midpage
C. Economic Justification
1. Random Assignment/Monte Carlo Analysis
D. Consumer Furnaces Rule Comment Period
Notes

American Gas Association v. DOEAmerican Gas Association v. DOE

Court of Appeals for the D.C. Circuit
Nov 4, 2025
22-1030
Versions:

United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued November 21, 2024 Decided November 4, 2025

No. 22-1030

AMERICAN GAS ASSOCIATION, ET AL.,

PETITIONERS

v.

UNITED STATES DEPARTMENT OF ENERGY AND CHRIS

WRIGHT, SECRETARY, U.S. DEPARTMENT OF ENERGY,

RESPONDENTS

CITY OF NEW YORK, ET AL.,

INTERVENORS

Consolidated with 23-1285, 23-1337

On Petitions for Review of Final Rules

of the U.S. Department of Energy

Mithun Mansinghani argued the cause for petitioners.

With him on the joint briefs were Michael B. Schon, Renée M.

Lani, Randolph L. Elliott, Samantha L. Fugagli, Drew F.

Waldbeser, Adeline Kenerly Lambert, Michael L. Murray, and

Matthew J. Agen.

Andrew R. Varcoe, Stephanie A. Maloney, Jeremy C.

Marwell, and Nathan Campbell were on the brief for amicus

curiae the Chamber of Commerce of the United States of

America in support of petitioners.

Jonathan Skrmetti, Attorney General, Office of the

Attorney General for the State of Tennessee, J. Matthew Rice,

Solicitor General, Whitney Hermandorfer, Director of

Strategic Litigation, Matthew D. Cloutier, Assistant Solicitor

General; Steve Marshall, Attorney General, Office of the

Attorney General for the State of Alabama, Ashley Moody,

Attorney General, Office of the Attorney General for the State

of Florida; Theodore E. Rokita, Attorney General, Office of the

Attorney General for the State of Indiana; Kris W. Kobach,

Attorney General, Office of the Attorney General for the State

of Kansas; Liz Murrill, Attorney General, Office of the

Attorney General for the State of Louisiana; Andrew Bailey,

Attorney General, Office of the Attorney General for the State

of Missouri; Gentner Drummond, Attorney General, Office of

the Attorney General for the State of Oklahoma; Tim Griffin,

Attorney General, Office of the Attorney General for the State

of Arkansas; Chris Carr, Attorney General, Office of the

Attorney General for the State of Georgia; Brenna Bird,

Attorney General, Office of the Attorney General for the State

of Iowa; Russell Coleman, Attorney General, Office of the

Attorney General for the Commonwealth of Kentucky; Lynn

Fitch, Attorney General, Office of the Attorney General for the

State of Mississippi; Michael T. Hilgers, Attorney General,

Office of the Attorney General for the State of Nebraska; Alan

Wilson, Attorney General, Office of the Attorney General for

the State of South Carolina; Ken Paxton, Attorney General,

Office of the Attorney General for the State of Texas; Patrick

Morrisey, Attorney General, Office of the Attorney General for

the State of West Virginia; and Jason Miyares, Attorney

General, Office of the Attorney General for the

Commonwealth оf Virginia, were on the brief for amici curiae

States of Tennessee, et al. in support of petitioners.

J. Mark Little and Megan H. Berge were on the brief for

amici curiae National Multifamily Housing Council, et al. in

support of petitioners.

Steven H. Hazel, Attorney, U.S. Department of Justice,

argued the cause for respondents. With him on the brief were

Brian M. Boynton, Principal Deputy Assistant Attorney

General, Michael S. Raab, Attorney, and Samuel Walsh,

General Counsel, U.S. Department of Energy. Sarah Carroll

and John Starcher, Attorneys, U.S. Department of Justice,

entered appearances.

Letitia James, Attorney General, Office of the Attorney

General for the State of New York, Jeffrey W. Lang, Deputy

Solicitor General, Brian Lusignan, Assistant Solicitor General,

Morgan Anna Costello, Laura Mirman-Heslin, Timothy

Hoffman, and Christopher Gore, Assistant Attorneys General,

and; Kevin Breiner and Timothy D. Ballo, Earthjustice; Emily

Davis, Natural Resources Defense Council; Andrea Joy

Campbell, Attorney General, Office of the Attorney General

for the Commonwealth of Massachusetts, Turner Smith,

Assistant Attorney General; Muriel Goode-Trufant, Acting

Corporation Counsel, Christopher Gene King, Senior Counsel,

New York City Law Department; Brian L. Schwab, Attorney

General, Office of the Attorney General for the District of

Columbia, Caroline S. Van Zile, Deputy Solicitor General;

Aaron Frey, Attorney General, Office of the Attorney General

for the State of Maine, Robert L. Martin, Assistant Attorney

General; Kwame Raoul, Attorney General, Office of the

Attorney General for the State of Illinois, Elizabeth Dubats,

Assistant Attorney General; Anthony G. Brown, Attorney

General, Office of the Attorney General for the State of

Maryland, John B. Howard, Jr., Special Assistant Attorney

General, Steven Jay Goldstein, Assistant Attorney General;

Keith Ellison, Attorney General, Office of the Attorney

General for the State of Minnesota, Peter Surdo, Special

Assistant Attorney General; Matthew J. Platkin, Attorney

General, Office of the Attorney General for the State of New

Jersey, David Apy, Assistant Attorney General; Aaron D. Ford,

Attorney General, Office of the Attorney General for the State

of Nevada, Heidi Parry Stern, Solicitor General; Raúl Torrez,

Attorney General, Office of the Attorney General for the State

of New Mexico, William Granthan, Assistant Attorney

General, Ellen F. Rosenblum, Attorney General, Office of the

Attorney General for the State of Oregon, Paul Garrahan,

Attorney-in-Charge, Steve Novick, Special Assistant Attorney

General; Robert W. Ferguson, Attorney General, Office of the

Attorney General for the State of Washington, Stephen Scheele,

Assistant Attorney General; and Charity Clark, Attorney

General, Office of the Attorney General for the State of

Vermont, and Hannah Yindra, Assistant Attorney General,

were on the brief for respondent-intervenors.

Jason A. Schwartz was on the brief for amicus curiae the

Institute for Policy Integrity at New York University Sсhool of

Law in support of respondents.

Before: PILLARD, WILKINS, and RAO, Circuit Judges.

Opinion for the Court filed by Circuit Judge WILKINS.

Dissenting opinion filed by Circuit Judge RAO.

WILKINS, Circuit Judge: After the Department of Energy

(“DOE”) promulgated amended energy efficiency standards

for consumer furnaces (residential non-weatherized gas

furnaces and mobile home gas furnaces) and certain

commercial water heaters under the Energy Policy and

Conservation Act (“EPCA”), Petitioners—who are a number

of trade associations, manufacturers, and energy providers—

filed petitions for review in this Court challenging DOE’s

actions. Energy Conservation Program: Energy Conservation

Standards for Consumer Furnaces, 88 Fed. Reg. 87502 (Dec.

18, 2023) (“Consumer Furnaces Rule”); Energy Conservation

Program: Energy Conservation Standards for Commercial

Water Heating Equipment, 88 Fed. Reg. 69686 (Oct. 6, 2023)

(“Commercial Water Heaters Rule”); Energy Conservation

Program for Appliance Standards: Energy Conservation

Standards for Residential Furnaces and Commercial Water

Heaters, 86 Fed. Reg. 73947 (Dec. 29, 2021) (“2021

Interpretive Rule”).

In this consolidated case, Petitioners contend that DOE’s

amended energy efficiency standards will expel

non-condensing consumer furnaces and commercial water

heaters—which they allege offer consumers unique

performance characteristics and features—out of the market

because they will be unable to meet the newly amended energy

efficiency standards, unlike their condensing counterparts.

Petitioners also argue that DOE did not provide adequate

economic justification, as is required by EPCA, before

promulgating the amended efficiency standards. Lastly,

Petitioners allege that DOE failed to adhere to procedural

requirements as provided by EPCA when promulgating the

Consumer Furnaces Rule. Because each of Petitioners’

arguments fail, we deny the petitions.

I. Background

A.

EPCA, amended in 1992, was enacted in order “to provide

for improved energy efficiency1 of . . . major appliances, and

certain other consumer products[,]” among other purposes. 42

U.S.C. § 6201(5). Consumer products such as refrigerators,

freezers, air conditioners, water heaters, furnaces, ovens,

television sets, etc. are “covered products” under EPCA and are

subject to improved energy efficiency standards as authorized

by the Secretary of DOE. Id. §§ 6292(a), 6295(a). As relevant

to this case, DOE was mandated to set energy conservation

standards for consumer furnaces and commercial water heaters

under subsections 6295(f) and 6313(a), respectively.

EPCA also authorizes DOE to make amendments to

energy conservation standards after certain times and

triggering events. Id. §§ 6295(m), 6313(a)(6). For example,

regarding commercial furnaces, subsection 6295(m)(1)

provides that “[n]ot later than 6 years after issuance of any final

rule . . . amending a standard” DOE will either publish a notice

that the standards do not need to be amended, or publish a

notice of proposed rulemaking including the new proposed

standards. A later provision of the statute provides that any

amended energy conservation standard for consumer furnaces

“shall . . . achieve the maximum improvement in energy

efficiency . . . [that] is technologically feasible and

economically justified.” Id. § 6295(o)(2)(A). Likewise, for

commercial water heaters, subsection 6313(a)(6) provides that

DOE will amend efficiency standards to be at least consistent

with the standards set by the American Society of Heating,

Refrigerating and Air-Conditioning Engineers (“ASHRAE”).

2021 Interpretive Rule, 86 Fed. at 73948. If DOE chooses to

apply a more stringent efficiency standard for commercial

water heaters, the standard needs to result in “significant

additional conservation of energy,” and be “technologically

feasible and economically justified” by clear and convincing

evidence. Id. § 6313(a)(6)(A)(ii)(II).

Congress set out several factors for DOE to consider when

determining whether an amended energy standard is

economically justified. The statutes ask DOE to consider:

  • (I) the economic impact of the standard
  • on the manufacturers and on the

    consumers of the products subject to

    the standard;

  • (II) the savings in operating costs
  • throughout the estimated average life

    of the product in the type (or class)

    compared to any increase in the price

    of, or in the initial charges for, or

    maintenance expenses of, the

    products that are likely to result from

    the imposition of the standard;

  • (III) the total projected quantity of energy
  • savings likely to result directly from

    the imposition of the standard;

  • (IV) any lessening of the utility or the
  • performance of the products likely to

result from the imposition of the

standard;

  • (V) the impact of any lessening of
  • competition, as determined in writing

    by the Attorney General, that is likely

    to result from the imposition of the

    standard;

  • (VI) the need for national energy
  • conservation; and

  • (VII) other factors the Secretary considers
  • relevant.

Id. § 6313(a)(6)(B)(ii); see also id. § 6295(o)(2)(B)(i) (same)2

Importantly, and as relevant to this case, DOE may not

prescribe an amended standard if any “interested persons”

establish “by a preponderance of the evidence that [an

efficiency] standard is likely to result in the unavailability in

the United States in any product type (or class) of performance

characteristics (including reliability, features, sizes, capacities,

and volumes) that are substantially the same as those generally

available in the United States.” Id. § 6313(a)(6)(B)(iii)(II)(aa);

see also id. § 6295(o)(4) (“[DOE] may not prescribe an

amended . . . standard . . . if [DOE] finds . . . that interested

persons have established by a preponderance of the evidence

that the standard is likely to result in the unavailability in the

[U.S.] in any covered product type (or class) of performance

characteristics (including reliability), features, sizes,

capacities, and volumes that are substantially the same as those

generally available in the [U.S.] at the time of [DOE’s]

finding.”).3

B.

Before discussing the procedural history of this case, a

brief overview of the mechanics of condensing versus

non-condensing consumer furnaces and commercial water

heaters is necessary. In a non-condensing consumer furnace or

commercial water heater, a heat exchanger burns gas which is

used to heat the air (for furnaces) or water (for water heaters).

The rest of the heated gas, which is not used for the appliance,

is transferred out of a building via an unpowered heat

exchanger, like a vertical chimney. The vents for non-

condensing appliances are “designed to avoid excessive

condensate production in the vent.” Consumer Furnaces Rule,

88 Fed. Reg. at 87563 n.111. In a condensing consumer

furnace or commercial water heater, on the other hand, a

second powered heat exchanger is used to capture the excess

heat not used to heat air or water. This second heat exchanger

turns the excess heat into condensed ‍‌‌‌​‌‌‌‌‌‌‌​‌‌​​‌‌‌‌​​​​​​‌​‌​​​​​​‌​​‌​​‌​‌​​​‌‍water vapor, then transfers

the cooler air out through a fanned horizontal vent and the

liquid condensate out through a drain. This added heat

exchanger makes the condensing appliance more efficient

overall as compared to its non-condensing counterpart.

Additionally, the vents that are used in a condensing appliance

are “corrosion-resistant,” like plastic, id. at 87562–63 & n.111,

and therefore non-condensing appliances and condensing

appliances are unable to share the same vents. Id. at 87536; see

also Commercial Water Heaters Rule, 88 Fed. Reg. at 69710

(same).

On March 12, 2015, DOE published a notice of proposed

rulemaking (“NOPR”) to amend energy conservation standards

for consumer furnaces. In this March 2015 NOPR, “DOE

tentatively concluded that the methods by which a furnace is

vented . . . do not provide any separate performance-related

impacts,” and therefore аre not a “unique utility to consumers

beyond the basic function of providing heat, which all furnaces

perform.” 2021 Interpretive Rule, 86 Fed. Reg. at 73949. After

publishing a notice of data availability, DOE supplemented its

NOPR on September 23, 2016 (referred to as a “SNOPR”),

proposing to establish capacity-based product classes, and

“reiterated its tentative conclusion that methods of venting do

not provide any performance-related utility separate from the

basic function of a furnace.” Id. Separately, DOE published a

NOPR to amend energy conservation standards for commercial

water heaters on May 31, 2016, in which DOE also tentatively

concluded that condensing and non-condensing commercial

water heaters “provide the same hot water” for commercial

consumers and therefore do not require separate equipment

classes. Id. In each of these notices, DOE “proposed

amend[ing] energy conservation standards that would

effectively require [consumer furnaces and commercial water

heaters] . . . to use condensing technology to meet the proposed

amended standards,” and would “effectively eliminate[] all

non-condensing [consumer furnaces and commercial water

heaters] . . . currently on the market.” Id.

On October 18, 2018, Petitioners submitted a petition for

rulemaking to DOE. In it they asked DOE to: (1) issue an

interpretive rule stating that the agency’s proposed energy

conservation standards would result in the unavailability of

“performance characteristics” in consumer furnaces and

commercial water heaters, and (2) withdraw the proposed

energy conservation standards because of that finding. DOE

published the petition and requested public comment.

On July 11, 2019, after considering public comments,

DOE published a notice of a proposed interpretive rule

(“NOPIR”) that non-condensing technology “constitute[s] a

performance-related ‘feature’ . . . that cannot be eliminated

through adoption of an energy conservation standard.” Id. at

73949–50. This was eventually followed by a final interpretive

rule on January 15, 2021, “determining that, in the context of

residential furnaces . . . [and] commercial water

heaters . . . use of non-condensing technology (and associated

venting) constitutes a performance-related ‘feature.’” Id. at

73950. DOE found that the reasons non-condensing

technology offers unique “feature[s]” is because it “(1)

[a]void[s] complex installations in certain locations

constrained by space, existing venting, and availablе drainage;

(2) avoid[s] the encroachment on usable space that would occur

in certain installations; and (3) do[es] not enhance the level of

fuel switching that might accompany standard setting absent a

separate product/equipment class for non-condensing

appliance[s].” Id. Following this final interpretive rule, DOE

withdrew its March 12, 2015, NOPR.

Then, about seven months later, on August 27, 2021, DOE

published another NOPIR where it “re-examined the

conclusions reached in the January 2021” final interpretive

rule. In this August 2021 NOPIR, DOE proposed to “re-instate

its historical interpretation of” “performance characteristics”

and “features” to conclude that “non-condensing technology”

for consumer furnaces and commercial water heaters is “not a

performance-related ‘feature’ for the purpose of the EPCA.”

Id. at 73948, 73950.

On the same day, August 27, 2021, DOE requested

comment on the NOPIR with the comment period scheduled to

close on September 27, 2021. However, after receiving a

request from Petitioners, DOE extended the comment period to

October 12, 2021.

When the comment period closed DOE issued a Final

Interpretive Rule on December 29, 2021. Consistent with its

March 2015 NOPR, September 2016 SNOPR, and May 2016

NOPR, DOE concluded that non-condensing technology in

consumer furnaces and commercial water heaters does not

offer performance-related “feature[s]” as compared to

condensing consumer furnaces and commercial water heaters.

Id. at 73951. DOE once again found that there was no unique

utility to consumers offered by non-condensing technology as

both non-condensing and condensing appliance’s function is to

provide heated air or water. DOE concluded “[u]pon further

consideration” that “utility is determined through the benefits

and usefulness the feature provides to the consumer while

interacting with the product.” Id. Therefore, differences in

cost or complexity of installation “do not make any method of

venting a performance-related feature.” Id. Instead, DOE

explained that those considerations were more appropriate

under its economic justification analysis under

subsections 6295(o)(2)(B)(i) and 6313(a)(6)(B)(ii).

On October 6, 2023, DOE published a Final Rule updating

the efficiency standards for commercial water heaters after

determining the revised efficiency standards “represent[ed] the

maximum improvement in energy efficiency that [was]

technologically feasible and economically justified.”

Commercial Water Heaters Rule, 88 Fed. Reg. at 69687. The

amended efficiency standards for commercial water heaters

were estimated to save 5.6 percent energy usage relative to the

case without amended standards. Id. at 69688. Likewise, on

December 18, 2023, DOE amended energy conservation

standards for consumer furnaces that included residential non-

weatherized gas furnaces and mobile home gas furnaces.

Consumer Furnaces Rule, 88 Fed. Reg. at 87503. DOE

estimated that the amended standards for consumer furnaces

would save 4.77 quadrillion British thermal units (“Btu”),

which represented a 3.2 percent savings if compared to a

scenario without amended efficiency stаndards. Id. at 87504.

Petitioners ask us to vacate DOE’s 2021 Interpretive Rule,

the Commercial Water Heaters Rule, and the Consumer

Furnaces Rule.

II. Analysis

A. Jurisdiction and Standing

We have jurisdiction to review the petitions under 42

U.S.C. sections 6306(b) and 6316. This Court will “hold

unlawful and set aside agency action, findings, and conclusions

found to be . . . arbitrary, capricious, an abuse of discretion, or

otherwise not in accordance with law” or “without observance

of procedure required by law.” 5 U.S.C. § 706(2)(A), (D). We

will not “substitute [our] judgment for that of the agency,”

Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut.

Auto. Ins. Co., 463 U.S. 29, 43 (1983)

, nor will we “supply a

reasoned basis for the agency’s action that the agency itself has

not given.” Id. (citing SEC v. Chenery Corp., 332 U.S. 194,

196 (1947)

). If the “agency [has] examine[d] the relevant data

and articulate[d] a satisfactory explanation for its action

including a ‘rational connection between the facts found and

the choice made’” we will uphold the decision. Id. (quoting

Burlington Truck Lines, Inc. v. United States, 371 U.S. 156,

168 (1962)

); see also Loper Bright Enters. v. Raimondo, 603

U.S. 369, 395–96 (2024)

. The agency must “clearly disclose[]”

“the grounds upon which . . . [it] acted” by substantial evidence.

T-Mobile S., LLC v. City of Roswell, 574 U.S. 293, 301 (2015);

42 U.S.C. § 6306(b)(2) (“No rule under section . . . 6295 of this

title may be affirmed unless supported by substantial

evidence.”).

An association has standing on behalf of its members if at

least one member has standing to sue individually. Sierra Club

v. DOE, 107 F.4th 1012, 1014 (D.C. Cir. 2024)

(citing Hunt v.

Wash. State Apple Advert. Comm’n, 432 U.S. 333, 343 (1977)

).

An association also must show that “the interests it seeks to

protect are germane to the organization’s purpose” and that

“neither the claim asserted nor the relief requested requires the

participation of individual members in the lawsuit.” Hunt, 432

U.S. at 343

.

Petitioners American Gas Association (“AGA”),

American Public Gas Association (“APGA”), and National

Propane Gas Association (“NPGA”) are trade associations.

AGA advocates for natural gas companies and customers;

APGA advocates for publicly owned or operated natural gas

systems; and, NPGA represents various entities in the propane

industry. AGA, APGA, and NPGA have adequately supported

their claim of associational standing in their declarations by

alleging that their members expect to incur economic loss if the

Consumer Furnaces and Commercial Water Heaters Final

Rules are not vacated. They allege that without vacatur their

members will be injured when consumers switch from natural

gas to electric appliances. Pet’rs’ Decl. Addendum at 3–

4 ¶¶ 7–9, 6–7 ¶¶ 6–7, 18–19 ¶¶ 6–8, 31–33 ¶¶ 7–9, 36 ¶¶ 6–8;

see Am. Pub. Gas Ass’n. v. DOE, 72 F.4th 1324, 1336 (D.C.

Cir. 2023)

(holding that petitioners “demonstrated standing

through declarations attesting to their expectations of economic

losses caused by the [f]inal [r]ule that may be remedied by

vacatur of the rule”).

Petitioner Thermo Products, LLC (“Thermo”) is a

manufacturer of gas and oil furnaces and claims its standing to

challenge the 2021 Interpretive Rule and the Consumer

Furnaces Rule is “self-evident.” We agree. A petitioner suffers

an injury in fаct by an agency when the agency promulgates a

regulation that prohibits a petitioner from producing or selling

a product that they would have otherwise been able to produce

or sell. See Energy Future Coal. v. EPA, 793 F.3d 141, 144

(D.C. Cir. 2015)

(holding that petitioners faced an injury in fact

when they “claim that they face a regulatory

impediment . . . that prevents their product from being used as

a test fuel”). Thermo alleges that DOE’s 2021 Interpretive

Rule and Consumer Furnaces Rule will impose standards that

its noncondensing residential furnaces will not be able to meet

or be redesigned to meet. Pet’rs’ Decl. Addendum at 14–

15 ¶¶ 5–7. Thermo claims that as a result it will not be able to

sell non-condensing furnaces, which will cause it to “face

interrupted and possibly lost revenue streams,” “abandon”

product designs “in which it has invested large amounts of

capital,” and reverse changes in its operations. Id. ¶ 7. We also

find that Thermo has demonstrated causation and redressability

by alleging that the loss of sales it may face will be directly

caused by the efficiency standards imposed in the Consumer

Furnaces Rule, and vacating the ‍‌‌‌​‌‌‌‌‌‌‌​‌‌​​‌‌‌‌​​​​​​‌​‌​​​​​​‌​​‌​​‌​‌​​​‌‍rule will redress the alleged

injury. See Energy Future Coal., 793 F.3d at 144.4

(holding that if one

B. Performance Characteristics and Features

Turning to the merits of the petition: We next determine

whether DOE was correct to conclude that non-condensing

appliances offer performance characteristics or features that are

substantially the same as those offered by condensing

appliances. 42 U.S.C. §§ 6295(o)(4),

6313(a)(6)(B)(iii)(II)(aa). We note that DOE’s interpretation

of EPCA does not bind us, but “it may be especially

informative ‘to the extent it rests on factual premises within . . .

[DOE’s] expertise.’” Loper Bright Enters., 603 U.S. at 402

(quoting Bureau of Alcohol, Tobacco and Firearms v. FLRA,

464 U.S. 89, 98, n.8 (1983)

). “Such expertise has always been

one of the factors which may give an Executive Branch

interpretation particular ‘power to persuade, if lacking power

to control.’” Id. (quoting Skidmore v. Swift & Co., 323 U.S.

134, 140 (1944)

).

Congress gave DOE “a degree of discretion” to decide

what constitutes a performance characteristic or feature under

EPCA. Id. at 2263. “The burden of producing evidence and

proving that a[n efficienсy] standard level will result in the

unavailability of certain characteristics, etc., rests on interested

persons asserting the claim of unavailability.” H.R. REP. NO.

100-11, at 23 (1987); 42 U.S.C. §§ 6295(o)(4),

6313(a)(6)(B)(iii)(II)(aa). Petitioners must make this showing

before DOE by a preponderance of the evidence.

We begin with the plain text of the statute. See United

States v. Braxtonbrown-Smith, 278 F.3d 1348, 1352 (D.C. Cir.

2002)

(“In construing a statute, the court begins with the plain

language of the statute.”). All parties, including the dissent,

see Dissenting Op. 8–9, agree that the plain meaning of

“performance characteristics” is broad. The term

“performance” is simply defined as “the execution of an

action,” Performance, MERRIAM-WEBSTER INC. (Ninth New

Collegiate 1985), and “characteristic” is defined as “a

distinguishing trait, quality, or property.” Characteristic,

MERRIAM-WEBSTER INC. (Ninth New Collegiate 1985).

Additionally, “feature” means “the structure, form, or

appearance” and “a prominent part or characteristic.” Feature,

MERRIAM-WEBSTER INC. (Ninth New Collegiate 1985).

The parties agree that the plain text of “performance

characteristic” means a product attribute that provides utility to

consumers desiring to use the product.5 Pet’rs’ Br. 46; Resp’ts’

Br. 26 (performance characteristics “provide a consumer

unique utility during the operation of the appliance”) (quoting

2021 Interpretive Rule, 86 Fed. Reg. at 73955); Oral Arg. Tr.

at 5:11–20 (When asked for his definition of “performance

characteristic” at oral argument, Petitioners’ counsel stated that

it is “a product attribute that provides utility to consumers

desiring to use the product.”). In other words, a performance

characteristic “has to be . . . about using the product,” and

“doesn’t include things unrelated to the performance of the

product,” Oral Arg. Tr. at 5:23-25. Instead, a performance

characteristic is related to “the product[’s] . . . useful output.”

2021 Interpretive Rule, 86 Fed. Reg. at 73955.

Moreover, because every appliance offers a unique

function to consumers, the concept of a feature or performance

characteristic is “very case-specific.” 2021 Interpretive Rule,

86 Fed. Rеg. at 73948. “No single definition could effectively

capture the potential for features across the broad array of

consumer products and commercial equipment subject to

EPCA’s regulatory scheme.” Id. Therefore, because the plain

text of the statute does not get us home, we will look beyond it

to resolve the specific ambiguity here as it relates to consumer

furnaces and commercial water heaters. See Braxtonbrown-

Smith, 278 F.3d at 1352

(“Where the language is subject to

more than one interpretation and the meaning of Congress is

not apparent from the language itself, the court may be forced

to look to the general purpose of Congress in enacting the

statute and to its legislative history for helpful clues.”)

The parties’ dispute centers around the specific ambiguity

of what product attributes of small furnaces and water heaters

Congress concluded had utility to consumers such that they

warrant protection against energy conservation standards that

could eliminate them from the market. Specifically, the parties

dispute whether venting mechanisms, installation factors, or

space-related attributes encompass features that Congress

meant to treat as providing utility to consumers.

Beginning with venting mechanisms: Petitioners contend

that non-condensing appliances, which use unpowered venting

like vertical chimneys, offer performance characteristics to

consumers that condensing appliances do not. According to

Petitioners, condensing appliances are incompatible with

venting systems like chimneys because condensing appliances

require a fan to generate enough pressure to push or pull gases

outside. Pet’rs’ Br. 12. Petitioners further contend that

condensing appliances require plumbing drains to dispose of

condensate and cannot share vents with non-condensing

appliances. Pet’rs’ Br. 13. Petitioners argue that consumers

derive utility from a product by, for example, not “hav[ing] to

renovate their homes,” “to accommodate the use of

[condensing] products for which they were not architecturally

designed.” Oral Arg. Tr. 6:4; J.A. 324.

Congress was well aware of Petitioners’ perspective

regarding venting mechanics for small gas furnaces when it

amended EPCA in 1987. AGA submitted a statement before

the Subcommittee on Energy Conservation and Power in 1986

expressing concern that energy efficiency standards in EPCA

“would ban the conventional, atmospherically vented furnace”

beсause it would not be able to meet the prescribed efficiency

percentage. A Bill to Amend the Energy Policy and

Conservation Act with Respect to Energy Conservation

Standards for Appliances: Hearing on H.R. 5465 Before the

H. Subcomm. on Energy Conservation & Power, 99th Cong.

149 (1986). After hearing Petitioners’ perspective, the

Committee on Energy and Commerce issued the amended

EPCA bill the following year. In it, the Committee provided

that “[e]xamples of ‘performance characteristics’ of particular

products [were]: safety; cooling; refrigeration and heating;

dehumidification; ability to clean or dry without adverse

effects; serviceability; and incidence and cost o[f] repair.”

H.R. REP. NO. 100-11, at 23 (1987). Additionally, “[e]xamples

of ‘features’ [were]: automatic defrost, through the door ice,

size of room air conditioners, and noise levels.” Id. Therefore,

despite AGA’s comments, the Committee did not state that

venting mechanics were examples of performance

characteristics or features for consumer furnaces. However, it

did specifically provide that heat was a performance

characteristic. The dissent does not discuss this part of the

legislative history.

We think the Committee on Energy and Commerce’s

examples make good sense. At a certain level, it is obvious that

consumers do not buy small furnaces or commercial water

heaters because of how the appliance vents. In fact, venting is

a quality that both condensing and non-condensing appliances

share. It “is one of the basic components found in every gas-

fired furnace.” Consumer Furnaces Rule, 88 Fed. Reg. at

87535; see also Commercial Water Heaters Rule, 88 Fed. Reg.

at 69709 (“[V]enting, like a gas burner or heat exchanger, is

one of the basic components found in every gas-fired water

heater (condensing or noncondensing.”). The dissent seems to

overlook this aspect by arguing, without support, that “some

consumers here will be effectively deprived of gas-powered

appliances entirely.” Dissenting Op 12 n.1. This is simply not

true since gas-fired condensing options will still be available to

consumers.

Instead, the unique utility a consumer furnace or

commercial water heater provides to the consumer is that they

either provide hot air or hot water, respectively. If Congress

intended particular methods of venting such as unpowered

venting to be a performance characteristic, it had an

opportunity to clearly state as much—but it did not. See

Mississippi ex rel. Hood v. AU Optronics Corp., 571 U.S. 161,

169 (2014)

(“Had Congress intended . . . [Petitioners’ view of

the statute], it easily could have drafted language to that

effect.”).

This understanding is also consistent with DOE’s

historical view of whether an appliance provides a unique

utility to consumers.6 Take vented and ventless residential

(discussing DOE’s 2020 Final Rule

clothes dryers as an example. In 2011, DOE separated ventless and vented residential clothes dryers into two separate classes because DOE recognized that having a ventless clothes dryer was a unique utility for consumers who live in areas where a vented dryer would not be possible to use (like apartments in certain high-rise buildings). See Energy Conservation Program: Energy Conservation Standards for Residential Clothes Dryers and Room Air Conditioners, 76 Fed. Reg. 22454, 22485 (Apr. 21, 2011). DOE found that “a substantial subset of consumers . . . would be deprived of the benefits of . . . having [a] clothes-drying appliance in their residence entirely unless DOE established a ventless clothes dryers product class.” 2021 Interpretive Rule, 86 Fed. Reg. at 73957. Venting was treated as a performance charaсteristic in the clothes dryer context because the alternative venting option (non-vented) impacted whether a consumer could use or install the particular appliance at all in a large class of applications.7

times in clothes washers and dryers. Cycle times have been understood as “a valuable consumer utility and performance-related feature” in the context of clothes washers and clothes dryers because consumers value the utility of having an option for a shorter cycle time. Energy Conservation Program: Establishment of New Product Classes for Residential Clothes Washers and Consumer Clothes Dryers, 85 Fed. Reg. 81359, 81361 (2020).

Not so with condensing consumer water heaters or furnaces. When DOE had to determine whether consumer water heaters that utilize heat ‍‌‌‌​‌‌‌‌‌‌‌​‌‌​​‌‌‌‌​​​​​​‌​‌​​​​​​‌​​‌​​‌​‌​​​‌‍pump technology versus electric resistance technology should be placed in separate classes, DOE concluded that they did not. See Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Poоl Heaters, 75 Fed. Reg. 20112, 20135 (April 16, 2010). DOE concluded that even though an additional water drain had to be installed if a consumer decides to use a heat pump, that small installation requirement did not change the utility of providing heated water to consumers, and moreover that “heat pump water heaters could replace traditional electric resistance storage water heaters in most residences, although the installation requirements may be quite costly.” Id. So is the case here. DOE found that “[i]n all cases” “consumers facing the prospect of replacing a non-condensing residential furnace or commercial water heater with a condensing . . . [appliance] do have options available to either modify existing venting or install a new venting system to accommodate a condensing . . . [appliance], or to install a feasible alternative.” 2021 Interpretive Rule, 86 Fed. Reg. at 73957.

Next, Petitioners contend that “space-related attributes” are performance characteristics that are “intertwined” with the function of a consumer furnace and a commercial water heater. Pet’rs’ Br. 48–50.

Recall that Petitioners’ burden is a heavy one—they must “establish[] by a preponderance of the evidence that a[n

efficiency] standard is likely to result in the unavailability in the United States in any product type (or class) of performance characteristics (including . . . sizes, capacities, and volumes) that are substantially the same as those generally available in the United States.” 42 U.S.C. § 6313(a)(6)(B)(iii)(II)(aa); see also id. § 6295(o)(4) (same). Substantial evidence in the record before us shows that “interested persons” failed to carry that burden.

In regards to commercial water heaters, DOE explained in the 2021 Interpretive Rule that condensing technology does not “require[] an increase in the overall size of a water heater” and that “a condensing appliance would not result in a loss of useful space for most consumers.” 2021 Interpretive Rule, 86 Fed. Reg. at 73955; see also id. at 73957 n.13 (“DOE surveyed the dimensions of representative commercial water heaters . . . and found the height and diameter dimensions comparable.”). Moreover, after conducting a review of both condensing and non-condensing appliances having similar input ratings and storage volumes from multiple manufactures, DOE found that the “overall dimensions for condensing models were not significantly larger than for non-condensing models.” Id. at 73955. Specifically, DOE found that “non-condensing residential furnaces and commercial water heaters are not significantly different in overall footprint, size, or heating capacity from their condensing counterparts.” Id. at 73957.

Petitioners argue that DOE’s analysis of the space-related characteristics of consumer furnaces and commercial water heaters is inconsistent with how it has analyzed other products like residential condensing and non-condensing furnace fans, washing machines, and central air conditioners. Petitioners argue that the reason Congress separated efficiency stаndards for residential furnace fans used in mobile homes into its own product class, for example, was due to the size constraints that

manufactured homes face. Pet’rs’ Br. 47–55; see Energy Conservation Program for Consumer Products: Energy Conservation Standards for Residential Furnace Fans, 78 Fed. Reg. 64068, 64077 (Oct. 25, 2013). Although Petitioners may be correct that size constraints were one of the factors DOE considered when promulgating efficiency standards for furnace fans used in mobile homes versus those not used in mobile homes, they oversimplify DOE’s analysis. DOE separated furnace fans based on characteristics such as whether the furnace fan was weatherized (meaning that it could be used outdoors), the type of energy source the furnace fan used, and whether the furnace fan was condensing or non-condensing. See Energy Conservation Program for Consumer Products, 78 Fed. Reg. at 64077. DOE explained that it separated these categories based on “internal structure and application-specific design differences that impact furnace fan energy consumption.” Id. Specifically for condensing furnaces, DOE explаined that the separate fan class structure “allow[ed] for differentiation of products with designs that achieve higher thermal efficiency but may have lower fan performance.” Id. at 64080. Therefore, unlike space-related attributes of consumer furnaces and commercial water heaters, the design of mobile home furnace fans is directly related to performance requirements of the particular product.

Petitioners also point to front-loading and top-loading washing machines to support their contention that size and installation limits are “performance characteristics.” Pet’rs’ Br. 48; Energy Conservation Standards for Residential Clothes Washers, 84 Fed. Reg. 37794 (Aug. 2, 2019). However, unlike condensing and non-condensing consumer furnaces and commercial water heaters, washing machine capacity has a direct impact on efficiency levels and “the location of access” to a washing machine “provides distinct consumer utility.” Energy Conservation Standards for Residentiаl Clothes

Washers, 84 Fed. Reg. at 37797. For example, front-loading washers may be preferable to those with disabilities because the angle may be easier to access, whereas top-loading washers may be preferred by the elderly “because it is easier to reach the laundry without excessive bending” or those who appreciate the ability to add more clothes while the cycle has already begun. 2021 Interpretive Rule, 86 Fed. Reg. at 73953. In contrast, “a consumer’s interaction with a furnace or water heater . . . [is] a simple one.” Id. “After the consumer adjusts the thermostat or faucet, the user receives the requested heated air or water.” Id.

Likewise, Petitioners’ argument regarding Congress’s decision to separate “space-constrained central air conditioners” from other central air conditioners misses the point. DOE explained that it separated these two product classes because “space-constrained central air conditioners prоvide centralized air conditioning in locations with space constraints that would preclude the use of other types of central air conditioners.” Id. at 73957. “Space-constrained central air conditioners have an indoor or outdoor unit that is limited in size due to the location in which the unit operates.” Id. This explanation does not mean that space-related attributes always will dictate whether a product should be separated into its own product class, however.8 As DOE explained, when it came to

analyzing non-condensing consumer furnaces and commercial water heaters, it found that they were “not significantly different in overall footprint, size, or heating capacity from their condensing counterparts.” Id.

Lastly, as to installation factors: DOE recognized that “installation of condensing products/equipment [sometimes] requires modifications to the installed space . . . and that such modifications may impact the installation cost and/or complexity.” Id. at 73962. Because DOE found that consumers are able to replace non-condensing appliances with condensing appliances in “all cases,” we agree that installation factors are more appropriately addressed in the economic-justification analysis because installation factors will not prevent the replacement of non-condensing appliances, but may financially deter consumers from doing so. See id. at 73957. The language of subsections 6295(o)(4) and 6313(a)(6)(B)(iii)(II) bolster this reasoning because neither includes a reference of “installation factors” or “installation costs” as a factor that Congress was concerned about as it relates to the unavailability provisions in EPCA. However,

subsections 6295(o)(2)(B)(i)9 and 6313(a)(6)(B)(ii)10 more appropriately capture a consideration of the installation costs and factors under the “economic impact” and the “initial charges for” the products on consumers.

In sum, the record fails to support Petitioners’ claim that condensing consumer furnaces and commercial water heaters are not “substantially the same” as their non-condensing counterparts. We have no reason to second-guess DOE’s view, “especially since it ‘rests on the agency’s evaluations of scientific data within its area of expertise.’” Actavis Elizabeth LLC v. FDA, 625 F.3d 760, 766 (D.C. Cir. 2010) (quoting

Serono Labs., Inc. v. Shalala, 158 F.3d 1313, 1320 (D.C. Cir. 1998)). We find that, although not identical, condensing consumer furnaces and commercial water heaters offer substantially the same performance characteristics and features as non-condensing options. 42 U.S.C. §§ 6295(o)(4), 6313(a)(6)(B)(iii)(II)(aa); see H.R. REP. NO. 100-11, at 23 (1987) (explaining that “substantially the same” does not mean “identical”). We are satisfied that DOE has “fulfilled its duty to ‘examine the relevant data and articulate a satisfactory explanation for its’” conclusion that Petitioners failed to show, by a preponderance of the evidence, that non-condensing consumer furnaces and commercial water heaters offer performance characteristics that are unlike those offered by their condensing counterparts. Ark Initiative v. Tidwell, 816 F.3d 119, 127 (D.C. Cir. 2016) (quoting State Farm, 463 U.S. at 43).

C. Economic Justification

We next determine whether DOE acted arbitrarily in concluding that the amended standards for consumer furnaces and commercial water heaters were economically justified. DOE must show that its amended efficiency standards in the Consumer Furnaces Rule are supported by substantial evidence—a burden common to actions we review under the Administrative Procedure Act. 42 U.S.C. § 6306(b)(2); see Biestek v. Berryhill, 587 U.S. 97, 102 (2019) (“The phrase ‘substantial evidence’ is a ‘term of art’ used throughout administrative law to describe how courts are to review agency factfinding.” (quoting T-Mobile S., LLC, 574 U.S. 293, 301 (2015))). However, the energy efficiency standards in the Commercial Water Heaters Rule must be economically justified “by clear and convincing evidence.” 42 U.S.C. § 6313(a)(6)(A)(ii)(II). “[C]lear and convincing evidence requires . . . the Secretary . . . to have an ‘abiding conviction’ that her findings

. . . are ‘highly probable’ to be true. APGA v. DOE, 22 F.4th 1018, 1025 (D.C. Cir. 2022) (“APGA I”) (quoting Colorado v. New Mexico, 467 U.S. 310, 316 (1984)). Our review, even under the clear and convincing standard, is to determine whether it was reasonable for the agency to conclude that it met this standard. Id. at 1025–26 (citing Sea Island Broad. Corp. of S.C. v. FCC, 627 F.2d 240, 244 (D.C. Cir. 1980)).

1. Random Assignment/Monte Carlo Analysis

Petitioners take issue with the widely used random assignment test (also known as Monte Carlo analysis) that DOE utilized as part of the economic analysis for the amended efficiency standards for both the Consumer Furnace Final Rule and the Commercial Water Heater Final Rule. Petitioners argue that DOE relied on an assumption that consumers make appliance purchases randomly without weighing economic benefits, and that DOE failed to give a reasoned explanation for doing so.

The random assignment test or Monte Carlo analysis is used across industries ranging from physical sciences to high finance. Lyondell Chem. Co. v. Occidental Chem. Corp., 608 F.3d 284, 293 (5th Cir. 2010). It was first used a little under a century ago by physicists conducting nuclear weapons research. Id.; see also AT&T Svs., Inc. v. FCC, 21 F.4th 841, 847 (D.C. Cir. 2021) (noting that Monte Carlo analysis was “[d]eveloped by scientists working on the Manhattan Project”). This methodology is “particularly useful when reaching an exact numerical result is impossible or infeasible and the data provide[s] a known range—a minimum and a maximum, for example—but leave[s] the exact answer uncertain.” Lyondell Chem. Co., 608 F.3d at 293. A random assignment test or Monte Carlo analysis “runs hundreds of simulations, and produces a range of possible outcomes.” AT&T Svs., Inc., 21

F.4th at 847. This type of analysis “can provide a ‘more complete view of potential outcomes and their associated likelihoods.’” Id. (quoting FED. JUDICIAL CTR. & NAT’L RSCH. COUNCIL, REFERENCE MANUAL ON SCI. EVIDENCE 469 (3d ed. 2011)). The Environmental Protection Agency has explained that Monte Carlo analysis can be a “viable statistical tool[] for analyzing variability and uncertainty in risk assessments.” Lyondell Chem. Co., 608 F.3d at 293 (quotation omitted) (citing EPA, GUIDING PRINCIPLES FOR MONTE CARLO ANALYSIS, EPA/630/R-97/001, at 1 (1997)).

The random assignment test is not new to either AGA or DOE. This Court recently considered the issue of whether DOE arbitrarily conducted its life-cycle cost (“LCC”) analysis when it randomly assigned commercial packaged boilers to buildings without weighing the kind of building the boiler was being assigned to. APGA I, 22 F.4th at 1027. When DOE conducted its no-new-standards case analysis, it assumed that “the distribution of efficiencies among shipped boilers [was] the same as the distribution of efficiencies across the models listed in the [Air-Conditioning, Heating, and Refrigeration Institute (“AHRI”)] data base.” Id. APGA and other petitioners contended that DOE “failed to recognize that a purchaser of commercial packaged boilers would rationally consider the costs and benefits of its investment and is likely to buy the boiler that produces the best economic performance for its building.” Id.

Instead of explaining its analysis, DOE “rather dismissively” explained that it did not have the data that would be necessary to run an alternative analysis to the one it conducted. Id. Additionally, DOE listed possible market failures that its LCC analysis addressed, but did not provide evidence to show that the market failures it listed affected the market for commercial packaged boilers. Id. We remanded

the case back to DOE, without vacatur, and ordered DOE to provide a “more complete response” since the “assignment of efficiencies to the buildings in the sample was a crucial part of the analysis supporting the DOE’s conclusion that a more stringent [energy efficiency] standard was warranted.” Id. We held that DOE’s response that it “essentially . . . did the best it could with the data it had” was “not enough to justify [an] assum[ption that] a purchaser’s decisions w[ould] not align with its econоmic interests in purchasing a boiler.” Id. Therefore, we could not conclude that DOE’s amended efficiency standards were supported by clear and convincing evidence under subsection 6313(a)(6)(A)(ii)(II). Id. at 1028.

This Court did not discredit, nor decide, that the random assignment test should not have been used in DOE’s LCC analysis in APGA I. Instead, we merely ordered DOE to go back and provide more reasoned explanations for its analysis and respond to the petitioners’ concerns. The case before us is unlike what we considered in APGA I. DOE’s LCC here was “the sum of the purchase price of a piece of equipment (including its installation and sales tax) and the operating expense (including energy, maintenance, and repair expenditures) discounted over the lifetime of the equipment.” Commercial Water Heaters Rule, 88 Fed. Reg. at 69704; Consumer Furnaces Rule, 88 Fed Reg. at 87528 (same). To calculate the LLC, DOE needed a “variety of inputs, such as product prices, product energy consumption, energy prices, maintenance and repair costs, product lifetime, and discount rates appropriate for consumers.” Commercial Water Heaters Rule, 88 Fed. Reg. at 69704; Consumer Furnaces Rule, 88 Fed Reg. at 87528 (same).

DOE used real-world historical data for its inputs which included the highest quality summary statistics submitted by interested persons as well as data submitted by individual

households. Consumer Furnaces Rule, 88 Fed. Reg. at 87555. The data used correlated inputs to “individual building characteristics” such as “heating load, building shell indices, installation costs, and no-new-standards case efficiency probability.” Id.; see also Commercial Water Heaters Rule, 88 Fed. Reg. at 69731 (explaining that in relation to commercial water heaters DOE’s analysis captured the average hot water loads on equipment, but did not necessarily capture extremes). “DOE develop[ed] probabilities for as many inputs to the LCC analysis as possible, to reflect the distribution of impacts as comprehensively as possible.” Consumer Furnaces Rule, 88 Fed. Reg. at 87555; see also Commercial Water Heaters Rule, 88 Fed. Reg. at 69731 (same). It also developed sensitivity scenarios “to specifically address the potential uncertainty in some key input parameters.” Consumer Furnaces Rule, 88 Fed. Reg. at 87555. Contrary to Petitioners’ argument, DOE included “an increasing penetration of condensing furnaces” into its analysis based on the trend that consumers are progressively purchasing condensing furnaсes and water heaters even without new standards. Consumer Furnaces Rule, 88 Fed. Reg. at 87556; Pet’rs’ Br. 75–77. DOE then responded to comments from interested persons and provided “additional sensitivity scenarios to demonstrate that its conclusions of economic justification [were] robust.” Consumer Furnaces Rule, 88 Fed. Reg. at 87555.11

Petitioners’ argument—that DOE did not provide a reasoned explanation for assuming that consumers sometimes

do not act in their best economic interest—is not supported by the record before us. The dissent seems to take this even farther by contending that DOE “assumed consumers never consider costs when choosing between gas-fired appliances.” Dissenting Op. 15 (emphasis in original). But this is once again simply not true. See e.g., Consumer Furnaces Rule, 88 Fed. at 87584 (“DOE [did] not mak[e] an assumption that consumers never consider the economics of their purchasing decision.”).

Although DOE’s burden for the Commercial Water Heaters Final Rule was a high one—clear and convincing evidence—there is substantial evidence in the record to show that they met the mark. In order “[t]o accurately estimate the share of consumers that would be affected by a potential energy conservation standard,” DOE analyzed the LCC of commercial water heaters “under the no-new standards case (i.e., the case without amended or new energy conservation standards).” Commercial Water Heaters Rule, 88 Fed. Reg. at 69757.

“DOE developed the no-new-standards distribution of equipment using data from DOE’s Compliance Certification database and data submitted by AHRI regarding condensing versus non-condensing equipment.” Id. DOE then assigned a commercial water heater to each building it had in its sample based “on the forecasted efficiency distribution (which is constrained by the shipment and model data collected by DOE and submitted by AHRI) and accounts for consumers that [we]re already purchasing efficient” commercial water heaters. Id.

Specifically, regarding Petitioners’ concern that DOE used data which suggests that consumers do not act in their best economic interest—DOE explained that disregarding that data “would not be representative of the [commercial water heater] market. Commercial Water Heaters Rule, 88 Fed. Reg. at 69760. DOE “took into account all of the available data

concerning the market implementation of condensing natural gas-fired [commercial water heater] equipment.” Id. at 69757. From this data, DOE projected commercial water heater shipments by efficiency level over the analysis period. Id. “[B]ased on the presence of well-understood market failures and a corresponding lack of data showing a correlation between [commercial water heater] efficiency and building hot water load,” DOE concluded that “a random assignment of efficiencies best accounts for consumer behavior in the” commercial water heater market. Id. at 69758. DOE explained that it “is aware of multiple market failures that prevent [] purely economic decision making[,]” and random assignment “reflect[s] the full range of consumer behaviors, including those consumers who make purely economic decisions.” Id. Therefore, the dissent’s argument that the random assignment test never accounts for costs is simply not supported by the record and misunderstands the inputs to the analysis.

Even for large economic purchases, like the purchase of a commercial water heater, DOE “acknowledge[d] that economic factors play a role” but that an analysis “based solely on economic measures . . . most likely would not fully and accurately reflect actual real-world installations.” Id. DOE reasoned that consumers make decisions based on factors like the timing of the purchase, competing demands for the funds, loss aversion, sensitivity to information salience, and other forms of bounded rationality. Id. (citing Richard H. Thaler & Shlomo Bernartzi, Save More Tomorrow: Using Behavioral Economics ‍‌‌‌​‌‌‌‌‌‌‌​‌‌​​‌‌‌‌​​​​​​‌​‌​​​​​​‌​​‌​​‌​‌​​​‌‍to Increase Employee Saving, 112 J. OF POL. ECON. S164, S164–S187 (2004) (Nobel laureate Richard H. Thaler’s work on behavioral economics)). These factors are amplified when the decisions involved are complex and infrequent—like

purchasing water heaters for commercial buildings. Id. at 69758–60.12

We also find that DOE’s explanation regarding why consumers may not always act in their best economic interest when purchasing consumer furnaces was also reasonably explained and supported by substantial evidence in the record. First, DOE explained that Petitioners’ contention is a “significant[] mischaracteriz[ation]” of DOE’s analysis. Consumer Furnaces Rule, 88 Fed. Reg. at 87580. DOE similarly analyzed the LCC of consumer furnaces under the “no-new-standards case.” Id.. at 87574–80. DOE “estimate[d] not only the expected market share of products at varying efficiencies, but also estimate[d] how such products will be used.” Id. at 87574. DOE used a base case that “reflect[ed] three analytical steps: (1) an estimate of the buildings likely to use furnaces, (2) an estimate of the efficiency of the furnaces that would be sold absent the rule; and (3) the matching of particular furnace efficiencies with particular building types.” Id. Each building in the sample was then assigned a furnace at a state level and a building specific level. Id. at 87576. DOE once again concluded that “[r]andom assignment of efficiencies reflects the full range of consumer behaviors in th[e] market, including consumers who make economically beneficial decisions and consumers that, due to market failures, do not.” Id. at 87574. The random assignment method “simulate[d] behavior in the furnace market, where market failures result in purchasing decisions not being perfectly aligned with economic interests, and it d[id] so more realistically than relying only on apparent cost-

effectiveness[.]” Id. at 87576. In other words, the random assignment method accounts for the fact that consumers do sometimes base decisions on cost-effectiveness. DOE considered available data to determine whether any modifications needed to be made. Id. at 87574–75. This data included historical information about shipments of condensing and non-condensing furnaces in various regions around the country, and accounted for the fact that consumers are already purchasing furnaces at higher efficiency levels. Id. at 87575.

Petitioners contend that DOE “assum[ed] rationality is not the typical behavior” for consumers, Pet’rs’ Br. 74 (emphasis omitted), but the record shows that DOE once again acknowledged that economic factors “play a role” when consumers purchase furnaces, but that an economic analysis “based solely” on life-cycle costs or payback periods “would not fully and accurately reflect actual real-world installations.” Consumer Furnaces Rule, 88 Fed. Reg. at 87576. Instead, DOE took market failures into account because it could not “assume that all purchasers of furnaces make economically rational or irrational decisions one-hundred percent of the time.” Id. For example, DOE responded that Petitioners’ approach “depends on the assumption . . . that homeowners [always] know . . . the efficiency of their homes’ insulation and windows, such that they always make heating investments accordingly.” Id. at 87580. DOE explained that that assumption would not be realistic and is “unsupported by the available evidence.” Id. at 87576. Therefore, the random assignment “methodology is not an assertion of еconomic irrationality, but instead, it is a methodological approximation of complex consumer behavior.” Id. at 87580.

Petitioners also contend that DOE assumed that “new homebuilders routinely act against their own economic interest” and that consumers do not purchase furnaces

depending on the type of climate they are in. Pet’rs’ Br. 78, 82–83. Both contentions are contradicted by the record before us. DOE’s analysis did “incorporate and reflect regional market share data.” Consumer Furnaces Rule, 88 Fed. Reg. at 87581. DOE explained that “[f]or States with a large majority of consumers already purchasing more-efficient furnaces[,] . . . the analysis assign[ed] a correspondingly large majority of households with an efficient furnace at or above the adopted efficiency level in the no-new-standards case.” Id. For example, states with colder weather have a higher market share of condensing furnaces because they are more efficient, and therefore less costly to run. Further, DOE’s analysis also included “a greater probability that new construction is assigned higher-efficiency furnaces in the no-new-standards case, given the typically lower installation costs in new construction.” Id.

The dissent responds with two contentions: (1) DOE provided no explanation on why its model reflected that, in some cases, consumers would choose to install a condensing furnace in a building where it would have been cheaper to install a non-condensing furnace; and (2) DOE “provide[d] no rebuttal to petitioners’ expert” who argued that the random assignment model “assigned a more expensive option to new buildings . . . and to existing homeowners” most of the time. Dissenting Op. 18–19. But, DOE did address the dissent’s concerns and adjusted its model based on new construction vs. replacement installations. Consumer Furnaces Rule, 88 Fed. Reg. at 87582. As noted supra, DOE explained its model reflected real-world data which included “the State-level shipments market share data.” Id. at 87584. “For example, in States with a low current market share of condensing furnaces, the [model was] constrained to assign mostly non-condensing furnaces in the no-new-standards case, reflecting the current market[.]” Id. Therefore, instead of making assumptions

devoid of data, DOE used the entirety of the data at its disposal to conduct its analysis. Further, to respond to commenters who argued that DOE’s analysis produced an illogical outcome, DOE reiterated that the analysis “simply reflect[ed] the reality of the current market.” Id. And even so, DOE explained that this outcome was “limited to only a few percent [of cases predominately] in new construction.” Id. Further, “[e]ven if DOE were to exclude these . . . outcomes as extreme outlier results, the LCC analysis would [still] demonstrate economic justification[.]” Id.

Another reason the present case is unlike the random assignment analysis conducted by DOE in APGA I is that DOE considered all the scientific literature relevant to its LCC analysis, and all data submitted in the course of the rulemaking for both the Consumer Furnaces Final Rule and the Commercial Water Heaters Final Rule. Id. at 87580; Commercial Water Heaters Rule, 88 Fed. Reg at 69758–59. DOE cited the availаble literature it was aware of, and repeatedly requested more data from interested persons. Consumer Furnaces Rule, 88 Fed. Reg. at 87580–81. Despite Petitioners’ disagreement, they provided DOE with no alternative “specific external data, information, or studies that could be incorporated into [DOE’s] analysis.” Id. at 87581; see also Consumer Water Heaters Rule, 88 Fed. Reg. at 69699. Further, regarding installation costs, DOE responded to comments by interested persons by “enhanc[ing]” its estimates “a number of times” to address the comments. Consumer Furnaces Rule, 88 Fed. Reg. at 87555.

Overall, we find that DOE’s economic justification analysis and conclusions were robust. The economic justification analysis independently and sufficiently supported DOE’s conclusion that the amended efficiency standards were economically justified, and we need not address the impacts of

fuel switching in DOE’s analysis. This is so for two main reasons: (1) “[t]he amended standards plainly do not compel fuel switching” since the Final Rules do “not ban gas” appliances; and (2) DOE concluded that even if the impacts of fuel switching were not included in its economic justification analysis, the amended standards would still be economically justified. Id. at 87590, 87595; Commercial Water Heaters Rule, 88 Fed. Reg. at 69771–72.

D. Consumer Furnaces Rule Comment Period

Lastly, Petitioners contend that DOE did not provide a meaningful opportunity for stakeholders to comment on the Consumer Furnaces Rule, and therefore the Rule is procedurally flawed.

On July 7, 2022, DOE published a NOPR and request for comment on the proposed energy conservation standards for consumer furnaces. Energy Conservation Program: Energy Conservation Standards for Consumer Furnaces, 87 Fed. Reg. 40590 (July 7, 2022). DOE asked that any “comments, data, and information regarding th[e] NOPR” be submitted “no later than September 6, 2022.” Id. at 40590. In its analysis of the impact that the amended or new efficiency standards would have, DOE used “Monte Carlo simulations to incorporate uncertainty and variability into the analysis” by “randomly sampl[ing] input values from probability distributions” and gas furnace “user samples.” Id. at 40627. To implement this, DOE used an add-on tool in Microsoft Excel called Crystal Ball™, which is a “commercially-available software tool” that can “facilitate the creation of” randomized models “by generating probability distributions and summarizing results within Excel.” Id. n.86. Each time that Excel is opened with the Crystal Ball™ add-on, it produces a slight variation in the data generated. So, when DOE published its LCC spreadsheet

accompanying the NOPR, it “inadvertently” used a version of the LCC spreadsheet that showed a slight variation of what was included in the published NOPR and an accompanying Technical Support Document (“TSD”), although the results shown in the spreadsheet were similar to those included in the NOPR and TSD. Energy Conservation Standards for Consumer Furnaces, 87 Fed. Reg. 52861, 52862 (Aug. 30, 2022).

After interested parties, including Petitioners, alerted DOE that the spreadsheet varied from the table results included in the NOPR and TSD, DOE issued a Notification of Data Availability (“NODA”) in which DOE published a revised version of the LCC spreadsheet that was static and supported the NOPR. DOE also extended the NOPR comment period an extra thirty-days to October 6, 2022, and announced that it would hold—at Petitioners’ request—a public meeting webinar workshop where it would “provide instruction on the operation of the LCC spreadsheet.” Id. In total, DOE provided interested pаrties ninety-days to comment on the Consumer Furnaces Rule.

Nonetheless, Petitioners contend that the ninety-days was a “break-neck” comment period. Pet’rs’ Br. 104. We cannot agree. 42 U.S.C. subsection 6295(p)(2) provides that DOE shall “afford interested persons an opportunity, during a period of not less than 60 days, to present oral and written comments . . . on matters relating to” proposed new or amended energy conservation standards. Petitioners acknowledge this sixty-day statutory requirement, but contend that DOE “promise[d] that stakeholders w[ould] have at least 75 days to comment on proposed rulemaking” as was provided

in DOE regulations at the time.13 Pet’rs’ Br. 102; see 10 C.F.R. pt. 430, subpt. C, app. A(6)(b)(2) (2022). But as Petitioners acknowledge in their briefing, the seventy-five-day allotment provided in the appendix to the regulation did “not intend[] to, and [did] not, create any right or benefit, substantive or procedural” that DOE was required to adhere to. 10 C.F.R. pt. 430, subpt. C, app. A(3)(c) (2022). It was only required to provide at least sixty days for interested parties to comment—which it did. Moreover, the regulation expressly authorized DOE to “deviate” from the 75-day period for comments if DOE found it “necessary or appropriate” and provided “notice of the deviation and an explanation.” Id. pt. 430, subpt. C, app. A(3)(a) (2022). DOE explained in the NOPR that it was “necessary and appropriate” to only provide the statutory minimum for comments in this NOPR because DOE was facing “an overdue statutory deadline” and the “analytical methods used . . . [in the] NOPR [were] similar to those used in previous rulemaking notices.” Energy Conservation Standards for Consumer Furnaces, 87 Fed. Reg. at 40607.

Moreover, because the static spreadsheet DOE provided the public on August 30, 2022, did not amount to “critical factual material,” it was not necessary to extend the comment period past the thirty-days it already provided. See Chamber of Com. v. SEC, 443 F.3d 890, 900 (D.C. Cir. 2006) (“[F]urther notice and comment are not required when additional fact gathering merely supplements information in the rulemaking record by checking or confirming prior assessments without changing methodology, [or] by confirming or corroborating data in the rulemaking record.” (citations omitted)). This is becausе, as DOE explained, its Monte Carlo analysis utilized

random number generation, where the sequence of random numbers was expected to change, but “[t]he relative comparison of the various proposed energy conservation standard levels in the published LCC spreadsheet remain[ed] similar to the comparison presented in the NOPR.” Energy Conservation Standards for Consumer Furnaces, 87 Fed. Reg. at 52862. Therefore, DOE’s “conclusions of the analysis, the policy decision, and associated rationale [we]re not impacted by [the] sampling variability” in the two different LCC spreadsheets. Id.

III.

Because each of Petitioners’ arguments fail for the reasons explained, the petitions are denied.

So ordered.

Notes

1
“The term ‘energy efficiency’ means the ratio of the useful output of services from a consumer product” or an article of industrial equipment “to the energy use of such product” or article. 42 U.S.C. § 6291(5); 2021 Interpretive Rule, 86 Fed. Reg. at 73955.
2
Although the language of these subsections varies slightly, the parties agree that they are not materially different for the issues raised in this case. Pet’rs’ Br. 9; Resp’ts’ Br. 4 n.1.
3
Again, although the phrasing of the subsections are not identical, the parties concede that the two sections are materially similar for the issues raised in this case. Pet’rs’ Br. 9–10, 45; Resp’ts’ Br. 4 n.1.
4
Because we conclude that AGA, APGA, NPGA, and Thermo have standing, we need not address Spire Inc., Spire Alabama Inc., and Spire Missouri Inc.’s standing. See Ams. for Safe Access v. Drug Enf’t Admin., 706 F.3d 438, 443 (D.C. Cir. 2013) petitioner “has individual standing, we need not address the issue for the other [p]etitioners”).
5
It seems that the dissent would also agree with this definition. See Dissenting Op. 12 (“Under the best meaning of EPCA, a ‘performance characteristic’ is a distinctive product attribute that provides utility to the consumer.”).
6
For example, in the context of dishwashers, “DOE’s longstanding view [has been] that performance [means] ‘utility accessible to the layperson and based on user operation.” See Louisiana v. DOE, 90 F.4th 461, 474 (5th Cir. 2024) establishing a new product class for residential dishwashers, Energy Conservation Program: Establishment of a New Product Class for Residential Dishwashers, 85 Fed. Reg. 68723, 68727 (2020)) (internal quotation marks omitted). A practical example is cycle
7
Instead of acknowledging the reason that ventless and vented clothes dryers were treated as a separate product class, the dissent cites the same rule and contends that “the Department has consistently set distinct efficiency standards for products based on compatibility with venting systems.” Dissenting Op. 11. However, this contention overlooks the “case-specific” reason that ventless and vented clothes dryers were separated into two different product classes—ventless clothes dryers are the only available option for those who live in certain high-rise buildings. See 2021 Interpretive Rule, 86 Fed. Reg. at 73948; see also id. at 73957 (“[I]f a ventless clothes dryer were not available, no clothes dryer would be available for certain locations”). That is, however, not the case for condensing and non-condensing consumer furnaces and commercial water heaters as we explain.
8
Take, for example, packaged terminal air conditioners (“PTACs”) and terminal heat pumps (“PTHPs”). In 2008, DOE separated standard size, 16 inches high by 42 inches wide, PTACs and PTHPs in a separate efficiency class from non-standardized PTACs and PTHPs. Energy Conservation Program for Commercial and Industrial Equipment: Packaged Terminal Air Conditioner and Packaged Terminal Heat Pump Energy Conservation Standards, 73 Fed. Reg. 58772 (2008). DOE explained that the industry standardized the wall sleeve dimensions for PTACs and PTHPs built after the mid-1980s. Id. at 58782. However, in buildings constructed before the mid-1980s, like “high-rise buildings found in large cities” non-standard size equipment that varies in size is typically used. Id. DOE created two different product classes for standard size PTACs and PTHPs versus their non-standard size counterparts because “altering the existing wall sleeve opening to accommodate the more efficient, standard size equipment could include extensive structural changes to the building, which could be very costly, and is, therefore rarely done.” Id.
9
Subsections 6295(o)(2)(B)(i)(I) and (II) provide that: [i]n determining whether a standard is economically justified, the Secretary shall . . . determine whether the benefits of the standard exceed its burdens by, to the greatest extent practicable, considering— (I) the economic impact of the standard on the manufacturers and on the consumers of the products subject to such standard; [and] (II) the savings in operаting costs throughout the estimated average life of the covered product in the type (or class) compared to any increase in the price of, or in the initial charges for, or maintenance expenses of, the covered products which are likely to result from the imposition of the standard.
10
Subsections 6313(a)(6)(B)(ii)(I) & (II) are materially the same as subsections 6295(o)(2)(B)(i)(I) and (II).
11
Despite the inputs DOE used and the analysis it performed, the dissent believes that we somehow found solace in DOE’s analysis because it was “longer,” see Dissenting Op. 20, but no where do we conclude ‍‌‌‌​‌‌‌‌‌‌‌​‌‌​​‌‌‌‌​​​​​​‌​‌​​​​​​‌​​‌​​‌​‌​​​‌‍that DOE’s reasoning was sound based on the length—instead we base our holding on the reasoned explanation DOE provided and its calculus based on the entirety of the data in the record before it.
12
Despite these explanations, the dissent somehow contends that DOE did not provide evidence that market failures affect the market, see Dissenting Op. 20, while at the same time providing no evidence that consumers make economically sound decisions 100% of the time.
13
10 C.F.R. pt. 430, subpt. C, app. A(6)(b)(2) (2024) was amended, effective June 24, 2024, and presently provides that “[t]here will be not less than 60 days for public comment on the NOPR.”

Case Details

Case Name: American Gas Association v. DOE
Court Name: Court of Appeals for the D.C. Circuit
Date Published: Nov 4, 2025
Citations: 157 F.4th 476; 22-1030
Docket Number: 22-1030
Court Abbreviation: D.C. Cir.
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