5538 Federal Register / Vol. 90, No. 11 / Friday, January 17, 2025 / Rules and Regulations 

TABLE 8.7—STANDARD RMC VALUES—Continued 

‘‘g Force’’ 

RMC percentage 

Warm soak Cold soak 

15 min. spin 

(percent) 

4 min. spin 

(percent) 

15 min. spin 

(percent) 

4 min. spin 

(percent) 

650 ................................................... 23.0 26.4 24.1 28.0 

8.8 Calculate the corrected RMC value for 

each extractor test condition, RMCcloth-corr as 

follows: 

RMCcloth-corr = A × RMCcloth-avg + B 

Where: 

RMCcloth-avg = the average RMC value, as 

calculated in section 8.6 of this appendix 

for each extractor test condition, 

expressed as a decimal, and 

A and B are the coefficients of the linear least 

squares fit as determined in section 8.7 

of this appendix. 

8.9 Calculate the root mean square error of 

the linear fit, RMSE. For test cloth lots 

qualified after February 18, 2025, the RMSE 

must be less than or equal to 0.012 for the 

test cloth lot to be considered acceptable. The 

RMSE is calculated as follows: 

Where: 

RMCstandard_i = the RMCstandard value in Table 

8.7 of this appendix for the ith extractor 

test condition, expressed as a decimal, 

RMCcloth-corr_i = the corrected RMC value, as 

calculated in section 8.8 of this appendix 

for the ith extractor test condition, 

expressed as a decimal, and 

N = the number of extractor test conditions 

listed in Table 8.7 of this appendix = 20. 

* * * * * 

[FR Doc. 2025–00986 Filed 1–16–25; 8:45 am] 

BILLING CODE 6450–01–P 

DEPARTMENT OF ENERGY 

10 CFR Part 431 

[EERE–2022–BT–TP–0019] 

RIN 1904–AF08 

Energy Conservation Program: Test 

Procedure for Compressors 

AGENCY: Office of Energy Efficiency and 

Renewable Energy, Department of 

Energy. 

ACTION: Final rule. 

SUMMARY: The U.S. Department of 

Energy (‘‘DOE’’) is amending the test 

procedure for compressors to correct an 

error and to ensure that pressure ratio is 

expressed in terms of absolute pressure. 

DOE is also correcting the formula for 

isentropic efficiency and specific energy 

consumption of the packaged 

compressor by incorporating a K6

correction factor to correct for 

differences in pressure ratio when 

testing at differing elevations. Finally, 

DOE is amending the definition of ‘‘air 

compressor’’ to include a minor 

clarification and revise a typographical 

error. 

DATES: The effective date of this rule is 

April 2, 2025. The amendments will be 

mandatory for product testing starting 

July 16, 2025. 

The incorporation by reference of 

certain publications listed in the rule is 

approved by the Director of the Federal 

Register on April 2, 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-0019. 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: 

Mr. Jeremy Dommu, U.S. Department 

of Energy, Office of Energy Efficiency 

and Renewable Energy, Building 

Technologies Office, EE–2J, 1000 

Independence Avenue SW, Washington, 

DC 20585–0121. Telephone: (202) 586– 

9870. Email: ApplianceStandards

Questions@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) 586–9496. Email: 

Peter.Cochran@hq.doe.gov. 

SUPPLEMENTARY INFORMATION: 

DOE incorporates by reference the 

following industry standards into title 

10 of the Code of Federal Regulation 

(‘‘CFR’’) part 431: 

IEC 60584–1:2013, Thermocouples— 

Part 1: EMF specifications and 

tolerances, edition 3.0, August 2013 

(‘‘IEC 60584–1:2013’’). 

IEC 60584–3:2021, Thermocouples— 

Part 3: Extension and compensating 

cables—Tolerances and identification 

system, edition 3.0, February 2021 (‘‘IEC 

60584–3:2021’’). 

Copies of IEC 60584–1:2013 and IEC 

60584–3:2021 may be purchased from 

International Electrotechnical 

Commission (‘‘IEC’’) Central Office, 3, 

rue de Varembe ́, Case Postale 131, CH– 

1211, Geneva, Switzerland +41 22 919 

02 11, or by going to webstore.iec.ch. 

ISO 1217:2009(E), Displacement 

compressors—Acceptance tests, fourth 

edition, July 1, 2009 (‘‘ISO 

1217:2009(E)’’). 

ISO 1217:2009/Amd.1:2016(E), 

Displacement compressors—Acceptance 

tests (fourth edition, July 1, 2009), 

AMENDMENT 1: Calculation of 

isentropic efficiency and relationship 

with specific energy, April 15, 2016 

(‘‘ISO 1217:2009/Amd.1:2016(E)’’). 

ISO 5167–1:2022(E), Measurement of 

fluid flow by means of pressure 


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Federal Register / Vol. 90, No. 11 / Friday, January 17, 2025 / Rules and Regulations 5539 

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 

reflect the last statutory amendments that impact 

Parts A and A–1 of EPCA. 

2For editorial reasons, upon codification in the 

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

differential devices inserted in circular 

cross-section conduits running full— 

Part 1: General principles and 

requirements, third edition, June 2022 

(‘‘ISO 5167–1:2022(E)’’). 

ISO 9300:2022(E), Measurement of 

gas flow by means of critical flow 

nozzles, third edition, June 2022 (‘‘ISO 

9300:2022(E)’’). 

Copies of ISO 1217:2009(E), ISO 

1217:2009/Amendment 1:2016(E), ISO 

5167–1:2022(E), and ISO 9300:2022(E) 

may be purchased from International 

Organization for Standardization 

(‘‘ISO’’) at Chemin de Blandonnet 8, CP 

401, 1214 Vernier, Geneva, Switzerland 

+41 22 749 01 11, or by going to 

www.iso.org. 

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 

1. Reciprocating Compressors 

2. Centrifugal Compressors 

3. Compressor Motor Nominal Horsepower 

4. Lubricant-Free Compressors 

5. Brushed Motors 

6. Output Pressure Less Than 75 psig 

7. Integrated Dryers 

B. Updates to Industry Standards 

1. ISO 1217:2009(E) as the Basis for This 

Test Procedure 

2. Ambient Temperature Range 

Requirement 

C. Definitions 

1. Multi-Element Air Compressors 

D. Efficiency Metrics 

1. Load Point for Fixed-Speed Compressors 

2. Load Points for Variable-Speed 

Compressors 

3. Inclusion of Unloaded Operation for 

Fixed-Speed Compressors 

4. Part-Load Performance of Fixed-Speed 

Compressors With Variable-Airflow 

Controls 

E. Test Method 

1. K6 Correction Factor 

2. Correction of Pressure Ratio at Full-Load 

Operating Pressure Formula 

3. Tolerances for Measured Energy 

Efficiency Values 

F. Reporting 

G. Test Procedure Costs and 

Harmonization 

1. Amendment to Incorporate K6

Correction Factor 

2. Amendment To Update Formula for 

Pressure Ratio at Full-Load Operating 

Pressure 

3. Amendment to Update Definition of 

‘‘Air Compressor’’ 

4. Harmonization With Industry Standards 

H. Effective and Compliance Dates 

I. Renumbering of Appendix A 

IV. Procedural Issues and Regulatory Review 

A. Review Under Executive Orders 12866, 

13563, and 14094 

B. Review Under the Regulatory Flexibility 

Act 

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 

Compressors are included in the list 

of ‘‘covered equipment’’ (via the clause 

classifying certain types of ‘‘industrial 

equipment’’ as ‘‘covered equipment’’) 

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. 

6311(1)(L), 6311(2)(B)(i), and 6312(b)). 

DOE’s test procedures for compressors 

are currently prescribed at subpart T of 

part 431 of title 10 of the Code of 

Federal Regulations (10 CFR part 431). 

The following sections discuss DOE’s 

authority to establish and amend test 

procedures for compressors and relevant 

background information regarding 

DOE’s consideration of test procedures 

for this equipment. 

A. Authority 

The Energy Policy and Conservation 

Act, Public Law 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 C of 

EPCA,2 added by Public Law 95–619, 

Title IV, section 441(a), established the 

Energy Conservation Program for 

Certain Industrial Equipment, which 

sets forth a variety of provisions 

designed to improve energy efficiency. 

This equipment includes compressors, 

the subject of this document. Under 

EPCA, DOE may include a type of 

industrial equipment, including 

compressors, as covered equipment if it 

determines that doing so is necessary to 

carry out the purposes of Part A–1. (42 

U.S.C. 6311(1)(L), 6311(2)(B)(i), and 

6312(b)). The purpose of Part A–1 is to 

improve the efficiency of electric motors 

and pumps and certain other industrial 

equipment to conserve the energy 

resources of the Nation. (42 U.S.C. 

6312(a)). On November 15, 2016, DOE 

published a final rule, which 

determined that coverage for 

compressors is necessary to carry out 

the purposes of Part A–1 of Title III of 

EPCA. 81 FR 79991. (42 U.S.C. 

6311(1)(L); 42 U.S.C. 6311 (2)(A); 42 

U.S.C. 6311 (2)(B)(i)) 

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 include definitions (42 U.S.C. 

6311), test procedures (42 U.S.C. 6314), 

labeling provisions (42 U.S.C. 6315), 

energy conservation standards (42 

U.S.C. 6313), and the authority to 

require information and reports from 

manufacturers (42 U.S.C. 6316; 42 

U.S.C. 6296). 

The Federal testing requirements 

consist of test procedures that 

manufacturers of covered equipment 

must use as the basis for: (1) certifying 

to DOE that their equipment complies 

with the applicable energy conservation 

standards adopted pursuant to EPCA (42 

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

(2) making other representations about 

the efficiency of that equipment (42 

U.S.C. 6314(d)). Similarly, DOE must 

use these test procedures to determine 

whether the equipment complies with 

relevant standards promulgated under 

EPCA. (42 U.S.C. 6316(a); 42 U.S.C. 

6295(s)) 

Federal energy efficiency 

requirements for covered equipment 

established under EPCA generally 

supersede State laws and regulations 

concerning energy conservation testing, 

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

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

6297). DOE may, however, grant waivers 

of Federal preemption for particular 

State laws or regulations, in accordance 

with the procedures and other 

provisions of EPCA. 42 U.S.C. 

6316(b)(2)(D). 

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

the criteria and procedures DOE must 

follow when prescribing or amending 

test procedures for covered equipment. 

EPCA requires that any test procedures 

prescribed or amended under this 

section must be reasonably designed to 

produce test results that reflect energy 

efficiency, energy use, or estimated 

annual operating cost of a given type of 

covered equipment during a 


KHAMMOND on DSK9W7S144PROD with RULES
5540 Federal Register / Vol. 90, No. 11 / Friday, January 17, 2025 / Rules and Regulations 

3Associated documents are available in the 

rulemaking docket at www.regulations.gov/docket/ 

EERE-2019-BT-PET-0017. 

4The slide material presented during the webinar 

has been published on DOE’s website: 

www.energy.gov/sites/default/files/2022-05/ 

compressors-101.pdf. 

representative average use cycle (as 

determined by the Secretary) and 

requires that test procedures not be 

unduly burdensome to conduct. (42 

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

EPCA also requires that, at least once 

every 7 years, DOE evaluate test 

procedures for each type of covered 

equipment, including compressors, to 

determine whether amended test 

procedures would more accurately or 

fully comply with the requirements for 

the test procedures to not be unduly 

burdensome to conduct and be 

reasonably designed to produce test 

results that reflect energy efficiency, 

energy use, and estimated operating 

costs during a representative average 

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

In addition, if the Secretary 

determines that a test procedure 

amendment is warranted, the Secretary 

must publish proposed test procedures 

in the Federal Register and afford 

interested persons an opportunity (of 

not less than 45 days’ duration) to 

present oral and written data, views, 

and arguments on the proposed test 

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

determines that test procedure revisions 

are not appropriate, DOE must publish 

its determination not to amend the test 

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

DOE is publishing this final rule in 

satisfaction of the 7-year review 

requirement specified in EPCA. (42 

U.S.C. 6314(b)(1)) 

B. Background 

DOE’s existing test procedure for 

compressors appears at title 10 of the 

Code of Federal Regulations (CFR) part 

431, subpart T, appendix A—Uniform 

Test Method for Certain Air 

Compressors (hereafter ‘‘appendix A’’). 

As stated, DOE published a final rule 

on November 15, 2016, in which DOE 

determined that coverage of 

compressors is necessary to carry out 

the purposes of Part A–1 of Title III of 

EPCA. 81 FR 79991. DOE’s test 

procedure for determining compressor 

energy efficiency of certain varieties of 

compressors was established in a final 

rule published on January 4, 2017 

(hereafter, the ‘‘January 2017 Final 

Rule’’). 82 FR 1052. 

On May 17, 2019, DOE published a 

notice of petition for rulemaking and 

request for comment regarding the test 

procedure for compressors in response 

to a petition from Atlas Copco North 

America (‘‘Atlas Copco’’). 84 FR 22395. 

Atlas Copco’s petition was received on 

April 17, 2019. Atlas Copco requested 

that DOE amend the compressors test 

procedure to specify that manufacturers 

could satisfy the test procedure 

requirements by using the industry test 

method for rotary air compressor energy 

efficiency, ISO 1217:2009(E) 

‘‘Displacement compressors— 

Acceptance tests’’. In the notice of 

petition for rulemaking, DOE sought 

comment as to whether to proceed with 

the petition, but took no position at the 

time regarding the merits of the 

suggested rulemaking or the assertions 

made by Atlas Copco. 84 FR 22395.3

On January 10, 2020, DOE published 

a final rule for energy conservation 

standards for air compressors (hereafter, 

the ‘‘January 2020 ECS Final Rule’’). 85 

FR 1504. Compliance with the energy 

conservation standards established in 

the January 2020 ECS Final Rule is 

required for compressors manufactured 

starting on January 10, 2025. 10 CFR 

431.345. 

On May 6, 2022, DOE issued a 

Request for Information (‘‘RFI’’) for a 

test procedure for compressors to 

consider whether to amend DOE’s test 

procedure for compressors (hereafter, 

the ‘‘May 2022 RFI’’). 87 FR 27025. To 

inform interested parties and to 

facilitate this process, DOE identified 

certain issues associated with the 

currently applicable test procedure on 

which DOE is interested in receiving 

comment. On June 6, 2022, DOE granted 

a 14-day extension to the public 

comment period, allowing comments to 

be submitted until June 20, 2022. 87 FR 

34220. 

In general, representations of 

compressor performance must be in 

accordance with the DOE test 

procedure. (42 U.S.C. 6314(d)). 

However, DOE guidance (issued Dec. 6, 

2017; revised Jun. 8, 2018) stated that it 

would discretionarily not enforce this 

requirement until compliance with a 

standard is required or a labeling 

requirement is established. On May 2, 

2022, DOE announced that it was 

suspending the enforcement policy 

regarding the test procedure for air 

compressors and removed the policy 

from the DOE enforcement website. 

Following retraction of the 

enforcement policy and to aid 

manufacturers in understanding DOE’s 

regulatory requirements regarding the 

test procedure and forthcoming energy 

conservation standards, DOE held a 

‘‘Compressors Regulations 101’’ webinar 

on May 24, 2022. The webinar reviewed 

testing, rating, certification, and 

compliance responsibilities.4

On February 13, 2023, DOE published 

a notice of proposed rulemaking and 

announcement of public meeting for test 

procedures for compressors (hereafter, 

the ‘‘February 2023 NOPR’’). 88 FR 

9199. To inform interested parties and 

to facilitate this process, DOE identified 

certain issues associated with the 

currently applicable test procedure on 

which DOE is interested in receiving 

comment. On March 22, 2023, DOE held 

a public meeting (hereafter, the ‘‘March 

2023 Public Meeting’’) to obtain 

stakeholder input regarding the issues 

and proposed amendments raised by the 

February 2023 NOPR. 

DOE received comments in response 

to the February 2023 NOPR from the 

interested parties listed in table I.1. 

TABLE I.1—LIST OF COMMENTERS WITH WRITTEN SUBMISSIONS IN RESPONSE TO THE FEBRUARY 2023 NOPR 

Commenter(s) Reference in this final rule Comment No. 

in the docket Commenter type 

Compressed Air & Gas Institute ........................................ CAGI ................................................... 21 Trade Association. 

Saylor-Beall Air Compressors ........................................... Saylor-Beall ........................................ 22 Manufacturer. 

Sullivan-Palatek, Inc .......................................................... Sullivan-Palatek .................................. 23 Manufacturer. 

Kaeser Compressors ......................................................... Kaeser Compressors .......................... 24 Manufacturer. 

Ingersoll Rand .................................................................... Ingersoll Rand .................................... 25 Manufacturer. 

Northwest Energy Efficiency Alliance, and Northwest 

Power and Conservation Council.

NEEA & NPCC ................................... 26 Efficiency Organizations. 

Pacific Gas and Electric Company, San Diego Gas and 

Electric, and Southern California Edison.

CA IOUs ............................................. 27 Utility Companies. 


KHAMMOND on DSK9W7S144PROD with RULES
Federal Register / Vol. 90, No. 11 / Friday, January 17, 2025 / Rules and Regulations 5541 

5The parenthetical reference provides a reference 

for information located in the docket of DOE’s 

rulemaking to develop test procedures for 

compressors. (Docket No. EERE–2022–BT–TP–0019, 

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

references are arranged as follows: (commenter 

name, comment docket ID number, page of that 

document). 

TABLE I.1—LIST OF COMMENTERS WITH WRITTEN SUBMISSIONS IN RESPONSE TO THE FEBRUARY 2023 NOPR— 

Continued 

Commenter(s) Reference in this final rule Comment No. 

in the docket Commenter type 

Appliance Standard Awareness Project, American Council for an Energy-Efficient Economy, and Natural Resources Defense Council.ASAP, ACEEE, & NRDC ................... 28 Efficiency Organizations. 

A parenthetical reference at the end of 

a comment quotation or paraphrase 

provides the location of the item in the 

public record.5 To the extent that 

interested parties have provided written 

comments that are substantively 

consistent with any oral comments 

provided during the March 2023 Public 

Meeting, DOE cites the written 

comments throughout this final rule. 

DOE did not identify any oral comments 

provided during the March 2023 Public 

Meeting that are not substantively 

addressed by written comments. 

II. Synopsis of the Final Rule 

In this final rule, DOE is amending 

subpart T of title 10 of the Code of 

Federal Regulations, part 431 (10 CFR 

part 431), which contains definitions, 

materials incorporated by reference, and 

the test procedure for determining the 

energy efficiency of certain varieties of 

compressors, as follows: 

(1) Correct the formula for calculating 

isentropic efficiency and specific energy 

consumption of the packaged 

compressor by incorporating a K6 

correction factor to correct for the 

change in pressure ratio when testing at 

differing elevations; 

(2) Revise the formula for pressure 

ratio at full-load operating pressure 

currently in 10 CFR part 431, subpart T 

to correct a typographical error, and to 

calculate pressure ratio using terms 

expressed in absolute pressure; and 

(3) Modify the current definition of 

‘‘air compressor’’ to clarify that 

compressors with more than one 

compression element are still within the 

scope of this test procedure, and to 

revise the typographical error of 

‘‘compressor element’’ to ‘‘compression 

elements.’’ 

DOE’s actions are summarized in 

table II.1 compared to the current test 

procedure as well as the reason for the 

proposed change. 

TABLE II.1—SUMMARY OF CHANGES IN AMENDED TEST PROCEDURE

DOE test procedure prior to amendment Amended test procedure Attribution 

References ISO 1217:2009(E) Annex C (excluding sections 

C.1.2, C.2.1, C.3, C.4.2.2, C.4.3.1, and C.4.5) for calculating isentropic efficiency and specific energy consumption of the packaged compressor.

Adds the K6 correction factor in the formula calculating 

isentropic efficiency and specific energy consumption of 

the packaged compressor in order to correct for the 

change in pressure ratio when testing at differing elevations. Incorporates by reference Annex B, section 

B.4.5 of ISO 1217:2009(E).

Error correction. 

Pressure ratio at full-load operating pressure formula in 10 

CFR part 431, subpart T contains an error, as the wrong 

formula is presented.

Corrects the pressure ratio at full-load operating pressure 

formula in 10 CFR part 431, subpart T.

Error correction. 

Air Compressor Definition: A compressor designed to compress air that has an inlet open to the atmosphere or 

other source of air, and is made up of a compression 

element (bare compressor), driver(s), mechanical equipment to drive the compressor element, and any ancillary 

equipment.

Air Compressor Definition: A compressor designed to 

compress air that has an inlet open to the atmosphere 

or other source of air, and is made up of one or more 

compression elements (bare compressors), driver(s), 

mechanical equipment to drive the compression elements, and any ancillary equipment.

Clarification. 

DOE has determined that the 

amendments described in section III and 

adopted in this document will more 

accurately comply with the 

requirements that test procedures be 

reasonably designed to produce test 

results that reflect energy use during a 

representative average use cycle and are 

not unduly burdensome to conduct. (42 

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

adopted in this final rule will ensure 

that any test for isentropic efficiency 

and specific energy consumption of a 

packaged compressor performed at any 

elevation other than 364 ft, or during 

low- or high-pressure weather events, 

will be correct. As such, these 

amendments will ensure accurate 

measured/calculated efficiency of 

compressors. DOE has also determined 

that these amendments will not require 

retesting or recertification solely as a 

result of DOE’s adoption of the 

amendments to the test procedures 

since the amendment aligns the test 

procedure with existing industry 

practice. Additionally, DOE has 

determined that the amendments will 

not increase the cost of testing. 

Discussion of DOE’s actions are 

addressed in detail in section III of this 

document. 

The effective date for the amended 

test procedures adopted in this final 

rule is 75 days after publication of this 

document in the Federal Register. 

Representations of energy use or energy 

efficiency must be based on testing in 

accordance with the amended test 

procedures beginning 180 days after the 

publication of this final rule. 

III. Discussion 

In the following sections, DOE adopts 

certain amendments to its test 

procedure for compressors. For each 

amendment, DOE provides relevant 

background information, explains why 


KHAMMOND on DSK9W7S144PROD with RULES
5542 Federal Register / Vol. 90, No. 11 / Friday, January 17, 2025 / Rules and Regulations 

the amendment merits consideration, 

discusses relevant public comments, 

and adopts an approach. 

A. Scope of Applicability 

DOE’s test procedure applies to a 

compressor that meets all of the 

following criteria: is an air compressor; 

is a rotary compressor; is not a liquid 

ring compressor; is driven by a 

brushless electric motor; is a lubricated 

compressor; has a full-load operating 

pressure of 75–200 pounds per square 

inch gauge (psig); is not designed and 

tested to the requirements of the 

American Petroleum Institute Standard 

619; has full-load actual volume flow 

rate greater than or equal to 35 cubic 

feet per minute (cfm), or is distributed 

in commerce with a compressor motor 

nominal horsepower greater than or 

equal to 10 horsepower (hp); and has a 

full-load actual volume flow rate less 

than or equal to 1,250 cfm, or is 

distributed in commerce with a 

compressor motor nominal horsepower 

less than or equal to 200 hp. 10 CFR 

431.344. 

DOE received comments both 

supporting and opposing scope changes. 

CAGI, supported by Kaeser 

Compressors, Ingersoll Rand, SaylorBeall, and Sullivan-Palatek, stated that 

they support DOE’s proposal to 

maintain the current scope of the test 

procedure. (CAGI, No. 21 at pp. 1–3; 

Kaeser Compressors, No. 24 at pp. 3–5; 

Ingersoll Rand, No. 25 at pp. 1–3; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) On the other 

hand, NEEA & NPCC, CA IOUs, and 

ASAP, ACEEE, & NRDC encouraged 

DOE to consider expanding the scope of 

the test procedure to include additional 

air compressor types. (NEEA & NPCC, 

No. 26 at pp. 2–4; CA IOUs, No. 27 at 

pp. 2–9; ASAP, ACEEE, & NRDC, No. 28 

at pp. 1–3) 

As discussed in more detail in the 

following sections, DOE is not 

amending the scope of the test 

procedure at this time. DOE may 

consider test procedure scope 

expansion, including related comments 

discussed in this final rule, in a future 

test procedure rulemaking. 

DOE responds to specific scope 

expansion topics in sections III.A.1 

through III.A.7 of this final rule. 

1. Reciprocating Compressors 

As stated in section III.A of this 

document, the current test procedure for 

compressors applies to rotary 

compressors (and, therefore, does not 

apply to reciprocating compressors). 10 

CFR 431.344. In the February 2023 

NOPR, DOE proposed to continue 

excluding reciprocating compressors 

from the scope of the test procedure. 88 

FR 9199, 9203. DOE stated that it will 

continue reviewing potential test 

procedures for reciprocating 

compressors, including existing test 

methods, and may consider expanding 

the scope of the test procedure to 

include these compressors in a future 

test procedure rulemaking. Id. DOE also 

asked for comment regarding its 

proposal to not include reciprocating 

compressors within the scope of test 

procedure applicability. Id. 

In response to the February 2023 

NOPR, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all expressed support 

for the DOE proposal to exclude 

reciprocating compressors from the 

scope of test procedure applicability. 

(CAGI, No. 21 at p. 1; Kaeser 

Compressors, No. 24 at p. 3; Ingersoll 

Rand, No. 25 at p. 1; Saylor-Beall, No. 

22 at p. 1; Sullivan-Palatek, No. 23 at p. 

1) 

However, in response to the request 

for comment, NEEA & NPCC 

recommended that DOE modify the 

proposed test procedure or develop a 

new test procedure for testing both oneand three-phase reciprocating 

compressors because ISO 1217:2009(E) 

contains a commonly used test 

procedure for rating reciprocating 

compressors among manufacturers. 

However, NEEA & NPCC commented 

that the reasons discussed in the 

February 2023 NOPR (88 FR 9199, 9202) 

for DOE not using ISO 1217:2009(E), as 

currently written, as the test method for 

reciprocating compressors are 

reasonable. NEEA & NPCC also stated 

that, by establishing a test procedure for 

reciprocating compressors, DOE is 

ensuring consistent representation of 

efficiency in this market and creating a 

path for industry stakeholders to gather 

data on this equipment type that would 

better inform future rulemakings. (NEEA 

& NPCC, No. 26 at pp. 2–3) ASAP, 

ACEEE, & NRDC agreed with this point 

and added that, given the significant 

potential energy savings for 

reciprocating compressors, DOE should 

consider the inclusion of reciprocating 

compressors within the test procedure 

scope. ASAP, ACEEE, & NRDC also 

stated that this would make it easier for 

DOE to pursue future energy 

conservation standards for reciprocating 

compressors and could provide helpful 

efficiency data to support voluntary 

programs. (ASAP, ACEEE, & NRDC, No. 

28 at pp. 2–3) 

DOE agrees that there could be 

benefits to including reciprocating 

compressors within the scope of the test 

procedure. DOE also agrees that the test 

method in ISO 1217:2009(E) might be 

appropriate for some reciprocating 

compressors but inappropriate for 

others, as there are a wide range of 

intended duty cycles for reciprocating 

compressors. 

DOE is continuing to exclude 

reciprocating compressors from the 

scope of the compressors test procedure. 

DOE will continue reviewing potential 

test procedures for reciprocating 

compressors, including existing test 

methods, and may consider expanding 

the scope of the test procedure to 

include reciprocating compressors in a 

future test procedure rulemaking. 

2. Centrifugal Compressors 

As stated in section III.A of this 

document, the current test procedure for 

compressors applies to rotary positive 

displacement compressors (and 

therefore does not apply to centrifugal 

air compressors). 10 CFR 431.344. In the 

February 2023 NOPR, DOE proposed to 

continue excluding centrifugal 

compressors from the scope of the test 

procedure. 88 FR 9199, 9203. DOE 

stated that it will continue to review 

and consider potential test methods for 

centrifugal compressors and may 

consider developing test procedures for 

centrifugal compressors as a part of a 

future rulemaking process. Id. DOE also 

asked for comment regarding its 

proposal to not include centrifugal 

compressors within the scope of test 

procedure applicability and regarding 

whether dynamic compressor varieties 

other than centrifugal compete with the 

air compressor categories discussed in 

the February 2023 NOPR. Id. 

In response to the request for 

comment in the February 2023 NOPR, 

CAGI, Kaeser Compressors, Ingersoll 

Rand, Saylor-Beall, and Sullivan-Palatek 

all expressed support for DOE’s 

proposal to exclude centrifugal 

compressors from the scope of test 

procedure applicability. (CAGI, No. 21 

at p. 2; Kaeser Compressors, No. 24 at 

p. 3; Ingersoll Rand, No. 25 at p. 1; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) Additionally, in 

response to the request for comment 

regarding clarification on ‘‘dynamic’’ 

versus ‘‘centrifugal’’ compressors, CAGI, 

Kaeser Compressors, Ingersoll Rand, 

Saylor-Beall, and Sullivan-Palatek all 

supported the position that centrifugal 

compressors are the only form of 

dynamic compressor that competes with 

the air compressor categories discussed 

in the February 2023 NOPR. (CAGI, No. 

21 at p. 2; Kaeser Compressors, No. 24 

at p. 3; Ingersoll Rand, No. 25 at p. 2; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) 

NEEA & NPCC also recommended 

that DOE consider a separate future test 


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procedure rulemaking for centrifugal 

compressors, which would create a path 

for expanding the current test procedure 

scope to rotary compressors up to 500 

hp. NEEA & NPCC commented that 

centrifugal compressors make up a 

small market share but represent 18 

percent of annual energy consumption 

for industrial compressors, and are 

typically above 200 hp. NEEA & NPCC 

also stated that rotary and centrifugal 

compressors from 200 hp to 500 hp 

represent 25 percent of total commercial 

and industrial compressor energy 

consumption. NEEA & NPCC stated that 

ISO 5389 is an industry-accepted test 

procedure for centrifugal compressors 

and recommended this as an option for 

a future centrifugal compressor test 

procedure rulemaking. NEEA & NPCC 

also stated that there is little overlap in 

the applications that would use a 

centrifugal compressor instead of a 

rotary compressor because centrifugal 

compressors are more expensive and are 

used for specific applications that 

require clean air. (NEEA & NPCC, No. 26 

at pp. 3–4) 

CA IOUs recommended DOE expand 

the scope of this test procedure to cover 

centrifugal compressors. CA IOUs stated 

that dynamic air compressors account 

for approximately 18 percent of total 

industrial air compressor national 

energy consumption. CA IOUs also 

stated that the inclusion of dynamic 

compressors would give end users more 

data to compare with and that these 

compressors provide oil- and 

particulate-free air, which would allow 

them to compete with regulated and 

large positive displacement rotary 

compressors in certain applications. (CA 

IOUs, No. 27 at pp. 7–9) ASAP, ACEEE, 

& NRDC also encouraged DOE to 

include centrifugal compressors in the 

scope of this test procedure final rule 

due to the significance of their energy 

usage and the fact that centrifugal 

compressors may compete with large 

rotary positive displacement 

compressors. ASAP, ACEEE, & NRDC 

added that ISO 5389, the industry test 

procedure for dynamic compressors, 

could potentially serve as the basis of 

the test procedure. (ASAP, ACEEE, & 

NRDC, No. 28 at p. 3) 

It is true that centrifugal compressors 

can compete with large rotary positive 

displacement compressors, as stated by 

commenters. (CA IOUs, No. 27 at pp. 8– 

9; ASAP, ACEEE, & NRDC, No. 28 at p. 

3) DOE discussed the potential for 

competition between these categories in 

the January 2017 Final Rule. 82 FR 

1052, 1061–1063. Competition between 

these categories is considerable above 

200 hp, and this reasoning was used to 

set the upper bound of the compressor 

test procedure motor nominal 

horsepower at 200 hp. 82 FR 1052, 

1062. As discussed in section III.A.3 of 

this final rule, DOE is maintaining this 

upper bound on compressor motor 

nominal horsepower in the test 

procedure. This ensures that there is not 

considerable competition between 

unregulated centrifugal compressors 

and regulated positive displacement 

rotary compressors within the scope of 

the DOE compressors test procedure. 

DOE has not yet determined a test 

procedure for centrifugal compressors 

that would produce test results that 

reflect efficiency during a representative 

average use cycle and that would not be 

unduly burdensome to conduct. (42 

U.S.C. 6314(a)(2)) Due to the reasons 

discussed in the February 2023 NOPR 

and previous paragraphs, DOE is not 

expanding the scope of this test 

procedure to include centrifugal 

compressors. DOE continues to review 

and consider potential methods for 

centrifugal compressors and may 

consider developing test procedures for 

centrifugal compressors as part of a 

future rulemaking process. 

3. Compressor Motor Nominal 

Horsepower 

As stated in section III.A of this 

document, the current test procedure for 

compressors applies to compressors that 

have a full-load operating pressure of 75 

to 200 psig (inclusive) and either (1) a 

full-load actual volume flow rate of 35 

to 1,250 cfm (inclusive) or (2) 

compressor motor nominal horsepower 

of 10 to 200 hp (inclusive). 10 CFR 

431.344. In the February 2023 NOPR, 

DOE tentatively determined that the 

same burden concerns as discussed in 

the January 2017 Final Rule would 

continue to exist for the current 

compressor market. 88 FR 9199, 9203. 

These include a small number of 

shipments of units greater than 200 hp 

and the potential for competitive 

disadvantage for rotary positive 

displacement compressors that compete 

with centrifugal compressors. Id. 

Therefore, DOE did not propose any 

changes to the current horsepower range 

of 10 to 200 hp for the existing test 

procedure in the February 2023 NOPR. 

Id. DOE asked for comment regarding 

the determination to not include 

compressors with a horsepower rating 

above 200 hp within the scope of test 

procedure applicability. Id. 

In response to the February 2023 

NOPR, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all expressed support 

for the DOE proposal to not include 

compressors with a horsepower rating 

above 200 hp within the scope of test 

procedure applicability. (CAGI, No. 21 

at p. 2; Kaeser Compressors, No. 24 at 

pp. 3–4; Ingersoll Rand, No. 25 at p. 2; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) 

Kaeser Compressors encouraged DOE 

to investigate increasing the maximum 

horsepower above 200 hp to 500 hp in 

a future rulemaking. (Kaeser 

Compressors, No. 24 at p. 2) NEEA & 

NPCC recommended that DOE consider 

a separate future test procedure 

rulemaking for centrifugal compressors, 

which would create a path for 

expanding the current test procedure 

scope to rotary compressors up to 500 

hp. NEEA & NPCC also stated that rotary 

and centrifugal compressors from 200 

hp to 500 hp represent 25 percent of 

total commercial and industrial 

compressor energy consumption. (NEEA 

& NPCC, No. 26 at pp. 3–4) 

CA IOUs recommended that DOE 

expand the scope of the test procedure 

to cover large (201–500 hp) rotary 

positive displacement air compressors. 

CA IOUs stated that all compressor 

types in this size range consume 29 

percent of total industrial air 

compressor energy, and that increasing 

the scope of the test procedure would 

support the goal of fully evaluating the 

cost-effectiveness, technological 

feasibility, and economically justified 

savings opportunities for end users. CA 

IOUs also stated that air compressor 

manufacturers voluntarily provide CAGI 

data sheets for large and oil-free rotary 

positive displacement air compressors, 

therefore the additional test burden of 

covering compressors with motors 

operating at 201–500 hp is limited. CA 

IOUs provided data showing that there 

is a wide range of isentropic efficiencies 

for rotary positive displacement 

compressors with motor nominal power 

greater than 200 hp. Finally, CA IOUs 

provided data indicating that centrifugal 

compressors likely compete with fixedspeed rotary positive displacement 

compressors to provide baseload, but 

they do not likely compete with 

variable-speed rotary positive 

displacement compressors providing 

low part load. (CA IOUs, No. 27 at pp. 

2–7) 

ASAP, ACEEE, & NRDC also 

encouraged DOE to expand the scope of 

the test procedure to cover rotary 

positive displacement air compressors 

greater than 200 hp. ASAP, ACEEE, & 

NRDC disagreed with DOE’s rationale 

for excluding rotary compressors greater 

than 200 hp for several reasons. First, 

ASAP, ACEEE, & NRDC indicated that 

CAGI performance data is already 

available for many of these larger 

models. Second, ASAP, ACEEE, & 

NRDC acknowledged that larger 


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compressors have lower shipment 

numbers, but they indicated that DOE 

has recently expanded the scope of the 

electric motors test procedure to 750 hp 

and stated that very large electric motors 

are also often low-volume, custom 

products. Third, ASAP, ACEEE, & 

NRDC stated that most compressor 

manufacturers make both in-scope 

rotary compressors and out-of-scope 

compressors, so it is unclear whether 

certain manufacturers would be 

disadvantaged by inclusion of larger 

rotary compressors. Finally, ASAP, 

ACEEE, & NRDC stated that DOE should 

consider expanding the test procedure 

scope to currently out-of-scope 

compressor types, such as centrifugal 

compressors, as this would mitigate 

concerns over disadvantaging certain 

manufacturers or pushing the market 

towards out-of-scope substitutions. 

(ASAP, ACEEE, & NRDC, No. 28 at pp. 

1–2) 

DOE recognizes that a considerable 

amount of the market for compressors 

greater than 200 hp is served by 

centrifugal compressors. As discussed 

in the January 2017 Final Rule, the 

inclusion of rotary compressors greater 

than 200 hp could create a competitive 

disadvantage for manufacturers of these 

compressors, as centrifugal compressors 

of the same horsepower do not have the 

same testing and representation 

requirements. 82 FR 1052, 1061–1062. 

DOE concluded at the time that this 

competitive advantage could incentivize 

users to switch from regulated rotary 

compressors to unregulated centrifugal 

compressors, thus creating a 

competitive advantage for 

manufacturers of unregulated 

centrifugal compressors. Id. Although 

commenters have indicated that these 

categories compete in only a subset of 

the market and that some manufacturers 

make both regulated and unregulated 

compressors, the same competitive 

issues still largely exist today. 

Although ASAP, ACEEE, & NRDC 

have suggested that DOE can mitigate 

the concerns over competition by 

covering both rotary positive 

displacement and centrifugal 

compressors over 200 hp in the test 

procedure scope (ASAP, ACEEE, & 

NRDC, No. 28 at pp. 1–2), section III.A.2 

of this final rule discusses that DOE is 

continuing to exclude centrifugal 

compressors from the scope of the test 

procedure at this time. As a result, in 

order to ensure that there is not 

considerable competition between 

unregulated centrifugal compressors 

and regulated positive displacement 

rotary compressors, DOE is also 

continuing to exclude rotary positive 

displacement compressors over 200 hp 

from the scope of the test procedure at 

this time. 

For the reasons discussed in the 

February 2023 NOPR and the previous 

paragraphs, DOE is maintaining the 

current horsepower range of 10 to 200 

hp for this test procedure final rule. 

DOE continues to review and consider 

potential methods for testing positive 

displacement rotary compressors with 

nominal motor horsepower greater than 

and less than the current scope and may 

consider developing test procedures for 

these compressors as part of a future 

rulemaking process. 

4. Lubricant-Free Compressors 

As stated in section III.A of this 

document, the current test procedure for 

compressors applies to lubricated 

compressors (and therefore does not 

apply to lubricant-free compressors). 10 

CFR 431.344. In the February 2023 

NOPR, DOE proposed to not expand the 

scope of the test procedure to include 

lubricant-free compressors. 88 FR 9199, 

9203–9204. DOE stated that it may 

evaluate the justification for developing 

test procedures for lubricant-free 

compressors as part of a future 

rulemaking process. DOE also asked for 

comment regarding its proposal to not 

include lubricant-free compressors 

within the scope of test procedure 

applicability. 

In response to the request for 

comment, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all responded in 

agreement with DOE’s proposal to not 

include lubricant-free compressors 

within the scope of test procedure 

applicability. (CAGI, No. 21 at p. 2; 

Kaeser Compressors, No. 24 at p. 4; 

Ingersoll Rand, No. 25 at p. 2; SaylorBeall, No. 22 at p. 1; Sullivan-Palatek, 

No. 23 at p. 1) 

Kaeser Compressors encouraged DOE 

to evaluate recently added/verified test 

standards for oil-free compressors and 

blowers for potential incorporation in a 

future rulemaking. Kaeser Compressors 

also added that, since there are many 

different compressor and blower 

technologies in the oil-free category, 

they may require different ways to 

develop efficiency and test standards. 

(Kaeser Compressors, No. 24 at p. 2) 

ASAP, ACEEE, & NRDC 

recommended DOE expand the scope of 

this test procedure to cover lubricantfree compressors, because including 

lubricant-free compressors would 

mitigate the risk of unregulated product 

substitutions, which was a concern in 

the January 2017 Final Rule. (ASAP, 

ACEEE, & NRDC, No. 28 at p. 3) 

DOE discussed lubricant-free 

compressors in both the January 2017 

Final Rule (82 FR 1052, 1063) and the 

January 2020 ECS Final Rule (85 FR 

1504, 1519–1520), concluding that 

justification did not exist at the time to 

support extending the scope of test 

procedures or energy conservation 

standards to apply to lubricant-free 

compressors. DOE has determined that 

the conclusion made in the 2017 and 

2020 final rules still applies for 

lubricant-free compressors. 

ASAP, ACEEE, & NRDC 

recommended that DOE mitigate the 

risk of unregulated product 

substitutions by expanding the scope of 

the test procedure to cover lubricantfree compressors and other categories of 

compressors, such as centrifugal and 

scroll compressors, instead of excluding 

lubricant-free compressors. (ASAP, 

ACEEE, & NRDC, No. 28 at p. 3) Section 

III.A.2 of this final rule, however, 

discusses that DOE is continuing to 

exclude centrifugal compressors from 

the scope of the test procedure at this 

time. As a result, in order to ensure that 

there is not competition between 

unregulated centrifugal compressors 

and regulated lubricant-free positive 

displacement rotary compressors, DOE 

is also excluding lubricant-free rotary 

positive displacement compressors from 

the scope of the test procedure at this 

time. 

For the reasons discussed in the 

previous paragraphs, at this time, DOE 

is not expanding the scope of the test 

procedure to include lubricant-free 

compressors. DOE may evaluate the 

justification for developing test 

procedures for lubricant-free 

compressors as part of a future 

rulemaking process. 

5. Brushed Motors 

As stated in section III.A, the current 

test procedure for compressors applies 

only to compressors with brushless 

motors. 10 CFR 431.344. In the February 

2023 NOPR, DOE proposed to not 

expand the scope of the test procedure 

to include compressors with brushed 

motors. 88 FR 9199, 9204. DOE stated 

that it may evaluate the justification for 

developing test procedures for 

compressors with brushed motors as 

part of a future rulemaking process. 

DOE also asked for comment regarding 

its proposal to not include compressors 

with brushed motors within the scope of 

test procedure applicability. 

In response to the request for 

comment, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all responded in 

agreement with DOE’s proposal to 

exclude compressors with brushed 

motors from the scope of test procedure 

applicability. (CAGI, No. 21 at p. 2; 


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Kaeser Compressors, No. 24 at p. 4; 

Ingersoll Rand, No. 25 at p. 2; SaylorBeall, No. 22 at p. 1; Sullivan-Palatek, 

No. 23 at p. 1) 

ASAP, ACEEE, & NRDC encouraged 

DOE to include compressors with 

brushed motors in the test procedure 

scope. (ASAP, ACEEE, & NRDC, No. 28 

at p. 1) ASAP, ACEEE, & NRDC 

commented that they were concerned 

that manufacturers could consider 

replacing brushless motors with less 

efficient brushed motors to avoid 

compressor regulations. (ASAP, ACEEE, 

& NRDC, No. 28 at p. 3) 

DOE discussed compressors with 

brushed motors in both the January 

2017 Final Rule (82 FR 1052, 1060) and 

the January 2020 ECS Final Rule (85 FR 

1504, 1515), concluding that the burden 

associated with establishing testing 

requirements for brushed motor 

compressors outweighed the associated 

benefits. This was because, although 

there were potential benefits to 

expanding scope to include these 

models, brushed motors are uncommon 

in compressors with significant 

operating hours, and most brushed 

motor compressors are not tested for 

efficiency. 82 FR 1052, 1060. In 

addition, DOE stated that brushed 

motors are uncommon in compressors 

with significant potential energy savings 

(i.e., high operating hours) due to higher 

maintenance costs, short operating lives, 

significant acoustic noise, and electrical 

arcing. Id. For these reasons, DOE 

concluded that brushed motors are not 

a viable substitution risk for 

compressors within the scope of the 

DOE compressor test procedure. Id. 

DOE has determined that the 

conclusions made in the January 2017 

Final Rule still apply for compressors 

with brushed motors. Due to this 

reasoning, at this time, DOE is not 

expanding the scope of the test 

procedure to include compressors with 

brushed motors. DOE may evaluate the 

inclusion of compressors with brushed 

motors as part of a future rulemaking. 

6. Output Pressure Less Than 75 psig 

As stated in section III.A, the current 

test procedure for compressors applies 

only to compressors that have a fullload operating pressure greater than or 

equal to 75 psig and less than or equal 

to 200 psig. 10 CFR 431.344. In the 

February 2023 NOPR, DOE proposed to 

not include equipment for compressed 

air applications for pressures under 75 

psig within the scope of test procedure 

applicability. 88 FR 9199, 9204. DOE 

stated that it may evaluate the 

justification for developing test 

procedures for compressors with output 

pressure of less than 75 psig as part of 

a future rulemaking process. Id. DOE 

also asked for comment regarding its 

proposal to not include equipment for 

compressed air applications for 

pressures under 75 psig within the 

scope of test procedure applicability. Id. 

In response to the request for 

comment, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all commented in 

agreement with DOE’s proposal to not 

include compressors with output 

pressure less than 75 psig. (CAGI, No. 

21 at p. 2; Kaeser Compressors, No. 24 

at p. 4; Ingersoll Rand, No. 25 at p. 2; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) 

Kaeser Compressors encouraged DOE 

to evaluate recently added/verified test 

standards for oil-free compressors and 

blowers for potential incorporation in a 

future rulemaking, which would 

include pressure ranges of 50–160 psig. 

Kaeser Compressors added that 1–30 

psig is also a large area of energy 

consumption, which includes 

wastewater treatment and other aeration 

and conveying applications that include 

24/7 operation. (Kaeser Compressors, 

No. 24 at p. 2) 

At this time, DOE is not expanding 

the scope of the test procedure to 

include compressors with output 

pressure of less than 75 psig. DOE 

discussed compressors with output 

pressure of less than 75 psig in both the 

January 2017 Final Rule (82 FR 1052, 

1062–1063) and the January 2020 ECS 

Final Rule (85 FR 1504,1519), 

concluding that justification did not 

exist at the time to support extending 

the scope of either test procedures or 

energy conservation standards to apply 

to compressors with output pressure of 

less than 75 psig. DOE has determined 

that the conclusion made in the January 

2017 Final Rule and the January 2020 

ECS Final Rule still applies for 

compressors with output pressure of 

less than 75 psig. DOE may evaluate the 

justification for developing test 

procedures for compressors with output 

pressure of less than 75 psig as part of 

a future rulemaking process. 

7. Integrated Dryers 

In response to the February 2023 

NOPR, Kaeser Compressors commented 

that, while integrated dryers inside a 

compressor package are not listed in the 

DOE procedure, it might be necessary to 

specifically exclude them from this test 

procedure. (Kaeser Compressors, No. 24 

at p. 8) 

Section 2.2.4 of appendix A contains 

tables 1 and 2, which specify the 

compressor components and ancillary 

equipment that must be present and 

installed when testing an air 

compressor. These tables were 

discussed in the January 2017 Final 

Rule. 82 FR 1052, 1055–1057, 1080– 

1082. Table 1 to appendix A contains 

the equipment that must be present and 

installed for all tests. If the compressor 

is distributed in commerce without an 

item from table 1 to appendix A, the 

manufacturer must provide an 

appropriate item to be installed for the 

test. If any of the equipment listed in 

table 2 to appendix A is distributed in 

commerce with units of the compressor 

basic model, it must be present and 

installed for all tests specified in 

appendix A. Additional ancillary 

equipment beyond the items listed in 

tables 1 and 2 to appendix A may be 

installed for the test, if distributed in 

commerce with the compressor, but this 

additional ancillary equipment is not 

required. 

Neither table 1 nor table 2 to 

appendix A specify an integrated dryer, 

or any type of dryer, as a piece of 

equipment that must be installed for 

testing. Table 1 to appendix A specifies 

a moisture separator and drain, but this 

is different from a dryer, in that a 

moisture separator removes liquid water 

from the air, whereas a dryer removes 

water vapor from the air. As a result, an 

integrated dryer is not required to be 

present and installed for the tests 

specified in the compressors test 

procedure. A manufacturer may install 

an integrated dryer for the tests if the 

integrated dryer is distributed in 

commerce with the compressor, but the 

integrated dryer is not required. 

Although Kaeser Compressors 

suggested that it might be necessary to 

specifically exclude integrated dryers 

from the test procedure, DOE is not 

doing that in this final rule. As 

discussed in the previous paragraphs, a 

manufacturer is not required to install 

an integrated dryer for testing, but the 

manufacturer may install an integrated 

dryer if they wish to represent the 

performance of their compressor with 

an integrated dryer installed. This 

flexibility is indicated by the text of 

section 2.2.4 of appendix A and tables 

1 and 2 to appendix A, and no changes 

are required at this time to clarify this 

flexibility. 

B. Updates to Industry Standards 

1. ISO 1217:2009(E) as the Basis for This 

Test Procedure 

DOE’s current test procedure 

incorporates by reference certain 

sections of ISO 1217:2009(E) as 

amended through Amendment 1:2016 

for test methods and acceptance tests 

regarding volume rate of flow and 

power requirements of displacement 


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compressors, in addition to the 

operating and testing conditions that 

apply when a full performance test is 

specified. In the February 2023 NOPR, 

DOE did not propose amendments to 

the existing reference to ISO 

1217:2009(E) as amended through 

Amendment 1:2016 as the basis for the 

compressors test procedure. 88 FR 9199, 

9204–9205. DOE also asked for 

comment regarding its initial 

determination to continue to use ISO 

1217:2009(E) as amended through 

Amendment 1:2016 as the basis for the 

compressors test procedure. 

In response to the request for 

comment, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all commented in 

agreement with DOE’s proposal to 

continue to use ISO 1217:2009(E) as 

amended through Amendment 1:2016 as 

the basis for the compressors test 

procedure. (CAGI, No. 21 at p. 3; Kaeser 

Compressors, No. 24 at p. 4; Ingersoll 

Rand, No. 25 at p. 2; Saylor-Beall, No. 

22 at p. 1; Sullivan-Palatek, No. 23 at p. 

1) 

DOE agrees with the comments 

received and is continuing to 

incorporate by reference certain sections 

of ISO 1217:2009(E) as amended 

through Amendment 1:2016 in the 

compressors test procedure at 10 CFR 

431.343. As discussed in section III.E.1, 

DOE is revising 10 CFR 431.343 to add 

section B.4.5 of Annex B of ISO 

1217:2009(E) to the list of sections that 

DOE is incorporating by reference in the 

compressors test procedure. See section 

III.E.1 for a full discussion of this 

revision. 

2. Ambient Temperature Range 

Requirement 

DOE adopted the ambient temperature 

range for testing of 68 to 90 °F in the 

January 2017 Final Rule partially in 

response to concern that creating a 

climate-controlled space for testing 

compressors could be a significant 

burden on small businesses. DOE stated 

that this temperature range provides 

representative measurements without 

unduly burdening manufacturers. 82 FR 

1052, 1079–1080. In the February 2023 

NOPR, DOE proposed to maintain the 

current ambient temperature range 

requirement of 68 to 90 °F for testing air 

compressors. 88 FR 9199, 9205. DOE 

also asked for comment regarding its 

proposal to maintain the current 

ambient temperature range requirement. 

In response to the request for 

comment, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all commented in 

agreement with DOE’s proposal to 

maintain the current ambient 

temperature range requirement of 68 to 

90 °F for testing air compressors. (CAGI, 

No. 21 at p. 3; Kaeser Compressors, No. 

24 at p. 5; Ingersoll Rand, No. 25 at p. 

2; Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) They added that 

narrowing the range or specifying 

specific requirements would add burden 

to the industry without providing any 

advantages to consumers. (Id.) 

For the reasons discussed in the 

February 2023 NOPR and the previous 

paragraphs, DOE is not amending the 

current ambient temperature range 

requirement of 68 to 90 °F for testing air 

compressors in this final rule. 

C. Definitions 

1. Multi-Element Air Compressors 

Air compressors may include 

multiple compression elements to 

increase compression efficiency or to 

generate a greater pressure increase than 

would be possible with a single 

compression element. The current 

definition of ‘‘air compressor’’ specifies 

inclusion of a compression element but 

does not exclude air compressors that 

include more than one compression 

element. DOE discussed the current 

definition of ‘‘air compressor’’ as 

applying to multi-element air 

compressors in both the January 2017 

Final Rule (82 FR 1052, 1068) and the 

January 2020 ECS Final Rule, in which 

multi-staging was identified as a 

technology option for improving the 

energy efficiency of compressors. 85 FR 

1504, 1537. 

In the February 2023 NOPR, DOE 

tentatively determined that revising the 

definition of ‘‘air compressor’’ to 

explicitly include air compressors with 

more than one compression element 

would reduce the probability that the 

definition is misinterpreted to exclude 

air compressors with more than one 

compression element. 88 FR 9199, 

9205–9206. DOE proposed to amend the 

definition of ‘‘air compressor’’ such that 

‘‘compression element (bare 

compressor)’’ is replaced by ‘‘one or 

more compression elements (bare 

compressors).’’ Id. Additionally, DOE 

proposed to change ‘‘compressor 

element’’ to ‘‘compression elements’’ to 

correct a typographical error. Id. DOE 

also issued a request for comment in the 

February 2023 NOPR regarding its 

proposed amendment of the definition 

of ‘‘air compressor.’’ 88 FR 9199, 9206. 

In response to the request for 

comment, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, SullivanPalatek, and CA IOUs all expressed 

support for DOE’s proposed amendment 

to the definition of ‘‘air compressor.’’ 

(CAGI, No. 21 at p. 2; Kaeser 

Compressors, No. 24 at p. 4; Ingersoll 

Rand, No. 25 at p. 2; Saylor-Beall, No. 

22 at p. 1; Sullivan-Palatek, No. 23 at p. 

1; CA IOUs, No. 27 at p. 1) 

The current formulation of the 

definition of ‘‘air compressor’’ does not 

exclude air compressors with more than 

one compression element; nonetheless, 

stating expressly that multi-element 

compressors meet the definition of ‘‘air 

compressor’’ limits the potential for 

misinterpretation. 

For the reasons discussed in the 

February 2023 NOPR and the preceding 

paragraphs, DOE is amending the 

definition of ‘‘air compressor’’ to be ‘‘a 

compressor designed to compress air 

that has an inlet open to the atmosphere 

or other source of air, and is made up 

of one or more compression elements 

(bare compressors), driver(s), 

mechanical equipment to drive the 

compression elements, and any 

ancillary equipment.’’ 

D. Efficiency Metrics 

1. Load Point for Fixed-Speed 

Compressors 

The current efficiency metric for 

fixed-speed compressors, full-load 

package isentropic efficiency, uses a 

single load point at 100 percent of fullload actual volume flow rate. In the 

February 2023 NOPR, DOE proposed to 

maintain the requirement to measure 

the performance of fixed-speed 

compressors at full load, or more 

specifically, full-load actual volume 

flow rate at full-load operating pressure, 

as described in paragraph 3.3.1 of 

appendix A. 88 FR 9199, 9209. DOE also 

asked for comment on whether the test 

procedure reflects actual operating costs 

for compressors based on their realistic 

average use cycles. Id. 

In response to the February 2023 

NOPR, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all expressed support 

for the provision that the test procedure 

can be considered reflective of realistic 

average use cycles. They commented 

that, in practical terms, no one 

compressor installation will have 

identical or predictable use cycles, and 

that the current regulatory provision to 

certify fixed-speed machines based on 

their performance at 100 percent flow 

rate and for variable-speed machines 

based on a weighted average for flow 

conditions provides a realistic, 

representative framework for testing, 

certifying, and presenting meaningful 

and consistent data to customers. (CAGI, 

No. 21 at p. 5; Kaeser Compressors, No. 

24 at p. 8; Ingersoll Rand, No. 25 at p. 

4; Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) 


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6Available at iso.org/standard/85352.html. 

For the reasons discussed in the 

February 2023 NOPR and preceding 

paragraphs, DOE is not proposing to 

alter the current metric for fixed-speed 

compressors in this test procedure final 

rule. 

2. Load Points for Variable-Speed 

Compressors 

The part-load package isentropic 

efficiency metric for variable-speed air 

compressors uses three load points: 40, 

70, and 100 percent of full-load actual 

volume flow rate. In the February 2023 

NOPR, DOE proposed to continue using 

those load points. 88 FR 9199, 9208– 

9209. DOE requested comment on its 

proposal to maintain the number of load 

points for variable-speed air 

compressors and to not include points 

with greater than 100 percent of fullload actual volume flow rate. Id. 

In response to the request for 

comment in the February 2023 NOPR, 

CAGI, Kaeser Compressors, Ingersoll 

Rand, Saylor-Beall, and Sullivan-Palatek 

all expressed support for the DOE 

proposal to maintain the number of test 

points and to not include points with 

greater than 100-percent load. 

For the reasons discussed in the 

February 2023 NOPR and the previous 

paragraphs, in this final rule, DOE is 

maintaining the load points for the partload package isentropic efficiency 

metric for variable-speed air 

compressors at 100 percent, 70 percent, 

and 40 percent of full-load actual 

volume flow rate. 

3. Inclusion of Unloaded Operation for 

Fixed-Speed Compressors 

The isentropic efficiency metric for 

fixed-speed compressors currently 

includes performance at full-load 

operation only. No measure of 

performance is included from unloaded 

operation. In the February 2023 NOPR, 

DOE proposed to maintain this 

exclusion of unloaded operation from 

the isentropic efficiency metric. 88 FR 

9199, 9208. 

ASAP, ACEEE, & NRDC encouraged 

DOE to explore how unloaded power 

measurements could be incorporated 

into the test procedure. ASAP, ACEEE, 

& NRDC stated that fixed-speed air 

compressors are tested and evaluated 

only at full load. However, they 

elaborated that fixed-speed compressors 

often include controls such as ‘‘load/ 

unload’’ or ‘‘start/stop’’ and commented 

that testing and evaluating fixed-speed 

compressor efficiency at both fully 

loaded and fully unloaded (i.e., zero 

flow) conditions would be more 

representative of typical usage. ASAP, 

ACEEE, & NRDC further stated that the 

CAGI Performance Verification Program 

already specifies testing at a fully 

unloaded test point, and that capturing 

differences in unloaded power usage 

will become increasingly important as 

compressor efficiencies improve. 

(ASAP, ACEEE, & NRDC, No. 28 at p. 3) 

NEEA & NPCC recommended that 

DOE include a no-load power 

measurement in the test procedure for 

fixed-speed compressors that use start/ 

stop and load/unload control strategies. 

NEEA & NPCC stated that unlike 

variable-airflow controls, fixed-speed air 

compressors that use start/stop and 

load/unload control strategies operate at 

either fully loaded or fully unloaded 

states, and testing units that have start/ 

stop or load/unload control strategies at 

fully loaded and fully unloaded states 

would be more representative of typical 

usage. NEEA & NPCC commented that 

the January 2020 ECS Final Rule 

indicates that a significant portion of 

annual energy consumption is spent in 

a no-load or fully unloaded state for 

fixed-speed compressors with unload 

strategies. NEEA & NPCC further stated 

that, because the metric does not 

currently account for a no-load power, 

DOE can’t consider technologies that 

reduce no-load power consumption in 

its standard analysis; manufacturers that 

develop products that use less energy in 

no-load are not given credit in their 

regulated ratings; and the DOE test 

procedure assumption for non-operating 

hours is zero, which is not in agreement 

with the analysis performed in the 

January 2020 ECS Final Rule and does 

not align with the typical usage of 

compressors. NEEA & NPCC also stated 

that standby mode and off mode energy 

consumption measurements are 

required for all consumer products’ test 

procedures, and that including a noload power measurement for industrial 

equipment that consumes power in a 

no-load state, such as start/stop and 

load/unload compressors, ensures 

consistency in test procedure 

requirements across industrial and 

consumer products. (NEEA & NPCC, No. 

26 at pp. 5–6) 

NEEA & NPCC disagreed with DOE’s 

statement in the February 2023 NOPR 

that testing at a no-load state is not an 

essential output of the test procedure 

and, therefore, would cause unneeded 

incremental burden on testing and 

reporting requirements. NEEA & NPCC 

stated that DOE requiring testing at a noload state is the necessary step for noload power measurement to be an 

essential output of the test procedure. 

NEEA & NPCC also stated that the 

incremental burden of testing a unit at 

a no-load state is minimal, as units 

under test are already set up for testing 

at specified load points and the CAGI 

data sheets already specify tolerances 

for testing at a fully unloaded test point. 

(NEEA & NPCC, No. 26 at p. 6) 

DOE agrees that information 

describing unloaded states of operation 

could be useful to the end user. This 

subject was discussed in the January 

2017 Final Rule. 82 FR 1052, 1068– 

1070. This included mention of possible 

methods to include loaded and 

unloaded points in a representative 

manner, including, potentially, the 

energy required during the transient 

periods between loaded and unloaded 

operation. Id. At the time, it was noted 

that there were no methods that had 

been developed and accepted by 

industry consensus, although Atlas 

Copco did provide an example of a 

cycle energy requirement approach to 

consider the energy during loaded 

operation, unloaded operation, and the 

transient periods between loaded and 

unloaded operation. Id. At the time, 

DOE did not include unloaded 

performance in its isentropic efficiency 

metric because there was no accepted 

industry test method. Id. DOE indicated 

at the time that DOE may consider 

incorporating such a method in future 

rulemakings if the metric gains 

acceptance in the industry and the test 

method can be formalized and validated 

beyond a case study. 82 FR 1052, 1069. 

DOE also stated that manufacturers may 

measure and advertise unloaded power, 

but it would not require measurement of 

unloaded performance as part of the test 

procedure. 82 FR 1052, 1070. 

At the current time, DOE is not aware 

that an industry standard test method 

has been developed to provide a 

representative measure of performance 

across loaded and unloaded operation. 

In a comment in response to the 

February 2023 NOPR, Kaeser 

Compressors indicated that DOE could 

consider new industrial standards for a 

future rulemaking, including ISO 4376, 

Cycle energy requirement.6 This 

standard is described on the ISO 

website as measuring the additional 

energy required for a single cycle caused 

by transient conditions, which sounds 

similar to the method from Atlas Copco 

that was discussed in the January 2017 

Final Rule. The standard is currently 

listed as ‘‘under development’’ on the 

ISO website, and DOE is not aware of 

any compressors that are currently rated 

using this standard. As a result, it 

appears that this standard is not 

currently being used widely by 

industry. DOE is also not aware of any 

other industry consensus method to 


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combine loaded and unloaded 

performance. 

The concerns that existed in the 

January 2017 Final Rule regarding the 

lack of an accepted industry test method 

to combine loaded and unloaded 

performance still exist. As a result, DOE 

is not including any measure of 

unloaded performance in the metrics of 

the compressors test procedure at this 

time, although manufacturers may 

measure and advertise unloaded power. 

DOE may consider including unloaded 

performance in the metrics of the 

compressors test procedures as part of a 

future rulemaking process. 

4. Part-Load Performance of FixedSpeed Compressors With VariableAirflow Controls 

The isentropic efficiency metric for 

fixed-speed compressors includes 

performance at full-load operation only. 

No measure of performance is included 

from part-load operation. In the 

February 2023 NOPR, DOE proposed to 

maintain this exclusion of part-load 

operation from the isentropic efficiency 

metric for fixed-speed compressors. 88 

FR 9199, 9208. 

ASAP, ACEEE, & NRDC encouraged 

DOE to include voluntary testing and 

reporting of part-load performance of 

fixed-speed compressors with variableairflow controls. ASAP, ACEEE, & 

NRDC stated that fixed-speed 

compressors sold with variable-airflow 

controls, such as ‘‘variable 

displacement’’ or ‘‘inlet modulation,’’ 

can provide similar utility as variablespeed compressors. Thus, ASAP, 

ACEEE, & NRDC stated that DOE should 

provide specific voluntary provisions to 

test and rate compressors with variableairflow controls (e.g., using the variablespeed compressor test points at 40, 70, 

and 100 percent of full load). ASAP, 

ACEEE, & NRDC further stated that partload testing of fixed-speed compressors 

with airflow controls would facilitate 

comparison of part-load efficiency 

among variable-airflow compressors as 

well as between variable-airflow and 

variable-speed compressors. Finally, 

ASAP, ACEEE, & NRDC indicated that 

these provisions would also ensure that 

any manufacturer representations of 

variable-airflow compressor part-load 

performance are consistent across the 

industry. (ASAP, ACEEE, & NRDC, No. 

28 at pp. 3–4) 

NEEA & NPCC recommended DOE 

coordinate with CAGI in rating fixedspeed rotary compressors with variableairflow controls at variable load points 

to align with variable-speed 

compressors. NEEA & NPCC stated that 

many fixed-speed rotary compressors 

have variable-airflow controls and nonflat load profiles. Fixed-speed 

compressors that use variable-airflow 

controls, such as inlet valve modulation 

and variable displacement, provide the 

same function as variable-speed 

compressors; however, these 

compressors are tested only at full-load 

operation currently. Testing fixed-speed 

rotary compressors with variable-airflow 

controls at variable load points would 

be more representative of typical usage 

and produce a more representative 

isentropic efficiency. Furthermore, 

NEEA & NPCC stated that by not testing 

compressors with variable-airflow 

controls at part-load set points, 

consumers cannot compare and select 

the most efficient air compressors for 

part-load operations. (NEEA & NPCC, 

No. 26 at p. 4) 

NEEA & NPCC disagreed with DOE’s 

reasoning in the February 2023 NOPR 

that because fixed-speed rotary 

compressors in the CAGI data sheets are 

rated at only full-load isentropic 

efficiency, establishing part-load 

isentropic efficiencies for compressors 

with variable-airflow controls in the test 

procedure is not warranted at this time. 

NEEA & NPCC stated that DOE should 

consider improvements to the testing of 

variable-airflow compressors for several 

reasons. First, NEEA & NPCC stated that 

DOE is not limited to CAGI’s 

performance verification program or the 

information on CAGI data sheets in their 

test procedure, and that DOE should 

fully consider the burden and value of 

changes to the testing of fixed-speed 

variable-airflow compressors. Second, 

NEEA & NPCC commented that the 

January 2020 ECS Final Rule indicated 

that about 37 percent of fixed-speed 

industrial air compressors use inlet 

valve modulation or variable 

displacement with high, low, or even 

load profiles, indicating that a 

significant portion of fixed-speed air 

compressors are tested in conditions at 

which they rarely or never operate. 

Finally, NEEA & NPCC commented that 

there may be a significant savings 

opportunity for fixed-speed rotary 

compressors with variable-airflow 

controls, and that DOE should 

investigate the savings opportunity by 

testing these compressors the same as 

variable-speed compressors. NEEA & 

NPCC stated that if significant savings 

potential is noted, DOE should update 

testing to better reflect the energy 

consumption and potential for savings 

in this equipment. In addition, NEEA & 

NPCC stated that DOE could also 

coordinate with CAGI on how to 

include these reporting requirements in 

their data sheets so that both continue 

to align, should DOE make changes. 

(NEEA & NPCC, No. 26 at p. 6) 

DOE agrees that a part-load package 

isentropic efficiency metric for fixedspeed variable-airflow compressors 

could acceptably represent the typical 

energy use of fixed-speed compressors 

with variable-airflow controls. This 

subject was discussed in the January 

2017 Final Rule. 82 FR 1052, 1072– 

1073. At the time, it was noted that 

CAGI was doing preliminary work on 

developing a method for one of these 

control methods (variable 

displacement), but that there was not 

yet an industry consensus method for 

measuring the part-load performance of 

variable-airflow fixed-speed 

compressors. Id. at 82 FR 1073. The lack 

of an accepted test method was one of 

the reasons that DOE did not include a 

part-load package isentropic efficiency 

metric for fixed-speed variable-airflow 

compressors in the test procedure. The 

other reasons included the lack of 

historical part-load performance data for 

these compressors and the approach 

taken by CAGI and the EU Lot 31 draft 

standard. Id. DOE also acknowledged in 

the January 2017 Final Rule that partload performance information for these 

varieties of compressors can provide 

valuable information for the end user, 

and that manufacturers of fixed-speed 

compressors may continue making 

graphical or numerical representations 

of package isentropic efficiency and 

package specific power as functions of 

flow rate or rotational speed. Id. 

At the current time, DOE is not aware 

of an industry consensus method for 

measuring part-load package isentropic 

efficiency for fixed-speed variableairflow compressors, nor is DOE aware 

of this metric being used widely for this 

category of compressors. As a result, the 

concerns that existed in the January 

2017 Final Rule regarding the lack of an 

accepted industry test method still exist. 

Therefore, DOE is not including any 

measure of part-load package isentropic 

efficiency for fixed-speed variableairflow compressors in the compressors 

test procedure at this time. DOE may 

consider part-load package isentropic 

efficiency for fixed-speed variableairflow compressors as part of a future 

rulemaking process. 

E. Test Method 

1. K6 Correction Factor 

ISO 1217:2009(E) contains several 

correction factors that correct for 

variables of the environment, process 

gas, and compressor operation. The K6

correction factor in ISO 1217:2009(E) is 

labeled in section 4.1 of ISO 

1217:2009(E) as the correction factor for 


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the isentropic exponent. The DOE test 

procedure uses only a subset of the 

correction factors in ISO 1217:2009(E), 

and it does not use the K6 correction 

factor. The DOE test procedure specifies 

in sections 3.3.2.2, 3.4.3.2, 3.4.4.2, and 

3.5 of appendix A to multiply measured 

power by the K5 correction factor, which 

is labeled in section 4.1 of ISO 

1217:2009(E) as the correction factor for 

the inlet pressure, polytropic exponent, 

and pressure ratio. 

In response to the May 2022 RFI, DOE 

received comments about potentially 

needing to use the K6 correction factor 

in certain situations. CAGI, supported 

by Kaeser Compressors, commented that 

if testing is conducted at sites 

significantly above sea level, use of the 

K6 correction factor may be necessary to 

obtain accurate representative results. 

(CAGI, No. 11 at p. 2; Kaeser 

Compressors, No. 17 at p. 1) 

In the February 2023 NOPR, DOE 

explained that DOE had deliberately 

omitted the K6 correction factor during 

the January 2017 Final Rule. 82 FR 

1052, 1084; 88 FR 9199, 9206. As listed 

in the footnotes of the January 2017 

Final Rule, the isentropic exponent of 

air has some limited variability with 

atmospheric conditions, and DOE 

adopted a fixed value of 1.400 to align 

with the EU Lot 31 draft standard’s 

metric calculations. Id. As such, DOE 

did not propose to amend the current 

fixed value of 1.400 for the isentropic 

exponent in the February 2023 NOPR. 

88 FR 9199, 9206. DOE also asked for 

comment regarding its initial 

determination to continue to use a fixed 

value of 1.400 for the isentropic 

exponent, as opposed to incorporating a 

K6 correction factor. Id. 

In response to the request for 

comment, CAGI, supported by Kaeser 

Compressors, Ingersoll Rand, SaylorBeall, and Sullivan-Palatek, commented 

in support of DOE’s initial 

determination to continue to use a fixed 

value of 1.400 for the isentropic 

exponent of air. However, they added 

that to ensure results derived from 

testing at elevation are accurate, the K6

correction factor is necessary to 

incorporate both isentropic exponent 

and pressure ratio. They indicated that 

is necessary to correct the measured 

power with both the K5 and K6

correction factors in order to correct for 

inlet pressure and pressure ratio. The 

DOE test procedure directs that 

performance be normalized to a 

reference ambient inlet pressure of 100 

kPa, approximately corresponding to an 

altitude of 364 ft above sea level. CAGI 

presented a table illustrating that 

calculated results are incorrect at 

elevations greater than and less than 364 

ft if K6 is not used. (CAGI, No. 21 at pp. 

3–5; Kaeser Compressors, No. 24 at p. 6; 

Ingersoll Rand, No. 25 at p. 3; SaylorBeall, No. 22 at p. 1; Sullivan-Palatek, 

No. 23 at p. 1) The commenters also 

indicated that correcting the DOE test 

procedure to include K6 will reduce 

burdens and potential burdens for the 

industry, because currently the DOE test 

method and its correction deviates from 

the national consensus standard. They 

also stated that correcting the procedure 

will not result in a need to retest and 

recertify but will ensure that any 

verification/certification performed at 

any elevation other than 364 ft or during 

low- or high-pressure weather events 

will be correct. (CAGI, No. 21 at pp. 4– 

5; Kaeser Compressors, No. 24 at pp. 8– 

9; Ingersoll Rand, No. 25 at pp. 4–5; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) 

After reviewing CAGI’s comments and 

the content of ISO 1217:2009(E), DOE 

now understands that K6 is required to 

calculate package isentropic efficiency 

and specific power accurately in the 

DOE test procedure. Although K5 is 

labeled as ‘‘correction factor for inlet 

pressure, polytropic exponent and 

pressure ratio’’ and K6 is labeled as 

‘‘correction factor for isentropic 

exponent’’ in section 4.1 of ISO 

1217:2009(E), which appears to be 

inaccurate. K5, as determined in section 

C.4.3.2 of Annex C to ISO 1217:2009(E), 

appears to correct only for inlet 

pressure, because it is a ratio of inlet 

pressures. K6, as determined in section 

B.4.5 of Annex B to ISO 1217:2009(E), 

appears to correct for both the isentropic 

exponent and pressure ratio, because it 

contains ratios of isentropic exponents 

and pressure ratios. In the case of the 

DOE test procedure, for which a fixed 

value of 1.400 is used for the isentropic 

exponent, K6 will correct for only 

pressure ratio. For the packaged 

compressors covered by the DOE test 

procedure, both inlet pressure and 

pressure ratio change with elevation and 

weather conditions. By including the K5

correction factor but excluding the K6

correction factor, the DOE test 

procedure currently corrects for 

variations in inlet pressure but does not 

correct for variations in pressure ratio. 

By including K6 as well, the DOE test 

procedure will correct for variations in 

both inlet pressure and pressure ratio, 

thereby resulting in more accurate 

measurements of isentropic efficiency 

and specific power. 

To incorporate the K6 correction 

factor, DOE is making the following 

changes in the DOE test procedure. 

First, DOE is incorporating by reference 

section B.4.5 of ISO 1217:2009(E) into 

subpart T of 10 CFR part 431, which 

includes equations to calculate the K6

correction factor: equation B.9 for 

single-stage displacement compressors 

with or without cooling and multi-stage 

compressors without intercooling, and 

equation B.10 for multi-stage 

displacement compressors with 

intercoolers. Second, DOE is revising 

sections 3.3.2.2, 3.4.3.2, 3.4.4.2, and 3.5 

of appendix A to multiply measured 

power by both K5 and K6, instead of 

only multiplying measured power by 

K5. 

As indicated by commenters, these 

changes will make the results of the 

DOE test procedure more accurate, 

reduce burden by making the DOE test 

procedure consistent with the industry 

test method, and not require any 

retesting or recertifying. 

2. Correction of Pressure Ratio at FullLoad Operating Pressure Formula 

Section 3.6 of appendix A specifies a 

formula for pressure ratio at full-load 

operating pressure, which is used to 

classify whether a machine or apparatus 

qualifies as a compressor, as the 

definition of ‘‘compressor’’ stated in 10 

CFR 431.342 states that the machine or 

apparatus must have a pressure ratio at 

full-load operating pressure greater than 

1.3. Pressure ratio at full-load operating 

pressure does not factor directly into the 

measured values of compressor 

performance. 

In response to the May 2022 RFI, DOE 

received comments noting that there is 

an apparent error in the formula for 

pressure ratio. In the February 2023 

NOPR, DOE concurred with the 

commenters that the current formula 

contains an error, as it both does not 

match the discussion in the preamble of 

the January 2017 Final Rule and does 

not contain terms related to the 

calculation of pressure ratio at full-load 

operating pressure. 88 FR 9199, 9207. 

The current formula for pressure ratio 

at full-load operating pressure 

inadvertently duplicates a formula used 

in a calculation related to determining 

a represented value of performance for 

a compressor basic model from a tested 

sample of units. Specifically, the current 

formula of pressure ratio at full-load 

operating pressure exactly matches the 

formula for the lower 95-percent 

confidence limit (‘‘LCL’’) of the true test 

mean divided by 0.95. In the February 

2023 NOPR, DOE proposed to change 

the formula for pressure ratio at fullload operating pressure in section 3.6 of 

appendix A to rectify this error and 

reflect the proper pressure ratio at fullload operating pressure equation that 

will be utilized in the test procedure. 

The numerator of this proposed formula 

for pressure ratio incorporated full-load 


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operating pressure, determined in 

section 4.3.4 of appendix A (Pa gauge), 

while the denominator was standard 

atmospheric pressure, 100 kPa. 88 FR 

9199, 9207. 

DOE requested comment in the 

February 2023 NOPR regarding its 

proposal to correct the equation for 

pressure ratio at full-load operating 

pressure. In response, CAGI, supported 

by Kaeser Compressors, Ingersoll Rand, 

Saylor-Beall, and Sullivan-Palatek, 

commented in support of DOE’s 

proposal to correct the equation for 

pressure ratio at full-load operating 

pressure to amend a previous 

typographical error. In addition, the 

commenters noted that pressure ratio 

must always be calculated in terms of 

absolute pressure and recommended the 

addition of 100 kPa to the numerator of 

the equation to achieve this. (CAGI, No. 

21 at p. 4; Kaeser Compressors, No. 24 

at p. 7; Ingersoll Rand, No. 25 at p. 4; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) 

DOE evaluated the stakeholders’ 

recommendation to express pressure 

ratio in terms of absolute pressure and 

agrees with the proposed solution. 

‘‘Absolute pressure’’ is defined as 

pressure relative to a perfect vacuum. In 

the correction proposed in the February 

2023 NOPR, the equation for pressure 

ratio expresses pressure in terms of 

gauge pressure in the numerator and 

absolute pressure in the denominator. 

88 FR 9199, 9207. ‘‘Gauge pressure’’ is 

defined as the pressure above 

atmospheric pressure and has a different 

reference pressure compared to absolute 

pressure. For the calculated pressure 

ratio to be accurate, both the numerator 

and denominator must be expressed in 

terms of absolute pressure. 

As a result, in this test procedure final 

rule, DOE is amending the formula for 

pressure ratio at full-load operating 

pressure in section 3.6 of appendix A to 

rectify the typographical error and to 

adjust the proposed equation so that 

pressure ratio is calculated in terms of 

absolute pressure by adding 

atmospheric pressure of 100 kPa to the 

numerator. The amended calculation for 

pressure ratio at full-load operating 

pressure is shown below in equation 1: 

Where: 

PR = pressure ratio at full-load operating 

pressure; 

P1 = 100 kPa; and 

PFL = full-load operating pressure, 

determined in section 4.3.4 of appendix 

A to subpart T of part 431 (Pa gauge). 

This change has no effect on the scope 

of compressors subject to the test 

procedure and does not increase the 

associated testing burden on 

manufacturers. 

3. Tolerances for Measured Energy 

Efficiency Values 

DOE adopted the tolerances specified 

in table 1 of ISO 1217:2009(E) in the 

January 2017 Final Rule in order to 

align with ISO 1217:2009(E), as 

amended, to reduce the burden and cost 

to manufacturers. DOE stated that most 

manufacturers currently use ISO 

1217:2009(E), and with the 

modifications adopted in the January 

2017 Final Rule, the test methods 

established for compressors are 

intended to produce results equivalent 

to those produced historically under 

ISO 1217:2009(E). 82 FR 1052, 1076. In 

the February 2023 NOPR, DOE proposed 

to continue to use the tolerances for 

measured energy efficiency values 

specified in ISO 1217:2009(E) and asked 

for comment regarding this proposal. 88 

FR 9199, 9205. 

In response to the request for 

comment, CAGI, Kaeser Compressors, 

Ingersoll Rand, Saylor-Beall, and 

Sullivan-Palatek all commented in 

support of DOE’s proposal to continue 

to use the tolerances for measured 

energy efficiency values specified in 

ISO 1217:2009(E). (CAGI, No. 21 at p. 3; 

Kaeser Compressors, No. 24 at p. 5; 

Ingersoll Rand, No. 25 at p. 2; SaylorBeall, No. 22 at p. 1; Sullivan-Palatek, 

No. 23 at p. 1) CAGI stated that 

uncertainty of measurement and 

variation in performance as a result of 

variation in manufacturing needs to be 

reflected in data presented to 

consumers, and that tolerances defined 

in Annex C of ISO 1217:2019 relate only 

to the verification of the measured 

parameters by a practical test. Id. 

For the reasons discussed in the 

previous paragraphs, DOE is not 

amending the tolerances for measured 

energy efficiency values specified in 

ISO 1217:2009(E). 

F. Reporting 

Manufacturers, including importers, 

must use product-specific certification 

templates to certify compliance to DOE. 

For compressors, the certification 

template reflects the general 

certification requirements specified at 

10 CFR 429.12 and the product-specific 

requirements specified at 10 CFR 

429.63. DOE is not amending the 

product-specific certification 

requirements for these products at this 

time. 

G. Test Procedure Costs and 

Harmonization 

EPCA requires that test procedures 

established by DOE not be unduly 

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

6293(b)(3)) The following sections 

discuss DOE’s evaluation of estimated 

costs associated with the amendments 

included in this final rule. 

In this final rule, DOE is amending 

the test procedure for compressors by: 

(1) correcting the formula for calculating 

isentropic efficiency and specific energy 

consumption of the packaged 

compressor to the specified pressure 

ratio by incorporating a K6 correction 

factor, (2) updating the formula for 

pressure ratio at full-load operating 

pressure currently presented in 

appendix A to rectify a previous error, 

and (3) modifying the current definition 

of ‘‘air compressor’’ to clarify that 

compressors with more than one 

compression element are still within the 

scope of this test procedure, and to 

revise the typographical error of 

‘‘compressor element’’ to ‘‘compression 

element.’’ 

1. Amendment To Incorporate K6 

Correction Factor 

In the February 2023 NOPR, DOE 

issued a request for comment on the 

benefits and burdens of the proposed 

updates to the test procedure for 

compressors. 88 FR 9199, 9210. In 

response to DOE’s request for comment, 

regarding DOE’s amendment to include 

a K6 correction factor, DOE received 

comments from CAGI, supported by 

Kaeser Compressors, Ingersoll Rand, 

Saylor-Beall, and Sullivan-Palatek, 

stating that this correction will reduce 

potential burdens for the industry. 

These commenters commented that, 


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currently, the DOE test method and its 

correction deviate from the national 

consensus standard. These commenters 

believe this deviation was not 

intentional, as it provides no benefit and 

reduces test accuracy. These 

commenters further stated that the error 

and deviation are more significant the 

farther the elevation is from 364 ft. 

These commenters also stated that error 

can occur during atmospheric weather 

events leading to extreme low or high 

pressure, and that testing that is not 

performed at the exact rated full-load 

operating pressure is incorrectly 

converted to efficiency and specific 

power in the current DOE test 

procedure. CAGI elaborated that 100 

kPa represents the mean ambient 

pressure at 111 m (364 ft), and that if lab 

elevation differs significantly from this 

level, measurements deriving efficiency 

will deviate when using the DOE test 

method. CAGI stated that, using the 

industry standard correction, the 

efficiency as measured (with no 

corrections) is the same exact value as 

applying K5 and K6 factors to correct 

specific power consumption and 

deriving isentropic efficiency at the 

conclusion (as presented in Annex C 

and Annex H of ISO 1217:2009). CAGI 

concluded that correcting the test 

procedure using their recommendations 

will not result in a need to retest and 

recertify, but will ensure that any 

verification/certification performed at 

any elevation other than 364 ft or during 

low- or high-pressure events will be 

correct. (CAGI, No. 21 at pp. 5–6; Kaeser 

Compressors, No. 24 at pp. 8–9; 

Ingersoll Rand, No. 25 at pp. 4–5; 

Saylor-Beall, No. 22 at p. 1; SullivanPalatek, No. 23 at p. 1) 

DOE agrees with the stakeholder 

comments that the incorporation of the 

K6 correction factor will not add any test 

burden or associated costs and will only 

increase the accuracy of efficiency 

representations in this test procedure. 

DOE has also determined that this 

amendment will not require retesting or 

recertification solely as a result of DOE’s 

adoption of the amendment to the test 

procedures, since the amendment aligns 

the test procedure with existing 

industry practice. Current industry 

practice is to use the K6 correction factor 

to correct for error introduced by nonstandard ambient pressures when 

testing at elevations above or below 364 

ft. As such, although the newly 

incorporated correction factor would 

alter the final efficiency output of the 

DOE test procedure for compressors 

tested at non-standard ambient 

pressures as compared to the incorrect 

calculation in the current test 

procedure, this correction will not result 

in a need for manufacturers to retest or 

to update the isentropic efficiency 

ratings of their compressors because the 

industry already uses the appropriate 

correction factor consistent with the 

existing industry test procedure. This 

amendment serves to harmonize the 

DOE test procedure with the existing 

industry practice for testing compressor 

efficiency. 

DOE does not anticipate any added 

test burden or associated costs from the 

amendment incorporating the K6

correction factor, as: (1) the test method 

follows accepted industry practice, and 

(2) representations of compressor 

efficiency would not need to be 

updated, since the amendment DOE is 

adopting in this final rule will align 

DOE’s test procedure with current 

industry testing practice, making it so 

manufacturers do not need to retest 

their models. As any representations are 

voluntary prior to the compliance date 

of any energy conservation standards for 

compressors, there is no direct burden 

associated with any of the testing 

requirements adopted in this final rule. 

2. Amendment To Update Formula for 

Pressure Ratio at Full-Load Operating 

Pressure 

The amendment regarding updating 

the formula for pressure ratio at fullload operating pressure will not impact 

the representations of compressor 

energy efficiency/energy use. The 

definition of a compressor is ‘‘a machine 

or apparatus that converts different 

types of energy into the potential energy 

of gas pressure for displacement and 

compression of gaseous media to any 

higher-pressure values above 

atmospheric pressure and has a pressure 

ratio at full-load operating pressure 

greater than 1.3,’’ as stated in 10 CFR 

431.342. In the test procedure for 

compressors, the calculation of pressure 

ratio at full-load operating pressure is 

only used to determine if a compressor 

meets the statutory definition of 

‘‘compressor’’ by ensuring that the 

pressure ratio at full-load operating 

pressure is greater than 1.3. As such, 

this amendment does not impact 

representations of energy efficiency/ 

energy use, and DOE does not anticipate 

any added test burden or associated 

costs for manufacturers stemming from 

this correction to the compressors test 

procedure. 

3. Amendment To Update Definition of 

‘‘Air Compressor’’ 

DOE does not anticipate any added 

test burden or associated costs from the 

amendment updating the definition of 

‘‘air compressor.’’ This amendment 

serves to clarify that compressors with 

more than one compression element are 

still within the scope of this test 

procedure, and to revise the 

typographical error of ‘‘compressor 

element’’ to ‘‘compression elements.’’ 

As such, DOE does not anticipate any 

added test burden or associated costs for 

compressor manufacturers due to this 

amendment. 

4. Harmonization With Industry 

Standards 

DOE’s established practice is to adopt 

relevant industry standards as DOE test 

procedures, unless such methodology 

would be unduly burdensome to 

conduct or would not produce test 

results that reflect the energy efficiency, 

energy use, water use (as specified in 

EPCA), or estimated operating costs of 

that product during a representative 

average use cycle. 10 CFR 431.4; section 

8(c) of appendix A of 10 CFR part 430 

subpart C. In cases where the industry 

standard does not meet EPCA statutory 

criteria for test procedures, DOE will 

make modifications through the 

rulemaking process to these standards 

as the DOE test procedure. 

The test procedure for compressors at 

appendix A is based on, and 

incorporates by reference, much of ISO 

1217:2009(E), ‘‘Displacement 

compressors—Acceptance tests,’’ as 

amended through Amendment 1:2016. 

In this final rule, DOE will incorporate 

by reference section B.4.5 of Annex B of 

ISO 1217:2009(E) via amendment. The 

industry standards DOE has 

incorporated by reference for the test 

procedure for compressors are located 

in 10 CFR 431.343. 

H. Effective and Compliance Dates 

The effective date for the adopted test 

procedure amendment will be 75 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. 

6314(d)(1)) EPCA provides an allowance 

for individual manufacturers to petition 

DOE for an extension of the 180-day 

period if the manufacturer may 

experience undue hardship in meeting 

the deadline. (42 U.S.C. 6314(d)(2)) To 

receive such an extension, petitions 

must be filed with DOE no later than 60 

days before the end of the 180-day 

period and must detail how the 

manufacturer will experience undue 

hardship. (Id.) 


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I. Renumbering of Appendix A 

Currently, appendix A is organized 

using a hierarchy that uses Roman 

numerals (i.e., ‘‘I, II, III, IV . . .’’) for 

first-level headings, Latin capital letters 

for second-level headings (i.e., ‘‘A, B, C, 

D . . .’’), and Arabic numerals (i.e., 1, 2, 

3 . . .’’) for third-level headings. 

In this final rule, DOE is revising the 

numbering hierarchy of appendix A to 

use only Arabic numerals, consistent 

with the numbering hierarchy that DOE 

uses across test procedures for 

consumer products at 10 CFR part 430, 

subpart B and for commercial and 

industrial equipment generally at 10 

CFR part 431. For example, the current 

heading ‘‘I.B.2’’ of appendix A is 

renumbered to ‘‘2.2.2’’ (also reflecting 

the addition of a new section at the 

beginning of appendix A). This 

renumbering is for consistency purposes 

only and does not result in any 

substantive changes solely as a result of 

the renumbering. 

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 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. 

For manufacturers of compressors, the 

Small Business Administration (‘‘SBA’’) 

has set a size threshold, which defines 

those entities classified as ‘‘small 

businesses’’ for the purposes of the 

statute. DOE used the SBA’s small 

business size standards to determine 

whether any small entities would be 

subject to the requirements of the rule. 

13 CFR part 121. The size standards are 

listed by North American Industry 

Classification System (‘‘NAICS’’) code 

and industry description and are 

available at www.sba.gov/document/ 

support-table-size-standards. 

Compressor manufacturing is classified 

under NAICS 333912, ‘‘air and gas 

compressor manufacturing.’’ The SBA 

sets a threshold of 1,000 employees or 

less for an entity to be considered a 

small business in this category. This 

employment figure is enterprise-wide, 

encompassing employees at all parent, 

subsidiary, and sister corporations. 

To identify and estimate the number 

of small business manufacturers of 

equipment within the scope of this 

rulemaking, DOE conducted a market 

survey using available public 

information. DOE’s research involved 

industry trade association membership 

directories (including CAGI), individual 

company and online retailer websites, 

and market research tools (e.g., Hoovers 

reports) to create a list of companies that 

manufacture equipment covered by this 

rulemaking. DOE additionally reviewed 

publicly available data, data available 

through market research tools, and 

contacted select companies on its list, as 

necessary, to determine whether they 

met the SBA’s definition of a small 

business manufacturer. DOE screened 

out companies that do not offer 

equipment within the scope of this 

rulemaking, do not meet the definition 

of a ‘‘small business,’’ or are foreign 

owned and operated. 

DOE identified a total of 12 domestic 

small businesses manufacturing 

compressors. However, as previously 

stated, the amendments adopted in this 

final rule revise certain definitions and 

formulas to ensure the clarity and 

accuracy of existing requirements and 

procedures, and the amendments 

harmonize the DOE test procedure with 

existing industry practices, without 

requiring manufacturers to retest their 

compressors. DOE has determined that 

the adopted test procedure amendments 

would not impact testing costs 

otherwise experienced by 

manufacturers. 

Therefore, DOE concludes that the 

cost effects accruing from the final rule 

would not have a ‘‘significant economic 

impact on a substantial number of small 

entities,’’ and that the preparation of a 

FRFA is not warranted. DOE has 

submitted 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 compressors must 

certify to DOE that their products 

comply with any applicable energy 

conservation standards. To certify 

compliance, manufacturers must first 


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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 compressors. (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 

compressors in this final rule. Instead, 

DOE may consider proposals to amend 

the certification requirements and 

reporting for compressors 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 

compressors. 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 (Feb. 7, 1996), 

imposes on Federal agencies the general 

duty to adhere to the following 

requirements: (1) eliminate drafting 

errors and ambiguity; (2) write 

regulations to minimize litigation; (3) 

provide a clear legal standard for 

affected conduct rather than a general 

standard; and (4) promote simplification 

and burden reduction. Section 3(b) of 

Executive Order 12988 specifically 

requires that Executive agencies make 

every reasonable effort to ensure that the 

regulation (1) clearly specifies the 

preemptive effect, if any; (2) clearly 

specifies any effect on existing Federal 

law or regulation; (3) provides a clear 

legal standard for affected conduct 

while promoting simplification and 

burden reduction; (4) specifies the 

retroactive effect, if any; (5) adequately 

defines key terms; and (6) addresses 

other important issues affecting clarity 

and general draftsmanship under any 

guidelines issued by the Attorney 

General. Section 3(c) of Executive Order 

12988 requires Executive agencies to 

review regulations in light of applicable 

standards in sections 3(a) and 3(b) to 

determine whether they are met or it is 

unreasonable to meet one or more of 

them. DOE has completed the required 

review and determined that, to the 

extent permitted by law, 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 


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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 proposed 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 

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 compressors adopted in 

this final rule incorporate testing 

methods contained in certain sections of 

the following commercial standards: 

ISO 1217:2009(E), as amended through 

ISO 1217:2009(E)/Amd.1:2016. While 

this test procedure is not exclusively 

based on this industry testing standard, 

some components of the DOE test 

procedure adopt definitions, test 

parameters, measurement techniques, 

and additional calculations from them 

without amendment. DOE has evaluated 

these standards and is unable to 

conclude whether it fully complies with 

the requirements of section 32(b) of the 

FEAA (i.e., whether it was developed in 

a manner that fully provides for public 

participation, comment, and review.) In 

the January 2017 Final Rule, DOE 

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 received no comments 

objecting to their use. 82 FR 1052, 1099. 

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 

The following standards have not 

previously been approved for 

incorporation by reference in subpart T, 

appendix A, but are incorporated by 

reference in this final rule on the basis 

that they are referenced by other 

standards which had been previously 

and remain incorporated by reference in 

subpart T, appendix A. 

ISO 1217:2009(E), ‘‘Displacement 

compressors—Acceptance tests,’’ fourth 

edition, July 1, 2009. ISO 1217:2009(E) 

specifies methods for acceptance tests 

regarding volume rate of flow and 

power requirements of displacement 

compressors. It also specifies methods 

for testing liquid-ring type compressors 

and the operating and testing conditions 

which apply when a full performance 

test is specified. 

ISO 1217:2009/Amd.1:2016(E), 

Displacement compressors—Acceptance 

tests (fourth edition, July 1, 2009), 

AMENDMENT 1: Calculation of 

isentropic efficiency and relationship 

with specific energy, April 15, 2016. 

ISO 1217:2009/Amd.1.:2016(E) provides 

a method for the calculation of 

isentropic efficiency and relationship 

with specific energy. 

ISO 5167–1:2022(E), Measurement of 

fluid flow by means of pressure 

differential devices inserted in circular 

cross-section conduits running full— 

Part 1: General principles and 


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requirements, third edition, June 2022. 

ISO 5167–1:2022(E) defines terms and 

symbols and establishes the general 

principles for methods of measurement 

and computation of the flow rate of 

fluid flowing in a conduit by means of 

pressure differential devices (orifice 

plates, nozzles, Venturi tubes, cone 

meters, and wedge meters) when they 

are inserted into a circular cross-section 

conduit running full. The standard also 

specifies the general requirements for 

methods of measurement, installation 

and determination of the uncertainty of 

the measurement of flow rate. 

ISO 9300:2022(E), Measurement of gas 

flow by means of critical flow nozzles, 

third editions, June 2022. ISO 

9300:2022(E) specifies the geometry and 

method of use (installation in a system 

and operating conditions) of critical 

flow nozzles used to determine the mass 

flow rate of a gas flowing through a 

system basically without the need to 

calibrate the critical flow nozzle. It also 

gives the information necessary for 

calculating the flow rate and its 

associated uncertainty. 

IEC 60584–1:2013, Thermocouples— 

Part 1: EMF specifications and 

tolerances, edition 3.0, August 2013. IEC 

60584–1:2013 specifies reference 

functions and tolerances for letterdesignated thermocouples. 

IEC 60584–3:2021, Thermocouples— 

Part 3: Extension and compensating 

cables—Tolerances and identification 

system, edition 3.0, February 2021. IEC 

60584–3:2021 provides tolerances and 

an identification system necessary for 

the measurement of thermocouple 

circuits. 

In this final rule, DOE includes 

revisions to the regulatory text that 

contained references to section B.4.5 of 

Annex B of ISO 1217:2009(E), which 

was not specifically incorporated by 

reference before this test procedure final 

rule. 

See SUPPLEMENTARY INFORMATION

section of this document for availability 

information of this material. 

V. Approval of the Office of the 

Secretary 

The Secretary of Energy has approved 

publication of this final rule. 

List of Subjects in 10 CFR Part 431 

Administrative practice and 

procedure, Confidential business 

information, Energy conservation test 

procedures, Incorporation by reference, 

Reporting and recordkeeping 

requirements. 

Signing Authority 

This document of the Department of 

Energy was signed on January 10, 2025, 

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 January 13, 

2025. 

Treena V. Garrett, 

Federal Register Liaison Officer, U.S. 

Department of Energy. 

For the reasons stated in the 

preamble, DOE amends part 431 of 

chapter II of title 10 of the Code of 

Federal Regulations as set forth below: 

PART 431—ENERGY EFFICIENCY 

PROGRAM FOR CERTAIN 

COMMERCIAL AND INDUSTRIAL 

EQUIPMENT 

■ 1. The authority citation for part 431 

continues to read as follows: 

Authority: 42 U.S.C. 6291–6317; 28 U.S.C. 

2461 note. 

■ 2. Amend § 431.342 by revising the 

definition of ‘‘Air compressor’’ to read 

as follows: 

§ 431.342 Definitions concerning 

compressors. 

* * * * * 

Air compressor means a compressor 

designed to compress air that has an 

inlet open to the atmosphere or other 

source of air, and is made up of one or 

more compression elements (bare 

compressors), driver(s), mechanical 

equipment to drive the compression 

elements, and any ancillary equipment. 

* * * * * 

■ 3. Revise § 431.343 to read as follows: 

§ 431.343 Materials incorporated by 

reference. 

(a) Certain material is incorporated by 

reference into this subpart with the 

approval of the Director of the Federal 

Register in accordance with 5 U.S.C. 

552(a) and 1 CFR part 51. To enforce 

any edition other than that specified in 

this section, the 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 DOE and at the National 

Archives and Records Administration 

(NARA). Contact DOE at: the U.S. 

Department of Energy, Office of Energy 

Efficiency and Renewable Energy, 

Building Technologies Program, 1000 

Independence Avenue SW, EE–5B, 

Washington, DC 20024, (202) 586–9127, 

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

eere/buildings/building-technologiesoffice. For information on the 

availability of this material at NARA, 

visit www.archives.gov/federal-register/ 

cfr/ibr-locations.html or email: 

fr.inspection@nara.gov. The material 

may be obtained from the sources in 

paragraphs (b) and (c) of this section: 

(b) IEC. International Electrotechnical 

Commission Central Office, 3, rue de 

Varembe ́, Case Postale 131, CH–1211 

GENEVA 20, Switzerland; + 41 22 919 

02 11; webstore.iec.ch. 

(1) IEC 60584–1:2013, 

Thermocouples—Part 1: EMF 

specifications and tolerances, editions 

3.0, August 2013; IBR approved for 

appendix A to this subpart. 

(2) IEC 60584–3:2021, 

Thermocouples—Part 3: Extension and 

compensating cables—Tolerances and 

identification system, edition 3.0, 

February 2021; IBR approved for 

appendix A to this subpart. 

(c) ISO. International Organization for 

Standardization, Chemin de Blandonnet 

8, CP 401, 1214 Vernier, Geneva, 

Switzerland +41 22 749 01 11, 

www.iso.org. 

(1) ISO 1217:2009(E), Displacement 

compressors—Acceptance tests, fourth 

edition, July 1, 2009; IBR approved for 

appendix A to this subpart. 

(2) ISO 1217:2009/Amd.1:2016(E), 

Displacement compressors—Acceptance 

tests (fourth edition, July 1, 2009), 

AMENDMENT 1: Calculation of 

isentropic efficiency and relationship 

with specific energy, April 15, 2016; IBR 

approved for appendix A to this 

subpart. 

(3) ISO 5167–1:2022(E), Measurement 

of fluid flow by means of pressure 

differential devices inserted in circular 

cross-section conduits running full— 

Part 1: General principles and 

requirements, third edition, June 2022; 

IBR approved for appendix A to this 

subpart. 

(4) ISO 9300:2022(E), Measurement of 

gas flow by means of critical flow 

nozzles, third edition, June 2022; IBR 

approved for appendix A to this 

subpart. 

■ 4. Revise appendix A to subpart T to 

read as follows: 


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Appendix A to Subpart T of Part 431— 

Uniform Test Method for Certain Air 

Compressors. 

Note: Prior to July 16, 2025, any 

representations made with respect to the 

energy use or efficiency of compressors must 

be based on testing conducted in accordance 

with: 

(a) The applicable provisions of this 

appendix as they appeared in this subpart T 

of part 431 as of January 1, 2023; or 

(b) This appendix. 

Beginning July 16, 2025, representations 

with respect to energy use or efficiency of 

compressors, including compliance 

certifications, must be based on testing 

conducted in accordance with this appendix. 

1. Incorporation by Reference 

DOE incorporated by reference in 

§ 431.343, the entire standard for: IEC 60584– 

1:2013, IEC 60584–3:2021, ISO 1217:2009(E), 

ISO 1217:2009/Amd.1:2016(E), ISO 5167– 

1:2022, and ISO 9300:2022; however, only 

enumerated provisions of ISO 1217:2009(E) 

and ISO 1217:2009/Amd.1:2016(E) are 

applicable to this appendix as listed in 

section 1. 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 ISO 1217:2009(E) 

1.1.1 Section 2, Normative references; 

1.1.2 Section 3, Terms and definitions; 

1.1.3 Section 4, Symbols; 

1.1.4 Section 5, Measuring equipment, 

methods and accuracy (excluding 5.1, 5.5, 

5.7, and 5.8); 

1.1.5 Section 6, Test procedures: the 

introductory text to Section 6.2, Test 

arrangements, paragraphs 6.2(g) and 6.2(h), 

and Table 1—Maximum deviations from 

specified values and fluctuations from 

average readings of this appendix; 

1.1.6 Annex B (normative), Simplified 

acceptance test for bare displacement 

compressors, Section B.4.5 Comparison with 

specified values; 

1.1.7 Annex C (normative), Simplified 

acceptance test for electrically driven 

packaged displacement compressors 

(excluding C.1.2, C.2.1, C.3, C.4.2.2, C.4.3.1, 

and C.4.5). 

1.2 ISO 1217:2009/Amd.1:2016(E) 

1.2.1 Section 3.5.1: isentropic power; 

1.2.2 Section 3.6.1: isentropic efficiency; 

1.2.3 Annex H (informative), Isentropic 

efficiency and its relation to specific energy 

requirement, sections H.2, Symbols and 

subscripts, and H.3, Derivation of isentropic 

power. 

2. Measurements, Test Conditions, and 

Equipment Configuration 

2.1. Measurement Equipment. 

2.1.1. For the purposes of measuring air 

compressor performance, the equipment 

necessary to measure volume flow rate, inlet 

and discharge pressure, temperature, 

condensate, and packaged compressor power 

input must comply with the equipment and 

accuracy requirements specified in sections 

5.2, 5.3, 5.4, 5.6, and 5.9 of ISO 1217:2009(E), 

(including the applicable provisions of IEC 

60584–1 and IEC 60584–3, as referenced in 

section 5.3 of ISO 1217:2009(E) and the 

applicable provisions of ISO 5167–1 and ISO 

9300, as referenced in section 5.6 of ISO 

1217:2009(E)) and sections C.2.3 and C.2.4 of 

Annex C to ISO 1217:2009(E). 

2.1.2. Electrical measurement equipment 

must be capable of measuring true root mean 

square (RMS) current, true RMS voltage, and 

real power up to the 40th harmonic of 

fundamental supply source frequency. 

2.1.3. Any instruments used to measure a 

particular parameter specified in section 

2.1.1 of this appendix must have a combined 

accuracy of ±2.0 percent of the measured 

value at the fundamental supply source 

frequency, where combined accuracy is the 

square root of the sum of the squares of 

individual instrument accuracies. 

2.1.4. Any instruments used to directly 

measure the density of air must have an 

accuracy of ±1.0 percent of the measured 

value. 

2.1.5. Any pressure measurement 

equipment used in a calculation of another 

variable (e.g.,actual volume flow rate) must 

also meet all accuracy and measurement 

requirements of section 5.2 of ISO 

1217:2009(E). 

2.1.6. Any temperature measurement 

equipment used in a calculation of another 

variable (e.g.,actual volume flow rate) must 

also meet all accuracy and measurement 

requirements of section 5.3 of ISO 

1217:2009(E). 

2.1.7. Where ISO 1217:2009(E) refers to 

‘‘corrected volume flow rate,’’ the term is 

deemed synonymous with the term ‘‘actual 

volume flow rate,’’ as defined in section 3.4.1 

of ISO 1217:2009(E). 

2.2. Test Conditions and Configuration of 

Unit Under Test 

2.2.1. For both fixed-speed and variablespeed compressors, conduct testing in 

accordance with the test conditions, unit 

configuration, and specifications of section 

6.2 paragraphs (g) and (h) of ISO 

1217:2009(E) and sections C.1.1, C.2.2, C.2.3, 

C.2.4, C.4.1, C.4.2.1, C.4.2.3, and C.4.3.2 of 

Annex C to ISO 1217:2009(E). 

2.2.2. The power supply must: 

(a) Maintain the voltage greater than or 

equal to 95 percent and less than or equal to 

110 percent of the rated value of the motor, 

(b) Maintain the frequency within ±5 

percent of the rated value of the motor, 

(c) Maintain the voltage unbalance of the 

power supply within ±3 percent of the rated 

values of the motor, and 

(d) Maintain total harmonic distortion 

below 12 percent throughout the test. 

2.2.3. Ambient Conditions. The ambient air 

temperature must be greater than or equal to 

68 °F and less than or equal to 90 °F for the 

duration of testing. There are no ambient 

condition requirements for inlet pressure or 

relative humidity. 

2.2.4. All equipment indicated in table 1 of 

this appendix must be present and installed 

for all tests specified in this appendix. If the 

compressor is distributed in commerce 

without an item from table 1 of this 

appendix, the manufacturer must provide an 

appropriate item to be installed for the test. 

Additional ancillary equipment may be 

installed for the test, if distributed in 

commerce with the compressor, but this 

additional ancillary equipment is not 

required. If any of the equipment listed in 

table 2 of this appendix is distributed in 

commerce with units of the compressor basic 

model, it must be present and installed for 

all tests specified in this appendix. 

TABLE 1—EQUIPMENT REQUIRED DURING TEST

Equipment Fixed-speed rotary air compressors 

Variable-speed 

rotary air compressors 

Driver ................................................................................................................... Yes .......................................... Yes. 

Bare compressors ................................................................................................ Yes .......................................... Yes. 

Inlet filter .............................................................................................................. Yes .......................................... Yes. 

Inlet valve ............................................................................................................. Yes .......................................... Yes. 

Minimum pressure check valve/backflow check valve ........................................ Yes .......................................... Yes. 

Lubricant separator .............................................................................................. Yes .......................................... Yes. 

Air piping .............................................................................................................. Yes .......................................... Yes. 

Lubricant piping ................................................................................................... Yes .......................................... Yes. 

Lubricant filter ...................................................................................................... Yes .......................................... Yes. 

Lubricant cooler ................................................................................................... Yes .......................................... Yes. 

Thermostatic valve ............................................................................................... Yes .......................................... Yes. 

Electrical switchgear or frequency converter for the driver ................................. Yes .......................................... Not applicable.* 

Device to control the speed of the driver (e.g., variable speed drive) ................ Not applicable ** ...................... Yes. 

Compressed air cooler(s) .................................................................................... Yes .......................................... Yes. 

Pressure switch, pressure transducer, or similar pressure control device ......... Yes .......................................... Yes. 


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TABLE 1—EQUIPMENT REQUIRED DURING TEST—Continued 

Equipment Fixed-speed rotary air compressors 

Variable-speed 

rotary air compressors 

Moisture separator and drain .............................................................................. Yes .......................................... Yes. 

* This category is not applicable to variable-speed rotary air compressors. 

** This category is not applicable to fixed-speed rotary air compressors. 

TABLE 2—EQUIPMENT REQUIRED DURING TEST, IF DISTRIBUTED IN COMMERCE WITH THE BASIC MODEL

Equipment Fixed-speed rotary air compressors 

Variable-speed rotary air compressors 

Cooling fan(s) and motors ................................................................................... Yes .......................................... Yes. 

Mechanical equipment ......................................................................................... Yes .......................................... Yes. 

Lubricant pump .................................................................................................... Yes .......................................... Yes. 

Interstage cooler .................................................................................................. Yes .......................................... Yes. 

Electronic or electrical controls and user interface ............................................. Yes .......................................... Yes. 

All protective and safety devices ......................................................................... Yes .......................................... Yes. 

2.2.5. The inlet of the compressor under 

test must be open to the atmosphere and take 

in ambient air for all tests specified in this 

appendix. 

2.2.6. The compressor under test must be 

set up according to all manufacturer 

instructions for normal operation (e.g., verify 

lubricant level, connect all loose electrical 

connections, close off bottom of unit to floor, 

cover forklift holes). 

2.2.7. The piping connected to the 

discharge orifice of the compressor must be 

of a diameter at least equal to that of the 

compressor discharge orifice to which it is 

connected. The piping must be straight with 

a length of at least 6 inches. 

2.2.8. Transducers used to record 

compressor discharge pressure must be 

located on the discharge piping between 2 

inches and 6 inches, inclusive, from the 

discharge orifice of the compressor. The 

pressure tap for transducers must be located 

at the highest point of the pipe’s cross 

section. 

3. Determination of Package Isentropic 

Efficiency, Package Specific Power, and 

Pressure Ratio at Full-Load Operating 

Pressure 

3.1 Data Collection and Analysis. 

3.1.1. Stabilization. Record data at each 

load point under steady-state conditions. 

Steady-state conditions are achieved when a 

set of two consecutive readings taken at least 

10 seconds apart and no more than 60 

seconds apart are within the maximum 

permissible fluctuation from the average (of 

the two consecutive readings), as specified in 

table 1 of ISO 1217:2009(E) for— 

(a) Discharge pressure; 

(b) Temperature at the nozzle or orifice 

plate, measured per section 5.3 of ISO 

1217:2009(E); and 

(c) Differential pressure over the nozzle or 

orifice plate, measured per section 5.2 of ISO 

1217:2009(E). 

3.1.2. Data Sampling and Frequency. At 

each load point, record a minimum set of 16 

unique readings, collected over a minimum 

time of 15 minutes. Each consecutive reading 

must be no more than 60 seconds apart, and 

not less than 10 seconds apart. All readings 

at each load point must be within the 

maximum permissible fluctuation from 

average specified in table 1 of ISO 

1217:2009(E) for— 

(a) Discharge pressure; 

(b) Temperature at the nozzle or orifice 

plate, measured per section 5.3 of ISO 

1217:2009(E); and 

(c) Differential pressure over the nozzle or 

orifice plate, measured per section 5.2 of ISO 

1217:2009(E). 

If one or more readings do not meet the 

requirements, then all previous readings 

must be disregarded and a new set of at least 

16 new unique readings must be collected 

over a minimum time of 15 minutes. Average 

the readings to determine the value of each 

parameter to be used in subsequent 

calculations. 

3.1.3. Calculations and Rounding. Perform 

all calculations using raw measured values. 

Round the final result for package isentropic 

efficiency to the thousandth (i.e., 0.001), for 

package specific power in kilowatts per 100 

cubic feet per minute to the nearest 

hundredth (i.e., 0.01), for pressure ratio at 

full-load operating pressure to the nearest 

tenth (i.e., 0.1), for full-load actual volume 

flow rate in cubic feet per minute to the 

nearest tenth (i.e., 0.1), and for full-load 

operating pressure in pounds per square inch 

gauge (psig) to the nearest integer (i.e., 1). All 

terms and quantities refer to values 

determined in accordance with the 

procedures set forth in this appendix for the 

tested unit. 

3.2. Full-Load Operating Pressure and FullLoad Actual Volume Flow Rate 

Determine the full-load operating pressure 

and full-load actual volume flow rate 

(referenced throughout this appendix) in 

accordance with the procedures prescribed in 

section 4 of this appendix. 

3.3. Full-Load Package Isentropic Efficiency 

for Fixed- and Variable-Speed Air 

Compressors 

Use this test method to test fixed-speed air 

compressors and variable-speed air 

compressors. 

3.3.1. Test unit at full-load operating 

pressure and full-load volume flow rate 

according to the requirements established in 

sections 2, 3.1, and 3.2 of this appendix. 

Measure volume flow rate and calculate 

actual volume flow rate in accordance with 

section C.4.2.1 of Annex C to ISO 

1217:2009(E) with no corrections made for 

shaft speed. Measure discharge gauge 

pressure and packaged compressor power 

input. Measured discharge gauge pressure 

and calculated actual volume flow rate must 

be within the deviation limits for discharge 

pressure and volume flow rate specified in 

tables C.1 and C.2 of Annex C to ISO 

1217:2009(E), where full-load operating 

pressure and full-load actual volume flow 

rate (as determined in section 4 of this 

appendix) are the targeted values. 

3.3.2. Calculate the package isentropic 

efficiency at full-load operating pressure and 

full-load actual volume flow rate (full-load 

package isentropic efficiency, hisen,FL) using 

the equation for isentropic efficiency in 

section 3.6.1 of ISO 1217:2009(E) as modified 

by ISO 1217:2009/Amd.1:2016(E). For Pisen,

use the isentropic power required for 

compression at full-load operating pressure 

and full-load actual volume flow rate, as 

determined in section 3.3.2.1 of this 

appendix. For Preal, use the real packaged 

compressor power input at full-load 

operating pressure and full-load actual 

volume flow rate, as determined in section 

3.3.2.2 of this appendix. 

3.3.2.1. Calculate the isentropic power 

required for compression at full-load 

operating pressure and full-load actual 

volume flow rate using equation (H.6) of 

Annex H to ISO 1217:2009/Amd.1:2016(E). 

For qV1, use the actual volume flow rate 

(cubic meters per second) calculated in 

section 3.3.1 of this appendix. For p1, use 100 

kPa. For p2, use the sum of 

(a) 100 kPa, and 

(b) The measured discharge gauge pressure 

(Pa) from section 3.3.1 of this appendix. For 

K, use the isentropic exponent (ratio of 

specific heats) of air, which, for the purposes 

of this test procedure, is 1.400. 

3.3.2.2. Calculate real packaged compressor 

power input at full-load operating pressure 

and full-load actual volume flow rate using 

the following equation: 

Preal,100≠ = K5 · K6 · PPR,100%

Where: 


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K5 = correction factor for inlet pressure, as 

determined in section C.4.3.2 of Annex C to 

ISO 1217:2009(E). For calculations of this 

variable use a value of 100 kPa for 

contractual inlet pressure; 

K6 = correction factor for pressure ratio, as 

determined in section B.4.5 of Annex B to 

ISO 1217:2009(E). For calculations of this 

variable use a value of 1.400 for isentropic 

exponent, and for contractual pressure ratio, 

use the ratio of (a) The sum of 100 kPa and 

the measured discharge gauge pressure (kPa) 

from section 3.3.1 of this appendix, to 

(b) 100 kPa; and 

PPR,100% = packaged compressor power input 

reading at full-load operating pressure 

and full-load actual volume flow rate 

measured in section 3.3.1 of this 

appendix (W). 

3.4. Part-Load Package Isentropic 

Efficiency for Variable-Speed Air 

Compressors 

Use this test method to test variablespeed air compressors. 

3.4.1. Test unit at two load points: 

(a) Full-load operating pressure and 

70 percent of full-load actual volume 

flow rate and 

(b) Full-load operating pressure and 

40 percent of full-load actual volume 

flow rate, according to the requirements 

established in sections 2, 3.1, and 3.2 of 

this appendix. To reach each specified 

load point, adjust the speed of the driver 

and the backpressure of the system. For 

each load point, measure volume flow 

rate and calculate actual volume flow 

rate in accordance with section C.4.2.1 

of Annex C to ISO 1217:2009(E), with 

no corrections made for shaft speed. For 

each load point, measure discharge 

gauge pressure and packaged 

compressor power input. Measured 

discharge gauge pressure and calculated 

actual volume flow rate must be within 

the deviation limits for discharge 

pressure and volume flow rate specified 

in tables C.1 and C.2 of Annex C to ISO 

1217:2009(E). 

3.4.2. For variable-speed compressors, 

calculate the part-load package 

isentropic efficiency using the following 

equation: 

hisen,PL = w40% × hisen,40% + w70% × hisen,70%

+ w100% × hisen,100%

Where: 

hisen,PL = part-load package isentropic 

efficiency for a variable-speed 

compressor; 

hisen,100% = package isentropic efficiency at 

full-load operating pressure and 100 

percent of full-load actual volume flow 

rate, as determined in section 3.3.2 of 

this appendix; 

hisen,70% = package isentropic efficiency at 

full-load operating pressure and 70 

percent of full-load actual volume flow 

rate, as determined in section 3.4.3 of 

this appendix; 

hisen,40% = package isentropic efficiency at 

full-load operating pressure and 40 

percent of full-load actual volume flow 

rate, as determined in section 3.4.4 of 

this appendix; 

w40% = weighting at 40 percent of full-load 

actual volume flow rate and is 0.25; 

w70% = weighting at 70 percent of full-load 

actual volume flow rate and is 0.50; and 

w100% = weighting at 100 percent of full-load 

actual volume flow rate and is 0.25. 

3.4.3. Calculate package isentropic 

efficiency at full-load operating pressure 

and 70 percent of full-load actual 

volume flow rate using the equation for 

isentropic efficiency in section 3.6.1 of 

ISO 1217:2009(E) as modified by ISO 

1217:2009/Amd.1:2016(E). For Pisen, use 

the isentropic power required for 

compression at full-load operating 

pressure and 70 percent of full-load 

actual volume flow rate, as determined 

in section 3.4.3.1 of this appendix. For 

Preal, use the real packaged compressor 

power input at full-load operating 

pressure and 70 percent of full-load 

actual volume flow rate, as determined 

in section 3.4.3.2 of this appendix. 

3.4.3.1. Calculate the isentropic power 

required for compression at full-load 

operating pressure and 70 percent of 

full-load actual volume flow rate using 

equation (H.6) of Annex H to ISO 

1217:2009/Amd.1:2016(E). For qV1, use 

actual volume flow rate (cubic meters 

per second) at full-load operating 

pressure and 70 percent of full-load 

actual volume flow rate, as calculated in 

section 3.4.1 of this appendix. For p1,

use 100 kPa. For p2, use the sum of 

(a) 100 kPa, and 

(b) Discharge gauge pressure (Pa) at 

full-load operating pressure and 70 

percent of full-load actual volume flow 

rate, as calculated in section 3.4.1 of this 

appendix. For K, use the isentropic 

exponent (ratio of specific heats) of air, 

which, for the purposes of this test 

procedure, is 1.400. 

3.4.3.2. Calculate real packaged 

compressor power input at full-load 

operating pressure and 70 percent of 

full-load actual volume flow rate using 

the following equation: 

Preal,70% = K5 · K6 · PPR,70%

Where: 

K5 = correction factor for inlet pressure, as 

determined in section C.4.3.2 of Annex 

C to ISO 1217:2009(E). For calculations 

of this variable use a value of 100 kPa 

for contractual inlet pressure; 

K6 = correction factor for pressure ratio, as 

determined in section B.4.5 of Annex B 

to ISO 1217:2009(E). For calculations of 

this variable use a value of 1.400 for 

isentropic exponent, and for contractual 

pressure ratio, use the ratio of 

(a) The sum of 100 kPa and the measured 

discharge gauge pressure (kPa) from the test 

at 70 percent of full-load actual volume flow 

rate in section 3.4.1 of this appendix, to 

(b) 100 kPa; and 

PPR,70% = packaged compressor power input 

reading at full-load operating pressure 

and 70 percent of full-load actual volume 

flow rate, as measured in section 3.4.1 of 

this appendix (W). 

3.4.4. Calculate package isentropic 

efficiency at full-load operating pressure 

and 40 percent of full-load actual 

volume flow rate using the equation for 

isentropic efficiency in section 3.6.1 of 

ISO 1217:2009(E) as modified by ISO 

1217:2009/Amd.1:2016(E). For Pisen, use 

the isentropic power required for 

compression at full-load operating 

pressure and 40 percent of full-load 

actual volume flow rate, as determined 

in section 3.4.4.1 of this appendix. For 

Preal, use the real packaged compressor 

power input at full-load operating 

pressure and 40 percent of full-load 

actual volume flow rate, as determined 

in section 3.4.4.2 of this appendix. 

3.4.4.1. Calculate the isentropic power 

required for compression at full-load 

operating pressure and 40 percent of 

full-load actual volume flow rate using 

equation (H.6) of Annex H to ISO 

1217:2009/Amd.1:2016(E). For qV1, use 

actual volume flow rate (cubic meters 

per second) at full-load operating 

pressure and 40 percent of full-load 

actual volume flow rate, as calculated in 

section 3.4.1 of this appendix. For p1,

use 100 kPa. For p2, use the sum of 

(a) 100 kPa, and 

(b) Discharge gauge pressure (Pa) at 

full-load operating pressure and 40 

percent of full-load actual volume flow 

rate, as calculated in section 3.4.1 of this 

appendix. For K, use the isentropic 

exponent (ratio of specific heats) of air, 

which, for the purposes of this test 

procedure, is 1.400. 

3.4.4.2. Calculate real packaged 

compressor power input at full-load 

operating pressure and 40 percent of 

full-load actual volume flow rate using 

the following equation: 

Preal,40% = K5 · K6 · PPR,40%

Where: 

K5 = correction factor for inlet pressure, as 

determined in section C.4.3.2 of Annex 

C to ISO 1217:2009(E). For calculations 

of this variable use a value of 100 kPa 

for contractual inlet pressure; 

K6 = correction factor for pressure ratio, as 

determined in section B.4.5 of Annex B 

to ISO 1217:2009(E). For calculations of 

this variable use a value of 1.400 for 

isentropic exponent, and for contractual 

pressure ratio, use the ratio of 

(a) The sum of 100 kPa and the measured 

discharge gauge pressure (kPa) from the test 

at 40 percent of full-load actual volume flow 

rate in section 3.4.1 of this appendix, to 

(b) 100 kPa; and 

PPR,40% = packaged compressor power input 

reading at full-load operating pressure 

and 40 percent of full-load actual volume 


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Federal Register / Vol. 90, No. 11 / Friday, January 17, 2025 / Rules and Regulations 5559 

flow rate, as measured in section 3.4.1 of 

this appendix (W). 

3.5. Determination of Package Specific 

Power 

For both fixed and variable-speed air 

compressors, determine the package 

specific power, at any load point, using 

the equation for specific energy 

consumption in section C.4.4 of Annex 

C to ISO 1217:2009(E) and other values 

measured pursuant to this appendix, 

with no correction for shaft speed. 

Calculate PPcorr in section C.4.4 of 

Annex C to ISO 1217:2009(E) using the 

following equation: 

PPcorr = K5 · K6 · PPR

Where: 

K5 = correction factor for inlet pressure, as 

determined in section C.4.3.2 of Annex 

C to ISO 1217:2009(E). For calculations 

of this variable use a value of 100 kPa 

for contractual inlet pressure; 

K6 = correction factor for pressure ratio, as 

determined in section B.4.5 of Annex B 

to ISO 1217:2009(E). For calculations of 

this variable use a value of 1.400 for 

isentropic exponent, and for contractual 

pressure ratio, use the ratio of 

(a) The sum of 100 kPa and the measured 

discharge gauge pressure (kPa) from the 

test used to determine the package 

specific power, to 

(b) 100 kPa; and 

PPR = packaged compressor power input 

reading (W), as determined in section 

C.2.4 of Annex C to ISO 1217:2009(E). 

3.6. Determination of Pressure Ratio at 

Full-Load Operating Pressure 

Pressure ratio at full-load operating 

pressure, as defined in § 431.342, is 

calculated using the following equation: 

Where: 

PR = pressure ratio at full-load operating 

pressure; 

P1 = 100 kPa; and 

PFL = full-load operating pressure, 

determined in section 4.3.4 of this 

appendix (Pa gauge). 

4. Method To Determine Maximum FullFlow Operating Pressure, Full-Load 

Operating Pressure, and Full-Load 

Actual Volume Flow Rate 

4.1. Principal Strategy 

The principal strategy of this method 

is to incrementally increase discharge 

pressure by 2 psig relative to a starting 

point, and identify the maximum fullflow operating pressure at which the 

compressor is capable of operating. The 

maximum discharge pressure achieved 

is the maximum full-flow operating 

pressure. The full-load operating 

pressure and full-load actual volume 

flow rate are determined based on the 

maximum full-flow operating pressure. 

4.2. Pre-test Instructions 

4.2.1. Safety. For the method 

presented in section 4.3.1 of this 

appendix, only test discharge pressure 

within the safe operating range of the 

compressor, as specified by the 

manufacturer in the installation and 

operation manual shipped with the unit. 

Make no changes to safety limits or 

equipment. Do not violate any 

manufacturer-provided motor 

operational guidelines for normal use, 

including any restriction on 

instantaneous and continuous input 

power draw and output shaft power 

(e.g., electrical rating and service factor 

limits). 

4.2.2. Adjustment of Discharge Pressure 

4.2.2.1. If the air compressor is not 

equipped, as distributed in commerce 

by the manufacturer, with any 

mechanism to adjust the maximum 

discharge pressure output limit, proceed 

to section 4.2.3 of this appendix. 

4.2.2.2. If the air compressor is 

equipped, as distributed in commerce 

by the manufacturer, with any 

mechanism to adjust the maximum 

discharge pressure output limit, then 

adjust this mechanism to the maximum 

pressure allowed, according to the 

manufacturer’s operating instructions 

for these mechanisms. Mechanisms to 

adjust discharge pressure may include, 

but are not limited to, onboard digital or 

analog controls, and user-adjustable 

inlet valves. 

4.2.3. Driver speed. If the unit under 

test is a variable-speed compressor, 

maintain maximum driver speed 

throughout the test. If the unit under 

test is a fixed-speed compressor with a 

multi-speed driver, maintain driver 

speed at the maximum speed 

throughout the test. 

4.2.4. Measurements and Tolerances 

4.2.4.1. Recording. Record data by 

electronic means such that the 

requirements of section 4.2.4.5 of this 

appendix are met. 

4.2.4.2. Discharge Pressure. Measure 

discharge pressure in accordance with 

section 5.2 of ISO 1217:2009(E). Express 

compressor discharge pressure in psig 

in reference to ambient conditions, and 

record it to the nearest integer. Specify 

targeted discharge pressure points in 

integer values only. The maximum 

allowable measured deviation from the 

targeted discharge pressure at each 

tested point is ±1 psig. 

4.2.4.3. Actual Volume Flow Rate. 

Measure actual volume flow rate in 

accordance with section C.4.2.1 of 

Annex C to ISO 1217:2009(E) (where it 

is called ‘‘corrected volume flow rate’’) 

with no corrections made for shaft 

speed. Express compressor actual 

volume flow rate in cubic feet per 

minute at inlet conditions (cfm). 

4.2.4.4. Stabilization. Record data at 

each tested load point under steadystate conditions, as determined in 

section 3.1.1 of this appendix. 

4.2.4.5. Data Sampling and 

Frequency. At each load point, record a 

set of at least of two readings, collected 

at a minimum of 10 seconds apart. All 

readings at each load point must be 

within the maximum permissible 

fluctuation from the average (of the two 

consecutive readings), as specified in 

3.1.2 of this appendix. Average the 

measurements to determine the value of 

each parameter to be used in subsequent 

calculations. 

4.2.5 Adjusting System 

Backpressure. Set up the unit under test 

so that backpressure on the unit can be 

adjusted (e.g., by valves) incrementally, 

causing the measured discharge 

pressure to change, until the compressor 

is in an unloaded condition. 

4.2.6 Unloaded Condition. A unit is 

considered to be in an unloaded 

condition if capacity controls on the 

unit automatically reduce the actual 

volume flow rate from the compressor 

(e.g., shutting the motor off, or 

unloading by adjusting valves). 

4.3. Test Instructions 

4.3.1. Adjust the backpressure of the 

system so the measured discharge 

pressure is 90 percent of the expected 

maximum full-flow operating pressure, 

rounded to the nearest integer, in psig. 

If the expected maximum full-flow 

operating pressure is not known, then 

adjust the backpressure of the system so 

that the measured discharge pressure is 

65 psig. Allow the unit to remain at this 

setting for 15 minutes to allow the unit 

to thermally stabilize. Then measure 

and record discharge pressure and 

actual volume flow rate at the starting 

pressure. 

4.3.2. Adjust the backpressure of the 

system to increase the discharge 

pressure by 2 psig from the previous 

value, allow the unit to remain at this 

setting for a minimum of 2 minutes, and 

proceed to section 4.3.3 of this 

appendix. 

4.3.3. If the unit is now in an 

unloaded condition, end the test and 

proceed to section 4.3.4 of this 

appendix. If the unit is not in an 

unloaded condition, measure discharge 

pressure and actual volume flow rate, 

and repeat section 4.3.2 of this 

appendix. 


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5560 Federal Register / Vol. 90, No. 11 / Friday, January 17, 2025 / Rules and Regulations 

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 

reflect the last statutory amendments that impact 

Parts A and A–1 of EPCA. 

4.3.4. Of the discharge pressures 

recorded under stabilized conditions in 

sections 4.3.1 through 4.3.3 of this 

appendix, identify the largest. This is 

the maximum full-flow operating 

pressure. Determine the full-load 

operating pressure as a self-declared 

value greater than or equal to the lesser 

of (A) 90 percent of the maximum fullflow operating pressure, or (B) 10 psig 

less than the maximum full-flow 

operating pressure. 

4.3.5 The full-load actual volume 

flow rate is the actual volume flow rate 

measured at the full-load operating 

pressure. If the self-declared full-load 

operating pressure falls on a previously 

tested value of discharge pressure, then 

use the previously measured actual 

volume flow rate as the full-load actual 

volume flow rate. If the self-declared 

full-load operating pressure does not fall 

on a previously tested value of 

discharge pressure, then adjust the 

backpressure of the system to the selfdeclared full-load operating pressure 

and allow the unit to remain at this 

setting for a minimum of 2 minutes. The 

measured actual volume flow rate at this 

setting is the full-load actual volume 

flow rate. 

[FR Doc. 2025–01002 Filed 1–16–25; 8:45 am] 

BILLING CODE 6450–01–P 

DEPARTMENT OF ENERGY 

10 CFR Part 431 

[EERE–2024–BT–DET–0012] 

RIN 1904–AE57 

Energy Conservation Program: 

Commercial Warm Air Furnaces; Final 

Determination 

AGENCY: Office of Energy Efficiency and 

Renewable Energy, Department of 

Energy. 

ACTION: Final determination. 

SUMMARY: On June 2, 2023, the U.S. 

Department of Energy (‘‘DOE’’ or the 

‘‘Department’’) published a test 

procedure final rule which established 

test procedures for commercial warm air 

furnaces (‘‘CWAFs’’). On August 1, 

2023, the Air-Conditioning, Heating, 

and Refrigeration Institute (‘‘AHRI’’) 

filed a petition for review of the final 

rule in the United States Court of 

Appeals for the Fourth Circuit. In a 

February 6, 2024, order, the Fourth 

Circuit granted a voluntary remand of 

the final rule to the Department of 

Energy (‘‘DOE’’) to determine whether 

establishment of the test procedure for 

the thermal efficiency two (‘‘TE2’’) 

metric is supported by the specific 

provisions applicable to CWAFs under 

the Energy Policy and Conservation Act 

(‘‘EPCA’’). More specifically, DOE 

agreed in this voluntary remand to not 

enforce the TE2 test procedure unless 

and until the Department determines 

that the TE2 test procedure is consistent 

with the amended industry test 

procedure, or determines, supported by 

clear and convincing evidence, that the 

amended industry test procedure fails to 

satisfy the statutory requirements. This 

document provides DOE’s 

determination that the amended 

industry test procedure fails to satisfy 

EPCA’s statutory requirements. 

DATES: The effective date of July 3, 2023, 

for the TE2 test procedure is confirmed. 

ADDRESSES: The docket for this activity, 

which includes Federal Register 

notices, 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 

information that is exempt from public 

disclosure. 

The docket web page can be found at 

www.regulations.gov/docket/EERE2024-BT-DET-0012. 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: Ms. 

Julia Hegarty, 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) 597– 

6737. 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: 

Table of Contents 

I. Introduction 

A. Authority 

B. Energy Conservation Standards 

Rulemaking Process Under EPCA 

C. Background 

II. Discussion 

A. Appendix B Test Procedure for TE2 

B. Comment Period Length 

C. Application of the ASHRAE Trigger 

Provision in 42 U.S.C. 6314(a)(4)(B) 

III. Conclusion 

IV. Procedural Issues and Regulatory Review 

V. Approval of the Office of the Secretary 

I. Introduction 

A. Authority 

The Energy Policy and Conservation 

Act, Public Law 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 C of 

EPCA, added by Public Law 95–619, 

title IV, sec. 441(a), established the 

Energy Conservation Program for 

Certain Industrial Equipment, which 

sets forth a variety of provisions 

designed to improve energy efficiency. 

This equipment includes CWAFs, the 

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

6311(1)(J)). 

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 include definitions (42 U.S.C. 

6311), test procedures (42 U.S.C. 6314), 

labeling provisions (42 U.S.C. 6315), 

energy conservation standards (42 

U.S.C. 6313), and the authority to 

require information and reports from 

manufacturers (42 U.S.C. 6316; 42 

U.S.C. 6296). 

The Federal testing requirements 

consist of test procedures that 

manufacturers of covered equipment 

must use as the basis for: (1) certifying 

to DOE that their equipment complies 

with the applicable energy conservation 

standards adopted pursuant to EPCA (42 

U.S.C. 6316(b); 42 U.S.C. 6296), and (2) 

making other representations about the 

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

6314(d)). Similarly, DOE uses these test 

procedures to determine whether the 

equipment complies with relevant 

standards promulgated under EPCA. 

DOE’s test procedures for CWAFs are 

currently prescribed at subpart D of part 

431 of title 10 of the Code of Federal 

Regulations (‘‘CFR’’). 

Federal energy efficiency 

requirements for covered equipment 

established under EPCA generally 

supersede state laws and regulations 

concerning energy conservation testing, 

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

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


KHAMMOND on DSK9W7S144PROD with RULES