,Full,Certification 

w X 100 

A,Full,Certification PB,Full,Certification 

EER2 - <JR.Full 14.10 EER2B.Full - EER2B,Full.Certification 

B.Full - p w B.Full EER2B.Full.Certification 

X 100 

-6.0% 

-6.4% 

-

11.6% 

-6.0% 

0.0% 

-6.0% 
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1263 

64Minimum-speed-limiting variable-speed HPs 

are defined at section 3.2.32 of AHRI 210/240–202X 

Draft and 3.2.31 of AHRI 1600–202X Draft as: A 

heat pump for which the minimum compressor 

speed (represented by revolutions per minute or 

motor power input frequency) is higher than its 

minimum value for operation in a 47 °F ambient 

temperature for any bin temperature tj for which the 

calculated heating load is less than the calculated 

intermediate-speed capacity. 

65Rheem suggested that either the phrase ‘‘. . . 

where the range of capacity does not vary by more 

than 15 percent’’ should be deleted fully, or the 

words ‘‘. . . does not vary’’ should be replaced with 

the word ‘‘varies,’’ since the AHRI USE STC’s intent 

when developing this requirement was to 

encapsulate systems that cycle on/off, instead of 

modulating between compressor speeds/stages. 

the . DOE realizes that using the 

efficiency ratios to adjust power 

measurements may result in inflated 

energy efficiencies of the variablecapacity compressor units that DOE will 

run a CVP on. Therefore, DOE is 

adopting the proposed revision by the 

Joint Advocates and modifying the 

equations at 10 CFR 429.134(k)(4)(v)(B) 

that are used to adjust the power 

measurements for certification tests 

requiring adjustment with no CVP 

interval (any required certification test 

other than AFull, FLow, H1Low, H3Full, and 

H4Full), as follows: 

Cooling full power: 

Cooling minimum power: 

Heating minimum power: 

Regarding the Joint Advocates’ 

recommendation to establish a rerate 

and recertify provision similar to the 

one in the October 2022 VRF Final Rule 

(see § 429.43(b)(5)), DOE notes that if a 

variable-capacity compressor system 

meets the minimum standards after the 

CVP assessment or enforcement, but the 

recalculated metric is lower than the 

value certified to DOE, DOE may choose 

to take enforcement action regarding 

invalid certification of the basic model. 

At this time, DOE is not adopting the 

rerate and recertify provision but may 

consider inclusion in a future 

certification rulemaking. 

In response to the CVP enforcement 

provisions, Rheem requested several 

clarifications and made its own 

recommendations, including some 

changes and corrections to the finalized 

standards, AHRI 210/240–2024 and 

AHRI 1600–2024. 

Rheem requested clarification from 

DOE on the provisions in 10 CFR 

429.134(k)(4)(iii)(B) and (D). 89 FR 

24206, 24259. (Rheem, No. 34 at p. 6) 

Rheem noted that at 10 CFR 

429.134(k)(4)(iii)(B) and (D), DOE 

proposed maximum allowable 

tolerances between the heating capacity 

and heating efficiency measured during 

the full-load interval of the CVP and the 

corresponding certification test. (Id.) 

Rheem commented that the proposed 

regulatory text in the section reads as if 

the full-load interval of the heating 

mode CVP must be conducted at both 

17 °F and 5 °F, while section I4.2.1 of 

AHRI 210/240–2024 and AHRI 1600– 

2024 does not require full-load interval 

of the heating CVP to be conducted at 

both 17 °F and 5 °F for all heat pumps. 

(Id.) Additionally, Rheem noted that in 

10 CFR 429.134(k)(4)(i)(C), DOE 

proposed that the CVP will be allowed 

to be terminated without conducting the 

minimum load interval if, according to 

10 CFR 429.134(k) (4)(ii)(B), a system is 

determined to be a variable-capacity 

certified, single-capacity system. 89 FR 

24206, 24258. (Rheem, No. 34 at p. 6) 

Rheem commented that it interprets this 

provision to mean that in such a case, 

capacity, and energy efficiency 

tolerance at low-load intervals, as per 10 

CFR 429.134(k)(4)(iii)(C) and (D), will 

not be necessary. (Id.) In 10 CFR 

429.134(k)(v)(B), Rheem noted that DOE 

proposed to use the capacity slope 

factor (‘‘CSF’’) and power slope factor 

(‘‘PSF’’) for extrapolating an ‘‘adjusted’’ 

heating capacity and heating power 

consumption at H3 (17 °F outdoor dry 

bulb temperature) test condition when 

the compressor is operating at low stage, 

using the system‘s measured 

performance during the heating mode 

CVP’s low-load interval. (Id.) 89 FR 

24206, 24260–24261. Rheem 

commented that the values of CSF and 

PSF will be adopted from AHRI 210/ 

240–2024 or from section 3.6.4.1(b) of 

the current appendix M1, and it 

questioned their accuracy for low-speed 

compressor operation, since they were 

derived for compressor operation at full 

speed. (Rheem, No. 34 at p. 6) In its 

comment, Rheem also questioned the 

extrapolation using these CSF and PSF 

values for minimum-speed-limiting heat 

pumps, as defined 64 in AHRI 210/240– 

2024 and AHRI 1600–2024. (Id.) Finally, 

Rheem pointed to a typographical error 

in sections I4.3.1.4 of AHRI 210/240– 

2024 and AHRI 1600–2024, and it made 

suggestions for correcting it.65 (Id.) 

Rheem commented that since no indoor 

entering wet bulb temperature is 

prescribed for any of the load and 

transition intervals of the heating CVP, 

corrections should be made in section 

I5.1 and section I5.1.3 of AHRI 210/240– 

2024 and AHRI 1600–2024 to reflect 

that any tolerances on indoor entering 

wet bulb temperatures should only be 

applicable to the cooling mode CVP 

tests. (Id. at p. 7) 

In response to Rheem‘s comments, 

DOE clarifies that since the CVP for 

enforcement will be carried out as per 

appendix I of the AHRI 210/240 and 

AHRI 1600 standards, the full-load 

interval of the heating mode CVP at 5 °F 

will only be enforced for those CHPs 

that have reported regulatory 


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p CVP,A,Full 

PB,Full = PB,Full,Certification X PA,Full,Certification 

PcvP,F,Low 

PB,Low = PB,Low,Certification X PF,Low,Certification 

PcvP,Hl,Low 

PHO,Low = PHO,Low,Certification X PHl,Low,Certification 
1264 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

66 In the October 2022 CAC Final Rule, DOE 

defined ‘‘variable-speed communicating coil-only 

central air conditioner or heat pump’’ and 

‘‘variable-speed non-communicating coil-only 

central air conditioner or heat pump.’’ 87 FR 

64550,64589. DOE‘s understanding is that JCI is 

referring to non-communicating variable-speed coilonly (‘‘VSCO’’) CAC/HPs in their comment, since 

the October 2022 CAC Final Rule established a twostage test procedure for non-communicating VSCO 

CAC/HPs. 87 FR 6450, 64591–64597. Such systems 

will only be tested using an on-off control signal 

and will not have any tests at intermediate speeds. 

Id. 

67AHRI 210/240–2024 section 3.2.81 defines 

Variable Capacity System (Variable Capacity Airconditioner or Variable Capacity Heat Pump): an 

air-conditioner or heat pump that has either a) a 

variable capacity compressor, or b) a digital 

compressor, and that controls the system by 

monitoring system operation and automatically 

modulating the compressor output, indoor airflow, 

and other system parameters as required in order 

to maintain the indoor room temperature. 

performance at the H4full test, while the 

CVP at 17 °F will be carried out for all 

CHPs, including units for which 

performance at H4full conditions has not 

been reported. Additionally, DOE 

clarifies that for systems that are 

determined to be variable-capacity 

certified, single-capacity systems, as per 

10 CFR 429.134(k) (4)(ii)(B), there will 

be no need to conduct the minimum 

load interval, and therefore, Rheem’s 

understanding that capacity and energy 

efficiency tolerance at low load 

intervals, as per 10 CFR 

429.134(k)(4)(iii)(C) and (D), will not be 

applicable, is correct. Regarding 

Rheem’s comment on the use of CSF 

and PSF values from the AHRI 

standards, DOE notes that it has not 

received any test data from stakeholders 

that would indicate that the use of these 

slope factors is inaccurate at low 

compressor speed tests. In the absence 

of any test data, DOE is maintaining the 

CSF values of 0.0204/°F for split 

systems and 0.0262/°F for singlepackage units, and PSF value of 

0.00455/°F, as per the April 2024 NOPR, 

to extrapolate an adjusted heating 

capacity and heating power 

consumption at H3 (17 °F) test 

conditions when the compressor is 

operating at low stage, using tested 

system performance during the heating 

CVP’s low load interval. The CSF and 

PSF values are used for extrapolation at 

the H3Low test condition capacity and 

heating power consumption only for 

Variable Capacity Certified, Two 

Capacity Systems, when the control 

device for conducting the CVP and 

certification tests does not meet the 

requirements of monitoring and 

adjustment of the compressor speed and 

indoor blower speed, as outlined in 10 

CFR 429.134 (k)(4)(v)(A). 

In response to Rheem’s comment on 

questioning this extrapolation for 

minimum-speed-limiting heat pumps, 

no evidence has been provided by 

Rheem to argue that the current CSF and 

PSF values may be inexact for the 

aforementioned extrapolation. However, 

DOE recognizes the concern raised by 

Rheem, and notes that systems 

determined to be Variable Capacity 

Certified, Two Capacity Systems, after 

conducting the CVP, will not be subject 

to extrapolation using the minimum 

speed limiting heat pump adjustments, 

as per equations 11.189 to 11.194 of 

AHRI 210/240–2024 when tested in 

accordance with appendix M1, and per 

equations 11.199 to 11.204 of AHRI 

1600–2024, when tested in accordance 

with appendix M2. Additionally, DOE 

clarifies that there are no typographical 

errors in sections I4.3.1.4 of AHRI 210/ 

240 and AHRI 1600—the phrase ‘‘. . . 

where the range of capacity does not 

vary by more than 15 percent’’ is 

referring to the range of capacity the 

unit can modulate from its high-/oncapacity value and is therefore 

consistent with the intent of this 

section. Regarding Rheem’s comment on 

tolerances on indoor entering wet bulb 

temperature and indoor leaving wet 

bulb temperature (in sections I5.1 and 

I5.1.3, respectively) in AHRI 210/240 

and AHRI 1600, being applicable to 

cooling mode CVP tests only, DOE 

agrees, and it is making amendments at 

10 CFR 429.134(k)(4)(iii)(A) as follows 

(additions shown in italics): 

The data collected in the CVP per 

paragraph (k)(4)(i)(A) or paragraph 

(k)(4)(i)(B) of this section shall be 

evaluated for the duration of the 

individual CVP full or minimum load 

interval, excluding the preliminary 30 

minutes of equilibrium data, to 

determine compliance with test 

condition tolerances and test operating 

tolerances listed in section I5.1 of 

appendix I of AHRI 210/240–2024 

(incorporated by reference, see § 429.4) 

(if testing in accordance with appendix 

M1); or of AHRI 1600–2024 

(incorporated by reference, see § 429.4) 

(if testing in accordance with appendix 

M2), with the exception that the indoor 

entering wet bulb deviation in section 

I5.1 and test operating tolerance in 

section I5.1.3 are applicable only for 

cooling mode CVP. 

JCI also requested clarity on various 

aspects of the CVP enforcement 

provisions. (JCI, No. 35 at pp. 2–3). In 

particular, JCI expressed concern about 

systems that utilize variable-capacity 

compressors rated as ‘‘coil only’’ 

systems and ‘‘certified’’ to DOE as 

variable-capacity systems, but which are 

rated and tested per two-speed test 

procedures.66 (Id.) JCI asserted that its 

concern stems from the broad definition 

of variable-capacity systems in AHRI 

210/240–2024.67 (Id.) JCI commented 

that according to its interpretation, if 

such a system is certified to DOE as a 

multi- or variable-stage design but is 

tested to the coil-only two-stage test 

procedure, then the system is subject to 

CVP test requirements. (Id.) 

In a similar vein, JCI requested 

clarification on whether such systems, 

classified as OUWNMs (since they are 

sold in commerce without matching 

indoor units), would be subject to rating 

and testing per the CVP requirements. 

(JCI, No. 35 at pp. 2–3) Finally, JCI 

requested for clarification on whether 

DOE-certified, two-stage systems that 

have discrete fixed capacities and 

airflow rates, but are equipped with 

variable-capacity compressors, will be 

subject to the CVP enforcement or not. 

(Id. at p. 3) 

In response to JCI’s comment 

regarding the variable-speed coil-only 

(‘‘VSCO’’) test provisions in the October 

2022 CAC TP Final Rule, DOE clarifies 

that once the revised appendix M1 and 

the new appendix M2 are finalized, the 

VSCO test provisions for noncommunicating and communicating 

systems in the current appendix M1 will 

be sunset. This is because these 

provisions are not part of the AHRI 210/ 

240 and AHRI 1600 standards, which 

are the basis of the revised appendix 

M1, and new appendix M2, 

respectively. Therefore, all VSCO 

systems will be certified and tested as 

variable-capacity compressor systems, 

and DOE may conduct the CVP on such 

units, to see if they comply with the 

variable-speed definition. JCI’s question 

regarding OUWNMs is unclear— 

however, DOE clarifies that the CVP is 

applicable to all variable-speed systems, 

and therefore, if such systems are 

certified as variable-speed systems, they 

will be subject to CVP enforcement. 

Finally, DOE clarifies that the CVP 

enforcement is applicable only to 

systems that are certified as variablecapacity compressor systems, as defined 

in section 3.2.80 of AHRI 210/240–2024 

and AHRI 1600–2024. Therefore, any 

systems that are certified as twocapacity (or two-stage) systems, as 

defined in section 3.2.76 of AHRI 210/ 

240–2024 and AHRI 1600–2024, will 

not be subject to CVP enforcement by 

DOE. 

GE Appliances supported the addition 

of a CVP for enforcement testing of 

variable-speed systems, but it 

commented that a number of lingering 

issues require resolution before DOE 

utilizes the CVP for enforcement testing. 


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Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1265 

68 GE Appliances gave an example of hybrid 

control where an adaptor can be connected to a 24– 

V thermostat and variable-speed communicating 

equipment. For such control systems, the 

thermostat sends an on/off signal, and the adaptor 

then decides the set point temperature during unit 

operation. 

69 DOE would like to clarify that if the adapter is 

an integral part of every unit shipped without a 

proprietary control that would otherwise not 

operate, the adapter would be connected to the 

simulated thermostat signal. 

70Currently, 10 CFR 429.16 (b)(3) describes the 

sampling plan for enforcement of CAC/HPs. 

71 DOE‘s interpretation is that LG is referring to 

the Compliance Certification Database, available at 

www.regulations.doe.gov/ccms. 

(GE Appliances, No. 37 at p. 4) GE 

Appliances also commented that 

additional test data is required for 

validation of some provisions proposed 

by DOE in the April 2024 NOPR. (Id.) 

GE Appliances commented that the 

AHRI 210/240 standard specifies that 

the CVP tests should be done either 

with a proprietary control or with a 

simulated thermostat control, but it 

requested that DOE clarify when a 

control is considered proprietary, since 

multiple types of control systems are 

available, including those with hybrid 

control capability.68 (Id. at pp. 5–6) 

In response to GE Appliances, DOE 

clarifies that the differences between a 

proprietary control and simulated 

(generic) thermostat were discussed in 

detail with the stakeholders during the 

development of the AHRI 210/240 and 

AHRI 1600 standards. It is DOE’s 

understanding and intent for 

implementation of the CVP that the 

‘‘control’’ is the device that senses 

temperature in the conditioned space, 

has a user interface that allows setting 

of a desired space temperature (the ‘‘set 

point’’), and provides a signal or 

communication to the CAC or HP 

system that initiates system operation 

and/or steps or level of operation to 

reduce the gap between the temperature 

and the set point. Accordingly, as per 

the example scenario presented by GE 

Appliances in their comment, an 

adapter 69 provided as part of the system 

or specified for installation that allows 

the basic model to connect with any 

generic (non-proprietary) thermostat is 

not the ‘‘control.’’ In the case in which 

such an adapter allows a generic 

thermostat to be installed in the 

conditioned space, the generic 

thermostat is the control, and the 

simulation of the generic thermostat (as 

described in section I3.1 of AHRI 210/ 

240–2024 and AHRI 1600–2024) would 

be used. Only when the device 

measuring the space temperature and 

providing user input to adjust the set 

point is proprietary would installation 

of the proprietary device for the test be 

used. Any system having a ‘‘hybrid’’ 

control approach that could use either a 

generic or proprietary ‘‘control’’ would 

be tested using the generic approach. 

LG also made several comments in 

response to the CVP enforcements 

proposed by DOE in the April 2024 

NOPR. 89 FR 24206, 24258–24261. LG 

pointed out that as per the CVP, the 

indoor room‘s set point is controlled 

according to the virtual load approach, 

in which the range of temperature 

difference between the thermostat set 

point and the indoor room condition 

during the proposed CVP test is 0–3 °F. 

(LG, No. 38 at pp. 1–2) LG questioned 

whether the virtual load is appropriate 

for variable-capacity systems that do not 

operate at minimum speed when the 

indoor room temperature is not close to 

the thermostat set point. (Id.) LG further 

expressed concern that the term 

‘‘certification’’ test was not fully 

specified, as it could mean either (1) the 

tested value of the certification test, or 

(2) the value of the enforcement test 

conducted under the same conditions as 

the certification test. (Id. at p. 2) LG 

commented that if the ‘‘certification’’ 

test was (1), it requests clarification if 

this would be a mean value of the two 

or more tested samples. (Id.) However, 

if it was (2), then LG requested that DOE 

provide more information on sample 

size and election.70 (Id.) Finally, LG 

recommended that due to existing 

deviations during testing, instead of 

comparing the CVP test values with the 

certification test values during 

enforcement, they should be compared 

to values provided by the manufacturer 

in the DOE database.71 (Id.) 

In response to LG‘s comment, DOE 

clarifies that the return air temperature 

equation in appendix I of AHRI 210/ 

240–2024 is a function of the previous 

return air temperature target, 

RAT(t),time, the calculated virtual load 

(VLs for cooling mode CVP, and VL for 

heating mode CVP) at target outdoor 

ambient dry-bulb temperature Tj, 

measured unit capacity, and a thermal 

mass constant, C. The difference 

between the thermostat set-point and 

indoor room dry-bulb temperature is 

dependent on the unit control and 

operation. The virtual load and return 

air temperature equations ensure the 

temperature difference between the 

thermostat set-point and indoor room 

dry-bulb temperature are within 1 °F for 

systems that control the unit properly. 

The difference between the thermostat 

set-point and indoor room dry-bulb 

temperature could reach 3 °F only if the 

unit could not achieve the virtual load 

target capacity at each test interval. 

Further, DOE clarifies that ‘‘the 

corresponding certification test’’ refers 

to an enforcement test conducted in 

accordance with appendix M1 or 

appendix M2, as applicable. The sample 

size of the selected units will be in 

accordance with provisions in 10 CFR 

429.110. Finally, DOE clarifies that 

during the CVP enforcement, 

comparisons of the CVP full and 

minimum load intervals will be made to 

the certification test conducted just 

before the CVP tests. 

Carrier requested clarity from DOE on 

determining variable-speed unit 

operation when the intermediate tests 

do not show satisfactory variable-speed 

characteristics. (Carrier, No. 29 at p. 2) 

Specifically, Carrier commented that it 

was unclear on whether DOE‘s proposal 

on a system‘s cycling between stages is 

an accurate way of determining it is a 

single-capacity versus a two-capacity 

system, if the intermediate CVP 

requirement is not met. (Id.) 

In response to Carrier‘s comment, 

DOE clarifies that 10 CFR 

429.134(k)(4)(C)(ii)(B) and (k)4)(C)(ii)(C) 

state that after conducting the CVP 

enforcement tests, the unit under test 

will be determined to be a variablecapacity certified, single-capacity 

system, or a variable-capacity certified, 

two-capacity system, on the basis of the 

test results as per appendix I of AHRI 

210/240 and AHRI 1600 (see section 

III.E.1 of this document for details). DOE 

reiterates that this determination, on 

whether a system is single capacity or 

two capacity, on the basis of its cycling 

between off and single-stage/capacity 

level and cycling between more than 

one stage/capacity level, respectively, 

represents industry consensus on this 

matter. This is because this 

determination was discussed and agreed 

upon with AHRI and all other 

stakeholders, during development of 

appendix I of the AHRI 210/240 and 

AHRI 1600 standards. 

J. Test Procedure Costs and Impacts 

EPCA requires that test procedures 

proposed by DOE not be unduly 

burdensome to conduct. (42 U.S.C. 

6293(b)(3)) As discussed, DOE is 

updating the current Federal test 

procedure for CAC/HPs at appendix M1 

consistent with the relevant industry 

consensus test procedure, AHRI 210/ 

240–2024. DOE is also establishing a 

new Federal test procedure at 10 CFR 

part 430, subpart B, appendix M2, 

consistent with the new industry 

consensus test procedure, AHRI 1600– 

2024. Appendix M2 would not be 

required for use until the compliance 

date of amended standards for CAC/ 

HPs. DOE is also amending its 


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72Manufacturers are not required to perform 

laboratory testing on all basic models. In 

accordance with 10 CFR 429.16, CAC/HP 

manufacturers may elect to use AEDMs. 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 to reduce the 

burden and cost associated with testing. 

representation and enforcement 

provisions for CAC/HPs. 

1. Appendix M1 

In the April 2024 NOPR, DOE 

proposed to incorporate by reference 

AHRI 210/240–202X Draft and relevant 

industry standards referenced in AHRI 

210/240–202X Draft at appendix M1. 89 

FR 24206, 24244. DOE also proposed to 

amend certain provisions for 

representations and enforcement in 10 

CFR part 429, consistent with the 

changes proposed to the test procedure. 

Id. DOE noted that the proposed 

revisions to appendix M1 would retain 

the current efficiency metrics (i.e., 

EER2, SEER2, and HSPF2). Id. DOE 

walked through the anticipated 

compliance costs associated with the 

proposed test procedure at appendix M1 

and tentatively determined that 

proposed amendments would not result 

in an increase in testing cost relative to 

the current test procedure. Id. DOE also 

tentatively concluded that the proposed 

revisions to the test procedure in 

appendix M1 would not change 

efficiency ratings for CAC/HPs, and 

therefore would not require retesting or 

redesign solely as a result of DOE’s 

adoption of the proposed amendments 

to the DOE test procedure, if made final. 

Id. DOE requested comment on these 

tentative determinations under Issue 5 

of the April 2024 NOPR. Id. 

In response, Lennox was supportive 

of DOE’s tentative determinations, 

commenting that it believes the 

proposed appendix M1 amendments in 

the April 2024 NOPR should result in a 

test procedure that is not unduly 

burdensome to conduct, consistent with 

EPCA statutory requirements. (Lennox, 

No. 24 at p. 6) While less supportive 

overall, Carrier commented that it agrees 

the proposed amendments to appendix 

M1 in the April 2024 NOPR would not 

result in any retesting or any increase in 

testing cost for a typical CAC/HP. 

(Carrier, No. 29 at p. 5) In addition, 

Carrier asserted that test costs and 

burden would increase, however, for 

certain products as a result of the 

proposed CVP- and CCHP-related 

provisions. (Id.) 

In addition to Carrier, Rheem and LG 

were also less supportive of DOE’s 

tentative determinations, citing the 

additional test costs and burden 

associated with CVP testing. (Carrier, 

No. 29 at p. 5; LG, No. 38 at p. 3; Rheem, 

No. 34 at p. 7) More specifically, Rheem 

commented that additional costs 

associated with the proposed test 

procedure will stem from modifications 

to psychrometric test cells in order to 

comply with the CVP. (Rheem, No. 34 

at p. 7) LG commented that an extensive 

amount of time and associated costs are 

necessary to conduct CVP testing. (LG, 

No. 38 at p. 3) LG asserted that, in 

addition to 30 minutes of stabilization 

time, it takes a minimum of 11.5 hours 

and a maximum of 20.5 hours for the 

cooling CVP test, and a minimum of 

16.5 hours and a maximum of 28.5 

hours for the CCHP heating CVP test, 

resulting in third-party testing costs 

between 13,000 and 24,000 U.S. dollars. 

(Id.) 

In response to the Carrier, Rheem, and 

LG comments regarding additional test 

costs and burden associated with the 

CVP, DOE reiterates that the proposed 

CVP for variable-capacity compressor 

systems in appendix I of AHRI 210/240– 

2024 is not mandatory for 

manufacturers to perform. In the April 

2024 NOPR, DOE also noted that, to the 

extent that a manufacturer has not 

already verified the appropriateness of 

the fixed performance during regulatory 

tests as compared to native control 

operation (i.e., the system may currently 

be improperly certified), a manufacturer 

may need to adjust fixed-speed 

overrides used in regulatory tests in 

accordance with the CVP and 

subsequently rerun the regulatory tests. 

89 FR 24206, 24244–24245. However, 

having no strong evidence to the 

contrary, DOE noted it expects that 

current variable-capacity certifications 

are generally consistent with system 

performance. Id. As such, DOE 

concluded that any such cost to verify 

performance and potentially retest is 

negligible. Id. 

In response to Carrier’s comment 

regarding additional test costs and 

burden associated with CCHP 

provisions (i.e., the required H42 test for 

products claimed as CCHPs), DOE 

reiterates that a manufacturer’s claim of 

CCHP status for its product is optional. 

89 FR 24206, 24244–24245. DOE also 

reiterates that it anticipates products 

choosing to certify as CCHPs are most 

likely to be already testing at the 5 °F 

condition, and hence have no added 

costs or test burden associated with 

them. Id. 

In this final rule, DOE is updating the 

incorporation by reference to AHRI 210/ 

240–2024, the finalized version of AHRI 

210/240–202X Draft. DOE is also 

referencing the relevant industry 

standards referenced in AHRI 210/240– 

2024 at appendix M1. As noted earlier, 

there are no substantial differences 

between AHRI 210/240–2024 and AHRI 

210/240–202X Draft. As such, DOE’s 

assessment of test procedure costs for 

appendix M1 are consistent with the 

April 2024 NOPR. 

DOE has determined that the 

amendments to appendix M1 and the 

representation and enforcement 

provisions would improve the 

representativeness, accuracy, and 

reproducibility of the test results and 

would not be unduly burdensome for 

manufacturers to conduct. DOE has 

determined that the amendments would 

not result in an increase in testing cost 

from the current test procedure. The 

revisions to the test procedure in 

appendix M1 for measuring EER2, 

SEER2, and HSPF2 per AHRI 210/240– 

2024 would not increase third-party 

laboratory testing costs per unit relative 

to the current DOE test procedure. DOE 

estimates the current costs for physical 

testing, including off mode testing, to 

range from $10,800 to $19,800, 

depending on the configuration of the 

CAC/HP (single-stage, two-stage, 

variable-capacity). Further, DOE has 

concluded that the revisions to the test 

procedure in appendix M1 would not 

change efficiency ratings for CAC/HPs, 

and therefore would not require 

retesting or redesign solely as a result of 

DOE’s adoption of the proposed 

amendments to the DOE test 

procedure.72

2. Appendix M2 

In the April 2024 NOPR, DOE 

proposed to incorporate by reference 

AHRI 1600–202X Draft and relevant 

industry standards referenced in AHRI 

1600–202X Draft at appendix M2. 89 FR 

24206, 24245. DOE also proposed to 

establish provisions for determining 

SCORE and SHORE, the new efficiency 

metrics applicable to appendix M2. Id. 

DOE walked through the anticipated 

compliance costs associated with the 

proposed test procedure at appendix M2 

and tentatively determined that 

proposed amendments would not result 

in an increase in testing cost relative to 

the current test procedure. Id. DOE 

tentatively concluded that the proposed 

revisions to the test procedure in 

appendix M2 would change efficiency 

ratings for CAC/HPs—however, DOE 

noted testing and recertification based 

on appendix M2 would not be required 

until DOE adopts any amended CAC/HP 

standards in terms of the new metrics in 

a future energy conservation standards 

rulemaking. Id. DOE requested comment 


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on these tentative determinations under 

Issue 6 of the April 2024 NOPR. Id. 

In response, Lennox was supportive 

of DOE’s tentative determinations, 

commenting that it believes the 

proposed appendix M2 in the April 

2024 NOPR should result in a test 

procedure that is not unduly 

burdensome to conduct, consistent with 

EPCA statutory requirements. (Lennox, 

No. 24 at p. 6) Carrier agreed that the 

proposed appendix M2 in the April 

2024 NOPR would not result in any 

increase in testing cost for a typical 

CAC/HP from the proposed appendix 

M1. (Carrier, No. 29 at p. 6) Rheem 

commented that it is not aware of 

available data to support the use of a 

different cost basis for appendix M2 

testing. (Rheem, No. 34 at p. 7) 

In this final rule, DOE is updating the 

incorporation by reference to AHRI 

1600–2024, the finalized version of 

AHRI 1600–202X Draft. DOE is also 

referencing the relevant industry 

standards referenced in AHRI 210/240– 

2024 at appendix M1. As noted earlier, 

there are no substantial differences 

between AHRI 1600–2024 and AHRI 

1600–202X Draft. As such, DOE’s 

assessment of test procedure costs for 

appendix M2 are consistent with the 

April 2024 NOPR. 

DOE has determined that the 

amendments to appendix M2 and the 

representation and enforcement 

provisions would improve the 

representativeness, accuracy, and 

reproducibility of the test results and 

would not be unduly burdensome for 

manufacturers to conduct. DOE has 

determined that the amendments would 

not result in an increase in testing cost 

from the current test procedure. The 

revisions to the test procedure in 

appendix M2 for measuring EER2, 

SCORE, and SHORE per AHRI 1600– 

2024 would not increase third-party 

laboratory testing costs per unit relative 

to the current DOE test procedure. DOE 

estimates the current costs for physical 

testing to range from $10,800 to $19,800, 

depending on the configuration of the 

CAC/HP (single-stage, two-stage, 

variable-capacity). DOE has concluded 

that the proposed revisions to the test 

procedure in appendix M2 would 

change efficiency ratings for CAC/HPs— 

however, testing and recertification 

based on appendix M2 would not be 

required until DOE adopts any amended 

CAC/HP standards in terms of the new 

metrics in a future energy conservation 

standards rulemaking. 

K. Effective, Compliance, and Other 

Required Use Dates 

The effective date for the adopted test 

procedure amendment will be 30 days 

after publication of this final rule in the 

Federal Register. EPCA prescribes that 

all representations of energy efficiency 

and energy use, including those made 

on marketing materials and product 

labels must be made in accordance with 

an amended test procedure, beginning 

180 days after publication of the final 

rule in the Federal Register. (42 U.S.C. 

6293(c)(2)) However, CAC/HPs are not 

required to be tested according to the 

test procedure in appendix M2 (that 

relies on the SCORE and SHORE 

metrics) until the compliance date of 

amended energy conservation standards 

denominated in terms of SCORE and 

SHORE, should DOE adopt such 

standards. 

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. 6293(c)(3)) 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.) To the extent the 

modified test procedure adopted in this 

final rule is required only for the 

evaluation and issuance of updated 

efficiency standards, compliance with 

the amended test procedure does not 

require use of such modified test 

procedure provisions until the 

compliance date of updated standards. 

Upon the compliance date of test 

procedure provisions in this final rule 

any waivers that had been previously 

issued and are in effect that pertain to 

issues addressed by such provisions are 

terminated. 10 CFR 430.27(h)(3). 

Recipients of any such waivers are 

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 adopted in this document 

pertain to issues addressed by waiver 

granted to Samsung (88 FR 36558, Case 

No. 2022–009), as discussed in section 

III.E.4 of this final rule. To the extent 

that such interim waiver permits the 

petitioner to test according to an 

alternate test procedure to appendix M1, 

the interim waiver will terminate on the 

date the amendments to the appendix 

M1 test procedure take effect (i.e., 180 

days after publication of the test 

procedure final rule in the Federal 

Register). 

Notably, the amendments adopted in 

this final rule do not pertain to issues 

addressed by the interim waiver granted 

to Johnson Controls Inc. (‘‘JCI’’) (88 FR 

72449, Case No. 2023–005) This interim 

waiver permits JCI to test certain basic 

models of CAC/HPs that use variablespeed, oil-injected scroll compressors 

(‘‘VSS systems’’) with a 72-hour breakin period, in lieu of the 20-hour breakin limit prescribed in appendix M1. (Id.) 

The 72-hour break-in period permitted 

to the specific VSS systems listed in 

JCI’s interim waiver is unique to the 

CAC/HP market, and DOE continues to 

assess whether there is a generalizable 

need for an extended break-in period for 

certain VSS systems beyond the specific 

basic models subject to the interim 

waiver granted to JCI. As such, DOE is 

not amending the test procedure to 

address the issues presented in the 

interim waiver granted to JCI at this 

time. To the extent the interim waiver 

permits JCI to test according to an 

alternate test procedure to appendix M1, 

the interim waiver will terminate on the 

date testing is required according to 

appendix M2, which will occur on the 

compliance date for updated efficiency 

standards. DOE notes that JCI may 

petition for another waiver at the time 

testing is required according to 

appendix M2. 

Additionally, as discussed in section 

III.E.7 of this final rule, DOE recognizes 

that stakeholders have requested 

clarification regarding the interaction of 

EPA’s refrigerant regulations and DOE’s 

certification and rating requirements for 

CAC/HPs. See table III–5 for a 

consolidated summary of the interaction 

of DOE’s OUWNM certification and 

rating requirements under the EPA 

regulations timeline. 


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TABLE III–5—SUMMARY OF CERTIFICATION AND RATING REQUIREMENT TIMELINES

Indoor or 

outdoor unit 

manufactured or 

imported 

Distributed as Outdoor units with 

>700 GWP refrigerant 

Indoor units with 

>700 GWP refrigerant 

Before 1/1/2025 ........... Matched System ........ Per EPA, matched systems can be installed prior to January 1, 2026 as long as they were 

manufactured prior January 1, 2025. 

..................................... Must be certified/rated in combinations with 

indoor units as distributed in commerce before 1/1/2025 and the matched system 

must comply with applicable standard; i.e., 

do not need to be certified/rated as 

OUWNM. 

Must be certified/rated in combinations with 

outdoor units distributed in commerce before 1/1/2025 and the matched system 

must comply with the applicable standard. 

Indoor Unit or Outdoor 

Unit.

Per EPA, indoor and outdoor units can also be installed as replacement units on or after January 1, 2025. 

On or after 1/1/2025 .... Matched System ........ Per EPA, matched systems can no longer be installed on or after January 1, 2026. 

Indoor Unit or Outdoor 

Unit.

Per EPA, indoor and outdoor units can be installed only as replacement units on or after January 1, 2026. 

Must be certified/rated and as OUWNM and 

comply with the applicable standard. Recertification/rerating required if previous ratings were matched combinations. No new 

certification of matched systems allowed. 

Must be certified/rated in combinations with 

outdoor units distributed in commerce before 1/1/2025 and the matched system 

must comply with the applicable standard. 

No new certification of matched systems 

allowed. 

IV. Procedural Issues and Regulatory 

Review 

A. Review Under Executive Orders 

12866, 13563, and 14094 

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) and amended by E.O. 14094, 

‘‘Modernizing Regulatory Review,’’ 88 

FR 21879 (April 11, 2023), 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’’) in the Office of Management 

and Budget (‘‘OMB’’) 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 this preamble, this final 

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 final 

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 a final regulatory flexibility analysis 

(‘‘FRFA’’) for any final rule where the 

agency was first required by law to 

publish a proposed rule 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 

(August 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. 

DOE reviewed this final rule under 

the provisions of the Regulatory 

Flexibility Act and the procedures and 

policies published on February 19, 

2003. DOE has concluded that this 

rulemaking will not have a significant 

impact on a substantial number of small 

entities. Compliance with this test 

procedure is not required unless and 

until new energy conservation standards 

are established for covered CAC/HPs— 

accordingly, there are no compliance 

costs stemming directly from this 

rulemaking. 

Still, although it is not required, DOE 

has undertaken a review of CAC/HP 

small business manufacturers and, in 

the following, is presenting the costs 

that those business may expect if testing 

on the basis of this test procedure were 

required in the future. 


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73U.S. Department of Energy Compliance 

Certification Management System, available at 

www.regulations.doe.gov/ccms (last accessed July 

30, 2023). 

74California Energy Commission’s Modernized 

Appliance Efficiency Database System, available at 

cacertappliances.energy.ca.gov/Login.aspx. (Last 

accessed Sept. 22, 2023). 

75Natural Resources Canada searchable product 

list, available at oee.nrcan.gc.ca/pml-lmp/ (last 

accessed Sept 19, 2023). 

76Manufacturers are not required to perform 

laboratory testing on all basic models. In 

accordance with 10 CFR 429.16, CAC/HP 

manufacturers may elect to use AEDMs. 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 to reduce the 

burden and cost associated with testing. 

1. Estimated Number of Small Entities 

For the April 2024 NOPR, DOE 

conducted a focused inquiry into small 

business manufacturers of the products 

covered by this rulemaking. DOE used 

the SBA’s small business size standards 

to determine whether any small entities 

would be subject to the requirements of 

the rule. The size standards are listed by 

North American Industry Classification 

System (‘‘NAICS’’) code as well as by 

industry description and are available at 

www.sba.gov/document/support-tablesize-standards. Manufacturing CAC/HPs 

is classified under NAICS 333415, ‘‘AirConditioning and Warm Air Heating 

Equipment and Commercial and 

Industrial Refrigeration Equipment 

Manufacturing.’’ 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 used 

available public information to identify 

potential small manufacturers. DOE 

accessed the Compliance Certification 

Database 73 (‘‘CCD’’), the Modernized 

Appliance Efficiency Database System 74

(‘‘MAEDbS’’), and the National 

Resources Canada database 75

(‘‘NRCan’’) to create a list of companies 

that import or otherwise manufacture 

the products covered by this final rule. 

Once DOE created a list of potential 

manufacturers, DOE used market 

research tools to determine whether any 

met the SBA’s definition of a small 

entity—based on the total number of 

employees for each company including 

parent, subsidiary, and sister entities— 

and gather annual revenue estimates. 

Based on DOE’s analysis, DOE 

identified 23 OEMs manufacturing 

CAC/HPs covered by this test 

procedure. DOE screened out companies 

that do not meet the small entity 

definition and, additionally, screened 

out companies that are largely or 

entirely foreign owned and operated. Of 

the 23 OEMs identified OEMs, six were 

identified as domestic small businesses. 

DOE did not receive comments on the 

April 2024 NOPR in regard to its 

estimate of domestic small businesses. 

2. Estimate of Small Business Testing 

Costs 

This final rule adopts updated 

industry test standards for CAC/HPs. 

DOE is updating the current Federal test 

procedure for CAC/HPs at appendix M1 

consistent with the finalized version of 

the relevant industry consensus test 

procedure, AHRI 210/240–2024. DOE is 

also proposing a new Federal test 

procedure at 10 CFR part 430, subpart 

B, appendix M2, consistent with the 

finalized version of the industry 

consensus test procedure, AHRI 1600– 

2024. More specific amendments to the 

DOE test procedure are summarized in 

the following subsections. 

(a) Cost and Compliance Associated 

With Appendix M1 

In appendix M1, DOE is incorporating 

by reference AHRI 210/240–2024 for 

CAC/HPs and to amend certain 

provisions for representations and 

enforcement in 10 CFR part 429, 

consistent with the changes to the test 

procedure. 89 FR 24206, 24244. The 

revisions to appendix M1 would retain 

the previous test procedure’s efficiency 

metrics—EER2, SEER2, and HSPF2. The 

testing requirements in appendix M1 are 

generally consistent with those in AHRI 

210/240–2024, which in turn references 

ANSI/ASHRAE 37–2009, ANSI/ 

ASHRAE 16–2016, and ANSI/ASHRAE 

116–2010. This revision to the test 

procedure in appendix M1 for 

measuring EER2, SEER2, and HSPF2 

would not increase third-party 

laboratory testing costs per unit relative 

to the current DOE test procedure. The 

Controls Verification Procedure (‘‘CVP’’) 

for variable-capacity compressor 

systems in appendix I of AHRI 210/240– 

2024 is not mandatory for 

manufacturers to perform, and DOE 

considers these developmental costs to 

be negligible and not burdensome to 

manufacturers. The H4full test (outdoor 

dry-bulb temperature of 5 °F) will be 

mandatory, but DOE anticipates no 

added costs as units that will certify as 

CCHPs are likely currently testing at the 

5 °F condition. The determination of 

cut-in and cut-out temperatures in 

appendix J of the AHRI 210/240–2024 

would be included in DOE’s 

enforcement provisions and would not 

be mandatory for manufacturer testing, 

and thus manufacturers will not incur 

additional costs. Additionally, CAC/HPs 

equipped with mandatory circulation 

systems will have their cyclic 

degradation coefficients evaluated using 

respective cyclic tests, but DOE 

anticipates no added costs to 

manufacturers since cyclic tests are 

already often conducted on CAC/HPs 

(regardless of whether they are 

equipped with a mandatory constant 

circulation system) to improve the 

default cyclic degradation coefficients. 

DOE has concluded that the revisions 

to the test procedure in appendix M1 

would not change efficiency ratings for 

CAC/HPs, and therefore would not 

require retesting as a result of DOE’s 

adoption of this amendment to the test 

procedure.76 Further, the test procedure 

in appendix M1 would not increase 

third-party laboratory testing costs per 

unit; DOE estimates that the costs for 

physical testing prior to these 

amendments would range from $10,800 

to $19,800, depending on the 

configuration of the CAC/HP (singlestage, two-stage, variable-capacity). 

Therefore, DOE does not expect that the 

test procedure amendments in appendix 

M1 would result in manufacturers, 

including small manufacturers, 

incurring additional testing costs. 

(b) Cost and Compliance Associated 

With Appendix M2 

In appendix M2, DOE is establishing 

a new test procedure that references the 

industry test procedure, AHRI 1600– 

2024, for measuring new efficiency 

metrics, SCORE and SHORE. 89 FR 

24204, 23245. Appendix M2 will not be 

effective until new standards are 

established for CAC/HPs that rely on 

metrics present in appendix M2, should 

DOE adopt such standards. The testing 

requirements in appendix M2 are 

generally consistent with those in AHRI 

1600–2024, which in turn references 

ANSI/ASHRAE 37–2009, ANSI/ 

ASHRAE 16–2016, and ASHRAE 116– 

2010. This revision to the test procedure 

in appendix M2 for measuring EER, 

SCORE, and SHORE is not expected to 

increase third-party laboratory testing 

costs per unit relative to the prior DOE 

test procedure. The standby and offmode power consumption of auxiliary 

components is determined using 

appendix G of AHRI 1600–2024 and 

does not differ substantially from the 

process to determine off-mode power 

from the current version of appendix 

M1, in section 3.13. The adoption of the 

new cooling and heating metric will not 

result in increased testing costs as 

compared to the previous test 

procedure. The other amendments— 

which include (a) building load lines 

and temperature bin hours for 

calculation of SCORE and SHORE, (b) 


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1270 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

77 DOE estimates that a mechanical engineer 

would take 60 hours to create an AEDM. The fully 

burdened wage of a mechanical engineer is 68.05 

based on an unburdened median wage of $47.84 

and on wages representing 70.3 percent of labor 

costs. Average cost of third-party testing would be 

$14,400 given the previously described range of 

costs. See www.bls.gov/oes/current/oes172141.htm 

for the wage figure and www.bls.gov/news.release/ 

archives/ecec_06182024.pdf for the wage 

percentage of labor costs figure. 

default fan power coefficients for coilonly systems, and (c) air flow limits to 

address inadequate dehumidification— 

also will not affect testing costs. 

The overall testing cost is not 

expected to increase with appendix M2. 

DOE estimates the costs of physical 

testing for the new metrics SCORE and 

SHORE to range from $10,800 to 

$19.800, depending on the configuration 

of the CAC/HP (single-stage, two-stage, 

variable-capacity). Additionally, DOE 

allows the use of AEDMs. The use of an 

AEDM is expected to be less costly than 

physical testing of large numbers of 

CAC/HP models; DOE estimates the cost 

to develop an AEDM to be $19,383 per 

AEDM for a basic model, which 

includes the cost of physical testing 

done at a third-party laboratory to 

validate the AEDM.77 The development 

of the AEDM would reduce the need for 

physical testing on the part of 

manufacturers. Once the AEDM is 

developed, DOE estimates that it would 

take five minutes of an engineer’s time 

to determine efficiency for each 

individual model within a basic model 

using the AEDM. 

DOE understands all manufacturers 

currently certifying in the AHRI 

Directory (including small businesses) 

will be testing their models in 

accordance with AHRI 1600–2024, the 

industry test procedure DOE is 

referencing at appendix M2. As stated, 

testing and certification of the SCORE 

and SHORE metrics will not be required 

until the compliance date of any future 

energy conservation standards based on 

these metrics; however, DOE anticipates 

manufacturers will need to re-test their 

models to rate them in terms of the 

SCORE and SHORE metrics to comply 

with the AHRI certification program, 

and the re-rating will occur prior to a 

possible future energy conservation 

standards rulemaking. Accordingly, 

DOE has determined that the test 

procedure amendments would not add 

any additional testing burden to 

manufacturers—including the six 

domestic small manufacturers. 

3. Certification Statement 

Based on the de minimis cost impacts, 

DOE certifies that this final rule does 

not have a ‘‘significant economic impact 

on a substantial number of small 

entities,’’ and determined that the 

preparation of a FRFA is not warranted. 

DOE will transmit a certification and 

supporting statement of factual basis to 

the Chief Counsel for Advocacy of the 

Small Business Administration for 

review under 5 U.S.C. 605(b). 

C. Review Under the Paperwork 

Reduction Act of 1995 

Manufacturers of CAC/HPs must 

certify to DOE that their products 

comply with any applicable energy 

conservation standards. To certify 

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 CAC/HPs. (See generally 10 

CFR part 429.) The collection-ofinformation requirement for the 

certification and recordkeeping is 

subject to review and approval by 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 amending the certification 

or reporting requirements for CAC/HPs 

in this final rule. Instead, DOE may 

consider proposals to amend the 

certification requirements and reporting 

for CAC/HPs 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 final rule, DOE establishes test 

procedure amendments that it expects 

will be used to develop and implement 

future energy conservation standards for 

CAC/HPs. 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 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. Accordingly, neither an 

environmental assessment nor an 

environmental impact statement is 

required. 

E. Review Under Executive Order 13132 

Executive Order 13132, ‘‘Federalism,’’ 

64 FR 43255 (August 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 examined this final rule 

and determined that it will 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 

final 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 (February 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 


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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, this final 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 

regulatory action resulting 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 

www.energy.gov/gc/office-generalcounsel. DOE examined this final 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 

Act, 1999 (Pub. L. 105–277) requires 

Federal agencies to issue a Family 

Policymaking Assessment for any 

proposed rule or policy that may affect 

family well-being. When developing a 

Family Policymaking Assessment, 

agencies must assess whether: (1) the 

action strengthens or erodes the stability 

or safety of the family and, particularly, 

the marital commitment; (2) the action 

strengthens or erodes the authority and 

rights of parents in the education, 

nurture, and supervision of their 

children; (3) the action helps the family 

perform its functions, or substitutes 

governmental activity for the function; 

(4) the action increases or decreases 

disposable income or poverty of families 

and children; (5) the proposed benefits 

of the action justify the financial impact 

on the family; (6) the action may be 

carried out by State or local government 

or by the family; and whether (7) the 

action establishes an implicit or explicit 

policy concerning the relationship 

between the behavior and personal 

responsibility of youth, and the norms 

of society. In evaluating the above 

factors, DOE has concluded that it is not 

necessary to prepare a Family 

Policymaking Assessment as none of the 

above factors are implicated. Further, 

this determination would not have any 

financial impact on families nor any 

impact on the autonomy or integrity of 

the family as an institution. 

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 regulation 

will 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%20

Updated%20IQA%20Guidelines%20

Dec%202019.pdf. DOE has reviewed 

this final 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 

significant energy action. A ‘‘significant 

energy action’’ is defined as any action 

by an agency that promulgates 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 is 

likely to have a significant adverse effect 

on the supply, distribution, or use of 

energy; or (2) is designated by the 

Administrator of OIRA as a significant 

energy action. For any significant energy 

action, the agency must give a detailed 

statement of any adverse effects on 

energy supply, distribution, or use if the 

regulation is implemented, and of 

reasonable alternatives to the action and 

their expected benefits on energy 

supply, distribution, and use. 

This regulatory action 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 


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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 modifications to the test 

procedure for CAC/HPs adopted in this 

final rule incorporates testing methods 

contained in certain sections of the 

following commercial standards: AHRI 

210/240–2024, AHRI 1600–2024, ANSI/ 

ASHRAE 37–2009 ANSI/ASHRAE 16– 

2016 and ASHRAE 116–2010. 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 has 

consulted with both the Attorney 

General and the Chairman of the FTC 

about the impact on competition of 

using the methods contained in these 

standards and has received no 

comments objecting to their use. 

M. Congressional Notification 

As required by 5 U.S.C. 801, DOE will 

report to Congress on the promulgation 

of this rule before its effective date. The 

report will state that it has been 

determined that the rule is not a ‘‘major 

rule’’ as defined by 5 U.S.C. 804(2). 

N. Description of Materials Incorporated 

by Reference 

In this final rule, DOE incorporates by 

reference the following test standards: 

AHRI 210/240–2024. This test 

standard is an update to AHRI 210/240– 

2023 (2020), an industry-accepted test 

procedure for measuring the 

performance of Unitary Air-source Airconditioners & Heat Pump Equipment. 

The revised appendix M1 will be 

consistent with provisions in AHRI 210/ 

240–2024. 

AHRI 1600–2024. This test standard is 

a major update to AHRI 210/240–2023 

(2020), introducing new seasonal 

cooling and heating efficiency metrics, 

namely SCORE and SHORE. The new 

appendix M2 will be consistent with 

provisions in AHRI 210/240–2024. 

Copies of AHRI 210/240–2024 and 

AHRI 1600–2024 can be obtained from 

AHRI, 2311 Wilson Blvd., Suite 400, 

Arlington, VA 22201, (703) 524–8800, or 

found online at www.ahrinet.org. 

ASHRAE 37–2009. This test standard 

is an industry-accepted test procedure 

that provides a method of test for many 

categories of air conditioning and 

heating equipment. 

ANSI/ASHRAE 16. This test standard 

is an industry-accepted test procedure 

that provides a method of test for room 

air conditioners, packaged terminal air 

conditioners, and packaged terminal 

heat pumps. 

ANSI/ASHRAE 116–2010. This test 

standard is an industry-accepted test 

procedure that provides a method of test 

for electrically driven, residential aircooled air conditioners and heat pumps 

with cooling capacity of 65,000 Btu/hr. 

and less. 

Copies of ASHRAE 37–2009, ANSI/ 

ASHRAE 16 and ANSI/ASHRAE 116– 

2010 are available on ASHRAE’s 

website at www.ashrae.org. 

The following standards were 

previously approved for incorporation 

by reference in the regulatory sections 

where they appear, and no changes are 

made: AHRI 210/240–2008, AHRI 1160, 

and ANSI 1230–2010. 

V. Approval of the Office of the 

Secretary 

The Secretary of Energy has approved 

publication of this final rule. 

List of Subjects 

10 CFR Part 429 

Administrative practice and 

procedure, Confidential business 

information, Energy conservation, 

Household appliances, Imports, 

Incorporation by reference, 

Intergovernmental relations, Reporting 

and recordkeeping requirements, Small 

businesses. 

10 CFR Part 430 

Administrative practice and 

procedure, Confidential business 

information, Energy conservation, 

Household appliances, Imports, 

Incorporation by reference, 

Intergovernmental relations, Small 

businesses. 

Signing Authority 

This document of the Department of 

Energy was signed on December 18, 

2024, by Jeffrey Marootian, Principal 

Deputy Assistant Secretary for Energy 

Efficiency and Renewable Energy, 

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 December 

19, 2024. 

Treena V. Garrett, 

Federal Register Liaison Officer, U.S. 

Department of Energy. 

For the reasons stated in the 

preamble, DOE amends parts 429 and 

430 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 § 429.4 by: 

■ a. Revising paragraphs (a) and (c) 

introductory text; 

■ b. Redesignating paragraphs (c)(2) 

through (7) as paragraphs (c)(3) through 

(8); and 

■ c. Adding new paragraph (c)(2) and 

paragraph (c)(9). 

The revisions and additions read as 

follows: 

§ 429.4 Materials incorporated by 

reference. 

(a) Certain material is incorporated by 

reference into this part with the 

approval of the Director of the Federal 

Register under 5 U.S.C. 552(a) and 1 

CFR part 51. To enforce any edition 

other than that specified in this section, 

the U.S. Department of Energy (DOE) 

must publish a document in the Federal 

Register and the material must be 

available to the public. All approved 

incorporation by reference (IBR) 

material is available for inspection at 

the Department of Energy (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 Office, EE–5B, 1000 

Independence Avenue SW, Washington, 

DC 20585–0121; (202) 586–9127; 

Buildings@ee.doe.gov; www.energy.gov/ 

eere/buildings/appliance-andequipment-standards-program. For 

information on the availability of this 

material at NARA, visit 

www.archives.gov/federal-register/cfr/ 

ibr-locations or email fr.inspection@

nara.gov. The material may be obtained 

from the sources in the following 

paragraphs of this section. 

* * * * * 


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(c) AHRI. Air-Conditioning, Heating, 

and Refrigeration Institute, 2311 Wilson 

Blvd., Suite 400, Arlington, VA 22201, 

(703) 524–8800, or go to: 

www.ahrinet.org. 

* * * * * 

(2) AHRI Standard 210/240–2024 (I– 

P), (‘‘AHRI 210/240–2024’’), 

Performance Rating of Unitary Airconditioning and Air-source Heat Pump 

Equipment, copyright 2024; IBR 

approved for § 429.134. 

* * * * * 

(9) AHRI Standard 1600–2024 (I–P), 

(‘‘AHRI 1600–2024’’), Performance 

Rating of Unitary Air-conditioning and 

Air-source Heat Pump Equipment, 

copyright 2024; IBR approved for 

§ 429.134. 

* * * * * 

■ 3. Amend § 429.16 by revising 

paragraphs (a)(1) and (2), (a)(3)(i), (b)(2), 

(b)(3)(ii), (c)(1)(i)(B), (c)(1)(ii), (c)(3), 

(d)(2), and (f) to read as follows: 

§ 429.16 Central air conditioners and 

central air conditioning heat pumps. 

(a) * * * 

(1) Required represented values. 

Determine the represented values 

(including as applicable, SEER2, EER2, 

HSPF2, PW,OFF, SCORE, SHORE, EER, 

cooling capacity, and heating capacity) 

for the individual models/combinations 

(or ‘‘tested combinations’’) specified in 

the following table. 

TABLE 1 TO PARAGRAPH (a)(1) 

Category Equipment subcategory Required represented values 

Single-Package Unit .................................................... Single-Package Air Conditioner (AC) (including 

space-constrained).

Every individual model distributed 

in commerce. 

Single-Package Heat Pump (HP) (including spaceconstrained).Every individual model distributed 

in commerce. 

Outdoor Unit and Indoor Unit (Distributed in Commerce by Outdoor Unit Manufacturer (OUM)).Single-Split-System AC with Single-Stage or TwoStage Compressor (including Space-Constrained 

and Small-Duct, High Velocity Systems (SDHV)).

Every individual combination distributed in commerce. Each 

model of outdoor unit must include a represented value for at 

least one coil-only individual 

combination that is distributed in 

commerce and which is representative of the least efficient 

combination distributed in commerce with that particular model 

of outdoor unit. For that particular model of outdoor unit, additional represented values for 

coil-only and blower-coil individual combinations are allowed, 

if distributed in commerce. 

Single-Split System AC with Other Than SingleStage or Two-Stage Compressor (including 

Space-Constrained and SDHV).

Every individual combination distributed in commerce, including 

all coil-only and blower-coil combinations. 

Single-Split-System HP (including Space-Constrained and SDHV).Every individual combination distributed in commerce. 

Multi-Split, Multi-Circuit, or Multi-Head Mini-Split 

Split System—non-SDHV (including Space-Constrained).

For each model of outdoor unit, at 

a minimum, a non-ducted ‘‘tested combination.’’ For any model 

of outdoor unit also sold with 

models of ducted indoor units, a 

ducted ‘‘tested combination.’’ 

The ducted ‘‘tested combination’’ must comprise the highest 

static variety of ducted indoor 

unit distributed in commerce 

(i.e., conventional, mid-static, or 

low-static). Additional representations are allowed, as described in paragraphs (c)(3)(i) 

and (ii) of this section, respectively. 

Multi-Split, Multi-Circuit, or Multi-Head Mini-Split 

Split System—SDHV.

For each model of outdoor unit, an 

SDHV ‘‘tested combination.’’ Additional representations are allowed, as described in paragraph (c)(3)(iii) of this section. 

Indoor Unit Only Distributed in Commerce by Independent Coil Manufacturer (ICM).Single-Split-System Air Conditioner (including 

Space-Constrained and SDHV).

Single-Split-System Heat Pump (including SpaceConstrained and SDHV).

Every individual combination distributed in commerce. 


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TABLE 1 TO PARAGRAPH (a)(1)—Continued 

Category Equipment subcategory Required represented values 

Multi-Split, Multi-Circuit, or Multi-Head Mini-Split 

Split System—SDHV.

For a model of indoor unit within 

each basic model, an SDHV 

‘‘tested combination.’’ Additional 

representations are allowed, as 

described in paragraph (c)(3)(iii) 

of this section. 

Outdoor Unit with no Match ................................................................................................................................ Every model of outdoor unit distributed in commerce (tested 

with a model of coil-only indoor 

unit as specified in paragraph 

(b)(2)(i) of this section. 

(2) PW,OFF. Represented values of 

PW,OFF are only required when 

determining represented values in 

accordance with 10 CFR part 430, 

subpart B, appendix M1. If individual 

models of single-package systems or 

individual combinations (or ‘‘tested 

combinations’’) of split systems that are 

otherwise identical are offered with 

multiple options for off-mode-related 

components, determine the represented 

value for the individual model/ 

combination with the crankcase heater 

and controls that are the most 

consumptive. A manufacturer may also 

determine represented values for 

individual models/combinations with 

less consumptive off-mode options; 

however, all such options must be 

identified with different model numbers 

for single-package systems or for 

outdoor units (in the case of split 

systems). 

(3) * * * 

(i) If a model of outdoor unit (used in 

a single-split, multi-split, multi-circuit, 

multi-head mini-split, and/or outdoor 

unit with no match system) is 

distributed in commerce and approved 

for use with multiple refrigerants, a 

manufacturer must determine all 

represented values for that model using 

each refrigerant that can be used in an 

individual combination of the basic 

model (including outdoor units with no 

match or ‘‘tested combinations’’). This 

requirement may apply across the listed 

categories in the table 1 to paragraph 

(a)(1) of this section. A refrigerant is 

considered approved for use if it is 

listed on the nameplate of the outdoor 

unit. 

* * * * * 

(b) * * * 

(2) Individual model/combination 

selection for testing. (i) Table 2 to this 

paragraph (b)(2)(i) identifies the 

minimum testing requirements for each 

basic model that includes multiple 

individual models/combinations; if a 

basic model spans multiple categories or 

subcategories listed in table 2, multiple 

testing requirements apply. For each 

basic model that includes only one 

individual model/combination, test that 

individual model/combination. 

TABLE 2 TO PARAGRAPH (b)(2)(i) 

Category Equipment subcategory Must test: With: 

Single-Package Unit .................. Single-Package AC (including 

Space-Constrained).

Single-Package HP (including 

Space-Constrained).

The individual model with the 

lowest seasonal.

energy efficiency ratio 2 

(SEER2).

(when testing in accordance 

with appendix M1.

to subpart B of 10 CFR part 

430).

or seasonal cooling and offmode rating.

efficiency (SCORE) (when testing.

in accordance with appendix 

M2 to subpart..

B of 10 CFR part 430) .............

N/A. 

Outdoor Unit and Indoor Unit 

(Distributed in Commerce by 

OUM).

Single-Split-System AC with 

Single-Stage or Two-Stage 

Compressor (including 

Space-Constrained and 

Small-Duct, High Velocity 

Systems (SDHV)).

The model of outdoor unit ........ A model of coil-only indoor unit. 

Single-Split-System HP with 

Single-Stage or Two-Stage 

Compressor (including 

Space-Constrained and 

SDHV).

The model of outdoor unit ........ A model of indoor unit. 

Single-Split System AC or HP 

with Other Than SingleStage or Two-Stage Compressor having a coil-only individual combination (including Space-Constrained and 

SDHV).

The model of outdoor unit ........ A model of coil-only indoor unit. 


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TABLE 2 TO PARAGRAPH (b)(2)(i)—Continued 

Category Equipment subcategory Must test: With: 

Single-Split System AC or HP 

with Other Than SingleStage or Two-Stage Compressor without a coil-only individual combination (including Space-Constrained and 

SDHV).

The model of outdoor unit ........ A model of indoor unit. 

Multi-Split, Multi-Circuit, or 

Multi-Head Mini-Split Split 

System—non-SDHV (including Space-Constrained).

The model of outdoor unit ........ At a minimum, a ‘‘tested combination’’ composed entirely of 

non-ducted indoor units. For any models of outdoor units 

also sold with models of ducted indoor units, test a second 

‘‘tested combination’’ composed entirely of ducted indoor 

units (in addition to the non-ducted combination). The ducted 

‘‘tested combination’’ must comprise the highest static variety of ducted indoor unit distributed in commerce (i.e., conventional, mid-static, or low-static). 

Multi-Split, Multi-Circuit, or 

Multi-Head Mini-Split Split 

System—SDHV.

The model of outdoor unit ........ A ‘‘tested combination’’ composed entirely of SDHV indoor 

units. 

Indoor Unit Only (Distributed in 

Commerce by ICM).

Single-Split-System Air Conditioner (including Space-Constrained and SDHV).A model of indoor unit .............. The least efficient model of outdoor unit with which it will be 

paired where the least efficient model of outdoor unit is the 

model of outdoor unit in the lowest SEER2 combination 

(when testing under appendix M1 to subpart B of 10 CFR 

part 430) or SCORE combination (when testing under appendix M2 to subpart B of 10 CFR part 430) as certified by 

the OUM. If there are multiple models of outdoor unit with 

the same lowest SEER2 (when testing under appendix M1 

to subpart B of 10 CFR part 430) or SCORE (when testing 

under appendix M2 to subpart B of 10 CFR part 430) represented value, the ICM may select one for testing purposes. 

Single-Split-System Heat Pump 

(including Space-Constrained 

and SDHV).

Nothing, as long as an equivalent air conditioner basic 

model has been tested. If an 

equivalent air conditioner 

basic model has not been 

tested, must test a model of 

indoor unit.

Multi-Split, Multi-Circuit, or 

Multi-Head Mini-Split Split 

System—SDHV.

A model of indoor unit .............. A ‘‘tested combination’’ composed entirely of SDHV indoor 

units, where the outdoor unit is the least efficient model of 

outdoor unit with which the SDHV indoor unit will be paired. 

The least efficient model of outdoor unit is the model of outdoor unit in the lowest SEER2 combination (when testing 

under appendix M1 to subpart B of 10 CFR part 430) or 

SCORE combination (when testing under appendix M2 to 

subpart B of 10 CFR part 430) as certified by the OUM. If 

there are multiple models of outdoor unit with the same lowest SEER2 represented value (when testing under appendix 

M1 to subpart B of 10 CFR part 430) or SCORE represented value (when testing under appendix M2 to subpart 

B of 10 CFR part 430), the ICM may select one for testing 

purposes. 

Outdoor Unit with No Match ...... ................................................... The model of outdoor unit ........ A model of coil-only indoor unit meeting the requirements of 

section 4 of appendix M1 (when testing under appendix M1 

to subpart B of 10 CFR part 430); or meeting the requirements of section 3 of appendix M2 (when testing under appendix M2 to subpart B of 10 CFR part 430). 

(ii) When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, each individual model/ 

combination (or ‘‘tested combination’’) 

identified in table 2 to paragraph 

(b)(2)(i) of this section is not required to 

be tested for PW,OFF. Instead, at a 

minimum, among individual models/ 

combinations with similar off-mode 

construction (even spanning different 

models of outdoor units), a 

manufacturer must test at least one 

individual model/combination for 

PW,OFF. 

(iii) When testing in accordance with 

appendix M2 to subpart B of 10 CFR 

part 430 and determining SCORE and 

SHORE, each individual model/ 

combination (or ‘‘tested combination’’) 

identified in table 2 to paragraph 

(b)(2)(i) of this section is not required to 

be tested for values of P1 (off-mode 

power in shoulder season) and P2 (offmode power in heating Season). Instead, 

at a minimum, among individual 

models/combinations with similar offmode construction (even spanning 

different models of outdoor units), a 

manufacturer must test at least one 

individual model/combination, for 

which P1 and P2 are the most 

consumptive. 

(3) * * * 

(ii) EER2, SEER2, HSPF2, SCORE, 

EER, and SHORE. Any represented 

value of the energy efficiency or other 

measure of energy consumption 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, 


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(B) The lower 90 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 t0.90 is the 

Student’s t-Distribution Value for a 90 

percent one-tailed confidence interval 

with n-1 degrees of freedom (from 

appendix A to this subpart). Round 

represented values of EER2, SEER2, 

HSPF2, EER, SCORE and SHORE to the 

nearest 0.05. 

* * * * * 

(c) * * * 

(1) * * * 

(i) * * * 

(B) The represented values of the 

measures of energy efficiency or energy 

consumption through the application of 

an AEDM in accordance with paragraph 

(d) of this section and § 429.70. An 

AEDM may only be used to determine 

represented values for individual 

models or combinations in a basic 

model (or separate approved refrigerants 

within an individual combination) other 

than the individual model or 

combination(s) required for mandatory 

testing under paragraph (b)(2) of this 

section. 

(ii) When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, for every individual model/ 

combination within a basic model tested 

pursuant to paragraph (b)(2) of this 

section, but for which PW,OFF testing was 

not conducted, the represented value of 

PW,OFF may be assigned through, either: 

(A) The testing result from an 

individual model/combination of 

similar off-mode construction; or 

(B) The application of an AEDM in 

accordance with paragraph (d) of this 

section and § 429.70. 

* * * * * 

(3) For multi-split systems, multicircuit systems, and multi-head minisplit systems. The following applies: 

(i) When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, or appendix M2 to subpart B 

of 10 CFR part 430, for basic models that 

include additional varieties of ducted 

indoor units (i.e., conventional, lowstatic, or mid-static) other than the one 

for which representation is required in 

paragraph (a)(1) of this section, if a 

manufacturer chooses to make a 

representation, the manufacturer must 

conduct testing of a tested combination 

according to the requirements in 

paragraph (b)(3) of this section. 

(ii) When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, or appendix M2 to subpart B 

of 10 CFR part 430, for basic models that 

include mixed combinations of indoor 

units (any two kinds of non-ducted, 

low-static, mid-static, and conventional 

ducted indoor units), the represented 

value for the mixed combination is the 

mean of the represented values for the 

individual component combinations as 

determined in accordance with 

paragraph (b)(3) of this section. 

(iii) When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, or appendix M2 to subpart B 

of 10 CFR part 430, for basic models 

including mixed combinations of SDHV 

and another kind of indoor unit (any of 

non-ducted, low-static, mid-static, and 

conventional ducted), the represented 

value for the mixed SDHV/other 

combination is the mean of the 

represented values for the SDHV and 

other tested combination as determined 

in accordance with paragraph (b)(3) of 

this section. 

(iv) All other individual combinations 

of models of indoor units for the same 

model of outdoor unit for which the 

manufacturer chooses to make 

representations must be rated as 

separate basic models, and the 

provisions of paragraphs (b)(1) through 

(3) and (c)(3)(i) through (iii) of this 

section apply. 

(v) When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, and with respect to PW,OFF

only, for every individual combination 

(or ‘‘tested combination’’) within a basic 

model tested pursuant to paragraph 

(b)(2) of this section, but for which 

PW,OFF testing was not conducted, the 

representative values of PW,OFF may be 

assigned through either: 

(A) The testing result from an 

individual model or combination of 

similar off-mode construction, or 

(B) Application of an AEDM in 

accordance with paragraph (d) of this 

section and § 429.70. 

(d) * * * 

(2) Energy efficiency. Any represented 

value of the EER2, SEER2, HSPF2, EER, 

SCORE and SHORE, or other measure of 

energy efficiency of an individual 

model/combination for which 

consumers would favor higher values 

must be less than or equal to the output 

of the AEDM but no less than the 

standard. 

* * * * * 

(f) Represented values for the Federal 

Trade Commission. Use the following 

represented value determinations to 

meet the requirements of the Federal 

Trade Commission. 

(1) Annual operating cost—cooling. 

Determine the represented value of 

estimated annual operating cost for 

cooling-only units or the cooling portion 

of the estimated annual operating cost 

for air-source heat pumps that provide 

both heating and cooling, as follows: 

(i) When using appendix M1 to 

subpart B of 10 CFR part 430, the 

product of: 

(A) The quotient of the represented 

value of cooling capacity, in Btu’s per 

hour as determined in paragraph 

(b)(3)(iii) of this section, and multiplied 

by 0.93 for variable speed heat pumps 

only, divided by the represented value 

of SEER2, in Btu’s per watt-hour, as 

determined in paragraph (b)(3)(ii) of this 

section. 

(B) The representative average use 

cycle for cooling of 1,000 hours per 

year; 

(C) A conversion factor of 0.001 

kilowatt per watt; and 

(D) The representative average unit 

cost of electricity in dollars per 

kilowatt-hour as provided pursuant to 

section 323(b)(2) of the Act. 

(ii) When using appendix M2 to 

subpart B of 10 CFR part 430, the 

product of: 

(A) The quotient of the represented 

value of cooling capacity, in Btu’s per 

hour as determined in paragraph 

(b)(3)(iii) of this section, and multiplied 

by 0.93 for variable speed heat pumps 

only, divided by the represented value 

of SCORE, in Btu’s per watt-hour, as 

determined in paragraph (b)(3)(ii) of this 

section. 

(B) The representative average use 

cycle for cooling of 1,457 hours per 

year; 

(C) A conversion factor of 0.001 

kilowatt per watt; and 

(D) The representative average unit 

cost of electricity in dollars per 


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kilowatt-hour as provided pursuant to 

section 323(b)(2) of the Act. 

(2) Annual operating cost—heating. 

Determine the represented value of 

estimated annual operating cost for airsource heat pumps that provide only 

heating or for the heating portion of the 

estimated annual operating cost for airsource heat pumps that provide both 

heating and cooling, as follows: 

(i) When using appendix M1 to 

subpart B of 10 CFR part 430, the 

product of: 

(A) The quotient of the represented 

value of cooling capacity (for air-source 

heat pumps that provide both cooling 

and heating) in Btu’s per hour, as 

determined in paragraph (b)(3)(iii) of 

this section, or the represented value of 

heating capacity (for air-source heat 

pumps that provide only heating), as 

determined in paragraph (b)(3)(iii) of 

this section, divided by the represented 

value of HSPF2, in Btu’s per watt-hour, 

calculated for Region IV, as determined 

in paragraph (b)(3)(ii) of this section; 

(B) The representative average use 

cycle for heating of 1,572 hours per 

year; 

(C) The adjustment factor of 1.15 (for 

heat pumps that are not variable speed) 

or 1.07 (for heat pumps that are variable 

speed), which serves to adjust the 

calculated design heating requirement 

and heating load hours to the actual 

load experienced by a heating system; 

(D) A conversion factor of 0.001 

kilowatt per watt; and 

(E) The representative average unit 

cost of electricity in dollars per 

kilowatt-hour as provided pursuant to 

section 323(b)(2) of the Act; 

(ii) When using appendix M2 to 

subpart B of 10 CFR part 430, the 

product of: 

(A) The quotient of the represented 

value of cooling capacity (for air-source 

heat pumps that provide both cooling 

and heating) in Btu’s per hour, as 

determined in paragraph (b)(3)(iii) of 

this section, or the represented value of 

heating capacity (for air-source heat 

pumps that provide only heating), as 

determined in paragraph (b)(3)(iii) of 

this section, divided by the represented 

value of SHORE, in Btu’s per watt-hour, 

as determined in paragraph (b)(3)(ii) of 

this section; 

(B) The representative average use 

cycle for heating of 972 hours per year; 

(C) The adjustment factor of 1.15 (for 

heat pumps that are not variable speed) 

or 1.07 (for heat pumps that are variable 

speed), which serves to adjust the 

calculated design heating requirement 

and heating load hours to the actual 

load experienced by a heating system; 

(D) A conversion factor of 0.001 

kilowatt per watt; and 

(E) The representative average unit 

cost of electricity in dollars per 

kilowatt-hour as provided pursuant to 

section 323(b)(2) of the Act; 

(3) Annual operating cost—total. 

Determine the represented value of 

estimated annual operating cost for airsource heat pumps that provide both 

heating and cooling by calculating the 

sum of the quantity determined in 

paragraph (f)(1) of this section added to 

the quantity determined in paragraph 

(f)(2) of this section. 

(4) Regional annual operating cost— 

cooling. Determine the represented 

value of estimated regional annual 

operating cost for cooling-only units or 

the cooling portion of the estimated 

regional annual operating cost for airsource heat pumps that provide both 

heating and cooling as follows: 

(i) When using appendix M1 to 

subpart B of 10 CFR part 430, the 

product of: 

(A) The quotient of the represented 

value of cooling capacity, in Btu’s per 

hour as determined in paragraph 

(b)(3)(iii) of this section, and multiplied 

by 0.93 for variable speed heat pumps 

only, divided by the represented value 

of SEER2, in Btu’s per watt-hour, as 

determined in paragraph (b)(3)(ii) of this 

section; 

(B) The estimated number of regional 

cooling load hours per year determined 

from the following table: 

TABLE 4 TO PARAGRAPH (f)(4)(i)(B) 

Climatic region Regional cooling 

load hours 

I ....................................... 2,400 

II ...................................... 1,800 

III ..................................... 1,200 

IV .................................... 800 

V ..................................... 400 

VI .................................... 200 

(C) A conversion factor of 0.001 

kilowatts per watt; and 

(D) The representative average unit 

cost of electricity in dollars per 

kilowatt-hour as provided pursuant to 

section 323(b)(2) of the Act. 

(ii) When using appendix M2 to 

subpart B of part 430, regional annual 

operating cost for cooling-only units or 

the cooling portion of the estimated 

regional annual operating cost airsource heat pumps that provide both 

heating and cooling, does not apply. 

(5) Regional annual operating cost— 

heating. Determine the represented 

value of estimated regional annual 

operating cost for air-source heat pumps 

that provide only heating or for the 

heating portion of the estimated regional 

annual operating cost for air-source heat 

pumps that provide both heating and 

cooling as follows: 

(i) When using appendix M1 to 

subpart B of 10 CFR part 430, the 

product of: 

(A) The estimated number of regional 

heating load hours per year determined 

from the following table: 

TABLE 5 TO PARAGRAPH (f)(5)(i)(A) 

Climatic region Regional cooling 

load hours 

I ....................................... 493 

II ...................................... 857 

III ..................................... 1,247 

IV .................................... 1,701 

V ..................................... 2,202 

VI .................................... 1,842 

(B) The quotient of the represented 

value of cooling capacity (for air-source 

heat pumps that provide both cooling 

and heating) in Btu’s per hour, as 

determined in paragraph (b)(3)(iii)(C) of 

this section, or the represented value of 

heating capacity (for air-source heat 

pumps that provide only heating), as 

determined in paragraph (b)(3)(iii) of 

this section, divided by the represented 

value of HSPF2, in Btu’s per watt-hour, 

calculated for the appropriate 

generalized climatic region of interest, 

and determined in paragraph (b)(3)(iii) 

of this section; 

(C) The adjustment factor of 1.15 (for 

heat pumps that are not variable speed) 

or 1.07 (for heat pumps that are variable 

speed), which serves to adjust the 

calculated design heating requirement 

and heating load hours to the actual 

load experienced by a heating system; 

(D) A conversion factor of 0.001 

kilowatts per watt; and 

(E) The representative average unit 

cost of electricity in dollars per 

kilowatt-hour as provided pursuant to 

section 323(b)(2) of the Act. 

(ii) When using appendix M2 to 

subpart B of 10 CFR part 430, regional 

annual operating cost for air-source heat 

pumps that provide only heating or for 

the heating portion, does not apply. 

(6) Regional annual operating cost— 

total. For air-source heat pumps that 

provide both heating and cooling, the 

estimated regional annual operating cost 

is the sum of the quantity determined in 

paragraph (f)(4) of this section added to 

the quantity determined in paragraph 

(f)(5) of this section. 

(7) Annual operating cost—rounding. 

Round any represented values of 

estimated annual operating cost 

determined in paragraphs (f)(1) through 

(6) of this section to the nearest dollar 

per year. 


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■ 4. Amend § 429.70 by revising 

paragraphs (e)(1) and (e)(2)(i)(A) to read 

as follows: 

§ 429.70 Alternative methods for 

determining energy efficiency and energy 

use. 

* * * * * 

(e) * * * 

(1) Criteria an AEDM must satisfy. A 

manufacturer may not apply an AEDM 

to an individual model/combination to 

determine its represented values (EER2, 

SEER2, HSPF2, SCORE, EER, SHORE 

and/or PW,OFF) pursuant to this section 

unless authorized pursuant to 

§ 429.16(d) and: 

(i) The AEDM is derived from a 

mathematical model that estimates the 

energy efficiency or energy 

consumption characteristics of the 

individual model or combination (EER2, 

SEER2, HSPF2, EER, SCORE, SHORE 

and/or PW,OFF) as measured by the 

applicable DOE test procedure; and 

(ii) The manufacturer has validated 

the AEDM in accordance with 

paragraph (e)(2) of this section. 

(2) * * * 

(i) * * * 

(A) Minimum testing. The 

manufacturer must test each basic 

model as required under § 429.16(b)(2). 

* * * * * 

■ 5. Amend § 429.134 by revising 

paragraph (k) to read as follows: 

§ 429.134 Product-specific enforcement 

provisions. 

* * * * * 

(k) Central air conditioners and heat 

pumps. Before July 7, 2025, the 

provisions in this section of this title as 

it appeared in the 10 CFR parts 200–499 

edition revised as of January 1, 2023, are 

applicable. On and after July 7, 2025, 

the following provisions apply. 

(1) Verification of cooling capacity. 

The cooling capacity of each tested unit 

of the individual model (for singlepackage systems) or individual 

combination (for split systems) will be 

measured pursuant to the test 

requirements of § 430.23(m) of this 

chapter. The mean of the 

measurement(s) (either the measured 

cooling capacity for a single unit sample 

or the average of the measured cooling 

capacities for a multiple unit sample) 

will be used to determine the applicable 

standards for purposes of compliance. 

(2) Verification of CD value. (i) For 

central air conditioners and heat pumps 

other than models of outdoor units with 

no match, if manufacturers certify that 

they did not conduct the optional tests 

to determine the CDc and/or CDh value 

for an individual model (for singlepackage systems) or individual 

combination (for split systems), as 

applicable, for each unit tested, the 

default CDc and/or CDh value will be 

used as the basis for the calculation of 

SEER2 or HSPF2 when testing in 

accordance with appendix M1 to 

subpart B of 10 CFR part 430, or SCORE 

or SHORE when testing in accordance 

with appendix M2 to subpart B of 10 

CFR part 430. If manufacturers certify 

that they conducted the optional tests to 

determine the CDc and/or CDh value for 

an individual model (for single-package 

systems) or individual combination (for 

split systems), as applicable, the 

following provisions apply. 

(A) If testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, the CDc and/or CDh value will 

be measured for each unit tested 

pursuant to appendix M1 to subpart B 

of 10 CFR part 430 and the result for 

each unit tested (either the tested value 

or the default value, as selected 

according to the criteria for the cyclic 

test in section E17 of AHRI 210/240– 

2024 (incorporated by reference, see 

§ 429.4)) will be used as the basis for 

calculation of SEER2 or HSPF2. 

(B) If testing in accordance with 

appendix M2 to subpart B of 10 CFR 

part 430, the CDc and/or CDh value will 

be measured for each unit tested 

pursuant to appendix M2 to subpart B 

of 10 CFR part 430 and the result for 

each unit tested (either the tested value 

or the default value, as selected 

according to the criteria for the cyclic 

test in section E17 of AHRI 1600–2024 

(incorporated by reference, see § 429.4)) 

will be used as the basis for calculation 

of SCORE or SHORE. 

(ii) For models of outdoor units with 

no match, DOE will use the default CDc

and/or CDh pursuant to appendix M1 to 

subpart B of 10 CFR part 430 or 

appendix M2 to subpart B of 10 CFR 

part 430, as applicable. 

(3) Verification of cut-out and cut-in 

temperatures for central heat pumps. (i) 

When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430, the cut-out and cut-in 

temperatures may be verified using the 

method in appendix J of AHRI 210/240– 

2024 (incorporated by reference, see 

§ 429.4). If this method is conducted, 

the tested TOFF,T and TON,T values 

determined in the test shall be used as 

the cut-out and cut-in temperatures, 

respectively, to calculate HSPF2. 

(ii) When testing in accordance with 

appendix M2 to subpart B of 10 CFR 

part 430, the cut-out and cut-in 

temperatures may be verified using the 

method in appendix J of AHRI 1600– 

2024 (incorporated by reference, see 

§ 429.4). If this method is conducted, 

the tested TOFF,T and TON,T values 

determined in the test shall be used as 

the cut-out and cut-in temperatures, 

respectively, to calculate SHORE. 

(4) Verification of Variable Capacity 

Operation and of Fixed Settings for the 

Compressor and the Indoor Fan when 

Testing Variable Capacity Compressor 

Systems—(i) Conducting the controls 

verification procedure (CVP). A CVP 

may be performed for any model 

certified as a variable capacity 

compressor system for the purposes of 

assessment or enforcement testing 

conducted according to appendix M1 to 

subpart B of 10 CFR part 430 or 

appendix M2 to subpart B of 10 CFR 

part 430 (i.e., the certification tests), as 

applicable. For a heat pump, either a 

cooling mode CVP, a heating mode CVP, 

or both may be conducted, as elected by 

DOE. If a CVP is not conducted, the 

override instructions for the compressor 

and indoor fan, as specified by the 

manufacturer, will be used to conduct 

the tests per appendix M1 to subpart B 

of 10 CFR part 430 or, appendix M2 to 

subpart B of 10 CFR part 430, as 

applicable. 

(A) When testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430. The CVP will be conducted 

per appendix I of AHRI 210/240–2024 

(incorporated by reference, see § 429.4). 

(B) When testing in accordance with 

appendix M2 to subpart B of 10 CFR 

part 430. The CVP will be conducted 

per appendix I of AHRI 1600–2024 

(incorporated by reference, see § 429.4). 

(C) Variable capacity certified, single 

capacity systems. For systems 

determined to be variable capacity 

certified, single capacity systems as 

described in paragraph (k)(4)(ii)(B) of 

this section, the CVP cooling and 

heating minimum intervals may be 

omitted. 

(ii) Variable capacity determination. 

(A) If the unit tested does meet the 

definition of a variable capacity 

compressor system based on 

performance of the CVP per paragraph 

(k)(4)(i)(A) or paragraph (k)(4)(i)(B) of 

this section, the efficiency metrics 

(SEER2, HSPF2, EER2, SCORE, SHORE, 

EER as applicable) shall be determined 

using the certification test applicable to 

variable capacity compressor systems. 

(B) If the unit tested does not meet the 

definition of a variable capacity 

compressor system based on 

performance of the CVP per paragraph 

(k)(4)(i)(A) or (B) of this section, and the 

tested unit is instead determined to be 

a variable capacity certified, single 

capacity system, the efficiency metrics 

(SEER2, HSPF2, EER2, SCORE, SHORE, 

EER as applicable) shall be determined 

using the certification test applicable to 


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variable capacity certified, single 

capacity systems. 

(C) If the unit tested does not meet the 

definition of a variable capacity 

compressor system based on 

performance of the CVP per paragraph 

(k)(4)(i)(A) or (B) of this section, and the 

tested unit is instead determined to be 

a variable capacity certified, two 

capacity system, the efficiency metrics 

(SEER2, HSPF2, EER2, SCORE, SHORE, 

EER as applicable) shall be determined 

using the certification test applicable to 

variable capacity certified, two capacity 

systems. 

(D) If, for a heat pump, a CVP is 

conducted for just one of the operating 

modes (heating or cooling), the system 

classifications for both modes will be 

based on the results of the one CVP 

conducted. 

(iii) CVP tolerance evaluation for full 

and minimum load intervals. (A) The 

data collected in the CVP per paragraph 

(k)(4)(i)(A) or (B) of this section shall be 

evaluated for the duration of the 

individual CVP full or minimum load 

interval excluding the preliminary 30 

minutes of equilibrium data, to 

determine compliance with test 

condition tolerances and test operating 

tolerances listed in section I5.1 of 

appendix I of AHRI 210/240–2024 (if 

testing in accordance with appendix M1 

to subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)) 

or of AHRI 1600–2024 (if testing in 

accordance with appendix M2 to 

subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)), 

with the exception that indoor entering 

wet bulb deviation in I5.1 and test 

operating tolerance in I5.1.3 is 

applicable only for cooling mode CVP. 

(1) If the specified tolerances are met 

under system operation for 60 minutes, 

the average capacity and average power 

measured over this 60-minute test 

interval shall be recorded. 

(2) If the four-hour time limit is 

reached by the system without 

maintaining the tolerances for a 60- 

minute period, but two successive test 

period sub-intervals are identified, each 

a minimum of 30 minutes, and 

comprised of a whole number of 

compressor cycles (either compressor 

on-off cycles or speed/capacity cycles) 

or in which minimal fluctuations of the 

compressor speed/capacity level are 

observed, where both the time averaged 

integrated capacity and time averaged 

integrated power of the two successive 

test period sub-intervals are observed to 

be within two percent of each other, a 

single capacity average and a single 

power average shall be recorded, both 

averaged over compressor-on periods of 

the two successive test period subintervals. These average capacity and 

power values shall be considered the 

capacity and power values recorded for 

the test interval. 

(3) If the four-hour time limit is 

reached by the system without 

complying with either paragraph 

(k)(4)(iii)(A)(1) or (2) of this section, the 

time averaged integrated capacity and 

time averaged integrated power shall be 

recorded for only the compressor-on 

periods over the final 120 minutes of the 

test interval. 

(B) Determine whether the measured 

capacity for each full load interval, as 

evaluated per the CVP conducted in 

paragraph (k)(4)(i)(A) or (B) of this 

section, is no more than 6% less than 

the corresponding certification test 

capacity, as follows: 

Where: 

q ̇ A,Full = Certification test capacity at AFull

condition, 

q ̇CVP,A,Full = CVP test capacity at AFull

condition, 

q ̇ H3,Full = Certification test capacity at H3Full

condition, 

q ̇CVP,H3,Full = CVP test capacity at H3Full

condition, 

q ̇ H4,Full = Certification test capacity at H4Full

condition, 

q ̇CVP,H4,Full= CVP test capacity at H4Full

condition, 

(C) Determine whether the measured 

capacity for each minimum load 

interval, as evaluated per the CVP 

conducted in paragraph (k)(4)(i)(A) or 

(B) of this section, is no more than 6% 

less than the corresponding certification 

test capacity, as follows: 

Where: 

q ̇CVP,F,Low= CVP test capacity at FLow

condition, 

q ̇ F,Low = Certification test capacity at FLow

condition, 

q ̇CVP,H1,Low = CVP test capacity at H1Low

condition, 

q ̇ H1,Low= Certification test capacity at H1Low

condition, 

(D) Determine whether the measured 

efficiency for the full and minimum 

load interval, as evaluated per the CVP 

conducted in paragraph (k)(4)(i)(A) or 

(B) of this section, is no more than 10% 

less than the corresponding certification 

test efficiency, as follows: 


ddrumheller on DSK120RN23PROD with RULES2ER07JA25.016</GPH> ER07JA25.017</GPH>

llA,Full- ilcvP,A,Full Cooling full: 

llA,Full 

X 100 :S 6.0 

Heating full (17oF): llH3,Ful'.- ilcvP,H3,Full X 100 :S 6.0 

qH3,Full 

Heating full (5oF): llH4,Ful'.- ilcvP,H4,Full X 100 :S 6.0 

qH4,Full 

llCVP,F,Low- ilF,Low Cooling minimum: ___;;_'--'---'--'--'-'----'---'-"'--

qA,Full 

X 100 :S 6.0 

Heating minimum: ilcvP,Hl,_Low - ilm,Low X 100 :S 6.0 

qH3,Full 
1280 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

(E) Cooling and heating efficiency 

requirements are shown using EER2 and 

COP2 to align with testing in 

accordance with appendix M1 to 

subpart B of 10 CFR part 430. When 

testing in accordance with appendix M2 

to subpart B of 10 CFR part 430, replace 

EER2 with EER, and COP2 with COP. 

(iv) Evaluation of results when CVP 

tolerances are met. If the tolerances for 

capacity and efficiency are met by the 

applicable full and minimum load 

intervals as per paragraphs (k)(4)(iii)(B) 

through (D) of this section, the certified 

override instructions for the compressor 

and indoor fan, as specified by the 

manufacturer, shall be deemed valid, 

and the efficiency metrics (SEER2, 

HSPF2, EER2, SCORE, SHORE, EER as 

applicable), shall be determined based 

on these certification tests with no 

adjustments determined based on the 

CVP results. 

(v) Evaluation of results when CVP 

tolerances are not met. If the tolerances 

for capacity and efficiency are not met 

by the applicable full and minimum 

load intervals as per paragraphs 

(k)(4)(iii)(B) through (D) of this section, 

the unit shall be tested per instructions 

in paragraphs (k)(4)(v)(A) through (C) of 

this section, as applicable. The 

instructions in paragraphs (k)(4)(v)(A) 

through (C) shall be followed, as 

applicable, only for the certification 

tests corresponding to the out of 

tolerance compressor speed interval 

based on the evaluations of paragraphs 

(k)(4)(iii)(B) through (D). For all 

compressor speed intervals for which 

the capacity and EER2/COP2/EER/COP 

are in tolerance as per paragraphs 

(k)(4)(iii)(B) through (D), the 

corresponding certification tests shall be 

used without adjustments. 

(A) The instructions of this paragraph 

shall be applied to systems for which 

the same control device used as per the 

CVP conducted in paragraph (k)(4)(i)(A) 

or (B) of this section is used as the 

means for overriding the controls, and 

both of the following are supported by 

the control device: monitoring of the 

compressor and indoor blower speed 

during native-control operation without 

otherwise impacting the control of the 

system; and monitoring and adjustment 

of the compressor and indoor blower 

speed during certification tests, where 

monitoring and adjustment means the 

control device has the ability to display 

and make discrete adjustments, as 

required, to the compressor and indoor 

blower speeds without additional 

hardware or non-publicly available 

software. 

(1) The compressor and indoor blower 

speed shall be monitored during the 

CVP conducted in paragraph (k)(4)(i)(A) 

or (B) of this section. The average 

compressor and indoor blower speeds 

and indoor air volume rate shall be 

evaluated for the same time period(s) 

used as described in paragraph 

(k)(4)(iii)(A) of this section to determine 

average capacity and power for the CVP 

test. The compressor speed for the 

certification test shall be set at this 

average value observed during the 

corresponding CVP test interval. The 

indoor blower speed shall be set as 

described in section 6.1.5 of AHRI 210/ 

240–2024 (if testing in accordance with 

appendix M1 to subpart B of 10 CFR 

part 430; (incorporated by reference, see 

§ 429.4)) or of AHRI 1600–2024 (if 

testing in accordance with appendix M2 

to subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)), 

except the ‘‘specified airflow’’ shall be 

set as the average value observed during 

the corresponding CVP test interval. The 

same adjusted compressor speed shall 

be used for the other certification tests 

that require the same speed, as 

applicable, as detailed in table 1 to this 

paragraph (k)(4)(v)(A). Specifically, for 

each of the CVP tests listed in the first 

column for which either the capacity 

tolerances of paragraph (k)(4)(iii)(B) or 

(C) of this section are not met or the 

efficiency tolerances of paragraph 

(k)(4)(iii)(D) of this section are not met, 

the certification tests to be conducted 

again using the compressor speed 

determined in the corresponding CVP 

test are listed in the last three columns 

of the table, depending on which of the 

three kinds of system the model is 

designated. 

(2) If required, the adjusted q ̇ H3,Full

and PH3,Full shall be used to calculate 

q ̇ k=2hcalc(47) and Pk=2hcalc(47), 

respectively, to represent performance 

at 47 °F as described in section 11.2.2.4 

of AHRI 210/240–2024 (if testing in 

accordance with appendix M1 to 

subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)) 

or of AHRI 1600–2024 (if testing in 

accordance with appendix M2 to 

subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)) 

and for use in calculating performance 

at 35 °F. If required, the adjusted H1Low

and H3Low tests shall be used to 

calculate q ̇thi,H2,Low and PH2,Low, 

respectively, as described in section 

6.1.3.4 of AHRI 210/240–2024 (if testing 

in accordance with appendix M1 to 

subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)) 

or of AHRI 1600–2024 (if testing in 

accordance with appendix M2 to 

subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)). 

No adjustments are required for 

intermediate or nominal compressor 

speed tests or, if cyclic tests are 

conducted, for the degradation 

coefficient(s). 


ddrumheller on DSK120RN23PROD with RULES2ER07JA25.018</GPH> ER07JA25.019</GPH>

Cooling full: EER2A,Full- EER2cvP,A,Full X l00 ::S lO.0 

EER2A,Full 

Cooling minimum: EER2F,Low- EER2cvP,F,Low X 100 ::S 10.0 

EER2F,Low 

Heating full (5oF): COP2H4,Full- COP2cvP,H4,Full X 100 < 10.0 

COP2H4,Full -

Heating full (17oF): COP2H3,Full- COP2cvP,H3,Full X 100 ::S 10.0 

COP2H3,Full 

H t. . . COP2H1 Low- COP2cvP Hl Low X l00 ::S l 0.0 ea mg m1mmum: ' ' ' 

COP2H1,Low 
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1281 

TABLE 1 TO PARAGRAPH (k)(4)(v)(A) 

CVP test 

Certification tests that use the indicated CVP test compressor speed or would have certification test 

results adjusted per paragraph (k)(4)(v)(B) of this section, if the CVP test is out of capacity or EER/COP 

tolerance per paragraph (k)(4)(iii) of this section 

Variable capacity certified, single 

capacity system 

Variable capacity certified, 

two capacity system Variable capacity system 

AFull ................................................ AFull, BFull ...................................... AFull, BFull ...................................... AFull, BFull. 

FLow ................................................ N/A ................................................ BLow, FLow ..................................... BLow, FLow. 

H1Low ............................................. N/A ................................................ H0Low, H1Low, H3Low .................... H0Low, H1Low. 

H3Full .............................................. H2Full, H3Full ................................. H3Full ............................................. H3Full. 

H4Full .............................................. H4Full ............................................. H4Full ............................................. H4Full. 

(B) The instructions of this paragraph 

shall be applied to systems for which 

the means for overriding the compressor 

and indoor blower speed as discussed in 

paragraph (k)(4)(v)(A) of this section is 

not provided by the control used for 

conducting the CVP. For each of the 

CVP tests listed in the first column of 

table 1 to paragraph (k)(4)(v)(A) of this 

section for which either the capacity 

tolerances of paragraph (k)(4)(iii)(B) or 

(C) of this section are not met or the 

efficiency tolerances of paragraph 

(k)(4)(iii)(D) of this section are not met, 

depending on which of the three kinds 

of system the model is designated, the 

certification test results to be adjusted 

based on the results of the CVP test are 

indicated by the last three columns of 

the table for each CVP test listed in the 

first column. 

(1) The average capacities and 

power(s) measured during the CVP time 

period(s) described in paragraph 

(k)(4)(iii)(A) of this section shall be used 

(with no adjustment for tests having a 

CVP interval). For the certification tests 

requiring adjustment with no CVP 

interval (any required certification test 

in column 2, 3, or 4 of table 1 to 

paragraph (k)(4)(v)(A) of this section 

other than AFull, FLow, H1Low, H3Full and 

H4Full for which the column 1 CVP 

interval did not meet capacity or EER2/ 

COP2/EER/COP tolerances), the 

capacity and power shall be adjusted. 

The capacity shall be adjusted by 

applying the ratio of the capacity 

measured during the CVP test interval 

divided by the capacity measured 

during the certification test (for the 

corresponding CVP interval). The power 

shall be adjusted by applying the ratio 

of the power measured during the CVP 

test interval divided by the power 

measured during the certification test 

(for the corresponding CVP interval), as 

follows: 

Cooling full capacity: 

Cooling full power: 

Cooling minimum capacity: 

Cooling minimum power: 

Heating minimum capacity: 


ddrumheller on DSK120RN23PROD with RULES2ER07JA25.020</GPH> ER07JA25.021</GPH> ER07JA25.022</GPH> ER07JA25.023</GPH>

C/.cvP,A,Full 

C/.B,Full = C/.B,Full,Certification X Cf.A,Full,Certification 

p CVP,A,Full 

PB,Full = PB,Full,Certification X PA,Full,Certification 

C/.cvP,F,Low 

C/.B,Low = C/.B,Low,Certification X C/.F,Low,Certification 

PcvP,F,Low 

PB,Low = PB,Low,Certification X PF,Low,Certification 
1282 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

Heating minimum power: 

Where: 

CSF = 0.0204/°F, capacity slope factor for 

Split Systems 

CSF = 0.0262/°F, capacity slope factor for 

Single Package Units 

PSF = 0.00455/°F, power slope factor for all 

products 

(2) If required, the measured QH3,Full

and EH3,Full from the CVP shall be used 

to calculate q ̇ k=2hcalc(47) and 

Pk=2hcalc(47), respectively, to represent 

performance at 47 °F as described in 

section 11.2.2.4 of AHRI 210/240–2024 

(if testing in accordance with appendix 

M1 to subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)) 

or of AHRI 1600–2024 (if testing in 

accordance with appendix M2; 

(incorporated by reference, see § 429.4)), 

and for use in calculating performance 

at 35 °F. If required, the measured H1Low

from the CVP and the adjusted H3Low

tests shall be used to calculate q ̇thi,H2,Low

and PH2,Low, respectively, as described in 

section 6.1.3.4 of AHRI 210/240–2024 (if 

testing in accordance with appendix M1 

to subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)) 

or of AHRI 1600–2024 (if testing in 

accordance with appendix M2 to 

subpart B of 10 CFR part 430; 

(incorporated by reference, see § 429.4)). 

No adjustments are required for 

intermediate or nominal compressor 

speed tests or, if cyclic tests are 

conducted, the degradation 

coefficient(s). 

(C) If the test unit is determined to be 

variable capacity certified, single 

capacity system, or variable capacity 

certified, two capacity system and is not 

certified or marketed for use with only 

a proprietary control device, the same 

simulated thermostat low voltage signal 

that resulted in full speed compressor 

operation for the full load intervals shall 

be used for all certification full load 

tests. If the test unit is determined to be 

variable capacity certified, two capacity 

system and is not certified or marketed 

for use with only a proprietary control 

device the same simulated thermostat 

low voltage signal that resulted in lowspeed compressor operation for the low 

load intervals shall be used for all 

certification low load tests. 

* * * * * 

PART 430—ENERGY CONSERVATION 

PROGRAM FOR CONSUMER 

PRODUCTS 

■ 6. The authority citation for part 430 

continues to read as follows: 

Authority: 42 U.S.C. 6291–6309; 28 U.S.C. 

2461 note. 

■ 7. Amend § 430.2 by revising the 

definition of ‘‘Central air conditioner or 

central air conditioning heat pump’’ to 

read as follows. 

§ 430.2 Definitions. 

* * * * * 

Central air conditioner or central air 

conditioning heat pump means a 

product, other than a packaged terminal 

air conditioner, packaged terminal heat 

pump, single-phase single-package 

vertical air conditioner with cooling 

capacity less than 65,000 Btu/h, singlephase single-package vertical heat pump 

with cooling capacity less than 65,000 

Btu/h, computer room air conditioner, 

or unitary dedicated outdoor air system 

as these equipment categories are 

defined at § 431.92 of this chapter, 

which is powered by single phase 

electric current, air cooled, rated below 

65,000 Btu per hour, not contained 

within the same cabinet as a furnace, 

the rated capacity of which is above 

225,000 Btu per hour, and is a heat 

pump or a cooling unit only. A central 

air conditioner or central air 

conditioning heat pump may consist of: 

A single-package unit; an outdoor unit 

and one or more indoor units; an indoor 

unit only; or an outdoor unit with no 

match. In the case of an indoor unit only 

or an outdoor unit with no match, the 

unit must be tested and rated as a 

system (combination of both an indoor 

and an outdoor unit). 

* * * * * 

■ 8. Amend § 430.3 by: 

■ a. Removing ‘‘appendices M and M1’’ 

and adding in its place ‘‘appendix M’’ 

in paragraph (b)(4) introductory text; 

■ b. Revising paragraphs (c) and (g)(1) 

through (3); 

■ c. Removing ‘‘appendices M and M1’’ 

and adding in its place ‘‘appendix M’’ 

in paragraphs (g)(4) introductory text 

and (g)(21); 

■ d. Redesignating paragraphs (g)(22) 

through (24) as paragraphs (g)(23) 

through (25); and 

■ e. Adding new paragraph (g)(22). 

The revisions and addition read as 

follows: 

§ 430.3 Materials incorporated by 

reference. 

* * * * * 

(c) AHRI. Air-Conditioning, Heating, 

and Refrigeration Institute, 2311 Wilson 

Blvd., Suite 400, Arlington, VA 22201, 

(703) 524–8800, or go to: 

www.ahrinet.org. 

(1) ANSI/AHRI 210/240–2008 with 

Addenda 1 and 2 (‘‘AHRI 210/240– 

2008’’), 2008 Standard for Performance 

Rating of Unitary Air-Conditioning & 

Air-Source Heat Pump Equipment, 

ANSI approved October 27, 2011 

(Addendum 1 dated June 2011 and 

Addendum 2 dated March 2012); IBR 

approved for appendix M to subpart B, 

as follows: 

(i) Section 6—Rating Requirements, 

Section 6.1—Standard Ratings, 6.1.3— 

Standard Rating Tests, 6.1.3.2— 

Electrical Conditions; 


ddrumheller on DSK120RN23PROD with RULES2ER07JA25.024</GPH> ER07JA25.025</GPH>

C/.cvP,Hl,Low 

Cf.HO,Low = Cf.HO,Low,Certification X C/.Hl,Low,Certification 

C/.cvP,Hl,Low 

C/.H3,Low = (1 + 30 · CSF) 

p CVP,Hl,Low 

PHO,Low = PHO,Low,Certification X PHl,Low,Certification 

p CVP,Hl,Low 

PH3,Low = (1 + 30 · PSF) 
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1283 

(ii) Section 6—Rating Requirements, 

Section 6.1—Standard Ratings, 6.1.3— 

Standard Rating Tests, 6.1.3.4— 

Outdoor-Coil Airflow Rate; 

(iii) Section 6—Rating Requirements, 

Section 6.1—Standard Ratings, 6.1.3— 

Standard Rating Tests, 6.1.3.5— 

Requirements for Separated Assemblies; 

(iv) Figure D1—Tunnel Air Enthalpy 

Test Method Arrangement; 

(v) Figure D2—Loop Air Enthalpy 

Test Method Arrangement; and 

(vi) Figure D4—Room Air Enthalpy 

Test Method Arrangement. 

(2) AHRI Standard 210/240–2024 (I– 

P), (‘‘AHRI 210/240–2024’’), 

Performance Rating of Unitary Airconditioning and Air-source Heat Pump 

Equipment; IBR approved for appendix 

M1 to subpart B. 

(3) AHRI Standard 1160–2009 (‘‘AHRI 

1160’’), Performance Rating of Heat 

Pump Pool Heaters, 2009; IBR approved 

for appendix P to subpart B. 

(4) ANSI/AHRI 1230–2010 with 

Addendum 2 (‘‘AHRI 1230–2010’’), 

2010 Standard for Performance Rating of 

Variable Refrigerant Flow (VRF) MultiSplit Air-Conditioning and Heat Pump 

Equipment (including Addendum 1 

dated March 2011), ANSI approved 

August 2, 2010 (Addendum 2 dated 

June 2014); IBR approved for appendix 

M to subpart B, as follows: 

(i) Section 3—Definitions (except 3.8, 

3.9, 3.13, 3.14, 3.15, 3.16, 3.23, 3.24, 

3.26, 3.27, 3.28, 3.29, 3.30, and 3.31); 

(ii) Section 5—Test Requirements, 

Section 5.1 (untitled), 5.1.3–5.1.4; 

(iii) Section 6—Rating Requirements, 

Section 6.1—Standard Ratings, 6.1.5— 

Airflow Requirements for Systems with 

Capacities <65,000 Btu/h [19,000 W]; 

(iv) Section 6—Rating Requirements, 

Section 6.1—Standard Ratings, 6.1.6— 

Outdoor-Coil Airflow Rate (Applies to 

all Air-to-Air Systems); 

(v) Section 6—Rating Requirements, 

Section 6.2—Conditions for Standard 

Rating Test for Air-cooled Systems 

<65,000 Btu/h [19,000W] (except table 

8); and 

(vi) Table 4—Refrigerant Line Length 

Correction Factors. 

(5) AHRI Standard 1600–2024 (I–P) 

(‘‘AHRI 1600–2024’’), Performance 

Rating of Unitary Air-conditioning and 

Air-source Heat Pump Equipment; IBR 

approved for appendix M2 to subpart B. 

* * * * * 

(g) * * * 

(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, ANSI approved November 1, 

2016; IBR approved for appendices F, 

M1, and M2 to subpart B. 

(2) ANSI/ASHRAE 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 M 

to subpart B, as follows: 

(i) Section 5—Requirements; 

(ii) Section 6—Instruments; 

(iii) Section 7—Methods of Testing; 

and 

(iv) Section 8—Compressor Testing. 

(3) ANSI/ASHRAE Standard 37–2009, 

(‘‘ASHRAE 37–2009’’), Methods of 

Testing for Rating Electrically Driven 

Unitary Air-Conditioning and Heat 

Pump Equipment, ANSI approved June 

25, 2009; IBR approved for appendices 

CC, CC1, M1, and M2 to subpart B. 

* * * * * 

(22) ANSI/ASHRAE Standard 116– 

2010, (‘‘ANSI/ASHRAE 116–2010’’), 

Methods of Testing for Rating Seasonal 

Efficiency of Unitary Air Conditioners 

and Heat Pumps, ANSI approved 

February 24, 2010, IBR approved for 

appendices M1 and M2 to subpart B. 

* * * * * 

■ 9. Amend § 430.23 by revising 

paragraph (m) to read as follows: 

§ 430.23 Test procedures for the 

measurement of energy and water 

consumption. 

* * * * * 

(m) Central air conditioners and heat 

pumps. See the note at the beginning of 

appendices M1 and M2 to this subpart 

to determine the appropriate test 

method. Determine all values discussed 

in this section using a single appendix. 

(1) Determine cooling capacity from 

the steady-state wet-coil test (A or Afull

Test), as per instructions in section 2 of 

appendix M1 or M2 to this subpart, and 

rounded off to the nearest: 

(i) To the nearest 50 Btu/h if cooling 

capacity is less than 20,000 Btu/h; 

(ii) To the nearest 100 Btu/h if cooling 

capacity is greater than or equal to 

20,000 Btu/h but less than 38,000 Btu/ 

h; and 

(iii) To the nearest 250 Btu/h if 

cooling capacity is greater than or equal 

to 38,000 Btu/h and less than 65,000 

Btu/h. 

(2) Determine seasonal energy 

efficiency ratio 2 (SEER2) as described 

in sections 2 and 5 of appendix M1 to 

this subpart or seasonal cooling and offmode rating efficiency (SCORE) as 

described in sections 2 and 4 of 

appendix M2 to this subpart, and round 

off to the nearest 0.025 Btu/W-h. 

(3) Determine energy efficiency ratio 2 

(EER2) as described in section 2 of 

appendix M1 or energy efficiency ratio 

(EER) as described in section 2 of 

appendix M2 to this subpart and round 

off to the nearest 0.025 Btu/W-h. EER2 

(for appendix M1 to this subpart) or EER 

(for appendix M2 to this subpart) is the 

efficiency from the A or Afull test, 

whichever applies. 

(4) Determine heating seasonal 

performance factor 2 (HSPF2) as 

described in sections 2 and 5 of 

appendix M1 to this subpart or seasonal 

heating and off-mode rating efficiency 

(SHORE) as described in sections 2 and 

4 of appendix M2 to this subpart, and 

round off to the nearest 0.025 Btu/W-h. 

(5) Determine PW,OFF, average offmode power consumption, as described 

in section 3 of appendix M1 to this 

subpart, and round off to the nearest 0.5 

W. Average off-mode power 

consumption is not required when 

testing in accordance with appendix M2 

to this subpart. 

(6) Determine all other measures of 

energy efficiency or consumption or 

other useful measures of performance 

using appendix M1 or M2 of this 

subpart. 

* * * * * 

■ 10. Revise appendix M1 to subpart B 

of part 430 to read as follows: 

Appendix M1 to Subpart B of Part 

430—Uniform Test Method for 

Measuring the Energy Consumption of 

Central Air Conditioners and Heat 

Pumps 

Note: Prior to July 7, 2025, representations 

with respect to the energy use or efficiency 

of central air conditioners and heat pumps, 

including compliance certifications, must be 

based on testing conducted in accordance 

with: 

(a) Appendix M1 to this subpart, in the 10 

CFR parts 200 through 499 edition revised as 

of January 1, 2023; or 

(b) This appendix M1. 

Beginning July 7, 2025, and prior to the 

compliance date of amended standards for 

central air conditioners and heat pumps 

based on Seasonal Cooling and Off-mode 

Rating Efficiency (SCORE) and Seasonal 

Heating and Off-mode Rating Efficiency 

(SHORE), representations with respect to 

energy use or efficiency of central air 

conditioners and heat pumps, including 

compliance certifications, must be based on 

testing conducted in accordance with this 

appendix. 

Beginning on the compliance date of 

amended standards for central air 

conditioners and heat pumps based on 

SCORE and SHORE, representations with 

respect to energy use or efficiency of central 

air conditioners and heat pumps, including 

compliance certifications, must be based on 

testing conducted in accordance with 

appendix M2 to this subpart. 


ddrumheller on DSK120RN23PROD with RULES2
1284 Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 

Manufacturers may also certify compliance 

with any amended energy conservation 

standards for central air conditioners and 

heat pumps based on SCORE or SHORE prior 

to the applicable compliance date for those 

standards, and those compliance 

certifications must be based on testing in 

accordance with appendix M2 to this 

subpart. 

1. Incorporation by Reference 

In § 430.3, DOE incorporated by reference 

the entire standard for AHRI 210/240–2024, 

ANSI/ASHRAE 16, ASHRAE 37–2009 and 

ANSI/ASHRAE 116–2010. However, certain 

enumerated provisions of AHRI 210/240– 

2024, ANSI/ASHRAE 16, ASHRAE 37–2009 

and ANSI/ASHRAE 116–2010, as set forth in 

sections 1.1 through 1.4 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. 

1.1. AHRI 210/240–2024 

(a) Section 1 Purpose is inapplicable, 

(b) Section 2 Scope is inapplicable, 

(c) The following subsections of Section 3 

Definitions are inapplicable: 3.2.16 (Doubleduct system), 3.2.20 (Gross capacity), 3.2.46 

(Oil Recovery Mode), 3.2.51 (Published 

Rating), 3.2.63 (Standard Filter), 3.2.78 

(Unitary Air-conditioner), 3.2.79 (Unitary 

Heat Pump), 

(d) Section 4 Classifications is 

inapplicable, 

(e) The following subsection of Section 5 

Test Requirements is inapplicable: 5.1.6.2 

(Outdoor Unit with No Match (OUWNM)), 

(f) The following subsections of Section 6 

Rating Requirements are inapplicable: 6.1.8, 

6.2, 6.3, 6.4 and 6.5 

(g) Section 7 Minimum Data Requirements 

for Published Ratings is inapplicable, 

(h) Section 8 Operating Requirements is 

inapplicable, 

(i) Section 9 Marking and Nameplate Data 

is inapplicable, 

(j) Section 10 Conformance Conditions is 

inapplicable, 

(k) Appendix A References—Normative is 

inapplicable, 

(l) Appendix B References—Informative is 

inapplicable, 

(m) Appendix C Secondary Capacity Check 

Requirements—Normative is inapplicable, 

(n) Appendix F Unit Configurations for 

Standard Efficiency Determination— 

Normative is inapplicable, 

(o) Appendix H Verification Testing— 

Normative is inapplicable, 

(p) Appendix I Controls Verification 

Procedure—Normative is inapplicable, and 

(q) Appendix J Determination of Cut in and 

Cut out temperatures—Normative is 

inapplicable. 

1.2. ANSI/ASHRAE 37–2009 

(a) Section 1—Purpose is inapplicable, 

(b) Section 2—Scope is inapplicable, and 

(c) Section 4—Classification is 

inapplicable. 

1.3. ANSI/ASHRAE 16–2016 

(a) Section 1—Purpose is inapplicable, 

(b) Section 2—Scope is inapplicable, and 

(c) Section 4—Classification is 

inapplicable. 

1.4. ANSI/ASHRAE 116–2010 

(a) Section 1—Purpose is inapplicable, 

(b) Section 2—Scope is inapplicable, 

(c) Section 4—Classification is 

inapplicable, 

(d) Section 7—Methods of Test is 

inapplicable, 

(e) References is inapplicable, 

(f) Appendix A—Example Bin Calculations 

is inapplicable, and 

(g) Appendix B—Bibliography is 

inapplicable. 

2. General 

Determine the cooling capacity, heating 

capacity, and applicable energy efficiency 

metrics (SEER2, HSPF2, and EER2) in 

accordance with the specified sections of 

AHRI 210/240–2024 and the applicable 

provisions of ANSI/ASHRAE 16, ASHRAE 

37–2009, and ANSI/ASHRAE 116–2010. The 

AFull (cooling mode) and H1Full or H1Nom

(heating mode, if applicable) shall have a 

secondary capacity check completed. For all 

other tests in each mode, it is permissible to 

not use a secondary capacity check. For 

cooling mode tests of variable capacity 

systems, the compressor shall operate at the 

same cooling full speed, measured by RPM 

of power input frequency (Hz), for both AFull

and BFull tests. Additionally, the compressor 

shall operate at the same cooling minimum 

speed, measured by RPM or power input 

frequency (Hz), for the BLow, FLow, GLow, and 

ILow tests. 

Sections 3, 4, and 5 of this appendix 

provide additional instructions for testing. In 

cases where there is a conflict, the language 

of this appendix takes highest precedence, 

followed, in order, by: AHRI 210/240–2024, 

ASHRAE 37–2009, ANSI/ASHRAE 16 and 

ANSI/ASHRAE 116–2010. 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. 

3. Off-Mode Power 

Determine off-mode power, PW, OFF, in 

accordance with section 11.3 and appendix 

G of AHRI 210/240–2024. 

4. Outdoor Units With No Match (OUWNM) 

4.1. Definition. An Outdoor Unit that is not 

distributed in commerce with any indoor 

units, that meets any of the following criteria: 

(a) Is designed for use with a refrigerant 

that makes the unit banned for installation 

when paired with a new Indoor Unit to create 

a new system, according to EPA regulations 

in 40 CFR chapter I, subchapter C, 

(b) Is designed for use with a refrigerant 

that has a 95 °F midpoint saturation absolute 

pressure that is ±18 percent of the 95 °F 

saturation absolute pressure for R–22 and 

global warming potential greater than 150 per 

EPA regulations in 40 CFR 84.64, or 

(c) Is shipped without a specified 

refrigerant from the point of manufacture or 

is shipped such that more than two pounds 

of refrigerant are required to meet the charge 

per section 5.1.8 of AHRI 210/240–2024. This 

shall not apply if either: 

(1) The factory charge is equal to or greater 

than 70% of the outdoor unit internal volume 

times the liquid density of refrigerant at 

95 °F, or 

(2) An A2L refrigerant is approved for use 

and listed in the certification report. 

4.2. Testing. An OUWNM shall be tested at 

a single cooling air volume rate with an 

indoor coil having nominal tube diameter of 

0.375 in and an NGIFS of 1.0 or less (as 

determined in section 5.1.6.3 of AHRI 210/ 

240–2024). Tested values of CDc and/or CDh

are not permitted. The default value, 0.25, 

shall be used for both cooling and heating 

mode testing. 

5. Test Conditions 

5.1. Test Conditions for Certifying 

Compliance with Standards. The following 

conditions specified in AHRI 210/240–2024 

apply when testing to certify to the SEER2 

and HSPF2 energy conservation standards in 

§ 430.32(c). 

(a) For cooling mode, use the rating 

conditions specified in table 8 of AHRI 210/ 

240–2024 and the fractional cooling bin 

hours in table 15 of AHRI 210/240–2024 to 

determine SEER2, and EER2 for models 

subject to regional standards in terms of 

EER2. 

(b) For heat pump heating mode, use the 

rating conditions specified in table 8 of AHRI 

210/240–2024 and the fractional heating bin 

hours specified for Region IV in table 16 of 

AHRI 210/240–2024 to determine the heating 

efficiency metric, HSPF2. 

5.2. Optional Representations. 

Representations of EER2 made using the 

rating conditions specified in table 8 of AHRI 

210/240–2024 are optional for models not 

subject to regional standards in terms of 

EER2. Representations of HSPF2 made using 

the rating conditions specified in table 8 of 

AHRI 210/240–2024 and the fractional 

heating hours specified for Regions other 

than Region IV in table 16 of AHRI 210/240– 

2024 are optional. Representations of COPpeak

made using appendix K are optional. 

■ 11. Add appendix M2 to subpart B of 

part 430 to read as follows: 

Appendix M2 to Subpart B of Part 

430—Uniform Test Method for 

Measuring the Energy Consumption of 

Central Air Conditioners and Heat 

Pumps 

Note: Prior to July 7, 2025, representations 

with respect to the energy use or efficiency 

of central air conditioners and heat pumps, 

including compliance certifications, must be 

based on testing conducted in accordance 

with: 

(a) Appendix M1 to this subpart, in the 10 

CFR parts 200 through 499 edition revised as 

of January 1, 2023; or 

(b) Appendix M1 to this subpart. 

Beginning July 7, 2025, and prior to the 

compliance date of amended standards for 

central air conditioners and heat pumps 

based on Seasonal Cooling and Off-mode 

Rating Efficiency (SCORE) and Seasonal 

Heating and Off-mode Rating Efficiency 

(SHORE), representations with respect to 

energy use or efficiency of central air 

conditioners and heat pumps, including 


ddrumheller on DSK120RN23PROD with RULES2
Federal Register / Vol. 90, No. 4 / Tuesday, January 7, 2025 / Rules and Regulations 1285 

compliance certifications, must be based on 

testing conducted in accordance with 

appendix M1 to this subpart. 

Beginning on the compliance date of 

amended standards for central air 

conditioners and heat pumps based on 

SCORE and SHORE, representations with 

respect to energy use or efficiency of central 

air conditioners and heat pumps, including 

compliance certifications, must be based on 

testing conducted in accordance with this 

appendix. 

Manufacturers may also certify compliance 

with any amended energy conservation 

standards for central air conditioners and 

heat pumps based on SCORE or SHORE prior 

to the applicable compliance date for those 

standards, and those compliance 

certifications must be based on testing in 

accordance with this appendix. 

1. Incorporation by Reference 

In § 430.3, DOE incorporated by reference 

the entire standard for AHRI 1600–2024, 

ANSI/ASHRAE 16, ASHRAE 37–2009, and 

ANSI/ASHRAE 116–2010. However, certain 

enumerated provisions of AHRI 1600–2024, 

ANSI/ASHRAE 16, ASHRAE 37–2009, and 

ANSI/ASHRAE 116–2010, as set forth in 

sections 1.1 through 1.4 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. 

1.1. AHRI 1600–2024 

(a) Section 1 Purpose is inapplicable, 

(b) Section 2 Scope is inapplicable, 

(c) The following sections of Section 3 

Definitions are inapplicable: 3.2.16 (Doubleduct system), 3.2.20 (Gross capacity), 3.2.45 

(Oil Recovery Mode), 3.2.50 (Published 

Rating), 3.2.63 (Standard Filter), 3.2.78 

(Unitary Air-conditioner), 3.2.79 (Unitary 

Heat Pump), 

(d) Section 4 Classifications is 

inapplicable, 

(e) The following subsection of Section 5 

Test Requirements is inapplicable: 5.1.6.2 

(Outdoor Unit with No Match (OUWNM)), 

(f) The following subsections of Section 6 

Rating Requirements are inapplicable: 6.1.8, 

6.2, 6.3, 6.4 and 6.5 

(g) Section 7 Minimum Data Requirements 

for Published Ratings is inapplicable, 

(h) Section 8 Operating Requirements is 

inapplicable, 

(i) Section 9 Marking and Nameplate Data 

is inapplicable, 

(j) Section 10 Conformance Conditions is 

inapplicable, 

(k) Appendix A References—Normative is 

inapplicable, 

(l) Appendix B References—Informative is 

inapplicable, 

(m) Appendix C Secondary Capacity Check 

Requirements—Normative is inapplicable, 

(n) Appendix F Unit Configurations for 

Standard Efficiency Determination— 

Normative is inapplicable, 

(o) Appendix H Verification Testing— 

Normative is inapplicable, 

(p) Appendix I Controls Verification 

Procedure—Normative is inapplicable, and 

(q) Appendix J Determination of Cut in and 

Cut out temperatures—Normative is 

inapplicable. 

1.2. ANSI/ASHRAE 37–2009 

(a) Section 1—Purpose is inapplicable, 

(b) Section 2—Scope is inapplicable, and 

(c) Section 4—Classification is 

inapplicable. 

1.3. ANSI/ASHRAE 16–2016 

(a) Section 1—Purpose is inapplicable, 

(b) Section 2—Scope is inapplicable, and 

(c) Section 4—Classification is 

inapplicable. 

1.4. ANSI/ASHRAE 116–2010 

(a) Section 1—Purpose is inapplicable, 

(b) Section 2—Scope is inapplicable, 

(c) Section 4—Classification is 

inapplicable, 

(d) Section 7—Methods of Test is 

inapplicable, 

(e) References is inapplicable, 

(f) Appendix A—Example Bin Calculations 

is inapplicable, and 

(g) Appendix B—Bibliography is 

inapplicable. 

2. General 

Determine the applicable energy efficiency 

metrics (SCORE, SHORE, and EER) in 

accordance with the specified sections of 

AHRI 1600–2024 and the applicable 

provisions of ANSI/ASHRAE 16, ASHRAE 

37–2009, and ANSI/ASHRAE 116–2010. The 

AFull (cooling mode) and H1Full or H1Nom

(heating mode, if applicable) shall have a 

secondary capacity check completed. For all 

other tests in each mode, it is permissible to 

not use a secondary capacity check. For 

cooling mode tests of variable capacity 

systems, the compressor shall operate at the 

same cooling full speed, measured by RPM 

of power input frequency (Hz), for both AFull

and BFull tests. Additionally, the compressor 

shall operate at the same cooling minimum 

speed, measured by RPM or power input 

frequency (Hz), for the BLow, FLow, GLow, and 

ILow tests. 

Sections 3 and 4 of this appendix provide 

additional instructions for testing. In cases 

where there is a conflict, the language of this 

appendix takes highest precedence, followed, 

in order, by: AHRI 1600–2024, ASHRAE 37– 

2009, ANSI/ASHRAE 16, and ANSI/ASHRAE 

116–2010. 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. 

3. Outdoor Units With No Match (OUWNM) 

3.1. Definition. An Outdoor Unit that is not 

distributed in commerce with any indoor 

units, that meets any of the following criteria: 

(a) Is designed for use with a refrigerant 

that makes the unit banned for installation 

when paired with a new Indoor Unit as a 

system, according to EPA regulations in 40 

CFR chapter I, subchapter C, 

(b) Is designed for use with a refrigerant 

that has a 95 °F midpoint saturation absolute 

pressure that is ±18 percent of the 95 °F 

saturation absolute pressure for R–22 and a 

global warming potential greater than 150 per 

EPA regulations in 40 CFR 84.64, or 

(c) Is shipped without a specified 

refrigerant from the point of manufacture or 

is shipped such that more than two pounds 

of refrigerant are required to meet the charge 

per section 5.1.8 of AHRI 1600–2024. This 

shall not apply if either: 

(1) The factory charge is equal to or greater 

than 70% of the outdoor unit internal volume 

times the liquid density of refrigerant at 95 °F 

or, 

(2) An A2L refrigerant is approved for use 

and listed in the certification report 

3.2. Testing. An OUWNM shall be tested at 

a single cooling air volume rate with an 

indoor coil having nominal tube diameter of 

0.375 in and an NGIFS of 1.0 or less (as 

determined in section 5.1.6.3 of AHRI 1600– 

2024). Tested values of CDc and/or CDh are 

not permitted. The default value, 0.25, shall 

be used for both cooling and heating mode 

testing. 

4. Test Conditions 

4.1. Test Conditions for Certifying 

Compliance with Standards. The following 

conditions specified in AHRI 1600–2024 

apply if testing to certify to the SCORE and 

SHORE energy conservation standards in 

§ 430.32(c). 

(a) For cooling mode, use the rating 

conditions specified in table 8 of AHRI 1600– 

2024 and the ‘U.S. National Average’ cooling 

conditioning hours and shoulder season 

hours in table 15 of AHRI 1600–2024, to 

determine SCORE, and EER for models 

subject to regional standards in terms of EER. 

(b) For heat pump heating mode, use the 

rating conditions specified in table 8 of AHRI 

1600–2024 and the ‘U.S. National Average’ 

heating conditioning hours and shoulder 

season hours specified in table 18 of AHRI 

1600–2024 to determine the heating 

efficiency metric, SHORE. 

4.2. Optional Representations. 

Representations of EER made using the rating 

conditions specified in table 8 of AHRI 1600– 

2024 are optional for models not subject to 

regional standards in terms of EER. 

Representations of SHORE made using the 

rating conditions specified in table 8 of AHRI 

1600–2024 and the ‘Cold Climate Average’ 

heating conditioning hours and shoulder 

season hours in table 18 of AHRI 1600–2024 

are optional. Representations of COPpeak

made using appendix K are optional. 

[FR Doc. 2024–30852 Filed 1–6–25; 8:45 am] 

BILLING CODE 6450–01–P 


ddrumheller on DSK120RN23PROD with RULES2