Energy Conservation Program: Test Procedures for Air-Cooled, Evaporatively-Cooled, and Water-Cooled Commercial Package Air Conditioners and Heat Pumps

Federal RegisterAug 17, 2023

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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 431

[EERE-2023-BT-TP-0014]

RIN 1904-AD93

Energy Conservation Program: Test Procedures for Air-Cooled, Evaporatively-Cooled, and Water-Cooled Commercial Package Air Conditioners and Heat Pumps

AGENCY:

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

ACTION:

Notice of proposed rulemaking and request for comment.

SUMMARY:

The U.S. Department of Energy (DOE) proposes to amend the Federal test procedures for air-cooled commercial package air conditioners and heat pumps with a rated cooling capacity greater than or equal to 65,000 Btu/h, evaporatively-cooled commercial package air conditioners, and water-cooled commercial package air conditioners to incorporate by reference the latest versions of the applicable industry test standards. Specifically, DOE proposes: to amend the current test procedure for this equipment for measuring the current cooling and heating metrics—integrated energy efficiency ratio (IEER) and coefficient of performance (COP), respectively; and to establish a new test procedure for this equipment that would adopt two new metrics—integrated ventilation, economizer, and cooling (IVEC) and integrated ventilation and heating efficiency (IVHE). Testing to the IVEC and IVHE 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 the subject equipment. DOE welcomes written comments from the public on any subject within the scope of this document (including 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 notice of proposed rulemaking (NOPR) no later than October 16, 2023.

See

section V, “Public Participation,” for further details.

Meeting:

DOE will hold a public meeting via webinar on Thursday, September 7, 2023, 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-2023-BT-TP-0014. Follow the instructions for submitting comments. Alternatively, interested persons may submit comments, identified by docket number EERE-2023-BT-TP-0014 and/or RIN 1904-AD93, by any of the following methods:

Email: CUACHP2023TP0014@ee.doe.gov.

Include the docket number EERE-2023-BT-TP-0014 and/or RIN 1904-AD93 in the subject line of the message.

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. If possible, please submit all items on a compact disc (CD), in which case it is not necessary to include printed copies.

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 (Public Participation).

Docket:

The docket for this activity, which includes

Federal Register

notices, public meeting webinar 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-2023-BT-TP-0014.

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

See

section V (Public Participation) 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-5B, 1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: (202) 287-5904. Email:

ApplianceStandardsQuestions@ee.doe.gov.

Ms. Melanie Lampton, U.S. Department of Energy, Office of the General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: (240) 571-5157. Email:

Melanie.Lampton@hq.doe.gov.

For further information on how to submit a comment, review other public comments and the docket, or participate in the public meeting webinar, 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 a previously approved incorporation by reference and to incorporate by reference the following industry standards into parts 429 and 431:

AHRI Standard 340/360-2022 (I-P),

2022 Standard for Performance Rating of Commercial and Industrial Unitary Air-conditioning and Heat Pump Equipment,

AHRI approved January 26, 2022 (AHRI 340/360-2022).

Copies of AHRI 340/360-2022 can be obtained from the Air-Conditioning, Heating, and Refrigeration Institute (AHRI), 2311 Wilson Blvd., Suite 400, Arlington, VA 22201 (703) 524-8800, or online at:

www.ahrinet.org/standards/search-standards.

AHRI Standard 1340(I-P)-202X Draft,

Performance Rating of Commercial and Industrial Unitary Air-conditioning and Heat Pump Equipment

(AHRI 1340-202X Draft). AHRI 1340-202X Draft is in draft form and its text was provided to DOE for the purposes of review only during the drafting of this NOPR. If this industry test standard is formally adopted, DOE intends to incorporate by reference the final published version of AHRI 1340 in DOE's subsequent test procedure final rule. If there are substantive changes between the draft and published versions for which DOE receives stakeholder comments in response to this NOPR recommending that DOE adopt provisions consistent with the published version of AHRI 1340, then DOE may consider adopting those provisions. If there are substantive changes between the draft and published versions for which

stakeholder comments do not express support, DOE may adopt the substance of the AHRI 1340-202X Draft or provide additional opportunity for comment on the changes to the industry consensus standard.

A copy of the AHRI 1340-202X Draft is provided in the docket for this rulemaking for review.

ANSI/ASHRAE Standard 37-2009,

Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment,

ASHRAE approved June 24, 2009 (ANSI/ASHRAE 37-2009).

Copies of ANSI/ASHRAE 37-2009 can be obtained from the American Society of Heating, Refrigerating and Air-Conditioning Engineers, 180 Technology Parkway, Peachtree Corners, GA 30092, (404) 636-8400, or online at:

www.ashrae.org.

See

section IV.M of this document for a further discussion of these standards.

Table of Contents

I. Authority and Background

A. Authority

B. Background

II. Synopsis of the Notice of Proposed Rulemaking

III. Discussion

A. Scope of Applicability

B. Definitions

1. CUAC and CUHP Definition

2. Basic Model Definition

3. Double-Duct Definition

4. Metric Definitions

C. Updates to Industry Test Standards

1. AHRI 340/360

2. AHRI 1340

3. ASHRAE 37

D. Consideration of the ACUAC and ACUHP Working Group TP Term Sheet

E. DOE Proposed Test Procedures

F. Efficiency Metrics and Test Conditions

1. Comments Received on Metrics

a. IEER Test Conditions and Weighting Factors

b. Energy Efficiency Metrics for ECUACs and WCUACs

c. Cyclic Degradation Factor for Cooling

d. Economizing and Ventilation

e. External Static Pressure Requirements

f. Damper Leakage, Energy Recovery Systems, and Crankcase Heaters

g. Controls Verification Procedure

h. Heating Efficiency Metric

2. Test Conditions Used for Current Metrics in Appendix A

3. Test Conditions Used for New Metrics in Proposed Appendix A1

4. IVEC

5. IVHE

a. IVHE for Colder Climates

6. Additions and Revisions to the IVEC and IVHE Metrics Not Included in the Term Sheet

a. Cooling Weighting Factors Adjustment

b. ESP Testing Target Calculation

c. Test Instructions for Splitting ESP Between Return and Supply Ductwork

d. Default Fan Power and Maximum Pressure Drop for Coil-Only Systems

e. Component Power Measurement

f. IVHE Equations

g. Non-Standard Low-Static Indoor Fan Motors

7. Efficiency Metrics for ECUACs and WCUACs

a. Heat Rejection Components for WCUACs

8. Efficiency Metrics for Double-Duct Systems

G. Test Method Changes in AHRI Standard 340/360

1. Vertical Separation of Indoor and Outdoor Units

2. Measurement of Air Conditions

3. Refrigerant Charging Instructions

4. Primary and Secondary Methods for Capacity Measurements

5. Atmospheric Pressure

a. Adjustment for Different Atmospheric Pressure Conditions

b. Minimum Atmospheric Pressure

c. Atmospheric Pressure Measurement

6. Condenser Head Pressure Controls

7. Length of Refrigerant Line Exposed to Outdoor Conditions

8. Indoor Airflow Condition Tolerance

9. ECUACs and WCUACs With Cooling Capacity Less Than 65,000 Btu/h

10. Additional Test Method Topics for ECUACs

a. Outdoor Air Entering Wet-Bulb Temperature

b. Make-Up Water Temperature

c. Piping Evaporator Condensate to Condenser Sump

d. Purge Water Settings

e. Condenser Spray Pumps

f. Additional Steps To Verify Proper Operation

H. General Comments Received in Response to the July 2017 TP RFI

I. Configuration of Unit Under Test

1. Summary

2. Background

3. Proposed Approach for Exclusion of Certain Components

a. Components Addressed Through Test Provisions of 10 CFR Part 431, Subpart F, appendices A and A1

b. Components Addressed Through Representation Provisions of 10 CFR 429.43

c. Enforcement Provisions of 10 CFR 429.134

d. Testing Specially Built Units That Are Not Distributed in Commerce

J. Represented Values

1. Cooling Capacity

2. Single-Zone Variable-Air-Volume and Multi-Zone Variable-Air-Volume

3. Confidence Limit

4. AEDM Tolerance for IVEC and IVHE

5. Minimum Part-Load Airflow

K. Enforcement Procedure for Verifying Cut-In and Cut-Out Temperatures

L. Proposed Organization of the Regulatory Text for CUACs and CUHPs

M. Compliance Date

N. Test Procedure Costs and Impact

1. Appendix A

2. Appendix A1

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 A

b. Cost and Compliance Associated With Appendix A1

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

6. Significant Alternatives to the Rule

C. Review Under the Paperwork Reduction Act of 1995

D. Review Under the National Environmental Policy Act of 1969

E. Review Under Executive Order 13132

F. Review Under Executive Order 12988

G. Review Under the Unfunded Mandates Reform Act of 1995

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

I. Review Under Executive Order 12630

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

K. Review Under Executive Order 13211

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

M. Description of Materials Incorporated by Reference

V. Public Participation

A. Participation in the Webinar

B. Procedure for Submitting Prepared General Statements for Distribution

C. Conduct of the Webinar

D. Submission of Comments

E. Issues on Which DOE Seeks Comment

VI. Approval of the Office of the Secretary

I. Authority and Background

Small, large, and very large commercial package air conditioning and heating equipment are included in the list of “covered equipment” for which DOE is authorized to establish and amend energy conservation standards and test procedures. (42 U.S.C. 6311(1)(B)-(D)) Commercial package air conditioning and heating equipment includes as equipment categories the air-cooled commercial unitary air conditioners with a rated cooling capacity greater than or equal to 65,000 Btu/h (ACUACs) and air-cooled commercial unitary heat pumps with a rated cooling capacity greater than or equal to 65,000 Btu/h (ACUHPs), evaporatively-cooled commercial unitary air conditioners (ECUACs), and water-cooled commercial unitary air conditioners (WCUACs), which are the subject of this NOPR.

(ECUACs,

WCUACs, and ACUACs and ACUHPs including double-duct equipment are collectively referred to as CUACs and CUHPs in this document.) The current DOE test procedures for CUACs and CUHPs are codified at title 10 of the Code of Federal Regulations (CFR) part 431, subpart F, section 96, Table 1. The following sections discuss DOE's authority to establish and amend test procedures for CUACs and CUHPs, as well as relevant background information regarding DOE's proposed amendments to the test procedures for this equipment.

While ACUACs with rated cooling capacity less than 65,000 Btu/h are included in the broader category of CUACs, they are not addressed in this NOPR. The test procedure for ACUACs with rated cooling capacity less than 65,000 Btu/h have been addressed in a separate rulemaking:

see

Docket No. EERE-2017-BT-TP-0018-0031. All references within this NOPR to ACUACs and ACUHPs exclude

equipment with rated cooling capacity less than 65,000 Btu/h.

A. Authority

The Energy Policy and Conservation Act, Public Law 94-163 (42 U.S.C. 6291-6317, as codified), as amended (EPCA),

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

of EPCA, added by Public Law 95-619, Title IV, section 441(a), established the Energy Conservation Program for Certain Industrial Equipment, which sets forth a variety of provisions designed to improve energy efficiency. This covered equipment includes small, large, and very large commercial package air conditioning and heating equipment. (42 U.S.C. 6311(1)(B)-(D)) Commercial package air conditioning and heating equipment includes CUACs and CUHPs, which are the subject of this document.

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.

For editorial reasons, upon codification in the U.S. Code, Part C was redesignated Part A-1.

The energy conservation program under EPCA consists essentially of four parts: (1) testing, (2) labeling, (3) Federal energy conservation standards, and (4) certification and enforcement procedures. Relevant provisions of EPCA include definitions (42 U.S.C. 6311), energy conservation standards (42 U.S.C. 6313), test procedures (42 U.S.C. 6314), labeling provisions (42 U.S.C. 6315), and the authority to require information and reports from manufacturers (42 U.S.C. 6316; 42 U.S.C. 6296).

The Federal testing requirements consist of test procedures that manufacturers of covered equipment must use as the basis for: (1) certifying to DOE that their equipment complies with the applicable energy conservation standards adopted pursuant to EPCA (42 U.S.C. 6316(b); 42 U.S.C. 6296), and (2) making representations about the efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE uses these test procedures to determine whether the equipment complies with relevant standards promulgated under EPCA.

Federal energy efficiency requirements for covered equipment established under EPCA generally supersede State laws and regulations concerning energy conservation testing, labeling, and standards. (42 U.S.C. 6316(a) and (b); 42 U.S.C. 6297) DOE may, however, grant waivers of Federal preemption in limited circumstances for particular State laws or regulations, in accordance with the procedures and other provisions of EPCA. (42 U.S.C. 6316(b)(2)(D))

Under 42 U.S.C. 6314, EPCA also sets forth the general criteria and procedures DOE is required to follow when prescribing or amending test procedures for covered equipment. Specifically, EPCA requires that any test procedure prescribed or amended under this section must be reasonably designed to produce test results that reflect energy efficiency, energy use, and estimated operating cost of a given type of covered equipment (or class thereof) during a representative average use cycle and requires that such test procedures not be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)-(3))

As discussed, CUACs and CUHPs are classified as commercial package air conditioning and heating equipment. EPCA requires that the test procedures for commercial package air conditioning and heating equipment be those generally accepted industry testing procedures or rating procedures developed or recognized by AHRI or ASHRAE, as referenced in ASHRAE Standard 90.1, “Energy Standard for Buildings Except Low-Rise Residential Buildings” (ASHRAE Standard 90.1). (42 U.S.C. 6314(a)(4)(A)) Further, if such an industry test procedure is amended, DOE must update its test procedure to be consistent with the amended industry test procedure, unless DOE determines, by rule published in the

Federal Register

and supported by clear and convincing evidence, that the amended test procedure would not meet the requirements in 42 U.S.C. 6314(a)(2) and (3) related to representative use and test burden, in which case DOE may establish an amended test procedure that does satisfy those statutory provisions. (42 U.S.C. 6314(a)(4)(B) and (C))

EPCA also requires that, at least once every seven years, DOE evaluate test procedures for each type of covered equipment, including CUACs and CUHPs, to determine whether amended test procedures would more accurately or fully comply with the requirements for the test procedures to not be unduly burdensome to conduct and be reasonably designed to produce test results that reflect energy efficiency, energy use, and estimated operating costs during a representative average use cycle. (42 U.S.C. 6314(a)(1)-(3))

In addition, if DOE determines that a test procedure amendment is warranted, the Department must publish proposed test procedures in the

Federal Register

and afford interested persons an opportunity (of not less than 45 days duration) to present oral and written data, views, and arguments on the proposed test procedures. (42 U.S.C. 6314(b)) If DOE determines that test procedure revisions are not appropriate, DOE must publish in the

Federal Register

its determination not to amend the test procedures. (42 U.S.C. 6314(a)(1)(A)(ii))

DOE is proposing amendments to the test procedures for CUACs and CUHPs in satisfaction of its aforementioned statutory obligations under EPCA. (42 U.S.C. 6314(a)(4)(A)) and (42 U.S.C 6314(a)(1)-(3))

B. Background

DOE's existing test procedure for CUACs and CUHPs appears at 10 CFR 431.96 (Uniform test method for the measurement of energy efficiency of commercial air conditioners and heat pumps). The test procedure for ACUACs and ACUHPs with a rated cooling capacity of greater than or equal to 65,000 Btu/h specified in 10 CFR 431.96 references appendix A to subpart F of part 431 (Uniform Test Method for the Measurement of Energy Consumption of Air-Cooled Small (≥65,000 Btu/h), Large, and Very Large Commercial Package Air Conditioning and Heating Equipment, referred to as appendix A in this document). Appendix A references certain sections of ANSI/AHRI Standard 340/360-2007, 2007 Standard for Performance Rating of Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment, approved by ANSI on October 27, 2011 and updated by addendum 1 in December 2010 and addendum 2 in June 2011 (ANSI/AHRI 340/360-2007); ANSI/ASHRAE Standard 37-2009, Methods of Testing for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment (ANSI/ASHRAE 37-2009); and specifies other test procedure requirements related to minimum external static pressure (ESP), optional break-in period, refrigerant charging, setting indoor airflow, condenser head pressure controls, standard airflow and air quantity, tolerance on capacity at

part-load test points, and condenser air inlet temperature for part-load tests.

The DOE test procedure for ECUACs and WCUACs with a rated cooling capacity of greater than or equal to 65,000 Btu/h specified in 10 CFR 431.96 incorporates by reference ANSI/AHRI 340/360-2007 (excluding section 6.3 of ANSI/AHRI 340/360-2007 and including paragraphs (c) and (e) of § 431.96.

) The DOE test procedure for ECUACs and WCUACs with a rated cooling capacity of less than 65,000 Btu/h incorporates by reference ANSI/AHRI Standard 210/240-2008, “2008 Standard for Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump Equipment,” approved by ANSI on October 27, 2011 and updated by addendum 1 in June 2011 and addendum 2 in March 2012 (ANSI/AHRI 210/240-2008).

Paragraphs (c) and (e) of 10 CFR 431.96 address optional break-in provisions and additional provisions regarding set up, respectively.

On October 26, 2016, ASHRAE published ASHRAE Standard 90.1-2016, which included updates to the test procedure references for CUACs and CUHPs (excluding CUACs and CUHPs with a rated cooling capacity less than 65,000 Btu/h) to reference AHRI Standard 340/360-2015, 2015 Standard for Performance Rating of Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment (AHRI 340/360-2015).

This action by ASHRAE triggered DOE's obligations under 42 U.S.C. 6314(a)(4)(B), as outlined previously. On July 25, 2017, DOE published a request for information (RFI) (July 2017 TP RFI) in the

Federal Register

to collect information and data to consider amendments to DOE's test procedures for certain categories of commercial package air conditioning and heating equipment including CUACs and CUHPs. 82 FR 34427. As part of the July 2017 TP RFI, DOE identified several aspects of the currently applicable Federal test procedures for CUACs and CUHPs that might warrant modifications, in particular: incorporation by reference of the most recent version of the relevant industry standard(s); efficiency metrics and calculations; and clarification of test methods.

Id.

at 82 FR 34439-34445. DOE also requested comment on any additional topics that may inform DOE's decisions in a future test procedure rulemaking, including methods to reduce regulatory burden while ensuring the procedures' accuracies.

Id.

at 82 FR 34448.

The previous version of ASHRAE Standard 90.1 (

i.e.,

ASHRAE Standard 90.1-2013) references ANSI/AHRI 340/360-2007.

DOE received a number of comments regarding CUACs and CUHPs in response to the July 2017 TP RFI from interested parties. Table I.1 lists the commenters that provided comments relevant to CUACs and CUHPs, along with each commenter's abbreviated name used throughout this NOPR.

Discussion of the relevant comments, and DOE's responses, are provided in the appropriate sections of this document.

The parenthetical reference provides a reference for information located in a docket related to DOE's rulemaking to develop test procedures for CUACs and CUHPs. As noted, the July 2017 RFI addressed a variety of different equipment categories and is available under docket number EERE-2017-BT-TP-0018, which is maintained at

www.regulations.gov.

As this NOPR addresses only CUACs and CUHPs, it has been assigned a separate docket number (

i.e.,

EERE-2022-BT-STD-0015). The references are arranged as follows: (commenter name, comment docket ID number, page of that document).

Table I.1—List of Commenters With Written Submissions in Response to the July 2017 TP RFI Relevant to CUACs and CUHPs

Name of commenter

Abbreviation used

Comment No. in the docket

Commenter type

Air-Conditioning, Heating, and Refrigeration Institute

AHRI

Trade Association.

Appliance Standards Awareness Project, Alliance to Save Energy, American Council for an Energy-Efficient Economy, Northwest Energy Efficiency Alliance, and Northwest Power and Conservation Council

ASAP, ASE,

et al

Efficiency Advocacy Organizations.

Carrier Corporation

Carrier

Manufacturer.

Goodman Global Inc

Goodman

Manufacturer.

Ingersoll Rand

Trane

Manufacturer.

Lennox International Inc

Lennox

Manufacturer.

National Comfort Institute

NCI

Trade Association.

Pacific Gas and Electric Company, Southern California Gas Company, San Diego Gas and Electric, and Southern California Edison; (collectively referred to as the “California Investor-Owned Utilities”)

CA IOUs

Utilities.

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

For cases in which this NOPR references comments received in response to the July 2017 TP RFI (which are contained within a different docket

), the full docket number (rather than just the document number) is included in the parenthetical reference.

The parenthetical reference provides a reference for information located in the relevant docket, which is maintained at

www.regulations.gov.

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

Comments submitted in response to the July 2017 TP RFI are available in Docket No. EERE-2017-BT-TP-0018.

At the time DOE published the July 2017 TP RFI, the applicable version of ASHRAE Standard 90.1 was the 2016 edition, which referenced AHRI Standard 340/360-2015, 2015 Standard for Performance Rating of Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment as the test procedure for CUACs and CUHPs. On October 24, 2019, ASHRAE published ASHRAE Standard 90.1-2019, which updated the relevant AHRI Standard 340/360 reference to the 2019 edition,

2019 Standard for Performance Rating of Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment

(AHRI 340/360-2019). In January 2022, AHRI published additional updates to its test procedure standard for CUACs and CUHPs, with the publication of AHRI Standard 340/360-2022,

2022 Standard for Performance Rating of Commercial and Industrial Unitary Air-conditioning and Heat Pump Equipment

(AHRI 340/360-2022), which DOE is proposing to reference in the amended test procedure in appendix A to subpart F of 10 CFR part 431 in this NOPR. These industry test standards are discussed further in section III.C of this NOPR. To the extent that comments on the July 2017 TP RFI are still relevant to AHRI 340/360-2022, DOE addresses such comments in the following sections.

For ECUACs and WCUACs with a rated cooling capacity less than 65,000 Btu/h, ASHRAE Standard 90.1-2016 references ANSI/AHRI 210/240-2008. After the publication of the July 2017 RFI, AHRI published AHRI Standard 210/240-2017,

2017 Standard for Performance Rating of Unitary Air-conditioning & Air-source Heat Pump Equipment

(AHRI 210/240-2017). ASHRAE Standard 90.1-2019 references AHRI 210/240-2017 as the test procedure for ECUACs and WCUACs with rated cooling capacities less than 65,000 Btu/h. After the publication of AHRI 210/240-2017, AHRI released two updates to that industry standard: (1) AHRI Standard 210/240-2017 with Addendum 1,

2017 Standard for Performance Rating of Unitary Air-conditioning & Air-source Heat Pump Equipment

(AHRI 210/240-2017 with Addendum 1), which was published in April 2019; and (2) AHRI Standard 210/240-2023,

2023 Standard for Performance Rating of Unitary Air-conditioning & Air-source Heat Pump Equipment

(AHRI 210/240-2023), which was published in May 2020.

On May 12, 2020, DOE published an RFI in the

Federal Register

regarding energy conservation standards for ACUACs, ACUHPs, and commercial warm air furnaces (May 2020 ECS RFI). 85 FR 27941. In response to the May 2020 ECS RFI, DOE received comments from various stakeholders, including ones related to the test procedure for ACUACs and ACUHPs. Table I.2 lists the stakeholders whose comments in response to the May 2020 ECS RFI were related to the ACUAC and ACUHP test procedures and have been considered in this rulemaking. For cases in which this NOPR references comments received in response to the May 2020 ECS RFI (which are contained within a different docket

), the full docket number (rather than just the item entry number) is included in the parenthetical reference.

Comments submitted in response to the May 2020 ECS RFI are available in Docket No. EERE-2019-BT-STD-0042.

Table I.2—List of Commenters With Written Submissions in Response to the May 2020 ECS RFI Relevant to CUAC and CUHP Test Procedures

Name of commenter

Abbreviation used

Comment No. in the docket

Commenter type

Appliance Standards Awareness Project, American Council for an Energy Efficient Economy, California Energy Commission, Natural Resources Defense Council, and Northeast Energy Efficiency Partnerships

ASAP, ACEEE,

et al

Efficiency Advocacy Organizations and State Agency.

Carrier Corporation

Carrier

Manufacturer.

Goodman Manufacturing Company

Goodman

Manufacturer.

John Walsh

Walsh

Individual.

Kristin Heinemeier

Heinemeier

Individual.

Northwest Energy Efficiency Alliance

NEEA

Efficiency Advocacy Organization.

Pacific Gas and Electric Company, San Diego Gas and Electric, and Southern California Edison; (collectively referred to as the “California Investor-Owned Utilities”)

CA IOUs

Utilities.

Trane Technologies

Trane

Manufacturer.

Verified Inc

Verified

Efficiency Advocacy Organization.

On May 25, 2022, DOE published an RFI in the

Federal Register

regarding test procedures and energy conservations standards for CUACs and CUHPs (May 2022 TP/ECS RFI). 87 FR 31743. In response to the May 2022 TP/ECS RFI, DOE notes that it received comments from various stakeholders related to the test procedure for CUACs and CUHPs. Table I.3 lists the stakeholders whose comments in response to the May 2022 TP/ECS RFI were related to the CUAC and CUHP test procedures and have been considered in this proposed rulemaking. For cases in which this NOPR references comments received in response to the May 2022 TP/ECS RFI (which are contained within a different docket

), the full docket number (rather than just the item entry number) is included in the parenthetical reference.

Comments submitted in response to the May 2022 ECS/TP RFI are available in Docket No. EERE-2022-BT-STD-0015.

Table I.3—List of Commenters With Written Submissions in Response to the May 2022 TP/ECS RFI Relevant to CUAC and CUHP Test Procedures

Name of commenter

Abbreviation used

Comment No. in the docket

Commenter type

Air-Conditioning Heating and Refrigeration Institute

AHRI

Manufacturer.

Appliance Standards Awareness Project, American Council for an Energy-Efficient Economy

ASAP and ACEEE

Efficiency Advocacy Organizations.

Carrier Corporation

Carrier

Manufacturer.

Lennox International Inc

Lennox

Manufacturer.

New York State Energy Research and Development Authority

NYSERDA

State Agency.

Northwest Energy Efficiency Alliance

NEEA

Efficiency Advocacy Organization.

Pacific Gas and Electric Company, San Diego Gas and Electric, and Southern California Edison; (collectively referred to as the “California Investor-Owned Utilities”)

CA IOUs

Utilities.

Trane Technologies

Trane

Manufacturer.

On July 29, 2022, DOE published in the

Federal Register

a notice of intent to establish a working group for commercial unitary air conditioners and heat pumps (Working Group) to negotiate proposed test procedures and amended energy conservation standards for this equipment (July 2022 Notice of Intent). 87 FR 45703. The Working Group was established under the Appliance Standards and Rulemaking Federal Advisory Committee (ASRAC) in accordance with the Federal Advisory Committee Act (FACA) (5 U.S.C App 2) and the Negotiated Rulemaking Act (NRA) (5 U.S.C. 561-570, Pub. L. 104-320). The purpose of the Working Group was to discuss, and if possible, reach consensus on recommended amendments to the test procedures and energy conservation standards for ACUACs and ACUHPs. The Working Group consisted of 14 voting members, including DOE. (

See

appendix A, Working Group Members, Document No. 65 in Docket No. EERE-2022-BT-STD-0015) On December 15, 2022, the Working Group signed a term sheet of recommendations regarding ACUAC and ACUHP test procedures to be submitted to ASRAC, the contents of which are referenced throughout this NOPR (referred to hereafter as the ACUAC and ACUHP Working Group TP Term Sheet). (

See Id.

) The ACUAC and ACUHP Working Group TP Term Sheet was approved by ASRAC on March 2, 2023. These recommendations are discussed further in section III.D of this NOPR.

In January 2023, ASHRAE published ASHRAE Standard 90.1-2022, which included updates to the test procedure references for CUACs and CUHPs with cooling capacities greater than or equal to 65,000 Btu/h, specifically referencing AHRI 340/360-2022. For ECUACs and WCUACs with capacities less than 65,000 Btu/h, ASHRAE Standard 90.1-2022 references AHRI 210/240-2023.

Notably, ECUACs and WCUACs with a rated cooling capacity less than 65,000 Btu/h were removed from the scope of AHRI 210/240-2023, and are instead included in the scope of AHRI 340/360-2022. DOE discusses this change in scope to the industry test procedure and comments received related to ECUACs and WCUACs with a cooling capacity less than 65,000 Btu/h in section III.G.9 of this NOPR.

Following the publication of ASHRAE Standard 90.1-2022, AHRI is currently working on an update to the AHRI standard 340/360

(

i.e.,

AHRI Standard 1340(I-P)-202X Draft,

Performance Rating of Commercial and Industrial Unitary Air-conditioning and Heat Pump Equipment

(AHRI 1340-202X Draft)).

DOE has provided a copy of AHRI 1340-202X Draft in the docket for this rulemaking, available at

www.regulations.gov/docket/EERE-2023-BT-TP-0014.

AHRI Standard 1340 is in draft form and its text was provided to DOE for the purposes of review only during the drafting of this NOPR. Note that the draft AHRI Standard 1340 may be further revised, edited, delayed, or withdrawn prior to publication by the AHRI Standards Technical Committee (STC).

II. Synopsis of the Notice of Proposed Rulemaking

In this NOPR, DOE proposes to update its test procedures for CUACs and CUHPs by: (1) updating the reference in the Federal test procedure to the most recent version of the industry test procedure, AHRI 340/360-2022, for measuring integrated energy efficiency ratio (IEER), energy efficiency ratio (EER), and coefficient of performance (COP); and (2) establishing a new test procedure that references the most recent draft version of industry test procedure, AHRI 1340-202X Draft, and is consistent with recommendations from the ACUAC and ACUHP Working Group TP Term Sheet that DOE should include new efficiency metrics (integrated ventilation, economizer, and cooling (IVEC) and integrated ventilation and heating efficiency (IVHE)) and new testing requirements. If a finalized version of AHRI 1340-202X Draft is not published before the final rule or if there are substantive changes between the draft and published versions of AHRI 340/360, DOE may adopt the substance of the AHRI 1340-202X Draft or provide additional opportunity for comment on the final version of that industry consensus standard.

To implement the proposed changes, DOE proposes: (1) to amend appendix A to incorporate by reference AHRI 340/360-2022 for CUACs and CUHPs, while maintaining the current efficiency metrics; and (2) to add a new appendix A1 to subpart F of 10 CFR part 431. At 10 CFR part 431.96, “Uniform test method for the measurement of energy efficiency of commercial air conditioners and heat pumps,” DOE would list appendix A1 as the applicable test method for CUACs and CUHPs for any standards denominated in terms of IVEC and IVHE. Appendix A1 would utilize the AHRI 1340-202X Draft, including the new IVEC and IVHE efficiency metrics recommended by the ACUAC and ACUHP Working Group TP Term Sheet. Use of appendix A1 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 A1 would be required, appendix A would no longer be used as part of the Federal test procedure. DOE is also proposing more general updates to establish a definition for the terms “commercial unitary air conditioner” and “commercial unitary heat pump.” Lastly, DOE is proposing to amend certain provisions within DOE's regulations for representation and enforcement consistent with the proposed test procedure amendments.

Table I.1 summarizes the current DOE test procedure for CUACs and CUHPs, DOE's proposed changes to that test procedure, and the reason for each proposed change.

Table II.1—Summary of Changes in Proposed Test Procedure Relative to Current Test Procedure

Current DOE test procedure

Proposed test procedure

Attribution

Incorporates by reference

1. ANSI/AHRI 340/360-2007 for CUACs and CUHPs with a cooling capacity greater than or equal to 65,000 Btu/h; and

2. ANSI/AHRI 210/240-2008 for ECUACs and WCUACs with a cooling capacity less than 65,000 Btu/h

Incorporate by reference AHRI 340/360-2022 and ANSI/ASHRAE 37-2009 in appendix A. Utilize AHRI 1340-202X Draft and incorporate by reference ANSI/ASHRAE 37-2009 in a new appendix A1

Update to the most recent industry test procedures.

Includes provisions for determining EER, IEER, and COP

Appendix A maintains provisions for determining EER, IEER, and COP. Appendix A1 includes provisions for determining EER2, COP2, IVEC, and IVHE

Updates to the applicable industry test procedures.

Does not include certain CUAC and CUHP provisions regarding over-rating capacity and specific components for determination of represented values in 10 CFR 429.43

Includes provisions in 10 CFR 429.43 specific to CUACs and CUHPs to determine represented values for units with specific components, and to prevent cooling capacity over-rating

Improve representativeness of test procedure.

Does not include certain CUAC- and CUHP-specific enforcement provisions in 10 CFR 429.134

Adopts product-specific enforcement provisions for CUACs and CUHPs regarding: (1) verification of cooling capacity for determining ESP requirements and (2) testing of units with specific components

Clarify how DOE will conduct enforcement testing.

Should DOE adopt the amendments described in this proposed rule, the effective date for the amended test procedure would be 30 days after publication of the test procedure final rule in the

Federal Register

DOE has tentatively determined that the proposed amendments to the CUAC and CUHP test procedures would not be unduly burdensome. Furthermore, DOE has tentatively determined that the proposed amendments to appendix A, if made final, would not alter the measured efficiency of CUACs and CUHPs 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 A, 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 A beginning 360 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 A1 would alter the measured efficiency of CUACs and CUHPs, in part because the amended test procedure would adopt different energy efficiency metrics than in the current test procedure. DOE has tentatively determined that the proposed amendments to appendix A1, if made final, would increase the cost of testing relative to the current test procedure. Tentative cost estimates are discussed in section III.M of this document. As discussed, use of appendix A1 would not be required until the compliance date of any amended energy conservation standard denominated in terms of the new metrics in appendix A1, should DOE adopt such standards.

The proposed amendments to representation requirements in 10 CFR 429.43 would not be required until 360 days after publication in the

Federal Register

of a test procedure final rule.

Discussion of DOE's proposed actions are addressed in detail in section III of this NOPR.

III. Discussion

In the following sections, DOE proposes certain amendments to its test procedures for CUACs and CUHPs. For each proposed amendment, DOE provides relevant background information, explains why the amendment merits consideration, discusses relevant public comments, and proposes a potential approach.

A. Scope of Applicability

This rulemaking applies to ACUACs and ACUHPs with a rated cooling capacity greater than or equal to 65,000 Btu/h, including double-duct air conditioners and heat pumps, as well as ECUACs and WCUACs of all capacities. Definitions that apply to CUACs and CUHPs are discussed in section III.B of this NOPR.

DOE's regulations for CUACs and CUHPs cover both single-package units and split systems. See the definition of “commercial package air-conditioning and heating equipment” at 10 CFR 431.92. A split system consists of a condensing unit—which includes a condenser coil, condenser fan and motor, and compressor—that is paired with a separate component that includes an evaporator coil to form a complete refrigeration circuit for space conditioning. One application for condensing units is to be paired with an air handler (which includes an evaporator coil), such that the combined system (

i.e.,

the condensing unit with air handler) meets the definition of a split system CUAC or CUHP. It should be pointed out that AHRI has a certification program for unitary large equipment that includes certification of CUACs, CUHPs, and condensing units. DOE notes that as part of the AHRI certification program for unitary large equipment, manufacturers who sell air-cooled condensing units with a rated cooling capacity greater than or equal to 65,000 Btu/h and less than 135,000 Btu/h must certify condensing units as a complete system (

i.e.,

paired with an air handler) according to the AHRI 340/360 test procedure.

However, for condensing units with a rated cooling capacity greater than or equal to 135,000 Btu/h and less than 250,000 Btu/h, the AHRI certification program allows manufacturers to certify condensing units as a complete system according to AHRI 340/360 or optionally certify as a condensing unit only according to AHRI Standard 365, “Standard for Performance Rating of Commercial and Industrial Unitary Air-Conditioning Condensing Units” (AHRI 365). DOE emphasizes that these AHRI testing and certification requirements differ from the Federal test procedure at 10 CFR 431.96, which requires testing to ANSI/AHRI 340/360-2007 and does not permit certifying to DOE as a condensing unit only according to AHRI 365. Additionally, the AHRI

certification program does not include unitary split systems or condensing units with cooling capacities above 250,000 Btu/h, whereas the Federal test procedure and standards (codified at 10 CFR 431.96 and 10 CFR 431.97, respectively) cover all CUACs and CUHPs with cooling capacities up to 760,000 Btu/h. Once again, DOE emphasizes that condensing unit models distributed in commerce with air handlers with cooling capacities up to 760,000 Btu/h are covered as commercial package air-conditioning and heating equipment (

see

definition at 10 CFR 431.92) and as such are subject to the Federal regulations specified for CUACs and CUHPs regarding test procedures (10 CFR 431.96), energy conservation standards (10 CFR 431.97), and certification and representation requirements (10 CFR 429.43).

See

appendix A of the AHRI Unitary Large Equipment Certification Program Operations Manual (January 2021). This can be found at

https://www.ahrinet.org/sites/default/files/2022-08/ULE_OM.pdf.

B. Definitions

1. CUAC and CUHP Definition

In the May 2020 ECS RFI, DOE requested comment on whether the definitions that apply to CUACs and CUHPs (including the definitions for small, large, and very large commercial package air conditioning and heating equipment) require any revisions—and if so, how those definitions should be revised. 85 FR 27941, 27945 (May 12, 2020). DOE also requested comment on whether additional equipment definitions are necessary to close any potential gaps in coverage between equipment types.

Id.

Trane commented that the overall definition for commercial package air conditioning and heating equipment is very broad and covers equipment that is used in specific industrial applications (

e.g.,

computer room air conditioners (CRACs), dedicated outdoor air systems (DOASes), and indoor agricultural systems) for which the CUAC/CUHP test procedure and IEER metric should not apply.

Trane recommended that DOE should separately regulate these categories of equipment with specific definitions, test procedures, and energy conservation standards. (Trane, EERE-2019-BT-STD-0042-0016, pp. 2-3)

The IEER metric represents a weighted average of full-load and part-load efficiencies, weighted according to the average amount of time operating at each load point. Additionally, IEER incorporates reduced condenser temperatures (

i.e.,

reduced outdoor ambient temperatures) for part-load operation.

Goodman commented that ambiguity exists regarding DOASes used for dry-climate applications, as these systems could be rated and tested in accordance with AHRI Standard 340/360, as well as AHRI Standard 920, and that updating definitions to address these specific system types based on mixed-air or 100-percent air applications would provide some clarity in the marketplace. (Goodman, EERE-2019-BT-STD-0042-0017, p. 2)

Regarding DOASes, in a final rule published in the

Federal Register

on July 27, 2022, DOE defined a direct expansion-dedicated outdoor air system (DX-DOAS) as a unitary dedicated outdoor air system that is capable of dehumidifying air to a 55 °F dew point—when operating under Standard Rating Condition A as specified in Table 4 or Table 5 of AHRI 920-2020 (incorporated by reference, 10 CFR 431.95) with a barometric pressure of 29.92 in Hg—for any part of the range of airflow rates advertised in manufacturer materials, and has a moisture removal capacity of less than 324 lb/h. 87 FR 45164, 45170, 45198. DOE has tentatively concluded that this definition provides the requisite specificity sought by Goodman's comment.

More broadly, as in this NOPR, DOE has previously used the colloquial terms “commercial unitary air conditioners” and “commercial unitary heat pump” (

i.e.,

CUACs and CUHPs), to refer to certain commercial package air conditioning and heating equipment, recognizing that CUAC is not a statutory term and is not currently used in the CFR.

See

79 FR 58948, 58950 (Sept. 30, 2014); 80 FR 52676, 52676 (Sept. 1, 2015). As codified in regulation, the classes for which EPCA prescribed standards have been grouped under the headings “commercial air conditioners and heat pumps” (10 CFR 431.96, Table 1) and “air conditioning and heating equipment” (10 CFR 431.97, Table 1), although these are not defined terms. These classes have also been identified by the broader equipment type with which they are associated (

i.e.,

small, large, or very large commercial package air conditioning and heating equipment).

Id.

DOE agrees with the commenters that a more tailored definition regarding the equipment categories covered by these umbrella terms may provide additional benefits in terms of clarity.

Consequently, in this NOPR, DOE proposes to establish a definition for “commercial unitary air conditioner and commercial unitary heat pump” to assist in distinguishing between the regulated categories of commercial package air conditioning and heating equipment. The proposed definition is structured to indicate categories of commercial package air conditioning and heating equipment that are excluded from the definition, rather than stipulating features or characteristics of CUACs and CUHPs. Specifically, the proposed definition would exclude single package vertical air conditioners and heat pumps (SPVUs), variable refrigerant flow multi-split air conditioners and heat pumps, and water-source heat pumps. To the extent that a unit could be considered either a CUAC or a CRAC, such unit would be excluded from the CUAC definition if marketed solely for applications specific to the CRAC equipment category. To the extent that a unit could be either a CUAC or a DX-DOAS, such unit would be excluded from the CUAC definition if it is only capable of providing ventilation and conditioning of 100-percent outdoor air or it is marketed in all materials as only having such capability. DOE notes that, when gathering information for potential enforcement of CRAC, CUAC or a DX-DOAS standards, DOE may consider marketing materials claiming that a unit is a CRAC, CUAC or DX-DOAS by any party. Any marketing, by any party, could signal that a unit is not only a CRAC, CUAC, or a DX-DOAS. DOE notes that to the extent that a basic model is covered under more than one equipment category (

e.g.,

CRAC and CUAC) it would be subject to the regulations applicable to each equipment class that covers that basic model.

DOE proposes the following definition:

Commercial unitary air conditioner and commercial unitary heat pump

means any small, large, or very large air-cooled, water-cooled, or evaporatively-cooled commercial package air conditioning and heating equipment that consists of one or more factory-made assemblies that provide space conditioning; but does not include:

(1) single package vertical air conditioners and heat pumps,

(2) variable refrigerant flow multi-split air conditioners and heat pumps,

(3) water-source heat pumps;

(4) equipment marketed only for use in computer rooms, data processing rooms, or other information technology cooling applications, and

(5) equipment only capable of providing ventilation and conditioning of 100-percent outdoor air marketed only for ventilation and conditioning of 100-percent outdoor air.

DOE recognizes that there may be models on the market that would be covered by DOE regulations for multiple equipment categories. As discussed in a previous notice addressing CRACs, such models would have to be tested and rated according to the requirements for each applicable equipment class of

standards (

e.g.,

CRAC and CUAC).

See

77 FR 16769, 16773 (March 22, 2012).

Issue 1:

DOE seeks comment on its proposed definition for CUACs and CUHPs.

2. Basic Model Definition

The current definition for “basic model” in DOE's regulations includes a provision applicable for “small, large, and very large air-cooled or water-cooled commercial package air conditioning and heating equipment (excluding air-cooled, three-phase, small commercial package air conditioning and heating equipment with a cooling capacity of less than 65,000 Btu/h).” 10 CFR 431.92. Consistent with DOE's proposed definition for “commercial unitary air conditioner and commercial unitary heat pump,” DOE proposes to similarly update the definition of “basic model” so that this provision instead applies to the proposed term “commercial unitary air conditioner and commercial unitary heat pump.” DOE notes that the term in the current “basic model” definition includes ACUACs, ACUHPs, and WCUACs, but does not explicitly include ECUACs, (DOE notes that the definition of “commercial package air-conditioning and heating equipment” at 10 CFR 431.92 makes clear that that term includes evaporatively-cooled equipment. Consequently, ECUACs are clearly part of the relevant basic model definition, so the omission of the term “evaporatively-cooled” from the heading should not impact the proper functioning and use of the test procedure. However, DOE is proposing to update the relevant heading to dispel any confusion in that regard.) This proposal thereby includes ECUACs in this provision of the “basic model” definition—

i.e.,

because ECUACs are included within the proposed term “commercial unitary air conditioner and commercial unitary heat pump,” as discussed in section III.B.1 of this NOPR. It would further clarify that this provision of the “basic model” definition refers only to CUACs and CUHPs, and not to any other category of equipment that is “small, large, and very large commercial package air conditioning and heating equipment”.

DOE also proposes editorial changes more generally to the definition of “basic model” specified in 10 CFR 431.92. The current definition begins with “

Basic model

includes” and each equipment category-specific provision of the definition begins with the equipment category name, followed by the word “means,” followed by the basic model definition for that category (

e.g.,

“

Computer room air conditioners

means all units . . .”). However, this wording could be misinterpreted to read as a definition of each equipment category, rather than as the definition of what constitutes a basic model for each equipment category. Therefore, DOE proposes to revise the definition to instead begin with “Basic model means” and then revise each equipment category specific provision to begin with “For” and replace the word “means” with a colon (

e.g.,

“For

Computer room air conditioners:

all units . . .”). These proposed changes to the basic model definition are editorial and would not change the current understanding of what constitutes a basic model for each equipment category.

3. Double-Duct Definition

DOE established a definition for “double-duct air conditioner or heat pump” at 10 CFR 431.92 (referred to as “double-duct air conditioners and heat pumps” or “double-duct systems”) in an energy conservation standards direct final rule published in the

Federal Register

on January 15, 2016 (January 2016 Direct Final Rule). 81 FR 2420, 2529. This definition was included in a term sheet by the ASRAC working group for commercial package air conditioners (Commercial Package Air Conditioners Working Group) as part of the rulemaking that culminated with the January 2016 Direct Final Rule. (

See

Document No. 93 in Docket No. EERE-2013-BT-STD-0007, pp. 4-5) DOE defines double-duct systems as air-cooled commercial package air conditioning and heating equipment that: (1) Is either a horizontal single package or split-system unit; or a vertical unit that consists of two components that may be shipped or installed either connected or split; (2) Is intended for indoor installation with ducting of outdoor air from the building exterior to and from the unit, as evidenced by the unit and/or all of its components being non-weatherized, including the absence of any marking (or listing) indicating compliance with UL 1995,

“Heating and Cooling Equipment,” or any other equivalent requirements for outdoor use; (3) If it is a horizontal unit, a complete unit has a maximum height of 35 inches; if it is a vertical unit, a complete unit has a maximum depth of 35 inches; and (4) Has a rated cooling capacity greater than or equal to 65,000 Btu/h and up to 300,000 Btu/h. 10 CFR 431.92.

Underwriters Laboratory (UL) 1995,

UL Standard for Safety for Heating and Cooling Equipment

(UL 1995).

In the May 2020 ECS RFI, DOE requested comment on whether the definitions that apply to ACUACs and ACUHPs, including double-duct systems, require any revisions—and if so, how those definitions should be revised. 85 FR 27941, 27945. (May 12, 2020).

In response to the May 2020 ECS RFI, Carrier recommended that DOE review the current definitions for double-duct systems, as well as the definition for SPVUs, asserting that the current definitions for double-duct systems and SPVUs do not clearly delineate the two equipment categories. Carrier stated that while double-duct systems and SPVUs are extraordinarily similar in application, double-duct systems have longer ductwork to bring air from outside the building to the condensing section of the unit, whereas SPVUs must remain in close proximately to an exterior wall. (Carrier, EERE-2019-BT-STD-0042-0013 at p. 2)

In response, DOE notes that section 3.7 of AHRI 340/360-2022 and section 3.12 of the AHRI 1340-202X Draft specify the following definition for double-duct systems: an air conditioner or heat pump that complies with all of the following: (1) Is either a horizontal single package or split-system unit; or a vertical unit that consists of two components that can be shipped or installed either connected or split; or a vertical single packaged unit that is not intended for exterior mounting on, adjacent interior to, or through an outside wall; (2) Is intended for indoor installation with ducting of outdoor air from the building exterior to and from the unit, where the unit and/or all of its components are non-weatherized; (3) If it is a horizontal unit, the complete unit shall have a maximum height of 35 in. or the unit shall have components that do not exceed a maximum height of 35 in. If it is a vertical unit, the complete (split, connected, or assembled) unit shall have components that do not exceed maximum depth of 35 in.; (4) Has a rated cooling capacity greater than and equal to 65,000 Btu/h and less than or equal to 300,000 Btu/h.

In comparison to DOE's definition, DOE notes the following regarding the definition for double-duct system in section 3.7 of AHRI 340/360-2022 and section 3.12 of the AHRI 1340-202X Draft: (1) vertical single packaged units not intended for exterior mounting on, adjacent interior to, or through an outside wall can be classified as double-duct systems; (2) the maximum dimensions apply to each component of a split system; and (3) the AHRI 340/360-2022 and AHRI 1340-202X Draft definition does not include compliance with UL 1995 as a criterion for determining whether a model is non-

weatherized. For the reasons discussed in the following paragraphs, DOE has tentatively concluded that the definition for double-duct system in section 3.7 of AHRI 340/360-2022 and section 3.12 of the AHRI 1340-202X Draft more appropriately classifies double-duct systems and differentiates this equipment from other categories of commercial package air conditioning and heating equipment.

Regarding vertical single package units, the DOE definitions for SPVUs at 10 CFR 431.92 include models that are intended for exterior mounting on, adjacent interior to, or through an outside wall. In the January 2016 Direct Final Rule, DOE agreed with the exclusion of vertical single package units from the definition for “double-duct system” because SPVUs are separately regulated.

81 FR 2420, 2446 (Jan. 15, 2016). However, the exclusion of all vertical single package units from the definition for “double-duct system” adopted in the January 2016 Direct Final Rule means that vertical single package models that do not meet the SPVU definition (

i.e.,

are not intended for exterior mounting on, adjacent interior to, or through an outside wall) are not explicitly covered by the definitions for SPVUs or double-duct systems. Because the reasoning provided in the January 2016 Direct Final Rule was to exclude SPVUs from the double-duct definition, DOE has tentatively concluded that vertical single package units that do not meet the SPVU definition were inadvertently excluded from the DOE double-duct definition. Therefore, DOE has tentatively determined that the clarification in the AHRI 340/360-2022 definition for “double-duct systems” (

i.e.,

inclusion of vertical single package units not intended for exterior mounting on, adjacent interior to, or through an outside wall) is appropriate and consistent with the intent of the Commercial Package Air Conditioners Working Group that initially drafted the current “double-duct system” definition.

See

81 FR 2420, 2446. (Jan. 15, 2016). This clarification also addresses Carrier's concern that the current definitions do not clearly differentiate double-duct systems from SPVUs.

Specifically, DOE stated in the January 2016 Direct Final Rule that single package vertical units are already covered under separate standards (10 CFR 431.97(d)). As a result, to ensure that SPVUs are not covered under the definition of double-duct equipment, DOE agrees with the ASRAC Term Sheet recommendations that for vertical double-duct units, only those with split configurations (that may be installed with the two components attached together) should be included as part of this separate equipment class.

Regarding maximum height and depth dimensions, the revised definition in section 3.7 of AHRI 340/360-2022 and section 3.12 of the AHRI 1340-202X draft specifies that for systems with multiple components, the maximum dimensions apply to each component of the unit. Because split systems are installed separately from each other, DOE has tentatively concluded that it is appropriate for the maximum dimensions for split systems to apply to each component, rather than the combined system.

Regarding determination of whether a model is non-weatherized, the AHRI 340/360-2022 and AHRI 1340-202X Draft definition does not include the criterion regarding the absence of any marking (or listing) indicating compliance with UL 1995 as an indication that the unit is intended for indoor installation. Upon examination of UL 1995, DOE recognizes that the scope of the standard is not limited to models intended for outdoor installation, and therefore, that compliance with UL 1995 does not necessarily indicate that a model is intended for outdoor installation and/or is weatherized. Therefore, DOE tentatively agrees with removing the reference to UL 1995 in the double-duct definition, and instead specifying that double-duct systems are intended for indoor installation (

e.g.,

the unit and/or all of its components are non-weatherized).

Based on the preceding discussion, DOE has tentatively determined that the definition for “double-duct system” in AHRI 340/360-2022 and the AHRI 1340-202X Draft better implements the intent of DOE and the Commercial Package Air Conditioners Working Group to create a separate equipment class of ACUACs and ACUHPs that are designed for indoor installation and that would require ducting of outdoor air from the building exterior. 81 FR 2420, 2446 (Jan. 15, 2016). Thus, DOE is proposing to revise the definition of double-duct air conditioners and heat pumps in 10 CFR 431.92 to reflect the updated definition for double-duct systems in section 3.7 of AHRI 340/360-2022 and section 3.12 of the AHRI 1340-202X Draft.

4. Metric Definitions

As mentioned in section II and discussed in further detail in sections III.F.4 and III.F.5 of this NOPR, DOE is proposing to adopt new cooling and heating metrics in appendix A1 (

i.e.,

IVEC and IVHE). Additionally, DOE is proposing three metrics for optional representations in appendix A1, as discussed further in section III.F.3 of this NOPR: energy efficiency ratio 2 (EER2), coefficient of performance 2 (COP2), and IVHE for colder climates (IVHE

). Consistent with this approach, DOE is proposing to add new definitions for the terms “IVEC,” “IVHE,” “EER2,” and “COP2” to 10 CFR 431.92. The proposed definitions describe what each metric represents, the test procedure used to determine each metric, and specific designations applicable to each metric (

e.g.,

IVHE

C. Updates to Industry Test Standards

The following sections discuss the changes included in the most recent updates to AHRI 340/360 and ASHRAE 37, which are incorporated by reference in the current DOE test procedure for ACUACs and ACUHPs with a rated cooling capacity greater than or equal to 65,000 Btu/h at 10 CFR 431.96 and 10 CFR part 431, subpart F, appendix A. AHRI 340/360 is also incorporated by reference in the current DOE test procedure for ECUACs and WCUACs with a rated cooling capacity greater than or equal to 65,000 Btu/h at 10 CFR 431.96.

1. AHRI 340/360

As noted previously, DOE's current test procedures for ACUACs, ACUHPs, and ECUACs and WCUACs with a rated cooling capacity greater than or equal to 65,000 Btu/h incorporates by reference ANSI/AHRI 340/360-2007. DOE's current test procedure for ECUACs and WCUACs with a rated cooling capacity less than 65,000 Btu/h incorporates by reference ANSI/AHRI 210/240-2008.

The most recent version of ASHRAE Standard 90.1, (

i.e.,

ASHRAE Standard 90.1-2022), references AHRI 340/360-2022 as the test procedure for ACUACs, ACUHPs, and ECUACs and WCUACs with a rated cooling capacity greater than or equal to 65,000 Btu/h. ASHRAE Standard 90.1-2022 included updates to the test procedure references for ECUACs and WCUACs with capacities less than 65,000 Btu/h to reference AHRI 210/240-2023. However, ECUACs and WCUACs with capacities less than 65,000 Btu/h are outside of the scope of AHRI 210/240-2023 and are instead included in AHRI 340/360-2022. Given these changes to the relevant industry test standards, DOE believes that such reference was an oversight.

The following list includes substantive additions in AHRI 340/360-2022 as compared to ANSI/AHRI 340/360-2007, which is edition referenced in the current Federal test procedure and applies to CUACs and CUHPs:

1. A method for testing double-duct systems at non-zero ESP (see section

6.1.3.7 and appendix I of AHRI 340/360-2022);

2. A method for comparing relative efficiency of indoor integrated fan and motor combinations (IFMs) that allows CUACs and CUHPs with non-standard (

i.e.,

higher ESP) IFMs to be rated in the same basic model as otherwise identical models with standards IFMs (see section D4.2 of Appendix D of AHRI 340/360-2022);

3. Requirements for indoor and outdoor air condition measurement (see appendix C of AHRI 340/360-2022);

4. Detailed provisions for setting indoor airflow and ESP (see sections 6.1.3.4-6.1.3.6 of AHRI 340/360-2022) and refrigerant charging instructions to be used in cases in which manufacturer's instructions conflict or are incomplete (see section 5.8 of AHRI 340/360-2022); and

5. ECUACs and WCUACs with cooling capacities less than 65,000 Btu/h are included within the scope of the standard.

As discussed, DOE is proposing to amend its test procedure for CUACs and CUHPs by incorporating by reference AHRI 340/360-2022 in appendix A.

2. AHRI 1340

The recommendations of the ACUAC and ACUHP Working Group TP Term Sheet are being incorporated into an updated version of AHRI 340/360 currently being drafted (

i.e.,

AHRI 1340-202X Draft) that will supersede AHRI 340/360-2022.

The AHRI 1340-202X Draft includes recommendations from the ACUAC and ACUHP Working Group TP Term Sheet described in section III.D of this NOPR (including the IVEC and IVHE metrics). The AHRI 1340-202X Draft also includes the following revisions and additions to the IVEC and IVHE metrics not included in the ACUAC and ACUHP Working Group TP Term Sheet, which are discussed in detail in sections III.F.5.a, III.F.6, and III.F.7.a of this NOPR:

1. Detailed test instructions for splitting ESP between the return and supply ductwork, consistent with ESP requirements recommended in the ACUAC and ACUHP Working Group TP Term Sheet;

2. Corrections to the hour-based IVEC weighting factors included in the ACUAC and ACUHP Working Group TP Term Sheet;

3. Correction of the equation in the ACUAC and ACUHP Working Group TP Term Sheet for calculating adjusted ESP for any cooling or heating tests conducted with an airflow rate that differs from the full-load cooling airflow;

4. Addition of separate hour-based weighting factors and bin temperatures to calculate a separate version of IVHE that is representative of colder climates, designated IVHEC

5. Changes to the default fan power and maximum pressure drop used for testing coil-only systems;

6. Additional instruction for component power measurement during testing;

7. Corrections to equations used for calculating IVHE;

8. Provisions for testing with non-standard low-static indoor fan motors; and

9. Revision to the power adder for WCUACs that reflects power that would be consumed by field-installed heat rejection components.

In this NOPR, DOE proposes to incorporate by reference the AHRI 1340-202X Draft in its appendix A1 test procedure. AHRI Standard 1340 is in draft form and its text was provided to DOE for the purposes of review for this NOPR. Note that the draft AHRI Standard 1340 may be further revised, edited, delayed, or withdrawn prior to publication by the AHRI Standards Technical Committee. If AHRI has published a final version, DOE intends to update its incorporation by reference to the final published version of AHRI 1340, unless there are substantive changes between the draft and published versions, in which case DOE may adopt the substance of the AHRI 1340-202X Draft or provide additional opportunity for comment on the changes to the industry consensus standard.

3. ASHRAE 37

ANSI/ASHRAE 37-2009, which provides a method of test for many categories of air conditioning and heating equipment, is referenced for testing CUACs and CUHPs by both AHRI 340/360-2022 and the AHRI 1340-202X Draft. More specifically, sections 5 and 6 and appendices C, D, and E of AHRI 340/360-2022 and sections 5 and 6 and appendices C, D, and E of the AHRI 1340-202X Draft reference methods of test in ANSI/ASHRAE 37-2009. DOE currently incorporates by reference ANSI/ASHRAE 37-2009 in 10 CFR 431.95, and the current incorporation by reference applies to the current Federal test procedure for ACUACs and ACUHPs specified at appendix A. The current Federal test procedures at 10 CFR 431.96 for ECUACs and WCUACs do not explicitly reference ANSI/ASHRAE 37-2009. Given that DOE is proposing to expand the scope of appendix A to include testing of ECUACs and WCUACs as well as the fact that AHRI 340/360-2022 references ANSI/ASHRAE 37-2009 for several test instructions, DOE has tentatively concluded that it is appropriate for the existing incorporation by reference of ANSI/ASHRAE 37-2009 in appendix A to apply to testing ECUACs and WCUACs. Given that the AHRI 1340-202X 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 A1.

D. Consideration of the ACUAC and ACUHP Working Group TP Term Sheet

In response to the May 2022 TP/ECS RFI, DOE received comments from several stakeholders indicating support for the formation of an ASRAC working group to convene and discuss representative test conditions for CUACs and CUHPs. (AHRI, EERE-2022-BT-STD-0015-0008, at pp. 1-2; CA IOUs, EERE-2022-BT-STD-0015-0012, at pp. 1-2; Lennox, EERE-2022-BT-STD-0015-0009, at pp. 1-2; NEEA, EERE-2022-BT-STD-0015-0013, at pp. 6-7; Trane, EERE-2022-BT-STD-0015-0014, at p. 2)

As a result, DOE published in the

Federal Register

the July 2022 Notice of Intent. 87 FR 45703 (July 29, 2022). DOE then established the Working Group in accordance with FACA and NRA. The Working Group consisted of 14 members and met six times, while the Working Group's subcommittee met an additional seven times. The Working Group meetings were held between September 20, 2022, and December 15, 2022, after which the Working Group successfully reached consensus on an amended test procedure. The Working Group signed a term sheet of recommendations on December 15, 2022. (

See

EERE-2022-BT-STD-0015-0065) The Working Group addressed the following aspects of the test procedure for ACUACs and ACUHPs:

1. Mathematical representation of cooling efficiency:

The current cooling metric specified by AHRI 340/360-2022 (

i.e.,

IEER) represents a weighted average of the measured energy efficiency ratios (EER) measured at four distinct test conditions, whereas the proposed IVEC metric is calculated as the total annual cooling capacity divided by the total annual energy use, as discussed further in section III.F.4 of this document. The Working Group agreed that this calculation approach provides a more mathematically accurate way of representing the cooling efficiency of ACUACs and ACUHPs compared to the current approach used for IEER. As part of this equation format,

the IVEC metric also uses hour-based weighting factors to represent the time spent per year in each operating mode.

2. Integrated heating metric:

The current heating metric for ACUHPs (

i.e.,

COP) represents the ratio of heating capacity to the power input, calculated at a single test condition of 47 °F. COP does not account for the performance at part-load or over the range of temperatures seen during an average heating season, and it does not include energy use in heating season ventilation mode. IVHE accounts for both full-load and part-load operation at a range of typical ambient temperatures seen during the heating season, and it includes energy use in heating season ventilation mode. Analogous to IVEC, the proposed IVHE metric is calculated as the total annual heating load divided by the total annual energy use, as discussed further in section III.F.5 of this document, and the metric also uses hour-based weighting factors to represent the time spent per year in each operating mode.

3. Operating modes other than mechanical cooling:

The IEER metric currently does not include the energy use of operating modes other than mechanical cooling, such as economizer-only cooling and cooling season ventilation. The newly established IVEC metric includes the energy use of these other modes.

4. ESP:

The IVEC and IVHE metrics require increased ESPs—in comparison to the ESPs required for determining IEER and COP—to more accurately represent ESPs and corresponding indoor fan power that would be experienced in real-world installations.

5. Crankcase heater operation:

The current IEER metric includes crankcase heater power consumption only when operating at part-load compressor stages (

i.e.,

for part-load cooling operation, crankcase heater power is included only for higher-stage compressors that are staged off, and it is not included for lower-stage compressors when all compressors are cycled off). The COP metric does not include any crankcase heater power consumption. In contrast, the IVEC and IVHE metrics include all annual crankcase heater operation, including when all compressors are cycled off in part-load cooling or heating, ventilation mode, unoccupied no-load hours, and in heating season (for ACUACs only).

6. Oversizing:

The current IEER and COP metrics do not consider that ACUACs and ACUHPs are typically oversized in field installations. In contrast, the proposed IVEC and IVHE metrics include an oversizing factor of 15 percent (

i.e.,

it is assumed that the unit's measured full-load cooling capacity is 15 percent higher than the peak building cooling load and peak building heating load). Accounting for oversizing is more representative of the load fractions seen in field applications and better enables the test procedure to differentiate efficiency improvements from the use of modulating/staged components.

Based on discussions related to these six topics, the Working Group developed the ACUAC and ACUHP Working Group TP Term Sheet, which includes the following recommendations:

1. A recommendation to adopt the latest version of AHRI 340/360-2022 with IEER and COP metrics required for compliance beginning 360 days from the date a test procedure final rule publishes (See Recommendation #0);

2. The IVEC efficiency metric, to be required on the date of amended energy conservation standards for ACUACs and ACUHPs (See Recommendation #1);

3. Hour-based weighting factors for the IVEC metric (See Recommendation #2);

4. Details on determination of IVEC, including provisions for determining IVEC in appendix B of the ACUAC and ACUHP Working Group TP Term Sheet (See Recommendation #3);

5. Target load fractions and temperature test conditions for IVEC, which account for oversizing (See Recommendation #4);

6. A requirement that representations of full-load EER be made in accordance with the full-load “A” test (See Recommendation #5);

Similar to the current test procedure for determining IEER, the test procedure recommended in the ACUAC and ACUHP Working Group TP Term Sheet includes four cooling tests designated with letters “A”, “B”, “C”, and “D.” The “A” test is a full-load cooling test, while the “B,” “C,” and “D” tests are part-load cooling tests.

7. A requirement to provide representations of airflow used for the full load “A” test and the part load “D” test (

i.e.,

the airflow used in the lowest-stage test for the D point), and a provision for determining the minimum airflow that can be used for testing (See Recommendation #6);

8. The IVHE efficiency metric (See Recommendation #7);

9. Hour-based weighting factors, load bins, and outdoor air temperatures for each bin (

i.e.,

temperatures used for the building heating load line, not test temperature conditions) for the IVHE metric (See Recommendation #8);

10. The test conditions and list of required and optional tests and representations for the IVHE metric (See Recommendation #9);

11. Provisions for manufacturers to certify cut-in and cut-out temperatures for heat pumps to DOE and provisions for a DOE verification test of those temperatures (See Recommendation #10);

12. Commitment of the Working Group to analyze ventilation and fan-only operation included in the IVEC and IVHE metrics to validate that these metrics adequately capture fan energy use during the energy conservation standards portion of the negotiated rulemaking. If the IVEC and IVHE levels do not adequately drive more efficient air moving systems that are technologically feasible and economically justified, the Working Group committed to developing a metric addressing furnace fan energy use (See Recommendation #11);

13. ESP requirements for the IVEC and IVHE metrics, requirements for splitting the ESP requirements between the return and supply ducts, and a requirement that certified airflow for full load and D bin be made public in the DOE Compliance Certification Database (See Recommendation #12);

14. Provisions requiring manufacturers to certify crankcase heater wattages and tolerances for certification (See Recommendation #13); and

15. Provisions that the contents of the ACUAC and ACUHP Working Group TP Term Sheet be implemented in a test procedure NOPR and final rule, with the final rule issuing no later than any energy conservation standards direct final rule. (See Recommendation #14)

E. DOE Proposed Test Procedures

As discussed, EPCA requires that test procedures for covered equipment, including CUACs and CUHPs, be reasonably designed to produce test results that reflect energy efficiency, energy use, and estimated operating costs of a type of industrial equipment (or class thereof) during a representative average use cycle (as determined by the Secretary), and shall not be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)) DOE has tentatively determined that the recommendations specified in the ACUAC and ACUHP Working Group TP Term Sheet are consistent with this EPCA requirement and is proposing amendments to the existing test procedure in appendix A and a new test procedure in appendix A1 in accordance with the Term Sheet.

In this NOPR, DOE is proposing to maintain the current efficiency metrics of IEER, EER, and COP in appendix A, and is proposing to reference AHRI 340/360-2022 in appendix A for measuring the existing metrics. Thus, the proposed

amendments to appendix A would not affect the measured efficiency of CUACs and CUHPs or require retesting solely as a result of DOE's adoption of the proposed amendments to the appendix A test procedure, if made final. Additionally, DOE is proposing to establish a new test procedure at appendix A1 that would adopt the AHRI 1340-202X Draft, including the newly proposed IVEC and IVHE metrics, ideally through incorporation by reference of a finalized version of that industry test standard. (If a finalized version of the AHRI 1340-202X Draft is not published before the test procedure final rule, or if there are substantive changes between the draft and published versions of the standard that are not supported by stakeholder comments in response to this NOPR, DOE may adopt the substance of the AHRI 1340-202X Draft or provide additional opportunity for comment on the final version of that industry consensus standard.) Use of appendix A1 would not be required until the compliance date of any amended standards denominated in terms of the new metrics in appendix A1, should such standards be adopted.

Specifically, in appendix A, DOE is proposing to adopt the following sections of AHRI 340/360-2022: sections 3 (with certain exclusions

), 4, 5, and 6, and appendices A, C, D (excluding sections D1 through D3

), and E.

DOE is not proposing to reference the following provisions in section 3 of AHRI 340/360-2022 because the terms are either defined at 10 CFR 431.92 or are not needed for the proposed DOE test procedure: 3.2 (Basic Model), 3.4 (Commercial and Industrial Unitary Air-conditioning Equipment), 3.5 (Commercial and Industrial Unitary Heat Pump), 3.7 (Double-duct System), 3.8 (Energy Efficiency Ratio), 3.12 (Heating Coefficient of Performance), 3.14 (Integrated Energy Efficiency Ratio), 3.23 (Published Rating), 3.26 (Single Package Air-Conditioners), 3.27 (Single Package Heat Pumps), 3.29 (Split System Air-conditioners), 3.30 (Split System Heat Pump), 3.36 (Year Round Single Package Air-conditioners).

For reasons discussed in section III.I of this NOPR, DOE is proposing provisions regarding configuration of unit under test at 10 CFR 429.43(a)(3)(v)(A), appendix A, and appendix A1 that are distinct from the provisions in sections D1 through D3 of AHRI 340/360-2022.

As previously mentioned in section I.B of this NOPR, DOE's test procedure for ACUACs and ACUHPs currently specifies additional test procedure requirements in sections 3 through 10 of the current appendix A that are not included in ANSI/AHRI 340/360-2007 and that are related to minimum ESP, optional break-in period, refrigerant charging, setting indoor airflow, condenser head pressure controls, tolerance on capacity at part-load test points, and condenser air inlet temperature for part-load tests. Similarly, DOE's test procedure for ECUACs and WCUACs currently specifies additional test procedure requirements in paragraphs (c) and (e) of 10 CFR 431.96 regarding optional break-in period and additional provisions for equipment setup. DOE has tentatively determined that these DOE test procedure requirements that are specified in appendix A and paragraphs (c) and (e) of 10 CFR 431.96 no longer need to be separately specified due to the addition of equivalent provisions in AHRI 340/360-2022 and the AHRI 1340-202X Draft. Therefore, DOE is proposing to remove these provisions from appendix A and to revise Table 1 to 10 CFR 431.96 such that paragraphs (c) and (e) are no longer listed as requirements for ECUACs and WCUACs, instead utilizing the relevant provisions in AHRI 340/360-2022.

Further, in both appendix A and appendix A1, DOE is proposing to incorporate by reference ANSI/ASHRAE 37-2009 and to utilize all sections of that industry test method except sections 1 (Purpose), 2 (Scope), and 4 (Classifications).

Specifically for appendix A1, DOE is proposing to adopt sections of AHRI 1340-202X Draft for measuring the IVEC and IVHE metrics, which are generally consistent with the recommendations from the ACUAC and ACUHP Working Group TP Term Sheet. In the proposed appendix A1, DOE is proposing to adopt the following sections of the AHRI 1340-202X Draft: sections 3 (with certain exclusions) 4, 5, and 6.1 through 6.3, and appendices A, C, D (excluding D1 through D3), and E. Sections III.F.3, III.F.4, III.F.5, and III.F.6 of this NOPR include further discussion on the IVEC and IVHE metrics, as well as additions and revisions to the IVEC and IVHE metrics that are included in the AHRI 1340-202X Draft but not in the ACUAC and ACUHP Working Group TP Term Sheet. Sections III.F.7 and III.F.6.d of this NOPR include further discussion on the IVEC and IVHE metrics specified in the AHRI 1340-202X Draft that DOE is proposing to adopt in appendix A1 for ECUACs, WCUACs, and double-duct systems.

The ACUAC and ACUHP Working Group TP Term Sheet applies only to the test procedures for ACUACs and ACUHPs excluding double-duct systems. However, AHRI 1340-202X Draft includes additional provisions for determining IVEC and IVHE for double-duct systems, ECUACs, and WCUACs—indicating industry consensus that these metrics are appropriate for these categories of CUACs and CUHPs. DOE has tentatively determined that the test procedures for CUACs and CUHPs as proposed would improve the representativeness of the current Federal test procedure for CUACs and CUHPs and would not be unduly burdensome to conduct. Specifically, DOE has tentatively concluded that testing CUACs and CUHPs (including double-duct systems, ECUACs, and WCUACs) in accordance with the test provisions in the most recent draft of the applicable consensus industry test procedure AHRI 1340-202X Draft (which incorporates recommendations of the ACUAC and ACUHP Working Group TP Term Sheet, including adopting the new IVEC and IVHE metrics) would provide more representative results and more fully comply with the requirements of 42 U.S.C. 6314(a)(2) than testing strictly in accordance with AHRI 340/360-2022. Therefore, DOE is proposing to amend the test procedure for CUACs and CUHPs to adopt in the proposed new appendix A1 the test provisions in AHRI 1340-202X Draft and ASHRAE 37-2009.

Issue 2:

DOE requests feedback on its proposal to adopt the IVEC and IVHE metrics as determined under AHRI 1340-202X Draft in appendix A1 of the Federal test procedure for ACUACs and ACUHPs (including double-duct systems), ECUACs, and WCUACs.

F. Efficiency Metrics and Test Conditions

In response to the July 2017 TP RFI, May 2020 ECS RFI, and May 2022 TP/ECS RFI, DOE received comment on a number of topics related to changing the metrics and/or test conditions used for determining CUAC and CUHP efficiency. The following sections: (1) summarize comments received on these topics; (2) discuss the current test conditions and metrics in appendix A; (3) discuss the test conditions and metrics proposed to be included in appendix A1; (4) discuss the newly proposed IVEC metric; (5) discuss the newly proposed IVHE metric; (6) discuss additions and revisions to the IVEC and IVHE metrics that are included in the AHRI 1340-202X Draft but not the ACUAC and ACUHP Working Group TP Term Sheet; and (7) discuss metrics specific to double-duct systems.

1. Comments Received on Metrics

In response to the July 2017 TP RFI, May 2020 ECS RFI, and May 2022 TP/ECS RFI, DOE received comments regarding a number of test procedure topics. In the following subsections, DOE briefly summarizes these topics,

including the corresponding comments received and DOE's responses.

DOE notes that many of the issues raised by commenters had not yet been addressed through an industry consensus test procedure at the time the comments were submitted to DOE. Many of these issues were raised subsequently during the Working Group, and the newly proposed IVEC and IVHE metrics would largely address the major concerns previously expressed by commenters.

a. IEER Test Conditions and Weighting Factors

In the July 2017 TP RFI, DOE welcomed comment on any aspect of the existing test procedures for CUACs and CUHPs not specifically addressed by the RFI, particularly with regard to information that would improve the representativeness of the test procedures. 82 FR 34427, 34448. (July 25, 2017).

With respect to the IEER test conditions and weighting factors, the CA IOUs suggested raising the highest ambient dry-bulb temperature test point used for determining IEER, stating that the 95 °F condition specified in the test procedure does not reflect the conditions experienced in the western climate and on many rooftops throughout the country. (CA IOUs, EERE-2017-BT-TP-0018-0007 at p. 3)

Additionally, in response to the May 2020 ECS RFI, DOE received comments and test data from Verified recommending changes to the IEER weighting factors and indoor and outdoor air temperature test conditions in AHRI 340/360, particularly to account for the use of economizers (discussed further in section III.F.1.d) and changes in climate due to global climate change. (Verified, EERE-2019-BT-STD-0042-0011 at pp. 3-7) DOE also received comments from two individuals supporting the statements made by Verified. (Heinemeier, EERE-2019-BT-STD-0042-0012 at p. 1; Walsh, EERE-2019-BT-STD-0042-0018 at p. 1)

In response to the May 2022 TP/ECS RFI, DOE received several comments regarding the weighting factors used in the IEER metric, specifically relating to the building types considered in the current test procedure. ASAP and ACEEE asserted that the current IEER weighting factors should be adjusted to account for additional building types that were not considered when initially developing IEER. (ASAP and ACEEE, EERE-2022-BT-STD-0015-0011, at p. 2)

Carrier noted that IEER was developed using three building types (specifically, office, retail, and school buildings) and asserted that for an updated analysis, the 16 building types currently in ASHRAE 90.1 should be considered where applicable to ACUACs and ACUHPs. (Carrier, EERE-2022-BT-STD-0015-0010, at pp. 14-15) Carrier also noted that it had developed a model that outputs load profiles for the 16 ASHRAE 90.1 building types for each of the 19 global climate zones in ASHRAE 169-2013 and was using its model to evaluate the effects of ventilation, ASHRAE 90.1 requirements for economizer free cooling and energy recovery, updated heating metrics, different climate zones and building load profiles, and updated ESPs. (Carrier, EERE-2022-BT-STD-0015-0010, at pp. 1-6)

Additionally, Carrier noted that the weighting factors developed during the 2005 process to create IEER were based on ton-hours and not purely on hours, noting that high-capacity hours have more weight than the lower capacity hours in terms of energy use. (Carrier, EERE-2022-BT-STD-0015-0010, at pp. 12-13). Carrier also explained that the weighting for the A test condition was based on the 97-percent to 100-percent capacity range because it would not have been appropriate to use a larger bin with the rating condition at the extreme upper limit of the bin.

Id.

Carrier recommended that if DOE were to update the cooling metric, DOE should consider the following: (1) oversizing, (2) re-evaluating test points and weighting factors if ventilation and economizing are included, (3) test uncertainty at very low loads, and (4) varying return air temperatures.

Id.

AHRI stated that energy use during cooling varies based on climate zone, building type, construction, and use, and that ASHRAE SSPC 90.1 has developed reference cities for all 19 climate zones and defined 16 reference buildings that represent 83 percent of the market. (AHRI, EERE-2022-BT-STD-0015-0008, at p. 5)

As presented in the September 20-21, 2022, Working Group meetings, the Working Group evaluated the weighting factors and test conditions specified in conjunction with the newly proposed IVEC metric using the models developed by Carrier, which include several ASHRAE 90.1 building types and climate zones for which ACUACs and ACUHPs are installed. (

See

EERE-2022-BT-STD-0015-0019, pp. 9-22) The weighting factors and their development are further discussed in section III.F.4 of this NOPR. DOE believes that these provisions address the issues raised by commenters as summarized previously in this section, and proposes to adopt in appendix A1 the adjusted IVEC weighting factors that are specified in AHRI 1340-202X Draft and discussed in section III.F.6.a of this NOPR.

b. Energy Efficiency Metrics for ECUACs and WCUACs

For ECUACs and WCUACs of all regulated cooling capacities, DOE currently prescribes standards in terms of the EER metric for cooling-mode operation. 10 CFR 431.97(b);

see

Table 1 to 10 CFR 431.97. This differs from ACUACs and ACUHPs with cooling capacities greater than or equal to 65,000 Btu/h (excluding double-duct systems), for which DOE currently prescribes energy conservation standards in terms of the IEER metric for cooling-mode operation and in terms of COP for heating-mode operation. 10 CFR 431.97(b);

see

Table 3 and Table 4 to 10 CFR 431.97. Unlike EER, which represents the efficiency of the equipment operating only at full load, IEER represents the efficiency of operating at part-load conditions of 75 percent, 50 percent, and 25 percent of capacity in addition to the efficiency at full load. The IEER metric provides a more representative measure of energy consumption in actual operation of CUACs and CUHPs by weighting the full-load and part-load efficiencies with the average amount of time the equipment spends operating at each load point. AHRI 340/360-2022 includes both the EER and IEER metrics for ECUACs and WCUACs. ASHRAE 90.1-2019 and ASHRAE 90.1-2022 specify minimum efficiency levels for ECUACs and WCUACs in terms of both EER and IEER.

As discussed in the July 2017 RFI, ANSI/AHRI 340/360-2007 includes a method for testing and calculating IEER for ECUACs and WCUACs. DOE requested comment and data on whether the IEER part-load conditions and IEER weighting factors are representative of the operation of field-installed ECUACs and WCUACs, and on the typical cycling losses of field-installed ECUACs and WCUACs. 82 FR 34427, 34440 (July 25, 2017).

On this topic, AHRI, Carrier, and Goodman commented that the weighting factors are based on building load profiles and should not depend on equipment category. (AHRI, EERE-2017-BT-TP-0018-0011 at p. 22; Carrier, EERE-2017-BT-TP-0018-0006 at p. 8; Goodman, EERE-2017-BT-TP-0018-0014 at p. 3) ASAP, ASE,

et al.

encouraged DOE to adopt IEER as the efficiency metric for ECUACs and WCUACs, stating that ECUACs and WCUACs spend most of their operating

time in part load, and that using IEER for these equipment types would provide consistency in ratings with ACUACs and ACUHPs and better represent performance in the field. (ASAP, ASE,

et al.,

EERE-2017-BT-TP-0018-0009 at pp. 4-5) In contrast, Goodman stated that the WCUAC market is so small that there would be no value in changing the regulated metric to IEER for such equipment. (Goodman, EERE-2017-BT-TP-0018-0014 at p. 3)

DOE responds to these commenters as follows. In the proposed appendix A, for ECUACs and WCUACs, DOE proposes to include both the required EER metric and the optional IEER metric, as well as the test procedure specified in AHRI 340/360-2022, in the DOE test procedure so as to allow for required representations using the EER metric and optional representations using the IEER metric. In a final determination published in the

Federal Register

on July 14, 2021, DOE discussed the potential for amended energy conservation standards for ECUACs and WCUACs denominated in terms of IEER, but the Department concluded that such a metric change was not warranted and ultimately maintained the current standards denominated in terms of EER. 86 FR 37001, 37004-37005. As part of this rulemaking, DOE is proposing the IEER provisions as an optional test procedure to allow for consistent and comparable representations in terms of IEER when testing to appendix A, should a manufacturer choose to make such representations.

As discussed, DOE is proposing to adopt the IVEC metric for ECUACs and WCUACs in the proposed appendix A1, as determined in the AHRI 1340-202X Draft. DOE has tentatively concluded that the inclusion of the IVEC metric for ECUACs and WCUACs in AHRI 1340-202X Draft represents industry consensus that the metric provides a representative measure of efficiency for ECUACs and WCUACs. Section III.F.6.d of this NOPR includes further discussion of the IVEC metric for ECUACs and WCUACs.

c. Cyclic Degradation Factor for Cooling

In section 6.2.3.2 of AHRI 340/360-2022, units that are unable to reduce their capacity to meet one of the IEER part load rating points (

i.e.,

75 percent, 50 percent, or 25 percent) are tested under steady-state conditions at the minimum stage of compression that the unit is able to achieve. In real-world installations, these same units would typically operate under non-steady-state conditions because the compressor would cycle to reduce the unit's capacity to meet the desired cooling load. AHRI 340/360-2022 require units unable to reduce their capacity below one of the part load rating points have the EER for that rating point calculated using a cyclic degradation coefficient. This degradation coefficient, which is calculated based on the load fraction and ranges from 1 to 1.13, is included in the denominator of the EER calculation for that rating point and is multiplied by the sum of the compressor and condenser fan power in order to simulate the efficiency degradation of compressor and condenser fan cycling.

With respect to cyclic degradation, DOE received a comment in response to the July 2017 TP RFI from the CA IOUs recommending that DOE investigate the cyclic degradation factor in AHRI 340/360-2015 to verify that the degradation coefficient will never exceed 1.13. (CA IOUs, EERE-2017-BT-TP-0018-0007 at p. 2)

DOE also received a comment in response to the May 2020 ECS RFI from Verified questioning the validity of the cyclic degradation factor in AHRI 340/360-2019, stating that its laboratory tests found that relative cycling losses of a 7.5-ton system were more than double the losses for a 3-ton system. (Verified, EERE-2019-BT-STD-0042-0011 at p. 10)

While the Working Group discussed calculation methods for IVEC during the ACUAC and ACUHP Working Group meetings, the Working Group did not discuss any alternatives to the cyclic degradation approach specified in AHRI 340/360-2022. Additionally, the ACUAC and ACUHP Working Group TP Term Sheet includes the cyclic degradation calculation method specified in AHRI 340/360-2022 as part of the IVEC metric calculation method. At this time, DOE lacks clear and convincing evidence to deviate from the cyclic degradation approach in AHRI 340/360-2022 that is recommended in the ACUAC and ACUHP Working Group TP Term Sheet and included in AHRI 1340-202X Draft. Therefore, DOE is not proposing to adopt a cyclic degradation approach that differs from the approach specified in these documents.

d. Economizing and Ventilation

In 2015, DOE initiated a rulemaking effort for the ASRAC Commercial and Industrial Fans and Blowers Working Group (CIFB Working Group) to negotiate the scope, test procedure, and standards for commercial and industrial fans and blowers. 80 FR 17359. The CIFB Working Group issued a term sheet with recommendations regarding the energy conservation standards, test procedures, and efficiency metrics for commercial and industrial fans and blowers (CIFB Term Sheet). (

See

Document No. 179 in Docket No. EERE-2013-BT-STD-0006.) Recommendation #3 of the CIFB Term Sheet identifies a need for DOE's test procedures and related efficiency metrics for CUACs and CUHPs to more fully account for the energy consumption of fans embedded in regulated commercial air-conditioning equipment. (

Id.

at pp. 3-4) In addition, the CIFB Working Group recommended that in the next round of test procedure rulemakings, DOE should consider revising efficiency metrics that include energy use of supply and condenser fans to include the energy consumption during all relevant operating modes (

e.g.,

auxiliary heating mode, ventilation mode, and part-load operation). (

Id.

)

The Commercial Package Air Conditioners Working Group also developed recommendations regarding fan energy use in a term sheet. (See Document No. 93 in Docket No. EERE-2013-BT-STD-0007) The Commercial Package Air Conditioners Working Group recommended that DOE initiate a rulemaking with a primary focus of better representing total fan energy use in real-world installations, including consideration of fan operation for operating modes other than mechanical cooling and heating.

(

Id.

at p. 2)

Mechanical cooling and heating refer to a ACUAC and ACUHP using the refrigeration cycle to cool and heat the indoor space, and does not refer to other forms of unit operation (

e.g.,

economizing, ventilation, or supplemental heating).

As part of the July 2017 TP RFI, DOE requested comment and data on the operation of CUAC and CUHP supply fans when there is no demand for heating and cooling, as well as the impact of ancillary functions (

e.g.,

primary heating, auxiliary heating, and economizers

) on the use and operation of the supply fan. 82 FR 34427, 34440.

An economizer is a system that enables an ACUAC or ACUHP to supply outdoor air instead of return air from the conditioned space in order to reduce or eliminate mechanical cooling operation in mild or cold weather conditions. In economizer-only cooling, the indoor fan runs to supply outdoor air to meet cooling load, but there is no mechanical cooling operation—

i.e.,

compressor(s) and condenser fans do not operate.

In response to the July 2017 TP RFI, Carrier and AHRI commented that fan operation in ventilation hours cannot properly be accounted for without including economizer operation in testing. (Carrier, EERE-2017-BT-TP-0018-0006 at p. 9; AHRI, EERE-2017-BT-TP-0018-0011 at p. 23)

AHRI and Goodman commented that manufacturers and third-party laboratories do not currently have test

facilities that can accommodate testing of ACUACs and ACUHPs with economizers operating because such testing requires air to be pulled from the outdoor room into the indoor room. (AHRI, EERE-2017-BT-TP-0018-0011 at p. 22; Goodman, EERE-2017-BT-TP-0018-0014 at p. 3) AHRI further stated that because of the lack of test facilities to accommodate this type of testing, incorporation of ventilation into an efficiency metric is still not practical. (AHRI, EERE-2017-BT-TP-0018-0011 at p. 23)

In the May 2022 TP/ECS RFI, DOE acknowledged a need to further investigate the prevalence and operating hours of economizers and ventilation. DOE requested comment and data on several issues including the number of units installed with economizers per climate zone, the operating hours of economizers by climate zone, and the methodology used to determine operating hours in each cooling mode, especially those that might contribute to the creation of a new metric.

In response to the May 2022 TP/ECS RFI, the CA IOUs, NYSERDA, and ASAP and ACEEE commented that the current test procedure does not account for the fan energy use outside of mechanical cooling and heating modes. (CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 2; ASAP and ACEEE, EERE-2022-BT-STD-0015-0011, at pp. 1-2, NYSERDA, EERE-2022-BT-STD-0015-0007, at p. 3)

Specifically, the CA IOUs recommended that DOE consider the California 2022 Title 24 codes and standards enhancement effort for potential solutions. (CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 2)

NYSERDA recommended that DOE consider factoring in fan energy using temperature rise provisions, further detailed in comments submitted by NYSERDA in response to the commercial warm air furnace test procedure NOPR published February 5, 2022 (

see

87 FR 10726). (NYSERDA, EERE-2022-BT-STD-0015-0007, at p. 3)

Regarding the distribution of installed economizers, AHRI stated that although many economizers are field-installed, AHRI is considering collecting data on factory-installed economizers, particularly by state or climate zone. (AHRI, EERE-2022-BT-STD-0015-0008, at p. 5) AHRI did not provide any such data in its comment.

ASAP and ACEEE cited AHRI data indicating that economizers are typically installed in CUACs. ASAP and ACEEE noted that ASHRAE 90.1-2019 requires economizers in all but one climate zone, suggesting the importance of incorporating fan energy use during economizer only cooling mode. (ASAP and ACEEE, EERE-2022-BT-STD-0015-0011, at pp. 1-2)

Lennox commented that its information indicates that the percentage of CUACs and CUHPs shipped with factory installed economizers ranges from around 30 percent to 80 percent by state, averaging around 55 percent in the U.S. (Lennox, EERE-2022-BT-STD-0015-0009, at p. 5) Lennox noted that the total percentage is likely far higher than this level when field-installed economizers are taken into account.

Id.

Lennox also stated that its information indicates that a higher fraction of equipment in northern climates contain economizers than in warmer southern climates. Lennox recommended that DOE review the standard and code requirements for where economizers are required in order to assess the fraction of products installed with economizers in each climate zone.

Id.

Carrier commented that, based on the market distribution data used for the ASHRAE 90.1 determination, economizers are required on approximately 96 percent of the 16 reference buildings' weighted sales. (Carrier, EERE-2022-BT-STD-0015-0010, at pp. 9-10)

Regarding economizer hours and methodology for determination of hours in each bin load, AHRI stated that DOE should use the heating and cooling load modeling used to develop IEER to understand the heating, cooling, and economizing hours for CUACs and CUHPs. (AHRI, EERE-2022-BT-STD-0015-0008, at p. 3)

Carrier provided data showing the hours CUACs and CUHPs spend in economizer only, integrated economizer, and mechanical only cooling developed as part of ASHRAE 90.1 economizer studies it has conducted. (Carrier, EERE-2022-BT-STD-0015-0010, at p. 12) Carrier stated that the 2005 analysis performed to determine the IEER metric was based on the mechanical cooling operation, including hours where integrated economizers are used, but that it did not account for the benefits of the economizer capacity. (Carrier, EERE-2022-BT-STD-0015-0010, at pp. 12-13)

In addition to distribution and operating information, DOE received multiple recommendations in response to the May 2022 TP/ECS RFI relating to the inclusion of economizer or ventilation data in a new efficiency metric.

The CA IOUs stated that economizer performance is highly dependent on the use of climate-zone appropriate controls, and that economizers are often shipped with conservative default control settings appropriate for warm and moist areas. (CA IOUs, EERE-2022-BT-STD-0015-0012, at pp. 3-4) The CA IOUs asserted that including economizers in the CUAC and CUHP energy efficiency metric would not be beneficial because it would preempt climate-zone-dependent economizer requirements in building codes.

Id.

The CA IOUs explained that economizers and their installed controls are often sold by third parties, and that original equipment manufacturers (OEMs) usually do not determine the method of economizer control or quality of construction.

Id.

The CA IOUs stated that DOE may need to determine if independently manufactured economizers fall within its statutory authority and if it is feasible to regulate them.

Id.

Furthermore, the CA IOUs asserted that designing a test procedure that measures a significant difference between models may be challenging unless the test includes operation as an integrated economizer, in which case the difference in performance would be driven by the unit's capacity control and turndown capability.

Id.

Carrier asserted that the downside of including the ventilation cooling hours in a new cooling metric is that it would decrease the focus on the mechanical cooling, and that evaluation of mechanical cooling performance was the intent of the current IEER metric. (Carrier, EERE-2022-BT-STD-0015-0010, at pp. 9-10) Carrier requested that if the IEER metric and test procedure are modified to include ventilation fan power, the benefits of the economizer and also energy recovery be included to account for the actual capabilities of such a large application base.

Id.

Based on comments received in response to the July 2017 TP RFI and the May 2020 ECS RFI, DOE recognized in the May 2022 TP/ECS RFI a need to further investigate fan operation during ventilation or air circulation/filtration and economizing. Specifically, while comments received previously had indicated the prevalence of multi-speed fans that reduce fan speed in these operating modes, the commenters had not indicated how the fan speed in these operating modes typically compares to fan speed when operating at the lowest stage of compressor cooling. Thus, in the May 2022 TP/ECS RFI, DOE sought feedback on the supply airflow and fan power at the lowest stage of compression for variable air volume and staged air volume fans in relation to ventilation, air circulation, and

economizer-only cooling. 87 FR 31743, 31750-31751.

In response to the May 2022 TP/ECS RFI, AHRI and Lennox recommended that DOE review ASHRAE 62.1 “Ventilation for Acceptable Indoor Air Quality,” which specifies minimum ventilation rates and other measures to achieve proper indoor air quality control in commercial buildings. (AHRI, EERE-2022-BT-STD-0015-0008, at pp. 4-5; Lennox, EERE-2022-BT-STD-0015-0009, at pp. 4-5) AHRI noted that ventilation rates specified by ASHRAE 62.1 vary from 18 percent to 60 percent based on building type. (AHRI, EERE-2022-BT-STD-0015-0008, at p. 4) AHRI also noted that ASHRAE 90.1-2019 provides minimum requirements for the CUACs and CUHPs, including the requirement to have two-speed fans.

Id.

AHRI stated that airflow, including during ventilation, will be different for CUACs and CUHPs if the product is multi-zone variable air volume (MZVAV), single-zone variable air volume (SZVAV), or constant volume, and that the relationship between fan power, airflow, and code requirements must be considered when developing a metric change that incorporates ventilation. (AHRI, EERE-2022-BT-STD-0015-0008, at pp. 4-5) AHRI also stated that ventilation occurs only during occupied mode. (AHRI, EERE-2022-BT-STD-0015-0008, at p. 5)

Lennox stated that CUAC and CUHP systems are generally designed to meet minimum ventilation requirements in all operating modes. (Lennox, EERE-2022-BT-STD-0015-0009, at p. 5) Lennox recommended that for the test procedure, the airflow in ventilation-only mode be set at the same as the airflow used at the minimum stage of capacity.

Id.

Lennox stated that for economizer-only cooling, the systems are generally designed to meet a supply air temperature setpoint, and that the supply airflow volume is influenced by outside air temperature and/or the cooling demand of the conditioned space to attain this setpoint.

Id.

Lennox stated that the economizer-only supply airflow might not be the same as the lowest stage of compression and can be less than the airflow at the lowest stage of compression.

Id.

Carrier stated that for ventilation-only operation, the airflow may or may not be the same as the minimum stage of capacity, and that the airflow depends on the controls and application, as well as the required ventilation rate. (Carrier, EERE-2022-BT-STD-0015-0010, at p. 9) Carrier also stated that fan speeds can be higher during economizer cooling operation.

Id.

Carrier noted that ASHRAE 90.1 requires economizers to be capable of 100-percent airflow and that the maximum economizer capacity be used before turning on the mechanical cooling of the integrated economizer option.

Id.

NEEA noted that CUAC and CUHP standard rating conditions do not consider operating modes where ventilation air (either mixed or not mixed with return air) is actively heated or cooled. NEEA stated that it recognizes that the impact of certain features—including economizers and ventilation systems—will vary depending on the amount of ventilation air introduced by the CUAC/CUHP. NEEA described, for example, that in 30-percent and 100-percent outside air systems, energy recovery represents a significant opportunity for energy savings, whereas in 0-percent outside systems, enclosure improvements or reducing damper leakage may present the greatest opportunity for energy savings. NEEA asserted that by only accounting for 0-percent outside air cooling and heating modes, the current efficiency metrics give misleading signals to manufacturers and consumers about what models will decrease energy consumption. NEEA recommended that DOE consider how the market categorizes CUAC and CUHP equipment and ensure that DOE product definitions align with the market and not just what is simplest for regulation. (NEEA, EERE-2022-BT-STD-0015-0013 at p. 6)

During negotiations for the Working Group, the Working Group agreed not to include testing with economizers operating due to test burden and repeatability concerns. (

See

EERE-2022-BT-STD-0015-0048 at pp. 55-57) However, the Working Group agreed to include operating hours and fan energy use associated with economizer operation (reflecting both factory-installed and field-installed economizers). (

See

EERE-2022-BT-STD-0015-0053 at pp. 9, 32) DOE and other participating stakeholders then assessed market data of economizer distribution. Due to the wide distribution of economizers identified through this analysis, all caucuses agreed to include the economizer benefit and energy use in the new integrated cooling metric—IVEC. To ensure representative consideration of economizers in the cooling metric, the calculation for the IVEC metric incorporates both the cooling benefit and energy use associated with the hours of cooling contribution provided in integrated economizing and economizer-only cooling modes. The IVEC metric also includes the energy use associated with cooling season ventilation operation. To determine the breakdown of hours among economizer-only cooling, integrated economizer, mechanical cooling-only, and cooling season ventilation operation for the IVEC metric, the Working Group utilized the previously discussed building modeling of several ASHRAE 90.1 building types and climate zones in which CUACs and CUHPs are installed. DOE has tentatively determined that the proposed inclusion of fan energy for economizing and ventilation operating modes in the IVEC cooling metric—in conjunction with other proposed test condition changes—addresses the concerns previously raised regarding fan energy representation in the efficiency metric, and proposes to adopt the IVEC metric as specified in the AHRI 1340-202X Draft.

e. External Static Pressure Requirements

In the testing of air conditioners and heat pumps, ESP requirements simulate the resistance that the indoor fan must overcome from the air distribution system when installed in real-world installations. Both AHRI 210/240 (

i.e.,

the 2008, 2017, and 2023 versions) and AHRI 340/360 (

i.e.,

the 2007, 2015, 2019, and 2022 versions) specify minimum ESPs for testing based on the unit's rated capacity. Minimum ESPs are specified in Table 7 of AHRI 340/360-2022 and range from 0.10-0.20 inches of water column (in. H

O) for ACUACs and ACUHPs with a rated cooling capacity less than 65,000 Btu/h, and range from 0.2-0.75 in. H

O for all CUACs with cooling capacity greater than or equal to 65,000 Btu/h. These values align with the ESP requirements specified in the current DOE test procedure.

In 2015, the Commercial Package Air Conditioners Working Group recommended that the energy use analysis conducted for the January 2016 Direct Final Rule should use higher ESPs than those specified in the DOE test procedure to help better simulate real-world applications. 81 FR 2420, 2470 (Jan. 15, 2016). Specifically, the Commercial Package Air Conditioners Working Group recommended ESPs of 0.75 and 1.25 in. H

O, which corresponded to the ESPs used in modified building simulations of the cooling load.

Id.

The ESP values recommended by the Commercial Package Air Conditioners Working Group did not vary with capacity. Recommendation #2 of the term sheet developed by the Commercial Package Air Conditioners Working Group suggested that DOE should amend the test procedure for CUACs and CUHPs to better represent the total fan energy use

by considering alternative ESPs. (

See

Document No. 93 in Docket No. EERE-2013-BT-STD-0007 at p. 2) Higher ESPs at the same airflow would result in higher fan power measured during testing and would, therefore, result in fan energy use comprising a larger fraction of total energy use measured during the test.

In the May 2022 TP/ECS RFI, DOE sought data and comment on representative ESPs in the field of all CUACs and CUHPs. 87 FR 31743, 31749 (May 25, 2022). NEEA provided a comment, recommending generally that DOE establish a more representative ESP value for testing all CUACs and CUHPs based on the previous recommendation from the Commercial Package Air Conditioners Working Group. (NEEA, EERE-2022-BT-STD-0015-0013 at pp. 7-8) NEEA noted that the ESP levels used by DOE for the energy use analysis during the last energy conservation standards rulemaking for ACUACs and ACUHPs are two to three times higher than the required ESPs in the existing test procedure.

Id.

NEEA stated that these values were more representative of units in the field due to the ESP used in this test procedure not including the return ductwork pressure loss, which NEEA described as significant because many units do not include return fans.

Id.

The CA IOUs supported updates to the CUAC and CUHP test procedure to improve the representation of fan energy use, particularly by updating the required ESPs in the test procedure. (CA IOUs, EERE-2022-BT-STD-0015-0012 at p. 2) Specifically regarding ESPs, the CA IOUs encouraged DOE to explore California's 2022 Title 24 codes and standards-enhancement effort for air distribution enhancements.

Id.

The CA IOUs, as well as NYSERDA and ASAP and ACEE, recommended that DOE consider alternative ESP values more representative of units in real-world installations. (CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 2; ASAP and ACEEE, EERE-2022-BT-STD-0015-0011, at pp. 1-2; NYSERDA, EERE-2022-BT-STD-0015-0007, at p. 3)

AHRI and Lennox stated that CUACs and CUHPs are designed to cover a range of ESPs, noting that big box retail stores could have an ESP of 0.5 in. H

O and that multi-story offices could exceed ESPs of 2.0 in. H

O. (AHRI, EERE-2022-BT-STD-0015-0008 at pp. 2-3; Lennox, EERE-2022-BT-STD-0015-0009 at p. 2) AHRI noted that the Commercial Package Air Conditioners Working Group agreed to use 0.75 and 1.25 in. H

O for the energy conservation standards energy use analysis.

Id.

AHRI stated that its members were unable to form a consensus position on the issue of representative ESPs for CUACs and CUHPs before the comment period ended; however, AHRI may submit supplementary comments to DOE or a working group if one were to be formed. (AHRI, EERE-2022-BT-STD-0015-0008 at p. 3)

Lennox stated that while its review of data was ongoing regarding a representative ESP recommendation, it found the ESP levels used by the Commercial Package Air Conditioners Working Group to be reasonable. Lennox recommended that the ESPs used for testing increase according to the capacity breaks specified in AHRI 340/360 because ESPs generally increase with product capacity. (Lennox, EERE-2022-BT-STD-0015-0009 at pp. 2-3) Lennox also commented the applied static pressure from ECUACs and WCUACs did not vary from similar air source products and recommended similar values be used for product performance comparison. (

Id.

at p. 3)

Carrier stated that it agreed some adjustments to the ESPs might be appropriate, but that several things need to be reviewed before the ESPs are revised. Carrier also stated that ESPs can vary significantly depending on the application. Specifically, Carrier stated that some applications can use concentric ductwork, where ESPs are likely higher than the current ESPs in AHRI 340/360-2022; and other applications use variable air volume (VAV) systems, which have more extensive ductwork and added pressure drop from terminals. Carrier stated that for larger equipment, the applications are more complex because the equipment is larger and ductwork design can vary based on the building design. Carrier mentioned a general trend that static pressure and ductwork length increase with equipment size, but also mentioned that this depends on the building design, configuration, and system type. Carrier stated that it is in the process of reviewing job design data and applications and will have that data for further discussions once it is received. Additionally, Carrier stated that performing an analysis of the ASHRAE Standard 90.1 fan power budget addendum BO may also provide additional insight to proper static pressure levels. (Carrier, EERE-2022-BT-STD-0015-0010 at p. 7)

In the May 2022 RFI, DOE also sought specific data on ESPs for ECUACs and WCUACs with cooling capacities less than 65,000 Btu/h, as well as feedback on whether a representative ESP value for testing would be 0.5 in H

O (as referenced for air-cooled CUACs <65,000 Btu/h in AHRI 210/240-2023), the range of 0.10 to 0.20 in H

O (from AHRI 340/360-2022), or alternative values. For WCUACs with a cooling capacity of less than 65,000 Btu/h, DOE's preliminary analysis showed that these units may typically be installed above dropped ceilings in commercial buildings. For ECUACs with a cooling capacity of less than 65,000 Btu/h, DOE's preliminary analysis shows that these units are primarily marketed for residential applications, which suggests that it may be appropriate to align the ESP requirements for ECUACs with a cooling capacity of less than 65,000 Btu/ h with those specified for CAC/HPs in 10 CFR part 430, subpart B, appendix M1 (appendix M1) (

i.e.,

0.5 in H

O for conventional units). Therefore, DOE considered whether it was appropriate for the same ESP requirements to be applied for both ECUACs and WCUACs with a cooling capacity of less than 65,000 Btu/h. 87 FR 31743, 31750 (May 25, 2022).

Carrier stated that the ESPs for ECUACs and WCUACs less than 65,000 Btu/h in the field would not be much different than the average values used for the AHRI 210/240-2023 analysis.

Carrier asserted that ESP values in the field might be lower than those ESPs, because some ECUACs and WCUACs with a capacity less than 65,000 Btu/h are applied with short supply ducts and no return ducts or can also be used with concentric ducts. (Carrier, EERE-2022-BT-STD-0015-0010 at pp. 7-8) Lennox recommended the ESP value of 0.5 in H

O from AHRI 210/240-2023 be used for ECUACs and WCUACs with cooling capacity less than 65,000 Btu/h. (Lennox, EERE-2022-BT-STD-0015-0009 at p. 3)

In its comment, Carrier mentioned the “AHRI 210/240-2003 analysis.” Because there is no 2003 version of AHRI 210/240 and the ESP requirements for air-cooled central air conditioners and heat pumps with cooling capacity less than 65,000 Btu/h were updated in AHRI 210/240-2023, DOE interprets the intent of Carrier's comment as referring to AHRI 210/240-2023.

The majority of comments received in response to both the July 2017 TP RFI and May 2022 TP/ECS RFI indicate that higher ESP requirements for testing would be more representative of all CUACs and CUHPs in the field. The ESP requirements included in the ACUAC and ACUHP Working Group TP Term Sheet reflect consensus among Working Group members regarding higher ESP requirements for testing. The AHRI 1340-202X Draft specifies provisions for determining the IVEC and IVHE metrics for double-duct systems, ECUACs, and WCUACs, including higher ESP requirements for testing consistent with

the ACUAC and ACUHP Working Group TP Term Sheet. Because the ACUAC and ACUHP Working Group TP Term Sheet does not include provisions for testing ECUACs and WCUACs, the term sheet does not include ESP requirements for testing equipment with cooling capacity less than 65,000 Btu/h. The AHRI 1340-202X Draft includes an ESP requirement of 0.5 in H

O for testing ECUACs and WCUACs with cooling capacity less than 65,000 Btu/h, which is consistent with the ESP requirement specified in AHRI 210/240-2023 for comparable air-cooled equipment. DOE has tentatively concluded that the ESP requirements specified in AHRI 1340-202X Draft represent industry consensus for testing CUACs and CUHPs and provide a more representative measure of energy efficiency. Therefore, as discussed in sections III.F.4 and III.F.5 of this NOPR, DOE is proposing to adopt the ESP requirements specified in AHRI 1340-202X Draft as part of the IVEC and IVHE metrics.

f. Damper Leakage, Energy Recovery Systems, and Crankcase Heaters

In response to the May 2022 TP/ECS RFI, DOE received several comments recommending that damper leakage, energy recovery systems, and crankcase heaters be addressed in the test procedure for ACUACs and ACUHPs.

NEEA recommended that DOE create a test procedure that accounts for energy losses and gains from auxiliary components, considers energy saved from increased enclosure insulation, and considers variation alongside potentially incorporating CSA P.8,

Thermal efficiencies of industrial and commercial gas-fired packaged furnaces.

(NEEA, EERE-2022-BT-STD-0015-0013, at pp. 2-6) NEEA highlighted the significant energy savings potential of heat recovery ventilation (HRV) and energy recovery ventilation (ERV) systems. NEEA stated that its research indicates such systems can reduce energy use by 24 percent in commercial warm air furnaces in Northwest climate zones. Accordingly, NEEA recommended that energy recovery be incorporated into the test procedure and performance metric for CUACs and CUHPs.

Id.

With regard to insulation, NEEA stated that while building codes such as ASHRAE 90.1 stipulate maximum damper leakage, the requirements do not apply to the resale market, causing a significant number of units available today to have significantly higher leakage rates than code requirements.

Id.

NEEA recommended that DOE investigate the savings potential of increased insulation and account for its benefit across all operating modes in test procedure and efficiency metrics, as non-conditioning operating periods are not currently accounted for.

Id.

NEEA stated that its research indicates that increased enclosure insulation can improve heating season energy savings, and that NEEA expects there would be cooling season savings as well that are not currently accounted for.

Id.

NEEA provided examples of subcomponent performance characteristics that could be used as part of a whole box metric approach, including AHRI 1060 for energy recovery, ANSI/AMCA Standard 500-D-18 for damper leakage, and AHRI 1350 for evaluation of enclosure insulation material and thickness for casing loss.

Id.

NEEA recommended that DOE consider the approach implemented in CSA P.8 to account for different outdoor air configurations, which could be emulated to account for different percentages of ventilation air without adding additional test burden.

Id.

The CA IOUs expressed concern that energy use of equipment components, such as crankcase heaters, is significant and not represented in the IEER metric. (CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 6) The CA IOUs therefore recommended that off-mode and standby energy consumption be accounted for when updating the CUAC/HP test procedure and metric.

Id.

As discussed, the Working Group assessed the impact of energy from additional operating modes, as well as crankcase heaters and controls power, and the metrics recommended in the ACUAC and ACUHP Working Group TP Term Sheet include: (1) in the IVEC metric—economizer-only cooling, cooling season ventilation mode, crankcase heat operation, and controls power in unoccupied no-load cooling season hours; and (2) in the IVHE metric—heating season ventilation mode, crankcase heat operation, and controls power in unoccupied no-load heating season hours. (

See

EERE-2022-BT-STD-0015-0065) Additionally, damper leakage was discussed during the Working Group meetings, and the Working Group ultimately voted not to address this issue in the IVEC and IVHE metrics. (

See

EERE-2022-BT-STD-0015-0055, pp. 7-9) While cabinet insulation and the effects of ERVs and HRVs were discussed during the Working Group discussions, no proposals were made to include them in the new metrics. All members of the Working Group voted to recommend inclusion of the IVEC and IVHE metrics in the DOE test procedure for ACUACs and ACUHPs. DOE has tentatively determined that the issues regarding additional operating modes raised by commenters are adequately addressed by provisions in the ACUAC and ACUHP Working Group TP Term Sheet, and these provisions are also included in the AHRI 1340-202X Draft. Further, at this time DOE lacks clear and convincing evidence to justify proposing any deviations from the IVEC and IVHE metrics specified in AHRI 1340-202X Draft to address damper leakage, cabinet insulation, or ERVs and HRVs. Therefore, DOE proposes to adopt the IVEC and IVHE metrics specified in AHRI 1340-202X Draft in appendix A1.

g. Controls Verification Procedure

In response to the May 2022 TP/ECS RFI, DOE also received several comments regarding recommendations for a controls verification procedure. The CA IOUs, ASAP and ACEEE, and NEEA suggested that DOE consider a controls verification procedure (CVP) in the DOE test procedure. (CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 5; ASAP and ACEEE, EERE-2022-BT-STD-0015-0011, at pp. 2-3; NEEA, EERE-2022-BT-STD-0015-0013, at p. 5) Specifically, the CA IOUs recommended that DOE consider a CVP similar to the one developed for variable refrigerant flow multi-split systems (VRF multi-split systems) to validate that the controls used within CUACs and CUHPs with variable speed compressors are used effectively. (CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 5) ASAP and ACEEE stated that the CVP should include requirements for testing under native controls to better reflect performance of equipment in the field. (ASAP and ACEEE, EERE-2022-BT-STD-0015-0011, at pp. 2-3) ASAP and ACEEE stated that this would mirror the CVP included in the December 2021 test procedure NOPR for VRF multi-split systems (

See

86 FR 70644) and the native control requirement in the residential cold climate heat pump challenge in the September 2021 specifications.

Id.

NEEA recommended that DOE consider a verification procedure to test that economizer controls operate as intended. (NEEA, EERE-2022-BT-STD-0015-0013, at p. 5) Due to what NEEA asserted is a significant energy savings opportunity of economizer cooling if the controls are verified, NEEA recommended that economizers be incorporated into the efficiency metric through a calculation-based approach.

Id.

DOE notes that members from NEEA, ASAP, and the CA IOUs were involved during the Working Group negotiations

and provided input on the included test procedure requirements. The resulting ACUAC and ACUHP Working Group TP Term Sheet does not contain any provisions for a CVP and was agreed upon by all members of the Working Group. As such, DOE believes that the issues raised by these stakeholders are resolved on this matter. Further, commenters did not provide sufficient information that would justify or inform development of a CVP for CUACs and CUHPs, and at this time, DOE lacks clear and convincing evidence to propose any test procedure amendments that deviate from the AHRI 1340-202X Draft to address controls verification.

h. Heating Efficiency Metric

In the May 2022 TP/ECS RFI, DOE stated that it was considering whether incorporating heating performance at temperatures lower than 47 °F would improve the representativeness of the DOE test procedure for ACUHPs, and how such performance would differ between CUHPs with different types of supplementary heat (

e.g.,

electric resistance heat and furnaces) and the climate regions in which CUHPs are typically installed. As such, in the May 2022 TP/ECS RFI, DOE requested comment on data relating to CUHP shipments and typical regions they are shipped to, distribution of heating types shipped with CUHPs, and the lowest outdoor temperatures CUHPs are expected to operate at alongside cut in and cut out temperature data. 87 FR 31743, 31750-31753.

Carrier provided data showing the shipment-weighted market share by building type for CUACs and CUHPs; however, Carrier noted that the actual shipment data by building type would be best obtained from AHRI for the whole U.S. industry. (Carrier, EERE-2022-BT-STD-0015-0010, at p. 13)

In response to the request for comment regarding shipment data of CUHPs, Lennox and the CA IOUs commented that the market for CUHPs is growing alongside electrification efforts, but still represents a small fraction of the overall CUAC and CUHP market. (Lennox, EERE-2022-BT-STD-0015-0009, at pp. 3-4; CA IOUs, EERE-2022-BT-STD-0015-0012, at pp. 4-5) Additionally, Lennox stated that the CUHP market is primarily concentrated in the south and southwestern regions of the country, with the majority located in California and Arizona.

Id.

Lennox acknowledged the importance of CUHP market growth and test procedure improvements but recommended that DOE fully evaluate industry capability and incremental burden associated with test procedure amendments to prevent undue burden.

Id.

NYSERDA noted that in an effort to decarbonize, the Climate Action Council of New York set a 2030 goal that heat pumps should provide space heating and cooling for 10 percent to 20 percent of commercial space statewide, and that heat pumps should become the majority of new purchases for space and water heating by the late 2020s. (NYSERDA, EERE-2022-BT-STD-0015-0007, at pp. 1-2)

Carrier stated that the commercial heat pump market is generally limited to models under 20 tons because the demand for large heat pumps in commercial buildings is currently very small. (Carrier, EERE-2022-BT-STD-0015-0010, at p. 8) Carrier noted that commercial load profiles are significantly different than residential buildings, that commercial buildings have much higher cooling loads than residential buildings, and that commercial buildings tend to operate during the day and are often unoccupied during the evening when temperatures are lower.

Id.

In response to the request for comment regarding the distribution of supplementary heating types shipped with CUHPs, Carrier stated that currently, it only provides CUHPs with electric heat as backup, mostly because the different load profiles in commercial buildings are more cooling intensive. (Carrier, EERE-2022-BT-STD-0015-0010, at p. 8) Carrier also stated that with the growing interest in use of heat pumps in colder climates, it is evaluating the use of backup gas heat.

Id.

Lennox stated that it does not offer CUHP products with factory-installed supplementary electric heat and described the difficulty in tracking field-installed electric heat accessories. (Lennox, EERE-2022-BT-STD-0015-0009, at p. 4) Lennox noted that dual-fuel CUHP products with factory-installed gas furnaces comprise less than 1 percent of the CUHP and CUAC markets but could expand as CUHPs are implemented in climates with heating capacity requirements exceeding current CUHP abilities.

Id.

In response to the request for data on the operating temperatures for CUHPs, AHRI stated that the lowest outdoor temperatures at which CUHPs typically operate in mechanical heating mode would be between 5 °F and 15 °F, and that the cut-out temperature is not dependent on supplementary heat. (AHRI, EERE-2022-BT-STD-0015-0008, at p. 4) AHRI stated that the purpose of supplementary heat is to provide comfort conditions to buildings, and that a compressor cut-out temperature is required to protect equipment.

Id.

Carrier stated that currently, its CUHPs are rated to operate down to −10 °F with a few limited to −5 °F and 0 °F, and that at these very low temperatures, auxiliary electric heat is required. (Carrier, EERE-2022-BT-STD-0015-0010, at p. 8) Carrier also stated that currently, there is no set temperature for mechanical heating lockout.

Id.

Lennox stated that industry compressor cut-out temperatures range from over 15 °F to −15 °F depending on unit design. (Lennox, EERE-2022-BT-STD-0015-0009, at p. 4) Lennox commented that with electric heating, cut-out temperatures are typically set to the lowest available setting, while compressor cut-out temperature is normally more flexible and typically set to a higher temperature with furnace supplementary heating.

Id.

In addition to the data and information provided regarding specific heat pump issues, DOE received recommendations from multiple stakeholders regarding potential new heating efficiency metrics. The CA IOUs encouraged DOE to adopt an updated heating metric to match the expected increase in market share and recommended using a metric that is representative of an average use cycle. (CA IOUs, EERE-2022-BT-STD-0015-0012, at pp. 4-5) Additionally, the CA IOUs expressed support for a seasonal heating metric, similar to HSPF2 for consumer heat pumps, which could account for performance at different ambient conditions, defrost operation, and standby modes.

Id.

The CA IOUs also noted that separate product categories could also be considered, such as for cold-climate CUHPs.

Id.

NYSERDA stated that a heating efficiency metric could utilize heating-specific weighting factors similar to those used in the approach for IEER calculations and could take into account heating mode tests at all three conditions, alongside proposing two new required test conditions. (NYSERDA, EERE-2022-BT-STD-0015-0007, at pp. 1-2) NYSERDA also recommended the new metric utilize fractional heating bin hours for a representative region, and account for the typical load profiles for the 16 DOE commercial prototype buildings.

Id.

Lennox asserted that reasonably designed test procedure amendments could encourage CUHP product improvements in low temperature performance and accelerate market expansion. (Lennox, EERE-2022-BT-STD-0015-0009, at p. 4)

Specifically, NYSERDA, the CA IOUs, and ASAP and ACEEE supported an update to the CUHP heating metric to

account for performance under 17 °F and 5 °F ambient conditions. (NYSERDA, EERE-2022-BT-STD-0015-0007, at pp. 1-2; CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 4; ASAP and ACEEE, EERE-2022-BT-STD-0015-0011, at p. 1) All three groups recommended that DOE incorporate a test at 5 °F as an optional test condition.

Id.

The CA IOUs also recommended accounting for defrost performance, and that DOE track the development of ASHRAE RP-1831 “Validation of a Test Method for Applying a Standardized Frost Load on a Test Evaporator in a Test Chamber with an Operating Conditioning System” to consider whether it can help the development of a test procedure that incorporates defrost performance. (CA IOUs, EERE-2022-BT-STD-0015-0012, at p. 4)

Carrier stated that it is not aware of how many test laboratories in the United States have the capabilities of testing on ACUHPs at low ambient conditions. (Carrier, EERE-2022-BT-STD-0015-0010, at p. 9) Carrier asserted that if DOE were to require testing at lower ambient conditions for ACUHPs, manufacturers and third-party labs may be required to invest substantial capital in psychrometric room upgrades.

Id.

During the Working Group ASRAC negotiations, extensive discussions were held and analyses were conducted on improving the representativeness of the heating metric for ACUHPs by creating a seasonal metric. As a result of these discussions and analyses, Working Group members reached consensus on the IVHE metric to better represent ACUHP energy use across a range of operation conditions, and specified test conditions and procedures for determining IVHE in the ACUAC and ACUHP Working Group TP Term Sheet. The tests for determining IVHE include required and optional tests at varying load levels (

i.e.,

full-load, part-load, and for variable-speed equipment, boost compressor speed) and outdoor air dry-bulb temperatures (specifically 47 °F, 17 °F, and 5 °F). The IVHE metric also accounts for defrost operation by including a defrost degradation coefficient for low-temperature operation (less than 40 °F). DOE has tentatively determined that the IVHE metric included in the ACUAC and ACUHP Working Group TP Term Sheet and the AHRI 1340-202X Draft addresses concerns raised by commenters, and as discussed further in section III.F.5 of this NOPR, DOE is proposing to adopt the IVHE metric as specified in the AHRI 1340-202X Draft in appendix A1.

2. Test Conditions Used for Current Metrics in Appendix A

As discussed, DOE proposes to update the current test procedure for CUACs and CUHPs (which DOE proposes to specify for ACUACs and ACUHPs, ECUACs, and WCUACs in appendix A) to reference the updated industry test standard AHRI 340/360-2022 and retain the current metrics for CUACs and CUHPs. AHRI 340/360-2022 designates certain test conditions for test procedures characterized as “standard rating tests” and certain other test conditions for test procedures characterized as “performance operating tests.” The “standard rating tests” are used for determining representations of cooling capacity, heating capacity, and cooling and heating efficiencies. The “performance operating tests” evaluate other operating conditions, such as “maximum operating conditions” (

see

section 8 of AHRI 340/360-2022), which DOE is not proposing to include in the DOE test procedure. Specifically, Table 6 of AHRI 340/360-2022 specifies test conditions for standard rating and performance operating tests for CUACs and CUHPs. The relevant conditions for EER and IEER cooling tests are those referred to as “standard rating conditions” in AHRI 340/360-2022. To clarify this distinction, DOE proposes to specify explicitly in section 3 of appendix A that the cooling test conditions used for representations as required under the DOE regulations are: (1) for equipment subject to standards in terms of EER, the “Standard Rating Conditions, Cooling” conditions specified in Table 6 of AHRI 340/360-2022; and (2) for equipment subject to standards in terms of IEER, the “Standard Rating Conditions, Cooling” and “Standard Rating Part-Load Conditions (IEER)” conditions specified in Table 6 of AHRI 340/360-2022.

For heating mode tests of CUHPs, Table 6 of AHRI 340/360-2022 includes “Standard Rating Conditions” for both a “High Temperature Steady-state Test for Heating” and a “Low Temperature Steady-state Test for Heating” (conducted at 47 °F and 17 °F outdoor air dry-bulb temperatures, respectively). To clarify which conditions are applicable for representations as required under the DOE regulations, DOE proposes to specify explicitly in section 3 of appendix A that the heating test conditions used for compliance are the “Standard Rating Conditions (High Temperature Steady-state Heating)” conditions specified in Table 6 of AHRI 340/360-2022. Further, DOE proposes to also include the low-temperature (

i.e.,

17 °F) heating test condition specified in Table 6 of AHRI 340/360-2022 (referred to as “Low Temperature Steady-state Heating”) in the proposed test procedure and specify in section 3 of appendix A that representations of COP at this low-temperature heating condition are optional.

3. Test Conditions Used for New Metrics in Proposed Appendix A1

As discussed, DOE is proposing to include the new test procedure recommended in the ACUAC and ACUHP Working Group TP Term Sheet and included in the AHRI 1340-202X Draft in a new appendix A1. This proposal includes adopting the new IVEC and IVHE metrics discussed in sections III.F.4 and III.F.5 of this NOPR.

The AHRI 1340-202X Draft designates certain test conditions for test procedures characterized as “standard rating tests” and certain other test conditions for test procedures characterized as “performance operating tests.” The “standard rating tests” are used for determining representations of cooling capacity, heating capacity, and cooling and heating efficiencies. The “performance operating tests” evaluate other operating conditions, such as “maximum operating conditions” (

see

section 8 of AHRI 1340-202X Draft), which DOE is not proposing to include in the DOE test procedure at appendix A1. Specifically, Table 7 of AHRI 1340-202X Draft specifies test conditions for standard rating and performance operating tests for CUACs and CUHPs. The relevant test conditions for IVEC tests, as well as EER2 representations, are those referred to as “standard rating conditions” in the AHRI 1340-202X Draft. To clarify this distinction, DOE proposes to specify explicitly in section 3 of appendix A1 that the cooling conditions used for representations as required under the DOE regulations are the “Standard Rating Conditions, Cooling” and “Standard Rating Part-Load Conditions (IVEC)” specified in Table 7 of AHRI 1340-202X Draft. Additionally, DOE proposes to include provisions for optional representations of EER2.

For heating mode tests of ACUHPs, Table 7 of the AHRI 1340-202X Draft includes “Standard Rating Conditions, Heating” for three outdoor temperature conditions at 47 °F, 17 °F, and 5 °F. Additionally, the table includes “Standard Rating Part-Load Conditions (IVHE),” which includes optional part load conditions for rating units with the IVHE metric. The required test conditions for IVHE representations are the “Standard Rating Conditions Heating” at 47 °F and 17 °F. The optional test conditions for IVHE

representations are the “Standard Rating Conditions Heating” at 5 °F and “Standard Rating Part-Load Conditions (IVHE)”. To clarify this, DOE proposes to specify explicitly in section 3 of appendix A1 that the heating conditions used for representations as required under the DOE regulations are the “Standard Rating Conditions Heating” at 47 and 17 °F specified in Table 7 of AHRI 1340-202X Draft. Further, DOE proposes to also include the 5 °F heating test condition as well as the part load test conditions specified in Table 7 of AHRI 1340-202X Draft (referred to as “Standard Rating Conditions Heating (5 °F ambient)” and “Standard Rating Part-Load Conditions (IVHE)” respectively) in the proposed test procedure and specify in section 3 of appendix A1 that testing to the low-temperature heating conditions and the part load conditions are optional for representations of IVHE. Additionally, DOE proposes to include provisions for optional representations of COP2

, COP2

, and COP2

at the 47, 17, and 5 °F heating test conditions previously discussed.

4. IVEC

The following section provides a summary of the development and final recommendations regarding the IVEC cooling metric proposals in the ACUAC and ACUHP Working Group TP Term Sheet and DOE's corresponding proposals for inclusion in the appendix A1 test procedure.

As discussed, for the newly proposed cooling metric, the Working Group determined to modify the climate zones and building types accounted for in the test procedure compared to those included in the current DOE test procedure. To do so, the Working Group utilized hour-based weighting factors. To develop these weighting factors, members of the Working Group used building modeling developed by Carrier that was based on 10 ASHRAE 90.1 building prototypes across all U.S. climate zones. (

See

EERE-2022-BT-STD-0015-0019) This resulted in hour-based weighting factors, which are provided in Recommendation #2 of the ACUAC and ACUHP Working Group TP Term Sheet.

The ACUAC and ACUHP Working Group concluded that including economizer-only cooling and cooling season ventilation operating modes in a seasonal cooling metric would improve the representativeness for ACUACs and ACUHPs. Appendix B of the ACUAC and ACUHP Working Group TP Term Sheet provides the recommended calculation method for the IVEC method and includes sections specifying the methods for including ventilation and economizer-only cooling operation in the calculation of IVEC.

As discussed in section III.F.1.e of this NOPR, the Working Group also considered ESP requirements for the newly proposed IVEC and IVHE metrics. Stakeholders indicated the need for higher ESP requirements to improve representativeness of field performance. Additionally, stakeholders discussed the importance of maintaining uniformity in testing of units at higher ESP conditions. (

See

EERE-2022-BT-STD-0015-0062 at p. 11) The ESP requirements agreed to by the Working Group are provided in Recommendation #12 of the ACUAC and ACUHP Working Group TP Term Sheet and include the following:

1. Higher ESP requirements for testing:

As discussed previously, the minimum ESP conditions recommended by the Working Group are provided in Table III.1.

Table III.1—Minimum ESP Requirements for IVEC and IVHE Recommended by the ACUAC and ACUHP Working Group

Rated cooling capacity

ESP

(in H

≥65 and <135 kBtu/h

0.75

≥135 and <240 kBtu/h

1.0

≥240 and <280 kBtu/h

1.0

≥280 and <760 kBtu/h

1.5

2. Economizer pressure drop:

ASHRAE 90.1-2022 requires the use of economizers for comfort cooling applications for almost all U.S. climate zones. The analysis conducted by Carrier in support of the Working Group indicates that over 96 percent of buildings require the use of economizers. Economizers installed in CUACs and CUHPs add internal static pressure that the indoor fan has to overcome, even when the economizer dampers are closed. The current DOE test procedure does not require the installation of an economizer on a tested unit, and DOE is aware that manufacturers generally do not test CUACs and CUHPs with economizers installed. The ESP requirements specified by the current DOE test procedure are the same regardless of whether a unit is tested with or without an economizer. As such, testing a unit without an economizer does not reflect the total static pressure that would be experienced in the field for installations that require the use of an economizer. In order to better represent the fan power of ACUACs and ACUHPs that are typically installed with economizers, the Working Group recommended that for all units tested without an economizer installed, 0.10 in. H

O shall be added to the full load ESP values specified in Table III.1.

3. Return and supply static split requirements:

Test procedures for CUACs and CUHPs include ESP requirements that reflect the total ESP applied within the return and supply ductwork of the test setup. The current Federal test procedure does not specify requirements for how ESP is distributed during testing (

i.e.,

the relative contribution from return ductwork versus supply ductwork). Given the recommendation to increase the required ESP levels for testing (as discussed in section III.F.1.e of this document), the Working Group concluded that the higher ESP conditions could cause variability in test results if the distribution of ESP between return ductwork and supply ductwork were not specified in the revised test procedure. To ensure repeatable and reproducible testing conditions for CUAC and CUHP units, the Working Group recommended specifying that ESP requirements be split with 25 percent applied in the return ductwork and the remaining 75 percent applied in the supply ductwork. The Working Group further recommended that the fraction of ESP applied in the return ductwork shall have a −5/+0 percent tolerance (

i.e.,

the return static must be within 20 to 25 percent of the total ESP) for the full-load cooling test. In a case where there is no additional restriction on the return duct and more than 25 percent of the ESP is already applied in the return ductwork without a restriction, then greater than 25 percent ESP in the return ductwork would be allowed. Once set for the full-load cooling test, these restriction settings shall remain unchanged for the other cooling and heating tests conducted.

To incorporate the various changes involved in testing requirements and weighting factors already discussed, the Working Group created the IVEC metric provided in Recommendation #1 with further specifications in appendix B of the ACUAC and ACUHP Working Group TP Term Sheet. The IVEC metric is essentially a summation formula analogous to the seasonal energy efficiency ratio 2 (SEER2) metric designated for residential central air conditioner (CAC) equipment. (

See

appendix M1 to subpart B of part 430 “Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps”) Specifically, the IVEC metric is calculated by dividing the total annual

cooling capacity by the total annual energy use. Key aspects encompassed in the proposed IVEC metric include the following:

1. Accounting for energy consumed in different modes:

The IVEC metric includes energy use during mechanical cooling, integrated mechanical and economizer cooling, economizer-only cooling, cooling season ventilation, unoccupied no-load hours, and heating season operation of crankcase heat (for CUACs only). Appendix B of the ACUAC and ACUHP Working Group TP Term Sheet specifies instructions for determining energy consumption during each mode.

2. Testing parameters:

The ACUAC and ACUHP Working Group TP Term Sheet further specifies instructions in appendix B for the mechanical cooling tests at each target mechanical load. These methodologies and tolerances mirror those specified in AHRI 340/360-2022, including a 3-percent tolerance on the target mechanical load for part-load tests, and in cases when the target mechanical load cannot be met within tolerance, instructions for using interpolation and cyclic degradation to determine the performance at the target test point.

3. Target load percentages:

Recommendation #4 of the ACUAC and ACUHP Working Group TP Term Sheet includes target conditions for testing, including load percentages for testing units at part-load conditions. For each bin, the specified target load percent (% Loadi) reflects the average load as a percentage of the full-load capacity for that bin met by using all modes of cooling, and is used for determining total annual cooling provided in the numerator of the IVEC equation. The target mechanical load percent (% Loadi, mech) is the average load for each bin met only through mechanical cooling (

i.e.,

mechanical-only cooling and the mechanical portion of integrated mechanical and economizer cooling) and is the target load fraction used for the part-load cooling test for each bin.

As mentioned, the IVEC metric includes the annual operation of crankcase heaters for CUACs and CUHPs. Appendix B of the ACUAC and ACUHP Working Group TP Term Sheet further specifies the accounting of crankcase heater energy consumption in each operating mode. Recommendation #2 of the ACUAC and ACUHP Working Group TP Term Sheet specifies hour-based weighting factors to account for crankcase heat operation in unoccupied no-load cooling season hours for CUACs and CUHPs as well as heating season hours for CUACs. Appendix B of the ACUAC and ACUHP Working Group TP Term Sheet also specifies that for part-load cooling tests, crankcase heat is accounted for in power measurements of higher stage compressors that are staged off during testing, while crankcase heat operation of lower-stage compressors when cycled off as well as crankcase heat operation in other operating modes is calculated using the certified crankcase heater power.

The IVEC metric also accounts for a 15-percent oversizing factor. Accordingly, the target load percentages specified in Recommendation #4 include this 15 percent oversizing factor. Additionally, the A test condition is excluded from the IVEC calculation; however, the A test is still a required test point for determining full load capacity.

IVEC includes outdoor and return air dry-bulb and wet-bulb test temperatures that differ from those used in the current test procedure for determining IEER, as shown in Table III.2.

Table III.2—IEER and IVEC Test Temperatures

Test point

IEER test conditions

Outdoor air dry bulb temperature

(°F)

Return air

temperature

(dry bulb/wet bulb)

(°F)

IVEC test conditions

Outdoor air dry bulb temperature

(°F)

Return air

temperature

(dry bulb/wet bulb)

(°F)

80/67

81.5

80/67

77/64

80/67

77/64

80/67

77/64

The IVEC metric also limits the minimum airflow that can be used for testing. This minimum airflow limit calculation method is based on the average ventilation rate determined in building modeling performed to develop IVEC and is a function of the full-load cooling capacity. Unlike AHRI 340/360-2022 (

see

section 6.1.3.4.5), the provisions for determining IVEC do not specify separate test provisions for setting airflow during part-load tests of MZVAV units. Rather, the part-load airflow used for testing all CUACs and CUHPs would be based on the certified part-load cooling airflow.

Based on the discussions in the Working Group, DOE understands that the changes recommended for the IVEC metric are intended to result in an efficiency metric that is more representative of CUAC and CUHP operation. Therefore, DOE tentatively agrees with the approach recommended by the Working Group and is pro

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