[Federal Register Volume 88, Number 48 (Monday, March 13, 2023)]
[Rules and Regulations]
[Pages 15510-15555]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-03982]



[[Page 15509]]

Vol. 88

Monday,

No. 48

March 13, 2023

Part II





Department of Energy





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10 Part 429, 430





Energy Conservation Program: Test Procedure for Consumer Boilers; Final 
Rule

  Federal Register / Vol. 88 , No. 48 / Monday, March 13, 2023 / Rules 
and Regulations  

[[Page 15510]]


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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 430

[EERE-2019-BT-TP-0037]
RIN 1904-AE83


Energy Conservation Program: Test Procedure for Consumer Boilers

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'') amends its test 
procedure for consumer boilers established under the Energy Policy and 
Conservation Act. This rulemaking fulfills DOE's obligation to review 
its test procedures for covered products at least once every seven 
years. The revisions include: incorporating by reference the latest 
versions of the industry standards currently referenced in the Federal 
test procedure; relocating the test procedure to a new appendix 
separate from the residential furnace test procedure; removing an 
extraneous definition from its regulatory definitions; and making 
clarifying corrections to calculations. These revisions will improve 
the representativeness of the test method and will not be unduly 
burdensome to conduct.

DATES: The effective date of this rule is April 12, 2023. The 
amendments will be mandatory for product testing starting September 11, 
2023.
    The incorporation by reference of certain material listed in the 
rule is approved by the Director of the Federal Register as of April 
12, 2023. The incorporation by reference of certain other material 
listed in the rule was approved by the Director of the Federal Register 
on March 23, 2009, and February 16, 2016.

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-2019-BT-TP-0037. 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]">ApplianceStandards[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-2J, 
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: 
(240) 597-6737. Email: [email protected]">ApplianceStandards[email protected].
    Ms. Amelia Whiting, U.S. Department of Energy, Office of the 
General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 
20585-0121. Telephone: (202) 586-2588. Email: 
[email protected].

SUPPLEMENTARY INFORMATION: DOE maintains material previously approved 
for incorporation by reference in part 430: ANSI/ASHRAE 103-1993 and 
ASTM D2156-09 (Reapproved 2013). DOE incorporates by reference the 
following industry standards into 10 CFR part 430:
    ANSI/ASHRAE Standard 41.6-2014, ``Standard Method for Humidity 
Measurement,'' ANSI-approved July 3, 2014 (``ASHRAE 41.6-2014'').
    ANSI/ASHRAE 103-2017, ``Method of Testing for Annual Fuel 
Utilization Efficiency of Residential Central Furnaces and Boilers,'' 
ANSI-approved July 3, 2017 (``ASHRAE 103-2017'').
    Copies ofANSI/ASHRAE 41.6-2014 and ANSI/ASHRAE 103-2017 can be 
obtained from the American Society of Heating, Refrigerating and Air-
Conditioning Engineers, Inc. (ASHRAE), 180 Technology Parkway NW, 
Peachtree Corners, GA 30092, (800) 527-4723 or (404) 636-8400, or 
online at www.ashrae.org.
    ASTM International (``ASTM'') Standard D2156-09 (Reapproved 2018), 
``Standard Test Method for Smoke Density in Flue Gases from Burning 
Distillate Fuels,''approved October 1, 2018 (``ASTM D2156-09 
(R2018)'').
    Copies of ASTM D2156-09 (R2018) can be obtained from ASTM 
International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, 
PA 19428-2959 or online at www.astm.org.
    International Electrotechnical Commission (``IEC'') 62301, 
``Household electrical appliances--Measurement of standby power,'' 
(Edition 2.0) 2011-01 (``IEC 62301'').
    Copies of IEC 62301 can be obtained from the International 
Electrotechnical Commission (``IEC''), 3 Rue de Varembe, Case Postale 
131, 1211 Geneva 20, Switzerland; or online at webstore.iec.ch.
    See section IV.N of this document for a further discussion of these 
standards.

Table of Contents

I. Authority and Background
    A. Authority
    B. Background
II. Synopsis of the Final Rule
III. Discussion
    A. Scope of Applicability
    1. Combination Space/Water Heating Boilers
    2. Heat Pump Boilers
    B. Definitions
    C. Metric
    D. Updates to Industry Standards
    1. ANSI/ASHRAE 103
    2. IEC 62301 and ASTM D2156-09
    E. Steady-State Efficiency for Condensing Modulating Boilers
    F. Corrections and Clarifications
    1. Off-Cycle Losses
    2. Conversion Factor for British Thermal Units
    3. Oil Pressure Instrumentation Error
    4. Gas Inlet Conditions
    5. Active Mode Electrical Energy Consumption
    6. Circulator Pumps
    7. Units With Draft Hoods or Draft Diverters
    8. Rounding of AFUE
    G. Other Test Procedure Topics
    1. Outdoor Design Temperature
    2. Ambient Conditions
    3. Combustion Settings
    4. Supplemental Test Instructions
    5. Input Rates for Step Modulating Boilers
    6. Return Water Temperature
    7. Standby Mode and Off Mode Electrical Energy Consumption
    8. Full Fuel Cycle Efficiency
    9. Idle Losses
    H. Alternative Efficiency Determination Methods
    I. Certification Provisions for Cast-Iron Boilers
    J. Effective and Compliance Dates
    K. Test Procedure Costs
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Orders 12866 and 13563
    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

[[Page 15511]]

I. Authority and Background

    Furnaces, which include consumer boilers, are included in the list 
of ``covered products'' for which the U.S. Department of Energy 
(``DOE'') is authorized to establish and amend energy conservation 
standards and test procedures. (42 U.S.C. 6291(23); 42 U.S.C. 
6292(a)(5)) DOE's energy conservation standards and test procedures for 
consumer boilers are currently prescribed at 10 CFR 430.32(e)(2) and 10 
CFR part 430, subpart B, appendix N, Uniform Test Method for Measuring 
the Energy Consumption of Furnaces and Boilers (``appendix N''), 
respectively.\1\ The following sections discuss DOE's authority to 
establish test procedures for consumer boilers and relevant background 
information regarding DOE's consideration of test procedures for this 
product.
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    \1\ Upon the effective date of this final rule, the test 
procedure for consumer boilers will be relocated to 10 CFR 430, 
subpart B, appendix EE.
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A. Authority

    The Energy Policy and Conservation Act, Public Law 94-163, as 
amended (``EPCA''),\2\ 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 \3\ 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 furnaces, which include consumer 
boilers, the subject of this document. (42 U.S.C. 6292(a)(5))
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    \2\ 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.
    \3\ 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 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 
boilers, to determine whether amended test procedures would more 
accurately or fully comply with the requirements for the test 
procedures to not be unduly burdensome to conduct and be reasonably 
designed to produce test results that reflect energy efficiency, energy 
use, and estimated operating costs during a representative average use 
cycle or period of use. (42 U.S.C. 6293(b)(1)(A))
    If the Secretary determines, on her own behalf or in response to a 
petition by any interested person, that a test procedure should be 
prescribed or amended, the Secretary shall promptly publish in the 
Federal Register proposed test procedures and afford interested persons 
an opportunity to present oral and written data, views, and arguments 
with respect to such procedures. The comment period on a proposed rule 
to amend a test procedure shall be at least 60 days and may not exceed 
270 days. In prescribing or amending a test procedure, the Secretary 
shall take into account such information as the Secretary determines 
relevant to such procedure, including technological developments 
relating to energy use or energy efficiency of the type (or class) of 
covered products involved. (42 U.S.C. 6293(b)(2)) If DOE determines 
that test procedure revisions are not appropriate, DOE must publish its 
determination not to amend the test procedures.
    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. (Id.) Any such amendment must consider the 
most current versions of the International Electrotechnical Commission 
(``IEC'') Standard 62301 \4\ and IEC Standard 62087 \5\ as applicable. 
(42 U.S.C. 6295(gg)(2)(A))
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    \4\ IEC 62301, Household electrical appliances--Measurement of 
standby power (Edition 2.0, 2011-01).
    \5\ 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 in satisfaction of the 7-year 
review requirement specified in EPCA. (42 U.S.C. 6293(b)(1)(A))

B. Background

    As stated, DOE's existing test procedure for consumer boilers 
appears at Title 10 of CFR part 430, subpart B, appendix N, Uniform 
Test Method for Measuring the Energy Consumption of Furnaces and 
Boilers (``appendix N'') and is used to determine the annual fuel 
utilization efficiency (``AFUE''), which is the regulatory metric for 
consumer boilers.
    DOE most recently updated its test procedure for consumer boilers 
in a final rule published in the Federal Register on January 15, 2016 
(``January 2016 Final Rule''). 81 FR 2628. The January 2016 Final Rule 
amended the existing DOE test procedure for consumer boilers to improve 
the consistency and accuracy of test results generated using the DOE 
test procedure and to reduce test burden. In particular, the 
modifications relevant to consumer boilers included: (1) clarifying the 
definition of the electrical power term ``PE''; (2) adopting a smoke 
stick test for determining whether minimum default

[[Page 15512]]

draft factors can be applied; (3) allowing for optional measurement of 
condensate during establishment of steady-state conditions; (4) 
updating references to the applicable installation and operation 
(``I&O'') manual and providing clarifications for when the I&O manual 
does not specify test setup; and (5) revising the AFUE reporting 
precision. DOE also revised the definitions of several terms in the 
test procedure and added an enforcement provision to provide a method 
of test for DOE to determine compliance with the automatic means design 
requirement mandated by the Energy Independence and Security Act of 
2007, Public Law 110-140 (Dec. 19, 2007). 81 FR 2628, 2629-2630.
    On May 15, 2020, DOE published in the Federal Register a request 
for information (``May 2020 RFI'') seeking comments on the existing DOE 
test procedure for consumer boilers, which incorporates by reference 
ANSI/ASHRAE Standard 103-1993. 85 FR 29352. ANSI/ASHRAE 103-1993 
provides test procedures for determining the AFUE of residential 
central furnaces and boilers. In the May 2020 RFI, DOE requested 
comments, information, and data about a number of issues, including: 
(1) the test procedure's scope and definitions; (2) updates to industry 
standards; (3) ambient test conditions; (4) provisions for testing 
boilers with manually adjustable combustion airflow; (5) calculation of 
steady-state heat loss for condensing, modulating boilers; and (6) 
provisions for testing step modulating boilers. Id. at 85 FR 29354-
29357. DOE also sought comment generally on whether the current test 
procedures are reasonably designed to produce results that measure 
energy efficiency during a representative average use cycle or period 
of use, whether any potential amendments would make the test procedure 
unduly burdensome to conduct, whether existing test procedures limit a 
manufacturer's ability to provide additional features, the impact of 
any potential amendments on manufacturers including small businesses, 
whether there are any potential issues related to emerging smart 
technologies, and generally any other aspect of the test procedure for 
consumer boilers. Id. at 85 FR 23957.
    On March 15, 2022, DOE published in the Federal Register a notice 
of proposed rulemaking (``March 2022 NOPR'') proposing to amend the 
current test procedure to incorporate by reference the most current 
revision to the applicable industry standard that was available at the 
time, ANSI/ASHRAE 103-2017, ``Methods of Testing for Annual Fuel 
Utilization Efficiency of Residential Central Furnaces and Boilers,'' 
as well as updating the definitions to reflect the changes in ANSI/
ASHRAE 103-2017 as compared to the version of the standard currently 
incorporated by reference (i.e., ANSI/ASHRAE 103-1993). 87 FR 14624. In 
addition, the March 2022 NOPR proposed to update appendix N to remove 
the provisions applicable only to consumer boilers and to rename the 
appendix ``Uniform Test Method for Measuring the Energy Consumption of 
Furnaces.'' Correspondingly, DOE proposed to relocate the test 
procedure specific to consumer boilers at 10 CFR 430 subpart B to a new 
appendix, EE, ``Uniform Test Method for Measuring the Energy 
Consumption of Boilers'' (``appendix EE''). Id.
    On April 7, 2022, DOE held a public meeting via webinar to solicit 
feedback from stakeholders on the requests for comment in the March 
2022 NOPR.
    DOE received comments in response to the March 2022 NOPR from the 
interested parties listed in Table I.1.

            Table I.1--List of Commenters With Written Submission in Response to the March 2022 NOPR
----------------------------------------------------------------------------------------------------------------
                                                     Reference in this    Comment No. in
                  Commenter(s)                          final rule          the docket        Commenter type
----------------------------------------------------------------------------------------------------------------
American Gas Association and American Public Gas  AGA and APGA..........              25  Utility Associations.
 Association.
Air-Conditioning, Heating, and Refrigeration      AHRI..................              26  Trade Association.
 Institute.
A.O. Smith Corporation..........................  A.O. Smith............              24  Manufacturer.
John Busse......................................  Busse.................              22  Individual.
Bradford White Corporation......................  BWC...................              19  Manufacturer.
Pacific Gas and Electric Company, San Diego Gas   CA IOUs...............              20  Utilities.
 and Electric, and Southern California Edison
 (collectively, the California Investor-Owned
 Utilities).
Crown Boiler Company............................  Crown.................              16  Manufacturer.
Appliance Standards Awareness Project, American   Joint Advocates.......              21  Efficiency
 Council for an Energy-Efficient Economy,                                                  Organizations.
 Consumer Federation of America, National
 Consumer Law Center Natural Resources Defense
 Council, and Northwest Energy Efficiency
 Alliance.
New York State Energy Research and Development    NYSERDA...............              23  State Agency.
 Authority.
Rheem Manufacturing Company.....................  Rheem.................              18  Manufacturer.
U.S. Boiler Company.............................  U.S. Boiler...........              17  Manufacturer.
----------------------------------------------------------------------------------------------------------------

    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 April 7, 2022, public meeting, DOE cites the written 
comments throughout this final rule. DOE did not identify any oral 
comments provided during the webinar that are not substantively 
addressed by written comments.
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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 boilers. (Docket No. EERE-2019-BT-TP-
0037, 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 updates appendix N to remove the provisions 
applicable only to consumer boilers and to rename the appendix 
``Uniform Test Method for Measuring the Energy Consumption of 
Furnaces.'' Correspondingly, this final rule establishes a new test 
procedure specific to consumer boilers in a new appendix EE. In 
appendix EE, DOE includes all provisions currently included in appendix 
N relevant to consumer boilers, with the following modifications:
    (1) Incorporate by reference the current version of the applicable 
industry standard, ANSI/ASHRAE 103-2017, ``Methods of Testing for 
Annual Fuel Utilization Efficiency of

[[Page 15513]]

Residential Central Furnaces and Boilers,'' which includes several 
updates to the test method.
    (2) Incorporate by reference the current version of ASTM Standard 
D2156-09 (Reapproved 2018), ``Standard Test Method for Smoke Density in 
Flue Gases from Burning Distillate Fuels.''
    (3) Incorporate by reference ANSI/ASHRAE 41.6-2014, ``Standard 
Method for Humidity Measurement.''
    (4) Update the definitions to reflect the changes in ANSI/ASHRAE 
103-2017 as compared to ANSI/ASHRAE 103-1993.
    (5) Provide corrections to erroneous calculations and add 
clarifications to test conditions and setup requirements.
    DOE is also removing the definition of ``outdoor furnace or 
boiler'' from 10 CFR 430.2.
    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.

      Table II.1--Summary of Changes in the Amended Test Procedure
------------------------------------------------------------------------
  DOE test procedure prior to
           amendment            Amended test procedure     Attribution
------------------------------------------------------------------------
Incorporated by reference       Incorporates by         Harmonization
 industry standard ANSI/ASHRAE   reference ANSI/ASHRAE   with industry
 103-1993.                       103-2017 in the new     standard
                                 appendix EE.            update.
Incorporated by reference the   Incorporates by         Harmonization
 procedure for adjusting oil-    reference the           with industry
 fired burner by referencing     procedure for           standard
 industry standard ASTM D2156-   adjusting oil-fired     update.
 09 (Reapproved 2013).           burner by referencing
                                 industry standard
                                 ASTM D2156-09
                                 (Reapproved 2018) in
                                 the new appendix EE.
Limited the maximum relative    Incorporates by         Referenced by
 humidity of the test room       reference ANSI/ASHRAE   industry
 during certain tests but did    41.6-2014               standard ANSI/
 not provide specific            instructions for        ASHRAE 103-
 instructions for how to         measuring relative      2017, which is
 measure relative humidity.      humidity of the test    being
                                 room in the new         incorporated by
                                 appendix EE.            reference in
                                                         this final
                                                         rule.
Included a definition for       Removes the definition  Unused
 ``outdoor furnace or boiler''   for ``outdoor furnace   definition.
 at 10 CFR 430.2.                or boiler''.
Included an undefined term,     Adds a definition for   Increase clarity
 ``standard cubic foot of        ``standard cubic foot   for testing
 gas''.                          of gas'' in new         conditions.
                                 appendix EE.
Defined ``control'' and         Adopts the definitions  Harmonization
 ``isolated combustion           for the terms           with industry
 system'' in appendix N.         ``control'' and         standard
                                 ``isolated combustion   update.
                                 system'' from ASHRAE
                                 103-2017 in new
                                 appendix EE.
Referenced calculations in      Includes an amended     Correction.
 ANSI/ASHRAE 103-1993 which      calculation for
 yielded a circular reference    balance-point
 when calculating the steady-    temperature (TC)
 state efficiency for            which resolves the
 condensing modulating boilers.  circular reference in
                                 new appendix EE.
Referenced Table 9 in ANSI/     References Table 7 of   Harmonization
 ASHRAE 103-1993, which          ANSI/ASHRAE 103-2017    with industry
 assigned fixed values for the   in the new appendix     standard
 average on-time and off-time    EE, which uses          update.
 per cycle for two-stage and     calculations for
 modulating boilers.             determining the
                                 average on-time and
                                 off-time per cycle
                                 for two-stage and
                                 modulating boilers.
Specified cycle times (tON and  Provides additional     Clarification to
 tOFF) to a fraction of a        specification in        reduce test
 second through reference to     appendix EE to          burden.
 ANSI/ASHRAE 103-1993 Table 9.   require that
                                 calculated cycle
                                 timings shall be
                                 rounded to the
                                 nearest second.
Calculated oversize factor      Adopts the ANSI/ASHRAE  Harmonization
 from a lookup table based on    103-2017 methodology    with industry
 design heating requirement      of assigning a          standard
 (``DHR'') in ANSI/ASHRAE 103-   constant value of       update.
 1993.                           0.70 to [alpha] to
                                 represent the
                                 national average
                                 oversize factor in
                                 appendix EE.
Used a purge time limit of 5    Applies the 30-second   Harmonization
 seconds to determine whether    limit in appendix EE    with industry
 heat-up and cool-down tests     for determining when    standard
 may be optionally omitted,      the heat-up and cool-   update.
 whereas a purge time limit of   down tests may be
 30 seconds was used to          optionally omitted.
 determine whether a post-
 purge (tP) of 0 seconds could
 be assigned in calculations.
Limited the maximum value of    Removes the maximum     Harmonization
 post-purge (tP) to 180          value of 180 seconds    with industry
 seconds if a purge time of      in appendix EE and      standard
 greater than 3 minutes was      requires an             update.
 observed.                       additional
                                 temperature
                                 measurement to be
                                 taken if the post-
                                 purge is greater than
                                 3 minutes.
Referenced calculations for     Specifies the correct   Correction.
 off-cycle infiltration losses   calculation for off-
 in ANSI/ASHRAE 103-1993 which   cycle infiltration
 had a typographical error       losses through
 where the conversion from       reference to ANSI/
 minutes to hours was            ASHRAE 103-2017 and
 performed incorrectly.          corrects minutes to
                                 hours conversion
                                 error in new appendix
                                 EE.
Provided inconsistent unit      Corrects the            Correction.
 conversion factor from watts    conversion factor
 (``W'') to British thermal      from W to Btu/h to
 units per hour (``Btu/h''),     3.412 throughout new
 using values of 3.412 or        appendix EE.
 3.413.
Required the use of a gas       Requires the use of a   Clarification to
 having a specific gravity as    gas having a specific   reduce test
 shown in Table 1 of ANSI/       gravity                 burden.
 ASHRAE 103-1993.                ``approximate'' to
                                 what is shown in
                                 Table 1 of ANSI/
                                 ASHRAE 103-2017 in
                                 the new appendix EE.
Referenced incorrect sections   Revises 10 CFR          Correction.
 of appendix N test procedure    430.23(n)(1) to
 regarding average annual        update references
 auxiliary electrical            regarding average
 consumption determination       annual auxiliary
 provisions at 10 CFR            electrical
 430.23(n)(1).                   consumption to the
                                 correct sections of
                                 appendix N and the
                                 new appendix EE.
Referenced values in ANSI/      References values in    Harmonization
 ASHRAE 103-1993 for             ANSI/ASHRAE 103-2017    with industry
 determining national average    for determining         standard
 burner operating hours          national average BOH,   update.
 (``BOH''), average annual       average annual EF,
 fuel energy consumption         and average annual
 (``EF''), and average annual    EAE in the new
 auxiliary electrical energy     appendix EE.
 consumption (``EAE'').

[[Page 15514]]

 
Included instructions for the   Includes units of       Correction.
 setup of boilers with draft     measure for R-value
 hoods or draft diverters        in the new appendix
 which specified a minimum R-    EE.
 value for insulation but did
 not specify the units of
 measure for R-value.
------------------------------------------------------------------------

    DOE has determined that the amendments described in section III of 
this document and adopted in this final rule will not substantively 
impact the measured efficiency of consumer boilers 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. Discussion 
of DOE's actions is addressed in detail in section III of this 
document.
    The effective date for the amended test procedures adopted in this 
final rule is 30 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 procedures 
beginning 180 days after the publication of this final rule.

III. Discussion

    The subsequent sections of this final rule discuss specific topics 
raised in this rulemaking, including comments DOE received in response 
to the March 2022 NOPR. These topics include: scope of applicability of 
the test procedure, definitions in the test procedure, the AFUE metric, 
updates to industry standards, clarifications and corrections to the 
current test procedure, and test conditions.
    In addition, DOE received comments relating to the general 
processes by which DOE amends test procedures and energy conservation 
standards for covered products and equipment.
    BWC urged DOE to consider the cumulative regulatory burden placed 
on manufacturers that produce several different types of regulated 
products for which there are simultaneous rulemakings. BWC noted that 
additional burdens on manufacturers include changes to ENERGY STAR 
specifications; the Securities and Exchange Commission's proposed rule 
to enhance and standardize climate-related disclosures; updated state 
and local codes; demand-response requirements for electric water 
heaters in Western States; lower nitrogen oxides (NOX) 
emissions proposals in the State of California; proposed amendments to 
California Proposition 65; and extended producer responsibility 
legislation recently enacted in both Maine and Oregon. (BWC, No. 19 at 
p. 4-5)
    In response, DOE notes that cumulative regulatory burden on 
manufacturers is assessed as part of energy conservation standards 
rulemakings. The amendments to the consumer boilers test procedure, as 
promulgated by this final rule, are not expected to add burden to 
manufacturers because the amendments do not substantially impact 
efficiency ratings or alter the type of equipment necessary to perform 
testing. Test costs and burden are discussed in section III.K of this 
document.
    AGA and APGA commented that DOE should implement the 
recommendations from the recent National Academies of Sciences, 
Engineering, and Medicine report (``NASEM report'') \7\ into all of its 
appliance rulemakings for test procedures or energy conservation 
standards. AGA and APGA reiterated recommendations pertaining to 
analyses that DOE conducts in order to determine whether potential new 
or amended energy conservation standards are technologically feasible 
and economically justified. (AGA and APGA, No. 25, p. 3) For example, 
AGA and APGA highlighted the NASEM report's recommendations that DOE 
pay greater attention to the justification for its standards, expand 
the Cost Analysis segment of the Engineering Analysis for its rules, 
put greater weight on ex post and market-based evidence markups, place 
greater emphasis on providing an argument for the plausibility and 
magnitude of any market failure related to the energy efficiency gap, 
and give greater attention to a broader set of potential market 
failures on the supply side. Id.
---------------------------------------------------------------------------

    \7\ Although not specified, DOE interprets this comment to refer 
to the National Academies of Science, Engineering, and Medicine 2021 
report entitled ``Review of Methods Used by the U.S. Department of 
Energy in Setting Appliance and Equipment Standards.'' Copies of the 
report are available at nap.nationalacademies.org/catalog/25992/review-of-methods-used-by-the-us-department-of-energy-in-setting-appliance-and-equipment-standards.
---------------------------------------------------------------------------

    Given that this is a test procedure rulemaking for which DOE must 
meet specific statutory criteria as outlined in 42 U.S.C. 6293(b)(3), 
the recommendations in the NASEM report which pertain specifically to 
the processes by which DOE analyzes energy conservation standards are 
misplaced. DOE will consider this comment in a separate rulemaking 
considering all product categories.

A. Scope of Applicability

    As discussed, in the context of ``covered products,'' EPCA includes 
boilers in the definition of ``furnace.'' (42 U.S.C. 6291(23)) EPCA 
defines the term ``furnace'' to mean a product which utilizes only 
single-phase electric current, or single-phase electric current or DC 
current in conjunction with natural gas, propane, or home heating oil, 
and which: (1) is designed to be the principal heating source for the 
living space of a residence; (2) is not contained within the same 
cabinet with a central air conditioner whose rated cooling capacity is 
above 65,000 Btu/h; (3) is an electric central furnace, electric 
boiler, forced-air central furnace, gravity central furnace, or low 
pressure steam or hot water boiler; and (4) has a heat input rate of 
less than 300,000 Btu/h for electric boilers and low pressure steam or 
hot water boilers and less than 225,000 Btu/h for forced-air central 
furnaces, gravity central furnaces, and electric central furnaces. Id. 
DOE has codified this definition in its regulations at 10 CFR 430.2.
    DOE defines ``electric boiler'' as an electrically powered furnace 
designed to supply low pressure steam or hot water for space heating 
application. A low pressure steam boiler operates at or below 15 pounds 
per square inch gauge (``psig'') steam pressure; a hot water boiler 
operates at or below 160 psig water pressure and 250 degrees Fahrenheit 
([deg]F) water temperature. 10 CFR 430.2.
    DOE defines ``low pressure steam or hot water boiler'' as an 
electric, gas or oil burning furnace designed to supply low pressure 
steam or hot water for space heating application. 10 CFR 430.2. As with 
an electric boiler, a low pressure steam boiler operates at or below 15 
pounds psig steam pressure; a hot water boiler operates at or below 160 
psig water pressure and 250 [deg]F water temperature. Id.
    The scope of the test procedure for consumer boilers is currently 
specified

[[Page 15515]]

in section 1 of appendix N, which references section 2 of ANSI/ASHRAE 
103-1993. In relevant part, section 2 of ANSI/ASHRAE 103-1993 states 
that the industry test standard applies to boilers \8\ with inputs less 
than 300,000 Btu/h; having gas, oil, or electric input; and intended 
for use in residential applications. Further, ANSI/ASHRAE 103-1993 
applies to equipment that utilizes single-phase electric current or 
low-voltage DC current.
---------------------------------------------------------------------------

    \8\ ASHRAE 103-1993 defines a boiler as ``a self-contained fuel-
burning or electrically heated appliance for supplying low pressure 
steam or hot water for space heating application.'' This definition 
covers electric boilers and low pressure steam or hot water boilers 
as those terms are defined by DOE at 10 CFR 430.2.
---------------------------------------------------------------------------

    DOE is not changing the scope of products covered by its consumer 
boiler test procedure in this final rule. The following sections 
discuss specific types of boilers that DOE addressed in the March 2022 
NOPR with respect to whether such products are covered by the scope of 
DOE's test procedure.
1. Combination Space/Water Heating Boilers
    Some consumer boilers are capable of providing both space heating 
and domestic hot water heating, and are often referred to as 
``combination'' boilers. In the March 2022 NOPR, DOE responded to 
comments from the Northwest Energy Efficiency Alliance (``NEEA'') and 
Rheem recommending that DOE consider developing a separate test 
procedure for combination space and domestic hot water boilers. 87 FR 
14622, 14626-14627. While DOE did not propose a specific definition for 
combination space and water heating boilers in the NOPR, DOE noted 
that, to the extent that a combination space and water heating product 
meets the definition of electric boiler or low pressure steam or hot 
water boiler, it is subject to the test procedure at appendix N and 
energy conservation standards for consumer boilers at 10 CFR 
430.32(e)(2), and must be tested and rated accordingly. 87 FR 14622, 
14625-14626. DOE also stated that it is unaware of any design 
characteristics of combination space and water heating products that 
would prevent their testing according to appendix N. Id.
    DOE did not receive any comments in response to the March 2022 NOPR 
with regard to combination space and heating water boilers. In this 
final rule, DOE reiterates its statements presented in the March 2022 
NOPR with respect to combination boilers. To the extent that a 
combination space and water heating product meets the definition of 
electric boiler or low pressure steam or hot water boiler, it is 
subject to the test procedure at appendix N (or, as of the effective 
date of this final rule, appendix EE) and energy conservation standards 
for consumer boilers at 10 CFR 430.32(e)(2), and must be tested and 
rated accordingly.
2. Heat Pump Boilers
    In the March 2022 NOPR, DOE discussed comments received in response 
to the May 2021 RFI with regard to hydronic air-to-water and water-to-
water heat pumps. DOE tentatively determined that air-to-water and 
water-to-water heat pumps meet the definitional criteria to be 
classified as a consumer boiler. 87 FR 14622, 14625. DOE noted that 
these products utilize only single-phase electric current, are designed 
to be the principal heating source for the living space of a residence, 
are not contained within the same cabinet with a central air 
conditioner whose rated cooling capacity is above 65,000 Btu/h, meet 
the definition of an electric boiler,\9\ and have a heat input rate of 
less than 300,000 Btu/h (i.e., the requirement for electric boilers). 
As such, they meet the criteria of ``furnace'' as defined in 10 CFR 
430.2. Id. at 87 FR 14625-14626.
---------------------------------------------------------------------------

    \9\ ``Electric boiler'' means an electrically powered furnace 
designed to supply low pressure steam or hot water for space heating 
application. A low pressure steam boiler operates at or below 15 
psig steam pressure; a hot water boiler operates at or below 160 
psig water pressure and 250 [deg]F water temperature. 10 CFR 430.2.
---------------------------------------------------------------------------

    In the March 2022 NOPR, DOE also tentatively determined that the 
test procedure in appendix N does not address such products and would 
not provide a rated value that is representative of the performance of 
these products. Id. at 14626. In particular, DOE noted that the AFUE 
metric for electric boilers in ANSI/ASHRAE 103-1993 is calculated as 
100 percent minus jacket loss,\10\ which provides a representative 
measure of efficiency for electric boilers using electric resistance 
technology, for which an efficiency value of 100 percent (the ratio of 
heat output to energy input) is the maximum upper limit that 
technically could be achieved. DOE tentatively concluded that the AFUE 
metric would not provide a representative or meaningful measure of 
efficiency for a boiler with a heat pump supplying the heat input, 
because heat pump efficiency (in terms of heat output to energy input) 
typically exceeds 100 percent, and the AFUE metric does not allow for 
ratings greater than 100 percent for electric boilers. Id.
---------------------------------------------------------------------------

    \10\ The term ``jacket loss'' is used by industry to mean the 
transfer of heat from the outer surface (i.e., jacket) of a boiler 
to the ambient air surrounding the boiler.
---------------------------------------------------------------------------

    Based on these considerations, DOE tentatively determined that 
hydronic air-to-water and water-to-water heat pumps are consumer 
boilers under EPCA, but that due to the lack of a Federal test 
procedure, such products are not subject to the current performance 
standards at 10 CFR 430.32(e). Id.
    In response to the March 2022 NOPR, Crown and U.S. Boiler \11\ 
stated that hydronic heat pumps should not be classified as boilers 
under EPCA because hydronic heat pumps cannot deliver water at the same 
temperatures and heating capacities as traditional boilers. Crown and 
U.S. Boiler further commented that it is unclear whether hydronic heat 
pumps are ``designed to be the principal heating source for a living 
space of a residence'' (a requirement to meet the definition of a 
furnace at 10 CFR 430.2) because these products are mostly incapable of 
reaching above 150 [deg]F on a design day, whereas traditional boilers 
are designed to deliver water at a temperature of 180 [deg]F or higher. 
Crown and U.S. Boiler also stated that gas, oil, and electric 
resistance boilers are capable of heating any hot water or steam 
heating system throughout the entire heating season, whereas hydronic 
heat pumps do not have such capabilities. Crown and U.S. Boiler stated 
that heat pumps and boilers provide different consumer utility, and 
suggested that presenting heat pumps to consumers as ``boilers'' could 
create confusion with regard to the different capabilities of each. 
(Crown, No. 16 at p. 1-2; -U.S. Boiler, No. 17 at p. 1-2)
---------------------------------------------------------------------------

    \11\ DOE notes that both Crown and U.S. Boiler's comments stated 
that the companies are subsidiaries of Burnham Holdings, Inc. 
(``BHI''). The comments submitted by Crown and U.S. Boiler in 
response to the March 2022 NOPR were identical in content.
---------------------------------------------------------------------------

    AHRI and AGA and APGA commented that hydronic heat pumps cannot 
currently provide the same functionality as boilers for high 
temperature installations as they are unable to provide water at or 
over 210 [deg]F, and that this lack of utility should disqualify these 
products from being considered in the boiler test procedure. (AHRI, No. 
26 at p. 2; AGA and APGA, No. 25 at p. 2)
    BWC disagreed with DOE's tentative determination that air-to-water 
and water-to-water heat pumps should be defined as consumer boilers. 
BWC stated that heat pump products and consumer boilers have pronounced 
differences that should prevent them from being defined as the same 
product.

[[Page 15516]]

BWC noted that boilers and heat pumps \12\ are already separate product 
categories on DOE's website and certified separately through DOE's 
Compliance Certification Management System. BWC also stated that 
hydronic heat pumps are rated to Coefficient of Performance (``COP'') 
rather than AFUE (for boilers), and that the unique technologies 
utilized by both product types necessitate different methods for 
testing and rating them. BWC further stated that consumer boilers are 
designed exclusively to provide a heating utility, whereas hydronic 
heat pumps can be used to provide both space heating and cooling. (BWC, 
No. 19 at p. 2-3)
---------------------------------------------------------------------------

    \12\ DOE understands BWC is referring to central air 
conditioning and heat pump units.
---------------------------------------------------------------------------

    Rheem supported DOE's tentative determination that hydronic air-to-
water and water-to-water heat pumps are consumer boilers under EPCA. 
Rheem stated that although these products may not necessarily be able 
to achieve the same maximum temperatures as conventional boilers 
(without electric resistance or gas backup), hydronic heat pump boilers 
can still provide adequate space heating in many applications. Rheem 
recommended that DOE either add procedures to test hydronic heat pumps 
in this consumer boiler test procedure rulemaking or initiate a 
separate test procedure rulemaking. Rheem asserted that these products 
perform the same function as other types of boilers and should be 
tested and rated in a similar manner, and that DOE could use the 
current AFUE test procedure as a guide to produce an ``AFUE metric'' 
for hydronic heat pumps that combines the various energy use modes and 
input rate conditions with test conditions and operating assumptions 
that are representative of hydronic heat pumps. Rheem stated that any 
differences in ability to meet consumer heating demands should be 
considered in the development of energy conservation standards, as 
opposed to the test procedure. (Rheem, No. 18 at p. 2)
    NYSERDA agreed with DOE's tentative determination that air-to-water 
and water-to-water heat pumps should be considered boilers under EPCA. 
NYSERDA recommended that DOE develop a test procedure for these heat 
pumps and combination space heating and water heating products. NYSERDA 
asserted that the adoption of these test procedures will also enable 
future standards revisions to adopt more efficient heat pump levels of 
performance. (NYSERDA, No. 23 at p. 5-6)
    In consideration of the comments received on this issue, as well as 
further consideration of the discussion presented in the March 2022 
NOPR, DOE has concluded that hydronic air-to-water and water-to-water 
heat pumps meet the definitional criteria to be classified as a 
consumer boiler. In particular, as noted initially in the March 2022 
NOPR, DOE concludes that these products utilize only single-phase 
electric current, are designed to be the principal heating source for 
the living space of a residence, and are not contained within the same 
cabinet with a central air conditioner whose rated cooling capacity is 
above 65,000 Btu/h. In addition, electric heat pump boilers meet the 
definition of an electric boiler; and gas-fired heat pump boilers meet 
the definition of a low pressure steam or hot water boiler and have a 
heat input rate of less than 300,000 Btu/h (i.e., the requirement for 
electric boilers and low pressure steam or hot water boilers). As such, 
these products meet the criteria of ``furnace'' as defined in 10 CFR 
430.2.
    With respect to comments from Crown, U.S. Boiler, AHRI, and AGA and 
APGA suggesting hydronic air-to-water heat pumps and water-to-water 
heat pumps should be excluded from the definition because they cannot 
provide the same maximum water temperature as non-heat pump hydronic 
systems, DOE notes that neither EPCA nor DOE's definitions at 10 CFR 
430.2 provide a minimum water temperature requirement. In addition, in 
response to comments that hydronic heat pumps serve different 
applications than boilers, DOE notes that hydronic heat pumps are 
marketed as providing the principal heating source for a residence, and 
nothing in EPCA's or DOE's definition would exclude them based on their 
ability to also provide cooling.
    DOE recognizes that hydronic heat pump products differ 
significantly from non-heat pump boilers, and that the current test 
procedure for consumer boilers (as well as the amended test procedure 
established by this final rule) would not provide test results that are 
representative of the energy use or energy efficiency of an air-to-
water or water-to-water heat pump product. Because of these differences 
and uncertainty regarding the most representative approach to testing 
these products, DOE is not establishing separate test procedures for 
hydronic heat pump products in this final rule. Although air-to-water 
and water-to-water heat pump products meet all the definitional 
criteria to be considered a consumer boiler, the Department requires 
more information in order to determine a representative approach for 
testing these products. Further consideration of an appropriate test 
procedure for such products would be provided in a separate test 
procedure rulemaking. Section III.C of this document further discusses 
the applicability of the AFUE metric to hydronic heat pump products.

B. Definitions

    In addition to the overarching definition of ``furnace'' (which 
includes boilers) and the associated definitions for ``electric 
boiler'' and ``low pressure steam or hot water boiler'' presented in 
section III.A of this document, DOE also has defined ``outdoor 
boilers'' and ``weatherized warm air boilers'' at 10 CFR 430.2 as 
follows:
     ``Outdoor furnace or boiler'' is a furnace or boiler 
normally intended for installation out-of-doors or in an unheated space 
(such as an attic or a crawl space).
     ``Weatherized warm air furnace or boiler'' means a furnace 
or boiler designed for installation outdoors, approved for resistance 
to wind, rain, and snow, and supplied with its own venting system.
    In the March 2022 NOPR, DOE proposed to remove the definition of 
``outdoor furnace or boiler'' from its regulations, noting that the 
definition is not used for the energy conservation standards for 
boilers at 10 CFR 430.32(e)(2)(iii), nor for applying the test 
procedure.\13\ 87 FR 14622, 14626-14627. DOE sought comment on its 
proposal to remove the definition of ``outdoor furnace or boiler'' from 
its regulations and whether removing the definition for ``outdoor 
furnace or boiler'' would impact the application of the test procedure 
or energy conservation standards for any such products.
---------------------------------------------------------------------------

    \13\ Specifically, with respect to the test procedure, DOE noted 
that different jacket loss factors are applied based on whether a 
boiler is intended to be installed indoors, outdoors, or as an 
isolated combustion system. The heating seasonal efficiency 
(EffyHS) calculation, which is an element of AFUE, is 
based on the assumption that all weatherized boilers are located 
outdoors (see section 10.1 of appendix N). Appendix N does not 
specify a separate jacket loss assumption for outdoor furnaces or 
boilers.
---------------------------------------------------------------------------

    Rheem and BWC supported DOE's proposal to remove the definition of 
``outdoor furnace or boiler'' from 10 CFR 430.2. (Rheem, No. 18 at p. 
2; BWC, No. 19 at p. 1) A.O. Smith stated that removal of this 
definition from the DOE regulations would not have a negative impact on 
the application of the test procedure or energy conservation standards. 
(A.O. Smith, No. 24 at p. 2) AHRI and AGA and APGA also supported 
removing the definition and

[[Page 15517]]

stated that the removal would add clarity and consistency to the test 
procedure. (AHRI, No. 26 at p. 2; AGA and APGA, No. 25 at p. 2)
    For the reasons discussed in the March 2022 NOPR, and in 
consideration of these comments, in this final rule DOE finalizes its 
proposal to remove the definition of ``outdoor furnace or boiler'' from 
10 CFR 430.2.
    In the March 2022 NOPR, DOE proposed to incorporate by reference 
ANSI/ASHRAE 103-2017, including the definitions included therein. 87 FR 
14622, 14627. DOE noted that ANSI/ASHRAE 103-2017 includes definitions 
for ``air intake terminal,'' ``control,'' and ``isolated combustion 
system'' that are not in ANSI/ASHRAE 103-1993. Id. The definitions for 
``control'' and ``isolated combustion system'' in ANSI/ASHRAE 103-2017 
are almost identical to the definitions for those terms currently 
defined in sections 2.3 and 2.7 of appendix N, respectively. Therefore, 
DOE proposed to remove the definitions for ``control'' and ``isolated 
combustion system'' from DOE's consumer boiler test procedure, as they 
would be redundant with the definitions incorporated by reference 
through ANSI/ASHRAE 103-2017, if the proposal to incorporate by 
reference ANSI/ASHRAE 103-2017 were finalized. Id.
    Rheem, The CA IOUs, A.O. Smith, AHRI, and AGA and APGA supported 
incorporating by reference the definitions in ANSI/ASHRAE 103-2017 and 
removing the separate definitions for ``control'' and ``isolated 
combustions system'' from DOE's test procedure. (Rheem, No. 18 at p. 3; 
CA IOUs, No. 20 at p. 1; A.O. Smith, No. 24 at p. 3; AHRI, No. 26 at p. 
2; AGA and APGA, No. 25 at p. 2)
    For the reasons discussed in the March 2022 NOPR, and in 
consideration of these comments, DOE is removing the separate 
definitions for ``control'' and ``isolated combustion system'' from the 
consumer boiler test procedure, as proposed in the March 2022 NOPR. The 
definitions for these products are instead provided through DOE's 
incorporation by reference of ANSI/ASHRAE 103-2017, as discussed 
further in section III.D.1 of this final rule.
    In response to the March 2022 NOPR, Busse suggested that DOE add a 
definition for ``standard cubic unit of gas'' as follows:
    ``Standard cubic foot of gas: The amount of gas that would occupy 1 
cubic foot when at a temperature of 60 [deg]F, if saturated with water 
vapor, and under a pressure equivalent to that of 30 inches mercury 
column.'' (Busse, No. 22 at p. 9)
    Busse stated that a definition of standard cubic foot of gas is 
necessary to comply with the conditions specified in section 7.1 of 
appendix N, Fuel Supply.\14\ Busse further stated that the suggested 
definition would be consistent with industry standards NFPA 54/ANSI 
Z223.1, National Fuel Gas Code, and CSA 4.9/ANSI Z21.13, Gas-Fired Low 
Pressure Steam and Hot Water Boilers and asserted that manufacturers 
are familiar with this definition when conducting performance testing. 
Busse noted that the difference between a saturated ``wet'' and 
unsaturated ``dry'' cubic foot of gas is 1.73 percent at standard 
temperature and pressure. Busse also recommended that DOE modify the 
language of section 7.3 of appendix N, Gas Burner, to replace ``gas 
characteristics at a temperature of 60 [deg]F and atmospheric pressure 
of 30 in of Hg'' with reference to this new definition, i.e., ``gas 
characteristics to standard cubic foot of gas, as defined in section 2 
of this appendix,'' in specifying the conditions needed to correct the 
burner input rate.\15\ (Busse, No. 22 at p. 9-10)
---------------------------------------------------------------------------

    \14\ Section 7.1 of appendix N requires determining the actual 
higher heating value in Btu per standard cubic foot for the gas to 
be used in the test within an error no greater than 1 percent.
    \15\ Busse also commented that, with respect to the current 
instruction to ``Correct the burner input rate to reflect gas 
characteristics,'' technically the Ideal Gas Laws can be applied 
only to the volume of gas consumed and the higher heating value, and 
not to the burner input rate.
---------------------------------------------------------------------------

    In response, DOE notes that as proposed in the March 2022 NOPR, 
section 7.3 of appendix EE would require that the burner input rate be 
corrected to reflect gas characteristics at a temperature of 60 [deg]F 
and atmospheric pressure of 30 in of Hg when adjusting the burner input 
rate. Therefore, an additional definition for a standard cubic foot of 
gas for the purpose of referencing it in sections 7.1 and 7.3 (which is 
consistent with the language in section 9.1.2.2.1 of both ANSI/ASHRAE 
103-1993 and ANSI/ASHRAE 103-2017) would be unnecessary; however, it 
may be useful for clarification.
    As such, DOE is adding a definition for a ``standard cubic foot of 
gas'' to section 2 of appendix EE to specify the temperature and 
pressure for a standard cubic foot of gas.

C. Metric

    As discussed, the energy conservation standards for consumer 
boilers rely on the AFUE metric. 10 CFR 430.32(e)(2). For gas-fired and 
oil-fired boilers, AFUE accounts for fossil fuel consumption in active, 
standby, and off modes, but does not include electrical energy 
consumption. For electric boilers, AFUE accounts for electrical energy 
consumption in active mode. EPCA defines the term ``annual fuel 
utilization efficiency,'' in part, as the efficiency descriptor for 
furnaces and boilers. (42 U.S.C. 6291(20)) In addition, DOE has 
established separate metrics and energy conservation standards for 
power consumption during standby mode and off mode (PW,SB 
and PW,OFF, respectively). 10 CFR 430.32(e)(2)(iii)(B).
    AFUE is defined by ASHRAE 103 (both the 1993 and 2017 versions) as 
the ratio of annual output energy to annual input energy, which 
includes any non-heating-season pilot input loss but does not include 
electric energy for gas- or oil-fired furnaces or boilers. For gas- and 
oil-fired boilers, the AFUE test generally consists of steady-state, 
cool down, and heat up tests, during which various measurements are 
taken (e.g., flue gas temperature, concentration of CO2 in 
the flue gas). (See sections 9.1, 9.5, and 9.6 of both ANSI/ASHRAE 103-
1993 and ANSI/ASHRAE 103-2017.) For condensing boilers, condensate 
collection tests during steady-state and cyclic operation are also 
specified. (See sections 9.2 and 9.8 of both ANSI/ASHRAE 103-1993 and 
ANSI/ASHRAE 103-2017.) The test measurements are used in conjunction 
with certain assumptions to calculate the AFUE. (See section 11 of both 
ANSI/ASHRAE 103-1993 and ANSI/ASHRAE 103-2017.)
    In the March 2022 NOPR, after tentatively concluding that hydronic 
heat pumps meet the definitional criteria to be considered a consumer 
boiler but that the existing test procedure does not apply to them, DOE 
sought comment on whether any other industry test methods exist for 
determining the heating efficiency of air-to-water or water-to-water 
heat pumps. DOE sought comment specifically on AHRI 550/590, and 
whether it would be appropriate for adoption as a Federal test 
procedure for such products, and if so, whether modifications could be 
made to result in an AFUE rating. 87 FR 14622, 14626.
    NYSERDA urged DOE to adopt appropriate, industry-recognized test 
procedures to support informed consumer choice between electric 
resistance and heat pump products. (NYSERDA, No. 23 at p. 5-6)
    BWC stated that it believes DOE has correctly identified the 
appropriate test procedures for both consumer boilers and hydronic heat 
pumps at this time, with those procedures being ASHRAE 103-2017 and 
AHRI 550/590 respectively. (BWC, No. 19 at p 2-3)

[[Page 15518]]

Rheem identified AHRI 550/590 as an industry test method to determine 
maximum and part-load COP values but noted this test method would have 
to be modified to account for standby mode and off mode energy use as 
well as to produce an AFUE metric. (Rheem, No. 18 at p. 2)
    The Joint Advocates stated that while AHRI 550/590 is appropriate 
for evaluating the performance of consumer air-to-water heat pumps, it 
is only applicable for water-to-water heat pumps with a capacity 
greater or equal to 135,000 Btu/h. The Joint Advocates stated that 
ASHRAE/ANSI/AHRI/ISO Standard 13256-2 is more appropriate for consumer 
water-to-water heat pumps and referred to international standards EN 
14511 and EN 14825 as starting points. The Joint Advocates asserted 
that a seasonal performance rating analogous to AFUE could be 
established and encouraged DOE to establish these procedures in a 
timely manner so that consumers have access to efficiency ratings based 
on a standardized test procedure. Finally, the Joint Advocates stated 
that based on 2015 Residential Energy Consumption Survey (``RECS'') 
data, hydronic systems are the main heating means in 8 percent of U.S. 
homes overall and the main heating means for 28 percent of households 
in the Northeastern United States. (Joint Advocates, No. 21 at p. 1-2)
    A.O. Smith stated that ISO Standard 13256-2 would be the most 
appropriate test method for water source heat pump water heaters 
intended to be used as consumer hot water boilers, and that AHRI 
Standard 550/590 would be the most appropriate test method for air 
source heat pump water heaters intended to be used as consumer hot 
water boilers. Pertaining specifically to AHRI 550/590, A.O. Smith 
stated that the test procedure to measure COP has fundamental 
differences than the test procedure to measure AFUE, and that there is 
no means of deriving an AFUE value from the COP measurement. In 
addition, A.O. Smith claimed that if the limit for consumer heat pump 
water ``boilers'' is defined by an input rate of less than 300,000 Btu/
h, then the output for these products will include products with 
heating capacities up to 900,000 Btu/h, which would be outside the 
scope of a consumer boiler. A.O. Smith recommended that DOE review the 
referenced performance standards, as they define the heating capacity 
based on the heat moved into the water being heated, whereas DOE's 
definition is based on the energy being consumed by the boiler. (A.O. 
Smith, No. 24 at p. 2)
    As stated in section III.A.2 of this document, DOE has concluded 
that hydronic heat pumps meet the definitional criteria to be covered 
as a consumer boiler under EPCA's statutory definition at 42 U.S.C. 
6291(23) and DOE's regulatory definition at 10 CFR 430.2. However, DOE 
is not adopting a separate test procedure or metric for hydronic heat 
pumps in this final rule because the Department requires more 
information in order to determine a representative approach for testing 
these products. DOE will continue to consider the appropriate metric to 
assess the efficiency of such products, and any proposed test procedure 
would be addressed in a separate test procedure rulemaking in the 
future.

D. Updates to Industry Standards

    The DOE test method for consumer boilers references several 
industry standards, including ANSI/ASHRAE 103 for various testing 
requirements pertaining to determination of AFUE, certain sections of 
IEC 62301 (Second Edition) for determining the electrical standby mode 
and off mode energy consumption, and ASTM D2156-09 (Reapproved 2013) 
for adjusting oil burners. The following sections discuss DOE's 
amendments pertaining to the incorporation by reference of these 
industry standards.
1. ANSI/ASHRAE 103
    As discussed, ANSI/ASHRAE 103-1993 is referenced throughout 
appendix N for various testing requirements pertaining to determination 
of the AFUE of consumer boilers. ANSI/ASHRAE 103-1993 provides 
procedures for determining the AFUE of consumer boilers (and furnaces). 
As mentioned previously, ANSI/ASHRAE 103-1993 has been updated multiple 
times. In the rulemaking that culminated in the January 2016 Final 
Rule, DOE initially proposed to incorporate by reference the most 
recent version of ANSI/ASHRAE 103 available at the time (i.e., ANSI/
ASHRAE 103-2007), but ultimately declined to adopt the proposal in the 
final rule based on concerns about the impact this change would have on 
AFUE ratings of products distributed in commerce at that time. 81 FR 
2628, 2632-2633 (Jan. 15, 2016). DOE stated that further evaluation was 
needed to determine the potential impacts of ANSI/ASHRAE 103-2007 on 
the measured AFUE of boilers. Id. DOE theorized that ANSI/ASHRAE 103-
2007 might better account for the operation of two-stage and modulating 
products and stated that DOE may further investigate adopting it or a 
successor test procedure in the future. Id.
    After the January 2016 Final Rule, ANSI/ASHRAE 103 was again 
updated in 2017 (i.e., ANSI/ASHRAE 103-2017). In the May 2020 RFI, DOE 
identified several substantive differences between ANSI/ASHRAE 103-1993 
and ANSI/ASHRAE 103-2017 that pertain to consumer boilers and requested 
further comment on the differences between ANSI/ASHRAE 103-1993 and 
ANSI/ASHRAE 103-2017. 85 FR 29352, 29355.
    In the March 2022 NOPR, DOE discussed additional differences 
between ANSI/ASHRAE 103-1993 and ANSI/ASHRAE 103-2017 raised by 
commenters in response to the May 2020 RFI. 87 FR 14622, 14628-14631. 
The differences between the two versions of the standard are discussed 
in detail in sections III.D.1.a through III.D.1.f of this document. 
After considering the differences between the standards and the 
potential impact, DOE proposed to incorporate by reference the most 
recent version (at the time) of ANSI/ASHRAE 103, i.e., ANSI/ASHRAE 103-
2017. 87 FR 14622, 14630. DOE tentatively concluded that the 
improvements included in ANSI/ASHRAE 103-2017 provide a more 
representative average use cycle for consumer boilers, in particular 
for two-stage and modulating boilers, and that the change would not 
materially alter the burden or cost of conducting an AFUE test. Id. DOE 
also noted that test data indicate the update to the 2017 edition of 
ASHRAE 103 could result in changes to the measured AFUE of two-stage 
and modulating boilers ranging from -0.50 percent to 0.23 percent, with 
no discernable trend in the direction or magnitude of change, and that 
several commenters indicated incorporating ANSI/ASHRAE 103-2017 would 
likely not impact rated values significantly. 87 FR 14622, 14631. DOE 
sought further comment on its proposal to incorporate by reference 
ANSI/ASHRAE 103-2017, the potential impact on ratings and whether 
retesting would be required. Id.
    Rheem agreed with DOE's tentative determination that the proposed 
amendments would result in minimal differences in AFUE ratings but 
requested that DOE test a representative sample of minimally compliant 
consumer boilers to determine the effect. Rheem requested that DOE 
provide this test data in the final rule and assess the impacts on the 
ongoing energy conservation standards rulemaking. Rheem additionally 
suggested that DOE could provide an enforcement policy to state that 
models tested and certified prior to the effective date of the test 
procedure final rule would be tested to the current appendix N test 
procedure during an enforcement investigation. (Rheem, No. 18 at p. 3-
4)

[[Page 15519]]

    As discussed, DOE's assessment of the changes in ANSI/ASHRAE 103-
2017, along with stakeholder comments provided throughout this 
rulemaking, indicate that the only update in the industry test 
procedure with the potential to impact ratings would be the change in 
cycle times. This topic is discussed in detail in section III.D.2.c of 
this document. The updated cycle times pertain to condensing boilers, 
which employ heat exchanger technologies with efficiency performance 
that surpasses the current minimum AFUE requirements for boilers at 10 
CFR 430.32(e)(2)(iii). As discussed in section III.D.2.c of this 
document, DOE conducted testing to determine that the impact on AFUE 
ratings of this change would be minimal. Based on this information, DOE 
has determined that the amendments to the consumer boilers test 
procedure will not have a significant or substantive impact on ratings, 
nor affect compliance of any products.
    On January 10, 2022, ASHRAE and ANSI approved a 2022 edition of 
ASHRAE 103 (i.e., ``ANSI/ASHRAE 103-2022''). DOE did not discuss ANSI/
ASHRAE 103-2022 in the March 2022 NOPR, and parties commenting in 
response to the March 2022 NOPR did not indicate that DOE should 
consider incorporating by reference ANSI/ASHRAE 103-2022. A March 4, 
2022, online publication by ANSI states that ANSI/ASHRAE 103-2022 
includes mostly editorial changes and quality improvements to test duct 
and plenum figure, the system number table, and figures for the surface 
heat transfer coefficient and coefficient of radiation.\16\ Given that 
stakeholders provided general support for adopting ANSI/ASHRAE 103-
2017, and that the updates in ANSI/ASHRAE 103-2022 do not substantively 
change the industry test procedure DOE is not considering ANSI/ASHRAE 
103-2022 in this rulemaking.
---------------------------------------------------------------------------

    \16\ Brad Kelechava, ``ANSI/ASHRAE 103-2022: AFUE Testing of 
Residential Furnaces and Boilers,'' The ANSI Blog, March 4, 2022, 
blog.ansi.org/ansi-ashrae-103-2022-fuel-efficiency-afue-testing/#gref. Last accessed October 5, 2022.
---------------------------------------------------------------------------

    The following subsections discuss the updates in ANSI/ASHRAE 103-
2017 with respect to ANSI/ASHRAE 103-1993.
a. Post-Purge Time
    Power vented units, power burner units, and forced-draft units use 
a combustion blower to exhaust the flue gas during operation. ``Post 
purge'' is defined in both ANSI/ASHRAE 103-1993 and ANSI/ASHRAE 103-
2017 as ``the design that permits the continued operation of the 
combustion blower in a power vented unit, power burner unit, or forced-
draft unit for a period of time after the main burner is shut off for 
the purpose of venting of residential flue gas in the heat exchanger 
and the venting system.'' For the determination of off-cycle flue 
losses, it is necessary to demarcate when the boiler has entered its 
off-cycle after completion of the post-purge period, especially since 
post-purge periods can last several minutes. Section 8.7 of appendix N 
specifies the timing of flue temperature measurements during the off-
cycle portion of the test method based on the length of the post-purge 
period. Section 8.7 of appendix N generally corresponds to section 
9.5.2.1 of ANSI/ASHRAE 103-1993, except that section 8.7 of appendix N 
specifies that when the post-purge time is less than or equal to 30 
seconds, it can be set to 0 and the cool-down test be conducted as if 
there is no post-purge; while section 9.5.2.1 of ANSI/ASHRAE 103-1993 
specifies that if post-purge time is less than or equal to 5 seconds, 
it shall be tested as if there is no post-purge. Additionally, the 
length of the post-purge cycle is used as one criterion for determining 
whether the heat-up and cool-down tests can optionally be omitted. 
Section 8.10 of appendix N generally corresponds to section 9.10 of 
ANSI/ASHRAE 103-1993, and both sections require a post-purge period of 
less than 5 seconds to optionally omit the heat-up and cool-down tests.
    Section 9.5.2.1 of ANSI/ASHRAE 103 was updated in the 2017 version 
to match DOE's requirement that if the post-purge period is 30 seconds 
or less, it shall be tested as if there is no post-purge. Additionally, 
in the March 2022 NOPR, DOE identified the post-purge time threshold 
being increased to 30 seconds in the criterion for determining whether 
the ``Optional Test Procedures for Conducting Furnaces and Boilers that 
have no OFF-Period Flue Loss'' is applicable as a change in ANSI/ASHRAE 
103-2017. DOE proposed to adopt the 30-second threshold in the newly 
proposed appendix EE, consistent with the change to ANSI/ASHRAE 103-
2017. 87 FR 14622, 14628.
    BWC stated that it appreciated DOE's inclusion of the change in 
post-purge time length to 30 seconds. (BWC, No. 19, p. 2-3)
    Additionally, in the March 2022 NOPR, DOE proposed minor changes to 
the test method for models with post-purge times longer than 3 minutes, 
consistent with the updates included in ANSI/ASHRAE 103-2017. 87 FR 
14622, 14631. Specifically, section 9.5.2.1 of ANSI/ASHRAE 103-2017 
requires that for cases where the post-purge period is greater than 3 
minutes, an additional measurement of the flue gas temperature during 
the cool-down test is required at the midpoint of the post-purge 
period. DOE proposed to adopt a harmonizing change in the newly 
proposed appendix EE. 87 FR 14622, 14631 and 14654.
    DOE did not receive any comments regarding this proposal. For the 
reasons discussed in the March 2022 NOPR, DOE is finalizing this 
amendment to section 8.5(d) of appendix EE.
b. Calculations for Omission of Heat-Up and Cool-Down Tests
    The current test procedure for consumer boilers allows certain 
units to omit the cool-down and heat-up tests. These include units that 
have been determined to have no measurable airflow through the 
combustion chamber and heat exchanger during the burner off-period and 
that have minimal post-purge periods (see section III.D.1.a of this 
document for discussion of post-purge time). For these boilers, the 
off-cycle losses are expected to be minimal. However, off-cycle losses 
(typically determined during the cool-down and heat-up tests) must be 
accounted for when determining the heating seasonal efficiency, 
EffyHS. Section 8.10 of appendix N currently states, ``In 
lieu of conducting the cool-down and heat-up tests, the tester may use 
the losses determined during the steady-state test described in section 
9.1 of ASHRAE 103-1993 when calculating heating seasonal efficiency, 
EffyHS.'' Accordingly, sections 10.2 and 10.3 of appendix N 
provide the appropriate equations to use when calculating 
EffyHS if the cool-down and heat-up tests are omitted per 
section 8.10 of appendix N. These equations are provided in sections 
10.2 and 10.3 of appendix N because they were not included in ANSI/
ASHRAE 103-1993.
    As discussed in the March 2022 NOPR, ANSI/ASHRAE 103-2017 makes 
several updates to include these equations, and the equations in ANSI/
ASHRAE 103-2017 are identical to those in appendix N. 87 FR 14622, 
14629. Due to this harmonizing update, DOE proposed not to include 
these equations in the new appendix EE and to instead directly 
reference the relevant sections in ANSI/ASHRAE 103-2017 (11.3.11.3, 
11.5.11.1, and 11.5.11.2). 87 FR 14622, 14631. DOE did not receive 
comment on this topic and is finalizing this amendment as proposed in 
the March 2022 NOPR.

[[Page 15520]]

c. Cycle Timings
    ANSI/ASHRAE 103-2017 includes calculations, originally included in 
ANSI/ASHRAE 103-2007, for determining the average on-time and off-time 
per cycle for two-stage and modulating boilers, rather than assigning 
fixed values as in ANSI/ASHRAE 103-1993. DOE received comments in 
response to the May 2020 RFI generally indicating that these updated 
cycle timings are more representative. DOE referenced test data from 
the previous rulemaking to ascertain the potential impact of this 
update and tentatively determined that the new method would be more 
representative and not unduly burdensome and have minimal impact on 
AFUE ratings. 87 FR 14622, 14628. Therefore, DOE proposed to adopt the 
updated cycle times via adoption of the ASHRAE 103-2017 as the 
reference standard in the newly proposed appendix EE. 87 FR 14622, 
14630.
    In addition, DOE discussed that data collected for the January 2016 
Final Rule \17\ for three models of condensing, modulating boilers 
showed that the changes in on-cycle and off-cycle times resulted in 
changes in AFUE of 0.11, -0.50, and 0.22 percent, respectively. For two 
models of non-condensing, modulating boilers, calculating the AFUE 
based on the on-cycle and off-cycle times in ANSI/ASHRAE 103-2007 
changed the AFUE by 0.11 and -0.14 percent, respectively. 87 FR 14622, 
14630.
---------------------------------------------------------------------------

    \17\ These data were presented at a public meeting for the March 
11, 2015, NOPR pertaining to test procedures for furnaces and 
boilers and can be found at www.regulations.gov/document/EERE-2012-BT-TP-0024-0021.
---------------------------------------------------------------------------

    In response to the March 2022 NOPR, BWC stated that it agreed with 
DOE's conclusion that the new average use cycle calculations from ANSI/
ASHRAE 103-2017 are more representative for modulating boilers and have 
little impact on efficiency ratings. (BWC, No. 19 at p. 4) The CA IOUs 
stated the ANSI/ASHRAE 103-2017 on/off time per cycle more accurately 
represents the typical operation for two-stage, modulating, and 
condensing boiler technologies. (CA IOUs, No. 20 at p. 1)
    AHRI requested that DOE provide more data regarding the impacts of 
cycle timing on condensing models. (AHRI, No. 26 at p. 3)
    In response to this request, DOE has conducted testing on two 
additional modulating condensing boilers to investigate the impact of 
the revised cycle timings on AFUE. Data collected from this testing is 
shown in Table III.1. For this investigation, DOE used the updated 
steady-state efficiency calculation method discussed in section III.E 
of this final rule for both the ANSI/ASHRAE 103-1993 and ANSI/ASHRAE 
103-2017 results such that the only variable influencing differences in 
AFUE ratings would be the cycle timings.

                 Table III.1--Impact of Cycle Timings on AFUE for Modulating Condensing Boilers
----------------------------------------------------------------------------------------------------------------
                                     ANSI/ASHRAE 103-1993              ANSI/ASHRAE 103-2017
                              ------------------------------------------------------------------- Change in AFUE
            Model                Cycle timings                    Cycle timings                      (percent)
                                    (mm:ss)      AFUE (percent)      (mm:ss)      AFUE (percent)
----------------------------------------------------------------------------------------------------------------
Unit No. 1...................  15:00 on/15:00             90.98  23:10 on/11:05            91.43           +0.45
                                off.                              off.
Unit No. 2...................  15:00 on/15:00             91.61  20:29 on/11:50            91.46           -0.15
                                off.                              off.
----------------------------------------------------------------------------------------------------------------

    As indicated in Table III.1, the change in cycle timings resulted 
in insignificant changes to the AFUE values (+0.45 percent and -0.15 
percent). These additional sample points are consistent with DOE's 
tentative determination that impacts to AFUE would be minimal as a 
result of the updated cycle timings in ANSI/ASHRAE 103-2017. Therefore, 
manufacturers would not be required to retest and rerate consumer 
boilers due to this change. Based on the discussion provided in the 
March 2022 NOPR, consideration of comments from interested parties, and 
this additional test data, DOE has determined that the updated approach 
in ANSI/ASHRAE 103-2017 increases the representativeness of the test 
procedure without being unduly burdensome.
    During its testing of these two boilers, DOE recognized that the 
determination of cycle timings in Table 7 of ANSI/ASHRAE 103-2017 does 
not specify the precision to which these timings (tON and 
tOFF) should be calculated (i.e., to the nearest minute or 
second). ANSI/ASHRAE 103-2017 provides no indication of whether these 
cycle timings can or should be rounded. Acknowledging that many testing 
facilities may only be able to time the burner cycling operation of the 
boiler under test to the nearest second, DOE is providing additional 
specification in appendix EE to require that calculated cycle timings 
shall be rounded to the nearest second. This clarification is not 
expected to impact results significantly but serves to improve 
repeatability and reproducibility of test results by clarifying the 
duration of the cycle time.
d. Oversize Factor
    The oversize factor for a boiler indicates the ratio between the 
boiler's nominal capacity and the home's heating load. This factor is 
represented by the symbol ``[alpha]'' and is determined in sections 
11.2.8.3 and 11.4.8.3 of ANSI/ASHRAE 103-1993 and sections 11.2.8.2 and 
11.4.8.2 of ANSI/ASHRAE 103-2017.
    ANSI/ASHRAE 103-2017 updates the method for calculating the 
oversize factor. While the oversize factor was calculated from a lookup 
table based on design heating requirement (``DHR'') in ANSI/ASHRAE 103-
1993, ANSI/ASHRAE 103-2017 assigns a constant value of 0.70 to [alpha] 
to represent the national average oversize factor. Based on DOE's 
assessment of its test data, DOE stated in the March 2022 NOPR that 
this change would be unlikely to have a substantive impact on AFUE 
ratings because the calculations are not particularly sensitive to 
changes in the oversize factor value. Specifically, DOE reviewed test 
data for three modulating, condensing boilers and found that the change 
in oversize factor from a calculated value, as specified in ANSI/ASHRAE 
103-1993, to 0.7 changed the AFUE rating by 0.01 AFUE percentage points 
or less for all 3 models. 87 FR 14622, 14629. In the March 2022 NOPR, 
DOE proposed to adopt the constant 0.7 oversize factor through 
incorporation by reference of ANSI/ASHRAE 103-2017. Id.
    BWC supported DOE's proposal to adopt the constant 0.7 oversize 
factor through incorporation of ANSI/ASHRAE 103-2017. BWC's analysis of 
this proposal demonstrated that adopting this approach would not have a 
significant impact on overall product efficiency. (BWC, No. 19 at p. 3)
    Busse stated that the oversize factor should be a constant value 
less than 0.4

[[Page 15521]]

based on an Air Conditioning Contractors of America (``ACCA'') 
equipment selection checklist \18\ indicating to installers that the 
selected equipment should be less than or equal to 140 percent of the 
designed total heating load. Busse commented that in the last 40 years, 
it has become apparent that oversized equipment is less efficient, such 
that a more appropriate oversize factor of approximately 0.35 is 
justified. (Busse, No. 22 at p. 6-7)
---------------------------------------------------------------------------

    \18\ ACCA ``Verifying ACCA Manual S[supreg] Procedures'' 
brochure, www.acca.org/HigherLogic/System/DownloadDocumentFile.ashx?DocumentFileKey=2f0a6828-2205-e112-745f-7215c9a85541&forceDialog=0. Last accessed October 7, 2022.
---------------------------------------------------------------------------

    In response, DOE notes that commenters did not provide field 
statistics that would help to determine what a national average 
representative oversize factor would be, nor is DOE aware of any such 
data. While contractors may be oversizing boilers to a lesser degree 
today than in the past, DOE expects that many replacements will be made 
on a like-for-like basis such that the input capacity of the 
replacement boiler will match that of the previous boiler (and thus 
maintain the same oversize factor as the previous boiler). Without 
sufficient nationally representative data to support deviation from the 
industry-accepted oversize factor specified in ANSI/ASHRAE 103-2017, 
DOE is adopting the provision to use a constant oversize factor of 0.70 
through incorporation by reference of ANSI/ASHRAE 103-2017. In 
addition, as discussed previously in this document and initially 
discussed in the March 2022 NOPR, based on a review of its test data 
DOE has determined that this change would not substantively impact on 
AFUE.
e. Annual Performance Metrics
    ANSI/ASHRAE 103-2017 changes the method for determining national 
average burner operating hours (``BOH''), average annual fuel energy 
consumption (``EF''), and average annual auxiliary 
electrical energy consumption (``EAE''),\19\ especially for 
two-stage and modulating products, based on a 2002 study from NIST.
---------------------------------------------------------------------------

    \19\ A typographical correction to the determination of 
EAE at 10 CFR 430.23(n) is discussed in section III.F.5 
of this final rule.
---------------------------------------------------------------------------

    The CA IOUs stated that ASHRAE 103-2017 utilizes differentiating 
calculations for annual operating hours and reduced fuel input rates 
that reflect real-world operation conditions of boilers that more 
accurately represents the typical operation for two-stage, modulating, 
and condensing boilers that spend a significant amount of time 
operating at part-load conditions. (CA IOUs, No. 20 at p. 1)
    These additional annual performance metrics are not required for 
representations or certifications to DOE at this time. Federal Trade 
Commission product labeling requirements at 16 CFR 305.8 specify that 
determinations of estimated annual energy consumption, estimated annual 
operating cost, and energy efficiency rating must be determined in 
accordance with the testing and sampling provisions required by DOE as 
set forth in subpart B of 10 CFR part 430. For boilers, the product 
labeling provisions are specified at 16 CFR 305.20(f) and currently 
only require AFUE to be presented. Thus, manufacturers are not required 
to report BOH, EF, or EAE for consumer boilers as 
of this final rule. However, manufacturers may voluntarily represent 
these values. To ensure that any voluntary representations of these 
values are conducted in accordance with the DOE test procedure, DOE is 
adopting the revised calculation methods in ANSI/ASHRAE 103-2017 for 
BOH, EF, and EAE.
f. Measurement of Relative Humidity
    The current DOE test procedure at appendix N, through incorporation 
by reference of ANSI/ASHRAE 103-1993, specifies limitations on the 
relative humidity of the ambient air of the test chamber when testing a 
condensing boiler. Sections 9.2 and 9.8.1 of ANSI/ASHRAE 103-1993 
state, ``The humidity of the room air shall at no time exceed 80 
percent'' but do not provide instruction on the instrumentation 
necessary to measure the relative humidity. ANSI/ASHRAE 103-2017 
provides new requirements in section 8.5.1 to follow ANSI/ASHRAE 41.6-
2014 in order to measure relative humidity for testing condensing 
boilers. Because the DOE test method and ANSI/ASHRAE 103-1993 currently 
limit relative humidity allowed during testing, DOE reasoned in the 
March 2022 NOPR that relative humidity already must be measured under 
the current procedure; thus, DOE tentatively concluded that the method 
prescribed by ANSI/ASHRAE 103-2017 would likely be similar to current 
practices and requested comment on this topic. 87 FR 14622, 14636-
14637.
    Busse suggested that DOE should verify that ANSI/ASHRAE 41.6-2014 
includes precision and calibration requirements. (Busse, No. 22 at p. 
9-10) DOE has reviewed ANSI/ASHRAE 41.6-2014 in detail and notes that 
it provides setup and calibration methods for both psychrometers and 
hygrometers (two types of instruments which can be used to measure 
relative humidity). Section 6 of ANSI/ASHRAE 41.6-2014 provides 
calibration requirements, and sections 7 and 8 of ANSI/ASHRAE 41.6-2014 
provide measurement methods, precision requirements, and measurement 
uncertainty analysis.
    As discussed further in section III.K of this document, DOE 
received comments indicating that introducing these new requirements 
for measurement and instrumentation would not be unduly burdensome to 
industry. In this final rule, DOE is incorporating by reference ANSI/
ASHRAE 41.6-2014 in appendix EE for the purpose of performing the 
required humidity measurement.
2. IEC 62301 and ASTM D2156-09
    DOE noted in the May 2020 RFI that the version of IEC 62301 
currently incorporated by reference in appendix N is still the most 
recent version, and the most recent iteration of ASTM D2156-09 is a 
version reapproved in 2018 that did not contain any changes from the 
2009 version. 85 FR 29352, 29355. DOE did not receive any comments 
pertaining to its incorporation by reference of IEC 62301 or ASTM 
D2156-09 and in the March 2022 NOPR proposed to maintain the current 
reference to IEC 62301, and to update the reference to ASTM D2156-09 to 
reflect the version that was reapproved in 2018. 87 FR 14622, 14628. 
DOE did not receive any comments related to its incorporation by 
reference of these standards. In this final rule, DOE is finalizing 
their adoption for appendix EE as proposed.

E. Steady-State Efficiency for Condensing Modulating Boilers

    In the May 2020 RFI and the March 2022 NOPR, DOE discussed that 
ANSI/ASHRAE 103-1993 and ANSI/ASHRAE 103-2017 yield a circular 
reference when calculating the steady-state efficiency for condensing 
modulating boilers. 85 FR 29352, 29357; 87 FR 14622, 14629.
    As discussed in the March 2022 NOPR, the circular reference arises 
within the calculation of steady-state efficiencies at maximum and 
minimum input rate, which depends in part on the steady-state heat loss 
due to condensate going down the drain at the maximum and reduced input 
rates. (See section 11.5.7.3 of ANSI/ASHRAE 103-2017, which refers to 
section 11.3.7.3.) The steady-state heat loss due to condensate going 
down the drain at the maximum and minimum input rates is calculated in 
part based on the national average outdoor air temperature at the 
maximum and minimum input rates.

[[Page 15522]]

(See section 11.5.7.2 of ANSI/ASHRAE 103-2017, which refers to section 
11.3.7.2.) The national average outdoor air temperatures at the maximum 
and minimum input rates are both a function of the balance point 
temperature. (See section 11.5.8.3 of ANSI/ASHRAE 103-2017, which 
refers to section 11.4.8.3.) The balance point temperature is 
calculated based on the oversize factor at maximum input rate (which 
is, as discussed previously, a constant value in ANSI/ASHRAE 103-2017) 
and the ratio of the heating capacity at the minimum input rate to the 
heating capacity at the maximum input rate. (See section 11.5.8.4 of 
ANSI/ASHRAE 103-2017, which references section 11.4.8.4.) The heating 
capacities at the minimum and maximum input rates are calculated based 
in part on the steady-state efficiencies at minimum and maximum input 
rates, respectively. (See section 11.5.8.1 of ANSI/ASHRAE 103-2017, 
which references section 11.4.8.1.) If the calculations were 
interpreted to refer back to the steady-state efficiencies at minimum 
and maximum input rates for a modulating, condensing model, as 
determined by section 11.5.7.2 of ANSI/ASHRAE 103-2017, a circular 
reference would result.
    However, since there is no specific instruction to use the values 
as calculated by section 11.5.7.2, DOE stated in the March 2022 NOPR 
that it interprets ANSI/ASHRAE 103-2017 to instruct that the steady-
state efficiency at maximum and reduced input rates be determined as 
specified in section 11.4.8.1, which refers to section 11.4.7, which in 
turn refers to section 11.2.7 for the calculation of steady-state 
efficiency for non-condensing, non-modulating boilers. 87 FR 14622, 
14629. The steady-state efficiencies at maximum and minimum input 
calculated using section 11.2.7 can then be used to obtain values for 
output capacities at the maximum and reduced input, which are needed to 
calculate the balance point temperature, the average outdoor air 
temperature at maximum and minimum input, and finally the heat loss due 
to condensate going down the drain at maximum and minimum input rates. 
Id.
    In the March 2022 NOPR, DOE proposed to add provisions to clarify 
the approach for calculating steady-state efficiencies at maximum and 
minimum input rates for condensing, modulating boilers using ANSI/
ASHRAE 103-2017. 87 FR 14622, 14629. Specifically, DOE proposed to 
codify provisions in section 10.1.2 of appendix EE to explain how to 
calculate these values without a circular reference, ultimately by 
referring back to section 11.2.7 of ANSI/ASHRAE 103-2017. 87 FR 14622, 
14655.
    Crown, U.S. Boiler, BWC, Rheem, A.O. Smith, AHRI, and AGA & APGA 
all supported DOE's proposal to provide additional specification that 
would avoid a circular reference in the test procedure. (A.O. Smith, 
No. 24 at p. 3; AGA & APGA, No. 25 at p. 2) Rheem recommended that each 
subsection in section 10.1.2 of appendix EE should not say ``previous 
step'' but should refer to the appropriate subsection. Specifically, 
Rheem recommended that DOE present an equation for balance point 
temperature, TC, in which the variables used in the equation 
reference the relevant sections in ANSI/ASHRAE 103-2017. (Rheem, No. 18 
at p. 3) Crown, U.S. Boiler, BWC, and AHRI all recommended the same 
revision for section 10.1.2 to improve the clarity of the section. 
(Crown, No. 16 at p. 3; U.S. Boiler, No. 17 at p. 2-3; BWC, No. 19 at 
p. 3; AHRI, No. 26 at p. 2-3) Specifically, the commenters recommended 
revising section 10.1.2 to replace the output capacity parameters 
QOUT,R and QOUT as follows:
    10.1.2 Calculate the balance point temperature (TC) for 
condensing, modulating boilers by using the following equation in place 
of that referenced by 11.5.8.4 [of ANSI/ASHRAE 103-2017]:
[GRAPHIC] [TIFF OMITTED] TR13MR23.000

Where:

TSH = typical average outdoor temperature at which a 
boiler starts operating, 65 [deg]F
TOA,T = the typical outdoor design temperature, 5 [deg]F
[alpha] = oversize factor, as defined in 11.4.8.2 [of ANSI/ASHRAE 
103-2017]
QIN = steady-state nameplate maximum fuel input rate
QIN,R = steady-state reduced input fuel input rate
LS,SSR = average sensible heat loss at steady state, 
reduced input operation
LS,SS = average sensible heat loss at steady state, 
maximum input operation

    In reviewing this equation, DOE agrees that the recommended 
equation adequately resolves the circular reference issue in the same 
manner as DOE proposed in the March 2022 NOPR, but with a simplified 
approach to specifying the correct calculations for determining the 
steady-state efficiency for condensing modulating boilers. Rather than 
determining QOUT and QOUT,R based on the steady-
state efficiencies EffySS and EffySS,R (using 
section 11.2.7 of ANSI/ASHRAE 103-2017) to calculate TC, the 
suggested equation simply inserts the appropriate variables directly 
into the equation for TC, providing the same result. DOE is 
therefore adopting this revised equation in section 10.1.3 of appendix 
EE.

F. Corrections and Clarifications

1. Off-Cycle Losses
    In response to the March 2022 NOPR, several commenters indicated 
that ANSI/ASHRAE 103-2017 has a typographical error in the equations 
used to determine LI,OFF1 and LS,OFF1 (off-cycle 
infiltration and sensible losses, respectively). Specifically, Crown 
and U.S. Boiler stated there is an error in section 11.2.10.8 of ANSI/
ASHRAE 103-2017 for the calculation of LI,OFF1. Crown and 
U.S. Boiler stated that the equation for LI,OFF1 in ANSI/
ASHRAE 103-1993 was erroneous because QIN was multiplied by 
60 when it should have been divided by 60. According to Crown and U.S. 
Boiler, ASHRAE attempted to correct this error in ANSI/ASHRAE 103-2007, 
but inadvertently copied the equation for LS,OFF1 to 
LI,OFF1 for units having post-purge times below 3 minutes, 
and this error was not corrected in the 2017 edition. (Crown, No. 16 at 
p. 3; U.S. Boiler, No. 17 at p. 3) Similarly, Rheem identified this 
issue involving the factor of 60 in the equations for 
LS,OFF1 and LI,OFF1 and asked DOE to evaluate the 
impact on ratings. (Rheem, No. 18, p. 6)
    DOE has examined the equations for LS,OFF1 and 
LI,OFF1 in ANSI/ASHRAE 103-2017 and understands that the 
factor of 60 is used to convert the cycle times (reported in minutes) 
into hours because the input rate is expressed in terms of Btu/h. Thus, 
the cycle times must be divided by 60 to convert these values into 
hours. Section 11.2.10.6 of ANSI/ASHRAE 103-2017 performs this 
operation correctly for determining LS,OFF1, but the factor 
of 60 is used incorrectly in sections 11.2.10.6 and 11.2.10.8 of ANSI/
ASHRAE 103-1993.
    As Crown and U.S. Boiler indicated, industry has been aware of this 
error

[[Page 15523]]

since the development of ANSI/ASHRAE 103-2007. As such, DOE expects 
that current ratings are determined based on the corrected use of the 
factor of 60. In particular, DOE is aware that the Gas Appliance 
Manufacturers Association (GAMA) \20\ developed a computer program to 
calculate AFUE.\21\ DOE has reviewed a version of this program (dated 
October 15, 2003) and determined this calculation was corrected in the 
underlying code. Based on this finding, correcting the use of the 
factor of 60 (by incorporating by reference ANSI/ASHRAE 103-2017) 
should not affect the ratings of products which have already been 
tested and certified. Furthermore, these calculations apply only to 
consumer boilers that have system numbers 2, 3, or 4 with post-purge 
times greater than 30 seconds, which DOE understands to be a relatively 
low fraction of the market based on its own compliance testing.
---------------------------------------------------------------------------

    \20\ GAMA and the Air-Conditioning and Refrigeration Institute 
(ARI) merged in 2008 to form AHRI.
    \21\ In the May 2020 RFI, DOE discussed the industry-developed 
computer program that calculates AFUE based on ANSI/ASHRAE 103-1993 
``AFUE v1.2.'' This software was most recently updated in April 
2004. 85 FR 29352, 29356.
---------------------------------------------------------------------------

    DOE notes that section 11.2.10.8 of ANSI/ASHRAE 103-1993 provided 
the correct equation for LI,OFF1 for models with post-purge 
periods that are less than or equal to 3 minutes (albeit with the 
aforementioned error with the factor of 60).
    The equation for L I,OFF1 for models with post-purge 
periods that are greater than to 3 minutes is corrected in ANSI/ASHRAE 
103-2017 and is adopted in this final rule through incorporation by 
reference.
2. Conversion Factor for British Thermal Units
    In the March 2022 NOPR, DOE noted inconsistencies in the conversion 
factors from watts (W) or kilowatts (kW) to British thermal units per 
hour (Btu/h), in which some sections used a conversion factor of 3.412 
and other sections use 3.413. 87 FR 14622, 14634. DOE stated that the 
conversion factor between watts and Btu/h is generally accepted to be 1 
watt = 3.412142 Btu/h (or 1 Btu/h = 0.2930711 watts), as published in 
the 2021 ASHRAE Handbook--Fundamentals.\22\ Id. This value is more 
appropriately rounded to 3.412 W/(Btu/h); therefore, DOE proposed 
correcting the test procedures to use 3.412 W/(Btu/h) in all 
calculations where 3.413 W/(Btu/h) was previously used. Id. DOE stated 
in the March 2022 NOPR that it did not expect this correction to affect 
AFUE ratings. Id.
---------------------------------------------------------------------------

    \22\ 2021 ASHRAE Handbook--Fundamentals (I-P Edition). Peachtree 
Corners, GA: American Society of Heating, Refrigeration and Air-
Conditioning Engineers, 2021. Available at www.ashrae.org/technical-resources/ashrae-handbook/description-2021-ashrae-handbook-fundamentals.
---------------------------------------------------------------------------

    DOE did not receive comments on this topic. For the reasons 
discussed here and in the March 2022 NOPR, this final rule implements a 
conversion factor of 3.412 in each instance within new appendix EE. DOE 
also amends appendix N--which will remain applicable to consumer 
furnaces other than boilers--to use the corrected conversion factor.
3. Oil Pressure Instrumentation Error
    Section 6.3 of ANSI/ASHRAE 103-2017 states, ``Instruments for 
measuring gas, oil, air, water, and steam pressure shall be calibrated 
so that the error is no greater than the following.'' However, the 
specifications that follow omit the instrumentation requirements 
applicable to measuring oil pressure. Section 6.3(b) of ANSI/ASHRAE 
103-1993 included the oil pressure specification.
    In response to the March 2022 NOPR, Rheem commented that DOE should 
add the oil pressure instrumentation specification from ANSI/ASHRAE 
103-1993 to section 5 of the new appendix EE test procedure. (Rheem, 
No. 18 at p. 6)
    This final rule reinstates the omitted provisions from section 6.3 
of ANSI/ASHRAE 103-1993 in section 5 of appendix EE.
4. Gas Inlet Conditions
    Section 7.1 of appendix N references Table 1 of ANSI/ASHRAE 103-
1993 for maintaining the gas supply, ahead of all controls for a 
furnace,\23\ at an acceptable test pressure. The natural gas inlet 
pressure shall be between the ``normal'' and ``increased'' values shown 
in Table 1 of ANSI/ASHRAE 103-1993. Table 1 in ANSI/ASHRAE 103-2017 
provides identical gas inlet pressures to those in ANSI/ASHRAE 103-1993 
(this table is presented in section 8.2.1.3 of ASHRAE 103-2017, which 
is excluded from reference in the current appendix N test procedure). 
Table 1 also specifies the specific gravity of the test gases. The 
pressures and specific gravity of the test gases are reproduced in 
Table III.2 of this document.
---------------------------------------------------------------------------

    \23\ This term refers to the broader definition of ``furnace,'' 
which includes warm air furnaces and boilers.

 Table III.2--Natural Gas Inlet Pressures and Specific Gravity of Test Gases in Table 1 of ANSI/ASHRAE 103-1993
                                            and ANSI/ASHRAE 103-2017
----------------------------------------------------------------------------------------------------------------
                                                                    Test pressure (inches water
                                                                              column)                Specific
                              Type                               -------------------------------- gravity (air =
                                                                      Normal         Increased         1.0)
----------------------------------------------------------------------------------------------------------------
Natural.........................................................             7.0           10.50             .65
Manufactured....................................................             3.5            5.25             .38
Butane..........................................................            11.0           13.00            2.00
Propane.........................................................            11.0           13.00            1.53
----------------------------------------------------------------------------------------------------------------

    In response to the March 2022 NOPR, Crown and U.S. Boiler stated 
that the gas inlet pressure requirements in section 8.2.1.3 of ANSI/
ASHRAE 103-2017 are appropriate and necessary for units with pilot 
lights because most pilots have no pressure regulation within the 
appliance itself, and thus the input rate of the pilot is determined in 
large part by the inlet pressure. Crown and U.S. Boiler noted, however, 
that since continuous standing pilots are prohibited by EPCA on 
consumer boilers, such restrictive requirements on the gas inlet 
pressure are no longer necessary in the Federal test procedure and may 
place undue burden on test labs. Crown and U.S. Boiler commented that 
maintaining a 7.0 inches water column (``in. w.c.'') minimum inlet 
pressure is not always possible in some test labs, nor is it necessary 
as long as the regulator outlet pressure can be maintained, and the 
nameplate input

[[Page 15524]]

achieved. Crown and U.S. Boiler further indicated that expensive gas 
booster equipment may be necessary to meet the 7.0 in. w.c. minimum. 
Crown and U.S. Boiler stated that gas appliances are generally listed 
for use up to 14.0 in. w.c. inlet pressure, so there is also no reason 
to reduce this pressure to 10.5 in. w.c. on a boiler without a 
continuous pilot in order to provide results that are repeatable and 
representative of what can be expected in the field. In order to afford 
labs greater flexibility while still preventing boilers from being 
tested at gas inlet pressures for which they are not intended to be 
used in the field, Crown and U.S. Boiler suggested replacing the second 
sentence of section 8.2.1.3 of ANSI/ASHRAE 103-2017 with: ``The gas 
supply, ahead of all controls for a furnace, shall be maintained at a 
test pressure within the upper and lower limits shown in the 
manufacturer's instructions or on the boiler itself. In the absence of 
any such limits, the gas supply pressure shall be maintained between 
the normal and increased values shown in Table 1 of ANSI/ASHRAE 103-
2017.'' (Crown, No. 16 at p. 2-3; U.S. Boiler, No. 17 at p. 2)
    Busse urged DOE to modify the language in section 7.1 of appendix 
EE to include the term ``approximately'' when referring to meeting the 
specific gravity requirements in Table 1 of ANSI/ASHRAE 103-2017, 
asserting that the omission of this term suggests that DOE expects the 
specific gravity to be exactly as shown in Table 1 without providing 
instrument requirements for measuring. (Busse, No. 22 at p. 10)
    At 42 U.S.C. 6295(f)(3)(A), EPCA mandates that gas-fired boilers 
manufactured on or after September 1, 2012, must not have a constant 
burning pilot. DOE agrees that the test procedure requirements in 
appendix N (which reference Table 1 of ANSI/ASHRAE 103-1993) have a 
greater contribution to maintaining the reproducibility and 
repeatability of test results for consumer boilers with constant 
burning pilots; however, it is currently unclear to DOE what the 
impacts of updating the natural gas inlet pressure requirements as 
suggested would be on measured efficiency ratings for boilers without 
constant burning pilots. Crown and U.S. Boiler did not provide data to 
indicate that their suggested approach of relying on the manufacturer's 
instructions for setting natural gas inlet pressure will not 
significantly impact ratings. Manufacturers have not previously 
expressed concern regarding the ability to meet the inlet pressure 
requirements in appendix N, and no waivers have been received for 
consumer boilers that are not compatible with the inlet pressure 
provisions. This suggests that manufacturers and test laboratories have 
been able to meet these setup requirements since compliance with the 
currently applicable appendix N test procedure has been required (July 
13, 2016).
    For these reasons, DOE has determined that no correction to the 
natural gas inlet pressure requirements is necessary at this time and 
is adopting the reference to Table 1 of ANSI/ASHRAE 103-2017 in section 
7.1 of appendix EE as proposed in the March 2022 NOPR. Regarding 
Busse's suggestion to include the word ``approximately'' in reference 
to the specific gravity values referenced in section 7.1, DOE agrees 
that the specific gravity may not be exactly as provided in Table 1 of 
ANSI/ASHRAE 103-2017 because variations exist due to differences in gas 
composition in supply sources. DOE understands that the purpose of 
specifying the gas characteristics in Table 1 of ANSI/ASHRAE 103-2017 
is to ensure that the energy content in the gas is consistent for the 
repeatability and reproducibility of the test. DOE notes that explicit 
tolerances are provided for the higher heating value of the gas used, 
such that providing explicit tolerances for the specific gravity of the 
gas would be redundant. As such, DOE is adopting Busse's suggestion to 
state that the specific gravity of the gas should be ``approximately'' 
that shown in Table 1 of ANSI/ASHRAE 103-2017.
5. Active Mode Electrical Energy Consumption
    As previously discussed, AFUE does not include active mode 
electrical consumption for gas-fired and oil-fired boilers. Instead, 
the DOE test procedure includes provisions for determining the average 
annual auxiliary electrical energy consumption for gas-fired and oil-
fired boilers (EAE), as a separate metric from AFUE, that 
accounts for active mode, standby mode, and off mode electrical 
consumption. (See appendix N, section 10.4.3.) EAE is 
referenced by the calculations at 10 CFR 430.23(n)(1) for determining 
the estimated annual operating cost for furnaces. However, the 
provisions at 10 CFR 430.23(n) include several incorrect references to 
sections in appendix N. In the March 2022 NOPR, DOE proposed to correct 
10 CFR 430.23(n)(1) to reference the appropriate sections of appendix N 
where the currently codified provisions point to the wrong sections. 
Additionally, DOE proposed to revise 10 CFR 430.23(n)(1) such that 
sections in appendix N are referenced for furnaces and sections in 
appendix EE are referenced for boilers. 87 FR 14622, 14633, and 14643.
    DOE did not receive any comments on this topic. In this final rule, 
DOE adopts these corrections as proposed.
6. Circulator Pumps
    Section 8.2 of the proposed appendix EE from the March 2022 NOPR 
included instructions on the electrical energy consumption measurements 
for various boiler components in order to calculate PE, the electrical 
power involved in burner operation. 87 FR 14622, 14654. It stated that 
the measurement of PE must include the boiler pump if so equipped. Id.
    In response to the March 2022 NOPR, Rheem noted that section 2 of 
the proposed appendix EE defines a ``boiler pump'' \24\ as being 
separate from the circulating water pump; however, the term 
``circulating water pump'' is not defined in the proposed appendix EE 
or ANSI/ASHRAE 103-2017. Rheem recommended that DOE add a definition 
for ``circulating water pump'' to clarify the difference between these 
pumps and to reduce confusion when performing the procedure in section 
8.2 of appendix EE, which refers to both pump types. (Rheem, No. 18 at 
p. 5-6)
---------------------------------------------------------------------------

    \24\ Section 2.2 of appendix N defines a ``boiler pump'' as a 
pump installed on a boiler that is separate from the circulating 
water pump.
---------------------------------------------------------------------------

    DOE notes that the definition for ``boiler pump'' was established 
in the January 2016 Test Procedure Final Rule. 81 FR 2628, 2647. In the 
January 2016 Test Procedure Final Rule, in describing devices that use 
power during the active mode, DOE discussed a secondary pump for 
boilers (i.e., boiler pump) used to maintain a minimum flow rate 
through the boiler heat exchanger, which is most typically associated 
with condensing boiler designs. Id. at 81 FR 2633. In the preamble to 
the January 2016 Test Procedure Final Rule, DOE stated that it would 
define a boiler pump as, ``a pump installed on a boiler that maintains 
adequate water flow through the boiler heat exchanger and that is 
separate from the circulating water pump;'' however, this definition 
was not codified with the additional clarification that the boiler pump 
maintains adequate water flow through the heat exchanger. Id. at 81 FR 
2634. In order to improve the clarity of the boiler pump definition, 
DOE is revising this definition to reflect the language which was 
inadvertently omitted from the January 2016 Test Procedure Final Rule.
    Additionally, section 9.1.2.2 of ANSI/ASHRAE 103-2017 states that, 
for hot water boilers, the circulating water

[[Page 15525]]

pump nameplate power is to be used to determine the electrical power to 
the circulating water pump (BE), and if the pump nameplate power is not 
available, use the pump power listed in the water pump manufacturer's 
literature or use 0.13 kW. In response to the March 2022 NOPR, Busse 
suggested that, because circulator pumps do not have a ``nameplate'' 
power value, the water pump manufacturer's literature could be used 
instead for calculating the value of BE. Busse also commented that the 
default value of 0.13 kW in ANSI/ASHRAE 103-2017 may not be appropriate 
for modern electronically commutated motor-based circulator pumps. 
(Busse, No. 22 at p. 11)
    At this time, DOE does not have sufficient data on circulating 
water pumps used with consumer hot water boilers to specify a more 
representative power draw to be used in lieu of manufacturer-reported 
information (either on a nameplate or in the I&O manual). As ANSI/
ASHRAE 103-2017 is currently the industry-accepted test standard \25\ 
for consumer boilers, DOE expects that the provisions for circulator 
pump power remain representative for current installations. 
Additionally, DOE notes that the value of BE is not a factor that 
determines AFUE (see section III.C for discussion about the AFUE 
metric).
---------------------------------------------------------------------------

    \25\ ANSI/ASHRAE 103-2022 does not provide substantive updates 
to provisions for circulator pump power.
---------------------------------------------------------------------------

7. Units With Draft Hoods or Draft Diverters
    Section 6.4 of appendix N provides installation instructions for 
units with draft hoods or draft diverters. Among other requirements, 
this section specifies installing the stack damper in accordance with 
the ``I&O manual.''
    In response to the March 2022 NOPR, Rheem commented that section 
6.4 of appendix N appeared to have been omitted from the proposed 
appendix EE. Rheem noted that these provisions are still relevant to 
boilers and should be carried over into the new appendix EE test 
procedure. (Rheem, No. 18 at p. 6)
    The March 2022 NOPR proposed in section 6 (``Apparatus'') of 
appendix EE to reference section 7 of ANSI/ASHRAE 103-2017 
(``Apparatus'') including sections 7.2.3.1 and 7.3.3.1. Section 7.3.3.1 
of ANSI/ASHRAE 103-2017 specifies stack and flue installation 
requirements for boilers with draft hoods or draft diverters by 
referencing section 7.2.3.1 of ANSI/ASHRAE 103-2017. The language in 
section 7.2.3.1 of ANSI/ASHRAE 103-2017 is identical to the provisions 
in section 6.4 of the current appendix N, except that section 7.2.3.1 
specifies that the stack damper be installed in accordance with the 
``manufacturer's instructions'' rather than the ``I&O manual'' 
specified in section 6.4. DOE's proposal to reference sections 7.2.3.1 
and 7.3.3.1 of ANSI/ASHRAE 103-2017 through reference to section 7 in 
the new appendix EE test procedure maintained the installation 
instructions for units with draft hoods or draft diverters in appendix 
EE. This final rule maintains the reference to section 7 of ANSI/ASHRAE 
103-2017 in section 6 of appendix EE.
    DOE has determined, however, that maintaining the more specific 
reference to the manufacturer's I&O manual, rather than a general 
reference to manufacturer's instructions, will ensure the 
reproducibility of the test procedure by providing a more specific 
reference to the document that must be consulted with regard to 
installing the stack damper. Therefore, this final rule adds an 
exception in section 6 of appendix EE to specify referencing the I&O 
manual in lieu of manufacturer's instructions in section 7.2.3.1 of 
ANSI/ASHRAE 103-2017.
8. Rounding of AFUE
    In response to the March 2022 NOPR, Busse observed an inconsistency 
between requirements to round the AFUE at 10 CFR 430.23(n)(2)(iii) and 
requirements to truncate the AFUE at 10 CFR 429.18(a)(2)(vii). (Busse, 
No. 22 at p. 11)
    On July 22, 2022, DOE published a final rule regarding 
certification requirements for several covered products and equipment, 
including consumer boilers (``July 2022 Certification Final Rule''). 87 
FR 43952. In an amendment established by that final rule, effective 
August 22, 2022, DOE modified 10 CFR 429.18(a)(2)(vii) to state that 
AFUE must be rounded to the nearest one-tenth of a percentage point. 
Id. at 87 FR 43968. As this amendment provides consistency between the 
certification requirement and the test procedure, no further correction 
is required in this rulemaking.

G. Other Test Procedure Topics

    In the course of this rulemaking, DOE solicited feedback on 
additional aspects of the current test procedure for consumer boilers 
to assess whether they remain representative of the energy consumption 
during an average use cycle. DOE did not propose to amend the test 
procedure for consumer boilers with regard to these topics in the March 
2022 NOPR, and after consideration of comments received in response to 
that NOPR, DOE determined not to amend the test procedure accordingly. 
Comments received with regard to these topics are discussed in the 
following subsections.
1. Outdoor Design Temperature
    ANSI/ASHRAE 103-2017 assigns a value of 5 [deg]F for the typical 
outdoor design temperature and 42 [deg]F for the average outdoor air 
temperature, represented by TOA,T and TOA, 
respectively. The outdoor design temperature is the lowest expected 
temperature at which the boiler can satisfy the home's heating demand, 
while the average outdoor air temperature is the average temperature 
during the heating season.
    In response to the March 2022 NOPR, Busse stated that the 5 [deg]F 
outdoor design temperature used in ANSI/ASHRAE 103-1993 \26\ may be out 
of date due to climate change and suggested that different outdoor 
design temperatures could be assigned for furnaces and boilers. (Busse, 
No. 22 at p. 4) Similarly, Busse indicated that a 42 [deg]F average 
outdoor air temperature may no longer be valid based on recent climate 
change data. (Busse, No. 22 at p. 11)
---------------------------------------------------------------------------

    \26\ DOE notes that the same requirement is also specified in 
ANSI/ASHRAE 103-2017.
---------------------------------------------------------------------------

    In response, DOE notes that homes in the United States--
particularly in the Northeast region, where most boilers are 
installed--still experience temperatures as low as 5 [deg]F during the 
heating season \27\ despite climate change trends. DOE does not have 
any data, nor did Busse or other commenters provide any such data, 
suggesting a value other than 5 [deg]F that would provide more 
representative test results. As such, DOE is maintaining 5 [deg]F as 
the outdoor design temperature in the appendix EE test procedure for 
consumer boilers.
---------------------------------------------------------------------------

    \27\ For example, daily temperature data for the Albany, NY, 
area for the winter of 2022 (December 1, 2021, through March 1, 
2022) shows 13 days during which the observed temperature reached at 
or below 5 [deg]F. The Duluth, MN, area experienced 55 days during 
which the observed temperature reached at or below 5 [deg]F during 
the same time period. Data for these areas are available at 
www.weather.gov/wrh/Climate?wfo=aly and www.weather.gov/wrh/Climate?wfo=dlh. Last accessed October 7, 2022.
---------------------------------------------------------------------------

    Regarding the average outdoor air temperature, DOE examined average 
outdoor air temperatures for the contiguous United States during the 
months of October, November, December, January, February, and March 
(i.e., the months during which consumer boilers would be expected to 
operate).\28\ This data indicates that from

[[Page 15526]]

2012 through 2022, average outdoor air temperatures during these months 
is 41 [deg]F, which aligns closely with the value of 42 [deg]F 
specified in ANSI/ASHRAE 103-2017. Therefore, in this final rule, DOE 
is maintaining the value of 42 [deg]F for TOA as specified 
by ANSI/ASHRAE 103-2017.
---------------------------------------------------------------------------

    \28\ These temperatures are published by the National Oceanic 
and Atmospheric Administration and are available at 
www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/national/time-series. Last accessed October 7, 2022.
---------------------------------------------------------------------------

2. Ambient Conditions
    The current test procedure for consumer boilers in appendix N, 
through incorporation by reference of ANSI/ASHRAE 103-1993, specifies 
that the ambient air temperature during testing must be between 65 
[deg]F and 100 [deg]F for non-condensing boilers, and between 65 [deg]F 
and 85 [deg]F for condensing boilers (see section 7 of appendix N and 
section 8.5.2 of ANSI/ASHRAE 103-1993). In addition, the relative 
humidity cannot exceed 80 percent during condensate measurement (see 
section 8 of appendix N and section 9.2 of ANSI/ASHRAE 103-1993).
    In the May 2020 RFI, DOE requested comment and data on the effects 
of ambient temperature and relative humidity on AFUE results, whether 
the current ranges of allowable conditions adversely impact the 
representativeness of AFUE values or repeatability of AFUE testing, and 
whether a narrower range of allowable ambient conditions would increase 
testing burden. 85 FR 29352, 29356.
    As discussed in the March 2022 NOPR, DOE received comments from 
AHRI and manufacturers supporting the current range of allowable 
operating conditions, while the CA IOUs and NEEA suggested limiting 
this range to reflect the temperatures of spaces where boilers may be 
installed. 87 FR 14622, 14631.
    DOE investigated concerns regarding the ambient conditions as part 
of the January 2016 Final Rule (see 81 FR 2628, 2638; Jan. 15, 2016). 
Testing conducted in support of the January 2016 Final Rule indicated 
there was no definitive impact of variation of ambient conditions on 
the resultant AFUE, and DOE determined there was not adequate data to 
justify changing the test procedure to narrow the ranges. In the March 
2022 NOPR, DOE provided a similar tentative determination based on the 
lack of sufficient evidence, and thus did not propose any changes at 
that time. 87 FR 14622, 14631-14632.
    In response, while the CA IOUs supported incorporation by reference 
of ANSI/ASHRAE 103-2017, they encouraged DOE to reexamine the impacts 
of ambient conditions on AFUE ratings by conducting additional testing. 
(CA IOUs, No. 20 at p. 2) NYSERDA requested that DOE revise the test 
procedure to ensure that condensing and non-condensing boilers are 
tested under the same ambient conditions to allow consumers to make 
informed decisions between these products. NYSERDA also requested that 
DOE review the impacts of ambient temperature on boiler performance and 
review the jacket loss assumptions based on likely real-world operating 
conditions. Citing that DOE has not provided a further study on ambient 
conditions since the 2016 rulemaking, NYSERDA urged DOE to revisit the 
issue of ambient temperature impacts on consumer boiler performance and 
conduct additional analysis and/or testing either as part of the 
current rulemaking or in anticipation of the next statutorily mandated 
review. (NYSERDA, No. 23 at p. 5)
    The Joint Advocates stated they did not believe that separate 
ambient conditions are necessary for non-condensing and condensing 
boilers, and that the range of allowable ambient temperatures is too 
broad to accurately measure energy use during a representative average 
use cycle. The Joint Advocates cited course material from Continuing 
Education and Development, Inc. indicating that a variation in ambient 
temperature of 20 [deg]F can affect the thermal efficiency of a 
commercial package boiler by over 0.5 percent, and therefore suggested 
that DOE require the ambient temperature to be maintained between 65 
[deg]F and 85 [deg]F for all consumer boilers. (Joint Advocates, No. 21 
at p. 3)
    Busse stated that a boiler tested at the current temperature and 
humidity limits should perform at a higher AFUE than when tested at a 
``normal'' lab condition of 70 [deg]F and 50 percent relative humidity 
due to higher water vapor content and higher dew point temperature and 
thus recommended limiting the test room conditions to 75 [deg]F and 55 
percent relative humidity. Busse noted that the National Bureau of 
Standards Information Report (``NBSIR'') recommended limits on the 
original test room conditions,\29\ and that water vapor content and dew 
point temperature vary significantly with temperature (specifically 
providing information at 42 [deg]F [average outdoor air temperature], 
70 [deg]F [``normal'' lab condition], and 85 [deg]F [maximum allowable 
during AFUE test]). Busse also cited Burnham Holdings, Inc. (``BHI'') 
test data for a single condensing boiler which showed a change in AFUE 
of 1.3 percent when the relative humidity was changed from 
approximately 30 percent to 70 percent. (Busse, No. 22 at p. 5)
---------------------------------------------------------------------------

    \29\ Busse's comment references two reports from National Bureau 
of Information: NBSIR 78-1543: ``Recommended Testing and Calculation 
Procedures for Determining the Seasonal Performance of Residential 
Central Furnaces and Boilers'' (September 1978) and NBSIR 80-2110, 
``Recommended Testing and Calculation Procedures for Estimating the 
Seasonal Performance of Residential Condensing Furnaces and 
Boilers'' (April 1981).
---------------------------------------------------------------------------

    DOE notes the data collected thus far has been on a limited sample 
of boilers, and the information required to amend the ambient 
conditions should reflect the array of boiler designs on the market. 
The impact of the ambient air conditions would vary based on how the 
ambient air interacts with the boiler during its normal operation. As 
noted previously, in the January 2016 NOPR, DOE concluded that the test 
data was not definitive enough to provide justification for changing 
the ambient conditions. Regarding the data submitted by Busse, DOE 
notes that BHI also provided that data point in a comment responding to 
the May 2020 RFI (BHI, No. 11 at p. 2, 11). As discussed in the March 
2022 NOPR, although BHI provided test data for a single unit showing a 
difference in performance under different conditions, DOE notes that 
DOE's previous test data, obtained from multiple units, did not 
indicate conclusively that ambient test conditions within the current 
bounds cause substantive differences in AFUE. As a result, DOE is not 
amending the test procedure for consumer boilers to narrow or revise 
the ambient test conditions at this time due to insufficient conclusive 
evidence demonstrating the impact on AFUE for various boiler types.
3. Combustion Settings
    In the course of the rulemaking for the January 2016 Final Rule, to 
provide for greater consistency in burner airflow settings during 
testing, DOE proposed specifying that the excess air ratio, flue oxygen 
(``O2'') percentage, or flue carbon dioxide 
(``CO2'') percentage be within the middle 30th percentile of 
the acceptable range specified in the I&O manual. 80 FR 12876, 12883, 
12906 (Mar. 11, 2015). In absence of a specified range in the I&O 
manual, DOE proposed requiring the combustion airflow to be adjusted to 
provide between 6.9 percent and 7.1 percent dry flue gas O2, 
or the lowest dry flue gas O2 percentage that produces a 
stable flame, no carbon deposits, and an air-free flue gas carbon 
monoxide (``CO'') ratio below 400 parts per million (``ppm'') during 
the steady-state test described in section 9.1 of ANSI/

[[Page 15527]]

ASHRAE 103-2007, whichever is higher. 80 FR 12876, 12906. However, 
after considering comments regarding the representativeness of the 
proposal and the potential impact on rated AFUE, DOE determined in the 
January 2016 Final Rule that further study was needed to determine how 
such changes would impact AFUE ratings. 81 FR 2628, 2636.
    In the May 2020 RFI, DOE requested comment on whether more specific 
instructions for setting the excess air ratio, flue O2 
percentage, and/or flue CO2 percentage should be provided in 
the consumer boilers test procedure, and if so, what those instructions 
should entail. 85 FR 29352, 29356. DOE was particularly interested in 
understanding whether such a change would improve the 
representativeness of the test method, and whether it would impact test 
burden.
    In the March 2022 NOPR, after considering comments received in 
response to the May 2020 RFI, DOE tentatively concluded that it lacked 
sufficient data and information to indicate that establishing a 
requirement for setting the excess air ratio, flue O2 
percentage, and/or flue CO2 percentage would provide ratings 
that are more representative than the ratings provided under the 
current approach. Therefore, DOE tentatively determined to maintain the 
current test procedure and did not propose to establish a requirement 
for setting the excess air ratio, flue O2 percentage, and/or 
flue CO2 percentage. 87 FR 14622, 14633.
    In response to the March 2022 NOPR, the CA IOUs encouraged DOE to 
examine the impacts of excess air ratio, flue oxygen percentage, and 
flue carbon dioxide percentage on AFUE ratings by conducting additional 
testing. (CA IOUs, No. 20 at p. 2) The Joint Advocates also encouraged 
DOE to investigate the efficiency impacts of combustion airflow 
settings and to consider establishing criteria around those settings in 
the test procedure in order to provide more accurate product rankings. 
The Joint Advocates asserted that excess air, which can be determined 
by flue gas O2 and CO2 concentrations, affects 
combustion efficiency and, as an example, cited a 2002 fact sheet 
published by the National Renewable Energy Laboratory that indicated 
combustion efficiency of commercial boilers can be increased by 1 
percent for each 15 percent reduction in excess air ratio.\30\ (Joint 
Advocates, No. 21 at p. 3-4)
---------------------------------------------------------------------------

    \30\ The fact sheet referenced by the Joint Advocates is 
available at: https://www.nrel.gov/docs/fy02osti/31496.pdf. (Last 
accessed 11/3/2022).
---------------------------------------------------------------------------

    NYSERDA recommended that DOE study how excess oxygen impacts the 
efficiency of the boiler operation. NYSERDA pointed out that DOE 
received input from multiple stakeholders regarding changes to excess 
air ratio, flue O2 percentage, and/or flue CO2 
percentage in the 2016 rulemaking cycle. NYSERDA urged DOE to either 
revisit this proposal regarding excess oxygen or commit to further 
study of this topic for a future revision. (NYSERDA, No. 23 at p. 4-5)
    Busse suggested updating the test procedure to include two 
requirements: (1) verify reduced input rate is 98 percent or greater 
than nameplate minimum input rate and, if less than 98 percent, adjust 
controls or settings as specified in the I&O manual and restart test at 
maximum input rate or, if 98 percent or greater, no additional control 
or setting changes are allowed; and (2) verify combustion products do 
not exceed 400 parts per million air-free and there are no deposits of 
carbon on the burner, and correct these conditions, if necessary, as 
specified in the I&O manual. Busse stated that a reduced input rate 
below 98 percent of nameplate minimum input rate would likely result in 
a higher efficiency, and that requiring adjustment and restarting a 
test when above 102 percent of nameplate minimum input rate could 
increase test burden. Busse further stated that these provisions would 
strive towards more accurate AFUE results while not greatly increasing 
the testing burden. (Busse, No. 22 at p. 10)
    In the January 2016 Final Rule, DOE explained that industry 
stakeholders indicated that the current practice is typically to use 
the CO2 percentage at the ``top'' of the manufacturer's 
specified range, and in some cases, even higher than that. Stakeholders 
provided data suggesting that the impacts on AFUE could be significant 
but variable,\31\ and there was also concern that some products may not 
feature any means of providing combustion setting adjustment. Finally, 
commenters indicated that DOE must evaluate the burden associated with 
potential re-testing should combustion setting specifications require 
manufacturers to re-rate their products. As discussed previously, DOE 
ultimately agreed that further study was needed on the impacts of the 
CO2 percentage on AFUE and, therefore, declined to adopt the 
proposed amendments. 81 FR 2628, 2635-2636. Thus, there remained a lack 
of certainty regarding what settings would be most representative of 
field use.
---------------------------------------------------------------------------

    \31\ AHRI stated that the results of the testing of three 
residential boilers that it conducted at Intertek Testing 
Laboratories indicate that the proposed revised burner setup 
requirements change AFUE by 0.3 percent for each 1 percent 
difference in the CO2 values. By contrast, Burnham stated 
that based on test data that it provided, for an oil-fired hot water 
boiler with an 11.5 to 12.5 percent CO2 adjustment range 
in the I&O manual, DOE's proposed adjustment would reduce AFUE by as 
much as 1.0 percent compared to the rating under the existing test 
procedure. 81 FR 2628, 2636.
---------------------------------------------------------------------------

    DOE did not receive any information in response to the March 2022 
NOPR that provided further clarity on this issue. Therefore, DOE has 
determined that it still lacks sufficient information to indicate that 
establishing a specification for excess air ratio, flue O2 
percentage, and/or flue CO2 percentage would provide ratings 
that are more representative than the ratings provided under the 
current approach, and that doing so would not be unduly burdensome.
    Therefore, DOE is maintaining the current instructions and is not 
establishing additional requirements specifying excess air ratio, flue 
O2 percentage, and/or flue CO2 percentage.
4. Supplemental Test Instructions
    In the March 2022 NOPR, DOE responded to comments from BHI 
suggesting that DOE create a repository of supplemental test 
instructions, similar to that currently in place for commercial 
boilers,\32\ instead of requiring a waiver to allow for use of specific 
test instructions not included in the I&O manual or the DOE test 
procedure. 87 FR 14622, 14635-14636. Specifically, BHI asserted that 
control systems are increasingly complex, which makes it impractical to 
run the test without special tools or codes, and that there are safety 
and reliability concerns with putting testing-specific instructions in 
the I&O manual. BHI also asserted that the use of the waiver process 
for these test instruction issues is burdensome, unnecessary, and 
inconsistent with the test procedure for commercial boilers.
---------------------------------------------------------------------------

    \32\ For commercial boilers, DOE provides that a certification 
report may include supplemental testing instructions, if such 
information is necessary to run a valid test. Specifically, 
supplemental information must include any additional testing and 
testing set-up instructions (e.g., specific operational or control 
codes or settings) which would be necessary to operate the basic 
model under the required conditions specified by the relevant test 
procedure. 10 CFR 429.60(b)(4).
---------------------------------------------------------------------------

    In response, DOE noted that BHI did not provide specific examples 
of test instructions that would not be able to be included in the I&O 
manual due to concerns about safety or reliability, and that would thus 
need to be presented in a waiver. In addition, DOE noted it has not 
received any petitions for waiver for any basic models of consumer 
boilers,

[[Page 15528]]

indicating there is not a problem with testing absent such additional 
information. Therefore, DOE did not propose to establish a repository 
for test instructions for consumer boilers and stated that if testing 
of a consumer boiler necessitates controls or instructions other than 
those included in the I&O manual, manufacturers may petition for a 
waiver under the process established at 10 CFR 430.27. DOE sought 
further comment on whether supplemental test instructions are necessary 
for consumer boilers. 87 FR 14622, 14636.
    Rheem recommended that DOE use the I&O manual provided with the 
product as the primary instruction for testing a consumer boiler, and 
where a manufacturer participates in a third-party certification 
program (such as AHRI's) and declares supplemental instructions for 
product testing, the manufacturer should have the option to use such 
instructions for audit or enforcement testing. (Rheem, No. 18 at p. 5) 
A.O. Smith recommended that some supplemental instructions from 
manufacturers could ensure consistency in testing, such as the need to 
use the recirculation loop to prevent flashing in the heat exchanger or 
instructions to remove a water temperature sensor and plug the opening. 
(A.O. Smith, No. 24 at p. 5) Busse suggested that supplemental test 
instructions are necessary for minimum input rate adjustment (for step-
modulating condensing boilers) and for steam boiler low water cutoff 
(wherein the feature periodically turns off the burner to monitor the 
settled water level and therefore prevents the boiler from operating 
continuously during a steady-state test). (Busse, No. 22 at p. 9)
    As discussed in the March 2022 NOPR, DOE has not received any 
petitions for waivers for any basic models of consumer boilers, 
indicating there is not a problem with testing absent such additional 
information. Should testing of a consumer boiler necessitate controls 
or instructions other than those included in the I&O manual, 
manufacturers may petition for a waiver under the process established 
at 10 CFR 430.27.
5. Input Rates for Step Modulating Boilers
    Appendix N includes a number of specific provisions for consumer 
boilers with step modulating controls. Boilers with step modulating 
controls are capable of operating at reduced input rates (i.e., less 
than that maximum nameplate input rate) and gradually or incrementally 
increasing or decreasing the input rate as needed to meet the heating 
load. The test procedure currently requires step modulating boilers to 
be tested at the maximum rate and the minimum (i.e., reduced) input 
rate for the steady-state test (referencing section 9.1 of ANSI/ASHRAE 
103-1993), the reduced input rate for the cool-down test (referencing 
section 9.5.2.4 of ANSI/ASHRAE 103-1993), and the reduced input rate 
for the heat-up test (referencing section 9.6.2.1 of ANSI/ASHRAE 103-
1993). In addition, both the optional tracer gas test and the 
measurement of condensate under cyclic conditions, when conducted, are 
performed at the reduced input rate (referencing sections 9.7.5 and 9.8 
of ANSI/ASHRAE 103-1993, respectively). ANSI/ASHRAE 103-2017 contains 
the same input rate requirements for modulating boilers as ANSI/ASHRAE 
103-1993.
    In the May 2020 RFI, DOE requested comment on whether the existing 
provisions for testing step modulating boilers appropriately reflect 
the performance of such boilers. If not, DOE sought specific 
recommendations on the changes that would be necessary to make the test 
procedure more representative for such products. 85 FR 29352, 29357. 
Commenters indicated these provisions were adequate, and DOE did not 
propose any amendments to the provisions for testing step modulating 
boilers in the March 2022 NOPR. 87 FR 14622, 14633.
    In response to the March 2022 NOPR, BWC stated that it appreciated 
DOE not proposing that step modulating units account for operation at 
any additional input rates beyond those specified in the current test 
procedure. BWC stated that the test methods in ANSI/ASHRAE 103-2017 
sufficiently measure the performance of these units at different input 
rates and are representative of a product's average use cycle. (BWC, 
No. 19, p. 4)
    For the reasons discussed in the March 2022 NOPR, and in 
consideration of the comments received, DOE is not adopting any changes 
to the provisions for testing step modulating boilers in this final 
rule.
6. Return Water Temperature
    The test procedure at appendix N currently requires a nominal 
return water temperature (``RWT'') of 120 [deg]F to 124 [deg]F for non-
condensing boilers and 120 [deg]F  2 [deg]F for condensing 
boilers (see section 7 of appendix N and sections 8.4.2.3 and 8.4.2.3.2 
of ANSI/ASHRAE 103-1993, which are incorporated by reference).
    In response to the May 2020 RFI, the CA IOUs requested that DOE 
consider adopting multiple RWTs in the amended test procedure for 
consumer boilers, consistent with the methodology being developed by 
the ASHRAE Standard 155P Committee for testing and rating commercial 
boilers, which requires testing at multiple RWTs depending on the 
operational characteristics of the boiler. As discussed in the March 
2022 NOPR, DOE considers the impact of varying RWTs on field-installed 
efficiency in its energy conservation standards rulemakings. In the 
previous energy conservation standards rulemaking for consumer boilers, 
DOE developed AFUE adjustment factors for low, medium, and high RWT 
scenarios and estimated that, on average, AFUE would vary from the 
rated value by 2.66 percent to +3.15 percent depending on the model 
characteristics and RWT (see 81 FR 2320, 2354); however, DOE noted 
there is still a wide range of potential RWTs in the field. Thus, in 
the March 2022 NOPR, DOE sought additional comment on whether the RWT 
requirements in the current test method and ANSI/ASHRAE 103-2017 are 
representative and appropriate, and whether any specific changes to the 
required conditions could improve representativeness. DOE also sought 
comment on any associated test burden with changing RWTs. 87 FR 14622, 
14633.
    In response, the CA IOUs reiterated their request for DOE to review 
whether the 120 [deg]F RWT requirement is appropriately representative 
of real-world operating conditions. (CA IOUs, No. 20 at p. 2)
    AHRI and AGA & APGA urged DOE to align return water temperatures 
with those in ANSI/ASHRAE 103-2017. (AHRI, No. 26 at p. 3; AGA & APGA, 
No. 25 at p. 2)
    BWC supported DOE's tentative conclusion of including the single 
return water temperature specified in ANSI/ASHRAE 103-2017 for ease of 
comparison between models and manufacturers. (BWC, No. 19 at p. 4) BWC 
asserted that a single condition would not increase the test burden. 
(BWC, No. 19 at p. 4)
    A.O. Smith commented that the current return water temperature is 
representative of an average value for the wide range of operating 
temperatures in the field and indicated that requiring testing to 
multiple conditions may require adjustment of the standards. A.O. Smith 
added that non-condensing boilers are more likely to be installed in 
systems with higher supply and return water temperatures, and 
condensing boilers are more likely to be installed in systems with 
lower temperatures. (A.O. Smith, No. 24 at p.

[[Page 15529]]

3-4) A.O. Smith stated that testing at multiple water temperatures 
would add testing burden to a test that could already span two days to 
complete, and that the burden to retest and rerate products would also 
include updating heat output ratings and safety certifications. (Id.)
    Rheem supported maintaining the return water temperature in the 
current test method, asserting that any change that could make the 
return water temperature more representative would be outweighed by the 
testing and certification burden on manufacturers. Specifically, Rheem 
noted that slight changes to the water temperature would not produce 
significantly more representative results, and major changes would 
require retesting of nearly all consumer boilers. (Rheem, No. 18 at p. 
4)
    Crown and U.S. Boiler supported the use of the water temperatures 
specified by ANSI/ASHRAE 103-2017 to reduce testing burden and 
complication. Crown and U.S. Boiler stated that a single set of water 
temperatures for all types of hot water boilers is appropriate to avoid 
consumer confusion, increased certification burden, and departure from 
the industry test method. Crown and U.S. Boiler added that changes to 
these water temperatures would cause significant changes in AFUE 
ratings for condensing boilers. (Crown, No. 16 at p. 3-4; U.S. Boiler, 
No. 17 at p. 3-4)
    NYSERDA noted that return water temperature has a significant 
impact on boiler performance and urged DOE to incorporate return water 
temperatures that more accurately reflect real-world conditions. 
NYSERDA stated that the 120 [deg]F return water temperature is too low, 
does not represent the boiler running conditions according to a 
research study done by The Electric and Gas Program Administrators of 
Massachusetts Part of the Residential Evaluation Program Area in 
2015,\33\ and should be considered closer to 140 [deg]F. NYSERDA 
claimed that the rationale for choosing the 120 [deg]F return water 
temperature from 1978 is outdated and inconsistent with DOE's current 
test procedure methodologies for commercial HVAC equipment. NYSERDA 
recommended that DOE test at both 120 [deg]F and 140 [deg]F for return 
water temperatures but stated that if DOE had to test at only one 
temperature, it should be 140 [deg]F. (NYSERDA, No. 23 at p. 2-4)
---------------------------------------------------------------------------

    \33\ High Efficiency Heating Equipment Impact Evaluation, 
Prepared for: The Electric and Gas Program Administrators of 
Massachusetts Part of the Residential Evaluation Program Area, March 
2015 at 22, available at ma-eeac.org/wp-content/uploads/High-Efficiency-Heating-Equipment-Impact-Evaluation-Final-Report.pdf.
---------------------------------------------------------------------------

    The Joint Advocates urged DOE to continue to investigate return 
water temperatures used in the test procedure to capture more 
representative performance, directing attention to data presented in 
appendix 7B to DOE's preliminary analysis technical support document 
(``TSD''),\34\ which indicated that there was an impact of return water 
temperature on the thermal efficiency \35\ of a boiler. The Joint 
Advocates suggested that multiple temperatures (i.e., 108 [deg]F and 
158 [deg]F) would be more appropriate to be able to differentiate 
amongst different condensing boiler models, and that non-condensing 
boilers should be tested at a higher temperature of 158 [deg]F. (Joint 
Advocates, No. 21 at p. 2-3)
---------------------------------------------------------------------------

    \34\ Appendix 7B of the preliminary analysis TSD is available at 
www.regulations.gov at Docket Number EERE-2019-BT-STD-0036. The data 
can be found in chapter 7B, page 11.
    \35\ Thermal efficiency for a commercial packaged boiler is 
determined using test procedures prescribed under 10 CFR 431.86 and 
is the ratio of the heat absorbed by the water or the water and 
steam to the higher heating value in the fuel burned. Data presented 
in the May 2022 Preliminary Analysis TSD reflected the performance 
of commercial packaged boilers due to the absence of information on 
consumer boilers.
---------------------------------------------------------------------------

    Busse stated that the current RWT settings were from NBSIR 80-2110 
and asserted that the underlying assumptions for the current return 
water temperature found in NBSIR 80-2110, pages 1-2 are out of date or 
invalid.\36\ Busse stated that the average distribution system water 
temperature in the current DOE test procedure should be closer to 133 
[deg]F based on heat load calculations to maintain a home at 65 [deg]F. 
Busse noted that the current test procedure has an average distribution 
system water temperature of 130 [deg]F (based on a return water 
temperature of 120 [deg]F and an outlet temperature of 140 [deg]F). 
However, Busse added that the average distribution system water 
temperature may be too high based on current or historically available 
heat distribution products, and that review literature from two cast-
iron baseboard manufacturers and two finned-tube copper baseboard 
manufacturers suggest an average distribution system water temperature 
of 127 [deg]F would be more representative. Busse stated that current 
industry practice for step-modulating, condensing boilers may not allow 
operation at the original 190 [deg]F average boiler water temperature 
(200 [deg]F supply) or deliver 140 [deg]F supply temperature at the 42 
[deg]F average outdoor temperature at the default controller settings. 
(Busse, No. 22 at p. 2-4) Busse recommended that a separate test should 
be required for determining heating capacity using a 180 [deg]F return 
supply water temperature (or the maximum supply temperature allowed by 
the control system, if less than 200 [deg]F), or, alternatively, the 
current return water temperature could be used with consideration of 
sensible heat losses only in order to estimate the steady-state 
efficiency for a noncondensing operation at high return water 
temperatures. (Busse, No. 22 at p. 6) Busse also asserted that boilers 
with reported ratings of 95 percent or 96 percent AFUE have such 
ratings as a result of a flawed calculation in the current test 
procedure, which does not account for the portion of the season during 
which the boiler would operate in a non-condensing mode (due to return 
water temperatures being higher than 120 [deg]F in certain conditions). 
(Busse, No. 22 at p. 11-12)
---------------------------------------------------------------------------

    \36\ Kelly, George E. and Kuklewicz, Mark E., NBSIR 80-2110: 
Recommended Testing and Calculation Procedures for Estimating the 
Seasonal Performance of Residential Condensing Furnaces and Boilers, 
National Bureau of Standards (Sponsored by U.S. Department of 
Energy), April 1981.
---------------------------------------------------------------------------

    As acknowledged by commenters, the specification of RWT has a 
substantive impact on the AFUE of boilers. Condensing boilers in 
particular achieve higher efficiency levels by extracting latent heat 
from the flue gases in addition to sensible heat (i.e., the 
condensation of flue gases releases a substantial amount of energy into 
the water that is being heated). However, flue gases can condense only 
if the dew point temperature of the vapor is reached. If the return 
(inlet) water is hotter than this dew point temperature, then 
condensation of the flue gases cannot occur in the heat exchanger, and 
the boiler operates in a non-condensing mode, reducing AFUE.
    In addition to the recommendations provided by commenters, DOE 
research indicates a range of RWTs in consumer applications. DOE is 
aware that many existing consumer boiler installations require the RWT 
to be 160 [deg]F and some even as high as 180 [deg]F.\37\ However, as 
new applications such as radiant floor heating and heat pump boilers 
become more prevalent in the market, DOE recognizes that some new 
boilers may be installed in homes that require lower

[[Page 15530]]

RWTs. In addition, condensing boilers in new installations would be 
subject to lower RWTs because radiant floor heating and hydronic air 
handler applications represent a substantial proportion of new hot 
water boiler installations.\38\ DOE research indicates some 
installations have RWT conditions as low as 85 [deg]F in certain 
cases.\39\ DOE notes that the midpoint of the range of RWTs observed 
through DOE's research (ranging between 85 [deg]F and 160 [deg]F) is 
122 [deg]F, which is reasonably close to the 120 [deg]F condition 
specified in appendix N and the industry test procedures. Given these 
considerations, DOE has determined that testing a consumer boiler at a 
single ``high'' RWT, as suggested by the Joint Advocates, NYSERDA, and 
Busse, would be less representative than the conditions specified by 
the current test procedure.
---------------------------------------------------------------------------

    \37\ On May 4, 2022, DOE published in the Federal Register a 
notice of availability of the preliminary analysis for energy 
conservation standards for consumer boilers (the ``May 2022 
Preliminary Analysis''). 87 FR 26304. DOE provided a technical 
support document (``TSD'') for the May 2022 Preliminary Analysis in 
the rulemaking docket. Id. In the energy use analysis of the May 
2022 Preliminary Analysis TSD, DOE estimated that 90 percent of 
condensing boilers installed as replacements to non-condensing 
boilers would be subject to a higher RWT of 158 [deg]F to 160 
[deg]F.
    \38\ In the May 2022 Preliminary Analysis, DOE estimated that 
condensing boilers in new installations (new constructions or new 
owners) would be subject to an average RWT of 108 [deg]F. See 
Appendix 7B of the preliminary analysis TSD, available at: 
www.regulations.gov/document/EERE-2019-BT-STD-0036-0021.
    \39\ See, for example: www.barronheating.com/blog/the-book-on-
radiant-heating-when-it-makes-sense-and-when-it-might-not/
#:~:text=Radiant%2Dfloor%20heating%20systems%20typically,55%E2%80%937
0%C2%B0C). (Last accessed on October 6, 2022)
---------------------------------------------------------------------------

    DOE also acknowledges the concerns raised by manufacturers 
regarding the potential need to retest and recertify all consumer 
boilers if a new test condition were to be required in addition to the 
currently established 120 [deg]F condition. EPCA requires DOE to 
establish test procedures that are reasonably designed to produce test 
results that measure energy efficiency of a consumer boiler during a 
representative average use cycle or period of use, as determined by the 
Secretary, and shall not be unduly burdensome to conduct. (42 U.S.C. 
6293(b)(3)) Based on the considerations discussed in this section, DOE 
has determined that it lacks data and information to conclude that a 
different RWT (or multiple RWTs) would be more representative than the 
current RWT requirements such that it would justify the potential 
burden of such a change. Hence, in this final rule, DOE is finalizing 
its proposal from the March 2022 NOPR to incorporate by reference the 
test conditions in ANSI/ASHRAE 103-2017. Should additional data or 
information become available in the future, DOE would consider this 
topic again in a subsequent test procedure rulemaking.
7. Standby Mode and Off Mode Electrical Energy Consumption
    As discussed in section I.A of this final rule, EPCA requires that 
DOE amend test procedures to include standby mode and off mode energy 
consumption, ``taking into consideration the most current versions of 
Standards 62301 and 62087 of the International Electrotechnical 
Commission.'' (42 U.S.C. 6295(gg)(2)(A)) The DOE test method currently 
references IEC 62301 (Edition 2.0 2011-01), which provides instructions 
for measuring standby mode and off mode energy consumption. IEC 62301 
provides several options for measuring the standby mode and off mode 
power consumption using either the ``sampling method,'' ``average 
reading method,'' or ``direct meter reading method.'' Although these 
methods vary, if the standby or off mode consumption is stable, each 
method can be completed in under 1 hour, and the sampling method can be 
completed in as little as 15 minutes.
    In the March 2022 NOPR, DOE tentatively determined that the 
provisions in IEC 62301 provide an appropriate representation of 
standby mode and off mode energy consumption of consumer boilers and 
are not unduly burdensome; hence DOE did not propose any changes. 
Because commenters responding to the May 2020 RFI recommended 
streamlining the procedure for determining standby mode and off mode 
energy consumption, in the March 2022 NOPR DOE requested further 
comment on whether a simplified approach for measuring standby mode and 
off mode electrical energy consumption is appropriate and would provide 
accurate, representative results that are comparable to those obtained 
with IEC 62301. 87 FR 14622, 14634.
    In response, BWC commented that the standby mode and off mode test 
methods are appropriate and do not need to be amended at this time. 
(BWC, No. 19 at p. 4)
    Rheem stated that the current approach for measuring standby and 
off mode electrical energy consumption is not overly burdensome and 
should be maintained. Rheem also recommended that DOE examine a 
combined AFUE metric that includes standby and off mode electrical 
energy use, asserting that an increase in standby and off mode energy 
use may be needed to accommodate an increase in overall efficiency, and 
thus a combined AFUE metric would provide for greater design 
flexibility. (Rheem, No. 18 at p. 4)
    DOE considered an integrated AFUE metric (``AFUEI'') in 
a test procedure final rule published October 20, 2010 (``October 2010 
Final Rule''), which established the standby mode and off mode 
electrical energy use metrics. 75 FR 64621, 64626-64627 (Oct. 20, 
2010). In the October 2010 Final Rule, DOE explored the possibility of 
regulating AFUEI; however, commenters objected that the 
approach would provide an ineffective basis for regulation, and thus it 
was not ``technically feasible'' to integrate AFUE with standby mode 
and off mode energy consumption. Id. Separate metrics were established 
because the magnitude of the standby mode and off mode energy 
consumption was very small compared to the active mode fuel 
consumption, and, as a result, it was not possible to discern different 
levels of standby and off mode power consumption (i.e., 
AFUEI values were essentially identical to AFUE values). Id.
    Neither Rheem nor other commenters have presented DOE with any 
information to suggest that the conclusions from the October 2010 Final 
Rule--specifically, that an integrated metric would not be technically 
feasible--are no longer applicable. Furthermore, DOE is not aware of 
any current industry-accepted test procedure that combines the current 
AFUE metric with the standby mode and off mode power consumption 
metrics. For these reasons, DOE is not adopting any new provisions for 
a combined metric in this final rule.
    A.O. Smith recommended eliminating the standby mode and off mode 
power consumption testing due to the little impact the associated power 
consumption has on the total efficiency of a consumer boiler (less than 
a fraction of one percent). A.O. Smith indicated that procuring the 
adequate equipment and instrumentation required for this testing is 
burdensome. A.O. Smith also commented that removing these requirements 
would afford manufacturers the opportunity to potentially add safety 
enhancements such as carbon monoxide sensors, which require a small 
heating element to prevent premature failure, as well as options for 
control displays and ways to reduce cycling losses. (A.O. Smith, No. 24 
at p. 4) A.O. Smith recommended that if DOE were to keep the standby 
mode and off mode tests as part of the test procedure, the standby mode 
and off mode power consumption should be measured with a simple current 
measurement with a calibrated watt meter. (A.O. Smith, No. 24 at p. 6)
    As discussed, EPCA requires that DOE include in its test procedures 
a method

[[Page 15531]]

for measuring standby mode and off mode power consumption, unless 
technically infeasible. (42 U.S.C. 6295(gg)(2)(A)) Further, in doing 
so, EPCA requires that DOE must consider IEC Standard 62301 and IEC 
Standard 62087. (42 U.S.C. 6295(gg)(2)(A)) Section 4.4 of IEC 62301 
provides instruction on selecting acceptable power measuring 
instrumentation by specifying power measurement uncertainty bounds, 
frequency response, and long-term averaging (integrating) requirements. 
DOE notes that if a calibrated watt meter is capable of meeting these 
requirements, then it may be used in accordance with section 4.4 of IEC 
62301.
    AHRI noted that standby mode and off mode power consumption should 
not count as a loss because all energy brought into the system provides 
useful resistive heat to the building. AHRI stated that similar logic 
is used to give electric boilers a rating of 100 percent efficiency. 
(AHRI, No. 26 at p. 3)
    While electrical component power draws that dissipate small amounts 
of heat to the surroundings may contribute to useful heating to the 
building, the building does not always demand heating. During the 
cooling season, any heat dissipated would be counterproductive. 
Furthermore, not all boilers are located in conditioned spaces. In 
addition, as discussed previously, EPCA requires DOE to include in its 
test procedures a method for measuring standby mode and off mode power 
consumption. (42 U.S.C. 6295(gg)(2)(A)) For these reasons, DOE makes no 
change to its inclusion of standby mode and off mode power in this 
final rule.
    In conclusion, DOE has determined that no changes to the standby 
mode and off mode test provisions are warranted. As such, the new 
appendix EE test procedure maintains the same test methods for 
measuring these metrics as specified in the current appendix N test 
procedure.
8. Full Fuel Cycle Efficiency
    The full fuel cycle (``FFC'') accounts for the energy consumed in 
extracting, processing, and transporting fuels. In the March 2022 NOPR, 
DOE responded to comments received in response to the May 2020 RFI 
requesting that DOE consider incorporating an FFC analysis into the 
test procedure in order to allow for direct comparisons between fossil 
fuel-fired systems and electric systems. 87 FR 14622, 14634. DOE 
responded that FFC is typically considered in energy conservation 
standards rulemakings--not as a metric for representing product 
efficiency. Id. In the March 2022 NOPR, DOE maintained its previous 
conclusion from the January 2016 Final Rule that a mathematical 
adjustment to the test procedure to account for FFC is not appropriate 
because the mathematical adjustment to the site-based energy descriptor 
relies on information that is updated annually, which would require 
annual updating of the test method. Id.
    In response to the March 2022 NOPR, BWC stated that the FFC 
efficiency and source efficiency analysis are not appropriate to 
include in the Federal test procedure. (BWC, No. 19, p. 4)
    For the reasons discussed in the March 2022 NOPR, DOE maintains in 
this final rule its previous determination not to account for FFC in 
the consumer boiler test procedure.
9. Idle Losses
    In the March 2022 NOPR, DOE responded to comments received in 
response to the May 2020 RFI requesting that DOE consider ``idle 
losses'' that are not captured in the AFUE metric. 87 FR 14622, 14628. 
Specifically, Energy Kinetics asserted that oversizing of boilers can 
lead to wasted energy to heat up the boiler but not contribute to the 
heating of the hydronic loop. In the March 2022 NOPR, DOE stated that 
EPCA (42 U.S.C. 6295(f)(3)(A)-(B)) requires hot water boilers to have 
an automatic means for adjusting water temperature, which limits idle 
losses. DOE indicated that idle losses could be further addressed in 
the determination of AFUE; however, there was insufficient data to 
propose amendments to the test procedure to do so. DOE sought further 
comment from interested parties on the topic. 87 FR 14622, 14628.
    In response to the March 2022 NOPR, Rheem agreed with DOE's 
statement that the prescriptive design requirements in EPCA at 42 
U.S.C. 6295(f)(3) effectively reduce idle losses in the field. Rheem 
noted that if idle losses, both electrical and fossil fuel, were fully 
accounted for in the AFUE metric, then a standard could be proposed 
that would not require separate design requirements. (Rheem, No. 18 at 
p. 5)
    DOE has determined that there remains insufficient information to 
further address idle losses in this rulemaking as it pertains to the 
determination of AFUE in the new appendix EE test procedure for 
consumer boilers.

H. Alternative Efficiency Determination Methods

    At 10 CFR 429.70, DOE includes provisions for alternative 
efficiency determination methods (``AEDMs''), which are computer 
modeling or mathematical tools that predict the performance of non-
tested basic models. They are derived from mathematical models and 
engineering principles that govern the energy efficiency and energy 
consumption characteristics of a type of covered equipment. These 
computer modeling and mathematical tools, when properly developed, can 
provide a relatively straight-forward and reasonably accurate means to 
predict the energy usage or efficiency characteristics of a basic model 
of a given covered product or equipment and reduce the burden and cost 
associated with testing. 78 FR 79579, 79580 (Dec. 31, 2013; the 
``December 2013 AEDM Final Rule''). Where authorized by regulation, 
AEDMs enable manufacturers to rate and certify their basic models by 
using the projected energy use or energy efficiency results derived 
from these simulation models in lieu of testing. Id. at 78 FR 79580.
    DOE does not currently authorize the use of AEDMs for consumer 
boilers, whereas DOE does authorize the use of AEDMs for commercial 
packaged boilers.\40\ Manufacturers of consumer boilers (or furnaces 
more generally) are not authorized to use an AEDM to determine ratings 
for these products. However, manufacturers of cast-iron boilers may 
determine AFUE for models at a capacity other than the highest or 
lowest of the group of basic models having identical intermediate 
sections and combustion chambers through linear interpolation of data 
obtained for the smallest and largest capacity units of the family. See 
10 CFR 429.18(a)(2)(iv)(A). These provisions already provide 
manufacturers with an alternative method of rating consumer boilers 
without testing every model, and this alternative method reduces 
manufacturer test burden.
---------------------------------------------------------------------------

    \40\ In the December 2013 AEDM Final Rule, DOE explained that 
the AEDM provisions extend to those products or equipment which 
``have expensive or highly-customized basic models.'' 78 FR 79579, 
79580. The current AEDM provisions for commercial HVAC equipment 
(including commercial package boilers, for example) were in part the 
result of a negotiated rulemaking effort by the Appliance Standards 
and Rulemaking Federal Advisory Committee (ASRAC) in 2013. Id. 
Boilers designed for residential applications were not considered at 
the time. 78 FR 79579.
---------------------------------------------------------------------------

    In the March 2022 NOPR, DOE requested comment on whether AEDM 
provisions similar to those in place for commercial equipment would be 
necessary and appropriate for consumer boilers. 87 FR 14622, 14635.
    A.O. Smith stated that adding an AEDM option for consumer boilers 
would be reasonable; however, there is

[[Page 15532]]

greater value to have an AEDM for commercial products given that those 
models can be engineered to order. (A.O. Smith, No. 24 at p. 4) Busse 
indicated that the breadth of a product line with similar geometries 
and performance would not seem to justify an AEDM; however, an AEDM may 
be the only method to avoid testing each model. (Busse, No. 22 at p. 8)
    In consideration of these comments, as well as considerations 
discussed in the March 2022 NOPR (see 87 FR 14622, 14635), in this 
final rule, DOE concludes that manufacturer testing burden is 
alleviated by the linear interpolation provisions for cast-iron 
boilers, such that an AEDM for consumer boilers more broadly is not 
warranted at this time.

I. Certification Provisions for Cast-Iron Boilers

    As discussed in the March 2022 NOPR, the certification provisions 
at 10 CFR 429.18(a)(2)(iv)(A) alleviate testing burden for cast-iron 
boilers, which are commonly constructed of identical cast-iron heat 
exchanger sections. Boilers of the same cast-iron product family are 
often constructed so that the heating capacity can be increased by 
adding more sections to the heat exchanger. When a product family is 
designed in this way, linear interpolation is accurate \41\ to predict 
the performance of intermediately-sized boilers. The March 2022 NOPR 
sought data and other information that would demonstrate that using a 
linear interpolation method for heat exchanger materials other than 
cast-iron would produce representative test results. 87 FR 14622, 
14635.
---------------------------------------------------------------------------

    \41\ Test data analyzed as part of the 1979 rulemaking which 
established these provisions showed that the annual fuel utilization 
efficiency, energy consumption, and estimated annual operating cost 
of sectional cast-iron boilers can be accurately predicted by a 
linear interpolation based on data obtained from units having the 
smallest and largest number of intermediate sections. 44 FR 22410, 
22415 (April 13, 1979).
---------------------------------------------------------------------------

    AHRI and AGA and APGA supported extending of the use of linear 
interpolation to heat exchanger materials other than cast-iron, stating 
that linear interpolation is a valid calculation method for these 
products, as proven by the current cast-iron allowance. (AHRI, No. 26 
at p. 4; AGA and APGA, No. 25 at p. 2)
    A.O. Smith supported use of the interpolation method for boilers 
with heat exchangers other than cast-iron, stating that its copper 
finned-tube boilers have a tray of tubes that increase in length 
proportionate to input rate, are consistent in geometry, and have only 
incremental changes proportionate to input rate. A.O. Smith added that 
its Lochinvar brand models have seven input rates ranging from 45,000 
Btu/h through 260,000 Btu/h and all perform near 84.0-percent AFUE. 
(A.O. Smith, No. 24 at p. 5)
    Rheem did not support the use of linear interpolation for 
certification of consumer boilers beyond what is already allowed for 
cast-iron boilers, stating that interpolation produces less accurate 
results than results derived from actual tests. (Rheem, No. 18 at p. 4)
    Busse did not support using a linear interpolation method for heat 
exchanger materials other than cast-iron. Busse asserted that any 
difference and/or non-proportionality in excess air, flue loading, and/
or flue cross-sectional area could produce non-linear results, which is 
also why cast-iron units equipped with draft hoods, draft diverters, or 
induced draft systems are more prone to producing non-linear results. 
(Busse, No. 22 at p. 7-8)
    Based on DOE's review of product literature, DOE has determined 
that heat exchangers made of different materials may not be constructed 
with identical additive components the way cast-iron sectional heat 
exchangers are constructed; hence, the linear interpolation method may 
be less viable for other heat exchanger materials. DOE notes that 
stakeholders commenting in support of using linear interpolation for 
materials other than cast-iron did not provide any data to demonstrate 
the viability of a linear interpolation method for other heat exchanger 
materials. Given the concerns raised by Rheem and Busse regarding the 
potential for non-linear results for intermediately-sized boilers with 
non-cast-iron heat exchangers, as well as DOE's review of product 
literature, DOE has concluded that there is not enough information to 
substantiate such a provision at this time. Hence, in this final rule, 
DOE maintains that the linear interpolation AEDM method applies only to 
cast-iron boilers.
    Additionally, Busse recommended the following clarifications for 
using linear interpolation: (1) clarify if interpolated values are 
derived from truncated or pre-truncated AFUE values of smallest and 
largest capacity units, (2) update 10 CFR part 429 to allow 
interpolation of heating capacity derived from unrounded 
EffySS values of smallest and largest capacity units, and 
(3) require third-party test agencies to qualify AFUE and heating 
capacity on an ``interpolated'' model. (Busse, No. 22 at p. 7-8)
    First, as discussed in section III.F.8, DOE has amended the 
certification requirements for AFUE in the July 2022 Certification 
Final Rule to require that AFUE must be rounded to the nearest tenth of 
a percentage point when this value is reported. 87 FR 43968. Thus, as 
of this final rule, truncation is no longer used to report AFUE. DOE is 
clarifying in this final rule, however, that manufacturers may use 
either the rounded or unrounded AFUE values of the smallest and largest 
capacity units for linear interpolation. DOE is making this 
determination based on the fact that the results of the linear 
interpolation would be minimally impacted by rounding AFUE to the 
nearest tenth of a percentage point, compared to using unrounded 
values.
    Second, DOE notes that heating capacity (QOUT), which is 
calculated in the current test procedure as a function of steady-state 
efficiency (EffySS), is not required to be certified to DOE 
at this time, nor has DOE proposed to make this a requirement. 
Currently, manufacturers must certify the nameplate input rate 
(QIN), which is a separate metric and not a function of 
EffySS. Hence, DOE is not updating the linear interpolation 
provisions to include heating capacity (QOUT).
    Third, requiring third-party testing to qualify AFUE ratings 
derived using the linear interpolation method would eliminate the 
reduction in test burden achieved with the alternate linear 
interpolation approach. DOE notes, however, that it can conduct 
assessment or enforcement testing on consumer boiler models, and this 
process serves to verify ratings (see subpart C to 10 CFR part 429).
    In conclusion, DOE has determined in this final rule not to amend 
the linear interpolation provisions for consumer boilers.

J. Effective and Compliance Dates

    The effective date for the adopted test procedure amendment will be 
30 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(copyright)(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

[[Page 15533]]

manufacturer will experience undue hardship. (Id.)

K. 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 the March 2022 NOPR, DOE discussed that the amendments proposed 
to the test procedure for consumer boilers would be expected to have 
minimal impact on efficiency ratings such that manufacturers would not 
be required to retest and recertify ratings. 87 FR 14622, 14625, 14636. 
DOE also tentatively determined that the proposed amendments would not 
impact testing costs or increase burden. DOE requested feedback from 
stakeholders on these tentative determinations. Id.
    A.O. Smith supported DOE's determination that the proposed 
incorporation by reference of ASHRAE 41.6-2014 will not increase 
testing burden. A.O. Smith also stated that DOE's estimate for third-
party AFUE testing is reasonable and agreed that the proposed 
incorporation by reference of ANSI/ASHRAE 103-2017 is not unduly 
burdensome. (A.O. Smith, No. 24 at p. 5) A.O. Smith stated that 
although there may be fractional changes in the AFUE rating as a result 
of testing to the 2017 version, these should not necessitate retesting 
or rerating of any existing boilers. A.O. Smith also supported having a 
publicly available AFUE calculation tool to enhance consistency of 
results across the industry. (A.O. Smith, No. 24 at p. 3)
    Rheem stated that the test costs under the proposed appendix EE 
test procedure are likely to remain similar to the current appendix N 
test procedure. (Rheem, No. 18 at p. 5)
    AHRI stated that it previously commented that a move to ANSI/ASHRAE 
103-2017 would not result in increased test burden; however, it had 
come to AHRI's attention that there are manufacturers using automated 
programs that would incur an increased test burden. (AHRI, No. 26 at p. 
4)
    DOE understands that AHRI is referring to pre-programmed cycle 
times, which execute burner on and off functions at pre-determined 
times per the DOE test procedure. From DOE's own testing of the impact 
of cycle timings at a third-party lab using an automated program, DOE 
has determined that these parameters can be simple to re-program and 
that doing so would not constitute undue test burden. As discussed in 
section III.D.1.c, other commenters requested DOE to further 
investigate whether the update in cycle times would increase burden by 
requiring retesting. Based on test data indicating little variation in 
test results due to the update in cycle times, DOE has determined that 
the impact of these amendments on ratings would be minimal. With regard 
to providing a publicly available AFUE calculation tool, DOE provides 
test report templates on its certification website,\42\ including a 
template for the consumer boiler test procedure.
---------------------------------------------------------------------------

    \42\ Standardized test report templates are available online at: 
www.energy.gov/eere/buildings/standardized-templates-reporting-test-results.
---------------------------------------------------------------------------

    For this final rule, DOE has evaluated the impacts on ratings 
resulting from its adoption of the test methods in the updated industry 
test standard, ANSI/ASHRAE 103-2017. These updates are discussed in 
detail in section III.D.1 of this final rule. Based on this review, DOE 
has determined that manufacturers will be able to rely on data 
generated under the current test procedure. As such, it is unlikely 
that retesting of consumer boilers would be required solely as a result 
of DOE's adoption of the finalized amendments to the test procedure. 
However, if a manufacturer were to retest a model using the amended 
test procedure as finalized, DOE estimates that the cost of performing 
the amended AFUE test at a third-party laboratory would be $3,600, the 
same as the cost of performing the current AFUE test. This estimate 
represents an increase of $600 from the cost estimate in the March 2022 
NOPR, to account for overall increases in laboratory testing fees.

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Orders 12866 and 13563

    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), 
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 the 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,

[[Page 15534]]

2003. DOE certifies that this rule, if adopted, would not have 
significant economic impact on a substantial number of small entities. 
The factual basis of this certification is set forth below.
    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 
boilers, 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)) DOE is publishing 
this final rule in satisfaction of the 7-year review requirement 
specified in EPCA. (42 U.S.C. 6293(b)(1)(A))
    DOE did not receive written comments that specifically addressed 
impacts on small businesses or that were provided in response to the 
March 2022 NOPR.
    The Small Business Administration (``SBA'') has set a size 
threshold, which defines those entities classified as ``small 
businesses'' for the purposes of the statute. DOE used the SBA's small 
business size standards to determine whether any small entities would 
be subject to the requirements of the rule. See 13 CFR part 121. The 
products covered by this rule are classified under North American 
Industry Classification System (``NAICS'') code 333414,\43\ ``Heating 
Equipment (except Warm Air Furnaces) Manufacturing.'' In 13 CFR 
121.201, the SBA sets a threshold of 500 employees or fewer for an 
entity to be considered as a small business for this category. This 
employment figure is enterprise-wide, encompassing employees at the 
parent, subsidiary, and sister corporations.
---------------------------------------------------------------------------

    \43\ The SBA size standards (effective October 1, 2022) are 
listed by NAICS code and industry description and are available at: 
www.sba.gov/document/support-table-size-standards (last accessed on 
December 1, 2022).
---------------------------------------------------------------------------

    Consistent with the March 2022 NOPR, DOE relied on the Compliance 
Certification Database (``CCD''),\44\ the AHRI database,\45\ the 
California Energy Commission's Modernized Appliance Efficiency Database 
System (``MAEDbS''),\46\ the ENERGY STAR Product Finder database,\47\ 
and the prior consumer boiler energy conservation standards rulemaking 
to create a list of companies that import or otherwise manufacture the 
products covered by this final rule. DOE used the publicly available 
information and subscription-based market research tools (e.g., reports 
from Dun & Bradstreet \48\) to identify 27 original equipment 
manufacturers (``OEMs'') affected by this final rule. Of the 27 OEMs, 
DOE identified five domestic OEMs of consumer boilers that met the SBA 
definition of a ``small business'' and are not foreign-owned and 
operated.
---------------------------------------------------------------------------

    \44\ U.S. Department of Energy Compliance Certification 
Database, available at: www.regulations.doe.gov/certification-data/products.html.
    \45\ The AHRI Database is available at: www.ahridirectory.org 
(last accessed March 3, 2021).
    \46\ California Energy Commission's MAEDbS is available at 
cacertappliances.energy.ca.gov/Pages/ApplianceSearch.aspx (last 
accessed September 22, 2021).
    \47\ The ENERGY STAR Product Finder database is available at 
energystar.gov/productfinder/ (last accessed September 22, 2021).
    \48\ D&B Hoovers [verbar] Company Information [verbar] Industry 
Information [verbar] Lists, app.dnbhoovers.com/ (last accessed 
September 29, 2022).
---------------------------------------------------------------------------

    In this final rule, DOE updates appendix N to remove the provisions 
applicable only to consumer boilers and to rename the current appendix 
as ``Uniform Test Method for Measuring the Energy Consumption of 
Furnaces.'' Correspondingly, this final rule establishes a new test 
procedure at 10 CFR part 430 subpart B, appendix EE, ``Uniform Test 
Method for Measuring the Energy Consumption of Boilers'' (``appendix 
EE''). In the new appendix EE, DOE includes all provisions currently 
included in appendix N relevant to consumer boilers, with the following 
modifications:
    (1) Incorporate by reference the current revision to the applicable 
industry standard, ANSI/ASHRAE 103-2017, ``Methods of Testing for 
Annual Fuel Utilization Efficiency of Residential Central Furnaces and 
Boilers.''
    (2) Incorporate by reference the current revision of ASTM Standard 
D2156-09 (Reapproved 2018), ``Standard Test Method for Smoke Density in 
Flue Gases from Burning Distillate Fuels.''
    (3) Incorporate by reference ANSI/ASHRAE 41.6-2014, ``Standard 
Method for Humidity Measurement.''
    (4) Update the definitions to reflect the changes in ANSI/ASHRAE 
103-2017 as compared to ANSI/ASHRAE 103-1993.
    (5) Provide corrections to erroneous calculations and add 
clarifications to test conditions and setup requirements.
    DOE is also removing the definition of outdoor furnace or boiler 
from 10 CFR 430.2.
    DOE has determined that the amendments adopted in this final rule 
will not substantively impact the measured efficiency of consumer 
boilers or require retesting or recertification solely as a result of 
DOE's adoption of the amendments to the test procedures. As outlined in 
Table II.1 of this final rule, the new appendix EE includes all 
provisions currently included in appendix N relevant to consumer 
boilers, with modifications to: harmonize with industry standard 
updates; provide corrections to erroneous calculations; and add 
clarifications to test conditions and setup requirements. Additionally, 
the update to use more representative cycle timings and oversize 
factors in the new appendix EE test procedure was demonstrated to have 
minimal impact on AFUE ratings as a result of testing. See section 
III.K of this final rule for additional details on test procedure 
costs. DOE also determined that the amendments would not increase the 
testing costs or burden associated with the DOE test procedure for 
consumer boilers, as the cost to test consumer boilers under the 
amended test procedure is $3,600, the same as the cost to test consumer 
boilers under the existing test procedure.
    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.

C. Review Under the Paperwork Reduction Act of 1995

    Manufacturers of consumer boilers 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 boilers. 
(See

[[Page 15535]]

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 boilers in this final rule.
    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 boilers. 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 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.

[[Page 15536]]

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 energy.gov/sites/prod/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 its 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 boilers 
adopted in this final rule incorporates testing methods contained in 
certain sections of the following commercial standards: ASHRAE Standard 
103-2017, ASTM D2156-09 (R2018), and ASHRAE Standard 41.6-2014. DOE has 
evaluated these standards and is unable to conclude whether it fully 
complies with the requirements of section 32(b) of the FEAA (i.e., 
whether it was 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 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 103-2017 is an industry accepted test standard that provides 
procedures for determining the annual fuel utilization efficiency of 
consumer furnaces and boilers. Specifically, the test procedure 
codified by this final rule references sections of ASHRAE 103-2017 for 
definitions, classifications, requirements, instruments, methods of 
testing, testing procedures, nomenclature, and calculations for 
determining the AFUE of consumer boilers.
    ASHRAE 41.6-2014 is an industry accepted test standard that 
includes instructions for measuring the relative humidity of test 
chamber air. Specifically, the test procedure codified by this final 
rule references sections of ASHRAE 103-2017 that in turn reference 
ASHRAE 41.6-2014 for air humidity measurement instructions.
    These test standards are all readily available from ANSI 
(webstore.ansi.org) or ASHRAE (www.ashrae.org).
    ASTM D2156-09 (R2018) is an industry accepted test standard that 
includes instructions for determining the amount of smoke produced by 
an oil burner to ensure the burner is adjusted properly. Specifically, 
the test procedure codified by this final rule references sections of 
ASTM D2156-09 (R2018) for these instructions.
    This test standard is readily available from ASTM International 
(www.astm.org).
    IEC 62301 is an industry-accepted test procedure for measuring 
standby mode and off mode energy consumption. The test procedure 
codified by this final rule references IEC 62301 for performing the 
standby mode and off mode power measurements for consumer boilers. This 
test standard is readily available from IEC (webstore.iec.ch).
    The following standards included in the regulatory text were 
previously approved for incorporation by reference for the locations in 
which they appear in this final rule: ANSI/ASHRAE 103-1993, and ASTM 
D2156-09 (Reapproved 2013).

V. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this final 
rule.

List of Subjects

10 CFR Part 429

    Administrative practice and procedure, Confidential business 
information, Energy conservation, Household appliances, Imports, 
Intergovernmental relations, Reporting and recordkeeping requirements, 
Small businesses.

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 February 
21, 2023, by Francisco Alejandro Moreno,

[[Page 15537]]

Acting Assistant Secretary for Energy Efficiency and Renewable 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 February 22, 2023.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.

    For the reasons stated in the preamble, DOE amends parts 429 and 
430 of chapter II of title 10, Code of Federal Regulations as set forth 
below:

PART 429--CERTIFICATION COMPLIANCE AND ENFORCEMENT FOR CONSUMER 
PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT

0
1. The authority citation for part 429 continues to read as follows:

    Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.


Sec.  429.134  [Amended]

0
2. Section 429.134 is amended by:
0
a. In paragraph (h) introductory text, removing the words ``appendix 
N'' and adding in their place the word ``appendix EE'';
0
b. In paragraph (h)(1)(i)(A), removing the words ``section 6 of 
appendix N'' and adding in their place the words ``section 6 of 
appendix EE''; and
0
c. In paragraph (h)(2)(i)(A), removing the words ``appendix N'' and 
adding in their place the words ``appendix EE''.

PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

0
3. The authority citation for part 430 continues to read as follows:

    Authority: 42 U.S.C. 6291-6309; 28 U.S.C. 2461 note.


Sec.  430.2  [Amended]

0
4. Section 430.2 is amended by removing the definition of ``Outdoor 
furnace or boiler''.

0
5. Section 430.3 is amended by:
0
a. In paragraph (g)(11), removing the words ``appendix F'' and adding 
in their place the words ``appendices F and EE'';
0
b. In paragraph (g)(17), removing the words ``appendix O'' and adding 
in their place the words ``Sec.  430.23 and appendices O and EE'';
0
c. Revising paragraph (j) introductory text;
0
d. In paragraph (j)(3), removing the words ``appendix O'' and adding in 
their place the words ``appendices O and EE''; and
0
e. In paragraph (p)(7), removing the text ``CC, and FF'' and adding in 
their place ``CC, EE, and FF''.

    The revision reads as follows:


Sec.  430.3  Materials incorporated by reference.

* * * * *
    (j) ATSM. ASTM International, 100 Barr Harbor Drive, Post Office 
Box C700, West Conshohocken, PA 19428-2959, (877) 909-2786, 
www.astm.org.
* * * * *

0
6. Section 430.23 is amended by revising paragraph (n) to read as 
follows:


Sec.  430.23  Test Procedures for the measurement of energy and water 
consumption.

* * * * *
    (n) Furnaces. (1) The estimated annual operating cost for furnaces 
is the sum of:
    (i) The product of the average annual fuel energy consumption, in 
Btu's per year for gas or oil furnaces or in kilowatt-hours per year 
for electric furnaces, determined according to section 10.2.2 or 10.3 
of appendix N of this subpart, respectively, (for furnaces, excluding 
low pressure steam or hot water boilers and electric boilers) or 
section 10.2.2 or 10.3 of appendix EE of this subpart, respectively 
(for low pressure steam or hot water boilers and electric boilers), and 
the representative average unit cost in dollars per Btu for gas or oil, 
or dollars per kilowatt-hour for electric, as appropriate, as provided 
pursuant to section 323(b)(2) of the Act; plus
    (ii) The product of the average annual auxiliary electric energy 
consumption in kilowatt-hours per year determined according to section 
10.2.3 of appendix N of this subpart (for furnaces, excluding low 
pressure steam or hot water boilers and electric boilers) or section 
10.2.3 of appendix EE of this subpart (for low pressure steam or hot 
water boilers and electric boilers) of this subpart, and the 
representative average unit cost in dollars per kilowatt-hour as 
provided pursuant to section 323(b)(2) of the Act.
    (iii) Round the resulting sum to the nearest dollar per year.
    (2) The annual fuel utilization efficiency (AFUE) for furnaces, 
expressed in percent, is the ratio of the annual fuel output of useful 
energy delivered to the heated space to the annual fuel energy input to 
the furnace.
    (i) For gas and oil furnaces, determine AFUE according to section 
10.1 of appendix N (for furnaces, excluding low pressure steam or hot 
water boilers and electric boilers) or section 10.1 of appendix EE (for 
low pressure steam or hot water boilers and electric boilers) of this 
subpart, as applicable.
    (ii) For electric furnaces, excluding electric boilers, determine 
AFUE in accordance with section 11.1 of ANSI/ASHRAE 103-1993 
(incorporated by reference, see Sec.  430.3); for electric boilers, 
determine AFUE in accordance with section 11.1 of ANSI/ASHRAE 103-2017 
(incorporated by reference, see Sec.  430.3).
    (iii) Round the AFUE to one-tenth of a percentage point.
    (3) The estimated regional annual operating cost for furnaces is 
calculated as follows:
    (i) When using appendix N of this subpart for furnaces excluding 
low pressure steam or hot water boilers and electric boilers (see the 
note at the beginning of appendix N of this subpart),
    (A) For gas or oil-fueled furnaces,

(EFR x CBTU) + (EAER x CKWH)

Where:

EFR = the regional annual fuel energy consumption in Btu 
per year, determined according to section 10.7.1 of appendix N of 
this subpart;
CBTU = the representative average unit cost in dollars 
per Btu of gas or oil, as provided pursuant to section 323(b)(2) of 
the Act;
EAER = the regional annual auxiliary electrical energy 
consumption in kilowatt-hours per year, determined according to 
section 10.7.2 of appendix N of this subpart; and
CKWH = the representative average unit cost in dollars 
per kilowatt-hour of electricity, as provided pursuant to section 
323(b)(2) of the Act.

    (B) For electric furnaces,

(EER x CKWH)

Where:

EER = the regional annual fuel energy consumption in 
kilowatt-hours per year, determined according to section 10.7.3 of 
appendix N of this subpart; and
CKWH is as defined in paragraph (n)(3)(i)(A) of this 
section.

    (ii) When using appendix EE of this subpart for low pressure steam 
or hot water boilers and electric boilers (see the note at the 
beginning of appendix EE of this subpart),
    (A) For gas or oil-fueled boilers,

(EER x CBTU) + (EAER x CKWH)


[[Page 15538]]


Where:

EFR = the regional annual fuel energy consumption in Btu 
per year, determined according to section 10.5.1 of appendix EE of 
this subpart;
CBTU and CKWH are as defined in paragraph 
(n)(3)(i)(A) of this section; and
EAER = the regional annual auxiliary electrical energy 
consumption in kilowatt-hours per year, determined according to 
section 10.5.2 of appendix EE of this subpart.

    (B) For electric boilers,

(EER x CKWH)

Where:

EER = the regional annual fuel energy consumption in 
kilowatt-hours per year, determined according to section 10.5.3 of 
appendix EE of this subpart; and
CKWH is as defined in paragraph (n)(3)(i)(A) of this 
section.

    (iii) Round the estimated regional annual operating cost to the 
nearest dollar per year.
    (4) The energy factor for furnaces, expressed in percent, is the 
ratio of annual fuel output of useful energy delivered to the heated 
space to the total annual energy input to the furnace determined 
according to either section 10.6 of appendix N of this subpart (for 
furnaces, excluding low pressure steam or hot water boilers and 
electric boilers) or section 10.4 of appendix EE of this subpart (for 
low pressure steam or hot water boilers and electric boilers), as 
applicable.
    (5) The average standby mode and off mode electrical power 
consumption for furnaces shall be determined according to section 8.10 
of appendix N of this subpart (for furnaces, excluding low pressure 
steam or hot water boilers and electric boilers) or section 8.9 of 
appendix EE of this subpart (for low pressure steam or hot water 
boilers and electric boilers), as applicable. Round the average standby 
mode and off mode electrical power consumption to the nearest tenth of 
a watt.
    (6) Other useful measures of energy consumption for furnaces shall 
be those measures of energy consumption which the Secretary determines 
are likely to assist consumers in making purchasing decisions and which 
are derived from the application of appendix N of this subpart (for 
furnaces, excluding low pressure steam or hot water boilers and 
electric boilers) or appendix EE of this subpart (for low pressure 
steam or hot water boilers and electric boilers).
* * * * *

0
7. Appendix N to subpart B of part 430 is revised to read as follows:

Appendix N to Subpart B of Part 430--Uniform Test Method for Measuring 
the Energy Consumption of Consumer Furnaces Other Than Boilers

0. Incorporation by Reference

    DOE incorporated by reference in Sec.  430.3, the entire standards 
for ASTM D2156R13 and IEC 62301. DOE also incorporated selected 
provisions of ASHRAE 103-1993.
    1. Scope. The scope of this appendix is as specified in section 2 
of ASHRAE 103-1993 as it pertains to furnaces other than low pressure 
steam or hot water boilers or to electric boilers. Low pressure steam 
or hot water boilers and electric boilers are addressed in appendix EE 
of this subpart.
    2. Definitions. Definitions include those specified in section 3 of 
ASHRAE 103-1993 and the following additional and modified definitions.
    Active mode means the condition in which the furnace is connected 
to the power source, and at least one of the burner, electric 
resistance elements, or any electrical auxiliaries such as blowers, are 
activated.
    Control means a device used to regulate the operation of a piece of 
equipment and the supply of fuel, electricity, air, or water.
    Draft inducer means a fan incorporated in the furnace that either 
draws or forces air into the combustion chamber.
    Gas valve means an automatic or semi-automatic device consisting 
essentially of a valve and operator that controls the gas supply to the 
burner(s) during normal operation of an appliance. The operator may be 
actuated by application of gas pressure on a flexible diaphragm, by 
electrical means, by mechanical means or by other means.
    Installation and operation (I&O) manual means instructions for 
installing, commissioning, and operating the furnace, which are 
supplied with the product when shipped by the manufacturer.
    Isolated combustion system means a system where a unit is installed 
within the structure, but isolated from the heated space. A portion of 
the jacket heat from the unit is lost, and air for ventilation, 
combustion and draft control comes from outside the heated space.
    Multi-position furnace means a furnace that can be installed in 
more than one airflow configuration (i.e., upflow or horizontal; 
downflow or horizontal; upflow or downflow; and upflow, or downflow, or 
horizontal).
    Off mode means a mode in which the furnace is connected to a mains 
power source and is not providing any active mode or standby mode 
function, and where the mode may persist for an indefinite time. The 
existence of an off switch in off position (a disconnected circuit) is 
included within the classification of off mode.
    Off switch means the switch on the furnace that, when activated, 
results in a measurable change in energy consumption between the 
standby and off modes.
    Oil control valve means an automatically or manually operated 
device consisting of an oil valve for controlling the fuel supply to a 
burner to regulate burner input.
    Standby mode means any mode in which the furnace is connected to a 
mains power source and offers one or more of the following space 
heating functions that may persist:
    (a) Activation of other modes (including activation or deactivation 
of active mode) by remote switch (including thermostat or remote 
control), internal or external sensors, and/or timer; and
    (b) Continuous functions, including information or status displays 
or sensor-based functions.
    Thermal stack damper means a type of stack damper that relies 
exclusively upon the changes in temperature in the stack gases to open 
or close the damper.
    3. Classifications. Classifications are as specified in section 4 
of ASHRAE 103-1993 for furnaces.
    4. Requirements. Requirements are as specified in section 5 of 
ASHRAE 103-1993 for furnaces.
    5. Instruments. Instruments must be as specified in section 6 of 
ASHRAE 103-1993.
    6. Apparatus. The apparatus used in conjunction with the furnace 
during the testing must be as specified in section 7 of ASHRAE 103-1993 
(except for the excluded sub-sections as enumerated at Sec.  
430.3(g)(15)); and as specified in sections 6.1 through 6.5 of this 
appendix.
    6.1 General.
    (a) Install the furnace in the test room in accordance with the I&O 
manual, as defined in section 2.6 of this appendix, except that if 
provisions within this appendix are specified, then the provisions 
herein drafted and prescribed by DOE govern. If the I&O manual and any 
additional provisions of this appendix are not sufficient for testing a 
furnace, the manufacturer must request a waiver from the test procedure 
pursuant to Sec.  430.27.
    (b) If the I&O manual indicates the unit should not be installed 
with a return duct, then the return (inlet) duct specified in section 
7.2.1 of ASHRAE 103-1993 is not required.

[[Page 15539]]

    (c) Test multi-position furnaces in the least efficient 
configuration. Testing of multi-position furnaces in other 
configurations is permitted if energy use or efficiency is represented 
pursuant to the requirements in 10 CFR part 429.
    (d) The apparatuses described in section 6 of this appendix are 
used in conjunction with the furnace during testing. Each piece of 
apparatus shall conform to material and construction specifications 
listed in this appendix and in ASHRAE 103-1993, and the reference 
standards cited in this appendix and in ASHRAE 103-1993.
    (e) Test rooms containing equipment must have suitable facilities 
for providing the utilities (including but not limited to environmental 
controls, applicable measurement equipment, and any other technology or 
tools) necessary for performance of the test and must be able to 
maintain conditions within the limits specified in section 6 of this 
appendix.
    6.2 Forced-air central furnaces (direct vent and direct exhaust).
    (a) Units not equipped with a draft hood or draft diverter must be 
provided with the minimum-length vent configuration recommended in the 
I&O manual or a 5-ft flue pipe if there is no recommendation provided 
in the I&O manual (see Figure 4 of ASHRAE 103-1993). For a direct 
exhaust system, insulate the minimum-length vent configuration or the 
5-ft flue pipe with insulation having an R-value not less than 7 and an 
outer layer of aluminum foil. For a direct vent system, see section 7.5 
of ASHRAE 103-1993 for insulation requirements.
    (b) For units with power burners, cover the flue collection box 
with insulation having an R-value of not less than 7 and an outer layer 
of aluminum foil before the cool-down and heat-up tests described in 
sections 9.5 and 9.6 of ASHRAE 103-1993, respectively. However, do not 
apply the insulation for the jacket loss test (if conducted) described 
in section 8.6 of ASHRAE 103-1993 or the steady-state test described in 
section 9.1 of ASHRAE 103-1993.
    (c) For power-vented units, insulate the shroud surrounding the 
blower impeller with insulation having an R-value of not less than 7 
and an outer layer of aluminum foil before the cool-down and heat-up 
tests described in sections 9.5 and 9.6, respectively, of ASHRAE 103-
1993. However, do not apply the insulation for the jacket loss test (if 
conducted) described in section 8.6 of ASHRAE 103-1993 or the steady-
state test described in section 9.1 of ASHRAE 103-1993. Do not insulate 
the blower motor or block the airflow openings that facilitate the 
cooling of the combustion blower motor or bearings.
    6.3 Downflow furnaces. Install an internal section of vent pipe the 
same size as the flue collar for connecting the flue collar to the top 
of the unit, if not supplied by the manufacturer. However, do not 
insulate the internal vent pipe during the jacket loss test (if 
conducted) described in section 8.6 of ASHRAE 103-1993 or the steady-
state test described in section 9.1 of ASHRAE 103-1993. 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 103-1993. 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 an R-value not less than 7 and 
an outer layer of aluminum foil. (See Figure 3-E of ASHRAE 103-1993.)
    6.4 Units with draft hoods or draft diverters. Install the stack 
damper in accordance with the I&O manual. Install 5 feet of stack above 
the damper.
    (a) For units with an integral draft diverter, cover the 5-ft stack 
with insulation having an R-value of not less than 7 and an outer layer 
of aluminum foil.
    (b) For units with draft hoods, insulate the flue pipe between the 
outlet of the furnace and the draft hood with insulation having an R-
value of not less than 7 and an outer layer of aluminum foil.
    (c) For units with integral draft diverters that are mounted in an 
exposed position (not inside the overall unit cabinet), cover the 
diverter boxes (excluding any openings through which draft relief air 
flows) before the beginning of any test (including jacket loss test) 
with insulation having an R-value of not less than 7 and an outer layer 
of aluminum foil.
    (d) For units equipped with integral draft diverters that are 
enclosed within the overall unit cabinet, insulate the draft diverter 
box with insulation as described in section 6.4.c before the cool-down 
and heat-up tests described in sections 9.5 and 9.6, respectively, of 
ASHRAE 103-1993. However, do not apply the insulation for the jacket 
loss test (if conducted) described in section 8.6 of ASHRAE 103-1993 or 
the steady-state test described in section 9.1 of ASHRAE 103-1993.
    6.5 Condensate collection. Attach condensate drain lines to the 
unit as specified in the I&O manual. Maintain a continuous downward 
slope of drain lines from the unit. Additional precautions (such as 
eliminating any line configuration or position that would otherwise 
restrict or block the flow of condensate or checking to ensure a proper 
connection with condensate drain spout that allows for unobstructed 
flow) must be taken to facilitate uninterrupted flow of condensate 
during the test. Collection containers must be glass or polished 
stainless steel to facilitate removal of interior deposits. The 
collection container must have a vent opening to the atmosphere.
    7. Testing conditions. The testing conditions must be as specified 
in section 8 of ASHRAE 103-1993 (except for the excluded sub-sections 
as enumerated at Sec.  430.3(g)(15)); and as specified in sections 7.1 
to 7.9 of this appendix, respectively.
    7.1 Fuel supply, gas. In conducting the tests specified herein, 
gases with characteristics as shown in Table 1 of ASHRAE 103-1993 shall 
be used. Maintain the gas supply, ahead of all controls for a furnace, 
at a test pressure between the normal and increased values shown in 
Table 1 of ASHRAE 103-1993. Maintain the regulator outlet pressure at a 
level approximating that recommended in the I&O manual, as defined in 
section 2.6 of this appendix, or, in the absence of such 
recommendation, to the nominal regulator settings used when the product 
is shipped by the manufacturer. Use a gas having a specific gravity as 
shown in Table 1 of ASHRAE 103-1993 and with a higher heating value 
within 5% of the higher heating value shown in Table 1 of 
ASHRAE 103-1993. Determine the actual higher heating value in Btu per 
standard cubic foot for the gas to be used in the test within an error 
no greater than 1%.
    7.2 Gas burner. Adjust the burners of gas-fired furnaces to their 
maximum Btu input ratings at the normal test pressure specified by 
section 7.1 of this appendix. Correct the burner input rate to reflect 
gas characteristics at a temperature of 60 [deg]F and atmospheric 
pressure of 30 in of Hg and adjust down to within 2 percent 
of the hourly Btu nameplate input rating specified by the manufacturer 
as measured during the steady-state performance test in section 8 of 
this appendix. Set the primary air shutters in accordance with the I&O 
manual to give a good flame at this condition. If, however, the setting 
results in the deposit of carbon on the burners during any test 
specified herein, the tester shall adjust the shutters and burners 
until no more carbon is

[[Page 15540]]

deposited and shall perform the tests again with the new settings (see 
Figure 9 of ASHRAE 103-1993). After the steady-state performance test 
has been started, do not make additional adjustments to the burners 
during the required series of performance tests specified in section 9 
of ASHRAE 103-1993. If a vent-limiting means is provided on a gas 
pressure regulator, keep it in place during all tests.
    7.3 Modulating gas burner adjustment at reduced input rate. For 
gas-fired furnaces equipped with modulating-type controls, adjust the 
controls to operate the unit at the nameplate minimum input rate. If 
the modulating control is of a non-automatic type, adjust the control 
to the setting recommended in the I&O manual. In the absence of such 
recommendation, the midpoint setting of the non-automatic control shall 
be used as the setting for determining the reduced fuel input rate. 
Start the furnace by turning the safety control valve to the ``ON'' 
position.
    7.4 Oil burner. Adjust the burners of oil-fired furnaces to give a 
CO2 reading specified in the I&O manual and an hourly Btu 
input during the steady-state performance test described in section 8 
of this appendix. Ensure the hourly BTU input is within 2% 
of the normal hourly Btu input rating as specified in the I&O manual. 
Smoke in the flue may not exceed a No. 1 smoke during the steady-state 
performance test as measured by the procedure in ASTM D2156R13). 
Maintain the average draft over the fire and in the flue during the 
steady-state performance test at the value specified in the I&O manual. 
Do not allow draft fluctuations exceeding 0.005 in. water. Do not make 
additional adjustments to the burner during the required series of 
performance tests. The instruments and measuring apparatus for this 
test are described in section 6 of this appendix and shown in Figure 8 
of ASHRAE 103-1993.
    7.5 Temperature Rise Targets. Adjust air throughputs to achieve a 
temperature rise that is the higher of a and b, below, unless c 
applies. A tolerance of 2 [deg]F is permitted.
    (a) 15 [deg]F less than the nameplate maximum temperature rise or
    (b) 15 [deg]F higher than the minimum temperature rise specified in 
the I&O manual.
    (c) A furnace with a non-adjustable air temperature rise range and 
an automatically controlled airflow that does not permit a temperature 
rise range of 30 [deg]F or more must be tested at the midpoint of the 
rise range.
    7.6 Temperature Rise Adjustments. Establish the temperature rise 
specified in section 7.5 of this appendix by adjusting the circulating 
airflow. This adjustment must be accomplished by symmetrically 
restricting the outlet air duct and varying blower speed selection to 
obtain the desired temperature rise and minimum external static 
pressure, as specified in Table 4 of ASHRAE 103-1993. If the required 
temperature rise cannot be obtained at the minimum specified external 
static pressure by adjusting blower speed selection and duct outlet 
restriction, then the following applies.
    (a) If the resultant temperature rise is less than the required 
temperature rise, vary the blower speed by gradually adjusting the 
blower voltage so as to maintain the minimum external static pressure 
listed in Table 4 of ASHRAE 103-1993. The airflow restrictions shall 
then remain unchanged. If static pressure must be varied to prevent 
unstable blower operation, then increase the static pressure until 
blower operation is stabilized, except that the static pressure must 
not exceed the maximum external static pressure as specified by the 
manufacturer in the I&O manual.
    (b) If the resultant temperature rise is greater than the required 
temperature rise, then the unit can be tested at a higher temperature 
rise value, but one not greater than nameplate maximum temperature 
rise. In order not to exceed the maximum temperature rise, the speed of 
a direct-driven blower may be increased by increasing the circulating 
air blower motor voltage.
    7.7 Measurement of jacket surface temperature. Divide the jacket of 
the furnace into 6-inch squares when practical, and otherwise into 36-
square-inch regions comprising 4-inch by 9-inch or 3-inch by 12-inch 
sections, and determine the surface temperature at the center of each 
square or section with a surface thermocouple. Record the surface 
temperature of the 36-square-inch areas in groups where the temperature 
differential of the 36-square-inch areas is less than 10 [deg]F for 
temperature up to 100 [deg]F above room temperature, and less than 20 
[deg]F for temperatures 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 103-1993).
    7.8 Installation of vent system. Keep the vent or air intake system 
supplied by the manufacturer in place during all tests. Test units 
intended for installation with a variety of vent pipe lengths with the 
minimum vent length as specified in the I&O manual, or a 5-ft. flue 
pipe if there are no recommendations in the I&O manual. Do not connect 
a furnace employing a direct vent system to a chimney or induced-draft 
source. Vent combustion products solely by using the venting 
incorporated in the furnace and the vent or air intake system supplied 
by the manufacturer. For units that are not designed to significantly 
preheat the incoming air, see section 7.4 of this appendix and Figure 
4a or 4b of ASHRAE 103-1993. For units that do significantly preheat 
the incoming air, see Figure 4c or 4d of ASHRAE 103-1993.
    7.9 Additional optional method of testing for determining DP and DF 
for furnaces. On units whose design is such that there is no measurable 
airflow through the combustion chamber and heat exchanger when the 
burner(s) is (are) off as determined by the optional test procedure in 
section 7.9.1 of this appendix, DF and DP may be 
set equal to 0.05.
    7.9.1 Optional test method for indicating the absence of flow 
through the heat exchanger. Manufacturers may use the following test 
protocol to determine whether air flows through the combustion chamber 
and heat exchanger when the burner(s) is (are) off. The minimum default 
draft factor may be used only for units determined pursuant to this 
protocol to have no airflow through the combustion chamber and heat 
exchanger.
    7.9.1.1 Test apparatus. Use a smoke stick that produces smoke that 
is easily visible and has a density less than or approximately equal to 
air. Use a smoke stick that produces smoke that is non-toxic to the 
test personnel and produces gas that is unreactive with the environment 
in the test chamber.
    7.9.1.2 Test conditions. Minimize all air currents and drafts in 
the test chamber, including turning off ventilation if the test chamber 
is mechanically ventilated. Wait at least two minutes following the 
termination of the furnace on-cycle before beginning the optional test 
method for indicating the absence of flow through the heat exchanger.
    7.9.1.3 Location of the test apparatus. After all air currents and 
drafts in the test chamber have been eliminated or minimized, position 
the

[[Page 15541]]

smoke stick based on the following equipment configuration:
    (a) For horizontal combustion air intakes, approximately 4 inches 
from the vertical plane at the termination of the intake vent and 4 
inches below the bottom edge of the combustion air intake; or
    (b) for vertical combustion air intakes, approximately 4 inches 
horizontal from vent perimeter at the termination of the intake vent 
and 4 inches down (parallel to the vertical axis of the vent).
    7.9.1.4 Duration of test. Establish the presence of smoke from the 
smoke stick and then monitor the direction of the smoke flow for no 
less than 30 seconds.
    7.9.1.5 Test results. During visual assessment, determine whether 
there is any draw of smoke into the combustion air intake vent.
    (a) If absolutely no smoke is drawn into the combustion air intake, 
the furnace meets the requirements to allow use of the minimum default 
draft factor pursuant to section 7.9 of this appendix.
    (b) If there is any smoke drawn into the intake, proceed with the 
methods of testing as prescribed in section 8.8 of ASHRAE 103-1993.
    8. Test procedure. Conduct testing and measurements as specified in 
section 9 of ASHRAE 103-1993 (except for the excluded sub-sections as 
enumerated at Sec.  430.3(g)(15)); and as specified in sections 8.1 
through 8.10 of this appendix. Section 8.4 of this appendix may be used 
in lieu of section 9.2 of ASHRAE 103-1993.
    8.1 Fuel input. For gas units, measure and record the steady-state 
gas input rate in Btu/hr, including pilot gas, corrected to standard 
conditions of 60 [deg]F and 30 in. Hg. Use measured values of gas 
temperature and pressure at the meter and barometric pressure to 
correct the metered gas flow rate to the above standard conditions. For 
oil units, measure and record the steady-state fuel input rate.
    8.2 Electrical input. During the steady-state test, perform a 
single measurement of all of the electrical power involved in burner 
operation (PE), including energizing the ignition system, controls, gas 
valve or oil control valve, and draft inducer, if applicable.
    During the steady-state test, perform a single measurement of the 
electrical power to the circulating air blower (BE).
    8.3 Input to interrupted ignition device. For burners equipped with 
an interrupted ignition device, record the nameplate electric power 
used by the ignition device, PEIG, or record that 
PEIG = 0.4 kW if no nameplate power input is provided. 
Record the nameplate ignition device on-time interval, tIG, 
or, if the nameplate does not provide the ignition device on-time 
interval, measure the on-time interval with a stopwatch at the 
beginning of the test, starting when the burner is turned on. Set 
tIG = 0 and PEIG = 0 if the device on-time 
interval is less than or equal to 5 seconds after the burner is on.
    8.4 Optional test procedures for condensing furnaces, measurement 
of condensate during the establishment of steady-state conditions. For 
units with step-modulating or two-stage controls, conduct the test at 
both the maximum and reduced inputs. In lieu of collecting the 
condensate immediately after the steady state conditions have been 
reached as required by section 9.2 of ASHRAE 103-1993, condensate may 
be collected during the establishment of steady state conditions as 
defined by section 9.1.2.1 of ASHRAE 103-1993. Perform condensate 
collection for at least 30 minutes. Measure condensate mass immediately 
at the end of the collection period to prevent evaporation loss from 
the sample. Record fuel input for the 30-minute condensate collection 
test period. Observe and record fuel higher heating value (HHV), 
temperature, and pressures necessary for determining fuel energy input 
(Qc,ss). Measure the fuel quantity and HHV with errors no greater than 
1%. The humidity for the room air shall at no time exceed 80%. 
Determine the mass of condensate for the establishment of steady state 
conditions (Mc,ss) in pounds by subtracting the tare container weight 
from the total container and condensate weight measured at the end of 
the 30-minute condensate collection test period.
    8.5 Cool-down test for gas- and oil-fueled gravity and forced-air 
central furnaces without stack dampers. Turn off the main burner after 
completing steady-state testing, and measure the flue gas temperature 
by means of the thermocouple grid described in section 7.6 of ASHRAE 
103-1993 at 1.5 minutes (TF,OFF(t3)) and 9 
minutes (TF,OFF(t4)) after shutting off the 
burner. When taking these temperature readings, the integral draft 
diverter must remain blocked and insulated, and the stack restriction 
must remain in place. On atmospheric systems with an integral draft 
diverter or draft hood and equipped with either an electromechanical 
inlet damper or an electromechanical flue damper that closes within 10 
seconds after the burner shuts off to restrict the flow through the 
heat exchanger in the off-cycle, bypass or adjust the control for the 
electromechanical damper so that the damper remains open during the 
cool-down test.
    For furnaces that employ post-purge, measure the length of the 
post-purge period with a stopwatch. Record the time from burner ``OFF'' 
to combustion blower ``OFF'' (electrically de-energized) as 
tP. If the measured tP is less than or equal to 
30 seconds, set tP at 0 and conduct the cool-down test as if 
there is no post-purge. If tP is prescribed by the I&O 
manual or measured to be greater than 180 seconds, stop the combustion 
blower at 180 seconds and use that value for tP. Measure the 
flue gas temperature by means of the thermocouple grid described in 
section 7.6 of ASHRAE 103-1993 at the end of the post-purge period, 
tP(TF,OFF (tP)), and at the time (1.5 
+ tP) minutes (TF,OFF(t3)) and (9.0 + 
tP) minutes (TF,OFF(t4)) after the 
main burner shuts off.
    8.6 Cool-down test for gas- and oil-fueled gravity and forced-air 
central furnaces without stack dampers and with adjustable fan control. 
For a furnace with adjustable fan control, measure the time delay 
between burner shutdown and blower shutdown, t\+\. This time delay, 
t\+\, will be 3.0 minutes for non-condensing furnaces or 1.5 minutes 
for condensing furnaces or until the supply air temperature drops to a 
value of 40 [deg]F above the inlet air temperature, whichever results 
in the longest fan on-time. For a furnace without adjustable fan 
control or with the type of adjustable fan control whose range of 
adjustment does not allow for the time delay, t\+\, specified above, 
bypass the fan control and manually control the fan to allow for the 
appropriate delay time as specified in section 9.5.1.2 of ASHRAE 103-
1993. For a furnace that employs a single motor to drive both the power 
burner and the indoor air circulating blower, the power burner and 
indoor air circulating blower must be stopped at the same time.
    8.7 [Reserved]
    8.8 Calculation options. The rate of the flue gas mass flow through 
the furnace and the factors DP, DF, and 
DS are calculated by the equations in sections 11.6.1, 
11.6.2, 11.6.3, 11.6.4, 11.7.1, and 11.7.2 of ASHRAE 103-1993. On units 
whose design is such that there is no measurable airflow through the 
combustion chamber and heat exchanger when the burner(s) is (are) off 
(as determined by the optional test procedure in section 7.9 of this 
appendix), DF and DP may be set equal to 0.05.
    8.9 Optional test procedures for condensing furnaces that have no 
off-period flue losses. For units that have applied the test method in 
section 7.9 of this appendix to determine that no

[[Page 15542]]

measurable airflow exists through the combustion chamber and heat 
exchanger during the burner off-period and having post-purge periods of 
less than 5 seconds, the cool-down and heat-up tests specified in 
sections 9.5 and 9.6 of ASHRAE 103-1993 may be omitted. In lieu of 
conducting the cool-down and heat-up tests, the tester may use the 
losses determined during the steady-state test described in section 9.1 
of ASHRAE 103-1993 when calculating heating seasonal efficiency, 
EffyHS.
    8.10 Measurement of electrical standby and off mode power.
    8.10.1 Standby power measurement. With all electrical auxiliaries 
of the furnace not activated, measure the standby power 
(PW,SB) in accordance with the procedures in IEC 62301, 
except that section 8.5, Room Ambient Temperature, of ASHRAE 103-1993 
and the voltage provision of section 8.2.1.4, Electrical Supply, of 
ASHRAE 103-1993 shall apply in lieu of the corresponding provisions of 
IEC 62301 at section 4.2, Test room, and the voltage specification of 
section 4.3, Power supply. Frequency shall be 60Hz. Clarifying further, 
IEC 62301 section 4.4, Power measurement instruments, and Section 5, 
Measurements, apply in lieu of ASHRAE 103-1993 section 6.10, Energy 
Flow Rate. Measure the wattage so that all possible standby mode 
wattage for the entire appliance is recorded, not just the standby mode 
wattage of a single auxiliary. Round the recorded standby power 
(PW,SB) to the second decimal place, except for loads 
greater than or equal to 10W, which must be recorded to at least three 
significant figures.
    8.10.2 Off mode power measurement. If the unit is equipped with an 
off switch or there is an expected difference between off mode power 
and standby mode power, measure off mode power 
(PW,OFF) in accordance with the standby power 
procedures in IEC 62301, except that section 8.5, Room Ambient 
Temperature, of ASHRAE 103-1993 and the voltage provision of section 
8.2.1.4, Electrical Supply, of ASHRAE 103-1993 shall apply in lieu of 
the corresponding provisions of IEC 62301 at section 4.2, Test room, 
and the voltage specification of section 4.3, Power supply. Frequency 
shall be 60Hz. Clarifying further, IEC 62301 section 4.4, Power 
measurement instruments, and section 5, Measurements, apply for this 
measurement in lieu of ASHRAE 103-1993 section 6.10, Energy Flow Rate. 
Measure the wattage so that all possible off mode wattage for the 
entire appliance is recorded, not just the off mode wattage of a single 
auxiliary. If there is no expected difference in off mode power and 
standby mode power, let PW,OFF = PW,SB, in which 
case no separate measurement of off mode power is necessary. Round the 
recorded off mode power (PW,OFF) to the second decimal 
place, except for loads greater than or equal to 10W, in which case 
round the recorded value to at least three significant figures.
    9. Nomenclature. Nomenclature includes the nomenclature specified 
in section 10 of ASHRAE 103-1993 and the following additional 
variables:

Effmotor = Efficiency of power burner motor
PEIG = Electrical power to the interrupted ignition device, 
kW
RT,a = RT,F if flue gas is measured
= RT,S if stack gas is measured
RT,F = Ratio of combustion air mass flow rate to 
stoichiometric air mass flow rate
RT,S = Ratio of the sum of combustion air and relief air 
mass flow rate to stoichiometric air mass flow rate
tIG = Electrical interrupted ignition device on-time, min.
Ta,SS,X = TF,SS,X if flue gas temperature is 
measured, [deg]F
= TS,SS,X if stack gas temperature is measured, [deg]F
yIG = Ratio of electrical interrupted ignition device on-
time to average burner on-time
yP = Ratio of power burner combustion blower on-time to 
average burner on-time
ESO = Average annual electric standby mode and off mode 
energy consumption, in kilowatt-hours
PW,OFF = Furnace off mode power, in watts
PW,SB = Furnace standby mode power, in watts

    10. Calculation of derived results from test measurements. Perform 
calculations as specified in section 11 of ASHRAE 103-1993 (except for 
the excluded sub-sections as enumerated at Sec.  430.3(g)(15)); and as 
specified in sections 10.1 through 10.11 and Figure 1 of this appendix.
    10.1 Annual fuel utilization efficiency. The annual fuel 
utilization efficiency (AFUE) is as defined in sections 11.2.12 (non-
condensing systems), 11.3.12 (condensing systems), 11.4.12 (non-
condensing modulating systems) and 11.5.12 (condensing modulating 
systems) of ASHRAE 103-1993, except for the definition for the term 
EffyHS in the defining equation for AFUE. EffyHS 
is defined as:

EffyHS = heating seasonal efficiency as defined in sections 
11.2.11 (non-condensing systems), 11.3.11 (condensing systems), 11.4.11 
(non-condensing modulating systems) and 11.5.11 (condensing modulating 
systems) of ASHRAE 103-1993, except that for condensing modulating 
systems sections 11.5.11.1 and 11.5.11.2 are replaced by sections 10.2 
and 10.3 of this appendix. EffyHS is based on the 
assumptions that all weatherized warm air furnaces are located outdoors 
and that non-weatherized warm air furnaces are installed as isolated 
combustion systems.

    10.2 Part-load efficiency at reduced fuel input rate. If the option 
in section 8.9 of this appendix is not employed, calculate the part-
load efficiency at the reduced fuel input rate, EffyU,R, for 
condensing furnaces equipped with either step-modulating or two-stage 
controls, expressed as a percent and defined as:


[[Page 15543]]


[GRAPHIC] [TIFF OMITTED] TR13MR23.001

Where:

LL,A = value as defined in section 11.2.7 of ASHRAE 103-
1993,
LG = value as defined in section 11.3.11.1 of ASHRAE 103-
1993, at reduced input rate,
LC = value as defined in section 11.3.11.2 of ASHRAE 103-
1993 at reduced input rate,
LJ = value as defined in section 11.4.8.1.1 of ASHRAE 
103-1993 at maximum input rate,
tON = value as defined in section 11.4.9.11 of ASHRAE 
103-1993,
QP = pilot fuel input rate determined in accordance with 
section 9.2 of ASHRAE 103-1993 in Btu/h,
QIN = value as defined in section 11.4.8.1.1 of ASHRAE 
103-1993,
tOFF = value as defined in section 11.4.9.12 of ASHRAE 
103-1993 at reduced input rate,
LS,ON = value as defined in section 11.4.10.5 of ASHRAE 
103-1993 at reduced input rate,
LS,OFF = value as defined in section 11.4.10.6 of ASHRAE 
103-1993 at reduced input rate,
LI,ON = value as defined in section 11.4.10.7 of ASHRAE 
103-1993 at reduced input rate,
LI,OFF = value as defined in section 11.4.10.8 of ASHRAE 
103-1993 at reduced input rate,
CJ = jacket loss factor and equal to:
= 0.0 for furnaces intended to be installed indoors
= 1.7 for furnaces intended to be installed as isolated combustion 
systems
= 3.3 for furnaces intended to be installed outdoors
LS,SS = value as defined in section 11.4.6 of ASHRAE 103-
1993 at reduced input rate,
CS = value as defined in section 11.3.10.1 of ASHRAE 103-
1993 at reduced input rate.

    10.3 Part-Load Efficiency at Maximum Fuel Input Rate. If the option 
in section 8.9 of this appendix is not employed, calculate the part-
load efficiency at maximum fuel input rate, EffyU,H, for 
condensing furnaces equipped with two-stage controls, expressed as a 
percent and defined as:
[GRAPHIC] [TIFF OMITTED] TR13MR23.002

Where:

LL,A = value as defined in section 11.2.7 of ASHRAE 103-
1993,
LG = value as defined in section 11.3.11.1 of ASHRAE 103-
1993 at maximum input rate,
LC = value as defined in section 11.3.11.2 of ASHRAE 103-
1993 at maximum input rate,
LJ = value as defined in section 11.4.8.1.1 of ASHRAE 
103-1993 at maximum input rate,
tON = value as defined in section 11.4.9.11 of ASHRAE 
103-1993,
QP = pilot fuel input rate determined in accordance with 
section 9.2 of ASHRAE 103-1993 in Btu/h,
QIN = value as defined in section 11.4.8.1.1 of ASHRAE 
103-1993,
tOFF = value as defined in section 11.4.9.12 of ASHRAE 
103-1993 at maximum input rate,
LS,ON = value as defined in section 11.4.10.5 of ASHRAE 
103-1993 at maximum input rate,
LS,OFF = value as defined in section 11.4.10.6 of ASHRAE 
103-1993 at maximum input rate,

[[Page 15544]]

LI,ON = value as defined in section 11.4.10.7 of ASHRAE 
103-1993 at maximum input rate,
LI,OFF = value as defined in section 11.4.10.8 of ASHRAE 
103-1993 at maximum input rate,
CJ = value as defined in section 10.2 of this appendix,
LS,SS = value as defined in section 11.4.6 of ASHRAE 103-
1993 at maximum input rate,
CS = value as defined in section 11.4.10.1 of ASHRAE 103-
1993 at maximum input rate.

    10.4 National average burner operating hours, average annual fuel 
energy consumption, and average annual auxiliary electrical energy 
consumption for gas or oil furnaces.
    10.4.1 National average number of burner operating hours. For 
furnaces equipped with single-stage controls, the national average 
number of burner operating hours is defined as:

BOHSS = 2,080 (0.77) (A) DHR - 2,080 (B)

Where:

2,080 = national average heating load hours
0.77 = adjustment factor to adjust the calculated design heating 
requirement and heating load hours to the actual heating load 
experienced by the heating system
A = 100,000/[341,200 (yP PE + yIG 
PEIG + y BE) + (QIN - QP) 
EffyHS], for forced draft unit, indoors
= 100,000/[341,200 (yP PE Effmotor + 
yIG PEIG + y BE) + (QIN - 
QP) EffyHS], for forced draft unit, isolated 
combustion system,
= 100,000/[341,200 (yP PE (1 - Effmotor) + 
yIG PEIG + y BE) + (QIN - 
QP) EffyHS], for induced draft unit, indoors, 
and
= 100,000/[341,200 (yIG PEIG + y BE) + 
(QIN - QP) EffyHS], for induced 
draft unit, isolated combustion system.
DHR = typical design heating requirements as listed in Table 8 (in 
kBtu/h) of ASHRAE 103-1993, using the proper value of 
QOUT defined in section 11.2.8.1 of ASHRAE 103-1993.
B = 2 QP (EffyHS) (A)/100,000

Where:

Effmotor = nameplate power burner motor efficiency 
provided by the manufacturer,
= 0.50, an assumed default power burner efficiency if not provided 
by the manufacturer.
100,000 = factor that accounts for percent and kBtu
yP = ratio of induced or forced draft blower on-time to 
average burner on-time, as follows:
1 for units without post-purge;
1 + (tP/3.87) for single stage furnaces with post purge; 
or
1 + (tP/10) for two-stage and step modulating furnaces 
with post purge.
PE = all electrical power related to burner operation at full load 
steady-state operation, including electrical ignition device if 
energized, controls, gas valve or oil control valve, and draft 
inducer, as determined in section 8.2 of this appendix.
yIG = ratio of burner interrupted ignition device on-time 
to average burner on-time, as follows:
0 for burners not equipped with interrupted ignition device;
(tIG/3.87) for single-stage furnaces; or
(tIG/10) for two-stage and step modulating furnaces;
PEIG = electrical input rate to the interrupted ignition 
device on burner (if employed), as defined in section 8.3 of this 
appendix
y = ratio of blower on-time to average burner on-time, as follows:
1 for furnaces without fan delay;
1 + (t\+\-t-)/3.87 for single-stage furnaces with fan 
delay; or
1 + (t\+\-t-)/10 for two-stage and step modulating 
furnaces with fan delay.
BE = circulating air fan electrical energy input rate at full-load 
steady-state operation as defined in section 8.2 of this appendix.
tP = post-purge time as defined in section 8.5 of this 
appendix
= 0 if tP is equal to or less than 30 seconds
tIG = on-time of the burner interrupted ignition device, 
as defined in section 8.3 of this appendix
QIN = as defined in section 11.2.8.1 of ASHRAE 103-1993
QP = as defined in section 11.2.11 of ASHRAE 103-1993
EffyHS = as defined in section 11.2.11 (non-condensing 
systems) or section 11.3.11.3 (condensing systems) of ASHRAE 103-
1993, percent, and calculated on the basis of:
isolated combustion system installation, for non-weatherized warm 
air furnaces; or outdoor installation, for furnaces that are 
weatherized.
2 = ratio of the average length of the heating season in hours to 
the average heating load hours
t\+\ = delay time between burner shutoff and the blower shutoff 
measured as defined in section 9.5.1.2 of ASHRAE 103-1993
t- = as defined in section 9.6.1 of ASHRAE 103-1993

    10.4.1.1 For furnaces equipped with two stage or step modulating 
controls the average annual energy used during the heating season, 
EM, is defined as:

EM = (QIN-QP) BOHSS + 
(8,760-4,600) QP

Where:

QIN = as defined in section 11.4.8.1.1 of ASHRAE 103-1993
QP = as defined in section 11.4.12 of ASHRAE 103-1993
BOHSS = as defined in section 10.4.1 of this appendix, in 
which the weighted EffyHS as defined in section 11.4.11.3 
or 11.5.11.3 of ASHRAE 103-1993 is used for calculating the values 
of A and B, the term DHR is based on the value of QOUT 
defined in section 11.4.8.1.1 or 11.5.8.1.1 of ASHRAE 103-1993, and 
the term (yPPE + yIGPEIG + yBE) in 
the factor A is increased by the factor R, which is defined as:
R = 2.3 for two stage controls
= 2.3 for step modulating controls when the ratio of minimum-to-
maximum output is greater than or equal to 0.5
= 3.0 for step modulating controls when the ratio of minimum-to-
maximum output is less than 0.5
A = 100,000/[341,200 (yP PE + yIG 
PEIG + y BE) R + (QIN-QP) 
EffyHS], for forced draft unit, indoors
= 100,000/[341,200 (yP PE Effmotor + 
yIG PEIG + y BE) R + (QIN-
QP) EffyHS], for forced draft unit, isolated 
combustion system,
= 100,000/[341,200 (yP PE (1-Effmotor) + 
yIG PEIG + y BE) R + (QIN-
QP) EffyHS], for induced draft unit, indoors, 
and
= 100,000/[341,200 (yIG PEIG + y BE) R + 
(QIN-QP) EffyHS], for induced draft 
unit, isolated combustion system.

Where:

Effmotor = nameplate power burner motor efficiency 
provided by the manufacturer,
= 0.50, an assumed default power burner efficiency if not provided 
by the manufacturer.
EffyHS = as defined in section 11.4.11.3 or 11.5.11.3 of 
ASHRAE 103-1993, and calculated on the basis of:
isolated combustion system installation, for non-weatherized warm 
air furnaces; or outdoor installation, for furnaces that are 
weatherized.
8,760 = total number of hours per year
4,600 = as defined in section 11.4.12 of ASHRAE 103-1993

    10.4.1.2 For furnaces equipped with two-stage or step-modulating 
controls, the national average number of burner operating hours at the 
reduced operating mode (BOHR) is defined as:

BOHR = XR EM/QIN,R

Where:

XR = as defined in section 11.4.8.7 of ASHRAE 103-1993
EM = as defined in section 10.4.1.1 of this appendix
QIN,R = as defined in section 11.4.8.1.2 of ASHRAE 103-
1993

    10.4.1.3 For furnaces equipped with two-stage controls, the 
national average number of burner operating hours at the maximum 
operating mode (BOHH) is defined as:

BOHH = XH EM/QIN

Where:

XH = as defined in section 11.4.8.6 of ASHRAE 103-1993
EM = as defined in section 10.4.1.1 of this appendix
QIN = as defined in section 11.4.8.1.1 of ASHRAE 103-1993

    10.4.1.4 For furnaces equipped with step-modulating controls, the 
national average number of burner operating hours at the modulating 
operating mode (BOHM) is defined as:

BOHM = XH EM/QIN,M

Where:

XH = as defined in section 11.4.8.6 of ASHRAE 103-1993
EM = as defined in section 10.4.1.1 of this appendix
QIN,M = QOUT,M/(EffySS,M/100)

[[Page 15545]]

QOUT,M = as defined in section 11.4.8.10 or 11.5.8.10 of 
ASHRAE 103-1993, as appropriate
EffySS,M = as defined in section 11.4.8.8 or 11.5.8.8 of 
ASHRAE 103-1993, as appropriate, in percent
100 = factor that accounts for percent


    10.4.2 Average annual fuel energy consumption for gas or oil fueled 
furnaces. For furnaces equipped with single-stage controls, the average 
annual fuel energy consumption (EF) is expressed in Btu per 
year and defined as:

EF = BOHSS (QIN-QP) + 8,760 
QP

Where:

BOHSS = as defined in section 10.4.1 of this appendix
QIN = as defined in section 11.2.8.1 of ASHRAE 103-1993
QP = as defined in section 11.2.11 of ASHRAE 103-1993
8,760 = as defined in section 10.4.1.1 of this appendix

    10.4.2.1 For furnaces equipped with either two-stage or step 
modulating controls, EF is defined as:

EF = EM + 4,600 QP


Where:
EM = as defined in section 10.4.1.1 of this appendix
4,600 = as defined in section 11.4.12 of ASHRAE 103-1993
QP = as defined in section 11.2.11 of ASHRAE 103-1993

    10.4.2.2 [Reserved]
    10.4.3 Average annual auxiliary electrical energy consumption for 
gas or oil-fueled furnaces. For furnaces equipped with single-stage 
controls, the average annual auxiliary electrical consumption 
(EAE) is expressed in kilowatt-hours and defined as:

EAE = BOHSS (yP PE + yIG 
PEIG + yBE) + ESO

Where:

BOHSS = as defined in section 10.4.1 of this appendix
yP = as defined in section 10.4.1 of this appendix
PE = as defined in section 10.4.1 of this appendix
yIG = as defined in section 10.4.1 of this appendix
PEIG = as defined in section 10.4.1 of this appendix
y = as defined in section 10.4.1 of this appendix
BE = as defined in section 10.4.1 of this appendix
ESO = as defined in section 10.11 of this appendix

    10.4.3.1 For furnaces equipped with two-stage controls, 
EAE is defined as:

EAE = BOHR (yP PER + 
yIG PEIG + yBER) + BOHH 
(yP PEH + yIG PEIG + y 
BEH) + ESO

Where:

BOHR = as defined in section 10.4.1.2 of this appendix
yP = as defined in section 10.4.1 of this appendix
PER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
yIG = as defined in section 10.4.1 of this appendix
PEIG = as defined in section 10.4.1 of this appendix
y = as defined in section 10.4.1 of this appendix
BER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
BOHH = as defined in section 10.4.1.3 of this appendix
PEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
BEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
ESO = as defined in section 10.11 of this appendix

    10.4.3.2 For furnaces equipped with step-modulating controls, 
EAE is defined as:

EAE = BOHR (yP PER + 
yIG PEIG + y BER) + BOHM 
(yP PEH + yIG PEIG + y 
BEH) + ESO

Where:

BOHR = as defined in section 10.4.1.2 of this appendix
yP = as defined in section 10.4.1 of this appendix
PER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
yIG = as defined in section 10.4.1 of this appendix
PEIG = as defined in section 10.4.1 of this appendix
y = as defined in section 10.4.1 of this appendix
BER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
BOHM = as defined in 10.4.1.4 of this appendix
PEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
BEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
ESO = as defined in section 10.11 of this appendix

    10.5 Average annual electric energy consumption for electric 
furnaces. For electric furnaces, the average annual electrical energy 
consumption (EE) is expressed in kilowatt-hours and defined 
as:

EE = 100 (2,080) (0.77) DHR/(3.412 AFUE) + ESO

Where:

100 = to express a percent as a decimal
2,080 = as defined in section 10.4.1 of this appendix
0.77 = as defined in section 10.4.1 of this appendix
DHR = as defined in section 10.4.1 of this appendix
3.412 = conversion factor from watt-hours to Btu
AFUE = as defined in section 11.1 of ASHRAE 103-1993, in percent, 
and calculated on the basis of:
isolated combustion system installation, for non-weatherized warm 
air furnaces; or
outdoor installation, for furnaces that are weatherized.
ESO = as defined in section 10.11 of this appendix.

    10.6 Energy factor.
    10.6.1 Energy factor for gas or oil furnaces. Calculate the energy 
factor, EF, for gas or oil furnaces defined as, in percent:

EF = (EF-4,600 (QP))(EffyHS)/
(EF + 3,412 (EAE))

Where:

EF = average annual fuel consumption as defined in 
section 10.4.2 of this appendix
4,600 = as defined in section 11.4.12 of ASHRAE 103-1993
QP = pilot fuel input rate determined in accordance with 
section 9.2 of ASHRAE 103-1993 in Btu/h
EffyHS = annual fuel utilization efficiency as defined in 
sections 11.2.11, 11.3.11, 11.4.11 or 11.5.11 of ASHRAE 103-1993, in 
percent, and calculated on the basis of:
isolated combustion system installation, for non-weatherized warm 
air furnaces; or
outdoor installation, for furnaces that are weatherized.
3,412 = conversion factor from kW to Btu/h
EAE = as defined in section 10.4.3 of this appendix

    10.6.2 Energy factor for electric furnaces. The energy factor, EF, 
for electric furnaces is defined as:

EF = AFUE

Where:

AFUE = annual fuel utilization efficiency as defined in section 
10.4.3 of this appendix, in percent

    10.7 Average annual energy consumption for furnaces located in a 
different geographic region of the United States and in buildings with 
different design heating requirements.
    10.7.1 Average annual fuel energy consumption for gas or oil-fueled 
furnaces located in a different geographic region of the United States 
and in buildings with different design heating requirements. For gas or 
oil-fueled furnaces, the average annual fuel energy consumption for a 
specific geographic region and a specific typical design heating 
requirement (EFR) is expressed in Btu per year and defined 
as:

EFR = (EF-8,760 QP) (HLH/2,080) + 
8,760 QP

Where:


[[Page 15546]]


EF = as defined in section 10.4.2 of this appendix
8,760 = as defined in section 10.4.1.1 of this appendix
QP = as defined in section 11.2.11 of ASHRAE 103-1993
HLH = heating load hours for a specific geographic region determined 
from the heating load hour map in Figure 1 of this appendix
2,080 = as defined in section 10.4.1 of this appendix

    10.7.2 Average annual auxiliary electrical energy consumption for 
gas or oil-fueled furnaces located in a different geographic region of 
the United States and in buildings with different design heating 
requirements. For gas or oil-fueled furnaces, the average annual 
auxiliary electrical energy consumption for a specific geographic 
region and a specific typical design heating requirement 
(EAER) is expressed in kilowatt-hours and defined as:

EAER = (EAE-ESO) (HLH/2080) + 
ESOR

Where:

EAE = as defined in section 10.4.3 of this appendix
ESO = as defined in section 10.11 of this appendix
HLH = as defined in section 10.7.1 of this appendix
2,080 = as defined in section 10.4.1 of this appendix
ESOR = as defined in section 10.7.3 of this appendix.

    10.7.3 Average annual electric energy consumption for electric 
furnaces located in a different geographic region of the United States 
and in buildings with different design heating requirements. For 
electric furnaces, the average annual electric energy consumption for a 
specific geographic region and a specific typical design heating 
requirement (EER) is expressed in kilowatt-hours and defined 
as:

EER = 100 (0.77) DHR HLH/(3.412 AFUE) + ESOR

Where:

100 = as defined in section 10.4.3 of this appendix
0.77 = as defined in section 10.4.1 of this appendix
DHR = as defined in section 10.4.1 of this appendix
HLH = as defined in section 10.7.1 of this appendix
3.412 = as defined in section 10.4.3 of this appendix
AFUE = as defined in section 10.4.3 of this appendix
ESOR = ESO as defined in section 10.11 of this 
appendix, except that in the equation for ESO, the term 
BOH is multiplied by the expression (HLH/2080) to get the 
appropriate regional accounting of standby mode and off mode loss.

    10.8 Annual energy consumption for mobile home furnaces
    10.8.1 National average number of burner operating hours for mobile 
home furnaces (BOHSS). BOHSS is the same as in 
section 10.4.1 of this appendix, except that the value of 
EffyHS in the calculation of the burner operating hours, 
BOHSS, is calculated on the basis of a direct vent unit with 
system number 9 or 10.
    10.8.2 Average annual fuel energy for mobile home furnaces 
(EF). EF is same as in section 10.4.2 of this 
appendix except that the burner operating hours, BOHSS, is 
calculated as specified in section 10.8.1 of this appendix.
    10.8.3 Average annual auxiliary electrical energy consumption for 
mobile home furnaces (EAE). EAE is the same as in 
section 10.4.3 of this appendix, except that the burner operating 
hours, BOHSS, is calculated as specified in section 10.8.1 
of this appendix.
    10.9 Calculation of sales weighted average annual energy 
consumption for mobile home furnaces. To reflect the distribution of 
mobile homes to geographical regions with average HLHMHF 
values different from 2,080, adjust the annual fossil fuel and 
auxiliary electrical energy consumption values for mobile home furnaces 
using the following adjustment calculations.
    10.9.1 For mobile home furnaces, the sales weighted average annual 
fossil fuel energy consumption is expressed in Btu per year and defined 
as:

EF,MHF = (EF-8,760 QP) 
HLHMHF/2,080 + 8,760 QP

Where:

EF = as defined in section 10.8.2 of this appendix
8,760 = as defined in section 10.4.1.1 of this appendix
QP = as defined in section 10.2 of this appendix
HLHMHF = 1880, sales weighted average heating load hours 
for mobile home furnaces
2,080 = as defined in section 10.4.1 of this appendix

    10.9.2 For mobile home furnaces, the sales-weighted-average annual 
auxiliary electrical energy consumption is expressed in kilowatt-hours 
and defined as:

EAE,MHF = EAE HLHMHF/2,080

Where:

EAE = as defined in section 10.8.3 of this appendix
HLHMHF = as defined in section 10.9.1 of this appendix
2,080 = as defined in section 10.4.1 of this appendix

    10.10 [Reserved]
    10.11 Average annual electrical standby mode and off mode energy 
consumption. Calculate the annual electrical standby mode and off mode 
energy consumption (ESO) in kilowatt-hours, defined as:

ESO = (PW,SB (4160-BOH) + 4600 PW,OFF) 
K

Where:

PW,SB = furnace standby mode power, in watts, as measured 
in section 8.10.1 of this appendix
4,160 = average heating season hours per year
BOH = total burner operating hours as calculated in section 10.4 of 
this appendix for gas or oil-fueled furnaces. Where for gas or oil-
fueled furnaces equipped with single-stage controls, BOH = 
BOHSS; for gas or oil-fueled furnaces equipped with two-
stage controls, BOH = (BOHR + BOHH); and for 
gas or oil-fueled furnaces equipped with step-modulating controls, 
BOH = (BOHR + BOHM). For electric furnaces, 
BOH = 100(2080)(0.77)DHR/(Ein 3.412(AFUE))
4,600 = as defined in section 11.4.12 of ASHRAE 103-1993
PW,OFF = furnace off mode power, in watts, as measured in 
section 8.10.2 of this appendix
K = 0.001 kWh/Wh, conversion factor from watt-hours to kilowatt-
hours

Where:

100 = to express a percent as a decimal
2,080 = as defined in section 10.4.1 of this appendix
0.77 = as defined in section 10.4.1 of this appendix
DHR = as defined in section 10.4.1 of this appendix
Ein = steady-state electric rated power, in kilowatts, 
from section 9.3 of ASHRAE 103-1993
3.412 = as defined in section 10.4.3 of this appendix
AFUE = as defined in section 11.1 of ASHRAE 103-1993 in percent

[[Page 15547]]

[GRAPHIC] [TIFF OMITTED] TR13MR23.003


0
8. Appendix EE to subpart B of part 430 is added to read as follows:

Appendix EE to Subpart B of Part 430--Uniform Test Method For Measuring 
the Energy Consumption of Consumer Boilers

    0. Incorporation by reference
    DOE incorporated by reference in Sec.  430.3, the entire standard 
for ASHRAE 103-2017, ASHRAE 41.6-2014, ASTM D2156-09 (R2018), and IEC 
62301. However, only enumerated provisions of ASHRAE 103-2017 are 
applicable to this appendix, as follows. In cases where there is a 
conflict, the language of the test procedure in this appendix takes 
precedence over the incorporated standards.
    0.1 ASHRAE 103-2017
    (a) Section 2 ``Scope'' as referenced in section 1 of this 
appendix;
    (b) Section 3 ``Definitions'' as referenced in section 2 of this 
appendix;
    (c) Section 4 ``Classifications'' as referenced in section 3 of 
this appendix;
    (d) Section 5 ``Requirements'' as referenced in section 4 of this 
appendix;
    (e) Section 6 ``Instruments'' as referenced in sections 5 and 8 of 
this appendix;
    (f) Section 7 ``Apparatus'' (except for sections 7.1 and 7.8) as 
referenced in sections 6, 7.7, and 8.6 of this appendix;
    (g) Section 8 ``Methods of Testing'' (except for sections 8.3.1.3, 
8.3.3.1, 8.4.1.1, 8.4.1.1.1, 8.4.1.2, 8.6.1.1, 8.7.2, and 8.8.3) as 
referenced in sections 7 and 8 of this appendix;
    (h) Section 9 ``Test Procedure'' (except for 9.1.2.2.1, 9.1.2.2.2, 
9.5.2.1, 9.7.4, and 9.10) as referenced in sections 7.3, 8, and 10.4 of 
this appendix;
    (i) Section 10 ``Nomenclature'' as referenced in section 9 of this 
appendix; and
    (j) Section 11 ``Calculations'' as referenced in sections 8.8 and 
10 of this appendix.
    0.2 [Reserved]
    1. Scope. The scope of this appendix is as specified in section 2 
of ASHRAE 103-2017 as it pertains to low pressure steam or hot water 
boiler and electric boilers.
    2. Definitions. Definitions include those specified in section 3 of 
ASHRAE 103-2017 and the following additional and modified definitions.
    Active mode means the condition in which the boiler is connected to 
the power source, and at least one of the burner, electric resistance 
elements, or any electrical auxiliaries such as blowers or pumps, are 
activated.
    Boiler pump means a pump installed on a boiler that maintains 
adequate water flow through the boiler heat exchanger and that is 
separate from the circulating water pump.
    Draft inducer means a fan incorporated in the boiler that either 
draws or forces air into the combustion chamber.
    Gas valve means an automatic or semi-automatic device consisting 
essentially of a valve and operator that controls the gas supply to the 
burner(s) during normal operation of an appliance. The operator may be 
actuated by application of gas pressure on a flexible diaphragm, by 
electrical means, by mechanical means or by other means.
    Installation and operation (I&O) manual means instructions for 
installing, commissioning, and operating the boiler, which are supplied 
with the product when shipped by the manufacturer.
    Off mode means a mode in which the boiler is connected to a mains 
power source and is not providing any active mode or standby mode 
function, and where the mode may persist for an indefinite time. The 
existence of an off switch in off position (a disconnected

[[Page 15548]]

circuit) is included within the classification of off mode.
    Off switch means the switch on the boiler that, when activated, 
results in a measurable change in energy consumption between the 
standby and off modes.
    Oil control valve means an automatically or manually operated 
device consisting of an oil valve for controlling the fuel supply to a 
burner to regulate burner input.
    Standard cubic foot of gas means the amount of gas that would 
occupy 1 cubic foot when at a temperature of 60 [deg]F and under a 
pressure equivalent to that of 30 inches Hg if saturated with water 
vapor.
    Standby mode means any mode in which the boiler is connected to a 
mains power source and offers one or more of the following space 
heating functions that may persist:
    (a) To facilitate the activation of other modes (including 
activation or deactivation of active mode) by remote switch (including 
thermostat or remote control), internal or external sensors, or timer;
    (b) Continuous functions, including information or status displays 
or sensor-based functions.
    Thermal stack damper means a type of stack damper that relies 
exclusively upon the changes in temperature in the stack gases to open 
or close the damper.
    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.
    5. Instruments. Instruments must be as specified in section 6 of 
ASHRAE 103-2017. In addition to the requirements in Section 6.3 of 
ASHRAE 103-2017, instruments for oil pressure shall be calibrated so 
that the error is no greater than 0.5 psi.
    6. Apparatus. The apparatus used in conjunction with the boiler 
during the testing must be as specified in section 7 of ASHRAE 103-2017 
except for sections 7.1 and 7.8; and as specified in sections 6.1 and 
6.2 of this appendix. In section 7.2.3.1 of ASHRAE 103-2017, substitute 
``in accordance with the I&O manual'' for ``in accordance with 
manufacturer instructions'' with regard to installing the stack damper.
    6.1 General.
    (a) Install the boiler in the test room in accordance with the I&O 
manual, as defined in section 2.5 of this appendix, except that if 
provisions within this appendix are specified, then the provisions 
herein drafted and prescribed by DOE govern. If the I&O manual and any 
additional provisions of this appendix are not sufficient for testing a 
boiler, the manufacturer must request a waiver from the test procedure 
pursuant to Sec.  430.27.
    (b) The apparatuses described in section 6 of this appendix are 
used in conjunction with the boiler during testing. Each piece of 
apparatus shall conform to material and construction specifications 
listed in this appendix and in ASHRAE 103-2017, and the reference 
standards cited in this appendix and in ASHRAE 103-2017.
    (c) Test rooms containing equipment must have suitable facilities 
for providing the utilities (including but not limited to environmental 
controls, sufficient fluid source(s), applicable measurement equipment, 
and any other technology or tools) necessary for performance of the 
test and must be able to maintain conditions within the limits 
specified in section 6 of this appendix.
    6.2 Condensate collection. Attach condensate drain lines to the 
unit as specified in the I&O manual. Maintain a continuous downward 
slope of drain lines from the unit. Additional precautions (such as 
eliminating any line configuration or position that would otherwise 
restrict or block the flow of condensate or checking to ensure a proper 
connection with condensate drain spout that allows for unobstructed 
flow) must be taken to facilitate uninterrupted flow of condensate 
during the test. Collection containers must be glass or polished 
stainless steel to facilitate removal of interior deposits. The 
collection container must have a vent opening to the atmosphere.
    7. Testing conditions. The testing conditions must be as specified 
in section 8 of ASHRAE 103-2017 (except for the excluded sub-sections 
as enumerated in section 0.1(g) of this appendix); and as specified in 
sections 7.1 to 7.8 of this appendix, respectively. For condensing 
furnaces and boilers, the relative humidity of the room air shall be 
measured in accordance with one of the methods described in ASHRAE 
41.6-2014 (see section 8.5 of ASHRAE 103-2017).
    7.1 Fuel supply, gas. In conducting the tests specified herein, 
gases with characteristics as shown in Table 1 of ASHRAE 103-2017 shall 
be used. Maintain the gas supply, ahead of all controls for a boiler, 
at a test pressure between the normal and increased values shown in 
Table 1 of ASHRAE 103-2017. Maintain the regulator outlet pressure at a 
level approximating that recommended in the I&O manual, as defined in 
section 2.5 of this appendix, or, in the absence of such 
recommendation, to the regulator settings used when the product is 
shipped by the manufacturer. Use a gas having a specific gravity of 
approximately that shown in Table 1 of ASHRAE 103-2017 and with a 
higher heating value within 5% of the higher heating value 
shown in Table 1 of ASHRAE 103-2017. Determine the actual higher 
heating value in Btu per standard cubic foot of gas (defined in section 
2 of this appendix) to be used in the test within an error no greater 
than 1%.
    7.2 Installation of piping. Install piping equipment in accordance 
with the I&O manual. In the absence of such specification, install 
piping in accordance with section 8.3.1.1 of ASHRAE 103-2017.
    7.3 Gas burner. Adjust the burners of gas-fired boilers to their 
maximum Btu input ratings at the normal test pressure specified by 
section 7.1 of this appendix. Correct the burner input rate to reflect 
gas characteristics at a temperature of 60 [deg]F and atmospheric 
pressure of 30 in of Hg and adjust to within 2 percent of 
the hourly Btu nameplate input rating specified by the manufacturer as 
measured at the maximum input rate during the steady-state performance 
test in section 8 of this appendix. Set the primary air shutters in 
accordance with the I&O manual to give a good flame at this condition. 
If, however, the setting results in the deposit of carbon on the 
burners during any test specified herein, the tester shall adjust the 
shutters and burners until no more carbon is deposited and shall 
perform the tests again with the new settings (see Figure 9 of ASHRAE 
103-2017). After the steady-state performance test has been started, do 
not make additional adjustments to the burners during the required 
series of performance tests specified in section 9 of ASHRAE 103-2017. 
If a vent-limiting means is provided on a gas pressure regulator, keep 
it in place during all tests.
    7.4 Modulating gas burner adjustment at reduced input rate. For 
gas-fired boilers equipped with modulating-type controls, adjust the 
controls to operate the unit at the nameplate minimum input rate. If 
the modulating control is of a non-automatic type, adjust the control 
to the setting recommended in the I&O manual. In the absence of such 
recommendation, the midpoint setting of the non-automatic control shall 
be used as the setting for determining the reduced fuel input rate. 
Start the boiler by turning the safety control valve to the ``ON'' 
position. Use a supply water temperature that will allow for continuous 
operation without shutoff by

[[Page 15549]]

the control. If necessary to achieve such continuous operation, supply 
water may be increased above 120 [deg]F; in such cases, gradually 
increase the supply water temperature to determine what minimum supply 
water temperature, with a 20 [deg]F temperature rise across the boiler, 
will be needed to adjust for the minimum input rate at the reduced 
input rate control setting. Monitor regulated gas pressure out of the 
modulating control valve (or entering the burner) to determine when no 
further reduction of gas pressure results. The flow rate of water 
through the boiler shall be adjusted to achieve a 20 [deg]F temperature 
rise.
    7.5 Oil burner. Adjust the burners of oil-fired boilers to give a 
CO2 reading specified in the I&O manual and an hourly Btu 
input within 2% of the hourly Btu nameplate input rating as 
specified in the I&O manual and as measured at maximum input rate 
during steady-state performance test as described in section 8 of this 
appendix. Smoke in the flue may not exceed a No. 1 smoke during the 
steady-state performance test as measured by the procedure in ASTM 
D2156-09 (R2018). Maintain the average draft over the fire and in the 
flue during the steady-state performance test at the value specified in 
the I&O manual. Do not allow draft fluctuations exceeding 0.005 in. 
water. Do not make additional adjustments to the burner during the 
required series of performance tests. The instruments and measuring 
apparatus for this test are described in section 6 of this appendix and 
shown in Figure 8 of ASHRAE 103-2017.
    7.6 Measurement of jacket surface temperature. Divide the jacket of 
the boiler into 6-inch squares when practical, and otherwise into 36-
square-inch regions comprising 4 inch by 9 inch or 3 inch by 12 inch 
sections, and determine the surface temperature at the center of each 
square or section with a surface thermocouple. Record the surface 
temperature of the 36-square-inch areas in groups where the temperature 
differential of the 36-square-inch areas is less than 10 [deg]F for 
temperature up to 100 [deg]F above room temperature, and less than 20 
[deg]F for temperatures more than 100 [deg]F above room temperature.
    7.7 Installation of vent system. Keep the vent or air intake system 
supplied by the manufacturer in place during all tests. Test units 
intended for installation with a variety of vent pipe lengths with the 
minimum vent length as specified in the I&O manual, or a 5-ft. flue 
pipe if there are no recommendations in the I&O manual. Do not connect 
a boiler employing a direct vent system to a chimney or induced-draft 
source. Vent combustion products solely by using the venting 
incorporated in the boiler and the vent or air intake system supplied 
by the manufacturer. For units that are not designed to significantly 
preheat the incoming air, see section 7.5 of this appendix and Figure 
4a or 4b in section 7 of ASHRAE 103-2017. For units that do 
significantly preheat the incoming air, see Figure 4c or 4d in section 
7 of ASHRAE 103-2017.
    7.8 Additional optional method of testing for determining 
DP and DF. On units whose design is such that 
there is no measurable airflow through the combustion chamber and heat 
exchanger when the burner(s) is (are) off as determined by the optional 
test procedure in section 7.8.1 of this appendix, DF and 
DP may be set equal to 0.05.
    7.8.1 Optional test method for indicating the absence of flow 
through the heat exchanger. Manufacturers may use the following test 
protocol to determine whether air flows through the combustion chamber 
and heat exchanger when the burner(s) is (are) off. The minimum default 
draft factor may be used only for units determined pursuant to this 
protocol to have no airflow through the combustion chamber and heat 
exchanger.
    7.8.1.1 Test apparatus. Use a smoke stick that produces smoke that 
is easily visible and has a density less than or approximately equal to 
air. Use a smoke stick that produces smoke that is non-toxic to the 
test personnel and produces gas that is unreactive with the environment 
in the test chamber.
    7.8.1.2 Test conditions. Minimize all air currents and drafts in 
the test chamber, including turning off ventilation if the test chamber 
is mechanically ventilated. Wait at least two minutes following the 
termination of the boiler on-cycle before beginning the optional test 
method for indicating the absence of flow through the heat exchanger.
    7.8.1.3 Location of the test apparatus. After all air currents and 
drafts in the test chamber have been eliminated or minimized, position 
the smoke stick based on the following equipment configuration:
    (a) For horizontal combustion air intakes, approximately 4 inches 
from the vertical plane at the termination of the intake vent and 4 
inches below the bottom edge of the combustion air intake; or
    (b) for vertical combustion air intakes, approximately 4 inches 
horizontal from vent perimeter at the termination of the intake vent 
and 4 inches down (parallel to the vertical axis of the vent). In the 
instance where the boiler combustion air intake is closer than 4 inches 
to the floor, place the smoke device directly on the floor without 
impeding the flow of smoke.
    7.8.1.4 Duration of test. Establish the presence of smoke from the 
smoke stick and then monitor the direction of the smoke flow for no 
less than 30 seconds.
    7.8.1.5 Test results. During visual assessment, determine whether 
there is any draw of smoke into the combustion air intake vent.
    If absolutely no smoke is drawn into the combustion air intake, the 
boiler meets the requirements to allow use of the minimum default draft 
factor provided in section 7.8 of this appendix.
    If there is any smoke drawn into the intake, proceed with the 
methods of testing as prescribed in section 8.8 of ASHRAE 103-2017.
    7.8.2 [Reserved]
    8. Test procedure. Conduct testing and measurements as specified in 
Section 9 of ASHRAE 103-2017 (except for the excluded sub-sections as 
enumerated in section 0.1(h) of this appendix); and as specified in 
sections 8.1 through 8.9 of this appendix. Section 8.4 of this appendix 
may be used in lieu of section 9.2 of ASHRAE 103-2017.
    8.1 Fuel input. For gas units, measure and record the steady-state 
gas input rate in Btu/h, including pilot gas, corrected to standard 
conditions of 60 [deg]F and 30 in. Hg. Use measured values of gas 
temperature and pressure at the meter and barometric pressure to 
correct the metered gas flow rate to the above standard conditions. For 
oil units, measure and record the steady-state fuel input rate. For 
maximum input rate, the measured burner input rate shall be within 
2% of the hourly Btu nameplate input rating 
(QIN) specified by the manufacturer. For modulating furnaces 
and boilers operating at reduced input rate, the measured reduced heat 
input rate (QIN,R) shall be recorded. At the discretion of 
the one testing, the hourly Btu nameplate minimum input rating 
specified by the manufacturer may be used in the calculations in place 
of QIN,R if the measured rate is within 2% of 
the nameplate rating.
    8.2 Electrical input. During the steady-state test, perform a 
single measurement of all of the electrical power involved in burner 
operation (PE), including energizing the ignition system, controls, gas 
valve or oil control valve, and draft inducer, if applicable. For 
boilers, the measurement of PE must include the boiler pump if so 
equipped. If the boiler pump does not operate during the measurement of 
PE, add the boiler pump nameplate power to the

[[Page 15550]]

measurement of PE. If the boiler pump nameplate power is not available, 
use 0.13 kW. For hot water boilers, use the circulating water pump 
nameplate power for BE, or if the pump nameplate power is not 
available, use 0.13 kW.
    8.3 Input to interrupted ignition device. For burners equipped with 
an interrupted ignition device, record the nameplate electric power 
used by the ignition device, PEIG, or record that 
PEIG = 0.4 kW if no nameplate power input is provided. 
Record the nameplate ignition device on-time interval, tIG, 
or, if the nameplate does not provide the ignition device on-time 
interval, measure the on-time interval with a stopwatch at the 
beginning of the test, starting when the burner is turned on. Set 
tIG = 0 and PEIG = 0 if the device on-time 
interval is less than or equal to 5 seconds after the burner is on.
    8.4 Cycling Test Requirements. For the measurement of condensate 
heat loss under cyclic conditions (for condensing boilers), section 9.8 
of ASHRAE 103-2017 shall apply. Cycle times calculated from Table 7 of 
ASHRAE 103-2017 shall be rounded to the nearest second.
    8.5 Optional test procedures for condensing boilers, measurement of 
condensate during the establishment of steady-state conditions. For 
units with step-modulating or two-stage controls, conduct the test at 
both the maximum and reduced inputs. In lieu of collecting the 
condensate immediately after the steady state conditions have been 
reached as required by section 9.2 of ASHRAE 103-2017, condensate may 
be collected during the establishment of steady state conditions as 
defined by section 9.1.2.1 of ASHRAE 103-2017. Perform condensate 
collection for at least 30 minutes. Measure condensate mass immediately 
at the end of the collection period to prevent evaporation loss from 
the sample. Record fuel input for the 30-minute condensate collection 
test period. Observe and record fuel higher heating value (HHV), 
temperature, and pressures necessary for determining fuel energy input 
(QC,SS). Measure the fuel quantity and HHV with errors no 
greater than 1%. The humidity for the room air shall at no time exceed 
80%. Determine the mass of condensate for the establishment of steady 
state conditions (MC,SS) in pounds by subtracting the tare 
container weight from the total container and condensate weight 
measured at the end of the 30-minute condensate collection test period.
    8.6 Cool-down test for gas- and oil-fueled boilers without stack 
dampers. After steady-state testing has been completed, turn the main 
burner(s) ``OFF'' and measure the flue gas temperature at 3.75 minutes 
(temperature designated as TF,OFF(t3)) and 22.5 
minutes (temperature designated as TF,OFF(t4)) 
after the burner shut-off using the thermocouple grid described in 
section 7.6 of ASHRAE 103-2017.
    a. During this off-period, for units that do not have pump delay 
after shut-off, do not allow any water to circulate through the hot 
water boilers.
    b. For units that have pump delay on shut-off, except those having 
pump controls sensing water temperature, the unit control must stop the 
pump. Measure and record the time between burner shut-off and pump 
shut-off (t\+\) to the nearest second.
    c. For units having pump delay controls that sense water 
temperature, operate the pump for 15 minutes and record t\+\ as 15 
minutes. While the pump is operating, maintain the inlet water 
temperature and flow rate at the same values as used during the steady-
state test, as specified in sections 9.1 and 8.4.2.3 of ASHRAE 103-
2017.
    d. For boilers that employ post-purge, measure the length of the 
post-purge period with a stopwatch. Record the time from burner ``OFF'' 
to combustion blower ``OFF'' (electrically de-energized) as 
tP. Measure the flue gas temperature by means of the 
thermocouple grid described in section 7.6 of ASHRAE 103-2017 at the 
end of the post-purge period tP 
(TF,OFF(tP)) and at (3.75 + tP) 
minutes (TF,OFF(t3)) and (22.5 + tP) 
minutes (TF,OFF(t4)) after the main burner shuts 
off. If tP is prescribed by the I&O manual or measured to be 
greater than 3 minutes, also measure the flue gas temperature at the 
midpoint of the post-purge period tP/2 
(TF,OFF(tP/2)). If the measured tP is 
less than or equal to 30 seconds, record tP as 0 and conduct 
the cool-down test as if there is no post-purge.
    8.7 [Reserved]
    8.8 Calculation options. The rate of the flue gas mass flow through 
the boiler and the factors DP, DF, and 
DS are calculated by the equations in sections 11.6.1, 
11.6.2, 11.6.3, 11.6.4, 11.7.1, and 11.7.2 of ASHRAE 103-2017. On units 
whose design is such that there is no measurable airflow through the 
combustion chamber and heat exchanger when the burner(s) is (are) off 
(as determined by the optional test procedure in section 7.8 of this 
appendix), DF and DP may be set equal to 0.05.
    8.9 Optional test procedures for condensing boilers that have no 
off-period flue losses. For units that have applied the test method in 
section 7.8 of this appendix to determine that no measurable airflow 
exists through the combustion chamber and heat exchanger during the 
burner off-period and having post-purge periods of less than 30 
seconds, the cool-down and heat-up tests specified in sections 9.5 and 
9.6 of ASHRAE 103-2017 may be omitted. In lieu of conducting the cool-
down and heat-up tests, the tester may use the losses determined during 
the steady-state test described in section 9.1 of ASHRAE 103-2017 when 
calculating heating seasonal efficiency, EffyHS.
    8.10 Measurement of electrical standby and off mode power.
    8.10.1 Standby power measurement. With all electrical auxiliaries 
of the boiler not activated, measure the standby power 
(PW,SB) in accordance with the procedures in IEC 62301, 
except that section 8.5, Room Ambient Temperature, of ASHRAE 103-2017 
and the voltage provision of section 8.2.1.4, Electrical Supply, of 
ASHRAE 103-2017 shall apply in lieu of the corresponding provisions of 
IEC 62301 at section 4.2, Test room, and the voltage specification of 
section 4.3, Power supply. Frequency shall be 60Hz. Clarifying further, 
IEC 62301 section 4.4, Power measurement instruments, and section 5, 
Measurements, apply in lieu of ASHRAE 103-2017 section 6.10, Energy 
Flow Rate. Measure the wattage so that all possible standby mode 
wattage for the entire appliance is recorded, not just the standby mode 
wattage of a single auxiliary. Round the recorded standby power 
(PW,SB) to the second decimal place, except for loads 
greater than or equal to 10W, which must be recorded to at least three 
significant figures.
    8.10.2 Off mode power measurement. If the unit is equipped with an 
off switch or there is an expected difference between off mode power 
and standby mode power, measure off mode power 
(PW,OFF) in accordance with the standby power 
procedures in IEC 62301, except that section 8.5, Room Ambient 
Temperature, of ASHRAE 103-2017 and the voltage provision of section 
8.2.1.4, Electrical Supply, of ASHRAE 103-2017 shall apply in lieu of 
the corresponding provisions of IEC 62301 at section 4.2, Test room, 
and the voltage specification of section 4.3, Power supply. Frequency 
shall be 60Hz. Clarifying further, IEC 62301 section 4.4, Power 
measurement instruments, and section 5, Measurements, apply for this 
measurement in lieu of SHRAE 103-2017 section 6.10, Energy Flow Rate. 
Measure the wattage so that all possible off mode wattage for the 
entire appliance is recorded, not just the off mode wattage of a single 
auxiliary. If there is no expected difference in off

[[Page 15551]]

mode power and standby mode power, let PW,OFF = 
PW,SB, in which case no separate measurement of off mode 
power is necessary. Round the recorded off mode power 
(PW,OFF) to the second decimal place, except for loads 
greater than or equal to 10W, in which case round the recorded value to 
at least three significant figures.
    9. Nomenclature. Nomenclature includes the nomenclature specified 
in Section 10 of ASHRAE 103-2017 and the following additional 
variables:

Effmotor = Efficiency of power burner motor
PEIG = Electrical power to the interrupted ignition device, 
kW
RT,a = RT,F if flue gas is measured
= RT,S if stack gas is measured
RT,F = Ratio of combustion air mass flow rate to 
stoichiometric air mass flow rate
RT,S = Ratio of the sum of combustion air and relief air 
mass flow rate to stoichiometric air mass flow rate
tIG = Electrical interrupted ignition device on-time, min.
Ta,SS,X = TF,SS,X if flue gas temperature is 
measured, [deg]F
= TS,SS,X if stack gas temperature is measured, [deg]F
yIG = Ratio of electrical interrupted ignition device on-
time to average burner on-time
yP = Ratio of power burner combustion blower on-time to 
average burner on-time
ESO = Average annual electric standby mode and off mode 
energy consumption, in kilowatt-hours
PW,OFF = Boiler off mode power, in watts
PW,SB = Boiler standby mode power, in watts

    10. Calculation of derived results from test measurements. Perform 
calculations as specified in section 11 of ASHRAE 103-2017, except for 
appendices B and C; and as specified in sections 10.1 through 10.7 and 
Figure 1 of this appendix.
    10.1 Annual fuel utilization efficiency. The annual fuel 
utilization efficiency (AFUE) is as defined in sections 11.2.12 (non-
condensing systems), 11.3.12 (condensing systems), 11.4.12 (non-
condensing modulating systems) and 11.5.12 (condensing modulating 
systems) of ASHRAE 103-2017, except for the following:
    10.1.1 Off-cycle Infiltration Heat Loss. The off-cycle infiltration 
heat loss (LI,OFF1) is as defined in sections 11.2.10.8 
(non-condensing systems), 11.3.10.8 (condensing systems), 11.4.10.8 
(non-condensing modulating systems) and 11.5.10.8 (condensing 
modulating systems) of ASHREAE 103-2017, with the following exception. 
For systems numbered 2, 3, and 4, with a post-purge time of 3 minutes 
or less, LI,OFF1 shall be determined as follows:
[GRAPHIC] [TIFF OMITTED] TR13MR23.004

    10.1.2 Determination of EffyHS in the Defining Equation 
for AFUE. EffyHS is defined as:

EffyHS = heating seasonal efficiency as defined in sections 
11.2.11 (non-condensing systems), 11.3.11 (condensing systems), 11.4.11 
(non-condensing modulating systems) and 11.5.11 (condensing modulating 
systems) of ASHRAE 103-2017, and is based on the assumptions that 
weatherized boilers are located outdoors and that non-weatherized 
boilers are installed indoors.

    10.1.3 Balance Point Temperature for Condensing Modulating Boilers. 
Calculate the balance point temperature (TC) for condensing, 
modulating boilers by using the following equation in place of that 
referenced by section 11.5.8.4 of ASHRAE 103-2017: TC =
[GRAPHIC] [TIFF OMITTED] TR13MR23.005

Where:

TSH = typical average outdoor temperature at which a 
boiler starts operating, 65 [deg]F
TOA,T = the typical outdoor design temperature, 5 [deg]F
[alpha] = oversize factor, as defined in 11.4.8.2
QIN = steady-state nameplate maximum fuel input rate
QIN,R = steady-state reduced input fuel input rate
LS,SSR = average sensible heat loss at steady state, 
reduced input operation
LS,SS = average sensible heat loss at steady state, 
maximum input operation

    10.2 National average burner operating hours, average annual fuel 
energy consumption, and average annual auxiliary electrical energy 
consumption for gas or oil boilers.
    10.2.1 National average number of burner operating hours.
    10.2.1.1 For boilers equipped with single-stage controls, the 
national average number of burner operating hours is defined as:

BOHSS = 2,080 (0.77) (A) [(QOUT/1000)/
(1+[alpha])]-2,080 (B)

Where:

2,080 = national average heating load hours
0.77 = adjustment factor to adjust the calculated design heating 
requirement and heating load hours to the actual heating load 
experienced by the heating system
A = 100,000/[341,200 (yP PE + yIG 
PEIG + y BE) + (QIN-QP) 
EffyHS], for forced draft unit, indoors
= 100,000/[341,200 (yP PE (1-Effmotor) + 
yIG PEIG + y BE) + (QIN-
QP) EffyHS], for induced draft unit, indoors, 
and
QOUT = value as defined in section 11.2.8.1 of ASHRAE 
103-2017.
[alpha] = value as defined in section 11.2.8.2 of ASHRAE 103-2017.

[[Page 15552]]

B = 2 QP (EffyHS) (A)/100,000

Where:

Effmotor = nameplate power burner motor efficiency 
provided by the manufacturer,
= 0.50, an assumed default power burner efficiency if not provided 
by the manufacturer.
100,000 = factor that accounts for percent and kBtu
yP = ratio of induced or forced draft blower on-time to 
average burner on-time, as follows:
1 for units without post-purge;
1 + (tP/tON) for single stage boilers with 
post purge; or
PE = all electrical power related to burner operation at full load 
steady-state operation, including electrical ignition device if 
energized, controls, gas valve or oil control valve, draft inducer, 
and boiler pump, as determined in section 8.2 of this appendix.
yIG = ratio of burner interrupted ignition device on-time 
to average burner on-time, as follows:
0 for burners not equipped with interrupted ignition device;
(tIG/tON) for single stage boilers
PEIG = electrical input rate to the interrupted ignition 
device on burner (if employed), as defined in section 8.3 of this 
appendix
y = ratio of pump on-time to average burner on-time, as follows:
1 for boilers without a pump delay;
1 + (t\+\/tON) for single-stage boilers with pump delay;
BE = circulating water pump electrical energy input rate at full-
load steady-state operation as defined in section 8.2 of this 
appendix.
tP = post-purge time as defined in section 8.5 of this 
appendix
= 0 if tP is equal to or less than 30 seconds
tIG = on-time of the burner interrupted ignition device, 
as defined in section 8.3 of this appendix
QIN = as defined in section 11.2.8.1 of ASHRAE 103-2017
QP = as defined in section 11.2.11 of ASHRAE 103-2017
EffyHS = as defined in section 11.2.11 (non-condensing 
systems) or section 11.3.11.3 (condensing systems) of ASHRAE 103-
2017, percent, and calculated on the basis of:
indoor installation, for non-weatherized boilers; or outdoor 
installation, for boilers that are weatherized.
2 = ratio of the average length of the heating season in hours to 
the average heating load hours
t\+\ = delay time between burner shutoff and the pump shutoff 
measured as defined in section 8.5 of this appendix.
tON = value as defined in Table 7 of ASHRAE 103-2017.

10.2.1.2 For boilers equipped with two-stage or step-modulating 
controls, the national average number of burner operating hours at the 
reduced operating mode (BOHR) is defined as:

BOHR = XR (2080)(0.77)[(QOUT/1,000)/
(1+[alpha])](AR)-2080(BR)

Where:

XR = as defined in section 11.4.8.6 of SHRAE 103-2017
2080 = as defined in section 10.2.1.1 of this appendix
0.77 = as defined in section 10.2.1.1 of this appendix
QOUT = as defined in section 11.4.8.1.1 or 11.5.8.1.1 of 
ASHRAE 103-2017
[alpha] = as defined in section 11.4.8.2 of ASHRAE 103-2017
AR = 100,000/[341,200(yP,RPER + 
yIG,RPEIG + yRBER) + 
(QIN,R-QP) EffyU,R] for forced 
draft unit, indoors; and
= 100,000/[341,200(yP,RPER (1-
Effmotor) + yIG,RPEIG + 
yRBER) + (QIN,R-QP) 
EffyU,R] for induced draft unit, indoors
BR = 2QP (EffyU,R) (AR)/
100,000
100,000 = conversion factor accounting for percent and 1,000 Btu/
kBtu
341,200 = conversion factor accounting for percent and 3412 Btu/h/kW
yP,R = 1 + (tp/tON,R) for two-stage 
and step modulating boilers with post purge
PER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
yIG,R = tIG/tON,R
PEIG = as defined in section 8.3 of this appendix
yR = 1 + (t\+\)/tON,R for two-stage and step 
modulating boilers with fan delay
BER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
QIN,R = as defined in section 11.4.8.1.2 of ASHRAE 103-
2017
QP = as defined in section 11.4.12 of ASHRAE 103-2017
EffyU,R = as defined in section 11.4.11.1 or 11.5.11.1 of 
ASHRAE 103-2017, and calculated on the basis of:
indoor installation, for non-weatherized boilers; or
outdoor installation, for boilers that are weatherized.
Effmotor = nameplate power burner motor efficiency 
provided by the manufacturer,
= 0.50, an assumed default power burner efficiency if not provided 
by the manufacturer.

    10.2.1.3 For boilers equipped with two-stage controls, the national 
average number of burner operating hours at the maximum operating mode 
(BOHH) is defined as:

BOHH = XH (2080)(0.77)[(QOUT/1,000)/
(1+[alpha])](AH)--2080(BH)

Where:

XH = as defined in section 11.4.8.5 of SHRAE 103-2017
2080 = as defined in section 10.2.1.1 of this appendix
0.77 = as defined in section 10.2.1.1 of this appendix
QOUT = as defined in section 11.4.8.1.1 or 11.5.8.1.1 
ofASHRAE 103-2017
[alpha] = as defined in section 11.4.8.2 of ASHRAE 103-2017
AH = 100,000/[341,200(yP,HPEH + 
yIG,HPEIG + yHBEH) + 
(QIN,H--QP) EffyU,H] for forced 
draft unit, indoors; and
= 100,000/[341,200(yP,HPEH (1--
Effmotor) + yIG,HPEIG + 
yHBEH) + (QIN,H--QP) 
EffyU,H] for induced draft unit, indoors
BH = 2QP (EffyU,H) (AH)/
100,000
100,000 = conversion factor accounting for percent and 1,000 Btu/
kBtu
341,200 = conversion factor accounting for percent and 3412 Btu/h/kW
yP,H = 1 + (tp/tON,H) for two-stage 
and step modulating boilers with post purge
PEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
yIG,H = tIG/tON,H
PEIG = as defined in section 8.3 of this appendix
yH = 1 + (t\+\)/tON,H for two-stage and step 
modulating boilers with fan delay
BEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
QIN,H = as defined in section 11.4.8.1.1 of ASHRAE 103-
2017
QP = as defined in section 11.4.12 of ASHRAE 103-2017
EffyU,H = as defined in section 11.4.11.2 or 11.5.11.2 of 
ASHRAE 103-2017, and calculated on the basis of:
indoor installation, for non-weatherized boilers; or
outdoor installation, for boilers that are weatherized.
Effmotor = nameplate power burner motor efficiency 
provided by the manufacturer,
= 0.50, an assumed default power burner efficiency if not provided 
by the manufacturer.

    10.2.1.4 For boilers equipped with step-modulating controls, the 
national average number of burner operating hours at the modulating 
operating mode (BOHM) is defined as:

BOHM = XH (2080)(0.77)[(QOUT/1,000)/
(1+[alpha])](AM)--2080(BM)

Where:

XH = as defined in section 11.4.8.5 of ASHRAE 103-2017
2080 = as defined in section 10.2.1.1 of this appendix
0.77 = as defined in section 10.2.1.1 of this appendix
QOUT = as defined in section 11.4.8.1.1 or 11.5.8.1.1 of 
ASHRAE 103-2017
[alpha] = as defined in section 11.4.8.2 of ASHRAE 103-2017
AM = 100,000/[341,200(yP,HPEH + 
yIG,HPEIG + yHBEH) + 
(QIN,M--QP) EffyU,M] for forced 
draft unit, indoors; and
= 100,000/[341,200(yP,HPEH (1--
Effmotor) + yIG,HPEIG + 
yHBEH) + (QIN,M--QP) 
EffyU,M] for induced draft unit, indoors
BM = 2QP (EffyU,M) (AM)/
100,000
100,000 = conversion factor accounting for percent and 1,000 Btu/
kBtu
341,200 = conversion factor accounting for percent and 3412 Btu/h/kW
yP,H = 1 + (tp/tON,H) for two-stage 
and step modulating boilers with post purge
PEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
yIG,H = tIG/tON,H
PEIG = as defined in section 8.3 of this appendix
yH = 1 + (t\+\)/tON,H for two-stage and step 
modulating boilers with fan delay

[[Page 15553]]

BEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
QIN,M = (100)(QOUT,M/EffySS,M)
QOUT,M = as defined in section 11.4.8.9 or 11.5.8.9 of 
ASHRAE 103-2017
EffySS,M = value as defined in section 11.4.8.7 or 
11.5.8.7 of ASHRAE 103-2017
QP = as defined in section 11.4.12 of ASHRAE 103-2017
EffyU,M = as defined in section 11.4.9.2.3 or 11.5.9.2.3 
of ASHRAE 103-2017, and calculated on the basis of:
indoor installation, for non-weatherized boilers; or
outdoor installation, for boilers that are weatherized.
Effmotor = nameplate power burner motor efficiency 
provided by the manufacturer,
= 0.50, an assumed default power burner efficiency if not provided 
by the manufacturer.

    10.2.2 Average annual fuel energy consumption for gas or oil fueled 
boilers.
    10.2.2.1 For boilers equipped with single-stage controls, the 
average annual fuel energy consumption (EF) is expressed in 
Btu per year and defined as:

EF = BOHSS (QIN - QP) + 
8,760 QP

Where:

BOHSS = as defined in section 10.2.1.1 of this appendix
QIN = as defined in section 11.2.8.1 of ASHRAE 103-2017
QP = as defined in section 11.2.11 of ASHRAE 103-2017
8,760 = total number of hours per year.

    10.2.2.2 For boilers equipped with either two-stage or step 
modulating controls, EF is defined as follows. For two-stage 
control:

    EF = (BOHH)(QIN) + 
(BOHR)(QIN,R) + [8760 - (BOHH + 
BOHR)]QP

    For step-modulating control:

EF = (BOHM)(QIN,M) + 
(BOHR)(QIN,R) + [8760 - (BOHH + 
BOHR)]QP
Where:

BOHH = as defined in section 10.2.1.3 of this appendix
BOHR = as defined in section 10.2.1.2 of this appendix
BOHM = as defined in section 10.2.1.4 of this appendix
QIN = as defined in section 11.2.8.1 of ASHRAE 103-2017
QIN,R = as defined in section 11.4.8.1.2 of ASHRAE 103-
2017
QIN,M = as defined in section 10.2.1.4 of this appendix
8,760 = total number of hours per year
QP = as defined in section 11.2.11 of ASHRAE 103-2017.

    10.2.3 Average annual auxiliary electrical energy consumption for 
gas or oil-fueled boilers.
    10.2.3.1 For boilers equipped with single-stage controls, the 
average annual auxiliary electrical consumption (EAE) is 
expressed in kilowatt-hours and defined as:

EAE = BOHSS (yP PE + yIG 
PEIG + yBE) + ESO

Where:

BOHSS = as defined in section 10.2.1.1 of this appendix
yP = as defined in section 10.2.1.1 of this appendix
PE = as defined in section 10.2.1.1 of this appendix
yIG = as defined in section 10.2.1.1 of this appendix
PEIG = as defined in section 10.2.1.1 of this appendix
y = as defined in section 10.2.1.1 of this appendix
BE = as defined in section 10.2.1.1 of this appendix
ESO = as defined in section 10.7 of this appendix.

    10.2.3.2 For boilers equipped with two-stage controls, 
EAE is defined as:

EAE = BOHR (yP,R PER + 
yIG,R PEIG + yRBER) + 
BOHH (yP,H PEH + yIG,H 
PEIG + yHBEH) + ESO
Where:

BOHR = as defined in section 10.2.1.2 of this appendix
yP,R = as defined in section 10.2.1.2 of this appendix
PER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
yIG,R = as defined in section 10.2.1.2 of this appendix
PEIG = as defined in section 10.2.1.1 of this appendix
yR = as defined in section 10.2.1.2 of this appendix
BER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
BOHH = as defined in section 10.2.1.3 of this appendix
PEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
yP,H = as defined in section 10.2.1.3 of this appendix
yIG,H = as defined in section 10.2.1.3 of this appendix
BEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
yH = as defined in section 10.2.1.3 of this appendix
ESO = as defined in section 10.7 of this appendix.

    10.2.3.3 For boilers equipped with step-modulating controls, 
EAE is defined as:

EAE = BOHR (yP,R PER + 
yIG,R PEIG + yR BER) + 
BOHM (yP,H PEH + yIG,H 
PEIG + yHBEH) + ESO

Where:

BOHR = as defined in section 10.2.1.2 of this appendix
yP,R = as defined in section 10.2.1.2 of this appendix
PER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
yIG,R = as defined in section 10.2.1.2 of this appendix
PEIG = as defined in section 10.2.1 of this appendix
yR = as defined in section 10.2.1.2 of this appendix
BER = as defined in section 8.2 of this appendix and 
measured at the reduced fuel input rate
BOHM = as defined in 10.2.1.4 of this appendix
yP,H = as defined in section 10.2.1.3 of this appendix
PEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
yIG,H = as defined in section 10.2.1.3 of this appendix
yH = as defined in section 10.2.1.3 of this appendix
BEH = as defined in section 8.2 of this appendix and 
measured at the maximum fuel input rate
ESO = as defined in section 10.7 of this appendix.

    10.3 Average annual electric energy consumption for electric 
boilers. For electric boilers, the average annual electrical energy 
consumption (EE) is expressed in kilowatt-hours and defined 
as:

EE = 100 (2,080) (0.77) [QOUT/(1+[alpha])]/(3412 
AFUE) + ESO

Where:

100 = to express a percent as a decimal
2,080 = as defined in section 10.2.1.1 of this appendix
0.77 = as defined in section 10.2.1.1 of this appendix
QOUT = as defined in section 11.2.8 of ASHRAE 103-2017
[alpha] = as defined in section 11.2.8.2 of ASHRAE 103-2017
3412 = conversion factor from kilowatt-hours to Btu
AFUE = as defined in section 11.1 of ASHRAE 103-2017, in percent, 
and calculated on the basis of:
indoor installation, for non-weatherized boilers; or
outdoor installation, for boilers that are weatherized.
ESO = as defined in section 10.7 of this appendix.

    10.4 Energy factor.
    10.4.1 Energy factor for gas or oil boilers. Calculate the energy 
factor, EF, for gas or oil boilers defined as, in percent:

EF = (EF - 4,600 (QP))(EffyHS)/
(EF + 3,412 (EAE))

Where:

EF = average annual fuel consumption as defined in 
section 10.2.2 of this appendix
4,600 = as defined in section 11.4.12 of ASHRAE 103-2017
QP = pilot fuel input rate determined in accordance with 
section 9.2 of ASHRAE 103-2017 in Btu/h

[[Page 15554]]

EffyHS = annual fuel utilization efficiency as defined in 
sections 11.2.11, 11.3.11, 11.4.11 or 11.5.11 of ASHRAE 103-2017, in 
percent, and calculated on the basis of:
indoor installation, for non-weatherized boilers; or
outdoor installation, for boilers that are weatherized.
3,412 = conversion factor from kW to Btu/h
EAE = as defined in section 10.2.3 of this appendix.

10.4.2 Energy factor for electric boilers. The energy factor, EF, for 
electric boilers is defined as:

EF = AFUE

Where:

AFUE = annual fuel utilization efficiency as defined in section 10.3 
of this appendix, in percent.

    10.5 Average annual energy consumption for boilers located in a 
different geographic region of the United States and in buildings with 
different design heating requirements.
    10.5.1 Average annual fuel energy consumption for gas or oil-fueled 
boilers located in a different geographic region of the United States 
and in buildings with different design heating requirements. For gas or 
oil-fueled boilers, the average annual fuel energy consumption for a 
specific geographic region and a specific typical design heating 
requirement (EFR) is expressed in Btu per year and defined 
as:

EFR = (EF - 8,760 QP) (HLH/2,080) + 
8,760 QP

Where:

EF = as defined in section 10.2.2 of this appendix
8,760 = as defined in section 10.2.2 of this appendix
QP = as defined in section 11.2.11 of ASHRAE 103-2017
HLH = heating load hours for a specific geographic region determined 
from the heating load hour map in Figure 1 of this appendix
2,080 = as defined in section 10.2.1.1 of this appendix.

    10.5.2 Average annual auxiliary electrical energy consumption for 
gas or oil-fueled boilers located in a different geographic region of 
the United States and in buildings with different design heating 
requirements. For gas or oil-fueled boilers, the average annual 
auxiliary electrical energy consumption for a specific geographic 
region and a specific typical design heating requirement 
(EAER) is expressed in kilowatt-hours and defined as:

EAER = (EAE-ESO) (HLH/2080) + 
ESOR

Where:

EAE = as defined in section 10.2.3 of this appendix
ESO = as defined in section 10.7 of this appendix
HLH = as defined in section 10.5.1 of this appendix
2,080 = as defined in section 10.2.1.1 of this appendix
ESOR = as defined in section 10.5.3 of this appendix.

    10.5.3 Average annual electric energy consumption for electric 
boilers located in a different geographic region of the United States 
and in buildings with different design heating requirements. For 
electric boilers, the average annual electric energy consumption for a 
specific geographic region and a specific typical design heating 
requirement (EER) is expressed in kilowatt-hours and defined 
as:

EER = 100 (0.77) [QOUT/(1+[alpha])] HLH/(3.412 
AFUE) + ESOR

Where:

100 = as defined in section 10.2.3 of this appendix
0.77 = as defined in section 10.2.1.1 of this appendix
QOUT = as defined in section 11.2.8.1 of ASHRAE 103-2017
[alpha] = as defined in section 11.2.8.2 of ASHRAE 103-2017
HLH = as defined in section 10.5.1 of this appendix
3.412 = as defined in section 10.2.3 of this appendix
AFUE = as defined in section 10.2.3 of this appendix
ESOR = ESO as defined in section 10.7 of this 
appendix, except that in the equation for ESO, the term 
BOH is multiplied by the expression (HLH/2080) to get the 
appropriate regional accounting of standby mode and off mode loss.

    10.6 [Reserved]
    10.7 Average annual electrical standby mode and off mode energy 
consumption. Calculate the annual electrical standby mode and off mode 
energy consumption (ESO) in kilowatt-hours, defined as:

ESO = (PW,SB (4160-BOH) + 4600 PW,OFF) 
K

Where:

PW,SB = boiler standby mode power, in watts, as measured 
in section 8.9.1 of this appendix
4,160 = average heating season hours per year
BOH = total burner operating hours as calculated in section 10.2 of 
this appendix for gas or oil-fueled boilers. Where for gas or oil-
fueled boilers equipped with single-stage controls, BOH = 
BOHSS; for gas or oil-fueled boilers equipped with two-
stage controls, BOH = (BOHR + BOHH); and for 
gas or oil-fueled boilers equipped with step-modulating controls, 
BOH = (BOHR + BOHM). For electric boilers, BOH 
= 100(2080)(0.77)[QOUT/(1+[alpha])]/(Ein 
3412(AFUE))
4,600 = as defined in section 11.4.12 of ASHRAE 103-2017
PW,OFF = boiler off mode power, in watts, as measured in 
section 8.9.2 of this appendix
K = 0.001 kWh/Wh, conversion factor from watt-hours to kilowatt-
hours

Where:

100 = to express a percent as a decimal
2,080 = as defined in section 10.2.1.1 of this appendix
0.77 = as defined in section 10.2.1.1 of this appendix
QOUT = as defined in section 11.2.8 of ASHRAE 103-2017
[alpha] = as defined in section 11.2.8.2 of ASHRAE 103-2017
Ein = steady-state electric rated power, in kilowatts, 
from section 9.3 of ASHRAE 103-2017
3412 = as defined in section 10.3 of this appendix
AFUE = as defined in section 11.1 of ASHRAE 103-2017 in percent.
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