[Federal Register Volume 81, Number 89 (Monday, May 9, 2016)]
[Proposed Rules]
[Pages 28588-28655]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-09539]



[[Page 28587]]

Vol. 81

Monday,

No. 89

May 9, 2016

Part III





Department of Energy





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10 CFR Parts 429, 430, and 431





 Energy Conservation Program for Certain Commercial and Industrial 
Equipment: Test Procedure for Commercial Water Heating Equipment; 
Proposed Rule

  Federal Register / Vol. 81 , No. 89 / Monday, May 9, 2016 / Proposed 
Rules  

[[Page 28588]]


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DEPARTMENT OF ENERGY

10 CFR Parts 429, 430, and 431

[Docket No. EERE-2014-BT-TP-0008]
RIN 1904-AD18


Energy Conservation Program for Certain Commercial and Industrial 
Equipment: Test Procedure for Commercial Water Heating Equipment

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

ACTION: Notice of proposed rulemaking (NOPR) and announcement of public 
meeting.

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SUMMARY: The U.S. Department of Energy (DOE) proposes to revise its 
test procedures for commercial water heaters, unfired hot water storage 
tanks, and hot water supply boilers (henceforth, ``commercial water 
heating (CWH) equipment'') established under the Energy Policy and 
Conservation Act of 1975 (EPCA), as amended. In this NOPR, DOE proposes 
several changes, including: Updating references of industry test 
standards to incorporate by reference the most recent versions of the 
industry standards; proposing modifications to the existing test 
methods for certain classes of CWH equipment; developing new test 
procedures for determining the efficiency of unfired hot water storage 
tanks, commercial heat pump water heaters, and flow-activated 
instantaneous water heaters; proposing clarifications on test set-up 
and settings for various classes of CWH equipment; revising the 
certification requirements for CWH equipment; and proposing associated 
implementing regulations including definitions. DOE announces a public 
meeting to receive comment on these proposed test procedure amendments, 
and it also welcomes written comments and data from the public on all 
aspects of this proposal.

DATES: 
    Meeting: DOE will hold a public meeting on June 6, 2016, from 9:30 
a.m. to 12:00 p.m., in Washington, DC. The meeting will also be 
broadcast as a webinar. See section V, ``Public Participation,'' for 
webinar registration information, participant instructions, and 
information about the capabilities available to webinar participants.
    Comments: DOE will accept comments, data, and information regarding 
this NOPR before and after the public meeting, but no later than July 
8, 2016. See section V, ``Public Participation,'' for details.

ADDRESSES: The public meeting will be held at the U.S. Department of 
Energy, Forrestal Building, Room 8E-089, 1000 Independence Avenue SW., 
Washington, DC 20585. To attend, please notify Ms. Brenda Edwards at 
(202) 586-2945. Further attendance instructions can be found in section 
V, ``Public Participation.''
    Instructions: All comments submitted must identify the NOPR for 
Test Procedures for Commercial Water Heating Equipment, and provide 
docket number EERE-2014-BT-TP-0008 and/or regulatory identification 
number (RIN) 1904-AD18. Interested persons are encouraged to submit 
comments using the Federal eRulemaking Portal at www.regulations.gov. 
Follow the instructions for submitting comments. Alternatively, 
interested persons may submit comments by any of the following methods:
     Email: CommWaterHeatingEquip [email protected]. 
Include the docket number and/or RIN in the subject line of the 
message. Submit electronic comments in WordPerfect, Microsoft Word, 
PDF, or ASCII file format, and avoid the use of special characters or 
any form of encryption.
     Postal Mail: Ms. Brenda Edwards, U.S. Department of 
Energy, Building Technologies Office, Mailstop EE-5B, 1000 Independence 
Avenue SW., Washington, DC 20585-0121. If possible, please submit all 
items on a compact disc (CD), in which case it is not necessary to 
include printed copies.
     Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department 
of Energy, Building Technologies Office, 950 L'Enfant Plaza SW., Suite 
600, Washington, DC 20024. Telephone: (202) 586-2945. If possible, 
please submit all items on a CD, in which case it is not necessary to 
include printed copies.
    DOE will not accept telefacsimilies (faxes). For detailed 
instructions on submitting comments and additional information on the 
rulemaking process, see section V of this document (Public 
Participation).
    Docket: The docket is available for review at www.regulations.gov, 
including Federal Register notices, public meeting attendee lists and 
transcripts, comments, and other supporting documents/materials. All 
documents in the docket are listed in the www.regulations.gov index. 
However, not all documents listed in the index may be publicly 
available, such as information that is exempt from public disclosure.
    A link to the docket Web page can be found at: http://www.regulations.gov/#!docketDetail;D=EERE-2014-BT-TP-0008. This Web 
page contains a link to the docket for this rulemaking on the 
www.regulations.gov site. The www.regulations.gov Web page contains 
simple instructions on how to access all documents, including public 
comments, in the docket. See section V, ``Public Participation,'' for 
further information on how to submit comments through 
www.regulations.gov.
    For further information on how to submit a comment, review other 
public comments and the docket, or participate in the public meeting, 
contact Ms. Brenda Edwards at (202) 586-2945 or by email: 
[email protected].

FOR FURTHER INFORMATION CONTACT:
Ms. Ashley Armstrong, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, EE-5B, 
1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone: 
(202) 586-6590. Email: [email protected].
Mr. Eric Stas, U.S. Department of Energy, Office of the General 
Counsel, GC-33, 1000 Independence Avenue SW., Washington, DC 20585-
0121. Telephone: (202) 586-9507. Email: [email protected].

    For more information on how to submit a comment, or review other 
public comments and the docket, contact Ms. Brenda Edwards, U.S. 
Department of Energy, Office of Energy Efficiency and Renewable Energy, 
Building Technologies Office, Mailstop EE-5B, 1000 Independence Avenue 
SW., Washington, DC 20585-0121. Telephone: (202) 586-2945. Email: 
[email protected].

SUPPLEMENTARY INFORMATION: DOE intends to incorporate by reference the 
following industry standards into part 431:
    (1) Gas Appliance Manufacturers Association (GAMA) Standard IWH-TS-
1, March 2003 edition, ``Method to Determine Performance of Indirect-
Fired Water Heaters,'' sections 4, 5, 6.0, and 6.1;
    (2) American National Standards Institute (ANSI) Standard Z21.10.3-
2015/Canadian Standards Association (CSA) Standard 4.3-2015, ``Gas-
fired Water Heaters, Volume III, Storage Water Heaters with Input 
Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous,'' 
annex E.1;
    (3) ANSI/American Society of Heating Refrigeration and Air-
Conditioning Engineers (ASHRAE) Standard 118.1-2012, ``Method of 
Testing for Rating Commercial Gas, Electric, and Oil Service Water-
Heating Equipment'';
    (4) ASTM International (ASTM) C177-13, ``Standard Test Method for

[[Page 28589]]

Steady-State Heat Flux Measurements and Thermal Transmission Properties 
by Means of the Guarded-Hot-Plate Apparatus'';
    (5) ASTM C518-10, ``Standard Test Method for Steady-State Thermal 
Transmission Properties by Means of the Heat Flow Meter Apparatus;'' 
and
    (6) ASTM D2156-09, ``Standard Test Method for Smoke Density in Flue 
Gases from Burning Distillate Fuels.''
    Copies of GAMA IWH-TS-1, March 2003 edition, can be obtained from 
the Air-conditioning, Heating, and Refrigeration Institute (AHRI), 2111 
Wilson Blvd., Suite 500, Arlington, VA 22201, (703) 524-8800, or by 
going to http://www.ahrinet.org/App_Content/ahri/files/standards%20pdfs/Indirect-Fired%20Water%20Heater%20Testing%20Standard03.pdf.
    Copies of ANSI Z21.10.3-2015/CSA 4.3-2015 and ANSI/ASHRAE 118.1-
2012 can be obtained from the American National Standards Institute, 25 
W. 43rd Street, 4th Floor, New York, NY 10036, (212) 642-4800, or by 
going to http://webstore.ansi.org/.
    Copies of ASTM C177-13, ASTM C518-10, and ASTM D2156-09 can be 
obtained from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, 
West Conshohocken, PA 19428-2959, (610) 832-9585, or by going to http://www.astm.org/Standard/index.html.
    See IV.M. for a further discussion of these standards.

Table of Contents

I. Authority and Background
II. Synopsis of the Notice of Proposed Rulemaking
III. Discussion
    A. Updated Industry Test Methods
    1. ANSI Z21.10.3 Testing Standard
    2. ASTM Standard Test Method D2156
    3. ASTM Test Standards C177-13 and C518-10
    B. Test Method Repeatability and Ambient Test Conditions
    C. Test Method for Unfired Hot Water Storage Tanks
    D. Procedure for Setting the Tank Thermostat for Storage and 
Storage-Type Instantaneous Water Heaters
    E. Clarifications to the Thermal Efficiency and Standby Loss 
Test Procedures
    F. Definitions for Certain Consumer Water Heaters and Commercial 
Water Heating Equipment
    1. Consumer Water Heaters
    2. Commercial Water Heating Equipment
    3. Residential-Duty Commercial Water Heaters
    4. Storage-Type Instantaneous Water Heaters
    G. Standby Loss Test for Flow-Activated Instantaneous Water 
Heaters
    H. Test Set Up for Commercial Instantaneous Water Heaters and 
Hot Water Supply Boilers
    I. Changes to the Standby Loss Test for Instantaneous Water 
Heaters and Hot Water Supply Boilers Other Than Flow-Activated 
Instantaneous Water Heaters
    J. Test Procedure for Rating Commercial Heat Pump Water Heaters
    K. Fuel Input Rate
    L. Default Values for Certain Test Parameters for Commercial 
Water Heating Equipment
    M. Certification Requirements
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Orders 12866
    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 the Treasury and General Government 
Appropriations Act, 2001
    K. Review Under Executive Order 13211
    L. Review Under Section 32 of the Federal Energy Administration 
Act of 1974
    M. Description of Materials Incorporated by Reference
V. Public Participation
    A. Attendance at the Public Meeting
    B. Procedure for Submitting Requests To Speak and Prepared 
General Statements for Distribution
    C. Conduct of the Public Meeting
    D. Submission of Comments
    E. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary

I. Authority and Background

    Title III, Part C \1\ of the Energy Policy and Conservation Act of 
1975 (EPCA or the Act), Public Law 94-163 (42 U.S.C. 6311-6317, as 
codified), added by Public Law 95-619, Title IV, section 441(a), sets 
forth a variety of provisions designed to improve energy efficiency.\2\ 
It established the ``Energy Conservation Program for Certain Industrial 
Equipment,'' a program covering certain commercial and industrial 
equipment (hereafter referred to as ``covered equipment''), which 
includes the commercial water heating (CWH) equipment that is the 
subject of this rulemaking. (42 U.S.C. 6311(1)(K)) Title III, Part B 
\3\ of EPCA (42 U.S.C. 6291-6309, as codified) sets forth a variety of 
provisions designed to improve energy efficiency and established the 
Energy Conservation Program for Consumer Products Other Than 
Automobiles. This includes consumer water heaters, which are also 
addressed in this rulemaking. (42 U.S.C. 6292(a)(4))
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    \1\ For editorial reasons, Part C was codified as Part A-1 in 
the U.S. Code.
    \2\ All references to EPCA in this document refer to the statute 
as amended through the Energy Efficiency Improvement Act of 2015 
(EEIA 2015), Public Law 114-11 (April 30, 2015).
    \3\ For editorial reasons, upon codification in the U.S. Code, 
Part B was redesignated as Part A.
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    Under EPCA, energy conservation programs generally consist of four 
parts: (1) Testing; (2) labeling; (3) establishing Federal energy 
conservation standards; and (4) certification and enforcement 
procedures. The testing requirements consist of test procedures that 
manufacturers of covered products and equipment must use as both the 
basis for certifying to DOE that their products and equipment comply 
with the applicable energy conservation standards adopted pursuant to 
EPCA, and for making representations about the efficiency of that 
equipment. (42 U.S.C. 6293(c); 42 U.S.C. 6295(s); 42 U.S.C. 6314; 42 
U.S.C. 6316)
    The initial test procedures for CWH equipment were added to EPCA by 
the Energy Policy Act of 1992 (EPACT 1992), Public Law 102-486, and 
correspond to those referenced in ASHRAE and Illuminating Engineering 
Society of North America (IESNA) Standard 90.1-1989 (i.e., ASHRAE 
Standard 90.1-1989) which went into effect on October 24, 1992. (42 
U.S.C. 6314(a)(4)(A)) EPCA requires that if an industry test procedure 
that is referenced in ASHRAE Standard 90.1 is amended, DOE must amend 
its test procedure to be consistent with the amended industry test 
procedure, unless DOE determines that the amended test procedure is not 
reasonably designed to produce test results that reflect the energy 
efficiency, energy use, or estimated operating costs of the equipment 
during a representative average use cycle. In addition, DOE must 
determine that the amended test procedure is not unduly burdensome to 
conduct. (42 U.S.C. 6314(a)(2), (3) and (4)(B))
    If DOE determines that a test procedure amendment is warranted, it 
must publish a proposed test procedure in the Federal Register and 
offer the public an opportunity to present oral and written comments. 
(42 U.S.C. 6314(b)(1)-(2)) When amending a test procedure, DOE must 
determine to what extent, if any, the proposed test procedure would 
alter the equipment's energy efficiency as determined under the 
existing test procedure. (42 U.S.C. 6293(e); 42 U.S.C. 6314(a)(4)(C))
    The Energy Independence and Security Act of 2007 (EISA 2007), 
Public Law 110-140, amended EPCA to require that at least once every 7 
years, DOE must review test procedures for each type of covered 
equipment, including CWH equipment, and either: (1) Amend the test 
procedures if the Secretary determines that the amended test procedures 
would more accurately or

[[Page 28590]]

fully comply with the requirements of 42 U.S.C. 6314(a)(2)-(3),\4\ or 
(2) publish a notice of determination not to amend a test procedure. 
(42 U.S.C. 6314(a)(1)(A)) Under this requirement, DOE must review the 
test procedures for CWH equipment no later than May 16, 2019, which is 
7 years after the most recent final rule amending the Federal test 
method for CWH equipment.\5\ The final rule resulting from this 
rulemaking will satisfy the requirement to review the test procedure 
for CWH equipment within 7 years.
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    \4\ 42 U.S.C. 6314(a)(2) requires that test procedures be 
reasonably designed to produce test results which reflect energy 
efficiency, energy use, and estimated operating costs of a type of 
industrial equipment (or class thereof) during a representative 
average use cycle (as determined by the Secretary), and not be 
unduly burdensome to conduct.
    42 U.S.C. 6314(a)(3) requires that if the test procedure is a 
procedure for determining estimated annual operating costs, such 
procedure must provide that such costs are calculated from 
measurements of energy use in a representative average-use cycle (as 
determined by the Secretary), and from representative average unit 
costs of the energy needed to operate such equipment during such 
cycle. The Secretary must provide information to manufacturers of 
covered equipment regarding representative average unit costs of 
energy.
    \5\ DOE published a final rule in the Federal Register on May 
16, 2012, that, in relevant part, amended its test procedure for 
commercial water-heating equipment. 77 FR 28928.
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    DOE's test procedure for CWH equipment is found at 10 CFR 431.106, 
Uniform test method for the measurement of energy efficiency of 
commercial water heaters and hot water supply boilers (other than 
commercial heat pump water heaters).\6\ DOE's test procedure for CWH 
equipment provides a method for determining the thermal efficiency and 
standby loss of CWH equipment. In a direct final rule for test 
procedures for CWH equipment, DOE incorporated by reference certain 
sections of the ANSI Standard Z21.10.3-1998 (ANSI Z21.10.3-1998), Gas 
Water Heaters, Volume III, Storage Water Heaters With Input Ratings 
Above 75,000 Btu Per Hour, Circulating and Instantaneous. 69 FR 61974, 
61983 (Oct. 21, 2004). On May 16, 2012, DOE published a final rule for 
certain commercial heating, air-conditioning, and water-heating 
equipment in the Federal Register that, among other things, updated the 
test procedures for certain CWH equipment by incorporating by reference 
ANSI Z21.10.3-2011. 77 FR 28928, 28996. These updates did not 
materially alter DOE's test procedure for CWH equipment.
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    \6\ DOE has reserved a place in its regulations for a test 
procedure for commercial heat pump water heaters at 10 CFR 431.107, 
Uniform test method for the measurement of energy efficiency for 
commercial heat pump water heaters.
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    The American Energy Manufacturing Technical Corrections Act 
(AEMTCA), Public Law 112-210, was signed into law on December 18, 2012, 
and amended EPCA to require that DOE publish a final rule establishing 
a uniform efficiency descriptor and accompanying test methods for 
consumer water heaters and certain CWH equipment. (42 U.S.C. 
6295(e)(5)) AEMTCA required DOE to replace the current efficiency 
metric for consumer water heaters (energy factor) and the current 
efficiency metrics for commercial water heaters (thermal efficiency and 
standby loss) with a uniform efficiency descriptor. (42 U.S.C. 
6295(e)(5)(C)) Further, AEMTCA required that the uniform efficiency 
descriptor and accompanying test method apply, to the maximum extent 
possible, to all water heating technologies currently in use and to 
future water heating technologies. (42 U.S.C. 6295(e)(5)(H)) However, 
AEMTCA allowed DOE to exclude from the uniform efficiency descriptor, 
specific categories of covered water heaters that do not have 
residential uses, that can be clearly described, and that are 
effectively rated using the current thermal efficiency and standby loss 
descriptors. (42 U.S.C. 6295(e)(5)(F))
    DOE published a final rule for test procedures for certain CWH 
equipment on July 11, 2014 (``July 2014 final rule''). 79 FR 40542. The 
final rule modified the current consumer water heater metric (energy 
factor) to create uniform energy factor (UEF), the descriptor to be 
used as the uniform efficiency descriptor for all consumer water 
heaters and certain CWH equipment that have residential uses. Id. at 
40544. The final rule excluded certain CWH equipment from the uniform 
descriptor equipment that has no residential use, that can be clearly 
identified and described, and that are effectively rated using the 
current thermal efficiency and standby loss efficiency descriptors. In 
the July 2014 final rule, DOE defined and adopted a new test method for 
``residential-duty commercial water heaters,'' which are commercial 
water heaters that have residential uses. Id.
    In this rulemaking for CWH equipment test procedures, DOE only 
considers amended test procedures for the CWH equipment classes that do 
not have residential applications and that are not ``residential-duty 
commercial water heaters'' as adopted in the July 2014 final rule.\7\ 
On February 27, 2014, DOE published in the Federal Register a request 
for information (February 2014 RFI) to seek public comments on several 
issues associated with the current test procedure for CWH equipment. 79 
FR 10999. DOE accepted comments and information on the February 2014 
RFI until March 31, 2014, and considered all feedback received when 
developing the proposals contained in this rulemaking. Each of the 
issues raised in the February 2014 RFI is discussed in detail in 
section III, along with comments received on the issues and DOE's 
responses. In addition, several topics not addressed in the February 
2014 RFI but brought up by interested parties in their comments are 
discussed in section III of this NOPR.
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    \7\ Although DOE did not consider amended test procedures for 
residential-duty commercial water heaters, DOE proposes to amend the 
definitions pertaining to these equipment, as discussed in section 
III.F.3.
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    In support of its rulemaking effort, DOE typically seeks comments 
from the public and uses them to conduct in-depth technical analyses of 
publicly-available test standards and other relevant information. As 
noted above, this NOPR discusses the comments received by DOE in 
response to the February 2014 RFI and summarizes all proposed updates 
and amendments to the current test procedure. In its efforts to 
continually engage the public and interested parties in the rulemaking 
process, DOE seeks data and public input on all aspects of this 
rulemaking, in order to improve the testing methodologies, to 
accurately reflect commercial use, and to produce repeatable results. 
DOE also requests feedback from interested parties and stakeholders on 
the proposed amendments to the current test procedures for CWH 
equipment.

II. Synopsis of the Notice of Proposed Rulemaking

    The February 2014 RFI raised several issues regarding the thermal 
efficiency and standby loss test methods for CWH equipment. Several 
other issues which were not part of the RFI were brought up through 
stakeholder feedback and comments on the RFI. In this NOPR, DOE 
discusses all issues identified by DOE and interested parties, and 
proposes to modify the current test procedures based on these issues, 
as necessary, in order to improve the consistency and accuracy of test 
results generated using the DOE test procedure while minimizing test 
burden.
    As provided in 10 CFR 431.105, the current DOE test procedure 
incorporates by reference the ANSI Z21.10.3-2011 test method for use in 
10 CFR 431.106, and that latter provision specifically directs one to 
follow Exhibits G.1 and

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G.2 of the industry test procedure. In 2013, ANSI updated its test 
method and released a more recent version, i.e., ANSI Z21.10.3-2013/
Canadian Standards Association (CSA) 4.3-2013, Gas-fired Water Heaters, 
Volume III, Storage Water Heaters with Input Ratings Above 75,000 Btu 
Per Hour, Circulating and Instantaneous (hereinafter referred to as 
``ANSI Z21.10.3-2013''). In the February 2014 RFI, DOE stated its plan 
to amend its test procedure to reference ANSI Z21.10.3-2013, the 
updated industry test method for measuring thermal efficiency and 
standby loss. 79 FR 10999, 11001-11002 (Feb. 27, 2014). However, since 
publication of the February 2014 RFI, ANSI updated its test method 
twice. First, an updated version was approved on July 2, 2014, and 
released in August 2014, specifically, ANSI Z21.10.3-2014/CSA 4.3-2014, 
Gas-fired Water Heaters, Volume III, Storage Water Heaters with Input 
Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous 
(hereinafter referred to as ``ANSI Z21.10.3-2014''). Another updated 
version was then approved on October 5, 2015, and released in November 
2015, specifically, ANSI Z21.10.3-2015/CSA 4.3-2015, Gas-fired Water 
Heaters, Volume III, Storage Water Heaters with Input Ratings Above 
75,000 Btu Per Hour, Circulating and Instantaneous (hereinafter 
referred to as ``ANSI Z21.10.3-2015''). DOE is proposing to incorporate 
by reference annexes E.1 of this latest industry test procedure (ANSI 
Z21.10.3-2015) for measuring thermal efficiency and standby loss.
    After a careful review of ANSI Z21.10.3-2015, DOE found one 
significant difference between the sections of the test standard that 
are currently referenced by DOE (i.e., Exhibits G.1 and G.2 of ANSI 
Z21.10.3-2011) and those contained in ANSI Z21.10.3-2015 (i.e., Annexes 
E.1 and E.2). This difference is in the temperature differential terms 
used in the equations to calculate standby loss in Annex E.2 of ANSI 
Z21.10.3-2015 and Exhibit G.2 of ANSI Z21.10.3-2011. The equations in 
Annex E.2 of ANSI Z21.10.3-2015 and Exhibit G.2 of ANSI Z21.10.3-2011 
are meant to calculate standby loss, which is defined as the average 
hourly energy required to maintain the stored water temperature 
expressed as a percentage of the total heat content of the stored water 
above room temperature. However, the temperature differential term used 
in the denominator of the standby loss equation in Annex E.2 of ANSI 
Z21.10.3-2015 does not represent the total heat content of the water 
heater. Therefore, DOE has tentatively concluded that it is appropriate 
to use the standby loss equation in Exhibit G.2 of ANSI Z21.10.3-2011, 
which is both accurate and best represents the standby loss expressed 
as a percentage per hour of the total heat content of the stored water 
above room temperature. Therefore, DOE proposes to include the equation 
for standby loss `S' presented in Exhibit G.2 of ANSI Z21.10.3-2011 in 
the DOE test procedure for all covered commercial storage water heaters 
and storage-type instantaneous water heaters (see section III.F for 
discussion on DOE's proposed definition for ``storage-type 
instantaneous water heater''). However, for instantaneous water heaters 
and hot water supply boilers other than storage-type instantaneous 
water heaters, DOE proposes separate standby loss test procedures and 
equations, as discussed in sections III.G and III.I. DOE did not find 
any other significant differences between Annexes E.1 and E.2 of ANSI 
Z21.10.3-2015 and Exhibits G.1 and G.2 of ANSI Z21.10.3-2011. 
Therefore, other than the reference for the standby loss equation, DOE 
proposes to update the reference in its test procedures for CWH 
equipment (as applicable) to the most recent version of the industry 
test standard. Specifically, DOE proposes to incorporate by reference 
Annex E.1 of ANSI Z21.10.3-2015. This issue is further discussed in 
section III.A of this rulemaking.
    DOE's current test procedure for oil-fired CWH equipment at 10 CFR 
431.106 also refers to ASTM Standard D2156-80 (``ASTM D2156-80''), 
``Standard Test Method for Smoke Density in Flue Gases from Burning 
Distillate Fuels.'' Specifically, this industry method is cited to 
determine that smoke in the flue does not exceed a No. 1 smoke spot 
number. A more recent version of this standard, ASTM Standard D2156-09 
(``ASTM D2156-09''), ``Standard Test Method for Smoke Density in Flue 
Gases from Burning Distillate Fuels,'' was approved in 2009 and 
reapproved in 2013. DOE carefully reviewed the two versions of this 
industry method and identified no significant differences that would 
affect the determination of smoke spot number as referred to in DOE's 
test procedure. Therefore, DOE proposes to incorporate by reference 
ASTM D1256-09 for the purpose of determining the smoke spot number.
    However, DOE also proposes clarifications to the procedure for 
determining the smoke spot number. First, DOE proposes to clarify that 
the smoke spot number must be determined prior to taking measurements 
for the efficiency tests (i.e., the thermal efficiency test or standby 
loss test). Specifically, for the thermal efficiency test, DOE proposes 
to require that the smoke spot number be determined after a steady-
state condition has been reached but before beginning measurements for 
the thermal efficiency test. For the standby loss test, DOE proposes to 
require that the smoke spot number be determined after the first cut-
out before beginning measurements for the standby loss test. However, 
DOE proposes not to require that the smoke spot test be conducted prior 
to beginning an efficiency test (i.e., thermal efficiency or standby 
loss) if no settings on the water heater have been changed and the 
water heater has not been turned off since the end of a previously run 
efficiency test. DOE also proposes that the requirements for when to 
conduct the smoke spot test also apply to measurement of the 
CO2 reading, which is required by DOE's current test 
procedures for oil-fired CWH equipment at 10 CFR 431.106. Second, DOE 
proposes to require that the smoke measuring device be connected to an 
open-ended tube that projects into the flue \1/4\ to \1/2\ of the pipe 
diameter. This proposed clarification regarding the smoke measuring 
device is based on the requirements for commercial space-heating 
boilers in the ANSI/AHRI Standard 1500 (``AHRI 1500-2015''), ``2015 
Standard for Performance Rating of Commercial Space Heating Boilers.'' 
Because this requirement comes from an industry-accepted test method, 
DOE expects this requirement to lead to minimal test burden for 
manufacturers and would simply serve to clarify the test set-up.
    DOE's current definition for ``R-value'' at 10 CFR 431.102 
references two industry test methods: (1) ASTM Standard Test Method 
C177-97 (``ASTM C177-97''), ``Standard Test Method for Steady-State 
Heat Flux Measurements and Thermal Transmission Properties by Means of 
the Guarded-Hot-Plate Apparatus''; and (2) ASTM Test Standard C518-91 
(``ASTM C518-91''), ``Standard Test Method for Steady-State Thermal 
Transmission Properties by Means of the Heat Flow Meter Apparatus.'' 
More recent versions of ASTM C177 and ASTM C518 were published in 
October 2013 and June 2010, respectively: (1) ASTM Standard Test Method 
C177-13 (``ASTM C177-13''), ``Standard Test Method for Steady-State 
Heat Flux Measurements and Thermal Transmission Properties by Means of 
the Guarded-Hot-Plate Apparatus''; and (2) ASTM Test

[[Page 28592]]

Standard C518-10 (``ASTM C518-10''), ``Standard Test Method for Steady-
State Thermal Transmission Properties by Means of the Heat Flow Meter 
Apparatus.'' After careful review, DOE has tentatively concluded that 
there are no substantive differences in the procedures for measuring R-
value between the two versions of ASTM C177 or between the two versions 
of ASTM C518. Based upon its analysis, DOE proposes to incorporate by 
reference ASTM Standard Test Methods C177-13 and C518-10 and update its 
references to these versions in the definition for ``R-value'' at 10 
CFR 431.102, in order to maintain up-to-date references to industry 
test methods.
    Among the comments received by DOE on the published RFI, several 
commenters raised concerns with regards to the repeatability of the 
standby loss test method as set forth in the current DOE test method 
(which references Exhibit G.2 of ANSI Z21.10.3-2011). To address these 
concerns of test repeatability, DOE proposes several improvements to 
both the thermal efficiency and standby loss test methods, which are 
discussed in detail in section III.B of this rulemaking.
    Unfired hot water storage tanks are covered equipment included in 
the scope of this rulemaking. These tanks store hot water and do not 
consume fuel or electricity for the purpose of heating water, so any 
energy efficiency improvements would target standby loss associated 
with heat loss from the stored water. Currently, unfired hot water 
storage tanks are required to have thermal insulation with a minimum 
thermal resistance (R-value) of 
12.5[emsp14][deg]F[middot]ft\2\[middot]hr/Btu. See 10 CFR 431.110. In 
the February 2014 RFI, DOE requested comment on whether the R-value 
requirement was an appropriate energy efficiency descriptor and whether 
it should adopt a standby loss test and metric to replace the current 
R-value requirement. DOE also noted that determining the R-value of a 
single sample does not assess whether this value is applicable to the 
entire tank surface area, including bottom, top, and fitting areas. 79 
FR 10999, 11002 (Feb. 27, 2014). After considering public comments from 
stakeholders and interested parties, DOE proposes to adopt a standby 
loss test for unfired storage tanks that is based, in part, on existing 
industry test methods (i.e., GAMA Testing Standard IWH-TS-1 (March 2003 
edition)). Energy conservation standards for unfired hot water storage 
tanks will remain in terms of the current insulation R-value 
requirement until DOE completes a future rulemaking to establish 
standards in terms of the proposed standby loss metric, presuming such 
metric is adopted in the test procedure final rule. This proposed 
standby loss test method is discussed in detail in section III.C.
    Another issue raised by DOE in the February 2014 RFI regarded the 
method of setting the tank thermostat prior to conducting the thermal 
efficiency test. 79 FR 10999, 11002-03 (Feb. 27, 2014). The current 
Federal test procedure at 10 CFR 431.106 references Exhibits G.1 and 
G.2 of ANSI Z21.10.3-2011, which requires water heaters to achieve a 
maximum mean tank temperature of 140[emsp14][deg]F  
5[emsp14][deg]F after the thermostat reduces the gas supply to a 
minimum. However, some CWH equipment may experience difficulty in 
attaining a mean tank temperature of 140[emsp14][deg]F  
5[emsp14][deg]F due to the design of the heat exchanger and positioning 
of the thermostat sensor. Such systems may in fact be able to supply 
water at a temperature of 140[emsp14][deg]F  
5[emsp14][deg]F, but yet not meet the mean tank temperature 
requirement. As a result, DOE proposes to modify the test procedure for 
gas-fired and oil-fired storage water heaters and storage-type 
instantaneous water heaters to use the outlet water temperature as the 
set point for setting the thermostat, rather than the mean tank 
temperature. This change would still ensure the water heater provides 
water at the specified temperature, while accommodating models that are 
not designed to have high mean tank temperatures (i.e., condensing 
water heaters) or that rely upon stratification. The set point 
temperature value would remain the same at 140[emsp14][deg]F  5[emsp14][deg]F. However, for electric storage water heaters, 
DOE proposes to maintain a mean tank temperature requirement for the 
standby loss test because of complications with setting the thermostats 
for each electric heating element. Specifically, it is unclear how each 
thermostat could be set to provide a designated outlet water 
temperature in a way that would differ from the method used for a mean 
tank temperature requirement. Additional discussion of this issue is 
contained in section III.D.
    In the February 2014 RFI, DOE requested information on whether any 
clarifications are needed in the thermal efficiency test procedure to 
indicate water flow requirements or to account for changes in thermal 
energy stored within the water heater during the duration of the test. 
79 FR 10999, 11003 (Feb. 27, 2014). Based on the comments received, DOE 
has tentatively concluded that the current test procedure prescribed in 
10 CFR 431.106 does not require any amendment to account for changes in 
stored thermal energy or water flow requirements during the thermal 
efficiency test method. The existing test procedure requires the water 
heater to attain steady-state conditions with no variation of outlet 
water temperature in excess of 2[emsp14][deg]F over a period of 3 
minutes. Once steady-state conditions are achieved, the internal tank 
temperature maintains a constant value, indicating that the stored 
energy in the water heater remains constant as long as the firing rate 
remains constant. While DOE has tentatively concluded that an amendment 
to account for stored energy changes is not needed, DOE proposes to 
introduce a statement clarifying that during the thermal efficiency 
test, the burner must continuously fire at the full firing rate (i.e., 
no modulation or cut-outs) for the entire duration of the thermal 
efficiency test, and the outlet water temperature must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature. DOE also proposes to clarify that during the thermal 
efficiency and standby loss tests, no settings on the water heating 
equipment can be changed until measurements for the test have finished. 
Additional discussion of these issues is contained in section III.E.
    In this NOPR, DOE proposes several changes to the definitions 
included in the regulations for consumer water heaters at 10 CFR 430.2 
and for CWH equipment at 10 CFR 431.102. For consumer water heaters, 
DOE proposes to remove exemptions from the definitions that exclude 
units that heat water to temperatures greater than 180[emsp14][deg]F 
and units with a storage capacity greater than 120 gallons. DOE also 
proposes to remove the definitions for consumer ``electric heat pump 
water heater'' and ``gas-fired heat pump water heater.'' DOE proposes 
the following changes to the definitions for CWH equipment: (1) 
Replacing all mentions of the terms ``input rating'' or ``rated input'' 
with the term ``fuel input rate'' in the context of gas-fired or oil-
fired CWH equipment, based on the proposed changes regarding fuel input 
rate that are further discussed in section III.K; (2) modifying DOE's 
definitions for ``instantaneous water heater'' and ``storage water 
heater'' by adding the input criteria that separate consumer water 
heaters and commercial water heaters and removing several phrases that 
do not serve to clarify coverage of units under the definitions; and 
(3) removing the definition of ``packaged boiler.'' DOE also proposes 
to modify the definition for ``residential-duty commercial water 
heater'' by removing from its scope the following classes, for which 
the input criteria indicating

[[Page 28593]]

residential application do not allow classification of any units: 
electric storage water heaters, heat pump water heaters with storage, 
gas-fired instantaneous water heaters, and oil-fired instantaneous 
water heaters. Additional discussion of these proposed changes to DOE's 
definitions for consumer water heaters and CWH equipment is provided in 
section III.F.
    Water heaters with storage tanks and submerged fire-tube heat 
exchangers that have input ratings above 4,000 Btu/h per gallon of 
water stored are currently classified as instantaneous water heaters 
and hot water supply boilers with a storage volume greater than or 
equal to 10 gallons. However, DOE believes that these units that are 
equipped with storage tanks are fundamentally different from other 
instantaneous water heaters, and, therefore, the Department proposes to 
define the term ``storage-type instantaneous water heater.'' DOE also 
proposes that such units would be tested according to the same method 
as used for commercial storage water heaters. Additional discussion of 
these issues are contained in section III.F.4.
    Instantaneous water heaters and hot water supply boilers are 
covered equipment subject to the current Federal test procedure as set 
forth in 10 CFR 431.106. In response to the February 2014 RFI, AHRI 
raised an issue with regards to the applicability of the standby loss 
test procedure described in Exhibit G.2 of ANSI Z21.10.3-2011 for 
instantaneous water heaters and hot water supply boilers that have no 
means of initiating burner operation without an active flow of water 
through the equipment. Additionally, ANSI Z21.10.3-2015 was updated 
from previous versions of the industry testing standard to include a 
new test method for measuring the standby loss of tube-type 
instantaneous water heaters, which AHRI recommended DOE use for 
determining the standby loss of such instantaneous water heaters and 
hot water supply boilers. DOE identified numerous problematic issues 
with this procedure and tentatively decided not to incorporate it by 
reference in its test procedures for CWH equipment. (The AHRI comments 
and this test method are discussed it in greater detail, along with 
DOE's proposed standby loss test procedure for flow-activated 
instantaneous water heaters, in section III.G.) The current standby 
loss test procedure involves shutting off the flow of water through the 
water heater and calculating the amount of energy required to raise the 
internally stored water temperature to a thermostatically-set value 
when it drops to a point at which it needs to be reheated. For such a 
test, it is assumed that when the stored water reaches the minimum 
allowable water temperature (below the thermostat set point) a control 
signal activates that will initiate the next firing or heating cycle. 
This is true for most CWH equipment; however, flow-activated 
instantaneous water heaters require flow of water through the heater to 
initiate the next firing or heating cycle. In these designs, if there 
is no continuous water flow, the next firing or heating cycle is not 
triggered even if the temperature of hot water inside the heater falls 
below the thermostat set point. To address this issue, DOE proposes to 
adopt a separate standby loss test for flow-activated instantaneous 
water heaters. DOE currently only prescribes standby loss standards for 
gas-fired and oil-fired instantaneous water heater and hot water supply 
boilers with a storage capacity greater than or equal to 10 gallons. 
The proposed test method would apply to all units that meet the 
proposed definition for ``flow-activated instantaneous water heater,'' 
and is described in detail in section III.G.
    The current thermal efficiency and standby loss test method 
requires the water heater to be set up as per Figure 2 in ANSI 
Z21.10.3-2011, which is identical to Figure 3 in ANSI Z21.10.3-2015. 
Although the figures provide an unscaled pictorial arrangement of the 
test set up, neither Figure 2 in ANSI Z21.10.3-2011 nor Figure 3 in 
ANSI Z21.10.3-2015 specifies the exact location of the outlet water 
temperature measurement. DOE understands that this unspecified location 
for outlet water temperature measurement could lead to inconsistent 
test results and an inaccurate representation of the actual outlet 
water temperature, especially if the outlet water temperature 
represents the internal stored water temperature for instantaneous 
water heaters and hot water supply boilers (as proposed in this NOPR 
and discussed in section III.G and III.I). Moreover, the temperature-
sensing installations, as set forth in Annex E.1 of ANSI Z21.10.3-2015, 
do not provide clear instructions for installing temperature-sensing 
means for instantaneous water heaters and hot water supply boilers. 
Considering the issues related to temperature measurement for 
instantaneous water heaters and hot water supply boilers, DOE proposes 
to specify the temperature-sensing location for the outlet water 
temperature such that the tip or junction of the sensor is less than or 
equal to 5 inches away from the water heater jacket and requirements 
for placement of the temperature-sensing probe in the water line for 
both supply and outlet water measurement. In addition to this issue, 
DOE also proposes to add supply and outlet water valves at locations 
closer to the water heater. Specifically, DOE proposes to add a supply 
water valve within a distance of 5 inches from the water heater jacket 
and an outlet water valve within a distance of 10 inches from the water 
heater jacket. Currently, the test set up does not clearly indicate the 
location of the water supply valves. These valves would be turned off 
at the start of the standby loss test for instantaneous water heaters 
and hot water supply boilers (as proposed in this NOPR and discussed in 
section III.G and III.I). DOE also proposes to add provisions for 
outlet water temperature measurement and placement of water valves for 
instantaneous water heaters and hot water supply boilers that have 
multiple supply and outlet water connections and that are shipped with 
piping installed by the manufacturer. Finally, DOE proposes to clarify 
the conditions for using a re-circulating loop. The proposed provisions 
are similar to those specified in ANSI Z21.10.3-2011 (and ANSI 
Z21.10.3-2015), and further details on this issue are contained in 
section III.H.
    In response to the RFI, manufacturers also raised the issue of the 
applicability of the current Federal standby loss test procedure to 
instantaneous water heaters and hot water supply boilers that are not 
tank-type water heaters and that have a storage capacity of ten gallons 
or more (all comments on this topic are discussed in section III.I of 
this NOPR). The Federal standby loss test procedure in 10 CFR 431.106 
incorporates by reference Exhibit G.2 of ANSI Z21.10.3-2011, which 
requires the measurement of mean tank temperature to calculate standby 
loss. Instantaneous water heaters and hot water supply boilers 
generally are not equipped with an integral storage tank, but rather 
the stored water is contained within the heat exchanger. Therefore, 
measuring the mean tank temperature for such type of equipment would 
not be possible (as a storage tank does not exist). Moreover, due to 
the complex geometry and design of the heat exchangers of such 
equipment, obtaining an accurate value of the mean stored water 
temperature inside the heat exchanger would be difficult, or in some 
cases, may be impossible. To address this issue, DOE proposes to use 
the outlet water temperature as a conservative estimate for the mean 
tank temperature. This approach is similar to that used for the standby 
loss test for

[[Page 28594]]

flow-activated water heaters and would be significantly less burdensome 
than using other means to accurately measure the stored water 
temperature inside the heat exchanger. Additional details on this test 
procedure are provided in section III.I.
    In the February 2014 RFI, DOE also requested comments on 
development of a test procedure for commercial heat pump water heaters 
(CHPWHs). 79 FR 10999, 11003 (Feb. 27, 2014). Based on the comments 
received, DOE proposes to incorporate by reference ANSI/ASHRAE Standard 
118.1-2012, Method of Testing for Rating Commercial Gas, Electric, and 
Oil Service Water-Heating Equipment (ANSI/ASHRAE Standard 118.1-2012) 
to use as the basis for the Federal CHPWH test method, with several 
modifications discussed in further detail in III.J. DOE also proposes 
to adopt rating conditions for four categories of CHPWHs: (1) Air-
source CHPWHs; (2) direct geo-exchange CHPWHs; (3) ground water-source 
CHPWHs; and (4) indoor water-source CHPWHs. The proposed rating 
conditions are based on ANSI/AHRI Standard 1300 (I-P)-2013: Performance 
Rating of Commercial Heat Pump Water Heaters. Additional discussion of 
this proposed test procedure is contained in section III.J.
    In its current regulations for CWH equipment in subpart G to 10 CFR 
part 431, DOE includes several terms referring to the input capacity, 
and does not include any method for determining or verifying the input 
capacity during testing. In this NOPR, DOE proposes to define ``fuel 
input rate'' for gas-fired and oil-fired CWH equipment and proposes a 
procedure for calculating the fuel input rate during the thermal 
efficiency test. DOE proposes that the gas consumption be measured 
every 10 minutes, and that the calculated fuel input rates for each 10-
minute interval of the thermal efficiency test cannot vary by more than 
 2 percent between each reading. DOE also proposes means to 
verify the fuel input rate. Additional discussion of these proposed 
changes regarding fuel input rate is contained in section III.K.
    In this NOPR, DOE proposes several changes to its certification 
requirements at 10 CFR part 429. First, DOE proposes to add 
requirements to 10 CFR 429.44 that manufacturers must certify whether 
gas-fired and oil-fired instantaneous water heaters and hot water 
supply boilers contain submerged heat exchangers, so that such models 
can be classified under DOE's proposed definition for ``storage-type 
instantaneous water heaters.'' Second, DOE proposes to require 
manufacturers to certify whether instantaneous water heaters and hot 
water supply boilers require flow through the water heater to initiate 
burner ignition. Further discussion of these proposed changes are 
included in section III.M. Additionally, DOE proposes default values 
for these parameters to be used in testing if the parameters are not 
reported in manufacturer literature shipped with the equipment or the 
supplemental test instructions. Further discussion of these proposed 
default values are included in section III.L.
    In any rulemaking to amend a test procedure, DOE must determine to 
what extent, if any, the proposed test procedure would alter the 
measured energy efficiency of any covered product as determined under 
the existing test procedure. (42 U.S.C. 6293(e)(1); 42 U.S.C. 
6314(a)(4)(C)) DOE expects that the proposed changes to the test 
procedure will not significantly alter the efficiency ratings for a 
most classes of CWH equipment. There could, however, be changes to the 
measured energy efficiency for unfired hot water storage tanks. If DOE 
adopts the changes to the existing test procedures proposed in this 
NOPR for those products, then DOE will establish energy conservations 
standards for unfired hot water storage tanks in terms of a new standby 
loss metric in a separate rulemaking, and the test procedure changes 
related to unfired hot water storage tanks will not apply until 
compliance is required with the new standards. DOE also proposes a new 
test procedure for measuring standby loss of flow-activated 
instantaneous water heaters with a storage capacity greater than or 
equal to 10 gallons. However, DOE does not believe this proposed test 
procedure will affect the measured energy efficiency of flow-activated 
instantaneous water heaters.

III. Discussion

    In response to the February 2014 RFI, DOE received eight written 
comments from the following interested parties: Bradford White 
Corporation (Bradford White); A.O. Smith Corporation (A.O. Smith); HTP, 
Inc. (HTP); Rheem Manufacturing Company (Rheem); Edison Electric 
Institute (EEI); Air-Conditioning, Heating, and Refrigeration Institute 
(AHRI); American Public Power Association (APPA); and the American 
Council for an Energy-Efficient Economy (ACEEE) and National Resources 
Defense Council (NRDC), who filed a joint comment (henceforth referred 
to as ``Joint Advocates''). These interested parties commented on a 
range of issues, including those identified by DOE in the February 2014 
RFI, as well as several other pertinent issues. The issues, the 
comments received, DOE's responses to those comments, and the resulting 
proposed changes to the test procedures for CWH equipment, are 
discussed in the following subsections.

Updated Industry Test Methods

    DOE's test procedure for measuring the energy efficiency for CWH 
equipment currently incorporates by reference the industry standard 
ANSI Z21.10.3-2011 at 10 CFR 431.105. Additionally, DOE lists ASTM 
Standard Test Methods D2156-80, C177-13, and C518-10 as sources of 
information and guidance in 10 CFR 431.104. DOE defines ``ASTM Standard 
Test Method D2156-80'' at 10 CFR 431.102, and points to this source in 
DOE's current test procedure at 10 CFR 431.106. DOE points to ASTM 
C177-13 and ASTM C518-10 in its definition for ``R-value'' at 10 CFR 
431.102. The following subsections discuss proposed revisions to DOE's 
test procedure for CWH equipment vis-[agrave]-vis these industry 
standards.
1. ANSI Z21.10.3 Testing Standard
    As noted above, DOE's test procedure for measuring the energy 
efficiency for CWH equipment currently incorporates by reference the 
industry standard ANSI Z21.10.3-2011 at 10 CFR 431.105. Specifically, 
the DOE test procedures at 10 CFR 431.106 directs one to follow 
Exhibits G.1 and G.2 of ANSI Z21.10.3-2011 for measuring thermal 
efficiency and standby loss, respectively. An updated edition of the 
industry test method, ANSI Z21.10.3-2013/CSA 4.3-2013, was approved on 
March 25, 2013, and released in July 2013.
    In the February 2014 RFI, DOE requested feedback on the 
appropriateness of replacing references to ANSI Z21.10.3-2011 with 
equivalent references to ANSI Z21.10.3-2013 (which, at that time, was 
the most current industry testing standard). 79 FR 10999, 11001-02 
(Feb. 27, 2014). All parties that commented on this issue agreed with 
DOE that ANSI Z21.10.3-2013 was an appropriate replacement for ANSI 
Z21.10.3-2011. (Bradford White, No. 8 at p. 1;\8\ Rheem, No. 3 at p. 1; 
HTP, No. 5 at pp. 1-2; A.O. Smith,

[[Page 28595]]

No. 7 at p. 1; Joint Advocates, No. 4 at p. 1; and AHRI, No. 2 at p. 1)
---------------------------------------------------------------------------

    \8\ A notation in this form provides a reference for information 
that is in the docket of DOE's rulemaking to develop test procedures 
for commercial water heating equipment (Docket No. EERE-20014-BT-TP-
0008), which is maintained at www.regulations.gov. This notation 
indicates that the statement preceding the reference is document 
number 8 in the docket for the test procedure rulemaking for 
commercial water heating equipment, and appears at page 1 of that 
document.
---------------------------------------------------------------------------

    However, since publication of the February 2014 RFI, ANSI updated 
its test method twice. First, an updated version was approved on July 
2, 2014, and released in August 2014--ANSI Z21.10.3-2014/Canadian 
Standards Association (CSA) 4.3-2014, Gas-fired Water Heaters, Volume 
III, Storage Water Heaters with Input Ratings Above 75,000 Btu Per 
Hour, Circulating and Instantaneous (hereinafter referred to as ``ANSI 
Z21.10.3-2014''). Another updated version was then approved on October 
5, 2015, and released in November 2015--ANSI Z21.10.3-2015/CSA 4.3-
2015, Gas-fired Water Heaters, Volume III, Storage Water Heaters with 
Input Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous 
(hereinafter referred to as ``ANSI Z21.10.3-2015''). DOE reviewed ANSI 
Z21.10.3-2015 and compared it with ANSI Z21.10.3-2011, and found one 
significant difference between the sections of the test method that DOE 
currently references in its test procedures for CWH equipment (i.e., 
Exhibits G.1 and G.2 of ANSI Z21.10.3-2011) and those contained in ANSI 
Z21.10.3-2015 (i.e., Annexes E.1 and E.2). In Exhibit G.2 of ANSI 
Z21.10.3-2011, the current DOE test procedure, the equation for standby 
loss `S' is presented as:
[GRAPHIC] [TIFF OMITTED] TP09MY16.267

    In Annex E.2 of ANSI Z21.10.3-2015, the equation is exactly the 
same, except that the [Delta]3term in the denominator of the 
second term of the equation is replaced by [Delta]T4. Based 
on the definitions for the terms provided in both ANSI Z21.10.3-2011 
and ANSI Z21.10.3-2015, [Delta]T3 refers to the difference 
between the average value of the mean tank temperature and the average 
value of the ambient room temperature expressed in [deg]F. The term 
[Delta]T4 is defined as the difference between the final and 
the initial mean tank temperature.
    DOE has tentatively concluded that the standby loss equation 
provided in ANSI Z21.10.3-2011 (and ANSI Z21.10.3-2013) is appropriate. 
If the [Delta]T3 term is replaced with the 
[Delta]T4 term in the second term of the standby loss 
equation as specified by ANSI Z21.10.3-2015, then the term 
[Delta]T4 would cancel out, and the equation will not 
include the temperature difference between the final and initial mean 
tank temperature that corresponds to the heat lost by the water heater 
during the course of the test. Therefore, DOE proposes to adopt as part 
of appendices A and B to subpart G of part 431 the standby loss 
equation as specified in Exhibit G.2 of ANSI Z21.10.3-2011 (and also 
included in ANSI Z21.10.3-2013) for calculating the standby loss of all 
storage water heaters and storage-type instantaneous water heaters. DOE 
also proposes to re-arrange the terms of the equation to improve the 
readability of the equation, and remove the gas consumption term for 
electric water heaters. For instantaneous water heaters and hot water 
supply boilers other than storage-type instantaneous water heaters, DOE 
proposes separate standby loss test procedures and equations in 
sections III.G and III.I.
    DOE did not find any other substantive differences between Exhibits 
G.1 and G.2 of ANSI Z21.10.3-2011 and Annexes E.1 and E.2 of ANSI 
Z21.10.3-2015. Therefore, DOE proposes to incorporate by reference 
Annex E.1 of ANSI Z21.10.3-2015 in its proposed test procedures for CWH 
equipment. DOE does not propose to incorporate by reference Annex E.2 
of ANSI Z21.10.3-2015; however, DOE has included certain language from 
Annex E.2 in its standby loss test procedures proposed in this NOPR.
    ANSI Z21.10.3-2015 also includes a new efficiency test procedure--
Annex E.3, ``Method of test for measuring standby loss for tube type 
instantaneous water heaters with 10 or greater gallons of storage.'' 
This procedure provides a method to test standby loss of instantaneous 
water heaters and hot water supply boilers, including those that 
require flow of water to activate the burner or heating element (i.e., 
``flow-activated instantaneous water heaters''). DOE reviewed this test 
procedure, and it is discussed in further detail in section III.G, 
where DOE proposes a new standby loss test procedure for flow-activated 
instantaneous water heaters.
    DOE also proposes a procedure similar to that specified in section 
5.27 of ANSI Z21.10.3-2015 for determining the storage volume of CWH 
equipment. DOE's proposed language only includes clarifying differences 
from the language in section 5.27 of ANSI Z21.10.3-2015, and DOE 
believes that the clarifying differences would not affect conduct of 
the test procedure between DOE's proposed procedure and the method 
included in section 5.27 of ANSI Z21.10.3-2015. DOE's proposed 
procedure for determining storage volume is discussed in further detail 
in section III.G.
2. ASTM Standard Test Method D2156
    DOE's current test procedure for oil-fired CWH equipment at 10 CFR 
431.106 points to ASTM Standard Test Method D2156-80. Specifically, DOE 
requires that smoke in the flue does not exceed No. 1 smoke as measured 
by the procedure in ASTM D2156-80. However, there is a more recent 
version of ASTM D2156 that was approved on December 1, 2009, and 
reapproved on October 1, 2013. After careful review of D2156-80 and 
D2156-09, DOE has tentatively concluded that no substantive changes 
were made between these versions in the test method for determining the 
smoke spot number. Therefore, DOE proposes to incorporate by reference 
this newer version, ASTM D2156-09, in its test procedures for oil-fired 
CWH equipment, in appendices A, C, and E to subpart G of 10 CFR part 
431.
    DOE's current requirement for smoke spot number of flue gas for 
oil-fired CWH equipment requires that the smoke in the flue does not 
exceed No. 1 smoke, but does not specify when during the test to 
determine the smoke spot number. To improve consistency and 
repeatability of testing of CWH equipment, DOE is proposing to specify 
when to conduct the smoke spot test. DOE considered several options for 
this specification. The first option DOE considered would be to require 
determination of the smoke spot number after steady-state operation has 
been achieved, but prior to beginning measurement for the thermal 
efficiency test. The second option considered would be to require 
determination of the smoke spot number before and after conduct of the 
test. The third option considered would be to require determination of 
the smoke spot number before, after, and during the test. Specifically, 
in the third option, the

[[Page 28596]]

smoke spot number would be determined during the thermal efficiency 
test 15 minutes after the beginning of the test. This is similar to the 
requirement to determine the smoke spot number every 15 minutes during 
the thermal efficiency and combustion efficiency tests that is 
specified for commercial space heating boilers in AHRI 1500-2015.
    After considering these three options and the relative benefits and 
test burden they might provide, DOE has tentatively concluded that 
determining the smoke spot number prior to conduct of efficiency 
testing sufficiently assesses the combustion performance while 
minimizing test burden for manufacturers. DOE reasoned that it is 
unlikely for the smoke density to change to a significant extent during 
a steady-state test if the burner settings are maintained throughout 
the test. As discussed in section III.E, DOE is also proposing to add a 
clarifying statement to the test procedure stating that the settings on 
CWH equipment during the thermal efficiency test are not be changed 
once steady-state conditions have been established. Therefore, DOE has 
tentatively concluded that it is not necessary to require determination 
of the smoke spot number during or after efficiency testing, and rather 
proposes to require determination of the smoke spot number before 
beginning measurement for efficiency testing. Specifically, for the 
thermal efficiency test, DOE proposes to require determination of the 
smoke spot number after steady-state condition has been reached (as 
determined by no variation of outlet water temperature in excess of 
2[emsp14][deg]F over a 3-minute period). For the standby loss test, DOE 
proposes to require determination of the smoke spot number after the 
first cut-out before beginning measurements for the standby loss test. 
DOE also proposes to require that the CO2 reading, which is 
required to be measured when testing oil-fired CWH equipment under 
DOE's current test procedures specified at 10 CFR 431.106, also be 
measured at the time required for determination of the smoke spot 
number.
    DOE also proposes to clarify that the smoke spot test and 
measurement of CO2 reading are required before conduct of 
the thermal efficiency test or standby loss test (as applicable) of 
oil-fired CWH equipment with one exception. DOE proposes that, if no 
settings on the water heater have been changed and the water heater has 
not been turned off since the end of a previously run efficiency test, 
a second smoke spot test or CO2 reading is not required 
prior to beginning another efficiency test (i.e., thermal efficiency or 
standby loss).
    Additionally, to further clarify the appropriate method for 
determining the smoke spot number, DOE proposes to adopt specifications 
to the test procedure for the set-up for measuring the smoke density. 
Specifically, DOE proposes to require that the smoke measuring device 
be connected to an open-ended tube, and that this tube must project 
into the flue \1/4\ to \1/2\ of the pipe diameter. These proposed 
requirements are from the same as those specified for commercial space-
heating boilers in AHRI 1500-2015.
    Issue 1: DOE seeks comment on its proposed incorporation by 
reference of ASTM D2156-09, and on its proposed additional 
specifications for how to set up the smoke spot test, and when to 
conduct the smoke spot test and measure the CO2 reading.
3. ASTM Test Standards C177-13 and C518-10
    DOE's current definition for ``R-value'' at 10 CFR 431.102 
references two industry test methods: ASTM Standard Test Method C177-97 
and ASTM Test Standard Method C518-91.
    A more recent version of ASTM C177 was approved in September 2013 
and published in October 2013 (ASTM C177-13). After careful review, DOE 
has tentatively concluded that there are no substantive differences in 
the procedures for measuring R-value between the two versions of ASTM 
C177. Additionally, a more recent version of ASTM C518 was approved in 
May 2010 and published in June 2010 (ASTM C518-10). After careful 
review, DOE has tentatively concluded that there are no substantive 
differences in the procedures for measuring R-value between the two 
versions of ASTM C518. Therefore, DOE proposes to incorporate by 
reference ASTM Standard Test Methods C177-13 and C518-10 and to update 
its references to these versions in the definition for ``R-value'' at 
10 CFR 431.102.
    Issue 2: DOE seeks comment on its proposed incorporation by 
reference of ASTM C177-13 and C518-10 for the definition of ``R-
value.''

B. Test Method Repeatability and Ambient Test Conditions

    As discussed in section III.A of this rulemaking, the DOE test 
procedure for CWH equipment currently incorporates by reference ANSI 
Z21.10.3-2011 at 10 CFR 431.105, and DOE proposes to incorporate by 
reference Annex E.1 of the updated version of the standard, ANSI 
Z21.10.3-2015, for measuring thermal efficiency and standby loss, 
respectively.
    The test method for thermal efficiency of CWH equipment in Annex 
E.1 of ANSI Z21.10.3-2015 (and also in Exhibit G.1 of ANSI Z21.10.3-
2011) requires that the thermostat be set so that the gas supply is 
reduced to a minimum, once the mean tank temperature reaches 
140[emsp14][deg]F  5[emsp14][deg]F. Then water is supplied 
continuously to the water heater at a temperature of 70[emsp14][deg]F 
 2[emsp14][deg]F. The outlet water temperature is adjusted 
by varying the flow rate until the temperature is constant at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature. After the outlet water reaches steady state, water flow 
(measured by weight) is recorded for a 30-minute test period, along 
with supply and outlet water temperatures, the ambient room 
temperature, and fuel and electricity consumption. These data collected 
during the 30-minute test period are used to calculate the thermal 
efficiency.
    The standby loss test method in Annex E.2 of ANSI Z21.10.3-2015 
(and also in Exhibit G.2 of ANSI Z21.10.3-2011) stipulates that a 
commercial water heater must be set up as described for the thermal 
efficiency test and that the unit must be put into operation with the 
burner gas supply opened. After the first burner cut-out,\9\ the unit 
is allowed to remain in standby mode until the second burner cut-out, 
at which point the collection of test data begins. Test data are 
recorded at 15 minute intervals, and the test ends at either the first 
cut-out after 24 hours have elapsed, or when 48 hours have elapsed, 
whichever occurs first. The ambient room temperature, mean tank 
temperature, fuel and electricity consumption, and time are measured 
during the test and used to calculate the standby loss.
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    \9\ By ``burner cut-out,'' DOE refers to when the energy supply 
to a burner is reduced to a minimum.
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    In the February 2014 RFI, DOE requested information and data 
pertaining to the repeatability of thermal efficiency and standby loss 
test methods included in the ANSI Z21.10.3-2011 and ANSI Z21.10.3-2013 
test methods. 79 FR 10999, 11001-02 (Feb. 27, 2014).
    HTP commented that the thermal efficiency test is repeatable and is 
reasonably consistent between testing sites. (HTP, No. 5 at p. 2) No 
other interested parties provided information on the repeatability of 
the thermal efficiency test method in ANSI Z21.10.3.
    Several parties provided comments regarding the repeatability of 
the standby loss test method. HTP commented that the standby loss test

[[Page 28597]]

method produces data with significant lab-to-lab variation in test 
results and attributed this variation to the physics of the test and 
the ambient conditions of the test. HTP suggested investigating the 
effects of stipulating a maximum air draft in the test environment on 
repeatability of the standby loss test. (HTP, No. 5 at p. 2) HTP and 
AHRI commented that due to the small amount of energy consumption 
measured during the standby loss test, the error and variation 
associated with the tolerances of commercially-available test 
instrumentation has a larger influence on test results, resulting in a 
greater degree of variance for the standby loss test compared to the 
thermal efficiency test. (HTP, No. 5 at p. 2 and AHRI, No. 2 at p. 1)
    Based on these comments from interested parties, DOE investigated 
various potential test procedure modifications to reduce the 
variability of results from the test procedures for thermal efficiency 
and standby loss. In addition, DOE conducted investigative testing that 
helped inform the proposals discussed in this NOPR. DOE proposes the 
following seven modifications to the current thermal efficiency and 
standby loss test procedures, after tentatively determining that these 
modifications would reduce variation in results: (1) Stipulating a 
maximum air draft requirement of 50 ft/min as measured prior to 
beginning the thermal efficiency or standby loss tests; (2) tightening 
the ambient room temperature tolerance from 10.0[emsp14][deg]F to 5.0[emsp14][deg]F and the 
allowed variance from mean ambient temperature from 7.0[emsp14][deg]F to 2.0[emsp14][deg]F; (3) requiring 
measurement of test air temperature--the temperature of entering 
combustion air--and requiring the test air temperature not vary by more 
than 5[emsp14][deg]F from the ambient room temperature at 
any measurement interval during the thermal efficiency and standby loss 
tests for gas-fired and oil-fired CWH equipment; (4) establishing a 
requirement for ambient relative humidity of 60 percent 5 
percent during the thermal efficiency and standby loss tests for gas-
fired and oil-fired CWH equipment; (5) requiring a soak-in period prior 
to testing in which the water heater must sit without any draws taking 
place for at least 12 hours from the end of a recovery from a cold 
start; (6) specifying the locations of inlet and outlet temperature 
measurements for storage water heaters, storage-type instantaneous 
water heaters, and UFHWSTs; and (7) decreasing the time interval for 
data collection from fifteen minutes to 30 seconds in the thermal 
efficiency and standby loss tests. While manufacturers cited concerns 
regarding only the repeatability of the standby loss test in response 
to comments to the February 2014 RFI, DOE has tentatively concluded 
that the following proposed modifications would improve the 
repeatability of both tests. Unless otherwise specified in the 
following paragraphs, DOE proposes that these changes would apply to 
thermal efficiency and standby loss tests for all CWH equipment (as 
applicable).
    (1) Addition of a maximum air draft stipulation, as recommended by 
HTP. This modification would allow for more consistent ambient 
conditions between tests and testing locations, as well as limit the 
effect of air draft on testing results. DOE proposes to add a 
requirement that while conducting the thermal efficiency and standby 
loss tests and during the proposed soak-in period (as applicable), a 
water heater must be protected from drafts of more than 50 ft/min from 
room ventilation registers, windows, or other external sources of air 
movement, to be measured within three feet of the jacket of the water 
heater. This requirement is similar to the requirement adopted for 
testing consumer water heaters and certain commercial water heaters in 
the July 2014 final rule. 79 FR 40542, 40569 (July 11, 2014). DOE notes 
that Annex E.1 of ANSI Z21.10.3-2015 requires that water heater 
placement in the test room shall be protected from drafts. This 
modification simply clarifies the meaning of ``protected from drafts'' 
by setting a requirement for the maximum allowable draft during the 
test. DOE proposes that the air draft be measured prior to beginning 
the soak-in period and thermal efficiency and standby loss tests, and 
that no actions can be taken during the conduct of the tests or the 
soak-in period that would increase the air draft near the water heater 
being tested.
    (2) A decrease in the allowed maximum variance for ambient room 
temperature for both the thermal efficiency and standby loss tests. The 
current test procedure at 10 CFR 431.106 references Exhibits G.1 and 
G.2 of ANSI Z21.10.3-2011, which require that the ambient room 
temperature be maintained at 75[emsp14][deg]F  
10[emsp14][deg]F, and that the ambient room temperature not vary by 
more than 7[emsp14][deg]F from the average ambient room 
temperature during the test. DOE proposes requiring that the ambient 
room temperature be maintained at 75[emsp14][deg]F  
5[emsp14][deg]F and that the room temperature not vary by more than 
2.0[emsp14][deg]F from the average ambient room temperature 
while setting thermostats and verifying steady-state operation, between 
the first and second cut-outs prior to the standby loss test (as 
applicable), and during the thermal efficiency and standby loss tests 
and proposed soak-in period (as applicable) for all CWH equipment.
    (3) Addition of a requirement for measurement of test air 
temperature for gas-fired and oil-fired commercial water heating 
equipment. DOE understands that the entering air temperature can have a 
significant impact on combustion in gas-fired and oil-fired CWH 
equipment. To improve repeatability of the thermal efficiency and 
standby loss tests for these classes of equipment, DOE proposes to 
require measurement of test air temperature, within 2 feet of the air 
inlet to the water heater. For CWH equipment that does not have a 
specific air inlet, DOE proposes that the test air temperature be 
measured within 2 feet of the jacket of the water heater closest to 
where air would be drawn for combustion. DOE also proposes a 
requirement that the test air temperature may not vary by more than 
5[emsp14][deg]F from the ambient room temperature at any 
measurement interval during the course of the thermal efficiency or 
standby loss tests (as applicable) or while establishing steady-state 
operation prior to the thermal efficiency test for gas-fired and oil-
fired CWH equipment. For units with multiple air inlets, DOE proposes 
that the test air temperature must be measured at each air inlet, and 
that the specified tolerance on deviation from the ambient room 
temperature must be maintained at each air inlet. This required 
tolerance for test air temperature was modeled after AHRI 1500-2015 in 
order to remain consistent with common industry practices. However, DOE 
proposes that this test air temperature requirement not apply to the 
standby loss test for flow-activated instantaneous water heaters 
proposed in section III.G of this NOPR, because the burner will not 
activate during the test. DOE also does not propose a test air 
temperature requirement for electric water heaters because electric 
water heaters are not powered by combustion, and, therefore, the test 
air temperature does not affect the efficiency of the heating elements.
    (4) Establishment of a requirement for ambient relative humidity of 
60 percent 5 percent for gas-fired and oil-fired 
commercial water heating equipment. DOE understands that humidity can 
have a significant effect on the tested efficiency of gas-fired and 
oil-fired CWH equipment, particularly condensing equipment. High 
humidity would enable equipment to capture more latent heat from 
combustion gases, thereby resulting in a higher measured

[[Page 28598]]

efficiency. Therefore, the lack of a specification for ambient humidity 
in DOE's current test procedures for gas-fired and oil-fired CWH 
equipment can lead to variation in test results between test labs. DOE 
recognizes that this effect would be noticeable in tests for both 
thermal efficiency and standby loss. Therefore, DOE proposes to amend 
its test procedures by specifying a requirement that ambient relative 
humidity be set and maintained at 60 percent 5 percent for 
gas-fired and oil-fired CWH equipment while verifying steady-state 
operation and during the thermal efficiency and standby loss tests, so 
as to minimize this effect, which should reduce variability in test 
results. However, DOE proposes that this ambient humidity requirement 
not apply to the standby loss test for flow-activated instantaneous 
water heaters proposed in section III.G of this NOPR, because the 
burner will not activate during the test. DOE also does not propose an 
ambient humidity requirement for electric water heaters because 
electric water heaters are not powered by combustion and, therefore, 
the ambient air humidity does not affect the efficiency of the heating 
elements. Also, DOE proposes that the ambient relative humidity be 
measured and recorded at the same location as the test air temperature, 
and at 30-second intervals during the entire test. For units with 
multiple air inlets, DOE proposes that the ambient relative humidity 
must be measured at each air inlet, and that 60 percent 5 
percent must be maintained at each air inlet. DOE proposes that the 
ambient relative humidity must remain within the specified range at all 
times during conduct of the thermal efficiency and standby loss tests.
    (5) Addition of a requirement to perform a pre-test conditioning 
phase, also known as a soak-in period, for storage water heaters and 
storage-type instantaneous water heaters. This proposed provision would 
require that the water heater remain idle (i.e., no water draws) for at 
least 12 hours with the thermostats maintained at settings that would 
achieve the required water temperature (see section III.D for further 
detail on proposed requirements for setting the tank thermostat), prior 
to conducting either a thermal efficiency test or standby loss test. 
This modification is similar to the soak-in period requirement adopted 
for consumer water heaters and certain commercial water heaters in the 
July 2014 final rule. 79 FR 40542, 40571 (July 11, 2014). This 
requirement would help minimize transient heat transfer effects that 
may reduce the reproducibility of the current standby loss test. 
However, DOE proposes not to require a soak-in period be conducted 
prior to beginning an efficiency test (i.e., thermal efficiency or 
standby loss) if no settings on the water heater have been changed and 
the water heater has not been turned off since the end of a previously 
run efficiency test. DOE proposes a requirement for a soak-in period 
for unfired hot water storage tanks with different test conditions in 
section III.C.
    (6) Specifying the locations for inlet and outlet water temperature 
measurement for storage water heaters, storage-type instantaneous water 
heaters, and unfired hot water storage tanks. DOE's current test 
procedure for CWH equipment incorporates by reference the requirement 
in Exhibit G.1 of ANSI Z21.10.3-2011 that the inlet and outlet piping 
be immediately turned vertically downward from the connections on a 
tank-type water heater to form heat traps and that the thermocouples 
for measuring inlet and outlet water temperatures be installed before 
the inlet heat trap piping and after the outlet heat trap piping. While 
DOE agrees with the general position of the inlet and outlet 
thermocouples relative to the heat trap piping, the precise location of 
the thermocouples in terms of distance away from the water heater is 
not specified. The absence of a clearly defined location for the 
thermocouples can contribute to variability in the test results. 
Considering this issue, DOE proposes that the thermocouples be placed 
with total vertical piping length of 24 inches. For water heaters with 
vertical connections, the 24 inches of total vertical piping distance 
is divided into 6 inches of vertical piping upstream from the turn for 
the heat trap and 18 inches downstream from the turn for the heat trap. 
For water heaters that have horizontal water connections, DOE proposes 
that the thermocouples be placed with total horizontal piping length 
between the thermocouple location and the connection port of six 
inches. For water heaters that have vertical water connections, due to 
the differences in the size and dimensions of water heaters, it may not 
be possible to have the inlet and outlet water piping be turned 
vertically downward after a fixed horizontal distance of 6 inches away 
from the connection port. Therefore, for water heaters with vertical 
connections (opening top or bottom), DOE proposes that the horizontal 
distance be equal to the distance from the connection port to the edge 
of the water heater plus 2 inches. Figure III.1, Figure III.2, and 
Figure III.3 show the three proposed configurations for placement of 
inlet and outlet water thermocouples for tank-type water heaters. All 
dimensions shown in the figures and specified in this paragraph are 
measured from the outer surface of the pipes or water heater jacket (as 
applicable).
BILLING CODE 6450-01-P

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[GRAPHIC] [TIFF OMITTED] TP09MY16.268


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[GRAPHIC] [TIFF OMITTED] TP09MY16.269

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    (7) Increasing the frequency of data collection. To further reduce 
variability in test results, DOE proposes to decrease the length of the 
time interval between data collection during the thermal efficiency 
test from 1 minute to 30 seconds and during the standby loss test from 
15 minutes to 30 seconds for all CWH equipment (as applicable). This 
time interval would apply to the measurement of ambient room 
temperature, test air temperature, and ambient relative humidity for 
both the thermal efficiency and standby loss tests (as applicable). For 
the thermal efficiency test, the 30-second time interval would also 
apply to the measurement of supply and outlet water temperatures. For 
the standby loss test the 30-second time interval would apply to the 
measurement of mean tank temperature for storage and storage-type 
instantaneous water heaters (storage-type instantaneous water heaters 
are discussed in section III.F), and to measurement of outlet water 
temperature for instantaneous water heaters and hot water supply 
boilers. Additionally, DOE proposes that the fuel (i.e., gas or oil) 
consumption be measured at 10-minute intervals during the thermal 
efficiency test. These increases in frequency of data collection would 
increase data granularity, thereby providing more information to 
identify testing irregularities contributing to test result variance. 
This modification would also allow for more accurate timing of test 
start and stop, which may lead to more repeatable results.
    DOE also considered three other modifications to improve standby 
loss test repeatability, but ultimately decided against proposing these 
modifications for the reasons provided. The three additional considered 
but rejected modifications include:
    (1) An increase in the number of temperature sensors measuring 
internal tank temperature from six to twelve. These sensors would be 
located at the vertical midpoint of 12 equal volumes of water within 
the water heater. It was thought that this modification could 
potentially increase the reliability of the internal tank temperature 
data and allow better resolution of temperature stratification within 
the tank. However, based on preliminary test data, DOE observed that 
increasing the number of sensors had little effect on the outcome of 
the test and, thus, does not justify the additional burden.
    (2) An increase in the number of thermal probes used to measure 
ambient temperature from one to at least four. These probes could be 
located at the vertical midpoint of the tank at a perpendicular 
distance of 24 inches (61 cm) from the surface of the jacket, and in 
each cardinal direction (i.e., North, South, East, and West). It was 
thought that this modification could potentially help reduce 
uncertainty of the true ambient temperature profile around the water 
heater and the associated effect of this uncertainty on the measured 
standby loss of tested CWH equipment. However, based on preliminary 
test data, DOE observed that increasing the number of sensors had 
little effect on the ambient temperature readings, and, thus, little 
impact on the outcome of the test. Consequently, it would not justify 
the additional burden.
    (3) Lengthening the required period for establishing steady-state 
operation prior to the thermal efficiency test to thirty minutes. DOE's 
current test procedure references Exhibit G.1 of ANSI Z21.10.3-2011, 
which requires that the outlet water temperature be established as 
constant prior to conducting the thermal efficiency test, as determined 
by no variation in excess of 2[emsp14][deg]F over a 3-minute period. 
For some equipment, a 3-minute period may not be long enough to 
establish steady-state operation of gas-fired or oil-fired CWH 
equipment, and a water heater could conceivably exhibit no variation in 
excess of 2[emsp14][deg]F over a 3-minute period before establishing 
steady-state operation. Additionally, DOE notes that the current test 
procedure does not impose requirements for maximum variation in inlet 
water temperature or water flow rate during this period for verifying 
steady-state operation. Thus, DOE believes that extending the period 
for determining steady-state operation could improve test method 
repeatability, and DOE is seeking information and data regarding such a 
change. DOE notes that for commercial packaged boilers, which are 
similar equipment to some classes of CWH equipment, AHRI 1500-2015 
specifies a 30-minute warm-up period for determining steady-state 
operation has been achieved.
    Issue 3: DOE requests comments and data on its proposed changes to 
improve the repeatability of the thermal efficiency and standby loss 
test procedures for certain commercial water heating equipment. 
Specifically, DOE requests comment on its proposed requirements for 
ambient relative humidity. DOE does not propose this requirement for 
testing of electric water heaters, and seeks feedback on whether 
including such a requirement would improve the repeatability of the 
standby loss test for electric water heaters. DOE is also seeking 
comments regarding any additional changes that would improve the 
repeatability of the thermal efficiency and standby loss tests.
    Issue 4: DOE requests comment on the changes to improve test 
repeatability for its test procedures for certain CWH equipment that 
were identified but not proposed in this NOPR. If comments suggest that 
DOE should implement these changes, then DOE will evaluate whether it 
can adopt those changes in the final rule or must engage in further 
rulemaking. Particularly, DOE requests data showing what duration for 
the steady-state verification period would ensure steady-state 
operation is reached for gas-fired and oil-fired CWH equipment prior to 
the thermal efficiency test. DOE also seeks data that suggest suitable 
tolerances for water temperature and flow rate for this steady-state 
verification period. Additionally, DOE seeks comment on whether 
different requirements for establishing steady-state operation are 
warranted for each equipment class of CWH equipment.

C. Test Method for Unfired Hot Water Storage Tanks

    EPCA defines an ``unfired hot water storage tank'' (UFHWST) as a 
tank used to store water that is heated externally. (42 U.S.C. 
6311(12)(C)) The current Federal standard for this equipment type 
requires a minimum thermal insulation (R-value) of 12.5. 10 CFR 
431.110. DOE defines ``R-value'' as the thermal resistance of 
insulating material as determined based on ASTM Standard Test Method 
C177-97 or ASTM Standard Test Method C518-91 and expressed in 
[deg]F[middot]ft\2\[middot]h/Btu. 10 CFR 431.102. In section III.A.3 of 
this rulemaking, DOE proposes to update references to these standards 
in its definition for ``R-value'' by incorporating by reference ASTM 
C177-13 and ASTM C518-10.
    DOE is aware that some manufacturers ship UFHWSTs without 
insulation, and that uninsulated UFHWSTs may or may not then be 
insulated on-site. In this rulemaking, DOE makes clear that UFHWSTs 
shipped without insulation are not compliant with the Federal R-value 
standard. All UFHWSTs must either be shipped insulated to the R-value 
standard or shipped together with insulation meeting the R-value 
standard. Manufacturers of UFHWSTs must certify that the insulation 
meets the R-value standard prescribed in 10 CFR 431.110, and this 
certification must be based on testing according to the methods 
prescribed in the R-value definition. A UFHWST manufacturer may 
demonstrate compliance with the insulation requirements either by

[[Page 28602]]

conducting testing itself or by using test data from the insulation 
material producer. Further, manufacturers of UFHWSTs are responsible 
for retaining records of the underlying test data used for 
certification in accordance with current maintenance of records 
requirements set forth at 10 CFR 429.71.
    Because DOE includes ASTM test methods for measuring R-value in its 
definition of ``R-value,'' DOE does not currently specify a test 
procedure for measuring energy efficiency of UFHWSTs in 10 CFR 431.106. 
In the February 2014 RFI, DOE requested comment on whether the R-value 
is an adequate energy efficiency descriptor for UFHWSTs. DOE also 
requested comment on the potential for replacing R-value with standby 
loss, or another metric, as the energy efficiency descriptor for 
UFHWSTs, and how to establish a standby loss test or other test for 
this equipment if such a metric is appropriate. 79 FR 10999, 11002 
(Feb. 27, 2014).
    A.O. Smith, AHRI, and Rheem commented that there is no need for a 
test procedure to measure the R-value of the insulation on UFHWSTs. 
(A.O. Smith, No. 7 at pp. 1-2; AHRI, No. 2 at pp. 2-3; Rheem, No. 3 at 
pp. 1-2) AHRI also commented that the R-value requirement is in no way 
a measurement of the ``efficiency'' of an unfired storage tank, and 
that ASHRAE deliberately did not include a thermal efficiency or 
standby loss requirement for this equipment in ASHRAE Standard 90.1. 
(AHRI, No. 2 at pp. 2-3) Bradford White and HTP support the current 
requirement of a minimum insulation R-value, and Bradford White 
estimated that replacing the R-value metric with a metric requiring an 
efficiency test would require 3 days of testing per model. (Bradford 
White, No. 8 at p. 1; HTP, No. 5 at p. 2) AHRI, HTP, and Rheem also 
expressed support for the current two ASTM test methods (C177-97 and 
C518-91) for testing the R-value of insulation for UFHWSTs. (AHRI, No. 
2 at pp. 2-3; HTP, No. 5 at p. 2; Rheem, No. 3 at pp. 1-2)
    Joint Advocates noted that the two ASTM test methods are intended 
for flat samples, while UFHWSTs are generally pressure vessels with 
curved surfaces. (Joint Advocates, No. 4 at p. 2) Joint Advocates 
recommended replacing the present R-value requirement for UFHWSTs with 
a standby loss test similar to the test used for electric and fuel-
fired commercial water heaters because the current R-value requirement 
does not ensure that all surfaces of the tank are adequately insulated, 
nor does it encourage other methods to reduce heat loss, such as anti-
siphon connections and/or eliminating thermal bridges. Joint Advocates 
also recommended that for any units with legitimate needs for field 
insulation of UFWHSTs, DOE could either allow for a waiver or establish 
a separate class of uninsulated UFHWSTs. (Joint Advocates, No. 4 at p. 
2)
    A.O. Smith and AHRI also pointed out that there exists a group of 
UFHWSTs that are larger than standard volume models and are often built 
to order. (A.O. Smith, No. 7 at p. 2; AHRI, No. 2 at pp. 2-3) A.O. 
Smith and AHRI stated that these units are often shipped without 
insulation and subsequently field-insulated due to shipping and 
installation considerations that make it impractical to insulate at the 
site of manufacture. (A.O. Smith, No. 7 at p. 2; AHRI No. 2 at pp. 2-3)
    After considering these comments, DOE has tentatively determined 
that a measurement of energy efficiency of UFHWSTs is necessary to more 
fully comply with the requirements of 42 U.S.C. 6314(a)(2)-(3), and 
proposes a standby loss metric and test method to replace the current 
R-value requirement. Although DOE recognizes that requiring use of a 
standby loss test will increase test burden for manufacturers, DOE has 
tentatively concluded that the benefits of such a metric would outweigh 
this additional burden. Primarily, DOE agrees with Joint Advocates that 
a standby loss metric would encourage and credit energy-saving 
technologies that are not measured by the R-value of the insulation and 
ensure that all surfaces are adequately insulated. As a result, DOE 
proposes to establish a standby loss test method for UFHWSTs that 
monitors the decrease in tank temperature from a set temperature. In 
addition, DOE proposes to amend the definition of ``standby loss'' at 
10 CFR 431.102 to include unfired hot water storage tanks.
    Regarding the points from AHRI, A.O. Smith, and Joint Advocates 
about UFHWSTs that are shipped without insulation and subsequently 
field-insulated, DOE reiterates that all UFHWSTs must have a minimum 
thermal insulation R-value of 12.5 when they are shipped from the 
manufacturer. Any units shipped without a minimum thermal insulation of 
R-12.5 and then insulated on-site would not be compliant with DOE's 
current regulations.
    To determine the standby loss of an UFHWST, the storage capacity of 
the tank must first be determined. Section 5.27 of ANSI Z21.10.3-2015 
includes a method for measuring the storage capacity, and it states 
that this method is applicable to water heaters including storage 
vessels. DOE examined this method and found no reason why it would be 
inapplicable to UFHWSTs. Therefore, DOE proposes to use the test method 
described in section 5.27 of ANSI Z21.10.3-2015 to measure the storage 
capacity of UFHWSTs. DOE includes a procedure for determining storage 
volume in its proposed test procedure for UFHWSTs that has only 
clarifying differences from the method presented in section 5.27 of 
ANSI Z21.10.3-2015. DOE's proposed procedure for determining storage 
volume is discussed in further detail in section III.G.
    Next, DOE considered three possible test methods to determine the 
standby loss coefficient and hourly standby losses of an UFHWST. The 
first method considered--and the one that DOE proposes as the test 
method for UFHWSTs--is based on a method for assessing the energy 
efficiency of indirect water heaters, which was originally developed by 
the GAMA,\10\ and set forth in Testing Standard IWH-TS-1, ``Method to 
Determine Performance of Indirect-Fired Water Heaters'' (March 2003 
edition).\11\ Under this procedure, the tank is set up as would 
normally be done in the field, with potable water inlet and outlet 
piping and supply and return piping connected to an external heat 
source. This procedure specifies bringing the water in the tank to a 
mean temperature of 140[emsp14][deg]F by the external heat source, and 
then monitoring the stored water temperature while the heat source is 
inactive and the water temperature inside the tank decreases. A linear 
fit is applied to temperature data as the mean tank temperature drops 
from 137[emsp14][deg]F to 133[emsp14][deg]F to yield a temperature 
decay term with units of [deg]F/h. DOE proposes to use this test method 
as the basis of a test method to determine the standby loss of UFHWSTs 
but with several modifications. DOE has tentatively concluded that the 
use of Testing Standard IWH-TS-1 would sufficiently capture the heat 
loss of UFHWSTs and reduce burden to manufacturers relative to 
alternative methods, because it is already an industry-accepted 
procedure that is used in AHRI's certification program for indirect 
water heaters.
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    \10\ The Air-Conditioning and Refrigeration Institute (ARI) and 
GAMA merged to become AHRI on January 1, 2008.
    \11\ Available at: http://www.org/App_Content/ahri/files/standards%20pdfs/Indirect-Fired%20Water%20Heater%20Testing%20Standard03.pdf (last accessed 
February 12, 2015).
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    As noted in this preamble, DOE proposes several modifications to 
Testing Standard IWH-TS-1 to be included in DOE's proposed test

[[Page 28603]]

procedure for standby loss of UFHWSTs. First, because the nominal tank 
temperature for determining standby loss for commercial storage water 
heaters is 140[emsp14][deg]F, DOE proposes to calculate standby loss of 
UFHWSTs using temperature data collected as the mean tank temperature 
drops from 142[emsp14][deg]F to 138[emsp14][deg]F instead of 
137[emsp14][deg]F to 133[emsp14][deg]F. To do so, DOE proposes that the 
tank be filled with water that is heated sufficiently to achieve a mean 
tank temperature of 145[emsp14][deg]F and then be allowed to decrease 
from that point. Consequently, DOE also proposes to update the water 
density and specific heat capacity constants used in calculation of 
standby loss to 8.205 lb/gallon and 0.999 Btu/[deg]F[middot]lb 
respectively, to correspond to the mid-point of DOE's proposed 
temperature range (140[emsp14][deg]F), instead of the mid-point of the 
temperature range specified in Testing Standard IWH-TS-1 
(135[emsp14][deg]F). However, DOE notes that the value for specific 
heat capacity of water does not change as the temperature increases 
from 135[emsp14][deg]F to 140[emsp14][deg]F, with the number of 
significant figures specified in Testing Standard IWH-TS-1.
    DOE also proposes to adopt the same ambient room temperature 
requirement for all CWH equipment that is discussed in section III.B. 
Specifically, DOE proposes that the ambient room temperature must be 
maintained at 75[emsp14][deg]F  5[emsp14][deg]F during the 
test (as measured at each 30-second interval), and the measured room 
temperature must not vary by more than 2.0[emsp14][deg]F 
from the average ambient room temperature during the test. While 
Testing Standard IWH-TS-1 specifies an ambient room temperature of 
70[emsp14][deg]F, DOE notes that many manufacturers of UFHWSTs also 
manufacture storage water heaters. Therefore, DOE expects that 
manufacturer burden would be reduced if storage water heaters and 
UFHWSTs can be tested in the same test room, and DOE's proposal is 
consistent with that objective. Additionally, DOE proposes a 
requirement for maximum air draft in section III.B that applies to the 
soak-in period and standby loss test for UFHWSTs. Similar to ambient 
room temperature, DOE expects that aligning this requirement with that 
for other classes of CWH equipment will reduce testing burden for CWH 
manufacturers. DOE also proposes a requirement for a soak-in period to 
be conducted prior to beginning the standby loss test for UFHWSTs. In 
this soak-in period, the tank must sit without any draws taking place 
for at least 12 hours after being filled with water such that a mean 
tank temperature of 145[emsp14][deg]F  5[emsp14][deg]F is 
achieved. After completion of the soak-in period, DOE would require 
that the UFHWST be filled again such that a mean tank temperature of 
145[emsp14][deg]F  5[emsp14][deg]F is achieved, because the 
stored water temperature would decrease during the soak-in period. 
Additionally, DOE proposes requirements for piping insulation and water 
supply similar to those for other classes of CWH equipment included in 
Annex E.1 of ANSI Z21.10.3-2015.
    DOE also proposes to collect temperature data at intervals of 30 
seconds during this test, as opposed to the 15-minute intervals 
specified by the IWH-TS-1 test method. DOE has determined that a higher 
number of data points will improve the accuracy of the least-squares 
regression and that, given the data storage capacity of modern data 
acquisition equipment, the higher frequency of data collection will 
pose only a negligible additional burden upon laboratories, as compared 
to the current 15-minute data collection interval. DOE also proposes to 
convert the decay rate metric to the standby loss metric currently 
applied to commercial storage water heaters, which has units of Btu/h.
    DOE also considered two other approaches to determine the standby 
loss for UFHWSTs and is presenting these alternatives as part of this 
NOPR for comment on their merits compared to the proposed method. The 
first alternative is similar to the method proposed, but uses a 
different condition to end the standby loss test. Specifically, under 
this approach, the test would end 24 hours after the beginning of the 
test, instead of after the mean tank temperature reaches a specified 
temperature. However, the use of such a test ending condition would 
result in different final water temperatures for units with different 
rates of heat loss. This variation in final water temperature would 
impart an undesirable benefit to UFHWSTs that lose heat more quickly, 
because the rate of heat transfer from water to the surrounding air 
decreases as the corresponding temperature difference decreases. 
Additionally, DOE believes that a change in test ending condition to a 
24-hour time limit may result in unnecessary test burden for 
manufacturers, as it would likely extend the duration of the test. In 
light of the potential downsides to this alternative, DOE has 
tentatively concluded that the test method proposed in this document 
(based on the industry-accepted IWH-TS-1 test method) would 
sufficiently capture the rate of heat loss from the tank while 
potentially allowing for a shorter test time.
    DOE also considered a second alternative test method that would 
maintain the set point of the hot water within the UFHWST, by 
connecting an UFHWST to an external heat source (i.e., a water heater 
or boiler) that would replace water in the tank that has cooled down 
with water that has been heated by the external source. Circulation 
from the external heat source to the water heater would be controlled 
based on the internal tank temperature. The amount of water circulated 
into the UFHWST from the external source and the temperature of supply 
water and return water would be monitored during reheat cycles to 
determine the amount of energy supplied to the tank. This test would 
start one hour after a reheat cycle and would progress until one hour 
after completion of the first reheat cycle after 24 hours have elapsed 
since the start of the test. Calculation of standby loss would include 
the change in stored energy within the UFHWST, as well as energy 
supplied to the UFHWST by the external heat source. While this test 
method would more closely align with DOE's standby loss test procedures 
for electric and fuel-fired CWH equipment and be more representative of 
field use of UFHWSTs, DOE has tentatively concluded that this method 
would be overly burdensome to manufacturers and could lead to increased 
variability in test results. Use of other CWH equipment to heat water 
being supplied to the UFHWST could lead to variability based on 
variation in the equipment and piping used for testing. Based on 
preliminary test data, DOE observed similar results for a method that 
uses circulation with an external heat source and a method that does 
not; therefore, DOE has tentatively concluded that a method using 
circulation with an external heat source would not provide a more 
accurate result that would be commensurate with the additional testing 
burden of such an approach.
    Issue 5: DOE requests comment on the proposed test procedure to 
determine the standby loss for UFHWSTs, and on whether any other 
methods, including those detailed in this NOPR, would lead to a better 
test. Specifically, DOE solicits feedback on whether the proposed test 
would be long enough to determine an accurate standby loss rating, 
whether the use of a linear approximation of the temperature decay is 
sufficient to estimate the standby loss, whether running the test by 
simply letting the temperature decay (rather than providing external 
heat to bring the temperature of the water back to operational 
temperature) is appropriate, and whether the adoption of test

[[Page 28604]]

conditions (i.e., ambient room temperature, maximum air draft, water 
temperature) similar to that of other classes of CWH equipment is 
appropriate. DOE also seeks comment on whether any of its identified 
alternatives could be modified to improve their repeatability and to 
decrease test burden, thereby supporting further consideration.

D. Procedure for Setting the Tank Thermostat for Storage and Storage-
Type Instantaneous Water Heaters

    DOE's test method for measuring the energy efficiency of CWH 
equipment currently requires that the thermostat be set to achieve 
specific conditions for the mean tank temperature before the test may 
begin. In particular, section g of Exhibit G.1 of ANSI Z21.10.3-2011 
(which is currently incorporated by reference into the DOE test 
procedure) requires that before starting testing, the thermostat 
setting must be adjusted such that, when starting with the water in the 
system at 70[emsp14][deg]F  2[emsp14][deg]F, the maximum 
mean tank temperature will be 140[emsp14][deg]F  
5[emsp14][deg]F after the thermostat reduces the gas supply to a 
minimum. DOE understands that some units may have difficulty achieving 
the required mean tank temperature condition, and in the February 2014 
RFI DOE requested feedback on potential test procedure amendments to 
address this issue. 79 FR 10999, 11003 (Feb. 27, 2014).
    In response to the February 2014 RFI, the four manufacturers among 
the interested parties (A.O. Smith, Bradford White, HTP, and Rheem), as 
well as AHRI, expressed support for changing the set point conditions 
to require monitoring the outlet water temperature rather than the mean 
tank temperature. (Bradford White, No. 8 at p. 1; Rheem, No. 3 at p. 2; 
HTP, No. 5 at p. 2; A.O. Smith, No. 7 at p. 2; AHRI, No. 2 at p. 4) 
A.O. Smith, Rheem, and AHRI expressed support for maintaining the set 
point condition at 140[emsp14][deg]F  5[emsp14][deg]F for 
the outlet water temperature. (A.O. Smith, No. 7 at p. 2; Rheem, No. 3 
at p. 2; AHRI, No. 2 at p. 4) A.O. Smith stated that certain designs of 
CWH equipment cannot reach a mean tank temperature of 140[emsp14][deg]F 
 5[emsp14][deg]F, including down-fired, condensing 
equipment with reduced firing rates, and solar or other renewable 
source equipment. (A.O. Smith, No. 7 at p. 2) DOE received no comments 
opposing a potential change from setting the thermostat based on the 
mean tank temperature to setting the thermostat based on the 
temperature of the delivered water.
    After carefully considering these comments, DOE proposes to modify 
the thermal efficiency and standby loss test procedures for gas-fired 
and oil-fired storage water heaters and storage-type instantaneous 
water heaters to require that before starting testing, the thermostat 
setting be adjusted such that, when starting with the water in the 
system at 70 [deg]F  2 [deg]F, the maximum outlet water 
temperature will be 140 [deg]F  5 [deg]F after the 
thermostat reduces the gas supply to a minimum. DOE has tentatively 
concluded that changing from a mean tank temperature requirement to an 
outlet temperature requirement would better accommodate designs of gas-
fired and oil-fired water heaters that are not designed to have high 
mean tank temperatures (e.g., condensing water heaters) or that rely 
upon stratification.
    DOE does not propose changing the mean tank temperature requirement 
to an outlet water temperature requirement for electric storage water 
heaters because of complications with setting tank thermostats. 
Electric storage water heaters have multiple heating elements and a 
thermostat corresponding to each element, and each thermostat needs to 
be set prior to beginning the standby loss test. Therefore, DOE reasons 
that electric storage water heaters, which vary in configuration and 
number of heating elements, are not well-suited to an outlet water 
temperature requirement because it is unclear how the lower thermostats 
would be set to achieve a designated outlet water temperature. A 
consistent, reproducible process for setting the thermostats is 
essential to having a repeatable test. Therefore, DOE proposes to 
maintain a mean tank temperature requirement for the standby loss test 
for electric storage water heaters. However, DOE proposes to clarify 
its language specifying the method for setting thermostats in an 
electric storage water heater with multiple thermostats. Specifically, 
DOE proposes to clarify that the thermostats are to be set in immediate 
succession, starting from the topmost thermostat. DOE also proposes to 
clarify that when setting each thermostat, the mean tank temperature is 
calculated using only temperature readings measured at locations higher 
in the tank than the heating element corresponding to the thermostat 
being set, with the exception of the bottommost thermostat. Finally, 
DOE proposes to clarify that all thermostats below the thermostat being 
tested must be turned off so that no elements below the thermostat 
being tested are in operation.
    Issue 6: DOE seeks comment on its proposed change to its 
requirements for setting the tank thermostat in the thermal efficiency 
and standby loss test procedures for gas-fired and oil-fired storage 
and storage-type instantaneous water heaters from measurement of mean 
tank temperature to measurement of outlet water temperature.
    Issue 7: DOE seeks comment on its tentative decision to maintain a 
mean tank temperature requirement for the standby loss test for 
electric storage water heaters. DOE also requests comment on its 
clarifying language for setting tank thermostats for electric storage 
water heaters with multiple thermostats.

E. Clarifications to the Thermal Efficiency and Standby Loss Test 
Procedures

    The calculation of thermal efficiency included in the current DOE 
test procedure for gas-fired and oil-fired CWH equipment at 10 CFR 
431.106 (which incorporates the method used in Exhibit G.1 of ANSI 
Z21.10.3-2011) does not consider change in internal stored energy of 
the stored water.\12\ In the February 2014 RFI, DOE sought public 
comment on whether it is necessary to account for the potential 
variation in stored thermal energy inside the water heater during the 
course of the test, and specifically whether there is a need to account 
for losses in the internal stored energy in the thermal efficiency 
calculation. 79 FR 10999, 11003 (Feb. 27, 2014). In addition, DOE 
sought feedback on whether there is need for clarification to ensure 
that the water flow rate is adjusted so that the burner is fired at a 
constant firing rate or whether cycling of the burner is allowed. Id.
---------------------------------------------------------------------------

    \12\ The thermal efficiency test procedure in Exhibit G.1. of 
ANSI Z21.10.3-2011 is a steady-state procedure where the supply 
water temperature is maintained at 70[emsp14][deg]F  
2[emsp14][deg]F, outlet water temperature is maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature, and the flow rate is adjusted to a constant value that 
can maintain these temperatures throughout the duration of the test. 
Because the supply and outlet water temperatures and the water flow 
rate are not varied while taking the measurements to calculate the 
thermal efficiency, rate of change of stored energy in the water 
heater would be zero.
---------------------------------------------------------------------------

    In response, DOE received several comments from interested parties 
and stakeholders. AHRI commented that no change is required to the test 
procedure to address this issue. According to AHRI, the intent of the 
test method is that the burner be operated at a continuous, full-input 
firing rate, and once steady state is achieved, there would not be any 
issue with regards to potential changes in stored heat within the water 
heater. (AHRI, No. 2 at p. 4) Rheem deferred to AHRI's comments of not 
requiring any change in the thermal efficiency test method. (Rheem, No. 
3 at p. 2) Bradford White, HTP, and A.O.

[[Page 28605]]

Smith also commented on this issue. Bradford White did not see any 
merit in modifying the test procedure to account for variation in 
thermal energy stored in the tank. As a possible clarification, 
Bradford White suggested adding a sentence stating that, ``flow rate 
must achieve continuous full rate burner operation at the required 
stable outlet water temperature.'' According to Bradford White, stored 
energy would only be a significant consideration if the test conditions 
are not allowed to stabilize sufficiently or if the conditions are not 
controlled tightly. Bradford White recommended additional investigation 
of any modification that is proposed if DOE decides to amend the test 
procedure to account for stored energy changes. (Bradford White, No. 8 
at pp. 1-2) A.O. Smith commented that the current test procedure for 
determining thermal efficiency has been used for a very long time 
without any confusion, and accordingly, A.O. Smith did not recommend 
any changes in the current test procedure. (A.O. Smith, No. 7 at p. 2) 
HTP commented that units are commonly pre-conditioned before the test, 
and recommended requiring products be pre-conditioned as part of the 
DOE test method. Further, HTP asserted that if tanks are pre-
conditioned, it would not expect any additional accuracy achieved by 
accounting for the difference in energy maintained within the storage 
tank during the test. (HTP, No. 5 at p. 3) Joint Advocates encouraged 
any changes that would minimize systematic errors if the current test 
procedure is insufficiently specific and if an agreement can be reached 
on a reasonable method whose cost is commensurate to the value of the 
change. (Joint Advocates, No. 4 at p. 2)
    DOE considered all comments received from interested parties in 
response to this issue. Based on the comments received, DOE has 
tentatively decided not to implement any changes in the current thermal 
efficiency test methods or calculations for CWH equipment to account 
for changes in thermal energy stored in the water heater during the 
course of the 30-minute test. However, DOE proposes to clarify the 
requirements for maintaining steady-state operation throughout the 
thermal efficiency test. Specifically, DOE proposes to clarify that no 
settings on the water heater may be changed during the course of the 
thermal efficiency test, once steady-state operation is achieved, as 
determined by no variation of outlet water temperature in excess of 
2[emsp14][deg]F over a 3-minute period. This includes setting the flow 
rate during testing such that the heater operates at full firing rate 
(i.e., no modulation or cut-outs) for the entire duration of the test. 
Although the current test method is clear in requiring the test 
conditions to reach steady state prior to starting the test, there 
could be some confusion on whether these conditions are required to be 
maintained for the entire duration of the test. DOE proposes to add a 
statement to clarify steady-state operation during the thermal 
efficiency test. The proposed clarifying statement specifies that the 
test entity must maintain the outlet water temperature at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature and ensure the burner fires continuously at the full firing 
rate (i.e., no modulation or cut-outs) for the entire duration of the 
thermal efficiency test. Further, the proposed statement clarifies that 
once steady-state operation is achieved, as determined by no variation 
of the outlet water temperature in excess of 2[emsp14][deg]F over a 3-
minute period, no settings on the water heating equipment may be 
changed until measurements for the thermal efficiency test are 
finished.
    Additionally, DOE proposes to clarify a similar requirement for the 
standby loss test for CWH equipment other than those meeting DOE's 
proposed definition for ``flow-activated instantaneous water heater.'' 
DOE proposes to require that after the first cut-out before beginning 
the standby loss test, no settings may be changed on the water heating 
equipment until measurements for the standby loss test are finished.
    Issue 8: DOE requests comment on its proposed clarifying statements 
regarding steady-state operation and manipulation of CWH equipment 
settings during efficiency tests.

F. Definitions for Certain Consumer Water Heaters and Commercial Water 
Heating Equipment

1. Consumer Water Heaters
    EPCA's definition of water heater specifies input ratings at or 
below which water heaters are to be classified as consumer water 
heaters (e.g., 75,000 Btu/h for gas-fired storage water heaters; 12 kW 
for electric storage water heaters and electric instantaneous water 
heaters; 210,000 Btu/h for oil-fired instantaneous water heaters). (42 
U.S.C. 6291(27)) DOE's regulatory definition of ``water heater'' 
restates the definition from the consumer products part of EPCA. (42 
U.S.C. 6291(27); 10 CFR 430.2) In addition to adopting EPCA's 
definition of water heater, DOE had defined a variety of terms that 
helped specify the test procedure provisions that applied to specific 
kinds of water heaters. See, e.g., 10 CFR part 430, subpart B, appendix 
E, in the 10 CFR parts 200 to 499 edition, revised as of January 1, 
2015 (defining, for example, gas instantaneous water heater and 
electric storage-type water heater). These test procedure definitions 
included provisions related to water temperature design characteristics 
and rated storage volume. The standards at 10 CFR 430.32 and the water 
heater definition at 10 CFR 430.2 did not include any such limitations.
    In the July 11, 2014 test procedure final rule, in an effort to 
consolidate all relevant definitions in 10 CFR 430.2, DOE removed the 
definitions for specific kinds of consumer water heaters from its test 
method at appendix E to subpart B of part 430 and added definitions to 
10 CFR 430.2 (i.e., ``Electric heat pump water heater,'' ``Electric 
instantaneous water heater,'' ``Electric storage water heater,'' ``Gas-
fired heat pump water heater,'' ``Gas-fired instantaneous water 
heater,'' ``Gas-fired storage water heater,'' ``Oil-fired instantaneous 
water heater,'' and ``Oil-fired storage water heater''). 79 FR 40542, 
40549, 40566-67 (July 11, 2014). These definitions became effective on 
July 13, 2015, and excluded products with a rated storage capacity 
greater than 120 gallons and in some cases included limitations with 
respect to units designed to heat and store water at a thermostatically 
controlled temperature less than or equal to 180[emsp14][deg]F. 79 FR 
40542, 40566-67 (July 11, 2014). These changes to the definitions were 
proposed and finalized after the publication of the April 16, 2010 
final rule setting amended standards for consumer water heaters, and 
they were not effective until after the April 16, 2015 compliance date 
for those standards. As noted previously, the standards and definition 
set forth in EPCA do not include any requirement related to the water 
temperature or storage capacity. Therefore, prior to the effectiveness 
of July 2014 regulation, any product meeting the definition of a 
``water heater'' would have been subject to the statutory standards 
applicable to consumer water heaters, regardless of the water delivery 
temperature or storage capacity.
    DOE now proposes to correct the definitions for specific types of 
consumer water heaters included at 10 CFR 430.2 by removing from the 
definitions the specifications related to the water temperature and 
storage capacity. Thus, a model that would otherwise meet the 
definition of a consumer water heater does not ``become'' commercial as 
the result of the unit's capability of producing water

[[Page 28606]]

at temperatures above 180[emsp14][deg]F. More generally, a product that 
utilizes gas, oil, or electricity to heat potable water for use outside 
the heater upon demand that does not meet the statutory definition of 
``water heater'' at 42 U.S.C. 6291(27) as implemented by this proposed 
rule, if adopted, would be a commercial water heater, subject to the 
standards for such water heaters as set forth in 42 U.S.C. 6313.
    Furthermore, DOE notes that, if a manufacturer offers a product 
that meets the definition of a water heater at 10 CFR 430.2, but cannot 
be tested by the applicable test procedure, the manufacturer should 
notify DOE and request a waiver from the applicable test method using 
the procedures at 10 CFR 430.27. If a waiver were granted, DOE would 
update its test procedure in the next rulemaking for consumer water 
heaters. DOE does not anticipate, however, that such a waiver would be 
needed. The UEF test procedure was developed quite recently and was 
designed to span the consumer product/commercial equipment boundary; 
accordingly, DOE expects that all units (irrespective of designed water 
temperature and/or rated storage capacity) can be tested without 
difficulty.
    In its definitions at 10 CFR 430.2, DOE currently defines the terms 
``electric heat pump water heater'' and ``gas-fired heat pump water 
heater.'' In its energy conservation standards for consumer water 
heaters at 10 CFR 430.32(d), DOE does not use the terms ``electric heat 
pump water heater'' or ``gas-fired heat pump water heater.'' DOE's 
Uniform Test Method for Measuring the Energy Consumption of Water 
Heaters at appendix E to subpart B of part 430 also does not use these 
terms. Therefore, DOE proposes to remove these terms.
    As discussed in the previous paragraphs, DOE proposes to revise the 
definitions for ``Electric instantaneous water heater'', ``Electric 
storage water heater'', ``Gas-fired instantaneous water heater'', 
``Gas-fired storage water heater'', ``Oil-fired instantaneous water 
heater'', ``Oil-fired storage water heater'', in its regulations of 
consumer water heaters at 10 CFR 430.2 as set out in the regulatory 
text at the end of this document.
    Issue 9: DOE requests comment on its proposal to amend the 
definitions for consumer water heaters codified at 10 CFR 430.2 by 
removing the water temperature and storage capacity provisions. DOE 
also requests comment on its proposal to remove the definitions at 10 
CFR 430.2 for ``electric heat pump water heater'' and ``gas-fired heat 
pump water heater.''
2. Commercial Water Heating Equipment
    DOE currently includes several definitions that include the terms 
``rated input'' or ``input rating'' in its regulations for CWH 
equipment at 10 CFR 431.102. These definitions include ``hot water 
supply boiler,'' ``instantaneous water heater,'' ``residential-duty 
commercial water heater,'' and ``storage water heater.'' In section 
III.K of this NOPR, DOE proposes a new definition for ``fuel input 
rate,'' a value to be determined for all gas-fired and oil-fired CWH 
equipment. Therefore, DOE proposes to replace the terms ``rated input'' 
and ``input rating'' with the term ``fuel input rate'' for gas-fired 
and oil-fired CWH equipment in the definitions for CWH equipment at 10 
CFR 431.102.
    DOE's current definitions for ``storage water heater'' and 
``instantaneous water heater'' in its regulations for CWH equipment 
codified at 10 CFR 431.102 do not include any criteria that exclude 
units that meet DOE's current definitions for consumer water heaters, 
as codified at 10 CFR 430.2. Therefore, DOE proposes to clarify these 
definitions for commercial water heaters by adding the input capacity 
criteria that distinguish between consumer and commercial water heaters 
for each energy source, as specified in EPCA's definition for consumer 
water heater. (42 U.S.C. 6291(27)) These proposed changes are 
consistent with DOE's proposed changes to its definitions for consumer 
water heaters, as discussed in section III.F.1.
    DOE currently includes the definition for ``instantaneous water 
heater'' in its regulations for CWH equipment at 10 CFR 431.102. An 
instantaneous water heater is a water heater that has an input rating 
not less than 4,000 Btu/hr per gallon of stored water, and that is 
industrial equipment, including products meeting this description that 
are designed to heat water to temperatures of 180[emsp14][deg]F or 
higher.
    DOE believes that the last clause of the definition for 
``instantaneous water heater,'' which includes units capable of heating 
water to temperature at or above 180[emsp14][deg]F, does not serve a 
purpose in the definition. Without this clause, it would be assumed 
that units with this capability would be included in the definition 
because there is no restriction indicating otherwise. Therefore to 
simplify the definition, DOE proposes to remove this clause from the 
definition for ``instantaneous water heater.'' Additionally, with DOE's 
proposed addition of input criteria that distinguish between consumer 
and commercial water heaters previously discussed in this section, DOE 
believes that the clause ``that is industrial equipment'' does not 
serve to further clarify the scope of units covered by this definition. 
Therefore, DOE proposes to remove this clause from its definitions for 
``instantaneous water heater'' and ``storage water heater,'' and 
revises the definitions as set out in the regulatory text at the end of 
this document.
    In its regulations for CWH equipment at 10 CFR 431.102, DOE 
currently includes a definition for ``packaged boiler'' that is 
identical to that included for ``commercial packaged boiler'' at 10 CFR 
431.82. DOE includes this definition for ``packaged boiler'' at 10 CFR 
431.102 because the regulations for CWH equipment also include a 
definition for ``hot water supply boiler,'' and this definition 
specifies that a hot water supply boiler is a kind of packaged boiler. 
To simplify its regulations and reduce repetition, DOE proposes to 
remove the definition for ``packaged boiler'' from its regulations for 
CWH equipment at 10 CFR 431.102. Consequently, in its definition for 
``hot water supply boiler,'' DOE proposes to replace the term 
``packaged boiler'' with the term ``packaged boiler (as defined in 
Sec.  431.82).''
    Issue 10: DOE requests comment on its proposed changes to its 
definitions for CWH equipment: (1) Replacing the terms ``rated input'' 
and ``input rating'' with ``fuel input rate'' for gas-fired and oil-
fired CWH equipment to match DOE's proposed definition for ``fuel input 
rate;'' (2) modifying DOE's definitions for ``instantaneous water 
heater'' and ``storage water heater'' by adding the input criteria that 
separate consumer water heaters and commercial water heaters and 
removing several phrases that do not serve to clarify coverage of units 
under the definitions; and (3) removing the definition of ``packaged 
boiler.''
    In section III.G, DOE discusses the reasons for a separate test 
procedure for water heaters and hot water supply boilers that require 
flow of water for heating water, and proposes a definition for ``flow-
activated water heater,'' along with a test procedure for flow-
activated water heaters as set out in the regulatory text at the end of 
this document.
    In section III.J, DOE proposes a definition for ``commercial heat 
pump water heater,'' as well as a test procedure for commercial heat 
pump water heaters as set out in the regulatory text at the end of this 
document.

[[Page 28607]]

3. Residential-Duty Commercial Water Heaters
    As required by AEMTCA, DOE established a uniform efficiency 
descriptor and accompanying test method for consumer water heaters and 
certain commercial water heaters in the July 2014 final rule. 79 FR 
40542 (July 11, 2014). Specifically, AEMTCA required that the uniform 
efficiency descriptor and test method apply to all covered water 
heaters, including both consumer or commercial water heaters, except 
for certain commercial water heaters that do not have a residential 
use, can be clearly described, and are effectively rated using the 
thermal efficiency and standby loss descriptors. (42 U.S.C. 
6295(e)(5)(F)) In the July 2014 final rule, DOE established input and 
volume criteria to distinguish commercial water heaters that do not 
have residential applications, based on comments from stakeholders. 79 
FR 40542, 40586 (July 11, 2014). However, for four classes of 
residential-duty commercial water heaters--electric storage water 
heaters, heat pump water heaters, gas-fired instantaneous water 
heaters, and oil-fired instantaneous water heaters--the input criteria 
established to separate residential-duty commercial water heaters and 
commercial water heaters are identical to those codified at 10 CFR 
430.2 that separate consumer water heaters and commercial water 
heaters. The criteria for these classes are shown in Table III-1. 
Because these input criteria are identical, by definition, no models 
can be classified under these four residential-duty equipment classes. 
Therefore, to eliminate potential confusion, DOE proposes to remove 
these classes from the definition for ``residential-duty commercial 
water heater'' codified at 10 CFR 431.102.

    Table III-1--Indicator of Non-Residential Application for Certain
                        Classes of CWH Equipment
------------------------------------------------------------------------
                                        Indicator of non-residential
        Water heater class                       application
------------------------------------------------------------------------
Electric storage..................  Rated input >12 kW; Rated storage
                                     volume >120 gallons.
Heat pump with storage............  Rated input >12 kW; Rated current
                                     >24A at a rated voltage of not
                                     greater than 250 V; Rated storage
                                     volume >120 gallons.
Gas-fired instantaneous...........  Rated input >200 kBtu/h; Rated
                                     storage volume >2 gallons.
Oil-fired instantaneous...........  Rated input >210 kBtu/h; Rated
                                     storage volume >2 gallons.
------------------------------------------------------------------------

    DOE proposes to revise the definition for ``residential-duty 
commercial water heater'' as set out in the regulatory text at the end 
of this document.
    Issue 11: DOE requests comment on its proposal to modify the 
definition of ``residential-duty commercial water heater'' by removing 
from its scope the following classes: Electric storage water heaters, 
heat pump water heaters with storage, gas-fired instantaneous water 
heaters, and oil-fired instantaneous water heaters.
4. Storage-Type Instantaneous Water Heaters
    The definitions for ``instantaneous water heater'' and ``hot water 
supply boiler'' set forth in 10 CFR 431.102 include CWH equipment with 
an input rating of at least 4,000 Btu/h per gallon of stored water. 
These definitions, therefore, include both instantaneous water heaters 
and hot water supply boilers without integral storage tanks, as well as 
instantaneous water heaters with integral storage tanks (but with at 
least 4,000 Btu/h of input per gallon of stored water). DOE believes 
these two groups of equipment--water heaters with and without integral 
storage tanks--are fundamentally different in their construction and 
application and have different energy losses that need to be accounted 
for during efficiency testing. DOE has tentatively concluded that 
instantaneous water heaters with an integral storage tank (``storage-
type instantaneous water heaters'') should be tested in a manner 
similar to commercial storage water heaters. Therefore, DOE proposes to 
adopt a test method specifically applicable to ``storage-type 
instantaneous water heaters'' that is the same as the test method for 
commercial storage water heaters. DOE proposes to define ``storage-type 
instantaneous water heater'' as set out in the regulatory text at the 
end of this document.
    Issue 12: DOE seeks comment on its proposed definition of 
``storage-type instantaneous water heater.''
    It is DOE's understanding that storage-type instantaneous water 
heaters are very similar to storage water heaters, but with a higher 
ratio of input rating to tank volume. This higher input-volume ratio is 
achieved with a relatively larger heat exchanger paired with a 
relatively smaller storage tank. However, through a review of product 
literature, DOE noted no significant design differences between models 
in these two proposed equipment classes that warrant separate test 
procedures for thermal efficiency or standby loss. Therefore, DOE 
proposes that the proposed test procedures for storage water heaters 
apply also to storage-type instantaneous water heaters.

G. Standby Loss Test for Flow-Activated Instantaneous Water Heaters

    The current Federal standby loss test method for CWH equipment 
incorporates by reference ANSI Z21.10.3-2011, including Exhibit G.2 
which assumes that the water heater would automatically initiate the 
next firing cycle when the internal water temperature (measured using 
the internal tank thermostat) falls below its allowable minimum value. 
An underlying assumption for the standby loss test is that the ignition 
of the burner or activation of the electric element is solely dependent 
on the feedback control signal from the internal tank thermostat. This 
assumption, although true for most CWH equipment, is not applicable to 
certain instantaneous water heaters and hot water supply boilers that 
require continuous water flow through the heat exchanger in order to 
activate the next firing cycle.
    Measuring standby loss for such flow-activated instantaneous water 
heaters with a storage volume greater than or equal to 10 gallons was 
raised as an issue by AHRI. (AHRI, No. 2 at pp. 4-5) Specifically, AHRI 
commented that the current standby loss test is designed for tank-type 
water heaters and does not address water heaters that can fire only 
when hot water is being drawn. (AHRI, No. 2 at pp. 4-5) On August 25, 
2014, AHRI provided a supplemental comment with a recommended standby 
loss test method for tube-type instantaneous water heaters having a 
capacity of 10 gallons or more (``2014 AHRI-recommended test method''), 
which includes a suggested test method for models that are flow-
activated. AHRI also mentioned in its comments that their recommended 
test method is being considered as an addition to the ANSI Z21.10.3 
standard, and was at that time under review by the ANSI Z21/83 
committee. (AHRI, No. 10 at p. 1)
    DOE considered the comments received from AHRI and reviewed its

[[Page 28608]]

recommended standby loss test method for tube-type instantaneous water 
heaters having a capacity of 10 gallons or more. Based on its review, 
DOE agrees with AHRI's argument that the current standby loss test 
method as set forth in Exhibit G.2 of ANSI Z21.10.3-2011 (incorporated 
by reference in the DOE test procedures) is designed for 
thermostatically-controlled, tank-type (or storage) water heaters and 
acknowledges concerns about the applicability to flow-activated water 
heaters. The current test procedure does not provide any indication of 
how to test flow-activated instantaneous water heaters that have no 
means of firing or heating if there is no flow of water through the 
system. Therefore, DOE has tentatively concluded that a different 
standby loss test procedure is required for flow-activated 
instantaneous water heaters. To differentiate units for which the 
proposed standby loss test procedure discussed in this section will 
apply, DOE proposes to define ``flow-activated instantaneous water 
heater'' as set out in the regulatory text at the end of this document.
    Issue 13: DOE requests comment on its proposed definition for 
``flow-activated instantaneous water heater.'' Specifically, DOE 
requests feedback on whether the definition includes all units and 
designs for which a separate standby loss test procedure is warranted, 
and whether any units would be included that do not need a test method 
separate from the current standby loss test procedure for CWH 
equipment.
    DOE notes that the requirement to measure a ``mean tank 
temperature'' to calculate the standby loss would also be an issue for 
all instantaneous water heaters and hot water supply boilers that have 
a storage capacity of 10 gallons or more and that do not meet DOE's 
proposed definition of ``storage-type instantaneous water heater'', 
because these units do not have an integral tank, and the heat 
exchanger geometry can make obtaining an accurate reading of the water 
stored within the heat exchanger difficult to obtain. DOE has addressed 
this issue both in its proposed test method for flow-activated 
instantaneous water heaters contained within this section, and in 
proposed changes to the current standby loss test procedure for other 
instantaneous water heaters and hot water supply boilers discussed in 
section III.I of this NOPR.
    To develop a new Federal standby loss test procedure for flow-
activated instantaneous water heaters, DOE first reviewed the 2014 
AHRI-recommended test method. After its review, DOE identified 
potential issues and provided AHRI with questions seeking further 
clarifications on various aspects of their recommended test method 
related to conduct of the test, duration of test, flow and temperature 
measurements, and the equations used to calculate standby loss. On 
August 17, August 18, and December 14, 2015, DOE received separate 
responses from AHRI members Thermal Solutions Inc., Raypak Inc. and A. 
O. Smith, respectively.\13\ The responses provide answers to all the 
questions posed by DOE and clarified the intent of the 2014 AHRI-
recommended test method.
---------------------------------------------------------------------------

    \13\ The response from Thermal Solutions Inc. can be found in 
the docket for this rulemaking at: http://www.regulations.gov/#!documentDetail;D=EERE-2014-BT-TP-0008-0011.
    The response from Raypak Inc. can be found at: http://www.regulations.gov/#!documentDetail;D=EERE-2014-BT-TP-0008-0012.
    The responses from A.O. Smith can be found at: http://www.regulations.gov/#!documentDetail;D=EERE-2014-BT-TP-0008-0014.
---------------------------------------------------------------------------

    In November 2015, ANSI published an updated version of the ANSI 
Z21.10.3 test standard. This updated version, ANSI Z21.10.3-2015, 
includes Annex E.3, which describes a test method for measuring the 
standby loss of tube-type instantaneous water heaters having a storage 
capacity of 10 gallons or more. DOE reviewed this section carefully and 
found it to be similar to the Annex E.3 included in the 2014 AHRI-
recommended test method. The only difference DOE identified between the 
two versions of Annex E.3 was the referenced section for determining 
the volume of water contained in the water heater. Specifically, Annex 
E.3 in the 2014 AHRI-recommended test method references to section 5.27 
of ANSI Z21.10.3 for determining the water contained in the water 
heater, while Annex E.3 of ANSI Z21.10.3-2015 references section 5.28 
of ANSI Z21.10.3-2015, ``Capacities of tube type water heaters.'' After 
carefully comparing the 2014 AHRI-recommended test method with Annex 
E.3 of ANSI Z21.10.3-2015, DOE believes that ANSI Z21.10.3-2015 
renumbered section 5.27 as 5.28, and that AHRI's reference to section 
5.27 was referring to the section titled ``Capacities of tube type 
water heaters.'' Therefore, DOE has tentatively concluded that there 
are no substantive differences between the 2014 AHRI-recommended test 
method and the test method contained in Annex E.3 of ANSI Z21.10.3-
2015.
    As previously discussed, prior to the publication of ANSI Z21.10.3-
2015, DOE posed several questions and sought clarifications from AHRI 
on various aspects of the 2014 AHRI-recommended test method. Thermal 
Solutions Inc., Raypak Inc., and A.O. Smith provided responses to DOE's 
questions. The major issues on which DOE sought clarification, along 
with the manufacturer responses, are described in the following 
paragraphs.
    First, DOE sought clarification as to whether the 2014 AHRI-
recommended test method applies to all tube-type (thermostatically-
activated and flow-activated) water heaters with a storage capacity of 
10 gallons or more, or only to flow-activated instantaneous water 
heaters. DOE notes that AHRI's comments indicate that the test 
procedure is exclusively for flow-activated instantaneous water 
heaters. However, the title of the 2014 AHRI-recommended test method 
indicates that the test applies to all ``tube-type'' instantaneous 
water heaters. (AHRI, No. 10 at p.4) Judging by the title and the 
language used in the test method, DOE initially interpreted the test 
method as divided into two distinct parts: (1) The first part 
pertaining to tube-type instantaneous water heaters that are 
thermostatically-activated and are not flow-activated; \14\ and (2) the 
second part pertaining to water heaters that will neither initiate, nor 
cause actions that will initiate, burner operation based on a 
thermostatic control. DOE interpreted this second part of the test 
procedure to be applicable to flow-activated instantaneous water 
heaters that are not thermostatically-activated. However, the responses 
from Raypak and Thermal Solutions indicate that the entire 2014 AHRI-
recommended test method (Annex E.3) is exclusively meant for flow-
activated instantaneous water heaters. Raypak and Thermal Solutions 
stated that the first part of the test method is meant for water 
heaters that are flow-activated but may have some other form of energy-
consuming function or water circulation during the conduct of the 
standby loss test. (Thermal Solutions, No. 11 at p 1; Raypak, No. 12 at 
p. 2) A.O. Smith also stated that DOE's interpretation was incorrect, 
and that the 2014 AHRI-recommended test method is divided into two 
parts to cover different designs of instantaneous water heaters whose 
tube type heat exchangers happen to

[[Page 28609]]

store ten gallons or more. A.O. Smith further stated that the first 
part of the test method addresses instantaneous water heaters whose 
burners may activate by some specialty feature (e.g., frost control) 
and the second part of the test method addresses more common designs 
that are installed with a remote storage tank and a thermostat that 
activates the water pump, which then activates the burners. A.O. Smith 
also stated that the first part of the 2014 AHRI-recommended test 
method does not address thermostatically-activated models. (A.O. Smith 
No. 14 at p. 1)
---------------------------------------------------------------------------

    \14\ The first equation for standby loss calculated in the first 
part of 2014 AHRI-recommended test method includes a term for fuel 
consumed. The test procedure also states that the second equation is 
for units for which the main burner(s) do not cycle back on during 
the course of the test. Based on this language, DOE interpreted the 
first part (that includes the first and second equation) to be for 
units that are thermostatically-activated and not flow-activated.
---------------------------------------------------------------------------

    Thermal Solutions and Raypak did not comment on DOE's 
interpretation of the second part of the 2014 AHRI-recommended test 
method. However, judging by the response from A.O. Smith regarding the 
second part and the responses from A.O. Smith, Thermal Solutions, and 
Raypak regarding the first part, DOE infers that the second part of the 
test procedure is meant for flow-activated instantaneous water heaters 
that do not have any form of energy consumption or water circulation 
during the conduct of the standby loss test. (Thermal Solutions, No. 11 
at p 1; Raypak, No. 12 at p. 2; A.O. Smith No. 14 at p. 1)
    DOE also sought clarifications on the equations used to calculate 
the standby loss in both parts of the 2014 AHRI-recommended test 
method. In the first equation of the 2014 AHRI-recommended test method, 
DOE noticed an inconsistency in units of measurement. (AHRI, No. 10 at 
p. 5) When calculated, the first term of this equation has the units 
Btu/h, while the second term has the units 1/h. Mathematically, a 
subtraction or addition operation cannot be applied over two numbers 
that have different units of measurement. In their responses, the 
manufacturers also acknowledged the issues with regards to the 
equations for calculating standby loss and stated that AHRI has worked 
on a corrected derivation for the equations of this test procedure. 
(Thermal Solutions, No. 11 at p 3; Raypak, No. 12 at p. 4; A.O. Smith 
No. 14 at p. 3) DOE notes that later versions of the AHRI-recommended 
test methods (discussed later in this section) rectify this error in 
the first equation of the 2014 AHRI-recommended test method. However, 
the later versions of the AHRI-recommended test methods convert standby 
loss units from percent-per-hour of the heat content of the stored 
water to Btu-per-hour based on a temperature difference of the average 
value of the outlet water temperature minus the average value of the 
ambient temperature measured during the course of the test. This method 
of calculation does not match with the standby loss definition that is 
currently set forth in 10 CFR 431.102, which is based on a temperature 
difference of 70[emsp14][deg]F between the stored water and the ambient 
air. Therefore, DOE has tentatively decided not to consider this 
equation for the proposed standby loss test procedure for flow-
activated instantaneous water heaters.
    In the second equation of the 2014 AHRI-recommended test method, 
DOE sought to understand the rationale for choosing a temperature 
difference term that is equal to the difference between the outlet 
water temperature and supply water temperature to calculate the thermal 
energy lost during the test. (AHRI, No. 10 at p. 5) In the third 
equation of the 2014 AHRI-recommended test method, DOE sought to 
understand the rationale for assuming a constant temperature difference 
of 70[emsp14][deg]F between the supply water and the outlet water 
temperature. Further, the third equation appeared to assume that the 
outlet water in the water heater will cool down to the supply water 
temperature over a span of exactly 24 hours during the conduct of the 
test. (AHRI, No. 10 at p. 6) On the issue of considering the 
temperature difference between the outlet water temperature and supply 
water temperature to calculate the loss in thermal energy during the 
test, the manufacturers stated that AHRI has conservatively assumed the 
temperature of stored water inside the water heater to be equal to the 
outlet water temperature. The manufacturers stated that the geometry of 
these water heaters does not allow for the measurement of the mean 
stored water temperature inside the water heater. As a consequence, the 
commenters suggested using the outlet water temperature in place of the 
mean stored water temperature to carry out the standby loss 
calculations. (Thermal Solutions, No. 11 at pp. 3, 5; Raypak, No. 12 at 
pp. 4, 6; A.O. Smith No. 14 at pp. 3-5). The manufacturers also stated 
that they are willing to accept a conservative estimate of the standby 
loss in order to reduce the complexity and burden of the test method. 
(Thermal Solutions, No. 11 at p. 3; Raypak, No. 12 at p. 4; A.O. Smith 
No. 14 at p. 3-5)
    DOE also sought clarification on the duration of the standby loss 
test. In particular, DOE sought an answer to whether any consideration 
was given to the possibility that flow-activated water heater burners 
may not cycle on at any point during the test and instead cool down 
completely in less than 24 hours. The manufacturers' responses to this 
question indicated that the suggested test method includes a one-hour 
test, and it is assumed that all the heat is lost in the heat 
exchanger. (Thermal Solutions, No. 11 at p 4; Raypak, No. 12 at p. 4; 
A.O. Smith No. 14 at p. 5)
    Another issue that DOE sought clarification on is the method used 
to measure the storage volume of the water heater. Section 5.27 of ANSI 
Z21.10.3-2015 (that is the same as section 5.26 of ANSI Z21.10.3-2011, 
2013, and 2014), ``Capacities of storage vessels,'' describes a method 
of test to measure the storage volume of a water heater containing a 
storage vessel or with an input rating less than 4,000 Btu/h per gallon 
of water stored. The 2014 AHRI-recommended test method specifies using 
the methodology described in section 5.27 of ANSI Z21.10.3, that DOE 
believes corresponds to section 5.28 of ANSI Z21.10.3-2015, 
``Capacities of tube type water heaters.'' DOE reviewed section 5.28 of 
ANSI Z21.10.3-2015 carefully, and noticed that this section does not 
specify a method for determining the volume of tube-type water heaters; 
instead, it only states that the volume shall be determined. DOE sought 
clarifications on the rationale for using the test method described in 
section 5.28, ``Capacities of tube type water heaters'' of ANSI 
Z21.10.3-2015 as opposed to section 5.27, ``Capacities of storage 
vessels'' of ANSI Z21.10.3-2015 (that is the same as section 5.26 of 
ANSI Z21.10.3-2011, 2013 and 2014). Section 5.26 of ANSI Z21.10.3-2011 
is used for measuring the storage volume of all CWH equipment in 
Exhibit G.2 of ANSI Z21.10.3-2011, which is incorporated by reference 
in the current Federal standby loss test procedure.
    In response to this issue, the manufacturers stated that 
determining the stored volume using section 5.26 of ANSI Z21.10.3 
(which DOE interprets as referring to section 5.26 of ANSI Z21.10.3-
2011, 2013, and 2014, ``Capacities of storage vessels,'' which 
corresponds to section 5.27 of ANSI Z21.10.3-2015) is only required for 
water heaters that are known to have a stored water capacity greater 
than or equal to ten gallons and that the test is not required for 
water heaters with less than ten gallons of storage capacity. The 
manufacturers' comments indicate that they believe the test method to 
measure the storage volume is left to the discretion of the 
certification body. The manufacturers further stated that the test 
method in section 5.26 may not be a reliable test method for water 
heaters with small water volumes, manifold coils, and complex 
geometries. Moreover, they stated that heat exchangers used in the 
water heaters are

[[Page 28610]]

hydrostatically tested before the assembly, as required by the American 
Society of Mechanical Engineers (ASME) and will always have some 
residual water in the heat exchanger. According to the manufacturers, 
this residual water will result in inaccurate measurement of the 
volumetric capacity of the water heater. (Thermal Solutions, No. 11 at 
pp. 1-2; Raypak, No. 12 at p. 2; A.O. Smith No. 14 at pp. 1-2)
    Another issue that DOE noticed with the test procedure in Annex E.3 
of ANSI Z21.10.3-2015 is that (similar to the 2014 AHRI-recommended 
test method) the first part of Annex E.3 of ANSI Z21.10.3-2015 appears 
to be for thermostatically-activated units. Annex E.3 of ANSI Z21.10.3-
2015 does not appear to be applicable exclusively to flow-activated 
instantaneous water heaters as is indicated by the manufacturers in 
their responses and AHRI in the 2014 AHRI-recommended test method. 
(AHRI, No. 10 at p. 4; Thermal Solutions, No. 11 at pp. 1; Raypak, No. 
12 at pp. 1-2; A.O. Smith, No. 14 at p. 1)
    On December 2, 2015, AHRI submitted another supplemental comment to 
the February 2014 RFI that included a revised recommendation for a test 
method for measuring standby loss for tube-type commercial 
instantaneous water heaters and hot water supply boilers that contain 
more than 10 gallons of water (``2015 AHRI-recommended test method''). 
(AHRI (2015), No. 13, pp.1, 6-8) \15\ DOE compared the 2014 AHRI-
recommended test method with the 2015 AHRI-recommended test method to 
identify the differences between the two test methods. In the 2015 
AHRI-recommended test method, AHRI updated the equations for 
calculation of standby loss in its recommended Annex E.3. After 
reviewing these revised equations, DOE notes that the first equation in 
Annex E.3 of the 2015 AHRI-recommended test method is the result of 
converting the current equation for standby loss specified in Exhibit 
G.2 of ANSI Z21.10.3-2011 (but with the mean tank temperature replaced 
with the outlet water temperature) from units denominated as 
percentage-per-hour to units denominated as Btu-per-hour, by 
multiplying by a term consisting of k x Va x 
[Delta]T3/100.\16\ DOE also notes that the second equation 
provided in the 2015 AHRI-recommended test method is identical to the 
second equation that is provided in the 2014 AHRI-recommended test 
method and as stated in the test method, is used for water heaters for 
which the main burner(s) do not cycle on during the course of the test. 
The final equation in the 2015 AHRI-recommended test method specifies 
the time for the duration of the test as 24 hours, similar to the 2014 
AHRI-recommended test method. However, in the 2015 AHRI-recommended 
test method, the variables used in the final equation and the variables 
defined after the equation are not consistent--specifically, the 
equation contains the term [Delta]T4, while the list of 
variables below the equation includes [Delta]T5. The final 
equation in the 2015 AHRI-recommended test method uses 
[Delta]T4, while the final equation in the 2014 AHRI-
recommended test method uses [Delta]T5. Other than the 
differences mentioned in this paragraph, DOE tentatively determined 
that the 2015 AHRI-recommended test method contains no additional 
substantive differences from the previously submitted 2014 AHRI-
recommended test method. Therefore, other than these differences, all 
issues that DOE identified with the standby loss test in the 2014 AHRI-
recommended test method also apply to the 2015 AHRI-recommended test 
method.
---------------------------------------------------------------------------

    \15\ DOE received two supplemental comments from AHRI in 
response to the February 2014 RFI on December 2, 2015 and January 
11, 2016. Both comments are included in the docket under filing 
number EERE-2014-BT-TP-0008-0013. To differentiate between the two 
documents for citations, DOE uses ``AHRI (2015)'' and ``AHRI 
(2016)'' to refer to the comment received on December 2, 2015 and on 
January 11, 2016, respectively. Both supplemental comments can be 
found at: http://www.regulations.gov/#!documentDetail;D=EERE-2014-
BT-TP-0008-0013.
    \16\ Annex E.2 of ANSI Z21.10.3-2013 (and 2014) defines `K' as 
the nominal specific heat of water that has a value of 8.25 Btu per 
gallon. This is the same as `k' that is used by AHRI in their 
equations in the Annex E.3 of the 2015 and 2016 AHRI-recommended 
test method. The term Va refers to the measured volume expressed in 
gallons and measured as per section 5.27 of ANSI Z21.10.3-2015 and 
[Delta]T3 refers to the difference between the average 
value of the outlet water temperature and the average value of the 
ambient temperature expressed in [deg]F.
---------------------------------------------------------------------------

    On January 11, 2016, AHRI submitted a third supplemental comment to 
the February 2014 RFI that included a further revised recommendation 
for a test method for measuring standby loss for tube-type commercial 
instantaneous water heaters and hot water supply boilers that contain 
more than 10 gallons of water (``2016 AHRI-recommended test method''). 
(AHRI (2016), No. 13, pp.1, 6-8) After carefully reviewing this 
submission, DOE tentatively determined that the only difference between 
the 2015 AHRI-recommended test method and the 2016 AHRI-recommended 
test method are the temperature differences used in equations for 
calculating standby loss. Specifically, the temperature difference used 
in the first two equations in Annex E.3 of the 2016 AHRI-recommended 
test method is [Delta]T5, which represents the difference 
between the final outlet water temperature and the initial outlet water 
temperature. This differs from the temperature difference terms used in 
the corresponding standby loss equations in the 2015 AHRI-recommended 
test method, which are denoted as [Delta]T4 and defined as 
the difference between the average supply water temperature and the 
outlet temperature. In the final standby loss equation in Annex E.3, 
the temperature difference used is [Delta]T6, which 
represents 70[emsp14][deg]F, the difference between the supply and 
outlet water temperatures, and was previously denoted as 
[Delta]T5 in the corresponding equation in the 2015 AHRI-
recommended test method. These changes in temperature difference terms 
in standby loss equations help to clarify issues with these terms that 
DOE identified in the 2015 AHRI-recommended test method. However, with 
the exception of these temperature difference terms, the other issues 
that DOE identified with the 2014 and 2015 AHRI-recommended test 
methods also apply to the 2016 AHRI-recommended test method.
    DOE has considered the initially submitted 2014 AHRI-recommended 
test method, the clarifications provided by manufacturers, Annex E.3 of 
the recently published ANSI Z21.10.3-2015, and the recently submitted 
2015 and 2016 AHRI-recommended test methods in developing the proposed 
standby loss test procedure for flow-activated instantaneous water 
heaters. DOE agrees with certain aspects of the recommended test 
methods and the related clarifications; however, DOE tentatively 
concludes that there are several modifications that need to be made to 
the 2016 AHRI-recommended test method for it to be used as a Federal 
standby loss test procedure for flow-activated instantaneous water 
heaters. As noted previously, the only difference between the 2016 
AHRI-recommended test method and Annex E.3 of ANSI Z21.10.3-2015 is 
with regards to the first equation in both test methods and, similarly, 
DOE is not proposing to adopt the test method in Annex E.3 as the 
Federal test method. Rather, the following paragraphs describe DOE's 
proposed test method, including differences from both the 2016 AHRI-
recommendation and the ANSI Z21.10.3-2015 test method, and the reasons 
such changes are deemed necessary.
    As previously defined in this section, a flow-activated 
instantaneous water heater will initiate firing or heating only

[[Page 28611]]

when water is being drawn from the water heater. In Annex E.3 of ANSI 
Z21.10.3-2015 and the 2016 AHRI-recommended test method, the water 
heater is kept in standby mode, and no hot water is drawn from the 
equipment during the standby loss test. Under such conditions, the 
water heater would not be expected to initiate burner or heating 
element operation at any point during the course of the test since 
there is no flow to activate the heat source. As a result, hot water 
stored in the water heater in standby mode will continuously lose heat 
to the environment until the water temperature approaches the 
surrounding ambient air temperature. DOE considers this standby mode 
operation for flow-activated instantaneous water heaters to be 
characteristically different from the standby mode operation of 
thermostatically-activated water heaters, where the main burner or 
element(s) cycles on when the water temperature drops below the 
thermostat set point.
    The first part of Annex E.3 of ANSI Z21.10.3-2015 and the 2016 
AHRI-recommended test method appears to apply to water heaters that may 
circulate water or initiate some other energy-consuming function when 
hot water is not being drawn. If a water heater consumes energy for the 
purpose of heating water during the standby mode, then such a water 
heater would not fit the proposed definition of a ``flow-activated 
instantaneous water heater.'' Such water heaters would instead be 
covered by the proposed standby loss test method for instantaneous 
water heaters and hot water supply boilers that are not flow-activated, 
as discussed in section III.I of this NOPR. However, to account for 
other types of fuel consumption during standby mode (i.e., other than 
directly for the purpose of heating water), DOE has retained the fuel 
consumption terms in the proposed standby loss equation for flow-
activated instantaneous water heaters.
    The driving temperature difference that causes the constant heat 
loss to the ambient air from the water heater is the difference between 
the stored water and the ambient air temperature. This temperature 
difference must be factored into the standby loss calculations, as 
included in the 2016 AHRI-recommended test method, instead of the 
temperature difference between outlet and supply water that is used in 
Annex E.3 of ANSI Z21.10.3-2015 and the 2015 AHRI-recommended test 
method. In addition, the current standby loss test procedure that is 
set forth in Exhibit G.2 of ANSI Z21.10.3-2011 (incorporated by 
reference into the current DOE test procedure) calculates the standby 
loss as a percentage per hour of the total heat content of the water 
heater. In DOE's test procedure for gas-fired and oil-fired CWH 
equipment as set forth in 10 CFR 431.106, DOE uses this percent-per-
hour standby loss value to calculate the standby loss in terms of Btu/h 
based on the storage volume and a 70[emsp14][deg]F temperature 
difference between the stored water and the ambient air temperature. 
DOE notes that the 2016 AHRI-recommended test method converts from 
standby loss in terms of percent-per-hour to standby loss in terms of 
Btu-per-hour by multiplying by a term that includes 
[Delta]T3, which is defined in Annex E.3 of ANSI Z21.10.3-
2015 as the difference between the outlet water temperature and the 
average value of the ambient temperature. This is in contrast to: (1) 
DOE's current test procedure as specified in 10 CFR 431.106, which 
converts using a fixed 70[emsp14][deg]F temperature difference rather 
than using the measured temperature difference from testing and, (2) 
the current definition of ``standby loss'' specified in 10 CFR 431.102 
that defines ``standby loss'' as the average energy required to 
maintain the stored water temperature, expressed in Btu per hour based 
on a 70[emsp14][deg]F temperature differential between stored water and 
ambient temperature.
    DOE notes that use of a fixed 70[emsp14][deg]F temperature 
difference allows for straightforward conversion of standby loss from 
one set of units to another, while use of the measured temperature 
difference requires the availability of data from efficiency testing. 
DOE sees value in such a straightforward conversion, so that those 
without access to efficiency test data can still convert between the 
two values. Additionally, the standby loss test method that is proposed 
for flow-activated instantaneous water heaters already takes into 
account the measured temperature difference between the outlet water 
temperature and the ambient air temperature, making the additional 
inclusion of this term in the conversion unnecessary. Finally, use of a 
constant 70[emsp14][deg]F temperature difference would make the 
conversion in this proposed standby loss test procedure consistent with 
that in DOE's current test procedure at 10 CFR 431.106, and DOE also 
proposes this method of conversion to standby loss in terms of Btu/h 
for other classes of gas-fired and oil-fired CWH equipment in 
appendices A and C to subpart G of 10 CFR part 431. Therefore, DOE 
proposes to use the same approach of a constant 70[emsp14][deg]F 
temperature difference to calculate the standby loss for gas-fired and 
oil-fired flow-activated instantaneous water heaters. For electric 
flow-activated instantaneous water heaters, DOE proposes to maintain a 
standby loss metric in terms of a percent-per-hour value.
    As discussed in this preamble, the 2016 AHRI-recommended test 
method specifies setting a time duration of one hour for flow-activated 
water heaters that would not have any form of energy consumption to 
maintain the water temperature and that would eventually cool down to 
ambient temperature. DOE sees merit in setting a maximum time duration 
to mark the end of the test. However, DOE does not agree with having 
the time duration as the only criterion for ending the standby loss 
test. As noted previously, the standby loss test for flow-activated 
instantaneous water heaters resembles a constant cool down test where 
the main burner or heating element does not cycle on at any point in 
the course of the test. For these water heaters, it is very likely that 
the stored water in the unit cools down to the ambient temperature 
before 24 hours. In such a scenario, from the time the stored water 
temperature reaches the ambient temperature to the end of the 24 hours, 
the water heater will not experience any standby energy loss. However, 
the standby loss equation provided in the 2016 AHRI-recommended test 
method assumes that the entire heat loss takes place over a duration of 
24 hours. As a result, using the 2016 AHRI-recommended test method, the 
standby loss value calculated for water heaters that cool down before 
the 24-hour time period would understate the actual hourly heat loss 
from the water heater. Based on the 2016 AHRI-recommended test method, 
two water heaters that have the same storage volume and electricity 
consumption but different cooling rates as they both cool down to the 
ambient temperature within 24 hours would have the same standby loss 
value. DOE has determined that this would lead to an inaccurate 
comparison of the standby loss between two water heaters that lose heat 
at different rates. A similar issue would arise if the time duration 
were set to one hour or any specific value that might be less than the 
time it takes some water heater to cool to ambient temperature, because 
such a time criterion would capture the heat loss to different final 
water temperatures for different water heaters (i.e., two different 
water heaters would have different final water temperatures at the end 
of the set time period). This

[[Page 28612]]

variation in final water temperature would impart an undesirable 
benefit to water heaters that lose heat more quickly, because the rate 
of heat transfer from water to the surrounding air decreases as the 
corresponding temperature difference decreases.
    To avoid these issues and to compare standby loss of different 
water heaters with a more consistent approach, DOE proposes to use a 
temperature criterion in addition to a fixed maximum time duration to 
mark the end of the test. DOE proposes that the standby loss test be 
stopped at the first instance that the measured outlet water 
temperature is 35[emsp14][deg]F below the outlet water temperature 
measured at the start of the test. If the specified temperature drop in 
the outlet water temperature does not occur within a 24 hour time 
period then the test shall be stopped at the end of 24 hours from the 
start of the test.
    Finally, DOE must specify a method for determining the storage 
volume of the water heater. The manufacturers' responses stated that 
for some water heaters, it will not be necessary to measure the volume 
if it is less than 10 gallons. Although DOE does not currently 
prescribe a standby loss standard for instantaneous water heaters and 
hot water supply boilers with a storage volume below 10 gallons, DOE 
requires certification of the rated storage volume for all gas-fired 
and oil-fired instantaneous water heaters and hot water supply boilers. 
These certification requirements are set forth at 10 CFR 
429.44(c)(2)(iv) and (v).
    Because flow-activated instantaneous water heaters have heat 
exchanger designs similar to thermostatically-activated instantaneous 
water heaters, the issue of measuring the storage volume applies to all 
instantaneous water heaters and hot water supply boilers. Exhibit G.2 
of ANSI Z21.10.3-2011 (that is incorporated by reference into the 
current DOE test procedure) references section 5.26 of the same testing 
standard as a method to measure the storage volume of CWH equipment. In 
response to the February 2014 RFI, HTP raised an issue with regards to 
the measurement of storage volume for instantaneous water heaters and 
hot water supply boilers. HTP commented that due to various geometries 
and sizes, measurement of the storage volume by a third-party 
laboratory or manufacturer's facility would be difficult and may 
produce inconsistent results. (HTP, No. 5 at p. 2) As discussed 
earlier, this issue was also raised by manufacturers in response to 
DOE's questions on the 2014 AHRI-recommended standby loss test method 
for flow-activated instantaneous water heaters.
    DOE acknowledges the issues highlighted by manufacturers regarding 
use of section 5.26 of ANSI Z21.10.3-2011 (which corresponds to section 
5.27 of ANSI Z21.10.3-2015) to measure the storage volume of 
instantaneous water heaters and hot water supply boilers, including 
flow-activated and thermostatically-activated units. To find 
alternatives to this test method, DOE investigated other options for 
measuring the storage volume of such water heaters. Through its review, 
DOE did not identify an alternative test method suitable to measure the 
storage volume of instantaneous water heaters and hot water supply 
boilers that would not significantly increase the testing burden for 
manufacturers. Moreover, section 5.28, ``Capacities of tube type water 
heaters,'' of ANSI Z21.10.3-2015 does not specify a test method to 
measure the storage volume. Instead, section 5.28 of ANSI Z21.10.3-2015 
only states that the ``volume contained in the water heater shall be 
determined.'' The wording of this section and the manufacturers' 
responses on this test method appear to suggest that the actual method 
of determination of the volume is left to the discretion of the testing 
agency.
    The test method in section 5.27 of ANSI Z21.10.3-2015 requires the 
water heater to be weighed dry and empty, and then reweighed when 
filled with water. The difference in the two values of the weight 
equate to the weight of the stored water in the water heater. The 
weight of stored water can be converted into gallons by dividing by the 
density of water. Although section 5.27 of ANSI Z21.10.3-2015 
specifically states that the test be used for storage vessels or water 
heaters having an input rating of less than 4,000 Btu/h per gallon of 
capacity, the test method appears to be applicable to any CWH equipment 
that can be weighed both dry and after being filled with water. The 
energy conservation standards for instantaneous water heaters are 
dependent on the rated storage volume. The rated storage volume is 
needed to determine the appropriate equipment class and, for units with 
storage volume greater than or equal to 10 gallons, it is required to 
calculate the standby loss standard. Therefore, DOE must specify a test 
method to measure the storage volume of water heaters, rather than 
leave the decision of the appropriate method (e.g., direct measurement, 
calculation) to individual manufacturers or testing agencies, who may 
choose different methods for determining the storage volume, which 
could provide inconsistent results. Based on the foregoing reasoning, 
and the lack of alternative test methods to measure the storage volume, 
DOE tentatively concluded that the method presented in section 5.27 of 
ANSI Z21.10.3-2015 should be used for measurement of the storage volume 
of instantaneous water heaters and hot water supply boilers that do not 
meet DOE's proposed definition for ``storage-type instantaneous water 
heater,'' including thermostatically-activated and flow-activated 
instantaneous water heaters. However, because section 5.27 of ANSI 
Z21.10.3-2015 includes a limitation that the method is only applicable 
to units containing storage vessels, DOE proposes not to incorporate 
this section by reference, and instead proposes a test procedure very 
similar to the method in section 5.27 of ANSI Z21.10.3-2015, with only 
clarifying changes. Specifically, DOE proposes to remove the limitation 
that only storage vessels or water heaters having an input rating of 
less than 4,000 Btu/h per gallon of capacity can be tested using this 
method, and clarifies that the density of water at the measured water 
temperature is to be used to convert from the weight of water to the 
volume in gallons.
    Issue 14: DOE requests comment on its proposal to include a test 
procedure similar to that specified in section 5.27 of ANSI Z21.10.3-
2015 for measuring the storage volume of all instantaneous water 
heaters and hot water supply boilers, including flow-activated 
instantaneous water heaters. DOE also seeks information on alternative 
methods for measuring storage volume and the impact of residual water 
on measuring storage volume of instantaneous water heaters and hot 
water supply boilers. Further, DOE seeks comment on ways to remove 
residual water from the water heater that could allow for more accurate 
and consistent measurement of the storage volume of CWH equipment.
    Based on the AHRI-recommended test methods and the responses 
received from manufacturers, DOE proposes a new standby loss test 
procedure for flow-activated instantaneous water heaters. The proposed 
test procedure is based on the 2016 AHRI-recommended test method, 
specifically the second part of the test method that applies to flow-
activated water heaters that will not initiate burner operation over 
the course of the test. However, in developing the proposed test 
method, DOE has departed from the 2016 AHRI-recommended test method in 
several areas, including the method of test, time duration, and 
equations to calculate standby loss. DOE also conducted

[[Page 28613]]

investigative testing on flow-activated instantaneous water heaters 
that helped inform the proposals made to this test procedure. The 
following paragraphs describe DOE's proposed test method for measuring 
the standby loss of flow-activated instantaneous water heaters. The 
proposed test procedure is also included in the proposed regulatory 
text for appendix E to subpart G of part 431.
    The proposed standby loss test for flow-activated instantaneous 
water heaters can be started immediately after the thermal efficiency 
test, using the same test set-up and test conditions. Otherwise, if the 
standby loss test is conducted separately, install the water heater as 
per the specifications in section 2 of appendix E to subpart G of part 
431. As discussed in section III.H, DOE proposes required locations for 
temperature-sensing instrumentation for instantaneous water heaters and 
hot water supply boilers, including flow-activated instantaneous water 
heaters. For water heaters with multiple outlet water connections 
leaving the water heater jacket, apply the test set-up provisions 
proposed in section III.H (also included in appendix C to subpart G of 
part 431). The representative value of the outlet water temperature 
used for the standby loss calculations is obtained by taking the 
average of the water temperatures measured at each water connection 
leaving the water heater jacket. DOE proposes that the test entity set 
the data acquisition system to record the supply water temperature, 
outlet water temperature, ambient room temperature, and electrical 
consumption (as applicable) at intervals of every 30 seconds.
    DOE proposes the test be conducted as follows:
    Once the water heater is set up, supply water to the equipment 
being tested as per section (d) of Annex E.1 of ANSI Z21.10.3-2015. 
Adjust the water flow rate in such a way that the outlet water reaches 
a temperature of 70[emsp14][deg]F  2[emsp14][deg]F above 
the supply water temperature. After the outlet water temperature has 
remained constant with no variation of more than 2[emsp14][deg]F over a 
3-minute period and maintains a temperature of 70[emsp14][deg]F  2[emsp14][deg]F above the supply water temperature, turn off the 
supply and outlet water valves that are installed closest to the water 
heater (as per the provisions in appendix C to subpart G of part 431), 
and the water pump, simultaneously. Allow the water heater to cut-out. 
Immediately after the cut-out, begin recording measurements for the 
standby loss test.
    At this time, start the clock and record the initial outlet water 
temperature, ambient room temperature, and fuel (and electricity) meter 
reading. Continue to monitor and record the outlet water temperature, 
the ambient room temperature, the time elapsed from the start of the 
test, and the electricity consumption at 30-second intervals using a 
data acquisition system.
    Stop the test if the outlet water temperature decreases by 
35[emsp14][deg]F from the initial outlet water temperature within 24 
hours from the start of the test. Record the final outlet water 
temperature, final ambient room temperature, fuel consumed, electricity 
consumed, and the time elapsed from the start of the test.
    If the outlet water temperature does not decrease by 
35[emsp14][deg]F from the initial outlet water temperature within 24 
hours from the start of the test, then stop the test after 24 hours 
from the start of the test. Record the final outlet water temperature, 
final ambient room temperature, fuel consumed, electricity consumed, 
and the time elapsed from the start of the test.
    Use the equation below to calculate the standby loss in terms of 
percent of total heat content per hour.
[GRAPHIC] [TIFF OMITTED] TP09MY16.270

>Where,

[Delta]T1 = Outlet water temperature measured at the 
start of the test minus outlet water temperature measured at the end 
of the test, expressed in [deg]F
[Delta]T2 = Outlet water temperature at the start of the 
test minus the ambient room temperature at the start of the test, 
expressed in [deg]F
k = 8.25 Btu/gallon[middot][deg]F, the nominal specific heat of 
water
Va = Volume of water contained in the water heater in 
gallons
Et = Thermal efficiency of the water heater. For electric 
water heaters with immersed heating elements use 98 percent.
Ec = Electrical energy consumed by the water heater 
during the duration of the test in Btu
Cs = Correction applied to the heating value of a gas H, 
when it is metered at temperature and/or pressure conditions other 
than the standard conditions upon which the value of H is based. 
Cs is not applicable to oil-fired equipment.
Qs = Total fuel flow as metered for gas-fired and oil-
fired equipment, expressed in ft\3\ (gas) or lb (oil)
H = Higher heating value of gas, expressed in Btu/ft\3\ (gas) or 
Btu/lb (oil)
t = Total duration of the test in hours
S = Standby loss, the average hourly energy required to maintain the 
stored water temperature expressed as a percentage of the initial 
heat content of the stored water above room temperature

    For gas-fired and oil-fired flow-activated instantaneous water 
heaters, to calculate the standby loss in terms of Btu per hour, use 
the following equation:

SL = S% x K (Va)(70 [deg]F)

    Where, SL refers to the standby loss of the water heater, defined 
as the amount of energy required to maintain the stored water 
temperature expressed in Btu per hour.
    Issue 15: DOE requests comment from interested parties on all 
aspects of the proposed test procedure for flow-activated instantaneous 
water heaters. Specifically, DOE requests comment on its tentative 
decision to: (1) Base the test procedure on the second part of the 2016 
AHRI-recommended test method that applies to flow-activated water 
heaters that will not initiate burner operation over the course of the 
test; (2) stop the test following a 35[emsp14][deg]F  
2[emsp14][deg]F drop in the outlet water temperature or completion of 
24 hours, whichever occurs earlier; and (3) use the outlet water 
temperature as an approximation of the stored water temperature.

H. Test Set Up for Commercial Instantaneous Water Heaters and Hot Water 
Supply Boilers

    The current thermal efficiency and standby loss test methods as 
described in ANSI Z21.10.3-2011 require commercial instantaneous water 
heaters and hot water supply boilers to be set up in accordance with 
Figure 2 of that test standard. Although the figure is not drawn to 
scale and no measurements are specified, DOE notes that the 
temperature-sensing instruments for measuring outlet water temperature 
appear to be placed at a considerable distance away from the water 
heater being tested. Measuring the temperature at a significant 
distance away from the water heater could lead to an inaccurate 
representation of the outlet water temperature due to heat loss in the 
piping. Even if the pipes are insulated,

[[Page 28614]]

measuring temperature as close as possible to the outlet ports or 
possibly inside the port would yield a more accurate representation of 
the outlet water temperature. The heat loss from the piping would be 
higher while conducting the standby loss tests that could run for 
several hours to a maximum of 24 hours for flow-activated instantaneous 
water heaters and from 24 to 48 hours for other instantaneous water 
heaters and hot water supply boilers. Moreover, the new standby loss 
test procedure that is proposed for flow-activated instantaneous water 
heaters in this NOPR uses the outlet water temperature as an 
approximation for the stored water temperature inside the water heater. 
Therefore, it is important that the outlet water temperature be 
measured as close as possible to the water heater to minimize the 
effect of piping heat losses while conducting the standby loss test.
    To address these issues, DOE proposes to specify the location and a 
set of requirements for placement of the temperature sensors to ensure 
that they accurately represent the outlet water temperature for the CWH 
equipment. Specifically, DOE proposes that the tip or junction of the 
temperature sensor be placed: (1) In the water; (2) less than or equal 
to 5 inches away from the water heater jacket; (3) about the central 
axis of the water pipe; and (4) with a radiation protection shield. The 
type and number of temperature-sensing instruments is left to the 
discretion of the testing operator.
    Certain instantaneous CWH models have multiple outlet water 
connections leaving the jacket that are combined externally using 
common piping. For such units, DOE proposes that the temperature sensor 
placement conditions as proposed in the paragraph above be applied to 
each outlet water connection leaving the water heater jacket. To 
clarify, DOE proposes that for each outlet water connection leaving the 
water heater jacket, the temperature sensor be placed: (1) in the 
water; (2) less than or equal to 5 inches away from the water heater 
jacket; (3) about the central axis of the water pipe; and (4) with a 
radiation protection shield. For obtaining a single outlet water 
temperature value that is representative of the entire water heater, 
DOE proposes to take the average of the all outlet water temperature 
measurements (for each outlet water connection leaving the water heater 
jacket) for each recording of the data-acquisition unit. In addition to 
these provisions, DOE also proposes that while verifying steady-state 
operation (prior to the thermal efficiency test) and during the thermal 
efficiency test, the water temperatures recorded for each outlet water 
connection leaving the water heater jacket must: (1) Be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature, and (2) not differ from each other by more than 
2[emsp14][deg]F.
    Figure III.4, an adaptation of Figure 3 of ANSI Z21.10.3-2015, 
shows DOE's proposed location requirements for the temperature-sensing 
instruments for measuring the inlet and outlet water temperature of 
instantaneous water heaters (other than storage-type instantaneous 
water heaters) and hot water supply boilers.
    The current test procedure for instantaneous water heaters and hot 
water supply boilers does not clearly indicate the location and 
installation of the supply and outlet water valves. To obtain accurate 
measurements during standby operation, the water supply must be cut off 
to prevent mixing of water in the piping lines with that in the water 
heater during the standby loss test. To address this issue, DOE 
proposes to require supply and outlet water valves to be installed 
within a specified distance of the water heater. Specifically, for 
instantaneous water heaters and hot water supply boilers shipped 
without external piping installed at the point of manufacture, DOE 
proposes to require the supply water valve to be installed within 5 
inches of the jacket, and the outlet water valve to be installed within 
10 inches of the jacket. For instantaneous water heaters and hot water 
supply boilers with external piping assembled at the manufacturer's 
premises prior to shipment, DOE proposes to require the supply and 
outlet water valves to be installed within 5 inches of the end of the 
piping shipped with the unit. DOE also proposes that the supply and 
outlet water valves be used to turn off the water flow at the start of 
the standby loss test for instantaneous water heaters and hot water 
supply boilers (including ``flow-activated instantaneous water 
heaters''). Figure III.4 shows the location of the valves with respect 
to other instrumentation used in the test set-up for units shipped 
without external water piping installed.
    The current Federal thermal efficiency test as set forth in 10 CFR 
431.106, incorporates by reference Exhibit G.1 of ANSI Z21.10.3-2011, 
which requires the supply water temperature to be 70[emsp14][deg]F 
 2[emsp14][deg]F and the outlet water temperature to be 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature with the burner or heating element operating at its full 
firing rate. Certain instantaneous water heaters and hot water supply 
boilers, including flow-activated instantaneous water heaters that are 
designed to operate at higher inlet water temperatures, may not be able 
to achieve such a temperature rise. The current test procedure 
addresses this issue by allowing for the use of a recirculating loop 
(see Figure 3 of ANSI Z21.10.3-2015). Section 5.1.7 of ANSI Z21.10.3-
2015 (which contains Figure 3) also requires that the specified inlet 
water temperature shall not be less than 70[emsp14][deg]F or more than 
120[emsp14][deg]F. In this NOPR, DOE proposes to retain the option of 
using a recirculating loop and the limits on the inlet water 
temperature for instantaneous water heaters and hot water supply 
boilers that are not able to meet the outlet water temperature 
requirement at the full firing rate. DOE proposes to explicitly state 
the conditions for using a recirculating loop (i.e., that the unit 
under test is unable to meet the outlet temperature at the full firing 
rate) and to specify the limits set on the inlet water temperature 
(measured at T5), as contained in section 5.1.7 of ANSI 
Z21.10.3-2015. Figure III.4 shows the arrangement for optional use of a 
recirculating loop. DOE proposes to clarify that the supply water 
temperature measured at T1 must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F during the entire course 
of the thermal efficiency test (as applicable) and prior to starting 
the standby loss test, while the temperature measurement at 
T5 must not be less than 70[emsp14][deg]F or more than 
120[emsp14][deg]F.

[[Page 28615]]

[GRAPHIC] [TIFF OMITTED] TP09MY16.271

    Figure III.4 and the proposed specifications for the placement of 
temperature sensors, placement of water valves, and placement of a 
recirculating loop (when used) are included in appendix C to subpart G 
of part 431.
    Issue 16: DOE seeks comment on its proposed change to the location 
of temperature measurement for the outlet water temperature with the 
associated conditions for placement of temperature-sensing instruments 
in water pipes, as well as the placement of the supply and outlet water 
valves. Specifically, DOE requests comment on whether such a change 
would provide more accurate test results, and whether the change would 
be burdensome to manufacturers. Additionally, DOE requests information 
on any alternative arrangements to measure the outlet water temperature 
accurately and in close proximity to the hot water outlet of the tested 
CWH equipment.

I. Changes to the Standby Loss Test for Instantaneous Water Heaters and 
Hot Water Supply Boilers Other Than Flow-Activated Instantaneous Water 
Heaters

    Currently, all instantaneous water heaters and hot water supply 
boilers having a storage capacity of ten gallons or more are required 
to be tested for standby loss as per the test method in Exhibit G.2 of 
ANSI Z21.10.3-2011, which is incorporated by reference into DOE's 
current test procedure. In the February 2014 RFI, DOE sought comments 
on the repeatability of thermal efficiency and standby loss test 
methods included in the ANSI Z21.10.3-2011 and ANSI Z21.10.3-2013 test 
methods. 79 FR 10999, 11001-02 (Feb. 27, 2014). DOE discussed the 
comments received in response to this issue generally in section III.B 
of this NOPR. In its response to this issue, HTP stated that currently, 
there is no standby loss test method that is suitable for hot water 
supply boilers containing ten gallons or more of stored water. (HTP, 
No. 5 at p. 2) While responding to a different issue related to the 
applicability of standby loss test procedure to flow-activated water 
heaters, AHRI commented that the current standby loss test procedure is 
designed for tank-type water heaters which are thermostatically-
activated. (AHRI, No. 2 at p. 4)
    DOE reviewed the comments made by HTP and AHRI with regards to the 
standby loss test procedure for instantaneous water heaters and hot 
water supply boilers. DOE notes that the equation used to calculate 
standby loss in DOE's test method for instantaneous water heaters and 
hot water supply boilers (as specified in Exhibit G.2 of ANSI Z21.10.3-
2011) uses two temperature differential terms that both include the 
measurement of the mean tank temperature taken during the course of the 
test. To calculate the standby loss of CWH equipment, the current 
Federal test method requires parameters to be measured that allow for 
the calculation of: (1) The amount of energy consumed to maintain the 
stored water at the required temperature during standby mode; (2) the 
heat lost to the atmosphere from the stored water; and (3) the change 
in total heat content of the water heater between the start and the end 
of the test. Both the terms described in (2) and (3) are calculated 
using the stored water temperature, which are represented in DOE's 
current test method by the mean tank temperature measured during the 
standby loss test. Instantaneous water heaters and hot water supply 
boilers that do not meet DOE's proposed definition for ``storage-type 
instantaneous water heater'' (see section III.F of this document) are 
generally not equipped with an integral hot water storage tank, but 
rather, the stored water is contained within the heat exchanger. Unlike 
storage water heaters and storage-type instantaneous water heaters, 
these instantaneous water

[[Page 28616]]

heaters and hot water supply boilers generally have water-tube heat 
exchangers \17\ and do not store water at a uniform temperature in the 
heat exchanger. Due to complex heat exchanger geometries, an accurate 
measurement of the mean temperature of water stored within the heat 
exchanger is often difficult or impossible to obtain. As a result, DOE 
has tentatively concluded that modifications to the standby loss test 
method are warranted for instantaneous water heaters and hot water 
supply boilers that have a storage capacity of ten gallons or more, but 
that do not meet DOE's proposed definition for ``storage-type 
instantaneous water heater.'' In this NOPR, DOE proposes a separate 
standby loss test procedure in section III.G for flow-activated 
instantaneous water heaters, which have no means of burner or heating 
element activation unless hot water is drawn. In this section (i.e., 
section III.I), DOE proposes a new standby loss test procedure for 
instantaneous water heaters and hot water supply boilers. This proposed 
test procedure would only apply to instantaneous water heaters and hot 
water supply boilers that do not meet DOE's proposed definitions for 
``storage-type instantaneous water heater'' or ``flow-activated 
instantaneous water heater.'' The proposed test procedure is also 
specified in appendices C and D to subpart G of part 431.
---------------------------------------------------------------------------

    \17\ By water-tube heat exchangers, DOE refers to a heat 
exchanger where water flows inside heat exchanger tubes and is 
heated by an external source of energy.
---------------------------------------------------------------------------

    DOE encountered the same issue for flow-activated water heaters and 
addressed this problem in the proposed test procedure described in 
section III.G. While thermostatically-activated instantaneous water 
heaters and hot water supply boilers differ from flow-activated 
instantaneous water heaters in their mechanism to initiate burner or 
heating element operation, these two kinds of equipment share similar 
heat exchanger geometries and designs. In section III.G of this 
rulemaking, DOE discusses the responses received from manufacturers on 
this issue for the standby loss test method for flow-activated 
instantaneous water heaters. In summary, manufacturers suggested that a 
measurement of the outlet water temperature could be used as an 
approximation of the mean stored water temperature within the heat 
exchanger for the purpose of calculating standby loss. Due to the 
similarity in heat exchanger design between flow-activated and 
thermostatically-activated instantaneous water heaters and hot water 
supply boilers, DOE has tentatively concluded that the same rationale 
would apply for thermostatically-activated instantaneous water heaters 
and hot water supply boilers (i.e., a measurement of the outlet 
temperature can be used as a reasonable approximation of the mean 
stored water temperature within the heat exchanger for the purpose of 
calculating standby loss for thermostatically-activated instantaneous 
water heaters and hot water supply boilers). Therefore, DOE proposes to 
use the outlet water temperature as measured by the outlet water 
temperature sensor, instead of the mean tank temperature, to 
approximate the stored water temperature for the purpose of calculating 
standby loss for instantaneous water heaters and hot water supply 
boilers that do not meet DOE's proposed definition for ``storage-type 
instantaneous water heater,'' including flow-activated instantaneous 
water heaters.
    DOE also considered several other options to calculate or measure 
the average stored water temperature (e.g., using the average of the 
supply and outlet water temperature, inserting thermocouples inside the 
heat exchanger through the outlet port of the water heater, or using 
heat transfer equations to back calculate stored water temperature from 
the heat exchanger tube wall temperature). DOE has tentatively 
concluded that none of the other options considered would provide an 
accurate measurement of the average stored water temperature inside the 
water heater. Moreover, because of the complex heat exchanger geometry, 
there would be significant difficulty involved in attempting to 
calculate the average stored water temperature.
    DOE is also aware that in many applications, instantaneous water 
heaters or hot water supply boilers are used to supply hot water to an 
external tank where the water is stored at a fixed temperature. In 
these applications, a thermostat is often used to maintain the desired 
water temperature in the external tank as part of a recirculation loop. 
If the water temperature in the tank falls below the set point, then 
the thermostat directs the water heater to cycle on, and the 
recirculation pump circulates water throughout the loop, withdrawing 
water from the tank, and resupplying heated water back into the tank. 
While reviewing the standby loss test procedure for its applicability 
to thermostatically-activated instantaneous water heaters and hot water 
supply boilers, DOE considered the option of specifying an external 
UFHWST with specific characteristics (e.g., insulation, storage volume) 
to be able to calculate the mean tank temperature. However, DOE has 
tentatively decided not to use this approach to conduct the standby 
loss test for thermostatically-activated instantaneous water heaters 
because it would also include the standby loss that occurs in the 
external tank and therefore, would not be representative of the water 
heater itself. Therefore, DOE has decided not to use an external tank 
to measure the mean tank temperature to conduct the standby loss test 
for thermostatically-activated instantaneous water heaters and hot 
water supply boilers.
    Based on the discussion above, DOE proposes the following test 
procedure for determining the standby loss of instantaneous water 
heaters and hot water supply boilers (except for those that meet the 
proposed definition of a ``storage-type instantaneous water heater'' 
and ``flow-activated instantaneous water heater''). This proposal 
includes some language from Annex E.2 of ANSI Z21.10.3-2015.
    The proposed standby loss test method for instantaneous water 
heaters and hot water supply boilers (except those meeting the 
definition of ``storage-type instantaneous water heater'' and ``flow-
activated instantaneous water heater'') can be started immediately 
after the thermal efficiency test, using the same test set-up and test 
conditions. Otherwise, if the standby loss test is conducted 
separately, one would install the water heater as per Figure III.4 in 
section III.H of this rulemaking (Figure 4 in appendix C to subpart G 
of part 431) and section 2 of appendix C or D (as applicable) to 
subpart G of part 431 to set up the water heater for testing. As 
discussed in section III.H, DOE proposes required locations for 
temperature-sensing instrumentation and water valves for all 
instantaneous water heaters and hot water supply boilers, including 
flow-activated instantaneous water heaters, but excluding storage-type 
instantaneous water heaters. For water heaters with multiple supply or 
outlet water connections entering the water heater jacket, apply the 
outlet water temperature sensor and water valves placement provisions 
proposed in section III.H to each pipe connection entering or leaving 
the water heater. The representative value of the outlet water 
temperature used for the standby loss calculations is obtained by 
taking the average of the water temperatures measured at each water 
connection leaving the water heater jacket.
    DOE proposes that the test be conducted as follows:
    Once the water heater is set up, open the flow valves, start the 
water pump, open the gas supply valves (as

[[Page 28617]]

applicable), and then initiate the ignition process. After the water 
heater starts with the initiation of burner or heating element 
operation, monitor the supply and outlet water temperatures. Adjust the 
water flow rate in such a way that the outlet water temperature reaches 
a temperature of 70[emsp14][deg]F  2[emsp14][deg]F above 
the supply water temperature. Once this temperature is achieved, 
maintain the flow rate and keep monitoring the outlet water 
temperature. After the outlet water temperature has remained constant 
with no variation of more than 2[emsp14][deg]F over a 3-minute period, 
turn off the water supply and outlet valves and, if necessary, the 
water pump. The fuel supply must be kept on for the entire duration of 
the test for gas-fired and oil-fired equipment. After the first cut-
out, allow the water heater to remain in standby mode until the next 
cut-out.
    At this point, start the clock and record the initial outlet water 
and ambient room temperatures. Keep recording the outlet water 
temperature, the ambient room temperature, the time elapsed from the 
start of the test, the electricity consumption, and the fuel 
consumption at an interval of 30 seconds (as proposed in this 
rulemaking and discussed in section III.B) using a data acquisition 
system.
    The duration of this test will be the earlier of: (1) The first 
cut-out that occurs after 24 hours or (2) 48 hours.
    At the conclusion of the test, record the total fuel flow, 
electricity consumption, the final ambient room temperature, the time 
duration in hours rounded to the nearest one hundredth of an hour, and 
the final outlet water temperature.
    Use the equation below to calculate the standby loss in terms of 
percent of total heat content per hour.
[GRAPHIC] [TIFF OMITTED] TP09MY16.272

Where,

[Delta]T3 = Average value of outlet water temperature 
minus the average value of the ambient room temperature, expressed 
in [deg]F
[Delta]T4 = Final outlet water temperature measured at 
the end of the test minus the initial outlet water temperature 
measured at the start of the test, expressed in [deg]F
k = 8.25 Btu/gallon[middot][deg]F, the nominal specific heat of 
water
Va = Volume of water contained in the water heater in 
gallons
Et = Thermal efficiency of the water heater. For electric 
water heaters with immersed heating elements use 98 percent.
Ec = Electrical energy consumed by the water heater 
during the duration of the test in Btu
t = Total duration of the test in hours
Cs = Correction applied to the heating value of a gas H, 
when it is metered at temperature and/or pressure conditions other 
than the standard conditions upon which the value of H is based. 
Cs is not applicable to oil-fired equipment.
Qs = Total fuel flow as metered for gas-fired and oil-
fired equipment, expressed in ft\3\ (gas) or lb (oil).
H = Higher heating value of gas, expressed in Btu/ft\3\ (gas) or 
Btu/lb (oil)
S = Standby loss, the average hourly energy required to maintain the 
stored water temperature expressed as a percentage of the heat 
content of the stored water above room temperature

    The standby loss expressed in Btu per hour must be calculated as 
follows: SL (Btu per hour) = S (% per hour) x 8.25 (Btu/gal-[deg]F) x 
Measured Volume (gal) x 70 (degrees F).
    Issue 17: DOE requests comment on the proposed test procedure for 
instantaneous water heaters and hot water supply boilers (except those 
meeting the proposed definition of ``storage-type instantaneous water 
heater'' and ``flow-activated instantaneous water heater''). DOE also 
requests feedback on its tentative decision to use the outlet water 
temperature instead of the mean tank temperature or stored water 
temperature to conduct the standby loss test. Further, DOE requests 
suggestions on methods or approaches that can be used to measure the 
stored water temperature accurately.

J. Test Procedure for Rating Commercial Heat Pump Water Heaters

    In the February 2014 RFI, DOE raised an issue with regards to 
implementing a new test procedure for commercial heat pump water 
heaters (CHPWHs). 79 FR 10999, 11003 (Feb. 27, 2014). Currently, DOE 
does not have a test procedure for commercial heat pump water heaters 
(although a section is reserved at 10 CFR 431.107). Additionally, DOE 
does not currently have a definition for ``commercial heat pump water 
heater,'' as would help classify such units. Therefore, DOE proposes 
the following definition for commercial heat pump water heaters that 
includes air-source, water-source, and direct geo-exchange CHPWHs.
    Commercial heat pump water heater (CHPWH) means a water heater that 
uses a refrigeration cycle, such as vapor compression, to transfer heat 
from a low-temperature source to a higher-temperature sink for the 
purpose of heating potable water, and has a rated electric power input 
greater than 12 kW. Such equipment includes, but is not limited to, 
air-source heat pump water heaters, water-source heat pump water 
heaters, and direct geo-exchange heat pump water heaters.
    Issue 18: DOE requests comment on its proposed definition for 
``commercial heat pump water heater.''
    DOE is aware that ANSI/ASHRAE Standard 118.1-2012 (``ASHRAE 118.1-
2012''), Method of Testing for Rating Commercial Gas, Electric, and Oil 
Service Water-Heating Equipment is used as an industry test method for 
CHPWHs. ASHRAE 118.1-2012 includes several test methods, including a 
method for determining coefficient of performance (COPh), 
standby loss for commercial heat pump water heaters, and cooling output 
of air-source CHPWHs. DOE considered this test procedure for adoption 
as the Federal test method for CHPWHs. In addition to ASHRAE 118.1-
2012, DOE is also aware of another relevant industry standard, the 
ANSI/AHRI Standard 1300 (I-P)-2013 (``AHRI 1300''), Performance Rating 
of Commercial Heat Pump Water Heaters. AHRI 1300 specifies rating 
conditions (e.g., entering water temperature, leaving water 
temperature, and other evaporator side rating conditions) for testing 
CHPWHs, but it references ASHRAE 118.1-2012 for the actual procedure to 
conduct the test. DOE considered the rating conditions specified in 
AHRI 1300 for developing a test procedure for CHPWHs. In the February 
2014 RFI, DOE requested public comment on adopting an appropriate test 
procedure for CHPWHs. DOE sought comment on both of the aforementioned 
industry test methods and on whether any modifications would be needed 
for adopting them as the Federal test method. 79 FR 10999, 11003 (Feb. 
27, 2014).
    DOE received several comments from interested parties in response 
to this issue. Bradford White supported the use

[[Page 28618]]

of AHRI 1300 as an appropriate test method for rating CHPWHs. (Bradford 
White, No. 8 at p. 2) AHRI commented that the efficiency of CHPWHs 
should be measured at two rating conditions. AHRI also supported the 
use of AHRI 1300 as the test procedure to measure efficiency of CHPWHs, 
and HTP stated that it support AHRI's position on this topic. (AHRI, 
No. 2 at p. 4; HTP, No. 5 at p. 5) Rheem also supported the use of AHRI 
1300 as the rating standard. In addition, Rheem supported any 
modifications to AHRI 1300 that may be required to address issues 
identified by industry during testing. (Rheem, No. 3 at p. 2) APPA also 
supported the use of AHRI 1300 for testing CHPWHs and stated that the 
AHRI 1300 standard references ASHRAE 118.1, which represents an ANSI-
approved consensus of multiple stakeholders. (APPA, No. 6 at p. 2) EEI 
also supported the use of AHRI 1300 for rating CHPWHs. Both APPA and 
EEI expressed support for the adoption of an industry test procedure to 
minimize cost by avoiding duplicative testing standards. (APPA, No. 6 
at p. 2; EEI, No. 9 at p. 2) A.O. Smith recommended the use of ASHRAE 
118.1-2012 and stated that ASHRAE 118.1-2012 is being revised to 
harmonize its rating conditions with the conditions in AHRI 1300. (A.O. 
Smith, No. 7 at pp. 2-3)
    The Joint Advocates also commented that they strongly support DOE's 
efforts to adopt a consensus test procedure standard for CHPWHs. To 
assist DOE in the rulemaking, the Joint Advocates posed several 
questions that may influence DOE's direction for this rulemaking. The 
Joint Advocates asked whether there are any international standards 
that have lessons for U.S. practice. (Joint Advocates, No. 4 at pp. 2-
3) DOE reviewed the Collaborative Labeling and Appliance Standards 
Program's (CLASP's) Global Standards and Labeling Database \18\ and 
determined that no other country has adopted efficiency standards for 
CHPWHs. Additionally, DOE reviewed the Super-efficient Equipment and 
Appliance Deployment (SEAD) report on potential for harmonization of 
international standards for heat pump water heaters.\19\ This report 
primarily discussed residential heat pump water heaters and was not 
useful in the context of this commercial rulemaking.
---------------------------------------------------------------------------

    \18\ ``CLASP's Global S&L Database.'' CLASP (Dec. 7, 2015) 
(Available at: http://www.clasp.ngo/ResourcesTools/Tools/SL_Search).
    \19\ Additional information on international standards for HPWHs 
can be found at: http://tinyurl.com/jnx79ay.
---------------------------------------------------------------------------

    The Joint Advocates asked how first-hour supply capability is 
treated as a capacity measure for CHPWHs. (Joint Advocates, No. 4 at 
pp. 2-3) DOE acknowledges that delivery capacity of CWH equipment, 
including CHPWHs, is an important metric for selection and sizing of 
equipment. However, DOE does not believe such a capacity measure is 
needed in its test procedure for energy efficiency, as information 
regarding capacity is already typically readily available in 
manufacturer literature.
    The Joint Advocates asked about the potential impacts of ambient 
conditions on the test procedure. (Joint Advocates, No. 4 at pp. 2-3) 
In response, DOE conducted exploratory tests on different CHPWH units 
at the different rating conditions specified in ASHRAE 118.1-2012 and 
AHRI 1300. DOE considered the information and results gathered from 
these tests in the development of the proposed test procedure for 
CHPWHs. The exploratory tests are discussed in more detail later in 
this section.
    The Joint Advocates raised the issue of the need to consider the 
capabilities of different refrigerants to achieve temperature rise that 
is required for commercial applications (i.e., outlet water temperature 
of ~170[emsp14][deg]F). (Joint Advocates, No. 4 at pp. 2-3) DOE notes 
that most of the CHPWH models available on the market use R-134a, R-
410A or R-22 as refrigerants. Further, DOE notes that industry test 
standards (e.g., ASHRAE 118.1-2012 and AHRI 1300) specify an outlet 
water temperature of 120[emsp14][deg]F for testing of heat pump water 
heaters, and do not differentiate based on type of refrigerant used. 
DOE has found in examining CHPWHs, that an outlet water temperature of 
120[emsp14][deg]F is typical and readily achievable in applications 
that would be suitable for a CHWPH, regardless of refrigerant type. 
Based on the foregoing, DOE has tentatively decided not to provide 
different outlet water temperature conditions based on the type of 
refrigerant being used.
    The Joint Advocates suggested that DOE should consider a different 
requirement such as maximum rated temperature instead of a constant 
test temperature. (Joint Advocates, No. 4 at pp. 2-3) DOE's proposed 
test procedure for CHPWHs includes a provision allowing units that are 
unable to meet the outlet water temperature at low entering water 
temperatures to be tested using a higher supply temperature. These 
provisions are discussed in greater detail later on in this section.
    The Joint Advocates asked whether the cooled evaporator air could 
be used for cooling spaces and whether the energy value of this benefit 
could be included. (Joint Advocates, No. 4 at pp. 2-3) DOE appreciates 
that in some sites, cool air rejected from the evaporator coil may 
provide an ancillary benefit by providing additional space cooling. 
However, DOE does not propose to include a methodology to measure the 
cooling performance of a commercial heat pump water heater. DOE finds 
that such a methodology would be overly burdensome to manufacturers in 
relation to the uncertain benefit provided to commercial consumers.
    In addition, the Joint Advocates expressed their goals for the 
CHPWH standard as: (1) Allowing fair comparison between products and 
(2) giving contractors enough information to help customers make 
informed decisions. According to the Joint Advocates, CHPWHs will 
require a single metric to be useful and have suggested a blend of the 
current metrics as a single rating parameter. (Joint Advocates, No. 4 
at pp. 2-3) Although DOE proposes a test procedure for CHPWHs in this 
NOPR, the scope of this rulemaking does not include amending energy 
conservation standards for CHPWHs. In this NOPR, DOE only proposes a 
test procedure that manufacturers can use to rate their products, 
without a requirement to certify COPh ratings to DOE. In its 
analysis for this NOPR, DOE considered whether the proposed test 
procedures for all kinds of CHPWHs would allow for fair comparison 
between products. Specifically, DOE reviewed and proposes to 
incorporate by reference certain sections of relevant industry test 
methods to ensure DOE's test procedure is consistent with industry-
accepted test methods. DOE also conducted investigative testing of 
several air-source CHPWHs from different manufacturers to verify the 
appropriateness of the proposed test procedure and the consistency of 
results. With regards to the metric, DOE notes that the industry test 
standards (ASHRAE 118.1-2012 and AHRI 1300) use the coefficient of 
performance (COP) as the energy efficiency metric for rating CHPWHs. To 
ensure consistency with these industry test standards, DOE has 
tentatively decided to use the same energy efficiency metric (COP) for 
rating CHPWHs.
    The second supplemental comment from AHRI in response to the 
February 2014 RFI includes recommended rating conditions for testing 
several kinds of CHPWHs. (AHRI (2015), No. 13, pp. 1-2) AHRI 
recommended four categories of CHPWHs based on the heat source (i.e., 
air-source, direct geo-exchange, indoor water-source, and ground water-
source) with one set of rating conditions

[[Page 28619]]

for each category. (AHRI (2015), No. 13 at pp. 1-2) The AHRI-
recommended rating conditions that are specified in their comments are 
shown in Table III-2:

 Table III-2--AHRI-Recommended Classifications and Rating Conditions for
                               CHPWHs \20\
------------------------------------------------------------------------
  Classification based on heat source     Recommended rating conditions
------------------------------------------------------------------------
Air-source commercial heat pump water    Entering water temperature: 110
 heater.                                  [deg]F.
                                         Entering air conditions: 80.6
                                          [deg]F dry bulb and 71.2
                                          [deg]F wet bulb.
Direct geo-exchange commercial heat      Entering water temperature: 110
 pump water heater.                       [deg]F.
                                         Evaporator refrigerant
                                          temperature: 32 [deg]F.
Indoor water-source commercial heat      Entering water temperature: 110
 pump water heater.                       [deg]F.
                                         Evaporator entering water
                                          temperature: 68 [deg]F.
Ground water-source commercial heat      Entering water temperature: 110
 pump water heater.                       [deg]F.
                                         Evaporator entering water
                                          temperature: 50 [deg]F.
------------------------------------------------------------------------

    DOE reviewed AHRI's comments carefully and assessed whether the 
recommended rating conditions for CHPWHs would sufficiently cover the 
types of units that are available on the market. As indicated in Table 
III-2, AHRI recommended separate rating conditions for indoor water-
source CHPWHs and ground water-source CHPWHs, despite the fact that 
both utilize water or another liquid as the evaporator heat source. DOE 
sees merit in having separate rating conditions for indoor water-source 
and ground water-source units, because the temperature of water 
entering the evaporator would be different for each application. 
However, for the purpose of testing and rating CHPWHs, both indoor 
water-source CHPWHs and ground water-source CHPWHs can be tested using 
the same test procedure but with different rating conditions.
---------------------------------------------------------------------------

    \20\ The AHRI recommended classifications and rating conditions 
for CHPWHs can be found in their comments at: http://www.regulations.gov/#!documentDetail;D=EERE-2014-BT-TP-0008-0013.
---------------------------------------------------------------------------

    ASHRAE 118.1-2012 includes a similar classification with separate 
test procedures for air-source, direct geo-exchange, and water-source 
CHPWHs. The test procedure for water-source CHPWHs in ASHRAE 118.1-2012 
applies to both indoor water-source CHPWHs and ground water-source 
CHPWHs. After considering the applications and characteristics of the 
different kinds of CHPWHs and the classification used in ASHRAE 118.1-
2012, DOE proposes separate test procedures for air-source, direct geo-
exchange, and water-source CHPWHs. The proposed test procedure for 
water-source CHPWHs would be used to rate both ground water-source and 
indoor water-source models with different rating conditions for each 
category.
    To differentiate the four categories of CHPWHs from each other, DOE 
proposes to add definitions for ``Air-source commercial heat pump water 
heater'', ``Direct geo-exchange commercial heat pump water heater'', 
``Indoor water-source commercial heat pump water heater'', and ``Ground 
water-source commercial heat pump water heater,'' as set out in the 
regulatory text at the end of this document.
    Issue 19: DOE requests comment on the proposed categories of CHPWHs 
and related definitions. In particular, DOE requests comments on CHPWH 
heat sources that are currently available for commercial applications.
    To develop new test procedures for all four categories of CHPWHs, 
DOE reviewed both ASHRAE 118.1-2012 and AHRI 1300. As noted earlier, 
AHRI 1300 only provides rating conditions and references ASHRAE 118.1-
2012 for the actual test method. ASHRAE 118.1-2012 is an industry test 
method used to rate gas-fired, electric, and oil-fired CWH equipment. 
For the purpose of testing, ASHRAE 118.1-2012 classifies CHPWHs into 
two types: (1) ``Type IV''--equipment that can be operated without 
requiring a connection to a storage tank; and (2) ``Type V''--equipment 
that requires connection to a storage tank for operation. ASHRAE 118.1-
2012 specifies separate test methods to rate the two types of 
equipment. The test procedure described in ASHRAE 118.1-2012 for Type V 
units requires the unit to be connected to a tank that is either 
supplied by the manufacturer along with the unit or is specified by the 
manufacturer. However, after reviewing product literature, DOE notes 
that generally, CHPWH manufacturers neither supply a storage tank with 
the equipment, nor specify a tank appropriate for that equipment. The 
ASHRAE 118.1-2012 test procedure does not include a test method for 
Type V units for which an appropriate tank is neither supplied nor 
specified by the manufacturer. Without connecting an appropriate tank, 
Type V equipment cannot be tested using the Type V equipment test 
procedure as specified in ASHRAE 118.1-2012.
    DOE considered establishing a ``standard'' tank for rating the 
energy efficiency of Type V units that are not shipped with a tank and 
for which manufacturers do not specify the tank to be used. However, 
DOE tentatively determined that testing and rating a CHPWH by 
connecting it with a separately supplied tank could be an unfair 
representation of the actual rating of the unit itself since the 
efficiency of the system is highly dependent on the characteristics of 
the tank. Further, different CHPWHs may be designed for use with tanks 
having different characteristics. Theoretically, the combined 
efficiency rating of a CHPWH unit when operated along with the tank 
would be lower than the actual rating of that CHPWH unit alone, because 
the addition of a tank would allow for heat loss through the tank 
jacket and piping. Also, there may be inconsistencies in selecting 
tanks used for efficiency testing if manufacturers do not supply or 
specify an appropriate tank for the CHPWH units. This inconsistency 
could lead to energy savings smaller than expected for commercial 
consumers if CHPWHs are tested with storage tanks more efficient than 
those that those commercial consumers use.
    Considering these issues associated with testing a CHPWH unit with 
an external tank connected to it, DOE explored the possibility of 
formulating a new test method to test all CHPWH units as Type IV 
equipment (i.e., without connecting a hot water storage tank while 
testing). In order to verify the applicability of the Type IV test to 
all CHPWH units, DOE selected three air-source CHPWH units available on 
the market and tested them using the test procedure specified in ASHRAE 
118.1-2012. DOE tested the units at six different rating conditions 
specified for air-source CHPWHs by both ASHRAE

[[Page 28620]]

118.1-2012 and AHRI 1300, as shown in Table III-3. The units that were 
chosen for testing were purchased from different manufacturers and had 
varying levels of heating capacities (100,000 Btu/h; 30,000 Btu/h; and 
275,000 Btu/h). All of these units had an internal pump fitted within 
the unit, so no external pump was required to supply inlet water to the 
condenser of the heat pump.
    The test procedure for air-source CHPWHs as specified in ASHRAE 
118.1-2012 requires the CHPWH to be set up according to Figure 5 of 
that test standard. The water flow rate through the unit is adjusted in 
such a way that the outlet water temperature is maintained at 
120[emsp14][deg]F  5[emsp14][deg]F with no variation of 
more than 2[emsp14][deg]F over a three-minute period. DOE conducted the 
tests under six different rating conditions, which consist of three 
different evaporator entering air temperatures and two supply water 
temperature conditions. In all, DOE conducted six tests on each CHPWH 
unit. These test conditions are shown in Table III-3:

                  Table III-3--Rating Conditions for Testing Commercial Heat Pump Water Heaters
----------------------------------------------------------------------------------------------------------------
                                                                      Evaporator entering air        Condenser
                                                                       temperature [[deg]F]       entering water
                        Rating conditions                        --------------------------------   temperature
                                                                     Dry bulb        Wet bulb        [[deg]F]
----------------------------------------------------------------------------------------------------------------
1...............................................................         * 95            * 75                 70
2...............................................................           80.6            71.2               70
3...............................................................           50              44.3               70
4...............................................................         * 95            * 75              * 110
5...............................................................           80.6            71.2            * 110
6...............................................................           50              44.3            * 110
----------------------------------------------------------------------------------------------------------------
* Rating conditions which are included in ANSI/ASHRAE 118.1-2012. (Note, all rating conditions in this table are
  included in AHRI 1300-2013.)

    The results obtained from these tests indicate that not all the 
units were capable of achieving an outlet water temperature of 
120[emsp14][deg]F  5[emsp14][deg]F. The 30,000 Btu/h unit 
was the only unit capable of delivering the required outlet water 
temperature for all six rating conditions. For rating conditions 1, 2, 
and 3, the flow rate for the 30,000 Btu/h unit had to be sharply 
reduced to achieve the high temperature rise from a supply water 
temperature of 70[emsp14][deg]F to outlet water temperature of 
120[emsp14][deg]F  5[emsp14][deg]F. However, for the rating 
conditions 4, 5, and 6, the unit successfully delivered water at a 
temperature of 120[emsp14][deg]F  5[emsp14][deg]F at the 
manufacturer's specified flow rate.
    The 100,000 Btu/h unit was not able to achieve an outlet water 
temperature of 120[emsp14][deg]F  5[emsp14][deg]F at rating 
conditions 1 and 2. Moreover, the unit was unable to operate at rating 
conditions 3 and 6 (evaporator entering air dry bulb temperature of 
50[emsp14][deg]F) due to low ambient temperature conditions. When the 
unit was tested at rating conditions 4 and 5, the unit was successful 
at achieving the 120[emsp14][deg]F  5[emsp14][deg]F outlet 
water temperature at the manufacturer-rated water flow rate.
    The 275,000 Btu/h unit was capable of achieving the required 
120[emsp14][deg]F  5[emsp14][deg]F outlet water temperature 
when tested at rating conditions 1 and 2 with the manufacturer's rated 
water flow rate. However, the unit did not achieve the required outlet 
water temperature for any of the other rating conditions. A possible 
reason for this is the low ambient temperature resulting in lower heat 
being utilized by the heat pump. For rating conditions 4, 5, and 6 
where the supply water temperature is maintained at 110[emsp14][deg]F, 
the outlet water temperature exceeded 120[emsp14][deg]F  
5[emsp14][deg]F. The water flow rate for these conditions was at the 
manufacturer's rated flow rate, and the unit's design did not allow the 
flow rate to be increased above that value.
    Based on these tests, two conclusions can be drawn. First, rating 
conditions 3 and 6, representing an evaporator entering air dry bulb 
temperature of 50[emsp14][deg]F, were not achievable for two of the 
tested units, (i.e., the 100,000 Btu/h unit and the 275,000 Btu/h 
unit). One of the reasons for this is the reduced temperature 
difference between the refrigerant saturation temperature and the 
evaporator entering air temperature, which severely limits the 
evaporator performance. Second, the lower heating capacity units 
(30,000 Btu/h and 100,000 Btu/h) were able to achieve the required 
outlet water temperature of 120[emsp14][deg]F  
5[emsp14][deg]F at the manufacturer's rated supply water flow rate when 
the supply water temperature was set to 110[emsp14][deg]F, whereas the 
larger heating capacity unit (275,000 Btu/h) was able to meet the 
required outlet water temperature condition at the manufacturer's rated 
flow rate when the supply water temperature was set to 
70[emsp14][deg]F. This indicates that some units are sized to achieve a 
low water temperature rise, while others are sized to achieve a higher 
water temperature rise.
    On the basis of these exploratory tests, DOE was able to determine 
applicability of the test procedure described for ``Type IV'' units in 
ASHRAE 118.1-2012 to air-source CHPWH units. Based on the results and 
the discussion above, DOE has tentatively concluded that the method of 
test described for ``Type IV'' units in ASHRAE 118.1-2012 can be used 
to test air-source CHPWHs but with certain modifications. These 
proposed modifications include establishing: (1) A single evaporator 
air entering rating condition with a dry bulb temperature of 
80.6[emsp14][deg]F  1[emsp14][deg]F and a wet bulb 
temperature of 71.2[emsp14][deg]F  1[emsp14][deg]F; (2) a 
supply water temperature of 70[emsp14][deg]F  
1[emsp14][deg]F (or 110[emsp14][deg]F  1[emsp14][deg]F, 
only if the required outlet water temperature condition is not achieved 
while testing at a supply water temperature of 70[emsp14][deg]F  1[emsp14][deg]F).
    DOE did not conduct exploratory tests for other categories of 
CHPWHs (i.e., direct geo-exchange, indoor water-source, and ground 
water-source CHPWHs). As discussed previously, AHRI's initial comment 
recommended using AHRI 1300 for rating CHPWHs (which utilizes ASHRAE 
118.1-2012 as the actual procedure), and AHRI's supplemental comment 
suggested rating conditions appropriate for direct geo-exchange, indoor 
water-source, and ground water-source CHPWHs. As DOE has not identified 
any other industry test method applicable to CHPWHs, DOE has 
tentatively determined to use the test method for ``Type IV'' equipment 
specified in ASHRAE 118.1-2012 with rating conditions recommended by 
AHRI (Table III-2) for testing the energy efficiency of direct geo-
exchange, indoor water-source, and ground water-source CHPWHs. 
Specifically, DOE proposes that direct

[[Page 28621]]

geo-exchange CHPWHs be tested using the ASHRAE 118.1-2012 test 
procedure for ``Type IV'' direct geo-exchange heat pump water heaters 
with an entering water temperature of 110[emsp14][deg]F and evaporator 
refrigerant temperature of 32[emsp14][deg]F. DOE proposes indoor water-
source and ground water-source CHPWHs be tested according to the ASHRAE 
118.1-2012 test procedure for ``Type IV'' water-source heat pump water 
heaters, with an entering water temperature of 110[emsp14][deg]F and 
evaporator entering water temperature of 68[emsp14][deg]F and 
50[emsp14][deg]F for indoor water-source and ground water-source 
CHPWHs, respectively.
    ASHRAE 118.1-2012 provides several test procedure metrics for 
measuring energy efficiency (e.g., Coefficient of performance with full 
input rating (section 9.1.1 of ASHRAE 118.1), Coefficient of 
performance with reduced input rating (9.1.2 of ASHRAE 118.1), standby 
energy consumption (section 9.2 of ASHRAE 118.1), and cooling output 
(section 9.3 of ASHRAE 118.1)). Coefficient of performance refers to 
the ratio of the useful heat gained by the water (in Btu/h) to the 
electric power consumed by the unit (in Btu/h). For the current 
rulemaking, DOE proposes to use the test procedure for measuring 
coefficient of performance for full input rating. DOE also proposes to 
define ``coefficient of performance'' as set out in the regulatory text 
at the end of this document.
    As previously noted, DOE's proposed test procedure for rating 
CHPWHs would incorporate by reference certain relevant sections of 
ASHRAE 118.1-2012. The succeeding paragraphs highlight various sections 
that are relevant to testing units of all four categories of CHPWHs.
    DOE proposes that the instrumentation required for the new test 
procedure would be as described in section 6 of ASHRAE 118.1. Further, 
DOE proposes that the test set-up, piping, and temperature-sensing 
locations be as described in sections 7.1, 7.2.1, 7.3.2, 7.3.3, 7.5, 
and 7.6 of that industry standard for testing Type IV equipment. DOE 
also proposes to incorporate subsections 7.7.1 to 7.7.6 with the 
exclusion of section 7.7.5 of ASHRAE 118.1-2012. Section 7.7.5 of 
ASHRAE 118.1-2012 contains special requirements for testing a heat pump 
water heater for measurement of space cooling. Section 7.7.7 of ASHRAE 
118.1-2012 refers to Table 2 of the same test standard, which provides 
values for supply (or entering) water temperatures for testing CHPWHs. 
DOE has tentatively decided not to directly adopt section 7.7.7 of 
ASHRAE 118.1-2012 and instead proposes to adopt the following 
provisions to replace section 7.7.7 as follows:
Modifications for Water-Source CHPWHs and Direct Geo-Exchange CHPWHs
    DOE proposes to test direct geo-exchange, indoor water-source, and 
ground water-source CHPWHs with a nominal entering water temperature of 
110[emsp14][deg]F instead of the temperature specified in Table 2 
referenced by section 7.7.7 of ASHRAE 118.1.
Modifications for Air-Source CHPWHs
    DOE proposes that air-source CHPWH equipment be tested with a 
supply water temperature of 70[emsp14][deg]F  
1[emsp14][deg]F. If the required outlet water temperature condition 
(specified in section 8.7.2 of ASHRAE 118.1-2012) is not met while 
testing the unit at 70[emsp14][deg]F  1[emsp14][deg]F, only 
then should the supply water temperature be provided at 
110[emsp14][deg]F  1[emsp14][deg]F. DOE proposes to use the 
following steps for setting the supply water temperature that would be 
applicable to the air-source CHPWH unit being tested:
    (1) Set the supply water temperature at 70[emsp14][deg]F  1[emsp14][deg]F and the water flow rate to the rated pump flow 
rate and start operating the unit. Measure the outlet water temperature 
at this flow rate to check if an outlet water temperature of 
120[emsp14][deg]F  5[emsp14][deg]F is achieved as specified 
in section 8.7.2 of ASHRAE 118.1-2012. If the outlet water temperature 
is maintained at this condition (i.e., at a temperature of 
120[emsp14][deg]F  5[emsp14][deg]F and with no variation of 
more than 2[emsp14][deg]F over a three-minute period), then conduct the 
test as per section 9.1.1 of ASHRAE 118.1-2012.
    (2) If the outlet water temperature condition is not met, then 
adjust the flow rate in order to meet the required outlet water 
temperature condition as per section 8.7.2 of ASHRAE 118.1-2012. 
Measure the outlet water temperature at the adjusted flow rate to check 
if an outlet water temperature of 120[emsp14][deg]F  
5[emsp14][deg]F is achieved as specified in section 8.7.2 of ASHRAE 
118.1-2012. If the outlet water temperature is maintained at this 
condition (i.e., at a temperature of 120[emsp14][deg]F  
5[emsp14][deg]F and with no variation of more than 2[emsp14][deg]F over 
a three-minute period), then conduct the test as per section 9.1.1 of 
ASHRAE 118.1-2012.
    (3) If, after adjusting the flow rate within the range that is 
achievable by the pump, the equipment is unable to operate or deliver 
the required outlet water temperature, then reset the flow rate to the 
rated pump flow rate and change the supply water temperature to 
110[emsp14][deg]F  1[emsp14][deg]F. Measure the outlet 
water temperature at the rated pump flow rate to determine whether the 
outlet water temperature requirement is met as per section 8.7.2 of 
ASHRAE 118.1-2012. If the outlet water temperature is maintained at 
this condition (i.e., at a temperature of 120[emsp14][deg]F  5[emsp14][deg]F and with no variation of more than 
2[emsp14][deg]F over a three-minute period), then conduct the test as 
per section 9.1.1 of ASHRAE 118.1-2012.
    (4) If the outlet water temperature condition is not met, then 
adjust the flow rate in order to meet the required outlet water 
condition as per section 8.7.2 of ASHRAE 118.1-2012. Measure the outlet 
water temperature at the adjusted flow rate to check if an outlet water 
temperature of 110[emsp14][deg]F  1[emsp14][deg]F is 
achieved as specified in section 8.7.2 of ASHRAE 118.1-2012. If the 
outlet water temperature is maintained at this condition (i.e., at a 
temperature of 120[emsp14][deg]F  5[emsp14][deg]F and with 
no variation of more than 2[emsp14][deg]F over a three-minute period), 
then conduct the test as per section 9.1.1 of ASHRAE 118.1-2012.
    (5) If the outlet water temperature condition cannot be met, then a 
test procedure waiver is necessary to specify an alternative set of 
test conditions.
    DOE proposes to retain Table 3 of ASHRAE 118.1-2012, which provides 
tolerances of different parameters (e.g., water temperatures, water 
flow rates) and, sections 7.7.7.1 and 7.7.7.2 of ASHRAE 118.1-2012 that 
specifies requirements for measurement of water flow and temperature. 
If the CHPWH is equipped with a thermostat that controls the throttling 
valve, then use section 7.7.7.3 of ASHRAE 118.1-2012 to set up the 
thermostat. DOE also proposes to use sections 8.2.1 and 8.7.2 of ASHRAE 
118.1-2012 for specifying electrical supply and outlet water 
temperature requirements, respectively. The method of test would be as 
per the test procedure specified in section 9.1.1 of ASHRAE 118.1. The 
rating conditions in ASHRAE 118.1-2012 are contained tables B-1, B-2, 
and B-3 of appendix B5 of the industry test standard, and referenced 
from section 9.4.1 of that test method. Rather than use the rating 
conditions specified in ASHRAE 118.1-2012, DOE proposes to use a single 
rating condition for each category of CHPWHs as specified in Table III-
4:

[[Page 28622]]



           Table III-4--Proposed Rating Conditions for CHPWHs
------------------------------------------------------------------------
                                 Evaporator side       Condenser side
      Category of CHPWH         rating conditions     rating conditions
------------------------------------------------------------------------
Air-source commercial heat    Evaporator entering   Entering water
 pump water heater.            air conditions:       temperature: 70
                              Dry bulb: 80.6         [deg]F 
                               [deg]F    1 [deg]F. Vary
                               1 [deg]F and.         water flow rate (if
                              Wet bulb: 71.2         needed) to achieve
                               [deg]F    the outlet water
                               1 [deg]F.             temperature as
                                                     specified in
                                                     section 8.7.2 of
                                                     ASHRAE 118.1-2012.
                                                    If required outlet
                                                     water temperature
                                                     as specified in
                                                     section 8.7.2 of
                                                     ASHRAE 118.1-2012
                                                     is not met even
                                                     after varying the
                                                     flow rate, then
                                                     change the
                                                     condenser entering
                                                     water temperature
                                                     to 110 [deg]F  1 [deg]F.
                                                     Vary flow rate to
                                                     achieve the
                                                     conditions in
                                                     section 8.7.2 of
                                                     ASHRAE 118.1-2012.
Direct geo-exchange           Evaporator            Entering water
 commercial heat pump water    refrigerant           temperature: 110
 heater.                       temperature: 32       [deg]F 
                               [deg]F    1 [deg]F.
                               1 [deg]F.
Indoor water-source           Evaporator entering   Entering water
 commercial heat pump water    water temperature:    temperature: 110
 heater.                       68 [deg]F 
                               minus> 1 [deg]F.      1 [deg]F.
Ground water-source           Evaporator entering   Entering water
 commercial heat pump water    water temperature:    temperature: 110
 heater.                       50 [deg]F 
                               minus> 1 [deg]F.      1 [deg]F.
------------------------------------------------------------------------

    To calculate the final COPh value, DOE proposes to use 
section 10.3.1 of ASHRAE 118.1-2012.
    To further assess the new test method, DOE conducted a second round 
of experimental testing on the 100,000 Btu/h CHPWH unit. In this round, 
the test was carried out exactly as per the proposed test procedure 
specified in appendix F to subpart G of part 431 and proposed in this 
section of the NOPR. DOE tested the unit with evaporator entering air 
temperatures specified in appendix F to subpart G of part 431 (also 
specified in Table III-4). As proposed, the unit was first tested with 
a supply water temperature of 70[emsp14][deg]F  
1[emsp14][deg]F. At these rating conditions, the unit was unable to 
achieve an outlet water temperature of 120[emsp14][deg]F  
5[emsp14][deg]F, even after varying the supply water flow rate. The 
supply water temperature was then re-adjusted to 110[emsp14][deg]F 
 1[emsp14][deg]F. At this temperature, the unit was 
successful in delivering and maintaining an outlet water temperature of 
120[emsp14][deg]F  5[emsp14][deg]F with no variation of 
more than 2[emsp14][deg]F over a three-minute duration. Results show 
that the COPh value obtained in the second round of testing 
in reasonably close agreement between the COPh measured in 
the first round of testing, indicative of the repeatability and 
practicability of the proposed test procedure.
    Issue 20: DOE requests comment on all aspects of the proposed test 
procedure for commercial heat pump water heaters, and in particular, 
the proposal to test all units without a storage tank. DOE also invites 
comment on its recommended rating conditions, particularly the supply 
water temperatures for air-source commercial heat pump water heaters.

K. Fuel Input Rate

    In DOE's existing regulations, equipment classes and the standards 
that apply to them are determined partly on the basis of the input 
capacity of the CWH equipment. However, several terms are used in the 
existing DOE test procedures and energy conservation standards to 
describe the capacity of the CWH equipment, each of which is derived 
from the maximum rated fuel input rate to the CWH equipment. For 
example, the existing DOE test procedure for CWH equipment at 10 CFR 
431.106 uses the term ``hourly Btu input rate'' to describe the 
measured input rate during the test and ``manufacturer's specified 
input rate'' as the value to which the measured input rate should be 
compared. The energy conservation standards for CWH equipment at 10 CFR 
431.110 use the term ``nameplate input rate,'' which is intended to 
mean the same thing as ``manufacturer's specified input rate.'' While 
DOE's test procedure for oil-fired CWH equipment requires the hourly 
Btu input rate to be within 2 percent of the manufacturer's 
specified input rate, no procedure is included for measuring the input 
rate.
    To clarify standardize terminology throughout its regulations for 
CWH equipment and to determine the appropriate equipment class for CWH 
equipment, DOE proposes to define the term ``fuel input rate'' as set 
out in the regulatory text at the end of this document.
    DOE proposes to use this term in the division of equipment classes 
and applicable testing provisions to determine the fuel input rate. 
Manufacturers would be required to measure the fuel input rate during 
certification testing and use the mean of the measured values, after 
applying the applicable rounding provisions (discussed later in this 
section), in certification reports pursuant to 10 CFR 429.44(c)(2). DOE 
also notes that, for CWH equipment certified using an AEDM, the AEDM 
would be used to determine the fuel input rate and the same rounding 
provisions would apply. DOE believes it is critical to clarify how the 
fuel input rate is to be determined because the applicable standards 
for certain classes of CWH equipment are based in part on the fuel 
input rate. These proposed additions would clarify for manufacturers 
what energy conservation standard applies to a given basic model.
    DOE also proposes to include equations for determination of fuel 
input rate in its test procedures for gas-fired and oil-fired CWH 
equipment. DOE proposes to include Equations C2 and C3 from section 
C7.2.3 of AHRI 1500-2015 in its test procedures for calculation of fuel 
input rate for gas-fired and oil-fired CWH equipment, respectively. DOE 
also proposes that the fuel input rate be determined by measuring fuel 
consumption at 3 consecutive 10-minute intervals during the 30-minute 
thermal efficiency test. The overall fuel input rate for the thermal 
efficiency test will be calculated using the fuel consumption over the 
entire 30-minute test. DOE proposes that during the thermal efficiency 
test, the measured fuel input rate must not vary by more than 2 percent between 10-minute interval readings.
    Section 5.2.2 of AHRI 1500-2015 specifies rounding gross output (as 
defined in section 3.20 of AHRI 1500-2015) to the nearest 1,000 Btu/h. 
However, DOE regulations are based on input rate, not gross output. 
Therefore, DOE proposes adding a requirement to the DOE test procedure 
that values of

[[Page 28623]]

fuel input rate for each unit tested be rounded to the nearest 1,000 
Btu/h.
    Additionally, DOE proposes that, for its enforcement testing, the 
overall fuel input rate for the thermal efficiency test would be 
measured pursuant to 10 CFR 431.106 and compared against the fuel input 
rate certified by the manufacturer. If the measured fuel input rate is 
within 2 percent of the certified value, then DOE will use 
the certified value when determining which equipment class to regulate 
a model. If the measured fuel input rate is not within 2 
percent of the certified value, then DOE will attempt the following 
steps to bring the fuel input rate to within 2 percent of 
the certified value. First, DOE will attempt to adjust the gas pressure 
in order to increase or decrease the fuel input rate within the gas 
pressure range allowed by the test procedure. If the fuel input rate is 
still not within 2 percent of the certified value, DOE will 
then attempt to modify the gas inlet orifice (e.g. drill) accordingly. 
Finally, if these measures do not bring the fuel input rate to within 
2 percent of the certified value, DOE will use the measured 
fuel input rate when determining the equipment class. DOE proposes a 
fuel input rate tolerance of 2 percent based on the steady-
state criteria included in sections C4.1.1.1.4 and C4.1.2.1.5 of AHRI 
1500-2015, and has tentatively concluded that such a requirement would 
not impose additional testing burden or affect ratings. DOE proposes 
this verification process to provide manufacturers with additional 
information about how DOE will evaluate compliance.
    Issue 21: DOE seeks comment regarding its proposed definition and 
methodology for measuring and verifying fuel input rate for gas-fired 
and oil-fired CWH equipment.

L. Default Values for Certain Test Parameters for Commercial Water 
Heating Equipment

    DOE incorporates by reference Exhibits G.1 and G.2 of ANSI 
Z21.10.3-2011 (which correspond to Annexes E.1 and E.2 of ANSI 
Z21.10.3-2015) in its current test procedure for thermal efficiency and 
standby loss for CWH equipment. Some of the equipment settings for 
performing the test procedures as per Annex E.1 of ANSI Z21.10.3-2015 
(e.g., water supply pressure, venting requirements) are required to be 
specified by manufacturers. DOE proposes to include default values for 
these parameters in its test procedures, to be used if values are not 
specified in manufacturer literature shipped with the unit \21\ or 
supplemental test information. Specifically, if these values are not 
included in manufacturer literature shipped with the unit, then DOE 
will use the values included in the supplemental testing instructions 
if one is submitted with the certification report. If the values are 
neither included in manufacturer literature shipped with the unit or in 
the supplemental test instructions, then DOE will use the default 
values proposed in this NOPR. These test procedures and default values 
would apply to commercial water heating equipment other than 
residential-duty commercial water heaters.
---------------------------------------------------------------------------

    \21\ Manufacturer literature includes any information on 
settings, installation, and operation that is shipped with the 
equipment. This information can be in the form of installation and 
operation manuals, settings provided on a name plate, or product-
specific literature.
---------------------------------------------------------------------------

    For all commercial water heating equipment, DOE proposes a default 
value for maximum water supply pressure of 150 pounds per square inch 
(psi). For gas-fired commercial water heating equipment powered with 
natural gas, DOE proposes a default range of allowable gas supply 
pressure of 4.5 inches of water column (in. w.c.) to 10.5 in. w.c. For 
gas-fired commercial water heating equipment powered with propane, DOE 
proposes a default range of 11 in. w.c. to 13 in. w.c.
    DOE also includes several requirements specific to oil-fired 
equipment in its current test procedure for commercial water heating 
equipment as set forth in 10 CFR 431.106. These requirements include:
    (1) Venting Requirements--Connect a vertical length of flue pipe to 
the flue gas outlet of sufficient height so as to meet the minimum 
draft specified by the manufacturer; and (2) Oil Supply--Adjust the 
burner rate so that: (a) The hourly Btu input rate lies within 2 percent of the manufacturer's specified input rate, (b) the 
CO2 reading shows the value specified by the manufacturer, 
(c) smoke in the flue does not exceed No. 1 smoke as measured by the 
procedure in ASTM-D-2156-80, and (d) fuel pump pressure lies within 
10 percent of manufacturer's specifications.
    These requirements depend on manufacturer specifications, including 
the minimum draft, input rate, CO2 reading, and fuel pump 
pressure. Manufacturers are already required to certify the input rate 
of all covered oil-fired equipment in certification reports submitted 
to DOE for each basic model. However, not all manufacturers describe 
venting guidelines for their units using the same format and 
parameters, and DOE does not wish to establish default values that 
contradict manufacturer specifications. Therefore, DOE proposes to 
include a default value for fuel pump pressure and a default range for 
CO2 reading in its test procedures, which would only be used 
if the parameters are not specified in the manufacturer's literature 
shipped with the unit or in the supplemental test instructions. DOE 
proposes default values of an allowable range of 9-12 percent for 
CO2 reading, and 100 psig fuel pump pressure. DOE determined 
these values from examination of values for units currently on the 
market.
    Issue 22: DOE requests comment on its proposed default values for 
maximum water supply pressure for all equipment, allowable gas supply 
pressure range for equipment powered with natural gas and propane, and 
the CO2 reading and fuel pump pressure for oil-fired 
equipment.

M. Certification Requirements

    DOE proposes several changes to its certification requirements for 
commercial water heating equipment \22\ at 10 CFR part 429. DOE 
proposes to add two requirements to 10 CFR 429.44 for certification of 
instantaneous water heaters and hot water supply boilers. First, DOE 
proposes to add that manufacturers must certify whether instantaneous 
water heaters or hot water supply boilers contain submerged heat 
exchangers or heating elements, in order to allow for proper 
classification of units under DOE's proposed definition for ``storage-
type instantaneous water heater.'' DOE's classification for storage-
type instantaneous water heaters is discussed in more detail in section 
III.F. Second, DOE proposes to add that manufacturers must certify 
whether instantaneous water heaters or hot water supply boilers require 
flow of water through the water heater to initiate burner ignition.
---------------------------------------------------------------------------

    \22\ DOE is also making an editorial change to the certification 
report provisions in 10 CFR 429.44(c) for commercial water heating 
equipment by replacing of the term ``water heater'' and 
abbreviations of water heater (i.e., WH) with the term ``water 
heating.''
---------------------------------------------------------------------------

    Issue 23: DOE requests comment on its proposed additional 
certification requirements for instantaneous water heaters and hot 
water supply boilers, and seeks feedback on any other information that 
should be included for any classes of CWH equipment.

[[Page 28624]]

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Orders 12866

    The Office of Management and Budget (OMB) has determined that test 
procedure rulemakings do not constitute ``significant regulatory 
actions'' under section 3(f) of Executive Order 12866, ``Regulatory 
Planning and Review,'' 58 FR 51735 (Oct. 4, 1993). Accordingly, this 
regulatory action was not subject to review under the Executive Order 
by the Office of Information and Regulatory Affairs (OIRA) in the 
Office of Management and Budget (OMB).

B. Review Under the Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq., as amended by 
the Small Business Regulatory Enforcement Fairness Act of 1996) 
requires preparation of an initial regulatory flexibility analysis 
(IRFA) for any rule that by law must be proposed for public comment and 
a final regulatory flexibility analysis (FRFA) for any such rule that 
an agency adopts as a final rule, unless the agency certifies that the 
rule, if promulgated, will not have a significant economic impact on a 
substantial number of small entities. A regulatory flexibility analysis 
examines the impact of the rule on small entities and considers 
alternative ways of reducing negative effects. Also, 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 Web site at: http://energy.gov/gc/office-general-counsel.
    This proposed rule would prescribe test procedure amendments that 
would be used to determine compliance with energy conservation 
standards for CWH equipment (except for CHPWHs). The proposed 
amendments would: (1) Update the referenced industry test standards by 
incorporating by reference ASTM D2156-09, ASTM C177-13, ASTM C518-10, 
and Annex E.1 of ANSI Z21.10.3-2015; (2) modify the thermal efficiency 
and standby loss tests for CWH equipment to improve repeatability; (3) 
include an updated test method for determining the efficiency of 
unfired hot water storage tanks; (4) change the method for setting the 
thermostat in the thermal efficiency test for gas-fired and oil-fired 
storage water heaters and storage-type instantaneous water heaters from 
measurement of mean tank temperature to measurement of outlet water 
temperature; (5) clarify test conditions required in the thermal 
efficiency test method with regard to stored energy loss and steady-
state operation; (6) define ``storage-type instantaneous water heater'' 
and modify several definitions for consumer water heaters and 
commercial water heating equipment included at 10 CFR 430.2 and 10 CFR 
431.102, respectively; (7) include a new test method for measurement of 
standby loss for flow-activated instantaneous water heaters; (8) 
specify temperature-sensing locations, water valve locations and 
clarifications for using a recirculating loop for thermal efficiency 
and standby loss testing of instantaneous water heaters and hot water 
supply boilers; (9) replace the measurement of mean tank temperature 
with outlet water temperature for thermostatically-activated 
instantaneous water heaters (other than storage-type instantaneous 
water heaters); (10) include a new test method for rating commercial 
heat pump water heaters; (11) establish a procedure for determining the 
fuel input rate of gas-fired and oil-fired CWH equipment and specify 
DOE's measures to verify fuel input rate; (12) add default values for 
certain testing parameters for commercial water heating equipment; and 
(13) modify DOE's certification requirements for commercial water 
heating equipment. DOE reviewed all of these proposed amendments to the 
existing test procedure under the provisions of the Regulatory 
Flexibility Act and the policies and procedures published on February 
19, 2003. 68 FR 7990. Accordingly, DOE has prepared the following IRFA 
for the equipment that is the subject of this rulemaking.
1. Description and Estimated Number of Small Entities to Which the 
Proposed Rule Would Apply
    For manufacturers of covered CWH equipment, 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. 65 FR 30836, 30848 (May 15, 2000), as amended at 77 FR 49991, 
50000, 50011 (August 20, 2012) and codified at 13 CFR part 121. The 
size standards are listed by North American Industry Classification 
System (NAICS) code and industry description and are available at: 
http://www.sba.gov/sites/default/files/Size_Standards_Table.pdf. 
Manufacturing of CWH equipment is classified under NAICS 333318, 
``Other Commercial and Service Industry Machinery Manufacturing.'' \23\ 
The SBA sets a size threshold of 1,000 employees or fewer for a 
manufacturer that falls under this category to qualify as a small 
business.
---------------------------------------------------------------------------

    \23\ On October 1, 2012, the NAICS code for ``Other Commercial 
and Service Industry Machinery Manufacturing,'' which includes 
manufacturing of commercial water heating equipment, changed from 
333319 to 333318.
---------------------------------------------------------------------------

    To estimate the number of companies that could be small business 
manufacturers of equipment covered by this rulemaking, DOE conducted 
market research and created a database of CWH equipment manufacturers 
that identified the manufacturers which qualify as small businesses 
among that list. DOE's research involved industry trade association 
membership directories (including AHRI \24\), public databases (e.g., 
the California Energy Commission Appliance Efficiency Database \25\), 
individual company Web sites, and market research tools (e.g., Hoovers 
reports \26\) to create a list of companies that manufacture or sell 
equipment covered by this rulemaking. DOE's research resulted in a list 
of all domestic small business manufacturers of CWH equipment covered 
by this rulemaking. DOE also contacted companies, as necessary, to 
determine if they both meet the SBA's definition of a ``small 
business'' manufacturer and have their manufacturing facilities located 
within the United States. DOE screened out companies that did not offer 
products covered by this rulemaking, did not meet the definition of a 
``small business,'' or a foreign-owned and operated. Based upon this 
analysis and comprehensive search, DOE identified 28 manufacturers of 
CWH equipment affected by changes proposed in this NOPR. Of these 28, 
DOE identified 16 as domestic small businesses. Fifteen of the 16 
domestic small businesses are original equipment manufacturers (OEMs) 
of CWH equipment covered by this rulemaking, while one rebrands 
equipment manufactured by other OEMs. These fifteen small businesses 
represent approximately 54 percent of domestic companies that 
manufacture CWH equipment affected by changes proposed in this NOPR.
---------------------------------------------------------------------------

    \24\ The AHRI Directory is available at: www.ahridirectory.org/ahriDirectory/pages/home.aspx.
    \25\ The CEC database is available at: http://www.energy.ca.gov/appliances/.
    \26\ Hoovers Inc., Company Profiles, Various Companies 
(Available at: www.hoovers.com/).

---------------------------------------------------------------------------

[[Page 28625]]

2. Description and Estimate of Compliance Requirements
    In the following sections, DOE discusses the potential burdens that 
could be faced by manufacturers of CWH equipment, particularly small 
businesses, as a result of each of the test procedure amendments 
proposed in this NOPR.
Updated Industry Test Methods
    The proposal to update the currently-referenced industry test 
method edition from ANSI Z21.10.3-2011 (Exhibits G.1 and G.2) to ANSI 
Z21.10.3-2015 (Annex E.1) would not impact the requirements, 
conditions, or duration of DOE's test procedures. DOE only identified 
one substantive difference between the efficiency test methods in each 
version--the standby loss equation. Because DOE tentatively concluded 
that the equation in the currently referenced ANSI Z21.10.3-2011 is 
correct and proposes to retain that equation in its test procedures, 
this updated reference to the industry test method should not affect 
conduct of or ratings from DOE's test procedure.
    DOE's current test procedure, specified at 10 CFR 431.106, also 
requires that flue gases from oil-fired CWH equipment not contain smoke 
that exceeds No. 1 smoke, as determined by ASTM Standard D2156-80. In 
this NOPR, DOE proposed to update this reference and incorporate by 
reference the most recent version of this test method, ASTM D2156-09. 
DOE did not identify any significant differences between the two 
versions of this test method; therefore, DOE has tentatively concluded 
that this updated reference should not affect results from its test 
procedure. Additionally, DOE proposes several clarifications to the 
procedure for determining smoke spot number. First, DOE proposes to 
clarify that the smoke spot number is to be determined once steady-
state operation is achieved but before beginning measurements for the 
thermal efficiency test. Second, DOE proposes to require that the smoke 
measuring device be connected to an open-ended tube that projects into 
the flue \1/4\ to \1/2\ of the pipe diameter. This requirement for the 
smoke measuring device is adopted from those specified for commercial 
space heating boilers in AHRI 1500-2015. DOE also proposes to clarify 
that the smoke spot test is required before conduct of the thermal 
efficiency test or standby loss test (as applicable) of oil-fired CWH 
equipment. However, DOE proposes not to require the smoke spot test be 
conducted prior to beginning an efficiency test (i.e., thermal 
efficiency or standby loss) if no settings on the water heater have 
been changed and the water heater has not been turned off since the end 
of a previously run efficiency test. DOE also proposes that the 
CO2 reading be measured at the same times that are required 
for determining the smoke spot number.
    DOE proposes clarification of the test procedure for determining 
smoke spot number because the current procedure as specified in 10 CFR 
431.106 does not specify the timing or location of measuring the smoke 
spot number. DOE considers conduct of the smoke spot test and 
measurement of CO2 reading before the thermal efficiency 
test begins to be a less burdensome method than measuring during the 
test, and, therefore, does not consider this clarification likely to 
increase testing burden to manufacturers. Additionally, DOE considers 
its clarification regarding when the smoke spot test and measurement of 
CO2 reading are not needed (i.e., when the standby loss test 
is conducted after the thermal efficiency test) to reduce burden 
compared to a requirement to measure before the standby loss test or 
compared to the current test procedure, which simply states that the 
flue cannot exceed No. 1 smoke. Finally, DOE considers its proposed 
specification of the location within the flue for determination of 
smoke spot number unlikely to increase burden to manufacturers, given 
that this requirement was adopted from an industry-accepted test method 
for similar commercial HVAC equipment.
    DOE's current definition for ``R-value'' at 10 CFR 431.102 
references two industry test methods, ASTM C177-97 and ASTM C518-91. In 
this NOPR, DOE proposes to incorporate by reference the most recent 
versions of these test methods: ASTM C177-13 and ASTM C518-10. DOE did 
not identify any significant differences in the procedures for 
measuring R-value between the two versions of ASTM C177 or between the 
two versions of ASTM C518. Therefore, this updated reference should not 
affect results for calculation of R-value per DOE's definition at 10 
CFR 431.102.
Test Procedure Repeatability and Ambient Conditions
    The proposed modifications to the thermal efficiency and standby 
loss test methods include: (1) Stipulating a maximum air draft 
requirement of 50 ft/min as measured prior to beginning the thermal 
efficiency or standby loss tests; (2) tightening the ambient room 
temperature tolerance from 10.0[emsp14][deg]F to 5.0[emsp14][deg]F and the allowed variance from mean ambient 
temperature from 7.0[emsp14][deg]F to 2.0[emsp14][deg]F; (3) requiring measurement of test air 
temperature--the temperature of entering combustion air--and requiring 
the test air temperature not vary by more than 5[emsp14][deg]F from the ambient room temperature at any 
measurement interval during the thermal efficiency and standby loss 
tests for gas-fired and oil-fired CWH equipment; (4) establishing a 
requirement for ambient relative humidity of 60 percent 5 
percent during the thermal efficiency and standby loss tests for gas-
fired and oil-fired CWH equipment; (5) requiring a soak-in period prior 
to testing in which the water heater must sit without any draws taking 
place for at least 12 hours from the end of a recovery from a cold 
start; (6) specifying the locations of inlet and outlet temperature 
measurements for storage water heaters, storage-type instantaneous 
water heaters, and UFHWSTs; and (7) decreasing the time interval for 
data collection from fifteen minutes to 30 seconds in the thermal 
efficiency and standby loss tests.
    For the first modification, depending on the conditions in the 
manufacturer's testing area, the manufacturer may need to protect the 
testing area from drafts greater than 50 ft/min. This draft protection 
could be accomplished by using wind barriers such as moveable walls, 
minimizing the opening and closing of doors near the test stand, or 
sealing windows. To measure draft velocity, manufacturers may have to 
purchase instrumentation that DOE estimates could cost up to $250. 
However, any manufacturer of residential water heaters should already 
have this instrumentation and be able to comply with this stipulation, 
because it is similar to the requirement established for testing 
residential water heaters in the July 2014 final rule. 79 FR 40542, 
40569 (July 11, 2014).
    For the second, third, and fourth modifications that propose 
changes to specified ambient conditions, manufacturers may not need to 
make any changes if the ambient temperature and relative humidity in 
their testing area already meet the proposed tolerances. DOE is aware 
that the proposed constraints may in some cases require laboratories to 
move testing from an uncontrolled environment (i.e., outdoors or 
facilities open to the outdoors) to a controlled environment. However, 
DOE understands this to be a small number of cases, and that testing is 
routinely performed in a laboratory setting with typical heating, 
ventilating, and air-conditioning systems and controls. DOE notes that 
the limits are intended to prevent the test from being conducted in 
extreme ambient conditions, and that the ambient

[[Page 28626]]

temperature requirements are typical for building heating, ventilating, 
and air-conditioning systems in normal operating condition. However, if 
the ambient temperature or relative humidity in the testing area do not 
already meet these tolerances, the manufacturer may need to improve 
climate regulation of the test environment, possibly by improving the 
controls of their thermostats, or preventing hot or cold drafts from 
entering the testing environment. DOE estimates that improving the 
controls of the thermostat and preventing hot or cold drafts from 
entering the testing environment could involve four to eight hours of 
labor by a general technician. At a rate of $40 per hour for a 
laboratory technician, DOE estimates the cost for this amount of labor 
to be between $160 and $320, which DOE believes is modest in comparison 
to the overall cost of product development and certification.\27\
---------------------------------------------------------------------------

    \27\ Based on mean hourly wage from Bureau of Labor Statistics 
for Mechanical Engineering Technician, occupational code 17-3027: 
http://www.bls.gov/oes/current/oes173027.htm. Mean hourly wage is 
multiplied by 1.5 to estimate associated benefits and overhead.
---------------------------------------------------------------------------

    For the third modification, manufacturers need to measure the test 
air temperature, which is measured within two feet of the combustion 
air inlet. While this requirement was adopted from an industry test 
method for commercial packaged boilers, AHRI 1500-2015, it is not 
currently required for testing of CWH equipment. Therefore, 
manufacturers would need to install temperature measuring devices in 
close proximity to the air intake. However, DOE believes that a 
requirement for this temperature measurement would not present any 
significant testing burden to manufacturers, because it would simply 
involve one more temperature measurement than is already being 
conducted, and the temperature readings could be recorded using the 
same data acquisition software that is used for measuring the ambient 
room temperature.
    The fifth modification specifies a 12-hour pre-conditioning period 
prior to conducting the standby loss test for storage water heaters and 
storage-type instantaneous water heaters. While this would add to the 
time required to conduct the test, it would not require extra personnel 
and would not necessitate the development of additional test platforms. 
DOE understands that a preconditioning period is already implemented by 
manufacturers as a best practice to allow the water heater to achieve 
operational temperature, so the added burden from the 12-hour soak-in 
would be minimal. In addition, these tests can be conducted in the same 
facilities used for the current energy testing of these products, so 
there would be no additional facility costs required by this proposal.
    The sixth modification specifies the location for measurement of 
inlet and outlet temperature for storage water heaters, storage-type 
instantaneous water heaters, and UFHWSTs. DOE expects these lengths to 
align with the piping set-ups currently used in most testing of CWH 
equipment. If slight modifications would be needed to the set-ups 
currently used, DOE believes that these modifications would be simple 
and merely involve adding or removing several inches of piping. 
Additionally, DOE proposes set-ups for tanks water heaters and storage 
tanks with connections on the top, side, or bottom--thereby minimizing 
the likelihood that a significant change to the set-up currently used 
by manufacturers would be needed. Therefore, DOE has tentatively 
concluded that this aspect of its proposal would not present a 
significant burden to manufacturers, including small businesses.
    Finally, DOE proposes reducing the time interval for data 
collection during the thermal efficiency test from 1 minute to 30 
seconds and during the standby loss test from 15 minutes to 30 seconds. 
Because manufacturers are already required to measure at one-minute 
intervals for the current thermal efficiency test, DOE reasons that 
manufacturers already use a computer-connected data acquisition system. 
Changing the time intervals for recording measurements on a data 
acquisition system is a quick process that requires the operator to 
simply change the parameters on the computer using the data acquisition 
system software. Therefore, the manufacturers would not incur any 
additional testing costs due to the proposed changes in the data 
recording time intervals.
Unfired Hot Water Storage Tanks
    DOE also proposes to adopt a new metric and test procedure for 
testing the efficiency of unfired hot water storage tanks. In order to 
comply with Federal regulations, unfired hot water storage tanks are 
currently required to meet a minimum thermal insulation R-value of 12.5 
[middot][deg]F[middot]ft\2\[middot]h/Btu. In this NOPR, DOE proposes to 
adopt a new standby loss metric determined by a new standby loss test 
method for this class. If this test procedure is adopted, certification 
of standby loss for covered unfired hot water storage tanks would not 
be required unless and until DOE establishes energy conservation 
standards in terms of standby loss for this class. However, DOE 
acknowledges that absent a standby loss standard, some manufacturers 
may choose to rate the efficiency of their unfired hot water storage 
tank models to help distinguish their products from competitor 
offerings.
    Manufacturers likely already have all necessary equipment and 
instrumentation for the proposed test method for unfired hot water 
storage tanks, because such equipment and instrumentation are already 
needed for testing of other CWH equipment classes. Through its review 
of the market, DOE found that all unfired hot water storage tank 
manufacturers also produce other covered CWH equipment, such as storage 
water heaters, instantaneous water heaters, or hot water supply 
boilers. Therefore, DOE has tentatively concluded that manufacturers 
would not incur any additional test facility costs. Small manufacturers 
with a small number of UFHWST offerings could choose to conduct testing 
with a third-party lab, which DOE estimates would cost no more than 
$3,000 per tested UFHWST.
    DOE estimates that testing of each unfired hot water storage tank 
would take less than 2 days, including set-up and testing of storage 
volume and standby loss. However, the majority of this time would not 
require attendance by any employees. DOE estimates that setting up and 
removing the unfired hot water storage tanks from the test stand might 
require 2-3 hours of time from a laboratory technician. At a rate of 
$40 per hour for a laboratory technician, DOE estimates the cost for 
this amount of labor to be no more than $80-$120. Additionally, DOE 
estimates it would take approximately 1 hour of a lab technician's time 
to complete the test procedure per model tested, which would result in 
a cost of $40. Therefore, the total labor cost of testing an unfired 
hot water storage tank would be $120-$160 per model.
    Issue 24: DOE requests comment on its cost estimates for 
manufacturers to test their unfired hot water storage tanks according 
to DOE's proposed test method.
Thermostat Settings
    DOE proposes to change the measurement of temperature in the 
thermal efficiency test by measuring the outlet water temperature 
rather than the mean tank temperature for gas-fired and oil-fired 
storage water heaters and storage-type instantaneous water

[[Page 28627]]

heaters. This proposal was suggested by manufacturers so that their 
models can more easily meet the specified conditions in the test 
procedure without having to sacrifice thermal efficiency gains when 
designing equipment. Because the outlet water temperature is already 
measured in the current test method, this proposal would simplify DOE's 
test procedure, and would not create any additional test burden for 
manufacturers, including small businesses.
Clarifications to the Thermal Efficiency and Standby Loss Test 
Procedures
    DOE proposes to add clarifying statements to its thermal efficiency 
and standby loss test procedures. Specifically, DOE proposes to clarify 
that that during the thermal efficiency test, the burner must 
continuously fire at the full firing rate for the entire duration of 
the test and that the outlet water temperature must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature. DOE also proposes to clarify that during the thermal 
efficiency and standby loss tests, no settings on the water heating 
equipment can be changed until measurements for the test have finished. 
As discussed in section III.E, several manufacturers indicated that 
there was not a problem with the current test procedure, as there is a 
general understanding that the burner must fire at its full input rate 
throughout the course of the test. Additionally, DOE expects that the 
majority of manufacturers already perform the thermal efficiency and 
standby loss tests in a manner as clarified in DOE's proposal. 
Therefore, DOE has tentatively concluded that its proposed clarifying 
statements would only serve to remove any potential confusion regarding 
its test procedures, and would not add any burden to manufacturers, 
including small businesses.
Storage-Type Instantaneous Water Heaters
    DOE proposes a new definition for ``storage-type instantaneous 
water heater,'' which are instantaneous water heaters with integral 
storage tanks and a submerged heat exchanger(s) or heating element(s). 
DOE believes this kind of water heater should be tested similar to 
storage water heaters. However, DOE does not currently prescribe 
separate test procedures for storage water heaters and instantaneous 
water heaters. Only in the test procedures proposed in this NOPR does 
DOE prescribe separate standby loss test methods for storage water 
heaters and instantaneous water heaters. Additionally, DOE's research 
suggests that manufacturers already categorize units falling under 
DOE's proposed definition for ``storage-type instantaneous water 
heater'' with storage water heaters. Therefore, DOE has tentatively 
concluded that applying the test procedure prescribed for storage water 
heaters to storage-type instantaneous water heaters would not present a 
burden for manufacturers, including small businesses.
Flow-Activated Instantaneous Water Heaters
    Currently, all instantaneous water heaters and hot water supply 
boilers having a capacity of 10 gallons or more are required to undergo 
the same standby loss test that is prescribed in Exhibit G.2 of ANSI 
Z21.10.3-2011. However, in this NOPR, DOE is proposing a new and 
separate standby loss test procedure for flow-activated instantaneous 
water heaters.
    In the proposed standby loss test procedure, the flow-activated 
instantaneous water heater being tested would not cycle on at any point 
in the course of the test. Therefore, the amount of fuel consumption is 
not needed for standby loss calculations. This modification will 
simplify the test and reduce the amount of data processing required for 
calculating standby loss metric. As a result, this modification would 
be beneficial to all manufacturers, including small businesses.
    The second difference pertains to the duration of the test. In the 
current test procedure, the equipment is tested until the first cut-out 
that occurs after 24 hours or 48 hours, whichever comes first. In the 
proposed standby loss test procedure for flow-activated instantaneous 
water heaters, the test ends when the outlet water temperature drops by 
35[emsp14][deg]F or after 24 hours, whichever comes first. DOE has 
tentatively concluded that it is very likely that a 35[emsp14][deg]F 
drop in outlet water temperature will occur before 24 hours. Therefore, 
this proposed modification would likely be beneficial to all 
manufacturers, including small businesses, as it would reduce the time 
required to conduct the standby loss test. In addition, DOE notes that 
the maximum test length of 24 hours in the proposed test method is the 
same as the current minimum test length in the existing test procedure, 
so the proposed test would always result in a test length either 
shorter or equal to that of the current test.
    The third difference is with regards to the measurement recording 
intervals. In the current test procedure, the time interval between two 
successive readings is 1 minute for the thermal efficiency test and 15 
minutes for a standby loss test. In the proposed standby loss test 
method for flow-activated instantaneous water heaters, DOE has proposed 
to shorten the time interval to 30 seconds. As with other types of CWH 
equipment, because manufacturers are already required to measure at 
one-minute intervals for the thermal efficiency test, DOE believes that 
manufacturers already use a computer-connected data acquisition system. 
Changing the time intervals for recording measurements on a data 
acquisition system is a quick process that requires the operator to 
simply change the parameters on the computer using the data acquisition 
system software. Therefore, DOE believes that manufacturers would not 
incur any additional testing costs due to the proposed changes in the 
data recording time intervals.
    In summary, DOE has tentatively concluded that the proposed standby 
loss test procedure for flow-activated water heaters would not impose 
any significant additional burden on manufacturers, including small 
businesses.
Changes to the Test Set-Up for Instantaneous Water Heaters and Hot 
Water Supply Boilers
    For the thermal efficiency and standby loss tests of instantaneous 
water heaters and hot water supply boilers, DOE proposes to move the 
outlet water temperature-sensing location closer to the CWH equipment 
being tested, with several requirements for the placement of the 
temperature-sensing probe in the outlet water line. DOE also proposes 
to require the supply water valve be within a distance of 5 inches and 
an outlet water valve be within a distance of 10 inches from the water 
heater jacket. These modifications in the test set-up would require: 
(1) Moving the tee pipe fitting that is used to hold the outlet water 
temperature sensing instrument to a location immediately outside the 
CWH equipment; and (2) moving the supply water valve and outlet water 
valve that are already installed further away from the water heater to 
the a location closer to the CWH equipment. In case a new tee is 
required, DOE estimates that such a fitting would cost approximately 
$50. DOE reasons that the benefits of better representation of the 
outlet water temperature and close proximity of the water valves that 
need to be shut off to retain the hot water in the water heater during 
the standby loss test outweighs the small potential cost of an 
additional pipe fitting. In addition to these changes, DOE also 
proposes to clarify

[[Page 28628]]

the conditions for using a recirculating loop. The use of a 
recirculating loop is allowed in the current test procedure, and, thus, 
this modification would not cause an increase in testing cost. 
Therefore, DOE has tentatively concluded that the adjustments described 
in this paragraph would not impose a significant burden on 
manufacturers, including small businesses.
Modified Standby Loss Test Procedure for Instantaneous Water Heaters 
and Hot Water Supply Boilers
    DOE's current standby loss test procedure for CWH equipment at 10 
CFR 431.106, which incorporates by reference Exhibit G.2 of ANSI 
Z21.10.3-2011, requires the measurement of the mean tank temperature to 
calculate standby loss. In this NOPR, DOE proposes to replace the 
measurement of mean tank temperature with the outlet water temperature 
for conducting the standby loss test for instantaneous water heaters 
and hot water supply boilers that do not meet DOE's proposed definition 
of ``storage-type instantaneous water heater.'' This proposed 
modification to the current test procedure would only change the terms 
that are used in calculating standby loss. The recording of the outlet 
water temperature is already required in the thermal efficiency test 
procedure for all CWH equipment. Therefore, the only change that the 
manufacturers would be required to make would be to record the outlet 
water temperature during the standby loss test. Accordingly, DOE has 
tentatively concluded that these proposed changes would not be unduly 
burdensome to manufacturers, including small businesses.
Commercial Heat Pump Water Heaters
    DOE currently does not prescribe a test procedure for commercial 
heat pump water heaters. In this NOPR, DOE proposes to adopt a new test 
procedure for measurement of the COPh of CHPWHs. If this 
test procedure is adopted, certification of COPh for CHPWHs 
would not be required unless and until DOE establishes energy 
conservation standards for this class in terms of COPh. 
However, DOE acknowledges that in the absence of a Federal 
COPh standard, some manufacturers may choose to rate the 
efficiency of their commercial heat pump water heaters to help 
distinguish their equipment from competitor offerings.
    DOE believes that manufacturers of CHPWHs already have the 
equipment, instrumentation, and facilities (including psychrometric 
chambers) for testing their units according to the proposed test 
method, because these would be needed for product development and 
measurement of COPh values absent a DOE test method. 
However, DOE acknowledges that some manufacturers may need to purchase 
equipment, instrumentation, or test stands for measurement of 
COPh according to the proposed test method. For testing air-
source CHPWH units, DOE estimates that the cost to build a test stand 
and a surrounding psychrometric chamber for the testing of CHPWHs would 
cost no more than $300,000. While the duration of the proposed test for 
air-source CHWPHs is 30 minutes, DOE estimates the total time, 
including the time needed for set-up and stabilizing the outlet water 
temperatures prior to the test, may reach five hours. At a rate of $40 
per hour for a laboratory technician, DOE estimates the cost for this 
labor would be $200 per model tested.
    Given the small market size of air-source CHPWHs, DOE believes that 
most manufacturers without test facilities capable of testing air-
source CHPWHs according to DOE's proposed test procedure would choose 
to conduct testing at a third-party lab. DOE estimates that the average 
air-source CHPWH manufacturer sells six models, and that the cost of 
testing an air-source CHPWH would not exceed $10,000. Therefore, the 
average testing burden for manufacturers of air-source CHPWHs without 
testing facilities should not exceed $60,000.
    For indoor water-source and ground water-source CHPWHs, water 
solution conditioning and recirculation equipment similar to a chiller 
would be required for testing, in addition to equipment needed for 
testing air-source CHPWHs (e.g., standard piping, instrumentation, a 
data acquisition system, and test stand). DOE expects most 
manufacturers already have such equipment in order to test and provide 
ratings for their current product offerings. However, DOE acknowledges 
that there may be some manufacturers that do not currently have 
equipment sufficient for conducting DOE's proposed test procedure. DOE 
estimates the total cost of a chiller to be about $20,000. The cost of 
instrumentation, piping, and a data acquisition unit could add up to an 
additional $5,000. Therefore, DOE does not expect capital investments 
would exceed $25,000 per manufacturer. DOE estimates that following the 
test procedure, it would take approximately 5-6 hours to set up the 
unit and to conduct the test. At a lab technician labor cost of $40 per 
hour, DOE estimates the total labor cost incurred to test each unit 
would be between $200 and $240. Alternatively, some manufacturers, 
including small businesses, may choose to test their units at third-
party laboratories instead of investing in in-house testing facilities. 
DOE estimates that the cost of such testing would not exceed $3,000 per 
unit. DOE estimates that manufacturers may test about 6 models annually 
at third-party laboratories. Therefore, the total estimated cost burden 
for any such manufacturers would not be more than $18,000.
    Based on the proposed test procedure, the test set-up for ground or 
indoor water-source CHPWHs would be similar to that for direct geo-
exchange CHPWHs, with the only difference being that the test set-up 
for direct geo-exchange CHPWHs includes an additional solution heat 
exchanger. Similar to water-source CHPWHs, DOE expects that most 
manufacturers of direct geo-exchange CHPWHs already have such equipment 
in order to test and provide ratings for their current product 
offerings. DOE understands that the cost of this solution heat 
exchanger would be the only cost to be added to the total estimated 
cost for testing ground and indoor water-source CHPWHs in order to 
arrive at the estimated cost of testing a direct geo-exchange CHPWH. 
DOE estimates the cost of a liquid-to-liquid heat exchanger to be not 
more than $30,000. Therefore, the total estimated capital investment 
cost for testing a direct geo-exchange CHPWH would not exceed $55,000. 
Similar to water-source CHPWH manufacturers, DOE understands that many 
manufacturers of direct geo-exchange CHPWHs, including small 
businesses, may choose to test their units at third-party laboratories 
instead of investing in in-house testing facilities. DOE estimates the 
cost of such testing would not exceed $5,000 per unit.
Default Values for Certain Test Parameters
    In this NOPR, DOE proposes to add to its test procedure at 10 CFR 
431.106 default values for certain test parameters for CWH equipment, 
to be used if manufacturers do not report these in either the product 
literature that is shipped with the unit (e.g., installation and 
operations manual), or their supplemental instructions. DOE proposes 
the following default values: (1) A maximum allowable water pressure 
for all CWH equipment; (2) an allowable gas pressure range for gas-
fired CWH equipment; and (3) fuel pump pressure and a range for 
CO2 reading for oil-fired CWH equipment.

[[Page 28629]]

DOE does not expect the proposed default values to present a 
significant burden to manufacturers because these are basic parameters 
needed for proper use of CWH equipment and are, therefore, typically 
specified in manufacturer literature shipped with the unit.
3. Duplication, Overlap, and Conflict With Other Rules and Regulations
    DOE is not aware of any rules or regulations that duplicate, 
overlap, or conflict with the rule being proposed in this document.
4. Significant Alternatives to the Proposed Rule
    DOE considered alternative test methods and modifications to the 
test procedures for CWH equipment, and tentatively determined that 
there are no better alternatives than the modifications and procedures 
proposed in this NOPR. DOE examined relevant industry test standards, 
and incorporated these standards in the proposed test procedures 
whenever appropriate to reduce test burden to manufacturers. 
Specifically, this NOPR updates its test procedures for CWH equipment 
to incorporate by reference the following updated standards: ASTM 
D2156-09, ASTM C177-13, ASTM C518-10, and Annex E.1 of ANSI Z21.10.3-
2015. Additionally, DOE proposes three new test procedures in this 
NOPR: A standby loss test procedure for UFHWSTs, a standby loss test 
procedure for flow-activated instantaneous water heaters, and a test 
procedure for measurement of COPh of CHPWHs. For the 
COPh test for CHPWHs and the standby loss test for UFHWSTs, 
DOE proposes to incorporate by reference industry-accepted test methods 
(ASHRAE 118.1-2012 and sections 4, 5, 6.0, and 6.1 of GAMA Testing 
Standard IWH-TS-1, respectively). For the standby loss test procedure 
for flow-activated instantaneous water heaters, DOE proposes a test 
procedure similar to that recommended by AHRI in supplemental public 
comments to the February 2014 RFI, with modifications.

C. Review Under the Paperwork Reduction Act of 1995

    Manufacturers of CWH equipment must certify to DOE that their 
products comply with any applicable energy conservation standards. In 
certifying compliance, manufacturers must test their products according 
to the DOE test procedures for CWH equipment, including any amendments 
adopted for those test procedures, on the date that compliance is 
required. DOE has established regulations for the certification and 
recordkeeping requirements for all covered consumer products and 
commercial equipment, including CWH equipment. 76 FR 12422 (March 7, 
2011); 80 FR 5099 (Jan. 30, 2015). The collection-of-information 
requirement for 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 30 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.
    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 proposed rule, DOE proposes test procedure amendments that 
it expects will be used to develop and implement future energy 
conservation standards for commercial water heating equipment. 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, this proposed rule would 
amend the existing test procedure without affecting the amount, 
quality, or distribution of energy usage, and, therefore, would not 
result in any environmental impacts. Thus, this rulemaking is covered 
by Categorical Exclusion (CX) A5 under 10 CFR part 1021, subpart D, 
which applies to any rulemaking that interprets or amends an existing 
rule without changing the environmental effect of that rule. 
Accordingly, DOE has made a CX determination for this rulemaking, and 
neither an environmental assessment nor an environmental impact 
statement is required. DOE's CX determination for this proposed rule is 
available at: http://energy.gov/nepa/categorical-exclusion-cx-determinations-cx/.

E. Review Under Executive Order 13132

    Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 10, 
1999), imposes certain requirements on Federal 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 has examined this 
proposed rule and has tentatively determined that it would 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 equipment that is the subject of this 
proposed 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)) Therefore, Executive Order 13132 requires no further 
action.

F. Review Under Executive Order 12988

    With respect to 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. Regarding the review required by section 3(a), 
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

[[Page 28630]]

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 
tentatively determined that, to the extent permitted by law, the 
proposed 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 proposed regulatory action likely to result 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 them. On March 18, 1997, DOE published 
a statement of policy on its process for intergovernmental consultation 
under UMRA. 62 FR 12820. (This policy is also available at 
www.energy.gov/gc/office-general-counsel under ``Guidance & Opinions'' 
(Rulemaking)) DOE examined the proposed rule according to UMRA and its 
statement of policy and has tentatively determined that the rule 
contains neither an intergovernmental mandate, nor a mandate that may 
result in the expenditure by State, local, and Tribal governments, in 
the aggregate, or by the private sector, of $100 million or more in any 
year. Accordingly, no further assessment or analysis is required under 
UMRA.

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 rule would 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

    Pursuant to Executive Order 12630, ``Governmental Actions and 
Interference with Constitutionally Protected Property Rights,'' 53 FR 
8859 (March 18, 1988), DOE has determined that this proposed rule would 
not result in any takings that might require compensation under the 
Fifth Amendment to the U.S. Constitution.

J. Review Under the 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 Federal agencies to review 
most disseminations of information to the public under information 
quality 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). DOE has reviewed this proposed rule under the OMB and 
DOE guidelines and has concluded that it is consistent with the 
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 OIRA 
at OMB, a Statement of Energy Effects for any proposed significant 
energy action. A ``significant energy action'' is defined as any action 
by an agency that promulgates 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 proposed significant energy action, 
the agency must give a detailed statement of any adverse effects on 
energy supply, distribution, or use should the proposal be implemented, 
and of reasonable alternatives to the action and their expected 
benefits on energy supply, distribution, and use.
    DOE has tentatively concluded that the regulatory action in this 
document, which proposes amendments to the test procedure for measuring 
the energy efficiency of commercial water heating equipment, is not a 
significant energy action because it 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. Accordingly, DOE has not prepared a 
Statement of Energy Effects for this proposed rule.

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 et seq.), DOE must comply with all laws 
applicable to the former Federal Energy Administration, including 
section 32 of the Federal Energy Administration Act of 1974 (Pub. L. 
93-275), as amended by the Federal Energy Administration Authorization 
Act of 1977 (Pub. L. 95-70). (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.
    This proposed rule incorporates testing methods contained in the 
following commercial standards: (1) GAMA IWH-TS-1, ``Method to 
Determine Performance of Indirect-Fired Water Heaters,'' March 2003 
edition, sections 4, 5, 6.0, and 6.1; (2) ANSI Z21.10.3-2015/CSA 4.3-
2015, ``Gas-fired Water Heaters, Volume III, Storage Water Heaters with 
Input Ratings Above 75,000 Btu Per Hour, Circulating and 
Instantaneous,'' annex E.1; (3) ANSI/ASHRAE Standard 118.1-2012, 
``Method of Testing for Rating Commercial Gas, Electric, and Oil 
Service Water-Heating Equipment''; (4) ASTM D2156-09, ``Standard Test 
Method for Smoke Density in Flue Gases from Burning Distillate Fuels''; 
(5) ASTM C177-13, ``Standard Test Method

[[Page 28631]]

for Steady-State Heat Flux Measurements and Thermal Transmission 
Properties by Means of the Guarded-Hot-Plate Apparatus''; and (6) ASTM 
C518-10, ``Standard Test Method for Steady-State Thermal Transmission 
Properties by Means of the Heat Flow Meter Apparatus.'' While the 
proposed test procedures are not exclusively based on these standards, 
DOE's test procedures would adopt several provisions from these 
standards without amendment. The Department has evaluated these 
standards and is unable to conclude whether they fully comply with the 
requirements of section 32(b) of the FEAA, (i.e., that they were 
developed in a manner that fully provides for public participation, 
comment, and review). DOE will consult with the Attorney General and 
the Chairman of the FTC concerning the impact of these test procedures 
on competition, prior to prescribing a final rule.

M. Description of Materials Incorporated by Reference

    In this NOPR, DOE proposes to incorporate by reference the 
following test standards:
    (1) GAMA IWH-TS-1, ``Method to Determine Performance of Indirect-
Fired Water Heaters,'' March 2003 edition, sections 4, 5, 6.0, and 6.1;
    (2) ANSI Z21.10.3-2015/CSA 4.3-2015, ``Gas-fired Water Heaters, 
Volume III, Storage Water Heaters with Input Ratings Above 75,000 Btu 
Per Hour, Circulating and Instantaneous,'' annex E.1;
    (3) ANSI/ASHRAE Standard 118.1-2012, ``Method of Testing for Rating 
Commercial Gas, Electric, and Oil Service Water-Heating Equipment'';
    (4) ASTM D2156-09, ``Standard Test Method for Smoke Density in Flue 
Gases from Burning Distillate Fuels'';
    (5) ASTM C177-13, ``Standard Test Method for Steady-State Heat Flux 
Measurements and Thermal Transmission Properties by Means of the 
Guarded-Hot-Plate Apparatus''; and
    (6) ASTM C518-10, ``Standard Test Method for Steady-State Thermal 
Transmission Properties by Means of the Heat Flow Meter Apparatus.''
    GAMA IWH-TS-1 (March 2003 edition) is an industry-accepted test 
procedure for measuring the performance of indirect water heaters. In 
this NOPR, DOE proposes to incorporate by reference sections of this 
test procedure that address test set-up, instrumentation, and test 
conditions. GAMA IWH-TS-1, March 2003 edition, is available on AHRI's 
\28\ Web site at http://www.ahrinet.org/App_Content/ahri/files/standards%20pdfs/Indirect-Fired%20Water%20Heater%20Testing%20Standard03.pdf.
---------------------------------------------------------------------------

    \28\ ARI and GAMA merged to become AHRI on January 1, 2008.
---------------------------------------------------------------------------

    ANSI Z21.10.3-2015/CSA 4.3-2015 is an industry-accepted test 
procedure for measuring the performance of commercial water heaters. In 
this NOPR, DOE proposes to incorporate by reference sections of this 
test procedure that address test set-up, instrumentation, test 
conditions, and test conduct. ANSI Z21.10.3-2015/CSA 4.3-2015 is 
available on ANSI's Web site at http://webstore.ansi.org/RecordDetail.aspx?sku=ANSI+Z21.10.3-2015%2fCSA4.3-2015.
    ANSI/ASHRAE Standard 118.1-2012 is an industry-accepted test 
procedure for measuring the performance of commercial water heaters. 
ANSI/ASHRAE 118.1-2012 is available on ANSI's Web site at http://webstore.ansi.org/RecordDetail.aspx?sku=ANSI%2FASHRAE+Standard+118.1-2012.
    ASTM D2156-09 is an industry-accepted test procedure for 
determining the smoke spot number of flue gases. ASTM D2156-09 is 
available on ASTM's Web site at http://www.astm.org/Standards/D2156.htm.
    ASTM C177-13 is an industry-accepted test procedure for determining 
the R-value of a sample using a guarded-hot-plate apparatus. ASTM C177-
13 is available on ASTM's Web site at http://www.astm.org/Standards/C177.htm.
    ASTM C518-10 is an industry-accepted test procedure for determining 
the R-value of a sample using a heat flow meter apparatus. ASTM C518-10 
is available on ASTM's Web site at http://www.astm.org/Standards/C518.htm.

V. Public Participation

A. Attendance at the Public Meeting

    The time, date, and location of the public meeting are listed in 
the DATES and ADDRESSES sections at the beginning of this document. If 
you plan to attend the public meeting, please notify Ms. Brenda Edwards 
at (202) 586-2945 or [email protected]. All participants will 
undergo security processing upon building entry, and foreign nationals 
visiting DOE Headquarters are subject to advance security screening 
procedures which require advance notice prior to attendance at the 
public meeting. If a foreign national wishes to participate in the 
public meeting, please inform DOE of this fact as soon as possible by 
contacting Ms. Regina Washington at (202) 586-1214 or by email: 
[email protected] so that the necessary procedures can be 
completed.
    DOE requires visitors to have laptops and other devices, such as 
tablets, checked upon entry into the building. Any person wishing to 
bring these devices into the Forrestal Building must undergo additional 
screening and will be required to obtain a property pass. Visitors 
should avoid bringing laptops, or allow an extra 45 minutes to check 
in. Please report to the visitors desk to have devices checked before 
proceeding through security.
    Due to the REAL ID Act implemented by the Department of Homeland 
Security (DHS), there have been recent changes regarding identification 
(ID) requirements for individuals wishing to enter Federal buildings 
from specific States and U.S. territories. As a result, driver's 
licenses from the following States or territory will not be accepted 
for building entry, and instead, one of the alternate forms of ID 
listed below will be required.
    DHS has determined that regular driver's licenses (and ID cards) 
from the following jurisdictions are not acceptable for entry into DOE 
facilities: Alaska, American Samoa, Arizona, Louisiana, Maine, 
Massachusetts, Minnesota, New York, Oklahoma, and Washington.
    Acceptable alternate forms of Photo-ID include: U.S. Passport or 
Passport Card; an Enhanced Driver's License or Enhanced ID-Card issued 
by the States of Minnesota, New York or Washington (Enhanced licenses 
issued by these States are clearly marked Enhanced or Enhanced Driver's 
License); a military ID or other Federal government-issued Photo-ID 
card.
    In addition, attendees may participate in the public meeting via 
webinar. Webinar registration information, participant instructions, 
and information about the capabilities available to webinar 
participants will be published on DOE's Web site at: https://www1.eere.energy.gov/buildings/appliance_standards/standards.aspx?productid=36. Participants are responsible for ensuring 
their systems are compatible with the webinar software.
    The purpose of the meeting is to receive oral and written comments, 
data, and other information that would provide understanding about 
potential issues associated with this rulemaking. DOE must receive 
requests to speak at the meeting before 12:00 a.m. EST, June 3, 2016. 
DOE must receive a signed original and an electronic copy of any 
statement to be given at the public

[[Page 28632]]

meeting before 12:00 a.m. EST, June 3, 2016.

B. Procedure for Submitting Requests To Speak and Prepared General 
Statements for Distribution

    Any person who has an interest in the topics addressed in this 
document, or who is representative of a group or class of persons that 
has an interest in these issues, may request an opportunity to make an 
oral presentation at the public meeting. Such persons may hand-deliver 
requests to speak to the address shown in the ADDRESSES section at the 
beginning of this document between 9:00 a.m. and 4:00 p.m., Monday 
through Friday, except Federal holidays. Requests may also be sent by 
mail or email to Ms. Brenda Edwards, U.S. Department of Energy, 
Building Technologies Office, Mailstop EE-5B, 1000 Independence Avenue 
SW., Washington, DC 20585-0121, or [email protected]. Persons 
who wish to speak should include with their request a computer diskette 
or CD-ROM in WordPerfect, Microsoft Word, PDF, or text (ASCII) file 
format that briefly describes the nature of their interest in this 
rulemaking and the topics they wish to discuss. Such persons should 
also provide a daytime telephone number where they can be reached.
    DOE requests persons scheduled to make an oral presentation to 
submit an advance copy of their statements at least one week before the 
public meeting. At its discretion, DOE may permit persons who cannot 
supply an advance copy of their statement to participate, if those 
persons have made advance alternative arrangements with the Building 
Technologies Office. As necessary, requests to give an oral 
presentation should ask for such alternative arrangements.

C. Conduct of the Public Meeting

    DOE will designate a DOE official to preside at the public meeting 
and may also use a professional facilitator to aid discussion. The 
meeting will not be a judicial or evidentiary-type public hearing, but 
DOE will conduct it in accordance with section 336 of EPCA (42 U.S.C. 
6306). A court reporter will be present to record the proceedings and 
prepare a transcript. DOE reserves the right to schedule the order of 
presentations and to establish the procedures governing the conduct of 
the public meeting. There shall not be discussion of proprietary 
information, costs or prices, market share, or other commercial matters 
regulated by U.S. anti-trust laws. After the public meeting and until 
the end of the comment period, interested parties may submit further 
comments on the proceedings and any aspect of the rulemaking.
    The public meeting will be conducted in an informal, conference 
style. DOE will present summaries of comments received before the 
public meeting, allow time for prepared general statements by 
participants, and encourage all interested parties to share their views 
on issues affecting this rulemaking. Each participant will be allowed 
to make a general statement (within time limits determined by DOE), 
before the discussion of specific topics. DOE will allow, as time 
permits, other participants to comment briefly on any general 
statements.
    At the end of all prepared statements on a topic, DOE will permit 
participants to clarify their statements briefly and comment on 
statements made by others. Participants should be prepared to answer 
questions by DOE and by other participants concerning these issues. DOE 
representatives may also ask questions of participants concerning other 
matters relevant to this rulemaking. The official conducting the public 
meeting will accept additional comments or questions from those 
attending, as time permits. The presiding official will announce any 
further procedural rules or modification of the above procedures that 
may be needed for the proper conduct of the public meeting.
    A transcript of the public meeting will be included in the docket, 
which can be viewed as described in the Docket section at the beginning 
of this document and will be accessible on the DOE Web site. In 
addition, any person may buy a copy of the transcript from the 
transcribing reporter.

D. Submission of Comments

    DOE will accept comments, data, and information regarding this 
proposed rule before or after the public meeting, but no later than the 
date provided in the DATES section at the beginning of this proposed 
rule. Interested parties may submit comments, data, and other 
information using any of the methods described in the ADDRESSES section 
at the beginning of this notice of proposed rulemaking.
    Submitting comments via www.regulations.gov. The 
www.regulations.gov Web page will require you to provide your name and 
contact information. Your contact information will be viewable to DOE 
Building Technologies staff only. Your contact information will not be 
publicly viewable except for your first and last names, organization 
name (if any), and submitter representative name (if any). If your 
comment is not processed properly because of technical difficulties, 
DOE will use this information to contact you. If DOE cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, DOE may not be able to consider your comment.
    However, your contact information will be publicly viewable if you 
include it in the comment itself or in any documents attached to your 
comment. Any information that you do not want to be publicly viewable 
should not be included in your comment, nor in any document attached to 
your comment. Otherwise, persons viewing comments will see only first 
and last names, organization names, correspondence containing comments, 
and any documents submitted with the comments.
    Do not submit to www.regulations.gov information for which 
disclosure is restricted by statute, such as trade secrets and 
commercial or financial information (hereinafter referred to as 
Confidential Business Information (CBI)). Comments submitted through 
www.regulations.gov cannot be claimed as CBI. Comments received through 
the Web site will waive any CBI claims for the information submitted. 
For information on submitting CBI, see the Confidential Business 
Information section which follows.
    DOE processes submissions made through www.regulations.gov before 
posting. Normally, comments will be posted within a few days of being 
submitted. However, if large volumes of comments are being processed 
simultaneously, your comment may not be viewable for up to several 
weeks. Please keep the comment tracking number that www.regulations.gov 
provides after you have successfully uploaded your comment.
    Submitting comments via email, hand delivery/courier, or mail. 
Comments and documents submitted via email, hand delivery/courier, or 
mail also will be posted to www.regulations.gov. If you do not want 
your personal contact information to be publicly viewable, do not 
include it in your comment or any accompanying documents. Instead, 
provide your contact information in a cover letter. Include your first 
and last names, email address, telephone number, and optional mailing 
address. The cover letter will not be publicly viewable as long as it 
does not include any comments.
    Include contact information each time you submit comments, data, 
documents, and other information to DOE. If you submit via mail or hand 
delivery/courier, please provide all items on a

[[Page 28633]]

CD, if feasible, in which case it is not necessary to submit printed 
copies. No telefacsimiles (faxes) will be accepted.
    Comments, data, and other information submitted to DOE 
electronically should be provided in PDF (preferred), Microsoft Word or 
Excel, WordPerfect, or text (ASCII) file format. Provide documents that 
are not secured, that are written in English, and that are free of any 
defects or viruses. Documents should not contain special characters or 
any form of encryption, and, if possible, they should carry the 
electronic signature of the author.
    Campaign form letters. Please submit campaign form letters by the 
originating organization in batches of between 50 to 500 form letters 
per PDF or as one form letter with a list of supporters' names compiled 
into one or more PDFs. This reduces comment processing and posting 
time.
    Confidential Business Information. Pursuant to 10 CFR 1004.11, any 
person submitting information that he or she believes to be 
confidential and exempt by law from public disclosure should submit via 
email, postal mail, or hand delivery/courier two well-marked copies: 
One copy of the document marked ``confidential'' including all the 
information believed to be confidential, and one copy of the document 
marked ``non-confidential'' with the information believed to be 
confidential deleted. Submit these documents via email or on a CD, if 
feasible. DOE will make its own determination about the confidential 
status of the information and treat it according to its determination.
    Factors of interest to DOE when evaluating requests to treat 
submitted information as confidential include: (1) A description of the 
items; (2) whether and why such items are customarily treated as 
confidential within the industry; (3) whether the information is 
generally known by or available from other sources; (4) whether the 
information has previously been made available to others without 
obligation concerning its confidentiality; (5) an explanation of the 
competitive injury to the submitting person which would result from 
public disclosure; (6) when such information might lose its 
confidential character due to the passage of time; and (7) why 
disclosure of the information would be contrary to the public interest.
    It is DOE's policy that all comments may be included in the public 
docket, without change and as received, including any personal 
information provided in the comments (except information deemed to be 
exempt from public disclosure).

E. Issues on Which DOE Seeks Comment

    Although DOE welcomes comments on any aspect of this proposal, DOE 
is particularly interested in receiving comments and views of 
interested parties concerning the following issues:
    Issue 1: DOE seeks comment on its proposed incorporation by 
reference of ASTM D2156-09, and on its proposed additional 
specifications for how to set up the smoke spot test, and when to 
conduct the smoke spot test and measure the CO2 reading.
    Issue 2: DOE seeks comment on its proposed incorporation by 
reference of ASTM C177-13 and C518-10 for the definition of ``R-
value.''
    Issue 3: DOE requests comments and data on its proposed changes to 
improve the repeatability of the thermal efficiency and standby loss 
test procedures for certain commercial water heating equipment. 
Specifically, DOE requests comment on its proposed requirements for 
ambient relative humidity. DOE does not propose this requirement for 
testing of electric water heaters, and seeks feedback on whether 
including such a requirement would improve the repeatability of the 
standby loss test for electric water heaters. DOE is also seeking 
comments regarding any additional changes that would improve the 
repeatability of the thermal efficiency and standby loss tests.
    Issue 4: DOE requests comment on the changes to improve test 
repeatability for its test procedures for certain CWH equipment that 
were identified but not proposed in this NOPR. If comments suggest that 
DOE should implement these changes, then DOE will evaluate whether it 
can adopt those changes in the final rule or must engage in further 
rulemaking. Particularly, DOE requests data showing what duration for 
the steady-state verification period would ensure steady-state 
operation is reached for gas-fired and oil-fired CWH equipment prior to 
the thermal efficiency test. DOE also seeks data that suggest suitable 
tolerances for water temperature and flow rate for this steady-state 
verification period. Additionally, DOE seeks comment on whether 
different requirements for establishing steady-state operation are 
warranted for each equipment class of CWH equipment.
    Issue 5: DOE requests comment on the proposed test procedure to 
determine the standby loss for UFHWSTs, and on whether any other 
methods, including those detailed in this NOPR, would lead to a better 
test. Specifically, DOE solicits feedback on whether the proposed test 
would be long enough to determine an accurate standby loss rating, 
whether the use of a linear approximation of the temperature decay is 
sufficient to estimate the standby loss, whether running the test by 
simply letting the temperature decay (rather than providing external 
heat to bring the temperature of the water back to operational 
temperature) is appropriate, and whether the adoption of test 
conditions (i.e., ambient room temperature, maximum air draft, water 
temperature) similar to that of other classes of CWH equipment is 
appropriate. DOE also seeks comment on whether any of its identified 
alternatives could be modified to improve their repeatability and to 
decrease test burden, thereby supporting further consideration.
    Issue 6: DOE seeks comment on its proposed change to its 
requirements for setting the tank thermostat in the thermal efficiency 
and standby loss test procedures for gas-fired and oil-fired storage 
and storage-type instantaneous water heaters from measurement of mean 
tank temperature to measurement of outlet water temperature.
    Issue 7: DOE seeks comment on its tentative decision to maintain a 
mean tank temperature requirement for the standby loss test for 
electric storage water heaters. DOE also requests comment on its 
clarifying language for setting tank thermostats for electric storage 
water heaters with multiple thermostats.
    Issue 8: DOE requests comment on its proposed clarifying statements 
regarding steady-state operation and manipulation of CWH equipment 
settings during efficiency tests.
    Issue 9: DOE requests comment on its proposal to remove exemptions 
from the definitions for consumer water heaters codified at 10 CFR 
430.2 that exclude units that heat water to temperatures greater than 
180[emsp14][deg]F and units with a storage capacity greater than 120 
gallons. DOE also requests comment on its proposal to remove the 
definitions at 10 CFR 430.2 for ``electric heat pump water heater'' and 
``gas-fired heat pump water heater.''
    Issue 10: DOE requests comment on its proposed changes to its 
definitions for CWH equipment: (1) Replacing the terms ``rated input'' 
and ``input rating'' with ``fuel input rate'' for gas-fired and oil-
fired CWH equipment to match DOE's proposed definition for ``fuel input 
rate;'' (2) modifying DOE's definitions for ``instantaneous water 
heater'' and ``storage water heater'' by adding the input criteria that 
separate consumer water heaters and commercial water heaters and 
removing several phrases that do not serve to clarify coverage of units 
under the definitions;

[[Page 28634]]

and (3) removing the definition of ``packaged boiler.''
    Issue 11: DOE requests comment on its proposal to modify the 
definition of ``residential-duty commercial water heater'' by removing 
from its scope the following classes: Electric storage water heaters, 
heat pump water heaters with storage, gas-fired instantaneous water 
heaters, and oil-fired instantaneous water heaters.
    Issue 12: DOE seeks comment on its proposed definition of 
``storage-type instantaneous water heater.''
    Issue 13: DOE requests comment on its proposed definition for 
``flow-activated instantaneous water heater.'' Specifically, DOE 
requests feedback on whether the definition includes all units and 
designs for which a separate standby loss test procedure is warranted, 
and whether any units would be included that do not need a test method 
separate from the current standby loss test procedure for CWH 
equipment.
    Issue 14: DOE requests comment on its proposal to include a test 
procedure similar to that specified in section 5.27 of ANSI Z21.10.3-
2015 for measuring the storage volume of all instantaneous water 
heaters and hot water supply boilers, including flow-activated 
instantaneous water heaters. DOE also seeks information on alternative 
methods for measuring storage volume and the impact of residual water 
on measuring storage volume of instantaneous water heaters and hot 
water supply boilers. Further, DOE seeks comment on ways to remove 
residual water from the water heater that could allow for more accurate 
and consistent measurement of the storage volume of CWH equipment.
    Issue 15: DOE requests comment from interested parties on all 
aspects of the proposed test procedure for flow-activated instantaneous 
water heaters. Specifically, DOE requests comment on its tentative 
decision to: (1) Base the test procedure on the second part of the 2016 
AHRI-recommended test method that applies to flow-activated water 
heaters that will not initiate burner operation over the course of the 
test; (2) stop the test following a 35[emsp14][deg]F  
2[emsp14][deg]F drop in the outlet water temperature or completion of 
24 hours, whichever occurs earlier; and (3) use the outlet water 
temperature as an approximation of the stored water temperature.
    Issue 16: DOE seeks comment on its proposed change to the location 
of temperature measurement for the outlet water temperature with the 
associated conditions for placement of temperature-sensing instruments 
in water pipes, as well as the placement of the supply and outlet water 
valves. Specifically, DOE requests comment on whether such a change 
would provide more accurate test results, and whether the change would 
be burdensome to manufacturers. Additionally, DOE requests information 
on any alternative arrangements to measure the outlet water temperature 
accurately and in close proximity to the hot water outlet of the tested 
CWH equipment.
    Issue 17: DOE requests comment on the proposed test procedure for 
instantaneous water heaters and hot water supply boilers (except those 
meeting the proposed definition of ``storage-type instantaneous water 
heater'' and ``flow-activated instantaneous water heater''). DOE also 
requests feedback on its tentative decision to use the outlet water 
temperature instead of the mean tank temperature or stored water 
temperature to conduct the standby loss test. Further, DOE requests 
suggestions on methods or approaches that can be used to measure the 
stored water temperature accurately.
    Issue 18: DOE requests comment on its proposed definition for 
``commercial heat pump water heater.''
    Issue 19: DOE requests comment on the proposed categories of CHPWHs 
and related definitions. In particular, DOE requests comments on CHPWH 
heat sources that are currently available for commercial applications.
    Issue 20: DOE requests comment on all aspects of the proposed test 
procedure for commercial heat pump water heaters, and in particular, 
the proposal to test all units without a storage tank. DOE also invites 
comment on its recommended rating conditions, particularly the supply 
water temperatures for air-source commercial heat pump water heaters.
    Issue 21: DOE seeks comment regarding its proposed definition and 
methodology for measuring and verifying fuel input rate for gas-fired 
and oil-fired CWH equipment.
    Issue 22: DOE requests comment on its proposed default values for 
maximum water supply pressure for all equipment, allowable gas supply 
pressure range for equipment powered with natural gas and propane, and 
the CO2 reading and fuel pump pressure for oil-fired 
equipment.
    Issue 23: DOE requests comment on its proposed additional 
certification requirements for instantaneous water heaters and hot 
water supply boilers, and seeks feedback on any other information that 
should be included for any classes of CWH equipment.
    Issue 24: DOE requests comment on its cost estimates for 
manufacturers to test their unfired hot water storage tanks according 
to DOE's proposed test method.

VI. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this notice of 
proposed rulemaking.

List of Subjects

10 CFR Part 429

    Confidential business information, Energy conservation, Household 
appliances, Imports, Reporting and recordkeeping requirements.

10 CFR Part 430

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

10 CFR Part 431

    Administrative practice and procedure, Confidential business 
information, Incorporation by reference, Test procedures, Reporting and 
recordkeeping requirements.

    Issued in Washington, DC, on April 15, 2016.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy Efficiency, Energy Efficiency and 
Renewable Energy.

    For the reasons set forth in the preamble, DOE proposes to amend 
parts 429, 430, and 431 of chapter II, subchapter D 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.

0
2. Section 429.44 is amended by:
0
a. Revising paragraphs (b) and (c);
0
b. Redesignating paragraph (d) as (e) and revising newly redesignated 
paragraph (e); and
0
c. Adding and reserving a new paragraph (d).
    The additions and revisions read as follows:


Sec.  429.44  Commercial water heating equipment.

* * * * *
    (b) Determination of represented values for all types of commercial 
water heaters except residential-duty

[[Page 28635]]

commercial water heaters. Manufacturers must determine the represented 
values, which includes the certified ratings, for each basic model of 
commercial water heating equipment except residential-duty commercial 
water heaters, either by testing, in conjunction with the applicable 
sampling provisions, or by applying an AEDM as set forth in Sec.  
429.70.
    (1) Units to be tested. If the represented value for a given basic 
model is determined through testing:
    (i) The general requirements of Sec.  429.11 apply; and
    (ii) A sample of sufficient size must be randomly selected and 
tested to ensure that:
    (A) Any represented value of energy consumption or other measure of 
energy use of a basic model for which consumers would favor lower 
values must be greater than or equal to the higher of:
    (1) The mean of the sample, where:
    [GRAPHIC] [TIFF OMITTED] TP09MY16.273
    

And, x is the sample mean; n is the number of samples; and 
xi is the ith sample; or,
    (2) The upper 95 percent confidence limit (UCL) of the true mean 
divided by 1.05, where:
[GRAPHIC] [TIFF OMITTED] TP09MY16.274


And x is the sample mean; s is the sample standard deviation; n is the 
number of samples; and t0.95 is the t statistic for a 95% 
one-tailed confidence interval with n-1 degrees of freedom (from 
appendix A to subpart B of this part). And,
    (B) Any represented value of energy efficiency or other measure of 
energy consumption of a basic model for which consumers would favor 
higher values must be less than or equal to the lower of:
    (1) The mean of the sample, where:
    [GRAPHIC] [TIFF OMITTED] TP09MY16.275
    

And, x is the sample mean; n is the number of samples; and 
xi is the ith sample; or,
    (2) The lower 95 percent confidence limit (LCL) of the true mean 
divided by 0.95, where:
[GRAPHIC] [TIFF OMITTED] TP09MY16.276

    And x is the sample mean; s is the sample standard deviation; n is 
the number of samples; and t0.95 is the t statistic for a 
95% one-tailed confidence interval with n-1 degrees of freedom (from 
appendix A to subpart B of this part).
    (2) Alternative efficiency determination methods. In lieu of 
testing, a represented value of efficiency or consumption for a basic 
model must be determined through the application of an AEDM pursuant to 
the requirements of Sec.  429.70 and the provisions of this section, 
where:
    (i) Any represented value of energy consumption or other measure of 
energy use of a basic model for which consumers would favor lower 
values must be greater than or equal to the output of the AEDM and less 
than or equal to the Federal standard for that basic model; and
    (ii) Any represented value of energy efficiency or other measure of 
energy consumption of a basic model for which consumers would favor 
higher values must be less than or equal to the output of the AEDM and 
greater than or equal to the Federal standard for that basic model.
    (3) The representative value of fuel input rate of a basic model 
reported in accordance with paragraph (c)(2) of this section must be 
either the mean of the fuel input rate(s) measured for each tested unit 
of the basic model and determined in accordance with the test procedure 
in Sec.  431.106 of this chapter, or the value determined with an AEDM, 
and rounded to the nearest 1,000 Btu/h.
    (c) Certification reports. For commercial water heating equipment 
other than residential-duty commercial water heaters:
    (1) The requirements of Sec.  429.12 apply; and
    (2) Pursuant to Sec.  429.12(b)(13), a certification report must 
include the following public equipment-specific information:
    (i) Commercial electric storage water heaters: The standby loss in 
percent per hour (%/h) and the measured storage volume in gallons 
(gal).
    (ii) Commercial gas-fired and oil-fired storage water heaters: The 
thermal efficiency in percent (%), the standby loss in British thermal 
units per hour (Btu/h), the rated storage volume in gallons (gal), and 
the fuel input rate in British thermal units per hour (Btu/h) rounded 
to the nearest 1,000 Btu/h.
    (iii) Commercial water heaters and hot water supply boilers with 
storage capacity greater than 140 gallons: The thermal efficiency in 
percent (%), whether the storage volume is greater than 140 gallons 
(Yes/No); whether the tank surface area is insulated with at least R-
12.5 (Yes/No); whether a standing pilot light is used (Yes/No); for gas 
or oil-fired water heaters, whether the basic model has a fire damper 
or fan-assisted combustion (Yes/No); and, if applicable, pursuant to 10 
CFR 431.110, the standby loss in British thermal units per hour (Btu/h) 
and measured storage volume in gallons (gal).
    (iv) Commercial gas-fired and oil-fired instantaneous water heaters 
with storage capacity greater than or equal to 10 gallons and gas-fired 
and oil-fired hot water supply boilers with storage capacity greater 
than or equal to 10 gallons: The thermal efficiency in percent (%), the 
standby loss in British thermal units per hour (Btu/h); the rated 
storage volume in gallons (gal); the fuel input rate in British thermal 
units per hour (Btu/h) rounded to the nearest 1,000 Btu/h; whether a 
submerged heat exchanger is used (Yes/No); and whether flow through the 
water heater is required to initiate burner ignition (Yes/No).
    (v) Commercial gas-fired and oil-fired instantaneous water heaters 
with storage capacity less than 10 gallons and gas-fired and oil-fired 
hot water supply boilers with storage capacity less than 10 gallons: 
The thermal efficiency in percent (%), the rated storage volume in 
gallons (gal), and the fuel input rate in British thermal units per 
hour (Btu/h) rounded to the nearest 1,000 Btu/h.
    (vi) Commercial unfired hot water storage tanks: The thermal 
insulation (i.e., R-value) and stored volume in gallons (gal).
    (3) Pursuant to Sec.  429.12(b)(13), a certification report must 
include the following additional, equipment-specific information:
    (i) Whether the basic model is engineered-to-order; and
    (ii) For any basic model rated with an AEDM, whether the 
manufacturer elects the witness test option for verification testing. 
(See Sec.  429.70(c)(5)(iii) for options.) However, the manufacturer 
may not select more than 10 percent of AEDM-rated basic models to be 
eligible for witness testing.
    (4) Pursuant to Sec.  429.12(b)(13), a certification report may 
include supplemental testing instructions in PDF format. If necessary 
to run a valid test, the equipment-specific, supplemental information 
must include any additional testing and testing set-up instructions 
(e.g., whether a bypass loop was used for testing) for the basic model 
and all other information (e.g., operational codes or overrides for the 
control settings) necessary to operate the

[[Page 28636]]

basic model under the required conditions specified by the relevant 
test procedure. A manufacturer may also include with a certification 
report other supplementary items in PDF format for DOE's consideration 
in performing testing under subpart C of this part. For example, for 
gas-fired commercial water heating equipment (other than residential-
duty commercial water heaters): The maximum water pressure in pounds 
per square inch (psi), and the minimum and maximum gas supply pressure 
in inches of water column (in. w.c.)--including the gas pressure 
specifications for both natural gas and propane, if models powered by 
both natural gas and propane are certified under the same basic model; 
or for oil-fired commercial water heating equipment (other than 
residential-duty commercial water heaters): The maximum water pressure 
in pounds per square inch (psi), the allowable range for CO2 
reading in percent (%), and the fuel pump pressure in pounds per square 
inch gauge (psig); or for electric commercial water heating equipment 
(other than residential-duty commercial water heaters): The maximum 
water pressure in pounds per square inch (psi).
    (d) [Reserved]
    (e) Alternative methods for determining efficiency or energy use 
for commercial water heating equipment can be found in Sec.  429.70.

0
3. Section 429.134 is amended by adding paragraph (m) to read as 
follows:


Sec.  429.134.  Product-specific enforcement provisions.

* * * * *
    (m) Commercial water heating equipment other than residential-duty 
commercial water heaters--(1) Verification of fuel input rate. The fuel 
input rate of each tested unit of the basic model will be measured 
pursuant to the test requirements of Sec.  431.106 of this chapter. The 
measured fuel input rate (either the measured fuel input rate for a 
single unit sample or the average of the measured fuel input rates for 
a multiple unit sample) will be compared to the value of fuel input 
rate certified by the manufacturer. The certified fuel input rate will 
be considered valid only if the measured fuel input rate is within two 
percent of the certified fuel input rate.
    (i) If the certified fuel input rate is found to be valid, then the 
certified fuel input rate will serve as the basis for determination of 
the appropriate equipment class and calculation of the standby loss 
standard (as applicable).
    (ii) If the measured fuel input rate is not within two percent of 
the certified fuel input rate, attempt to achieve the certified fuel 
input rate (within two percent), DOE will first attempt to increase or 
decrease the gas pressure within the range specified in manufacturer's 
instructions in the installation and operation manual shipped with the 
commercial water heating equipment being tested or in supplemental 
instructions provided by the manufacturer. If the gas pressure range is 
not specified by the manufacturer in either of these sources, DOE will 
use the default range for gas pressure included in appendices A, C, and 
E to subpart G of part 431 of this chapter. If the measured fuel input 
rate is still not within two percent of the certified fuel input rate, 
DOE will attempt to modify the gas inlet orifice. If the measured fuel 
input rate still is not within two percent of the certified fuel input 
rate, the measured fuel input rate will serve as the basis for 
determination of the appropriate equipment class and calculation of the 
standby loss standard (as applicable).
    (2) [Reserved]

PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

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

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

0
5. Section 430.2 is amended by:
0
a. Removing the definitions of ``Electric heat pump water heater'' and 
``Gas-fired heat pump water heater''; and
0
b. Revising the definitions of ``Electric instantaneous water heater,'' 
``Electric storage water heater,'' ``Gas-fired instantaneous water 
heater,'' ``Gas-fired storage water heater,'' ``Oil-fired instantaneous 
water heater,'' and ``Oil-fired storage water heater.''
    The revisions read as follows:


Sec.  430.2  Definitions.

* * * * *
    Electric instantaneous water heater means a water heater that uses 
electricity as the energy source, has a nameplate input rating of 12 kW 
or less, and contains no more than one gallon of water per 4,000 Btu 
per hour of input.
* * * * *
    Electric storage water heater means a water heater that uses 
electricity as the energy source, has a nameplate input rating of 12 kW 
or less, and contains more than one gallon of water per 4,000 Btu per 
hour of input.
* * * * *
    Gas-fired instantaneous water heater means a water heater that uses 
gas as the main energy source, has a nameplate input rating less than 
200,000 Btu/h, and contains no more than one gallon of water per 4,000 
Btu per hour of input.
    Gas-fired storage water heater means a water heater that uses gas 
as the main energy source, has a nameplate input rating of 75,000 Btu/h 
or less, and contains more than one gallon of water per 4,000 Btu per 
hour of input.
* * * * *
    Oil-fired instantaneous water heater means a water heater that uses 
oil as the main energy source, has a nameplate input rating of 210,000 
Btu/h or less, and contains no more than one gallon of water per 4,000 
Btu per hour of input.
    Oil-fired storage water heater means a water heater that uses oil 
as the main energy source, has a nameplate input rating of 105,000 Btu/
h or less, and contains more than one gallon of water per 4,000 Btu per 
hour of input.
* * * * *

PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND 
INDUSTRIAL EQUIPMENT

0
6. The authority citation for part 431 continues to read as follows:

    Authority: 42 U.S.C. 6291-6317.

0
7. Section 431.102 is amended by:
0
a. Revising the section heading;
0
b. Revising the definitions of ``Hot water supply boiler,'' 
``Instantaneous water heater,'' ``R-value,'' ``Residential-duty 
commercial water heater,'' ``Standby loss,'' and ``Storage water 
heater'';
0
c. Adding, in alphabetical order, definitions for the terms ``Air-
source commercial heat pump water heater,'' ``Coefficient of 
performance,'' ``Commercial heat pump water heater,'' ``Direct geo-
exchange commercial heat pump water heater,'' ``Flow-activated 
instantaneous water heater,'' ``Fuel input rate,'' ``Ground water-
source commercial heat pump water heater,'' ``Indoor water-source 
commercial heat pump water heater,'' and ``Storage-type instantaneous 
water heater''; and
0
d. Removing the definitions of ``ASTM-D-2156-80'' and ``Packaged 
boiler.''
    The revisions and additions read as follows:


Sec.  431.102  Definitions concerning commercial water heaters, hot 
water supply boilers, unfired hot water storage tanks, and commercial 
heat pump water heaters.

    Air-source commercial heat pump water heater means a commercial 
heat pump water heater that utilizes surrounding air as the heat 
source.
* * * * *

[[Page 28637]]

    Coefficient of performance (COPh) means the 
dimensionless ratio of the rate of useful heat transfer gained by the 
water (expressed in Btu/h), to the rate of electric power consumed 
during operation (expressed in Btu/h).
    Commercial heat pump water heater (CHPWH) means a water heater that 
uses a refrigeration cycle, such as vapor compression, to transfer heat 
from a low-temperature source to a higher-temperature sink for the 
purpose of heating potable water, and has a rated electric power input 
greater than 12 kW. Such equipment includes, but is not limited to, 
air-source heat pump water heaters, water-source heat pump water 
heaters, and direct geo-exchange heat pump water heaters.
    Direct geo-exchange commercial heat pump water heater means a 
commercial heat pump water heater that utilizes the earth as a heat 
source and allows for direct exchange of heat between the earth and the 
refrigerant in the evaporator coils.
    Flow-activated instantaneous water heater means an instantaneous 
water heater or hot water supply boiler that does not activate the 
burner or heating element if no heated water is drawn from the unit.
    Fuel input rate means the maximum rate at which gas-fired or oil-
fired CWH equipment uses energy as determined using test procedures 
prescribed under Sec.  431.106.
    Ground water-source commercial heat pump water heater means a 
commercial heat pump water heater that utilizes ground water as the 
heat source.
    Hot water supply boiler means a packaged boiler (defined in Sec.  
431.82) that is industrial equipment and that:
    (1) Has a fuel input rate (for gas-fired or oil-fired equipment) or 
input rating (for electric equipment) from 300,000 Btu/h to 12,500,000 
Btu/h and of at least 4,000 Btu/h per gallon of stored water;
    (2) Is suitable for heating potable water; and
    (3) Meets either or both of the following conditions:
    (i) It has the temperature and pressure controls necessary for 
heating potable water for purposes other than space heating; or
    (ii) The manufacturer's product literature, product markings, 
product marketing, or product installation and operation instructions 
indicate that the boiler's intended uses include heating potable water 
for purposes other than space heating.
    Indoor water-source commercial heat pump water heater means a 
commercial heat pump water heater that utilizes indoor water as the 
heat source.
    Instantaneous water heater means a water heater that uses gas, oil, 
or electricity, including:
    (1) Gas-fired instantaneous water heaters with a fuel input rate 
both greater than 200,000 Btu/h and not less than 4,000 Btu/h per 
gallon of stored water;
    (2) Oil-fired instantaneous water heaters with a fuel input rate 
both greater than 210,000 Btu/h and not less than 4,000 Btu/h per 
gallon of stored water; and
    (3) Electric instantaneous water heaters with an input capacity 
both greater than 12 kW and not less than 4,000 Btu/h per gallon of 
stored water.
    R-value means the thermal resistance of insulating material as 
determined using ASTM Standard Test Method C177-13 or C518-10 
(incorporated by reference; see Sec.  431.105) and expressed in 
([deg]F[middot]ft\2\[middot]h/Btu).
    Residential-duty commercial water heater means any gas-fired 
storage, oil-fired storage, or electric instantaneous commercial water 
heater that meets the following conditions:
    (1) For models requiring electricity, uses single-phase external 
power supply;
    (2) Is not designed to provide outlet hot water at temperatures 
greater than 180[emsp14][deg]F; and
    (3) Does not meet any of the following criteria:

------------------------------------------------------------------------
                                           Indicator of non-residential
           Water heater type                       application
------------------------------------------------------------------------
Gas-fired Storage......................  Fuel input rate >105 kBtu/h;
                                          Rated storage volume >120
                                          gallons.
Oil-fired Storage......................  Fuel input rate >140 kBtu/h;
                                          Rated storage volume >120
                                          gallons.
Electric Instantaneous.................  Rated input >58.6 kW; Rated
                                          storage volume >2 gallons.
------------------------------------------------------------------------

    Standby loss means:
    (1) For electric commercial water heating equipment (not including 
commercial heat pump water heaters), the average hourly energy required 
to maintain the stored water temperature expressed as a percent per 
hour (%/h) of the heat content of the stored water above room 
temperature and determined in accordance with appendix B, D, or E to 
subpart G of part 431 (as applicable), denoted by the term ``S.''
    (2) For gas-fired and oil-fired commercial water heating equipment, 
the average hourly energy required to maintain the stored water 
temperature expressed in British thermal units per hour (Btu/h) based 
on a 70[emsp14][deg]F temperature differential between stored water and 
ambient room temperature and determined in accordance with appendix A, 
C, or E to subpart G of part 431 (as applicable), denoted by the term 
``SL''; or
    (3) For unfired hot water storage tanks, the average hourly energy 
lost from the storage tank when in standby mode expressed in British 
thermal units per hour (Btu/h) and determined in accordance with 
appendix G to subpart G of part 431, denoted by the term ``SL.''
    Storage water heater means a water heater that uses gas, oil, or 
electricity to heat and store water within the appliance at a 
thermostatically-controlled temperature for delivery on demand, 
including:
    (1) Gas-fired storage water heaters with a fuel input rate both 
greater than 75,000 Btu/h and less than 4,000 Btu/h per gallon of 
stored water;
    (2) Oil-fired storage water heaters with a fuel input rate both 
greater than 105,000 Btu/h and less than 4,000 Btu/h per gallon of 
stored water; and
    (3) Electric storage water heaters with an input capacity both 
greater than 12 kW and less than 4,000 Btu/h per gallon of stored 
water.
    Storage-type instantaneous water heater means an instantaneous 
water heater comprising a storage tank with a submerged heat 
exchanger(s) or heating element(s).
* * * * *


Sec.  431.104  [Removed]

0
8. Section 431.104 is removed.
0
9. Section 431.105 is amended by:
0
a. Redesignating paragraph (b) as (c) and revising newly redesignated 
paragraph (c); and
0
b. Adding paragraphs (b), (d), and (e).
    The revisions and additions read as follows:


Sec.  431.105  Materials incorporated by reference.

* * * * *
    (b) AHRI. Air-Conditioning, Heating, and Refrigeration Institute, 
2111 Wilson Blvd., Suite 500, Arlington, VA 22201, (703) 524-8800, or 
go to www.ahrinet.org.

[[Page 28638]]

    (1) GAMA Testing Standard IWH-TS-1, ``Method to Determine 
Performance of Indirect-fired Water Heaters,'' March 2003 edition, 
sections 4, 5, 6.0, and 6.1, IBR approved for appendix G to this 
subpart.
    (2) [Reserved]
    (c) ANSI. American National Standards Institute, 25 W. 43rd Street, 
4th Floor, New York, NY 10036, (212) 642-4900, or go to: http://www.ansi.org.
    (1) ANSI Z21.10.3-2015/CSA 4.3-2015 (``ANSI Z21.10.3-2015''), 
``Gas-fired Water Heaters, Volume III, Storage Water Heaters with Input 
Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous,'' 
Annex E.1, approved by ANSI on October 5, 2015, IBR approved for 
appendices A, B, C, D, and E to this subpart.
    (2) [Reserved]
    (d) ASHRAE. American Society of Heating, Refrigerating and Air-
conditioning Engineers, 1791 Tullie Circle NE., Atlanta, GA 30329, 
(800) 527-4723, or go to https://www.ashrae.org.
    (1) ANSI/ASHRAE Standard 118.1-2012, ``Method of Testing for Rating 
Commercial Gas, Electric, and Oil Service Water-Heating Equipment,'' 
approved by ASHRAE on October 26, 2012 and by ANSI on October 27, 2012, 
IBR approved for appendix F to this subpart.
    (2) [Reserved]
    (e) ASTM. ASTM International, 100 Barr Harbor Drive, P.O. Box C700, 
West Conshohocken, PA 19428-2959, (610) 832-9585, or go to http://www.astm.org.
    (1) ASTM C177-13, ``Standard Test Method for Steady-State Heat Flux 
Measurements and Thermal Transmission Properties by Means of the 
Guarded-Hot-Plate Apparatus,'' approved by ASTM on September 15, 2013, 
IBR approved for Sec.  431.102.
    (2) ASTM C518-10, ``Standard Test Method for Steady-State Thermal 
Transmission Properties by Means of the Heat Flow Meter Apparatus,'' 
approved by ASTM on May 1, 2010, IBR approved for Sec.  431.102.
    (3) ASTM D2156-09, ``Standard Test Method for Smoke Density in Flue 
Gases from Burning Distillate Fuels,'' approved by ASTM on December 1, 
2009 and reapproved by ASTM on October 1, 2013, IBR approved for 
appendices A, C, and E to this subpart.
0
10. Section 431.106 is revised to read as follows:


Sec.  431.106  Uniform test method for the measurement of energy 
efficiency of commercial water heating equipment.

    (a) Scope. This section contains test procedures for measuring, 
pursuant to EPCA, the energy efficiency of commercial water heating 
equipment.
    (b) Testing and calculations. Determine the energy efficiency of 
commercial water heating equipment by conducting the applicable test 
procedure(s):
    (1) Residential-duty commercial water heaters. Test in accordance 
with appendix E to subpart B of part 430 of this chapter.
    (2) Commercial water heating equipment other than residential-duty 
commercial water heaters. Test covered commercial water heating 
equipment by following the appropriate test procedures in appendices to 
subpart G of this part.
    (i) Gas-fired and oil-fired storage water heaters and storage-type 
instantaneous water heaters. Test according to appendix A to subpart G 
of this part.
    (ii) Electric storage water heaters and storage-type instantaneous 
water heaters. Test according to appendix B to subpart G of this part.
    (iii) Gas-fired and oil-fired instantaneous water heaters and hot 
water supply boilers (other than flow-activated instantaneous water 
heaters and storage-type instantaneous water heaters). Test according 
to appendix C to subpart G of this part.
    (iv) Electric instantaneous water heaters (other than flow-
activated instantaneous water heaters and storage-type instantaneous 
water heaters). Test according to appendix D to subpart G of this part.
    (v) Flow-activated instantaneous water heaters. Test according to 
appendix E to subpart G of this part.
    (vi) Commercial heat pump water heaters. Test according to appendix 
F to subpart G of this part.
    (vii) Unfired hot water storage tanks. Test according to appendix G 
to subpart G of this part.


Sec.  431.107  [Removed]

0
11. Section 431.107 is removed.
0
12. Add appendix A to subpart G of part 431 to read as follows:

Appendix A to Subpart G of Part 431--Uniform Test Method for the 
Measurement of Thermal Efficiency and Standby Loss of Gas-Fired and 
Oil-Fired Storage Water Heaters and Storage-Type Instantaneous Water 
Heaters

    Note: Prior to (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to the energy use or 
efficiency of the subject commercial water heating equipment in 
accordance with the results of testing pursuant to this appendix or 
the procedures in 10 CFR 431.106 that were in place on January 1, 
2016. On and after (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to energy use or 
efficiency of gas-fired and oil-fired storage water heaters and 
storage-type instantaneous water heaters in accordance with the 
results of testing pursuant to this appendix to demonstrate 
compliance with the energy conservation standards at 10 CFR 431.110.

1. General

    Determine the thermal efficiency and standby loss (as 
applicable) in accordance with the following sections of this 
appendix. Certain sections reference sections of Annex E.1 of ANSI 
Z21.10.3-2015 (incorporated by reference; see Sec.  431.105). Where 
the instructions contained in the sections below conflict with 
instructions in Annex E.1 of ANSI Z21.10.3-2015, the instructions 
contained herein control.

2. Test Set-Up

    2.1. Placement of Water Heater. A water heater for installation 
on combustible floors is to be placed on a \3/4\-inch plywood 
platform supported by three 2 x 4-inch runners. If the water heater 
is for installation on noncombustible floors, suitable 
noncombustible material is to be placed on the platform. When the 
use of the platform for a large water heater is not practical, the 
water heater may be placed on any suitable flooring. A wall-mounted 
water heater is to be mounted to a simulated wall section.
    2.2. Heat Trap and Thermocouple Installation. Inlet and outlet 
piping must be turned vertically downward from the connections on a 
tank-type water heater so as to form heat traps. Thermocouples for 
measuring supply and outlet water temperatures must be installed 
upstream from the inlet heat trap piping and downstream from the 
outlet heat trap piping, respectively, in accordance with Figure 1, 
2, or 3 (as applicable) of this section. The total vertical piping 
length between the thermocouple sensing location and the connection 
port must be equal to 24 inches. For water heaters with vertical 
connections, the 24 inches of total vertical piping length is 
divided into 6 inches of vertical piping upstream from the turn for 
the heat trap and 18 inches downstream from the turn for the heat 
trap. For water heaters that have vertical connections (top and 
bottom), the total horizontal piping between the connection port and 
the thermocouple sensing location must be equal to the distance 
between the water heater connection port and the edge of the water 
heater plus 2 inches. For water heaters that have horizontal 
connections, the total horizontal piping between the water heater 
connection port and the temperature sensing location must be equal 
to 6 inches. The water heater must meet the requirements shown in 
Figure 1, 2, or 3 (as applicable) at all times during the conduct of 
the thermal efficiency and standby loss tests. Any factory-supplied 
heat traps must be installed per the installation instructions while 
ensuring the requirements in Figure 1, 2, or 3 are met. All 
dimensions specified in Figure 1, 2, and 3 and in this section are 
measured

[[Page 28639]]

from the outer surface of the pipes and water heater outer casing 
(as applicable).
 BILLING CODE 6450-01-P
[GRAPHIC] [TIFF OMITTED] TP09MY16.277


[[Page 28640]]


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 BILLING CODE 6450-01-C

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    2.3. Thermocouples for Measurement of Mean Tank Temperature. For 
the standby loss test, install temperature-sensing means inside the 
tank for measurement of mean tank temperature according to the 
instructions in section f of Annex E.1 of ANSI Z21.10.3-2015 
(incorporated by reference; see Sec.  431.105). Calculate the mean 
tank temperature as the average of the six installed temperature-
sensing means.
    2.4. Piping Insulation. Insulate all water piping external to 
the water heater jacket, including heat traps and piping that are 
installed by the manufacturer or shipped with the unit, for at least 
4 ft of piping length from the connection at the appliance with 
material having an R-value not less than 
4[emsp14][deg]F[middot]ft\2\[middot]h/Btu. Ensure that the 
insulation does not contact any appliance surface except at the 
location where the pipe connections penetrate the appliance jacket.
    2.5. Temperature and Pressure Relief Valve Insulation. If the 
manufacturer has not provided a temperature and pressure relief 
valve, one shall be installed and insulated as specified in section 
2.4 of this appendix.
    2.6. Vent Requirements. Follow the requirements for venting 
arrangements specified in section c of Annex E.1 of ANSI Z21.10.3-
2015 (incorporated by reference; see Sec.  431.105).
    2.7. Energy Consumption. Install equipment that determines, 
within  1 percent:
    2.7.1. The quantity and rate of fuel consumed.
    2.7.2. The quantity of electricity consumed by factory-supplied 
water heater components, and of the test loop recirculating pump, if 
used.
    3. Test Conditions
    3.1. Water Supply. Follow the following provisions regarding the 
water supply to the water heater:
    3.1.1. The pressure of the water supply must be maintained 
between 40 psi and the maximum pressure specified by the 
manufacturer of the unit being tested. If the maximum water pressure 
is not specified by the manufacturer in literature shipped with the 
unit or supplemental test report instructions included with a 
certification report, then a default maximum value of 150 psi is to 
be used. The accuracy of the pressure-measuring devices must be 
 1.0 pounds per square inch (psi).
    3.1.2. Isolate the water heater using a shutoff valve in the 
supply line with an expansion tank installed in the supply line 
downstream of the shutoff valve. There must be no shutoff means 
between the expansion tank and the appliance inlet.
    3.1.3. During conduct of the thermal efficiency test, the 
temperature of the supply water must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F.
    3.2. Gas Supply Pressure for Gas-Fired Equipment. The outlet 
pressure of the gas appliance pressure regulator must be within the 
range specified by the manufacturer. If the allowable range of gas 
supply pressure is not specified by the manufacturer in literature 
shipped with the unit or supplemental test report instructions 
included with a certification report, then the outlet pressure of 
the gas appliance regulator must be within the default range of 4.5 
inches water column (in. w.c.) to 10.5 in. w.c. for natural gas-
powered units or 11 in. w.c. to 13 in. w.c. for propane-powered 
units. Obtain the higher heating value of the gas burned.
    3.3. Ambient Room Temperature. While setting the tank 
thermostats and verifying steady-state operation (prior to the 
thermal efficiency test), between the first and second cut-outs 
prior to the standby loss test, and during the soak-in period, 
thermal efficiency test, and standby loss test, maintain the ambient 
room temperature at 75[emsp14][deg]F  5[emsp14][deg]F at 
all times. Measure the ambient room temperature at 30-second 
intervals during these periods. Measure the ambient room temperature 
at the vertical mid-point of the water heater and approximately 2 
feet from the water heater jacket. Shield the sensor against 
radiation. Calculate the average ambient room temperature separately 
for the soak-in period, thermal efficiency test, and standby loss 
test. During the soak-in period and thermal efficiency and standby 
loss tests, the ambient room temperature must not vary by more than 
2.0[emsp14][deg]F at any reading from the average 
ambient room temperature.
    3.4. Test Air Temperature. While verifying steady-state 
operation (prior to the thermal efficiency test) and during the 
thermal efficiency and standby loss tests, the test air temperature 
must not vary by more than  5[emsp14][deg]F from the 
ambient room temperature at any reading. Measure the test air 
temperature at 30-second intervals during these periods and at a 
location within two feet of the air inlet of the water heater. For 
units with multiple air inlets, measure the test air temperature at 
each air inlet, and maintain the specified tolerance on deviation 
from the ambient room temperature at each air inlet. For CWH 
equipment without a specific air inlet, measure the test air 
temperature within two feet of a location on the water heater where 
combustion air is drawn.
    3.5. Ambient Humidity. While verifying steady-state operation 
(prior to the thermal efficiency test) and during the thermal 
efficiency and standby loss tests, maintain the ambient relative 
humidity of the test room at 60 percent  5 percent. 
Measure the ambient relative humidity at 30-second intervals during 
these periods. The ambient relative humidity must be measured at the 
same location as the test air temperature. For units with multiple 
air inlets, measure the ambient relative humidity at each air inlet, 
and maintain 60 percent  5 percent relative humidity at 
each air inlet.
    3.6. Maximum Air Draft. During the soak-in period, thermal 
efficiency test, and standby loss test, the water heater must be 
located in an area protected from drafts of more than 50 ft/min from 
room ventilation registers, windows, or other external sources of 
air movement. Prior to beginning the soak-in period, thermal 
efficiency test, and standby loss test, measure the air draft within 
three feet of the jacket of the water heater to ensure this 
condition is met. Ensure that no other changes that would increase 
the air draft are made to the test set up or conditions during the 
conduct of the tests.
    3.7. Setting the Tank Thermostat. Before starting the required 
soak-in period, the thermostat setting must first be obtained by 
starting with the water in the system at 70[emsp14][deg]F  2[emsp14][deg]F. The thermostat must then be set so that the 
maximum outlet water temperature, after the thermostat reduces the 
fuel supply to a minimum, is 140[emsp14][deg]F  
5[emsp14][deg]F.
    3.8. Additional Requirements for Oil-Fired Equipment.
    3.8.1. Venting Requirements. Connect a vertical length of flue 
pipe to the flue gas outlet of sufficient height so as to meet the 
minimum draft specified by the manufacturer.
    3.8.2. Oil Supply. Adjust the burner rate so that the following 
conditions are met:
    3.8.2.1. The CO2 reading is within the range 
specified by the manufacturer;
    3.8.2.2. The fuel pump pressure is within  10 
percent of manufacturer's specifications;
    3.8.2.3. If either the fuel pump pressure or range for 
CO2 reading are not specified by the manufacturer in 
literature shipped with the unit or supplemental test report 
instructions included with a certification report, then a default 
value of 100 psig is to be used for fuel pump pressure, and a 
default range of 9-12 percent is to be used for CO2 
reading; and
    3.8.2.4. Smoke in the flue does not exceed No. 1 smoke as 
measured by the procedure in ASTM D2156-09 (incorporated by 
reference, see Sec.  431.105). To determine the smoke spot number, 
connect the smoke measuring device to an open-ended tube. This tube 
must project into the flue \1/4\ to \1/2\ of the pipe diameter.
    3.8.2.5. For the thermal efficiency test, measure the 
CO2 reading and determine the smoke spot number after 
steady-state operation has been obtained as determined by no 
variation of outlet water temperature in excess of 2[emsp14][deg]F 
over a 3-minute period, but before beginning measurements for the 
thermal efficiency test. For the standby loss test, measure the 
CO2 reading and determine the smoke spot number after the 
first cut-out before beginning measurements for the standby loss 
test. However, measurement of the CO2 reading and conduct 
of the smoke spot test are not required prior to beginning an 
efficiency test (i.e., thermal efficiency or standby loss) if no 
settings on the water heater have been changed and the water heater 
has not been turned off since the end of a previously run efficiency 
test.
    3.9. Data Collection Intervals. Follow the data recording 
intervals specified in the following sections.
    3.9.1. Soak-In Period. Measure the air draft, in ft/min, before 
beginning the soak-in period. Measure the ambient room temperature, 
in [deg]F, every 30 seconds during the soak-in period.
    3.9.2. Thermal Efficiency Test. Follow the data recording 
intervals specified in Table 3.1 of this section.

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                  Table 3.1--Data To Be Recorded Before and During the Thermal Efficiency Test
----------------------------------------------------------------------------------------------------------------
                                                                                    Every 30         Every 10
                        Item recorded                            Before test      seconds \1\        minutes
----------------------------------------------------------------------------------------------------------------
Gas outlet pressure, in w.c..................................               X   ...............  ...............
Fuel higher heating value, Btu/ft\3\ (gas) or Btu/lb (oil)...               X   ...............  ...............
Oil pump pressure, psig (oil only)...........................               X   ...............  ...............
CO2 reading, % (oil only)....................................           X \1\   ...............  ...............
Oil smoke spot reading (oil only)............................            X\2\   ...............  ...............
Air draft, ft/min............................................               X   ...............  ...............
Time, minutes/seconds........................................  ...............               X   ...............
Fuel weight or volume, lb (oil) or ft\3\ (gas)...............  ...............  ...............           X \3\
Supply water temperature, [deg]F.............................  ...............               X   ...............
Outlet water temperature, [deg]F.............................  ...............               X   ...............
Ambient room temperature, [deg]F.............................  ...............               X   ...............
Test air temperature, [deg]F.................................  ...............               X   ...............
Ambient relative humidity, %.................................  ...............               X   ...............
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ These measurements are to be recorded at the start and end of the test, as well as every 30 seconds during
  the test.
\2\ The smoke spot test and CO2 reading are not required prior to beginning the thermal efficiency test if no
  settings on the water heater have been changed and the water heater has not been turned off since the end of a
  previously-run efficiency test (i.e., thermal efficiency or standby loss).
\3\ Fuel and electricity consumption over the course of the entire test must be measured and used in calculation
  of thermal efficiency.

    3.9.3. Standby Loss Test. Follow the data recording intervals 
specified in Table 3.2 of this section. Additionally, the fuel and 
electricity consumption over the course of the entire test must be 
measured and used in calculation of standby loss.

 Table 3.2--Data To Be Recorded Before and During the Standby Loss Test
------------------------------------------------------------------------
                                                             Every 30
             Item recorded                Before test      seconds \1\
------------------------------------------------------------------------
Gas outlet pressure, in w.c...........               X   ...............
Fuel higher heating value, Btu/ft\3\                 X   ...............
 (gas) or Btu/lb (oil)................
Oil pump pressure, psig (oil only)....               X   ...............
CO2 reading, % (oil only).............           X \2\   ...............
Oil smoke spot reading (oil only).....           X \2\   ...............
Air draft, ft/min.....................               X   ...............
Time, minutes/seconds.................  ...............               X
Mean tank temperature, [deg]F.........  ...............               X
Ambient room temperature, [deg]F......  ...............               X
Test air temperature, [deg]F..........  ...............               X
Ambient relative humidity, %..........  ...............               X
------------------------------------------------------------------------
Notes:
\1\ These measurements are to be recorded at the start and end of the
  test, as well as every 30 seconds during the test.
\2\ The smoke spot test and CO2 reading are not required prior to
  beginning the standby loss test if no settings on the water heater
  have been changed and the water heater has not been turned off since
  the end of a previously-run efficiency test (i.e., thermal efficiency
  or standby loss).

    4. Determination of Storage Volume. Determine the storage volume 
by subtracting the tare weight--measured while the system is dry and 
empty--from the weight of the system when filled with water and 
dividing the resulting net weight of water by the density of water 
at the measured water temperature.
    5. Soak-In Period. Prior to conducting a thermal efficiency test 
or standby loss test, a soak-in period must occur, in which the 
water heater must sit without any draws taking place for at least 12 
hours. Begin the soak-in period after setting the tank thermostats 
as specified in section 3.7 of this appendix, and maintain these 
settings throughout the soak-in period. However, a soak-in period is 
not required prior to beginning an efficiency test (i.e., thermal 
efficiency or standby loss) if no settings on the water heater have 
been changed and the water heater has not been turned off since the 
end of a previously run efficiency test.
    6. Thermal Efficiency Test. Conduct the thermal efficiency test 
as specified in section j of Annex E.1 of ANSI Z21.10.3-2015 
(incorporated by reference; see Sec.  431.105), with the exception 
of the provision stipulating the data collection intervals for water 
temperatures. Follow the additional provisions in the following 
sections:
    6.1. Steady-State Conditions. Adjust the water flow rate to a 
constant value such that the following conditions are always 
satisfied during the test. Once steady-state operation is achieved, 
as determined by no variation of the outlet water temperature in 
excess of 2[emsp14][deg]F over a 3-minute period, do not change any 
settings on the water heating equipment until measurements for the 
thermal efficiency test are finished.
    6.1.1. The outlet water temperature must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature.
    6.1.2. The burner must fire continuously at full firing rate 
(i.e., no modulation or cut-outs) for the entire duration of the 
thermal efficiency test.
    6.2. Determination of Fuel Input Rate. For the thermal 
efficiency test, record the fuel consumed at 10-minute intervals. 
Calculate the fuel input rate over each 10-minute period using the 
equations in section 6.3 of this appendix. The measured fuel input 
rates for these 10-minute periods must not vary by more than  2 percent between any two readings. Determine the overall 
fuel input rate using the fuel consumption for the entire duration 
of the thermal efficiency test. Round the overall fuel input rate to 
the nearest 1,000 Btu/h.
    6.3. Fuel Input Rate Calculation. To calculate the fuel input 
rate, use the following equations:
    6.3.1. For gas-fired CWH equipment, calculate the fuel input 
rate using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.279

Where,

Q = Fuel input rate, expressed in Btu/h
Qs = Total fuel flow as metered, ft\3\

[[Page 28643]]

Cs = Correction applied to the heating value of a gas 
Hgas, when it is metered at temperature and/or pressure 
conditions other than the standard conditions for which the value of 
Hgas is based
Hgas = Higher heating value of a gas, Btu/ft\3\
t = Duration of measurement of fuel consumption
    6.3.2. For oil-fired CWH equipment, calculate the fuel input 
rate using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.280

Where,
Q = Fuel input rate, expressed in Btu/h
Qs = Total weight of fuel, lb
Hoil = Higher heating value of oil, Btu/lb
t = Duration of measurement of fuel consumption

7. Standby Loss Test

    7.1. Begin fuel flow to the main burner(s) and put the appliance 
into operation.
    7.2. After the first cut-out, allow the water heater to remain 
in standby mode. At this point, do not change any settings on the 
water heating equipment until measurements for the standby loss test 
are finished.
    7.3. At the second cut-out, record the time and ambient room 
temperature, and begin measuring the fuel and electric consumption. 
Record the initial mean tank temperature.
    7.4. The duration of the test must be until the first cut-out 
that occurs after 24 hours or 48 hours, whichever comes first.
    7.5. Immediately after conclusion of the test, record the total 
fuel flow and electrical energy consumption, the final ambient room 
temperature, the duration of the standby loss test, and the final 
mean tank temperature. Calculate the average of the recorded values 
of the mean tank temperature and of the ambient air temperatures 
taken at each measurement interval, including the initial and final 
values.
    7.6. Standby Loss Calculation. To calculate the standby loss, 
follow the steps given below:
    7.6.1. The standby loss expressed as a percentage (per hour) of 
the heat content of the stored water above room temperature must be 
calculated using the following equation for gas-fired equipment:
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And using the following equation for oil-fired equipment:
[GRAPHIC] [TIFF OMITTED] TP09MY16.282

Where,

[Delta]T3 = Average value of the mean tank temperature 
minus the average value of the ambient room temperature, expressed 
in [deg]F
[Delta]T4 = Final mean tank temperature measured at the 
end of the test minus the initial mean tank temperature measured at 
the start of the test, expressed in [deg]F
k = 8.25 Btu/gallon[middot][deg]F, the nominal specific heat of 
water
Va = Volume of water contained in the water heater in 
gallons measured in accordance with section 4 of this appendix
Et = Thermal efficiency of the water heater measured in 
accordance with this appendix, expressed in %
Ec = Electrical energy consumed by the water heater 
during the duration of the test in Btu
t = Total duration of the test in hours
Cs= Correction applied to the heating value of a gas H, 
when it is metered at temperature and/or pressure conditions other 
than the standard conditions for which the value of H is based.
Qs = Total fuel flow as metered, expressed in ft\3\ (gas) 
or lb (oil)
H = Higher heating value of fuel, expressed in Btu/ft\3\ (gas) or 
Btu/lb (oil)
S = Standby loss, the average hourly energy required to maintain the 
stored water temperature expressed as a percentage of the heat 
content of the stored water above room temperature

    7.6.2. The standby loss expressed in Btu per hour must be 
calculated as follows: SL (Btu per hour) = S (% per hour) x 8.25 
(Btu/gal-[deg]F) x Measured Volume (gal) x 70 ([deg]F).

0
13. Add appendix B to subpart G of part 431 to read as follows:

Appendix B to Subpart G of Part 431--Uniform Test Method for the 
Measurement of Standby Loss of Electric Storage Water Heaters and 
Storage-Type Instantaneous Water Heaters

    Note: Prior to (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to the energy use or 
efficiency of the subject commercial water heating equipment in 
accordance with the results of testing pursuant to this appendix or 
the procedures in 10 CFR 431.106 that were in place on January 1, 
2016. On and after (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to energy use or 
efficiency of electric storage water heaters and storage-type 
instantaneous water heaters in accordance with the results of 
testing pursuant to this appendix to demonstrate compliance with the 
energy conservation standards at 10 CFR 431.110.

1. General

    Determine the standby loss in accordance with the following 
sections of this appendix. Certain sections reference sections of 
Annex E.1 of ANSI Z21.10.3-2015 (incorporated by reference; see 
Sec.  431.105). Where the instructions contained in the sections 
below conflict with instructions in Annex E.1 of ANSI Z21.10.3-2015, 
the instructions contained herein control.

2. Test Set-Up

    2.1. Placement of Water Heater. A water heater for installation 
on combustible floors is to be placed on a \3/4\-inch plywood 
platform supported by three 2 x 4-inch runners. If the water heater 
is for installation on noncombustible floors, suitable 
noncombustible material is to be placed on the platform. When the 
use of the platform for a large water heater is not practical, the 
water heater may be placed on any suitable flooring. A wall-mounted 
water heater is to be mounted to a simulated wall section.
    2.2. Heat Trap and Thermocouple Installation. Inlet and outlet 
piping must be turned vertically downward from the connections on a 
tank-type water heater so as to form heat traps. Thermocouples for 
measuring supply and outlet water temperatures must be installed 
upstream of the inlet heat trap piping and downstream of the outlet 
heat trap, respectively, in accordance with Figure 1, 2, or 3 (as 
applicable) presented in section 2.2 of appendix A to this subpart. 
The total vertical (upward and downward) piping between the 
thermocouples sensing location and the connection port must be 24 
inches. For water heaters with vertical connections, the 24 inches 
of total vertical piping length is divided into 6 inches of vertical 
piping upstream from the turn for the heat trap and 18 inches 
downstream from the turn for the

[[Page 28644]]

heat trap. For water heaters that have vertical connections (top and 
bottom), the total horizontal piping between the connection port and 
the thermocouple sensing location must be equal to the distance 
between the water heater connection port and the edge of the water 
heater plus 2 inches. For water heaters that have horizontal 
connections, the total horizontal piping between the water heater 
connection port and the temperature sensing location, must be equal 
to 6 inches. The water heater must meet the requirements shown in 
either Figure 1, 2, or 3 (as applicable) at all times during the 
conduct of the standby loss test. Any factory-supplied heat traps 
must be installed per the installation instructions while ensuring 
the requirements in Figure 1, 2, or 3 are met. All dimensions 
specified in Figure 1, 2, and 3 and in this section are measured 
from the outer surface of the pipes and water heater outer casing 
(as applicable).
    2.3. Thermocouples for Measurement of Mean Tank Temperature. 
Install temperature-sensing means inside the tank for measurement of 
mean tank temperature according to the instructions in section f of 
Annex E.1 of ANSI Z21.10.3-2015 (incorporated by reference; see 
Sec.  431.105). Calculate the mean tank temperature as the average 
of the six installed temperature-sensing means.
    2.4. Piping Insulation. Insulate all water piping external to 
the water heater jacket, including heat traps and piping that are 
installed by the manufacturer or shipped with the unit, for at least 
4 ft of piping length from the connection at the appliance with 
material having an R-value not less than 
4[emsp14][deg]F[middot]ft\2\[middot]h/Btu. Ensure that the 
insulation does not contact any appliance surface except at the 
location where the pipe connections penetrate the appliance jacket.
    2.5. Temperature and Pressure Relief Valve Insulation. If the 
manufacturer has not provided a temperature and pressure relief 
valve, one shall be installed and insulated as specified in section 
2.4 of this appendix.
    2.6. Energy Consumption. Install equipment that determines, 
within  1 percent, the quantity of electricity consumed 
by factory-supplied water heater components, and of the test loop 
recirculating pump, if used.

3. Test Conditions

    3.1. Water Supply. Follow the following provisions regarding the 
water supply to the water heater:
    3.1.1. The pressure of the water supply must be maintained 
between 40 psi and the maximum pressure specified by the 
manufacturer of the unit being tested. If the maximum water pressure 
is not specified by the manufacturer in literature shipped with the 
unit or supplemental test report instructions included with a 
certification report, then a default maximum value of 150 psi is to 
be used. The accuracy of the pressure-measuring devices must be 
 1.0 pounds per square inch (psi).
    3.1.2. Isolate the water heater using a shutoff valve in the 
supply line with an expansion tank installed in the supply line 
downstream of the shutoff valve. There must be no shutoff means 
between the expansion tank and the appliance inlet.
    3.2. Electrical Supply. Maintain the electrical supply voltage 
to within  5 percent of the center of the voltage range 
specified on the water heater nameplate.
    3.3. Ambient Room Temperature. While setting the tank 
thermostats, between the first and second cut-outs prior to the 
standby loss test, and during the soak-in period and standby loss 
test, maintain the ambient room temperature at 75[emsp14][deg]F 
 5[emsp14][deg]F at all times. Measure the ambient room 
temperature at 30-second intervals during these periods. Measure the 
ambient room temperature at the vertical mid-point of the water 
heater and approximately 2 feet from the water heater jacket. Shield 
the sensor against radiation. Calculate the average ambient room 
temperature separately for the soak-in period and the standby loss 
test. During the soak-in period and standby loss test, the room 
temperature must not vary more than  2.0[emsp14][deg]F 
at any reading from the average ambient room temperature.
    3.4. Maximum Air Draft. During the soak-in period and standby 
loss test, the water heater must be located in an area protected 
from drafts of more than 50 ft/min from room ventilation registers, 
windows, or other external sources of air movement. Prior to 
beginning the soak-in period and standby loss test, measure the air 
draft within three feet of the jacket of the water heater to ensure 
this condition is met. Ensure that no other changes that would 
increase the air draft are made to the test set up or conditions 
during the conduct of the tests.
    3.5. Setting the Tank Thermostats. Before starting the required 
soak-in period, the thermostat setting(s) must first be obtained as 
explained in the following sections.
    3.5.1. For water heaters with a single thermostat, the 
thermostat setting must be obtained by starting with the water in 
the system at 70[emsp14][deg]F  2[emsp14][deg]F. The 
thermostat must be set so that the maximum mean tank temperature 
after cut-out is 140[emsp14][deg]F  5[emsp14][deg]F.
    3.5.2. For water heaters with multiple adjustable thermostats, 
set the topmost thermostat first to yield a maximum mean water 
temperature after cut-out of 140[emsp14][deg]F  
5[emsp14][deg]F. Immediately after setting the top thermostat, 
sequentially set the lower thermostat(s) from highest to lowest so 
that each yields a maximum mean water temperature after cut-out 
equal to 140[emsp14][deg]F  5[emsp14][deg]F. When 
setting each thermostat (with the exception of the bottommost 
thermostat), calculate the mean tank temperature using only the 
temperature readings measured at locations higher in the tank than 
the heating element corresponding to the thermostat being set. While 
setting each thermostat, all thermostats below the thermostat being 
tested must be turned off so that no elements below the thermostat 
being tested are in operation. When setting the bottommost 
thermostat, calculate the mean tank temperature using all tank 
thermocouples. After cut-out by all thermostats in the water heater, 
the maximum mean tank temperature must be 140[emsp14][deg]F  5[emsp14][deg]F.
    3.6. Data Collection Intervals. Follow the data recording 
intervals specified in the following sections.
    3.6.1. Soak-In Period. Measure the air draft, in ft/min, before 
beginning the soak-in period. Measure the ambient room temperature, 
in [deg]F, every 30 seconds during the soak-in period.
    3.6.2. Standby Loss Test. Follow the data recording intervals 
specified in Table 3.1 of this section. Additionally, the 
electricity consumption over the course of the entire test must be 
measured and used in calculation of standby loss.

 Table 3.1--Data To Be Recorded Before and During the Standby Loss Test
------------------------------------------------------------------------
                                                             Every 30
             Item recorded                Before test      seconds \1\
------------------------------------------------------------------------
Air draft, ft/min.....................               X   ...............
Time, minutes/seconds.................  ...............               X
Mean tank temperature, [deg]F.........  ...............               X
Ambient room temperature, [deg]F......  ...............               X
------------------------------------------------------------------------
Notes:
\1\ These measurements are to be recorded at the start and end of the
  test, as well as every 30 seconds during the test.

    4. Determination of Storage Volume. Determine the storage volume 
by subtracting the tare weight--measured while the system is dry and 
empty--from the weight of the system when filled with water and 
dividing the resulting net weight of water by the density of water 
at the measured water temperature.
    5. Soak-In Period. Prior to conducting a standby loss test, a 
soak-in period must occur, in which the water heater must sit 
without any draws taking place for at least 12 hours. Begin the 
soak-in period after setting the tank thermostats as specified in 
section 3.5 of this appendix, and maintain these settings throughout 
the soak-in period.

6. Standby Loss Test

    6.1. Initiate normal operation of the water heater.

[[Page 28645]]

    6.2. After the first cut-out, allow the water heater to remain 
in standby mode. At this point, do not change any settings on the 
water heating equipment until measurements for the standby loss test 
are finished.
    6.3. At the second cut-out, record the time and ambient room 
temperature, and begin measuring the electric consumption. Record 
the initial mean tank temperature.
    6.4. The duration of the test must be until the first cut-out 
that occurs after 24 hours or 48 hours, whichever comes first.
    6.5. Immediately after conclusion of the test, record the total 
electrical energy consumption, the final ambient room temperature, 
the duration of the standby loss test, and the final mean tank 
temperature. Calculate the average of the recorded values of the 
mean tank temperature and of the ambient air temperatures taken at 
each measurement interval, including the initial and final values.
    6.6. Standby Loss Calculation. To calculate the standby loss, 
follow the steps given below:
    6.6.1. The standby loss expressed as a percentage (per hour) of 
the heat content of the stored water above room temperature must be 
calculated using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.283

Where,

[Delta]T3 = Average value of the mean tank temperature 
minus the average value of the ambient room temperature, expressed 
in [deg]F
[Delta]T4 = Final mean tank temperature measured at the 
end of the test minus the initial mean tank temperature measured at 
the start of the test, expressed in [deg]F
k = 8.25 Btu/gallon[middot][deg]F, the nominal specific heat of 
water
Va = Volume of water contained in the water heater in 
gallons measured in accordance with section 4 of this appendix
Et = Thermal efficiency--assume 98 percent for electric 
water heaters with immersed heating elements
Ec = Electrical energy consumed by the water heater 
during the duration of the test in Btu
t = Total duration of the test in hours
S = Standby loss, the average hourly energy required to maintain the 
stored water temperature expressed as a percentage of the heat 
content of the stored water above room temperature

0
14. Add appendix C to subpart G of part 431 to read as follows:

Appendix C to Subpart G of Part 431--Uniform Test Method for the 
Measurement of Thermal Efficiency and Standby Loss of Gas-Fired and 
Oil-Fired Instantaneous Water Heaters and Hot Water Supply Boilers 
(Other Than Flow-Activated Instantaneous Water Heaters and Storage-Type 
Instantaneous Water Heaters)

    Note: Prior to (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to the energy use or 
efficiency of the subject commercial water heating equipment in 
accordance with the results of testing pursuant to this appendix or 
the procedures in 10 CFR 431.106 that were in place on January 1, 
2016. On and after (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to energy use or 
efficiency of gas-fired and oil-fired instantaneous water heaters 
and hot water supply boilers (other than flow-activated 
instantaneous water heaters and storage-type instantaneous water 
heaters) in accordance with the results of testing pursuant to this 
appendix to demonstrate compliance with the energy conservation 
standards at 10 CFR 431.110.

1. General

    Determine the thermal efficiency and standby loss (as 
applicable) in accordance with the following sections of this 
appendix. Certain sections reference sections of Annex E.1 of ANSI 
Z21.10.3-2015 (incorporated by reference; see Sec.  431.105). Where 
the instructions contained in the sections below conflict with 
instructions in Annex E.1 of ANSI Z21.10.3-2015, the instructions 
contained herein control.

2. Test Set-Up

    2.1. Placement of Water Heater. A water heater for installation 
on combustible floors is to be placed on a \3/4\-inch plywood 
platform supported by three 2 x 4-inch runners. If the water heater 
is for installation on noncombustible floors, suitable 
noncombustible material is to be placed on the platform. When the 
use of the platform for a large water heater is not practical, the 
water heater may be placed on any suitable flooring. A wall-mounted 
water heater is to be mounted to a simulated wall section.
    2.2. Test Configuration. Set up the instantaneous water heater 
or hot water supply boiler in accordance with Figure 4 of this 
section.

[[Page 28646]]

[GRAPHIC] [TIFF OMITTED] TP09MY16.284

    2.2.1. If the instantaneous water heater or hot water supply 
boiler does not have any external piping, install a supply water 
valve within 5 inches of the water heater jacket, and install an 
outlet water valve within 10 inches of the water heater jacket. If 
the instantaneous water heater or hot water supply boiler includes 
external piping assembled at the manufacturer's premises prior to 
shipment, install water valves in the supply and outlet piping (as 
applicable) within 5 inches of the end of the piping supplied with 
the unit.
    2.2.2. If the water heater is not able to achieve an outlet 
water temperature of 70[emsp14][deg]F  2[emsp14][deg]F 
above the supply water temperature at a constant maximum fuel input 
rate, a recirculating loop with pump as shown in Figure 4 in section 
2.2 of this appendix must be used.
    2.2.2.1. If a recirculating loop with a pump is used then ensure 
that the inlet water temperature labeled as T5 in Figure 
4 in section 2.2 of this appendix, is greater than or equal to 
70[emsp14][deg]F and less than or equal to 120[emsp14][deg]F at all 
times during the thermal efficiency test and while achieving steady-
state conditions prior to the standby loss test.
    2.3. Installation of Temperature-Sensing Means. The temperature-
sensing means must be installed in a manner such that the tip or the 
junction of the temperature sensing probe is in the water; less than 
or equal to 5 inches away from the outer casing of the equipment 
being tested; in the line of the central axis of the water pipe; and 
enclosed in a radiation protection shield. Figure 4 in section 2.2 
of this appendix shows the placement of the outlet water 
temperature-sensing instrument at a maximum distance of 5 inches 
away from the surface of the jacket of the equipment being tested. 
For water heaters with multiple outlet water connections leaving the 
water heater jacket, temperature-sensing means must be installed for 
each outlet water connection leaving the water heater in accordance 
with the provisions in this section.
    2.4. Piping Insulation. Insulate all water piping external to 
the water heater jacket, including piping that are installed by the 
manufacturer or shipped with the unit, for at least 4 ft of piping 
length from the connection at the appliance with material having an 
R-value not less than 4[emsp14][deg]F[middot]ft\2\[middot]h/Btu. 
Ensure that the insulation does not contact any appliance surface 
except at the location where the pipe connections penetrate the 
appliance jacket.
    2.5. Temperature and Pressure Relief Valve Insulation. If the 
manufacturer has not provided a temperature and pressure relief 
valve, one shall be installed and insulated as specified in section 
2.4 of this appendix.
    2.6. Vent Requirements. Follow the requirements for venting 
arrangements specified in section c of Annex E.1 of ANSI Z21.10.3-
2015 (incorporated by reference; see Sec.  431.105).
    2.7. Energy Consumption. Install equipment that determines, 
within 1 percent:
    2.7.1. The quantity and rate of fuel consumed.
    2.7.2. The quantity of electricity consumed by factory-supplied 
water heater components, and of the test loop recirculating pump, if 
used.

3. Test Conditions

    3.1. Water Supply. Follow the following provisions regarding the 
water supply to the water heater:
    3.1.1. The pressure of the water supply must be maintained 
between 40 psi and the maximum pressure specified by the 
manufacturer of the unit being tested. If the maximum water pressure 
is not specified by the manufacturer in literature shipped with the 
unit or supplemental test report instructions included with a 
certification report, then a default maximum value of 150 psi is to 
be used. The accuracy of the pressure-measuring devices must be 
1.0 pounds per square inch (psi).
    3.1.2. During conduct of the thermal efficiency test, the 
temperature of the supply water must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F.
    3.2. Gas Supply Pressure for Gas-Fired Equipment. The outlet 
pressure of the gas appliance pressure regulator must be within the 
range specified by the manufacturer. If the allowable range of gas 
supply pressure is not specified by the manufacturer in literature 
shipped with the unit or supplemental test report instructions 
included with a certification report, then the outlet pressure of 
the gas appliance regulator must be within the default range of 4.5 
inches of water column (in. w.c.) to 10.5 in. w.c. for natural gas-
powered units, or 11 in. w.c. to 13 in. w.c. for propane-powered 
units. Obtain the higher heating value of the gas burned.
    3.3. Ambient Room Temperature. While verifying steady-state 
operation (prior to the thermal efficiency test), between the first 
and second cut-outs prior to the standby loss test (as applicable), 
and during the thermal

[[Page 28647]]

efficiency and standby loss tests (as applicable), maintain the 
ambient room temperature at 75[emsp14][deg]F  
5[emsp14][deg]F at all times. Measure the ambient room temperature 
at 30-second intervals during these periods. Measure the ambient 
room temperature at the vertical mid-point of the water heater and 
approximately 2 feet from the water heater jacket. Shield the sensor 
against radiation. Calculate the average ambient room temperature 
separately for the thermal efficiency and standby loss tests (as 
applicable). The ambient room temperature must not vary by more than 
2.0[emsp14][deg]F at any reading from the average 
ambient room temperature.
    3.4. Test Air Temperature. While verifying steady-state 
operation (prior to the thermal efficiency test) and during the 
thermal efficiency and standby loss tests (as applicable), the test 
air temperature must not vary by more than 5[emsp14][deg]F from the ambient room temperature at any 
reading. Measure the test air temperature at 30-second intervals 
during these periods and at a location within two feet of the air 
inlet of the water heater. For units with multiple air inlets, 
measure the test air temperature at each air inlet, and maintain the 
specified tolerance on deviation from the ambient room temperature 
at each air inlet. For CWH equipment without a specific air inlet, 
measure the test air temperature within two feet of a location on 
the water heater where combustion air is drawn.
    3.5. Ambient Humidity. While verifying steady-state operation 
(prior to the thermal efficiency test) and during the thermal 
efficiency and standby loss tests (as applicable), maintain the 
ambient relative humidity of the test room at 60 percent 5 percent. Measure the ambient relative humidity at 30-second 
intervals during these periods. The ambient relative humidity must 
be measured at the same location as the test air temperature. For 
units with multiple air inlets, measure the ambient relative 
humidity at each air inlet, and maintain 60 percent 5 
percent relative humidity at each air inlet.
    3.6. Maximum Air Draft. During the thermal efficiency and 
standby loss tests (as applicable), the water heater must be located 
in an area protected from drafts of more than 50 ft/min from room 
ventilation registers, windows, or other external sources of air 
movement. Prior to beginning the thermal efficiency and standby loss 
tests, measure the air draft within three feet of the jacket of the 
water heater to ensure this condition is met. Ensure that no other 
changes that would increase the air draft are made to the test set 
up or conditions during the conduct of the tests.
    3.7. Setting the Thermostat. Before beginning the thermal 
efficiency or standby loss tests, the thermostat setting must first 
be obtained by starting with the water in the system at 
70[emsp14][deg]F  2[emsp14][deg]F. The thermostat must 
then be set so that the maximum outlet water temperature, after the 
thermostat reduces the fuel supply to a minimum, is 
140[emsp14][deg]F  5[emsp14][deg]F.
    3.8. Additional Conditions for Units With Multiple Water 
Connections. For units with multiple water connections leaving the 
water heater, use the following provisions:
    3.8.1. The outlet water temperature measured from each 
connection leaving the water heater, must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature, and must not differ from any other outlet water 
connection by more than 2[emsp14][deg]F during the thermal 
efficiency test.
    3.8.2. To calculate the outlet water temperature representative 
for the entire unit, calculate the average of the outlet water 
temperature measured at each connection leaving the water heater 
jacket. This average must be taken for each reading recorded by the 
data acquisition unit. The outlet water temperature obtained for 
each reading must be used for carrying out all calculations for the 
thermal efficiency and standby loss tests.

3.9. Additional Requirements for Oil-Fired Equipment.

    3.9.1. Venting Requirements. Connect a vertical length of flue 
pipe to the flue gas outlet of sufficient height so as to meet the 
minimum draft specified by the manufacturer.
    3.9.2. Oil Supply. Adjust the burner rate so that the following 
conditions are met:
    3.9.2.1. The CO2 reading is within the range 
specified by the manufacturer;
    3.9.2.2. The fuel pump pressure is within 10 percent 
of manufacturer's specifications;
    3.9.2.3. If either the fuel pump pressure or range for 
CO2 reading are not specified by the manufacturer in 
literature shipped with the unit or supplemental test report 
instructions included with a certification report, then a default 
value of 100 psig is to be used for fuel pump pressure, and a 
default range of 9-12 percent is to be used for CO2 
reading; and
    3.9.2.4. Smoke in the flue does not exceed No. 1 smoke as 
measured by the procedure in ASTM D2156-09 (incorporated by 
reference, see Sec.  431.105). To determine the smoke spot number, 
the smoke measuring device shall be connected to an open-ended tube. 
This tube must project into the flue \1/4\ to \1/2\ of the pipe 
diameter.
    3.9.2.5. For the thermal efficiency test, measure the 
CO2 reading and determine the smoke spot number after 
steady-state operation has been obtained as determined by no 
variation of outlet water temperature in excess of 2[emsp14][deg]F 
over a 3-minute period, but before beginning measurements for the 
thermal efficiency test. For the standby loss test, measure the 
CO2 reading and determine the smoke spot number after the 
first cut-out before beginning measurements for the standby loss 
test. However, measurement of the CO2 reading and conduct 
of the smoke spot test are not required prior to beginning an 
efficiency test (i.e., thermal efficiency or standby loss) if no 
settings on the water heater have been changed and the water heater 
has not been turned off since the end of a previously run efficiency 
test.
    3.10. Data Collection Intervals. Follow the data recording 
intervals specified in the following sections.
    3.10.1. Thermal Efficiency Test. Follow the data recording 
intervals specified in Table 3.1 of this section.

                  Table 3.1--Data To Be Recorded Before and During the Thermal Efficiency Test
----------------------------------------------------------------------------------------------------------------
                                                                                    Every 30         Every 10
                        Item recorded                            Before test      seconds \1\        minutes
----------------------------------------------------------------------------------------------------------------
Gas outlet pressure, in w.c..................................               X   ...............  ...............
Fuel higher heating value, Btu/ft\3\ (gas) or Btu/lb (oil)...               X   ...............  ...............
Oil pump pressure, psig (oil only)...........................               X   ...............  ...............
CO2 reading, % (oil only)....................................           X \2\   ...............  ...............
Oil smoke spot reading (oil only)............................           X \2\   ...............  ...............
Air draft, ft/min............................................               X   ...............  ...............
Time, minutes/seconds........................................  ...............               X   ...............
Fuel weight or volume, lb (oil) or ft\3\ (gas)...............  ...............  ...............           X \3\
Supply water temperature, [deg]F.............................  ...............               X   ...............
Outlet water temperature, [deg]F.............................  ...............               X   ...............
Ambient room temperature, [deg]F.............................  ...............               X   ...............
Test air temperature, [deg]F.................................  ...............               X   ...............
Ambient relative humidity, %.................................  ...............               X   ...............
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ These measurements are to be recorded at the start and end of the test, as well as every 30 seconds during
  the test.
\2\ The smoke spot test and CO2 reading are not required prior to beginning the thermal efficiency test if no
  settings on the water heater have been changed and the water heater has not been turned off since the end of a
  previously-run efficiency test (i.e., thermal efficiency or standby loss).
\3\ Fuel and electricity consumption over the course of the entire test must be measured and used in calculation
  of thermal efficiency.


[[Page 28648]]

    3.10.2. Standby Loss Test. Follow the data recording intervals 
specified in Table 3.2 of this section. Additionally, the fuel and 
electricity consumption over the course of the entire test must be 
measured and used in calculation of standby loss.

 Table 3.2--Data To Be Recorded Before and During the Standby Loss Test
------------------------------------------------------------------------
                                                             Every 30
             Item recorded                Before test      seconds \1\
------------------------------------------------------------------------
Gas outlet pressure, in w.c...........               X   ...............
Fuel higher heating value, Btu/ft\3\                 X   ...............
 (gas) or Btu/lb (oil)................
Oil pump pressure, psig (oil only)....               X   ...............
CO2 reading, % (oil only).............           X \2\   ...............
Oil smoke spot reading (oil only).....           X \2\   ...............
Air draft, ft/min.....................               X   ...............
Time, minutes/seconds.................  ...............               X
Outlet water temperature, [deg]F......  ...............               X
Ambient room temperature, [deg]F......  ...............               X
Test air temperature, [deg]F..........  ...............               X
Ambient relative humidity, %..........  ...............               X
------------------------------------------------------------------------
Notes:
\1\ These measurements are to be recorded at the start and end of the
  test, as well as every 30 seconds during the test.
\2\ The smoke spot test and CO2 reading are not required prior to
  beginning the thermal efficiency test if no settings on the water
  heater have been changed and the water heater has not been turned off
  since the end of a previously-run efficiency test (i.e., thermal
  efficiency or standby loss).

    4. Determination of Storage Volume. Determine the storage volume 
by subtracting the tare weight--measured while the system is dry and 
empty--from the weight of the system when filled with water and 
dividing the resulting net weight of water by the density of water 
at the measured water temperature.
    5. Thermal Efficiency Test. Conduct the thermal efficiency test 
as specified in section j of Annex E.1 of ANSI Z21.10.3-2015 
(incorporated by reference; see Sec.  431.105), with the exception 
of the provision stipulating the data collection intervals for water 
temperatures. Follow the additional provisions in the following 
sections:
    5.1. Steady-State Conditions. Adjust the water flow rate to a 
constant value such that the following conditions are always 
satisfied during the test. Once steady-state operation is achieved, 
as determined by no variation of the outlet water temperature in 
excess of 2[emsp14][deg]F over a 3-minute period, do not change any 
settings on the water heating equipment until measurements for the 
thermal efficiency test are finished.
    5.1.1. The outlet water temperature must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature.
    5.1.2. The burner must fire continuously at full firing rate 
(i.e., no modulation or cut-outs) for the entire duration of the 
thermal efficiency test.
    5.2. Determination of Fuel Input Rate. For the thermal 
efficiency test, record the fuel consumption at 10-minute intervals. 
Calculate the fuel input rate for each 10-minute period using the 
equations in section 5.3 of this appendix. The measured fuel input 
rates for these 10-minute periods must not vary by more than  2 percent between any two readings. Determine the overall 
fuel input rate using the fuel consumption for the entire duration 
of the thermal efficiency test. Round the overall fuel input rate to 
the nearest 1,000 Btu/h.
    5.3. Fuel Input Rate Calculation. To calculate the fuel input 
rate, use the following equations:
    5.3.1. For gas-fired CWH equipment, calculate the fuel input 
rate using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.285

Where,

Q = Fuel input rate, expressed in Btu/h
Qs = Total fuel flow as metered, ft\3\
Cs = Correction applied to the heating value of a gas 
Hgas, when it is metered at temperature and/or pressure 
conditions other than the standard conditions for which the value of 
Hgas is based
Hgas = Higher heating value of a gas, Btu/ft\3\
t = Duration of measurement of fuel consumption

    5.3.2. For oil-fired CWH equipment, calculate the fuel input 
rate using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.286

Where,

Q = Fuel input rate, expressed in Btu/h
Qs = Total weight of fuel, lb
Hoil = Higher heating value of oil, Btu/lb
t = Duration of measurement of fuel consumption

6. Standby Loss Test

    6.1. Begin fuel flow to the main burner(s) and put the appliance 
into operation. Prior to beginning the standby loss test, the outlet 
water temperature must become constant, as indicated by no variation 
in excess of 2[emsp14][deg]F over a 3-minute period, unless no 
settings on the water heater were changed and the water heater has 
not been turned off since the completion of the thermal efficiency 
test.
    6.2. After ensuring the outlet water temperature is constant or 
if no settings on the water heater have been changed and the water 
heater has not been turned off since completion of the thermal 
efficiency test, turn off the supply water valve(s), the outlet 
water valve(s) (installed as per the provisions in section 2.2 of 
this appendix), and the water pump simultaneously and ensure that 
there is no flow of water through the water heater.
    6.3. After the first cut-out, allow the water heater to remain 
in standby mode. At this point, do not change any settings on the 
water heating equipment until measurements for the standby loss test 
are finished.
    6.4. At the second cut-out, record the time and ambient room 
temperature, and begin measuring the fuel and electric consumption. 
Record the initial outlet water temperature.
    6.5. The duration of the test must be until the first cut-out 
that occurs after 24 hours or 48 hours, whichever comes first.
    6.6. Immediately after conclusion of the test, record the total 
fuel flow and electrical energy consumption, the final ambient room 
temperature, the duration of the standby loss test, and the final 
outlet water temperature. Calculate the average of the recorded 
values of the outlet water temperature and of the ambient air 
temperatures taken at each measurement interval, including the 
initial and final values.
    6.7. Standby Loss Calculation. To calculate the standby loss, 
follow the steps given below:
    6.7.1. The standby loss expressed as a percentage (per hour) of 
the heat content of the stored water above room temperature must be 
calculated using the following equation for gas-fired equipment:

[[Page 28649]]

[GRAPHIC] [TIFF OMITTED] TP09MY16.287

    And using the following equation for oil-fired equipment:
    [GRAPHIC] [TIFF OMITTED] TP09MY16.288
    
Where,

[Delta]T3 = Average value of the outlet water temperature 
minus the average value of the ambient room temperature, expressed 
in [deg]F
[Delta]T4 = Final outlet water temperature measured at 
the end of the test minus the initial outlet water temperature 
measured at the start of the test, expressed in [deg]F
k = 8.25 Btu/gallon[middot][deg]F, the nominal specific heat of 
water
Va = Volume of water contained in the water heater in 
gallons measured in accordance with section 4 of this appendix
Et = Thermal efficiency of the water heater measured in 
accordance with this appendix, expressed in %
Ec = Electrical energy consumed by the water heater 
during the duration of the test in Btu
t = Total duration of the test in hours
Cs = Correction applied to the heating value of a gas H, 
when it is metered at temperature and/or pressure conditions other 
than the standard conditions for which the value of H is based.
Qs = Total fuel flow as metered, expressed in ft\3\ (gas) 
or lb (oil)
H = Higher heating value of gas or oil, expressed in Btu/ft\3\ (gas) 
or Btu/lb (oil)
S = Standby loss, the average hourly energy required to maintain the 
stored water temperature expressed as a percentage of the heat 
content of the stored water above room temperature

    6.7.2. The standby loss expressed in Btu per hour must be 
calculated as follows: SL (Btu per hour) = S (% per hour) x 8.25 
(Btu/gal-[deg]F) x Measured Volume (gal) x 70 ([deg]F).

0
15. Add appendix D to subpart G of part 431 to read as follows:

Appendix D to Subpart G of Part 431--Uniform Test Method for the 
Measurement of Standby Loss of Electric Instantaneous Water Heaters 
(Other Than Flow-Activated Instantaneous Water Heaters and Storage-Type 
Instantaneous Water Heaters)

    Note:  Prior to (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to the energy use or 
efficiency of the subject commercial water heating equipment in 
accordance with the results of testing pursuant to this appendix or 
the procedures in 10 CFR 431.106 that were in place on January 1, 
2016. On and after (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to energy use or 
efficiency of electric instantaneous water heaters (other than flow-
activated instantaneous water heaters and storage-type instantaneous 
water heaters) in accordance with the results of testing pursuant to 
this appendix to demonstrate compliance with the energy conservation 
standards at 10 CFR 431.110.

1. General

    Determine the standby loss (as applicable) in accordance with 
the following sections of this appendix. Certain sections reference 
sections of Annex E.1 of ANSI Z21.10.3-2015 (incorporated by 
reference; see Sec.  431.105). Where the instructions contained in 
the sections below conflict with instructions in Annex E.1 of ANSI 
Z21.10.3-2015, the instructions contained herein control.

2. Test Set-Up

    2.1. Placement of Water Heater. A water heater for installation 
on combustible floors is to be placed on a \3/4\-inch plywood 
platform supported by three 2 x 4-inch runners. If the water heater 
is for installation on noncombustible floors, suitable 
noncombustible material is to be placed on the platform. When the 
use of the platform for a large water heater is not practical, the 
water heater may be placed on any suitable flooring. A wall-mounted 
water heater is to be mounted to a simulated wall section.
    2.2. Test Configuration. Set up the water heater in accordance 
with Figure 4 in section 2.2 of appendix C to this subpart.
    2.2.1. If the instantaneous water heater or hot water supply 
boiler does not have any external piping, install a supply water 
valve within 5 inches of the water heater jacket, and install an 
outlet water valve within 10 inches of the water heater jacket. If 
the instantaneous water heater or hot water supply boiler includes 
external piping assembled at the manufacturer's premises prior to 
shipment, install water valves in the supply and outlet piping (as 
applicable) within 5 inches of the end of the piping supplied with 
the unit.
    2.2.2. If the water heater is not able to achieve an outlet 
water temperature of 70[emsp14][deg]F  2[emsp14][deg]F 
above the supply water temperature at a constant maximum fuel (or 
electricity) input rate, a recirculating loop with pump as shown in 
Figure 4 in section 2.2 of appendix C to this subpart must be used.
    2.2.2.1. If a recirculating loop with a pump is used then ensure 
that the inlet water temperature labeled as T5 in Figure 
4 in section 2.2 of appendix C to this subpart, is greater than or 
equal to 70[emsp14][deg]F and less than or equal to 
120[emsp14][deg]F at all times while achieving steady-state 
conditions prior to the standby loss test.
    2.3. Installation of Temperature-Sensing Means. The temperature-
sensing means must be installed in a manner such that the tip or the 
junction of the temperature sensing probe is in the water; less than 
or equal to 5 inches away from the outer casing of the equipment 
being tested; in the line of the central axis of the water pipe; and 
enclosed in a radiation protection shield. Figure 4 in section 2.2 
of appendix C to this subpart shows the placement of the outlet 
water temperature-sensing instrument at a maximum distance of 5 
inches away from the surface of the jacket of the equipment being 
tested. For water heaters with multiple outlet water connections 
leaving the water heater jacket, temperature-sensing means must be 
installed for each outlet water connection leaving the water heater 
in accordance with the provisions in this section.
    2.4. Piping Insulation. Insulate all the water piping external 
to the water heater jacket, including piping that are installed by 
the manufacturer or shipped with the unit, for at least 4 ft of 
piping length from the connection at the appliance with material 
having an R-value not less than 
4[emsp14][deg]F[middot]f\t2\[middot]h/Btu. Ensure that the 
insulation does not contact any appliance surface except at the 
location where the pipe connections penetrate the appliance jacket.
    2.5. Temperature and Pressure Relief Valve Insulation. If the 
manufacturer has not provided a temperature and pressure relief 
valve, one shall be installed and insulated as specified in section 
2.4 of this appendix.
    2.6. Energy Consumption. Install equipment that determines, 
within  1 percent, the quantity of electricity consumed 
by factory-supplied water heater components, and of the test loop 
recirculating pump, if used.

[[Page 28650]]

3. Test Conditions

    3.1. Water Supply. Follow the following provisions regarding the 
water supply to the water heater:
    3.1.1. The pressure of the water supply must be maintained 
between 40 psi and the maximum pressure specified by the 
manufacturer of the unit being tested. If the maximum water pressure 
is not specified by the manufacturer in literature shipped with the 
unit or supplemental test report instructions included with a 
certification report, then a default maximum value of 150 psi is to 
be used. The accuracy of the pressure-measuring devices must be 
 1.0 pounds per square inch (psi).
    3.2. Electrical Supply. Maintain the electrical supply voltage 
to within  5 percent of the center of the voltage range 
specified on the water heater nameplate.
    3.3. Ambient Room Temperature. Between the first and second cut-
outs prior to the standby loss test and during the standby loss 
test, maintain the ambient room temperature at 75[emsp14][deg]F 
 5[emsp14][deg]F at all times. Measure the ambient room 
temperature at 30-second intervals during these periods. Measure the 
ambient room temperature at the vertical mid-point of the water 
heater and approximately 2 feet from the water heater jacket. Shield 
the sensor against radiation. Calculate the average ambient room 
temperature for the standby loss test. The ambient room temperature 
must not vary more than  2.0[emsp14][deg]F at any 
reading from the average ambient room temperature.
    3.4. Maximum Air Draft. During the standby loss test, the water 
heater must be located in an area protected from drafts of more than 
50 ft/min from room ventilation registers, windows, or other 
external sources of air movement. Prior to beginning the standby 
loss test, measure the air draft within three feet of the jacket of 
the water heater to ensure this condition is met. Ensure that no 
other changes that would increase the air draft are made to the test 
set up or conditions during the conduct of the tests.
    3.5. Setting the thermostat. Before beginning the standby loss 
test, the thermostat setting must first be obtained by starting with 
the water in the system at 70[emsp14][deg]F  
2[emsp14][deg]F. While setting the thermostat, ensure that all 
heating elements are constantly operating. The thermostat must then 
be set so that the maximum outlet water temperature after cut-out is 
140[emsp14][deg]F  5[emsp14][deg]F.
    3.6. Additional Conditions for Units with Multiple Outlet Water 
Connections. For units with multiple outlet water connections 
leaving the water heater, use the following provisions:
    3.6.1. The outlet water temperature measured from each 
connection leaving the water heater prior to conducting the standby 
loss test must be maintained at 70[emsp14][deg]F  
2[emsp14][deg]F above the supply water temperature, and must not 
differ from any other outlet water connection by more than 
2[emsp14][deg]F prior to starting the standby loss test.
    3.6.2. To calculate the outlet water temperature representative 
for the entire unit, calculate the average of the outlet water 
temperature measured at each connection leaving the water heater 
jacket. This average must be taken for each reading recorded by the 
data acquisition unit. The outlet water temperature obtained for 
each reading must be used for carrying out all calculations for the 
standby loss test.
    3.7. Data Collection Intervals. During the standby loss test, 
follow the data recording intervals specified in Table 3.1 of this 
section. Also, the electricity consumption over the course of the 
entire test must be measured and used in calculation of standby 
loss.

 Table 3.1--Data To Be Recorded Before and During the Standby Loss Test
------------------------------------------------------------------------
                                                             Every 30
             Item recorded                Before test      seconds \1\
------------------------------------------------------------------------
Air draft, ft/min.....................               X   ...............
Time, minutes/seconds.................  ...............               X
Outlet water temperature, [deg]F......  ...............               X
Ambient room temperature, [deg]F......  ...............               X
------------------------------------------------------------------------
Note:
\1\ These measurements are to be recorded at the start and end of the
  test, as well as every 30 seconds during the test.

    4. Determination of Storage Volume. Determine the storage volume 
by subtracting the tare weight--measured while the system is dry and 
empty--from the weight of the system when filled with water and 
dividing the resulting net weight of water by the density of water 
at the measured water temperature.

5. Standby Loss Test

    5.1. Initiate normal operation of the water heater. Prior to 
beginning the standby loss test, the outlet water temperature must 
become constant, as indicated by no variation in excess of 
2[emsp14][deg]F over a 3-minute period.
    5.2. After ensuring the outlet water temperature is constant, 
turn off the supply water valve(s), the outlet water valve(s) 
(installed as per the provisions in section 2.2 of this appendix), 
and the water pump simultaneously and ensure that there is no flow 
of water through the water heater.
    5.3. After the first cut-out, allow the water heater to remain 
in standby mode. At this point, do not change any settings on the 
water heating equipment until measurements for the standby loss test 
are finished.
    5.4. At the second cut-out, record the time and ambient room 
temperature, and begin measuring the electric consumption. Record 
the initial outlet water temperature.
    5.5. The duration of the test must be until the first cut-out 
that occurs after 24 hours or 48 hours, whichever comes first.
    5.6. Immediately after conclusion of the test, record the total 
electrical energy consumption, the final ambient room temperature, 
the duration of the standby loss test, and the final outlet water 
temperature. Calculate the average of the recorded values of the 
outlet water temperature and of the ambient air temperatures taken 
at each measurement interval, including the initial and final 
values.
    5.7. Standby Loss Calculation. To calculate the standby loss, 
follow the steps given below:
    5.7.1. The standby loss expressed as a percentage (per hour) of 
the heat content of the stored water above room temperature must be 
calculated using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.289

Where,
[Delta]T3 = Average value of the outlet water temperature 
minus the average value of the ambient room temperature, expressed 
in [deg]F
[Delta]T4 = Final outlet water temperature measured at 
the end of the test minus the initial outlet water temperature 
measured at the start of the test, expressed in [deg]F
k = 8.25 Btu/gallon[middot][deg]F, the nominal specific heat of 
water
Va = Volume of water contained in the water heater in 
gallons measured in accordance with section 4 of this appendix
Et = Thermal efficiency--assume 98 percent for electric 
water heaters with immersed heating elements
Ec = Electrical energy consumed by the water heater 
during the duration of the test in Btu
t = Total duration of the test in hours
S = Standby loss, the average hourly energy required to maintain the 
stored water temperature expressed as a percentage of the heat 
content of the stored water above room temperature

    16. Add appendix E to subpart G of part 431 to read as follows:

[[Page 28651]]

Appendix E to Subpart G of Part 431--Uniform Test Method for the 
Measurement of Thermal Efficiency and Standby Loss of Flow-Activated 
Instantaneous Water Heaters

    Note: Prior to (date 360 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to the energy use or 
efficiency of the subject commercial water heating equipment in 
accordance with the results of testing pursuant to this appendix or 
the procedures in 10 CFR 431.106 that were in place on January 1, 
2016. On and after (date 30 days after date of publication of the 
test procedure final rule in the Federal Register), manufacturers 
must make any representations with respect to energy use or 
efficiency of flow-activated instantaneous water heaters in 
accordance with the results of testing pursuant to this appendix to 
demonstrate compliance with the energy conservation standards at 10 
CFR 431.110.

1. General

    Determine the thermal efficiency and standby loss (as 
applicable) in accordance with the following sections of this 
appendix. Certain sections reference sections of Annex E.1 of ANSI 
Z21.10.3-2015 (incorporated by reference; see Sec.  431.105). Where 
the instructions contained in the sections below conflict with 
instructions in Annex E.1 of ANSI Z21.10.3-2015, the instructions 
contained herein control.

2. Test Set-Up

    2.1. Placement of Water Heater. Place a water heater for 
installation on combustible floors on a \3/4\-inch plywood platform 
supported by three 2 x 4-inch runners. If the water heater is for 
installation on noncombustible floors, place suitable noncombustible 
material on the platform. When the use of the platform for a large 
water heater is not practical, the water heater may be placed on any 
suitable flooring. Mount a wall-mounted water heater to a simulated 
wall section.
    2.2. Test Configuration. Set up the instantaneous water heater 
in accordance with Figure 4 in section 2.2 of appendix C to this 
subpart.
    2.2.1. If the instantaneous water heater does not have any 
external piping, install a supply water valve within 5 inches of the 
water heater jacket, and install an outlet water valve within 10 
inches of the water heater jacket. If the instantaneous water heater 
or hot water supply boiler includes external piping assembled at the 
manufacturer's premises prior to shipment, install water valves in 
the supply and outlet piping (as applicable) within 5 inches of the 
end of the piping supplied with the unit.
    2.2.2. If the water heater is not able to achieve an outlet 
water temperature of 70[emsp14][deg]F  2[emsp14][deg]F 
above the supply water temperature at a constant maximum fuel input 
rate, a recirculating loop with pump as shown in Figure 4 in 
appendix C to this subpart must be used for conducting the tests.
    2.2.2.1. If a recirculating loop with a pump is used then ensure 
that the inlet water temperature labeled as T5 in Figure 
4 in section 2.2 of appendix C to this subpart, is greater than or 
equal to 70[emsp14][deg]F and less than or equal to 
120[emsp14][deg]F at all times during the thermal efficiency test 
and while achieving steady-state conditions prior to the standby 
loss test.
    2.3. Installation of Temperature-Sensing Means. The temperature-
sensing means must be installed in a manner such that the tip or the 
junction of the temperature sensing probe is in the water; less than 
or equal to 5 inches away from the outer casing of the equipment 
being tested; in the line of the central axis of the water pipe; and 
enclosed in a radiation protection shield. Figure 4 in section 2.2 
of appendix C to this subpart shows the placement of the outlet 
water temperature-sensing instrument at a maximum distance of 5 
inches away from the surface of the jacket of the equipment being 
tested. For water heaters with multiple outlet water connections 
leaving the water heater jacket, temperature-sensing means must be 
installed for each outlet water connection leaving the water heater 
in accordance with the provisions in this section.
    2.4. Piping Insulation. Insulate all water piping external to 
the water heater jacket, including piping that are installed by the 
manufacturer or shipped with the unit, for at least 4 ft of piping 
length from the connection at the appliance with material having an 
R-value not less than 4[emsp14][deg]F[middot]ft\2\[middot]h/Btu. 
Ensure that the insulation does not contact any appliance surface 
except at the location where the pipe connections penetrate the 
appliance jacket.
    2.5. Temperature and Pressure Relief Valve Insulation. If the 
manufacturer has not provided a temperature and pressure relief 
valve, one shall be installed and insulated as specified in section 
2.4 of this appendix.
    2.6. Vent Requirements. Follow the requirements for venting 
arrangements specified in section c of Annex E.1 of ANSI Z21.10.3-
2015 (incorporated by reference; see Sec.  431.105).
    2.7. Energy Consumption. Install equipment that determines, 
within  1 percent:
    2.7.1. The quantity and rate of fuel consumed (for gas-fired and 
oil-fired equipment).
    2.7.2. The quantity of electricity consumed by factory-supplied 
water heater components, and of the test loop recirculating pump, if 
used.

3. Test Conditions

    3.1. Water Supply. Follow the following provisions regarding the 
water supply to the water heater:
    3.1.1. The pressure of the water supply must be maintained 
between 40 psi and the maximum pressure specified by the 
manufacturer of the unit being tested. If the maximum water pressure 
is not specified by the manufacturer in literature shipped with the 
unit or supplemental test report instructions included with a 
certification report, then a default maximum value of 150 psi is to 
be used. The accuracy of the pressure-measuring devices must be 
 1.0 pounds per square inch (psi).
    3.1.2. During conduct of the thermal efficiency test, the 
temperature of the supply water must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F.
    3.2. Gas Supply Pressure for Gas-Fired Equipment. The outlet 
pressure of the gas appliance pressure regulator must be within the 
range specified by the manufacturer. If the allowable range of gas 
supply pressure is not specified by the manufacturer in literature 
shipped with the unit or supplemental test report instructions 
included with a certification report, then the outlet pressure of 
the gas appliance regulator must be within the default range of 4.5 
inches water column (in. w.c.) to 10.5 in w.c. for natural gas-
powered units or 11 in. w.c. to 13 in. w.c. for propane-powered 
units. Obtain the higher heating value of the gas burned.
    3.3. Ambient Room Temperature. While verifying steady-state 
operation (prior to the thermal efficiency test) and during the 
thermal efficiency test and standby loss tests (as applicable), 
maintain the ambient room temperature at 75[emsp14][deg]F  5[emsp14][deg]F at all times. Measure the ambient room 
temperature at 30-second intervals during these periods. Measure the 
ambient room temperature at the vertical mid-point of the water 
heater and approximately 2 feet from the water heater jacket. Shield 
the sensor against radiation. Calculate the average ambient room 
temperature separately for the thermal efficiency and standby loss 
tests (as applicable). The ambient room temperature must not vary 
more than 2.0[emsp14][deg]F at any reading from the 
average ambient room temperature.
    3.4. Test Air Temperature. While verifying steady-state 
operation (prior to the thermal efficiency test) and during the 
thermal efficiency test, the test air temperature must not vary by 
more than 5[emsp14][deg]F from the ambient room 
temperature at any reading. Measure the test air temperature at 30-
second intervals during these periods and at a location within two 
feet of the air inlet of the water heater. For units with multiple 
air inlets, measure the test air temperature at each air inlet, and 
maintain the specified tolerance on deviation from the ambient room 
temperature at each air inlet. For CWH equipment without a specific 
air inlet, measure the test air temperature within two feet of a 
location on the water heater where combustion air is drawn.
    3.5. Ambient Humidity. While verifying steady-state operation 
(prior to the thermal efficiency test) and during the thermal 
efficiency test, maintain the ambient relative humidity of the test 
room at 60 percent 5 percent during these periods. 
Measure the ambient relative humidity at 30-second intervals during 
conduct of the test(s). The ambient relative humidity must be 
measured at the same location as the test air temperature. For units 
that have multiple air inlets, measure the ambient relative humidity 
at each air inlet, and maintain 60 percent  5 percent 
relative humidity at each air inlet.
    3.6. Maximum Air Draft. During the thermal efficiency and 
standby loss tests (as applicable), the water heater must be located 
in an area protected from drafts of more than 50 ft/min from room 
ventilation registers, windows, or other external sources of air

[[Page 28652]]

movement. Prior to beginning the thermal efficiency and standby loss 
tests (as applicable), measure the air draft within three feet of 
the jacket of the water heater to ensure this condition is met. 
Ensure that no other changes that would increase the air draft are 
made to the test set up or conditions during the conduct of the 
tests.
    3.7. Additional Conditions for Units With Multiple Outlet Water 
Connections. For units with multiple outlet water connections 
leaving the water heater, use the following provisions:
    3.7.1. The outlet water temperature measured from each 
connection leaving the water heater must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature and must not differ from any other outlet water 
connection by more than 2[emsp14][deg]F during the thermal 
efficiency test.
    3.7.2. To calculate the outlet water temperature representative 
for the entire unit, calculate the average of the outlet water 
temperature measured at each connection leaving the water heater 
jacket. This average must be taken for each reading recorded by the 
data acquisition unit. The outlet water temperature obtained for 
each reading must be used for carrying out all calculations for the 
thermal efficiency and standby loss tests.

3.8. Additional Requirements for Oil-Fired Equipment.

    3.8.1. Venting Requirements. Connect a vertical length of flue 
pipe to the flue gas outlet of sufficient height so as to meet the 
minimum draft specified by the manufacturer.
    3.8.2. Oil Supply. Adjust the burner rate so that the following 
conditions are met:
    3.8.2.1. The CO2 reading is within the range 
specified by the manufacturer;
    3.8.2.2. The fuel pump pressure is within 10 percent 
of manufacturer's specifications;
    3.8.2.3. If either the fuel pump pressure or range for 
CO2 reading are not specified by the manufacturer in 
literature shipped with the unit or supplemental test report 
instructions included with a certification report, then a default 
value of 100 psig is to be used for fuel pump pressure, and a 
default range of 9-12 percent is to be used for CO2 
reading; and
    3.8.2.4. Smoke in the flue does not exceed No. 1 smoke as 
measured by the procedure in ASTM D2156-09 (incorporated by 
reference, see Sec.  431.105). To determine the smoke spot number, 
the smoke measuring device shall be connected to an open-ended tube. 
This tube must project into the flue \1/4\ to \1/2\ of the pipe 
diameter.
    3.8.2.5. For the thermal efficiency test, measure the 
CO2 reading and determine the smoke spot number after 
steady-state operation has been obtained as determined by no 
variation of outlet water temperature in excess of 2[emsp14][deg]F 
over a 3-minute period, but before beginning measurements for the 
thermal efficiency test. However, measurement of the CO2 
reading and conduct of the smoke spot test are not required prior to 
beginning the thermal efficiency test if no settings on the water 
heater have been changed and the water heater has not been turned 
off since the end of a previously run thermal efficiency test.
    3.9. Data Collection Intervals. Follow the data recording 
intervals specified in the following sections.
    3.9.1. Thermal Efficiency Test. Follow the data recording 
intervals specified in Table 3.1 for gas-fired and oil-fired CWH 
equipment.

                  Table 3.1--Data To Be Recorded Before and During the Thermal Efficiency Test
----------------------------------------------------------------------------------------------------------------
                                                                                    Every 30         Every 10
                        Item recorded                            Before test      seconds \1\        minutes
----------------------------------------------------------------------------------------------------------------
Gas outlet pressure, in w.c..................................               X   ...............  ...............
Fuel higher heating value, Btu/ft\3\ (gas) or Btu/lb (oil)...               X   ...............  ...............
Oil pump pressure, psig (oil only)...........................               X   ...............  ...............
CO2 reading, % (oil only)....................................           X \2\   ...............  ...............
Oil smoke spot reading (oil only)............................           X \2\   ...............  ...............
Air draft, ft/min............................................               X   ...............  ...............
Time, minutes/seconds........................................  ...............               X   ...............
Fuel weight or volume, lb (oil) or ft\3\ (gas)...............  ...............  ...............           X \3\
Supply water temperature, [deg]F.............................  ...............               X   ...............
Outlet water temperature, [deg]F.............................  ...............               X   ...............
Ambient room temperature, [deg]F.............................  ...............               X   ...............
Test air temperature, [deg]F.................................  ...............               X   ...............
Ambient relative humidity, %.................................  ...............               X   ...............
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ These measurements are to be recorded at the start and end of the test, as well as every 30 seconds during
  the test.
\2\ The smoke spot test and CO2 reading are not required prior to beginning the thermal efficiency test if no
  settings on the water heater have been changed and the water heater has not been turned off since the end of a
  previously-run thermal efficiency test.
\3\ Fuel and electricity consumption over the course of the entire test must be measured and used in calculation
  of thermal efficiency.

    3.9.2. Standby Loss Test. Follow the data recording intervals 
specified in Table 3.2 of this section. Additionally, the fuel and 
electricity consumption must be measured over the course of the 
entire test and used in calculation of standby loss.

 Table 3.2--Data To Be Recorded Before and During the Standby Loss Test
------------------------------------------------------------------------
                                                             Every 30
             Item recorded                Before test      seconds \1\
------------------------------------------------------------------------
Air draft, ft/min.....................               X   ...............
Time, minutes/seconds.................  ...............               X
Outlet water temperature, [deg]F......  ...............               X
Ambient room temperature, [deg]F......  ...............               X
------------------------------------------------------------------------
Note:
\1\ These measurements are to be recorded at the start and end of the
  test, as well as every 30 seconds during the test.

    4. Determination of Storage Volume. Determine the storage volume 
by subtracting the tare weight--measured while the system is dry and 
empty--from the weight of the system when filled with water and 
dividing the resulting net weight of water by the density of water 
at the measured water temperature.
    5. Thermal Efficiency Test. For gas-fired and oil-fired CWH 
equipment, conduct the thermal efficiency test as specified in 
section j of Annex E.1 of ANSI Z21.10.3-2015 (incorporated by 
reference; see Sec.  431.105), with the exception of the provision 
stipulating the data collection intervals for water temperatures. 
Additionally, follow the provisions in the following sections:

[[Page 28653]]

    5.1. Steady-State Conditions. Adjust the water flow rate to a 
constant value such that the following conditions are always 
satisfied during the test. Once steady-state operation is achieved, 
as determined by no variation of the outlet water temperature in 
excess of 2[emsp14][deg]F over a 3-minute period, do not change any 
settings on the water heating equipment until measurements for the 
thermal efficiency test are finished.
    5.1.1. The outlet water temperature must be maintained at 
70[emsp14][deg]F  2[emsp14][deg]F above the supply water 
temperature.
    5.1.2. The burner must fire continuously at full firing rate 
(i.e., no modulation or cut-outs) for the entire duration of the 
thermal efficiency test.
    5.2. Determination of Fuel Input Rate. For the thermal 
efficiency test, record the fuel consumption at 10-minute intervals. 
Calculate the fuel input rate for each 10-minute period using the 
equations in section 5.3 of this appendix. The measured fuel input 
rates for these 10-minute periods must not vary by more than 2 percent between any two readings. Determine the overall fuel 
input rate using the fuel consumption for the entire duration of the 
thermal efficiency test. Round the overall fuel input rate to the 
nearest 1,000 Btu/h.
    5.3. Fuel Input Rate Calculation. To calculate the fuel input 
rate, use the following equations:
    5.3.1. For gas-fired CWH equipment, calculate the fuel input 
rate using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.290

Where,

Q = Fuel input rate, expressed in Btu/h
Qs = Total fuel flow as metered, ft\3\
Cs = Correction applied to the heating value of a gas 
Hgas, when it is metered at temperature and/or pressure 
conditions other than the standard conditions for which the value of 
Hgas is based
Hgas = Higher heating value of a gas, Btu/ft\3\
t = Duration of measurement of fuel consumption

    5.3.2. For oil-fired CWH equipment, calculate the fuel input 
rate using the following equation:
[GRAPHIC] [TIFF OMITTED] TP09MY16.291

Where,

Q = Fuel input rate, expressed in Btu/h
Qs = Total weight of fuel, lb
Hoil = Higher heating value of a gas, Btu/lb
t = Duration of measurement of fuel consumption

6. Standby Loss Test

    6.1. Initiate normal operation of the water heater. Prior to 
beginning the standby loss test, unless no settings on the water 
heater were changed and the water heater has not been turned off 
since the completion of the thermal efficiency test, achieve steady-
state conditions for the outlet water temperature using the 
following provisions: set the supply water temperature to 
70[emsp14][deg]F  2[emsp14][deg]F. Adjust the water flow 
rate to attain an outlet water temperature of 70[emsp14][deg]F 
 2[emsp14][deg]F above the supply water temperature. 
Once the outlet water temperature is achieved, maintain the flow 
rate such to ensure that the outlet water temperature does not vary 
in excess of 2[emsp14][deg]F over a 3-minute period.
    6.2. After ensuring the outlet water temperature is constant or 
if no settings on the water heater have been changed and the water 
heater has not been turned off since completion of the thermal 
efficiency test, turn off the supply water valve(s) and the outlet 
water valve(s) (installed as per the provisions in section 2.2 of 
this appendix), and the water pump simultaneously and ensure that 
there is no flow of water through the water heater. Allow the water 
heater to cut out. After the burner or heating element cuts out, 
start recording the measurements for the standby loss test.
    6.3. At this time, record the time as t = 0 and record the 
initial outlet water temperature, ambient room temperature, and fuel 
and electricity meter readings. Continue to monitor and record the 
outlet water temperature, the time elapsed from the start of the 
test, and the electricity consumption at 30-second intervals using a 
data acquisition system.
    6.4. Stop the test when one of the following occurs:
    (1) The outlet water temperature decreases by 35[emsp14][deg]F 
from the initial outlet temperature within 24 hours from the start 
of the test, or
    (2) 24 hours has elapsed from the start of the test.
    Record the final outlet water temperature, fuel consumed, 
electricity consumed, and the time elapsed from the start of the 
test.
    6.5. Once the test is complete, use the applicable equation to 
calculate the standby loss in percent per hour:
    For gas-fired equipment:
t = Total duration of the test in hours
Cs = Correction applied to the heating value of a gas H, 
when it is metered at temperature and/or pressure conditions other 
than the standard conditions upon which the value of H is based.
Qs = Total fuel flow as metered, expressed in ft\3\ (gas) 
or lb (oil)
H = Higher heating value of gas or oil, expressed in Btu/ft\3\ (gas) 
or Btu/lb (oil)
S = Standby loss, the average hourly energy required to maintain the 
stored water temperature expressed as a percentage of the initial 
heat content of the stored water above room temperature

    6.6. For gas-fired and oil-fired flow-activated instantaneous 
water heaters, calculate the standby loss in terms of Btu per hour 
as follows:

    SL (Btu per hour) = S (% per hour) x 8.25 (Btu/gal-[deg]F) x 
Measured Volume (gal) x 70 ([deg]F)

    Where, SL refers to the standby loss of the water heater, 
defined as the amount of energy required to maintain the stored 
water temperature expressed in Btu per hour.

0
17. Add appendix F to subpart G of part 431 to read as follows:

Appendix F to Subpart G of Part 431--Uniform Test Method for the 
Measurement of Energy Efficiency of Commercial Heat Pump Water Heaters


    Note:  On and after (date 360 days after date of publication of 
the test procedure final rule in the Federal Register), 
manufacturers must make any representations with respect to energy 
use or efficiency of commercial heat pump water heaters in 
accordance with the results of testing pursuant to this appendix.

    1. General. Determine the COPh for CHPWHs using the 
test procedure set forth below. Certain sections below reference 
ASHRAE 118.1-2012 (incorporated by reference; see Sec.  431.105). 
Where the instructions contained below differ from those contained 
in ASHRAE 118.1-2012, the sections below control.
    2. Definitions and Symbols. The definitions and symbols are as 
listed in section 3 of ASHRAE 118.1-2012.
    3. Instrumentation. The instruments required for the test are as 
described in section 6 of ASHRAE 118.1-2012.
    4. Test Set-Up. Follow the provisions described in this section 
to install the CHPWH for testing.
    4.1. Test set-up and installation instructions
    4.1.1. For air-source CHPWHs, set up the unit for testing as per 
section 7.1 and Figure 5a in section 7.7.1 of ASHRAE 118.1-2012.
    4.1.2. For direct geo-exchange CHPWHs, set up the unit for 
testing as per section 7.1 and Figure 5b in section 7.7.2 of ASHRAE 
118.1-2012.
    4.1.3. For indoor water-source and ground water-source CHPWHs, 
set up the unit for testing as per section 7.1 and Figure 5c in 
section 7.7.3 of ASHRAE 118.1-2012.
    4.2. Use the water piping instructions described in section 7.2 
of ASHRAE 118.1-2012 and the special instructions described in 
section 7.7.6 of ASHRAE 118.1-2012. Insulate all the pipes used for 
connections with material having a thermal resistance of not less 
than 4 h[middot][deg]F[middot]ft\2\/Btu for a total piping length of 
not less than 4 feet from the water heater connection ports.
    4.3. Install the thermocouples, including the room 
thermocouples, as per the instructions in sections 7.3.2 and 7.3.3 
of ASHRAE 118.1-2012.
    4.4. Section 7.6 of ASHRAE 118.1-2012 must be used if the 
manufacturer neither submits nor specifies a water pump applicable 
for the unit for laboratory testing.
    4.5. Install the temperature sensors at the locations specified 
in Figure 5a, 5b, or 5c as applicable as per section 4.1 of this 
appendix. The sensor shall be installed in such a manner that the 
sensing portion of the device is positioned within the water flow 
and as close as possible to the center line of the pipe. Follow the 
instructions provided in sections 7.7.7.1 and 7.7.7.2 of ASHRAE 
118.1-2012 to install the temperature and flow-sensing instruments.
    4.6. Use the following evaporator side rating conditions as 
applicable for each category of CHPWHs. These conditions are also 
mentioned in Table 4 of this appendix:

[[Page 28654]]

    4.6.1. For air-source CHPWHs, maintain the evaporator air 
entering dry-bulb temperature at 80.6 [deg]F  1 [deg]F 
and wet-bulb temperature at 71.2 [deg]F  1 [deg]F 
throughout the conduct of the test.
    4.6.2. For direct geo-exchange CHPWHs, maintain the evaporator 
refrigerant temperature at 32[emsp14][deg]F  1 [deg]F.
    4.6.3. For indoor water-source CHPWHs, maintain the evaporator 
entering water temperature at 68 [deg]F  1 [deg]F.
    4.6.4. For ground water-source CHPWHs, maintain the evaporator 
entering water temperature at 50 [deg]F  1 [deg]F.
    4.7. The CHPWH being tested must be installed as per the 
instructions specified in sections 4.1 to 4.6 (as applicable) of 
this appendix. For all other installation requirements, use section 
7.7.4 of ASHRAE 118.1-2012 to resolve any issues related to 
installation (other than what is specified in this test procedure) 
of the equipment for testing. Do not make any alterations to the 
equipment except as specified in this appendix for installation, 
testing, and the attachment of required test apparatus and 
instruments.
    4.8. Use Table 3 of ASHRAE 118.1-2012 for measurement tolerances 
of various parameters.
    4.9. If the CHPWH is equipped with a thermostat that is used to 
control the throttling valve of the equipment then use the 
provisions in section 7.7.7.3 of ASHRAE 118.1-2012 to set up the 
thermostat.

5. Test Procedure

    Test all CHPWHs as per the provisions described in ASHRAE 118.1-
2012 for ``Type IV'' equipment. Tests for all CHPWH equipment must 
follow the steps described below.
    5.1. Supply the CHPWH unit with electricity at the voltage 
specified by the manufacturer. Follow the provisions in section 
8.2.1 of ASHRAE 118.1-2012 to maintain the electricity supply at the 
required level.
    5.2. Set the condenser supply water temperature and outlet water 
temperature per the following provisions and as set forth in Table 
5.1 of this section:

       Table 5.1--Evaporator and Condenser Side Rating Conditions
------------------------------------------------------------------------
                                 Evaporator side       Condenser side
      Category of CHPWH        rating  conditions    rating  conditions
------------------------------------------------------------------------
Air-source commercial heat    Evaporator entering   Entering water
 pump water heater.            air conditions:.      temperature: 70
                              Dry bulb: 80.6         [deg]F 
                               [deg]F    1 [deg]F. Vary
                               1 [deg]F.             water flow rate (if
                              Wet bulb: 71.2         needed) to achieve
                               [deg]F    the outlet water
                               1 [deg]F.             temperature as
                                                     specified in
                                                     section 8.7.2 of
                                                     ASHRAE 118.1-2012.
                                                    If the required
                                                     outlet water
                                                     temperature as
                                                     specified in
                                                     section 8.7.2 of
                                                     ASHRAE 118.1-2012
                                                     is not met even
                                                     after varying the
                                                     flow rate, then
                                                     change the
                                                     condenser entering
                                                     water temperature
                                                     to 110 [deg]F  1 [deg]F.
                                                     Vary flow rate to
                                                     achieve the
                                                     conditions in
                                                     section 8.7.2 of
                                                     ASHRAE 118.1-2012.
Direct geo-exchange           Evaporator            Entering water
 commercial heat pump water    refrigerant           temperature: 110
 heater.                       temperature: 32       [deg]F 
                               [deg]F    1 [deg]F.
                               1 [deg]F.
Indoor water-source           Evaporator entering   Entering water
 commercial heat pump water    water temperature:    temperature: 110
 heater.                       68 [deg]F 
                               minus> 1 [deg]F.      1 [deg]F.
Ground water-source           Evaporator entering   Entering water
 commercial heat pump water    water temperature:    temperature: 110
 heater.                       50 [deg]F 
                               minus> 1 [deg]F.      1 [deg]F.
------------------------------------------------------------------------

    5.2.1. For air-source CHPWHs:
    5.2.1.1. Set the supply water temperature to 70 [deg]F  1 [deg]F.
    5.2.1.2. Initiate operation at the rated pump flow rate and 
measure the outlet water temperature. If the outlet water 
temperature is maintained at 120 [deg]F  5 [deg]F with 
no variation in excess of 2 [deg]F over a three-minute period, as 
required by section 8.7.2 of ASHRAE 118.1-2012, skip to section 5.3 
of this appendix.
    5.2.1.3. If the outlet water temperature condition as specified 
in section 8.7.2 of ASHRAE 118.1-2012 is not achieved, adjust the 
water flow rate over the range of the pump's capacity. If, after 
varying the water flow rate, the outlet water temperature is 
maintained at 120 [deg]F  5 [deg]F with no variation in 
excess of 2 [deg]F over a three-minute period, as required by 
section 8.7.2 of ASHRAE 118.1-2012, skip to section 5.3 of this 
appendix.
    5.2.1.4. If, after adjusting the water flow rate within the 
range that is achievable by the pump, the outlet water temperature 
condition as specified in section 8.7.2 of ASHRAE 118.1-2012 is 
still not achieved, then change the supply water temperature to 110 
[deg]F  1 [deg]F and repeat the instructions from 
sections 5.2.1.2 and 5.2.1.3 of this appendix.
    5.2.1.5. If the outlet water temperature condition cannot be 
met, then a test procedure waiver is necessary to specify an 
alternative set of test conditions.
    5.2.2. For direct geo-exchange, indoor water-source, and ground 
water-source CHPWHs use the following steps:
    5.2.2.1. Set the condenser supply water temperature to 110 
[deg]F  1 [deg]F.
    5.2.2.2. Follow the steps specified in section 8.7.2 of ASHRAE 
118.1-2012 to obtain an outlet water temperature of 120 [deg]F 
 5 [deg]F with no variation in excess of 2 [deg]F over a 
three-minute period.
    5.3. Conduct the test as per section 9.1.1, ``Full Input 
Rating,'' of ASHRAE 118.1-2012. The flow rate, ``FR,'' referred to 
in section 9.1.1 of ASHRAE 118.1-2012 is the flow rate of water 
through the CHPWH expressed in gallons per minute obtained after 
following the steps in section 5.2 of this appendix. Use the 
evaporator side rating conditions specified in section 4.6 of this 
appendix to conduct the test as per section 9.1.1 of ASHRAE 118.1-
2012.
    5.4. Calculate the COPh of the CHPWH according to 
section 10.3.1 of the ASHRAE 118.1-2012 for the ``Full Capacity Test 
Method.''

0
18. Add appendix G to subpart G of part 431 to read as follows:

Appendix G to Subpart G of Part 431--Uniform Test Method for the 
Measurement of Energy Efficiency of Unfired Hot Water Storage Tanks


    Note: On and after (date 360 days after date of publication of 
the test procedure final rule in the Federal Register), 
manufacturers must make any representations with respect to energy 
use or efficiency of unfired hot water storage tanks in accordance 
with the results of testing pursuant to this appendix.

1. General

    Determine the standby loss in accordance with the following 
sections of this appendix. Certain sections reference sections of 
GAMA Testing Standard IWH-TS-1 (incorporated by reference; see Sec.  
431.105). Where the instructions contained in the sections below 
conflict with instructions in GAMA IWH-TS-1, the instructions 
contained herein control.
    2. Test Set-Up. Set up the unfired hot water storage tank for 
testing in accordance with sections 4, 5 (except for section 5.5), 
6.0, and 6.1 of GAMA IWH-TS-1.
    2.1. Piping Insulation. Insulate all water piping external to 
the water heater jacket, including heat traps and piping that are 
installed by the manufacturer or shipped with the unit, for at least 
4 ft of piping length

[[Page 28655]]

from the connection at the appliance with material having an R-value 
not less than 4[emsp14][deg]F[middot]ft\2\[middot]h/Btu. Ensure that 
the insulation does not contact any appliance surface except at the 
location where the pipe connections penetrate the appliance jacket.

3. Test Conditions

    3.1. Water Supply. Follow the following provisions regarding the 
water supply to the water heater:
    3.1.1. The pressure of the water supply must be maintained 
between 40 psi and the maximum pressure specified by the 
manufacturer of the unit being tested. If the maximum water pressure 
is not specified by the manufacturer in literature shipped with the 
unit or supplemental test report instructions included with a 
certification report, then a default maximum value of 150 psi is to 
be used. The accuracy of the pressure-measuring devices must be 
 1.0 pounds per square inch (psi).
    3.2. Ambient Room Temperature. During the soak-in period and 
standby loss test, maintain the ambient room temperature at 
75[emsp14][deg]F  5[emsp14][deg]F at all times. Measure 
the ambient room temperature at 30-second intervals during these 
periods. Measure the average ambient room temperature separately for 
the soak-in period and standby loss test. During the soak-in period 
and standby loss test, the measured room temperature must not vary 
more than 2.0[emsp14][deg]F at any reading from the 
average ambient room temperature.
    3.3. Maximum Air Draft. During the soak-in period and standby 
loss test, the storage tank must be located in an area protected 
from drafts of more than 50 ft/min from room ventilation registers, 
windows, or other external sources of air movement. Prior to 
beginning the soak-in period and standby loss test, measure the air 
draft within three feet of the jacket of the water heater to ensure 
this condition is met. Ensure that no other changes that would 
increase the air draft are made to the test set up or conditions 
during conduct of the test.
    3.4. Data Collection Intervals. Follow the data recording 
intervals specified in the following sections.
    3.4.1. Soak-In period. Measure the air draft, in ft/min, before 
beginning the soak-in period. Measure the ambient room temperature, 
in [deg]F, every 30 seconds during the soak-in period.
    3.4.2. Standby Loss Test. Follow the data recording intervals 
specified in Table 3.1 of this section.

 Table 3.1--Data To Be Recorded Before and During the Standby Loss Test
------------------------------------------------------------------------
                                                             Every 30
             Item recorded                Before test      seconds \1\
------------------------------------------------------------------------
Air draft, ft/min.....................               X   ...............
Time, minutes/seconds.................  ...............               X
Mean tank temperature, [deg]F.........  ...............               X
Ambient room temperature, [deg]F......  ...............               X
------------------------------------------------------------------------
Notes:
\1\ These measurements are to be recorded at the start and end of the
  test, as well as every 30 seconds during the test.

    4. Determination of Storage Volume. Determine the storage volume 
by subtracting the tare weight--measured while the system is dry and 
empty--from the weight of the system when filled with water and 
dividing the resulting net weight of water by the density of water 
at the measured water temperature.
    5. Soak-In Period. Prior to conducting a standby loss test, a 
soak-in period must occur, in which the tank must sit without any 
draws taking place for at least 12 hours. Begin the soak-in period 
after filling the tank with water such that a mean tank temperature 
of 145[emsp14][deg]F  5[emsp14][deg]F is achieved.

6. Standby Loss Test

    6.1. After conduct of the soak-in period but prior to the start 
of the standby loss test, fill the storage tank with water that is 
heated sufficiently to achieve a mean tank temperature of at least 
145[emsp14][deg]F.
    6.2. When the mean tank temperature falls to 142[emsp14][deg]F, 
start recording mean tank temperature and ambient room temperature 
at regular 30-second intervals as the tank temperature decays.
    6.3. When the mean tank temperature falls below 
138[emsp14][deg]F, stop the test and record the final mean tank 
temperature reading.
    6.4. Calculate the standby loss in Btu per hour as follows:
    6.4.1. Select the data points starting when the mean tank 
temperature first falls to 142[emsp14][deg]F and ending when the 
mean tank temperature first falls below 138[emsp14][deg]F. Calculate 
the uncorrected decay rate, DRu in [deg]F/h, by a least 
squares method as given by:
[GRAPHIC] [TIFF OMITTED] TP09MY16.293

Where:

n = Number of data points collected;
xi = Elapsed time of each data point from the start of 
the decay period when the tank first achieves a mean temperature of 
142[emsp14][deg]F (hours);
Ti = Mean tank temperature in [deg]F measured at each 30-
second interval during the decay period between the time when the 
mean tank temperature first falls to 142[emsp14][deg]F and when the 
mean tank temperature drops below 138[emsp14][deg]F.

    6.4.2. Calculate the mean tank water temperature decay rate, DR, 
in [deg]F/h, as follows:
[GRAPHIC] [TIFF OMITTED] TP09MY16.294

Where Ta is the average ambient room temperature during 
the test, [deg]F.

    6.4.3. The standby loss, SL, in Btu per hour, for unfired hot 
water storage tanks is determined as:

SL = DR x V x [rho] x Cp

Where:

V = tank volume expressed in gallons, measured in accordance with 
section 2.4 of this appendix
[rho] = 8.205 pounds per gallon, density of water at 
140[emsp14][deg]F
Cp = 0.999 Btu per pound-mass[middot][deg]F, specific 
heat of water at 140[emsp14][deg]F.

[FR Doc. 2016-09539 Filed 5-6-16; 8:45 am]
 BILLING CODE 6450-01-P