Energy Conservation Program: Test Procedure for Central Air Conditioners and Heat Pumps

Federal RegisterJan 7, 2025

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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 430

[EERE-2022-BT-TP-0028]

RIN 1904-AF49

Energy Conservation Program: Test Procedure for Central Air Conditioners and Heat Pumps

AGENCY:

Office of Energy Efficiency and Renewable Energy, Department of Energy.

ACTION:

Final rule.

SUMMARY:

This final rule amends the Federal test procedure for central air conditioners and heat pumps (“CAC/HPs”) to incorporate by reference the latest versions of the applicable industry standards. Specifically, DOE is incorporating by reference the latest version of the relevant industry consensus test standard, AHRI 210/240-2024 (I-P) for the current test procedure for CAC/HPs (“appendix M1”) for measuring the current cooling and heating metrics—seasonal energy efficiency ratio 2 (“SEER2”) and heating seasonal performance factor 2 (“HSPF2”). DOE is incorporating by reference the new industry consensus test standard, AHRI 1600-2024 (I-P), for a new test procedure (“appendix M2”) for CAC/HPs that adopts two new metrics—seasonal cooling and off-mode rating efficiency (“SCORE”) and seasonal heating and off-mode rating efficiency (“SHORE”). Testing to the SCORE and SHORE metrics would not be required until such time as compliance is required with any amended energy conservation standard based on the new metrics. Additionally, DOE is amending certain provisions of DOE's regulations related to representations and enforcement for CAC/HPs.

DATES:

The effective date of this rule is February 6, 2025. The amendments will be mandatory for product testing starting July 7, 2025. Manufacturers will be required to use the amended test procedure until the compliance date of any final rule establishing amended energy conservation standards based on the newly established test procedure. At such time, manufacturers will be required to begin using the newly established test procedure.

The incorporation by reference of certain publications listed in this rule is approved by the Director of the Federal Register on February 6, 2025.

ADDRESSES:

The docket, which includes

Federal Register

notices, public meeting attendee lists and transcripts, comments, and other supporting documents/materials, is available for review at

www.regulations.gov.

All documents in the docket are listed in the

www.regulations.gov

index. However, not all documents listed in the index may be publicly available, such as those containing information that is exempt from public disclosure.

A link to the docket web page can be found at

www.regulations.gov/docket/EERE-2022-BT-TP-0028.

The docket web page contains instructions on how to access all documents, including public comments, in the docket.

For further information on how to review the docket contact the Appliance and Equipment Standards Program staff at (202) 287-1445 or by email:

ApplianceStandardsQuestions@ee.doe.gov.

FOR FURTHER INFORMATION CONTACT:

Dr. Pradeep Prathibha, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Office, EE-5B, 1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: (240) 255-0630. Email:

ApplianceStandardsQuestions@ee.doe.gov.

Mr. Pete Cochran, U.S. Department of Energy, Office of the General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: (202) 586-4798. Email:

peter.cochran@hq.doe.gov.

SUPPLEMENTARY INFORMATION:

DOE maintains previously approved incorporations by reference and incorporates by reference the following industry standards into 10 CFR parts 429 and 430:

Copies of AHRI 210/240-2024 and AHRI 1600-2024 can be obtained from the Air-Conditioning, Heating, and Refrigeration Institute (AHRI), 2311 Wilson Blvd., Suite 400, Arlington, VA 22201, (703) 524-8800, or online at:

www.ahrinet.org.

ANSI/ASHRAE Standard 16-2016, Method of Testing for Rating Room Air Conditioners, Packaged Terminal Air Conditioners, and Packaged Terminal Heat Pumps for Cooling and Heating Capacity, ANSI approved November 1, 2016 (“ANSI/ASHRAE 16”).

ANSI/ASHRAE Standard 37-2009, Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, ANSI-approved June 25, 2009 (“ASHRAE 37-2009”).

ANSI/ASHRAE Standard 116-2010, Methods of Testing for Rating Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps, ANSI approved February 24, 2010 (“ANSI/ASHRAE 116-2010”).

Copies of ANSI/ASHRAE 16, ASHRAE 37-2009, and ANSI/ASHRAE 116-2010 can be purchased from the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (“ASHRAE”) website at

www.ashrae.org/resources—publications.

See

section IV.N of this document for further discussion of these standards.

Table of Contents

I. Authority and Background

A. Authority

B. Background

II. Synopsis of the Final Rule

III. Discussion

A. Scope of Applicability

B. Updates to Industry Standards

1. AHRI 210/240-2024

2. AHRI 1600-2024

3. ANSI/ASHRAE 37-2009

4. ANSI/ASHRAE 16-2016

5. ANSI/ASHRAE 116-2010

C. Revised CAC/HP Test Procedure

D. Efficiency Metrics

1. Metrics Applicable to Appendix M1

2. Metrics Applicable to Appendix M2

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

1. Controls Verification Procedure for Variable Speed Systems

2. Low-Temperature Heating Performance

3. Cut-Out and Cut-In Temperature Verification

4. Low-Static Single-Split Blower-Coil System Definition and Testing Provisions

5. Mandatory Constant Circulation Systems

6. Provisions for Outdoor Units With No Match

7. Inlet and Outlet Duct Configurations

8. Heat Comfort Controllers

F. Long-Term Changes in the CAC Test Procedure

1. Power Consumption of Auxiliary Components

2. Impact of Defrost on Performance

3. Updates to Building Load Lines and Temperature Bin Hours

4. Default Fan Power Coefficients for Coil-Only Systems

5. Air Flow Limits To Address Inadequate Dehumidification

G. General Comments Received in Response to the April 2024 NOPR

H. Represented Values

1. Represented Values for the Federal Trade Commission

2. Off-Mode Power

3. AEDM Tolerance for SCORE and SHORE

4. Removal of the AEDM Exception for Split-System CAC/HPs

I. Enforcement Provisions

1. Verifying Cut-Out and Cut-In Temperatures

2. Controls Verification Procedure

J. Test Procedure Costs and Impacts

1. Appendix M1

2. Appendix M2

K. Effective and Compliance Dates

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Orders 12866, 13563, and 14094

B. Review Under the Regulatory Flexibility Act

1. Descriptions of Reasons for Action

2. Objectives of, and Legal Basis for, Rule

3. Description and Estimate of Small Entities Regulated

4. Description and Estimate of Compliance Requirements

5. Duplication, Overlap, and Conflict With Other Rules and Regulations

1. Certification Statement

C. Review Under the Paperwork Reduction Act of 1995

D. Review Under the National Environmental Policy Act of 1969

E. Review Under Executive Order 13132

F. Review Under Executive Order 12988

G. Review Under the Unfunded Mandates Reform Act of 1995

H. Review Under the Treasury and General Government Appropriations Act, 1999

I. Review Under Executive Order 12630

J. Review Under Treasury and General Government Appropriations Act, 2001

K. Review Under Executive Order 13211

L. Review Under Section 32 of the Federal Energy Administration Act of 1974

M. Congressional Notification

N. Description of Materials Incorporated by Reference

V. Approval of the Office of the Secretary

I. Authority and Background

Central air conditioners (“CACs”) and central air conditioning heat pumps (“HPs”) (collectively, “CAC/HPs”) are included in the list of “covered products” for which the U.S. Department of Energy (“DOE”) is authorized to establish and amend energy conservation standards and test procedures. (42 U.S.C. 6292 (a)(3)) DOE's test procedure for CAC/HPs is currently prescribed at 10 CFR part 430, subpart B, appendix M1 (“appendix M1”). The following sections discuss DOE's authority to establish and amend the test procedure for CAC/HPs and relevant background information regarding DOE's consideration of the test procedure for this product.

A. Authority

The Energy Policy and Conservation Act, Pub. L. 94-163, as amended (“EPCA”),

authorizes DOE to regulate the energy efficiency of a number of consumer products and certain industrial equipment. (42 U.S.C. 6291-6317, as codified) Title III, Part B of EPCA

established the Energy Conservation Program for Consumer Products Other Than Automobiles, which sets forth a variety of provisions designed to improve energy efficiency. These products include CAC/HPs, the subject of this document. (42 U.S.C. 6292(a)(3))

All references to EPCA in this document refer to the statute as amended through the Energy Act of 2020, Public Law 116-260 (Dec. 27, 2020), which reflects the last statutory amendments that impact Parts A and A-1 of EPCA.

For editorial reasons, upon codification in the U.S. Code, Part B was redesignated Part A.

The energy conservation program under EPCA consists essentially of four parts: (1) testing, (2) labeling, (3) Federal energy conservation standards, and (4) certification and enforcement procedures. Relevant provisions of EPCA specifically include definitions (42 U.S.C. 6291), test procedures (42 U.S.C. 6293), labeling provisions (42 U.S.C. 6294), energy conservation standards (42 U.S.C. 6295), and the authority to require information and reports from manufacturers (42 U.S.C. 6296).

The Federal testing requirements consist of test procedures that manufacturers of covered products must use as the basis for: (1) certifying to DOE that their products comply with the applicable energy conservation standards adopted under EPCA (42 U.S.C. 6295(s)), and (2) making other representations about the efficiency of those products (42 U.S.C. 6293(c)). Similarly, DOE must use these test procedures to determine whether the products comply with any relevant standards promulgated under EPCA. (42 U.S.C. 6295(s))

Federal energy efficiency requirements for covered products established under EPCA generally supersede State laws and regulations concerning energy conservation testing, labeling, and standards. (42 U.S.C. 6297) DOE may, however, grant waivers of Federal preemption for particular State laws or regulations, in accordance with the procedures and other provisions of EPCA. (42 U.S.C. 6297(d))

Under 42 U.S.C. 6293, EPCA sets forth the criteria and procedures DOE must follow when prescribing or amending test procedures for covered products. EPCA requires that any test procedures prescribed or amended under this section shall be reasonably designed to produce test results which measure energy efficiency, energy use or estimated annual operating cost of a covered product during a representative average use cycle (as determined by the Secretary) or period of use and shall not be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3))

EPCA also requires that, at least once every seven years, DOE evaluate test procedures for each type of covered product, including CAC/HPs, to determine whether amended test procedures would more accurately or fully comply with the requirements for the test procedures to not be unduly burdensome to conduct and be reasonably designed to produce test results that reflect energy efficiency, energy use, and estimated operating costs during a representative average use cycle or period of use. (42 U.S.C. 6293(b)(1)(A))

If the Secretary determines, on her own behalf or in response to a petition by any interested person, that a test procedure should be prescribed or amended, the Secretary shall promptly publish in the

Federal Register

proposed test procedures and afford interested persons an opportunity to present oral and written data, views, and arguments with respect to such procedures. The comment period on a proposed rule to amend a test procedure shall be at least 60 days and may not exceed 270 days. In prescribing or amending a test procedure, the Secretary shall take into account such information as the Secretary determines relevant to such procedure, including technological developments relating to energy use or energy efficiency of the type (or class) of covered products involved. (42 U.S.C. 6293(b)(2)). If DOE determines that test procedure revisions are not appropriate, DOE must publish its determination not to amend the test procedures.

DOE's regulations at 10 CFR 430.27 provide that any interested person may seek a waiver from the test procedure requirements if certain conditions are met. A waiver requires manufacturers to use an alternate test procedure in situations in which the DOE test procedure cannot be used to test the product or equipment, or use of the DOE test procedure would generate unrepresentative results. 10 CFR 430.27(a)(1). DOE's regulations at 10 CFR 430.27(l) require that as soon as practicable after the granting of any waiver, DOE will publish in the

Federal Register

a notice of proposed rulemaking (“NOPR”) to amend its regulations so as to eliminate any need for the continuation of such waiver. As soon thereafter as practicable, DOE will publish in the

Federal Register

a final rule. 10 CFR 430.27(l).

In addition, EPCA requires that DOE amend its test procedures for all covered products to integrate measures of standby mode and off-mode energy consumption into the overall energy efficiency, energy consumption, or other

energy descriptor, unless the current test procedure already incorporates the standby mode and off-mode energy consumption, or if such integration is technically infeasible. (42 U.S.C. 6295(gg)(2)(A)(i)-(ii)) If an integrated test procedure is technically infeasible, DOE must prescribe separate standby mode and off-mode energy use test procedures for the covered product, if a separate test is technically feasible. (42 U.S.C. 6295(gg)(2)(A)(ii)) Any such amendment must consider the most current versions of the International Electrotechnical Commission (IEC) Standard 62301

and IEC Standard 62087

as applicable. (42 U.S.C. 6295(gg)(2)(A)) DOE is publishing this final rule in satisfaction of the seven-year review requirement specified in EPCA. (42 U.S.C. 6293(b)(1)(A))

IEC 62301,

Household electrical appliances—Measurement of standby power

(Edition 2.0, 2011-01).

IEC 62087,

Audio, video and related equipment—Methods of measurement for power consumption

(Edition 1.0, Parts 1-6: 2015, Part 7: 2018).

B. Background

On April 5, 2024, DOE published in the

Federal Register

a notice of proposed rulemaking (“NOPR”) (“April 2024 NOPR”) proposing to update the Federal test procedure for CAC/HPs by: (1) incorporating by reference at appendix M1 the most recent draft version of the AHRI Standard 210/240 industry test procedure, AHRI 210/240-202X Draft, for measuring SEER2 and HSPF2; and (2) establishing a new test procedure at 10 CFR part 430, subpart B, appendix M2 (“appendix M2”) that references the draft new industry test procedure, AHRI 1600-202X Draft, for measuring new efficiency metrics, seasonal cooling and off mode rating efficiency (“SCORE”), and seasonal heating and off mode rating efficiency (“SHORE”). 89 FR 24206. Copies of the AHRI drafts were added to the docket for this rulemaking for review by interested parties.

5 6

As stated in the April 2024 NOPR, if AHRI 210/240-202X Draft and AHRI 1600-202X Draft were to be finalized and formally adopted, DOE's intention would be to reference the final published version of AHRI 210/240 and AHRI 1600 in DOE's subsequent test procedure final rule. 89 FR 24206, 24209. DOE held a public meeting webinar on April 25, 2024 to discuss the proposed amendments to the CAC/HP test procedure presented in the April 2024 NOPR.

The AHRI 210/240-202X Draft test procedure is available in the docket for this rulemaking at:

www.regulations.gov/document/EERE-2022-BT-TP-0028-0017.

The AHRI 1600-202X Draft test procedure is available in the docket for this rulemaking at:

www.regulations.gov/document/EERE-2022-BT-TP-0028-0018.

DOE received comments in response to the April 2024 NOPR from the interested parties listed in table I.1.

Table I-1—List of Commenters With Written Submissions in Response to the April 2024 NOPR

Commenter(s)

Reference in this final rule

Comment No.

in the docket

Commenter type

Air-Conditioning, Heating, and Refrigeration Institute

AHRI

Trade Association.

Pacific Gas and Electric Company, San Diego Gas and Electric, and Southern California Edison; collectively, the California Investor-Owned Utilities

CA IOUs

Utilities.

Carrier Global Corporation

Carrier

Manufacturer.

Copeland LP

Copeland

Manufacturer.

Daikin Comfort Technologies North America Inc

Daikin

36 and 40

Manufacturer.

GE Appliances

Manufacturer.

Heating, Air-conditioning & Refrigeration Distributors International

HARDI

Trade Association.

Johnson Controls

JCI

Manufacturer.

Appliance Standards Awareness Project, National Consumer Law Center, and New York State Energy Research and Development Authority

Joint Advocates

Efficiency Organization, Consumer Advocacy Organization, and State Agency.

Keith Rice

HVAC R&D Engineer.

Lennox International Inc

Lennox

Manufacturer.

LG Electronics U.S.A., Inc

Manufacturer.

Mitsubishi Electric US

Mitsubishi

Manufacturer.

National Comfort Products

NCP

Manufacturer.

Northwest Energy Efficiency Alliance

NEEA

Efficiency Organization.

Rheem Manufacturing Company

Rheem

Manufacturer.

A parenthetical reference at the end of a comment quotation or paraphrase provides the location of the item in the public record.

To the extent that interested parties have provided written comments that are substantively consistent with any oral comments provided during the April 25, 2024 public meeting, DOE cites the written comments throughout this final rule. DOE did not identify any oral comments provided during the April 25, 2024, public meeting that are not substantively addressed by written comments.

The parenthetical reference provides a reference for information located in the docket of DOE's rulemaking to develop test procedures for CAC/HPs. (Docket No. EERE-2022-BT-TP-0028, which is maintained at:

www.regulations.gov

). The references are arranged as follows: (commenter name, comment docket ID number at page of that document).

In May 2024, AHRI finalized AHRI 210/240-202X Draft and AHRI 1600-202X Draft without substantial change, and published AHRI Standard 210/240-2024, “Performance Rating of Unitary Air-conditioning and Air-source Heat Pump Equipment” (“AHRI 210/240-2024”), and AHRI Standard 1600-2024, “Performance Rating of Unitary Air-conditioning and Air-source Heat Pump Equipment” (“AHRI 1600-2024”), respectively.

II. Synopsis of the Final Rule

In this final rule, DOE is updating its regulations for CAC/HPs by: (1) amending appendix M1 to incorporate by reference the latest industry standard, AHRI 210/240-2024, while maintaining the current efficiency metrics EER2, SEER2 and HSPF2; and (2) establishing a new appendix M2 that references the new industry test

procedure, AHRI 1600-2024, for measuring new efficiency metrics, EER, SCORE and SHORE. Appendix M2 would be the applicable test method for CAC/HPs for any standards denominated in terms of SCORE and SHORE. Use of appendix M2 would not be required until such time as compliance is required with any amended energy conservation standard based on the new metrics, should DOE adopt such standards. After the date on which compliance with appendix M2 would be required, appendix M1 would no longer be required as part of the Federal test procedure. DOE is also amending certain provisions within DOE's regulations for representation and enforcement consistent with the proposed test procedure amendments.

Table II.1 summarizes the adopted changes to the amended appendix M1 and the new appendix M2 test procedures, as well as the reason for the adopted change.

Table II-1—Summary of Changes in Amended Appendix M1 and New Appendix M2 Test Procedures Relative to Current Test Procedure

DOE test procedure

prior to amendment

Appendix M1

test procedure

Appendix M2

test procedure

Attribution

Incorporates by reference AHRI 210/240-2008

Incorporates by reference AHRI 210/240-2024

Incorporates by reference AHRI 1600-2024

Updates to the applicable industry test procedures.

Includes provisions for determining SEER2, HSPF2, EER2, and P

W,OFF

Maintains provisions for determining SEER2, HPSF2, EER2, and P

W,OFF

Includes provisions for determining SCORE and SHORE and maintains provisions for determining EER (same as EER2)

Updates to the applicable industry test procedures.

Includes certain CAC/HP provisions regarding determination of represented values in 10 CFR 429.16

Includes provisions to remove the alternative efficiency determination method (“AEDM”) exception for split-systems in 10 CFR 429.16

Includes provisions to remove the AEDM exception for split-systems, to extend the AEDM tolerance requirement to SCORE and SHORE, and to no longer require representations of the P

W,OFF

metric in 10 CFR 429.16

Improve representativeness of test procedure.

Does not include certain CAC/HP-specific enforcement provisions in 10 CFR 429.134(k)

Includes CAC/HP-specific enforcement provisions regarding verification of cut-out and cut-in temperatures and a controls verification procedure

Clarify how DOE will conduct enforcement testing.

DOE has determined that the amendments to the CAC/HP test procedures in appendix M1 and newly established appendix M2 would not be unduly burdensome to conduct. Furthermore, DOE has determined that the amendments to appendix M1 would not alter the measured efficiency of CAC/HPs or require retesting or recertification solely as a result of DOE's adoption of the amendments to the test procedure. Additionally, DOE has determined that the amendments to appendix M1 would not increase the cost of testing. Representations of energy use or energy efficiency would be required to be based on testing in accordance with the amended test procedure in appendix M1 beginning 180 days after the date of publication of the test procedure final rule in the

Federal Register

DOE has determined, however, that new appendix M2 would alter the measured efficiency of CAC/HPs, in part because the amended test procedure would adopt different energy efficiency metrics than in the current test procedure. Additionally, DOE has determined that testing according to the new appendix M2 would not increase the cost of testing as compared to appendix M1. Cost estimates are discussed in section III.J of this document. As discussed, use of appendix M2 would not be required until the compliance date of amended energy conservation standards denominated in terms of SCORE and SHORE, should DOE adopt such standards.

The amendments to representation requirements in 10 CFR 429.16 would not be required until 180 days after publication in the

Federal Register

of this final rule.

Discussion of DOE's proposed actions are addressed in further detail in section III of this final rule.

III. Discussion

A. Scope of Applicability

This rulemaking applies to CAC/HPs. DOE defines the term

central air conditioner or central air conditioner heat pump

to mean a product, other than a packaged terminal air conditioner or packaged terminal heat pump, single-phase single-package vertical air conditioner with cooling capacity less than 65,000 British thermal units (“Btu”) per hour (“Btu/h”), single-phase single-package vertical heat pump with cooling capacity less than 65,000 Btu/h, computer room air conditioner, or unitary dedicated outdoor air system, as these equipment categories are defined at 10 CFR 431.92, which is powered by single-phase electric current, air-cooled, rated below 65,000 Btu/h, not contained within the same cabinet as a furnace, the rated capacity of which is above 225,000 Btu/h, and is a heat pump or a cooling unit only. A central air conditioner or central air conditioning heat pump may consist of: a single-package unit; an outdoor unit and one or more indoor units; an indoor unit only; or an outdoor unit with no match. In the case of an indoor unit only or an outdoor unit with no match, the unit

must

be tested and rated as a system (combination of both an indoor and an outdoor unit). For all central air conditioner and central air conditioning heat pump-related definitions, see appendix M or M1 of subpart B of this part. 10 CFR 430.2.

Consistent with the April 2024 NOPR, DOE is not proposing any changes to the CAC/HP definition. However, DOE notes that the last sentence in the CAC/HP definition includes references to see additional definitions in appendices M and M1. As noted in section II, in this final rule, DOE is incorporating by reference the latest industry standards, AHRI 210/240-2024 and AHRI 1600-2024, including the relevant definitions

in these standards. Therefore, references to appendices M and M1 are no longer relevant in the CAC/HP definition. To prevent confusion, DOE is removing the last sentence in the definition that contains these references. 10 CFR 430.2.

The current scope of the CACs/HP test procedure includes:

(a) Split-system air conditioners, including single-split, multi-head mini-split, multi-split (including variable refrigerant flow (“VRF”)), and multi-circuit systems;

(b) Split-system heat pumps, including single-split, multi-head mini-split, multi-split (including VRF), and multi-circuit systems;

(d) Single-package heat pumps;

(e) Small-duct, high-velocity systems (including VRF);

(f) Space-constrained products—air conditioners; and

(g) Space-constrained products—heat pumps.

See

section 1.1 of appendix M1.

DOE is not amending the scope of CACs/HPs covered by the test procedure in appendix M1 or appendix M2.

B. Updates to Industry Standards

DOE is incorporating by reference AHRI 210/240-2024 and the relevant standards it references as the basis for the updated appendix M1 test procedure. Similarly, DOE is incorporating by reference AHRI 1600-2024 and the relevant standards it references as the basis for the new appendix M2 test procedure. Incorporating each industry standard in full as the basis for each respective appendix would enable DOE to better harmonize with the industry standard and eliminate manufacturer burden in certifying with separate test procedures. The following sections discuss the referenced standards for appendices M1 and M2.

1. AHRI 210/240-2024

In the April 2024 NOPR, DOE noted that AHRI and other relevant stakeholders, including DOE, worked to develop a revised AHRI 210/240 standard, AHRI 210/240-202X Draft, that included updates to address issues pertaining to the CAC/HP test procedure with broad stakeholder consensus. 89 FR 24206, 24211-24212. DOE proposed to amend its test procedure for CAC/HPs at appendix M1 by incorporating by reference AHRI 210/240-202X Draft.

Id.

Because AHRI 210/240-202X Draft was in draft form at the time of the publication of the April 2024 NOPR, DOE noted that it intended to update its incorporation by reference to the final published version of AHRI 210/240-202X Draft in the final rule, unless the draft version is not finalized before the final rule or there are substantive changes between the draft and published versions, in which case DOE may adopt the substance of the AHRI 210/240-202X Draft or provide additional opportunity for comment on the substantive changes to the updated industry consensus standard.

Id.

In May 2024, AHRI published the finalized AHRI 210/240 standard, AHRI 210/240-2024, which did not include any significant deviations from AHRI 210/240-202X Draft.

AHRI, the CA IOUs, Carrier, Daikin, GE Appliances, JCI, Lennox, and NEEA were generally supportive of DOE`s proposal on updating appendix M1 by adopting the finalized AHRI 210/240 standard. (AHRI, No. 25 at p. 3; Carrier, No. 29 at p. 4; CA IOUs, No. 32 at p. 1; Daikin, No. 36 at p. 1; GE Appliances, No. 37 at pp. 4-5; JCI, No. 35 at p. 1; Lennox, No. 24 at p. 3; NEEA, No. 39 at p. 2) AHRI commented that it supports the adoption of AHRI 210/240-2024 as a revised appendix M1, but with minimal additions and some exclusions, and will be publishing an addendum to AHRI 210/240-2024 that will include the aforementioned minimal additions that DOE established in the April 2024 NOPR, including revision to the definition of outdoor unit with no match. (AHRI, No. 25 at p. 3)

The Joint Advocates and CA IOUs encouraged DOE to adopt AHRI 210/240-2024 in the new CAC/HP test procedure final rule as soon as possible. (Joint Advocates, No. 30 at p. 1; CA IOUs, No. 32 at p. 1) Carrier stated that it supports the incorporation by reference of AHRI 210/240-2024 into a revised appendix M1, but with some recommendations. (Carrier, No. 29 at p. 4) Rheem commented that even though it supported the adoption of the consensus AHRI 210/240-2024 in the updated Appendix M1, it was concerned that the new versions of ANSI/ASHRAE Standard 37-2009

and ANSI/ASHRAE Standard 16-2016

with major changes, which are to be published in the near future, are not currently referenced in AHRI 210/240-2024. (Rheem, No. 34 at p. 3) Specifically, Rheem pointed out that once the new versions of the aforementioned ASHRAE standards are published, AHRI 210/240-2024 should be revised to incorporate references to the revised standards, and subsequently, DOE should update appendix M1 to incorporate the revised AHRI 210/240-2024 by reference. (

Id.

at pp. 3-4) Rheem further commented that since AHRI 210/240-2024 cites sections of 10 CFR 429.16, and of appendix M1 to subpart B of 10 CFR part 430, it should be revised to ensure that these references to CFR are still appropriate, since DOE has proposed major revisions to these sections from the CFR. (

Id.

) Rheem pointed to the newly introduced enforcement provisions in 10 CFR 429.134(k), which require calculation of average capacity (10 CFR 429.134(k)(4)(iii)(A)(

) and (

)) or time-averaged integrated (10 CFR 429.134(k)(4)(iii)(A)(

)) capacity and power consumption, and Rheem suggested updates to appendix I of AHRI 210/240-2024 to state that average capacity, average power consumption, time-averaged integrated capacity, and time-integrated power consumption should be calculated according to the appropriate sections of AHRI 210/240-2024 and ANSI/ASHRAE 16, as applicable. (

Id.

) Rheem pointed out that table 8 of AHRI 210/240-2024, which lists the test conditions for CAC/HPs under test, does not include the details on how to measure the compressor speed for cooling full-speed tests (A2 and B2), and cooling minimum-speed tests (B1, F1, G1, and I1) for variable-speed compressor units, as currently specified in section 3.2.4(a) of appendix M1. (

Id.

at p. 4) Rheem commented that the aforementioned details should be added as notes under table 8 of AHRI 210/240-2024, after appropriate translations of the test nomenclature.

Id.

ANSI/ASHRAE 37-2009 provides a method of test for many categories of air-conditioning and heating products and equipment, including CAC/HPs.

ANS/ASHRAE 16-2016 provides a method of test for rating room air conditioners, packaged terminal air conditioners, and packaged terminal heat pumps.

Currently, all full-speed cooling and heating mode tests in appendix M1 are identified with “2” in the subscript of the relevant test, whereas AHRI 210/240-202X and AHRI 1600-202X identify them with the “Full” subscript. Similarly, all minimum-speed cooling and heating mode tests in appendix M1 are identified with “1” in the subscript of the relevant test, whereas AHRI 210/240-202X and AHRI 1600-202X identify them with the “Low” subscript.

In response to Rheem's comment, DOE notes that in the April 2024 NOPR, DOE proposed to incorporate by reference AHRI 210/240-202X draft and the AHRI 1600-202X draft, at revised appendix M1 and new appendix M2, respectively, while this final rule is updating these references to the final drafts, AHRI 210/240-2024 and AHRI 1600-2024. DOE has reviewed the finalized standards, AHRI 210/240-2024 and AHRI 1600-2024, and has concluded that all current references to 10 CFR 429.16 in the standards would

not require revision. Additionally, DOE clarifies that any further updates to appendix I of the AHRI 210/240 and AHRI 1600 standards to add the definitions of average capacity, average power consumption, time-averaged integrated capacity, and time-integrated power consumption will have to be initiated by AHRI, as part of an addendum. DOE has determined that additional definitions are not necessary at this time and notes that an updated appendix I to AHRI 210/240 and AHRI 1600 is not yet available for review; therefore, DOE is not adopting additional definitions as recommended by Rheem at this time. Regarding Rheem's comment on table 8 of AHRI 210/240-2024 lacking language from section 3.2.4 (a) of the current appendix M1 for maintaining the same full compressor speed for all full-speed cooling tests, and the same minimum compressor speed for all minimum-speed cooling tests, DOE is adding provisions in section 2 of the revised appendix M1 and section 2 of the new appendix M2, consistent with the existing requirement in appendix M1, as follows:

For cooling mode tests of variable capacity systems, the compressor shall operate at the same cooling full speed, measured by RPM of power input frequency (Hz), for both A

Full

and B

Full

tests. Additionally, the compressor shall operate at the same cooling minimum speed, measured by RPM or power input frequency (Hz), for the B

Low

, F

Low

, G

Low

, and I

Low

tests.

As noted, in May 2024, AHRI published AHRI 210/240-2024, which does not include any significant deviations from AHRI 210/240-202X Draft. As such, the adoption of AHRI 210/240-2024 in this final rule is consistent with the proposal to reference AHRI 210/240-202X Draft in the April 2024 NOPR.

Therefore, DOE is amending its test procedure for CAC/HPs by incorporating by reference AHRI 210/240-2024 for use in the new appendix M1. Specifically, in the new test procedure for CAC/HPs at appendix M1, DOE is adopting sections 3 (excluding 3.2.16, 3.2.20, 3.2.46, 3.2.51, 3.2.63, 3.2.78 and 3.2.79), 5 (excluding 5.1.6.2), 6.1-6.3, and 6.6, and Appendices D, E, G, and K of AHRI 210/240-2024.

DOE notes that the substance of these provisions remains the same as those proposed in the April 2024 NOPR, but AHRI did some reorganization in moving from AHRI 210/240-202X Draft to AHRI 210/240-2024. Consequently, the adopted section numbers cited here differ from those presented in DOE's proposed rule.

See

89 FR 24206, 24212.

Additionally, as proposed in the April 2024 NOPR, DOE is making additions and deletions to the incorporations by reference for the CAC/HP Federal test procedure (

see

10 CFR 430.3) to align with the references made within AHRI 210/240-2024. 89 FR 24206, 24212.

Currently, appendix M1 incorporates by reference: AMCA 210-2007,

AHRI 210/240-2008, AHRI 1230-2010,

ASHRAE 23.1-2010,

ANSI/ASHRAE 37-2009, and ASHRAE 116-2010. 10 CFR 430.3.

ANSI/AMCA 210-2007, ANSI/ASHRAE 51-2007, (“AMCA 210-2007”) Laboratory Methods of Testing Fans for Certified Aerodynamic Performance Rating, ANSI approved Aug. 17, 2007. A copy of AMCA 210-2007 can be purchased from the Air Movement and Control Association International Inc. (“AMCA”) website at

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

ANSI/AHRI 1230-2010 with Addendum 2, (“AHRI 1230-2010”): 2010 Standard for Performance Rating of Variable Refrigerant Flow (“VRF”) Multi-Split Air-Conditioning and Heat Pump Equipment, ANSI approved Aug. 2, 2010. A copy of AHRI 1230-2010 can be obtained from AHRI, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, USA, 703-524-8800, or by going to

www.ahrinet.org.

ANSI/ASHRAE 23.1-2010, (“ASHRAE 23.1-2010”): Methods of Testing for Rating the Performance of Positive Displacement Refrigerant Compressors and Condensing Units that Operate at Subcritical Temperatures of the Refrigerant, ANSI approved Jan. 28, 2010. A copy of ASHRAE 23.1-2010 can be obtained from the ASHRAE website at

www.ashrae.org/resources--publications.

In the amended test procedure at appendix M1, DOE is adding an incorporation by reference to ANSI/ASHRAE 16-2016 and removing incorporations by reference to AMCA 210-2007, AHRI 210/240-2008, AHRI 1230-2010, and ASHRAE 23.1-2010. Therefore, DOE is incorporating by reference AHRI 210/240-2024, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ANSI/ASHRAE 116-2010, at appendix M1.

2. AHRI 1600-2024

In parallel to the AHRI 210/240-202X Draft, AHRI and other relevant stakeholders, including DOE, worked to develop a forward-looking AHRI test procedure that would act as the successor to the AHRI 210/240-202X Draft and be effective in the long term (

i.e.,

AHRI 1600-202X Draft).

In the April 2024 NOPR, DOE proposed to establish a new test procedure for CAC/HPs at appendix M2 by incorporating by reference AHRI 1600-202X Draft (in its entirety). 89 FR 24206, 24212. DOE noted that it intended to update its incorporation by reference to the final published version of AHRI 1600-202X Draft in the final rule, unless the draft version is not finalized before the final rule or there are substantive changes between the draft and published versions, in which case DOE may adopt the substance of the AHRI 1600-202X Draft or provide additional opportunity for comment on the substantive changes to the updated industry consensus standard.

Id.

In May 2024, AHRI published the finalized AHRI 1600 standard, AHRI 1600-2024, which did not include any significant deviations from AHRI 1600-202X Draft.

Several stakeholders, namely Lennox, AHRI, Mitsubishi, Copeland, the CA IOUs, Rheem, Daikin, NEEA, and Carrier, appreciated DOE's efforts of collaborating with the stakeholders to develop the AHRI 1600 standard, and supported its adoption at appendix M2. (Lennox, No. 24 at p. 4; AHRI, No. 25 at p. 3;

Mitsubishi, No. 28 at p. 1; Copeland, No. 31 at p. 1; CA IOUs, No. 32 at p. 2; Rheem, No. 34 at p. 4; Daikin, No. 36 at p. 1; NEEA, No. 39 at p. 2; Carrier, No. 29 at p. 4) Rheem commented that in a similar vein to its comment made on AHRI 210/240-2024 (

see

section III.B.1 of this document), DOE should be aware that the revised editions of ANSI/ASHRAE Standard 37 and ANSI/ASHRAE Standard 16 are currently not referenced in AHRI Standard 1600-2024. (Rheem, No. 34 at p. 4) Rheem further pointed to DOE`s inclusion of the energy efficiency metric energy efficiency ratio 2 (“EER2) in 10 CFR 430.23(m)(2); several sections of 10 CFR 429.16 and 10 CFR 429.134(k)(4); and sections 2, 4.1, and 4.2 of appendix M2 to subpart B of 10 CFR part 430, which in turn incorporate AHRI 1600-2024 by reference, which only includes energy efficiency ratio (“EER”) as the efficiency metric, and not EER2. (

Id.

at p. 5) Rheem stated that this mismatch should be resolved by either DOE revising its relevant references from EER2 to EER, or that AHRI 1600-2024 should be revised to replace all instances of EER with EER2. (

Id.

) Further, Rheem pointed out that section 4.1 of the new appendix M2 references 10 CFR 431.97, in relation to certification to the energy conservation standards SCORE and SHORE, and suggested this citation should be changed to 10 CFR 430.32(c), which will be amended to prescribe energy conservation standards for CAC/HPs. (

Id.

) Additionally, as noted in section III.B.1 for AHRI 210/240-2024, Rheem commented that table 8 of AHRI 1600-2024 should contain sentences similar to section 3.2.4(a) of appendix M1, to

specify that for variable-speed compressor systems, the cooling full compressor speed for both A2 and B2 tests should be same, and the cooling minimum compressor speed for the B1, F1, G1, and I1 tests should remain the same. (

Id.

at p. 4)

While AHRI`s comment noted support for the adoption of the AHRI 1600 standard at appendix M1, DOE surmises that this is a typographical error, and AHRI intended to express support for adoption at appendix M2 instead. As proposed in the April 2024 NOPR, appendix M1 references the draft AHRI 210/240 standard.

In response to Rheem's comment regarding AHRI 210/240-2024 retaining the EER2 metric while AHRI 1600-2024 using the EER metric, DOE agrees with Rheem that this mismatch has potential to confuse users of the test procedure. DOE notes that the EER2 metric in AHRI 210/240-2024 is identical to the EER metric in AHRI 1600-2024. Both metrics are evaluated at the same test conditions and convey the same full-load efficiency information. Therefore, for appendix M1, which references AHRI 210/240-2024, DOE is retaining the EER2 metric. For appendix M2, which references AHRI 1600-2024, DOE is including EER as the full-load metric, with EER evaluated the same way as EER2 per appendix M1. DOE is making appropriates changes in the regulatory text at 10 CFR parts 429 and 430, and appendix M2, to reflect this clarification. In response to Rheem's comment for the citation of the SCORE and SHORE energy conservation standards in the April 2024 NOPR, DOE agrees that the correct citation is to 10 CFR 430.32(c), and not 10 CFR 431.97. Finally, as mentioned in section III.B.1 of this document, DOE is adding language to section 2 of appendix M2 to explicitly state that for variable-capacity compressor systems, the cooling full compressor speeds for both A

Full

and B

Full

tests should be identical, and the cooling minimum compressor speed for the B

Low

, F

Low

, G

Low

, and I

Low

tests should be identical.

As discussed, AHRI 1600-2024 does not include any significant deviations from AHRI 1600-202X Draft. As such, the adoption of AHRI 1600-2024 in this final rule is consistent with the proposal to reference AHRI 1600-202X Draft in the April 2024 NOPR.

DOE is amending its test procedure for CAC/HPs by incorporating by reference AHRI 1600-2024 for use in the new appendix M2. Specifically, in the new test procedure for CAC/HPs at appendix M2, DOE is adopting sections 3 (excluding 3.2.16, 3.2.20, 3.2.45, 3.2.50, 3.2.63, 3.2.78, and 3.2.79), 5 (excluding 5.1.6.2), 6 (excluding 6.1.8, 6.2, 6.3, 6.4, and 6.5), 11, and 12 and appendices D, E, G, K, and L of the AHRI 1600-202X Draft in the Federal test procedure for CAC/HPs at appendix M2.

Additionally, consistent with the April 2024 NOPR, DOE is also incorporating by reference ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ANSI/ASHRAE 116-2010, which are referenced within AHRI 1600-2024. Therefore, in total, DOE is proposing to incorporate by reference AHRI 1600-2024, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ANSI/ASHRAE 116-2010, at appendix M2.

3. ANSI/ASHRAE 37-2009

ANSI/ASHRAE 37-2009 provides a method of test for electrically driven unitary air-conditioning and heat pump equipment, which includes CAC/HPs. In the April 2024 NOPR, DOE proposed to incorporate by reference ANSI/ASHRAE 37-2009 at both appendix M1 and appendix M2, since AHRI 210/240-202X Draft and AHRI 1600-202X Draft both reference test instructions in ANSI/ASHRAE 37-2009. 89 FR 24206, 24212. The finalized versions of these draft standards, AHRI 210/240-2024 and the AHRI 1600-2024, also reference ANSI/ASHRAE 37-2009. More specifically, sections 5, 6, 8, and 11 and appendices C, D, E, I, and J of AHRI 210/240-2024 and AHRI 1600-2024 refer to methods of test in ANSI/ASHRAE 37-2009.

DOE currently incorporates by reference ANSI/ASHRAE 37-2009 in 10 CFR part 430, subpart B, and the current incorporation by reference applies to the current Federal test procedure for CAC/HPs specified at appendix M1. Given that AHRI 210/240-2024 Draft references ANSI/ASHRAE 37-2009 for several test instructions, DOE has concluded, consistent with the April 2024 NOPR, that it is appropriate to maintain the existing incorporation by reference of ANSI/ASHRAE 37-2009 in appendix M1. Additionally, given that AHRI 1600-2024 references ANSI/ASHRAE 37-2009 for several test instructions, DOE has concluded, consistent with the April 2024 NOPR, that it is appropriate to incorporate by reference ANSI/ASHRAE 37-2009 for use with appendix M2.

4. ANSI/ASHRAE 16-2016

ANSI/ASHRAE 16-2016, which provides a method of test for rating room air conditioners, packaged terminal air conditioners, and packaged terminal heat pumps, is referenced for testing CAC/HPs by both the AHRI 210/240-202X Draft and the AHRI 1600-202X Draft. Consequently, in the April 2024 NOPR, DOE proposed to incorporate by reference ANSI/ASHRAE 16-2016 at both appendix M1 and appendix M2. 89 FR 24206, 24213. The finalized versions of the AHRI draft standards, AHRI 210/240-2024 and AHRI 1600-2024, also reference ANSI/ASHRAE 16-2016. More specifically, section 5.1.1 of AHRI 210/240-2024 and AHRI 1600-2024 refer to testing of non-ducted CAC/HPs from provisions in ANSI/ASHRAE 16-2016, or by using a combination of provisions in ANSI/ASHRAE 37-2009 and ANSI/ASHRAE 116-2016.

Currently, ANSI/ASHRAE 16-2016 is not incorporated by reference in appendix M1. DOE has concluded that testing conducted per ANSI/ASHRAE 16-2016 for non-ducted CAC/HPs will not impact ratings in comparison to testing conducted per provisions in ANSI/ASHRAE 37-2009 and ANSI/ASHRAE 116-2010. Thus, given that AHRI 210/240-2024 and AHRI 1600-2024 refer to ANSI/ASHRAE 16-2016 as an option for testing of non-ducted CAC/HPs, and it does not impact ratings, DOE has concluded, consistent with the April 2024 NOPR, that it is appropriate to incorporate by reference ANSI/ASHRAE 16-2016 for appendices M1 and M2.

5. ANSI/ASHRAE 116-2010

ANSI/ASHRAE 116-2010, which provides a method of test for unitary air conditioners and heat pumps with a cooling capacity of 65,000 Btu/h and less, is referenced for testing CAC/HPs by both AHRI 210/240-202X Draft and AHRI 1600-202X Draft. Consequently, in the April 2024 NOPR, DOE proposed to incorporate by reference ANSI/ASHRAE 116-2010 at both appendix M1 and appendix M2. 89 FR 24206, 24213. The finalized versions of the AHRI draft standards, AHRI 210/240-2024 and AHRI 1600-2024, also reference ANSI/ASHRAE 116-2010. More specifically, sections 5, 6, 8, and 11 and appendices D and E of AHRI 210/240-2024 and AHRI 1600-2024 refer to methods of test in ANSI/ASHRAE 116-2010.

Given that AHRI 210/240-2024 references ANSI/ASHRAE 116-2010 for several test instructions, DOE has concluded, consistent with the April 2024 NOPR, that it is appropriate to maintain the incorporation by reference of ANSI/ASHRAE 116-2010 in appendix M1. Additionally, given that the AHRI 1600-2024 Draft references ANSI/ASHRAE 116-2010 for several test instructions, DOE has concluded, consistent with the April 2024 NOPR, that it is appropriate to incorporate by reference ANSI/ASHRAE 116-2010 for use with appendix M2.

C. Revised CAC/HP Test Procedure

As discussed, EPCA requires that test procedures for each type of covered product, including CAC/HPs, not be unduly burdensome to conduct and be reasonably designed to produce test

results that reflect energy efficiency, energy use, and estimated operating costs during a representative average use cycle or period of use. (42 U.S.C. 6293(b)(3))

In this final rule, DOE is maintaining the current efficiency metrics, EER2, SEER2 and HSPF2, at appendix M1 and is referencing AHRI 210/240-2024 for measuring the existing metrics. DOE has determined that the amendments to appendix M1 would not affect the measured efficiency of CAC/HPs or require retesting solely because of DOE's adoption of the amendments to the appendix M1 test procedure. At appendix M1, DOE is incorporating by reference the following sections of the AHRI 210/240-2024: sections 3 (with certain exclusions

), 5 (with one exclusion

), 6 (with certain exclusions

), 11, and 12, as well as appendices D, E, G, K, and L.

DOE is not incorporating by reference the following provisions in section 3 of AHRI 210/240-2024 because the terms are either defined in appendix M1, or are not needed for the DOE test procedure: 3.2.16 (Double-duct System), 3.2.20 (Gross Capacity), 3.2.46 (Oil Recovery Mode), 3.2.51 (Published Rating), 3.2.63 (Standard Filter), 3.2.78 (Unitary Air-conditioner), and 3.2.79 (Unitary Heat Pump).

DOE is not incorporating by reference the following provision in section 5 of AHRI 210/240-2024 because the term is defined in appendix M1: 5.1.6.2 (Outdoor Unit with No Match (OUWNM)).

DOE is not incorporating by reference the following provisions in section 6 of AHRI 210/240-2024 because the provisions are either defined in 10 CFR 429.16, or are not needed for the DOE test procedure: 6.1.8 (Tested Combinations or Tested Units), 6.2 (Application Ratings), 6.3 (Publication of Ratings), 6.4 (Ratings), and 6.5 (Uncertainty and Variability).

Additionally, DOE is establishing a new test procedure at appendix M2 that adopts AHRI 1600-2024, including the new SCORE and SHORE metrics.

Use of appendix M2 is not required until the compliance date of any amended standards denominated in terms of the new metrics for appendix M2, should such standards be adopted. At appendix M2, DOE is referencing the following sections of AHRI 1600-2024: sections 3 (with certain exclusions

), 5 (with one exclusion

), 6 (with certain exclusions

), 11, and 12 and appendices D, E, G, K and L.

As explained in Section III.B.2, DOE will replace EER2 in appendix M1 with EER in appendix M2. However, EER will be calculated in a manner identical to EER2, and both convey the same full load test information.

DOE is not incorporating by reference the following provisions in section 3 of AHRI 1600-2024 because the terms are either defined in appendix M1, or are not needed for the DOE test procedure: 3.2.16 (Double-duct System), 3.2.20 (Gross Capacity), 3.2.45 (Oil Recovery Mode), 3.2.50 (Published Rating), 3.2.63 (Standard Filter), 3.2.78 (Unitary Air-conditioner), and 3.2.79 (Unitary Heat Pump).

DOE is not incorporating by reference the following provision in section 5 of AHRI 1600-2024 because the term is defined in appendix M2: 5.1.6.2 (Outdoor Unit with No Match (OUWNM)).

DOE is not incorporating by reference the following provisions in section 6 of AHRI 1600-2024 D because the provisions are either defined in 10 CFR 429.16, or are not needed for the DOE test procedure: 6.1.8 (Tested Combinations or Tested Units), 6.2 (Application Ratings), 6.3 (Publication of Ratings), 6.4 (Ratings), and 6.5 (Uncertainty and Variability).

Further, at both appendix M1 and appendix M2, DOE is incorporating by reference the following: ANSI/ASHRAE 37-2009, except sections 1 (Purpose), 2 (Scope), and 4 (Classifications); ANSI/ASHRAE 16-2016 except sections 1 (Purpose), 2 (Scope), and 4 (Classifications); and ANSI/ASHRAE 116-2010 except sections 1 (Purpose), 2 (Scope), 4 (Classifications), and 7 (Methods of Test).

D. Efficiency Metrics

As discussed, DOE is updating the current Federal test procedure for CAC/HPs at appendix M1 consistent with the most recent draft version of the relevant industry consensus test procedure, AHRI 210/240-2024. DOE is also establishing a new Federal test procedure at 10 CFR part 430, subpart B, appendix M2, consistent with the new industry consensus test procedure, AHRI 1600-2024. Sections III.D.1 and III.D.2 of this document discuss which metrics are applicable for appendices M1 and M2, respectively.

1. Metrics Applicable to Appendix M1

Consistent with the April 2024 NOPR, appendix M1 maintains the current energy efficiency metrics (

i.e.,

EER2, SEER2, and HSPF2), and includes a new optional metric: the peak load coefficient of performance (“COP

peak

”), applicable to central heat pumps (“CHPs”). The amendments to appendix M1 to align with AHRI 210/240-2024 maintain the existing energy efficiency metrics, and DOE has determined that testing under appendix M1 would be consistent with the existing test procedure and there would be no impact on measured efficiencies.

2. Metrics Applicable to Appendix M2

The newly established appendix M2 introduces new integrated cooling and integrated heating efficiency metrics, namely SCORE and SHORE, respectively. Unlike SEER2 and HSPF2, which are seasonal energy efficiency descriptors, SCORE and SHORE are integrated metrics that include off mode power, P

W,OFF

. Hence, appendix M2 will not require separate representations for off mode power. Appendix M2 will retain the full-load EER metric, with EER evaluated in the same way as appendix M1.

Appendix M2 also includes the optional metric COP

peak

AHRI 1600-2024 replaced the EER2 and COP2 metrics from AHRI 210/240-2024 with EER and COP. For consistency, appendix M2 will follow the nomenclature in AHRI 1600-2024 and will hence use EER as the full-load metric, while appendix M1 will use the EER2 metric.

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

The following sections discuss issues that affect the CAC/HP test procedure in the near term—

i.e.,

they will be required 180 days after publication of the final rule. As previously explained, these near-term revisions are implemented at appendix M1 via incorporation by reference of the relevant industry consensus test procedure, AHRI 210/240-2024. DOE has reviewed AHRI 210/240-2024 and has concluded that it satisfies the EPCA requirement that test procedures should not be unduly burdensome to conduct and should be representative of an average use cycle. (42 U.S.C. 6293(b)(3)) These near-term amendments in appendix M1 do not alter the measured efficiency of CAC/HPs in terms of the current cooling and heating test metrics, SEER2 and HSPF2, or the current off mode metric, P

W,OFF

DOE clarifies that while all issues discussed subsequently within this section are near-term, they are also part of the long-term CAC/HP test procedure—

i.e.,

these revisions are also included in AHRI 1600-2024, which DOE is incorporating by reference at appendix M2. As such, when discussing these near-term changes, DOE makes references to both AHRI 210/240-2024 and AHRI 1600-2024.

1. Controls Verification Procedure for Variable-Speed Systems

Appendix M1 uses a steady-state test concept for variable-speed systems where test room conditions are kept within narrow operating tolerances for each test point, and the CAC/HP system is manually controlled to operate at a fixed specified compressor speed and airflow rate for each test point. As part of the previous rulemaking, several stakeholders encouraged DOE to review ways to improve the representativeness of the test procedures for CAC/HPs (especially variable-speed systems), particularly to consider test procedures where the unit operates under its own native controls in responding to conditioning loads (

i.e.,

load-based testing).

A load-based test method differs from the steady-state test method currently used in DOE test procedures for air-conditioning and heat pump equipment. In a steady-state test method, the indoor room is maintained at a constant temperature

throughout the test. In this type of test, any variable-speed or variable-position components of air conditioners and heat pumps are set in a fixed position, which is typically specified by the manufacturer. In contrast, a load-based test has the conditioning load applied to the indoor room using a load profile that approximates how the load varies for units installed in the field. In this type of test, an air-conditioning system or heat pump is allowed to automatically determine and vary its control settings in response to the imposed conditioning loads rather than relying on manufacturer-specified settings.

To review this topic in detail as part of the current rulemaking, in an RFI published on January 24, 2023, (the “January 2023 RFI”), DOE requested comments, information, and data pertaining to the consideration of load-based testing methodologies under development by various organizations and whether certain aspects of these methodologies might be adopted into the DOE test procedure. 88 FR 4091, 4098-4101.

In the April 2024 NOPR, based on review of the stakeholder comments received in response to the January 2023 RFI—specifically, that it has not yet been conclusively demonstrated that load-based testing methods have sufficient repeatability and reproducibility to be the basis of direct measurement of system performance—DOE tentatively concluded that use for direct measurement of performance for regulatory purposes would not be suitable at this time. 89 FR 24206, 24220. Instead, DOE tentatively concluded that it would be appropriate to continue to allow regulatory tests to use fixed-speed settings for testing variable-speed systems, while developing a controls verification procedure (“CVP”) that could be used for audit, assessment, and enforcement testing to ensure that the fixed-speed settings are representative of native (unfixed) control, in which the control system may vary compressor speed and/or indoor airflow.

Id.

DOE noted that AHRI and other relevant stakeholders, including DOE, participated in the development of revised AHRI test standards to address several issues raised in the January 2023 RFI, including the representativeness of fixed-speed testing for variable-speed systems. 89 FR 24206, 24220. From these discussions on the revised AHRI test standards, consensus was developed on using a CVP approach.

Id.

In section III.F.1.e of the April 2024 NOPR, DOE provided a summary of the CVP approach in Appendix I of AHRI 210/240-202X Draft and AHRI 1600-202X Draft. 89 FR 24206, 24220-24222.

DOE acknowledged that the CVP approach outlined in appendix I of the relevant AHRI drafts represented industry consensus regarding: (1) the verification of compliance of systems with the variable capacity system definition, and (2) verification of the consistency of fixed-speed settings of compressor and indoor fans with native control operation as part of enforcement. 89 FR 24206, 24222. DOE considered that the CVP approach presented a more representative test procedure for variable-speed systems operating in the field, because it provided a tool to verify that the fixed compressor speed settings and indoor air fan settings used in regulatory tests are representative of native control operation as the unit operates to maintain the thermostat set point,

i.e.,

indoor dry-bulb temperature.

Id.

For these reasons, DOE proposed to incorporate by reference appendix I of AHRI 210/240-202X Draft to support enforcement associated with testing conducted in accordance with appendix M1, and to incorporate by reference appendix I of AHRI 1600-202X Draft to support enforcement associated with testing conducted in accordance with appendix M2.

Id.

In response to DOE's proposal, several stakeholders, namely Lennox, the CA IOUs, Rheem, Daikin, GE Appliances, and Carrier, generally showed support for DOE's proposal on implementing the CVP approach for certification of variable-speed products. (Lennox, No. 24 at p. 2; CA IOUs, No. 32 at p. 2; Rheem, No. 34 at p. 5; Daikin, No. 36 at p. 3; GE Appliances, No. 37 at p. 4; Carrier, No. 29 at p. 5)

The Joint Advocates commented that even though it is not appropriate to adopt load-based testing for measuring the direct regulatory test performance of CAC/HPs due to insufficient information on repeatability and reproducibility of load-based testing methods, DOE should consider adopting them as an integral part of the test procedure in a future update to the CAC/HP test procedure. (Joint Advocates, No. 30 at pp. 3-4) Further, the Joint Advocates commented that test data that will better inform repeatability and reproducibility of load-based tests will be coming out in the near future. (

Id.

) The Joint Advocates expressed concern that since the CVP is only an enforcement provision, manufacturers are not required to conduct it while rating their product, and hence, adopting some version of load-based testing will ensure that all certified ratings are more representative of unit performance in the field. (

Id.

)

In response to the Joint Advocates' comment, DOE reiterates that it explored the potential of adopting a load-based method for direct measurement of performance in the April 2024 NOPR. However, as discussed in the April 2024 NOPR, the consensus of affected stakeholders was to adopt a CVP approach instead of a wholesale load-based method test procedure. 89 FR 24206, 24222. DOE is not aware of additional information, such as new load-based test data, available for review to assess the feasibility of adopting load-based testing as a mandatory part of the CAC/HP test procedure. Even though the CVP is primarily intended for use by DOE for assessment and enforcement purposes, it is expected that manufacturers will preemptively utilize the CVP to evaluate the fixed-speed settings used for certification tests of their variable-speed products to ensure consistency with native-control operation.

AHRI 210/240-2024 and AHRI 1600-2024, the industry standards DOE is referencing in this final rule, finalized the relevant test method for the CVP at appendix I without any substantial change as compared to their corresponding drafts. Therefore, consistent with the April 2024 NOPR, DOE is incorporating by reference appendix I of AHRI 210/240-2024 to support enforcement associated with testing conducted in accordance with appendix M1, and to incorporate by reference appendix I of AHRI 1600-2024 to support enforcement associated with testing conducted in accordance with appendix M2. The enforcement provisions are discussed in more detail in section III.I.2 of this document.

2. Low-Temperature Heating Performance

In the April 2024 NOPR, DOE proposed to incorporate by reference AHRI 210/240-202X and AHRI 1600-202X Drafts and adopt several test procedure provisions that pertained to low-temperature heating performance. 89 FR 24206, 24222-24225. Specifically, DOE proposed to (1) reference the definition of “cold climate heat pump” (“CCHP”) contained in the AHRI drafts, (2) reference the requirement for products certified as a CCHP to conduct the H4 heating test (either the H4, H4

Full

, or H4

Boost

heating test, as applicable), (3) retain the current size-for-cooling approach, and (4) include COP

peak

as an optional representation for combined heat pump and electric resistance heat efficiency at 5 °F outdoor temperature for CHPs, as outlined in appendix K of AHRI 210/240-202X and AHRI 1600-202X Drafts,

at appendix M1 and appendix M2, respectively.

In several instances of the April 2024 NOPR, DOE incorrectly referred to appendix L of the

respective AHRI 210/240-202X and AHRI 1600-202X Drafts as the appendices regarding COP

peak

. (

See

89 FR 24206, 24225). These were typographical errors, since the appendices regarding COP

peak

are at appendix K of the respective AHRI 210/240-202X and AHRI 1600-202X Drafts.

DOE did not receive any comments regarding the aforementioned proposals in the April 2024 NOPR. AHRI 210/240-2024 and AHRI 1600-2024, the final versions of the draft AHRI standards, finalized the same low-temperature heating performance provisions without change. Therefore, consistent with the April 2024 NOPR proposal, DOE is incorporating by reference AHRI 210/240-2024 and AHRI 1600-2024 and adopting the low-temperature heating performance provisions discussed in the aforementioned paragraphs.

3. Cut-Out and Cut-In Temperature Verification

Appendix J of AHRI 210/240-202X Draft and also of AHRI 1600-202X Draft includes a test applicable to all CHPs to determine cut-out and cut-in temperatures (

i.e.,

off

and T

respectively).

In the April 2024 NOPR, DOE proposed that during assessment and enforcement testing of CHPs, DOE may verify the cut-out and cut-in temperatures using the test specified in appendix J of AHRI 210/240-202X Draft, when conducting assessment and enforcement testing associated with appendix M1, and the test specified in appendix J of AHRI 1600-202X Draft, when conducting assessment and enforcement testing associated with appendix M2. The proposal indicated that, if conducting the appendix J cut-out/cut-in verification, the tested values determined for these temperatures would be used as the T

off

and T

values for the unit. 89 FR 24206, 24226.

In several instances of the April 2024 NOPR, DOE incorrectly referred to appendix K of the respective AHRI 210/240-202X and AHRI 1600-202X Drafts as the appendices regarding cut-out and cut-in temperature verification. (

See

89 FR 24206, 24226 and 89 FR 24206, 24243). These were typographical errors, since the appendices regarding cut-out and cut-in temperature verification are at appendix J of the respective AHRI 210/240-202X and AHRI 1600-202X Drafts.

AHRI 210/240-2024 and AHRI 1600-2024, the industry standards DOE is referencing in this final rule, finalized the relevant test method for determining cut-out and cut-in temperatures at appendix J without any substantial change as compared to their respective drafts. Therefore, consistent with the April 2024 NOPR, DOE is incorporating by reference appendix J of AHRI 210/240-2024 and AHRI 1600-2024 at appendix M1 and appendix M2, respectively.

As further discussed in section III.I.1 of this document, DOE may verify certified cut-out and cut-in temperatures using the test methods in appendix J of the relevant AHRI drafts for the purposes of assessment and enforcement testing.

4. Low-Static Single-Split Blower-Coil System Definition and Testing Provisions

Section 3.1.4.1.1 of appendix M1 defines the minimum external static pressure (“ESP”) for ducted blower-coil systems in table 4. For conventional blower-coil systems (

i.e.,

all CAC/HPs that are not classified as ceiling-mount, wall-mount, mobile home, low-static, mid-static, small-duct high-velocity (“SDHV”), or space-constrained), the minimum ESP is specified as 0.5 inches of water column (“in. wc.”). The definition for low-static blower-coil systems includes only multi-split and multi-head mini-split systems—it does not include single-split systems.

AHRI 210/240-202X Draft and AHRI 1600-202X Draft include a new definition specific for low-static single-split blower-coil systems, as shown below.

“Low-static single-split blower-coil system” means a ducted single-split system air conditioner or heat pump for which all of the following apply:

(1) The Outdoor Unit has a Specified cooling capacity less than or equal to 24,000 Btu/h;

(2) If the Outdoor Unit is a heat pump or a variable capacity air conditioner, it is separately Specified with a blower-coil indoor unit tested with a minimum 0.5 in H2O ESP, otherwise it is separately Specified with a coil-only indoor unit; and

(3) The Indoor Unit is marketed for and produces a maximum ESP less than 0.5 in H2O when operated at the Specified cooling full-load airflow not exceeding 400 scfm per Specified ton of cooling.

Both drafts also include provisions requiring low-static single-split blower-coil systems to be tested at their specified airflow (not to exceed 400 standardized cubic feet per minute (“scfm”) per specified ton of cooling capacity) at their maximum airflow setting. If the ESP achieved at the specified airflow is less than 0.1 in. wc., the provisions require adjustment of the airflow measurement apparatus fan to reduce airflow and increase ESP until a minimum of 0.1 in. wc. is achieved.

In the April 2024 NOPR, DOE proposed to incorporate by reference the new definition of low-static single-split blower-coil system and associated testing provisions, which would include single-split systems that cannot accommodate the 0.5 in. wc. required for testing single-split blower-coil systems in accordance with the current DOE test procedure in appendix M1. 89 FR 24206, 24227.

DOE did not receive any comments regarding the aforementioned proposals in the April 2024 NOPR. AHRI 210/240-2024 and AHRI 1600-2024 finalized the definition and testing provisions for low-static single-split blower-coil systems without substantial change as compared with their respective drafts. Therefore, consistent with the April 2024 NOPR proposals, DOE is incorporating by reference AHRI 210/240-2024 and AHRI 1600-2024, and adopting the definition and testing provisions for low-static single-split blower-coil systems.

In advance of adopting these changes, multiple manufacturers, including Samsung HVAC America LLC (“Samsung”),

Mitsubishi,

and Hisense (Guangdong) Air Conditioning Co. Ltd. (“Hisense”),

petitioned DOE for test procedure waivers pertaining to low-static single-split blower-coil systems. All petitions asserted nearly identical circumstances and model limitations—that it was impossible to test certain basic models according to appendix M1 because the models could not operate at the conventional minimum ESP requirement of 0.5 in. wc. found in table 4 of appendix M1. Subsequently, manufacturers could not certify compliance for or sell these products.

See

Samsung's petition at

www.regulations.gov/docket/EERE-2023-BT-WAV-0010.

See

Mitsubishi's petition at

www.regulations.gov/docket/EERE-2023-BT-WAV-0015.

See

Hisense's petition at

www.regulations.gov/docket/EERE-2023-BT-WAV-0011.

On June 5, 2023, DOE published a notification of petition for waiver and grant of an interim waiver that permits Samsung to use an alternative test procedure for the basic models subject to its petition. 88 FR 36558. The alternative test procedure allows Samsung to test its basic models that are designed for low-static, short-duct applications at 0.1 in. wc. ESP and to make proportional adjustments to fan power and capacity such that the results are equivalent to performance measured at 0.5 in. wc. ESP. 88 FR 36558, 36561-36563. DOE initially determined that this alternate test procedure was appropriate and allowed for the accurate measurement of the energy efficiency of the specified basic models, while alleviating the testing problems cited in implementing the DOE test procedure for the models.

Id.

In the April 2024 NOPR, DOE noted that, should the new definition of low-

static single-split blower-coil system and the associated testing provisions be adopted, DOE would terminate Samsung's interim waiver pending final determination. 89 FR 24206, 24227. The interim waiver was granted with the understanding that it was impossible to test the manufacturer's specific basic models according to the prescribed test procedures in appendix M1. Given that DOE is adopting provisions for low-static single-split blower-coil systems, DOE concludes that this alternate test procedure is no longer necessary. Therefore, DOE is terminating the aforementioned waiver for Samsung. DOE notes that the ratings for the subject Samsung basic models may change when moving to the amended appendix M1 test procedure outlined in this final rule.

DOE has not published a notification of petition for waiver or granted interim waivers for either the Mitsubishi or Hisense petitions. However, for the same reasons that DOE is terminating Samsung's aforementioned waiver, DOE concludes that an alternate test procedure is no longer necessary. DOE considers the petitions submitted by Mitsubishi and Hisense to be addressed sufficiently by the low-static single-split blower-coil system definition and testing provisions adopted in this final rule.

5. Mandatory Constant Circulation Systems

Currently, nearly all CAC/HP products are designed with R-410A as the refrigerant. However, under global warming potential (“GWP”) restrictions enacted by an Environmental Protection Agency (“EPA”) final rule published on October 24, 2023 (“October 2023 EPA final rule”), the use of R-410A is scheduled to be phased out for CAC/HP products.

88 FR 73098. The EPA Significant New Alternatives Policy (“SNAP”) Program evaluates and regulates substitutes for ozone-depleting chemicals (such as CAC/HP refrigerants) that are being phased out under the stratospheric ozone protection provisions of the Clean Air Act. (42 U.S.C. 7401

et seq.

)

Of interest to CAC/HPs, the EPA SNAP Program's list of viable substitutes

includes a group of refrigerants classified as A2L refrigerants. While these refrigerants have GWP levels meeting the requirements of the October 2023 EPA Final Rule, they face stricter safety requirements than R-410A due to the moderate flammability associated with their “2L” ASHRAE safety classification.

Many of the safety requirements specifically address mitigation of ignition risk in case of refrigerant leakage. One mitigation option for refrigerant leakage is air circulation, which can be initiated when a leak is detected, or the system can use “constant circulation,” running the fan, typically at a reduced speed, at all times. This latter approach has energy use implications, which are addressed in the AHRI 210/240 and AHRI 1600 standards.

EPA published an interim final rule on December 26, 2023 (“EPA Technology Transition Interim Final Rule”) that allows 1 additional year, until January 1, 2026, solely for the installation of new CAC/HPs using components manufactured or imported prior to January 1, 2025. 88 FR 88825.

Additional information regarding EPA's SNAP Program is available online at

www.epa.gov/ozone/snap/.

A list of EPA SNAP Program-approved refrigerant substitutes is available at

www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps.

ASHRAE assigns safety classification to refrigerants based on toxicity and flammability data. The capital letter designates a toxicity class based on allowable exposure, and the numeral denotes flammability. For toxicity, class A denotes refrigerants of lower toxicity, and class B denotes refrigerants of higher toxicity. For flammability, class 1 denotes refrigerants that do not propagate a flame when tested as per the standard; classes 2 and 2L denote refrigerants of lower flammability; and class 3 denotes highly flammable refrigerants (such as hydrocarbons).

DOE is aware that a refrigerant leakage detection system may also draw power, which would also be addressed in the AHRI 210/240 and AHRI 1600 test standards. However it is DOE's understanding that the impact of this power is much less than operation of the fan in constant circulation mode.

AHRI 210/240-202X Draft and AHRI 1600-202X Draft include a new definition for “mandatory constant circulation system” (“MCCS”). The updated industry standard drafts also include testing provisions for such systems, specifically requiring that CAC/HPs meeting the mandatory constant circulation system definition not use the default cooling and heating degradation coefficients, but rather evaluate these degradation coefficients using the respective cyclic tests specified by table 7 of AHRI 210/240-202X Draft and AHRI 1600-202X Draft, conducted in accordance with section E12 of appendix E of AHRI 210/240-202X Draft and AHRI 1600-202X Draft. In the April 2024 NOPR, DOE proposed to incorporate by reference the new definition of MCCS and the aforementioned testing provisions outlined in AHRI 210/240-202X Draft and AHRI 1600-202X Draft, at appendix M1 and appendix M2, respectively. 89 FR 24206, 24228.

In response to DOE's proposal, Carrier expressed support for the MCCS testing approach, but it commented that there is ambiguity regarding the specific products to which the MCCS testing approach applies. (Carrier, No. 29 at pp. 2-3) Carrier stated that for a CAC/HP system with a charge quantity between m1 and m2,

the room size in which the UL 60335-2-40 4th edition refrigerant safety standard allows the system to be installed (or the effective volume into which refrigerant would be dispersed in case of leakage) is limited. Further, this limitation can be stricter if the system does not employ air circulation, either continuously or initiated by a refrigerant leak detection system (“LDS”). (

Id.

) Carrier requested that DOE provide further specificity on the testing approach for products that might require air circulation as mitigation in some installations but not necessarily all installations. (

Id.

) Carrier recommended that DOE require all systems with a charge level greater than m1 and less than or equal to m2 that do not contain an LDS be tested as an MCCS since how and where these products are installed in the field are outside the manufacturer's control (besides a label specifying the required area). (

Id.

)

UL 60335-2-40 fourth edition defines charge quantities m1 and m2 based on the type of refrigerant.

In a rebuttal, Daikin opposed Carrier's aforementioned recommendation, for several reasons. (Daikin, No. 40 at p. 1) First, Daikin commented that UL 60335-2-40 4th edition is clear in its requirements for information that must be provided in installation instructions, including instructions regarding how to install the product in accordance with refrigerant safety codes, including how to meet the minimum floor area requirements. (

Id.

) Daikin specifically pointed to Annex DD of UL 60335-2-40 4th edition, which specifies that an original equipment manufacturer (“OEM”) must include details of minimum installation height, minimum floor area, and other appropriate information in installation instructions to ensure safety requirements are met. (

Id.

) Daikin also commented that CAC/HPs using A2L refrigerant, in addition to providing information in installation instructions, must have adequate warning labels (per Clause 7 of UL 60335-2-40 4th edition, Annex 101.DVF of UL 60335-2-40 4th edition, and EPA SNAP Rule 25), such that the installer will be well aware the product being installed needs special attention. (

Id.

)

Second, Daikin commented that the minimum floor area required by ASHRAE 15.2 (with which UL 60335-2-40 requires compliance), for some situations, does not depend on whether

the system employs circulation (whether continuous or LDS initiated) to meet mitigation requirements. (Daikin, No. 40 at p. 2)

Third, Daikin commented that, if a manufacturer chooses to use continuous circulation airflow as the method of leak mitigation, the manufacturer must conduct additional safety verification of that function, per Annex GG of UL 60335-2-40 4th edition (specifically, Clause GG.2.2.2DV). (Daikin, No. 40 at pp. 2-3) Annex GG of UL 60335-2-40 4th edition states that a product using continuous circulation shall (1) run the indoor fan continuously, except for short periods of maintenance and service; (2) detect or monitor continuously if the airflow rate drops below a specific level (Q

min

); and (3) if the airflow drops below the specified level, provide an output signal that airflow is reduced and disable compressor operation unless the compressor operation reduces the leak rate or the total amount of refrigerant released to the indoor space. Consequently, Daikin commented that, if the manufacturer chooses to rely on continuous circulation as the mitigation method, the OSHA-certified Nationally Recognized Testing Laboratory (“NRTL”) that certifies the product to meet the safety standard UL 60335-2-40 must check by inspection that the manufacturer runs the fan continuously. (

Id.

)

Fourth, Daikin commented on the DOE test procedure emphasis on installation instructions. (Daikin, No. 40 at p. 3) The DOE test procedure requirement to follow the OEM installation instructions when installing a system for testing is based on the premise that the installation instructions provide a setup representative of field installation. Thus, Daikin asserted it would be logical for DOE to be consistent and also assume that the installing contractor would follow requirements related to refrigerant safety that are laid out in installation instructions. (

Id.

)

In response to the Carrier and Daikin comments, it is DOE's understanding (as noted in Daikin's comment) that use of constant circulation as the method of refrigerant leakage risk mitigation requires that the CAC/HP product must be inherently designed with this feature—a contractor cannot be in compliance with UL 60335-2-40 4th edition requirements if the feature is selected in the field for a system that does not inherently already have it. Specifically, an NRTL must certify upon inspection that a product using constant circulation for safety code compliance indeed runs its indoor fan continuously. Thus, the circumstances “outside the manufacturer's control” involving installation by a contractor using constant circulation as the means of mitigation of systems without LDS and without MCCS that Carrier mentioned in its comment are violations of refrigerant safety codes. While such violations may occur in the future, DOE concludes that the seriousness of the potential consequences would make them infrequent,

i.e.,

such circumstances could not be considered representative of the installation of such systems. Therefore, DOE determines that, for testing according to the DOE test procedure, it is not appropriate to require testing using constant circulation for products with charge between m1 and m2 that don't have an LDS and are not inherently an MCCS. However, any product using constant circulation to comply with refrigerant safety codes that would meet the MCCS definition in AHRI 210/240-202X Draft and AHRI 1600-202X Draft could be verified to have this status by powering up the unit, and consequently will be required to test as an MCCS.

AHRI 210/240-2024 and AHRI 1600-2024 finalized the definition and testing provisions for MCCS without substantial change. DOE has determined that the definition and approach included in the finalized versions provide a more representative measure of CAC/HP efficiency for systems utilizing mandatory constant circulation as a means of refrigerant leakage mitigation. Therefore, consistent with the April 2024 NOPR proposals, DOE is incorporating by reference AHRI 210/240-2024 and AHRI 1600-2024 and adopting the definition and testing provisions for MCCS.

Daikin noted in its comment that the certification aspects of the MCCS test procedure changes were not included in the April 2024 NOPR. (Daikin, No. 40 at p. 3) Daikin recommended that DOE include as mandatory certification a declaration from the manufacturer regarding whether the CAC/HP product relies upon mandatory continuous circulation or not. (

Id.

) Further, Daikin suggested that whether a product uses continuous circulation or not could be validated by operation of the product when it is powered up, as well as validated by the safety agency (

i.e.,

NRTL) certification report. (

Id.

)

In response to Daikin's recommendation, DOE notes that it will consider certification requirements for CAC/HPs, including a requirement to certify whether the CAC/HP product relies upon mandatory constant circulation or not, in a separate rulemaking. However, DOE may validate whether a system utilizes constant circulation when powered up for the purposes of assessment or enforcement testing.

6. Dual-Fuel Heat Pumps

Heat pumps generally have reduced capacity and perform less efficiently at low ambient outdoor temperatures than they do at moderate ambient outdoor temperatures. Most heat pumps require some form of auxiliary heat when outdoor temperature is low to satisfy building load in excess of heat pump capacity. DOE is aware of HPs that combine the operation of a conventional electric HP with back-up heat provided by fuel, such as a gas fuel-fired furnace or boiler. These are referred to as “dual-fuel” systems or hybrid heat pumps (“HHPs”) and provide an alternative to heat pumps specifically designed to perform in cold climates (

i.e.,

cold climate heat pumps). Dual-fuel systems rely on heat pump operation at milder ambient temperatures, but switch to the back-up heating source at low ambient temperatures.

The AHRI 210/240-202X Draft and AHRI 1600-202X Draft included a new definition for dual-fuel heat pump systems. Additionally, the two AHRI drafts introduced a new seasonal efficiency metric, Dual Fuel Utilization Efficiency (“DFUE”), meant to capture the heating efficiency of such dual-fuel heat pump systems. Calculation of DFUE according to the draft standards is optional, requires no additional testing, and is outlined in appendix L of both standards.

In the April 2024 NOPR, DOE tentatively determined that while the definition and optional test approach included in the draft industry standards may provide a representative test approach for dual-fuel heat pump systems, DOE was at that time continuing to evaluate whether to include such provisions in its CAC/HP test procedures. 89 FR 24206, 24229. Therefore, DOE proposed to not incorporate by reference the new definition of dual-fuel heat pump and the optional seasonal efficiency metric, DFUE, outlined in the AHRI 210/240-202X and AHRI 1600-202X Drafts.

Id.

AHRI 210/240-2024 and AHRI 1600-2024 finalized the definition and optional seasonal efficiency metric, DFUE, for dual-fuel heat pump without substantial change. Based on DOE's continued evaluation of the dual-fuel provisions in the two AHRI drafts, DOE has concluded that such provisions are not necessary in the CAC/HP test procedures. Therefore, DOE is not incorporating by reference the new definition of dual-fuel heat pump and

the optional seasonal efficiency metric, DFUE, outlined in the AHRI 210/240-2024 and AHRI 1600-2024. However, DOE recognizes that representations of dual-fuel heat pump performance may be useful to consumers. Therefore, while DOE is not proposing provisions for dual-fuel heat pumps, DOE would allow manufacturers to make optional representations of dual-fuel heat pump performance consistent with available AHRI industry test standards.

DOE notes that since dual-fuel heat pump systems are comprised of two covered products currently subject to energy conservations standards (

i.e.,

a heat pump and a furnace), DOE would continue to require reporting of the relevant CAC/HP and consumer furnace heating metrics—EER2, SEER2, HSPF2, EER, SCORE and SHORE for CAC/HP, and AFUE for consumer furnaces; regardless of whether a manufacturer chooses to rate their dual-fuel heat pumps with the DFUE metric. DOE also notes that the current representation requirements at 10 CFR 429.16 require representation of every individual heat pump combination distributed in commerce. As such, installing an outdoor HP unit and an indoor coil with an existing furnace (or other air mover) that is not being replaced would constitute distribution in commerce of a coil-only heat pump combination for which DOE requires a coil-only representation.

7. Rating Individual Components of Split Systems

(a) Background

DOE's test procedure in appendix M1 and its rating and certification requirements for central air conditioners and heat pumps in 10 CFR 429.16 have provisions that apply based on the configurations in which these products are distributed in commerce. This includes provisions for outdoor units of a split system that are not distributed in commerce with any indoor units, which DOE's regulations refer to as an outdoor unit with no match (“OUWNM”).

Specifically, 10 CFR 429.16(b)(2) requires that the ratings for basic models of split-system central air conditioners or heat pumps distributed in commerce as an OUWNM be based on the testing of a model of coil-only indoor unit meeting the requirements of section 2.2e of appendix M1. Section 2.2.e of appendix M1 requires that an OUWNM be tested using a coil-only indoor unit with a single cooling air volume rate whose coil has round tubes of outer diameter no less than 0.375 inches, and normalized gross indoor fin surface (“NGIFS,” gross indoor fin surface divided by the measured cooling capacity) no greater than 1.0 square inch per British thermal unit per hour (sq in/Btu/hr). (10 CFR 429.16 (b)(2)(i) and appendix M1, section 2.2.e) These provisions were introduced in a final rule regarding CAC/HP test procedures published on June 8, 2016 (“June 2016 Final Rule”), to address outdoor-unit-only replacements of old R-22 outdoor units. 81 FR 36992, 37008-37012.

Effective January 1, 2010, EPA banned sales and distribution of CAC/HPs designed to use R-22, a hydrochlorofluorocarbon (“HCFC”) refrigerant that causes ozone depletion. 74 FR 66450 (Dec. 15, 2009). However, EPA continued to allow sale and distribution of “components” of CAC/HP systems for repair purposes, such as outdoor units.

Id.

at 74 FR 66452. In the June 2016 Final Rule, DOE introduced the testing provisions for OUWNMs to ensure that performance ratings for such installations would be representative of the replacement of outdoor units originally designed for R-22 and using the original indoor units.

See

81 FR 36992, 37008-37011.

In a final rule published on October 24, 2023 (“October 2023 EPA final rule”), pursuant to provisions of the American Innovation and Manufacturing Act (“AIM Act”), enacted on December 17, 2020 (42 U.S.C. 7675), EPA restricted the installation of residential and light commercial systems that are designed for hydrofluorocarbon (“HFC”) refrigerants having a GWP greater than 700, starting January 1, 2025. 88 FR 73098. On December 26, 2023, EPA published an amendment to the October 2023 EPA Final Rule that extended the installation deadline to January 1, 2026, as long as the “specified components” being installed were manufactured or imported prior to January 1, 2025 (“December 2023 EPA interim final rule”). 88 FR 88825.

Split-system CAC/HPs are included in the scope of residential and light commercial systems As such, new split-system CAC/HPs designed for use with R-410A and sold as a combination of an outdoor and indoor unit would be banned for installation, per the October 2023 EPA Final Rule. However, EPA provides an exemption, permitting the sales of specified components, to allow consumers to service and repair existing systems that are over the GWP limits defined in the October 2023 EPA Final Rule, provided the specified components are used only to service existing systems and are subject to labeling and reporting requirements. 88 FR 73098, 73124-73125. This provides an exemption for individual specified components of R-410A based split-system CAC/HPs to be sold as replacements, including condensing units and evaporator units, similar to the component exemption adopted by the EPA when R-22 was phased out. 74 FR 66450, 66459-66460.

(b) NOPR Proposal

In the April 2024 NOPR, DOE noted that while the current OUWNM provisions were precipitated by EPA's ruling on R-22 units, DOE's intention was to apply them more broadly to any case where an outdoor unit is sold without an indoor unit. 89 FR 24206, 24230. DOE noted that the current OUWNM provisions apply for any outdoor units that are distributed in commerce without an indoor matching pair, regardless of the refrigerant the outdoor unit employs.

Id.

DOE clarified that per the October 2023 EPA Final Rule, any outdoor unit designed for R-410A or any banned refrigerant as per EPA regulations, when distributed in commerce without an indoor unit on or after January 1, 2026, would be deemed an outdoor unit with no match.

Id.

DOE further noted that, similar to EPA requirements for the R-22 ban, EPA is allowing such an outdoor unit to be installed as a replacement specified component for an existing system but not to be installed with indoor units for installation as a complete split CAC/HP system.

Id.

DOE noted that appendix M1 currently does not explicitly define outdoor units with no match and that while AHRI 210/240-202X Draft and AHRI 1600-202X Draft define outdoor units with no match, the definition applies explicitly only to R-22 replacement outdoor units and outdoor units using refrigerants with properties similar to R-22.

Id.

Because the definition of outdoor unit with no match in AHRI 210/240-202X Draft and AHRI 1600-202X Draft is specifically focused on R-22 outdoor units, DOE proposed not to incorporate the definition by reference, and instead proposed a clarifying definition that is consistent with DOE's intention in the June 2016 Final Rule.

Id.

DOE proposed the following definition for OUWNM in the April 2024 NOPR for appendix M1:

Outdoor Unit with No Match (OUWNM).

An Outdoor Unit that is not distributed in commerce with any indoor units, and that meets any of the following criteria:

(a) Is designed for use with a refrigerant that makes the unit banned for installation when paired with an Indoor Unit as a system, according to EPA regulations,

(b) Is designed for use with a refrigerant that has a 95 °F midpoint saturation absolute pressure that is ± 18 percent of the 95 °F saturation absolute pressure for R-22, or

(c) Is shipped without a specified refrigerant from the point of manufacture or is shipped such that more than 2 pounds of refrigerant are required to meet the charge per section 5.1.8 of AHRI 210/240-202X Draft. This shall not apply if either (a) the factory charge is equal to or greater than 70 percent of the outdoor unit internal volume times the liquid density of refrigerant at 95 °F, or (b) an A2L refrigerant is approved for use and listed in the certification report.

DOE noted that the proposed definition of OUWNM for appendix M2 is the same as that for appendix M1, except that the reference in part (c) of the definition is to section 5.1.8 of AHRI 1600-202X Draft.

Id.

DOE tentatively concluded that the proposed definition would further help clarify that the existing test procedure and rating requirements for outdoor units with no match are applicable to R-410A-based systems and any other refrigerants banned by EPA regulations from January 1, 2026, as they have been previously, for R-22 and any other ozone-depleting refrigerants.

Id.

As proposed, the definition would apply to all types of outdoor units (

i.e.,

heat pump, air conditioner, single-speed, two-speed, variable-speed, etc.) and outdoor units with no match would continue to be tested with an indoor coil having a nominal tube diameter of 0.375 in and an NGIFS of 1.0 or less (as determined in section 5.1.6.3 of AHRI 210/240-202X Draft and AHRI 1600-202X Draft).

Id.

DOE clarified that the determination of represented values, alternative efficiency determination method (“AEDM”) requirements, combinations selected for testing, and certification report requirements applicable to outdoor units with no match would remain the same as those specified in table 1 to paragraph (a)(1), paragraph (c)(2), table 2 to paragraph (b)(2)(i), and paragraph (e)(3), respectively, in 10 CFR 429.16.

Id.

DOE noted that existing outdoor models currently distributed in commerce as part of a split-system basic model that transition to a replacement outdoor unit only would need to be tested, rated, and recertified under the provisions in 10 CFR 429.16 for an outdoor unit with no match.

Id.

DOE noted that the basic model number would need to change to reflect that the outdoor unit is no longer part of a combination as previously certified, but rather as an outdoor unit with no match; however, the outdoor unit model could still be assigned the same individual model number.

Id.

In response to its April 2024 NOPR, DOE received comments from stakeholders on a variety of issues related to compliance with DOE's regulations in the context of the October 2023 EPA Final Rule. These specific comments are addressed in the next section, but to ensure clarity this section first summarizes the key elements of compliance with DOE testing, rating, and certification requirements for these products during the period of implementation of the EPA rules.

As specified in the October 2023 EPA Final Rule, and modified in the December 2023 EPA interim final rule, installation of central air conditioner and heat pump systems manufactured or imported on or after January 1, 2025, that use a refrigerant with a GWP higher than 700 would be prohibited from being installed beginning on January 1, 2025. A system comprised of “specified components” manufactured or imported prior to January 1, 2025, can still be installed until January 1, 2026. The EPA's rule permits the continued manufacture, distribution, and installation of individual specified components that use higher GWP refrigerants on or after January 1, 2026, only as replacements for components in existing systems provided they are labeled for this use as specified in the EPA rule.

The DOE definition of the term “central air conditioner or central air conditioning heat pump” in 10 CFR 430.2 specifies that a central air conditioner or central air conditioning heat pump may consist of: A single-package unit; an outdoor unit and one or more indoor units; an indoor unit only; or an outdoor unit with no match. Further, the DOE definition specifies that in the case of an indoor unit only or an outdoor unit with no match, the unit must be tested and rated as a system (combination of both an indoor and an outdoor unit). In addition, DOE's requirements in 10 CFR 429.16(a) specify required representations based on how the model is distributed in commerce (

i.e.,

as part of a matched system, as an indoor unit only, or as an outdoor unit with no match).

DOE's rules for testing and rating covered products to establish compliance with energy conservation standards apply to basic models as distributed in commerce by the manufacturer (or importer). Although the deadlines for installation of specified components under EPA's rule apply to certain products based on their date of manufacture or import (

i.e.,

depending on whether they were manufactured prior to January 1, 2025), DOE's rules for how the manufacturer must test, rate, and certify their products apply based on the date of manufacture (or importation) and on how each basic model is distributed in commerce (

i.e.,

as part of a matched system or as an OUWNM), with the purpose being to ensure that each basic model complies with the energy conservation standard that applies to that basic model. A manufacturer or importer is not required to retest and/or recertify a basic model unless the manufacturer either makes a change to that basic model that would make it a new basic model under DOE's definition of that term in 10 CFR 430.2 or makes a change to the configuration in which it is being distributed in commerce such that a different tested combination requirement applies to it under 10 CFR 429.16. Stated within the context of the EPA's rule, a basic model of condensing unit that previously had been rated and certified to DOE in one or more combinations would not have to be re-tested and rated under the OUWNM provisions until such a time as the manufacturer ceases distribution of that basic model as part of a matched pair and begins distributing it as an OUWNM. At that point, the manufacturer must test, rate, and certify that condensing unit under the OUWNM as a new basic model, as under the basic model definition in 10 CFR 430.2 the model as an OUWNM cannot be the same basic model as it would have been in a combination.

For R-410A (or other refrigerant with GWP above 700) outdoor units manufactured (or imported) prior to January 1, 2025, which under the EPA's rule can still be installed as a system until January 1, 2026, the certifications of those models based on their tested combinations remain valid under DOE regulations as long as manufacturers continue to distribute them in commerce as a system. However, if at some point the manufacturer chooses to distribute in commerce the unit alone and not as a combination with any indoor units (either before January 1, 2026 or after that date as a service-only replacement component to comply with EPA's rule), the outdoor unit would have to be tested, rated, and certified in accordance with the OUWNM provisions. This also applies for R-410A (or other refrigerant with GWP above 700) outdoor units manufactured or imported on or after January 1, 2025, as DOE expects that manufacturers would cease distribution of the outdoor units

as part of a combination, as these systems could no longer be installed anywhere in the U.S. This certification as a new basic model must be made prior to the date at which the manufacturer begins distributing those outdoor units as an OUWMN and would be indicated to DOE in its certification reports via a discontinued model filing for the model as distributed in a combination and certification as a new basic model of OUWNM.

For an indoor unit intended only for replacement in an existing system and which is no longer distributed in commerce for installation as a combination, as would be the case for an existing system that uses a refrigerant banned by EPA, the requirement in 10 CFR 430.2 and table 1 of 10 CFR 429.16(a) for the indoor unit to be rated as part of a system would still apply even though the indoor unit is no longer being distributed in commerce as part of a combination. This rating requirement would apply regardless of whether the manufacturer of the indoor unit is an ICM. If the indoor unit uses a refrigerant allowed by EPA only for component replacement (

e.g.,

R-410A), the rating for such a unit would be based on a combination using that refrigerant, and per EPA regulations could not be distributed in commerce as a combination. However, this does not imply that the indoor unit cannot be rated, nor that the entire system would have to be replaced. DOE notes further that any such rating for the indoor unit must be compliant with current standards, and that any indoor units distributed in commerce for use in a system that uses a refrigerant subject to the EPA ban would need to have been certified to DOE as compliant with the applicable standards as part of a combination before January 1, 2025 and must have been tested and rated in every combination with an outdoor unit with which it has been previously distributed in commerce.

(d) Comments Received

In their response to the NOPR, the Joint Advocates and Lennox fully supported the proposed provisions for OUWNMs. The Joint Advocates agreed that DOE's clarifying definition for OUWNM will help ensure representative ratings and that the proposed definition is consistent with DOE's intent in the June 2016 Final Rule. (Joint Advocates, No. 30 at p. 3) Lennox strongly supported the DOE proposal that any outdoor unit designed for R-410A or any banned refrigerant as per EPA regulations, when distributed in commerce without an indoor unit on or after January 1, 2026, would be deemed an outdoor unit with no match. (Lennox, No. 24 at p. 2).

Several commenters requested more clarity or expressed concerns on DOE's OUWNM provisions. These are discussed in the following subsections.

(1) OUWNM Definition

ER07JA25.000

An Outdoor Unit that is not distributed in commerce

by the manufacturer

with any indoor units, and that meets any of the following criteria:

(a) is designed for use with a refrigerant that makes the unit banned for installation when paired with

a new

Indoor Unit as a system, according to EPA regulations in 40 CFR chapter I, subchapter C,

[provisions (b) and (c) unchanged]

Rheem requested that DOE consider simplifying the proposed definition for OUWNMs because some of the bullet points may overlap or conflict with each other. (Rheem, No. 34 at p. 3) Rheem noted that in SNAP Final Rule 237, EPA has approved R-32, R-452B, R-454A, R-454B, R-454C, and R-457A for use in residential and light commercial air-conditioning and heat pump end use, which also includes CAC/HPs. (

Id.

) Rheem commented that among these substitutes, R-454C and R-457A have a 95 °F midpoint saturation absolute pressure within 18 percent of the 95 °F saturation absolute pressure for R-22, thus meeting the provisions in 4.1(b) and 3.1(b) of the proposed OUWNM definition at appendix M1 and appendix M2, respectively. (

Id.

) Rheem suggested that DOE simplify the definition of OUWNM to avoid confusion. (

Id.

)

DOE appreciates that AHRI is taking steps to update AHRI 210/240-2024 and AHRI 1600-2024 standards to broaden the OUWNM provisions beyond R-22 outdoor units and make them applicable to any outdoor units that are distributed in commerce without an indoor matching pair, regardless of the refrigerant the outdoor unit employs. Such an implementation would be consistent with DOE's proposed definition of OUWNMs in the April

2024 NOPR. DOE disagrees with the addition of “by the manufacturer” in the OUWNM definition to qualify distribution in commerce, since under EPCA the term “distribution in commerce” also applies to subsequent distribution after the initial offering by the manufacturer. The proposed addition would undercut the general applicability of that term across the distribution chain as established in EPCA. As explained in DOE's March 7, 2011, final rule that established the certification provisions in Part 429, application of the term “distribution in commerce” would depend on a particular manufacturer's production practices, business decisions, and the facts and circumstances of a particular case. 76 FR 12422, 12426. . However, DOE agrees with the inclusion of the term “new” to clarify that the EPA ban specifically pertains to new system installations, and for further clarification is including the term “new” to describe both the indoor unit with which the outdoor unit is paired and the newly created system. In addition, notwithstanding the broad applicability of the term “distribute in commerce,” DOE notes that under 10 CFR 429.102(a)(6) it is a prohibited act for a manufacturer or private labeler to distribute in commerce any new covered product or covered equipment that is not in compliance with an applicable energy conservation standard prescribed under the Act, and therefore the obligation to certify that basic models are in compliance with the standards lies with the manufacturer and importer. This is also the basis for the requirement in 10 CFR 429.12(a) that each manufacturer, before distributing in commerce any basic model of a covered product or covered equipment subject to an applicable energy conservation standard, certify that the model meets the applicable energy conservation standard.

DOE agrees with Rheem that certain SNAP-approved refrigerants, for example R-454C and R-457A, have pressure-temperature relationship characteristics similar to R-22 and would meet provision (b) of the proposed OUWNM definition. DOE notes that both these refrigerants have GWPs equal to or less than 150, and thus could potentially be under consideration for future reductions in GWP as compared with refrigerants R-454B and R-32, the primary near-term candidates for transition from R-410A. To ensure that these SNAP-approved refrigerants would not be subject to provision (b) of the proposed OUWNM definition, DOE is qualifying provision (b) with a GWP limit—specifically, only refrigerants with GWP greater than 150 (per EPA's measure) would be subject to provision (b).

In summary, DOE is making minor modifications to the OUWNM definition as follows:

An Outdoor Unit that is not distributed in commerce with any indoor units, and that meets any of the following criteria:

(a) Is designed for use with a refrigerant that makes the unit banned for installation when paired with a new Indoor Unit as a system, according to EPA regulations in 40 CFR chapter I, subchapter C;

(b) Is designed for use with a refrigerant that has a 95 °F midpoint saturation absolute pressure that is ±18 percent of the 95 °F saturation absolute pressure for R-22 and a global warming potential greater than 150 per EPA regulations in 40 CFR 84.64; or

This shall not apply if either (a) the factory charge is equal to or greater than 70 percent of the outdoor unit internal volume times the liquid density of refrigerant at 95 °F, or (b) an A2L refrigerant is approved for use and listed in the certification report.

For Appendix M2, the definition references section 5.1.8 of AHRI 1600-2024.

(2) Clarity on Interaction With EPA Rule

AHRI and Carrier requested further clarity on how DOE's OUWNM provisions will interface with the October 2023 EPA final rule, particularly in terms of timing and scope. (AHRI, No. 25 at pp. 2-4; Carrier, No. 29 at p. 3)

AHRI appreciated DOE's proposal to expand the OUWNM definition to include HFC refrigerants having a GWP greater than 700, in line with EPA's ban, but noted that the interaction between the EPA and DOE regulations are complex and implementation questions remain. (AHRI, No. 25 at p. 2) AHRI cautioned that care must be taken to ensure industry and downstream distribution partners understand and can remain compliant with applicable regulations and that consumers who recently installed products with R-410A refrigerant have meaningful access to service parts for the useful life of their equipment. (

Id.

) AHRI noted that while no date has been included with the DOE-proposed OUWNM definition, the NOPR preamble presents the proposed date of 2026. (AHRI, No. 25 at p. 3) AHRI sought clarification that OUWNM ratings would only be required for split-system outdoor units using HFC refrigerants having a GWP greater than 700 manufactured after January 1, 2025. (

Id.

) AHRI attached a spreadsheet (Exhibit 1) that contained requests for clarification from DOE on questions regarding the prohibitions for manufacture, distribution, and installation of various product types. (AHRI, No. 25 at pp. 5-6). Specifically, AHRI requested clarification on whether DOE's proposal applies to split-system CAC/HP products imported into the United States, but which are not for sale in the United States. (

Id.

)

Carrier appreciated DOE's intent to further clarify the OUWNM requirements and noted that it is clear that the OUWNM category is the equivalent of EPA's service-only condenser allowance in the market. (Carrier, No. 29 at p. 3) Carrier commented that it supports DOE stating the application of OUWNM requirements to a service-only R-410A condensing unit, but requested that DOE provide additional clarity in the final rule on certain aspects, including effective date, which unit types OUWNM applies to, and the indoor airflow requirements. (

Id.

) In particular, Carrier requested that DOE make the following clarifications to better help the regulated community in complying with applicable efficiency and refrigerant regulations: (1) R-410A condensing units manufactured or imported on or after January 1, 2025 would need to be tested and rated as an OUWNM because EPA prohibits the installation of those outdoor units with a new indoor unit; (2) any R-410A outdoor and indoor units manufactured before January 1, 2025 could be sold and installed utilizing the existing DOE-certified system rating, because EPA is allowing installation; (3) since EPA prohibits the sale and installation of any R-410A outdoor and indoor units in 2026 regardless of production date, any remaining pre-2025 inventory held by a manufacturer would be required to be recertified using the OUWNM procedure when distributed in commerce on or after January 1, 2026; and (4) any pre-2025 R-410A air conditioners in the Southeast or Southwest regions could not be installed without being recertified as an OUWNM. (Carrier, No. 29 at p. 3)

In response to AHRI, DOE clarifies that OUWNM ratings for split-system outdoor units employing refrigerants with GWP greater than 700 would be required for units distributed in commerce as service-only placement

components (

i.e.,

not as a combination) from the point of manufacture and thus subject to DOE's testing and rating requirements for outdoor units with no match in Appendix M1 and 10 CFR 429.16. As discussed in the previous section of this notice, DOE expects that manufacturers would need to make this transition for units manufactured after January 1, 2025, which it intends to make available as service-only replacement components for existing systems. Regarding units that are imported into the United States but not distributed and sold for installation within the United States, DOE notes that its requirements specified in 10 CFR parts 429, 430, and 431 shall not apply to any covered product or covered equipment if: (a) such covered product or covered equipment is manufactured, sold, or held for sale for export from the United States or is imported for export; (b) such covered product or covered equipment or any container in which it is enclosed, when distributed in commerce, bears a stamp or label stating “NOT FOR SALE FOR USE IN THE UNITED STATES”; and (c) such product is, in fact, not distributed in commerce for use in the United States. 10 CFR 429.6.

DOE notes that the additional detail provided in the preceding section of this notice, and in the preceding paragraphs, is largely consistent with Carrier's suggestions. However, DOE wishes to correct two of Carrier's clarifications: (1) the recertification of remaining pre-2025 inventory would not be required provided those basic models were correctly certified based on how they were distributed at the time of their manufacture; and (2) the applicability of these provisions for units to be installed in the Southeast or Southwest do not differ from products subject to nationwide standards. The only difference for installation in the Southeast or Southwest is that the regional energy conservation standards would apply for such installations, as would otherwise be the case per 10 CFR 430.32(c)(6), and the efficiency rating as certified by the manufacturer must indicate those basic models comply with the applicable regional standards and may be installed in the Southeast and/or Southwest regions.

(3) Recertification of Units Already Distributed in Commerce

Several commenters expressed concern with the recertification as OUWNMs of units already distributed in commerce, when installed after January 1, 2026.

AHRI sought clarification on the intended meaning of the phrase “distributed in commerce.” (AHRI, No. 25 at p. 3) AHRI noted that the current DOE regulation places no restrictions on distribution of products if the product was initially certified and regional standards are not an issue for the product and location. (AHRI, No. 25 at p. 6) AHRI noted that DOE's NOPR proposal requires existing outdoor models currently distributed in commerce as part of a split-system basic model that transition to a replacement outdoor unit only to be tested, rated, and recertified under the provisions in 10 CFR 429.16 for an outdoor unit with no match. (

Id.

) AHRI noted that per EPCA, “distribution in commerce” means “to sell in commerce, to import, to introduce or deliver for introduction into commerce, or to hold for sale or distribution after introduction into commerce,” and that “distribution in commerce” applies to both the initial offering for sale by the manufacturer and the subsequent distribution by downstream partners (

i.e.,

sale by the distributor to the contractor, or the contractor to the homeowner). (

Id.

) AHRI cautioned that without linking the requirements to a manufacture/import date, DOE's proposal complicates the distribution of outdoor units manufactured pre-2025 that are no longer in possession of the manufacturer or private labeler. (

Id.

) AHRI questioned how DOE will enforce the proposal on products subject to national energy efficiency standards. (

Id.

)

AHRI contended that for products subject to national standards, DOE is constrained by the application of the base national standard, which “applies to all products manufactured or imported into the United States on and after the effective date of the standard.”

(AHRI, No. 25 at p. 6) Therefore, AHRI asserted that space-constrained products; small-duct high-velocity, air conditioners in the North; and heat pumps manufactured or imported prior to January 1, 2025 that were certified as compliant with the base national standard can still be installed in the United States until the inventory is depleted. (

Id.

) AHRI questioned how DOE could require manufacturers, distributors, or contractors to retroactively apply testing, rating, or certification requirements on outdoor units subject to national standards that were distributed in commerce and are no longer in the manufacturer's possession. (AHRI, No. 25 at pp. 6-7) AHRI requested for DOE to link the OUWNM definition to a manufacture/import date, as DOE's proposal complicates the distribution of outdoor units manufactured prior to January 1, 2025 that are no longer in possession of the manufacturer (or private labeler). (AHRI, No. 25 at p. 7) Similarly, for products subject to regional standards, AHRI questioned how DOE could require manufacturers, distributors, or contractors to retroactively apply testing, rating, or certification for outdoor units manufactured/imported in 2024 and no longer in possession of the manufacturer. (

Id.

) AHRI requested clarification on whether DOE intended that air conditioners slated for the Southeast and Southwest regions, manufactured/imported in 2024, and still in possession of the manufacturer be recertified as OUWNMs on January 1, 2025. (

Id.

)

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

AHRI noted that while the NOPR preamble states that “the basic model number would need to change to reflect that the outdoor unit is no longer part of a combination as previously certified, but rather as an outdoor unit with no match, but the outdoor unit model could still be assigned the same individual model number,” DOE has not described in the proposed regulatory text how the testing, rating, and recertification for outdoor units distributed in commerce by outdoor unit manufacturers (“OUMs”) for a former certified combination that transitions to OUWNMs for replacement will be completed. (AHRI, No. 25 at p. 6) AHRI expressed concern that this may create logistical complications, given that “distributed in commerce” applies to both the initial sale and the subsequent sale of products that have already entered commerce and are no longer in the possession of the manufacturer to be recertified. (

Id.

) AHRI contended that certification of a condensing unit as an OUWNM should apply to products manufactured after January 1, 2025. (

Id.

)

HARDI strongly opposed any restriction on the ability of its members to sell products already in inventory, including install date regulations, such as EPA's transitions program and the statutorily required install date in DOE's regional standards for split-system central air conditioners. (HARDI, No. 26 at pp. 1-2) HARDI commented that it believed install date requirements hinder the ability of the heating, ventilation, air-conditioning, and refrigeration industry to move to more energy-efficient or environmentally friendly products and that install date regulations that cause dead inventory are ineffective because they create waste, increase costs, and constitute a

regulatory taking.

(

Id.

) HARDI commented that it was its understanding that the phrase “currently distributed in commerce” does not intend to include CAC/HP equipment already in distributors' warehouses, but it asserted that, just like with the confusing compliance regime caused by the install date associated with regional standards for split-system central air conditioners, if this phrase is used in the final regulation, local compliance officials will prevent repairs to existing systems if the outdoor unit does not have proof of meeting the minimum efficiency standard. (HARDI, No. 26 at p. 2) HARDI suggested that the best course of action is to apply the OUWNM testing and certification requirements at the same date of manufacture timeline as the EPA requirement for outdoor condensing units to be marked “For servicing existing equipment only.” (

Id.

) HARDI noted that for split-system CAC/HPs, EPA requires anything manufactured after January 1, 2025 to be marked “For servicing existing equipment only.” (

Id.

) HARDI further noted that while new split-system CAC/HPs can be installed until January 1, 2026 using R-410A or other high-GWP refrigerants, EPA requires those systems to be manufactured before January 1, 2025, and outdoor units manufactured after January 1, 2025 can only be used as components, thereby meeting the proposed definition of OUWNMs. (

Id.

) HARDI recommended that DOE limit the need to test, rate, and recertify equipment to only outdoor units manufactured after January 1, 2025, as this will ensure that equipment intended to be installed as an OUWNM does meet the minimum efficiency requirements while not affecting equipment originally sold for installation as a matched system. (

Id.

)

HARDI notes that a regulatory taking is a “taking of property under the Fifth Amendment by way of regulation that seriously restricts a property owner's rights,”

Blacks Law Dictionary,

11th Edition. (HARDI, No. 26 at p. 1).

JCI expressed concerns with DOE's proposal to require recertification of units “currently distributed in commerce” to meet the OUWNM requirements, contending that requiring recertification of a component as part of a system that was previously certified as compliant and has already entered commerce,

i.e.,

is no longer in the possession of the original manufacturer, is overly burdensome for manufacturers, distributors, and contractors, and will be problematic for DOE to enforce without tying enforcement to the manufacture/import date. (JCI, No. 35 at p. 2) JCI recommended that for outdoor units that have entered commerce, the “date of manufacture” be used as the enforcement mechanism. (

Id.

) JCI commented that it was its understanding that outdoor units manufactured on or after January 1, 2025 would be required to meet DOE's OUWNM criteria if they were still in the possession of the original manufacturer. (

Id.

) JCI stated that clarifying that the OUWNM requirements would take effect on January 1, 2025, versus the NOPR date of January 1, 2026, reduces the amount of inventory in the channel that would require recertification. (

Id.

)

Rheem also expressed concern about language for OUWNMs applicable to “existing outdoor models currently distributed in commerce,” where these products would need to be recertified and given a new basic model number in the event that they are only eligible for component replacement per EPA's Technology Transitions rule. (Rheem, No. 34 at p. 3) Rheem asserted that the notion of obtaining proof of new rating and a different model number is unreasonable to require once the equipment has left manufacturer warehouses, as the application of new labels and rating certifications is impractical to carry out at the distributor and installer levels. (

Id.

) Rheem commented that EPA appears to recognize this impracticality and does not require relabeling of equipment made prior to January 1, 2025 to indicate “for service only.” (

Id.

) Rheem contended that a change in the test procedure should not render obsolete a product currently in commerce that was compliant at the time of manufacture. (

Id.

)

As indicated by AHRI, DOE notes that per EPCA, the terms “to distribute in commerce” and “distribution in commerce” mean to “sell in commerce, to import, to introduce or deliver for introduction into commerce, or to hold for sale or distribution after introduction into commerce.” (42 U.S.C. 6291(16)) Under the statutory definition, this term can apply to the initial offering of sale by a manufacturer or by subsequent distribution by downstream partners. As was discussed in the previous section, the December 2023 EPA Interim Final Rule allows for a 1-year sell-through period (until January 1, 2026) for any CAC/HP system employing a refrigerant with a GWP of 700 or greater, provided the specified component is manufactured or imported prior to January 1, 2025 (

see

40 CFR 84.54(c)(1)). Since EPA prohibits the installation of any specified CAC/HP components to create a new system employing a refrigerant with a GWP of 700 or greater on or after January 1, 2026, irrespective of the manufacturing date, any remaining pre-2025 inventory (

i.e.,

imported or manufactured before January 1, 2025) held by any channel of distribution (manufacturer or distributor) could not be installed as a system after January 1, 2026.

DOE's rating and certification requirements in 10 CFR 429.16 for central air conditioners and heat pumps apply based on how a manufacturer distributes the models in commerce. If the manufacturer ceases distribution in commerce of a model of outdoor unit that was previously part of a combination and begins distributing it only as an OUWNM to allow for use as a service-only replacement under the EPA's rules for components of an R-410A system, that model of outdoor unit would need to be recertified under the OUWNM requirements regardless of when that transition occurs, since the manufacturer (or private labeler) has an obligation to ensure that any basic model it distributes is compliant with the applicable energy conservation standard for the configuration (or configurations) in which the manufacturer distributes it. However, the requirement to recertify those basic models does not apply retroactively to units of a basic model that were already distributed in commerce as part of a combination and had been correctly certified according to DOE's regulations.

Regarding AHRI's concern about enforcement of national standards, DOE notes that no changes were proposed to national standards in the April 2024 NOPR, and none are being finalized in this rulemaking. The purpose of the clarification provided in this rulemaking is to ensure that manufacturers have a clear understanding of how to comply with DOE's certification requirements for products that will be subject to EPA regulations. DOE's certification provisions in 10 CFR 429.12(a) specify that each manufacturer, before distributing in commerce any basic model of a covered product or covered equipment subject to an applicable energy conservation standard set forth in parts 430 or 431, and annually thereafter . . . shall submit a certification report to DOE certifying that each basic model meets the applicable energy conservation standard(s). To the extent that outdoor units that were previously certified as compliant as part of a matched system begin being distributed in commerce as outdoor units with no match, they are being distributed as a new basic model, and therefore, must certify compliance with the applicable energy conservation

standards. The application of the base national standard, as referenced by AHRI, still applies to the outdoor unit based on its manufacture date, but compliance with that standard must be determined for the basic model distributed in commerce (

i.e.,

the OUWNM).

DOE notes that the EPA regulations include a 1-year sell-through period to reduce inventory of units that may be in danger of not complying with the EPA rule. DOE's rationale also applies to AHRI's concern on regional standards. However, DOE notes that there is confusion on the applicability of the EPA dates on the regional level. DOE clarifies, consistent with the national application, that air conditioners certified as able to be installed in the Southeast and Southwest regions manufactured or imported before January 1, 2025, and that have already been distributed in commerce, would not need to be certified as OUWNMs on January 1, 2025, provided the manufacturer had already certified compliance with the applicable energy conservation standards. For units intended for installation in the Southeast or Southwest regions, this would include a certification that they comply with those applicable standards. As previously explained in this notice, the only distinction from CAC/HP products that are not subject to regional efficiency standards is that split-system AC outdoor units certified as OUWNM would have to meet the applicable standards for the Southeast or Southwest regions to be installed in those regions.

DOE notes there may be confusion regarding the applicability of the compliance dates in the EPA rule and how these dates affect DOE regional standards requirements. To be clear, the EPA rule has no effect on DOE requirements. For certain split-system central air conditioning systems or certain OUWNMs to be installed in the Southeast or Southwest region consistent with DOE regional standards requirements, the system/OUWNM must be certified to DOE as compliant with the applicable regional standard(s), and the certification must indicate that the model/combination can be installed in the Southeast and/or Southwest region. While the EPA rule may change the approach a manufacture may take with respect to testing and certifying a particular model, it does not change DOE requirements.

In response to AHRI's concern that DOE has not described in the proposed regulatory text how the testing, rating, and recertification for OUWNMs will be completed, DOE notes that the testing requirements are laid out in section 4.2 of revised appendix M1 and section 3.2 of new appendix M2. Additionally, as noted in the April 2024 NOPR, and explained in the preceding section of this notice, existing outdoor models currently distributed in commerce as part of a split-system basic model that the manufacturer transitions to a replacement outdoor unit only would need to be tested, rated, and certified under the provisions in 10 CFR 429.16 for an outdoor unit with no match. 89 FR 24206, 24231. As described previously in this section, distribution of such a model as an OUWNM represents distribution in commerce of a new basic model, and accordingly, the basic model must be certified as compliant with the applicable energy conservation standards. DOE may consider additional certification requirements under a separate rulemaking regarding appliance and equipment certification.

In response to HARDI, DOE clarifies that the reporting obligations apply to manufacturers, and importers, and thus basic models previously distributed in commerce by the manufacturer that were certified by the manufacturer in accordance with 10 CFR 429.12 do not need to be recertified. Regarding HARDI's criticism of regulation based on install date requirements, DOE clarifies that, whereas the EPA rule is based on the date of installation, the application of the OUWNM provisions are based on the configuration in which the manufacturer (or importer) distributed the basic model from the point of manufacture (or import). It does not depend upon distributor or retail sales and offerings. DOE notes that the EPA regulations include a 1-year sell-through period for pre-2025 inventory to provide time to reduce inventory. The OUWNM provisions in this rulemaking simply align with the EPA action undertaken in the October 2023 EPA rule. In response to HARDI's recommendation to limit the need to test, rate, and recertify equipment to only outdoor units manufactured after January 1, 2025, DOE agrees that most inventory manufactured prior to January 1, 2025, will likely be distributed in commerce with indoor units and be installed prior to January 1, 2026; however, to the extent that any outdoor units manufactured prior to January 1, 2025, continue to be distributed in commerce by the manufacturer after January 1, 2026, as OUWNM, the manufacturer must test consistent with the requirements applicable to OUWNMs and certify the compliance of such models with the applicable energy conservation standard.

In response to JCI, DOE again stresses that the timing for implementation of the OUWNM provisions is tied to the EPA rule. Specifically, an outdoor unit no longer has a match when EPA requirements no longer allow installation with an indoor unit to create a new system, and thus must be certified to DOE as an OUWNM as it continues to be distributed in commerce. As discussed in III.E.7.c(2), DOE clarifies that any outdoor CAC/HP units manufactured or imported on or after January 1, 2025 and employing refrigerants with GWP greater than 700 (for example, R-410A), would need to be tested and rated as an OUWNM, consistent with the EPA requirement that such models be used “for servicing existing equipment only.” For units manufactured or imported before January 1, 2025 the existing DOE-certified system rating can be used, provided the manufacturer does not continue distribution of the outdoor units alone, because the EPA regulations permit installations of such systems until January 1, 2026. However, if the unit is distributed in commerce alone and not as a combination with any indoor units, as likely would be the case for products intended for installation as an individual replacement component of an existing system, the outdoor unit would have to be certified in accordance with the OUWNM provisions prior to the date at which the manufacturer begins distributing those outdoor units as an OUWMN, as indicated to DOE in its certification reports via a discontinued model filing for the model as distributed in a combination and certification as an OUWNM.

In response to Rheem's claim that EPA does not require relabeling of equipment made prior to January 1, 2025 to indicate “for service only,” DOE notes that the EPA labeling requirement at 40 CFR 84.58(b) states, “Effective upon the date listed for each subsector in § 84.54(c) . . . any specified component . . . that uses or is intended to use any regulated substance, or blend containing any regulated substance . . . must have a permanent label compliant with paragraph (c)

of this section containing the information in paragraph (a)(1) of this section. For specified components that are intended for use

with a regulated substance or blends containing a regulated substance that exceed the applicable GWP limit or HFC restriction, the label must state “For servicing existing equipment only” in addition to the other required labeling elements.” (

See

40 CFR 84.58(b)) 40 CFR 84.58(c) requires the label to list, at a minimum, the refrigerant and the date of manufacture. DOE is aware that there are two dates listed in the relevant paragraph for split-system CAC/HPs under section § 84.54(c)—January 1, 2025 and January 1, 2026. As discussed above and in the preceding section of this notice the December 2023 EPA Interim Final Rule pushed back the restriction on R-410A and similar refrigerants such that components manufactured prior to January 1, 2025 could be installed as part of systems prior to January 1, 2026, and thereafter would be installable only for servicing existing equipment. Thus, unless EPA intended for the “for servicing existing equipment only” words to be on specified components starting January 1, 2025, when they would still be allowed to be used for system installations, EPA regulations effectively state that the required label would have to be applied or changed while the component is in distribution,

i.e.,

after leaving the manufacturer but before installation. However, DOE notes that these labeling provisions are separate from its own regulatory requirements and that manufacturers seeking more specific guidance on the implementation of these provisions should consult EPA.

The reference is to paragraph (c) but should be to paragraph (d), which specifies label design (

e.g.,

English language, durable and printed/affixed to the product exterior surface, readily visible and legible, etc.). Paragraph (c) addresses products in the foam or aerosol sector and is not relevant for the refrigeration, air-conditioning, and heat pump sector addressed in paragraph (b).

Regarding Rheem's contention that a change in the test procedure should not render a currently compliant product obsolete, DOE notes that it is the EPA action, and not a change to the DOE test procedure, that would prevent the installation of a previously certified CAC/HP system. In accordance with this EPA action, DOE's OUWNM provisions in the test procedure provide a means for manufacturers to assign an energy efficiency rating to split-system outdoor units after the EPA has banned them for full-system installations. As discussed earlier in this section and in the preceding section, to the extent that the manufacturer of the outdoor unit of a previously certified CAC/HP system begins distributing it in commerce as an OUWNM, it would become a new basic model and the manufacturer would need to certify that it complies with the applicable energy conservation standard.

In a comment related to concerns regarding recertification as OUWNM of outdoor units already distributed in commerce, GE Appliances indicated that products currently in production would need redesign to comply with cut-out/cut-in temperature and CVP enforcement testing. (GE Appliances, No. 37 at p. 6) They commented that since import and production of legacy R-410A equipment will cease after January 1, 2025, there will be no need to redesign existing inventory, in order to comply with the cut-out/cut-in temperature and CVP enforcement test.

Id.

They pointed out that most of DOE`s energy efficiency enforcements are based on date of import or manufacture, so exclusion of R-410A legacy equipment from CVP and cut-out/cut-in enforcement testing would be consistent with this practice, and that failing to exclude these products from such enforcement would lead to stranded inventory, resulting in the loss of embodied carbon in the inventory, with little/no energy efficiency saving.

Id.

In response to the comment by GE Appliances, certifications required to be made by a manufacturer for the compressor and indoor blower speed of any variable capacity system at specific test conditions must represent normal operation. The CVP provisions established in this final rule describe how DOE would verify that certified values are appropriate for the purposes of DOE enforcement testing. Hence, DOE would expect existing properly-certified variable speed CAC/HPs and CHPs to pass the CVP enforcement with minimal or no adjustment to existing performance representations. Further, DOE certainly would not expect changes sufficient to call into question the compliance of such models with DOE efficiency standards. Similarly, although cut-out and cut-in temperatures are not currently required to be certified, DOE would expect manufacturers to have certified HSPF2 values that are consistent with the actual cut-out/cut-in characteristics of certified models. Manufacturers are not required themselves to conduct CVP testing. To the extent that manufacturers are correctly certifying performance of existing models, there would be no need to recertify or redesign such models in response to DOE implementing CVP testing for enforcement purposes. Therefore, DOE disagrees with the suggestion of GE Appliances, that there should be specific exclusions for legacy R-410A CAC/HPs from the CVP and cut-out/cut-in temperature enforcement provisions.

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

AHRI and Carrier requested clarity on whether the OUWNM provisions are applicable to multi-head mini-split, multi-split, or multi-circuit systems. (AHRI, No. 25 at pp. 4-5; Carrier, No. 29 at pp. 3-4).

Carrier requested that DOE confirm that the OUWNM certification requirement is applicable to all split-system condensing units within the scope of appendix M1, which includes single-split, multi-head mini-split, multi-split (including VRF), and multi-circuit air conditioner and heat pump systems. (Carrier, No. 29 at pp. 3-4) Specifically, Carrier commented that it believes multi-head mini-split and multi-split systems should also require the OUWNM certification. (

Id.

) Carrier noted that while these systems are generally intended to be installed with multiple indoor units, they can be installed with a single indoor unit, which could be ducted or ductless, and that multiple manufacturers have combinations that utilize a mini-split (traditionally known as a “ductless outdoor unit”) with a conventional “ducted” indoor unit and coil combination. (

Id.

) Carrier further noted that multi-split and mini-VRF outdoor units are able to be rated, certified, and used in combination with a single indoor unit as well as the typical multiple indoor units. (

Id.

) Carrier expressed concern that if OUWNM provisions are not required for these systems that can be installed with a single indoor unit, they could be used to replace the condenser on a system with an indoor unit that was never a certified combination, yielding poor system efficiencies. (

Id.

) Carrier commented that it was its understanding that EPA's reasoning to allow a service-only condenser was to address the customer concern of replacing their entire system upon a part failure in the condenser. (

Id.

) Carrier stated that in its experience, this does not happen regularly in the market, and if there is a premature part failure in the condenser, the part (

i.e.,

compressor, expansion valve, motor, control board, or coil) is replaced or repaired, especially in the case of complex outdoor units such as multi-split condensers. (

Id.

) Carrier noted that in the situation the condenser fails at end of life, it is common practice to replace the entire system. (

Id.

) For these reasons, Carrier requested that DOE clarify that all split-system condensing units within the scope of appendix M1 that are manufactured beginning January 1, 2025 with R-410A or any banned refrigerant must be certified as an OUWNM. (

Id.

AHRI noted that appendix M1 defines the tested combination of a multi-head mini-split, multi-split, or multi-circuit system to consist of one outdoor unit

with one or more compressors matched with between two and five indoor units. (AHRI, No. 25 at p. 4) AHRI further noted that appendix M1 requires that these indoor units must collectively have a nominal cooling capacity greater than or equal to 95 percent and less than or equal to 105 percent of the nominal cooling capacity of the outdoor unit. (

Id.

) AHRI requested that DOE confirm (1) if multi-head systems would test as OUWNM with one or two indoor units per appendix M1, section 2.2(e); and (2) if the preference is for testing multi-head systems with two (or more) indoor units, whether the coil-only indoor unit coil shall be split evenly between the two, or in another configuration. (AHRI, No. 25 at pp. 4-5).

DOE agrees with the reasons presented by Carrier and clarifies that the OUWNM provisions are applicable to all split-system CAC/HPs within the scope of appendix M1—including single-split, multi-head mini-split, multi-split (including VRF), and multi-circuit air conditioner and heat pump systems. As noted by AHRI, per appendix M1, the tested combination of a multi-head mini-split, multi-split, or multi-circuit system requires between two and five indoor units. However, the indoor unit requirements (which are based on the highest sales volume family) are not explicitly applicable for OUWNM testing. As indicated by Carrier, multi-head systems can be installed and are able to be rated with either a single indoor unit or multiple indoor units. To provide maximum flexibility to manufacturers and to limit test burden, DOE clarifies that, for multi-head systems being certified under the outdoor unit with no match provisions, (1) multi-head systems capable of being paired with a single indoor coil shall be tested with a single indoor coil; and (2) multi-head systems incapable of being paired with a single indoor coil shall be tested with the least amount (between two to five) of identical indoor coils. If testing with two or more indoor coils, all coils shall have the same dimensions. The current testing instructions in section 2.2(e) of appendix M1

are written for a single indoor coil, but the same concept of the NGIFS can be extended to two or more identical indoor coils. Specifically, when evaluating NGIFS with two or more indoor coils, the total summation of the fin surface area would include all coils. DOE may consider certification requirements to include whether one or more indoor coils were used to evaluate an OUWNM rating in a separate rulemaking.

These instructions are also included in sections 5.1.6.2 and 5.1.6.3 of AHRI 210/240-2024 and AHRI 1600-2024.

(5) Control Type and Communicating System

Carrier also requested that DOE clarify that OUWNM certification is required for all condensing units, regardless of the control type being used to generate the system rating. (Carrier, No. 29 at p. 4) Carrier noted that many of the communicating variable-speed condensers on the market today also have the capability to operate with a conventional 24-V non-communicating thermostat and that it would be extremely difficult to exclude these units from the OUWNM certification and ensure they were actually being matched with a certified communicating indoor unit that was previously installed. (

Id.

)

Conversely, GE Appliances commented that multi-head ductless split systems and VRF systems under 65k BTU, which are almost always variable-speed communicating systems, are unable to complete the existing test procedure for an OUWNM listing, as existing software does not support or allow a coil-only match without connection to a matched indoor unit. (GE Appliances, No. 37 at p. 4) GE asserted that the inability to provide replacement outdoor units to service existing communicating systems will lead to significant harm for consumers, the environment, and DOE's goals for heat pumps and variable-speed systems. (

Id.

) GE Appliances requested that DOE allow outdoor-unit-only listings for variable-speed communicating systems capable of supporting multiple indoor coils based on the lowest-performing system performance for the outdoor coil for any previously listed system or currently produced, compatible communicating coil. (

Id.

) GE Appliances asserted that because outdoor units for communicating systems can generally only work with matched indoor units using the same communications protocol, there is little risk of improper combinations to create systems that perform worse than efficiency levels required by DOE. (

Id.

) GE Appliances further commented that listing OUWNM units for these systems in this manner ensures accurate consumer information about expected product performance and also ensures service components' availability where they would otherwise be restricted. (

Id.

)

Mitsubishi also asserted that while it understands the broad industry support for DOE to extend the definition of OUWNM to R-410A outdoor units, the proposed language does not take into account the emergence and expansion of communicating variable-speed equipment. (Mitsubishi, No. 28 at p. 2) Mitsubishi contended that like every other inverter-driven variable-capacity ductless OEM, Mitsubishi systems and components are unable to test or operate with any coil in a lab or in the field that is not equipped with proprietary communication protocol and firmware, and that evaluating their outdoor units as OUWNMs renders these controls and advancements completely useless. (

Id.

) Mitsubishi requested that either communicating variable-speed systems be exempted from the OUWNM provisions, or that specific allowances be considered to enable communicating variable-capacity outdoor units to be tested in a way that demonstrates compliance with Federal efficiency minimum standards. (

Id.

)

DOE clarifies that the OUWNM requirements will apply to all split-system CAC/HPs units, whether they use proprietary controls to communicate conditioned-space temperature and/or humidity, use a generic thermostat, or allow either installation approach. Also, DOE understands that many ductless multi-split systems and VRF systems are variable-speed systems that employ software that requires the outdoor unit to be paired with a recognized indoor unit (

i.e.,

a pairing confirming system).

Manufacturers of ductless multi-split systems and VRF systems may already have the means to test these systems with a generic indoor unit or may need to reprogram their outdoor units to allow operation with a generic indoor unit, for units using a refrigerant with GWP greater than 700 that are manufactured after January 1, 2025. While the latter option may require additional software rework, this reprogramming would require limited engineering hours to implement, such that DOE does not consider it to be burdensome to manufacturers. In response to GE's proposal to allow outdoor-unit-only listings for such systems based on the lowest-performing system combination for the outdoor coil, and Mitsubishi's request for such systems to be exempted from the OUWNM provisions or given special

allowances, DOE notes that neither approach provides confirmation that a given outdoor unit could not be field paired with a nonproprietary indoor unit(s). Therefore, to maintain consistency across all split-system CAC/HPs, irrespective of the control type, DOE is exempting neither pairing confirming variable-speed systems nor variable-speed communicating systems from the OUWNM provisions, nor allowing either category of outdoor units to be rated based on its lowest-performing combination.

While the term used by commenters to refer to such systems is “communicating,” DOE notes that the current test procedure uses this term differently. Specifically, “communicating,” per the current test procedure, refers to the ability of the system to communicate in-space temperature with both the outdoor and indoor units, instead of communication between the indoor and outdoor units. DOE also notes that neither the AHRI test standards (210/240 and 1600) nor the test procedure being finalized in this rule use the term “communicating.” To prevent confusion, DOE is referring to these systems as “pairing confirming systems.”

(6) Service Coil Definition

GE Appliances and Mitsubishi requested revision to the “service coil” definition (

see

10 CFR appendix M1, section 1.2) to also include integrated indoor blowers within the definition's scope. (GE Appliances, No. 37 at pp. 1-3; Mitsubishi, No. 28 at p. 2)

ER07JA25.001

ER07JA25.002

GE Appliances contended that revising the definition of service coil to account for DFS systems is essential to protect consumers who have recently installed DFS systems using R-410A refrigerant and that without these revisions, indoor replacement units to repair DFS systems during their expected useful life may be limited, and consumers may be required to replace entire systems instead of merely components. (

Id.

) GE further commented that if DFS systems are not able to have indoor coil replacements, there is a risk of significant negative consumer sentiment toward DFS systems. (

Id.

)

Mitsubishi asserted that circumstances where full replacement of ductless indoor units would be significantly less costly than field replacement of individual parts would needlessly impact the pocketbooks of homeowners and consume scarce technician labor hours. (Mitsubishi, No. 28 at p. 2) Mitsubishi recommended a carve out or alteration of the current definition of service coil to allow ductless indoor units to be sold for purposes of service, as it would remedy this concern and be better aligned with the EPA Technology Transitions rule and guidance. (

Id.

)

DOE concurs with GE Appliances that mini-split, multi-split, and VRF systems have become more prevalent in the residential air-conditioning market. As noted by GE Appliances, the current service coil definition does not include indoor units that have integrated indoor blowers. DOE also notes that the service coil definition in AHRI 210/240-2024 and AHRI 1600-2024, the industry standards DOE is referencing in this final rule, also do not include integrated indoor blowers within the service coil definition. Both appendix M1 (see section 1.2 of appendix M1) and the AHRI standards define “indoor unit”, which includes integrated blowers within the definition's scope. The indoor unit definition in Appendix M1 also explicitly notes that a service coil is not an indoor unit. In relevance to the EPA rule, the labelling requirements at 40 CFR 84.58(b) clarify the installation allowances of indoor units. Specifically, 40 CFR 84.58(b) notes that, after January 1, 2025, specified components intended for use with banned refrigerants shall have the label “For servicing existing equipment only” attached. Any indoor units that are intended to be used with banned refrigerants (such as R-410A) fall within the scope of specified components and under the aforementioned regulatory provisions under the EPA's rule would need to have this label attached.

As was noted in the previous section of this notice, the CAC/HP definition in 10 CFR 430.2 includes a requirement that indoor units sold alone be rated as part of a combination. Specifically, the definition states “A central air conditioner or central air conditioning heat pump may consist of: A single-package unit; an outdoor unit and one or more indoor units;

an indoor unit only;

or an outdoor unit with no match. In the case of an indoor unit only or an outdoor unit with no match, the unit must be tested and rated as a system (combination of both an indoor and an outdoor unit).” Such indoor units may be distributed by indoor coil manufacturers (“ICMs”) which, as defined in Appendix M1, manufacture indoor units but do not manufacture single-package units or outdoor units. They may also be distributed in commerce alone and not as part of a combination by non-ICMs for the replacement market. For an indoor unit intended only for replacement in an existing system and which is no longer distributed in commerce for installation as a combination, as would be the case for an existing system that uses a refrigerant banned by EPA, the requirement in table 1 of 10 CFR 429.16(a) for the indoor unit to be rated as part of a system would still apply even though the indoor unit is no longer being distributed in commerce as part of a combination. This rating requirement would apply regardless of whether the manufacturer of the indoor unit is an ICM. If the indoor unit uses a refrigerant allowed by EPA only for component replacement (

e.g.,

for the indoor unit must be compliant with current standards, and that any indoor units distributed in commerce for use in a system that uses a refrigerant subject to the EPA ban would need to have been certified to DOE as compliant with the applicable standards as part of a combination before January 1, 2025.

(7) Space-Constrained Systems

NCP commented that it performed analysis, testing, and simulations of through-the-wall space-constrained R-410A systems to evaluate available options to meet the proposed OUWNM requirement for applicable outdoor condensing units. (NCP, No. 27 at p. 2) NCP contended that the results of this testing

indicated that its space-constrained outdoor condensing units would not meet applicable minimum efficiency requirements when rated using a generic indoor coil as specified by the OUWNM requirements. (

Id.

) NCP asserted that it was not aware of any space-constrained outdoor condensing units from other manufacturers that could meet efficiency requirements when rated as an OUWNM. (

Id.

) NCP asserted that the OUWNM requirements in DOE's proposed rule would effectively prohibit any space-constrained R-410A outdoor condensing unit after January 1, 2026, and leave manufacturers with stranded inventory. (NCP, No. 27 at p. 2) NCP contended that occupants of multifamily housing units with recently installed space-constrained R-410A split systems would be left without options for service replacement of their outdoor condensing unit section, beyond installation of the entire indoor and outdoor split system. (

Id.

) To provide relief from excessive cost burdens, NCP suggested that DOE should include language in the final rule that coil-only ratings for space-constrained split-system outdoor units with R-410A are permissible until January 1, 2028, for units manufactured before January 1, 2025. (

Id.

) Alternatively, NCP suggested that DOE should use its enforcement discretion to provide additional 2-year sell through before OUWNM ratings are required for through-the-wall space-constrained R-410A outdoor condensing units. (

Id.

)

NCP shared results of its analysis in confidential exhibits A and B.

DOE reviewed the confidential data provided by NCP for select outdoor unit models and agrees that the data suggests that these models cannot meet applicable minimum efficiency requirements when tested as OUWNMs. However, DOE notes that the data provided does not include performance data or estimates for designs with any technology improvements,

e.g.,

two-stage or variable-speed compressors. Thus it is not clear that compliance with Federal standards is impossible for space-constrained OUWNMs.

DOE further notes that NCP suggests a delay of the OUWNM requirement until January 1, 2028, but the need for replacemen

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