# Energy Conservation Program: Test Procedure for Central Air Conditioners and Heat Pumps > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2024-04784 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** April 5, 2024 - **Citation:** 89 FR 24206 ## Text 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: Notice of proposed rulemaking and announcement of public meeting. SUMMARY: The U.S. Department of Energy (“DOE”) proposes to amend 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 proposes: to amend 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”), respectively; and to establish a new test procedure (“appendix M2”) for CAC/HPs that would adopt 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 proposes to amend certain provisions of DOE's regulations related to representations and enforcement for CAC/HPs. DOE welcomes written comments from the public on any subject within the scope of this document (including relevant topics not raised in this proposal), as well as the submission of data and other relevant information. DATES: Comments: DOE will accept comments, data, and information regarding this proposal no later than June 4, 2024. See section V, “Public Participation,” for details. Meeting: DOE will hold a public meeting via webinar on Thursday, April 25, 2024, from 1:00 p.m. to 4:00 p.m. See section V, “Public Participation,” for webinar registration information, participant instructions, and information about the capabilities available to webinar participants. ADDRESSES: Interested persons are encouraged to submit comments using the Federal eRulemaking Portal at www.regulations.gov under docket number EERE-2022-BT-TP-0028. Follow the instructions for submitting comments. Alternatively, interested persons may submit comments, identified by docket number EERE-2022-BT-TP-0028, by any of the following methods: (1) Email: CACandHeatPump2022TP0028@ee.doe.gov. Include the docket number EERE-2022-BT-TP-0028 in the subject line of the message. (2) Postal Mail: Appliance and Equipment Standards Program, U.S. Department of Energy, Building Technologies Office, Mailstop EE-5B, 1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: (202) 287-1445. If possible, please submit all items on a compact disc (“CD”), in which case it is not necessary to include printed copies. (3) Hand Delivery/Courier: Appliance and Equipment Standards Program, U.S. Department of Energy, Building Technologies Office, 950 L'Enfant Plaza SW, 6th Floor, Washington, DC 20024. Telephone: (202) 287-1445. If possible, please submit all items on a CD, in which case it is not necessary to include printed copies. No telefacsimiles (“faxes”) will be accepted. For detailed instructions on submitting comments and additional information on this process, see section V of this document. Docket: The docket for this activity, which includes Federal Register notices, public meeting attendee lists and transcripts (if a public meeting is held), comments, and other supporting documents/materials, is available for review at www.regulations.gov. All documents in the docket are listed in the www.regulations.gov index. However, not all documents listed in the index may be publicly available, such as information that is exempt from public disclosure. The docket web page can be found at www.regulations.gov/docket/EERE-2022-BT-TP-0028. The docket web page contains instructions on how to access all documents, including public comments, in the docket. See section V for information on how to submit comments through www.regulations.gov. FOR FURTHER INFORMATION CONTACT: Mr. Lucas Adin, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Office, EE-2J, 1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: (202) 287-5904. 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) 586-9496. Email: peter.cochran@hq.doe.gov. For further information on how to submit a comment, review other public comments and the docket, or participate in a public meeting (if one is held), contact the Appliance and Equipment Standards Program staff at (202) 287-1445 or by email: ApplianceStandardsQuestions@ee.doe.gov. SUPPLEMENTARY INFORMATION: DOE proposes to maintain previously approved incorporations by reference and incorporate by reference the following industry standards into 10 CFR parts 429 and 430: AHRI 210/240-202X, 202X Standard for Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment (“AHRI 210/240-202X Draft”). AHRI 210/240-202X Draft is in draft form and this draft was announced for public review on November 16, 2023. 1 DOE references this version for the purposes of drafting this Notice of Proposed Rulemaking (“NOPR”). If this industry test standard is formally adopted, DOE intends to incorporate by reference the final published version of AHRI 210/240, not the current draft version, in DOE's subsequent test procedure final rule, unless there are substantive changes between the draft and final versions, in which case DOE may adopt the substance of the AHRI 210/240-202X Draft or provide additional opportunity for comment on the changes to the industry consensus standard. 1 Public review of AHRI 210/240-202X Draft was announced in the November 16, 2023 AHRI Update here: http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html. AHRI 1600-202X, 202X Standard for Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment (“AHRI 1600-202X Draft”). AHRI 1600-202X Draft is in draft form and this draft was announced for public review on November 16, 2023. 2 DOE references this version for the purposes of drafting this NOPR. If this industry test standard is formally adopted, DOE intends to incorporate by reference the final published version of AHRI 1600, not the current draft version, in DOE's subsequent test procedure final rule, unless 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 changes to the industry consensus standard. 2 Public review of AHRI 1600-202X Draft was also announced in the November 16, 2023 AHRI Update here: http://newsmanager.commpartners.com/ahri/issues/2023-11-16-email.html. Copies of the AHRI 210/240-202X Draft and AHRI 1600-202X Draft are available in the docket for this proposed rulemaking for review. 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 16-2016”). ANSI/ASHRAE Standard 37-2009, Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, ANSI approved June 25, 2009, (“ANSI/ASHRAE 37-2009”). ANSI/ASHRAE 116-2010, Methods of Testing for Rating Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps, ANSI approved February 24, 2010, (“ASHRAE 116-2010”). Copies of ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and 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.M of this document for further discussion of these standards. Table of Contents I. Authority and Background A. Authority B. Background II. Synopsis of the Notice of Proposed Rulemaking III. Discussion A. Scope of Applicability B. Definitions C. Updates to Industry Standards 1. AHRI 210/240-202X Draft 2. AHRI 1600-202X Draft 3. ANSI/ASHRAE 37-2009 4. ANSI/ASHRAE 16-2016 5. ANSI/ASHRAE 116-2010 D. Proposed CAC/HP Test Procedure E. Efficiency Metrics 1. Metrics Applicable to Appendix M1 2. Metrics Applicable to Appendix M2 F. Near-Term Changes in the CAC/HP Test Procedure 1. Representativeness of Fixed Speed Testing for Variable Speed (VS) Systems (a) Background (b) Comments Received (c) Commenter Conclusions Regarding Load-Based Testing (d) DOE's Conclusion and Approach (e) CVP Proposal 2. Low-Temperature Heating Performance (a) CCHP Definition (b) Mandatory H4 Heating Tests for CCHPs (c) Heating Load Line and Sizing for CCHPs (d) Cold Climate Heating Metric of Interest, COP peak 3. Cut-out and Cut-in Temperature Certification 4. Low-Static Single-Split Blower-Coil System Definition and Testing Provisions 5. Mandatory Constant Circulation Systems 6. Dual-Fuel Systems 7. Provisions for Outdoor Units With No Match 8. Inlet and Outlet Duct Configurations 9. Heat Comfort Controllers G. Long-Term Changes in the CAC Test Procedure 1. Power Consumption of Auxiliary Components (a) General Comments About Standby and Off Mode Power Consumption (b) Adjustment of Off Mode Power Consumption for Number of Compressors, System Capacity, and Variable Speed and Weighting of Off-Mode Test Power Measurements (c) Crankcase Heaters (d) Shoulder-Season Fan Power Consumption (e) Accounting for Auxiliary Components' Power Consumption 2. Impact of Defrost on Performance (a) Demand Defrost Credit (b) Supplementary Heat Usage 3. Updates to Building Load Lines and Temperature Bin Hours 4. Default Fan Power Coefficients for Coil-Only Systems 5. Indoor Ambient Test Conditions for Cooling Mode Tests 6. Air Flow Limits To Address Inadequate Dehumidification H. General Comments Received in Response to the January 2023 RFI I. Represented Values 1. Calculating 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 J. Enforcement Provisions 1. Verifying Cut-Out and Cut-In Temperatures 2. Controls Verification Procedure K. Test Procedure Costs and Impact 1. Appendix M1 2. Appendix M2 L. Compliance Date and Waivers IV. Procedural Issues and Regulatory Review A. Review Under Executive Orders 12866, 13563, and 14094 B. Review Under the Regulatory Flexibility Act 1. Description of Reasons Why Action Is Being Considered 2. Objectives of, and Legal Basis for, Rule 3. Description and Estimated Number of Small Entities Regulated 4. Description and Estimate of Compliance Requirements (a) Cost and Compliance Associated With Appendix M1 (b) Cost and Compliance Associated With Appendix M2 5. Duplication, Overlap, and Conflict With Other Rules and Regulations 6. Significant Alternatives to the Rule C. Review Under the Paperwork Reduction Act of 1995 D. Review Under the National Environmental Policy Act of 1969 E. Review Under Executive Order 13132 F. Review Under Executive Order 12988 G. Review Under the Unfunded Mandates Reform Act of 1995 H. Review Under the Treasury and General Government Appropriations Act, 1999 I. Review Under Executive Order 12630 J. Review Under Treasury and General Government Appropriations Act, 2001 K. Review Under Executive Order 13211 L. Review Under Section 32 of the Federal Energy Administration Act of 1974 M. Description of Materials Incorporated by Reference V. Public Participation A. Participation in the Webinar B. Procedure for Submitting Prepared General Statements for Distribution C. Conduct of the Public Meeting D. Submission of Comments E. Issues on Which DOE Seeks Comment VI. 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 DOE is authorized to establish and amend energy conservation standards and test procedures. (42 U.S.C. 6292(a)(3)) DOE's test procedures for CAC/HPs are currently prescribed at 10 CFR part 430, subpart B, appendix M1 (“appendix M1”). The following sections discuss DOE's authority to establish and amend test procedures for CAC/HPs and relevant background information regarding DOE's consideration of test procedures for this product. A. Authority The Energy Policy and Conservation Act, Pub. L. 94-163, as amended (“EPCA”), 3 authorizes DOE to regulate the energy efficiency of a number of consumer products and certain industrial equipment. (42 U.S.C. 6291-6317) Title III, Part B of EPCA 4 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)) 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 reflect the last statutory amendments that impact Parts A and A-1 of EPCA. 4 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 pursuant to EPCA (42 U.S.C. 6295(s)), and (2) making other representations about the efficiency of those consumer products (42 U.S.C. 6293(c)). Similarly, DOE must use these test procedures to determine whether the products comply with 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 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 or period of use and not be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3)) EPCA also requires that, at least once every 7 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. (42 U.S.C. 6293(b)(1)(A)(ii)) 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. (42 U.S.C. 6295(gg)(2)(A)) Standby mode and off mode energy consumption must be incorporated into the overall energy efficiency, energy consumption, or other energy descriptor for each covered product unless the current test procedures already account for and incorporate standby and off mode energy consumption or such integration is technically infeasible. If an integrated test procedure is technically infeasible, DOE must prescribe a separate standby mode and off mode energy use test procedure for the covered product, if 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 5 and IEC Standard 62087 6 as applicable. (42 U.S.C. 6295(gg)(2)(A)) 5 IEC 62301, Household electrical appliances—Measurement of standby power (Edition 2.0, 2011-01). 6 IEC 62087, Audio, video and related equipment—Methods of measurement for power consumption (Edition 1.0, Parts 1-6: 2015, Part 7: 2018). DOE is publishing this NOPR in satisfaction of the 7-year review requirement specified in EPCA. (42 U.S.C. 6293(b)(1)(A)) B. Background On January 5, 2017, DOE published a final rule regarding the Federal test procedures for CAC/HPs. 82 FR 1426 (“January 2017 Final Rule”). The January 2017 Final Rule amended the current test procedure at that time, 10 CFR part 430, subpart B, appendix M (“appendix M”) and established appendix M1, use of which was required beginning January 1, 2023, for any representations, including compliance certifications, made with respect to the energy use or efficiency of CAC/HPs. Appendix M provides for the measurement of the cooling and heating performance of CAC/HPs using the seasonal energy efficiency ratio (“SEER”) metric and heating seasonal performance factor (“HSPF”) metric, respectively. Appendix M1 specifies a revised SEER metric ( i.e., “SEER2”) and a revised HSPF metric ( i.e., “HSPF2”). On October 25, 2022, DOE published a final rule to address limited-scope amendments to the existing test procedures for CAC/HPs in appendix M1. 87 FR 64550 (“October 2022 Final Rule”). The October 2022 Final Rule provided changes to improve the functionality of appendix M1 to address the issues identified in test procedure waivers, improve representativeness, and correct typographical issues raised by commenters. Id. at 87 FR 64551. In the October 2022 Final Rule, DOE noted that several commenters indicated the need for test procedure amendments beyond the scope of the rulemaking. Id. at 87 FR 64554-64555. DOE received comments recommending consideration of load-based testing methods, controls validation (particularly for variable speed systems), amended metrics, amended definitions, and expansion of test methods to capture low-temperature heating performance for heat pumps. Id. In its response to these comments, DOE noted that it had initiated that rulemaking not as a comprehensive revision that would satisfy the 7-year lookback requirements ( see 42 U.S.C. 6293(b)(1)(A)), but to address a limited set of known issues, including those that have been raised through the test procedure waiver process. 87 FR 64554. DOE, however, also acknowledged that a future rulemaking may more comprehensively address the issues raised by the commenters. Id. On January 24, 2023, DOE published in the Federal Register a request for information (“RFI”) regarding the need for amendments to the test procedures for CAC/HPs, including the need for amendments to address the issues raised by commenters in the previous rulemaking, in satisfaction of the 7-year review requirements specified in EPCA. 88 FR 4091 (“January 2023 RFI”). In the January 2023 RFI, DOE requested comments, information, and data about a number of issues, and considered these issues in two separate categories: (1) 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; and (2) issues with the current appendix M1 test procedure that may or may not still be relevant if or when load-based concepts are adopted in the DOE test procedure. Id. at 88 FR 4092-4093. DOE received comments in response to the January 2023 RFI from the interested parties listed in Table I.1. Table I.1—List of Commenters With Written Submissions in Response to the January 2023 RFI Commenter(s) Reference in this NOPR Comment No. in the docket Commenter type Air-Conditioning, Heating, and Refrigeration Institute AHRI 14 Trade Association. Appliance Standards Awareness Project, American Council for an Energy-Efficient Economy, Consumer Federation of America, and National Consumer Law Center Joint Advocates 8 Efficiency Organizations and Consumer Advocacy Organizations. British Columbian Hydro and Power Authority BC Hydro 15 Utility. Pacific Gas and Electric Company, San Diego Gas and Electric, and Southern California Edison; collectively, the California Investor-Owned Utilities CA IOUs 10 Utilities. Carrier Global Corporation Carrier 5 Manufacturer. CoilPod LLC CoilPod 4 Service Provider. Daikin Comfort Technologies North America Inc Daikin 16 Manufacturer. Lennox International Inc Lennox 6 Manufacturer. National Comfort Products NCP 7 Manufacturer. Northwest Energy Efficiency Alliance NEEA 13 Efficiency Organization. New York State Energy Research and Development Authority NYSERDA 9 State Agency. Rheem Manufacturing Company Rheem 12 Manufacturer. Samsung HVAC Samsung 11 Manufacturer. A parenthetical reference at the end of a comment quotation or paraphrase provides the location of the item in the public record. 7 7 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, page of that document). In response to the January 2023 RFI, DOE received multiple comments regarding the energy conservation standards for CAC/HPs. Comments regarding energy conservation standards are outside the scope of consideration for this test procedure rulemaking and are not addressed in this NOPR. Topics related to energy conservation standards for CAC/HPs would be addressed in a separate rulemaking process. II. Synopsis of the Notice of Proposed Rulemaking In this NOPR, DOE proposes to update its test procedures for CAC/HPs by: (1) updating the reference in the Federal test procedure at appendix M1 to 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”). If AHRI 210/240-202X Draft and AHRI 1600-202X Draft are finalized and formally adopted, DOE intends to incorporate by reference the final published version of AHRI 210/240 and AHRI 1600 in DOE's subsequent test procedure final rule. To implement the proposed changes, DOE proposes: (1) to amend appendix M1 to incorporate by reference AHRI 210/240-202X Draft for CAC/HPs, while maintaining the current efficiency metrics; and (2) to add a new appendix M2 to subpart F of 10 CFR part 430 to incorporate by reference AHRI 1600-202X Draft, which introduces new efficiency metrics, SCORE and SHORE. DOE would list appendix M2 as 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 proposing to amend certain provisions within DOE's regulations for representation and enforcement consistent with the proposed test procedure amendments. Table II.1 summarizes the current DOE test procedure for CAC/HPs, DOE's proposed changes to that test procedure, and the reason for each proposed change. Table II.1—Summary of Changes in Proposed Appendix M1 and Proposed Appendix M2 Test Procedures Relative to Current Test Procedure Current DOE test procedure Proposed appendix M1 test procedure Proposed appendix M2 test procedure Attribution Incorporates by reference AHRI 210/240-2008 Incorporates by reference AHRI 210/240-202X Draft Incorporates by reference AHRI 1600-202X Draft 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 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 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 tentatively determined that the proposed amendments to the CAC/HP test procedures in appendix M1 and the proposed appendix M2 would not be unduly burdensome. Furthermore, DOE has tentatively determined that the proposed amendments to appendix M1, if made final, would not alter the measured efficiency of CAC/HPs or require retesting or recertification solely as a result of DOE's adoption of the proposed amendments to the test procedure. Additionally, DOE has tentatively determined that the proposed amendments to appendix M1, if made final, would not increase the cost of testing. If finalized, 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 tentatively determined, however, that the newly proposed test procedure at appendix M2 would, if adopted, 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 tentatively determined that the proposed amendments to appendix M2, if made final, would not increase the cost of testing. Tentative cost estimates are discussed in section III.L 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 proposed amendments to representation requirements in 10 CFR 429.43 would not be required until 180 days after publication in the Federal Register of a test procedure final rule. Discussion of DOE's proposed actions are addressed in further detail in section III of this NOPR. III. Discussion In the following sections, DOE proposes certain amendments to its test procedures for CAC/HPs. For each proposed amendment, DOE provides relevant background information, explains why the proposed amendment merits consideration, discusses relevant public comments, and proposes a potential approach. 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). 10 CFR 430.2. Appendix M1 applies to the following CACs/HPs: (a) Split-system air conditioners, including single-split, multi-head mini-split, multi-split (including 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; (c) Single-package air conditioners; (d) Single-package heat pumps; (e) Small-duct, high-velocity systems (including VRF); (f) Space-constrained products—air conditioners; and (g) Space-constrained products—heat pumps. See section 1.1 of appendix M1. DOE is not proposing to change the scope of CACs/HPs covered by the test procedure in appendix M1 or the proposed appendix M2. B. Definitions CAC/HPs are defined in 10 CFR 430.2, as described in the previous section. This definition was last amended in the October 2022 Final Rule. DOE revised the central air conditioner or central air conditioning heat pump definition so that it explicitly excluded certain equipment categories that met the CAC/HP definition based on their characteristics but are exclusively distributed in commerce for commercial and industrial applications. 87 FR 64550, 64573. DOE noted in the October 2022 Final Rule that there are certain types of equipment that meet the CAC/HP definition but are exclusively distributed in commerce for commercial and industrial applications, and that EPCA did not intend to regulate as consumer products. Id. As laid out in section 1.1 of appendix M1, the test procedure applies to CAC/ HPs, including the following categories, which are defined either in 10 CFR 430.2 or in section 1.2 of appendix M1: (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; (c) Single-package air conditioners; (d) Single-package heat pumps; (e) Small-duct, high-velocity systems (including VRF); (f) Space-constrained products—air conditioners; and (g) Space-constrained products—heat pumps. In the January 2023 RFI, DOE sought comment on whether the definition of CAC/HP needs revision, and whether the scope of the appendices M and M1 needs to be limited, expanded, clarified, or revised in any way. 8 88 FR 4091, 4093. 8 On January 1, 2023, use of appendix M1 became required for any representations—including compliance certifications—made with respect to the energy use, power, or efficiency of CAC/HPs. Prior to January 1, 2023, such representations were required to be based on the test procedure at appendix M to subpart B of 10 CFR part 430. In its response, Rheem requested a revision to the definition and scope of CAC/HPs covered by appendix M1 to add a new product class of “space-constrained vertical package” product. (Rheem, No. 12 at pp. 1-2) Rheem proposed that this new product class would meet all definitions of the current “space-constrained” product class but also consist of the following three additions: (1) is factory-assembled as a single package that has major components that are arranged vertically; (2) is intended for interior mounting on adjacent, interior to, or through an outside wall; (3) and is non-weatherized. ( Id. ) Rheem suggested the product class delineation should be used to establish a reasonable minimum test external static pressure (“ESP”) of 0.15 inches of water column (“in. wc.”), which Rheem claimed will result in more congruity between tested and actual unit operation for the consumer for these types of units. Id. Rheem asserted that DOE's current space-constrained product class is too general, and as a result puts unreasonable testing burden on “space-constrained vertical package” units. ( Id. ) Specifically, Rheem commented that the minimum ESP of 0.3 in. wc. required by appendix M1 for space-constrained products 9 is not representative of installations of these units. Rheem explained that “space-constrained vertical package” products are typically entirely installed inside a closet with a short supply duct of 5-15 feet, without a return duct, and usually are found within small multifamily or lodging applications (such as assisted living and low-income housing). ( Id. ) Additionally, Rheem noted that one of its brands, Friedrich, has multiple products in which operation at an ESP greater than 0.3 in. wc. is prohibited per the installation and operation instructions. ( Id. ) Rheem commented that designing and testing the equipment to meet the minimum 0.3 in. wc. requirement of the current space-constrained category will lead to size and cost changes that will serve no benefit to the consumer and would make replacement units cost or size prohibitive. ( Id. ) 9 See Table 4 of appendix M1 for the minimum ESP requirements for ducted blower-coil systems, including the 0.3 in. wc. requirement for space-constrained systems. DOE notes that Rheem's comment lacked sufficient information, such as product literature and test data, that would indicate that the current test procedure ESP requirement for “space-constrained” products is unsuitable for the products Rheem described in its comment, puts undue burden on manufacturers for testing, and is not representative of current installations of these units in the field. DOE is not aware of any space-constrained products that are not able to be tested according to the existing test procedure requirements. Given the limited information describing the products that are the subject of Rheem's comment, DOE is not proposing to amend the definition of space-constrained vertical package units within the scope of CAC/HPs. Regarding the scope and definition of CAC/HPs, AHRI, Carrier, and Lennox all submitted comments relating to a definition for heat pumps optimized for performance in cold climates. (AHRI, No. 14 at p. 7; Carrier, No. 5 at p. 2; Lennox, No. 6 at p. 3) Comments regarding heat pumps optimized for low-temperature heating performance are discussed in section III.F.2 of this NOPR. AHRI also submitted a comment regarding systems that use a heat pump and a furnace in combination as a source for heating ( i.e., “dual-fuel” heat pumps). (AHRI, No. 14 at p. 7) Comments regarding such systems are discussed in section III.F.6 of this NOPR. Notably, both Carrier and Lennox commented that they find the current scope of CAC/HPs covered by appendix M1 to be appropriate. (Carrier, No. 5 at p. 2; Lennox, No. 6 at p. 3) Lennox also stated that it finds the general definition of central air conditioner or central air conditioning heat pump to be adequate. (Lennox, No. 6 at p. 3) Except as noted, DOE is not proposing any further amendments to the definition of central air conditioner or to the scope of CAC/HPs covered by appendix M1 or the newly proposed appendix M2. C. Updates to Industry Standards DOE's current test procedures for CAC/HPs are codified at appendix M1 and incorporate by reference various industry standards. The regulatory text at appendix M1 has generally been closely aligned with the relevant industry standard for CAC/HPs, AHRI Standard 210/240—however, several rulemakings have changed the regulatory portions of appendix M1 over time with amendments and additions, not all of which have been mirrored in the AHRI 210/240 standards. Appendix M1 currently references ANSI/AHRI 210/240-2008 with Addenda 1 and 2 (“AHRI 210/240-2008” 10 ): 2008 Standard for Performance Rating of Unitary Air Conditioning & Air-Source Heat Pump Equipment. However, the latest AHRI Standard 210/240 is AHRI 210/240-2023, Standard for Performance Rating of Unitary Air Conditioning & Air Source Heat Pump Equipment, copyright 2020 (“AHRI 210/240-2023 (2020)” 11 ). 10 A copy of AHRI 210/240-2008 can be obtained from AHRI, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, USA, 703-524-8800, or by going to www.ahrinet.org. 11 A copy of AHRI 210/240-2023 (2020) can be obtained from AHRI, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, USA, 703-524-8800, or by going to www.ahrinet.org. Following publication of the January 2023 RFI, AHRI and other relevant stakeholders, including DOE, participated in the development of two updated industry standards relevant to CAC/HPs, the AHRI 210/240-202X Draft and the AHRI 1600-202X Draft. 12 DOE understands that these drafts were commissioned primarily to address the issues raised by DOE in the January 2023 RFI, and secondarily to harmonize the AHRI industry standards with the DOE test procedures, which were last amended in the October 2022 Final Rule. 12 Both draft standards are available in Docket No. EERE-2022-BT-TP-0028. DOE has reviewed both drafts and determined that they allow for a more representative measurement of the efficiencies of CAC/HPs than the current Federal test procedure, without being unduly burdensome. Rather than make more amendments to the regulatory text of the current appendix M1 test procedure, DOE is proposing to adopt each industry standard respectively as the basis for an updated appendix M1 and a new appendix M2, similar to how AHRI 210/240-2008 was adopted as the basis of the current appendix M1 test procedure. Specifically, DOE is proposing to incorporate by reference AHRI 210/240-202X Draft, and the relevant standards it references: ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010 as the basis for the updated appendix M1 test procedure. Similarly, DOE is proposing to incorporate by reference AHRI 1600-202X Draft, and the relevant standards it references ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010 as the basis for the new appendix M2 test procedure. Incorporating each industry standard would enable DOE to better harmonize with the industry standards and eliminate manufacturer burden in certifying with separate test procedures. 1. AHRI 210/240-202X Draft As previously discussed, AHRI and other relevant stakeholders, including DOE, worked to develop a revised AHRI 210/240 standard that would incorporate revisions to align with the October 2022 Final Rule, and additionally, seek to address the issues raised in the January 2023 RFI with broad stakeholder consensus. DOE understands that this new update is currently in draft form ( i.e., AHRI 210/240-202X Draft) and will supersede the current version of the standard, AHRI 210/240-2023 (2020). While AHRI 210/240-202X Draft does not introduce changes that would alter the measured efficiency of CAC/HPs, it does introduce new test provisions as compared to AHRI 210/240-2023 (2020), and addresses several issues that DOE raised in the January 2023 RFI. Section III.F of this NOPR includes further discussion of the changes that are reflected in AHRI 210/240-202X Draft. In light of these updates to AHRI 210/240-202X Draft, DOE is proposing to amend its test procedure for CAC/HPs at appendix M1 by incorporating by reference AHRI 210/240-202X Draft. DOE intends 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. Specifically, DOE is proposing to utilize sections 3 (excluding 3.2.15, 3.2.19, 3.2.47, 3.2.52, 3.2.64, 3.2.79 and 3.2.80), 5, 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 210/240-202X Draft in the Federal test procedure for CAC/HPs at appendix M1. Additionally, DOE is proposing additions and deletions to the incorporations by reference for the CAC/HP Federal test procedure to align with the references made within the AHRI 210/240-202X Draft. Currently, appendix M1 incorporates by reference: AMCA 210-2007, 13 AHRI 210/240-2008, AHRI 1230-2010, 14 ASHRAE 23.1-2010, 15 ANSI/ASHRAE 37-2009, and ASHRAE 116-2010. 10 CFR 430.3. 13 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. 14 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 . 15 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 proposed test procedures at appendix M1, DOE is proposing to add an incorporation by reference to ANSI/ASHRAE 16-2016 and remove incorporations by reference to AMCA 210-2007, AHRI 210/240-2008, AHRI 1230-2010 and ASHRAE 23.1-2010. Therefore, DOE is proposing to incorporate by reference the AHRI 210/240-202X Draft, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010, at appendix M1. 2. AHRI 1600-202X Draft 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). DOE is proposing to establish a new test procedure for CAC/HPs at appendix M2 by incorporating by reference AHRI 1600-202X Draft. DOE intends 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. Specifically, DOE is proposing to utilize sections 3 (excluding 3.1.15, 3.1.19, 3.1.47, 3.1.52, 3.1.65, 3.1.80, and 3.1.81), 5, 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. DOE is also proposing to incorporate by reference ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010, which are referenced within AHRI 1600-202X Draft. Therefore, in total, DOE is proposing to incorporate by reference the AHRI 1600-202X Draft, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ASHRAE 116-2010, at appendix M2. 3. ANSI/ASHRAE 37-2009 ANSI/ASHRAE 37-2009, which provides a method of test for many categories of air conditioning and heating products and equipment, is referenced for testing CAC/HPs by both AHRI 210/240-202X Draft and the AHRI 1600-202X Draft. More specifically, section 5 and appendices C, D, E, I, and J of AHRI 210/240-202X and AHRI 1600-202X Draft 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 210/240-202X Draft references ANSI/ASHRAE 37-2009 for several test instructions, DOE has tentatively concluded that it is appropriate to maintain the existing incorporation by reference of ANSI/ASHRAE 37-2009 in appendix M1. Additionally, given that the AHRI 1600-202X Draft references ANSI/ASHRAE 37-2009 for several test instructions, DOE is proposing to additionally 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. More specifically, section 5.1.1 of AHRI 210/240-202X Draft and AHRI 1600-202X Draft 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 tentatively 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 the AHRI 210/240-202X Draft and AHRI 1600 202X Draft refer to ANSI/ASHRAE 16-2016 as an option for testing of non-ducted CAC/HPs, and that it does not impact ratings, DOE has tentatively concluded 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. More specifically, sections 5, 6, 8, and 11 and appendices D and E of AHRI 210/240-202X Draft and AHRI 1600-202X Draft refer to methods of test in ANSI/ASHRAE 116-2010. Given that AHRI 210/240-202X Draft references ANSI/ASHRAE 116-2010 for several test instructions, DOE has tentatively concluded that it is appropriate to maintain the existing incorporation by reference of ANSI/ASHRAE 116-2010 in appendix M1. Additionally, given that the AHRI 1600-202X Draft references ANSI/ASHRAE 116-2010 for several test instructions, DOE is proposing to additionally incorporate by reference ANSI/ASHRAE 116-2010 for use with appendix M2. D. Proposed 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)(1)(A)) In this NOPR, DOE is proposing to maintain the current efficiency metrics of SEER2 and HSPF2 in appendix M1 and is proposing to reference AHRI 210/240-202X Draft in appendix M1 for measuring the existing metrics. DOE has tentatively determined that the proposed amendments to appendix M1 would not affect the measured efficiency of CAC/HPs or require retesting solely because of DOE's adoption of the proposed amendments to the appendix M1 test procedure, if made final. Additionally, DOE is proposing to establish a new test procedure at appendix M2 that would adopt the AHRI 1600-202X Draft, including the newly proposed SCORE and SHORE metrics. Use of appendix M2 would not be required until the compliance date of any amended standards denominated in terms of the proposed new metrics for appendix M2, should such standards be adopted. If finalized versions of AHRI 210/240 and AHRI 1600 are not published before the test procedure final rule, or if there are substantive changes between the drafts and published versions of the standards that are not supported by stakeholder comments in response to this NOPR, DOE may adopt the substance of the AHRI 210/240-202X Draft and AHRI 1600-202X Draft or provide additional opportunity for comment on the final version of that industry consensus standard. Specifically, at appendix M1, DOE is proposing to require the following sections of the AHRI 210/240-202X Draft: sections 3 16 , 5, 6 17 , 11, and 12, and appendices D, E, G, K, and L. At appendix M2, DOE is proposing to require the following sections of the AHRI 1600-202X Draft: sections 3 18 , 5, 6 19 , 11, and 12 and appendices D, E, G, K and L. 16 DOE is not proposing to include the following provisions from section 3 of AHRI 210/240-202X Draft because the terms are either defined in appendix M1, or are not needed for the proposed DOE test procedure: 3.2.15 (Double-duct system), 3.2.19 (Gross Capacity), 3.2.47 (Oil Recovery Mode), 3.2.52 (Published Rating), 3.2.64 (Standard Filter), 3.2.80 (Unitary Air-conditioner), and 3.2.81 (Unitary Heat Pump). 17 DOE is not proposing to include the following provisions from section 6 of AHRI 210/240-202X Draft because the provisions are either defined in 10 CFR 429.16, or are not needed for the proposed 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). 18 DOE is not proposing to include the following provisions from section 3 of AHRI 1600-202X Draft because the terms are either defined in appendix M1, or are not needed for the proposed DOE test procedure: 3.1.15 (Double-duct System), 3.1.19 (Gross Capacity), 3.1.47 (Oil Recovery Mode), 3.1.52 (Published Rating), 3.1.65 (Standard Filter), 3.1.80 (Unitary Air-conditioner), and 3.1.81 (Unitary Heat Pump). 19 DOE is not proposing to include the following provisions from section 6 of AHRI 1600-202X Draft because the provisions are either defined in 10 CFR 429.16, or are not needed for the proposed 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 proposing to incorporate by reference the following: ANSI/ASHRAE 37-2009; ANSI/ASHRAE 16-2016; and ANSI/ASHRAE 116-2010. Issue 1: DOE requests feedback on its proposal to revise appendix M1 to incorporate by reference AHRI 210/240-202X Draft for measuring the existing metrics, SEER2 and HSPF2. Issue 2: DOE requests feedback on its proposal to establish a new appendix M2, which would incorporate by reference AHRI 1600-202X Draft to determine the SCORE and SHORE metrics. E. Efficiency Metrics As discussed, DOE proposes to update 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 210/240-202X Draft. DOE is also proposing a new Federal test procedure at 10 CFR part 430, subpart B, appendix M2, consistent with the draft version of the industry consensus test procedure, AHRI 1600-202X Draft. Sections III.E.1 and III.E.2 indicate which metrics are applicable for appendices M1 and M2, respectively. 1. Metrics Applicable to Appendix M1 In the updated appendix M1, DOE proposes to maintain the current energy efficiency metrics ( i.e., energy efficiency ratio 2 (“EER2”), SEER2, and HSPF2), and to define a new optional metric: the peak load coefficient of performance (“COP peak ”), applicable to CHPs ( see details in section III.F.2.d of this document). The proposed revisions to appendix M1 to align with the most recent draft of AHRI 210/240-202X Draft maintain the existing energy efficiency metrics, and DOE has tentatively determined that testing under the proposed 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 As previously discussed in this NOPR, the proposed appendix M2 will introduce 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. DOE is proposing to retain EER2 in appendix M2, with EER2 evaluated in the same way as it was in appendix M1. DOE is also proposing the determination of an optional metric, COP peak , as discussed in section III.E.1 of this document, in appendix M2. F. 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 effective 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 210/240-202X Draft. DOE has reviewed AHRI 210/240-202X Draft 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)(1)(A)) These near-term amendments in appendix M1 would not alter the measured efficiency of CAC/HPs in terms of the current cooling and heating test metrics, SEER2 and HSPF2, respectively. DOE clarifies that while all issues discussed subsequently are considered near-term, they are also part of the long-term CAC/HP test procedure— i.e., these revisions are also included in AHRI 1600-202X Draft, which DOE is proposing to incorporate by reference at appendix M2. As such, when discussing these near-term changes, DOE makes references to both AHRI 210/240-202X Draft and AHRI 1600-202X Draft. 1. Representativeness of Fixed Speed Testing for Variable Speed (VS) Systems (a) Background Appendix M1 uses a steady-state test concept 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 the specified compressor speed and airflow rate for each test point. In the October 2022 Final Rule, several stakeholders encouraged DOE to review ways to improve the representativeness of the test procedures for CAC/HPs (especially variable speed), particularly to examine test procedures where the unit operates under its own native controls in responding to conditioning loads ( i.e., load-based testing). 20 DOE stated in the October 2022 Final Rule that the rulemaking had been initiated only to address a limited number of known issues in the current appendix M1 method, including those raised through the test procedure waiver process. 87 FR 64554, 64554. However, DOE also responded that in order to satisfy the 7-year lookback requirement (see 42 U.S.C. 6293(b)(1)(A)), a future rulemaking may address more comprehensively the issues raised by the commenters. ( Id. ) 20 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. As discussed in section I.B of this document, on January 24, 2023, DOE published the January 2023 RFI in order to collect data and information regarding the need to amend the test procedures for CAC/HPs, to address issues raised by commenters in the October 2022 Final Rule, and in satisfaction of the 7-year review requirement specified in EPCA. (42 U.S.C. 6293(b)(1)(A)). 87 FR 64554, 64554. In 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. Among the load-based testing methodologies summarized by DOE in the January 2023 RFI was the first edition of Canadian Standard Association (“CSA”) EXP07:19, “Load-based and climate-specific testing and rating procedures for heat pumps and air conditioners” (“EXP07”). 88 FR 4091, 4095. DOE notes that EXP07 was superseded by CSA SPE-07:23 21 (“SPE07”) in January 2023, an updated version of EXP07 with changes made based on comments received during a technical review period. 21 SPE07 is available for download at: wwwcsagroup.org/store/product/CSA%20SPE-07:23/ . (b) Comments Received In response to the January 2023 RFI, DOE received a variety of comments related to various aspects of load-based testing. The comments are summarized in the following sub-sections, segregated by topic as appropriate. (1) Repeatability and Reproducibility In the January 2023 RFI, DOE presented several initiatives and programs that were investigating, researching, and/or developing load-based test methods. 88 FR 4091, 4095-4098. DOE requested data and information to quantify which of these load-based methods—and any other that DOE is not aware of—had higher repeatability and reproducibility compared to the others, and also compared to fixed-speed tests. 88 FR 4091, 4099. In response, Samsung, Carrier, Daikin, Rheem, AHRI, and Lennox all commented that available test data have shown that the repeatability and reproducibility of load-based methods is not on par with current fixed-speed testing used for regulatory purposes. (Samsung, No. 11 at p. 1; Carrier, No. 5 at pp. 2-3; Daikin, No. 16 at pp. 2-3; Rheem, No. 12 at pp. 2-3; AHRI, No. 14 at pp. 8-9; Lennox, No. 6 at p. 3) Samsung asserted that adopting something unproven, like the load-based test methods, may create a chaotic situation in the marketplace, and will create additional test burden for manufacturers since load-based testing methods do not address alternative efficiency determination methods (“AEDMs”). (Samsung, No. 11 at p. 1) Carrier referred to the Technology Collaboration Program of Energy Efficient End-use Equipment, International Energy Efficiency (“4E IEA”) 22 and AHRI 8026 23 initiatives, which showed that load-based testing of the same units across different facilities showed high variability, and commented that more work and research needs to be done in order to reduce this variability before adopting load-based testing for determining energy efficiency of CAC/HP systems. (Carrier, No. 5 at pp. 2-3) Daikin also commented that until all issues pertaining to load-based testing are fully vetted, there would be significant problems with repeatability and reproducibility. (Daikin, No. 16 at pp. 2-3) Daikin mentioned several items that contribute to variability in load- based testing, such as the controller (room thermostat), controller setup, control modifications in the test chamber, and the application of the load. ( Id. at pp. 2-3) Daikin also requested that stakeholders thoroughly evaluate the secondary capacity check process during load-based testing, and compare that with the accuracy, repeatability, and reproducibility of conventional fixed-speed testing. (Daikin, No. 16 at p. 12) 22 “AC/HP Test Methods Investigative Testing: Phase 2 Preliminary Findings” 4E IEA presentation (May 7, 2021). See www.iea-4e.org/wp-content/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf . 23 Dhillon, P., Horton, W.T., & Braun, J.E. (2022). AHRI 8026—Repeatability and Reproducibility Assessment of CSA EXP07:19 and AHRI 210-240:2023. Air Conditioning, Heating, and Refrigeration Institute. Rheem and AHRI both referred to the results of AHRI 8026. (Rheem, No. 12 at pp. 2-3; AHRI, No. 14 at pp. 8-9) Rheem commented that per AHRI 8026, the transient conditions during load-based testing cause poorer repeatability and reproducibility in comparison to fixed-speed testing currently in appendix M1. (Rheem, No. 12 at pp. 2-3) Rheem further stated that even with appendix M1 testing, reproducibility of transient components like cyclic degradation and defrost can be challenging. ( Id. ) AHRI commented that AHRI 8026 results revealed concerns when it comes to repeatability and reproducibility of performance metrics of load-based testing. (AHRI, No. 14 at pp. 8-9) Further, AHRI noted that there are no analyses of control system parameter variability available for load-based testing, and that such analyses would require significant investments in lab facilities and technical training and none of the load-based testing methods address the use of AEDMs. ( Id.) Similarly, Lennox mentioned several items that affect the repeatability and reproducibility of load-based testing, including the varying degrees of test burden in the different methods, changes required to lab facilities to accommodate load-based testing, interaction between the unit under test and the lab facility, and how the lab facility affects the load-based tests. (Lennox, No. 6 at p. 3) Lennox expressed concern over the fact that labs may need to significantly invest in their facilities and resources if their present setups were found to positively or negatively influence load-based test results. ( Id.) NEEA commented that a pre-defined load test 24 may have greater repeatability and reproducibility in comparison to an adaptive load test, because multiple variables need to be controlled for an adaptive load, and there are several interactive effects between unit performance and test lab conditions. (NEEA, No. 13 at p. 6) NEEA referred to the 4E IEA program, 25 stating that preliminary results from phase 4 of 4 are expected to be available by mid-summer 2023, with full study results to be released at the end of 2023 or early in 2024. ( Id. ) 24 In its comment, NEEA defined a pre-defined load test as those where the unit under test (UUT) is subjected to pre-defined sensible or latent loads, and stated that the 4E program and the DOE CCHP Tech Challenge were examples of such a load based test method. They defined adaptive load test methods as those where a constant or variable sensible and latent is applied to the UUT, but the magnitude of the load can be altered, based on unit behavior, and stated that the SPE07 was an example of such a method. 25 “AC/HP Test Methods Investigative Testing: Phase 2 Preliminary Findings” 4E IEA presentation (May 7, 2021). See: www.iea-4e.org/wpcontent/uploads/2021/08/AC-HP-Test-Methods-Phase-2-key-Findings-2021-08-06-CLEAN.pdf . (2) Field Performance In the January 2023 RFI, DOE requested data showing that load-based testing was more representative of field performance, in comparison to conventional fixed-speed and fixed-setting test procedures. 88 FR 4091, 4099. DOE also requested data that would indicate whether CAC/HP units that performed poorly in the lab, when tested using load-based methods, also performed poorly in the field. Id. Carrier commented that it was not aware of publicly available data showing that load-based test methods are more or less representative than fixed-speed and fixed-setting test procedures. (Carrier, No. 5 at p. 3) Carrier further commented that even though there is value in verifying the operation of variable speed systems, it was unclear if a load-based test method would provide more representative tests in comparison to fixed-speed testing with a controls verification procedure (“CVP”) to confirm unit operation at the speeds specified in the fixed-speed tests. ( Id.) Similarly, Daikin stated that even though several studies are being conducted, there is a general lack of information and data to substantiate whether load-based testing or fixed-speed testing is more representative of real-world scenarios. (Daikin, No. 16 at p. 3) Daikin expressed concern over the fact that load-based test methods, such as SPE07, do not account for real-world scenarios when a CAC/HP is installed with a controller (or room thermostat) of a different brand than the manufacturer of the CAC/HP. ( Id.) Daikin commented that if controller operation is central to load-based testing, then smart thermostat manufacturers would also need to provide ratings when their product is matched with another manufacturer's CAC/HP, similar to the process followed by independent coil manufacturers (“ICMs”) for representing the ratings of their indoor coils with different combinations of other manufacturers' outdoor coils. ( Id.) Daikin also commented that load-based test methods currently do not address AEDM calculation methods for non-tested combinations (“NTCs”), nor do they have a method for ICMs to rate their indoor coil products with an outdoor unit that has been tested using load-based methods. ( Id.) Rheem commented that while it believed more studies are needed for evaluating the representativeness of load-based methods, field performance is very dependent on installation practices. (Rheem, No. 12 at p. 3) The CA IOUs commented that the current appendix M1 test procedure uses fixed compressor speeds and air volume rates with fixed indoor and outdoor temperature conditions, and is thus not representative of field use, indicating that the energy efficiencies may be misinterpreted. (CA IOUs, No. 10 at pp. 1-2) (3) Test Burden A critical component of load-based testing is the relevant burden(s) associated with the testing— i.e., total testing time, time needed for control system learning, number of official test points, time required to transition between test points, upgrades to laboratory equipment, and cost and time associated with training technicians to be able to conduct load-based testing. In the January 2023 RFI, DOE requested comment from stakeholders on information pertaining to the aforementioned test burdens. 88 FR 4091, 4099. In response, Carrier, Daikin, and Rheem commented that the test burden of load-based testing is generally more than that of fixed-speed testing. (Carrier, No. 5 at pp. 3-4; Daikin, No. 16 at pp. 3-4; Rheem, No. 12 at pp. 3-4) Regarding costs, Carrier commented that lab investments will be needed to emulate Virtual Building Load (“VBL”), 26 and Rheem commented that even though predicting the cost impact of emerging load-based methods is difficult, there will definitely be costs associated with changes to test chambers and equipment that manufacturers will have to bear. (Carrier, No. 5 at pp. 3-4; Rheem, No. 12 at pp. 3-4) Carrier and Daikin both commented that load-based testing methods would require more time to conduct due to the higher number of tests involved. (Carrier, No.5 at pp. 3-4; Daikin, No.16 at pp. 3-4) 26 Virtual Building Load is a load-based or native controls test procedure during which the software that controls the indoor test room conditions ( i.e., operates the indoor room reconditioning system) is programmed to mimic the response of building heating or cooling in real time by monitoring the capacity of the unit under test and adjusting the indoor room conditions according to the virtual building model. The virtual building model defines the time-dependent rate of change of the indoor room temperature and humidity conditions as a function of the target building load and the measured capacity of the tested system. Daikin also stated that during new product development, manufacturers only have to do a subset of appendix M1 tests, often iteratively, because results of those subsets are enough to inform the manufacturer of the design changes needed. (Daikin, No. 16 at pp. 3-4) Daikin commented that due to lack of experience with load-based methods such as SPE07, it would not be possible to do quick assessments like these. ( Id. at pp. 3-4) Finally, Daikin stated that changes to refrigerant regulations that will occur in 2023 will require a full redesign of the products, and manufacturers may not be able to accomplish that in a timely manner using load-based methods. ( Id. ) Rheem referred to the 4E IEA project report, in which it was estimated that the additional test burden due to the Target Compensation Load method will have a 60-percent to 250-percent increase in test burden. (Rheem, No. 12 at pp. 3-4) Rheem commented that load-based test methods would require changes to control schemes, additional test setups, and additional equipment, due to rapidly changing loads inside the chamber. ( Id. ) Rheem referred to several research studies 27 28 that showed load-based test methods are influenced by the thermal inertia of the psychrometric chambers in which the tests are conducted; thus, adaptation of the control system to this thermal inertia may be a time-consuming process. ( Id. ) AHRI stated that even though the value of load-based testing remains unknown, the burden has been quantified. (AHRI, No. 14 at p. 5) 27 Cremaschi, L., & Perez Paez, P. (2017). Experimental feasibility study of a new load-based method of testing for light commercial unitary heating, ventilation, and air conditioning (ASHRAE RP-1608). Science and Technology for the Built Environment, 23(7), 1178-1188. Available at www.tandfonline.com/doi/full/10.1080/23744731.2016.1274628 . 28 Göbel, S.A., Zottl, A., Noack, R., Mock, D., Wachau, A., Vering, C., & Müller, D. (2022, August). How to calibrate heat pump test stands for load-based testing—Towards technology-neutral prescriptions [Paper presentation]. 14th International Conference on Applied Energy, ICAE22, August 8-11, 2022, Bochum, Germany. Available at www.ebc.eonerc.rwth-aachen.de/go/id/dncb/file/855717?lidx=1 . In summary, all comments received indicated that the test burden for load-based testing will be higher than that of conventional fixed-speed testing laid out in appendix M1. (4) Thermostat Selection and Built-In Control Firmware Thermostats ( i.e., “control systems”) can vary significantly in their control algorithms and communication with the unit under test. Thus, thermostat selection can play a key role in the results of load-based tests. In the January 2023 RFI, DOE requested comment on several impacts of thermostats with respect to load-based testing, including the observed range of performance of the same unit tested with different thermostats, and consideration of whether a thermostat needs to be certified as part of the tested combination. 88 FR 4091, 4099. DOE also requested comment on what percentage of thermostats may be updated remotely versus in the field, and how unit behavior in the field depends on thermostats shipped with the unit versus those purchased from third-party suppliers. ( Id. ) In response to this issue, DOE received comments from several stakeholders. Carrier and Rheem commented that thermostats have a big impact on load-based test results. (Carrier, No. 5 at p. 4; Rheem, No. 12 at p. 4) Carrier commented that since the majority of HVAC systems in the market are not installed with a manufacturer`s thermostat, it would not be feasible for manufacturers to test with the different thermostats available. (Carrier, No. 5 at p. 4) Carrier further stated that only variable speed systems shipped with the manufacturer`s thermostat should have certification requirements. ( Id. ) The Joint Advocates and NYSERDA encouraged DOE to require certification of thermostats as part of the tested combination. (Joint Advocates, No. 8 at p. 2; NYSERDA, No. 9 at pp. 6-7) Specifically, the Joint Advocates encouraged DOE to investigate how the performance of single-stage, two-stage, and variable speed equipment is impacted by integrations of different thermostats, and to develop testing requirements for ensuring that the tested thermostat is representative of the one selected in the field. (Joint Advocates, No. 8 at pp. 2-3) NYSERDA commented that thermostat selection will be integral to a CVP, which verifies that the manufacturer`s supplemental testing instructions for setting critical parameters during fixed-speed testing are within the range of critical parameters that the system would utilize when operating under its native controls. (NYSERDA, No. 9 at pp. 6-7) NYSERDA further commented that communicating systems may only be compatible with certain thermostats; hence, DOE should have a regulatory requirement that discourages pairing such systems with third-party thermostats. ( Id. ) However, NYSERDA recognized that in some situations, such as for blower coil indoor units, the system has communication technology built in that allows the use of any thermostat, which may not require certification with external thermostats. ( Id. at p. 7) NYSERDA concluded that the actual firmware governing unit behavior is built into the unit, and not into the thermostat, meaning that updated testing would be required only in instances when the updated firmware results in an updated model number. ( Id.) AHRI stated that certification requirements will be complicated with thermostats, especially when utilizing those that are not specified by the manufacturer. (AHRI, No. 14 at pp. 9-10) AHRI also stated that different thermostats will give different load-based test results, and referred to an article stating that smart thermostats were only being used by 16 percent of households. ( Id. ) Daikin commented that due to the limited time allowed for submitting comments in response to the January 2023 RFI, it did not have thermostat-associated data to share with DOE other than that from its own “Daikin One” thermostat. (Daikin, No. 16 at pp. 4-5) Daikin stated that several issues pertain to thermostat selections, making load-based testing unrepresentative of real-world situations; for instance, Daikin questioned whether, in the case of systems installed with smart thermostats like Nest or EcoBee, the unit manufacturer will be responsible for rating the system if the thermostat receives a remote firmware upgrade. ( Id. ) Several commenters referred to Annex I of SPE07, which outlines a Thermostat Environment Emulator (“TEE”) developed by Purdue University that is a thermostat enclosure aimed at providing controlled airflow and temperature distribution to the air sensed by the thermostat. (Daikin, No. 16 at pp. 4-5; Joint Advocates, No. 8 at p. 3; NYSERDA, No. 9 at p. 7) Specifically, Daikin commented that the TEE demonstrated that thermostat location is an integral part of unit performance, but such an enclosure is not representative of real-world installations. (Daikin, No. 16 at pp. 4-5) In contrast, the Joint Advocates encouraged DOE to adopt something similar to the TEE in its test procedure so that reproducibility issues occurring between the various indoor rooms of psychrometric chambers (that conduct load-based testing) may be mitigated. (Joint Advocates, No. 8 at p. 3) Rheem pointed out that temperature sensors inside thermostats may not be as responsive or accurate as laboratory-grade temperature sensors, and because of this, temperature offsets are often necessary for tests done under native controls. (Rheem, No. 12 at p. 4) Rheem further commented that since these offsets may be influenced by the air flow rate over the thermostat, thermostat location, and orientation, there may be a requirement to dynamically modify this offset as the load-based test proceeds. ( Id. ) Rheem stated that remote update of unit/controller firmware is a relatively new feature, and therefore not as widely available as firmware updates done in the field by service technicians. ( Id. ) (5) Utilizing Distinct Test Methods for Different Purposes In the January 2023 RFI, DOE requested comment on whether there are any load-based methods that are being used for regulatory or voluntary incentive-based programs. 88 FR 4091, 4100. Rheem, AHRI, and NYSERDA all commented that they are unaware of any load-based methods being used for the aforementioned purposes. (Rheem, No. 12 at p. 4; AHRI, No. 14 at p. 10; NYSERDA, No. 9 at p. 9) Daikin commented that in 2024, U.S. Environmental Protection Agency (“EPA”) ENERGY STAR® Version 6.1 specifications (“ENERGY STAR Spec V6.1”) 29 will be required for the Canada Greener Homes Program, even though currently it is an optional load-based method applicable only to cold climate heat pumps (“CCHPs”). (Daikin, No. 16 at p. 5) Daikin pointed out that due to the resources and efforts required to develop new products with low global warming potential (“GWP”) refrigerants like R32, Daikin doubts it will engage in any non-mandatory load-based testing. ( Id. ) NYSERDA referred to three initiatives associated with load-based testing, namely (1) the Canadian market transformation roadmap presented at the 2018 Energy and Mines Ministers' Conference, 30 (2) British Columbia`s 2022 Heat Pump Technology Attraction Strategy, 31 and (3) a plan for differentiating advanced heat pumps using load-based testing criteria in the Northeast Energy Efficiency Partnerships (“NEEP”) qualified product list. 32 (NYSERDA, No. 9 at pp. 8-9) NYSERDA encouraged incentive-based approaches for advanced heat pumps that include: (1) a CVP to identify unit operation under native controls, (2) using regional HSPF2 to differentiate advanced heat pumps, and (3) prescribing capacity maintenance and coefficient of performance (“COP”) levels at 5 °F, similar to those in the ENERGY STAR Spec V6.1 requirements. ( Id. at p. 9) 29 Version 6.1 of the ENERGY STAR specification for CAC/HPs, revised in January 2022, can be found at www.energystar.gov/products/spec/central_air_conditioner_and_air_source_heat_pump_specification_version_6_0_pd . 30 NYSERDA referred to p. 32 of the 2018 report titled “Paving the Road to 2030 and Beyond: Market transformation road map for energy efficient equipment in the building sector.” Available at www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/electricity-alternative-energy/energy-efficiency/18-00072-nrcan-road-map-eng.pdf . 31 NYSERDA referred to pages 20, 25, and 26 of the Vancouver Energy Commission's BC Heat Pump Technology Attraction Strategy, available at vancouvereconomic.com/wp-content/uploads/2022/11/11-2022-BC-Heat-Pump-Strategy-Report-Web-1.1.pdf . 32 NYSERDA referred to page 14 of the “Advanced Heat Pump White paper,” available at www.mwalliance.org/sites/default/files/media-document/Advanced%20HP%20Whitepaper%20v1.13.pdf . (6) Comparison of Test Conditions of Appendix M1 and SPE07 In the January 2023 RFI, DOE provided a detailed explanation of the first edition of EXP07. 88 FR 4091, 4095. As previously mentioned, EXP07 was superseded by SPE07, an updated version of EXP07 with changes made based on comments received during a technical review period in January 2023. SPE07 is a load-based methodology where the unit under test is allowed to respond to a thermostat installed in the return air stream, while the indoor room conditioning equipment control is used to adjust that temperature (to represent heating or cooling conditioning load), mimicking the response of a typical building. The test sequences through a set of representative outdoor room conditions. In the January 2023 RFI, DOE pointed out that these test conditions differ from those laid out in appendix M1. 88 FR 4091, 4100. Due to these differences, DOE requested comment on how unit performance would compare when tested using the SPE07 test conditions (indoor as well as outdoor) and the appendix M1 test conditions. Id. DOE further requested feedback on the pros and cons of potentially revising the test conditions in appendix M1. Id. AHRI pointed out that the concept of SPE07 is interesting from a research perspective but not suitable for regulatory purposes. (AHRI, No. 14 at p. 5) AHRI noted that the seasonal COP metrics in SPE07 are climate zone dependent, and there is no metric that calculates unit performance at a national average level. (AHRI, No. 14 at pp. 5-6) AHRI pointed to 42 U.S.C. 6291(22), to state that the seasonal COP metrics cannot be adopted by DOE in appendix M1 as the efficiency descriptors. ( Id. at p. 6) Further, AHRI commented that SPE07 is currently not applicable to coil-only systems, which means that if adopted, the process of certification and enforcement for split systems would need to be overhauled. ( Id. ) AHRI also pointed that SPE07 currently does not address AEDMs, which implies that a regulatory regime under SPE07 would create significant test burden due to the large number of rated combinations of split-system units. ( Id. ) AHRI referred to the testing reporting requirements in appendix M1 for variable speed mini and multi-splits, stating that SPE07 does not properly define requirements for established ratings for these products. ( Id. at p.7) Finally, AHRI cited a section of 42 U.S.C 6293(b)(3) to point out that test procedures should not be unduly burdensome to conduct. 33 ( Id. ) AHRI commented that its commentary is limited to SPE07, stating that it is the most developed and established load-based methodology, but AHRI still does not see a viable pathway for SPE07 moving forward. ( Id. ) 33 From this comment, DOE considers that AHRI wanted to make the point that SPE07, as it currently stands, is unduly burdensome. Daikin and Rheem both commented that since appendix M1 and SPE07 have different performance metrics, their ratings cannot be compared. (Daikin, No. 16 at p. 5; Rheem, No. 12 at pp. 4-5) Daikin commented that it lacks data that can be shared comparing appendix M1 and SPE07 testing. (Daikin, No. 16 at p. 5) Daikin pointed out that the different indoor dry bulb and wet bulb temperature setpoints in appendix M1 and SPE07 would lead to different efficiencies, and the higher number of test points in SPE07 adds to test burden. (Daikin, No. 16 at p. 5) Daikin referred to how the tolerance of 10 percent was chosen when commercial HVAC products moved to a seasonal metric (integrated energy efficiency ratio (“IEER”)), from a peak load metric ( i.e., EER), rather than 5 percent, indicating that the tolerance for certified ratings would have to be increased if DOE adopted a load-based testing method for regulatory purposes. ( Id. at p. 6) Rheem referred to a research paper 34 to back its claim that relative rankings of SPE07 and appendix M1 are impossible. (Rheem, No. 12 at pp. 4-5) Rheem further pointed out that since the indoor dry bulb and wet bulb temperature in appendix M1 are the same for all tests, the time for testing is optimized. ( Id. ) Similarly, Carrier commented that research currently in progress would enable a comparison of the ranking of units when tested with appendix M1 and SPE07, but any conclusions cannot be reached currently. (Carrier, No. 5 at pp. 4-5) Samsung supported AHRI`s comment on SPE07 and stated that load-based testing is not currently at a stage where it may be adopted as the mandatory test procedure by DOE. (Samsung, No. 11 at p. 1) 34 Dhillon, P., Horton, W. T., & Braun, J. E. (2022). Comparison of residential heat pump heating seasonal performance based on load-based and steady-state testing methodologies. ASHRAE Transactions, 128(1), 181-189. Available at www.techstreet.com/standards/lv-22-c025-comparison-of-residential-heat-pump-heating-seasonal-performance-based-on-load-based-and-steady-state-testing-methodologies?product_id=2505150 . BC Hydro strongly encouraged DOE to adopt SPE07 as the next test procedure for CAC/HPs and referred to four NEEA papers 35 that highlighted lessons learned from EXP07 testing that prompted the update to SPE07. (BC Hydro, No. 15 at pp. 1-2) Similarly, both the CA IOUs and the Joint Advocates referred to a NEEP representativeness project 36 and encouraged DOE to update the CAC/HP test procedure on the basis of those results. (CA IOUs, No. 10 at p. 2; Joint Advocates, No. 8 at p. 2) NYSERDA commented that more work needs to be done in order to consider the VBL approach (used as the basis of testing in SPE07), and specifically referred to additional efforts needed to ensure the repeatability and reproducibility of this method—namely, field data to validate lab data, lab-to-lab round robin testing, and an uncertainty analysis method that accounts for the unit under test`s embedded controls and thermostat. (NYSERDA, No. 9 at p. 6) 35 Heat Pump and Air Conditioner Efficiency Ratings: Why Metrics Matter. Available at neea.org/resources/heat-pump-and-air-conditioner-efficiency-ratings-why-metrics-matter . EXP07:19 Load-Based and Climate-Specific Testing and Rating Procedures for Heat Pumps and Air Conditioners. Available at neea.org/resources/exp0719-load-based-and-climate-specific-testing-and-rating-procedures-for-heat-pumps-and-air-conditioners . CSA EXP07: Ongoing Progress, Lessons Learned, and Future Work in Load-based Testing of Residential Heat Pumps. Available at neea.org/resources/csa-exp07-ongoing-progress-lessons-learned-and-future-work-in-load-based-testing-of-residential-heat-pumps . EXP07 Value Engineering Memo and PowerPoint. Available at neea.org/resources/exp07-value-engineering-memo-and-powerpoint . 36 The NEEP Heat Pump Rating Representativeness Project. Available at neep.org/sites/default/files/media-files/hp_representativeness_research_project-rfp_7.7.21.pdf . Regarding test conditions, NYSERDA commented that it did not have specific analysis about the overall outdoor conditions but did point out: (1) SPE07 focuses on more extreme outdoor conditions; (2) different rankings of appendix M1 metrics and load-based testing results are mainly due to the influence of the unit`s native controls on operation and any minor changes to the appendix M1 test conditions will not have a big impact on rankings; and (3) the addition of a hot-dry SEER2 rating would better capture performance at extreme climates. 37 (NYSERDA, No. 9 at p. 10) AHRI recommended that a fair comparison of appendix M1 and SPE07 would involve a study where the test conditions of each are swapped and the test results compared. (AHRI, No. 14 at p. 10) AHRI added that measurement uncertainties associated with both procedures should be accounted for in the comparison as well. ( Id. ) 37 In one of its comments, NYSERDA referred to the contents in Table II-1, which outlines the applicability of the load-based methods to equipment types (ducted or non-ducted), and the capacity measurement procedure (calorimetric room or air enthalpy method). (NYSERDA, No. 9 at p. 9) NYSERDA commented that DOE did not point out that SPE07 applies to ducted equipment, and the ENERGY STAR CCHP CVP applies to non-ducted equipment. DOE would like to point out that it did, in fact, indicate in the table that SPE07 and the ENERGY STAR CCHP CVP are applicable to ducted and non-ducted equipment, respectively. (7) Communicating and Non-Communicating Variable Speed Systems Controls used with CAC/HPs may transfer information between system components ( i.e., communicating systems), or they may use more conventional low-voltage on-off signals to indicate “calls” for space conditioning and/or consumer selection of fan settings ( i.e., non-communicating). Communicating systems are defined as those that communicate the difference between space temperature and space setpoint temperature to the control that sets compressor speed and provides a signal to the indoor fan to set fan speed appropriate for compressor staging and air volume rate. 87 FR 16830, 16837. In the January 2023 RFI, DOE requested test data that could potentially show how the performance of communicating and non-communicating variable speed CAC/HPs compares when tested using load-based methods, and how do load-based methods address modulation of compressor speed for systems equipped with non-communicating controls. 88 FR 4091, 4100. In response, Daikin, Rheem, AHRI, and NYSERDA commented that they are not aware of any test or field data comparing the performance of communicating and non-communicating systems when tested using load-based methods. (Daikin, No. 16 at p. 6; Rheem, No. 12 at p. 5; AHRI, No. 14 at pp. 10-11; NYSERDA, No. 9 at p. 10) Daikin commented that load-based test methods would incentivize manufacturers to develop control schemes that optimize performance in the test lab rather than in the field. (Daikin, No. 16 at p. 6) Daikin further stated that the definition adopted by DOE in the October 2022 Final Rule 38 for Variable Speed Coil-Only systems was too restrictive and will limit technology and progress. ( Id. ) 38 Section 1.2 of appendix M1 defines “Communicating Variable Speed Coil-Only Central Air Conditioner or Heat Pump” as follows: Variable speed Communicating Coil-Only Central Air Conditioner or Heat Pump means a variable speed compressor system having a coil-only indoor unit that is installed with a control system that (a) communicates the difference in space temperature and space setpoint temperature (not a setpoint value inferred from on/off thermostat signals) to the control that sets compressor speed; (b) provides a signal to the indoor fan to set fan speed appropriate for compressor staging and air volume rate; and (c) has installation instructions indicating that the required control system meeting both (a) and (b) must be installed. Rheem commented that even for non-communicating systems, operating parameters of the refrigeration cycle are affected by the heat sink temperatures and heat source. Rheem listed suction pressure, liquid line pressure, return gas temperature, and liquid line temperature as the parameters, and cited a research paper 39 that outlined a variable system controlled by refrigerant superheat. (Rheem, No. 12 at p. 5) 39 Yang, D. S., Lee, G., Kim, M. S., Cho, Y. M., Hwang, Y. J., & Chung, B. Y. (2004). A study on the capacity control of a variable speed vapor compression system using superheat information at compressor discharge . In 10th International Refrigeration and Air Conditioning Conference at Purdue, July 12-15, 2004 . Purdue University Libraries, West Lafayette, IN. Available at docs.lib.purdue.edu/iracc/689/ . NYSERDA commented that a non-communicating thermostat would not typically allow the variable speed system to modulate, and the system will simply cycle on and off like a single-speed system. (NYSERDA, No. 9 at p. 10) NYSERDA cited a research paper indicating that for low-load conditions, variable speed units suffer more from cycling losses in comparison to single-stage and two-stage systems. ( Id. ) (8) Load-Based Testing for Single-Stage and Two-Stage Systems In the January 2023 RFI, DOE requested comment on whether there are aspects of single- and two-stage system operation that are not adequately captured by appendix M1, and if load-based testing should be applicable to them. 88 FR 4091, 4101. DOE also requested comment on whether the current cyclic tests in appendix M1 adequately capture cyclic losses associated with cycling of compressors when unit capacity exceeds building load. ( Id. ) In response, the Joint Advocates commented that even though load-based testing is best suited to accurately capture part-load operation of variable speed systems, it may be beneficial to apply it to single-stage and two-stage systems. (Joint Advocates, No. 8 at p. 2) In contrast, Carrier commented that appendix M1 captures the performance of single- and two-stage systems adequately, and the application of load-based testing to these systems will not provide any value. (Carrier, No. 5 at p. 5) Daikin commented that if fixed-speed testing (currently in appendix M1) is used for single-stage and two-stage products and load-based testing is used for variable speed products, then it will not be possible to compare these products on an equivalant basis. (Daikin, No. 16 at p. 6) Similarly, Rheem pointed out that load-based testing is mainly appropriate for variable speed products, and its suitability for single-stage and two-stage systems is questionable. (Rheem, No. 12 at p. 5) AHRI commented that any test procedure needs to compare different equipment classes on an equal basis. (AHRI, No. 14 at p. 11) Regarding cyclic losses, the Joint Advocates commented that appendix M1 fails to properly account for the cycling performance of units. (Joint Advocates, No. 8 at p. 2) The Joint Advocates referred to the current method of calculating the cyclic degradation coefficient in appendix M1 40 and cited a research paper 41 to highlight the issues in this calculation methodology. ( Id. ) Daikin pointed out the unsuitability of load-based tests for capturing cyclic losses, by stating that the cyclic tests in appendix M1 are executed with dry indoor coils since it is not easy to measure briskly changing moisture content during these tests. (Daikin, No. 16 at p. 6) Daikin added that for load-based cyclic tests, the coils will get wet, which will lead to concerns with the repeatability and reproducibility of capturing cyclic losses using load-based methods. ( Id. ) 40 Sections 3.5 and 3.8 of appendix M1 contain provisions for conducting optional cooling and heating cyclic tests. These cyclic tests are used to determine the Coefficient of Degradation (“CD”), which is incorporated into the calculation of SEER2 and HSPF2, to account for any compressor cycling losses. If the optional cyclic tests are not conducted, appendix M1 requires use of the default CD value of 0.25. However, for the majority of single- and two-stage systems, a lower CD can be achieved when completing the optional cyclic tests, which results in higher SEER2 and HSPF2. 41 Dhumane, Rohit; Qiu, Tianyue; Ling, Jiazhen; Aute, Vikrant Chandramohan; Hwang, Yunho; Radermacher, Reinhard; Kirkwood, Allen Chad; and Esformes, Jack, “Evaluating the Impact of the Measurement Setup on Cyclic Degradation Coefficient of Air Conditioning Systems” (2018). International Refrigeration and Air Conditioning Conference. Paper 2012. Available at docs.lib.purdue.edu/iracc/2012 . (9) Other Factors Affecting System Energy Use In the January 2023 RFI, DOE requested comment on how load-based testing could be used to capture other parameters that affect energy use of CAC/HPs, particularly, but not limited to, defrost systems, operation of electric resistance heat, operation of fans during the shoulder season, and operation of crankcase heaters during off-mode hours. 88 FR 4091, 4101. In response, Rheem commented that most power consumption is accounted for in the off-mode test procedure, 42 except fan-only operation, which may be difficult to capture in a load-based test since outside air is not introduced during operation. (Rheem, No. 12 at p. 5) AHRI commented that incorporation of the parameters and aspects mentioned by DOE would result in the need for new energy efficiency descriptors. (AHRI, No. 14 at p. 11) NYSERDA recommended that DOE adopt an average space heating capacity adjustment using a defrost degradation coefficient consistent with the provisions of a test procedure term sheet issued by the Appliance Standards and Rulemaking Federal Advisory Committee Commercial Unitary Air Conditioner and Heat Pump Working Group on December 15, 2022 (“2022 ASRAC CUAC and CUHP WG TP term sheet”). 43 (NYSERDA, No. 9 at pp. 10-11) NYSERDA commented that the cyclic defrost tests in appendix M1 (at outdoor temperature of 35 °F) could still be applicable for evaluating the maximum defrost degradation. ( Id. ) 42 Section 3.13 of appendix M1 outlines the procedure to determine off-mode average power ratings. 43 On July 21, 2022, ASRAC chartered the CUAC and CUHP Working Group to negotiate term sheets on the test procedure and energy conservation standards for CUACs and CUHPs. On December 15, 2022, the Working Group completed a term sheet for the test procedure, which is available at www.regulations.gov/document/EERE-2022-BT-STD-0015-0065 . (c) Commenter Conclusions Regarding Load-Based Testing In general, almost all commenters pointed toward several issues with load-based testing that make it infeasible for adoption as a regulatory test method at this time. Carrier commented that it is strongly opposed to DOE adopting any of the load-based testing procedures described in the January 2023 RFI since current research on these methods needs to be finalized before DOE incorporates them into the test procedure. (Carrier, No. 5 at p. 2) Daikin pointed out that while load-based testing may be appropriate when used as a CVP (similar to how it is used for VRF products in AHRI 1230-2021: 2021 Standard for Performance Rating of Variable Refrigerant Flow Multi-Split Air-Conditioning and Heat Pump Equipment (“AHRI 1230-2021”)), 44 it is not suitable for evaluating unit efficiency and capacity. (Daikin, No. 16 at p. 1) Daikin encouraged DOE to make modifications to the existing appendix M1 and adopt a CVP in appendix M1 that is similar to the VRF CVP, but not to adopt load-based testing as the primary regulatory test method. ( Id. at pp. 1-2) Similary, AHRI commented that although it will support the improvement of load-based testing as an academic pursuit, load-based testing has not yet developed sufficiently such that it may be used for regulatory purposes. (AHRI, No. 14 at p. 7) AHRI further commented it expects DOE to carefully evaluate all the information manufacturers have to report for certification of their products and also evaluate the burden for this reporting and testing if planning to adopt load-based testing. ( Id. ) NEEA stated that although it has published several articles that question the rank order performance ratings evaluated from fixed-speed testing, there is currently no clear evidence that exhibits the advantages of load-based testing. (NEEA, No. 13 at p. 1) NYSERDA commented that regarding the adoption of load-based methods for regulatory purposes, DOE should account for products such as coil-only systems, split system ACs or HPs with coil blowers, and multi-split products. 45 (NYSERDA, No. 9 at p. 6) NYSERDA further commented that there is still more work that needs to be done in order to make load-based testing suitable for DOE regulatory purposes. ( Id. ) Finally, NYSERDA stated that although it supports a feasible and representative load-based approach, developing a procedure could be challenging. ( Id. at p. 4) The CA IOUs encouraged DOE to collaborate with stakeholders to move to a test procedure that requires units to operate under native controls, but recognized that an industry-wide transition to load-based testing will be time consuming and cost intensive. (CA IOUs, No. 10 at pp. 1-2) The Joint Advocates commented that load-based testing methodologies would provide better information on the field operation of a CAC/HP, in comparison to the fixed-speed tests currently in appendix M1. (Joint Advocates, No. 8 at pp. 1-2) The Joint Advocates referred to how the native controls testing in DOE's Cold Climate Heat Pump Technology Challenge (“DOE CCHP Tech Challenge”) 46 was informed by the results of the steady-state regulatory tests, 47 and suggested that DOE could adopt a similar provision for both cooling and heating tests, in its amended load-based test procedure. ( Id. ) 44 See www.ahrinet.org/system/files/2023-06/AHRI_Standard_1230-2021.pdf . 45 DOE believes that NYSERDA made this comment owing to the fact that SPE07 does not explicitly state that it is applicable to these product types. 46 On May 19, 2021, DOE, in conjunction with EPA and NRCan, announced the DOE CCHP Tech Challenge as part of the Energy, Emissions and Equity (“E3”) Initiative. The specification of the DOE CCHP Tech Challenge is available at www.energy.gov/sites/default/files/2021-10/bto-cchp-tech-challenge-spec-102521.pdf . 47 As an example, if a heating capacity of 18,000 Btu/h was measured during the H1 1 regulatory test, the native controls “Min/Mild” test would apply an equivalent 18,000 Btu/h cooling load to the indoor room`s conditioning equipment. Instead of wholesale adoption of a load-based method, comments received on the January 2023 RFI pointed toward consensus preference for a limited form of load-based testing to verify steady-state regulatory test performance under native controls ( i.e., a CVP). Samsung, Lennox, AHRI, NYSERDA, NEEA, and Rheem all encouraged DOE to adopt a CVP that would ensure settings used during steady state tests are representative of those during native controls operation. (Samsung, No. 11 at pp. 1-2; Lennox, No. 6 at p. 3; AHRI, No. 14 at p. 7; NYSERDA, No. 9 at p. 5; NEEA, No. 13 at p. 3; Rheem, No. 12 at p. 3) Specifically, Lennox stated that while steady state testing currently used in appendix M1 should continue to be used, a CVP can be used to validate the settings used to test variable capacity systems. (Lennox, No. 6 at p. 3) AHRI commented that use of a CVP would be more repeatable and less burdensome than using load-based testing for direct measurement of performance, adding that CVPs have been used for other product categories and may need some adapatation for application to CAC/HPs. (AHRI, No. 14 at p. 9) Additionally, AHRI referred to a study it co-sponsored with NEEA to collect representative field data, which was expected to conclude at the end of winter 2022/2023. ( Id. at p. 9) NYSERDA described the CVP used in AHRI 1230-2021 for VRFs and recommended that DOE adopt something similar to it. (NYSERDA, No. 9 at p. 5) NYSERDA further recommended that DOE adopt the CVP outlined in ENERGY STAR Spec V6.1 for the low ambient heating steady-state tests in appendix M1, namely H3 2 and H4 2 . ( Id. at pp. 5-6) NYSERDA referred to how the wet bulb test conditon in the H4 heating test had increased from 3 °F to 4 °F, which would decrease test burden for labs if they conduct a load-based CVP outlined in ENERGY STAR Spec V6.1. ( Id. ) NYSERDA further encouraged DOE to adopt a “budget” method to account for variability in critical parameters during a CVP, and recommended incorporation of a CVP for validating the H1 1 (heating minimum) test, and also a minimum-speed CVP at outdoor dry bulb temperature of 17 °F. 48 ( Id. ) NYSERDA commented that performance of units at part-load at milder temperatures has a pronounced impact on the overall seasonal energy efficiency, especially when considering the intersection of low-speed loads beween 17 °F and 47 °F, highlighting that this impact was not fully considered in implementation of the “Min/Mild” CVP in the specifications of the DOE CCHP Tech Challenge. ( Id. at p. 6) NEEA referred to the two types of CVPs as descibed in section III.F.1.b. and commented the results of a study it performed called into question whether a CVP can truly capture the impact of native controls on unit performance. 49 ( Id. at pp. 3-6) Hence, NEEA commented that DOE needs additional test data to make any claims that CVP testing fully addresses the impact of native control logic on unit performance. Id. NEEA pointed to the representativeness study 50 being conducted by NEEP on three ducted and three non-ducted heat pumps, tested using AHRI 210/240 and SPE07, and stated that this study could potentially indicate what elements of a CVP are critical to include in a revised appendix M1, and also inform other issues raised by DOE in the RFI, namely the repeatability, reproducibility, and test burden of load-based methods when compared to fixed-speed testing. ( Id. at pp. 2-3) 48 Currently, appendix M1 only has a full-speed heating test at an ambient outdoor temperature of 17 °F, i.e., the H3 2 test. 49 Bruce Harley, Mark Alatorre, Christopher Dymond, Gary Hamer, “CSA EXP07: Ongoing Progress, Lessons Learned, and Future Work in Load-based Testing of Residential Heat Pumps” (2022). Purdue University. Available at docs.lib.purdue.edu/cgi/viewcontent.cgi?article=3455&context=iracc . 50 In its comment, NEEA pointed out that preliminary analysis and data from this study will be available probably by July 2023, but at the time of writing this NOPR, neither the analysis, nor the data, has become available. To summarize, comments from the January 2023 RFI indicated that stakeholders preferred a CVP for validating the performance of variable capacity systems, rather than adopting a load-based testing method for regulatory purposes. (d) DOE's Conclusion and Approach As mentioned previously, AHRI and other relevant stakeholders, including DOE, participated in the development of revised AHRI test standards to address the issues raised in the January 2023 RFI. In particular, the issues outlined in the aforementioned comments in regard to the representativeness of fixed-speed testing for variable speed systems were discussed in detail and consensus was developed on a CVP approach. 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 such methods have sufficient repeatability and reproducibility to be the basis of direct measurement of system performance, DOE has tentatively concluded that use for direct measurement of performance for regulatory purposes would not be suitable at this time. However, DOE also tentatively concludes that a CVP would be necessary to ensure that fixed-speed settings of variable speed systems would be achieved using native (unfixed) control. Thus, DOE proposes to adopt the CVP outlined in AHRI 210/240-202X Draft and AHRI 1600-202X Draft through incorporation by reference. The next section discusses the aforementioned CVP approach. (e) CVP Proposal Appendix I of the AHRI 210/240-202X Draft and AHRI 1600-202X Draft includes a CVP to verify variable capacity system operation. The CVP is intended to validate whether override of modulating components in regulatory tests is consistent with native control operation. The CVP verifies: (1) compliance with the variable capacity compressor system definition; and (2) consistency of fixed-position settings for the compressor and indoor fan used in steady-state regulatory tests with native control operation. The CVP in appendix I includes a set of three cooling tests conducted in series with intervening transition periods, including the full, intermediate, and minimum capacities. The CVP uses a modified VBL 51 approach to simulate space condition (temperature and humidity) response to system operation, as explained in section III.F.1.b.3 of this document. Similarly, the CVP also includes three or four heating tests conducted in series for CHPs—the fourth test is specified for those CHPs for which performance at 5 °F outdoor temperature is measured. Similar to the cooling tests, the heating tests have intervening transition periods between the full, intermediate, and minimum capacity test intervals. 51 The modified VBL in the CVP differs from the VBL in SPE07. For the modified VBL, the building load used in the equations does not depend on the indoor temperature and is a fixed function of target indoor and outdoor temperatures. For the three cooling tests, the indoor return air conditions are controlled by equations I1-I6 and paragraph I4.1.8 in AHRI 210/240-202X Draft and AHRI 1600-202X Draft— i.e., the indoor return air wet bulb temperature is set at 67 °F, and the indoor return air dry bulb target varies near 80 °F based on the varying system capacity and calculated building load. The temperature setpoint of the control of the system being tested is set throughout the series of tests near 80 °F with some adjustment to account for control bias and offset. The outdoor dry bulb temperature is held constant at three different levels during the three cooling-mode tests, but is controlled to ramp down from higher to lower temperature as the cooling mode CVP transitions between the full load, intermediate load, and low load test intervals. For the heating tests, the indoor return air conditions are controlled by equations I7-I13 in AHRI 210/240-202X Draft and AHRI 1600-202X Draft. The indoor return air dry bulb temperature varies near 70 °F based on the varying system capacity and calculated building load. The temperature setpoint of the control of the system being tested is set throughout the series of tests near 70 °F with some adjustment to account for control bias and offset. The outdoor dry bulb temperature is held constant at three or four different levels, but is controlled to ramp up from lower to higher temperature as the heating mode CVP transitions between the full load (at 5 °F if applicable and 17 °F outdoor dry bulb temperature), intermediate load, and low load test intervals. As noted, part of the CVP (the intermediate-load test) determines compliance with the variable-capacity compressor system definition. AHRI 210/240-202X Draft and AHRI 1600-202X Draft define variable capacity compressor systems as: Variable capacity compressor system means an air conditioner or heat pump that has either (a) a compressor that uses a variable speed drive or inverter to vary the compressor speed by four or more speeds in each mode of operation ( i.e., cooling/heating), or (b) a digital compressor that mechanically modulates output using a duty cycle; and which controls the system by monitoring system operation and automatically modulating the compressor output, indoor air flow and other system parameters as required in order to maintain the indoor room temperature. To determine compliance with the definition, the CVP results obtained from the intermediate load interval is evaluated based on section I4.3.1 of appendix I in in AHRI 210/240-202X Draft, which requires that the standard deviation of the system power does not exceed 20 percent of the mean system power. For a system that does not comply with this compressor power (or outdoor unit power) requirement, and cycles between off and a single stage or capacity level (+/−15 percent), the system is classified as a variable capacity certified, single capacity system. If this occurs for just one of the operating modes (heating or cooling) for a heat pump, the system is classified as variable capacity certified, single capacity for both modes. Additionally, a system that does not comply with the compressor power (or outdoor unit power) requirement is not classified as Variable Capacity Certified, Single-Capacity, and cycles between more than one stage or capacity level (+/−15 percent) is classified as a Variable Capacity Certified, Two-Capacity System. Again, this designation applies for both modes for a heat pump, even if the operation meets this description for one of the modes. These terms are defined in AHRI 210/240-202X Draft and AHRI 1600-202X Draft as: Variable Capacity Certified, Single Capacity System means a system that is certified as a variable capacity system but demonstrates Single-Capacity System behavior during the Variable Capacity Determination CVP in appendix I. Variable Capacity Certified, Two Capacity System means a system that is certified as a variable capacity system, but demonstrates Two-Capacity System behavior during the Variable Capacity Determination CVP in appendix I. Use of the Intermediate Load CVP test and its determination of compliance with the variable speed system definition in DOE enforcement testing is discussed in section III.K.2 of this document. The full-load and low-load intervals of the CVP determine if the fixed-speed settings for the compressor and indoor fan used during the regulatory test are consistent with those that occur when the unit is allowed to modulate under native controls, as it maintains the indoor room dry bulb temperature. During the cooling mode CVP, 52 the indoor return air wet bulb temperature is maintained at 67.0 °F, but the updated target indoor dry-bulb temperature setpoint for the indoor room reconditioning system, RAT ( t + Δ t ), is updated based on equations I4-I6 of AHRI 210/240-202X Draft and AHRI 1600-202X Draft, as shown below: 52 For brevity, only cooling mode is explained in the NOPR, to illustrate the 2nd part of the CVP. EP05AP24.049 Where, RAT (t) = the current indoor dry-bulb temperature setpoint for the indoor room reconditioning system Q s = the net sensible cooling capacity provided by the unit under test in the current time step, as determined by air-side measurements ( see note below) Δt = the time interval for updating the indoor room reconditioning system controller setpoint, in h C = the simulated thermal capacitance of the building interior, in units of Btu/°F, given by EP05AP24.050 VL s( T j ) = the sensible cooling portion of the modified VBL for target outdoor ambient dry-bulb temperature for each interval. The magnitude of VL s( T j ) is directly proportional to the certified cooling capacity at 67 °F outdoor ambient-dry bulb temperature— i.e., the F low test, and the target SHR from the F low regulatory tests, as illustrated in equations I1 and I3 of AHRI 210/240-202X Draft and AHRI 1600-202X Draft. Thus, this illustrates that the modulation of the compressor speed setting and indoor air flow rate is verified against those used in the regulatory tests, as the unit tries to maintain the indoor dry-bulb temperature. DOE proposes that load-based testing will be not part of the test procedure required for each test for any CAC/HP products. DOE acknowledges that the CVP approach outlined in appendix I of the relevant AHRI drafts represents industry consensus regarding the verification of compliance of systems with the variable capacity system definition, and to verify the consistency of fixed-speed settings of compressor and indoor fan with native control operation as part of enforcement. DOE considers that this CVP approach will provide a more representative test procedure for variable speed systems operating in the field, because it provides a tool to verify that the 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 setpoint, i.e., indoor dry-bulb temperature. Therefore, DOE is proposing to incorporate by reference appendix I of the 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 the AHRI 1600-202X Draft to support enforcement associated with testing conducted in accordance with appendix M2. This is discussed in more detail in section III.K.2 of this document. 2. Low-Temperature Heating Performance In the January 2023 RFI, DOE requested comment on several issues regarding the foundational work needed to improve the appendix M1 test procedure to better account for CAC/HP performance in cold climates, as recommended by NYSERDA during the previous rulemaking cycle that culminated in the October 2022 Final Rule. 88 FR 4091, 4103. In response to the low-temperature heating performance issues raised in the January 2023 RFI ( i.e., whether to make the H4 heating tests mandatory, whether the heating load line should be based on heating or cooling capacity, and methods of heat pump sizing), DOE received several comments regarding the establishment of a clear definition for a CCHP as well as potential ways of reporting performance for CCHPs. These aforementioned topics are detailed in separate sections below. (a) CCHP Definition In response to the January 2023 RFI, several stakeholders commented in support of establishing a definition for products specifically engineered to provide comfort heating at low ambient conditions ( i.e., CCHPs). Daikin recommended that DOE work with stakeholders to establish a clear definition for CCHPs, whether as a separate product class or an optional set of recognition criteria. (Daikin, No. 16 at p. 9) Similarly, AHRI commented in support of a uniform definition for products specifically engineered to provide comfort heating at low ambient conditions. (AHRI, No. 14 at pp. 2-3) AHRI commented that engagement from all stakeholders would be necessary to overcome the shortcomings of previous efforts to develop a definition for CCHPs. ( Id. ) Additionally, in forming a DOE definition for CCHPs, AHRI requested it be acknowledged that (1) not all U.S. consumers would benefit from higher-tech CCHPs, and (2) the topography of the United States makes it difficult to assign regions that would correlate heating degree days in the same way as is done for split-system air conditioners, as shown by Figure 1 53 of AHRI's response to the January 2023 RFI. (AHRI, No. 14 at p. 3) Referring to Figure 1, AHRI commented that it is easy to see the cooling degree day division between the North and South, as in effect today, and that heating degree days, on the other hand, meander and are very closely tied to elevation and longitude (to some extent). ( Id. ) 53 Figure 1 of AHRI's response to the January 2023 RFI shows average annual cooling and heating degree days in the contiguous United States from 1901-2000, using National Centers for Environmental Information (“NCEI”) data compiled by the National Oceanic and Atmospheric Administration (“NOAA”). (AHRI, No. 14 at p. 3) A degree day is equivalent to one day with an average temperature that is one degree above or below 65 °F. As p [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2024-04784. Public record. Not legal advice.