[Federal Register Volume 78, Number 213 (Monday, November 4, 2013)]
[Proposed Rules]
[Pages 66202-66248]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-26268]



[[Page 66201]]

Vol. 78

Monday,

No. 213

November 4, 2013

Part IV





Department of Energy





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10 CFR Parts 429, 430 and 431





Energy Conservation Program for Consumer Products and Certain 
Commercial and Industrial Equipment: Test Procedures for Residential 
and Commercial Water Heaters; Proposed Rule

  Federal Register / Vol. 78 , No. 213 / Monday, November 4, 2013 / 
Proposed Rules  

[[Page 66202]]


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DEPARTMENT OF ENERGY

10 CFR Parts 429, 430 and 431

[Docket Number EERE-2011-BT-TP-0042]
RIN 1904-AC53


Energy Conservation Program for Consumer Products and Certain 
Commercial and Industrial Equipment: Test Procedures for Residential 
and Commercial Water Heaters

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

ACTION: Notice of proposed rulemaking and announcement of public 
meeting.

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SUMMARY: The U.S. Department of Energy (DOE) proposes to revise its 
test procedure for residential water heaters and certain commercial 
water heaters established under the Energy Policy and Conservation Act. 
This rulemaking will fulfill DOE's statutory obligation for residential 
and certain commercial water heaters to review its test procedure for 
covered products and equipment at least once every seven years. In 
addition, this rulemaking will satisfy DOE's statutory obligation to 
develop a uniform efficiency descriptor for residential and commercial 
water heaters. The proposed test method would apply the same efficiency 
descriptor to all residential and certain commercial water heaters, and 
it would extend coverage to eliminate certain gaps in the current 
residential test procedure, update the simulated-use-test draw pattern, 
and update the water delivery temperature requirement. DOE is also 
announcing a public meeting to discuss and receive comments on issues 
presented in this test procedure rulemaking.

DATES: 
    Comments: DOE will accept comments, data, and information regarding 
this notice of proposed rulemaking (NOPR) before and after the public 
meeting, but no later than January 21, 2014. See section V, ``Public 
Participation,'' for details.
    Meeting: DOE will hold a public meeting on December 6, 2013 from 
9:00 a.m. to 4:00 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.

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. Please note that foreign nationals visiting DOE 
Headquarters are subject to advance security screening procedures. Any 
foreign national wishing to participate in the meeting should advise 
DOE as soon as possible by contacting Ms. Edwards at the phone number 
above to initiate the necessary procedures. Please also note that any 
person wishing to bring a laptop computer into the Forrestal Building 
will be required to obtain a property pass. Visitors should avoid 
bringing laptops, or allow an extra 45 minutes. Persons may also attend 
the public meeting via webinar. For more information, refer to section 
V, ``Public Participation,'' near the end of this notice of proposed 
rulemaking.
    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, identified by docket number EERE-2011-BT-TP-0042 
and/or RIN 1904-AC53, by any of the following methods:
     Email: [email protected]. Include 
EERE-2011-BT-TP-0042 and/or RIN 1904-AC53 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-2J, 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., 6th 
Floor, 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.
    Instructions: All submissions received must include the agency name 
and docket number and/or RIN for this rulemaking. No telefacsimilies 
(faxes) will be accepted. 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 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 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-2011-BT-TP-0042. This Web 
page contains a link to the docket for this notice of proposed 
rulemaking on the site. The Web page contains simple instructions on 
how to access all documents, including public comments, in the docket. 
See section V, ``Public Participation,'' for information on how to 
submit comments through www.regulations.gov.
    For 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-2J, 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-71, 1000 Independence Avenue SW., Washington, DC 20585-
0121. Telephone: (202) 586-9507. Email: [email protected].
    For information on how to submit or review public comments, contact 
Ms. Brenda Edwards, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, EE-2J, 
1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone: 
(202) 586-2945. Email: [email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Authority and Background
II. Summary of the Notice of Proposed Rulemaking
III. Discussion
    A. Scope
    1. Coverage Range of Uniform Metric and Test Procedure
    2. Storage Capacity Limits
    3. Input Capacity Limits
    4. Electric Instantaneous Water Heaters
    B. Uniform Efficiency Descriptor
    C. Draw Pattern
    D. Instrumentation
    E. Discrete Performance Tests
    F. Test Conditions
    1. Water Delivery Temperature
    2. Ambient Temperature and Relative Humidity
    3. Laboratory Airflow

[[Page 66203]]

    G. Annual Energy Consumption Calculation
    H. Conversion of Existing Energy Factor Ratings
    I. Other Issues
    J. Certification, Compliance, and Enforcement Issues
    K. Reference Standards
    L. Compliance With Other EPCA Requirements
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Order 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 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
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 B \1\ of the Energy Policy and Conservation Act of 
1975 (``EPCA'' or ``the Act''), Public Law 94-163 (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.\2\ These include residential 
water heaters, one subject of today's notice of proposed rulemaking. 
(42 U.S.C. 6292(a)(4)) Title III, Part C \3\ of EPCA, Public Law 94-163 
(42 U.S.C. 6311-6317, as codified), added by Public Law 95-619, Title 
IV, Sec. 441(a), established the Energy Conservation Program for 
Certain Industrial Equipment, which includes the commercial water-
heating equipment that is another subject of this rulemaking. (42 
U.S.C. 6311(1)(K))
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    \1\ For editorial reasons, upon codification in the U.S. Code, 
Part B was redesignated as Part A.
    \2\ All references to EPCA in this document refer to the statute 
as amended through the American Energy Manufacturing Technical 
Corrections Act (AEMTCA), Public Law 112-210 (Dec. 18, 2012).
    \3\ For editorial reasons, upon codification in the U.S. Code, 
Part C was redesignated Part A-1.
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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 other representations about the efficiency of 
those products. (42 U.S.C. 6293(c); 42 U.S.C. 6295(s); 42 U.S.C. 6314) 
Similarly, DOE must use these test requirements to determine whether 
the products comply with any relevant standards promulgated under EPCA. 
(42 U.S.C. 6295(s))
    Under 42 U.S.C. 6293, EPCA sets forth the criteria and procedures 
that DOE must follow when prescribing or amending test procedures for 
residential water heaters. EPCA provides, in relevant part, that any 
test procedures prescribed or amended under this section must be 
reasonably designed to produce test results which measure energy 
efficiency, energy use, or estimated annual operating cost of a covered 
product during a representative average use cycle or period of use, and 
must not be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3)) In 
addition, if DOE determines that a test procedure amendment is 
warranted, it must publish proposed test procedures and offer the 
public an opportunity to present oral and written comments on them. (42 
U.S.C. 6293(b)(2))
    For commercial water heaters, EPCA requires that if the test 
procedure referenced in the American Society of Heating, Refrigerating, 
and Air-Conditioning Engineers (ASHRAE) Standard 90.1 is updated, DOE 
must update its test procedure to be consistent with the amended test 
procedure in ASHRAE Standard 90.1, ``Energy Standard for Buildings 
Except Low-Rise Residential Buildings,'' unless DOE determines by rule 
published in the Federal Register and supported by clear and convincing 
evidence, that the amended test procedure is not reasonably designed to 
produce test results which reflect the energy efficiency, energy use, 
or estimated operating costs of that type of ASHRAE 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) and (4))
    In any rulemaking to amend a test procedure, DOE must determine the 
extent to which the proposed test procedure would alter the product's 
measured energy efficiency. (42 U.S.C. 6293(e)(1)) If DOE determines 
that the amended test procedure would alter the measured efficiency of 
a covered product, DOE must amend the applicable energy conservation 
standard accordingly. (42 U.S.C. 6293(e)(2))
    Further, the Energy Independence and Security Act of 2007 (EISA 
2007) amended EPCA to require that at least once every 7 years, DOE 
must review test procedures for all covered products and either amend 
test procedures (if the Secretary determines that amended test 
procedures would more accurately or fully comply with the requirements 
of 42 U.S.C. 6293(b)(3) for residential products or 42 U.S.C. 
6314(a)(2)-(3) for commercial equipment) or publish notice in the 
Federal Register of any determination not to amend a test procedure. 
(42 U.S.C. 6293(b)(1)(A); 42 U.S.C. 6314(a)(1)(A)) Under this 
requirement, DOE must review the test procedures for residential water 
heaters not later than December 19, 2014 (i.e., 7 years after the 
enactment of EISA 2007), and DOE must review the test procedures for 
commercial water heaters not later than May 16, 2019 (i.e., 7 years 
after the last final rule for commercial water heater test procedures 
\4\). Thus, the final rule resulting from this rulemaking will satisfy 
the requirement to review the test procedures for residential and 
certain commercial water heaters every seven years.
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    \4\ On May 16, 2012, DOE published a final rule in the Federal 
Register amending the test procedures for commercial water heaters. 
77 FR 28928.
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    DOE's test procedure for residential water heaters is found in the 
Code of Federal Regulations (CFR) at 10 CFR 430.23(e) and 10 CFR part 
430, subpart B, appendix E. The test procedure includes provisions for 
determining the energy efficiency (energy factor (EF)), as well as the 
annual energy consumption of these products. DOE's test procedure for 
commercial water heaters is found at 10 CFR 431.106; that test 
procedure incorporates by reference American National Standards 
Institute (ANSI) Z21.10.3, Gas Water Heaters--Volume III, Storage Water 
Heaters With Input Ratings Above 75,000 Btu Per Hour, Circulating and 
Instantaneous, and provides a method for determining the thermal 
efficiency and standby loss of this equipment.
    In addition to the test procedure review provision discussed above, 
EISA 2007 also amended EPCA to require DOE to amend its test procedures 
for all covered residential products to include measurement of standby 
mode and off mode energy consumption. (42 U.S.C. 6295(gg)(2)(A)) 
Consequently, DOE recently completed a rulemaking to

[[Page 66204]]

consider amending its test procedure for residential water heaters to 
include provisions for measuring the standby mode and off mode energy 
consumption of those products. Pursuant to the requirements of EPCA, 
DOE published a notice of proposed rulemaking (NOPR) in the Federal 
Register on August 30, 2010, for three different residential heating 
products (water heaters, pool heaters, and direct heating equipment) 
related to standby mode and off mode energy consumption, but the NOPR 
proposed no amendments to the DOE test procedure for residential water 
heaters because DOE tentatively concluded that standby mode and off 
mode energy consumption was already accounted for in the existing DOE 
test method.\5\ 75 FR 52892, 52895. Subsequently, DOE published a final 
rule in the Federal Register on December 17, 2012, which affirmed its 
conclusion that no changes were needed to the existing test procedure 
for residential water heaters. 77 FR 74559, 74561-74562. However, that 
rulemaking was limited to consideration of test procedure amendments to 
address the above-referenced standby mode and off mode requirements; it 
did not address several other potential issues in DOE's existing test 
procedure for residential water heaters. DOE addresses these issues in 
today's NOPR.
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    \5\ For more information, please visit DOE's Web site at: http://www1.eere.energy.gov/buildings/appliance_-standards/residential/
waterheaters.html.
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    On October 12, 2011, DOE published in the Federal Register a 
request for information (RFI) that identified and requested comment on 
a number of issues regarding the test procedures for residential water 
heaters. 76 FR 63211. DOE accepted comments and information on the RFI 
until November 28, 2011, and considered all feedback received when 
developing the proposals contained in this notice. Each of the issues 
raised in the 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 RFI but brought up by interested 
parties in their comments are discussed in section III of this NOPR.
    On December 18, 2012, the American Energy Manufacturing Technical 
Corrections Act (AEMTCA), Public Law 112-210, was signed into law. In 
relevant part, it amended EPCA to require that DOE publish a final rule 
establishing a uniform efficiency descriptor and accompanying test 
methods for covered residential water heaters and commercial water 
heating equipment within one year of the enactment of AEMTCA. (42 
U.S.C. 6295(e)(5)(B)) The final rule must replace the current energy 
factor, thermal efficiency, and standby loss metrics with a uniform 
efficiency descriptor. (42 U.S.C. 6295(e)(5)(C)) AEMTCA requires that, 
beginning one year after the date of publication of DOE's final rule 
establishing the uniform descriptor, the efficiency standards for 
covered water heaters must be denominated according to the uniform 
efficiency descriptor established in the final rule (42 U.S.C. 
6295(e)(5)(D)), and that DOE must develop a mathematical conversion 
factor for converting the measurement of efficiency for covered water 
heaters from the test procedures and metrics currently in effect to the 
new uniform energy descriptor. (42 U.S.C. 6295(e)(5)(E)(i)-(ii)) After 
the effective date of the final rule, covered water heaters shall be 
considered to comply with the final rule and with any revised labeling 
requirements established by the Federal Trade Commission (FTC) to carry 
out the final rule, if the covered water heater was manufactured prior 
to the effective date of the final rule and complies with the 
efficiency standards and labeling requirements in effect prior to the 
final rule. (42 U.S.C. 6295(e)(5)(K))
    AEMTCA also requires that the uniform efficiency descriptor and 
accompanying test method apply, to the maximum extent practicable, to 
all water-heating technologies currently in use and to future water-
heating technologies. (42 U.S.C. 6295(e)(5)(H)) AEMTCA allows DOE to 
provide an exclusion from the uniform efficiency descriptor for 
specific categories of otherwise 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))
    AEMTCA outlines DOE's various options for establishing a new 
uniform efficiency descriptor for water heaters. The options that 
AEMTCA provides to DOE include: (1) A revised version of the energy 
factor descriptor currently in use; (2) the thermal efficiency and 
standby loss descriptors currently in use; (3) a revised version of the 
thermal efficiency and standby loss descriptors; (4) a hybrid of 
descriptors; or (5) a new approach. (42 U.S.C. 6295(e)(5)(G)) Lastly, 
AEMTCA requires that DOE invite stakeholders to participate in the 
rulemaking process, and that DOE contract with the National Institute 
of Standards and Technology (NIST), as necessary, to conduct testing 
and simulation of alternative descriptors identified for consideration. 
(42 U.S.C. 6295(e)(5)(I)-(J))
    DOE published an RFI on January 11, 2013 requesting input on the 
various issues pertaining to water heaters discussed in AEMTCA. 78 FR 
2340. The feedback received from stakeholders was taken into 
consideration and is discussed further in section III of this NOPR.

II. Summary of the Notice of Proposed Rulemaking

    In this NOPR, DOE proposes to modify the current test procedures 
for residential water heaters and certain commercial water heaters. The 
proposed amendments would modify the test procedure to be more 
representative of conditions encountered in the field (including 
modifications to both the test conditions and the draw patterns) and 
expand the scope of the test procedure to apply to certain commercial 
water heaters and certain residential water heaters that are currently 
not covered by the test procedure. The following paragraphs summarize 
these proposed changes.
    DOE proposes to modify the test procedure for water heaters to 
establish a uniform descriptor that can be applied to: (1) All 
residential water heaters (including certain residential water heaters 
that are covered products under EPCA's definition of ``water heater'' 
at 42 U.S.C. 6291(27), but that are not covered under the existing test 
method); and (2) to certain commercial water heaters that have 
residential applications. This includes the proposed establishment of 
test procedure provisions that are applicable to water heaters with 
storage volumes between 2 gallons (7.6 L) and 20 gallons (76 L), and 
the proposed creation of a definition for ``electric instantaneous 
water heater.'' In addition, DOE proposes to establish a new equipment 
class of commercial water heaters and corresponding definition for 
``light commercial water heater.'' DOE proposes to require water 
heaters that would be classified as ``light commercial'' to be tested 
using the test procedure for the uniform efficiency descriptor being 
proposed in this NOPR.
    DOE is also proposing the use of multiple draw patterns for testing 
water heaters, with certain draw patterns prescribed as a function of 
equipment capacity. Further, DOE proposes updates to the water heater 
draw pattern to be more reflective of actual field usage based on 
recent field test data. Lastly, DOE is modifying the water delivery 
temperature requirement to better reflect conditions as seen in typical 
installations in the field.

[[Page 66205]]

III. Discussion

    In response to the October 2011 RFI, DOE received 19 written 
comments related to water heaters from the following interested 
parties: Pacific Gas and Electric Company (PGE), Applied Energy 
Technology (AET), Davis Energy Group, American Council for an Energy-
Efficient Economy (ACEEE), Southern California Edison (SCE), National 
Renewable Energy Laboratory (NREL), Natural Resources Canada (NRCan), 
Natural Resources Defense Council (NRDC), Air-Conditioning, Heating, 
and Refrigeration Institute (AHRI), Northwest Energy Efficiency 
Alliance (NEEA), American Gas Association (AGA), National Propane Gas 
Association (NPGA), A.O. Smith Corporation (AO Smith), Bradford White 
Corporation (Bradford White), Lochinvar, Stone Mountain Technologies, 
Bosch Thermotechnology Corp. (Bosch), General Electric Company (GE), 
and ASHRAE.
    In response to the January 2013 RFI, DOE received 18 written 
comments from the following interested parties: NREL, Bradford White, 
AGA, NPGA, AHRI, AO Smith, joint efficiency advocates (joint 
comment),\6\ GE, NEEA, Rheem Manufacturing Company (Rheem), American 
Public Gas Association (APGA), Edison Electric Institute (EEI), Heat 
Transfer Products Inc. (HTP), Natural Resources Canada (NRCan), Seisco 
International Limited (Seisco), Aquarensics, and two separate comments 
from the University of Houston--Clear Lake (UHCL1, UHCL2).
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    \6\ ACEEE submitted a joint comment on behalf of ACEEE, the 
Appliance Standards Awareness Project (ASAP), the National Consumer 
Law Center (NCLC), the Natural Resources Defense Council (NRDC), the 
Northeast Energy Efficiency Partnerships (NEEP), and the Northwest 
Power and Conservation Council (NPCC).
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    These interested parties commented on a range of issues, including 
those identified by DOE in the October 2011 RFI and the January 2013 
RFI, as well as several other pertinent issues. The issues on which DOE 
received comment, as well as DOE's response to those comments and the 
resulting proposed changes to the test procedures for water heaters, 
are discussed in the subsections immediately below.

A. Scope

    DOE's test procedures for residential water heaters codified at 10 
CFR 430.23(e) and 10 CFR part 430, subpart B, appendix E address gas-
fired, electric, and oil-fired storage-type (i.e., storage volume not 
less than 20 gallons (76 L)) and gas-fired and electric instantaneous-
type (i.e., storage volume less than 2 gallons (7.6 L)) water heaters. 
However, the DOE test procedure does not define ``electric 
instantaneous water heater.'' In addition, it does not address the 
following types of products: (1) Gas-fired water heaters that have a 
storage volume at or above 2 gallons and less than 20 gallons (76 L); 
(2) electric storage water heaters with storage volume less than 20 
gallons (76 L); and (3) storage water heaters with very large storage 
capacities, including oil-fired water heaters with storage volumes 
greater than 50 gallons (190 L), gas-fired water heaters with storage 
volumes above 100 gallons (380 L), and electric water heaters with 
storage volumes above 120 gallons (450 L). As discussed in the 
following sections, DOE proposes to expand the scope of coverage of its 
test method so that it is applicable to all products that meet the 
definition of residential water heater, including those products listed 
above which are currently not addressed by the existing DOE test 
method. DOE is also revising 10 CFR 430.32(d) to clarify the 
applicability of the existing standards with respect to the expanded 
test procedure scope.
    DOE's test procedures for commercial water heaters are found at 10 
CFR 431.106. In terms of capacity, the procedures for commercial water 
heaters cover storage water heaters with an input rating up to 4,000 
British thermal units (Btu) per hour (Btu/h) per gallon of stored 
water, instantaneous water heaters with input ratings not less than 
4,000 Btu/h per gallon of stored water, and hot water supply boilers 
with input ratings from 300,000 Btu/h to 12,500,000 Btu/h and of at 
least 4,000 Btu/h per gallon of stored water. Units using natural gas, 
oil, or electricity are covered by these test methods.
    EPCA includes definitions for both residential and commercial water 
heaters that set the scope of DOE's authority for these products. (42 
U.S.C. 6291(27); 42 U.S.C. 6311(12)) As required by AEMTCA, DOE 
proposes to create a uniform metric and test method for all covered 
water heaters,\7\ regardless of whether a particular water heater falls 
under the scope of residential water heaters or commercial water 
heaters as defined in EPCA. In doing so, DOE also proposes to expand 
the scope of the test procedure to include definitions and test methods 
for the types of products noted above that are not covered by DOE's 
residential test procedure. DOE identified these topics as issues for 
comment in the October 2011 RFI and the January 2013 RFI. 76 FR 63211, 
63212-63213 (Oct. 12, 2011); 78 FR 2340, 2344-2346 (Jan. 11, 2013).
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    \7\ As provided by 42 U.S.C. 6295(e)(5)(F), DOE is proposing to 
allow for the exclusion from the uniform efficiency descriptor of 
certain commercial water heaters that do not have a residential use 
and can be clearly described in the final rule and are effectively 
rated using the thermal efficiency and standby loss descriptors. The 
water heaters that DOE is proposing to exclude are discussed further 
in section III.A.1.
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1. Coverage Range of Uniform Metric and Test Procedure
    In the January 2013 RFI, DOE requested comment on whether the 
uniform efficiency descriptor required by AEMTCA should apply to all 
types of residential and commercial water heaters covered by EPCA, in 
addition to hot water supply boilers and unfired hot water storage 
tanks. In requesting comment, DOE acknowledged that AEMTCA provides for 
the possibility of an exclusion for certain water heaters from the 
uniform efficiency metric and accompanying test method. 78 FR 2340, 
2345-46 (Jan. 11, 2013).
    DOE received 7 comments that opposed DOE's tentative interpretation 
that AEMTCA requires the uniform descriptor to apply to all types of 
residential and commercial water heaters and indicated that DOE should 
utilize the statutory provision permitting an exclusion for any 
specific category of otherwise covered water heaters that do not have a 
residential use. (Bradford White, No. 30 at p. 2; AHRI, No. 33 at p. 1; 
AO Smith, No. 34 at p. 1; Joint comment, No. 35 at p. 2; NEEA, No. 37 
at p. 2; Rheem, No. 38 at p. 2; HTP, No. 41 at p. 1) \8\ Bradford White 
recommended that the uniform efficiency descriptor be limited to water 
heaters with inputs less than 200,000 Btu/h, which would cover those 
water heaters intended for residential applications. (Bradford White, 
No. 30 at p. 2) AHRI, AO Smith, Rheem, and HTP indicated that the 
legislation was intended to apply to residential products only and that 
development of a uniform metric and test method for all water heaters 
is not realistic given the substantially different duty cycles between 
water heaters meant for commercial applications and those meant for 
residential applications. (AHRI, No. 33 at pp. 1-2; AO Smith, No. 34 at 
p. 1; Rheem, No. 38 at p. 2; HTP, No. 41 at p. 1) The joint commenters 
supported a realignment of the scope that includes all water heaters 
except those clearly designed to deliver large amounts of hot water. 
(Joint comment, No. 35 at p. 2) NEEA recommended that DOE should focus 
on water heaters

[[Page 66206]]

meant for residential and small commercial applications. (NEEA, No. 37 
at p. 2) No commenters supported DOE's tentative interpretation that 
AEMTCA requires the uniform descriptor to apply to all types of 
residential and commercial water heaters.
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    \8\ All references to comments received in response to the 
October 2011 and January 2013 RFI's identify the commenter, the 
identification number applied by DOE, and the page of the comment 
package on which the particular point has been discussed.
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    After considering the comments received, DOE proposes to exclude 
from the uniform efficiency descriptor any specific category of water 
heater that does not have a residential use. As noted above, AEMTCA 
provides that DOE can exclude from the uniform descriptor any specific 
categories of covered water heaters that do not have a residential use, 
can be clearly described in the final rule, and are effectively rated 
using the current thermal efficiency and standby loss descriptors. (42 
U.S.C. 6295(e)(5)(F)) DOE received 13 comments regarding how to define 
water heaters that do not have a residential application. In light of 
these comments, DOE proposes to define a new classification of 
commercial water heaters for which the uniform efficiency descriptor 
would apply (i.e., ``light commercial water heaters''), which DOE 
believes can be clearly distinguished from the commercial water heaters 
for which the uniform descriptor would not apply under this proposal. 
DOE believes that the current metrics for commercial water heaters that 
are used only in commercial settings are appropriate and adequate to 
characterize the performance of such commercial water heaters. 
Commercial water heaters typically cycle less than residential water 
heaters due to longer run-times followed by standby periods. 
(Residential water heaters are typically subject to a number of small 
draws and short on-times throughout the day.) As a result, cycling 
losses of water heaters used in commercial applications are generally 
not as significant as those used in residential applications. Thus, DOE 
believes that thermal efficiency and standby loss metrics adequately 
characterize the efficiency in active and standby modes, respectively.
    AHRI, AO Smith, and HTP suggested that the following 
characteristics may be suitable to distinguish water heaters intended 
for non-residential use: (1) Designed to deliver water at a 
thermostatically controlled temperature of 180[emsp14][deg]F or more; 
(2) bear a Code Symbol Stamp signifying compliance with the 
requirements of the American Society of Mechanical Engineers (ASME) 
Boiler and Pressure Vessel Code; and (3) require electricity as the 
primary energy source and require the use of 3-phase external supply. 
(AHRI, No. 33 at p. 2; AO Smith, No. 34 at p. 1; HTP, No. 41 at p. 2) 
The joint commenters likewise stated that water heaters utilizing 3-
phase electric power, designed to deliver water above 
180[emsp14][deg]F, and falling under the guise of the ASME pressure 
vessel code are not typical of residential applications. (Joint 
comment, No. 35 at p. 2) NEEA commented that there are many water 
heaters with features that make them unsuitable for residential and 
small commercial applications and provided examples of units with set 
points of 180[emsp14][deg]F or higher, 3-phase power, and large input 
ratings and volumes. (NEEA, No. 37 at p. 2) AHRI, AO Smith, Rheem, and 
HTP also provided tables of rated inputs and storage volumes to 
distinguish water heaters that are not intended for residential 
applications. (AHRI, No. 33 at p. 2; AO Smith, No. 34 at p. 1; Rheem, 
No. 38 at p. 2; HTP, No. 41 at p. 2) Those limits are grouped by water 
heater type and are shown in Table III.1.

Table III.1--Suggested Capacity Limitations for Defining Non-Residential
                              Water Heaters
------------------------------------------------------------------------
                                Indicator of non-residential application
      Water heater type                       by commenter
------------------------------------------------------------------------
Gas-fired storage............  AHRI, Rheem: Rated input >100 kBtu/h;
                                Rated storage volume <20 gallons and
                                >100 gallons.
                               AO Smith: Rated Input > 100kBtu/h; Rated
                                storage volume >100 gallons.
                               HTP: Rated input >150 kBtu/h; Rated
                                storage volume <20 gallons and >120
                                gallons.
Oil-fired storage............  AHRI, AO Smith, Rheem: Rated input >140
                                kBtu/h; Rated storage volume >50
                                gallons.
Electric storage.............  AHRI, Rheem, HTP: Rated input >12 kW;
                                Rated storage volume <20 gallons and
                                >120 gallons.
                               AO Smith: Rated Input >12 kW; Rated
                                storage volume >120 gallons.
Heat Pump with Storage.......  AHRI, AO Smith, Rheem, HTP: Rated current
                                >24 Amperes; Rated voltage >250 V; Rated
                                storage volume >120 gallons.
Gas-fired instantaneous......  AHRI, AO Smith, Rheem, HTP: Rated input
                                >200 kBtu/h; Water volume >1 gallon per
                                4000 Btu/h of input.
Electric instantaneous.......  AHRI, Rheem: Rated input >12 kW; Water
                                volume >2 gallons.
                               AO Smith: Rated input >25 kW; Water
                                volume >2 gallons.
Oil-fired instantaneous......  AHRI, Rheem, AO Smith: Rated input >210
                                kBtu/h; Water volume >2 gallons.
------------------------------------------------------------------------

    Bradford White recommended that the new descriptor be limited to 
water heaters with inputs less than 200,000 Btu/h because, according to 
the commenter, water heaters with inputs greater than or equal to 
200,000 Btu/hr are not used in residential applications since such a 
high input is not required in these types of applications. (Bradford 
White, No. 30 at p. 2) AGA stated that efficiency descriptors and test 
methods are best developed through consensus-based processes and 
referred DOE to the scope that is currently present in ASHRAE Standard 
118.2, Method of Testing for Rating Residential Water Heaters. (AGA, 
No. 31 at 2)
    Upon considering these comments, DOE agrees with commenters that a 
unit requiring three-phase electricity would nearly always be used only 
in a commercial setting, as residential homes are wired almost 
exclusively for single-phase power. Likewise, DOE agrees with 
commenters that units with an ASME pressure vessel rating or units 
capable of delivering water at temperatures at or exceeding 
180[emsp14][deg]F would generally only be used in commercial settings. 
As a result, DOE proposes to use these three criteria as the basis for 
defining ``light commercial'' water heaters that have residential 
applications.
    DOE also considered the input and storage capacity criteria 
proposed by stakeholders to differentiate commercial water heaters that 
would only be used in non-residential applications from commercial 
water heaters that could have residential applications. DOE notes that 
equipment that was once classified as residential based on input 
capacity or storage volume might now be installed in a commercial 
setting and vice versa. Given that such changes occur over time as new 
technologies develop, DOE is declining to propose criteria in this NOPR 
on an input capacity basis. Instead, DOE believes that the three 
criteria discussed in the preceding

[[Page 66207]]

paragraph are adequate to define the class of commercial water heaters 
that could have residential applications.
    Consequently, DOE proposes to add the following definition of 
``light commercial water heater'' to 10 CFR 431.102:
    Light commercial water heater means any gas-fired, electric, or oil 
storage or instantaneous commercial water heater that meets the 
following conditions:
    (1) For models requiring electricity, uses single-phase external 
power supply;
    (2) Is not capable of delivering hot water at temperatures of 
180[emsp14][deg]F or above; and
    (3) Does not bear a Code Symbol Stamp signifying compliance with 
the requirements of the ASME Boiler and Pressure Vessel Code.
    Although light commercial water heaters could have residential 
applications, DOE notes that the new ``light commercial water heater'' 
definition represents a type of water heater that, to a significant 
extent, is distributed in commerce for industrial or commercial use. 
These water heaters were and continue to be covered industrial 
equipment, and, if these proposals are finalized, will continue to be 
subject to the regulations in part 431 and the certification 
requirements for commercial and industrial equipment in part 429. 
Similarly, although DOE recognizes that some consumer water heaters may 
be installed in a commercial setting, those waters heaters are covered 
consumer products for the purposes of DOE regulations, the regulations 
in part 430 continue to apply, and they must be certified as consumer 
products under part 429.
    If a commercial water heater does not meet all of these three 
conditions, it would be classified as a commercial water heater that 
would not be expected to be used in residential applications and would 
be subject to the current test methods prescribed in 10 CFR 431.106, 
which reference ANSI Z21.10.3. If a commercial water heater meets all 
three criteria, DOE proposes to consider it a ``light commercial water 
heater,'' which would be subject to the uniform efficiency descriptor 
and test method proposed in today's NOPR. Accordingly, DOE proposes to 
add a row to Table 1 of 10 CFR 431.106 specifying 10 CFR part 430, 
subpart B, Appendix E as the test method for this class of equipment. 
DOE seeks comment on both the proposed definition of ``light commercial 
water heater'' and the proposal to subject this equipment to the test 
methods at Appendix E. This is identified as issue 1 in section V.E, 
``Issues on Which DOE Seeks Comment.''
    DOE also received comments recommending that certain types of water 
heaters should be excluded from the uniform descriptor for various 
reasons. NREL commented that storage tanks do not make a complete water 
heating system, so an energy factor is not appropriate. NREL elaborated 
that a rating using a standby loss coefficient could be appropriate. 
(NREL, No. 29 at pp. 3-4) AHRI, AO Smith, and HTP recommended that DOE 
exclude from the descriptor: (1) Unfired storage tanks because they do 
not actually heat water; (2) add-on heat pumps because DOE has 
previously determined that these are not covered products and they are 
not complete water heaters; and (3) hot water supply boilers because, 
by definition, they have inputs exceeding the values listed in the 
commenters' recommendations and because these products are all subject 
to the requirements of the ASME Boiler and Pressure Vessel Code (AHRI, 
No. 33 at pp. 4-5; AO Smith, No. 34 at p. 3; HTP, No. 41 at p. 5) Rheem 
expressed support for AHRI's list of exclusions. (Rheem, No. 38 at p. 
2) NEEA recommended that DOE should exclude water storage tanks from 
the uniform descriptor because they are technically not water heaters 
and they simply store water heated elsewhere. NEEA also commented that 
unfired storage tanks should not be excused from all efficiency 
requirements since standby loss efficiency is important for all hot 
water storage vessels, regardless of where and how the water is heated. 
(NEEA, No. 37 at p. 2) Conversely, the joint commenters recommended 
that the uniform efficiency descriptor should be able to effectively 
measure the efficiency of electric heat pump water heaters without an 
integrated storage tank in the event it is included in future Federal 
coverage. (Joint comment, No. 35 at p. 5)
    DOE has tentatively determined that certain commercial equipment 
such as unfired storage tanks and add-on heat pump water heaters are 
not appropriately rated using the uniform descriptor applicable to 
other water heaters. Unfired storage tanks are not complete water-
heating systems and require additional equipment in the field to 
operate. Thus, DOE believes that other metrics may be more appropriate 
for these devices with limited functionality compared to actual water 
heaters, and that their performance as part of a complete water-heating 
system is so dependent upon other components of the system that use of 
the uniform descriptor may be unrepresentative of its performance as a 
system. For add-on heat pump water heaters, DOE agrees with 
stakeholders that DOE has previously determined that these are not 
covered residential products. As such, DOE only has authority to cover 
commercial add-on heat pumps; however, this equipment does not have 
residential applications, and, therefore, is not suitable for inclusion 
in the uniform efficiency descriptor. DOE has also tentatively 
determined that hot water supply boilers are more appropriately rated 
using the existing metrics for commercial water heaters, as this 
equipment has very high input ratings and are subject to the ASME 
Boiler and Pressure Vessel Code, and their use is similar to that of 
other commercial water heaters in commercial applications. DOE will 
address the types of water-heating equipment that are excluded from the 
uniform descriptor (e.g., unfired storage tanks, add-on heat pump water 
heaters, and hot water supply boilers) in a subsequent test procedure 
rulemaking.
2. Storage Capacity Limits
    Under the existing regulatory definitions, DOE's current 
residential water heater test procedures are not applicable to gas or 
electric water heaters with storage tanks that are at or above 2 
gallons (7.6 L) and less than 20 gallons (76 L). In terms of the high 
end of the capacity range, the current DOE test procedure for 
residential water heaters only applies to gas-fired water heaters with 
storage volumes less than or equal to 100 gallons (380 L), electric 
resistance and heat pump storage water heaters with storage volumes 
less than or equal to 120 gallons (450 L), and oil-fired water heaters 
with storage volumes less than or equal to 50 gallons (190 L). 10 CFR 
part 430, subpart B, appendix E, sections 1.12.1, 1.12.2, and 1.12.4.
    In the 1998 rulemaking establishing test procedures for residential 
water heaters, DOE proposed to include units with storage volumes 
between 2 and 20 gallons, but commenters raised concerns that the test 
procedure demand of 64.3 gallons per day was not appropriate for these 
small units. 63 FR 25996, 26000 (May 11, 1998). At that time, DOE 
concluded that the data to determine the appropriate daily hot water 
consumption did not exist and that alternative procedures proposed by 
commenters were not fully evaluated. For these reasons, the Department 
tabled consideration of the inclusion of these water heaters until a 
future revision of the DOE test procedure. In recent years, however, 
water heaters with such capacities have begun to populate the market. 
The definitions in

[[Page 66208]]

the DOE test procedure (cited above) specify that instantaneous-type 
water heaters have a storage volume of less than two gallons (7.6 L) 
and that electric or gas storage-type water heaters have a storage 
volume of 20 gallons (76 L) or more. The storage capacity of oil water 
heaters in the test method is not restricted by a lower limit, with the 
specification stating that an oil-fired storage water heater simply has 
a rated capacity less than or equal to 50 gallons (190 L). 10 CFR part 
430, subpart B, appendix E, sections 1.7 and 1.12. The definition for 
``Storage-type Water Heater of More than 2 Gallons (7.6 Liters) and 
Less than 20 Gallons (76 Liters)'' is currently reserved. Id. at 
section 1.12.5. DOE requested comment on the potential to address this 
gap in the October 2011 RFI, and received several comments from 
interested parties. 76 FR 63211, 63213 (Oct. 12, 2011).
    DOE received 11 comments in support of the inclusion of water 
heaters with storage volumes between 2 and 20 gallons. (Bradford White, 
No. 2 at p. 1; PGE, No. 3 at p. 1; SCE, No. 4 at p. 1; Stone Mountain 
Technologies, No. 5 at p. 2; AO Smith, No. 8 at p. 1; NEEA, No. 9 at p. 
2; AHRI, No. 12 at p. 1; NREL, No. 14 at p. 7; NRDC, No. 20 at p. 1; 
AET, No. 22 at p. 7; ACEEE, No. 24 at pp. 3-4). No comments were 
received opposed to this measure.
    AHRI, AO Smith, Bradford White, and Lochinvar suggested that a 
distinct test procedure is needed for electric storage water heaters 
with volumes between 2 and 20 gallons since the current test method is 
not suited for such point-of-use products and that this test method 
measure only the standby loss of the unit. (Bradford White, No. 2 at p. 
1; AO Smith, No. 8 at p.1; Lochinvar, No. 10 at p. 1; AHRI, No. 12 at 
p. 2) Stone Mountain Technologies stated further that all electric 
resistance water heaters should be subjected to only a standby loss 
test, because differences between models is almost solely based on 
standby losses. (Stone Mountain Technologies, No. 5 at p. 3) DOE has 
considered these points but has tentatively concluded that, for equity 
across water-heating technologies, all water heaters should be tested 
under a simulated-use profile as will be discussed in section III.C. 
DOE proposes a profile that is appropriate for point-of-use water 
heaters, so any concerns that the current test method is not suitable 
are addressed by the proposed test method. This profile will simulate 
the way that a point-of-use water heater is used in the field and will 
capture any operational characteristics that could affect its 
efficiency. DOE also believes that a simulated-use test will better 
capture any potential cycling losses or inefficiencies in meeting the 
demands imposed on all water heaters.
    After considering the comments received, DOE proposes to expand the 
scope of the water heater test procedure for the uniform efficiency 
descriptor to include water heaters with storage volumes between 2 and 
20 gallons. The proposed modifications will specify the method of test 
set-up (including instrumenting such water heaters), a test method to 
assess the delivery capacity, and the draw pattern that would be used 
to determine the energy efficiency of such units. The proposed 
amendments for water heaters with storage volumes between 2 and 20 
gallons are discussed in detail in section III.C of today's notice of 
proposed rulemaking.
    DOE is not aware of any residential water heaters available on the 
market with storage volumes above 100 gallons, 120 gallons, and 50 
gallons for gas-fired, electric (resistance and heat pump), and oil-
fired water heaters, respectively, that would be covered as residential 
products under EPCA. Due to the lack of water heaters with very large 
storage volumes that meet the definition of a residential ``water 
heater,'' DOE tentatively concluded in the October 2011 RFI that it is 
unnecessary to expand the scope of the test procedure to include gas-
fired products over 100 gallons, electric products over 120 gallons, or 
oil-fired products over 50 gallons, and requested comment on this 
tentative conclusion. 76 FR 63211, 63213 (Oct. 12, 2011).
    Four commenters (Bradford White, AO Smith, NEEA, AHRI) supported 
DOE's position to maintain the existing capacity limits for storage 
water heaters, while three commenters (Stone Mountain Technologies, 
NREL, AET) recommended that the test method be expanded to include all 
water heaters with storage volumes from 0 to 120 gallons. (Bradford 
White, No. 2 at p. 1; AO Smith, No. 8 at p. 1; NEEA, No. 9 at p. 2; 
AHRI, No. 12 at p. 1; Stone Mountain Technologies, No. 5 at p. 2; NREL, 
No. 14 at p. 8; AET, No. 22 at pp. 6-7) AET noted that the pressure 
vessel code from the American Society of Mechanical Engineers requires 
that vessels intended to store fluids under pressure must individually 
undergo a rigorous test and inspection procedure if they have volumes 
greater than 120 gallons. AET noted that because these test and 
certification procedures are expensive, manufacturers will avoid making 
products intended for residential use that require an ASME inspection 
and code stamp. For this reason, AET commented that the upper limit of 
120 gallons would be appropriate for all residential water heaters. AET 
further suggests that expanding the volume limit to 120 gallons would 
prevent manufacturers from evading efficiency standards by marketing 
water heaters slightly larger than the currently specified limits. 
(AET, No. 22 at pp. 6-7)
    The subsequent passage of AEMTCA has necessitated that DOE 
reconsider the scope of all water heater test procedures. DOE has 
considered these comments, as well as the provisions of AEMTCA, and 
proposes to expand the scope of the test procedure to include all 
covered water heaters that could have residential applications and 
remove the limitations on maximum storage volume that are currently in 
the residential test procedure for gas-fired, electric, and oil storage 
water heaters. The Department's authority to regulate water heaters is 
limited to those explicitly defined as covered products by EPCA. EPCA 
defines the term ``water heater'' as a product which utilizes oil, gas, 
or electricity to heat potable water for use outside the heater upon 
demand. (42 U.S.C. 6291(27)) Further, EPCA defines storage type units 
which include gas storage water heaters with an input of 75,000 Btu per 
hour or less, oil storage water heaters with an input of 105,000 Btu 
per hour or less, and electric storage water heaters with an input of 
12 kilowatts or less. EPCA also defines instantaneous type units, which 
are water heaters that contain no more than one gallon of water per 
4,000 Btu per hour of input, including gas instantaneous water heaters 
with an input of 200,000 Btu per hour or less, oil instantaneous water 
heaters with an input of 210,000 Btu per hour or less, and electric 
instantaneous water heaters with an input of 12 kilowatts or less. 
Lastly, EPCA defines covered heat pump type units, which have a maximum 
current rating of 24 amperes at a voltage no greater than 250 volts, 
and which are designed to transfer thermal energy from one temperature 
level to a higher temperature level for the purpose of heating water, 
and include all ancillary equipment such as fans, storage tanks, pumps, 
or controls necessary for the device to perform its function. Id.
    For commercial water heating equipment, EPCA defines ``storage 
water heater'' as a water heater that heats and stores water within the 
appliance at a thermostatically controlled temperature for delivery on 
demand, and does not include units with an input rating of 4000 Btu per 
hour or more per gallon of stored water. EPCA also defines 
``instantaneous water heater'' as a water

[[Page 66209]]

heater that has an input rating of at least 4000 Btu per hour per 
gallon of stored water. Lastly, EPCA defines the term ``unfired hot 
water storage tank'' as a tank used to store water that is heated 
externally. (42 U.S.C. 6311(12))
    AEMTCA requires that the new metric apply to the extent possible to 
all water-heating technologies used in residential applications. (42 
U.S.C. 6295(e)(5)(F) and (H)) DOE believes that the test method 
proposed in today's NOPR adequately addresses large water heaters 
regardless of storage volume, provided that they are used in 
residential applications. As noted previously in section III.A.1, DOE 
proposes to exclude units used only in non-residential applications, 
but DOE does not believe that storage volume alone would dictate 
whether a unit is residential or commercial. As noted by AET, the ASME 
pressure vessel code requires that vessels intended to store fluids 
under pressure must undergo a rigorous test and inspection procedure if 
they have volumes greater than 120 gallons. Any such products would be 
ASME pressure vessel rated, and under the definition of ``light 
commercial water heater'' proposed in section III.A.1, would not be 
subject to the uniform efficiency descriptor, which would effectively 
limit the maximum storage volume to 120 gallons for the purposes of 
using the uniform descriptor. For these reasons, DOE proposes to 
eliminate the maximum storage volume limitations from the residential 
water heater test procedure.
3. Input Capacity Limits
    DOE's current residential water heater test procedure is not 
applicable to gas-fired instantaneous water heaters with input 
capacities at or below 50,000 Btu/h or at or above 200,000 Btu/h. 10 
CFR Part 430, subpart B, Appendix E, section 1.7.2. In addition, the 
test procedure is not applicable to gas-fired storage water heaters 
with input capacities above 75,000 Btu/h, electric storage water 
heaters with input ratings above 12 kW, and oil-fired storage water 
heaters with input ratings above 105,000 Btu/h. 10 CFR Part 430, 
subpart B, Appnedix E, section 1.12.
    DOE proposes to eliminate the minimum limit on the firing rate of 
instantaneous gas water heaters of 50,000 Btu/h, as AEMTCA requires 
that the new metric apply to the maximum extent practical to all water-
heating technologies intended for residential application. (42 U.S.C. 
6295(e)(5)(F) and (H)) As discussed in section III.C, DOE proposes to 
adopt multiple draw patterns that would vary based on the delivery 
capacity of the water heater. Because the draw pattern would be 
dependent upon delivery capacity, DOE believes that small gas-fired 
instantaneous units could be appropriately tested under the proposed 
procedure. Thus, DOE believes there is no reason to retain this lower 
limit on gas-fired instantaneous water heater delivery capacity.
    Similarly, DOE proposes to remove the maximum input ratings for 
gas-fired, electric, and oil-fired storage water heaters, and for gas-
fired instantaneous water heaters from the test procedure. DOE believes 
that the proposed test procedure, because it varies based on delivery 
capacity, is applicable to units with input capacities above those 
included in the current residential water heater test procedure. 
Although these maximum input limitations were based upon DOE's ``water 
heater'' definition at 42 U.S.C. 6291(27), because AEMTCA requires that 
the new metric apply to all water-heating technologies except those 
that do not have a residential use, DOE believes that such limits are 
no longer controlling or appropriate in terms of the scope of the water 
heaters test procedure. As discussed in section III.A.1, given the 
technology shifts that occur over time, DOE does not believe input 
capacity limitations to be a consistent indicator of whether a product 
has a residential use.
4. Electric Instantaneous Water Heaters
    DOE's current test procedures do not contain a definition for 
``electric instantaneous water heater,'' but rather have a space 
reserved to define that term. 10 CFR Part 430, subpart B, appendix E, 
section 1.7.1. EPCA defines ``electric instantaneous water heater'' as 
having an input capacity of 12 kilowatts (kW) or less. (42 U.S.C. 
6291(27)(B)) As noted by commenters and discussed in section III.A.1, 
the heating power required for electric instantaneous water heaters 
intended for whole-home applications is typically much higher than the 
power capability commonly found in storage-type electric water heaters. 
Given the emergence of electric instantaneous water heaters on the 
market, DOE requested comment in the October 2011 RFI on addressing 
this gap in the test procedure by prescribing a definition specifically 
for the term ``electric instantaneous water heater.'' DOE noted in the 
RFI that although the 24-hour simulated use test in DOE's test 
procedure for instantaneous water heaters at 10 CFR Part 430, subpart 
B, appendix E, section 5.2.4 is titled ``24-hour Simulated Use Test for 
Gas Instantaneous Water Heaters,'' the method is also applicable for 
electric instantaneous water heaters. DOE requested comment on 
potential modifications to the DOE test procedure to address electric 
instantaneous water heaters.
    DOE received thirteen comments in support of the proposal to amend 
DOE's water heater test procedure to include electric instantaneous 
water heaters. (Bradford White, No. 2 at p. 1; PGE, No. 3 at p. 1; SCE, 
No. 4 at p. 1; Stone Mountain Technologies, No. 5 at p. 2; AO Smith, 
No. 8 at p. 1; NEEA, No. 9 at p. 2; Lochinvar, No. 10 at p. 1; AHRI, 
No. 12 at p. 1; NREL, No. 14 at p. 9; NRDC, No. 20 at p. 1; Bosch, No. 
17 at p. 1; AET, No. 22 at pp. 8-9; and ACEEE, No. 24 at p. 4.) DOE 
received no comments opposing such an inclusion. Bradford White, AO 
Smith, AHRI, NREL, AET, and ACEEE also suggested that the test 
procedure should be amended to cover electric instantaneous water 
heaters with heating rates higher than 12 kW in order to accommodate 
units that are meant to serve whole-home applications. (Bradford White, 
No. 2 at p. 1; AO Smith, No. 8 at p. 1; AHRI, No. 12 at p. 2; NREL, No. 
14 at p. 9; AET, No. 22 at pp. 8-9; ACEEE, No. 24 at p. 4) AHRI and 
ACEEE suggested that the test procedure for electric instantaneous 
water heaters should be made applicable to water heaters with inputs up 
to 25 kW (AHRI, No. 12 at p. 2; ACEEE, No. 24 at p. 4), while Bradford 
White suggested an input limit of 35 kW (Bradford White, No. 2 at p. 
1), and NREL recommended an input limit of 50 kW (NREL, No. 14 at p. 
9). AET commented that the upper limit be based on a maximum current of 
200 Amperes, which is the typical maximum value allowed in residences 
in the United States. (AET, No. 22 at pp. 8-9) In response to the 
January 2013 RFI, Aquarensics, UHCL1, UHCL2, and Seisco commented that 
the test method should cover electric instantaneous water heaters with 
input ratings in excess of 12 kW. (Aquarensics, No. 43 at p.1; UHCL1, 
No. 44 at p. 1; UHCL2, No. 45 at p. 1; Seisco, No. 47 at p. 1) Further, 
Aquarensics, UHCL1, UHCL2, and Seisco all commented that commercially-
available electric instantaneous water heaters that are designed for 
residential applications have input ratings greater than the current 
limit of 12 kW for residential electric water heaters under EPCA. 
(Aquarensics, No. 43 at p. 2; UHCL1, No. 44 at p. 1; UHCL2, No. 45 at 
p. 1; Seisco, No. 47 at p. 3) Aquarensics and UHCL2 noted residential 
applications that used units with an input rating of 28 kW. UHCL1 
commented that whole-house instantaneous water heaters typically 
require 25 kW to 35 kW.

[[Page 66210]]

Seisco stated that residential electric instantaneous water heaters 
having inputs above 30 kW are commonly built and have been used for 
residential applications since 1999. Seisco further stated that 
electric instantaneous water heaters with input ratings up to 35 kW are 
used for whole-house applications.
    After considering the comments on the RFIs, DOE proposes to amend 
its water heaters test procedure to include applicable provisions for 
electric instantaneous water heaters, and to define the term ``electric 
instantaneous water heater'' as follows:
    Electric Instantaneous Water Heater means a water heater that uses 
electricity as the energy source, initiates heating based on sensing 
water flow, is designed to deliver water at a controlled temperature of 
less than 180[emsp14][deg]F (82 [deg]C), and has a manufacturer's 
specified storage capacity of less than 2 gallons (7.6 liters). The 
unit may use a fixed or variable power input.
    DOE notes that the proposed definition would encompass both 
electric instantaneous water heaters that are residential (i.e., with 
an input capacity of 12 kW or less) and commercial (i.e., with an input 
capacity greater than 12 kW). Because water heaters both above and 
below 12 kW have residential applications, both types would be covered 
by the uniform efficiency descriptor. Today's proposed rule provides 
for a maximum flow rate test, as well as a test to obtain the energy 
efficiency expressed in terms of Energy Factor (EF). These tests are 
identical to those implemented for gas instantaneous water heaters.

B. Uniform Efficiency Descriptor

    AEMTCA provided the following options for the uniform efficiency 
descriptor metric: (1) A revised version of the energy factor 
descriptor currently in use; (2) the thermal efficiency and standby 
loss descriptors currently in use; (3) a revised version of the thermal 
efficiency and standby loss descriptors; (4) a hybrid of descriptors; 
or (5) a new approach. (42 U.S.C. 6295(e)(5)(G)) In the January 2013 
RFI, DOE requested comment on the appropriate metric to be used as the 
uniform descriptor. 78 FR 2340, 2344-45 (Jan. 11, 2013). Eight parties 
provided comments supporting the use of the energy factor metric, but 
obtained using a different method of test than provided in the current 
test procedure. (NREL, No. 29 at p. 1; Bradford White, No. 30 at p. 1; 
AHRI, No. 33 at p. 3; AO Smith, No. 34 at p. 2; GE, No. 36 at p. 1; 
NEEA, No. 37 at p. 1; Rheem, No. 38 at p. 3; HTP, No. 41 at p. 3) The 
joint comment indicated that the existing energy factor metric is 
inadequate and indicated support for a series of simulated use tests 
that would result in a revised energy factor. (Joint comment, No. 35 at 
p. 1) No comments were received that proposed the use of thermal 
efficiency, standby loss factor, or any new metrics.
    NREL stated that the thermal efficiency and standby loss metrics 
are not suitable as primary metrics for residential applications, 
because they do not completely capture performance. (NREL, No. 29 at p. 
1) AHRI and HTP indicated that the energy factor metric would enable 
testing agencies to build on prior experience in testing water heaters 
for residential applications, that it would result in an easier 
conversion from the current metric to the uniform descriptor, and that 
it can be technology neutral. (AHRI, No. 33 at pp. 3-4; HTP, No. 41 at 
p. 3) HTP also suggested a voluntary rating for combined water-heating 
and space-heating appliances based on ASHRAE Standard 124, Methods of 
Testing for Rating Combination Space-Heating and Water-Heating 
Appliances. (HTP, No. 41 at p. 4) AO Smith suggested that the uniform 
descriptor be given a qualifying name to distinguish it from the 
current energy factor, providing ``New Energy Factor'' as an example. 
(AO Smith, No. 34 at p. 2) GE indicated that an energy factor metric 
would be technology neutral and that it would minimize complexity in 
converting from the current metric to the uniform descriptor. (GE, No. 
36 at p. 1)
    NRCan provided a report documenting results of testing of two 
commercial water heaters that are marketed towards the residential 
sector under the existing residential test procedure. (NRCan, No. 42 at 
p. 1) The report did not identify any problems or concerns with testing 
these units under the existing test procedure.
    Based on these comments, DOE proposes a modified version of the 
existing energy factor metric as the uniform descriptor for products 
covered under this test procedure. DOE believes that an energy factor 
that is derived from a simulated use test will provide a technology-
neutral metric for the efficiency of water heaters intended for 
residential applications. The simulated use test will capture key 
performance aspects such as burner efficiency, standby loss, and 
cycling that affect energy efficiency seen by consumers. However, DOE 
will not adopt voluntary rating requirements for combination appliances 
at this time, as that is outside the scope of today's test procedure 
NOPR. Further, DOE does not plan to change the name, as suggested by 
A.O. Smith. The Department believes that because standards and ratings 
will be transitioned to the new metric and the old metric will be come 
obsolete, there will be little confusion by maintaining the name 
``energy factor.''

C. Draw Pattern

    The term ``draw pattern'' describes the number, flow rate, length, 
and timing of hot water removal from the water heater during testing. 
Primary decisions in developing draw patterns include the total amount 
of water to be removed during the test and the number of draws during 
the test. The total amount of water taken in each draw, which is a 
function of the flow rate and the length of the draw, must also be 
specified. Finally, the spacing between those draws is needed to 
complete the specification of the draw pattern.
    The current residential water heater test procedure includes a 24-
hour simulated-use test for determining energy factor. 10 CFR Part 430, 
subpart B, appendix E, sections 5.1.5 and 5.2.4. The 24-hour test 
specifies that 6 draws of equal volume be removed from the water heater 
in the first 6 hours of the test for a total draw of 64.3  
1.0 gallons (243.4  3.8 L).\9\ Following the six draws, the 
water heater sits in an idle mode for the remainder of the 24-hour 
test. Id. The draw pattern is the same regardless of the type (e.g., 
gas-fired, electric resistance, oil-fired, heat pump, storage, 
instantaneous) and characteristics (e.g., storage volume, input 
capacity) of the water heater.
---------------------------------------------------------------------------

    \9\ 10 CFR Part 430, subpart B, appendix E, section 5.1.5 
currently states, ``During the simulated use test, a total of 64. 
3 1.0 gallons (243  2.8 liters) shall be 
removed.'' DOE contends that the total is in error and should 
instead read ``64.3  1.0 gallons (243  2.8 
liters).'' No correction is proposed at this time since the quantity 
will change in the proposed test procedure.
---------------------------------------------------------------------------

    In the October 2011 RFI, DOE noted that recent data 
10 11 12 suggest that the draw pattern can impact the energy 
factor of a water heater and can potentially offer an advantage to one 
type of water heater technology over another. 76 FR 63211, 63213 (Oct. 
12, 2011). These studies also suggest that the existing draw pattern in 
the simulated use test may not be

[[Page 66211]]

representative of actual draw patterns to which water heaters are 
subjected in the field. Because different water heaters will be 
subjected to different field demands (consumer usage patterns) due to 
operational or performance differences, DOE proposes to revise the draw 
pattern to be more representative of typical usage patterns experienced 
in the field. DOE is also proposing to amend its test procedure to 
provide for different draw patterns for different water heaters based 
upon the characteristics of each water heater, such as the rate of hot 
water the unit can provide, the storage volume, and the heating rate 
(i.e., input rate). In the October 2011 RFI, DOE sought comment on 
improvements that could be made to DOE's existing 24-hour simulated use 
test procedure for water heaters. Additional comments were sought by 
and provided in response to the January 2013 RFI.
---------------------------------------------------------------------------

    \10\ Healy, WM, Ullah, T, and Roller, J., ``Input-Output 
Approach to Predicting the Energy Efficiency of Residential Water 
Heaters--Testing of Gas Tankless and Electric Storage Water 
Heaters,'' ASHRAE Transactions 117 (2011).
    \11\ Hoeschele, M.A. and Springer, D.A., ``Field and Laboratory 
Testing of Gas Tankless Water Heater Performance,'' ASHRAE 
Transactions 114 (2): 453-461 (2008).
    \12\ Bohac, D, Schoenbauer, B., Hewett, M., Lobenstein, M.S., 
Butcher, T. ``Actual Savings and Performance of Natural Gas Tankless 
Water Heaters,'' Center for Energy and Environment Report for 
Minnesota Office of Energy Security (August 30, 2010).
---------------------------------------------------------------------------

    DOE received 27 comments that addressed these issues. Four 
commenters (AGA, Bosch, General Electric, and Rheem) recommended that 
DOE maintain the test procedure as it currently stands. AGA argued the 
importance of consistency with previous ratings. (AGA, No. 13 at p. 1) 
Bosch commented that the current test procedure covers a large quantity 
of applications without trying to estimate the usage for any given 
household. (Bosch, No. 17 at p. 2) General Electric wrote that the six-
draw requirement is appropriate for medium-volume water heaters. (GE, 
No. 21 at pp. 1-2) Rheem suggested that the added scope of covered 
products called for by AEMTCA would best be handled by maintaining the 
existing residential water heater test procedure at this time while 
continuing to pursue an amended test method. (Rheem, No. 38 at p. 3) 
Rheem further argued that such an incremental approach would allow 
manufacturers to continue on a path to meet minimum efficiency 
requirements imposed by amended energy conservation standards.
    In total, DOE received twenty-three comments recommending that the 
Agency move away from the six-draw requirement as currently specified 
in the DOE test procedure (although certain of these comments were 
multiple submissions from the same interested party). (Bradford White, 
No. 2 at p. 2; PGE, No. 3 at p. 2; SCE, No. 4 at p. 2; Stone Mountain 
Technologies, No. 5 at p. 2; AO Smith, No. 8 at p. 2; NEEA, No. 9 at p. 
2; NPGA, No. 11 at pp. 1-2; AHRI, No. 12 at p. 2; NREL, No. 14 at pp. 
1-2; GTI, No. 15 at p. 2; NRCan, No. 16 at pp. 1-2; NRDC, No. 20 at p. 
2; AET, No. 22 at p. 2; ACEEE, No. 24 at p. 1; NREL, No. 29 at p. 2; 
Bradford White, No. 30 at p. 2; AHRI, No. 33 at p. 4; AO Smith, No. 34 
at p. 3; Joint comment, No. 35 at p. 1; GE, No. 36 at p. 1; NEEA, No. 
37 at p. 3; APGA, No. 39 at p. 2; AHRI, No. 46 at p. 1)
    Bradford White indicated its support for a 24-hour simulated use 
test because it is ``technology blind.'' (Bradford White, No. 2 at p. 
2) PGE and SCE recommended that the draw pattern be modified to reduce 
bias towards tankless water heaters, and that different draw patterns 
be applied based on the capacity of the water heater. (PGE, No. 3 at p. 
2; SCE, No. 4 at p. 2) Stone Mountain Technologies indicated that 
recent studies have shown that the efficiency of most gas-fired 
tankless models is overstated using the current DOE test procedure. The 
commenter stated that this finding, along with the addition of small 
water heaters within the scope of the test procedure, necessitate a 
modification to the current draw pattern. Further, Stone Mountain 
Technologies opined that an appropriate number of draws for a practical 
test method would be between 10 and 15. (Stone Mountain Technologies, 
No. 5 at p. 2) AO Smith and AHRI supported revising the test procedure 
while retaining the simulated-use concept and indicated that an AHRI 
industry effort is underway to develop a modified draw pattern. (AO 
Smith, No. 8 at p. 2; AHRI, No. 12 at p. 2; AHRI, No. 33 at p. 4; AO 
Smith, No. 34 at p. 3) AHRI submitted a proposed revised energy factor 
test method to DOE, which was considered for today's NOPR and is 
discussed below. (AHRI, No. 46, pp. 1-7) NEEA stated that it is clear 
that the draw pattern used in the current test procedure bears no 
resemblance to that seen in actual use, and accordingly, the current 
draw pattern should be abandoned. (NEEA, No. 9 at p. 2) NREL commented 
that the draw patterns in the new test must be statistically 
representative of actual usage, meaning that the frequency 
distributions of key variables in the test procedure (such as volume of 
draws and timing between draws) are reasonably matched to field data. 
Furthermore, it commented that DOE should ensure that any proposed test 
draw profile must be consistent with all relevant statistical 
distributions determined from the database of hot water draws created 
by the Lawrence Berkeley National Laboratory (LBNL). (NREL, No. 14 at 
pp. 1-2, 8) NREL also mentioned the efforts underway by ASHRAE to 
develop a test method based on multiple draw patterns that have 
different total draw volumes that are appropriate for water heaters of 
different sizes. (NREL, No. 29 at p. 2) NEEA likewise discussed these 
efforts by ASHRAE. (NEEA, No. 27 at p. 2)
    GTI discussed the effect of a greater number of draws during the 
test on the efficiency rating of instantaneous water heaters, and 
presented data on estimated energy factors and efficiencies under 
different draw patterns. (GTI, No. 15 at pp. 6-9) NRCan discussed 
changes being proposed to the committee responsible for Canadian 
Standards Association (CSA) P.3--Testing Method for Measuring Energy 
Consumption and Determining Efficiencies of Gas-Fired Storage Water 
Heaters. The committee is considering changing the current draw pattern 
and replacing it with a new pattern of 10 to 15 draws spread throughout 
the day, with the volume and time of each draw varying. NRCan also 
provided data from a field study in Ontario that included information 
on hot water draw patterns. (NRCan, No. 16 at p. 2) NRDC urged DOE to 
examine the existing data on draw patterns and to conduct its own 
further testing if necessary. (NRDC, No. 20 at p. 2) AET commented that 
the draw patterns need to be more realistic in terms of the number of 
repeated small draws and that it is important for tank-type, 
instantaneous, and tankless water heaters to all be rated using the 
same draw patterns for a given capability range, because comparisons 
among them will otherwise have little meaning. (AET, No. 22 at p. 2) 
ACEEE commented that the current draw pattern is no longer adequate for 
generating the information that consumers need to make wise purchasing 
decisions. In ACEEE's view, the six-draw test does not reflect patterns 
seen in field studies and that the current six-draw pattern is 
inadequate, primarily because different technologies that may lead to 
the same energy use in typical applications would get quite different 
EF ratings in the lab. (ACEEE, No. 24 at p. 1) Standards Committee 
118.2 of ASHRAE submitted minutes from a meeting held on June 28, 2011, 
indicating that the committee passed motions to develop new draw 
patterns for a simulated-use test. (ASHRAE, No. 25 at pp. 1-2)
    Fifteen commenters supported the implementation of different draw 
patterns based upon water heater capacities. Bradford White proposed 
three different draw patterns that would be applicable to water heaters 
of low use, normal-to-high use, and heavy-duty use. (Bradford White, 
No. 2 at pp. 5-6; Bradford White, No. 30 at pp. 13-15) PGE and SCE 
recommended that DOE prescribe draw patterns based on ranges of 
capacities of units or based upon burner size for tankless units. (PGE, 
No.

[[Page 66212]]

3 at p. 2; SCE, No. 4 at p. 2) Stone Mountain Technologies stated that 
the flow rate during individual draws and the total volume drawn during 
the test should be based on the hot water delivery capacity of the 
model. Furthermore, Stone Mountain Technologies suggested that the 
capacity should be based on the theoretical volume of hot water that 
can be delivered in 15 minutes using the energy storage and the net 
heat input. (Stone Mountain Technologies, No. 5 at p. 2) AHRI and AO 
Smith recommended that DOE should develop a simulated-use test that 
will vary for differing models based on some specified criterion such 
as storage volume or flow rate or other appropriate characteristic. 
(AHRI, No. 12 at p. 2; AO Smith, No. 8 at p. 2) NEEA indicated that its 
own laboratory testing and that of some others suggest that multiple 
draw patterns (perhaps 3 to 5) would be appropriate, depending on the 
capacity of the water heater. (NEEA, No. 9 at p. 2) NRCan indicated 
that the CSA P.3 committee is considering 3 or 4 categories for daily 
hot water use households: Low, medium, high, and, potentially, a point-
of-use category. The water heaters would be categorized by first-hour 
rating, maximum gallons per minute, or maximum heat input. (NRCan, No. 
16 at p. 2) General Electric commented that the draw pattern should be 
proportionately scaled up for large volume water heaters (greater than 
50 gallon capacity) and, similarly, scaled down for smaller water 
heaters (less than 50 gallons). (GE, No. 21 at p. 2) ACEEE stated that 
DOE must use different draw patterns for water heaters of different 
capacities and suggested that manufacturers should be allowed to choose 
how a particular product is rated. (ACEEE, No. 24 at p. 2) In response 
to the January 2013 RFI, the joint commenters recommended 5 different 
draw patterns for sizes ranging from point-of-use to very high use 
household/light commercial. The joint commenters noted work by LBNL and 
Stone Mountain Technologies in devising a capacity rating based on 
published storage volume and heat source size. (Joint comment, No. 35 
at p. 2) GE commented that water heaters should be tested based on 
their capacity as measured by the first-hour rating. (GE, No. 36 at p. 
1)
    AHRI provided a suggested simulated use test that described four 
different draw patterns that would be applied to a water heater based 
on its first-hour rating or maximum flow rate measurement. (AHRI, No. 
46 at pp. 5-6) As explained below, AHRI suggested cut-offs between the 
four different size categories at first-hour ratings of 20, 55, and 80 
gallons and at maximum flow rates of 1.5, 2.5, and 3.5 gallons per 
minute; all values correspond to a nominal outlet temperature of 135 
[deg]F and a nominal inlet temperature of 58 [deg]F. The draw patterns 
are based on a set of activities that would be expected in a typical 
residence, with the total volume removed per day for the four patterns 
being 15, 40, 64.2, and 82.75 gallons. The draw pattern for point-of-
use water heaters involved 11 draws, while the other three draw 
patterns involved 12 draws each. Flow rates varied for each draw during 
the draw pattern, except for the point-of-use draw pattern which 
imposed a fixed flow rate of 1 gallon per minute throughout the test.
    Applied Energy Technology acknowledged the need to test a water 
heater according to a draw pattern appropriate for its delivery 
capacity, but instead of supporting a suite of tests for water heaters 
of different capacity, it recommended that DOE consider a test approach 
applicable to water heaters of all sizes from which pieces of 
information are obtained pertaining to the particular capacity of the 
water heater under test. AET's suggested test method entails a series 
of draw clusters that simulate different end uses in a residence. Water 
heaters with a high capacity could presumably deliver sufficiently hot 
water at all times during the test, but water heaters with lower 
capacity may fail to provide water at a required temperature under 
those draw clusters that called for large volumes of hot water in a 
short time. Under AET's approach, a water heater would be rated for 
those clusters during which it could meet the demand placed upon it as 
determined by the outlet temperature during those draw clusters. (AET, 
No. 22 at pp. 18-37) AET commented that details of the test method 
needed to be refined, and no discussion was provided as to how to use 
the efficiency determined during each draw cluster for which the water 
heater could meet the demand to yield an energy factor.
    DOE has tentatively concluded that the current DOE test procedure's 
draw pattern applied during the simulated-use test can potentially 
yield results that are biased towards particular water-heating 
technologies. The DOE test procedure specifies a small number of draws 
per day when compared to typical usage, a relatively large time between 
draws, and uniform volumes of water per draw. The test procedure 
applies to all water heater technologies without regard to any inherent 
differences in performance across the technologies. A revised draw 
pattern in the simulated-use test that better reflects how water is 
actually used in different homes using different water heater 
technologies could allow for a more realistic representation of the 
expected energy consumption consumers would experience for a particular 
water heater technology.
    A test procedure that is completely uniform across all water heater 
types and sizes (i.e., no differences in the amount of hot water drawn 
or the number of draws, etc.) can provide results that are biased 
toward different water heater technologies. For electric resistance and 
fossil fuel-fired storage water heaters, the predominant factor 
affecting the energy factor is the total amount of water removed per 
day. At a given set point temperature, the water heater loses heat to 
the environment at an essentially constant rate regardless of the 
amount of water removed. Since the energy factor is the ratio of hot 
water energy delivered to the overall energy consumed by the water 
heater, which is a sum of that needed to heat the water and that which 
is lost to the environment, the energy factor increases when the 
numerator of that ratio increases. Hence, the energy factor increases 
when the amount of water delivered per 24 hours increases. The 
performance of these water heaters is not expected to depend upon the 
length of draws, the flow rates of draws, nor the spacing between the 
draws.
    Storage water heaters that rely on heat pump technology show the 
same efficiency trend with overall delivered water volume per day as 
seen with other storage water heater technologies, but it is also 
expected that the energy factors would depend upon the way that water 
is distributed among draws. A heat pump water heater operates most 
efficiently when the heat pump portion of the water heater provides the 
heat to the water as opposed to any backup electric resistance heating. 
This backup resistance heating is needed when the hot water in the 
appliance is depleted and a rapid amount of heat needs to be delivered 
to raise the stored water temperature back to the desired value. Since 
heat pumps tend to have a low heating rate, heat pump water heaters 
currently on the market incorporate resistance elements to provide that 
rapid heating. These resistance elements, however, dramatically reduce 
the efficiency. In the current test procedure, water heaters that have 
been tested do not require backup electric resistance heating to 
maintain an adequate water temperature within the tank since there is 
enough time between draws for the tank to fully recover to a

[[Page 66213]]

temperature that is above that which triggers the resistance elements. 
If a revised draw pattern would require a larger amount of water to be 
drawn from the water heater in a set period of time, either through a 
single larger draw or multiple draws spaced close together as would be 
more representative of average use, the heat pump water heater may be 
forced to utilize electric resistance heating to maintain the required 
tank temperature, and the energy factor would drop.
    For small storage water heaters in the ``point-of-use'' category 
(water heaters that generally are not intended to serve as a single 
water heater for all uses in a household), a test utilizing the current 
draw pattern would likely result in delivery of water during the draws 
that is below a temperature that would be considered useful by the 
resident. These units have a small stored volume of hot water that is 
appropriate for small uses such as hand washing but not for a draw of 
more than 10 gallons at 3 gallons per minute (gpm), as is imposed by 
the current test procedure. An efficiency test that takes into account 
these limitations should put a demand on the water heater that calls 
for individual draws less than those implemented in the current DOE 
test.
    Draw patterns and water heater cycling frequency likely have an 
effect on the measured efficiency of instantaneous water heaters. 
Instantaneous water heaters typically use large burners or heating 
elements to heat the water from the inlet temperature to the outlet 
temperature as it flows through the appliance. The burner typically is 
not energized until a water draw is initiated. Once the draw stops, the 
burner is shut off, and the remaining water in the appliance and the 
material making up the appliance gradually lose their heat and return 
to the ambient temperature. This heat loss (losses associated with 
heating up and cooling off of the burner) is considered a cycling loss, 
as the loss is associated with the cycling on and off of the water 
heater's main energy input.
    Draw patterns affect water heater cycling and, thus, the overall 
measured efficiency of the water heater. Shorter draws typically act to 
lower the measured efficiency because, as the water heater cycles more 
frequently, cycling losses increase. Further, cycling losses account 
for a larger portion of energy usage during shorter draws, resulting in 
a disproportionate amount of heat input going towards raising the 
temperature of the heat exchanger as opposed to raising the temperature 
of the water. Hence, shorter draws typically result in a lower measured 
efficiency. However, draws that are clustered closer together typically 
act to raise the measured efficiency by reducing cycling losses because 
the appliance may be able to maintain an elevated temperature between 
the end of one draw and the initiation of a subsequent draw. The 
cycling losses are mitigated by the fact that the appliance does not 
cool down as much after the end of one draw and thus does not need to 
be heated as much when the subsequent draw is initiated. Hence, shorter 
spacing between draws typically results in an increase in the water 
heater's measured efficiency.
    The efficiency of instantaneous water heaters is less affected by 
the total volume of hot water delivered per day than storage water 
heaters because their standby losses (i.e., losses associated with a 
water heater in standby mode, independent of the cycling losses 
discussed above) are negligible. Standby losses increase measured 
energy consumption without a corresponding increase in energy 
delivered, thereby decreasing the energy factor. An increase in the 
volume of water delivered per day results in a nearly proportional 
increase in energy consumption for instantaneous water heaters. The 
other drivers of total energy consumption are standby heat loss and 
cycling heat loss, with standby heat loss being essentially constant 
during the test and cycling losses being a function of the number of 
draws and their spacing. As these two losses approach zero, the 
dependence of energy factor on daily draw volume decreases since the 
energy consumption is dominated by that needed to heat the water, which 
vary proportionally. For water heaters currently on the market, the 
cycling losses experienced by instantaneous water heaters tend to be 
much less than the standby losses experienced by storage water heaters. 
Because standby losses increase measured energy consumption without a 
corresponding increase in energy delivered, the total energy 
consumption for instantaneous water heaters is much closer to the 
energy needed to heat the water than that seen with storage water 
heaters, and the dependence on daily draw volume is also lower.
    The flow rate at which water is drawn from the water heater may 
affect the measured efficiency of an instantaneous water heater. The 
heat transfer from the heat exchanger to the water is a function of the 
speed at which water moves through the heat exchanger; efficiency may 
increase at higher flow rates. Additionally, since instantaneous water 
heaters typically employ heating elements or burners with variable 
capacity to meet the desired outlet temperature at different flow 
rates, the efficiency of the heat input device (e.g., burner or heating 
element) may also vary depending upon the heating rate. This effect 
could either increase or decrease the overall efficiency depending upon 
the setting to which the heating element or burner is tuned.
    To summarize, under the current DOE test procedure, certain types 
of water heaters can provide results that are biased toward certain 
water heater technologies. The small number of draws imposed under the 
existing test procedure, relative to the actual number of draws noted 
in field usage data, reduces the measured cycling losses relative to 
those occurring in field conditions. By contrast, the duration of time 
between draws in the test procedure is relatively long when compared to 
field usage data, which effectively increases the measured cycling 
losses relative to those occurring in field conditions. Water heaters 
with low heating rates would appear to benefit since they could easily 
recover to operational temperature.
    The current DOE test procedure does not adequately measure energy 
efficiency during a representative average use cycle or period of use 
for some technologies. The uniform volume taken during each draw of the 
current test method does not simulate high-demand use, such as a long 
shower, that could change the way that a water heater operates, nor 
does it simulate performance under short draws during which water is 
not delivered at the prescribed set point temperature. Furthermore, DOE 
agrees with commenters who stated that the draw patterns should be 
based on the delivery capacity of the water heater because, as 
explained above, the measured water heater efficiency is influenced by 
the draw pattern incorporated into the test procedure and because a 
single draw pattern is not appropriate for the range of water heater 
sizes that fall under the scope of this test procedure. Consequently, 
DOE proposes a revised simulated-use test that involves four different 
draw patterns for water heaters of different capacities. Water heaters 
would be classified into the following usage categories (described 
below) corresponding to their usage capacity: (1) Point-of-use; (2) 
low; (3) medium; and (4) high. The proposed classifications are based 
on delivery capacity as determined in a first-hour rating test for 
storage-type water heaters or a maximum flow rate test for 
instantaneous water heaters.
    In crafting a proposed set of draw patterns, DOE considered and 
utilized

[[Page 66214]]

the recommended draw patterns submitted by commenters, in particular 
those submitted by Bradford White (Bradford White, No. 2 at p. 3; 
Bradford White, No. 30 at p. 11), AHRI (AHRI, No. 46 at p. 3), and AET 
(AET, No. 22 at p. 1). (DOE notes that no test data were supplied with 
any of the proposed test methods.) Additionally, DOE utilized data 
compiled by the LBNL \13\ that describes field studies of hot water 
usage to ensure that the draw patterns were representative of field 
use. LBNL found that typical usage in residences in North America is 
characterized by a large number of small volume draws, by a smaller 
volume of water per day than is currently prescribed in the residential 
test method, and by a significant variation in draw volume and number 
of draws per day. The data suggest development of a single typical draw 
pattern would be difficult and inappropriate. Instead, DOE has 
attempted to develop several draw patterns that capture key features 
affecting performance (e.g., length and frequency of draws, flow 
rates), while maintaining a test that will not be overly burdensome to 
conduct and which will produce repeatable results.
---------------------------------------------------------------------------

    \13\ Lutz, JD, Renaldi, Lekov A, Qin Y, and Melody M., ``Hot 
Water Draw Patterns in Single Family Houses: Findings from Field 
Studies,'' Lawrence Berkeley National Laboratory Report number LBNL-
4830E (May 2011) (Available at http://www.escholarship.org/uc/item/2k24v1kj) (last accessed October 18, 2013).
---------------------------------------------------------------------------

    Based upon this understanding, DOE proposes the following draw 
patterns containing volumes per day that are consistent with the data 
found by LBNL. The proposed low-use pattern calls for the water heater 
to provide 38 gallons per day, which is consistent with the median 
values found for households with 1 to 2 occupants. The proposed medium-
use pattern, which requires a supply of 55 gallons per day, is 
consistent with the median values found for households with 3 to 4 
occupants. The LBNL data show a median volume of hot water used for 
families with 5 or more occupants to be approximately 58 gallons. This 
unexpectedly low result might be attributable to the lower sample 
number of such large households. For this reason, DOE has departed from 
the LBNL field data and proposes a total volume of 84 gallons per day 
for the high-use pattern. This value is consistent with that proposed 
by Bradford White (Bradford White, No. 2 at p. 5) and AHRI (AHRI, No. 
46 at p. 6), and DOE believes that it is a representative number for 
high use cases based on the range of hot water usage per day reported 
by LBNL. While the LBNL report suggests that the number of draws of hot 
water per day could exceed 50, DOE has tentatively determined that 
imposing a draw pattern during a test with that many draws could lead 
to measurement difficulties owing to (1) the need to measure energy 
removal in such short draws; and (2) the potential variation inherent 
in precisely controlling so many draws. Accordingly, DOE has 
tentatively concluded that a smaller number of draws (ranging from 9 to 
14) will strike a balance between the need to capture cycling losses 
associated with water heater operation and the need for accurate 
measurement. Additionally, many of the short draws found in field tests 
are clustered close together in time. In these situations, cycling 
losses are negligible because the water heater remains at operational 
temperature over the course of the smaller draws. For these draws, 
energy efficiency can be reliably estimated by consolidating the 
multiple draws into a single larger draw.
    As discussed in section III.F, ``Test Conditions,'' DOE proposes 
that both the first-hour rating test and the maximum flow rate test 
will be carried out with the prescribed outlet water temperature at 125 
[deg]F. DOE proposes to modify the first-hour rating test to stop draws 
of hot water when the outlet water temperature drops 15 [deg]F below 
its maximum temperature during each draw. This cut-off temperature is a 
departure from the current test, which cuts off the draw when the 
outlet water temperature drops 25 [deg]F below the maximum recorded 
outlet temperature. With the nominal delivery temperature being 135 
[deg]F in the current test procedure, the cut-off temperature is 110 
[deg]F. This proposed change in temperature drop to trigger the end of 
a draw would maintain the approach that the minimum useful temperature 
of hot water is 110 [deg]F. This value is consistent with Table 3, 
Chapter 50 of the ASHRAE Handbook of HVAC Applications,\14\ which 
indicates that a representative temperature for showers and tubs is 110 
[deg]F. For water heaters with rated storage volumes at or above 20 
gallons, water will continue to be drawn at 3 gallons per minute during 
the first-hour rating test. For water heaters having rated storage 
volumes below 20 gallons that are not designed to provide a continuous 
supply of hot water, water will be drawn at a rate of 1 gallon per 
minute during the first-hour rating test. A water heater that is 
designed to provide a continuous supply of hot water at the set point 
temperature \15\ will be tested to obtain a maximum flow rate, while 
water heaters that are not so designed will be subject to a first-hour 
rating test.
---------------------------------------------------------------------------

    \14\ ASHRAE 2011, Handbook of HVAC Applications, Chapter 50 
Service Water Heating (Available at: https://www.ashrae.org/resources-publications/handbook).
    \15\ A set point temperature is the temperature that the user 
selects via a thermosat as the temperature of the delivered hot 
water at the outlet of the water heater.
---------------------------------------------------------------------------

    DOE proposes the following ranges of first-hour ratings and maximum 
flow rates to characterize storage and instantaneous water heaters, 
respectively:

Point-of-use:
    First-Hour Rating less than 20 gallons.
    Maximum Flow Rate less than 1.7 gallons per minute (gpm).
Low:
    First-Hour Rating greater than or equal to 20 gallons, less than 55 
gallons.
    Maximum Flow Rate greater than 1.7 gpm, less than 2.8 gpm.
Medium:
    First-Hour Rating greater than or equal to 55 gallons, less than 80 
gallons.
    Maximum Flow Rate greater than or equal to 2.8 gpm, less than 4 
gpm.
High:
    First-Hour Rating greater than or equal to 80 gallons.
    Maximum Flow Rate greater than or equal to 4 gpm.

    DOE based these proposed ranges (or ``bins'') on first-hour rating 
data for existing models, requirements of the current plumbing code, 
and recommended cut-offs proposed by Bradford White and AHRI. (Bradford 
White, No. 2 at pp. 4-5; Bradford White, No. 30 at p. 2; AHRI, No. 46 
at p. 4) In today's NOPR, DOE proposes to modify the set point 
temperature from the current 135 [deg]F to 125 [deg]F, as discussed 
further in section III.F.1. While it is acknowledged that the published 
first-hour rating data were taken at a set point temperature of 135 
[deg]F, limited testing shows that first-hour ratings at a set point 
temperature of 125 [deg]F are comparable to those at 135 [deg]F. The 
first-hour ratings of all water heaters on the market cluster around 
certain values to accommodate different levels of use. Those clusters 
are captured in the bins proposed here. DOE's proposed bins differ from 
those presented by Bradford White in its comments on the October 2011 
RFI and the January 2013 RFI, because the commenter's approach grouped 
medium-use and high-use water heaters into a common category and added 
a category for water heaters meant for so-called ``heavy-duty use.'' 
(Bradford White, No. 2 at pp. 4-5) DOE

[[Page 66215]]

has tentatively concluded that the categories defined by Bradford White 
group too many water heaters in the mid-use category. DOE's proposed 
first-hour rating categories match those proposed by AHRI. DOE believes 
that these breakpoints are appropriate based on minimum first-hour 
ratings required by the Uniform Plumbing Code.\16\ The code mandates 
minimum first-hour ratings for water heaters serving homes with 
different combinations of bedrooms and bathrooms. Four different 
minimum values are implemented by the code: 42, 54, 67, and 80 gallons.
---------------------------------------------------------------------------

    \16\ International Association of Plumbing and Mechanical 
Officials, ``2012 Uniform Plumbing Code'' (2012) (Available at 
www.iapmo.org) (last accessed March 29, 2013).
---------------------------------------------------------------------------

    DOE has tentatively concluded that its proposed usage categories 
are appropriate, given that they are consistent with the Uniform 
Plumbing Code, albeit with certain minor modifications. In considering 
the Uniform Plumbing Code, DOE considered 42 gallons per day as a lower 
limit for the low-use category, but concluded that it would not be 
realistic for a water heater intended to provide point-of-use 
functionality to deliver up to that level of water in one hour. 
Instead, DOE has tentatively decided to set the upper limit for point-
of-use water heaters and the lower limit for low-use water heaters at 
20 gallons per day. While water heaters with first-hour ratings below 
42 gallons per day may not be used as a single water heater for whole-
house applications, DOE believes that their use more closely resembles 
that of low-use water heaters rather than that of point-of-use water 
heaters. DOE has grouped homes with 2 to 4 bedrooms and less than 3 
bathrooms in the medium category, which would require minimum first-
hour ratings of 54 or 67. Five bedroom homes with up to 2.5 bathrooms 
or homes with three or more bathrooms would require water heaters with 
first-hour ratings at least 80 gallons per day; these water heaters fit 
into the proposed high-use category.
    DOE acknowledges the uncertainty in using data generated under the 
existing test procedure, which are based on a first-hour rating test 
conducted at a delivery temperature of 135 [deg]F, for establishing 
bins for the applicable draw patterns. Testing by DOE has indicated 
that storage water heaters with relatively high recovery rates yield 
higher first-hour ratings under the proposed procedure than under the 
current procedure, while those with low recovery rates tend to have 
slightly lower first-hour ratings at 125 [deg]F compared to the rating 
at 135 [deg]F. DOE seeks comments related to the translation of current 
first-hour ratings to a first-hour rating determined using the proposed 
125 [deg]F set point and the proposed breakpoints between the different 
size categories. This is identified as issue 2 in section V.E, ``Issues 
on Which DOE Seeks Comment.''
    The proposed maximum gpm ratings for instantaneous water heaters 
were devised based on expected uses for water heaters serving 
applications of different sizes. The categorizations are consistent 
with those suggested by AHRI, with the ratings being scaled up to 
account for the higher maximum flow rates expected at the lower set 
point temperature (125 [deg]F).
    DOE seeks comment on the proposed criteria for characterizing water 
heaters as point-of-use, low usage, medium usage, and high usage, and 
whether these criteria are appropriate and sufficient. This is 
identified as issue 3 in section V.E, ``Issues on Which DOE Seeks 
Comment.''
    For each sizing category, DOE proposes to apply a 24-hour 
simulated-use test to determine the energy factor. One of four separate 
draw patterns would be applied to each water heater based on the 
appropriate sizing category. The draw patterns would have the following 
number of draws per day: Point-of-use: 9; low: 11; medium: 12; and 
high: 14. DOE acknowledges that the number of draws per day in a 
typical household can often approach 100 and that the volume in each 
draw can be very small. However, DOE believes that a test with so many 
draws would be subject to large variability in results due to the 
challenges in accurately determining the energy content of such short 
draws. In contrast, DOE has tentatively concluded that the proposed 
draw patterns would capture the key ways in which hot water is used in 
residences while yielding a test that is repeatable.
    DOE's proposal uses a slightly modified version of the draw 
patterns submitted by Bradford White and AHRI in response to the 
January 2013 RFI as a basis for the low, medium, and high draw 
patterns; Bradford White did not submit a draw pattern for point-of-use 
water heaters. In addition, the patterns presented by Bradford White 
grouped medium-use water heaters with heavy use, so data were missing 
for both point-of-use and medium use water heaters. Additionally, 
information provided by AET has also been considered to craft some 
aspects of the draw patterns. AET provided information on typical uses 
that would be applied to a water heater in terms of flow rates, number 
of draws, and volumes. (AET, No. 22 at pp. 22-36) This information was 
utilized in drafting the proposed draw patterns for point-of-use and 
medium-use water heaters.
    A number of changes are proposed as compared to the current draw 
patterns found in the DOE simulated-use test procedure. First, the 
proposed draw patterns would involve more draws than are currently 
implemented, and the draws would vary in length during the simulated-
use test. Second, the spacing between the draws would vary to better 
capture the effects of different cycling times on the energy efficiency 
of the water heater. Third, the proposed draws would involve different 
flow rates during the test; these flow rates would be 1.0, 1.7, or 3.0 
gpm.\17\ The total volumes that would be removed for each category are 
in line with recent field data compiled by the Lawrence Berkeley 
National Laboratory that was previously discussed. DOE believes that 
the proposed draw patterns would improve the estimation of energy 
efficiency by considering the impact of shorter draws, lower flow 
rates, higher number of draws, and variable standby times between 
draws.
---------------------------------------------------------------------------

    \17\ For point-of-use models, the flow rate is specified as the 
lesser of 1 gpm or the maximum gpm. Therefore, if a unit were to 
have a maximum gpm rating below 1.0 gpm, that unit would be tested 
at its maximum gpm flow rate.
---------------------------------------------------------------------------

    DOE proposes draw patterns for implementation in the 24-hour 
simulated-use tests as outlined in Table III.2 through Table III.5. The 
total volume of water drawn in the proposed draw patterns are 10 
gallons for the point-of-use pattern, 38 gallons for the low-usage 
pattern, 55 gallons for the medium-usage pattern, and 84 gallons for 
the high-usage pattern.

[[Page 66216]]



                                     Table III.2--Point-of-Use Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                       Time during       Volume
            Draw number               test (hh:mm)     (gallons)                   Flow rate (gpm)
----------------------------------------------------------------------------------------------------------------
1..................................            0:00            2    Lesser of (1, max gpm).
2..................................            1:00            1    Lesser of (1, max gpm).
3..................................            1:05            0.5  Lesser of (1, max gpm).
4..................................            1:10            0.5  Lesser of (1, max gpm).
5..................................            1:15            0.5  Lesser of (1, max gpm).
6..................................            8:00            1    Lesser of (1, max gpm).
7..................................            8:15            2    Lesser of (1, max gpm).
8..................................            9:00            1.5  Lesser of (1, max gpm).
9..................................            9:15            1    Lesser of (1, max gpm).
----------------------------------------------------------------------------------------------------------------


                                       Table III.3--Low-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                                      Time during       Volume       Flow rate
                            Draw number                              test (hh:mm)     (gallons)        (gpm)
----------------------------------------------------------------------------------------------------------------
1.................................................................            0:00           15.0            1.7
2.................................................................            0:30            2              1
3.................................................................            1:00            1              1
4.................................................................           10:30            6              1.7
5.................................................................           11:30            4.0            1.7
6.................................................................           12:00            1.0            1
7.................................................................           12:45            1.0            1
8.................................................................           12:50            1.0            1
9.................................................................           16:15            2.0            1
10................................................................           16:45            2.0            1.7
11................................................................           17:00            3.0            1.7
----------------------------------------------------------------------------------------------------------------


                                     Table III.4--Medium-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                                      Time during       Volume       Flow rate
                            Draw number                              test (hh:mm)     (gallons)        (gpm)
----------------------------------------------------------------------------------------------------------------
1.................................................................            0:00           15              1.7
2.................................................................            0:30            2.0            1
3.................................................................            1:40            9.0            1.7
4.................................................................           10:30            9.0            1.7
5.................................................................           11:30            5.0            1.7
6.................................................................           12:00            1.0            1
7.................................................................           12:45            1.0            1
8.................................................................           12:50            1.0            1
9.................................................................           16:00            1.0            1
10................................................................           16:15            2.0            1
11................................................................           16:45            2.0            1.7
12................................................................           17:00            7.0            1.7
----------------------------------------------------------------------------------------------------------------


                                      Table III.5--High-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                                      Time during       Volume       Flow rate
                            Draw number                              test (hh:mm)     (gallons)        (gpm)
----------------------------------------------------------------------------------------------------------------
1.................................................................            0:00           27              3
2.................................................................            0:30            2.0            1
3.................................................................            0:40            1              1
4.................................................................            1:40            9.0            1.7
5.................................................................           10:30           15              3
6.................................................................           11:30            5.0            1.7
7.................................................................           12:00            1.0            1
8.................................................................           12:45            1.0            1
9.................................................................           12:50            1.0            1
10................................................................           16:00            2.0            1
11................................................................           16:15            2.0            1
12................................................................           16:30            2.0            1.7
13................................................................           16:45            2.0            1.7
14................................................................           17:00           14.0            3
----------------------------------------------------------------------------------------------------------------


[[Page 66217]]

    For instantaneous water heaters with maximum flow rates less than 1 
gpm, DOE proposes that the flow rates during all draws of the point-of-
use test will be set at the maximum gpm as determined during that test. 
DOE also proposes to tighten the tolerance on the volume removed in 
each draw from 0.5 gallons to 0.25 gallons since these patterns involve 
smaller draw volumes than in the current procedure.
    DOE proposes to utilize interim metrics during testing that would 
be used in calculations to normalize the test to standard conditions, 
as in the current test procedure, to account for deviations from the 
prescribed storage tank temperature, ambient temperature, water 
delivery temperature, and inlet water temperature. The standby loss 
coefficient is one interim metric that would be determined during the 
longest standby portion of each test in which no recovery or draws are 
taking place. The recovery efficiency is a second interim metric that 
would be determined based on the first draw of each test, with the 
energy supplied and consumed during subsequent draws being accounted 
for when a complete recovery does not occur prior to the second draw.
    DOE proposes to abandon the determination of recovery efficiency at 
different flow rates as currently done for instantaneous water heaters; 
test data have shown the difference between these recovery efficiencies 
as being less than five percent, and the resulting effect on the energy 
factor is negligible.
    DOE notes that the proposed draw patterns differ slightly from 
those suggested by AHRI in response to the January 2013 RFI. (AHRI, No. 
46 at pp. 5-6) In DOE's view, the proposed draw patterns appropriately 
differentiate between the size categories by increasing the number of 
draws as the size of the water heater increases. DOE also intends to 
minimize the different number of flow rates required for all tests, 
with the proposed draw patterns involving three different flow rates as 
opposed to the four specified by AHRI. The patterns proposed here have 
also been formulated to allow for the determination of key performance 
metrics that are needed for computing the energy factor, namely 
recovery efficiency and standby loss coefficient. DOE believes that the 
proposed patterns will ease those determinations. Finally, DOE has 
conducted testing according to the proposed patterns to validate the 
procedure and make adjustments as needed, whereas AHRI has not 
indicated that its specific patterns presented have been validated. In 
any event, DOE has tentatively concluded that the draw patterns 
proposed in today's NOPR are very similar to the patterns proposed by 
AHRI, and that little difference will be observed between ratings 
collected from either draw pattern. This assessment is based on the 
fact that the total volumes drawn per day for each category are 
comparable, the number of draws per day is comparable, and each pattern 
is based on a distribution that represents a cluster of draws in the 
morning and another cluster in the evening hours. Consequently, DOE has 
tentatively concluded that the patterns proposed in this NOPR are 
consistent with those presented by AHRI. DOE seeks comment on whether 
the proposed draw patterns for the different water heater size 
categories are appropriate. This is identified as issue 4 in section 
V.E, ``Issues on Which DOE Seeks Comment.''

D. Instrumentation

    DOE proposes to maintain the instrumentation installation 
requirements and piping configuration as currently specified in the 
residential water heater test procedure. Bradford White recommended 
that the internal temperature probe required in the current test 
procedure be eliminated and that all exposed piping on the inlet and 
outlet of the water heater be eliminated as much as possible. (Bradford 
White, No. 30 at p. 2) DOE is concerned that the removal of the 
internal temperature probe would not enable the critical correction for 
stored energy inside the water heater, a value that could move the 
energy factor by several points. For this reason, DOE proposes to 
maintain the internal temperature probe inside the tank of a storage 
water heater. DOE is also proposing to maintain the piping 
configuration as currently specified in the residential water heater 
test procedure, as some water heaters include particular technologies 
such as heat traps that minimize losses through piping connections. For 
storage water heaters having a rated volume below 20 gallons, which are 
not covered in the existing DOE test method, DOE proposes that the 
average tank temperature would be determined based on three temperature 
sensors located within the storage tank as opposed to the currently 
required six sensors for storage water heaters having a rated volume 
above 20 gallons. The three sensors would be located at the vertical 
midpoints of three sections of equal volume within the tank. For these 
units, DOE believes that three sensors are sufficient for determining 
the mean tank temperature and that the use of six sensors would provide 
little extra information and may add to the parasitic heat losses from 
these smaller units.
    DOE proposes to tighten the allowed accuracy on electric power and 
energy measuring equipment from the current value of  1 
percent to  0.5 percent. A study has shown the significant 
effect of the accuracy of the electric power measurements on the 
uncertainty in the overall energy factor.\18\ An analogous change was 
made in ASHRAE 118.2-2006, ``Method of Testing for Rating Residential 
Water Heaters,'' and DOE research confirms that equipment having this 
tolerance level can be readily procured. DOE also proposes to require 
that for mass measurements greater than or equal to 10 pounds (4.5 kg), 
a scale that is accurate within  0.5 percent of the reading 
be used to make the measurement.
---------------------------------------------------------------------------

    \18\ Healy WM, Lutz JD, and Lekov AB., ``Variability in Energy 
Factor Test Results for Residential Electric Water Heaters,'' HVAC&R 
Research, vol. 9, No. 4 (October 2003).
---------------------------------------------------------------------------

    DOE also proposes to modify the data acquisition rate of the inlet 
and outlet water temperature during draws. Currently, for all water 
heaters except variable firing rate instantaneous water heaters, 
temperature data measurements are taken at 5-second intervals starting 
15 seconds after the draw commences. For instantaneous water heaters 
with a variable firing rate, temperature data measurements are taken at 
5-second intervals starting 5 seconds after the draw commences. The 
proposed test procedure amendments call for temperature data at the 
inlet and outlet temperature sensors to be recorded at 3-second 
intervals starting 5 seconds after commencement of the draw for all 
water heaters. Accordingly, DOE also proposes to require that the time 
constant of the instruments used to measure the inlet and outlet water 
temperatures be no greater than 2 seconds. DOE anticipates that this 
approach would better capture the energy impact of water heater start-
up and cycling.

E. Discrete Performance Tests

    In the October 2011 RFI, DOE considered using a series of discrete 
tests as an alternative approach to using a single 24-hour simulated-
use test to determine the energy factor of residential water heaters. 
In a series of discrete performance tests, the results of various 
individual tests (e.g., thermal efficiency test, recovery efficiency 
test, standby loss test) would be used to calculate the energy factor. 
This approach would reduce testing burden, yield more repeatable 
results, and provide the ability to predict

[[Page 66218]]

performance over a broader range of applications. DOE requested 
comments on the feasibility and equitability of a series of discrete 
tests in the October 2011 RFI. 76 FR 63211, 63214 (Oct. 12, 2011).
    Two commenters (ACEEE, NREL) supported the general premise of 
discrete performance tests for rating water heaters, while 
acknowledging the challenges in implementing such an approach. More 
specifically, NREL indicated that studies are needed to validate that 
discrete tests would provide a computed energy factor with a level of 
accuracy equal to or better than a single simulated-use test. (NREL, 
No. 14 at p. 5) ACEEE indicated that discrete tests combined with an 
algorithm to determine the energy factor could reduce test time, 
produce ratings at a variety of usage patterns with a single set of 
tests, and could be used to account for novel features implemented by 
manufacturers to improve efficiency. ACEEE also acknowledged that the 
algorithms would still need to be developed and validated, a process 
with an unknown time frame. (ACEEE, No. 24 at pp. 2-3)
    Eleven commenters (Stone Mountain Technologies, AO Smith, NEEA, 
NPGA, AHRI, AGA, GTI, Bosch, NRDC, General Electric, and AET) opposed 
the use of discrete tests to determine the energy factor. AHRI and AO 
Smith stated that such tests have a limited use relative to the wide 
range of technologies being employed in current designs of residential 
water heaters since they would not be as equitable as a simulated-use 
approach. (AHRI, No. 12 at p. 2; AO Smith, No. 8 at p. 2) GTI commented 
that much uncertainty remains in the analytical methodology for 
generating rating metrics, its comparability across equipment 
categories, and whether the outcome would actually yield a simpler and 
more repeatable alternative to the current test procedure. (GTI, No. 15 
at p. 2) Stone Mountain Technologies stated that testing and analysis 
to date do not support such an approach. (Stone Mountain Technologies, 
No. 5 at p. 3) Bosch expressed support for the current draw profile and 
test approach because of what the commenter perceives as the extremely 
low repeatability and accuracy of test results at low input rates and 
the lack of data on appropriate draw patterns for use in calculating 
the energy factor. (Bosch, No. 17 at p. 2) General Electric expressed 
support for the current draw profile and test approach, arguing that it 
would more accurately focus on actual results and more closely 
approximate the real-world performance of residential water heaters. 
(GE, No. 21 at pp. 1-2) NEEA stated that the concept of using discrete 
performance tests to determine energy factor is not practical. (NEEA, 
No. 9 at p. 3) AGA commented that discrete performance tests have been 
shown to develop inconsistent results and impose new uncertainties in 
testing, and NRDC raised questions about the equitability of testing 
between technology types. (AGA, No. 13 at pp. 1-2; NRDC, No. 20 at p. 
2) AET stated that it does not believe that the approach would work in 
practice because of controls not working as designed, the presence of 
multiple operating modes on water heaters, and the need to conduct more 
characterization tests than initially expected. These issues with 
discrete performance tests would make the algorithms used to obtain an 
energy factor prone to error. (AET, No. 22 at pp. 5-6)
    DOE has decided not to pursue the use of discrete performance tests 
for rating the energy efficiency of residential water heaters given the 
potential inequity in test results across technologies, the added 
uncertainties in ratings, and the general lack of potentially suitable 
algorithms to develop an energy factor for water heaters. Rather, as 
discussed previously in section III.C, DOE is maintaining the single 
simulated-use test, which DOE believes can be a more, technology-blind 
method for determining the energy efficiency (EF) of water heaters.

F. Test Conditions

1. Water Delivery Temperature
    The current residential water heater test procedure calls for 
average hot water temperature within the storage tank to be set for 
delivery at 135 [deg]F  5 [deg]F (57.2 [deg]C  
2.8 [deg]C). 10 CFR part 430, subpart B, appendix E, section 2.4. 
However, DOE noted in the October 2011 RFI that the Underwriters 
Laboratories (UL) standards specify that manufacturers must ship 
residential water heaters with thermostats set at temperatures no 
greater than 125 [deg]F (52 [deg]C) to safeguard against scalding 
hazards (UL 174, Standard for Household Electric Storage Tank Water 
Heaters, Underwriters Laboratories (April 29, 2004)). DOE also noted 
that DOE's own research suggests that although the majority of water 
heaters are shipped with the thermostat preset to 120 [deg]F (49 
[deg]C), the average set point in use in the field is 124.2 [deg]F 
(51.2 [deg]C), suggesting that some homeowners or installers adjust the 
thermostat. 76 FR 63211, 63214 (Oct. 12, 2011).
    The set point impacts the performance of various types of water 
heaters differently, and as a result, DOE reexamined the 
appropriateness of the set point specification in the proposed test 
procedure. As noted in the October 2011 RFI, a higher delivery 
temperature has a disproportionately large and negative impact on heat 
pump water heater efficiency (as compared to other types of water 
heaters), because heat pump water heaters can have markedly different 
performance at elevated stored water temperature compared to 
temperatures more representative of typical residential usage. For 
other types of water heaters, heat transfer characteristics between the 
heating source and the water may differ at lower delivery temperatures, 
thereby affecting the efficiency. 76 FR 63211, 63214 (Oct. 12, 2011).
    However, DOE also noted in the October 2011 RFI that there are some 
concerns with using a lower set point temperature in the test 
procedure: (1) Some end uses (e.g., dishwasher operation) require hot 
water delivered at 130 [deg]F to 140 [deg]F (54 [deg]C to 60 [deg]C) 
for effective operation; and (2) there may be the potential for the 
growth of Legionella in hot water stored below 135 [deg]F (57 
[deg]C).\19\
---------------------------------------------------------------------------

    \19\ ASHRAE Guideline 12, ``Minimizing the Risk of Legionellosis 
Associated with Building Water Systems,'' states that the 
temperature range most favorable for amplification of legionellae 
bacteria is 77\0\-108 \0\F (25\0\-42 \0\C), and that document 
recommends that when practical, hot water should be stored at 
temperatures of 120 \0\F (49 \0\C) or above. However, the guideline 
also states that for high-risk situations (such as in health care 
facilities and nursing homes), hot water should be stored above 140 
\0\F (60 \0\C). For more information visit: www.ashrae.org.
---------------------------------------------------------------------------

    DOE sought comment on the appropriate set point temperature for the 
residential water heater test procedure and the benefits and concerns 
with using a lower temperature. Three commenters to the October 2011 
RFI (Bradford White, Bosch, and General Electric) recommended that the 
set point temperature should be kept at its current value of 135 [deg]F 
(57 [deg]C). Additionally, two commenters on the January 2013 RFI also 
recommended maintaining the set point at 135 [deg]F (57 [deg]C). 
(Bradford White, No. 30 at p. 2; AHRI, No. 46 at p. 2) Bosch stated 
that this value will maintain harmonization with test standards in 
Canada. General Electric indicated that plumbers may change the set 
point, but a lower temperature in the test procedure runs the risk of 
encouraging consumer dissatisfaction with water heaters that are 
otherwise properly sized for their household due not to lack of 
capacity, but to lack of properly adjusted storage temperatures. 
Additionally, General Electric indicated that DOE runs the risk

[[Page 66219]]

of encouraging energy inefficiency in actual use at higher set points 
of water heaters designed and optimized to test procedures at lower set 
points. (Bradford White, No. 2 at p. 2; Bosch, No. 17 at p. 2; GE, No. 
21 at pp. 2-3) In submitting a suggested test method, AHRI noted that 
it considered lower set points but that its recommendation is to 
continue to use 135 [deg]F as the set point in the test. AHRI indicated 
that its recommended draw patterns should be modified if DOE determines 
that a different set point temperature setting is appropriate. (AHRI, 
No. 46 at p. 2)
    Thirteen comments were submitted that recommended that the set 
point temperature be lowered from its current value. PGE, SCE, NREL, 
AET, and ACEEE recommended a set point temperature of 120 [deg]F (PGE, 
No. 3 at p. 2; SCE, No. 4 at p. 2; NREL, No. 14 at p. 4; AET, No. 22 at 
p. 3; ACEEE, No. 24 at p. 4), while NEEA recommended a value of 125 
[deg]F. (NEEA, No. 9 at p. 3; NEEA, No. 37 at p. 4) In a comment on the 
January 2013 RFI, the joint commenters supported a set point 
temperature between 120 [deg]F and 125 [deg]F. (Joint comment, No. 35 
at p. 3) Likewise, Stone Mountain Technologies and NRDC recommended a 
set point between 120 [deg]F and 125 [deg]F. (Stone Mountain 
Technologies, No. 5 at p. 3; NRDC, No. 20 at p. 2) AHRI and AO Smith 
did not suggest a specific value, but recommended that the set point 
temperature be lowered. (AHRI, No. 12 at p. 2; AO Smith, No. 8 at p 2) 
AET commented that the proposed ASHRAE Standard 188, (Standard 188P), 
``Prevention of Legionellosis Associated with Building Water Systems,'' 
and ASHRAE Guideline 12, ``Minimizing the Risk of Legionellosis 
Associated with Building Water Systems,'' are re-examining 
recommendations for preventing the growth of Legionella. AET stated 
that water temperatures in the range of 120 [deg]F are adequate to 
prevent Legionella colonies, provided that the water is maintained at a 
temperature ``high enough, long enough, and often enough.'' (AET, No. 
22 at pp. 11-12)
    AET commented that the test procedure should allow for variable 
delivery temperatures, because some point-of-use water heaters are 
designed to deliver water no hotter than 105 [deg]F (40.6 [deg]C) to 
110 [deg]F (43.3 [deg]C). AET argued that no credit should be given to 
water delivered at temperatures above the set point temperature, in 
order to discourage temperature overshoots. Likewise, AET argued that 
no credit should be given to water delivered at a temperature below 
that which is considered useful to the user (i.e., below 105 [deg]F 
(40.6 [deg]C)). (AET, No. 22 at p. 13)
    After carefully considering these comments, DOE proposes to lower 
the set point temperature of residential water heaters in the test 
procedure to 125 [deg]F. This value was primarily selected based on 
data available in DOE's analysis for the April 2010 energy conservation 
standards final rule as previously discussed, which found that the 
average set point temperature for residential water heaters is 124.2 
[deg]F (51.2 [deg]C). Additionally, the recent compilation of field 
data across the United States and southern Ontario by LBNL previously 
referenced found a median daily outlet water temperature of 122.7 
[deg]F (50.4 [deg]C); this value rounded to the nearest 5 [deg]F 
increment supports a test set point temperature of 125 [deg]F. This new 
value would apply to first-hour rating tests for storage water heaters, 
maximum flow rate tests for instantaneous water heaters, and energy 
factor tests for all water heaters.
    DOE appreciates the comment from AET regarding the new proposed 
guidelines for Legionella prevention, and tentatively concludes that a 
set point of 125 [deg]F in the test method would not result in safety 
concerns related to the growth of Legionella. Further, as discussed 
immediately above, DOE notes that water heaters are commonly set to 
temperatures in the range of 120 [deg]F to 125 [deg]F even though the 
current set point in the test method is 135 [deg]F. DOE does not expect 
consumer behavior related to set points to change if the set point is 
lowered in the test method.
    For first-hour rating tests, DOE proposes that draws would 
terminate when the outlet temperature drops 15 [deg]F (8.3 [deg]C) from 
its maximum outlet temperature during the draw, as opposed to the drop 
of 25 [deg]F (13.9 [deg]C) implemented in the current test procedure. 
This change would ensure that water delivered meets the nominal useful 
temperature of 110 [deg]F (43.3 [deg]C). DOE acknowledges that the 
Canadian test procedure requires testing at 135 [deg]F (57 [deg]C), but 
DOE is responsible for developing a water heater test procedure that 
reflects and is appropriate for the United States market. In response 
to comments indicating that DOE should retain the 135 [deg]F set point 
temperature, DOE believes that the test should be conducted at typical 
operating temperatures and should not penalize those units optimized 
for such typical conditions.
    GE commented that the set point temperature should be based upon 
the outlet water temperature as opposed to the average stored water 
temperature to allow newer technologies to be included in the protocol 
and to achieve the goal of being technology-neutral. (GE, No. 36 at p. 
2) HTP made a similar assertion that the set point should not be based 
on the mean tank temperature, noting that requiring a mean tank 
temperature could penalize condensing gas water heaters that rely on 
stratification and cooler water at the bottom of the tank to achieve 
better heat transfer resulting in the condensation of moisture within 
the flue gases. (HTP, No. 41 at p. 2) Due to these concerns, AHRI 
suggested an alternative method for setting the thermostat. Instead of 
setting the thermostat based on the mean tank temperature as determined 
by the internal tank temperature probe, AHRI suggested that the 
thermostat setting should be determined by drawing water from the water 
heater for several minutes to determine if the set point temperature is 
achieved. (AHRI, No. 46 at p. 5) AHRI proposed that the flow rate at 
which the water would be drawn during this procedure to set the 
thermostat would be 1 gpm for point-of-use water heaters and 1.7 gpm 
for all other size storage water heaters.
    DOE agrees in principle with the comments and the suggested 
approach presented by AHRI for setting the thermostat. After carefully 
considering these comments, DOE acknowledges that the current method 
for setting the thermostats of water heaters that rely on 
stratification may lead to outlet water temperatures significantly 
higher than would normally be expected in practice, since the top of 
the water heater needs to be at an elevated temperature compared to the 
mean temperature to meet the requirement that the mean temperature fall 
within the value specified in the test procedure. However, DOE is not 
aware of a simple method to assure that multiple thermostats are set 
appropriately by monitoring outlet water temperature during a draw.
    As a result, DOE proposes a method for determining the appropriate 
set point temperature that differs slightly from that proposed by AHRI. 
DOE proposes to apply the thermostat setting procedure that utilizes 
the outlet temperature during a draw, as suggested by AHRI, only to 
water heaters having a single thermostat. For water heaters with 
multiple thermostats, DOE proposes to maintain the procedure currently 
prescribed in the residential water heater test method which utilizes 
the internal tank temperature probes to determine if the water heater 
thermostat is set properly. DOE is not aware of any technologies that 
rely on stratification that utilize multiple thermostats, so it 
believes that the current approach for

[[Page 66220]]

setting the thermostat is appropriate for water heaters having multiple 
thermostats. DOE is also proposing to make a clear distinction by rated 
volume between those water heaters using a lower flow rate during this 
test compared to those using a higher flow rate since the thermostat 
setting will need to be done prior to the experimental determination of 
whether the water heater is to be considered a point-of-use water 
heater. While making this adjustment, DOE is maintaining calculations 
to normalize the standby loss to a mean tank temperature of 125 [deg]F 
 5 [deg]F (51.7[deg]C  2.8 [deg]C) to ensure 
equitable comparison between water heaters.
    DOE is interested in receiving comments on both the proposed set 
point temperature of 125 [deg]F  5 [deg]F, and the proposed 
approach to setting the thermostat for storage water heaters, 
particularly on the appropriateness of different methods for water 
heaters having a single thermostat compared to those with multiple 
thermostats. These are identified as issues 6 and 7 in section V.E, 
``Issues on Which DOE Seeks Comment.''
2. Ambient Temperature and Relative Humidity
    The residential water heater test procedure requires that testing 
be performed in an environment with an ambient air temperature fixed at 
67.5 [deg]F  2.5 [deg]F (19.7 [deg]C  1.4 
[deg]C). 10 CFR part 430, subpart B, appendix E, section 2.2. For heat 
pump water heaters, however, the environmental conditions are more 
tightly constrained with an ambient air temperature requirement of 67.5 
[deg]F  1 [deg]F (19.7 [deg]C  0.6 [deg]C) and 
a relative humidity requirement of 50 percent  1 percent. 
Id. These specifications for heat pump water heaters reflect the fact 
that heat pump water heater energy use is highly dependent on the 
ambient temperature and relative humidity. Because water heaters are 
placed in a wide variety of locations within and outside of a home, and 
given the large impact of these factors on heat pump water heater 
efficiency, DOE considered potential revisions to the ambient air test 
conditions set forth in the DOE test procedure in order to assess 
whether the currently-specified conditions are representative of 
conditions typically encountered in residential installations. In the 
October 2011 RFI, DOE requested comment on the appropriate ambient 
temperature and relative humidity testing points and tolerances for all 
types of residential water heaters. 76 FR 63211, 63214-15 (Oct. 12, 
2011).
    DOE received seven comments (Bradford White, Stone Mountain 
Technologies, AO Smith, AHRI, Bosch, General Electric, and AET) that 
supported the current ambient temperature and relative humidity 
conditions. Bradford White suggested that DOE should consider relaxing 
the tolerances for temperature and relative humidity when testing heat 
pump water heaters since it is very difficult to control to those 
conditions, recommending that the allowable ambient temperature 
variation be  2.5 [deg]F and the allowable variation in 
relative humidity be  5 percent. (Bradford White, No. 2 at 
p. 2; Stone Mountain Technologies, No. 5 at p. 3; AO Smith, No. 8 at p. 
2; AHRI, No. 12 at p. 2; Bosch, No. 17 at p. 2; GE, No. 21 at p. 3; 
AET, No. 22 at p. 4)
    NEEA submitted for DOE consideration as a test method a test plan 
that has been implemented in the Pacific Northwest in which heat pump 
water heaters are tested at both the current DOE specifications and at 
a second point with the ambient temperature at 50 [deg]F (10 [deg]C) 
and the relative humidity at 58 percent. A bin-weighted calculation 
using these two points would yield an energy factor, and NEEA stated 
that it believes that these conditions are more appropriate than the 
current ones for installations in the northern half of the United 
States and would lead to better estimates of the actual performance in 
the field. (NEEA, No. 9 at p. 3) NEEA reiterated the desire to test at 
multiple conditions in response to the January 2013 RFI. (NEEA, No. 37 
at p. 5) NRDC indicated that the conditions need to be re-examined but 
did not offer any suggestions. (NRDC, No. 20 at p. 2) ACEEE suggested 
that DOE should evaluate changing the ambient temperature to 50 [deg]F 
or other such value that approximates the national average winter 
basement temperature. (ACEEE, No. 24 at p. 3) Davis Energy Group 
presented data from a survey of homes in California that reported 
average ambient temperatures that ranged from 65.4 [deg]F to 71.7 
[deg]F. (Davis Energy Group, No. 6 at p. 1)
    After carefully considering these comments, DOE proposes to 
maintain the current ambient dry bulb temperature of between 65 [deg]F 
and 70 [deg]F when testing water heaters other than heat pump water 
heaters and at 67.5 [deg]F  1 [deg]F when testing heat pump 
water heaters. DOE also proposes to maintain relative humidity at 50 
percent, but to relax the tolerances to  2 percent relative 
humidity. DOE believes these conditions are generally representative of 
typical field conditions encountered by water heaters installed in the 
U.S. and has not found any data to justify changing these conditions. 
DOE proposes to relax the tolerance for relative humidity because 
research indicates that commonly-used, laboratory-grade relative 
humidity sensors have uncertainties on the order of 1 to 1.5 percent. 
For this reason, the tolerance cannot be expected to be below the 
accuracy in measuring that value. It should be noted, however, that the 
relative humidity can be obtained from measurements of dry bulb and wet 
bulb temperatures, and the determination of relative humidity through 
these temperature measurements would result in a measure of relative 
humidity with much lower uncertainty since dry bulb and wet bulb 
temperatures can be measured with high accuracy. However, most 
laboratories use relative humidity sensors which provide an accurate 
but less burdensome method for measuring relative humidity. DOE is also 
proposing to add a statement to the instrumentation section that 
specifies that the accuracy of relative humidity sensors shall be 
within  1.5 percent relative humidity.
3. Laboratory Airflow
    The existing test procedure specifies that the water heater shall 
be set up in an area that is protected from drafts. To clarify this 
statement, DOE proposes to add a stipulation that the area be protected 
from drafts of more than 50 ft/ min (2.5 m/s). This value is in 
accordance with specifications in Canadian Standard 745-03, ``Energy 
Efficiency of Electric Storage Tank Water Heaters and Heat Pump Water 
Heaters.''

G. Annual Energy Consumption Calculation

    The annual energy consumption is calculated for residential water 
heaters in the existing test procedure based on the daily energy 
consumption multiplied by 365 days. In a letter submitted to the FTC on 
September 16, 2013, regarding the labeling of residential water 
heaters, AHRI pointed out that calculating the annual energy 
consumption based on the daily energy consumption can lead to differing 
annual energy consumption, and consequently, differing estimated yearly 
operating costs, for water heater models with the exact same EF rating. 
AHRI specifically provided an example of two water heaters with 
differing daily energy consumption values, but with EF values that 
would round to the same value based on the DOE rounding requirements 
provided in 10 CFR 430.23(e). AHRI stated that having slightly 
different yearly operating cost

[[Page 66221]]

estimates for two water heaters with the same efficiency rating can be 
confusing to consumers, and somewhat misleading based on the accuracy 
of the test method. AHRI suggested revising the calculation of the 
annual energy consumption so that it is based on the EF rating.
    DOE agrees with AHRI regarding the calculation of the annual energy 
consumption and the accuracy of the test method. As a result, DOE 
proposes to adopt the calculation method suggested by AHRI for annual 
energy consumption, which is based on the nominal energy consumed 
during the test and the energy factor rating, rather than the daily 
energy consumption.

H. Conversion of Existing Energy Factor Ratings

    The proposed test procedure amendments could result in some types 
of water heaters reporting some numerical changes in EF due to the 
proposed changes in the draw pattern, set point temperature, and water 
delivery temperature. However, the extent of change can vary across the 
numerous design types of water heaters and, perhaps more importantly, 
within a given design type. This variability makes it difficult to 
capture the effect of the proposed test procedure amendments by a 
consistent, systematic adjustment to the current test procedure.
    Foreseeing these circumstances, AEMTCA amended EPCA to require that 
along with the uniform descriptor, DOE must develop a mathematical 
conversion factor to translate from the existing metrics to the uniform 
descriptor. (42 U.S.C. 6295(e)(5)(E)) AEMTCA provided that a 
manufacturer may apply the conversion factor to rerate existing models 
of covered water heaters that are in existence prior to the effective 
date of the final rule establishing the uniform descriptor. Further, 
the conversion factor must not affect the minimum efficiency 
requirements for covered water heaters, and, as a result, would not 
lead to a change in measured energy efficiency for existing products. 
DOE interprets these requirements to mean that DOE will be required to 
translate existing ratings from the current metrics to the new metric, 
while maintaining the stringency of the current standards. In the 
January 2013 RFI, DOE sought comment on the best approach for this 
conversion factor. 78 FR 2340, 2345 (Jan. 11, 2013).
    NREL stated that there is not a simple conversion factor that will 
work across all systems, but it provided a list of references with 
validated algorithms that could assist DOE in developing these 
conversion factors. (NREL, No. 29 at p. 4) AHRI and AO Smith commented 
that DOE should not simply test multiple units to determine an average 
difference between the current and new ratings and use that value to 
convert the ratings. (AHRI, No. 33 at p. 4; AO Smith, No. 34 at p. 3) 
The joint commenters supported the use of a ``good-enough'' 
mathematical conversion method to express existing ratings in terms of 
the new uniform descriptor and urged DOE to test a sample of existing 
products to validate the algorithmic conversion method. (Joint comment, 
No. 35 at p. 4) Considering the limited laboratory capacity to test all 
water heaters under the revised method of test, NEEA commented that DOE 
should assume that all water heaters that comply with current standards 
will also comply after the implementation of the new metrics. (NEEA, 
No. 37 at p. 6) EEI commented that the conversion factor should not 
make currently existing standards more stringent and should only be 
based on point-of-use metrics to be consistent with Federal law. (EEI, 
No. 40 at p. 2) HTP commented that the most exact approach would be to 
conduct an empirical analysis using curve fitting to actual test data, 
although the commenter acknowledged that there is not sufficient time 
for manufacturers to obtain this information and for the Department to 
then correlate and analyze the data. (HTP, No. 41 at p. 3)
    DOE notes these comments regarding the conversion factor and will 
consider them fully once the test procedure is finalized to assist in 
developing the conversion factor. DOE plans to conduct a separate 
rulemaking to establish the conversion factor once the test method is 
finalized, and in that rulemaking, DOE will establish a mathematical 
method for determining the rated efficiency under the new efficiency 
descriptor from the rated efficiency under the existing metrics. Should 
it become apparent in the rulemaking to establish the conversion factor 
that changes may be required in the test procedure, DOE would address 
any issues at that time. DOE also plans to translate its current energy 
conservation standards to equivalent standards denominated in the new 
uniform efficiency metric in the separate rulemaking.

I. Other Issues

    DOE also sought comments in the October 2011 RFI and the January 
2013 RFI on any other relevant issues that commenters believe could 
affect the test procedure for water heaters, and continues to seek 
comment in today's notice. 76 FR 63211, 63215 (Oct. 12, 2011); 78 FR 
2340, 2346 (Jan. 11, 2013). Although DOE has attempted to identify 
those portions of the test procedure where it believes amendments may 
be warranted, interested parties are welcome to provide comments on any 
aspect of the test procedure, including updates of referenced 
standards, as part of this comprehensive 7-year-review rulemaking.
    AET supported keeping the inlet water temperature at 58 [deg]F. 
(AET, No. 22 at p. 4) Davis Energy Group provided data on average inlet 
water temperatures reported in studies in California that ranged from 
64.2 [deg]F to 72.3 [deg]F. (Davis Energy Group, No. 6 at p. 3) Despite 
these values being higher than the current nominal temperature 
specified in the current DOE test procedure, DOE has not seen any data 
that suggests a different temperature is more appropriate on a national 
basis, so DOE has tentatively decided to maintain the inlet temperature 
at 58[emsp14][deg]F in the proposed test procedure.
    AHRI suggested an alternative means to prepare a storage-type water 
heater prior to commencement of the 24-hour simulated-use test. (AHRI, 
No. 46 at p. 7) AHRI suggested that DOE could improve the consistency 
of energy factor tests by running the draw patterns on two consecutive 
days, with measurements only taking place during the second 24-hour 
period. After careful consideration, DOE has tentatively concluded that 
this approach would lead to more consistent results since the state of 
the water heater at the beginning of the 24-hour test period will be 
similar to that at the end of the test period, thereby minimizing the 
need to make large corrections to the energy consumption values which 
could introduce errors. DOE is aware of testing conducted in this 
manner that has resulted in consistent values for the energy 
factor.\20\ DOE is tentatively proposing to require storage water 
heaters to be pre-conditioned in this manner. It is DOE's understanding 
that test laboratories must already let the water heater sit at 
temperature for an extended period of time to let the unit achieve 
operational temperature. Therefore, DOE reasons that the proposed pre-
conditioning routine might be done during this stage, thereby resulting 
in little or no added test time. DOE is interested in comment regarding 
the value of the pre-conditioning period and the incremental burden, if 
any, that

[[Page 66222]]

it would place on manufacturers. This is identified as issue 5 in 
section V.E, ``Issues on Which DOE Seeks Comment.''
---------------------------------------------------------------------------

    \20\ Healy WM,, Lutz JD, and Lekov AB., ``Variability in Energy 
Factor Test Results for Residential Electric Water Heaters,'' HVAC&R 
Research, vol. 9, No. 4 (October 2003).
---------------------------------------------------------------------------

    NREL argued that published metrics from the DOE test procedure 
should allow for calculation of performance under conditions outside 
the particular conditions imposed by the test procedure. (NREL, No. 29 
at p. 1) DOE does not propose to require any published metrics from the 
test procedure specifically for the purpose of calculating performance 
at various conditions outside of those imposed by the test method, as 
the purpose of the DOE test procedure is to determine compliance to 
minimum efficiency standards and to provide a basis for representation 
of energy performance to consumers.
    The joint comment urged DOE to consider several additional points. 
(Joint comment, No. 35 at p. 6) First, it raised the question as to the 
appropriate rating method for a hybrid solar water heating system whose 
tank might be passive or active. DOE notes that solar water heaters are 
not covered equipment under EPCA, and thus the DOE test method for 
water heaters need not address these systems. Further, hybrid solar 
water heating systems consisting of a stand-alone water heater with 
additional solar components that are added in the field could be tested 
according to the rating method provided for the water heater if the 
solar components were not present. The stand-alone heater would be 
subject to energy conservation standards without consideration of the 
benefits, if any, of the solar portion. Second, the joint commenters 
questioned how to rate ``hybrid'' fuel-fired units with tanks larger 
than 2 gallons. DOE believes that amendments proposed in this NOPR will 
cover those products--the storage volume gaps that currently exist in 
the scope would be removed under this proposal, and the proposed test 
method would cover those products. Lastly, the joint commenters asked 
whether test procedures should reflect energy savings from ``smart'' or 
``grid-interactive'' water heaters. DOE does not believe that a 
separate test procedure is warranted for this equipment, because they 
are functionally similar to non-grid-interactive water heaters. DOE 
acknowledges that usage patterns for grid-interactive water heaters may 
be very different from water heaters that are not grid-interactive or 
controlled as part of demand response programs. However, DOE believes 
that there is generally a wide range of usage patterns for all water 
heating products seen in the field, and it would be impractical to 
attempt to tailor the test method to every potential usage pattern. 
Thus, DOE believes that such differences in usage patterns are better 
addressed as part of standards analyses, rather than as a separate test 
method.
    PGE commented that a method is needed for reporting source energy 
consumption for future standards rulemakings, because the commenter 
opined that source energy is a more complete metric for representing 
the energy consumed by appliances and would yield a better comparison 
between the energy consumption of gas, electric, and gas/electric 
units. The commenter further opined that the test procedures should 
include calculations to allow for two energy factors, one based on site 
energy and one based on source energy. (PGE, No. 3 at p. 2) In response 
to the January 2013 RFI, DOE received additional comments related to 
source-based metrics. EEI stated that, consistent with other Federal 
laws, any new descriptor or conversion factor should only be based on 
point-of-use metrics. (EEI, No. 40 at p. 2) AGA, NPGA, and APGA all 
supported a metric based on the full fuel cycle that would provide a 
complete accounting of energy consumption from extraction, processing, 
and transportation of energy. (AGA, No. 31, at p. 3; NPGA, No. 32 at p. 
1; APGA, No. 39 at p. 1)
    In addressing this comment, DOE notes that the Department has 
historically presented national energy savings (NES) in terms of 
primary energy savings (i.e., source energy savings). However, in 
response to the recommendations of a committee on ``Point-of-Use and 
Full-Fuel-Cycle Measurement Approaches to Energy Efficiency Standards'' 
appointed by the National Academy of Science, DOE announced its 
intention to use full-fuel-cycle (FFC) measures of energy use and 
greenhouse gas and other emissions in the national impact analyses and 
emissions analyses included in future energy conservation standards 
rulemakings. 76 FR 51281(August 18, 2011). To this end, DOE has begun 
to also estimate energy savings using the FFC metric. The FFC metric 
includes the energy consumed in extracting, processing, and 
transporting primary fuels, and thus presents a more complete picture 
of the impacts of efficiency standards. DOE's approach is based on 
application of FFC multipliers for each fuel type used by covered 
products and equipment, as presented in DOE's statement of policy 
published in the Federal Register on August 18, 2011. Id.
    DOE has reviewed the water heater test procedures, including 
today's proposed amendments, in relation to the newly established FFC 
policy, and has tentatively concluded that no substantive amendments 
are needed to the water heater test procedures to accommodate the FFC 
policy. In support of this conclusion, the following discussion 
elaborates separately on the FFC policy implications for energy 
efficiency standards and representations.
    For the purposes of energy conservation standards, the test 
procedure-derived measure of energy consumption and efficiency, 
including the regulatory efficiency metric (i.e., EF) is sufficient and 
complete enough to allow for full consideration of the FFC impacts in 
the energy conservation standards analysis. In support of this 
conclusion, it is noted that the existing and future energy 
conservation standards for these products are, and are expected to 
continue to be, analyzed independently by fuel type. DOE believes this 
independent analytical approach eliminates any possible 
mischaracterization or inappropriate consideration of a standard's 
stringency that might be associated with the test procedure's 
regulatory metrics for these products. More specifically, the 
commenters' suggestion to add a source-based Energy Factor for water 
heaters would not add to or improve the standards analysis for water 
heaters because of the expansion of the standard's analysis already 
incorporated in the current approach.
    For the purposes of representations, DOE has also tentatively 
concluded that some small improvements to the water heater test 
procedure are deemed appropriate to accommodate the FFC policy. It is 
important to note that both the current test procedure and the proposed 
revised test method for this product incorporate numerous measures of 
energy consumption and efficiency, some of which are used in the 
regulatory context mentioned above and some of which support the 
consumer information objective of the test procedure. Although the main 
thrust of the PGE, AGA, APGA, and NPGA suggestions seems to be based on 
the assumption that the addition of a source-based energy factor would 
improve analysis for water heater standards, there also seems to be a 
suggestion that such inclusion would also provide improvement in a non-
regulatory or consumer information context. An important example of a 
non-regulatory metric is annual energy consumption, which provides a 
complete accounting of the energy consumption to the consumer and which 
can be used to estimate annual

[[Page 66223]]

operating cost. For water heaters, DOE proposes to add terms in the 
test method to quantify daily electric energy consumption separately 
from fossil fuel energy consumption and to add separate estimates of 
annual fossil fuel energy consumption and annual electrical energy 
consumption in addition to the overall annual energy consumption. This 
separation would allow the user of the test procedure to estimate 
operational cost of water heaters that use both fossil fuel and 
electricity based on the prices of those different energy sources. From 
a consumer's perspective, annual operating cost is particularly useful 
for the products that have dual fuel inputs. DOE believes this consumer 
cost perspective is reasonably reflected in the FFC (i.e., the source/
site factors recommended by the commenter are essentially numerically 
identical to the fuel cost ratios published biennially by the 
Secretary). Therefore, the commenters' suggested addition of a source-
based energy factor using the suggested multipliers is, in DOE's view, 
not likely to convey any improvement in product-to-product comparisons 
relative to annual operating cost. In fact, annual operating cost would 
likely be a superior basis of comparison for consumers, considering the 
familiarity with annual budgets and the lack of familiarity with 
source-based efficiency comparisons.
    In addition, and perhaps more importantly, annual operating cost 
provides a reasonable comparison across competing product types 
utilizing different fuels (e.g., electric water heaters and gas-fueled 
water heaters). Arguably, site-based energy factors for electric water 
heaters (typically approximately 0.9 for an electric resistance model) 
would be higher than the counterpart energy factors for gas water 
heaters (typically approximately 0.6), but not representative of the 
relative efficiency of each type of water heater. Thus, an 
inappropriate conclusion would be conveyed to consumers. DOE believes 
such inappropriate conclusions can be easily avoided in any consumer 
information program by focusing on annual operating cost. Here again, 
the biennial published unit cost of energy would protect the consumer 
from inappropriate conclusions. Accordingly, for purposes of 
representations, DOE is not aware, nor has it been made aware through 
responses to the request for information, of any specific problems, 
shortcomings, or misrepresentations resulting from the existing test 
procedure measures of energy consumption and efficiency as it relates 
to the FFC policy. The proposed amendments to the water heater test 
procedure would provide additional metrics that could be used should 
one desire more information related to the FFC policy for a particular 
application of the test method.
    DOE is interested in receiving comment on adding terms to quantify 
daily electric energy consumption separately from fossil fuel energy 
consumption and adding separate estimates of annual fossil fuel energy 
consumption and annual electrical energy consumption in addition to the 
overall annual energy consumption. This is identified as issue 8 in 
section V.E, ``Issues on Which DOE Seeks Comment.''
    A final issue raised by commenters is that heat pump water heaters 
that have recently entered the market typically have multiple 
operational modes, and the current DOE test procedure does not specify 
which mode should be used when the unit is undergoing testing. AO Smith 
and AHRI commented that all heat pump water heaters should be tested 
under a single mode of operation which is the default or ``out-of-the-
box'' condition. (AO Smith, No. 8 at p. 2; AHRI No. 12 at p. 3) DOE 
agrees with this comment and proposes a clarification to the test 
procedure to indicate that heat pump water heaters are to be tested in 
the default mode when obtaining both the first-hour rating and 
determining the energy factor. This clarification is consistent with 
guidance issued by DOE on June 12, 2012 (see: http://www1.eere.energy.gov/guidance/detail_search.aspx?IDQuestion=623&pid=2&spid=1).

J. Certification, Compliance, and Enforcement Issues

    In this notice of proposed rulemaking, DOE proposes to make several 
changes to its certification, compliance, and enforcement regulations 
at 10 CFR Part 429. First, DOE proposes to add requirements to 10 CFR 
429.17 that the rated value of storage tank volume must equal the mean 
of the measured storage volume of the units in the sample. DOE notes 
that there are currently no requirements from the Department limiting 
the amount of difference that is allowable between the tested (i.e., 
measured) storage volume and the ``rated'' storage volume that is 
specified by the manufacturer. DOE has tested 65 residential storage-
type water heaters, including 44 gas-fired water heaters, 19 electric 
water heaters, and 2 oil-fired water heaters. Through this testing, DOE 
has found that water heaters are consistently rated at storage volumes 
above their actual storage volume. For gas fired water heaters, the 
rated volume ranged from 1.5 to 15.6 percent above the measured volume, 
with the mean being 4.8 percent. For electric water heaters, the rated 
volume ranged from 5.0 to 10.6 percent above the measured volume, with 
the mean being 9.4 percent. DOE notes that its minimum energy 
conservation standards are based on the rated storage volume and 
decrease as rated storage volume increases. DOE also believes consumers 
often look to storage volume as a key factor in choosing a storage 
water heater. Consequently, DOE proposes to adopt rating requirements 
that the rated value must be the mean of the measured value. In 
addition, DOE proposes to specify that for DOE-initiated testing, a 
tested value within five percent of the rated value would be a valid 
test result where the rated storage volume would then be used in 
downstream calculations. If the test result of the volume is invalid 
(i.e., the measured value is more than five percent different than the 
rated value), then DOE proposes to use the measured value in 
determining the applicable minimum energy conservation standard and 
calculations within the test procedure. DOE proposes to specify similar 
requirements for light commercial water heaters.
    Additionally, because the first-hour and maximum gpm ratings will 
determine the applicable draw pattern for use during the energy factor 
test, DOE proposes to include rating requirements for those values. DOE 
proposes that the rated first-hour rating or maximum gpm rating, as 
applicable, must be the mean of the measured values of the sample used 
for certifying the basic model's efficiency rating. For DOE testing, 
the rating will be considered valid if it is within five percent of the 
certified rating. In such a case, DOE proposes that the rated value 
would be used for the purposes of choosing the appropriate draw pattern 
for the energy factor test. In the case of an invalid rating (i.e., the 
rated first-hour rating or maximum gpm rating is more than five percent 
different from the measured value), DOE proposes to use the measured 
value to determine the applicable draw pattern for the energy factor 
test.
    DOE has further considered section 7.0 of the current test 
procedure, ``Ratings for Untested Models,'' and believes that this 
information is more appropriately addressed in the 10 CFR part 429, 
which deals with requirements for certification of residential water 
heaters. DOE proposes to remove this section from Appendix E and place 
a similar section in 10 CFR 429.17. DOE

[[Page 66224]]

proposes to maintain the requirements for gas water heaters, which 
allow units using propane gas that have an input rating within 10 
percent of an identical natural gas unit to use the rating for the 
natural gas unit in lieu of separate testing. However, DOE proposes to 
eliminate the provisions for electric water heaters that currently 
allow a manufacturer of electric water heaters that are identical 
except with different input ratings to designate a standard input 
rating at which to test the water heater.
    Under the current procedure, the manufacturer of electric water 
heaters may designate the standard input rating that would apply to all 
models that are identical with the exception of the power input to the 
heating element and test only at single input rating. It provides 
instructions for specifying the first-hour rating of units with higher 
and lower input ratings than the standard rating. The procedure also 
provides that the energy factor can be assumed to be the same across 
all input ratings. DOE proposes to remove these provisions due to the 
proposed revisions in the test method for the first-hour rating and 
energy factor tests. The first-hour rating would be expected to vary 
based on the power input to the electric heating element, and under the 
revisions proposed in this test method the applicable draw pattern for 
the energy factor test would be based on the first-hour rating. As a 
result, it is important that the first-hour rating is accurate for the 
given model as it will potentially impact the draw pattern and the 
resultant EF rating.

K. Reference Standards

    DOE's test procedure for residential water heaters currently 
references two industry standards: American Society for Testing and 
Measurement (ASTM) D2156-80, ``Smoke Density in Flue Gases from Burning 
Distillate Fuels, Test Method for'' and ASHRAE Standard 41.1-1986, 
``Standard Measurement Guide: Section on Temperature Measurements.''
    DOE proposes to maintain these references in the uniform efficiency 
descriptor test method, but to update the reference standards to the 
most recent versions of the industry standards: ASTM D2156-09, 
``Standard Test Method for Smoke Density in Flue Gases from Burning 
Distillate Fuels'' and ASHRAE Standard 41.1-1986 (RA2006), ``Standard 
Method for Temperature Measurement.'' DOE has reviewed both of the 
updated standards and has tentatively concluded that their adoption 
would not substantially impact the test method.

L. Compliance With Other EPCA Requirements

    As mentioned above, in amending a test procedure, EPCA directs DOE 
to determine to what extent, if any, the test procedure would alter the 
measured energy efficiency or measured energy use of a covered product. 
(42 U.S.C. 6293(e)(1)) If the amended test procedure alters the 
measured energy efficiency or measured energy use, the Secretary must 
amend the applicable energy conservation standard to the extent the 
amended test procedure changes the energy efficiency of products that 
minimally comply with the existing standard. (42 U.S.C. 6293(e)(2)) The 
current energy conservation standards for residential water heaters are 
based on energy factor (EF), and the energy conservation standards for 
commercial water heaters are based on thermal efficiency and standby 
loss. DOE believes that the conversion factor (or factors) required by 
AEMTCA (as discussed in section III.G) will ensure that there is no 
change in measured energy efficiency.
    Consistent with 42 U.S.C. 6293(c), DOE typically requires that any 
representations of energy consumption of covered products must be based 
on any final amended test procedures 180 days after the publication of 
the test procedure final rule. However, in this instance, the statute 
specifically provides for an effective date of the test procedure final 
rule which is one year after the date of the publication of the final 
rule. (42 U.S.C. 6295(e)(5)(D)(ii)) In addition, AEMTCA provides for 
the use of a conversion factor that will apply beginning on the date of 
publication of the conversion factor in the Federal Register and ending 
on the later of 1 year after the date of publication of the conversion 
factor or December 31, 2015. (42 U.S.C. 6295(e)(5)(E)(v)) Thus, one 
year after the publication of the test procedure final rule, it will 
become effective, and manufacturers may at their discretion make 
representations of energy efficiency based either (a) on the final 
amended test procedures or (b) on the previous test procedures after 
applying the conversion factor. The previous test procedures for 
residential water heaters are set forth at 10 CFR part 430, subpart B, 
appendix E as contained in 10 CFR parts 200 to 499 edition revised as 
of January 1, 2013. The previous test procedures for commercial water 
heating equipment are set forth at 10 CFR 431.106 as contained in 10 
CFR parts 200 to 499 edition revised as of January 1, 2013. As required 
by AEMTCA, the conversion factor may be used until the later of one 
year after the publication of the factor, or December 31, 2015, after 
which time all testing must be conducted in accordance with the new 
amended test procedure. DOE notes that during the interim period 
manufacturers must use the same test procedure for representations of 
energy efficiency, including certifications of compliance.

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Order 12866

    The Office of Management and Budget 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 
(IFRA) 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: www.gc.doe.gov/gc/office-general-counsel.
    Today's proposed rule would prescribe test procedure amendments 
that would be used to determine compliance with energy conservation 
standards for residential water heaters and certain commercial water 
heaters. For residential water heaters and certain commercial water 
heaters, the proposed amendments would establish a uniform

[[Page 66225]]

efficiency descriptor which would be more representative of conditions 
encountered in the field (including modifications to both the test 
conditions and the draw patterns), and expand the scope of the test 
procedure to apply to certain residential water heaters and certain 
commercial water heaters that are currently not covered by the test 
procedure. DOE reviewed today's proposed rule under the provisions of 
the Regulatory Flexibility Act and the policies and procedures 
published on February 19, 2003. 68 FR 7990.
    For the manufacturers of the covered water heater products, 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, 30848-49 (May 15, 2000), as 
amended at 65 FR 53533, 53544-45 (Sept. 5, 2000) 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/idc/groups/public/documents/sba_homepage/serv_sstd_tablepdf.pdf. Residential water heater 
manufacturing is classified under NAICS 335228--``Other Major Household 
Appliance Manufacturing.'' The SBA sets a threshold of 500 employees or 
less for an entity to be considered as a small business. Commercial 
water heaters are classified under NAICS 333319 -``Other Commercial and 
Service Industry Machinery Manufacturing,'' for which SBA also sets a 
size threshold of 500 employees or fewer for being considered a small 
business.
    DOE has identified 13 manufacturers of residential water heaters 
(including manufacturers of products that fall under the proposed 
expanded scope) that can be considered small businesses. DOE identified 
nine manufacturers of ``light commercial'' water heaters that can be 
considered small businesses. Seven of the ``light commercial'' water 
heater manufacturers also manufacture residential water heaters, so the 
total number of water heater manufacturers impacted by this rule would 
be 15. DOE's research involved reviewing several industry trade 
association membership directories (e.g., AHRI), product databases 
(e.g., AHRI, CEC, and ENERGY STAR databases), individual company Web 
sites, and marketing research tools (e.g., Hoovers reports) to create a 
list of all domestic small business manufacturers of products covered 
by this rulemaking.
    For the reasons explained below, DOE has tentatively concluded that 
the test procedure amendments contained in this proposed rule would not 
have a significant economic impact on any manufacturer, including small 
manufacturers.
    For residential water heaters, the amendments proposed in today's 
notice of proposed rulemaking apply primarily to the draw pattern and 
water delivery temperature. Under DOE's existing test procedure, 
manufacturers must perform a simulated use test consisting of 6 draws 
of equal lengths with a water heater delivery temperature of 135 
[deg]F. If adopted, today's proposal would require manufacturers to 
perform a simulated use test consisting of 9 to 14 draws of varied 
length, depending on the capacity of the water heater, at a water 
delivery temperature of 125 [deg]F. The change in water delivery 
temperature requires no additional effort or expense for the 
manufacturer, because establishing the test temperature is simply a 
matter of choosing the appropriate setting on the water heater. 
Likewise, the change in the number of draws would also result in very 
little burden on manufacturers. The length and timing of draws for the 
existing test procedure are largely controlled automatically by 
computer control. The proposed changes would result in manufacturers 
having to reprogram the computer test programs to account for the new 
draw patterns. DOE estimates that this effort would take approximately 
one week to program and confirm operation of the amended test. It is 
estimated that approximately two days of a programmer's time would be 
needed at a cost of $1,000 including overhead and benefits. This one-
time cost is comparable to that charged by a third-party test 
laboratory for a single test, so it is not considered burdensome for 
water heater manufacturers. Since the simulated use test takes 24 hours 
under both the existing and proposed test method, the length of the 
test would not change. The current proposal does specify a 24-hour pre-
conditioning period prior to the 24-hour test for storage water 
heaters, however, which would add to the time required to conduct the 
test. This extra test time would not require extra personnel, but it 
may necessitate the development of additional test platforms to 
accommodate the amount of testing that a manufacturer must conduct. A 
duplicate test platform, if necessary, could result in an additional 
cost of approximately $5,000 in terms of materials and time needed for 
construction. DOE understands, however, that a 24-hour pre-conditioning 
period is already implemented by manufacturers as a best practice to 
allow the water heater to achieve operational temperature, so the added 
burden 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 
the proposed rule.
    Lastly, the only potential instrumentation upgrade required to 
conduct the test would be electric power and energy measuring equipment 
that meets the accuracy levels that have changed from  1 
percent to  0.5 percent. DOE believes that equipment 
meeting these tolerances is already the industry standard. Purchase of 
a new instrument, if needed, would be expected to cost approximately 
$1,000.
    For certain commercial water heaters included in the scope of this 
rulemaking, the efficiency test required for equipment would change 
from the thermal efficiency and standby loss tests specified in the 
current DOE test method, to the simulated use test for energy factor 
proposed in today's NOPR. The energy factor test is inherently more 
complex than the thermal efficiency and standby loss tests, and, thus, 
it may be more difficult to implement. However, the standby loss test 
takes a significant amount of time, which is comparable to the 24-hour 
simulated use test. Accordingly, overall testing time should remain 
fairly constant. DOE understands that the complexity of the energy 
factor test would impose additional costs on manufacturers due to the 
need to automate draw patterns, as compared to the thermal efficiency 
test. In addition, some hardware purchases may be needed to allow for 
computer-controlled draws of hot water that are required in a simulated 
use test. However, DOE notes that many commercial water heater 
manufacturers also manufacture residential water heaters, and may 
already have this equipment from testing of residential units. 
Nonetheless, DOE estimates that this hardware could cost approximately 
$1,000, assuming that the laboratory already has a computer-controlled 
data acquisition system to collect data during the thermal efficiency 
and standby loss tests currently required. DOE estimates the costs for 
a programmer to create a computer program that automatically controls 
the hot water draws would be similar to the costs above, but that the 
time required may be slightly longer if the program is being developed 
from scratch. Under such circumstances, DOE estimates that 5 days of 
programmer

[[Page 66226]]

time would be needed for a cost of $2,500, including overhead and 
benefits.
    Lastly, DOE considered the impacts on small businesses that 
manufacture residential water heaters that fall into categories that 
were previously not covered by the DOE residential water heater test 
procedure (e.g., models with storage volumes between 2 and 20 gallons). 
In reviewing the market for these products, DOE did not identify any 
manufacturers that did not also manufacture other types of water 
heating equipment. Thus, DOE believes that these manufacturers would 
already have the needed equipment and computer programs to conduct the 
current DOE test. For the reasons stated previously, DOE does not 
believe the proposed updates will cause significant additional burdens 
for these manufacturers.
    Accordingly, DOE tentatively concludes and certifies that this 
proposed rule would not have a significant economic impact on a 
substantial number of small entities, so DOE has not prepared a 
regulatory flexibility analysis for this rulemaking. DOE will provide 
its certification and supporting statement of factual basis to the 
Chief Counsel for Advocacy of the SBA for review under 5 U.S.C. 605(b).

C. Review Under the Paperwork Reduction Act of 1995

    Manufacturers of water heaters must certify to DOE that their 
products comply with all applicable energy conservation standards. In 
certifying compliance, manufacturers must test their products according 
to the DOE test procedure for water heaters, including any amendments 
adopted for the test procedure 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 residential and commercial water heaters. (76 FR 
12422 (March 7, 2011). 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 20 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 residential and commercial water heaters. 
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 procedures 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 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, 
neither an environmental assessment nor an environmental impact 
statement is required.

E. Review Under Executive Order 13132

    Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 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 products that are the subject of today's 
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)) No further action is required by Executive Order 13132.

F. Review Under Executive Order 12988

    Regarding the review of existing regulations and the promulgation 
of new regulations, section 3(a) of Executive Order 12988, ``Civil 
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal 
agencies the general duty to adhere to the following requirements: (1) 
Eliminate drafting errors and ambiguity; (2) write regulations to 
minimize litigation; (3) provide a clear legal standard for affected 
conduct rather than a general standard; and (4) promote simplification 
and burden reduction. 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 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 regulatory actions likely to result in a rule that may cause the 
expenditure by

[[Page 66227]]

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 ``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.gc.doe.gov/gc/office-general-counsel.) DOE 
examined today's 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 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 today's proposed rule under the OMB 
and DOE guidelines and has concluded that it is consistent with 
applicable policies in those guidelines.

K. Review Under Executive Order 13211

    Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355 
(May 22, 2001), requires Federal agencies to prepare and submit to OIRA 
at OMB, a Statement of Energy Effects for any 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.
    Today's regulatory action to amend the test procedures for 
measuring the energy efficiency of residential water heaters and 
certain commercial water heaters is not a significant regulatory action 
under Executive Order 12866 or any successor order. Moreover, it would 
not have a significant adverse effect on the supply, distribution, or 
use of energy, nor has it been designated as a significant energy 
action by the Administrator of OIRA. Therefore, it is not a significant 
energy action, and, accordingly, DOE has not prepared a Statement of 
Energy Effects for this rulemaking.

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.
    Today's proposed rule would incorporate testing methods contained 
in the following commercial standards: (1) ASTM D2156-09, ``Standard 
Test Method for Smoke Density in Flue Gases from Burning Distillate 
Fuels''; and (2) ASHRAE Standard 41.1-1986 (RA 2006), ``Standard Method 
for Temperature Measurement.'' While today's proposed test procedure is 
not exclusively based on these standards, components of the test 
procedures are adopted directly 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 
on competition of requiring manufacturers to use the test methods 
contained in these standards prior to prescribing a final rule.

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]. As explained in the 
ADDRESSES section, foreign nationals visiting DOE Headquarters are 
subject to advance security screening procedures. Any foreign national 
wishing to participate in the meeting should advise DOE of this fact as 
soon as possible by contacting Ms. Brenda Edwards to initiate the 
necessary procedures.
    In addition, you can attend the public meeting via webinar. Webinar 
registration information, participant instructions, and information 
about the capabilities available to webinar

[[Page 66228]]

participants will be published on DOE's Web site at: http://www1.eere.energy.gov/buildings/appliance_ standards/
rulemaking.aspx?ruleid=82. Participants are responsible for ensuring 
their systems are compatible with the webinar software.

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 
notice, 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 notice of proposed rulemakiing 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-2J, 1000 Independence 
Avenue SW., Washington, DC 20585-0121, or [email protected]. 
Persons who wish to speak should include in 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 selected to make an oral presentation to 
submit an advance copy of their statements at least one week before the 
public meeting. 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.
    Any person who has plans to present a prepared general statement 
may request that copies of his or her statement be made available at 
the public meeting. Such persons may submit requests, along with an 
advance electronic copy of their statement in PDF (preferred), 
Microsoft Word or Excel, WordPerfect, or text (ASCII) file format, to 
the appropriate address shown in the ADDRESSES section at the beginning 
of this notice of proposed rulemaking. The request and advance copy of 
statements must be received at least one week before the public meeting 
and may be emailed, hand-delivered, or sent by mail. DOE prefers to 
receive requests and advance copies via email. Please include a 
telephone number to enable DOE staff to make follow-up contact, if 
needed.

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, interested 
parties may submit further comments on the proceedings, as well as on 
any aspect of the rulemaking, until the end of the comment period.
    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 notice of the proposed rulemaking, 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 using any of the methods 
described in the ADDRESSES section at the beginning of this notice of 
proposed rulemaking.
    Submitting comments via 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 
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    Do not submit to www.regulations.gov information for which 
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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.
    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

[[Page 66229]]

simultaneously, your comment may not be viewable for up to several 
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Comments and documents submitted via email, hand delivery/ courier, or 
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    Include contact information each time you submit comments, data, 
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    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 
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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 
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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:
    1. Is the proposed definition of ``light commercial water heater'' 
appropriate, and is it appropriate to test commercial water heaters 
meeting this definition under the uniform descriptor, while testing all 
other commercial water heaters using thermal efficiency and standby 
loss?
    2. Is information or data available regarding the translation of 
current first-hour ratings to a first-hour rating determined using the 
proposed 125 [deg]F set point? What is the effect of such translation 
on the appropriate breakpoints between different size categories?
    3. Is the proposed method of characterizing water heaters as point-
of-use, low, medium, or high appropriate and sufficient?
    4. Are the draw patterns proposed for the different water heater 
size categories appropriate?
    5. What is the added burden, if any, in requiring a 24-hour pre-
conditioning period for storage-type water heaters compared to current 
practice?
    6. Is the proposed change to the nominal water delivery temperature 
to 125 [deg]F appropriate, and if not, what data or information is 
available that would justify a different water delivery temperature?
    7. Is the proposed method for setting the thermostat(s) of storage-
type water heaters appropriate?
    8. The addition of terms to quantify daily electric energy 
consumption separately from fossil fuel energy consumption and adding 
separate estimates of annual fossil fuel energy consumption and annual 
electrical energy consumption in addition to the overall annual energy 
consumption.

VI. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of today's 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, 
Incorporation by reference, Intergovernmental relations, Small 
businesses.

10 CFR Part 431

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

    Issued in Washington, DC, on October 28, 2013.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy Efficiency, Energy Efficiency and 
Renewable Energy.

    For the reasons stated 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 429.17 is amended by adding new paragraphs (a)(2)(iii), 
(a)(2)(iv), (c), and (d) to read as follows:


Sec.  429.17  Residential water heaters.

    (a) * * *
    (2) * * *

[[Page 66230]]

    (iii) Any represented value of the rated storage volume must be 
calculated as the mean of the measured storage volumes, Vst, 
of all the units within the sample.
    (iv) Any represented value of first-hour rating for storage water 
heaters or maximum gallons per minute (gpm for instantaneous water 
heaters must be calculated as the mean of the measured first-hour 
ratings or measured max gpm ratings, respectively, of all the units 
within the sample.
* * * * *
    (c) Determination of ratings for untested basic models. 
Manufacturers of gas-fired water heaters are not required to test other 
models that differ from tested basic models only in whether the unit 
uses natural gas or propane gas. In lieu of testing, the represented 
value for a model that utilizes propane gas must be identical to the 
basic model that utilizes natural gas as long as the rated input 
ratings are within 10% for both basic models.
    (d) Represented values. The requirements of Sec.  429.17 are 
applicable to all values reported in accordance with paragraphs (b) and 
(c) of this section. Represented values of energy factor shall be 
rounded off to the nearest 0.01.
0
3. Section 429.44 is amended by:
0
a. Redesignating paragraphs (a), (b) and (c) as (b), (c) and (d);
0
b. Adding a new paragraph (a); and
0
c. Revising newly redesignated paragraph (b).
    The revisions and additions read as follows:


Sec.  429.44  Commercial water heating equipment.

    (a) For light commercial water heaters, all represented values 
should be determined in accordance with Sec.  429.17.
    (b) Determination of Represented Value for All Types of Commercial 
Water Heaters except Light Commercial Water Heaters. Manufacturers can 
determine the represented value, which includes the certified rating, 
for each basic model of commercial water heating equipment except light 
commercial water heaters, either by testing, in conjunction with the 
applicable sampling provisions, or by applying a validated AEDM.
* * * * *
0
4. Add Sec.  429.134 to read as follows:


Sec.  429.134  Product-specific enforcement provisions.

    (a) [Reserved].
    (b) [Reserved].
    (c) [Reserved].
    (d) Residential Water Heaters and Light Commercial Water Heaters. 
(1) Verification of rated first-hour rating and rated maximum gpm 
rating. The first-hour rating (for storage water heaters) or maximum 
gallons per minute (gpm) rating (for instantaneous water heaters) of 
the basic model will be measured pursuant to the test requirements of 
part 430 for each unit tested. The results of the measurement(s) will 
be averaged and compared to the value of first-hour rating (for storage 
water heaters) or maximum gpm rating (for instantaneous water heaters) 
certified by the manufacturer. The certified rating will be considered 
valid only if the measurement is within five percent of the certified 
rating.
    (i) If the certified first-hour rating or maximum gpm rating is 
found to be valid, that rating will be used as the basis for 
determining the applicable draw pattern pursuant to the test 
requirements of part 430 for each unit tested.
    (ii) If the certified first-hour rating or maximum gpm rating is 
found to be invalid, the average measured rating will serve as the 
basis for determining the applicable draw pattern pursuant to the test 
requirements of part 430 for each unit tested.
    (2) Verification of rated storage volume. The storage volume of the 
basic model will be measured pursuant to the test requirements of part 
430 for each unit tested. The results of the measurement(s) will be 
averaged and compared to the rated storage volume certified by the 
manufacturer. The certified rating will be considered valid only if the 
measurement is within five percent of the certified rating.
    (i) If the certified rated storage volume is found to be valid, 
that volume will be used as the basis for calculation of the required 
energy factor for the basic model.
    (ii) If the certified rated storage volume is found to be invalid, 
the average measured volume will be used as the basis for calculation 
of the required energy factor for the basic model.

PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

0
5. 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
6. Section 430.2 is amended by adding the definitions of ``Electric 
instantaneous water heater,'' ``Electric storage water heater,'' ``Gas-
fired instantaneous water heater,'' ``Gas-fired storage water heater,'' 
``Heat pump water heater,'' and ``Oil storage water heater'' in 
alphabetical order, to read as follows:


Sec.  430.2  Definitions.

* * * * *
    Electric instantaneous water heater means a water heater that uses 
electricity as the energy source, initiates heating based on sensing 
water flow, is not capable of delivering water at a controlled 
temperature of 180 [deg]F (82 [deg]C) or greater, has a maximum 
nameplate input rating 12 kW (40,956 Btu/h) or less, and has a rated 
storage capacity of less than 2 gallons (7.6 liters). The unit may use 
a fixed or variable burner input.
* * * * *
    Electric storage water heater means a water heater that uses 
electricity as the energy source, is not capable of heating and storing 
water at a thermostatically controlled temperature of 180 [deg]F (82 
[deg]C) or greater, has a maximum nameplate input rating of 12 kW 
(40,956 Btu/h) or less, and has a rated storage capacity of not less 
than 2 gallons (7.6 liters) nor more than 120 gallons (450 liters).
* * * * *
    Gas-fired instantaneous water heater means a water heater that uses 
gas as the main energy source, initiates heating based on sensing water 
flow, is not capable of delivering water at a controlled temperature of 
180[emsp14] [deg]F (82 [deg]C) or greater, has a maximum nameplate 
input rating less than 200,000 Btu/h (210 MJ/h), and has a rated 
storage capacity of less than 2 gallons (7.6 liters). The unit may use 
a fixed or variable burner input.
    Gas-fired storage water heater means a water heater that uses gas 
as the main energy source, is not capable of heating and storing water 
at a thermostatically controlled temperature of 180[emsp14] [deg]F (82 
[deg]C) or greater, has a maximum nameplate input rating of 75,000 Btu/
h (79 MJ/h) or less, and has a rated storage capacity of not less than 
2 gallons (7.6 liters) nor more than 120 gallons (380 liters).
* * * * *
    Heat pump water heater means a water heater that uses electricity 
as the energy source, is not capable of heating and storing water at a 
thermostatically-controlled temperature of 180 [deg]F (82 [deg]C) or 
greater, has a maximum current rating of 24 amperes (including the 
compressor and all auxiliary equipment such as fans, pumps, controls, 
and, if on the same circuit, any resistive elements) for an input 
voltage of 250 volts or less, and, has a rated storage capacity of 120 
gallons (450 liters) or less.
* * * * *

[[Page 66231]]

    Oil storage water heater means a water heater that uses oil as the 
energy source, is not capable of heating and storing water at a 
thermostatically controlled temperature of 180[emsp14] [deg]F (82 
[deg]C) or greater, has a nameplate input rating of 105,000 Btu/h (110 
MJ/h) or less, and has a manufacturer's rated storage capacity of 120 
gallons (190 liters) or less.
* * * * *
0
7. Section 430.3 is amended by:
0
a. Adding paragraph (f)(11);
0
b. Redesignating paragraphs (h) through (p) as (i) through (o), 
respectively; and
0
c. Adding a new paragraph (h).
    The additions read as follows:


Sec.  430.3  Materials incorporated by reference.

* * * * *
    (f) * * *
    (11) ASHRAE 41.1-1986 (RA 2006), Standard Method for Temperature 
Measurement, ASHRAE approved June 27, 2007, ANSI approved March 25, 
2008, IBR approved for appendix E to subpart B of this part.
* * * * *
    (h) ASTM. American Society for Testing and Materials International, 
100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959 
(www.astm.org).
    (1) ASTM D2156-09 (``ASTM D2156''), Standard Test Method for Smoke 
Density in Flue Gases from Burning Distillate Fuels, Edition 09, ASTM 
approved December 1, 2009, IBR approved for appendix E to subpart B of 
this part.
    (2) [Reserved]
* * * * *
0
8. Section 430.23 is amended by revising paragraph (e) to read as 
follows:


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

* * * * *
    (e) Water Heaters. (1) The estimated annual operating cost for 
water heaters shall be--
    (i) For a gas or oil water heater, the sum of (a) the product of 
the annual gas or oil energy consumption, determined according to 
section 6.1.10 or 6.2.7 of appendix E of this subpart, times the 
representative average unit cost of gas or oil, as appropriate, in 
dollars per Btu as provided by the Secretary; plus (b) the product of 
the annual electric energy consumption, determined according to section 
6.1.9 or 6.2.6 of appendix E of this subpart, times the representative 
average unit cost of electricity in dollars per kilowatt-hour as 
provided by the Secretary, the resulting sum then being rounded off to 
the nearest dollar per year.
    (ii) For an electric water heater, the product of the annual energy 
consumption, determined according to section 6.1.9 or 6.2.6 of appendix 
E of this subpart, times the representative average unit cost of 
electricity in dollars per kilowatt-hour as provided by the Secretary, 
the resulting product then being rounded off to the nearest dollar per 
year.
    (2) For an individual test, the tested energy factor for a water 
heater shall be--
    (i) For a gas or oil water heater, as determined by section 6.1.7 
or 6.2.4 of appendix E of this subpart rounded to the nearest 0.01.
    (ii) For an electric water heater, as determined by section 6.1.7 
or 6.2.4 of appendix E of this subpart rounded to the nearest 0.01.
* * * * *
0
9. Appendix E to Subpart B of Part 430 is revised to read as follows:

Appendix E to Subpart B of Part 430--Uniform Test Method for Measuring 
the Energy Consumption of Water Heaters

    Note: After [date 365 days after publication of a final rule in 
the Federal Register that establishes a conversion factor, or 
December 31, 2015, whichever is later], any representations made 
with respect to the energy use or efficiency of residential water 
heaters and commercial water heaters covered by this test method 
must be made in accordance with the results of testing pursuant to 
this appendix.
    Manufacturers conducting tests of residential water heaters and 
commercial water heaters covered by this test method after [date 365 
days after publication of the test procedure final rule in the 
Federal Register] and prior to [date 365 days after publication of 
the final rule in the Federal Register that establishes a conversion 
factor, or December 31, 2015, whichever is later] must conduct such 
test in accordance with either this appendix or previous test 
method. For residential water heaters the previous test method is 
appendix E as it appeared at 10 CFR part 430, subpart B, appendix E, 
in the 10 CFR parts 200 to 499 edition revised as of January 1, 
2013. For commercial water heaters the previous test method is 10 
CFR 431.106 in the 10 CFR parts 200 to 499 edition revised as of 
January 1, 2013. Any representations made with respect to the energy 
use or efficiency of such water heaters must be in accordance with 
whichever version is selected.

1. Definitions

    1.1. Cut-in means the time when or water temperature at which a 
water heater control or thermostat acts to increase the energy or 
fuel input to the heating elements, compressor, or burner.
    1.2. Cut-out means the time when or water temperature at which a 
water heater control or thermostat acts to reduce to a minimum the 
energy or fuel input to the heating elements, compressor, or burner.
    1.3. Design Power Rating means the nominal power rating that a 
water heater manufacturer assigns to a particular design of water 
heater, expressed in kilowatts or Btu (kJ) per hour as appropriate.
    1.4. Draw Cluster means a collection of water draw events during 
the simulated-use test that are closely grouped in time.
    1.5. Energy Factor means the measure of water heater overall 
efficiency.
    1.6. First-Hour Rating means the estimate of the maximum volume 
of ``hot'' water that a storage-type water heater can supply within 
an hour that begins with the water heater fully heated (i.e., with 
all thermostats satisfied). It is a function of both the storage 
volume and the recovery rate.
    1.7. Heat Trap means a device which can be integrally connected 
or independently attached to the hot and/ or cold water pipe 
connections of a water heater such that the device will develop a 
thermal or mechanical seal to minimize the recirculation of water 
due to thermal convection between the water heater tank and its 
connecting pipes.
    1.8. Maximum gpm (L/ min) Rating means the maximum gallons per 
minute (liters per minute) of hot water that can be supplied by an 
instantaneous water heater while maintaining a nominal temperature 
rise of 67 [deg]F (37.3 [deg]C) during steady-state operation, as 
determined by testing in accordance with section 5.3.2 of this 
appendix.
    1.9. Rated Storage Volume means the water storage capacity of a 
water heater, in gallons (liters), as certified by the manufacturer 
pursuant to 10 CFR part 429.
    1.10. Recovery Efficiency means the ratio of energy delivered to 
the water to the energy content of the fuel consumed by the water 
heater.
    1.11. Recovery Period means the time when the main burner of a 
storage water heater is raising the temperature of the stored water.
    1.12. Standby means the time, in hours, during which water is 
not being withdrawn from the water heater. There are two standby 
time intervals used within this test procedure: 
[tau]stby,1 represents the elapsed time between the time 
at which the maximum mean tank temperature is observed after the 
first draw cluster and the minute prior to the start of the first 
draw following the end of the first draw cluster of the 24-hour 
simulated use test; [tau]stby,2 represents the total time 
during the 24-hour simulated use test when water is not being 
withdrawn from the water heater.
    1.13. Symbol Usage. The following identity relationships are 
provided to help clarify the symbology used throughout this 
procedure:

Cp specific heat of water
Eannual annual energy consumption of a water heater
Eannual,e annual electrical energy consumption of a water heater
Eannual,f annual fossil-fuel energy consumption of a water heater
Ef energy factor of a water heater
Fhr first-hour rating of a storage-type water heater
Fmax maximum gpm (L/ min) rating of an instantaneous water heater 
rated at a temperature rise of 67 [deg]F (37.3 [deg]C)

[[Page 66232]]

i a subscript to indicate the draw number during a test
Mi mass of water removed during the ith draw of the 24-hr simulated 
use test
M*i for storage-type water heaters, mass of water removed during the 
ith draw during the first-hour rating test
M10m for instantaneous water heaters, mass of water removed 
continuously during a 10-minute interval in the maximum gpm (L/min) 
rating test
n for storage-type water heaters, total number of draws during the 
first-hour rating test
N total number of draws during the 24-hr simulated use test
Q total fossil fuel and/or electric energy consumed during the 
entire 24-hr simulated use test
Qd daily water heating energy consumption adjusted for net change in 
internal energy
Qda Qd with adjustment for variation of tank to ambient 
air temperature difference from nominal value
Qdm overall adjusted daily water heating energy consumption 
including Qda and QHWD
Qe total electrical energy used during the 24-hour simulated use 
test
Qf total fossil fuel energy used by the water heater during the 24-
hour simulated use test
Qhr hourly standby losses
QHW daily energy consumption to heat water at the measured average 
temperature rise across the water heater
QHW,67 [deg]F daily energy consumption to heat quantity of water 
removed during test over a temperature rise of 67 [deg]F (37.3 
[deg]C)
QHWD adjustment to daily energy consumption, QHW, due to 
variation of the temperature rise across the water heater not equal 
to the nominal value of 67 [deg]F
Qr energy consumption of water heater from the beginning of the test 
to the end of the first recovery period following the first draw, 
which may extend beyond subsequent draws
Qstby total energy consumed by the water heater during the standby 
time interval [tau]stby,1
Qsu,0 total fossil fuel and/or electric energy consumed from the 
beginning of the test to the end of the cutout following the first 
draw cluster
Qsu,f total fossil fuel and/or electric energy consumed from the 
beginning of the test to the initiation of the first draw following 
the first draw cluster
T0 mean tank temperature at the beginning of the 24-hr simulated use 
test
T24 mean tank temperature at the end of the 24-hr simulated use test
Ta,stby average ambient air temperature during standby periods of 
the 24-hr simulated use test
Tdel for instantaneous water heaters, average outlet water 
temperature during a 10-minute continuous draw interval in the 
maximum gpm (L/ min) rating test
Tdel,i average outlet water temperature during the ith draw of the 
24-hr simulated use test
Tin for instantaneous water heaters, average inlet water temperature 
during a 10-minute continuous draw interval in the maximum gpm (L/ 
min) rating test
Tin,i average inlet water temperature during the ith draw of the 24-
hr simulated use test
Tmax,1 maximum measured mean tank temperature after cut-out 
following the first draw of the 24-hr simulated use test
Tstby average storage tank temperature during the standby period 
[tau]stby,2 of the 24-hr simulated use test
Tsu,0 maximum measured mean tank temperature at the beginning of the 
standby period which occurs after cut-out following the final draw 
of the first draw cluster
Tsu,f measured mean tank temperature at the end of the standby 
period which occurs at the minute prior to commencement of the first 
draw that follows the end of the first draw cluster
Tt,stby average storage tank temperature during the standby period 
[tau]stby,1 of the 24-hr simulated use test
T*del,i for storage-type water heaters, average outlet 
water temperature during the ith draw (i=1 to n) of the first-hour 
rating test
T*max,i for storage-type water heaters, maximum outlet 
water temperature observed during the ith draw (i=1 to n) of the 
first-hour rating test
T*min,i for storage-type water heaters, minimum outlet 
water temperature to terminate the ith draw (i=1 to n) of the first-
hour rating test
UA standby loss coefficient of a storage-type water heater
Vi volume of water removed during the ith draw (i=1 to N) of the 24-
hr simulated use test
V*i volume of water removed during the ith draw (i=1 to n) of the 
first-hour rating test
V10m for instantaneous water heaters, volume of water removed 
continuously during a 10-minute interval in the maximum gpm (L/ min) 
rating test
Vst measured storage volume of the storage tank
Wf weight of storage tank when completely filled with water
Wt tare weight of storage tank when completely empty of water
[eta]r recovery efficiency
[rho] density of water
[tau]stby,1 elapsed time between the time the maximum mean tank 
temperature is observed after the first draw cluster and the minute 
prior to the start of the first draw following the first draw 
cluster
[tau]stby,2 overall time of standby periods when no water is 
withdrawn during the 24-hr simulated use test

2. Test Conditions

    2.1 Installation Requirements. Tests shall be performed with the 
water heater and instrumentation installed in accordance with 
Section 4 of this appendix.
    2.2 Ambient Air Temperature. The ambient air temperature shall 
be maintained between 65.0 [deg]F and 70.0 [deg]F (18.3 [deg]C and 
21.1 [deg]C) on a continuous basis. For heat pump water heaters, the 
dry bulb temperature shall be maintained at 67.5 [deg]F  
1 [deg]F (19.7 [deg]C  0.6 [deg]C) and, in addition, the 
relative humidity shall be maintained between 48% and 52% throughout 
the test.
    2.3 Supply Water Temperature. The temperature of the water being 
supplied to the water heater shall be maintained at 58 [deg]F  2 [deg]F (14.4 [deg]C  1.1 [deg]C) throughout the 
test.
    2.4 Storage Tank Temperature. The thermostats of a storage-type 
water heater shall be set so that water is delivered at a 
temperature of 125 [deg]F  5 [deg]F (51.7[deg]C  2.8 [deg]C).
    2.5 Set Point Temperature. The thermostat of instantaneous water 
heaters shall be set to deliver water at a temperature of 125 [deg]F 
 5 [deg]F (51.7 [deg]C  2.8 [deg]C).
    2.6 Supply Water Pressure. During the test when water is not 
being withdrawn, the supply pressure shall be maintained between 40 
psig (275 kPa) and the maximum allowable pressure specified by the 
water heater manufacturer.
    2.7 Electrical and/ or Fossil Fuel Supply.
    2.7.1 Electrical. Maintain the electrical supply voltage to 
within 1% of the center of the voltage range specified 
by the water heater and/or heat pump manufacturer.
    2.7.2 Natural Gas. Maintain the supply pressure in accordance 
with the manufacturer's specifications. If the supply pressure is 
not specified, maintain a supply pressure of 7-10 inches of water 
column (1.7-2.5 kPa). If the water heater is equipped with a gas 
appliance pressure regulator, the regulator outlet pressure shall be 
within  10% of the manufacturer's specified manifold 
pressure. For all tests, use natural gas having a heating value of 
approximately 1,025 Btu per standard cubic foot (38,190 kJ per 
standard cubic meter).
    2.7.3 Propane Gas. Maintain the supply pressure in accordance 
with the manufacturer's specifications. If the supply pressure is 
not specified, maintain a supply pressure of 11-13 inches of water 
column (2.7-3.2 kPa). If the water heater is equipped with a gas 
appliance pressure regulator, the regulator outlet pressure shall be 
within  10% of the manufacturer's specified manifold 
pressure. For all tests, use propane gas with a heating value of 
approximately 2,500 Btu per standard cubic foot (93,147 kJ per 
standard cubic meter).
    2.7.4 Fuel Oil Supply. Maintain an uninterrupted supply of fuel 
oil. Use fuel oil having a heating value of approximately 138,700 
Btu per gallon (38,660 kJ per liter).

3. Instrumentation

    3.1 Pressure Measurements. Pressure-measuring instruments shall 
have an error no greater than the following values:

------------------------------------------------------------------------
        Item measured          Instrument accuracy  Instrument precision
------------------------------------------------------------------------
Gas pressure................  0.1 inch  0.05
                               of water column       inch of water
                               (0.025    column (0.012 kPa).
Atmospheric pressure........  0.1 inch  0.05
                               of mercury column     inch of mercury
                               (0.34     column (0.17 kPa).

[[Page 66233]]

 
Water pressure..............  1.0       0.50
                               pounds per square     pounds per square
                               inch (6.9 kPa).       minus>3.45 kPa).
------------------------------------------------------------------------

    3.2 Temperature Measurement
    3.2.1 Measurement. Temperature measurements shall be made in 
accordance with the Standard Method for Temperature Measurement, 
ASHRAE Standard 41.1-1986 (RA 2006).
    3.2.2 Accuracy and Precision. The accuracy and precision of the 
instruments, including their associated readout devices, shall be 
within the following limits:

------------------------------------------------------------------------
        Item measured          Instrument accuracy  Instrument precision
------------------------------------------------------------------------
Air dry bulb temperature....  0.2       0.1
                               [deg]F (0.1 [deg]C).    minus>0.06 [deg]C).
Air wet bulb temperature....  0.2       0.1
                               [deg]F (0.1 [deg]C).    minus>0.06 [deg]C).
Inlet and outlet water        0.2       0.1
 temperatures.                 [deg]F (0.1 [deg]C).    minus>0.06 [deg]C).
Storage tank temperatures...  0.5       0.25
                               [deg]F (0.3 [deg]C).    minus>0.14 [deg]C).
------------------------------------------------------------------------

    3.2.3 Scale Division. In no case shall the smallest scale 
division of the instrument or instrument system exceed 2 times the 
specified precision.
    3.2.4 Temperature Difference. Temperature difference between the 
entering and leaving water may be measured with any of the 
following:

a. A thermopile
b. Calibrated resistance thermometers
c. Precision thermometers
d. Calibrated thermistors
e. Calibrated thermocouples
f. Quartz thermometers
    3.2.5 Thermopile Construction. If a thermopile is used, it shall 
be made from calibrated thermocouple wire taken from a single spool. 
Extension wires to the recording device shall also be made from that 
same spool.
    3.2.6 Time constant. The time constant of the instruments used 
to measure the inlet and outlet water temperatures shall be no 
greater than 2 seconds.
    3.3 Liquid Flow Rate Measurement. The accuracy of the liquid 
flow rate measurement, using the calibration if furnished, shall be 
equal to or less than 1% of the measured value in mass 
units per unit time.
    3.4 Electrical Energy. The electrical energy used shall be 
measured with an instrument and associated readout device that is 
accurate within 0.5% of the reading.
    3.5 Fossil Fuels. The quantity of fuel used by the water heater 
shall be measured with an instrument and associated readout device 
that is accurate within 1% of the reading.
    3.6 Mass Measurements. For mass measurements greater than or 
equal to 10 pounds (4.5 kg), a scale that is accurate within 0.5% of the reading shall be used to make the measurement. For 
mass measurements less than 10 pounds (4.5 kg), the scale shall 
provide a measurement that is accurate within 0.1 pound 
(0.045 kg).
    3.7 Heating Value. The higher heating value of the natural gas, 
propane, or fuel oil shall be measured with an instrument and 
associated readout device that is accurate within 1% of 
the reading. The heating values of natural gas and propane must be 
corrected from those reported at standard temperature and pressure 
conditions to provide the heating value at the temperature and 
pressure measured at the fuel meter.
    3.8 Time. The elapsed time measurements shall be measured with 
an instrument that is accurate within 0.5 seconds per 
hour.
    3.9 Volume. Volume measurements shall be measured with an 
accuracy of 2% of the total volume.
    3.10 Relative Humidity. If a relative humidity (RH) transducer 
is used to measure the relative humidity of the surrounding air 
while testing heat pump water heaters, the relative humidity shall 
be measured with an accuracy of 1.5% RH.

4. Installation

    4.1 Water Heater Mounting. A water heater designed to be 
freestanding shall be placed on a \3/4\ inch (2 cm) thick plywood 
platform supported by three 2 x 4 inch (5 cm x 10 cm) runners. If 
the water heater is not approved for installation on combustible 
flooring, suitable non-combustible material shall be placed between 
the water heater and the platform. Counter-top water heaters shall 
be placed against a simulated wall section. Wall-mounted water 
heaters shall be supported on a simulated wall in accordance with 
the manufacturer-published installation instructions. When a 
simulated wall is used, the construction shall be 2 x 4 inch (5 cm x 
10 cm) studs, faced with \3/4\ inch (2 cm) plywood. For heat pump 
water heaters not delivered as a single package, the units shall be 
connected in accordance with the manufacturer-published installation 
instructions and the overall system shall be placed on the above-
described plywood platform. If installation instructions are not 
provided by the heat pump manufacturer, uninsulated 8 foot (2.4 m) 
long connecting hoses having an inside diameter of \5/8\ inch (1.6 
cm) shall be used to connect the storage tank and the heat pump 
water heater. The testing of the water heater shall occur in an area 
that is protected from drafts of more than 50 ft/ min (2.5 m/s) from 
room ventilation registers, windows, or other external sources of 
air movement.
    4.2 Water Supply. Connect the water heater to a water supply 
capable of delivering water at conditions as specified in Sections 
2.3 and 2.6 of this appendix.
    4.3 Water Inlet and Outlet Configuration. For freestanding water 
heaters that are taller than 36 inches (91.4 cm), inlet and outlet 
piping connections shall be configured in a manner consistent with 
Figures 1 and 2. Inlet and outlet piping connections for wall-
mounted water heaters shall be consistent with Figure 3. For 
freestanding water heaters that are 36 inches or less in height and 
not supplied as part of a counter-top enclosure (commonly referred 
to as an under-the-counter model), inlet and outlet piping shall be 
installed in a manner consistent with Figures 4, 5, and 6. For water 
heaters that are supplied with a counter-top enclosure, inlet and 
outlet piping shall be made in a manner consistent with Figures 7A 
and 7B, respectively. The vertical piping noted in Figures 7A and 7B 
shall be located (whether inside the enclosure or along the outside 
in a recessed channel) in accordance with the manufacturer-published 
installation instructions.
    All dimensions noted in Figures 1 through 7 shall be achieved. 
All piping between the water heater and inlet and outlet temperature 
sensors, noted as TIN and TOUT in the figures, 
shall be Type ``L'' hard copper having the same diameter as the 
connections on the water heater. Unions may be used to facilitate 
installation and removal of the piping arrangements. A pressure 
gauge and diaphragm expansion tank shall be installed in the supply 
water piping at a location upstream of the inlet temperature sensor. 
An appropriately rated pressure and temperature relief valve shall 
be installed on all water heaters at the port specified by the 
manufacturer. Discharge piping for the relief valve shall be non-
metallic. If heat traps, piping insulation, or pressure relief valve 
insulation are supplied with the water heater, they shall be 
installed for testing. Except when using a simulated wall, clearance 
shall be provided such that none of the piping contacts other 
surfaces in the test room.
    4.4 Fuel and/or Electrical Power and Energy Consumption. Install 
one or more instruments that measure, as appropriate, the quantity 
and rate of electrical energy and/or fossil fuel consumption in 
accordance with section 3.
    4.5 Internal Storage Tank Temperature Measurements. For water 
heaters with rated storage volumes greater than or equal to 20 
gallons, install six temperature measurement sensors inside the 
water heater tank with a vertical distance of at least 4 inches (100 
mm) between successive sensors. For water heaters with rated storage 
volumes between 2 and 20 gallons, install three temperature 
measurement sensors inside the water heater

[[Page 66234]]

tank. A temperature sensor shall be positioned at the vertical 
midpoint of each of the six equal volume nodes within a tank larger 
than 20 gallons or the three equal volume nodes within a tank 
between 2 and 20 gallons. Nodes designate the equal volumes used to 
evenly partition the total volume of the tank. As much as is 
possible, the temperature sensor should be positioned away from any 
heating elements, anodic protective devices, tank walls, and flue 
pipe walls. If the tank cannot accommodate six temperature sensors 
and meet the installation requirements specified above, install the 
maximum number of sensors which comply with the installation 
requirements. The temperature sensors shall be installed either 
through: (1) The anodic device opening; (2) the relief valve 
opening; or (3) the hot water outlet. If installed through the 
relief valve opening or the hot water outlet, a tee fitting or 
outlet piping, as applicable, shall be installed as close as 
possible to its original location. If the relief valve temperature 
sensor is relocated, and it no longer extends into the top of the 
tank, a substitute relief valve that has a sensing element that can 
reach into the tank shall be installed. If the hot water outlet 
includes a heat trap, the heat trap shall be installed on top of the 
tee fitting. Added fittings shall be covered with thermal insulation 
having an R value between 4 and 8 h[middot]ft\2\[middot][deg]F/Btu 
(0.7 and 1.4 m\2\[middot][deg]C/W).
    4.6 Ambient Air Temperature Measurement. Install an ambient air 
temperature sensor at the vertical mid-point of the water heater and 
approximately 2 feet (610 mm) from the surface of the water heater. 
The sensor shall be shielded against radiation.
    4.7 Inlet and Outlet Water Temperature Measurements. Install 
temperature sensors in the cold-water inlet pipe and hot-water 
outlet pipe as shown in Figures 1, 2, 3, 4, 5, 6, 7a, and 7b, as 
applicable.
    4.8 Flow Control. A valve or valves shall be installed to 
provide flow as specified in sections 5.2.4.1 and 5.4 for storage 
tank water heaters and sections 5.3.1 and 5.4 for instantaneous 
water heaters.
    4.9 Flue Requirements.
    4.9.1 Gas-Fired Water Heaters. Establish a natural draft in the 
following manner. For gas-fired water heaters with a vertically 
discharging draft hood outlet, a 5-foot (1.5-meter) vertical vent 
pipe extension with a diameter equal to the largest flue collar size 
of the draft hood shall be connected to the draft hood outlet. For 
gas-fired water heaters with a horizontally discharging draft hood 
outlet, a 90-degree elbow with a diameter equal to the largest flue 
collar size of the draft hood shall be connected to the draft hood 
outlet. A 5-foot (1.5-meter) length of vent pipe shall be connected 
to the elbow and oriented to discharge vertically upward. Direct 
vent gas-fired water heaters shall be installed with venting 
equipment specified in the manufacturer's instructions using the 
minimum vertical and horizontal lengths of vent pipe recommended by 
the manufacturer.
    4.9.2 Oil-Fired Water Heaters. Establish a draft at the flue 
collar at the value specified in the manufacturer's instructions. 
Establish the draft by using a sufficient length of vent pipe 
connected to the water heater flue outlet, and directed vertically 
upward. For an oil-fired water heater with a horizontally 
discharging draft hood outlet, a 90-degree elbow with a diameter 
equal to the largest flue collar size of the draft hood shall be 
connected to the draft hood outlet. A length of vent pipe sufficient 
to establish the draft shall be connected to the elbow fitting and 
oriented to discharge vertically upward. Direct-vent oil-fired water 
heaters should be installed with venting equipment as specified in 
the manufacturer's instructions, using the minimum vertical and 
horizontal lengths of vent pipe recommended by the manufacturer.

5. Test Procedures

    5.1 Operational Mode Selection. For water heaters that allow for 
multiple user-selected operational modes, all procedures specified 
in this appendix shall be carried out with the water heater in the 
same operational mode (i.e., only one mode). This operational mode 
shall be the default mode (or similarly-named, suggested mode for 
normal operation) as defined by the manufacturer in its product 
literature for giving selection guidance to the consumer. For heat 
pump water heaters, if a default mode is not defined in the product 
literature, each test shall be conducted under an operational mode 
in which both the heat pump and any electric resistance backup 
heating element(s) are activated by the unit's control scheme, and 
which can achieve the internal storage tank temperature specified in 
this test procedure; if multiple operational modes meet these 
criteria, the water heater shall be tested under the most energy-
intensive mode. If no default mode is specified and the unit does 
not offer an operational mode that utilizes both the heat pump and 
the electric resistance backup heating element(s), the first-hour 
rating test and the simulated-use test shall be tested in heat-pump-
only mode. For other types of water heaters where a default mode is 
not specified, test the unit in the most energy-intensive mode.
    5.2 Storage-type Water Heaters, Including Heat Pump Water 
Heaters.
    5.2.1 Determination of Storage Tank Volume. Determine the 
storage capacity, Vst, of the water heater under test, in 
gallons (liters), by subtracting the tare weight--measured while the 
tank is empty--from the gross weight of the storage tank when 
completely filled with water (with all air eliminated and line 
pressure applied as described in section 2.5) and dividing the 
resulting net weight by the density of water at the measured 
temperature.
    5.2.2 Setting the Thermostat.
    5.2.2.1 Single Thermostat Tanks.
    5.2.2.1.1 Water Heaters with Rated Volumes Less than 20 Gallons. 
Starting with a tank at the supply water temperature, initiate 
normal operation of the water heater. After cut-out, initiate a draw 
from the water heater at a flow rate of 1.0 gallon  0.25 
gallons per minute (3.8 liters  0.95 liters per minute) 
for 2 minutes. Starting 15 seconds after commencement of draw, 
record the outlet temperature at 15-second intervals until the end 
of the 2-minute period. Determine whether the maximum outlet 
temperature is within the range of 125 [deg]F  5 [deg]F 
(51.7 [deg]C  2.8 [deg]C). If not, turn off the water 
heater, adjust the thermostat, and then drain and refill the tank 
with supply water. Then, once again, initiate normal operation of 
the water heater, and repeat the 2-minute outlet temperature test 
following cut-out. Repeat this sequence until the maximum outlet 
temperature during the 2-minute test is within of 125 [deg]F  5 [deg]F (51.7 [deg]C  2.8 [deg]C).
    5.2.2.1.2 Water Heaters with Rated Volumes Greater than or Equal 
to 20 Gallons. Starting with a tank at the supply water temperature, 
initiate normal operation of the water heater. After cut-out, 
initiate a draw from the water heater at a flow rate of 1.7 gallons 
 0.25 gallons per minute (6.4 liters  0.95 
liters per minute) for 5 minutes. Starting 15 seconds after 
commencement of draw, record the outlet temperature at 15-second 
intervals until the end of the 5-minute period. Determine whether 
the maximum outlet temperature is within the range of 125 [deg]F 
 5 [deg]F (51.7 [deg]C  2.8 [deg]C). If not, 
turn off the water heater, adjust the thermostat, and then drain and 
refill the tank with supply water. Then, once again, initiate normal 
operation of the water heater, and repeat the 5-minute outlet 
temperature test following cut-out. Repeat this sequence until the 
maximum outlet temperature during the 5-minute test is within of 125 
[deg]F  5 [deg]F (51.7 [deg]C  2.8 [deg]C).
    5.2.2.2 Tanks with Two or More Thermostats. Follow the same 
sequence as for a single thermostat tank (i.e., start at the supply 
water temperature; operate normally until cut-out). Determine if the 
setting of the thermostat that controls the uppermost heating 
elements yields a maximum water temperature of 125 [deg]F  5 [deg]F (51.7 [deg]C  2.8 [deg]C), as measured 
by the in-tank sensors that are positioned above the uppermost 
heating element. If the tank temperature above the uppermost heating 
element is not within 125 [deg]F  5 [deg]F (51.7 [deg]C 
 2.8 [deg]C), turn off the water heater, adjust the 
thermostat, and then drain and refill the tank with supply water. 
The thermostat that controls the heating element positioned next 
highest in the tank shall then be set to yield a maximum water 
temperature of 125 [deg]F  5 [deg]F (51.7 [deg]C  2.8 [deg]C). This process shall be repeated for the remaining 
heating elements in reverse order of height until the thermostat 
controlling the lowest element is correctly adjusted. When adjusting 
the thermostat that controls the lowest element, the maximum mean 
tank temperature after cut-out, as determined using all the in-tank 
sensors, shall be 125 [deg]F  5 [deg]F (51.7 [deg]C 
 2.8 [deg]C). When adjusting all other thermostats, use 
only the in-tank temperature sensors positioned above the heating 
element in question to evaluate the maximum mean water temperature 
as measured by these sensors after cut-out. For heat pump water 
heaters that control an auxiliary resistive element, the thermostat 
shall be set in accordance with the manufacturer's installation 
instructions.
    5.2.3 Power Input Determination. For all water heaters except 
electric types, initiate normal operation (as described in section 
5.1) and determine the power input, P, to the main burners 
(including pilot light power, if any) after 15 minutes of operation. 
If the water heater is equipped with a gas appliance

[[Page 66235]]

pressure regulator, the regulator outlet pressure shall be set 
within 10% of that recommended by the manufacturer. For 
oil-fired water heaters, the fuel pump pressure shall be within 
10% of the manufacturer's specified pump pressure. All 
burners shall be adjusted to achieve an hourly Btu (kJ) rating that 
is within 2% of the value specified by the manufacturer. 
For an oil-fired water heater, adjust the burner to give a 
CO2 reading recommended by the manufacturer and an hourly 
Btu (kJ) rating that is within 2% of that specified by 
the manufacturer. Smoke in the flue may not exceed No. 1 smoke as 
measured by the procedure in ASTM-D-2156-09.
    5.2.4 First-Hour Rating Test.
    5.2.4.1 General. During hot water draws for water heaters with 
rated storage volumes greater than or equal to 20 gallons, remove 
water at a rate of 3.0  0.25 gallons per minute (11.4 
 0.95 liters per minute). During hot water draws, for 
storage-type water heaters with rated storage volumes below 20 
gallons, remove water at a rate of 1.0  0.25 gallon per 
minute ((3.8  0.95 liters per minute). Collect the water 
in a container that is large enough to hold the volume removed 
during an individual draw and suitable for weighing at the 
termination of each draw. Alternatively, a water meter may be used 
to directly measure the water volume(s) withdrawn.
    5.2.4.2 Draw Initiation Criteria. Begin the first-hour rating 
test by imposing a draw on the storage-type water heater. After 
completion of this first draw, initiate successive draws based on 
the following criteria. For gas-fired and oil-fired water heaters, 
initiate successive draws when the thermostat acts to reduce the 
supply of fuel to the main burner. For electric water heaters having 
a single element or multiple elements that all operate 
simultaneously, initiate successive draws when the thermostat acts 
to reduce the electrical input supplied to the element(s). For 
electric water heaters having two or more elements that do not 
operate simultaneously, initiate successive draws when the 
applicable thermostat acts to reduce the electrical input to the 
element located vertically highest in the storage tank. For heat 
pump water heaters that do not use supplemental resistive heating, 
initiate successive draws immediately after the electrical input to 
the compressor is reduced by the action of the water heater's 
thermostat. For heat pump water heaters that use supplemental 
resistive heating, initiate successive draws immediately after the 
electrical input to the compressor or the uppermost resistive 
element is reduced by the action of the applicable water heater 
thermostat. This draw initiation criterion for heat pump water 
heaters that use supplemental resistive heating, however, shall only 
apply when the water located above the thermostat at cut-out is 
heated to 125 [deg]F  5 [deg]F (51.7 [deg]C  
2.8 [deg]C).
    5.2.4.3 Test Sequence. Establish normal water heater operation. 
If the water heater is not presently operating, initiate a draw. The 
draw may be terminated any time after cut-in occurs. After cut-out 
occurs (i.e., all thermostats are satisfied), monitor the internal 
storage tank temperature sensors described in section 4.5 every 
minute and determine the mean tank temperature by averaging the 
values from these sensors.
    Initiate a draw after a maximum mean tank temperature (the 
maximum of the mean temperatures of the individual sensors) has been 
observed following a cut-out. Record the time when the draw is 
initiated and designate it as an elapsed time of zero ([tau]* = 0). 
(The superscript * is used to denote variables pertaining to the 
first-hour rating test). Record the outlet water temperature 
beginning 15 seconds after the draw is initiated and at 5-second 
intervals thereafter until the draw is terminated. Determine the 
maximum outlet temperature that occurs during this first draw and 
record it as T*max,1. For the duration of this first draw 
and all successive draws, in addition, monitor the inlet temperature 
to the water heater to ensure that the required 58 [deg]F  2 [deg]F (14.4 [deg]C  1.1 [deg]C) test condition 
is met. Terminate the hot water draw when the outlet temperature 
decreases to T*max,1-15 [deg]F (T*max,1-8.3 
[deg]C). Record this temperature as T*min,1. Following 
draw termination, determine the average outlet water temperature and 
the mass or volume removed during this first draw and record them as 
T*del,i and M*1 or V*1, 
respectively.
    Initiate a second and, if applicable, successive draw each time 
the applicable draw initiation criteria described in section 5.2.4.2 
are satisfied. As required for the first draw, record the outlet 
water temperature 15 seconds after initiating each draw and at 5-
second intervals thereafter until the draw is terminated. Determine 
the maximum outlet temperature that occurs during each draw and 
record it as T*max,i, where the subscript i refers to the 
draw number. Terminate each hot water draw when the outlet 
temperature decreases to T*max,i-15 [deg]F 
(T*max,i-8.3 [deg]C). Record this temperature as 
T*min,i. Calculate and record the average outlet 
temperature and the mass or volume removed during each draw 
(T*del,i and M*i or V*i, 
respectively). Continue this sequence of draw and recovery until one 
hour has elapsed, then shut off the electrical power and/or fuel 
supplied to the water heater.
    If a draw is occurring at an elapsed time of one hour, continue 
this draw until the outlet temperature decreases to 
T*max,n-15 [deg]F (T*max,n-8.3 [deg]C), at 
which time the draw shall be immediately terminated. (The subscript 
n shall be used to denote quantities associated with the final 
draw.) If a draw is not occurring at an elapsed time of one hour, a 
final draw shall be imposed at one hour. This draw shall proceed for 
a minimum of 30 seconds and shall be immediately terminated 
thereafter when the outlet temperature first indicates a value less 
than or equal to the cut-off temperature used for the previous draw 
(T*min,n-1). If an outlet temperature greater than 
T*min,n-1 is not measured within 30 seconds zero 
additional credit shall be given towards first-hour rating (i.e., 
M*n = 0 or V*n = 0) based on the final draw. 
After the final draw is terminated, calculate and record the average 
outlet temperature and the mass or volume removed during the draw 
(T*del,n and M*n or V*n, 
respectively).
    5.2.5 24-Hour Simulated Use Test.
    5.2.5.1 Selection of Draw Pattern. The water heater will be 
tested under a draw profile that depends upon the rated first-hour 
rating obtained following the test prescribed in section 5.2.4 of 
this appendix. One of four different patterns shall be applied based 
on the rated first-hour rating, as shown in Table I.

           Table I--Draw Pattern To Be Used for Storage Water Heaters Based on Rated First-Hour Rating
----------------------------------------------------------------------------------------------------------------
 Rated first-hour rating greater than   . . . and rated first-
             or equal to:               hour rating less than:   Draw pattern to be used in  simulated use test
----------------------------------------------------------------------------------------------------------------
0....................................  20.....................  Point-of-Use (Table III.1).
20...................................  55.....................  Low-Usage (Table III.2).
55...................................  80.....................  Medium-Usage (Table III.3).
80...................................  No upper limit.........  High-Usage (Table III.4).
----------------------------------------------------------------------------------------------------------------

    After completing the first-hour rating test in section 5.2.4, 
identify the appropriate draw pattern using Table I above. The draw 
patterns are provided in Tables III.1 through III.4 in section 5.4. 
Use the appropriate draw pattern when conducting the test sequence 
provided in section 5.2.5.2.
    5.2.5.2 Test Sequence. If the water heater is turned off, fill 
the water heater with supply water and apply pressure as described 
in section 2.6. Turn on the water heater and associated heat pump 
unit, if present. If the water heater is turned on, initiate a water 
draw that energizes the lowest heating element in the water heater. 
In either case, after the cut-out occurs, begin a 24-hour pre-
conditioning period that draws water in the pattern specified by 
Table I (i.e., using Table III.1, Table III.2, Table III.3, or Table 
III.4, depending on the rated first-hour rating). No data need to be 
recorded during this 24-hour pre-conditioning period. At the end of 
this period, the 24-hour simulated-use test will begin.
    At the start of the 24-hour test (after the 24-hour pre-
conditioning period), record the mean tank temperature 
(T0), and the electrical and/or fuel measurement 
readings, as appropriate. Begin the 24-hour simulated use test by 
withdrawing the volume specified

[[Page 66236]]

in the appropriate table in section 5.4 (i.e., Table III.1, Table 
III.2, Table III.3, or Table III.4, depending on the rated first-
hour rating) for the first draw at the flow rate specified. Record 
the time when this first draw is initiated and assign it as the test 
elapsed time ([tau]) of zero (0). Record the average storage tank 
and ambient temperature every minute throughout the 24-hour 
simulated use test. At the elapsed times specified in the applicable 
draw pattern table in section 5.4 for a particular draw pattern, 
initiate additional draws, removing the volume of hot water at the 
prescribed flow rate specified by the table. The maximum allowable 
deviation for any single draw is  0.25 gallons (1.9 
liters). The quantity of water withdrawn during the last draw shall 
be increased or decreased as necessary such that the total volume of 
water withdrawn equals the prescribed daily amount for that draw 
pattern  1.0 gallon ( 3.8 liters).
    All draws during the 24-hour simulated use test shall be made at 
the flow rates specified in the applicable draw pattern table in 
section 5.4, within a tolerance of  0.25 gallons per 
minute ( 0.95 liters per minute). Measurements of the 
inlet and outlet temperatures shall be made 5 seconds after the draw 
is initiated and at every subsequent 3-second interval throughout 
the duration of each draw. The arithmetic mean of the hot water 
discharge temperature and the cold water inlet temperature shall be 
determined for each draw (Tdel,i and Tin,i). 
Determine and record the net mass or volume removed (Mi 
or Vi), as appropriate, after each draw.
    At the end of the first recovery period following the first 
draw, which may extend beyond subsequent draws, record the maximum 
mean tank temperature observed after cut-out, Tmax,1, and 
the energy consumed by an electric resistance, gas or oil-fired 
water heater (including electrical energy), from the beginning of 
the test, Qr. For heat pump water heaters, the total 
electrical energy consumed during the first recovery by the heat 
pump (including compressor, fan, controls, pump, etc.) and, if 
applicable, by the resistive element(s) shall be recorded as 
Qr.
    At the end of the recovery period that follows the draw notated 
in the applicable draw pattern table in section 5.4 as the end of 
the first draw cluster during the test, determine and record the 
total electrical energy and/or fossil fuel consumed since the 
beginning of the test, Qsu,0. In preparation for 
determining the energy consumed during standby, record the reading 
given on the electrical energy (watt-hour) meter, the gas meter, 
and/or the scale used to determine oil consumption, as appropriate. 
Record the maximum value of the mean tank temperature after cut-out 
as Tsu,0. The time at which this value is attained is the 
start of the standby period. At 1-minute intervals, record the mean 
tank temperature and the electric and/or fuel instrument readings 
until the next draw is initiated. Just prior to initiation of the 
next draw, record the mean tank temperature as Tsu,f. If 
the water heater is undergoing recovery when the next draw is 
initiated, record the mean tank temperature Tsu,f at the 
minute prior to the start of the recovery. The time at which this 
value occurs is the end of the standby period. Determine the total 
electrical energy and/or fossil fuel energy consumption from the 
beginning of the test to this time and record as Qsu,f. 
Record the time interval between the time at which the maximum mean 
tank temperature is observed after the final draw of the first draw 
cluster and the end of the standby period as [tau]stby,1. 
Record the time during which water is not being withdrawn from the 
water heater during the entire 24-hour period as 
[tau]stby,2.
    5.3 Instantaneous Gas and Electric Water Heaters
    5.3.1 Setting the Outlet Discharge Temperature. Initiate normal 
operation of the water heater at the full input rating for electric 
instantaneous water heaters and at the maximum firing rate specified 
by the manufacturer for gas instantaneous water heaters. Monitor the 
discharge water temperature and set to a value of 125[emsp14][deg]F 
 5[emsp14][deg]F (51.7 [deg]C  2.8 [deg]C) 
in accordance with the manufacturer's instructions. If the water 
heater is not capable of providing this discharge temperature when 
the flow rate is 1.7 gallons  0.25 gallons per minute 
(7.6 liters  0.95 liters per minute), then adjust the 
flow rate as necessary to achieve the specified discharge water 
temperature.
    5.3.2 Maximum gpm Rating Test for Instantaneous Water Heaters. 
Establish normal water heater operation at the full input rate for 
electric instantaneous water heaters and at the maximum firing rate 
for gas instantaneous water heaters with the discharge water 
temperature set in accordance with section 5.3.1. During the 10-
minute test, either collect the withdrawn water for later 
measurement of the total mass removed, or alternatively, use a water 
meter to directly measure the water volume removed.
    After recording the scale or water meter reading, initiate water 
flow through the water heater, record the inlet and outlet water 
temperatures beginning 15 seconds after the start of the test and at 
subsequent 5-second intervals throughout the duration of the test. 
At the end of 10 minutes, turn off the water. Determine the mass of 
water collected, M10m, in pounds (kilograms), or the 
volume of water, V10m, in gallons (liters).
    5.3.3 24-hour Simulated Use Test for Instantaneous Water 
Heaters.
    5.3.3.1 Selection of Draw Pattern. The water heater will be 
tested under a draw profile that depends upon the rated maximum gpm 
rating obtained following the test prescribed in section 5.3.2. Four 
different patterns can be applied, and Table II shows which draw 
pattern is applied to a water heater based on its rated maximum gpm 
rating.

       Table II--Draw Pattern To Be Used for Instantaneous Water Heater Based on Rated Maximum GPM Rating
----------------------------------------------------------------------------------------------------------------
   Rated maximum gpm rating greater than or       . . . and rated maximum GPM       Draw pattern to be used in
                  equal to:                            rating less than:                simulated use test
----------------------------------------------------------------------------------------------------------------
0............................................  1.7.............................  Point-of-Use (Table III.1).
1.7..........................................  2.8.............................  Low-Usage (Table III.2).
2.8..........................................  4...............................  Medium-Usage (Table III.3).
4............................................  No upper limit..................  High-Usage (Table III.4).
----------------------------------------------------------------------------------------------------------------

    The draw patterns are provided in Tables III.1 through III.4 in 
section 5.4. Use the appropriate draw pattern when conducting the 
test sequence set forth in section 5.3.3.2.
    5.3.3.2 Test Sequence. Establish normal operation with the 
discharge water temperature at 125[emsp14][deg]F  
5[emsp14][deg]F (51.7 [deg]C  2.8 [deg]C) and set the 
flow rate set as determined in section 5.2. Prior to commencement of 
the 24-hour simulated use test, the unit shall remain in an idle 
state in which controls are active but no water is drawn through the 
unit for a period of one hour. With no draw occurring, record the 
reading given by the gas meter and/or the electrical energy meter as 
appropriate. Begin the 24-hour simulated use test by withdrawing the 
volume specified in Table III.1 through III.4 for the first draw at 
the flow rate specified. Record the time when this first draw is 
initiated and designate it as an elapsed time, [tau], of 0. At the 
elapsed times specified in Table III.1 through III.4 for a 
particular draw pattern, initiate additional draws, removing the 
volume of hot water at the prescribed flow rate specified in Table 
III.1 through III.4, with the maximum allowable deviation for any 
single draw being  0.5 gallons (1.9 liters). The 
quantity of water drawn during the final draw shall be increased or 
decreased as necessary such that the total volume of water withdrawn 
equals the prescribed daily amount for that draw pattern  1.0 gallon ( 3.8 liters).
    Measurements of the inlet and outlet water temperatures shall be 
made 5 seconds after the draw is initiated and at every 3-second 
interval thereafter throughout the duration of the draw. The 
arithmetic mean of the hot water discharge temperature and the cold 
water inlet temperature shall be determined for each draw. Record 
the scale used to measure the mass of the withdrawn water or the 
water meter reading, as appropriate, after each draw. At the end of 
the recovery period following the first draw, determine and record 
the fossil fuel and/or electrical energy consumed, Qr. 
Following the final draw and

[[Page 66237]]

subsequent recovery, allow the water heater to remain in the standby 
mode until exactly 24 hours have elapsed since the start of the test 
(i.e., since [tau] = 0). At 24 hours, record the reading given by 
the gas meter and/or the electrical energy meter as appropriate. 
Determine the fossil fuel and/or electrical energy consumed during 
the entire 24-hour simulated use test and designate the quantity as 
Q.
    5.4 Draw Patterns. The draw patterns to be imposed during 24-
hour simulated use tests are provided in Tables III.1 through III.4. 
Each water heater under test is to be subjected to one of the draw 
patterns based on its rated first-hour rating or rated maximum gpm 
rating as discussed in sections 5.2.5.1 and 5.3.3.1, respectively. 
Each draw pattern specifies the elapsed time in hours and minutes 
during the 24-hour test when a draw is to commence, the total volume 
of water in gallons (liters) that is to be removed during each draw, 
and the flow rate at which each draw is to be taken, in gallons 
(liters) per minute.

                                     Table III.1--Point-of-Use Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                                    Time during       Volume      Flow rate \**\
                            Draw No.                               test  [hh:mm]   [gallons (L)]    [gpm (Lpm)]
----------------------------------------------------------------------------------------------------------------
1 *.............................................................            0:00       2.0 (7.6)         1 (3.8)
2 *.............................................................            1:00       1.0 (3.8)         1 (3.8)
3 *.............................................................            1:05       0.5 (1.9)         1 (3.8)
4 *.............................................................            1:10       0.5 (1.9)         1 (3.8)
5 *.............................................................            1:15       0.5 (1.9)         1 (3.8)
6...............................................................            8:00       1.0 (3.8)         1 (3.8)
7...............................................................            8:15       2.0 (7.6)         1 (3.8)
8...............................................................            9:00       1.5 (5.7)         1 (3.8)
9...............................................................            9:15       1.0 (3.8)         1 (3.8)
----------------------------------------------------------------------------------------------------------------
                                 Total Volume Drawn per Day: 10 gallons (38 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.
** Should the water heater have a rated maximum gpm rating less than 1 gpm (3.8 Lpm), then all draws shall be
  implemented at a flow rate equal to the rated maximum gpm rating


                                       Table III.2--Low-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                                    Time during       Volume         Flow rate
                            Draw No.                               test (hh:mm)      (gallons)         (gpm)
----------------------------------------------------------------------------------------------------------------
1 *.............................................................            0:00     15.0 (56.8)       1.7 (6.4)
2 *.............................................................            0:30       2.0 (7.6)         1 (3.8)
3 *.............................................................            1:00       1.0 (3.8)         1 (3.8)
4...............................................................           10:30      6.0 (22.7)       1.7 (6.4)
5...............................................................           11:30      4.0 (15.1)       1.7 (6.4)
6...............................................................           12:00       1.0 (3.8)         1 (3.8)
7...............................................................           12:45       1.0 (3.8)         1 (3.8)
8...............................................................           12:50       1.0 (3.8)         1 (3.8)
9...............................................................           16:15       2.0 (7.6)         1 (3.8)
10..............................................................           16:45       2.0 (7.6)       1.7 (6.4)
11..............................................................           17:00      3.0 (11.4)       1.7 (6.4)
----------------------------------------------------------------------------------------------------------------
                                 Total Volume Drawn per Day: 38 gallons (144 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.


                                     Table III.3--Medium-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                                    Time during       Volume         Flow rate
                            Draw No.                               test  (hh:mm)     (gallons)         (gpm)
----------------------------------------------------------------------------------------------------------------
1 *.............................................................            0:00     15.0 (56.8)       1.7 (6.4)
2 *.............................................................            0:30       2.0 (7.6)         1 (3.8)
3 *.............................................................            1:40      9.0 (34.1)       1.7 (6.4)
4...............................................................           10:30      9.0 (34.1)       1.7 (6.4)
5...............................................................           11:30      5.0 (18.9)       1.7 (6.4)
6...............................................................           12:00       1.0 (3.8)         1 (3.8)
7...............................................................           12:45       1.0 (3.8)         1 (3.8)
8...............................................................           12:50       1.0 (3.8)         1 (3.8)
9...............................................................           16:00       1.0 (3.8)         1 (3.8)
10..............................................................           16:15       2.0 (7.6)         1 (3.8)
11..............................................................           16:45       2.0 (7.6)       1.7 (6.4)
12..............................................................           17:00      7.0 (26.5)       1.7 (6.4)
----------------------------------------------------------------------------------------------------------------
                                 Total Volume Drawn Per Day: 55 gallons (208 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.


[[Page 66238]]


                                      Table III.4--High-Usage Draw Pattern
----------------------------------------------------------------------------------------------------------------
                                                                    Time during       Volume         Flow rate
                            Draw No.                               test  (hh:mm)     (gallons)         (gpm)
----------------------------------------------------------------------------------------------------------------
1 *.............................................................            0:00      27.0 (102)        3 (11.4)
2 *.............................................................            0:30       2.0 (7.6)         1 (3.8)
3 *.............................................................            0:40       1.0 (3.8)         1 (3.8)
4 *.............................................................            1:40      9.0 (34.1)       1.7 (6.4)
5...............................................................           10:30     15.0 (56.8)        3 (11.4)
6...............................................................           11:30      5.0 (18.9)       1.7 (6.4)
7...............................................................           12:00       1.0 (3.8)         1 (3.8)
8...............................................................           12:45       1.0 (3.8)         1 (3.8)
9...............................................................           12:50       1.0 (3.8)         1 (3.8)
10..............................................................           16:00       2.0 (7.6)         1 (3.8)
11..............................................................           16:15       2.0 (7.6)         1 (3.8)
12..............................................................           16:30       2.0 (7.6)       1.7 (6.4)
13..............................................................           16:45       2.0 (7.6)       1.7 (6.4)
14..............................................................           17:00     14.0 (53.0)        3 (11.4)
----------------------------------------------------------------------------------------------------------------
                                 Total Volume Drawn Per Day: 84 gallons (318 L)
----------------------------------------------------------------------------------------------------------------
* Denotes draws in first draw cluster.

6. Computations

    6.1 Storage Tank and Heat Pump Water Heaters
    6.1.1 Storage Tank Capacity. The storage tank capacity, 
Vst, is computed using the following:
[GRAPHIC] [TIFF OMITTED] TP04NO13.030

Where:

Vst = the storage capacity of the water heater, gal (L)
Wf = the weight of the storage tank when completely 
filled with water, lb (kg)
Wt = the (tare) weight of the storage tank when 
completely empty, lb (kg)
[rho] = the density of water used to fill the tank measured at the 
temperature of the water, lb/gal (kg/L)

    6.1.2 First-Hour Rating Computation. For the case in which the 
final draw is initiated at or prior to an elapsed time of one hour, 
the first-hour rating, Fhr, shall be computed using,
[GRAPHIC] [TIFF OMITTED] TP04NO13.031

Where:

n = the number of draws that are completed during the first-hour 
rating test
V*i = the volume of water removed during the ith draw of 
the first-hour rating test, gal (L) or, if the mass of water is 
being measured,
[GRAPHIC] [TIFF OMITTED] TP04NO13.032

Where:

M*i = the mass of water removed during the ith draw of 
the first-hour rating test, lb (kg).
[rho] = the water density corresponding to the average outlet 
temperature measured during the ith draw, (T*del,i), lb/
gal (kg/L).

    For the case in which a draw is not in progress at the elapsed 
time of one hour and a final draw is imposed at the elapsed time of 
one hour, the first-hour rating shall be calculated using
[GRAPHIC] [TIFF OMITTED] TP04NO13.033

where n and V*i are the same quantities as defined above, 
and

V*n = the volume of water drawn during the nth (final) 
draw of the first-hour rating test, gal (L)
T* del,n-1 = the average water outlet temperature 
measured during the (n-1)th draw of the first-hour rating test, 
[deg]F ([deg]C).
T* del,n = the average water outlet temperature measured 
during the nth (final) draw of the first-hour rating test, [deg]F 
([deg]C).
T*min,n-1 = the minimum water outlet temperature measured 
during the (n-1)th draw of the first-hour rating test, [deg]F 
([deg]C).

    6.1.3 Recovery Efficiency. The recovery efficiency for gas, oil, 
and heat pump storage-type water heaters, [eta]r, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.034

Where:
M1 = total mass removed from the start of the 24-hour 
simulated use test to the end of the first recovery period, lb (kg), 
or, if the volume of water is being measured,
M1 = V1[rho]1

Where:

V1 = total volume removed from the start of the 24-hour 
simulated use test to the end of the first recovery period, gal (L).
[rho]1 = density of the water at the water temperature 
measured at the point where the flow volume is measured, lb/gal (kg/
L).
Cp1 = specific heat of the withdrawn water evaluated at 
(Tdel,1 + Tin,1)/2, Btu/(lb[middot][deg]F) 
(kJ/(kg[middot][deg]C))
Tdel,1 = average water outlet temperature measured during 
the draws from the start of the 24-hour simulated use test to the 
end of the first recovery period, [deg]F ([deg]C).

[[Page 66239]]

Tin,1 = average water inlet temperature measured during 
the draws from the start of the 24-hour simulated use test to the 
end of the first recovery period, [deg]F ([deg]C).
Vst = as defined in section 6.1.1.
[rho]2 = density of stored hot water evaluated at 
(Tmax,1 + To)/2, lb/gal (kg/L).
Cp2 = specific heat of stored hot water evaluated at 
(Tmax,1 + To)/2, Btu/(lb[middot][deg]F) (kJ/
(kg[middot][deg]C).
Tmax,1 = maximum mean tank temperature recorded after 
cut-out following the first recovery of the 24-hour simulated use 
test, [deg]F ([deg]C).
To = maximum mean tank temperature recorded prior to the 
first draw of the 24-hour simulated use test, [deg]F ([deg]C).
Qr = the total energy used by the water heater between 
cut-out prior to the first draw and cut-out following the first 
recovery period, including auxiliary energy such as pilot lights, 
pumps, fans, etc., Btu (kJ). (Electrical auxiliary energy shall be 
converted to thermal energy using the following conversion: 1 kWh = 
3412 Btu).

    The recovery efficiency for electric water heaters with immersed 
heating elements is assumed to be 98%.
    6.1.4 Hourly Standby Losses. The energy consumed as part of the 
standby loss test of the 24-hour simulated use test, Qstby, 
is computed as:

Qstby = Qsu,f-Qsu,0

Where:

Qsu,0 = cumulative energy consumption of the water heater 
from the start of the 24-hour simulated use test to the time at 
which the maximum mean tank temperature is attained after the 
recovery following the end of the first draw cluster, Btu (kJ).
Qsu,f = cumulative energy consumption of the water heater 
from the start of the 24-hour simulated use test to the minute prior 
to the start of the draw following the end of the first draw cluster 
or the minute prior to a recovery occurring at the start of the draw 
following the end of the first draw cluster, Btu (kJ).

    The hourly standby energy losses are computed as:
    [GRAPHIC] [TIFF OMITTED] TP04NO13.035
    
Where:

Qhr = the hourly standby energy losses of the water 
heater, Btu/h (kJ/h).
Vst = as defined in section 6.1.1.
[rho] = density of stored hot water, (Tsu,f + 
Tsu,0)/2, lb/gal (kg/L).
Cp = specific heat of the stored water, (Tsu,f 
+ Tsu,0)/2, Btu/(lb[middot]F), (kJ/(kg[middot]K))
Tsu,f = the mean tank temperature observed at the minute 
prior to the start of the draw following the first draw cluster or 
the minute prior to a recovery occurring at the start of the draw 
following the end of the first draw cluster, [deg]F ([deg]C).
Tsu,0 = the maximum mean tank temperature observed after 
the first recovery following the final draw of the first draw 
cluster, [deg]F ([deg]C).
[eta]r = as defined in section 6.1.3.
[tau]stby,1 = elapsed time between the time at which the 
maximum mean tank temperature is observed after the first draw 
cluster and the minute prior to the start of the first draw 
following the end of the first draw cluster of the 24-hour simulated 
use test or the minute prior to a recovery occurring at the start of 
the draw following the end of the first draw cluster, h.

    The standby heat loss coefficient for the tank is computed as:
    [GRAPHIC] [TIFF OMITTED] TP04NO13.036
    
Where:

UA = standby heat loss coefficient of the storage tank, Btu/
(h[middot][deg]F), (kJ/(h[middot][deg]C).
Tt,stby,1 = overall average storage tank temperature 
between the time when the maximum mean tank temperature is observed 
after cut-out following the first draw cluster and the minute prior 
to commencement of the next draw following the first draw cluster of 
the 24-hour simulated use test, [deg]F ([deg]C).
Ta,stby,1 = overall average ambient temperature between 
the time when the maximum mean tank temperature is observed after 
cut-out following the first draw cluster and the minute prior to 
commencement of the next draw following the first draw cluster of 
the 24-hour simulated use test, [deg]F ([deg]C).

    6.1.5 Daily Water Heating Energy Consumption. The daily water 
heating energy consumption, Qd, is computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.037

Where:

Q = Qf + Qe = total energy used by the water 
heater during the 24-hour simulated use test, including auxiliary 
energy such as pilot lights, pumps, fans, etc., Btu (kJ). 
(Electrical energy shall be converted to thermal energy using the 
following conversion: 1kWh = 3412 Btu.)
Qf = total fossil fuel energy used by the water heater 
during the 24-hour simulated use test, Btu (kJ).
Qe = total electrical energy used during the 24-hour 
simulated use test, Btu (kJ).
Vst = as defined in section 6.1.1.
[rho] = density of the stored hot water, evaluated at 
(T24 + T0)/2, lb/gal (kg/L)
Cp = specific heat of the stored water, evaluated at 
(T24 + T0)/2, Btu/(lb[middot]F), (kJ/
(kg[middot]K)).
T24 = mean tank temperature at the end of the 24-hour 
simulated use test, [deg]F ([deg]C).
T0 = mean tank temperature at the beginning of the 24-
hour simulated use test, recorded one minute before the first draw 
is initiated, [deg]F ([deg]C).
[eta]r = as defined in section 6.1.3.

    6.1.6 Adjusted Daily Water Heating Energy Consumption. The adjusted 
daily water heating energy consumption, Qda, takes into 
account that the temperature difference between the storage tank and 
surrounding ambient air may not be the nominal value of 57.5 [deg]F 
(125 [deg]F-67.5 [deg]F) or 32.0 [deg]C (51.7 [deg]C-19.7 [deg]C) due 
to the 10 [deg]F (5.6 [deg]C) allowable variation in storage tank 
temperature, 125 [deg]F  5 [deg]F (51.7 [deg]C  
2.8 [deg]C), and the 5 [deg]F (2.8 [deg]C) allowable variation in 
surrounding ambient temperature 65 [deg]F (18.3 [deg]C) to 70 [deg]C 
(21.1 [deg]C). The adjusted daily water heating energy consumption is 
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.038

Where:

Qda = the adjusted daily water heating energy 
consumption, Btu (kJ).
Qd = as defined in section 6.1.5.
Tstby,2 = the mean tank temperature during the total 
standby portion, [tau]stby,2, of the 24-hour test, [deg]F 
([deg]C).
Ta,stby,2 = the average ambient temperature during the 
total standby portion, [tau]stby,2, of the 24-hour test, 
[deg]F ([deg]C).
UA = as defined in section 6.1.4.

[[Page 66240]]

[tau]stby,2 = the number of hours during the 24-hour 
simulated test when water is not being withdrawn from the water 
heater.
    A modification is also needed to take into account that the 
temperature difference between the outlet water temperature and 
supply water temperature may not be equivalent to the nominal value 
of 67 [deg]F (125 [deg]F-58 [deg]F) or 37.3 [deg]C (51.7 [deg]C-14.4 
[deg]C). The following equations adjust the experimental data to a 
nominal 67 [deg]F (37.3 [deg]C) temperature rise.
    The energy used to heat water, Btu/day (kJ/day), may be computed 
as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.039

Where:

N = total number of draws in the draw pattern.
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb 
(kg)
Cpi = the specific heat of the water of the ith draw 
evaluated at (Tdel,i +Tin,i)/2, Btu/
(lb[middot][deg]F) (kJ/(kg[middot][deg]C)).
Tdel,i = the average water outlet temperature measured 
during the ith draw (i = 1 to N), [deg]F ([deg]C).
Tin,i = the average water inlet temperature measured 
during the ith draw (i = 1 to N), [deg]F ([deg]C).
[eta]r = as defined in section 6.1.3.

    The energy required to heat the same quantity of water over a 67 
[deg]F (37.3 [deg]C) temperature rise, Btu/day (kJ/day), is:
[GRAPHIC] [TIFF OMITTED] TP04NO13.040

    The difference between these two values is:

QHWD = QHW,67 [deg]F-QHW
or QHWD = QHW,37.3 [deg]C-QHW
This difference (QHWD) must be added to the adjusted 
daily water heating energy consumption value. Thus, the daily energy 
consumption value which takes into account that the temperature 
difference between the storage tank and ambient temperature may not 
be 57.5 [deg]F (32.0 [deg]C) and that the temperature rise across 
the storage tank may not be 67 [deg]F (37.3 [deg]C) is: 
Qdm = Qda + QHWD
    6.1.7 Energy Factor. The energy factor, Ef, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.042

Where:

N = total number of draws in the draw pattern
Qdm = the modified daily water heating energy consumption 
as computed in accordance with section 6.1.6, Btu (kJ)
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb 
(kg)
Cpi = the specific heat of the water of the ith draw, 
evaluated at (125 [deg]F + 58 [deg]F)/2 = 91.5 [deg]F ((51.7[deg]C + 
14.4[deg]C)/2 = 33 [deg]C), Btu/(lb[middot][deg]F) (kJ/
(kg[middot][deg]C)).

    6.1.8 Annual Energy Consumption. The annual energy consumption 
for storage-type and heat pump water heaters is computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.043

Where:

Ef = the energy factor as computed in accordance with 
section 6.1.8
365 = the number of days in a year
V = the volume of hot water drawn during the applicable draw 
pattern, gallons
 = 10 for the point-of-use draw pattern
 = 38 for the low usage draw pattern
 = 55 for the medium usage draw pattern
 = 84 for high usage draw pattern
[rho] = 8.24 lbm/gallon, the density of water at 125 
[deg]F
CP = 1.00 Btu/lbm[deg]F, the specific heat of 
water at 91.5 [deg]F
67 = the nominal temperature difference between inlet and outlet 
water

    6.1.9 Annual Electrical Energy Consumption. The annual 
electrical energy consumption in kilowatt-hours for storage-type and 
heat pump water heaters, Eannual,e, is computed as:

Eannual,e = Eannual*(Qe/Q)/3412

Where:

Eannual = the annual energy consumption as determined in 
accordance with section 6.1.8, Btu (kJ)
Qe = the daily electrical energy consumption as defined 
in section 6.1.5, Btu (kJ).
Q = total energy used by the water heater during the 24-hour 
simulated use test in accordance with section 6.1.5, Btu (kJ)
3412 = conversion factor from Btu to kWh

    6.1.10 Annual Fossil Fuel Energy Consumption. The annual fossil 
fuel energy consumption for storage-type and heat pump water 
heaters, Eannual,f, is computed as:


[[Page 66241]]


Eannual,f = Eannual-(Eannual,e x 
3412)

Where:

Eannual = the annual energy consumption as determined in 
accordance with section 6.1.8, Btu (kJ)
Eannual,e = the annual electrical energy consumption as 
determined in accordance with section 6.1.9, kWh
3412 = conversion factor from kWh to Btu

    6.2 Instantaneous Water Heaters.
    6.2.1 Maximum gpm (L/min) Rating Computation. Compute the 
maximum gpm (L/min) rating, Fmax, as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.044

which may be expressed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.045

Where:

M10m = the mass of water collected during the 10-minute 
test, lb (kg).
Tdel = the average delivery temperature, [deg]F ([deg]C).
Tin = the average inlet temperature, [deg]F ([deg]C).
[rho] = the density of water at the average delivery temperature, 
lb/gal (kg/L).
    If a water meter is used, the maximum gpm (L/min) rating is 
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.046

Where:

V10m = the volume of water measured during the 10-minute 
test, gal (L).
Tdel = as defined in this section.
Tin = as defined in this section.

    6.2.2 Recovery Efficiency. The recovery efficiency, 
[eta]r, is computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.047

Where:

M1 = total mass removed during the first draw of the 24-
hour simulated use test, lb (kg), or, if the volume of water is 
being measured,

M1 = V1 [middot] [rho]

Where:

V1 = total volume removed during the first draw of the 
24-hour simulated use test, gal (L).
[rho] = density of the water at the water temperature measured at 
the point where the flow volume is measured, lb/gal (kg/L).
Cp1 = specific heat of the withdrawn water, 
(Tdel,1 - Tin,1)/2, Btu/(lb[middot][deg]F) 
(kJ/(kg[middot][deg]C)).
Tdel,1 = average water outlet temperature measured during 
the first draw of the 24-hour simulated use test, [deg]F ([deg]C).
Tin,1 = average water inlet temperature measured during 
the first draw of the 24-hour simulated use test, [deg]F ([deg]C).
Qr = the total energy used by the water heater between 
cut-out prior to the first draw and cut-out following the first 
draw, including auxiliary energy such as pilot lights, pumps, fans, 
etc., Btu (kJ). (Electrical auxiliary energy shall be converted to 
thermal energy using the following conversion: 1 kWh = 3412 Btu.)
    6.2.3 Daily Water Heating Energy Consumption. The daily water 
heating energy consumption, Qd, is computed as:

Qd = Q

Where:

Q = Qf + Qe = the energy used by the 
instantaneous water heater during the 24-hour simulated use test.
Qf = total fossil fuel energy used by the water heater 
during the 24-hour simulated use test, Btu (kJ).
Qe = total electrical energy used during the 24-hour 
simulated use test, Btu (kJ).

    A modification is needed to take into account that the 
temperature difference between the outlet water temperature and 
supply water temperature may not be equivalent to the nominal value 
of 67 [deg]F (125 [deg]F - 58 [deg]F) or 37.3 [deg]C (51.7 [deg]C - 
14.4 [deg]C). The following equations adjust the experimental data 
to a nominal 67 [deg]F (37.3 [deg]C) temperature rise.
    The energy used to heat water may be computed as:
    [GRAPHIC] [TIFF OMITTED] TP04NO13.048
    
Where:

N = total number of draws in the draw pattern
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb 
(kg)

[[Page 66242]]

Cpi = the specific heat of the water of the ith draw 
evaluated at (Tdel,i + Tin,i)/2, Btu/ 
(lb[middot][deg]F) (kJ/(kg[middot][deg]C)).
Tdel,i = the average water outlet temperature measured 
during the ith draw (i = 1 to N), [deg]F ([deg]C).
Tin,i = the average water inlet temperature measured 
during the ith draw (i = 1 to N), [deg]F ([deg]C).
[eta]r = as defined in section 6.2.2.

    The energy required to heat the same quantity of water over a 67 
[deg]F (37.3 [deg]C) temperature rise is:
[GRAPHIC] [TIFF OMITTED] TP04NO13.049

Where:

N = total number of draws in the draw pattern
Mi = the mass withdrawn during the ith draw, lb (kg)
Cpi = the specific heat of water of the ith draw, Btu/
(lb[middot][deg]F) (kJ/(kg[middot][deg]C))
[eta]r = as defined in section 6.2.2.

    The difference between these two values is:

QHWD = QHW,67[deg]F - QHW

or QHWD = QHW,37.3[deg]C - QHW

This difference (QHWD) must be added to the adjusted 
daily water heating energy consumption value. Thus, the daily energy 
consumption value, which takes into account that the temperature 
difference between the storage tank and ambient temperature may not 
be 57.5 [deg]F (32.0 [deg]C) and that the temperature rise across 
the storage tank may not be 67 [deg]F (37.3 [deg]C), is:

Qdm = Qd + QHWD

    6.2.4 Energy Factor. The energy factor, Ef, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.050

Where:

N = total number of draws in the draw pattern
Qdm = the modified daily water heating energy consumption 
as computed in accordance with section 6.2.3, Btu (kJ)
Mi = the mass withdrawn for the ith draw (i = 1 to N), lb 
(kg)
Cpi = the specific heat of the water at the ith draw, 
evaluated at (125 [deg]F + 58 [deg]F)/2 = 91.5 [deg]F ((51.7 [deg]C 
+ 14.4 [deg]C)/2 = 33 [deg]C), Btu/(lb[middot] [deg]F) (kJ/
(kg[middot] [deg]C)).

    6.2.5 Annual Energy Consumption. The annual energy consumption 
for instantaneous-type water heaters, Eannual, is 
computed as:
[GRAPHIC] [TIFF OMITTED] TP04NO13.051

Where:

Ef = the energy factor as computed in accordance with 
section 6.2.4
365 = the number of days in a year.
V = the volume of hot water drawn during the applicable draw 
pattern, gallons
 = 10 for the point-of-use draw pattern
 = 38 for the low usage draw pattern
 = 55 for the medium usage draw pattern
 = 84 for high usage draw pattern
[rho] = 8.24 lbm/gallon, the density of water at 125 
[deg]F
CP = 1.00 Btu/lbm [deg]F, the specific heat of 
water at 91.5 [deg]F
67 = the nominal temperature difference between inlet and outlet 
water

    6.2.6 Annual Electrical Energy Consumption. The annual 
electrical energy consumption in kilowatt-hours for instantaneous-
type water heaters, Eannual, e, is computed as:

Eannual,e = Eannual*(Qe/Q)/3412

Where:

Qe = the daily electrical energy consumption as defined 
in section 6.2.3, Btu (kJ)
Eannual = the annual energy consumption as determined in 
accordance with section 6.2.5, Btu (kJ)
Q = total energy used by the water heater during the 24-hour 
simulated use test in accordance with section 6.2.3, Btu (kJ)
Qdm = the modified daily water heating energy consumption 
as computed in accordance with section 6.2.3, Btu (kJ)
3412 = conversion factor from Btu to kWh

    6.2.7 Annual Fossil Fuel Energy Consumption. The annual fossil 
fuel energy consumption for instantaneous-type water heaters, 
Eannual,f, is computed as:

Eannual,f = Eannual - (Eannual,e x 
3412)

Where:

Eannual,e = the annual electrical energy consumption as 
defined in section 6.2.6, kWh.
Eannual = the annual energy consumption as defined in 
section 6.2.5, Btu (kJ)
3412 = conversion factor from kWh to Btu


[[Page 66243]]


[GRAPHIC] [TIFF OMITTED] TP04NO13.052


[[Page 66244]]


[GRAPHIC] [TIFF OMITTED] TP04NO13.053


[[Page 66245]]


[GRAPHIC] [TIFF OMITTED] TP04NO13.054


[[Page 66246]]


* * * * *
0
10. Section 430.32 is amended by revising paragraph (d) to read as 
follows:


Sec.  430.32  Energy and water conservation standards and their 
compliance dates.

* * * * *
    (d) Water heaters. The energy factor of water heaters shall not be 
less than the following for products manufactured on or after the 
indicated dates.

----------------------------------------------------------------------------------------------------------------
                                                               Energy factor as of    Energy factor as of April
           Product class                 Storage volume         January 20, 2004               16, 2015
----------------------------------------------------------------------------------------------------------------
Gas-fired Storage Water Heater.....  >= 20 gallons and <=    0.67-(0.0019 x Rated    For tanks with a Rated
                                      100 gallons.            Storage Volume in       Storage Volume at or below
                                                              gallons).               55 gallons: EF = 0.675-
                                                                                      (0.0015 x Rated Storage
                                                                                      Volume in gallons).
                                                                                     For tanks with a Rated
                                                                                      Storage Volume above 55
                                                                                      gallons: EF = 0.8012-
                                                                                      (0.00078 x Rated Storage
                                                                                      Volume in gallons).
Oil-fired Storage Water Heater.....  <= 50 gallons.........  0.59-(0.0019 x Rated    EF = 0.68-(0.0019 x Rated
                                                              Storage Volume in       Storage Volume in
                                                              gallons).               gallons).
Electric Storage Water Heater......  >= 20 gallons and <=    0.97-(0.00132 x Rated
                                      120 gallons.            Storage Volume in
                                                              gallons).
                                                                                     For tanks with a Rated
                                                                                      Storage Volume at or below
                                                                                      55 gallons: EF = 0.960-
                                                                                      (0.0003 x Rated Storage
                                                                                      Volume in gallons). For
                                                                                      tanks with a Rated Storage
                                                                                      Volume above 55 gallons:
                                                                                      EF = 2.057-(0.00113 x
                                                                                      Rated Storage Volume in
                                                                                      gallons).
Tabletop Water Heater..............  >= 20 gallons and <=    0.93-(0.00132 x Rated   EF = 0.93-(0.00132 x Rated
                                      120 gallons.            Storage Volume in       Storage Volume in
                                                              gallons).               gallons).
Instantaneous Gas-fired Water        < 2 gallons...........  0.62-(0.0019 x Rated    EF = 0.82-(0.0019 x Rated
 Heater.                                                      Storage Volume in       Storage Volume in
                                                              gallons).               gallons).
Instantaneous Electric Water Heater  < 2 gallons...........  0.93-(0.00132 x Rated   EF = 0.93-(0.00132 x Rated
                                                              Storage Volume in       Storage Volume in
                                                              gallons).               gallons).
----------------------------------------------------------------------------------------------------------------
Note: The Rated Storage Volume equals the water storage capacity of a water heater, in gallons, as certified by
  the manufacturer.

    Exclusions. The energy conservation standards shown in this 
paragraph do not apply to the following types of water heaters: gas-
fired, oil-fired, and electric water heaters at or above 2 gallons 
storage volume and below 20 gallons storage volume; gas-fired water 
heaters above 100 gallons storage volume; oil-fired water heaters above 
50 gallons storage volume; electric water heaters above 120 gallons 
storage volume; gas-fired instantaneous water heaters at or below 
50,000 Btu/h.
* * * * *

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

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

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

0
12. Section 431.102 is amended by adding the definition of ``Light 
commercial water heater,'' in alphabetical order, to read as follows:


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

* * * * *
    Light commercial water heater means any gas-fired, electric, or oil 
storage or instantaneous commercial water heater that meets the 
following conditions:
    (1) For models requiring electricity, uses single-phase external 
power supply;
    (2) Is not capable of delivering hot water at temperatures of 180 
[deg]F or above; and
    (3) Does not bear a Code Symbol Stamp signifying compliance with 
the requirements of the ASME Boiler and Pressure Vessel Code.
* * * * *
0
13. In Sec.  431.106, paragraph (b), Table 2, is revised to read as 
follows:


Sec.  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).

* * * * *
    (b) * * *

[[Page 66247]]



      Table 2 to Sec.   431.106--Test Procedures for Commercial Water Heaters and Hot Water Supply Boilers
                                 [Other than commercial heat pump water heaters]
----------------------------------------------------------------------------------------------------------------
                                                     Use test set-up,
                                                      equipment, and     Test procedure
                                 Energy efficiency    procedures in       required for     With these additional
         Equipment type              descriptor         subsection     compliance on and       stipulations
                                                    labeled  ``Method        after
                                                       of Test'' of
----------------------------------------------------------------------------------------------------------------
Light Commercial Water Heater..  Energy Factor....  10 CFR 430,        (insert date 365   None.
                                                     Subpt. B, App. E.  days after
                                                                        publication of
                                                                        the final rule
                                                                        in the Federal
                                                                        Register that
                                                                        establishes a
                                                                        conversion
                                                                        factor, or
                                                                        December 31,
                                                                        2015, whichever
                                                                        is later).
Gas-fired Storage and            Thermal            ANSI Z21.10.3-     May 13, 2013.....  A. For all products,
 Instantaneous Water Heaters      Efficiency.        2011**, Exhibit   .................   the duration of the
 and Hot Water Supply Boilers*.  .................   G1.               May 13, 2013.....   standby loss test
                                 Standby Loss.....  ANSI Z21.10.3-                         shall be until
                                                     2011**, Exhibit                       whichever of the
                                                     G2.                                   following occurs
                                                                                           first after you begin
                                                                                           to measure the fuel
                                                                                           and/or electric
                                                                                           consumption: (1) The
                                                                                           first cutout after 24
                                                                                           hours or (2) 48
                                                                                           hours, if the water
                                                                                           heater is not in the
                                                                                           heating mode at that
                                                                                           time.
Oil-fired Storage and            Thermal            ANSI Z21.10.3-     May 13, 2013.....  B. For oil and gas
 Instantaneous Water Heaters      Efficiency.        2011**, Exhibit   .................   products, the standby
 and Hot Water Supply Boilers*.  .................   G1.               May 13, 2013.....   loss in Btu per hour
                                 Standby Loss.....  ANSI Z21.10.3-                         must be calculated as
                                                     2011**, Exhibit                       follows: SL (Btu per
                                                     G2.                                   hour) = S (% per
                                                                                           hour) x 8.25 (Btu/gal-
                                                                                           F) x Measured Volume
                                                                                           (gal) x 70 (degrees
                                                                                           F).
Electric Storage and             Standby Loss.....  ANSI Z21.10.3-     May 13, 2013.....  C. For oil-fired
 Instantaneous Water Heaters.                        2011**, Exhibit                       products, apply the
                                                     G2.                                   following in
                                                                                           conducting the
                                                                                           thermal efficiency
                                                                                           and standby loss
                                                                                           tests: (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. (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.
                                                                                          D. For electric
                                                                                           products, apply the
                                                                                           following in
                                                                                           conducting the
                                                                                           standby loss test:
                                                                                           (1) Assume that the
                                                                                           thermal efficiency
                                                                                           (Et) of electric
                                                                                           water heaters with
                                                                                           immersed heating
                                                                                           elements is 98
                                                                                           percent. (2) Maintain
                                                                                           the electrical supply
                                                                                           voltage to within
                                                                                           5 percent
                                                                                           of the center of the
                                                                                           voltage range
                                                                                           specified on the
                                                                                           water heater
                                                                                           nameplate. (3) If the
                                                                                           set up includes
                                                                                           multiple adjustable
                                                                                           thermostats, set the
                                                                                           highest one first to
                                                                                           yield a maximum water
                                                                                           temperature in the
                                                                                           specified range as
                                                                                           measured by the
                                                                                           topmost tank
                                                                                           thermocouple. Then
                                                                                           set the lower
                                                                                           thermostat(s) to
                                                                                           yield a maximum mean
                                                                                           tank temperature
                                                                                           within the specified
                                                                                           range.
                                                                                          E. Install water-tube
                                                                                           water heaters as
                                                                                           shown in Figure 2,
                                                                                           ``Arrangement for
                                                                                           Testing Water-tube
                                                                                           Type Instantaneous
                                                                                           and Circulating Water
                                                                                           Heaters.''
----------------------------------------------------------------------------------------------------------------
* As to hot water supply boilers with a capacity of less than 10 gallons, these test methods become mandatory on
  October 21, 2005. Prior to that time, you may use for these products either (1) these test methods if you rate
  the product for thermal efficiency, or (2) the test methods in Subpart E if you rate the product for
  combustion efficiency as a commercial packaged boiler.
** Incorporated by reference, see Sec.   431.105.

0
14. Section 431.107 is added to read as follows:


Sec.  431.107  Uniform test method for the measurement of energy 
efficiency of commercial heat pump water heaters.

[[Page 66248]]



                Table 1 to Sec.   431.107--Test Procedures for Commercial Heat Pump Water Heaters
----------------------------------------------------------------------------------------------------------------
                                                                Use test set-up,
                                                                 equipment, and
           Equipment type               Energy efficiency         procedures in      Test procedure required for
                                           descriptor          subsection labeled      compliance on and after
                                                              ``Method of Test'' of
----------------------------------------------------------------------------------------------------------------
Light Commercial Heat Pump Water     Energy Factor.........  10 CFR 430, Subpt. B,   (insert date 365 days after
 Heater with Integrated Storage                               App. E.                 publication of the final
 Tank.                                                                                rule in the Federal
                                                                                      Register that establishes
                                                                                      a conversion factor, or
                                                                                      December 31, 2015,
                                                                                      whichever is later)
All Other Types....................  [Reserved]............  [Reserved]............  [Reserved]
----------------------------------------------------------------------------------------------------------------

[FR Doc. 2013-26268 Filed 11-1-13; 8:45 am]
BILLING CODE 6450-01-P