[Federal Register Volume 89, Number 72 (Friday, April 12, 2024)]
[Rules and Regulations]
[Pages 25780-25804]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-07620]
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DEPARTMENT OF ENERGY
10 CFR Part 430
[EERE-2020-BT-TP-0041]
RIN 1904-AE15
Energy Conservation Program: Test Procedure for Consumer Furnace
Fans
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Final rule.
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SUMMARY: The U.S. Department of Energy (``DOE'') is amending the test
procedure for consumer furnace fans to: clarify the scope of
applicability of the furnace fan test procedure; incorporate by
reference the most recent versions of industry test methods; establish
a test method for furnace fans incapable of operating at the required
external static pressure; clarify testing of certain products,
including furnace fans with
[[Page 25781]]
modulating controls, certain two-stage furnaces that operate at reduced
input only for a preset period of time, and dual-fuel furnaces; and
make updates to improve test procedure repeatability and
reproducibility.
DATES: The effective date of this rule is June 26, 2024. The amendments
will be mandatory for product testing starting October 9, 2024.
The incorporation by reference of certain material listed in this
rule is approved by the Director of the Federal Register on June 26,
2024.
ADDRESSES: The docket, which includes Federal Register notices, public
meeting attendee lists and transcripts, comments, and other supporting
documents/materials, is available for review at www.regulations.gov.
All documents in the docket are listed in the www.regulations.gov
index. However, not all documents listed in the index may be publicly
available, such as those containing information that is exempt from
public disclosure.
A link to the docket web page can be found at www.regulations.gov/docket/EERE-2020-BT-TP-0041. The docket web page contains instructions
on how to access all documents, including public comments, in the
docket.
For further information on how to review the docket, contact the
Appliance and Equipment Standards Program staff at (202) 287-1445 or by
email: [email protected].
FOR FURTHER INFORMATION CONTACT:
Ms. Julia Hegarty, U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, Building Technologies Office, EE-5B,
1000 Independence Avenue SW, Washington, DC, 20585-0121. Telephone:
(240) 597-6737. Email: [email protected].
Ms. Kristin Koernig, U.S. Department of Energy, Office of the
General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC,
20585-0121. Telephone: (202) 586-3593. Email:
[email protected].
SUPPLEMENTARY INFORMATION: DOE maintains a previously approved
incorporation by reference (ASHRAE 41.1-1986 (Reapproved (``RA'')
2006)) and incorporates by reference the following industry standards
into 10 CFR part 430:
ANSI/ASHRAE Standard 37-2009 (Reaffirmed 2019), Methods of Testing
for Rating Electrically Driven Unitary Air-Conditioning and Heat
Pump Equipment,'' ASHRAE approved June 21, 2019 (``ASHRAE 37-2009
(RA 2019)'').
ANSI/ASHRAE Standard 37-2009 Errata Sheet, Errata Sheet for ANSI/
ASHRAE Standard 37-2009--Methods of Testing for Rating Electrically
Driven Unitary Air-Conditioning and Heat Pump Equipment, ASHRAE
approved March 27, 2019 (``ASHRAE 37-2009 Errata Sheet'').
ANSI/ASHRAE Standard 103-2017, Method of Testing for Annual Fuel
Utilization Efficiency of Residential Central Furnaces and Boilers,
ANSI-approved July 3, 2017 (``ASHRAE 103-2017'').
2021 ASHRAE Handbook--Fundamentals Inch-Pound Edition, Chapter 1,
``Psychrometrics''; copyright 2021 (``2021 ASHRAE Handbook'').
Copies of ASHRAE Standard 37-2009 (RA 2019), ASHRAE 37-2009 Errata
Sheet, ASHRAE Standard 103-2017, and the 2021 ASHRAE Handbook can be
obtained from the American Society of Heating, Refrigerating and Air-
Conditioning Engineers (``ASHRAE''), 180 Technology Parkway NW,
Peachtree Corners, GA 30092,(800) 527-4723 or (404) 636-8400, or online
at www.ashrae.org.
For a further discussion of these standards, please see section
IV.N of this document.
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope and Definitions
1. Air-Conditioning Products and Testing During Cooling
Operation
2. Dual-Fuel Heating Products
B. Referenced Industry Standards
1. Updates to Industry Standards
2. Additional References
C. Furnace Fans That Operate at Low External Static Pressures
D. Test Procedure Repeatability and Reproducibility
1. Fuel Input Rate Tolerance
2. Ambient Conditions
3. Airflow Determination
4. Location of External Static Pressure Measurements
5. Language Updates
E. Nomenclature and Equations
F. Thermocouple Accuracy
G. Alternatives to the FER Metric
H. Test Procedure Costs
I. Effective and Compliance Dates
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866, 13563, and 14094
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
M. Congressional Notification
N. Description of Materials Incorporated by Reference
V. Approval of the Office of the Secretary
I. Authority and Background
The Energy Policy and Conservation Act, as amended (``EPCA''),\1\
authorizes DOE to establish and amend energy conservation standards and
test procedures for consumer furnace fans. (42 U.S.C. 6295(f)(4)(D))
DOE's energy conservation standards and test procedure for consumer
furnace fans are currently prescribed at title 10 of the Code of
Federal Regulations (``CFR''), part 430, Sec. 430.32(y), and 10 CFR
part 430, subpart B, appendix AA (``appendix AA''), respectively. The
following sections discuss DOE's authority to establish a test
procedure for consumer furnace fans and relevant background information
regarding DOE's consideration of a test procedure for this product.
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\1\ 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.
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A. Authority
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 B of EPCA \2\ established the Energy Conservation
Program for Consumer Products Other Than Automobiles, which sets forth
a variety of provisions designed to improve energy efficiency. These
products include consumer furnace fans, the subject of this document.
(42 U.S.C. 6295(f)(4)(D))
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\2\ For editorial reasons, upon codification in the U.S. Code,
Part B was redesignated Part A.
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The energy conservation program under EPCA consists essentially of
four parts: (1) testing, (2) labeling, (3) Federal energy conservation
standards, and (4) certification and enforcement procedures. Relevant
provisions of EPCA specifically include definitions (42 U.S.C. 6291),
test procedures (42 U.S.C. 6293), labeling provisions (42 U.S.C. 6294),
energy conservation standards (42 U.S.C. 6295), and the authority to
require information and reports from manufacturers (42 U.S.C. 6296).
The testing requirements consist of test procedures that
manufacturers of covered products must use as the basis
[[Page 25782]]
for (1) certifying to DOE that their products comply with the
applicable energy conservation standards adopted under EPCA (42 U.S.C.
6295(s)), and (2) making other representations about the efficiency of
those products (42 U.S.C. 6293(c)). Similarly, DOE must use these test
procedures to determine whether the products comply with any relevant
standards promulgated under EPCA. (42 U.S.C. 6295(s))
Federal energy efficiency requirements for covered products
established under EPCA generally supersede State laws and regulations
concerning energy conservation testing, labeling, and standards. (42
U.S.C. 6297) DOE may, however, grant waivers of Federal preemption for
particular State laws or regulations, in accordance with the procedures
and other provisions of EPCA. (42 U.S.C. 6297(d))
Under 42 U.S.C. 6293, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered products. EPCA requires that any test procedures prescribed or
amended under this section shall be reasonably designed to produce test
results which measure energy efficiency, energy use, or estimated
annual operating cost of a covered product during a representative
average use cycle (as determined by the Secretary) or period of use and
shall not be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3))
EPCA also requires that, at least once every 7 years, DOE evaluate
test procedures for each type of covered product, including consumer
furnace fans, to determine whether amended test procedures would more
accurately or fully comply with the requirements for the test
procedures to not be unduly burdensome to conduct and be reasonably
designed to produce test results that reflect energy efficiency, energy
use, and estimated operating costs during a representative average use
cycle or period of use. (42 U.S.C. 6293(b)(1)(A))
If the Secretary determines, on her own behalf or in response to a
petition by any interested person, that a test procedure should be
prescribed or amended, the Secretary shall promptly publish in the
Federal Register proposed test procedures and afford interested persons
an opportunity to present oral and written data, views, and arguments
with respect to such procedures. The comment period on a proposed rule
to amend a test procedure shall be at least 60 days and may not exceed
270 days. In prescribing or amending a test procedure, the Secretary
shall take into account such information as the Secretary determines
relevant to such a procedure, including technological developments
relating to energy use or energy efficiency of the type (or class) of
covered products involved. (42 U.S.C. 6293(b)(2)) If DOE determines
that test procedure revisions are not appropriate, DOE must publish its
determination not to amend the test procedures.
In addition, EPCA requires that DOE amend its test procedures for
all covered products to integrate measures of standby mode and off mode
energy consumption into the overall energy efficiency, energy
consumption, or other energy descriptor, unless the current test
procedure already incorporates the standby mode and off mode energy
consumption, or if such integration is technically infeasible. (42
U.S.C. 6295(gg)(2)(A)) If an integrated test procedure is technically
infeasible, DOE must prescribe separate standby mode and off mode
energy use test procedures for the covered product, if a separate test
is technically feasible. (42 U.S.C. 6295(gg)(2)(A)(iii)) Any such
amendment must consider the most current versions of the International
Electrotechnical Commission (``IEC'') Standard 62301 \3\ and IEC
Standard 62087 \4\ as applicable. (42 U.S.C. 6295(gg)(2)(A))
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\3\ IEC 62301, Household electrical appliances--Measurement of
standby power (Edition 2.0, 2011-01).
\4\ IEC 62087, Audio, video and related equipment--Methods of
measurement for power consumption (Edition 1.0, Parts 1-6: 2015,
Part 7: 2018).
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DOE is publishing this final rule pursuant to the 7-year review
requirement specified in EPCA. (42 U.S.C. 6293(b)(1)(A))
B. Background
As discussed, DOE's existing test procedure for consumer furnace
fans appears at appendix AA. Appendix AA provides procedures and
calculations to determine the fan energy rating (``FER''), expressed as
watts per 1,000 cubic feet per minute of airflow (``W/1000 cfm'').
DOE established the test procedure for consumer furnace fans at
appendix AA in a final rule published on January 3, 2014 (``January
2014 Final Rule''). 79 FR 499. The test procedure is applicable to
furnace fans used by weatherized and non-weatherized gas furnaces, oil
furnaces, electric furnaces, and modular blowers.\5\ See section 1,
appendix AA. For each of these categories, the test procedure covers
both mobile home and non-mobile home models. The test procedure is not
applicable to non-ducted products, such as whole-house ventilation
systems without ductwork, central air-conditioning (``CAC'') condensing
unit fans, room fans, and furnace draft inducer fans because a
``furnace fan'' is defined as ``an electrically-powered device used in
a consumer product for the purpose of circulating air through
ductwork.'' 10 CFR 430.2.
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\5\ DOE defines the term ``modular blower'' in section 2.9 of
appendix AA as a product which only uses single-phase electric
current, and which is: (a) designed to be the principal air
circulation source for the living space of a residence; (b) not
contained within the same cabinet as a furnace or central air
conditioner; and (c) designed to be paired with heating,
ventilating, and air-conditioning (``HVAC'') products that have a
heat input rate of less than 225,000 Btu per hour and cooling
capacity less than 65,000 Btu per hour.
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As established in the January 2014 Final Rule, appendix AA
incorporates by reference the definitions, test setup and equipment,
and procedures for measuring steady-state combustion efficiency from
the 2007 version of American National Standards Institute (``ANSI'')/
American Society of Heating, Refrigeration, and Air-Conditioning
Engineers (``ASHRAE'') Standard 103, ``Method of Testing for Annual
Fuel Utilization Efficiency of Residential Central Furnaces and
Boilers'' (``ASHRAE 103-2007''). In addition to these provisions,
appendix AA includes provisions for apparatuses and procedures for
measuring temperature rise, external static pressure (``ESP''), and
furnace fan electrical input power. Appendix AA also incorporates by
reference provisions for measuring temperature and ESP from ANSI/ASHRAE
37-2009, ``Methods of Testing for Rating Electrically Driven Unitary
Air-Conditioning and Heat Pump Equipment'' (``ASHRAE 37-2009''),
including its reference in section 5.1 to ASHRAE 41.1-1986 (RA 2006),
``Standard Method for Temperature Measurement.'' Lastly, appendix AA
includes a reference to the psychrometric chapter (i.e., chapter 1) in
the 2001 ASHRAE Handbook--Fundamentals (``2001 ASHRAE Handbook'') for
use in calculating the specific volume of dry air at specified
operating conditions.
In the January 2014 Final Rule, DOE determined that there is no
need to address standby and off mode energy use in the test procedure
for consumer furnace fans, as the standby mode and off mode energy use
associated with furnace fans is measured by test procedures for the
products in which furnace fans are used (i.e., consumer furnaces and
consumer CACs and heat pumps). 79 FR 499, 504-505.
On July 7, 2021, DOE published in the Federal Register a request
for information (``July 2021 RFI'') seeking
[[Page 25783]]
comments on the existing DOE test procedure for consumer furnace fans
to determine whether amendments are warranted for the test procedure
for consumer furnace fans. 86 FR 35660. More specifically, DOE
requested comments, information, and data about a number of issues,
mainly concerning: test settings (including selection of airflow
control settings and ESP requirements for airflow settings other than
the maximum setting); incorporation by reference of the most recent
industry test method; clarifications for testing of certain products,
including furnace fans with modulating controls, furnace fans and
modular blowers tested with electric heat kits, certain two-stage
furnaces that operate at reduced input only for a preset period of
time, dual-fuel furnaces, and certain oil-fired furnaces; and issues
related to test procedure repeatability and reproducibility. Id.
On May 13, 2022, DOE published in the Federal Register a notice of
proposed rulemaking (``NOPR'') proposing to update appendix AA (``May
2022 NOPR''). 87 FR 29576. Specifically, DOE proposed to: (1) specify
testing instructions for furnace fans incapable of operating at the
required ESP; (2) incorporate by reference the most recent versions of
industry standards, ASHRAE 103-2017 and ASHRAE 37-2009 (RA 2019), in 10
CFR 430.3; (3) define dual-fuel furnace fans and exclude them from the
scope of appendix AA; (4) change the term ``default airflow-control
settings'' to ``specified airflow-control settings''; (5) add
provisions to directly measure airflow; (6) revise the ambient
temperature conditions allowed during testing to between 65 degrees
Fahrenheit (``[deg]F'') and 85 [deg]F for all units (both condensing
and non-condensing); and (7) assign an allowable range of relative
humidity during testing to be between 20 percent and 80 percent. 87 FR
29576, 29579. DOE held a webinar related to the May 2022 NOPR on May
19, 2022 (hereafter, the ``NOPR webinar'').
DOE received comments in response to the May 2022 NOPR from the
interested parties listed in Table II.1.
Table II.1--List of Commenters in Response to the May 2022 NOPR
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Reference in this final Comment No. in
Commenter(s) rule the docket Commenter type
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Air-Conditioning, Heating, and AHRI...................... 15 Trade Organization.
Refrigeration Institute.
Appliance Standards Awareness Project, Joint Commenters.......... 14 Efficiency Advocacy
American Council for an Energy- Organizations.
Efficient Economy, Northwest Energy
Efficiency Alliance, and the National
Consumer Law Center.
Pacific Gas and Electric Company, San CA IOUs................... 13; * 9 Utilities.
Diego Gas and Electric, Southern
California Edison; collectively, the
California Investor-Owned Utilities.
Carrier Global Corporation.............. Carrier................... 12 Manufacturer.
Johnson Controls Inc.................... JCI....................... 10 Manufacturer.
Lennox International Inc................ Lennox.................... 11 Manufacturer.
Morrison Products, Inc.................. Morrison.................. * 9 Manufacturer.
Rheem Manufacturing..................... Rheem..................... * 9 Manufacturer.
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* Comment No. 9 corresponds to the transcript for NOPR webinar.
A parenthetical reference at the end of a comment quotation or
paraphrase provides the location of the item in the public record.\6\
To the extent that interested parties have provided written comments
that are substantively consistent with any oral comments provided
during the NOPR webinar, DOE cites the written comments throughout this
final rule. Any oral comments provided during the webinar that are not
substantively addressed by written comments are summarized and cited
separately throughout this final rule.
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\6\ The parenthetical reference provides a reference for
information located in the docket of DOE's rulemaking to develop
test procedures for consumer furnace fans. (Docket No. EERE-2020-BT-
TP-0041, which is maintained at www.regulations.gov) The references
are arranged as follows: (commenter name, comment docket ID number,
page of that document).
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II. Synopsis of the Final Rule
In this final rule, DOE amends appendix AA to subpart B of 10 CFR
part 430, ``Uniform test method for measuring the energy consumption of
furnace fans,'' as follows:
Specify testing instructions for furnace fans incapable of
operating at the required ESP;
Incorporate by reference the most recent versions of
industry standards, ASHRAE 103-2017 and ASHRAE 37-2009 (RA 2019), in 10
CFR 430.3;
Incorporate by reference chapter 1 of the 2021 ASHRAE
Handbook;
Define dual-fuel furnace fans and exclude them from the
scope of appendix AA;
Change the term ``default airflow-control settings'' to
``specified airflow-control settings;''
Make clarifications to nomenclature, correct the value of
the conversion factor from Watts to BTU/h, and correct the units of
specific volume of dry air;
Revise the ambient temperature conditions allowed during
testing to between 65 [deg]F and 85 [deg]F for all units (both
condensing and non-condensing);
Assign an allowable range of relative humidity during
testing to be between 20 percent and 80 percent; and
Require that the power measurements be determined as an
average over the last 30 seconds of each steady state period at
intervals of no less than 1 per second, rather than taken as a single
point measurement.
The adopted amendments are summarized in Table II.1 compared to the
test procedure provision prior to the amendment, as well as the reason
for the adopted change.
[[Page 25784]]
Table II.1--Summary of Changes in the Amended Consumer Furnace Fan Test
Procedure
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DOE test procedure prior to Amended test
amendment procedure Attribution
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Does not specify instructions Specifies testing Address waiver
for testing furnace fans that instructions for from the prior
are incapable of operating at furnace fans test procedure.
the specified ESP. incapable of
operating at the
specified ESP.
Incorporates by reference ASHRAE Incorporates by Incorporate by
103-2007 and ASHRAE 37-2009. reference ASHRAE reference the
103-2017 and most recent
ASHRAE 37-2009 industry test
(RA 2019). procedures.
References 2001 ASHRAE Handbook Incorporates by Incorporate by
psychrometric chapter. reference the references all
2021 ASHRAE industry test
Handbook procedures that
psychrometric are referenced in
chapter (i.e., appendix AA.
chapter 1).
Does not address dual-fuel Defines dual-fuel Clarify scope of
furnace fans. furnace fans in coverage of the
appendix AA and test procedure.
explicitly
excludes them
from the scope of
the test method.
Defines ``default airflow- Defines Clarify selection
control settings''. ``specified of airflow
airflow-control control settings
settings'' to during testing
differentiate the
settings used in
testing from the
as-shipped
settings.
Utilizes potentially unclear Utilizes clearer Clarify
nomenclature, attributes the nomenclatures, nomenclature and
wrong value to the conversion attributes the correct typos.
factor from Watts to BTU/h, and correct value to
assigns the incorrect units to the conversion
the specific heat of dry air. factor from Watts
to BTU/h, and
assigns the
correct units to
the specific heat
of dry air.
Ambient temperature must remain Ambient Improve
between 65 [deg]F and 100 temperature must repeatability and
[deg]F for non-condensing remain between 65 reproducibility
furnaces and between 65 [deg]F [deg]F and 85 of test results.
and 85 [deg]F for condensing [deg]F for all
furnaces. furnaces.
Does not specify an allowable Requires ambient Improve
range of relative humidity. relative humidity repeatability and
to be maintained reproducibility
between 20% and of test results.
80% for all
furnaces.
Electrical input power is Electrical input Improve
measured as single point after power will be repeatability and
steady-state conditions are met. determined as the reproducibility
average value of of test results.
readings taken
over the last 30
seconds of each
steady state
period at
intervals of no
less than 1 per
second.
------------------------------------------------------------------------
DOE has determined that the amendments described in section III of
this document and adopted in this document will not alter the measured
efficiency of consumer furnace fans or require retesting or
recertification solely as a result of DOE's adoption of the amendments
to the test procedure. Additionally, DOE has determined that the
amendments will not increase the cost of testing. Discussion of DOE's
actions are addressed in detail in section III of this document
The effective date for the amended test procedure adopted in this
final rule is 75 days after publication of this document in the Federal
Register. Representations of energy use or energy efficiency must be
based on testing in accordance with the amended test procedure
beginning 180 days after the publication of this final rule.
III. Discussion
A. Scope and Definitions
1. Air-Conditioning Products and Testing During Cooling Operation
As discussed, a ``furnace fan'' is an electrically-powered device
used in a consumer product for the purpose of circulating air through
ductwork. 10 CFR 430.2. And, as stated, DOE's test procedure is
applicable to furnace fans used in weatherized and non-weatherized gas
furnaces, oil furnaces, electric furnaces, and modular blowers. See
section 1, appendix AA. The test procedure is not applicable to non-
ducted products, such as whole-house ventilation systems without
ductwork, CAC or central air-conditioning heat pump (``HP'') condensing
unit fans, small-duct high-velocity (``SDHV'') air conditioner unit
fans, room fans, and furnace draft inducer fans.
DOE received a comment in response to the July 2021 RFI that
suggested modifying the consumer furnace fans test procedure to account
for lower fan power during low-stage cooling operation. In the May 2022
NOPR, DOE requested information and data regarding the electrical
energy consumption of multi-stage furnace fans during low-stage cooling
operation, specifically in relation to single-stage furnace fans in
cooling mode. 87 FR 29576, 29580.
In response, JCI commented that a two-stage cooling blower offers
significant energy savings resultant, in part, from the circulating air
blower operating at a lower speed during low-stage cooling. JCI stated
that the electronically commutated motors (``ECMs'') used in units with
two-stage blowers are more efficient at lower speeds. JCI also
commented that the increased motor efficiency at low stage is not
reflected in the current furnace fan test procedure. JCI commented
that, unlike furnaces designed for strictly single-stage cooling,
furnaces designed for two-stage cooling applications typically include
thermostat connections for control and have the ability to switch
automatically to a lower blower speed when low-stage cooling is in
operation. JCI commented that the consumer furnace fan test procedure
should be modified to properly capture the actual field behavior of
two-stage cooling units. (JCI, No. 10 at p. 1)
Lennox stated that fan energy consumption is significantly reduced
when operating multi-stage furnace fans during low-stage cooling
operation relative to single-stage furnace fans operating in cooling
mode. Lennox suggested that fan energy for low-stage operations is
reduced by over 25 percent for two-stage products. Lennox commented
that field data indicate multi-stage products spend the majority of
operating hours in low-stage operation and that DOE should fully
consider low-stage and multi-stage operation because they are
representative of actual field operation. Lennox expressed support for
transitioning the currently applicable consumer furnace fan test
procedure to
[[Page 25785]]
include low-stage operation. (Lennox, No. 11 at p. 3)
Carrier commented that it does not have data regarding low-stage
cooling operation in relation to single-stage furnace fans in cooling
mode. However, Carrier stated that engineering principles suggest that
accounting for the low-stage fan electrical energy consumption would
make the FER rating more representative than the current method of
using the high-stage fan electrical energy consumption as if it were a
single-stage blower unit. Carrier suggested that DOE consider creating
a cooling capacity ratio multiplier to account for the reduced fan
electrical energy in low stage. (Carrier, No. 12 at pp. 1-2)
AHRI commented that there may be significant energy savings
associated with running multi-stage furnace fans during low-stage
cooling operation. AHRI stated that it is in favor of using low-stage
cooling operation for package units that employ two-stage or multi-
stage cooling modes. (AHRI, No. 15 at p. 2)
In response to these comments, DOE continues to evaluate the
potential benefits of accounting for lower fan power during low-stage
cooling operation, as well any additional testing burden that such test
provisions would entail. DOE has considered the feedback provided by
commenters and has concluded that at this time, DOE does not have
sufficient data and information to specify amended procedures for
testing furnace fans at low-stage cooling operation. In particular,
commenters did not provide sufficient data at this time to determine
representative additional test points and reapportion the operating
hours outlined in table IV.2 of appendix AA to reflect low-stage
cooling. Further, adding test points to DOE's test procedure for
consumer furnace fans would likely require manufacturers to recertify
units and could add burden to the test procedure. DOE is therefore not
modifying the consumer furnace fans test procedure to account for lower
fan power during low-stage cooling operation in this final rule, but
DOE may consider such provisions in a future test procedure rulemaking
for furnace fans.
In the May 2022 NOPR, DOE stated that it was not proposing to
include fans used in other types of heating, ventilating, and air-
conditioning (``HVAC'') products--such as CACs, HPs, and SDHV modular
blowers--within the scope of appendix AA. DOE tentatively concluded
that the electrical energy consumption of furnace fans used in the
aforementioned types of HVAC products will be accounted for by the
seasonal energy efficiency ratio 2 (``SEER2'') and heating seasonal
performance factor 2 (``HSPF2'') metrics measured by the test procedure
for CACs and HPs at appendix M1 to subpart B of part 430 (``appendix
M1''). 87 FR 29576, 29580.
In response to the May 2022 NOPR, the CA IOUs stated that the
calculations for the SEER2 and HSPF2 metrics do not account for the
fractional bin hours between 55 [deg]F and 64 [deg]F. The CA IOUs
commented that fan energy during any air circulation through the
ductwork at those temperatures is unaddressed in SEER2 and HSPF2;
therefore, the CA IOUs recommended that DOE further investigate the
fans installed in these residential HVAC products to determine if such
fans would meet the current furnace fan energy conservation standards
and consider including them in this rulemaking. (CA IOUs, No. 13 at p.
4)
The Joint Commenters stated that they agreed with DOE regarding
potential backsliding concerns about furnace fan energy use if single-
package air conditioner units with gas heat were excluded from the
scope of the furnace fan test procedure and stated that they support
continued inclusion of these products within the scope of the furnace
fan test procedure. (Joint Commenters, No. 14 at p. 1)
With regards to the comments from the CA IOUs and the Joint
Commenters. DOE notes that the test method of determining SEER2, Energy
Efficiency Ratio 2 (``EER2''), HSPF2, and PW,OFF for CACs
and HPs is provided at appendix M1. Table 19 of appendix M1 specifies
the distribution of fractional hours within cooling season temperature
bins for the calculation of SEER2. These bins range from 65 [deg]F to
104 [deg]F, and, accordingly, do not cover the 55 [deg]F to 64 [deg]F
range, as mentioned by the CA IOUs. Table 20 specifies the distribution
of fractional hours within heating season temperature bins for the
calculation of HSPF2, which range from -23 [deg]F to 62 [deg]F.
Collectively, these two tables cover the entire temperature range from
-23 [deg]F to 104 [deg]F except for the relatively narrow range between
62 [deg]F and 65 [deg]F.
As discussed in section I.A of this document, DOE is required by
EPCA to develop test procedures that are reasonably designed to produce
test results which measure energy efficiency, energy use or estimated
annual operating cost of a covered product during a representative
average use cycle (as determined by the Secretary) or period of use and
shall not be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3))
Accordingly, the SEER2 and HSPF2 metrics must reflect representative
average annual use of products subject to those metrics, including
CACs, HPs, and SDHV modular blowers, but do not necessarily need to
account for performance at every possible temperature condition. DOE
has previously determined that SEER2 and HSPF2 capture a representative
measure of CAC and HP performance, including fan energy consumption,
during heating and cooling operations. (See, for example, discussion of
appendix M1 amendments at 82 FR 1426, 1446-1460 (Jan. 5, 2017))
Therefore, DOE has determined that the consumer furnace fan test
procedure does not need to be amended to specifically address fan
energy use in CACs and HPs.
2. Dual-Fuel Heating Products
Some consumer heating products include an electric heat pump as
well as a gas burner and are often referred to as ``dual-fuel'' or
``hybrid heating'' units. These products are designed to provide space
heating with the heat pump and/or gas burner, depending on the
operating conditions (e.g., outdoor air temperature and heating
demand). The annual operating characteristics of a dual-fuel product
may differ significantly from a typical furnace because the inclusion
of a heat pump may change the operating time necessary to meet the
heating load demand when compared with a gas burner alone, resulting in
changes to the operating hours of the furnace fan. Additionally, as
stated in the May 2022 NOPR, the current DOE consumer furnace fan test
procedure does not specify provisions to set up or operate furnace fans
for dual-fuel heating units, and the estimated annual national
operating values in appendix AA may not be representative of average
use cycle for furnace fans installed in dual-fuel applications. 87 FR
29576, 29580.
However, as was also discussed in the May 2022 NOPR, dual-fuel
units are subject to the separate applicable standards for both HPs
(i.e., in terms of SEER2 and HSPF2) and furnaces (i.e., in terms of
annual fuel utilization efficiency (``AFUE'')). Therefore, DOE
tentatively concluded that the fan energy use of these products is
already accounted for by the metrics measured by the applicable test
procedure. The SEER2 and HSPF2 metrics measure the fan energy in its
cooling and heating modes, respectively, covering the two major
functions of furnace fans. Furthermore, furnace fans in dual-fuel
models have not been subject to appendix AA and, therefore, were not
[[Page 25786]]
part of the previous standards analysis. Id. at 87 FR 29581.
In the May 2022 NOPR, DOE proposed to define dual-fuel units as a
consumer product that includes both a heat pump and a burner in a
single cabinet. Further, DOE proposed to explicitly exclude furnace
fans used in them from the scope of appendix AA. Id.
In response to the May 2022 NOPR, the CA IOUs commented that dual-
fuel products--such as package units with electric heat pumps and a gas
burner that are intended to provide the same utility as a typical
weatherized, non-condensing furnace fan and a weatherized gas furnace--
will likely grow in popularity for consumers. The CA IOUs agreed with
DOE's assertion that the annual operating characteristics of a dual-
fuel product may differ significantly from a typical furnace but noted
this is not sufficient justification for exclusion from this
rulemaking. Moreover, the CA IOUs stated that manufacturers currently
need to test these furnace fans in otherwise identical package units
with a cooling-only coil and a furnace; therefore, including such
furnace fans in the scope would not increase manufacturer burden. The
CA IOUs suggested that because heat pump capacity is expected to
correlate to cooling capacity, units with lower heating capacity than
cooling capacity installed in high-heat-demand climate zones would
result in more gas-specific heating operation for a dual-fuel system
during heating degree days. The CA IOUs stated that, as a result, the
estimated national average operating hour values for calculating FER
are also relevant for dual-fuel systems. The CA IOUs therefore
recommended that DOE not exclude the furnace fans in dual-fuel heating
products from the scope of the test procedure. (CA IOUs, No. 13 at p.
4)
The Joint Commenters stated that the gas furnaces that are part of
dual-fuel units are essentially identical to those that are part of
currently covered single-package air conditioning units with a gas
furnace. The Joint Commenters added that they were unclear as to how
DOE made the determination that dual-fuel fans are presently excluded
from the currently applicable test procedure. The Joint Commenters
encouraged DOE to clarify its determination that dual-fuel fans are
excluded from the scope of the currently applicable consumer furnace
fan test procedure and to consider adding provisions for testing these
furnace fans. (Joint Commenters, No. 14 at pp. 1-2)
Conversely, Carrier, Lennox, and AHRI commented in support of the
proposed definition for dual-fuel units and the proposal to exclude the
furnace fans in them from the scope of appendix AA. (Carrier, No. 12 at
p. 2; Lennox, No. 11 at p. 3; AHRI, No. 15 at p. 2)
In response to these comments, DOE notes that although furnace fans
used in dual-fuel units were not explicitly excluded in the currently
applicable consumer furnace fan test procedure, the test procedure does
not specify provisions for the testing of these products. Additionally,
in response to the CA IOUs' suggestion that heating contribution from
the heat pump may be small in comparison to the furnace component, DOE
notes that these assumptions would not be applicable to all product
designs, nor is it necessarily representative of typical installations
and usage patterns throughout the U.S. Therefore, DOE continues to
conclude that the operating hours used in appendix AA would not be
representative of the fans in dual-fuel units. It follows that these
products necessarily were not intended to be subject to the currently
applicable consumer furnace fan test procedure. DOE further notes that
there is a distinction between packaged dual-fuel units, which include
both a furnace for heating operation and a heat pump for heating and
cooling operation, and package air conditioner units, which include
only a furnace for heating operation (along with an air conditioner
that provides cooling only). The single-package air conditioner system
can be tested according to the currently applicable test procedure for
furnace fans, the operating hours are representative for these
products, and furnace fans used in package air conditioners are
currently subject to the standards established for this product type.
Further, as noted previously in this section, the energy consumption of
the fans in dual-fuel heating products is already captured in the SEER2
and HSPF2 metrics specified in appendix M1. Therefore, to clarify the
distinction between dual-fuel products and products within the scope of
this consumer furnace fan test procedure, DOE is finalizing its
proposed definition for dual-fuel units within appendix AA in this
final rule. Accordingly, DOE is finalizing its proposal to specify more
explicitly that furnace fans in dual-fuel products are excluded from
the scope of appendix AA.
B. Referenced Industry Standards
1. Updates to Industry Standards
The currently applicable DOE test procedure for consumer furnace
fans incorporates by reference ASHRAE 103-2007, ASHRAE 37-2009, and
ASHRAE 41.1-1986 (RA 2006). Since publication of the January 2014 Final
Rule, ASHRAE published an update to ASHRAE 103, i.e., ASHRAE 103-2017,
and two addenda to ASHRAE 37-2009 (ASHRAE 37-2009 (RA 2019)). In the
May 2022 NOPR, DOE proposed to incorporate by reference ASHRAE 103-2017
and ASHRAE 37-2009 (RA 2019) in its test procedure for consumer furnace
fans to stay consistent with the latest industry testing practices. 87
FR 29576, 29581. Further, DOE proposed to update all references of
ASHRAE 37-2009 to ASHRAE 37-2009 (RA 2019). Id. Finally, DOE proposed
to maintain reference to ASHRAE 41.1-1986 (RA 2006). Id.
In response to the May 2022 NOPR, Carrier commented that it agrees
with the incorporation by reference of ASHRAE 103, ASHRAE 37, and
ASHRAE 41.1. Carrier stated these references are important for the
direct measurement method. (Carrier, No. 12 at p. 2) Additionally,
Carrier and AHRI recommended that the DOE adopt the most recent
versions of all ASHRAE standards relevant to this rule (i.e., ASHRAE
103-2022 and ASHRAE 41.1-2020). (Carrier, No. 12 at p. 2; AHRI, No. 15
at p. 2) Rheem and AHRI commented that DOE should consider the new
version of ASHRAE 37 that will be coming out soon. (Rheem, NOPR Webinar
Transcript, No. 9 at pp. 19-20; AHRI, No.15 at p. 4)
For the reasons discussed in the preceding section and in the May
2022 NOPR, DOE is finalizing its proposal to incorporate by reference
in appendix AA the most recent version of ASHRAE 37 (ASHRAE 37-2009 (RA
2019)). With regards to the comments from Rheem and AHRI, DOE notes
that a new version of ASHRAE 37 has not been published yet so DOE is
incorporating by reference the most recent version of ASHRAE 37.
Relatedly, DOE notes that ASHRAE 37-2009 (RA 2019) references ASHRAE
41.1-1986 (RA 2006) as opposed to the more recent ASHRAE 41.1-2020.
Consequently, to maintain consistency with ASHRAE 37-2009 (RA 2019),
DOE is finalizing its proposal to maintain the incorporation by
reference of ASHRAE 41.1-1986 (RA 2006) in appendix AA. In response to
the comments from Carrier and AHRI, DOE notes that ASHRAE 103-2022
updated the references to relevant standard test methods and standard
specifications from ASHRAE 103-2017. Notably, the amended ASHRAE 103
standard adds references to ASTM D396-2019, ``Standard Specification
for Fuel Oils'' and ANSI/ASHRAE Standard 41.6-2014, ``Standard Methods
for Humidity
[[Page 25787]]
Measurement,'' while removing the reference to Heat Transmission by
W.H. McAdams. As discussed, in the May 2022 NOPR, DOE proposed to
incorporate by reference ASHRAE 103-2017. 87 FR 29576, 29581. Although
DOE continues to evaluate the differences between ASHRAE 103-2017 and
ASHRAE 103-2022 (and the standards referenced therein), DOE has not yet
determined whether the changes between the versions of the standards
would impact appendix AA and, in turn, FER ratings. Therefore, DOE
maintains its proposal in the May 2022 NOPR and incorporates by
reference ASHRAE 103-2017 into appendix AA in this final rule. DOE will
continue to evaluate ASHRAE 103-2022 for future incorporation by
reference.
2. Additional References
Appendix AA as established in the January 2014 Final Rule included
a reference to the psychrometric chapter (i.e., chapter 1) in the 2001
ASHRAE Handbook for use in calculating the specific volume of dry air
at specified operating conditions. Although the 2001 ASHRAE Handbook
was not incorporated by reference in appendix AA at the time in the
January 2014 Final Rule, DOE notes that its inclusion in the test
procedure should necessitate its incorporation by reference. As the
2001 version of the ASHRAE Handbook is no longer widely available, DOE
is updating appendix AA to reference to the 2021 version of the ASHRAE
Handbook. Because appendix AA already references the 2001 version of
the ASHRAE Handbook, which uses the same method to determine the
specific volume of dry air as the 2021 version of the ASHRAE Handbook,
incorporating by reference chapter 1 of the 2021 ASHRAE Handbook will
not change the results of FER. DOE is therefore incorporating by
reference chapter 1, ``Psychrometrics'' of the 2021 ASHRAE Handbook
into appendix AA in this final rule.
C. Furnace Fans That Operate at Low External Static Pressures
On February 20, 2019, DOE received a petition for waiver and an
application for interim waiver from ECR International, Inc. (``ECR'')
for certain basic models of furnace fans that ECR described as belt-
driven, single-speed furnace fans designed for heating-only
applications in oil-fired warm air furnaces.\7\ ECR asserted that the
furnace fan basic models specified in the petition have design
characteristics that prevent testing of the basic model according to
the test procedure prescribed in the currently applicable appendix AA.
Specifically, ECR claimed that the specified products are not designed
to operate within the range of ESP required in the currently applicable
appendix AA and that testing such furnace fans at the required ESP
reduces airflow and increases temperature rise to the point where the
units shut off during testing due to high temperature limits, making it
impossible to achieve the steady-state operation required for
testing.\8\
---------------------------------------------------------------------------
\7\ See www.regulations.gov/document?D=EERE-2019-BT-WAV-0004-0001 at p. 1.
\8\ See id. at pp. 2-3.
---------------------------------------------------------------------------
On March 9, 2021, DOE published a Decision and Order (``2021
Decision and Order'') granting ECR a test procedure waiver specifying
an alternate test procedure that must be used to test and rate the
specified basic models.\9\ 86 FR 13530, 13534-13535.
---------------------------------------------------------------------------
\9\ See www.regulations.gov/document/EERE-2019-BT-WAV-0004-0015.
---------------------------------------------------------------------------
Specifically, the 2021 Decision and Order specified adjustments to
the ESP test conditions specified in section 8.6.1.2 of the currently
applicable appendix AA. Basic models subject to the 2021 Decision and
Order must be tested at the specified ESP. Id. The alternate test
procedure in the 2021 Decision and Order further specifies that if the
unit under test shuts down prior to completion of the test, the ESP
range is incrementally reduced by 0.05 inches of water column
(``w.c.''), and the test is to be re-run. Id. This process is repeated
until a range is reached at which the test can be conducted to its
conclusion, with a minimum allowable ESP range of 0.30-0.35'' w.c.,
which corresponds to the lowest ESP at which shut-off occurred in the
ECR data. Id.
The test procedure waiver provision at 10 CFR 430.27(l) provides
that, as soon as practicable after the granting of any waiver, DOE will
publish in the Federal Register a NOPR to amend its regulations so as
to eliminate any need for the continuation of such waiver. As soon
thereafter as practicable, DOE will publish in the Federal Register a
final rule. 10 CFR 430.27(l). Therefore, to amend the test procedure so
as to eliminate any need for the continuation of this waiver, in the
May 2022 NOPR, DOE proposed to add provisions requiring that furnace
fans be initially tested at the applicable ESP range specified in table
1 of appendix AA. If the unit under test is unable to complete the
testing (i.e., the unit shuts down), the ESP range would be
incrementally reduced by 0.05'' w.c. (e.g., for units designed to be
paired with an evaporator coil but without one installed, first from
0.65''-0.70'' to 0.60''-0.65'' w.c.). This process would be repeated
until an ESP range at which the test can be conducted to its conclusion
is reached. 87 FR 29576, 29582-29583.
In response to the May 2022 NOPR, Lennox, Carrier, and AHRI
commented that they support the proposed test procedure instructions
for products that cannot be tested at the ESPs in the currently
applicable test procedure. (Lennox, No. 11 at p. 3; Carrier, No. 12 at
p. 2; AHRI, No. 15 at p. 2) Lennox stated that it supports these test
procedure changes, which would eliminate the current test procedure
waiver and not create separate product classes for low-ESP products.
(Lennox, No. 11 at p. 3) JCI commented that the FER test procedure
should not specify a static pressure setting that is above the maximum
static pressure specified by the furnace manufacturer. (JCI, No. 10 at
pp. 4-5)
The Joint Commenters commented that this proposal could allow the
products subject to the 2021 Decision and Order (i.e., ``heating only''
products that cannot be tested at the ESPs in the currently applicable
test procedure) to meet the standard more easily. The Joint Commenters
stated that despite DOE's discussion in the May 2022 NOPR that these
``heating only'' furnace fans are not manufactured for the same
applications as other covered furnace fans (e.g., in a system with
cooling), the manufacturer literature for these ``heating-only'' models
repeatedly discusses usage in cooling applications. The Joint
Commenters encouraged DOE to further consider appropriate testing
provisions for ``heating-only'' furnace fans that cannot reach the ESPs
defined in appendix AA. (Joint Commenters, No. 14 at p. 2)
The CA IOUs commented that DOE should not require furnace fans that
cannot meet the required ESP to be tested using an alternative test
procedure because it would result in an unrepresentative metric.
Instead, the CA IOUs recommended that DOE either add a correction
factor or create a new product class for these products. (CA IOUs, No.
13 at p. 1) The CA IOUs stated that the method of reducing ESP until a
test could be complete would result in testing at a much lower airflow
and higher temperature rise than the maximum shown on the furnace
nameplate. The CA IOUs stated that operating at this condition
contradicts the manufacturer's installation and operating instructions
and is not representative of field use. The CA IOUs expressed concern
that this approach sets a precedent for manufacturers of
[[Page 25788]]
other products to deviate from Federal test procedures without changing
their product rating. (Id. at pp. 1-2) The CA IOUs stated that the
product for which the waiver was granted has a motor capable of
operating at the required ESP. Further, the CA IOUs stated that the
motor is supplied with a fixed belt drive that does not allow the fan
to run at the speed necessary to achieve the higher ESP. Finally, the
CA IOUs stated that the manufacturer's literature provides instructions
for changing the pulleys in the field to work at the required speed.
(Id. at p. 2)
In response to these comments, DOE notes that, as is discussed in
the grant of an interim waiver to ECR, test data submitted by ECR
showed that the specified furnace fan basic models stop operating at an
ESP between 0.30'' and 0.60'' w.c., depending on the particular basic
model, with units shutting down at an average ESP of 0.47'' w.c. 85 FR
50808, 50811. These ESPs are below the values listed in table 1 of
appendix AA, indicating that these units could not complete a test
according to the current consumer furnace fan test procedure without
the proposed changes to ESP requirements. DOE further notes that a unit
using a different motor or replacing the pulley, belt, or other
components would constitute a different basic model.
The CA IOUs reiterated their comments previously submitted in
response to the July 2021 RFI in which they demonstrated that for a
given speed, forward curve fan efficacy is higher at low airflow and
high ESP than at a low ESP with high airflow. The CA IOUs commented
that the requirement in the proposed test procedure would test the
fixed-speed fan at a much lower airflow and higher ESP than the fan
would operate at under normal conditions, resulting in a measured
efficacy that is significantly better than would result if the fan were
tested at a representative airflow. (Id. at p. 2) The CA IOUs stated
that the problem is exacerbated by the lack of correction to account
for the difference between the tested ESP and the ESP listed in table 1
of appendix AA in the reported FER. The CA IOUs noted that while they
are unaware of a validated equation specifically for FER, DOE employs a
similar correction for water-source heat pumps by incorporating ANSI/
AHRI/ASHRAE ISO Standard 1346-1:1998 (RA 2012). The CA IOUs noted that
water-source heat pumps require this correction to determine the power
consumption and capacity at the rating condition of 0.0'' wc because
the actual tests use a positive ESP. The CA IOUs commented that they
believe this DOE-approved equation applies equally well to furnace
fans. (Id. at pp. 2-3)
The CA IOUs also recommended that DOE require testing at an airflow
no less than that required to meet the maximum temperature rise on the
furnace nameplate. Alternatively, the CA IOUs suggested that DOE create
a new product class for heating-only units and require a specific ESP
in table 1 of appendix AA that is lower. The CA IOUs stated that this
would reduce test burden because the products would complete testing on
the first attempt rather than incrementally reducing ESP in further
attempts. The CA IOUs noted that there is a similar breakdown of
products based on application and static pressure for ducted blower
coil systems for central air conditioners and heat pumps. Further, the
CA IOUs stated that appendix M1 has different ESP test conditions for
conventional, low static, and mid static blower coil systems based on
the external static pressure produced during operation. (Id. at p.3)
In response to the comment from the CA IOUs, DOE notes that no data
indicate that the correction equation used for water-source heat pumps
is appropriate for use in the furnace fans test procedure. Because
these two products are tested according to different procedures, DOE
cannot conclude that this equation would be appropriate to use to
predict the change in FER. Further, as previously stated in the 2021
Decision and Order, validating an equation for extrapolating to FER at
an ESP that is higher than that at which the unit can operate may be
difficult or even not possible (as the unit cannot operate at that
point). See 86 FR 13530, 13533.
In addition, products that operate at low ESPs are typically used
in heating-only applications, and the products subject to the waiver
are not to make any representations in any public-facing materials that
these basic models are designed to be installed in systems that provide
both heating and cooling. Id. Therefore, DOE concludes that these
heating-only products do not compete with products intended for both
heating and cooling, and DOE is not implementing an adjustment factor
to the test procedure for furnace fans that are unable to complete
testing at the ESPs specified in table 1 of the revised appendix AA.
Additionally, DOE concludes that the proposed modified test provisions
reflect the actual use of these products that cannot operate at higher
ESPs and result in a metric that is representative.
Therefore, for the reasons discussed here and in the May 2022 NOPR,
in this final rule, DOE is finalizing its proposal to adopt the
modified test provisions for units that cannot meet the ESPs outlined
in table 1 of appendix AA.
D. Test Procedure Repeatability and Reproducibility
Comment responses to the July 2021 RFI indicated that stakeholders
encountered difficulty obtaining repeatable and reproducible FER
results using the current appendix AA. Based on feedback collected
during manufacturer interviews prior to the May 2022 NOPR, DOE
understands that there are several key areas of possible revision to
the currently applicable consumer furnace fan test procedure that could
improve repeatability and reproducibility. 87 FR 29576, 29583.
In response to the May 2022 NOPR, Lennox commented that it
evaluated over 60 furnace fans tested through the AHRI audit program
and found the correlation between manufacturer test values and audit
test values to be within an acceptable variation, such that test
procedure repeatability is not a concern. (Lennox, No. 11 at p. 1)
JCI referenced AHRI work project 8020 which, JCI stated, studied
the FER metric, attempted to develop a predictive metric, and reviewed
possible alternatives to the current standard. JCI quoted the results
of the AHRI project as follows: ``Appendix AA results in a wide metric
tolerance. AHRI's members report, and the research shows, that the
results are affected by the natural gas input rate and relative
humidity, which is problematic as testing is not conducted in a
controlled environment. Further, the current test method lends itself
to test inaccuracies resulting in the inability to achieve
repeatability.'' JCI also listed AHRI's recommendations for member
companies as follows: (1) evaluate their lab measurement systems,
procedures, and the uncertainty of each input variable; (2) test in a
controlled environment to reduce variability; and (3) complete a
statistical number of tests to improve rating confidence. JCI commented
that the first and third recommendations are feasible and less
expensive to the test labs, but JCI suggested that reduced variability
could be achieved through actions other than testing in a controlled
environment. (JCI, No. 10 at p. 2)
DOE notes that feedback from comment responses to the July 2021 RFI
and manufacturer interviews have indicated challenges with test
procedure repeatability and reproducibility in contrast to the comment
from Lennox. Additionally, DOE has received feedback that units are
often rated conservatively due to these repeatability
[[Page 25789]]
challenges. Further, in the May 2022 NOPR, DOE proposed and requested
feedback on specific solutions to minimize variability and uncertainty
in results. 87 FR 29576, 29583-29586. The following sections address
specific topics on which DOE has received feedback in this regard.
1. Fuel Input Rate Tolerance
DOE received feedback in response to the July 2021 RFI that the
natural gas input rate could impact FER, so DOE considered whether
tightening the tolerance on firing rate (from 2 percent)
would improve the repeatability of the test procedure without imposing
substantial burden. In a NOPR published on March 11, 2015, DOE
determined that it could not change the tolerance on firing rate
without increasing manufacturer burden because of variations in gas
valve performance. 80 FR 12875, 12886-12887. Because DOE is not aware
of any data suggesting it would now be possible to tighten this
tolerance without imposing substantial test burden, DOE did not propose
to change the tolerance on fuel input rating in the May 2022 NOPR. 87
FR 29576, 29583-29584.
In response to the May 2022 NOPR, AHRI, Carrier, and Lennox
commented that they support the decision not to tighten the tolerance
on fuel input ratings beyond what is required in ASHRAE 103-2017.
(AHRI, No. 15 at p. 2; Carrier, No. 12 at p. 2; Lennox, No. 11 at p. 3)
Lennox stated also that tightening the tolerance beyond 2
percent would increase manufacturer burden. (Lennox, No. 11 at p. 3)
For the reasons discussed in the May 2022 NOPR, and as supported by
these comments, DOE is not making any changes to the fuel input rating
in this final rule.
2. Ambient Conditions
In the May 2022 NOPR, DOE tentatively concluded that FER results
are affected by ambient air temperature and humidity. To help improve
the repeatability and reproducibility of test results, DOE proposed to
tighten the range of allowable ambient conditions during testing.
Specifically, DOE proposed to specify that ambient air temperature must
be maintained between 65 [deg]F and 85 [deg]F and relative humidity
must be maintained between 20 percent and 80 percent. 87 FR 29576,
29584. DOE tentatively concluded that these limits would not impose
additional burden on manufacturers while maintaining the
representativeness of the test procedure. Id.
DOE requested comment on these proposed constraints, and on its
tentative determination that this proposal would decrease variability
between tests. Id. at 87 FR 29584-29585.
In response to the May 2022 NOPR, Lennox, Carrier, and the Joint
Commenters commented that they support the proposed modifications to
the allowable ambient temperature range in appendix AA to be between 65
[deg]F and 85 [deg]F for non-condensing and condensing furnaces.
(Lennox, No. 11 at p. 4; Carrier, No. 12 at p. 3; Joint Commenters, No.
14 at p. 2) AHRI similarly commented that it supports the change in the
ambient air temperature requirement in appendix AA and suggested that
the change would not introduce additional burden. (AHRI, No. 15 at p.
2) Lennox and Carrier both commented that their laboratories have the
capability to condition the ambient air within the newly specified
range; therefore, the requirement will not add significant burden.
(Lennox, No. 11 at p. 4; Carrier, No. 12 at p. 3) Lennox stated that
this change will reduce FER variability for non-condensing furnaces as
well as standardize existing requirements for condensing furnaces.
(Lennox, No. 11 at p. 4)
Lennox, Carrier, JCI, and AHRI further commented that they support
the proposal to require maintaining the room relative humidity between
20 percent and 80 percent because it will decrease test variability
without adding significant burden. (Lennox, No. 11 at p. 4; Carrier,
No. 12 at p. 3; JCI, No. 10 at p. 2; AHRI, No. 15 at p. 3) However,
they each commented that a tighter range, for example 30 percent to 50
percent, for relative humidity would require FER testing to be
conducted in a special conditioned test room rather than in the main
laboratory test area, which would add significant manufacturer testing
burden. (Id.) Additionally, AHRI stated that the narrower band of 30 to
50 percent would require using tighter humidity controls in the test
room than the current requirement. (AHRI, No. 15 at p. 3) JCI similarly
stated that a tighter humidity range of 30 to 50 percent is beyond the
capability of existing lab facilities where FER testing is currently
performed. JCI stated that it does not support a relative humidity
range tighter than 20 to 80 percent. Furthermore, JCI commented that
the test repeatability of FER is less significantly sensitive to the
tolerance in relative humidity (``RH'') compared to other test
parameters. (JCI, No. 10 at p. 2)
For the reasons discussed in the May 2022 NOPR, and in
consideration of these stakeholder comment responses, DOE is finalizing
its proposal to specify in section 7.1 of appendix AA that the room
temperature shall not fall below 65 [deg]F (18.3 [deg]C) or exceed 85
[deg]F (29.4 [deg]C) and the relative humidity shall not fall below 20
percent or exceed 80 percent in this final rule.
3. Airflow Determination
Section 10.1 of the current appendix AA compares the input heat
energy to the heat picked up by the air when the furnace is in heating
mode based on the temperature rise of air passing through the furnace
and the specific conditions of the inlet air to calculate airflow in
the specified heating setting (``Qheat''). If this heating
mode airflow setting is the maximum airflow-control setting, then
Qheat is equal to the expected airflow at the maximum
airflow-control setting (``Qmax''). If this heating mode
airflow setting is not the maximum airflow-control setting, a second
calculation is performed to calculate Qmax based on
Qheat. Section 10.1, appendix AA. In the May 2022 NOPR, DOE
evaluated whether the current method of calculating airflow indirectly
based on measurements of other parameters leads to repeatability
challenges within the test procedure. 87 FR 29576, 29585.
Each parameter involved in the calculation of Qmax and
FER has its own inherent variability. Measuring airflow directly
reduces the number of parameters required to be measured and therefore
could reduce the overall variation inherent in the final FER value.
In the May 2022 NOPR, DOE acknowledged that requiring the use of an
airflow-measuring device for furnace fans could introduce a one-time
cost for manufacturers that either do not utilize such devices for
their current testing programs (presumably of other products) or do not
have enough of such devices available to test furnace fans in addition
to other HVAC products that use airflow-measuring devices. The
estimated cost of an airflow-measuring device is up to $50,000. Id.
In the May 2022 NOPR, DOE tentatively concluded that the benefits
of measuring airflow would directly outweigh the associated burdens and
that the requirement to directly measure airflow would not be unduly
burdensome. Id. DOE therefore proposed to require that airflow be
measured directly during each test. Id. Specifically, DOE proposed that
this measurement be done using the procedures and methods for measuring
airflow specified in ASHRAE 37-2009 (RA 2019), similar to how it is
done for central air conditioners and heat pumps.
[[Page 25790]]
Id. As part of this proposal, DOE proposed to incorporate by reference
Figure 12 of ANSI/Air Movement and Control Association International,
Inc. (``AMCA'') 210-07, ANSI/ASHRAE 51-07 (``AMCA 210-2007''), titled
``Laboratory Methods of Testing Fans for Certified Aerodynamic
Performance Rating;'' and Figure 14 of ANSI/ASHRAE Standard 41.2-1987
(RA 92), (``ASHRAE 41.2-1987 (RA 1992)''), titled ``Standard Methods
for Laboratory Airflow Measurement.'' Id. DOE requested comment on this
proposal. Id.
In the May 2022 NOPR, DOE also requested comment on whether it is
necessary to reference AMCA 210-2007 and ASHRAE 41.2-1987 (RA 1992) in
the test procedure instructions for constructing an airflow measuring
apparatus. Id. DOE also requested comment on alternative methods of
directly measuring airflow, such as methods outlined in AMCA 210 (e.g.,
the pitot traverse method),\10\ as well as duct-mounted airflow
measurement devices and anemometers, and whether these methods could
prove more accurate and repeatable. Id. Specifically, DOE requested
comment on alternative methods of direct airflow measurement, including
on the level of measurement accuracy associated with each approach and
any associated test burden. Id. at 87 FR 29585-29586.
---------------------------------------------------------------------------
\10\ See www.amca.org/assets/resources/public/pdf/Education%20Modules/AMCA%20210-16.pdf (last accessed January 11,
2023.)
---------------------------------------------------------------------------
In response to the May 2022 NOPR, the Joint Commenters expressed
support for the proposed requirement for direct measurement of airflow,
suggesting that it should improve repeatability and reproducibility.
(Joint Commenters, No. 14 at p. 2) Carrier commented that it would
support the test procedure change to direct airflow measurement
provided that gas heat operation is not required during the direct
airflow measurement test. (Carrier, No. 12 at pp. 3-4) Carrier added
that it performed comparison tests without gas heating operation on
four models, which represented a cross-section of non-weatherized gas
furnaces, to compare the methods of the currently applicable test
procedure to the proposed direct airflow measurement method. Carrier
reported that the results of the test showed slight favoring of the
current method over the direct measurement method; however, Carrier
stated that the FER results differed by less than 1 percent and maximum
airflow averaged 2 percent lower when using the direct measurement
method. (Id. at p. 4) AHRI stated that it has a limited data set and is
unable to provide a meaningful comparison between FER generated by the
direct and indirect airflow measurement methods. (AHRI, No. 15 at p. 3)
Lennox stated that the variation in airflow between DOE sample
units and AHRI audit units calculated under the currently applicable
test procedure would be similar to the typical variation when using
direct airflow measurement systems, as motor performance variation is
the primary driver for the airflow variation. (Lennox, No. 11 at p. 5)
Lennox commented that it did not support the proposal to change the
test procedure from the current method to a direct airflow measurement
method as it would cause a significant increase in manufacturer burden.
(Id. at p. 4) However, Lennox commented that, if DOE were to adopt the
proposal to measure airflow directly, DOE should carefully ensure that
results are cross-walked should ratings change as a result of direct
airflow measurement. (Id. at p. 5)
JCI commented that it does not support changing to direct
measurement of airflow because JCI is unsure if the proposed change to
directly measure airflow would resolve the repeatability issues
associated with the furnace fan test procedure. (JCI, No. 10 at pp. 2-
3, 4) JCI agreed that measuring airflow directly should reduce the
uncertainty in calculating maximum airflow compared to the current
method, but the proposed change does not guarantee that it would
constrain the uncertainty in the FER. JCI commented that the proposal
does not address furnace fan electrical consumption, which also has an
associated uncertainty. (JCI, No. 10 at pp. 2-3)
Carrier commented that the direct measurement method would improve
the accuracy of the test procedure while reducing the difficulty to run
it. Carrier suggested that, if DOE were to adopt the direct airflow
measurement method, DOE should consider applying the new test procedure
only to new models and allowing models tested under the existing test
procedure to remain compliant until that model is discontinued.
(Carrier, No. 12 at p. 4) Carrier stated that the proposed method of
direct airflow measurement would be a slight improvement in the burden
imposed on manufacturers from the furnace fans test procedure. (Id. at
p. 7)
AHRI noted that transitioning to the direct method would create a
significant burden for manufacturer test labs and third-party testing
facilities as the direct method would require a different set of
measurements and therefore additional equipment along with a
reconfiguration of the test setup that would require additional floor
space. AHRI added that the direct method would further increase testing
burden through doubling the number of samples run on code testers.
(AHRI, No. 15 at p. 3) AHRI commented that third-party and manufacturer
testing facilities would be required to construct code testers and
reconfigure heating labs to fit the sizeable instrumentation in order
to have the necessary set-up and capacity to conduct direct airflow
measurements. AHRI stated that if this is not an option due to space
constraints, third-party test facilities would need to move the set-up
equipment to small unitary test facilities that already have the built-
in flow meters. AHRI concluded that both of these options would
significantly increase test time and expenses, including operating
costs, and there would be a significant increase in burden for labs not
already set up to conduct this type of testing. (Id. at p. 7) AHRI
commented that manufacturers are equipped to conduct the current
furnace fan test procedure and stated that the additional burden posed
by transitioning to the direct method will outweigh the value of any
potential increased accuracy offered. (Id. at p. 3)
Additionally, AHRI commented that should DOE proceed with the
direct measurement method, the equipment should remain unfired
throughout the testing process. AHRI added that the use of flow
measurement devices with high temperature applications will create
significant issues and may decrease the life of said measurement
devices. AHRI stated that there is limited data available to make
accurate comparisons between methods. AHRI requested that data
supporting the reasoning for a transition to the direct measurement
method be made available prior to requiring the change. AHRI requested
that DOE conduct an adequate evaluation of the impact that the direct
measurement method will have on FER values and that a crosswalk be
created if necessary. Finally, AHRI suggested that DOE consider
alternative approaches to reduce testing burden while achieving the
same objectives. (Id. at p. 4)
Lennox commented that it does not support the proposed change of
the furnace fan test procedure from the current method to the direct
airflow measurement method due to the increased burden it would impose.
(Lennox, No. 11 at p. 1) Lennox commented that the current furnace fan
test setup allows the AFUE and FER test to be conducted in a single
setup, but a direct airflow measurement approach would require a second
setup which would significantly increase burden. (Id. at p. 5) Lennox
stated that measuring
[[Page 25791]]
airflow directly would cause significant upfront manufacturer costs to
purchase code testers and would additionally create ongoing operating
costs. Lennox added that additional investments in adequate lab and
personnel capacity for direct airflow measurement would be required.
Lennox stated that it has multiple product development facilities where
furnace fan testing is conducted, so investments would need to be made
in each facility. Lennox estimated the ongoing increase in burden to
conduct FER direct airflow testing to be up to a 100-percent increase
over the currently applicable test method. Lennox stated that DOE
should consider the total cumulative regulatory burden associated with
any changes to the FER test procedure to require direct airflow
measurement. (Lennox, No. 11 at p. 7) Lennox added that, because the
FER metric is a part of the AHRI audit program, the additional setup
would increase burden when conducting audits. Lennox commented that,
while manufacturers do directly measure airflow in the process of
developing airflow application tables, it is often done on one sample
and is not inclusive of all the iterations required in furnace
development, so burden would be added. (Id. at p. 5)
JCI commented that the instrumentation for airflow measurement is
often found in a different location than the gas lab, where heating
equipment is tested, and code tester labs are frequently unequipped to
supply fuel gas to a furnace or to dispose of flue gas. Furthermore,
JCI stated that the airflow code testers used by JCI and other
manufacturers are not intended to have heated air passing through them.
JCI noted that the proposed procedure presents issues because it
directs that the furnace burners be fired at the same time as the unit
is set up on the code tester for direct measurement of airflow. (JCI,
No. 10 at p. 3) JCI commented also that the only reason that burners
are fired in the current furnace fan test procedure is because they
must be fired in order to obtain the temperature rise value used in the
calculation of Qmax. JCI stated that if the airflow is to be
measured directly, there is no need to fire the burners during testing.
JCI also commented that changing to a direct airflow measurement would
add significant burden because it would require a separate setup from
the furnace test procedure, whereas the current furnace fan test
procedure setup is the same as the setup used for the furnace AFUE test
procedure. (Id. at p. 4)
JCI stated that independent testing should be conducted to verify
that the two test methods yield the same FER ratings. JCI noted that
DOE regulations require that if there is a change of test method, then
a unit that complies when tested by the old method must still be
compliant when tested by the new method. JCI stated that it would take
many months to verify that the hundreds of products they produce which
comply with the standards when tested to the currently applicable test
procedure still comply when tested according to the proposed method.
JCI commented that if test data reveal that the FER results are
different when tested according to the proposed method, DOE should be
prepared to adjust the maximum allowable FER rating to accommodate the
difference. (Id. at p. 3) Finally, JCI commented that the proposed
method would impose substantial additional test burden and/or equipment
costs and that there has been no demonstrated benefit to making the
change to direct airflow measurement. (Id. at p. 5)
Morrison commented that there are a variety of factors in the
airflow measurement procedure as outlined by ASHRAE 37 that could lead
to uncertainty associated with this procedure. Morrison noted that DOE
should investigate the error specific to this procedure as it relates
to furnace fan testing. (Morrison, NOPR Webinar Transcript, No. 9 at
pp. 20-23)
In response to the May 2022 NOPR, Lennox commented that AMCA 210-
2007 and ASHRAE 41.2-1987 (RA 1992) are associated with the direct
airflow measurement method, which Lennox does not support; therefore,
Lennox stated, the current furnace fan test procedure airflow
calculation is adequate. (Lennox, No. 11 at p. 5) Carrier recommended
that DOE reference ASHRAE 41.2-2018 as it is a newer and more current
standard. Carrier further commented that it does not recommend other
methods beyond ASHRAE 37-2009. (Carrier, No. 12 at p. 4) AHRI
recommended that DOE reference ASHRAE 41.2-2018, as opposed to ASHRAE
41.2-1987 (RA 1992), because it is more current. AHRI suggested that
establishing standardization across original equipment manufacturers
(``OEMs'') would be the best practice. AHRI stated that an updated
version of ASHRAE 37 is coming out soon and that ASHAE 37-2009 is the
industry standard for equipment and is preferred over AMCA 210-2007,
which is a fan-only standard. (AHRI, No. 15 at p. 4)
JCI stated that there are other less expensive measures that, if
progressively implemented, would result in repeatability improvements
in the furnace fan test procedure and, specifically, reduction in
maximum airflow variability. These measures include higher accuracy
requirements for instrumentation; providing additional clarity
regarding the thermocouple grid, statistical, and sampling techniques;
and limiting uncertainty in fuel input rate. JCI stated that these
measures would not impose additional burden and disruption to lab
facilities, would only require programmatic updates, would not incur
the expenses associated with purchasing a code tester, would not put
smaller OEMs at a competitive disadvantage, and would expedite
improving test procedure repeatability. (JCI, No. 10 at p. 3) Lennox
stated that while other airflow measurement methods exist, they are
generally less accurate than the methods specified in ASHRAE 37-2009
(RA 2019) and would consequently negate the purpose of transitioning to
a direct-airflow measurement method. (Lennox, No. 10 at p. 6)
AHRI noted that there are alternative instruments for direct
airflow measurement, but they are less accurate than the methods
specified in ASHRAE 37-2009 and would consequently negate the purpose
of transitioning to a direct airflow measurement method. (AHRI, No. 15
at p. 4)
The CA IOUs commented that ASHRAE 37 is sufficient, and that
referencing AMCA 210 is not necessary. The CA IOUs further commented
that they expect that a commercial industrial fans NOPR would lead to
an update AMCA 210-2016, and that this test procedure should reference
the 2016 version of AMCA 210 if any version is referenced. (CA IOUs,
NOPR Webinar Transcript, No. 9 at pp. 25-26)
In response to these comments regarding the proposals to measure
airflow directly in the furnace fan test procedure and to reference
AMCA 210-2007 and ASHRAE 41.2-1987 (RA 1992) in the furnace fan test
procedure, DOE maintains that measuring airflow directly using a code
tester could reduce the error associated with airflow measurement in
comparison to calculating the airflow and, in turn, reduce concerns
about the repeatability and reproducibility of the furnace fan test
procedure. However, since the May 2022 NOPR, DOE has conducted
preliminary testing to compare the values of Qmax and FER
determined according to the current test procedure for consumer furnace
fans and a modified test method similar to that proposed in the May
2022 NOPR that included direct airflow measurements.
[[Page 25792]]
The preliminary results indicated that values determined from tests
directly measuring airflow could differ from values determined using
the current test method. This preliminary testing did not indicate
whether such differences would be more or less representative than the
results obtained under the current test procedure requirements.
Further, during the preliminary testing, DOE attempted to test some
units in the heating mode without the burner firing, as suggested by
commenters in response to the May 2022 NOPR, but found that some units
were not able to be operated in this way, indicating that a test
procedure that requires the test to be conducted unfired may not be
possible for all furnace fans. Due to these concerns combined with
concerns raised by commenters about potential changes to ratings and
the burden associated with implementing this change, DOE has determined
to not finalize the proposal from the May 2022 NOPR to measure airflow
directly in this final rule. Relatedly, DOE is not incorporating by
reference AMCA 210-2007 and ASHRAE 41.2-1987 (RA 1992). Additionally,
DOE is adopting other provisions in this final rule that are intended
to improve repeatability of the current test procedure without
affecting existing ratings or significantly increasing test burden, as
discussed elsewhere in section III.D of this document. However, DOE is
still investigating the impact of direct airflow measurement on furnace
fan ratings, including the impact of running tests with and without the
burners firing during heating-mode tests, and may further assess
directly measuring airflow in a future test procedure rulemaking for
consumer furnace fans.
4. Location of External Static Pressure Measurements
Appendix AA currently requires that external static pressure be
measured 18 inches from the outlet. This differs from the requirements
outlined in section 6.4 of ASHRAE 37-2009, in which the measurement
location varies depending on the dimensions of the duct outlet. In the
May 2022 NOPR, DOE reevaluated this provision and how it might impact
the repeatability of the test procedure. 87 FR 29576, 29586. DOE
expressed concern that measuring at a fixed location of 18 in from the
outlet could lead to a less accurate and less repeatable measurement
than the approach provided in ASHRAE 37-2009 because the airflow
profile may not be fully developed. Id.
However, DOE did not have sufficient information to propose a
change in the May 2022 NOPR, and therefore requested comment on whether
requiring that the external static pressure be measured at the location
specified in section 6.4 of ASHRAE 37-2009, as opposed to specifying
that external static pressure taps always be placed 18 in from the
outlet (i.e., the instructions currently in appendix AA), could improve
test repeatability. Id. DOE also requested comment on whether
manufacturer facilities and other test laboratories would be able to
accommodate the added duct length during testing. Id. Further, if test
facilities would not be able to accommodate the added duct length
during testing, DOE requested comment on whether a different length
requirement could improve test repeatability while not preventing any
existing test facilities from completing a valid test for furnace fans.
Id.
In response to the May 2022 NOPR, Carrier and AHRI commented that
they are opposed to the change in location of measurement if the change
results in a higher FER value. If the change does not result in a
higher FER value, Carrier and AHRI stated that they would not be
opposed to the change. (Carrier, No. 12 at p. 5; AHRI, No. 15 at p. 5)
AHRI recommended that the furnace fan test procedure be aligned with
furnace test procedures because existing ductwork can be utilized and
AFUE will meet existing space constraints. (AHRI, No. 15 at p. 5)
AHRI and JCI stated that they do not support any change to the
location of pressure taps for furnace fan testing, and that if the
furnace is to be tested on the code tester, the ASHRAE standard for
that airflow measurement process includes a description of the duct
design and the location of pressure taps. (AHRI, No. 15 at p. 5; JCI,
No. 10 at p. 4) AHRI and JCI noted that for furnaces tested in the gas
heating lab, the ASHRAE 103 standard includes a description of the
ducts and pressure tap locations. (Id.) AHRI added that these standards
have been in use for many years and yield reliable and repeatable
results. AHRI stated that the FER test procedure does not need to
specify test duct details; it only needs to reference the appropriate
existing standard. (AHRI, No. 15 at p. 5) JCI commented that these
standards (e.g., ASHRAE 103) have been in use for many years and
provide reliable and repeatable results. JCI stated that the research
they conducted concluded that repeatability will not be improved by
changing the location of the pressure taps. Moreover, JCI stated that
placing the pressure taps at 18 in from the outlet (instead of at a
location based on the outlet dimensions) will result in measuring
pressure at inconsistent duct lengths within the turbulent flow
development region into the supply duct. JCI commented that DOE should
engage with OEMs in a research effort to test the assumption in this
proposal before finalizing the change. (JCI, No. 10 at p. 4)
Lennox commented that for the current method of calculating airflow
based on temperature rise, DOE should maintain the location of 18 in
from the outlet to standardize to the same test ducts used for all
safety and performance tests performed under Z21.47 and ASHRAE 103-
2017. Lennox added that DOE should gather test data that show that a
longer duct required by ASHRAE 37-2009, which would require an elbow
with 9 thermocouples added to measure outlet temperature, would justify
the added manufacturer burden of building additional ducts and
switching back and forth between these and those required by all other
tests. (Lennox, No. 11 at p. 6)
DOE notes that, in response to the discussion presented in the May
2022 NOPR regarding whether the current method for measuring ESP at a
fixed location of 18 in from the outlet could lead to a less accurate
and less repeatable measurement than the approach provided in ASHRAE
37-2009, commenters have not provided any data that demonstrate the
impact on accuracy or repeatability of changing the location of
external static pressure measurements, nor does DOE have any additional
information beyond the discussion provided in the May 2022 NOPR. And in
response to the comment from JCI, DOE notes that the currently
applicable test procedure at appendix AA requires that external static
pressure be measured 18 inches from the outlet, as opposed to a
measurement location that varies depending on the dimensions of the
duct outlet. Additionally, commenters generally did not support the
change to the location of pressure taps for consumer furnace fan
testing. For these reasons, DOE is not changing the ESP measurement
location in this final rule.
5. Language Updates
In the May 2022 NOPR, DOE responded to several comments in response
to the July 2021 RFI regarding revisions to the language in appendix AA
that could reduce confusion about the test procedure and, in turn,
improve test procedure repeatability. 87 FR 29576, 29586-29589.
a. Definitions
For furnace fans used in furnaces or modular blowers with single-
stage
[[Page 25793]]
heating, the three airflow-control settings required to be tested are:
the maximum setting, the default constant-circulation setting, and the
default setting when operated using the maximum heat input rate.\11\
For furnace fans used in furnaces or modular blowers with multi-stage
heating or modulating heating, the airflow-control settings to be
tested are: the maximum setting, the default constant-circulation
setting, and the default setting when operated using the reduced heat
input rate. See sections 8.6.1, 8.6.2, 8.6.3, appendix AA. For both
single-stage and two-stage or modulating units, if a default constant-
circulation setting is not specified, the lowest airflow-control
setting is used to represent constant circulation for testing. See
section 8.6.2, appendix AA.
---------------------------------------------------------------------------
\11\ For furnace fans where the maximum airflow control setting
is a heating setting, the maximum airflow-control setting test and
the default heating airflow-control setting test would be identical,
such that only two tests are required: (1) maximum airflow (which is
the same as the default heating setting) and (2) constant
circulation.
---------------------------------------------------------------------------
In addition, if the manufacturer specifies multiple heating
airflow-control settings, the highest heating airflow-control setting
specified for the given function (i.e., at the maximum or reduced
input, as applicable) is used. See section 8.6.3, appendix AA.
Inquiries sent to DOE since the publication of the January 2014
Final Rule indicate that there are differing interpretations regarding
the appropriate airflow-control settings for testing, with some
manufacturers interpreting the DOE consumer furnace fan test procedure
as requiring testing only the ``as-shipped'' airflow-control settings.
However, the definition for ``default airflow-control setting''
specifically states that ``[i]n instances where a manufacturer
specifies multiple airflow-control settings for a given function to
account for varying installation scenarios, the highest airflow-control
setting specified for the given function shall be used for the
procedures specified in this appendix.'' Section 2.6, appendix AA.
Further, the default airflow-control settings are defined as airflow-
control settings specified for installed use by the manufacturer. That
section in turn clarifies that the ``manufacturer specifications for
installed use'' are those specifications provided for typical consumer
installations in the product literature shipped with the product in
which the furnace fan is installed.
Additionally, inquiries sent to DOE indicate that some
manufacturers may be interpreting the test procedure to require testing
according to installation instructions printed on the control board.
However, DOE notes that the same control board may be used across
multiple products to reduce manufacturing complexity and costs, and, as
a result, instructions provided on a control board may not be
applicable to every unit in which a control board is used and could
contradict the specifications in product literature. For this reason,
DOE specifies in the definition of ``default airflow-control setting''
that the manufacturer specifications for installed use are those
specifications provided for typical consumer installations in the
product literature shipped with the product in which the furnace fan is
installed. Section 2.6, appendix AA.
Based on feedback received in response to the July 2021 RFI, DOE
proposed in the May 2022 NOPR to change the defined term at section 2.6
in appendix AA from ``default airflow-control settings'' to ``specified
airflow-control settings.'' This revised definition would avoid
potential misinterpretation of the term ``default,'' which is not
intended to limit testing to the as-shipped airflow-control settings.
87 FR 29576, 29587.
DOE also notes that there is currently conflicting direction from
sections 8.6.2 and 2.6 of appendix AA, with section 2.6 specifying that
the testing laboratory use the highest available airflow-control
setting and section 8.6.2 specifying that the testing laboratory use
the lowest available airflow-control setting. To address this
discrepancy, DOE also proposed in the May 2022 NOPR to add the phrase
``unless otherwise specified within the test procedure'' to the end the
definition of ``specified airflow-control settings'' to clarify that
the hierarchy within appendix AA is for the airflow-control settings to
be selected according to section 2.6, unless section 8.6.2 applies, in
which case section 8.6.2 should be used to select airflow-control
settings. Id.
In response to the May 2022 NOPR, Lennox and Carrier commented that
they support the proposal to change the term ``default airflow-control
settings'' to ``specified airflow-control settings.'' (Lennox, No. 11
at p. 6; Carrier, No. 12 at p. 5) JCI commented that while it agrees
with the need to clarify what speed tap is to be used for testing a
furnace in heating mode, the rule should explicitly state that the
heating speed to be used during heat-mode testing is the speed tap
specified by the furnace manufacturer in the product literature shipped
with the furnace. (JCI, No. 10 at p. 4) AHRI requested that DOE provide
clarification regarding what ``default airflow-control settings''
refers to and provide the reasoning for this change. AHRI also
suggested that DOE specify what is meant by ``unless otherwise
specified within the test procedure.'' (AHRI, No. 15 at p. 5)
Lennox added that it also supports the addition of the phrase
``unless otherwise specified within the test procedure.'' Lennox stated
that these changes would improve clarity. (Lennox, No. 11 at p. 6) JCI
commented that the phrase ``unless otherwise specified within the test
procedure'' is confusing, as the furnace should always be tested at the
manufacturer-specified heating speed and the test procedure should not
specify otherwise. (JCI, No. 10 at p. 4)
In response to the comment from JCI, DOE notes that the definition
it proposed in the May 2022 NOPR and is adopting in this final rule for
specified airflow-control settings explicitly states that these
settings are those in the product literature shipped with the product
in which the furnace fan is installed. In response to the comment from
AHRI, DOE notes that this change was proposed in response to inquiries
received since the publication of the January 2014 Final Rule. Some
inquiries expressed confusion regarding the distinction between the
``default airflow-control settings'' and the ``as-shipped airflow-
control settings.'' Others indicated that some manufacturers may be
interpreting the test procedure to require testing according to
installation instructions printed on the control board. By proposing to
change ``default airflow-control settings'' to ``specified airflow-
control settings,'' DOE intended to clarify that this refers to the
manufacturer-specified settings for each testing mode.
To provide clarity and resolve the conflicting instruction, in this
final rule, DOE is finalizing its proposal to change the term ``default
airflow-control settings'' to ``specified airflow-control settings''
and to add the phrase ``unless otherwise specified within the test
procedure'' to the end the definition of ``specified airflow-control
settings'' in section 2.9 of appendix AA.
b. Heating Airflow-Control Settings
In the May 2022 NOPR, DOE stated that it expects that if a fan
setting is identified for heating mode operation that the fan would be
capable operating in that mode at the ESP specified in appendix AA
(which is representative of a typical ESP that would be encountered in
the field) and at the specified temperature rise range. DOE requested
comment on whether it is necessary to specify that the maximum heating
airflow-control setting used during
[[Page 25794]]
testing be one that also allows for operation within the manufacturer-
specified temperature rise range during testing. DOE also requested
information regarding how often furnace fans operate outside of the
manufacturer-specified temperature rise range during FER testing under
the current requirements. 87 FR 29576, 29587.
In response to the May 2022 NOPR, Lennox, Carrier, AHRI, and JCI
suggested that the maximum heating airflow-control setting should allow
for operation within the manufacturer's specified rise range during
testing. (Lennox, No. 11 at p. 6; Carrier, No. 12 at p. 5; AHRI, No. 15
at p. 6; JCI, No. 10 at p. 4) Carrier stated that it creates
unnecessary confusion to require compliance otherwise. (Carrier, No. 12
at p. 5) JCI commented that realistic FER ratings depend on operating
the furnace in a realistic manner. JCI added that testing at heating
speeds resulting in a temperature rise outside of the manufacturer-
specified range is not a realistic operating condition. (JCI, No. 10 at
p. 4)
DOE agrees with the commenters that the temperature rise during
testing should be within the manufacturer-specified range. If the
temperature rise were outside of the manufacturer-specified range, it
would not be representative of typical performance. Therefore, in this
final rule, DOE is adding clarification in section 8.6.3 of appendix AA
that the maximum heating airflow-control setting used during testing be
one that also allows for operation within the manufacturer-specified
temperature rise range during testing.
c. Power Measurements
Sections 8.6.1.1, 8.6.1.2, 8.6.2, and 8.6.3 of appendix AA require
the following parameters to be measured after steady-state operation is
achieved: the furnace fan electrical input power, fuel or electric
resistance heat kit input energy, external static pressure, steady-
state efficiency, outlet air temperature, and/or temperature rise. DOE
is aware that some test facilities take a single reading for each of
these parameters after achieving the steady-state criteria. As noted in
the May 2022 NOPR, in DOE testing, during which these parameters were
measured in 1-second intervals throughout the steady-state period, data
showed that the values fluctuate sometimes significantly between
readings, even while steady-state conditions are maintained. 87 FR
29576, 29588. Due to the potential for significant differences from one
reading to the next, these fluctuations could contribute to
repeatability issues in FER testing if a value from a single point in
time is used for each test. In particular, DOE testing has shown that
the standard deviation of furnace fan power measurements for most units
over a 30-minute period (at steady state operation) can be up to 16
percent of the average, although for most units the standard deviation
is less than 1 percent of the average power consumption. DOE stated in
the May 2022 NOPR that it was considering whether further
clarifications are necessary for appendix AA to clarify how
manufacturers should take power measurements. Specifically, DOE
explained that that increasing the number of discrete measurements
taken (i.e., increasing the sample size) and averaging them to
determine each furnace fan power consumption measurement may yield a
result that is more representative and repeatable than using single
point measurements of the furnace fan power. Id. For example, DOE could
require that power measurements be based on the average value over a 1-
minute interval beginning immediately after steady-state operation has
been achieved, during which the power is measured at least once per
second. Alternatively, DOE could require furnace fan power measurements
to be based on the average of measurements taken over the entire
steady-state period at certain specified intervals (e.g., every minute
or every 5 minutes). Id.
In the May 2022 NOPR, DOE requested data and information on the
methods and granularity with which test facilities currently measure
the aforementioned variables, particularly furnace fan power
(EMax, ECirc, and EHeat). DOE also
requested comment on the intervals at which test facilities are
currently capable of recording these measurements with their current
instrumentation. Finally, DOE requested information on whether there
are variables aside from the fan power consumption variables for which
there are significant fluctuations in measurements that DOE should also
consider requiring be determined as an average of multiple
measurements. Id. at 87 FR 29588-29589.
DOE also requested comment on the number of samples that should be
taken, and the length of time over which data should be collected in
order for a representative average to be achieved. DOE requested
comment on the associated costs, if any, to upgrade measurement
instruments or software to be able to collect furnace fan power
consumption measurements at frequencies of once per second, once per
minute, once per 5 minutes, and/or other recommended sampling
frequencies. Id. at 87 FR 29589.
In response to the May 2022 NOPR, AHRI commented that the number of
samples per period of time is dependent on the specific testing
conditions; however, AHRI suggested that, generally, manufacturers take
power samples every second for 30 seconds, and in alternative testing
scenarios once every 2 seconds for 60 seconds to achieve representative
averages. (AHRI, No. 15 at p. 6)
Carrier, JCI, and AHRI recommended that short periods of average
power measurements should be allowed for instrumentation accuracy and
consistency. (Carrier, No. 12 at p. 5; Joint Commenters, No. 14 at pp.
2-3; AHRI, No. 15 at p. 6) Carrier stated that airflow pressure
measurements can fluctuate such that using a sample rate of one reading
per second for 30 seconds or some other variation to obtain a several-
reading average would be preferred. (Carrier, No. 12 at pp. 5-6) AHRI
commented that airflow pressure measurements especially have
fluctuations that are improved using averaging techniques over multiple
measurements and stated that the currently applicable test method on
existing equipment does not have the capacity to automatically collect
the requested data and information. AHRI noted that the test stand does
not have significant fluctuations in data values. (AHRI, No. 15 at p.
6) The Joint Commenters commented that DOE should consider requiring
time-averaged values for other test variable measurements as well.
(Joint Commenters, No. 14 at p. 3)
Carrier stated that it has not evaluated the associated costs to
upgrade lab infrastructure for more frequent readings. (Carrier, No. 12
at p. 6)
These stakeholder comments suggest that current laboratory setups
are capable of reporting power data in 1-second intervals and averaging
this reported data over the last thirty seconds of the furnace fan test
without incurring additional cost or burden. Therefore, in this final
rule, DOE is clarifying in section 8.6 of appendix AA that furnace fan
electrical input power (EMax, ECirc, and
EHeat) shall be determined using an average of the
measurements taken over the final 30 seconds of the test at an interval
no less frequent than every 1 second.
d. Other Language Clarifications
The title of section 8.3 of appendix AA is ``Steady-State
Conditions for Gas and Oil Furnaces,'' the title of section 8.4 is
``Steady-State Conditions for Electric Furnaces and Modular
[[Page 25795]]
Blowers,'' and the title of section 8.5 of appendix AA is ``Steady-
State Conditions for Cold Flow Tests.'' Sections 8.3 and 8.4 describe
the steady-state conditions for ``hot flow'' tests during which the
burner or heating element is on, while section 8.5 describes the
steady-state conditions for ``cold flow'' tests during which the burner
or heating element is off.
In the May 2022 NOPR, DOE proposed to amend the section titles to
include the terminology ``for Hot Flow Tests'' in the titles to provide
better consistency between the section titles and to provide clarity
for the intended use of sections 8.3 and 8.4 of appendix AA. 87 FR
29576, 29589. DOE did not receive any comments in response to this
proposal. For the reasons discussed here and in the May 2022 NOPR, DOE
is finalizing this change as proposed.
DOE also proposed in the May 2022 NOPR to redesignate the
description of operating-mode hours from ``cooling hours'' with
variable ``CH'' to ``maximum airflow hours'' with variable ``MH.'' DOE
tentatively concluded that these descriptions would be more accurate,
as the maximum airflow-control setting is not necessarily a cooling
airflow-control setting, and that this proposed change would provide
consistency with the description of the operational mode and
EMax measurement and avoid the implication that the maximum
airflow-control setting will always be a cooling mode. Id.
Finally, in the May 2022 NOPR, DOE proposed to add an asterisk
prior to the statement ``once the specified ESP has been achieved, the
same outlet duct restrictions shall be used for the remainder of the
furnace fan test'' in section 8.6.1.2 of appendix AA to link this
statement to the ESP column of table 1. Id. at 87 FR 29588. This change
would clarify the appropriate duct restrictions for testing and not
make any substantive changes. Id.
DOE did not receive any comments in response to these proposals.
Therefore, for the reasons discussed in this final rule and in the May
2022 NOPR, DOE is finalizing these changes as proposed.
E. Nomenclature and Equations
In response to comments submitted following the July 2021 RFI, DOE
considered several changes to the nomenclature and equations in
appendix AA. First, in the May 2022 NOPR, DOE noted the term
Qi in appendix AA, which refers to the airflow control
setting in airflow-control setting i, could lead to confusion as the
subscript ``i'' has two different meanings: the airflow-control setting
and the heat input setting. Id. at 87 FR 29589.
DOE also evaluated revising the nomenclature for variables and
conversion factors, including steady-state efficiency
(``EffySS''), the specific volume of dry air
(``vair''), jacket loss (``LJ''), airflow
(``Qi''), the conversion factor from hours to minutes (60),
the approximate specific heat of dry air (0.24), and the approximate
specific heat capacity of saturated water vapor (0.44). Id. at 87 FR
29589-29590.
In the May 2022 NOPR, DOE noted that, should DOE adopt its proposal
to measure airflow directly, the equations to calculate airflow would
no longer be needed. Id. at 87 FR 29590. (However, as discussed in
section III.D.3 of this document, DOE is not adopting its proposal to
measure airflow directly and is instead maintaining the equations for
calculating airflow.) Further, because the variable QIN,i
would be relevant regardless of whether DOE ultimately adopts its
proposal to directly measure airflow, DOE proposed to revise the
variable QIN,i within the test procedure for furnace fans at
appendix AA. Id. DOE also stated that should DOE not adopt the proposal
to measure airflow directly, DOE would propose to include the following
definitions in section 9 of appendix AA:
60 = conversion factor from hours to minutes (min/h)
0.24 = approximate specific heat capacity of dry air (Btu/lb-
[deg]F)
0.44 = approximate specific heat capacity of saturated water
vapor, (Btu/lb-[deg]F)
Effyss,i = Steady-State Efficiency in airflow-
control setting i. For gas and oil furnaces, Effyss,i as
specified in sections 11.2.7 (Non-Condensing and Non modulating),
11.3.7.3 (Condensing and Non modulating), 11.4.8.8 (Non-Condensing and
Modulating), or 11.5 (Condensing and Modulating) of ASHRAE 103-2017, in
%. For electric furnaces or modular blowers, Effyss,i equals
100, in %.
LJ = jacket loss as determined as specified in
section 8.6 of ASHRAE 103-2017 or a default value of 1% if the jacket
loss test is not performed, in %.
Ti,k, In = inlet air temperature at time of the
electrical power measurement, in [deg]F, in airflow-control setting i
and heat setting k, where i can be ``Circ'' to represent constant-
circulation (or minimum airflow) mode, ``Heat'' to represent heating
mode, or ``Max'' to represent maximum airflow (typically designated for
cooling) mode. If i = Heat, k can be ``H'' to represent the high heat
setting or ``R'' to represent the reduced heat setting. If i = Max or
Circ, k is not needed.
Ti,k, Out = average outlet air temperature as
measured by the outlet thermocouple grid at time of the electrical
power measurement, in [deg]F, in airflow-control setting i and heat
setting k, where i can be ``Circ'' to represent constant-circulation
(or minimum airflow) mode, ``Heat'' to represent heating mode, or
``Max'' to represent maximum airflow (typically designated for cooling)
mode If i = Heat, k can be ``H'' to represent the high heat setting or
``R'' to represent the reduced heat setting. If i = Max or Circ, k is
not needed.
[Delta]Ti,k = Ti,k, Out minus
Ti,k, In, which is the air throughput temperature rise in
setting i and heat setting k, in [deg]F
Qi,k = airflow in airflow-control setting i and
heat setting k, in cubic feet per minute (CFM)
QIN,k = measured fuel energy input rate, in Btu/h,
at specified operating conditions k based on the fuel's high heating
value (HHV) determined as required in section 8.2.1.3 or 8.2.2.3 of
ASHRAE 103-2017, where k can be ``H'' for the maximum heat setting or
``R'' for the reduced heat setting
vair = specific volume of dry air at specified
operating conditions per chapter 1 of the 2021 ASHRAE Handbook in
ft\3\/lb \12\
---------------------------------------------------------------------------
\12\ The current version of appendix AA defines vair
as ``the specific volume of dry air at specified operating
conditions per the equations in the psychrometric chapter in the
2001 ASHRAE Handbook in ft\3\/lb.'' DOE proposed an identical
definition in the May 2022 NOPR. 87 FR 29576, 29591. However, the
specific volume of dry air can be read from tables so, in this final
rule, DOE is removing the reference to equations in this definition
for clarity. Additionally, as previously discussed in section
III.B.2 in this document, DOE is now incorporating by reference
chapter 1 of the 2021 AHSRAE Handbook, which uses the same method to
determine the specific volume of dry air as the psychrometric
chapter of the 2001 ASHRAE Handbook.
---------------------------------------------------------------------------
Id.
Further, DOE proposed to correct the conversion factor from watts
to Btu/h to match the units designated for the fuel energy input rate
(QIN,k), changing it from 3,413 to 3.413. Id. Finally, DOE
noted that there should be different variables assigned to represent
relative humidity and the humidity ratio. To provide clarity regarding
these variables, DOE proposed to redesignate the variable for relative
humidity from ``W'' to ``q.'' Id. at 87 FR 29590-29591.
In response, AHRI and Carrier commented that ``W'' is defined as
humidity ratio; therefore, it would not be necessary to change ``W'' to
``q.'' (AHRI, No. 15 at p. 6; Carrier, No. 12 at p. 6) Lennox commented
it agreed with adding definitions to certain variables
[[Page 25796]]
and constants as proposed and to change the conversion factor to (Btu/
h)/W. (Lennox, No. 11 at p. 7)
With regards to the comments from AHRI and Carrier, while ``W'' is
defined as the humidity ratio in section 9 of appendix AA, DOE notes
that ``W'' is also defined as relative humidity in section 8.6.1 of
appendix AA. To provide clarity and distinguish between the two terms,
DOE is finalizing its proposal to designate ``q'' as the relative
humidity in section 8.6.1 of appendix AA. For the reasons discussed in
this final rule and in the May 2022 NOPR, DOE is finalizing the
additional proposals regarding nomenclature and equation adjustments in
appendix 9 of appendix AA, consistent with the proposals in the May
2022 NOPR.
F. Thermocouple Accuracy
Section 5.1 of appendix AA, which references section 5.1 of ASHRAE
37-2009, requires that temperature-measuring instruments must be
accurate to within 0.75 [deg]F. Section 6 of appendix AA references
section 7 of ASHRAE 103-2007 for the test apparatus setup. Section 7.6
of ASHRAE 103-2007 includes instructions to take temperature
measurements with thermocouple grids constructed of either 5, 9, or 17
thermocouples, depending on the stack diameter. The measurement
accuracy of a thermocouple grid depends on the type and number of
thermocouples used, as well as the magnitude of the air temperature
being measured.
In the May 2022 NOPR, DOE evaluated commenter feedback to the July
2021 RFI and tentatively concluded that, assuming that the stack
temperatures of gas furnaces would not likely exceed 450 [deg]F,
current instrumentation is adequate to measure the stack temperature of
furnaces on the market. Thus, DOE did not propose any changes to the
accuracy of temperature-measuring instruments in appendix AA. 87 FR
29576, 29591. DOE did not receive any comments in response to the May
2022 NOPR. As a result, this final rule makes no changes to the
specified accuracy of temperature measuring instruments in appendix AA.
G. Alternatives to the FER Metric
In response to the May 2022 NOPR, AHRI stated that the FER metric
may not be the most appropriate method for testing furnace fans. AHRI
stated that furnace fans are not sold directly to consumers and
consumers are generally unconcerned with FER values when selecting the
best product for their application. AHRI stated that it would
appreciate DOE working through concerns about this test procedure with
manufacturers to achieve a workable solution. (AHRI, No. 15 at p. 4)
Lennox stated that furnace fan standards do not impact consumer
buying decisions for the furnaces in which residential furnace fans are
used. Lennox added that when considering energy efficiency, consumers
evaluate AFUE because it represents the majority of the energy use of a
furnace, and furnace fans consume less than 2 percent of the overall
energy use of a residential furnace. Lennox recommended that DOE
explore less burdensome approaches regarding ensuring minimum furnace
fan efficiency. Lennox added that there are limited opportunities for
manufacturers to improve furnace fan energy efficiency and that it is
not likely to be economically justified for non-weatherized and
weatherized gas furnaces. (Lennox, No. 11 at p. 2)
In response to the comments from AHRI and Lennox, DOE notes that
AHRI and Lennox did not provide any specific suggestions as to an
alternate test procedure that would better satisfy EPCA's requirement
that the test procedure produce test results which measure energy
efficiency, energy use, or estimated annual operating cost of a furnace
fan during a representative average use cycle or period of use without
being unduly burdensome to conduct. (42 U.S.C. 6293(b)(3)) Throughout
this final rule, DOE has considered and responded to each comment
received regarding specific aspects of the furnace fan test procedure.
DOE has determined that the amended test procedure adopted in this
final rule produces a representative measure of furnace fan energy
efficiency and is not unduly burdensome to conduct. Regarding improved
furnace fan efficiencies, DOE evaluates opportunities for increased
efficiency as part of the separate energy conservation standards
rulemaking for consumer furnace fans.\13\
---------------------------------------------------------------------------
\13\ See docket ID EERE-2021-BT-STD-0029 on www.regulations.gov.
---------------------------------------------------------------------------
H. Test Procedure Costs
EPCA requires that test procedures proposed by DOE not be unduly
burdensome to conduct. (42 U.S.C. 6293(b)(3)) In this final rule, DOE
is finalizing its proposals to amend the existing test procedure for
consumer furnace fans by specifying a test method for furnace fans that
operate at low ESPs, updating the incorporation by reference of certain
industry test procedures to the most recent versions, clarifying the
scope of the definition of ``furnace fans,'' tightening ambient
conditions, clarifying language for airflow-control settings,
clarifying nomenclature, and correcting typographical errors. As
discussed in section III.D.3 of this document, DOE is not finalizing
its proposal to require direct measurement of airflow in this final
rule. DOE has determined that the amendments adopted in this final rule
will not impact test costs, as discussed in the remainder of this
section.
In response to a petition for waiver and an application for interim
waiver for heating-only furnace fans, DOE granted a waiver requiring
use of an alternate test procedure that specifies alternate ESP test
conditions for furnace fans that operate at low ESPs. Any such furnace
fan models currently on the market have already been granted a test
procedure waiver from DOE, which specifies use of the alternate test
procedure. As such, incorporating a similar methodology as the waiver
methodology into the test procedure for furnace fans that operate at
low ESPs will not result in any additional costs for manufacturers.
DOE is updating the material it incorporates by reference to
include more recent versions of ASHRAE 103 and ASHRAE 37. DOE is also
incorporating by reference chapter 1 of 2021 ASHRAE Handbook. As
discussed previously, DOE's review of these standards indicates that
reference to the revised versions of them will not impact FER ratings
and will not require that manufacturers recertify their units.
Therefore, manufacturers will not incur any additional costs.
Defining and explicitly excluding dual-fuel furnace fans from the
scope of appendix AA will make clear that such products are not subject
to testing under appendix AA and will not impose any additional burden.
In this final rule, DOE is also tightening ambient conditions to
limit the permissible ambient temperature range to between 65 [deg]F
and 85 [deg]F and the ambient humidity range to between 20 percent and
80 percent for both condensing and non-condensing furnaces. As
discussed, appendix AA currently already limits ambient temperatures to
between 65 [deg]F and 85 [deg]F, as well as humidity to below 80
percent for condensing furnaces, and DOE understands that testing
laboratories are generally able to meet these criteria in their testing
laboratories without the use of a specialized test chamber.
Additionally, based on feedback received from Lennox, Carrier, JCI, and
AHRI as outlined in section III.D.2 of this document and in
confidential manufacturer interviews, DOE has
[[Page 25797]]
concluded that it is unlikely that test laboratories would be unable to
meet a minimum relative humidity requirement of 20 percent because that
limit would exclude only the driest conditions. Therefore, DOE expects
that test laboratories will not incur additional cost in applying these
same temperature tolerances to testing of non-condensing furnaces as
well. These changes to the ambient condition requirements are intended
to increase the accuracy of FER ratings and the consistency of test
results but are not expected to change the actual performance of any
units. Additionally, DOE will not require units that are currently
certified to retest according to the updated test procedure.
DOE's remaining changes (clarifying nomenclature and fixing
typographic errors) will similarly not result in any changes to the
test conduct and therefore will not affect the cost of testing. For
these reasons, manufacturers will be able to rely on data generated
under the test procedure in effect prior to the adoption of this
amendment. However, if a manufacturer chooses to retest as a result of
these test procedure amendments, DOE estimates a testing cost of $3,500
per unit and a minimum total cost of $7,000 per basic model.
I. Effective and Compliance Dates
The effective date for the adopted test procedure amendment will be
75 days after publication of this final rule in the Federal Register.
EPCA prescribes that all representations of energy efficiency and
energy use, including those made on marketing materials and product
labels, must be made in accordance with an amended test procedure,
beginning 180 days after publication of the final rule in the Federal
Register. (42 U.S.C. 6293(c)(2)) EPCA provides an allowance for
individual manufacturers to petition DOE for an extension of the 180-
day period if the manufacturer may experience undue hardship in meeting
the deadline. (42 U.S.C. 6293(c)(3)) To receive such an extension,
petitions must be filed with DOE no later than 60 days before the end
of the 180-day period and must detail how the manufacturer will
experience undue hardship. (Id.)
Upon the compliance date of test procedure provisions in this final
rule, any waivers that had been previously issued and are in effect
that pertain to issues addressed by such provisions are terminated. 10
CFR 430.27(h)(3). Recipients of any such waivers are required to test
the products subject to the waiver according to the amended test
procedure as of the compliance date of the amended test procedure. The
amendments adopted in this document pertain to issues addressed by
waivers granted to ECR International, Inc. (Case number 2019-001). See
86 FR 13530.
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866, 13563, and 14094
Executive Order (``E.O.'') 12866, ``Regulatory Planning and
Review,'' as supplemented and reaffirmed by E.O. 13563, ``Improving
Regulation and Regulatory Review,'' 76 FR 3821 (Jan. 21, 2011), and
amended by E.O. 14094, ``Modernizing Regulatory Review,'' 88 FR 21879
(April 11, 2023), requires agencies, to the extent permitted by law, to
(1) propose or adopt a regulation only upon a reasoned determination
that its benefits justify its costs (recognizing that some benefits and
costs are difficult to quantify); (2) tailor regulations to impose the
least burden on society, consistent with obtaining regulatory
objectives, taking into account, among other things, and to the extent
practicable, the costs of cumulative regulations; (3) select, in
choosing among alternative regulatory approaches, those approaches that
maximize net benefits (including potential economic, environmental,
public health and safety, and other advantages; distributive impacts;
and equity); (4) to the extent feasible, specify performance
objectives, rather than specifying the behavior or manner of compliance
that regulated entities must adopt; and (5) identify and assess
available alternatives to direct regulation, including providing
economic incentives to encourage the desired behavior, such as user
fees or marketable permits, or providing information upon which choices
can be made by the public. DOE emphasizes as well that E.O. 13563
requires agencies to use the best available techniques to quantify
anticipated present and future benefits and costs as accurately as
possible. In its guidance, the Office of Information and Regulatory
Affairs (``OIRA'') in the Office of Management and Budget (``OMB'') has
emphasized that such techniques may include identifying changing future
compliance costs that might result from technological innovation or
anticipated behavioral changes. For the reasons stated in this
preamble, this final regulatory action is consistent with these
principles.
Section 6(a) of E.O. 12866 also requires agencies to submit
``significant regulatory actions'' to OIRA for review. OIRA has
determined that this final regulatory action does not constitute a
``significant regulatory action'' under section 3(f) of E.O. 12866.
Accordingly, this action was not submitted to OIRA for review under
E.O. 12866.
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires
preparation of a final regulatory flexibility analysis (``FRFA'') for
any final rule where the agency was first required by law to publish a
proposed rule for public comment, unless the agency certifies that the
rule, if promulgated, will not have a significant economic impact on a
substantial number of small entities. As required by Executive Order
13272, ``Proper Consideration of Small Entities in Agency Rulemaking,''
67 FR 53461 (August 16, 2002), DOE published procedures and policies on
February 19, 2003, to ensure that the potential impacts of its rules on
small entities are properly considered during the DOE rulemaking
process. 68 FR 7990. DOE has made its procedures and policies available
on the Office of the General Counsel's website: www.energy.gov/gc/office-general-counsel. DOE reviewed this final rule under the
provisions of the Regulatory Flexibility Act and the procedures and
policies published on February 19, 2003. DOE has concluded that the
rule would not have a significant impact on a substantial number of
small entities. The factual basis for this certification is as follows.
DOE used the Small Business Administration's (``SBA'') small
business size standards to determine whether any small entities would
be subject to the requirements of the rule. The size standards are
listed by North American Industry Classification System (``NAICS'')
code as well as by industry description and are available at
www.sba.gov/document/support--table-size-standards. Manufacturing of
consumer furnace fans is classified under NAICS 333415, ``Air-
Conditioning and Warm Air Heating Equipment and Commercial and
Industrial Refrigeration Equipment Manufacturing.'' The SBA sets a
threshold of 1,250 employees or fewer for an entity to be considered as
a small business for this category.\14\
---------------------------------------------------------------------------
\14\ U.S. Small Business Administration, ``Table of Size
Standards'' (effective December 19, 2022). Available at:
www.sba.gov/document/support-table-size-standards (last accessed
January 23, 2022).
---------------------------------------------------------------------------
DOE used available public information to identify potential small
manufacturers. DOE reviewed the
[[Page 25798]]
Compliance Certification Database \15\ (``CCD''), the Modernized
Appliance Efficiency Database System \16\ (``MAEDbS''), individual
company websites, and prior consumer furnace fan energy conservation
standards rulemakings to create a list of companies that import or
otherwise manufacture the products covered by this final rule. DOE then
consulted other publicly available data, such as manufacturer
specifications and product literature, U.S. import and export data
(e.g., Panjiva \17\) and basic model numbers, to identify OEMs of the
products covered by this rulemaking. DOE further relied on public
sources and subscription-based market research tools (e.g., Dun &
Bradstreet reports \18\) to determine company location, headcount, and
annual revenue. DOE screened out companies that do not offer products
covered by this rulemaking, do not meet the SBA's definition of a
``small business,'' or are foreign-owned and operated.
---------------------------------------------------------------------------
\15\ U.S. Department of Energy, Compliance Certification
Database. Available at: www.regulations.doe.gov/certification-data/#q=Product_Group_s%3A* (last accessed February 4, 2022).
\16\ California Energy Commission, Modernized Appliance
Efficiency Database System. Available at:
cacertappliances.energy.ca.gov/Pages/ApplianceSearch.aspx (last
accessed February 4, 2022).
\17\ Panjiva: S&P Global. Available at: panjiva.com/import-export/United-States (last access January 20, 2023).
\18\ The Dun & Bradstreet Hoovers subscription login is
accessible online at app.dnbhoovers.com/ (last accessed January 20,
2023).
---------------------------------------------------------------------------
DOE identified 25 OEMs offering consumer furnace fans for the U.S.
market. Of the 25 OEMs identified, DOE estimates that 8 companies
qualify as small businesses and are not foreign-owned and operated.
DOE did not receive written comments that specifically addressed
impacts on small businesses or that were provided in response to the
initial regulatory flexibility analysis.
In this final rule, DOE is finalizing its proposals to amend the
existing test procedure for consumer furnace fans by specifying a test
method for furnace fans that operate at low ESPs, incorporating by
reference the most recent industry test procedures, clarifying the
scope of the definition of ``furnace fans,'' tightening ambient
conditions, clarifying language for airflow-control settings, and
clarifying nomenclature and correcting typographical errors. DOE is not
finalizing its proposal to require direct measurement of airflow in
this final rule. DOE has determined that the amendments adopted in this
final rule will not impact test costs.
In response to a petition for waiver and an application for interim
waiver for heating-only furnace fans, DOE granted a waiver requiring
use of an alternate test procedure that specifies alternate ESP test
conditions for furnace fans that operate at low ESPs. Any such furnace
fan models currently on the market have already been granted a test
procedure waiver from DOE, which specifies use of the alternate test
procedure. As such, incorporating a similar methodology as the waiver
methodology into the test procedure for furnace fans that operate at
low ESPs will not result in any additional costs for manufacturers. DOE
is updating the material it incorporates by reference to include more
recent versions of ASHRAE 103 and ASHRAE 37. DOE is also incorporating
by reference chapter 1 of 2021 ASHRAE Handbook. As discussed
previously, DOE's review of these standards indicates that reference to
the newer versions of them will not impact FER and will not require
that manufacturers recertify their units. Therefore, manufacturers will
not incur any additional costs. Defining and explicitly excluding dual-
fuel furnace fans from the scope of appendix AA will make clear that
such products are not subject to testing under appendix AA and will not
impose any additional burden.
DOE is also tightening ambient conditions to limit the permissible
ambient temperature range to between 65 [deg]F and 85 [deg]F and the
ambient humidity range to between 20 percent and 80 percent for both
condensing and non-condensing furnaces. As discussed, appendix AA
currently already limits ambient temperatures to between 65 [deg]F and
85 [deg]F, as well as humidity to below 80 percent for condensing
furnaces, and DOE understands that testing laboratories are generally
able to meet these criteria in their testing laboratories without the
use of a specialized test chamber. Additionally, DOE concluded that it
is unlikely that test laboratories would be unable to meet a minimum
requirement of 20 percent, because that limit would exclude only the
driest conditions. Therefore, DOE expects that test laboratories will
not incur additional cost in applying these same temperature tolerances
to testing of non-condensing furnaces as well. These changes to the
ambient condition requirements are intended to increase the accuracy of
FER ratings and the consistency of test results but are not expected to
change the actual performance of any units. DOE will not require units
that are currently certified to retest according to the updated test
procedure.
DOE's remaining changes, which clarify nomenclature and fix
typographic errors, will not result in any changes to the test conduct
and therefore will not affect the cost of testing. For these reasons,
manufacturers will be able to rely on data generated under the test
procedure in effect prior to the adoption of this amendment.
DOE has determined that the amendments described in section III of
the final rule will not alter the measured efficiency of consumer
furnace fans, or require retesting or recertification solely as a
result of DOE's adoption of the amendments to the test procedures.
Additionally, DOE has determined that the amendments will not increase
the cost of testing. Therefore, DOE concludes that the cost effects
accruing from the final rule would not have a ``significant economic
impact on a substantial number of small entities,'' and that the
preparation of a FRFA is not warranted. DOE has submitted a
certification and supporting statement of factual basis to the Chief
Counsel for Advocacy of the Small Business Administration for review
under 5 U.S.C. 605(b).
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of consumer furnace fans must certify to DOE that
their products comply with any applicable energy conservation
standards. To certify compliance, manufacturers must first obtain test
data for their products according to the DOE test procedures, including
any amendments adopted for those test procedures. DOE has established
regulations for the certification and recordkeeping requirements for
all covered consumer products and commercial equipment, including
consumer furnace fans. (See generally 10 CFR part 429.) The collection-
of-information requirement for the certification and recordkeeping is
subject to review and approval by OMB under the Paperwork Reduction Act
(``PRA''). This requirement has been approved by OMB under OMB control
number 1910-1400. Public reporting burden for the certification is
estimated to average 35 hours per response, including the time for
reviewing instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information.
DOE is not amending the certification or reporting requirements for
consumer furnace fans in this final rule.
[[Page 25799]]
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
D. Review Under the National Environmental Policy Act of 1969
In this final rule, DOE establishes test procedure amendments that
it expects will be used to develop and implement future energy
conservation standards for consumer furnace fans. DOE has determined
that this rule falls into a class of actions that are categorically
excluded from review under the National Environmental Policy Act of
1969 (42 U.S.C. 4321 et seq.) and DOE's implementing regulations at 10
CFR part 1021. Specifically, DOE has determined that adopting test
procedures for measuring energy efficiency of consumer products and
industrial equipment is consistent with activities identified in 10 CFR
part 1021, appendix A to subpart D, A5 and A6. Accordingly, neither an
environmental assessment nor an environmental impact statement is
required.
E. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 4,
1999), imposes certain requirements on agencies formulating and
implementing policies or regulations that preempt State law or that
have federalism implications. The Executive order requires agencies to
examine the constitutional and statutory authority supporting any
action that would limit the policymaking discretion of the States and
to carefully assess the necessity for such actions. The Executive order
also requires agencies to have an accountable process to ensure
meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.
On March 14, 2000, DOE published a statement of policy describing the
intergovernmental consultation process it will follow in the
development of such regulations. 65 FR 13735. DOE examined this final
rule and determined that it will not have a substantial direct effect
on the States, on the relationship between the National Government and
the States, or on the distribution of power and responsibilities among
the various levels of government. EPCA governs and prescribes Federal
preemption of State regulations as to energy conservation for the
products that are the subject of this final rule. States can petition
DOE for exemption from such preemption to the extent, and based on
criteria, set forth in EPCA. (42 U.S.C. 6297(d)) No further action is
required by Executive Order 13132.
F. Review Under Executive Order 12988
Regarding the review of existing regulations and the promulgation
of new regulations, section 3(a) of Executive Order 12988, ``Civil
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal
agencies the general duty to adhere to the following requirements: (1)
eliminate drafting errors and ambiguity; (2) write regulations to
minimize litigation; (3) provide a clear legal standard for affected
conduct rather than a general standard; and (4) promote simplification
and burden reduction. Section 3(b) of Executive Order 12988
specifically requires that Executive agencies make every reasonable
effort to ensure that the regulation (1) clearly specifies the
preemptive effect, if any; (2) clearly specifies any effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct while promoting simplification and burden reduction;
(4) specifies the retroactive effect, if any; (5) adequately defines
key terms; and (6) addresses other important issues affecting clarity
and general draftsmanship under any guidelines issued by the Attorney
General. Section 3(c) of Executive Order 12988 requires Executive
agencies to review regulations in light of applicable standards in
sections 3(a) and 3(b) to determine whether they are met or it is
unreasonable to meet one or more of them. DOE has completed the
required review and determined that, to the extent permitted by law,
this final rule meets the relevant standards of Executive Order 12988.
G. Review Under the Unfunded Mandates Reform Act of 1995
Title II of the Unfunded Mandates Reform Act of 1995 (``UMRA'')
requires each Federal agency to assess the effects of Federal
regulatory actions on State, local, and Tribal governments and the
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531).
For a regulatory action resulting in a rule that may cause the
expenditure by State, local, and Tribal governments, in the aggregate,
or by the private sector of $100 million or more in any one year
(adjusted annually for inflation), section 202 of UMRA requires a
Federal agency to publish a written statement that estimates the
resulting costs, benefits, and other effects on the national economy.
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to
develop an effective process to permit timely input by elected officers
of State, local, and Tribal governments on a proposed ``significant
intergovernmental mandate,'' and requires an agency plan for giving
notice and opportunity for timely input to potentially affected small
governments before establishing any requirements that might
significantly or uniquely affect small governments. On March 18, 1997,
DOE published a statement of policy on its process for
intergovernmental consultation under UMRA. 62 FR 12820; also available
at www.energy.gov/gc/office-general-counsel. DOE examined this final
rule according to UMRA and its statement of policy and determined that
the rule contains neither an intergovernmental mandate, nor a mandate
that may result in the expenditure of $100 million or more in any year,
so these requirements do not apply.
H. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family
Policymaking Assessment for any rule that may affect family well-being.
This final rule will not have any impact on the autonomy or integrity
of the family as an institution. Accordingly, DOE has concluded that it
is not necessary to prepare a Family Policymaking Assessment.
I. Review Under Executive Order 12630
DOE has determined, under Executive Order 12630, ``Governmental
Actions and Interference with Constitutionally Protected Property
Rights,'' 53 FR 8859 (March 18, 1988), that this regulation will not
result in any takings that might require compensation under the Fifth
Amendment to the U.S. Constitution.
J. Review Under Treasury and General Government Appropriations Act,
2001
Section 515 of the Treasury and General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most
disseminations of information to the public under guidelines
established by each agency pursuant to general guidelines issued by
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). Pursuant
to OMB Memorandum M-19-15, Improving Implementation of the Information
Quality Act (April 24, 2019), DOE published updated guidelines which
are available at www.energy.gov/sites/prod/
[[Page 25800]]
files/2019/12/f70/
DOE%20Final%20Updated%20IQA%20Guidelines%20Dec%202019.pdf. DOE has
reviewed this final rule under the OMB and DOE guidelines and has
concluded that it is consistent with applicable policies in those
guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355
(May 22, 2001), requires Federal agencies to prepare and submit to OMB,
a Statement of Energy Effects for any significant energy action. A
``significant energy action'' is defined as any action by an agency
that promulgated or is expected to lead to promulgation of a final
rule, and that (1) is a significant regulatory action under Executive
Order 12866, or any successor order; and (2) is likely to have a
significant adverse effect on the supply, distribution, or use of
energy; or (3) is designated by the Administrator of OIRA as a
significant energy action. For any significant energy action, the
agency must give a detailed statement of any adverse effects on energy
supply, distribution, or use if the regulation is implemented, and of
reasonable alternatives to the action and their expected benefits on
energy supply, distribution, and use.
This regulatory action is not a significant regulatory action under
Executive Order 12866. Moreover, it would not have a significant
adverse effect on the supply, distribution, or use of energy, nor has
it been designated as a significant energy action by the Administrator
of OIRA. Therefore, it is not a significant energy action, and,
accordingly, DOE has not prepared a Statement of Energy Effects.
L. Review Under Section 32 of the Federal Energy Administration Act of
1974
Under section 301 of the Department of Energy Organization Act
(Pub. L. 95-91; 42 U.S.C. 7101), DOE must comply with section 32 of the
Federal Energy Administration Act of 1974, as amended by the Federal
Energy Administration Authorization Act of 1977. (15 U.S.C. 788;
``FEAA'') Section 32 essentially provides in relevant part that, where
a proposed rule authorizes or requires use of commercial standards, the
notice of proposed rulemaking must inform the public of the use and
background of such standards. In addition, section 32(c) requires DOE
to consult with the Attorney General and the Chairman of the Federal
Trade Commission (``FTC'') concerning the impact of the commercial or
industry standards on competition.
The modifications to the test procedure for consumer furnace fans
adopted in this final rule incorporate testing methods contained in
certain sections of the following commercial standards: ASHRAE 103-
2017, ASHRAE 37-2009 (RA 2019), and ASHRAE 41.1-1986 (RA 2006), as well
as chapter 1 of the 2021 ASHRAE Handbook. DOE has evaluated these
standards and is unable to conclude whether they fully comply with the
requirements of section 32(b) of the FEAA (i.e., whether they were
developed in a manner that fully provides for public participation,
comment, and review.) DOE has consulted with both the Attorney General
and the Chairman of the FTC about the impact on competition of using
the methods contained in these standards and has received no comments
objecting to their use.
M. Congressional Notification
As required by 5 U.S.C. 801, DOE will report to Congress on the
promulgation of this final rule before its effective date. The report
will state that it has been determined that the rule is not a ``major
rule'' as defined by 5 U.S.C. 804(2).
N. Description of Materials Incorporated by Reference
ASHRAE Standard 37-2009 (RA 2019) is an industry-accepted test
procedure that provides a method of test for many categories of air
conditioning and heating equipment. ANSI/ASHRAE Standard 37-2009 (RA
2019) is available on ANSI's website at webstore.ansi.org/RecordDetail.aspx?sku=ANSI%2FASHRAE+Standard+37-2009.
ASHRAE 37-2009 Errata Sheet is a technical corrections sheet for
ASHRAE 37-2009. The errata sheet for ASHRAE 37-2009 is reasonably
available on ASHRAE's website at: www.ashrae.org/.
ASHRAE 103-2017 is an industry-accepted test procedure for
measuring the performance of consumer furnaces and boilers. Copies of
ASHRAE 103-2017 may be purchased from ANSI at 1899 L Street, NW, 11th
Floor, Washington DC 20036, or by going to webstore.ansi.org/standards/ashrae/ansiashrae1032017.
The 2021 ASHRAE Handbook is an industry-accepted handbook that
covers basic principles and data used in the heating, ventilation, air-
conditioning, and refrigeration industries. The 2021 ASHRAE Handbook is
available on ASHRAE's website at www.ashrae.org/technical-resources/ashrae-handbook.
The following standard was previously approved for incorporation by
reference in the sections where it appears in this final rule and no
change is made: ASHRAE 41.1-1986 (RA 2006).
V. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this final
rule.
List of Subjects in 10 CFR Part 430
Administrative practice and procedure, Confidential business
information, Energy conservation, Household appliances, Imports,
Incorporation by reference, Intergovernmental relations, Small
businesses.
Signing Authority
This document of the Department of Energy was signed on March 25,
2024, by Jeff Marootian, Principal Deputy Assistant Secretary for
Energy Efficiency and Renewable Energy, pursuant to delegated authority
from the Secretary of Energy. That document with the original signature
and date is maintained by DOE. For administrative purposes only, and in
compliance with requirements of the Office of the Federal Register, the
undersigned DOE Federal Register Liaison Officer has been authorized to
sign and submit the document in electronic format for publication, as
an official document of the Department of Energy. This administrative
process in no way alters the legal effect of this document upon
publication in the Federal Register.
Signed in Washington, DC, on April 5, 2024.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
For the reasons stated in the preamble, DOE amends part 430 of
chapter II of title 10, Code of Federal Regulations as set forth below:
PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS
0
1. The authority citation for part 430 continues to read as follows:
Authority: 42 U.S.C. 6291-6309; 28 U.S.C. 2461 note.
0
2. Amend Sec. 430.3 by:
0
a. In paragraph (g)(3), removing the text ``appendices AA, CC, and
CC1'' and adding in its place the text ``appendices CC and CC1'';
0
b. Removing paragraph (g)(18);
0
c. Redesignating paragraphs (g)(19) through (22) as paragraphs (g)(20)
through (23);
0
d. Redesignating paragraphs (g)(5) through (17) as paragraphs (g)(7)
through (19), respectively;
[[Page 25801]]
0
e. Adding new paragraphs (g)(5) and (6);
0
f. In newly redesignated paragraph (g)(20), removing the text
``appendices O and EE'' and adding in its place the text ``appendices
O, AA, and EE''; and
0
g. Adding paragraph (g)(24).
The additions read as follows:
Sec. 430.3 Materials incorporated by reference.
* * * * *
(g) * * *
(5) ANSI/ASHRAE Standard 37-2009 (RA 2019) (``ASHRAE 37-2009 (RA
2019)''), Methods of Testing for Rating Electrically Driven Unitary
Air-Conditioning and Heat Pump Equipment, ASHRAE-approved June 21,
2019; IBR approved for appendix AA to subpart B.
(6) ANSI/ASHRAE Standard 37-2009 Errata Sheet (``ASHRAE 37-2009
Errata Sheet''), Errata Sheet for ANSI/ASHRAE Standard 37-2009--Methods
of Testing for Rating Electrically Driven Unitary Air-Conditioning and
Heat Pump Equipment, ASHRAE-approved March 27, 2019; IBR approved for
appendix AA to subpart B.
* * * * *
(24) 2021 ASHRAE Handbook--Fundamentals Inch-Pound Edition, Chapter
1, ``Psychrometrics'' (``2021 ASHRAE Handbook''), copyright 2021; IBR
approved for appendix AA to subpart B.
* * * * *
0
3. Appendix AA to subpart B of part 430 is revised to read as follows:
Appendix AA to Subpart B of Part 430--Uniform Test Method for Measuring
the Energy Consumption of Furnace Fans
Note: Prior to October 9, 2024, any representations with respect
to energy use or efficiency of furnace fans must be made either in
accordance with the results of testing pursuant to this appendix or
with the results of testing pursuant to this appendix as it appeared
in the 10 CFR parts 200-499 edition revised as of January 1, 2023.
On or after October 9, 2024, any representations, including
certifications of compliance, made with respect to the energy use or
efficiency of furnace fans must be made in accordance with the
results of testing pursuant to this appendix.
0. Incorporation by Reference
DOE incorporated by reference in Sec. 430.3, the entire
standard for ASHRAE 37-2009 (RA 2019), as corrected by the ASHRAE
37-2009 Errata Sheet; ASHRAE 41.1-1986; as well as Chapter 1 of the
2021 ASHRAE Handbook and ASHRAE 103-2017. In cases where there is a
conflict, the language of the test procedure in this appendix takes
precedence over the incorporated standards.
1. Scope. This appendix covers the test requirements used to
measure the energy consumption of fans used in weatherized and non-
weatherized gas furnaces, oil furnaces, electric furnaces, and
modular blowers. This appendix does not apply to furnace fans used
in dual-fuel units.
2. Definitions. Definitions include the definitions as specified
in section 3 of ASHRAE 103-2017 and the following additional
definitions, some of which supersede definitions found in ASHRAE
103-2017:
2.1. Active mode means the condition in which the product in
which the furnace fan is integrated is connected to a power source
and circulating air through ductwork.
2.2. Airflow-control settings are programmed or wired control
system configurations that control a fan to achieve discrete,
differing ranges of airflow--often designated for performing a
specific function (e.g., cooling, heating, or constant
circulation)--without manual adjustment other than interaction with
a user-operable control such as a thermostat that meets the
manufacturer specifications for installed-use. For the purposes of
this appendix, manufacturer specifications for installed-use shall
be found in the product literature shipped with the unit.
2.3. Dual-fuel unit means a consumer product that includes both
a heat pump and a burner in a single cabinet.
2.4. External static pressure (ESP) means the difference between
static pressures measured in the outlet duct and return air opening
(or return air duct when used for testing) of the product in which
the furnace fan is integrated.
2.5. Furnace fan means an electrically-powered device used in a
consumer product for the purpose of circulating air through
ductwork.
2.6. Modular blower means a product which only uses single-phase
electric current, and which:
(a) Is designed to be the principal air circulation source for
the living space of a residence;
(b) Is not contained within the same cabinet as a furnace or
central air conditioner; and
(c) Is designed to be paired with HVAC products that have a heat
input rate of less than 225,000 Btu per hour and cooling capacity
less than 65,000 Btu per hour.
2.7. Off mode means the condition in which the product in which
the furnace fan is integrated either is not connected to the power
source or is connected to the power source but not energized.
2.8. Seasonal off switch means a switch on the product in which
the furnace fan is integrated that, when activated, results in a
measurable change in energy consumption between the standby and off
modes.
2.9. Specified airflow-control settings are the airflow-control
settings specified for installed-use by the manufacturer. For the
purposes of this appendix, manufacturer specifications for
installed-use are those specifications provided for typical consumer
installations in the product literature shipped with the product in
which the furnace fan is installed. In instances where a
manufacturer specifies multiple airflow-control settings for a given
function to account for varying installation scenarios, the highest
airflow-control setting specified for the given function shall be
used for the procedures specified in this appendix, unless otherwise
specified within this test procedure.
2.10. Standby mode means the condition in which the product in
which the furnace fan is integrated is connected to the power source
and energized, but the furnace fan is not circulating air.
2.11. Thermal stack damper means a type of stack damper that
opens only during the direct conversion of thermal energy of the
stack gases.
3. Classifications. Classifications are as specified in section
4 of ASHRAE 103-2017.
4. Requirements. Requirements are as specified in section 5 of
ASHRAE 103-2017. In addition, Fan Energy Rating (FER) of furnace
fans shall be determined using test data and estimated national
average operating hours pursuant to section 10.1 of this appendix.
5. Instruments. Instruments must be as specified in section 6,
not including section 6.2, of ASHRAE 103-2017; and as specified in
sections 5.1 and 5.2 of this appendix.
5.1. Temperature. Temperature measuring instruments shall meet
the provisions specified in section 5.1 of ASHRAE 37-2009 (RA 2019)
(as corrected by the ASHRAE 37-2009 Errata Sheet), including the
references to ASHRAE 41.1-1986, and shall be accurate to within 0.75
degrees Fahrenheit (within 0.4 degrees Celsius).
5.1.1. Outlet Air Temperature Thermocouple Grid. Outlet air
temperature shall be measured as described in section 8.2.1.5.5 of
ASHRAE 103-2017 and illustrated in Figure 2 of ASHRAE 103-2017.
Thermocouples shall be placed downstream of pressure taps used for
external static pressure measurement.
5.2. Humidity. Air humidity shall be measured with a relative
humidity sensor that is accurate to within 5% relative humidity. Air
humidity shall be measured as close as possible to the inlet of the
product in which the furnace fan is installed.
6. Apparatus. The apparatus used in conjunction with the furnace
during the testing shall be as specified in section 7 of ASHRAE 103-
2017 except for section 7.1, the second paragraph of sections
7.2.2.2, 7.2.2.5, and 7.7, and as specified in sections 6.1, 6.2,
6.3, 6.4, 6.5, and 6.6 of this appendix.
6.1. General. The product in which the furnace fan is integrated
shall be installed in the test room in accordance with the product
manufacturer's written instructions that are shipped with the
product unless required otherwise by a specific provision of this
appendix. The apparatus described in this section is used in
conjunction with the product in which the furnace fan is integrated.
Each piece of the apparatus shall conform to material and
construction specifications and the reference standard cited. Test
rooms containing equipment shall have suitable facilities for
providing the utilities necessary for performance of the test and be
able to maintain conditions within the limits specified.
6.2. Downflow furnaces. Install the internal section of vent
pipe the same size as the flue collar for connecting the flue collar
to the top
[[Page 25802]]
of the unit, if not supplied by the manufacturer. Do not insulate
the internal vent pipe during steady-state test described in section
9.1 of ASHRAE 103-2017. Do not insulate the internal vent pipe
before the cool-down and heat-up tests described in sections 9.5 and
9.6, respectively, of ASHRAE 103-2017. If the vent pipe is
surrounded by a metal jacket, do not insulate the metal jacket.
Install a 5-ft test stack of the same cross-sectional area or
perimeter as the vent pipe above the top of the furnace. Tape or
seal around the junction connecting the vent pipe and the 5-ft test
stack. Insulate the 5-ft test stack with insulation having a minimum
R-value of 7 and an outer layer of aluminum foil. (See Figure 3-E of
ASHRAE 103-2017.)
6.3. Modular Blowers. A modular blower shall be equipped with
the electric heat resistance kit that is likely to have the largest
volume of retail sales with that particular basic model of modular
blower.
6.4. Ducts and Plenums. Ducts and plenums shall be built to the
geometrical specifications in section 7 of ASHRAE 103-2017 and
section 6.7 of this appendix. An apparatus for measuring external
static pressure shall be integrated in the plenum and test duct as
specified in sections 6.4 of ASHRAE 37-2009 (RA 2019) (as corrected
by the ASHRAE 37-2009 Errata Sheet), excluding specifications
regarding the minimum length of the ducting and minimum distance
between the external static pressure taps and product inlet and
outlet, and section 6.5 of ASHRAE 37-2009 (RA 2019) (as corrected by
the ASHRAE 37-2009 Errata Sheet). External static pressure measuring
instruments shall be placed between the furnace openings and any
restrictions or elbows in the test plenums or ducts. For all test
configurations, external static pressure taps shall be placed 18
inches from the outlet.
6.4.1. For tests conducted using a return air duct. Additional
external static pressure taps shall be placed 12 inches from the
product inlet. Pressure shall be directly measured as a differential
pressure as depicted in Figure 8 of ASHRAE 37-2009 (RA 2019) rather
than determined by separately measuring inlet and outlet static
pressure and subtracting the results.
6.4.2. For tests conducted without a return air duct. External
static pressure shall be directly measured as the differential
pressure between the outlet duct static pressure and the ambient
static pressure as depicted in Figure 7a of ASHRAE 37-2009 (RA
2019).
6.5. Air Filters. Air filters shall be removed.
6.6. Electrical Measurement. Only electrical input power to the
furnace fan (and electric resistance heat kit for electric furnaces
and modular blowers) shall be measured for the purposes of this
appendix. Electrical input power to the furnace fan and electric
resistance heat kit shall be sub-metered separately. Electrical
input power to all other electricity-consuming components of the
product in which the furnace fan is integrated shall not be included
in the electrical input power measurements used in the FER
calculation. If the procedures of this appendix are being conducted
at the same time as another test that requires metering of
components other than the furnace fan and electric resistance heat
kit, the electrical input power to the furnace fan and electric
resistance heat kit shall be sub-metered separately from one another
and separately from other electrical input power measurements.
7. Test Conditions. The testing conditions shall be as specified
in section 8, not including sections 8.5.2 and 8.6.1.1 of ASHRAE
103-2017; and as specified in sections 7.1 and 7.2 of this appendix.
7.1 Ambient Temperature and Humidity Conditions. During the time
required to perform all tests, maintain the room temperature within
5 [deg]F (2.8 [deg]C) of the air temperature value
measured at the end of the steady-state performance test
(TRA). For condensing furnaces and boilers, maintain the
relative humidity within 5% of the relative humidity
measured at the end of the steady-state performance test. During all
tests, the room temperature shall not fall below 65 [deg]F (18.3
[deg]C) or exceed 85 [deg]F (29.4 [deg]C) and the relative humidity
shall not fall below 20% or exceed 80%.
7.2. Measurement of Jacket Surface Temperature (optional). The
jacket of the furnace or boiler shall be subdivided into 6-inch
squares when practical, and otherwise into 36-square-inch regions
comprising 4 in. x 9 in. or 3 in. x 12 in. sections, and the surface
temperature at the center of each square or section shall be
determined with a surface thermocouple. The 36-square-inch areas
shall be recorded in groups where the temperature differential of
the 36-square-inch area is less than 10 [deg]F for temperature up to
100 [deg]F above room temperature and less than 20 [deg]F for
temperature more than 100 [deg]F above room temperature. For forced
air central furnaces, the circulating air blower compartment is
considered as part of the duct system and no surface temperature
measurement of the blower compartment needs to be recorded for the
purpose of this test. For downflow furnaces, measure all cabinet
surface temperatures of the heat exchanger and combustion section,
including the bottom around the outlet duct, and the burner door,
using the 36 square-inch thermocouple grid. The cabinet surface
temperatures around the blower section do not need to be measured
(see Figure 3-E of ASHRAE 103-2017.)
8. Test Procedure. Testing and measurements shall be as
specified in section 9 of ASHRAE 103-2017 except for sections
9.1.2.1, 9.3, 9.5.1.1, 9.5.1.2.1, 9.5.1.2.2, 9.5.2.1, and section
9.7.1; and as specified in sections 8.1 through 8.6 of this
appendix.
8.1. Direct Measurement of Off-Cycle Losses Testing Method.
[Reserved]
8.2. Measurement of Electrical Standby and Off Mode Power.
[Reserved]
8.3. Steady-State Conditions for Hot Flow Tests for Gas and Oil
Furnaces. Steady-state conditions are indicated by an external
static pressure within the range shown in table 1 to this appendix
and a temperature variation in three successive readings, taken 15
minutes apart, of not more than any of the following:
(a) 3 [deg]F in the stack gas temperature for furnaces equipped
with draft diverters;
(b) 5 [deg]F in the stack gas temperature for furnaces equipped
with either draft hoods, direct exhaust, or direct vent systems; and
(c) 1 [deg]F in the flue gas temperature for condensing
furnaces.
8.4. Steady-State Conditions for Hot Flow Tests for Electric
Furnaces and Modular Blowers. Steady-state conditions are indicated
by an external static pressure within the range shown in table 1 to
this appendix and a temperature variation of not more than 5 [deg]F
in the outlet air temperature in four successive temperature
readings taken 15 minutes apart.
8.5. Steady-State Conditions for Cold Flow Tests. For tests
during which the burner or electric heating elements are turned off
(i.e., cold flow tests), steady-state conditions are indicated by an
external static pressure within the range shown in table 1 to this
appendix and a variation in the difference between outlet
temperature and ambient temperature of not more than 3 [deg]F in
three successive temperature readings taken 15 minutes apart.
8.6. Fan Energy Rating (FER) Test.
8.6.1. Initial FER test conditions and maximum airflow-control
setting measurements. Measure the relative humidity (q) and dry bulb
temperature (Tdb) of the test room.
8.6.1.1. Furnace fans for which the maximum airflow-control
setting is not a specified heating airflow-control setting. The main
burner or electric heating elements shall be turned off. Adjust the
external static pressure to within the range shown in table 1 to
this appendix. Maintain these settings until steady-state conditions
are attained as specified in sections 8.3, 8.4, and 8.5 of this
appendix. Measure furnace fan electrical input power
(EMax), external static pressure (ESPMax), and
outlet air temperature (TMax,Out). The measurement of
EMax shall be taken over the final 30 seconds of the
steady-state period, at intervals of no less than 1 per second, and
averaged over the 30 second period.
8.6.1.2. Furnace fans for which the maximum airflow-control
setting is a specified heating airflow-control setting. Adjust the
main burner or electric heating element controls to the default heat
setting designated for the maximum airflow-control setting. Burner
adjustments shall be made as specified by section 8.4.1 of ASHRAE
103-2017. Adjust the furnace fan controls to the maximum airflow-
control setting. Adjust the external static to within the range
shown in table 1 to this appendix. Maintain these settings until
steady-state conditions are attained as specified in sections 8.3,
8.4, and 8.5 of this appendix and the temperature rise
([Delta]TMax) is at least 18 [deg]F. Measure furnace fan
electrical input power (EMax), fuel or electric
resistance heat kit input energy (QIN,H), external static
pressure (ESPMax), steady-state efficiency for this
setting (EffySS,Max) as specified in sections 11.2 and
11.3 of ASHRAE 103-2017, outlet air temperature
(TMax,Out), and temperature rise
([Delta]TMax). The measurement of EMax shall
be taken over the final 30 seconds of the steady-state period, at
intervals of no less than 1 per second, and averaged over the 30
second period.
[[Page 25803]]
Table 1--Required Minimum External Static Pressure in the Maximum
Airflow-Control Setting by Installation Type
------------------------------------------------------------------------
ESP (in. wc.)
Installation type *
------------------------------------------------------------------------
Units with an internal, factory-installed evaporator 0.50-0.55
coil...................................................
Units designed to be paired with an evaporator coil, but 0.65-0.70
without one installed..................................
Mobile home............................................. 0.30-0.35
------------------------------------------------------------------------
* Once the specified ESP has been achieved, the same outlet duct
restrictions shall be used for the remainder of the furnace fan test.
If the unit under test is unable to complete the testing (i.e., the
unit shuts down before completing a test), reduce the target ESP range
by 0.05'' w.c. and restart the test. Repeat this process until the
test can be completed.
8.6.2. Constant circulation airflow-control setting
measurements. The main burner or electric heating elements shall be
turned off. The furnace fan controls shall be adjusted to the
specified constant circulation airflow-control setting. If the
manufacturer does not specify a constant circulation airflow-control
setting in the installation and operations manual supplied with the
unit, the lowest airflow-control setting shall be used. Maintain
these settings until steady-state conditions are attained as
specified in sections 8.3, 8.4, and 8.5 of this appendix. Measure
furnace fan electrical input power (ECirc) and external
static pressure (ESPCirc). The measurement of
ECirc shall be taken over the final 30 seconds of the
steady-state period, at intervals of no less than 1 per second, and
averaged over the 30 second period.
8.6.3. Heating airflow-control setting measurements. For single-
stage gas and oil furnaces, the burner shall be fired at the maximum
heat input rate. For single-stage electric furnaces, the electric
heating elements shall be energized at the maximum heat input rate.
For multi-stage and modulating furnaces, the reduced heat input rate
settings shall be used. Burner adjustments shall be made as
specified by section 8.4.1 of ASHRAE 103-2017. After the burner is
activated and adjusted or the electric heating elements are
energized, the furnace fan controls shall be adjusted to operate the
fan in the specified heating airflow-control setting that also
allows for operation within the manufacturer-specified temperature
rise range. In instances where a manufacturer specifies multiple
airflow-control settings for a given function to account for varying
installation scenarios, the highest airflow-control setting
specified for the given function that also allows for operation
within the manufacturer-specified temperature rise range shall be
used. High heat and reduced heat shall be considered different
functions for multi-stage heating units. Maintain these settings
until steady-state conditions are attained as specified in sections
8.3, 8.4, and 8.5 of this appendix and the temperature rise
([Delta]THeat) is at least 18 [deg]F. Measure furnace fan
electrical input power (EHeat), fuel or electric
resistance heat kit input energy (QIN,k)external static
pressure (ESPHeat), steady-state efficiency for this
setting (EffySS) as specified in sections 11.2 and 11.3
of ASHRAE 103-2017, outlet air temperature (THeat, Out)
and temperature rise ([Delta]THeat). The measurement of
EHeat shall be taken over the final 30 seconds of the
steady-state period, at intervals of no less than 1 per second, and
averaged over the 30 second period.
9. Nomenclature. Nomenclature shall include the nomenclature
specified in section 10 of ASHRAE 103-2017 and the following
additional variables:
60 = conversion factor from hours to minutes, (min/h)
0.24 = approximate specific heat capacity of dry air, (Btu/lb-
[deg]F)
0.44 = approximate specific heat capacity of saturated water vapor,
(Btu/lb-[deg]F)
EffySS,i = Steady-State Efficiency in airflow-control
setting i. For gas and oil furnaces EffySS,i is specified
in sections 11.2.7 (Non-Condensing and Modulating), 11.3.7.3
(Condensing and Non-modulating), 11.4.8.8 (Non-Condensing and Non-
modulating), or 11.5 (Condensing and Modulating) of ASHRAE 103-2017,
in %. For electric furnaces or modular blowers, EffySS,i
equals 100, in %.
LJ = jacket loss as determined as specified in section
8.6 of ASHRAE 103-2017 or a default value of 1% if the jacket loss
test is not performed, in %
CCH = annual furnace fan constant-circulation hours
ECirc = furnace fan electrical consumption at the
specified constant-circulation airflow-control setting (or minimum
airflow-control setting operating point if a default constant-
circulation airflow-control setting is not specified), in watts
EHeat = furnace fan electrical consumption in the
specified heat airflow-control setting for single-stage heating
products or the specified low-heat setting for multi-stage heating
products, in watts
EMax = furnace fan electrical consumption in the maximum
airflow-control setting, in watts
ESPi = external static pressure, in inches water column,
at time of the electrical power measurement in airflow-control
setting i, where i can be ``Circ'' to represent constant-circulation
(or minimum airflow) mode, ``Heat'' to represent heating mode, or
``Max'' to represent cooling (or maximum airflow mode).
FER = fan energy rating, in watts/1000 cfm
HH = annual furnace fan heating operating hours
HCR = heating capacity ratio (nameplate reduced heat input capacity
divided by nameplate maximum input heat capacity)
kref = physical descriptor characterizing the reference
system
Tdb = dry bulb temperature of the test room in, [deg]F
Ti,k,in = inlet air temperature at time of the electrical
power measurement, in [deg]F, in airflow-control setting i and heat
setting k, where i can be ``Circ'' to represent constant-circulation
(or minimum airflow) mode, ``Heat'' to represent heating mode, or
``Max'' to represent maximum airflow (typically designated for
cooling) mode. If i = Heat, k can be ``H'' to represent high heat
setting or ``R'' to represent the reduced heat setting. If i = Max
or Circ, k is not needed.
Ti,k,out = average outlet air temperature as measured by
the outlet thermocouple grid at time of the electrical power
measurement, in [deg]F, in airflow-control setting i and heat
setting k, where i can be ``Circ'' to represent constant-circulation
(or minimum airflow) mode, ``Heat'' to represent heating mode, or
``Max'' to represent maximum airflow (typically designated for
cooling) mode. If i = Heat, k can be ``H'' to represent high heat
setting or ``R'' to represent the reduced heat setting. If i = Max
or Circ, k is not needed.
[Delta]Ti,k = Ti,k,Out minus
Ti,k,in, which is the air throughput temperature rise in
setting i and heat setting k, in [deg]F
Qi,k = airflow in airflow-control setting i and heat setting k, in
cubic feet per minute (CFM)
MH = annual furnace fan maximum airflow hours
QIN,k = nameplate fuel energy input rate, in Btu/h, at
specified operating conditions k, based on the fuel's high heating
value (``HHV'') determined as required in section 8.2.1.3 or 8.2.2.3
of ASHRAE 103-2017, where k can be ``H'' for the maximum heat
setting or ``R'' for the reduced heat setting.
W = humidity ratio in pounds water vapor per pounds dry air
vair = specific volume of dry air at specified operating
conditions per the 2021 ASHRAE Handbook, in ft\3\/lb
10. Calculation of derived results from test measurements for a
single unit. Calculations shall be as specified in section 11 of
ASHRAE 103-2017, except for appendices B and C; and as specified in
sections 10.1 through 10.10 and Figure 1 of this appendix.
10.1. Fan Energy Rating (FER)
[[Page 25804]]
[GRAPHIC] [TIFF OMITTED] TR12AP24.000
Where: QMax = QHeat for products for which the
maximum airflow-control setting is a specified heat setting, or
[GRAPHIC] [TIFF OMITTED] TR12AP24.001
For products for which the maximum airflow control setting is
only designated for cooling; and
[GRAPHIC] [TIFF OMITTED] TR12AP24.002
The estimated national average operating hours presented in
table 2 to this appendix shall be used to calculate FER.
Table 2--Estimated National Average Operating Hour Values for Calculating FER
----------------------------------------------------------------------------------------------------------------
Single-stage Multi-stage or modulating
Operating mode Variable (hours) (hours)
----------------------------------------------------------------------------------------------------------------
Heating............................... HH....................... 830 830/HCR.
Maximum Airflow....................... MH....................... 640 640.
Constant Circulation.................. CCH...................... 400 400.
----------------------------------------------------------------------------------------------------------------
Where:
[GRAPHIC] [TIFF OMITTED] TR12AP24.003
[FR Doc. 2024-07620 Filed 4-11-24; 8:45 am]
BILLING CODE 6450-01-P