[Federal Register Volume 78, Number 8 (Friday, January 11, 2013)]
[Proposed Rules]
[Pages 2340-2347]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-00483]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 78, No. 8 / Friday, January 11, 2013 / 
Proposed Rules  

[[Page 2340]]


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DEPARTMENT OF ENERGY

10 CFR Part 430

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


Energy Conservation Program: Test Procedures for Residential 
Water Heaters and Commercial Water Heaters

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

ACTION: Request for Information.

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SUMMARY: Through this Request for Information (RFI), the U.S. 
Department of Energy (DOE) is initiating the rulemaking and data 
collection process to develop a uniform efficiency descriptor and 
accompanying test method for residential water heaters and commercial 
water heaters. This test procedure rulemaking is intended to fulfill 
DOE's statutory obligation to develop a uniform efficiency descriptor 
for residential and commercial water heaters pursuant to the amendments 
to the Energy Policy and Conservation Act (EPCA) brought about by the 
American Energy Manufacturing Technical Corrections Act (AEMTCA; H.R. 
6582), which was signed into law on December 18, 2012 (Pub. L. 112-
210). To inform interested parties and to facilitate this process, DOE 
has identified several issues in this RFI on which DOE is particularly 
interested in receiving comment from interested parties. In overview, 
the issues outlined in this document are mainly associated with: 
Currently available efficiency metrics and test procedures for rating 
the efficiency of residential and commercial water heaters; the 
requirements for a uniform metric set forth in the AEMTCA; and 
available options for DOE to address those statutory requirements. DOE 
welcomes written comments from the public on any subject within the 
scope of this rulemaking (including relevant topics not specifically 
raised in this RFI).

DATES: Written comments and information are requested on or before 
February 11, 2013.

ADDRESSES: Interested persons are encouraged to submit comments using 
the Federal eRulemaking Portal at http://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 regulatory identification number (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 Program, Mailstop EE-2J, 1000 
Independence Avenue SW., Washington, DC 20585- 0121. Telephone: (202) 
586-2945. 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 Program, 6th Floor, 950 L'Enfant Plaza 
SW., 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 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 III of this document (Public Participation).
    Docket: For access to the docket to read background documents or 
comments received, go to the Federal eRulemaking Portal at http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Requests for additional information 
may be sent to Mr. Mohammed Khan, U.S. Department of Energy, Office of 
Energy Efficiency and Renewable Energy, Building Technologies Program, 
Mailstop EE-2J, 1000 Independence Avenue SW., Washington, DC 20585-
0121. Telephone: (202) 586-7892. 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 Program, EE-2J, 
1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone: 
(202) 586-2945. Email: [email protected].

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Introduction
    A. Authority and Background
    1. Residential Water Heaters
    2. Commercial Water Heaters
    B. The American Energy Manufacturing Technical Corrections Act 
(AEMTCA)
II. Discussion
    A. Implications of the AEMTCA
    B. Potential Approaches To Address the Requirements of the 
AEMTCA
    1. Revised Energy Factor Metric
    2. Existing Thermal Efficiency and Standby Loss Metrics
    3. Revised Thermal Efficiency and Standby Loss Metrics
    4. Hybrid Efficiency Metric
    5. New Approach
    C. Conversion Factor
    D. Exclusions
    E. Other Concerns
    1. Representative Test Procedures
    2. Measures of Delivery Capacity
    3. Implications for Current Energy Conservation Standards
III. Public Participation

I. Introduction

    The American Energy Manufacturing Technical Corrections Act 
(AEMTCA), Public Law 112-210, amended the Energy Policy and 
Conservation Act of 1975 (EPCA or the Act), Public Law 94-163, to 
require that the U.S. Department of Energy (DOE or the Department) 
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 
the

[[Page 2341]]

AEMTCA.\1\ (42 U.S.C. 6295(e)(5)) Historically, DOE has administered 
its energy conservation standards (and specified the requisite test 
procedures) for residential water heaters and commercial water heaters 
separately. Thus, the historical background and statutory authority for 
these products are divided along those lines in the discussion that 
follows (i.e., sections I.A.1 and I.A.2). In addition, background 
information on the AEMTCA is presented in section I.B.
---------------------------------------------------------------------------

    \1\ The AEMTCA was signed into law on December 18, 2012, so 
accordingly, DOE must complete the required rulemaking by December 
18, 2013.
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A. Authority and Background

1. Residential Water Heaters
    Residential water heaters are products that use oil, gas, or 
electricity to heat potable water for use outside the heater upon 
demand. These include storage type units, instantaneous type units, and 
heat pump type units.\2\ (42 U.S.C. 6291(27))
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    \2\ In a final rule published in the Federal Register on April 
16, 2010, DOE determined that heat pump type water heaters with an 
integrated storage tank are a type of electric storage water heater, 
but that heat pump type water heaters without an integrated storage 
tank do not meet the definition of a ``water heater'' and are, 
therefore, not covered equipment under EPCA. 75 FR 20112, 20126 and 
20135.
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    Title III, Part B \3\ of EPCA (42 U.S.C. 6291-6309, as codified) 
sets forth a variety of provisions designed to improve energy 
efficiency and establishes the Energy Conservation Program for Consumer 
Products Other Than Automobiles, which includes the residential water 
heaters that are, in part, the subject of today's notice. (42 U.S.C. 
6291(1)-(2) and 6292(a)(4))
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    \3\ This part was originally titled Part B. It was redesignated 
as Part A in the United States Code for editorial reasons.
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    This program authorizes DOE to establish technologically feasible, 
economically justified energy efficiency regulations for certain 
products and equipment that would be likely to result in substantial 
national energy savings. (42 U.S.C. 6295(o)(2)-(3)) Under EPCA, this 
program generally consists 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 must 
use as both the basis for certifying to DOE that their products comply 
with the applicable energy conservation standards adopted pursuant to 
EPCA, and for making representations about the efficiency of those 
products. (42 U.S.C. 6293(c); 42 U.S.C. 6295(s)) 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 and 6314, EPCA sets forth criteria and 
procedures that DOE must follow when prescribing or amending test 
procedures for covered products and equipment. 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) and 6314(a)(2))
    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) and 6314(b)) Also, 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), Public Law 110-140, amended EPCA to require that at least once 
every 7 years, DOE must review test procedures for all covered products 
and equipment and either amend the 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) or 6314(a)(2)) or 
publish notice in the Federal Register of any determination not to 
amend a test procedure. (42 U.S.C. 6293(b)(1)(A) and 6314(a)(1))
    The National Appliance Energy Conservation Act of 1987 (NAECA), 
Public Law 100-12, amended EPCA and established energy conservation 
standards for residential water heaters, as well as requirements for 
determining whether these standards should be amended. (42 U.S.C. 
6295(e)) Specifically, NAECA set minimum standards for residential 
water heaters in terms of the energy factor (EF) and required that DOE 
publish a final rule to determine whether the standard should be 
amended no later than January 1, 1992. (42 U.S.C. 6295(e)(1) and 
(4)(A)) It also required that DOE publish another final rule by January 
1, 2000 to determine whether standards in effect for such products 
should again be amended. (42 U.S.C. 6295(e)(4)(B))
    Pursuant to 42 U.S.C. 6295(e)(4)(A), DOE published a final rule in 
the Federal Register on January 17, 2001 (hereafter referred to as the 
``January 2001 final rule''), amending statutorily-prescribed energy 
conservation standards for residential water heaters. 66 FR 4474. 
Compliance with the standards in the January 2001 final rule was 
required by January 20, 2004. Pursuant to 42 U.S.C. 6295(e)(4)(B), DOE 
published a final rule in the Federal Register on April 16, 2010, 
amending the energy conservation standards for residential water 
heaters for a second time. 75 FR 20112. Compliance with the standards 
in the April 2010 final rule will be required beginning on April 16, 
2015. The current and future energy conservation standards for 
residential water heaters are presented in Table I.1 immediately below.

 Table I.1--Energy Conservation Standards for Residential Water Heaters
                           (10 CFR 430.32(d))
------------------------------------------------------------------------
                               Energy factor (EF)
        Product class           as of January 20,    Energy factor (EF)
                                      2004          as of April 16, 2015
------------------------------------------------------------------------
Gas-fired Storage...........  EF = 0.67 - (0.0019   For tanks with a
                               x Rated Storage       Rated Storage
                               Volume in gallons).   Volume at or below
                                                     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).

[[Page 2342]]

 
Electric Storage............  EF = 0.97 - (0.00132  For tanks with a
                               x Rated Storage       Rated Storage
                               Volume in gallons).   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).
Oil-fired Storage...........  EF = 0.59 - (0.0019   EF = 0.68 - (0.0019
                               x Rated Storage       x Rated Storage
                               Volume in gallons).   Volume in gallons).
Gas-fired Instantaneous.....  EF = 0.62 - (0.0019   EF = 0.82 - (0.0019
                               x Rated Storage       x Rated Storage
                               Volume in gallons).   Volume in gallons).
------------------------------------------------------------------------
Electric Instantaneous......     EF = 0.93 - (0.00132 x Rated Storage
                                          Volume in gallons).
Tabletop....................     EF = 0.93 - (0.00132 x Rated Storage
                                          Volume in gallons).
------------------------------------------------------------------------
Note: The Rated Storage Volume equals the water storage capacity of a
  water heater, in gallons, as specified by the manufacturer.

    DOE's test procedures for residential water heaters are found at 10 
CFR 430.23(e) and 10 CFR part 430, subpart B, appendix E, Uniform Test 
Method for Measuring the Energy Consumption of Water Heaters. The test 
procedures include provisions for determining the energy efficiency 
(EF), as well as the annual energy consumption of these products.
    The following provides a brief history of DOE's more recent test 
procedure rulemakings related to residential water heaters. The current 
DOE test procedures for residential water heaters were established by a 
final rule published in the Federal Register on May 11, 1998 (63 FR 
25996), and subsequently updated through final rules published in July 
1998 and January 2001. (63 FR 38737 (July 20, 1998); 66 FR 4474 (Jan. 
17, 2001)) The July 1998 final rule was a technical correction that 
added figures to the test procedure, and the January 2001 amendments 
added a definition to the test procedure, although the bulk of that 
final rule was dedicated to amended energy conservation standards for 
residential water heaters. On December 17, 2012, DOE published a final 
rule in the Federal Register, as required under 42 U.S.C. 6295(gg)(2), 
that concluded that no modifications were needed to the residential 
water heater test procedure to account for standby mode and off mode 
energy consumption, as the existing test procedure already accounted 
for those modes of energy consumption. 77 FR 74559. DOE initiated a 
rulemaking to consider updates to the water heater test procedure by 
publishing an RFI in the Federal Register on October 12, 2011 
(hereafter referred to as the October 2011 RFI). 76 FR 63211.
2. Commercial Water Heaters
    DOE's regulations include the following types of commercial water 
heating equipment: (1) Gas-fired, electric, and oil-fired commercial 
storage water heaters; (2) gas-fired and oil-fired instantaneous water 
heaters; (3) hot water supply boilers; and (4) unfired hot water 
storage tanks. 10 CFR 431.2. Commercial storage type water heaters heat 
and store water within the appliance at a thermostatically-controlled 
temperature for delivery on demand; commercial storage type water 
heaters do not include units with an input rating of 4,000 Btu per hour 
or more per gallon of stored water. 10 CFR 431.102. Commercial 
instantaneous type waters heater include water heaters that have an 
input rating of at least 4,000 Btu per hour per gallon of stored water, 
including products meeting this description that are designed to heat 
water to temperatures of 180 [deg]F or higher. Id. An unfired hot water 
storage tank is a tank used to store water that is heated externally. 
Id. DOE's regulations further clarify that all such units are 
industrial equipment. Id.
    DOE's regulations for commercial water heating equipment at 10 CFR 
431.102 also include hot water supply boilers, which are a type of 
packaged boiler that is industrial equipment and that:
    (1) Has an input rating from 300,000 Btu/h to 12,500,000 Btu/h and 
of at least 4,000 Btu/h per gallon of stored water,
    (2) Is suitable for heating potable water, and
    (3) Meets either or both of the following conditions:
    (i) It has the temperature and pressure controls necessary for 
heating potable water for purposes other than space heating, or
    (ii) The manufacturer's product literature, product markings, 
product marketing, or product installation and operation instructions 
indicate that the boiler's intended uses include heating potable water 
for purposes other than space heating.
    Title III, Part C \4\ of EPCA (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, a program 
which addresses the energy efficiency of certain types of commercial 
and industrial equipment, including the commercial water-heating 
equipment that is, in part, the subject of this rulemaking. Relevant 
provisions of the Act specifically include definitions (42 U.S.C. 
6311), energy conservation standards (42 U.S.C. 6313), test procedures 
(42 U.S.C. 6314), labelling provisions (42 U.S.C. 6315), and the 
authority to require information and reports from manufacturers (42 
U.S.C. 6316).
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    \4\ For editorial reasons, upon codification in the U.S. Code, 
Part C was redesignated Part A-1.
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    The Energy Policy and Conservation Act of 1992 (EPACT 1992), Public 
Law 102-486, amended EPCA and established energy conservation standards 
for commercial storage water heaters, instantaneous water heaters, and 
unfired water storage tanks. (42 U.S.C. 6313(a)(5)) Specifically, EPACT 
1992 set standards for various types of commercial water heating 
equipment in terms of minimum thermal efficiency (Et) and 
maximum standby loss (SL), based on the type of fuel used, the type of 
unit (e.g., storage type or instantaneous type), and the input 
capacity. The standard levels generally corresponded to the levels in 
the American Society of Heating, Refrigerating and Air Conditioning 
Engineers (ASHRAE) Standard 90.1, Energy Standard for Buildings Except 
Low-Rise Residential Buildings, as in effect on October 24, 1992 (i.e., 
ASHRAE Standard 90.1-1989). In acknowledgement of technological changes 
that yield energy efficiency benefits, Congress further directed DOE 
through EPCA to consider amending the existing Federal energy 
conservation

[[Page 2343]]

standard for commercial water heating equipment, each time ASHRAE 
Standard 90.1 is amended with respect to such equipment. (42 U.S.C. 
6313(a)(6)(A)) EPCA also requires that if a test procedure referenced 
in ASHRAE Standard 90.1 is updated, DOE must update its test procedure 
to be consistent with the amended test procedure, unless DOE determines 
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 the 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))
    Pursuant to the requirements of EPCA, DOE last amended the energy 
conservation standards for commercial water heating equipment in a 
final rule published in the Federal Register on January 12, 2001. 66 FR 
3336. The amended energy conservation standards largely corresponded to 
the levels contained in ASHRAE Standard 90.1-1999. In a direct final 
rule published in the Federal Register on October 21, 2004, DOE 
prescribed test procedures to rate the energy efficiency of commercial 
water heaters and hot water supply boilers, specifying definitions for 
these products as well as unfired hot water storage tanks. 69 FR 61974. 
The rule also recodified existing energy conservation standards to 
locate them in closer proximity in the CFR to the test procedures that 
DOE promulgated. The current standards for commercial water heating 
equipment are set forth at 10 CFR 431.110 and shown in Table I.2 below.

        Table I.2--Energy Conservation Standards for Commercial Water Heating Equipment (10 CFR 431.110)
----------------------------------------------------------------------------------------------------------------
                                                                   Energy conservation standard* (products
                                                                manufactured on and after October 29, 2003) **
              Product                         Size          ----------------------------------------------------
                                                                 Minimum thermal
                                                                   efficiency          Maximum standby loss ***
----------------------------------------------------------------------------------------------------------------
Electric storage water heaters.....  All...................  N/A...................  0.30 + 27/Vm(%/hr)
Gas-fired storage water heaters....  <=155,000 Btu/hr......  80%...................  Q/800 + 110(Vr) 1/2(Btu/hr)
                                     >155,000 Btu/hr.......  80%...................  Q/800 + 110(Vr) 1/2(Btu/hr)
Oil-fired storage water heaters....  <=155,000 Btu/hr......  78%...................  Q/800 + 110(Vr) 1/2(Btu/hr)
                                     >155,000 Btu/hr.......  78%...................  Q/800 + 110(Vr) 1/2(Btu/hr)
Gas-fired instantaneous water        <10 gal...............  80%...................  N/A
 heaters and hot water supply
 boilers.
                                     >=10 gal..............  80%...................  Q/800 + 110(Vr) 1/2(Btu/hr)
Oil-fired instantaneous water        <10 gal...............  80%...................  N/A
 heaters and hot water supply
 boilers.
                                     >=10 gal..............  78%...................  Q/800 + 110(Vr) 1/2(Btu/hr)
----------------------------------------------------------------------------------------------------------------
                          Product                                     Size            Minimum thermal insulation
----------------------------------------------------------------------------------------------------------------
Unfired hot water storage tank.............................  All...................  R-12.5
----------------------------------------------------------------------------------------------------------------
*Vm is the measured storage volume and Vr is the rated volume, both in gallons. Q is the nameplate input rate in
  Btu/h.
** For hot water supply boilers with a capacity of less than 10 gallons: (1) The standards are mandatory for
  products manufactured on and after October 21, 2005, and (2) products manufactured prior to that date, and on
  or after October 23, 2003, must meet either the standards listed in this table or the applicable standards in
  subpart E of this part for a ``commercial packaged boiler.''
*** Water heaters and hot water supply boilers having more than 140 gallons of storage capacity need not meet
  the standby loss requirement if: (1) The tank surface area is thermally insulated to R-12.5 or more, (2) a
  standing pilot light is not used and (3) for gas or oil-fired storage water heaters, they have a fire damper
  or fan-assisted combustion.

    DOE's test procedures for commercial water heaters (other than 
commercial heat pump water heaters) are found at 10 CFR 431.106 and as 
noted previously, were established in an October 21, 2004 direct final 
rule. 69 FR 61974. The test procedures for commercial water heating 
equipment are currently largely based on American National Standards 
Institute (ANSI) Z21.10.3-1998, Gas Water Heaters--Volume III, Storage 
Water Heaters with Input Ratings Above 75,000 Btu Per Hour, Circulating 
and Instantaneous. The test procedures include provisions for 
determining thermal efficiency and standby loss. DOE published a final 
rule in the Federal Register on May 16, 2012 that amended the test 
procedures for commercial water heating equipment to reference the most 
current industry standard (i.e., ANSI Z21.10.3-2011). 77 FR 28928. 
Compliance with the amended test procedures is required beginning on 
May 13, 2013.

B. The American Energy Manufacturing Technical Corrections Act (AEMTCA)

    The AEMTCA amended EPCA to require that DOE publish a final rule 
establishing a uniform efficiency descriptor and accompanying test 
methods for covered water heaters (both residential and commercial) not 
later than one year after the enactment of the AEMTCA. (42 U.S.C. 
6295(e)(5)(B)) The final rule must replace the current EF, 
Et, and SL metrics with a uniform efficiency descriptor. (42 
U.S.C. 6295(e)(5)(C)) Further, the 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 (i.e., EF for residential 
water heaters and Et and SL for commercial water heaters) to 
the new uniform energy descriptor. (42 U.S.C. 6295(e)(5)(E)(ii)) Such 
conversion factor would apply to affected water heaters that are tested 
prior to the establishment of the final rule. The AEMTCA requires that 
the conversion factor not affect the minimum efficiency requirements 
for covered water heaters. (42 U.S.C. 6295(e)(5)(E)(iii)) Covered water 
heaters shall be considered to comply with the final rule on and after 
the effective date of the final rule and with any revised labeling 
requirements established by the Federal Trade Commission to carry out 
the final rule if the covered water heater was

[[Page 2344]]

manufactured prior to the effective date of the final rule and complied 
with the efficiency standards and labeling requirements in effect prior 
to the final rule. (42 U.S.C. 6295(e)(5)(K))
    The AEMTCA 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)) However, the AEMTCA 
allows DOE to provide an exclusion from the uniform efficiency 
descriptor for any specific category of otherwise covered water heaters 
that do not have a residential use, 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))
    The AEMTCA also outlines DOE's options in terms of establishing a 
new uniform efficiency descriptor for water heaters. Specifically, the 
options provided to DOE for a uniform descriptor 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)) Each of these options is discussed in further detail in 
section II.B.
    Lastly, the AEMTCA also requires that DOE invite interested 
stakeholders to participate in the rulemaking process used to establish 
the final rule (42 U.S.C. 6295(e)(5)(I)), 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)(J))
    In response to the statutory provisions of the AEMTCA, DOE 
envisions developing an energy efficiency metric (or metrics) that 
covers all residential and commercial water heaters. Such metric (or 
metrics) would be determined through a test method that is as uniform 
as possible while still producing a rating that is representative of 
performance under conditions that approximate actual usage. 
Additionally, DOE will strive to develop a uniform test method that 
would minimize incremental test burdens on manufacturers to the extent 
possible.

II. Discussion

A. Implications of the AEMTCA

    DOE tentatively interprets the relevant provisions of the AEMTCA to 
mean that a single efficiency metric and test method should apply to 
all water heaters currently covered under residential and commercial 
test methods unless circumstances justify use of the exclusion provided 
under 42 U.S.C. 6295(e)(5)(F). This interpretation means that water 
heaters from the smallest capacity and size rating used in residential 
applications all the way up to the largest capacity covered under DOE's 
commercial water heater program should be subject to the same rating 
metric and testing procedures. These test methods and the resulting 
uniform rating metric should cover all fuel types and technologies, 
including storage water heaters, instantaneous water heaters, integral 
heat pump water heaters, non-integral heat pump water heaters, unfired 
hot water storage tanks, and hot water supply boilers. In addition, DOE 
believes it may be appropriate for the uniform descriptor and test 
methods to also address hot water supply boilers, which are included 
with other types of commercial water heating equipment in DOE's 
regulations at 10 CFR 431.110, although they are not explicitly called 
out among the covered products in 42 U.S.C. 6295(e)(5)(A). DOE is 
interested in receiving comment on whether the uniform efficiency 
descriptor should apply to all types of residential and commercial 
water heaters covered by EPCA, hot water supply boilers, and unfired 
hot water storage tanks. Lastly, DOE acknowledges that the AEMTCA 
provides for the possibility of an exclusion for certain water heaters 
from the uniform efficiency metric and accompanying test method (42 
U.S.C. 6295(e)(5)(F) and further discusses this exclusion below in 
section II.D.

B. Potential Approaches To Address the Requirements of the AEMTCA

    As noted previously, the AEMTCA provides five options by which DOE 
can meet the relevant requirements related to water heaters. (42 U.S.C. 
6295(e)(5)(G)) Each of these options is discussed for comment in the 
sections that immediately follow.
1. Revised Energy Factor Metric
    Energy factor is currently the regulating metric for residential 
water heaters. Energy factor is a measure of the overall efficiency of 
the water heater and accounts for efficiency during active, standby, 
and cyclical operation. DOE's test method for determining energy factor 
currently includes a 24-hour simulated use test consisting of six hot 
water draws followed by a standby period. 10 CFR part 430, subpart B, 
appendix E.
    DOE has tentatively decided that the revised energy factor approach 
would follow the general technique for determining energy factor that 
is currently in place for residential water heaters. The current 
approach provides the efficiency of the water heater over a defined 
period of time (currently 24 hours) subject to a specified usage 
profile and ambient conditions. Based on comments received in response 
to the October 2011 RFI (76 FR 63211), DOE believes that a 24-hour 
simulated-use test is the most viable method for obtaining the energy 
factor for residential water heaters.
    Advantages of such an approach are that it results in a single 
descriptor that is clear and concise for evaluating the efficiency of a 
water heater and that it is applicable across all fuel types, sizes, 
and technologies. All water heaters would be subject to a simulated-use 
test that is similar to the test currently required for residential 
water heaters. The simulated-use test provides a means by which the 
water heater's efficiency is determined under a pattern of 
representative usage. A properly designed simulated-use test can also 
be technologically agnostic, meaning that the test applies to water 
heaters utilizing any water heating technology and that it would 
properly represent the efficiency of one technology versus another for 
a particular application.
    A disadvantage of the current simulated-use test is that it 
requires assumptions of in-field usage, and a single use pattern as 
currently applied in the residential test procedure would not be 
appropriate for the wide range of water heaters covered under this 
legislation. The October 2011 RFI requested comments on the 
appropriateness of the draw pattern. 76 FR 63211, 63214 (Oct. 12, 
2011). Among the comments, some mentioned the need to implement 
multiple draw patterns appropriate for different size classes. This 
technique may provide more appropriate demands for a range of water 
heaters, and allow for an accurate representation of efficiency of a 
wide range of different water heaters, including those that are 
currently rated as commercial units. However, one potential 
disadvantage of using multiple, differing draw patterns would be the 
increased complexity of a simulated-use test and the added test time.
    In addition to comments on the appropriateness of a simulated-use 
test approach, DOE also seeks comment on draw patterns that could be 
used in extending such an approach to water heaters intended for the 
commercial market.

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2. Existing Thermal Efficiency and Standby Loss Metrics
    Thermal efficiency and standby loss are currently the regulating 
metrics for commercial water heating equipment, with the exception of 
unfired storage tanks which are regulated by minimum thermal 
insulation. Thermal efficiency accounts for the efficiency of a water 
heater during active operation, while standby loss accounts for 
efficiency during standby periods. DOE's test methods for determining 
thermal efficiency and standby loss reference the industry standard, 
ANSI Z21.10.3, and are specified at 10 CFR 431.106.
    DOE has tentatively decided that this option would use the thermal 
efficiency and standby loss metrics and test methods that are currently 
in place for the commercial water heating equipment for all covered 
water heaters, including residential units that are currently rated 
using energy factor.
    The key advantage of this approach is that the tests would be 
simpler to implement. No changes would be needed to the commercial 
water heaters test method, because that same test procedure, as it 
exists today, could be applied to both residential and commercial 
models. While this may be true from a technical perspective, there may 
be disadvantages in terms of characterizing representative use, as 
explained below.
    A disadvantage of this approach is that it does not account for 
energy efficiency performance during cyclical portions of water heater 
operation. Comments to the October 2011 RFI (76 FR 63211) indicated 
that field data show lower efficiency in the actual use compared to the 
rating obtained using the current DOE simulated use test because of 
cycling of the units between warm and cold states under usage typically 
seen in residences. The thermal efficiency is a measure of efficiency 
during the water delivery stage, and the standby loss factor is a 
measure of efficiency during the standby mode stage. Neither of these 
metrics would capture the losses associated with cyclical warm-up and 
cool-down of water heaters. It is also questionable whether thermal 
efficiency is an appropriate metric for smaller storage water heaters, 
because they are not designed to provide a large supply of hot water 
continuously. It should also be noted that the test procedure for 
residential water heaters utilized the thermal efficiency and standby 
loss tests up until 1990, when a simulated use test was adopted to make 
the test uniform across technologies, particularly for heat pump water 
heaters and gas instantaneous water heaters.
3. Revised Thermal Efficiency and Standby Loss Metrics
    DOE has tentatively decided that this approach would be a modified 
version of the current commercial water heater test procedure that 
results in the same descriptors, albeit with potentially modified 
meanings, as those currently used to rate commercial water heaters. One 
option would be to use a metric similar to the recovery efficiency and 
standby heat loss coefficient as computed in the current residential 
water heater test procedure.
    The advantage of such an approach is that simpler laboratory tests 
that are more repeatable could theoretically be used to rate 
efficiency. Revisions to the original metrics and test methods, such as 
changes to account for cycling effects, changes to the water delivery 
temperature, and ambient conditions, could make them more suitable for 
residential water heaters compared to the existing metrics.
    Disadvantages with this approach are the same as those discussed 
above in section II.B.2 for the existing thermal efficiency and standby 
loss metrics. Most notably, it is not clear that these metrics would 
capture efficiency effects of cycling water heaters on and off. 
Additionally, DOE is not aware of any proposed approaches other than 
those discussed related to the residential water heater test method 
incorporating revised thermal efficiency and standby loss descriptors, 
nor is it aware of what specifically can be done to revise or improve 
thermal efficiency and standby loss to accomplish the intent of the 
AEMTCA.
4. Hybrid Efficiency Metric
    DOE has tentatively decided that this approach would involve a 
combination of the current energy factor, thermal efficiency, and 
standby loss metrics into a new single uniform descriptor. DOE 
anticipates that such a metric would utilize some combination of the 
existing test procedures and aspects of the existing metrics to obtain 
information for the new hybrid metric.
    The advantage of such an approach is that parts or all of existing 
test methods could be utilized, thereby decreasing the effort for 
manufacturers and testing agencies in developing test programs even if 
certain portions of those test methods had not been previously applied 
to all models of water heaters.
    The disadvantage of such an approach could be that it would require 
more tests on each water heater if each water heater should need to 
undergo a test to determine multiple individual metrics that ultimately 
result in a single, hybrid metric, resulting in a higher burden on 
manufacturers. The testing method to obtain a uniform ``hybrid'' metric 
may lead to biases between different water heating technologies if the 
performance model fails to capture critical aspects of a particular 
technology's operation. This model may also require adjustment as new 
technologies emerge. Furthermore, DOE is not aware of any proposed 
approaches towards developing a hybrid metric, nor what specifically 
could be done by a hybrid metric to accomplish the intent of the 
AEMTCA.
5. New Approach
    DOE seeks comment on any other approach or descriptor that it 
should consider that has not previously been discussed.

C. Conversion Factor

    The AEMTCA requires that DOE develop a temporary mathematical 
conversion factor for converting the measurement of efficiency for 
covered water heaters from the existing test procedures to the new 
energy descriptor established under the final rule. (42 U.S.C. 
6295(e)(5)(E)) The allowance to use the conversion factor will expire 1 
year after publication of such conversion factor or December 31, 2015, 
whichever is later. (42 U.S.C. 6295(e)(5)(E)(v)) The form and magnitude 
of this mathematical conversion factor would depend on which option is 
chosen, and on the extent of accompanying test procedure modifications. 
Thus, particularly for comments related to new or adjusted metrics, DOE 
seeks comment on ways to convert from the existing metrics for the 
different types of residential and commercial water heaters to the 
uniform metric, as discussed above.

D. Exclusions

    The AEMTCA indicates that the final rule may exclude a specific 
category of covered water heaters from the uniform efficiency 
descriptor, if such category of water heaters: (1) Does not have a 
residential use and can be clearly described in the final rule; and (2) 
can be effectively rated using the existing thermal efficiency and 
standby loss descriptors. (42 U.S.C. 6295(e)(5)(F)) Tentatively, DOE 
does not view the exclusion as applying to all models that are solely 
offered for non-residential applications, and the Department notes that 
the statute states that DOE's final rule may exclude certain types of 
water heaters. Moreover, under 42 U.S.C. 6295(e)(5)(H), the AEMTCA 
states that ``[t]he efficiency descriptor and

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accompanying test method established under the final rule shall apply, 
to the maximum extent practicable, to all water heater technologies in 
use * * * and to future water heater technologies.'' If DOE were to 
review the exclusion in a broad manner, it would apply to a large 
subset of models that currently are characterized as commercial water 
heaters under DOE's regulatory scheme. In addition, it is unclear how 
the Department could create an equitable distinction for application of 
the exclusion based on a manufacturer's claim of intended use of its 
product. DOE also notes that no other statutory section specifically 
indicates that the uniform descriptor should only apply to water 
heaters intended for residential use, and thus, DOE believes the 
uniform descriptor should apply to all covered water heaters, unless a 
clear need exists and the statutory criteria for using the exclusion 
are met. It is DOE's position that an expansive view of the above-
referenced exclusion authority would largely undermine the purposes of 
AEMTCA in terms of achieving a uniform efficiency metric and test 
method for all water heaters.
    With the above understanding in mind, DOE has tentatively concluded 
that a uniform efficiency descriptor and test method would be possible 
for all water heaters covered by the statute, but DOE seeks comment on 
the types of water heaters, if any, that should be excluded, along with 
a rationale to support such exclusion. (42 U.S.C. 6295(e)(5)(F)) As an 
example, DOE notes that unfired storage tanks and commercial ``add-on'' 
heat pump water heaters (which are typically shipped without tanks and 
the paired with a storage tank or storage water heater) are not 
completely contained water heating systems, and are required to be 
paired with other water heating equipment in the field to operate as 
intended. As such, these types of equipment have specific 
characteristics that may not be conducive to a uniform efficiency 
metric, and certain efficiency metrics may not be applicable to these 
types of equipment depending on the testing requirements for that 
metric. DOE requests comment on whether these types of equipment should 
be excluded from the uniform efficiency descriptor requirement.
    If stakeholders were to suggest that DOE exclude certain heaters 
that do not have a residential use, comments are sought as to how to 
distinguish those water heaters based on characteristics of the 
products. DOE would be interested in comments regarding whether the 
storage volume, energy input capacity, output capacity as determined 
through testing, or another means would be appropriate for indicating 
which water heaters clearly do not have a residential use and are 
effectively rated under current procedures.
    At this point, the Department tentatively expects the exclusions, 
if any, to be limited in number. DOE seeks comments on the 
characteristics of any types of water heaters that should be excluded 
from this uniform efficiency descriptor, as well as the rationale for 
doing so.

E. Other Concerns

    DOE seeks comments on any other issues that may relate to the 
development of a uniform efficiency descriptor and test methods, and 
the requirements of the AEMTCA. In particular, DOE has identified 
several additional issues below for discussion.
1. Representative Test Procedures
    As noted above, under 42 U.S.C. 6293 and 6314, EPCA sets forth the 
criteria and procedures DOE must follow when prescribing or amending 
test procedures for covered products and equipment. 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) and 6314(a)(2)) Usage patterns between water heaters 
intended for residential applications and those intended for commercial 
applications, however, are vastly different, as dictated by factors 
such as water delivery temperature, flow rate, total volume of water 
delivered per day, and draw pattern. In addition, environmental factors 
that could affect performance (e.g., such as ambient air temperature, 
ambient relative humidity, and inlet water temperature) may also vary. 
DOE seeks comments on the best approaches to managing these wide ranges 
of conditions for testing purposes, while still meeting the 
requirements of EPCA to produce energy efficiency results during a 
representative period of use and not be unduly burdensome to conduct.
2. Measures of Delivery Capacity
    The current DOE residential water heater test procedure requires a 
test to measure the delivery capacity of the water heater, resulting in 
either a first-hour rating for storage water heaters or a maximum 
gallons-per-minute rating for instantaneous water heaters. No 
equivalent test for delivery capacity is present for commercial water 
heaters. DOE seeks comments on the need for this metric for water 
heaters intended for non-residential applications. Additionally, DOE 
seeks comments regarding the applicability of the metrics and test 
methods currently present in the residential water heater test 
procedure (first-hour rating, maximum gallons-per-minute) for 
commercial water heaters.
3. Implications for Current Energy Conservation Standards
    In developing the uniform efficiency descriptor, the AEMTCA 
requires that DOE develop a mathematical conversion factor (discussed 
in section II.C) for converting the measurement of efficiency for 
covered water heaters under the current test procedures to the uniform 
descriptor. The AEMTCA stipulates that the conversion factor shall not 
affect the minimum efficiency requirements for covered water heaters.
    To address this requirement, DOE plans to develop a conversion 
factor as discussed in section II.C and apply it to the current energy 
conservation standards to equate the standards under the existing 
metric and test procedures to the standards using the new uniform 
efficiency metric and test procedures. DOE requests comment on this 
approach to maintaining equivalent efficiency standards, and on the 
appropriate approach to develop the mathematical conversion.

III. Public Participation

    DOE invites all interested parties to submit in writing by February 
11, 2013, comments and information on matters addressed in this notice 
and on other matters relevant to DOE's consideration of a uniform 
efficiency descriptor and accompanying test methods for residential and 
commercial water heaters.
    After the close of the comment period, DOE will begin collecting 
data, conducting the relevant analyses, and reviewing the public 
comments. These actions will be taken to aid in the development of a 
test procedure NOPR for residential and commercial water heaters that 
establishes a uniform efficiency descriptor and accompanying test 
method.
    DOE considers public participation to be a very important part of 
the process for developing the uniform energy descriptor and developing 
updates to the test procedure, if necessary, to accommodate the new 
metric. DOE actively encourages the participation and interaction of 
the public during the comment period in each stage of the

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rulemaking process. Interactions with and between members of the public 
provide a balanced discussion of the issues and assist DOE in the 
rulemaking process. Anyone who wishes to be added to the DOE mailing 
list to receive future notices and information about this rulemaking 
should contact Ms. Brenda Edwards at (202) 586-2945, or via email at 
[email protected].

    Issued in Washington, DC, on January 7, 2013.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy Efficiency, Energy Efficiency and 
Renewable Energy.
[FR Doc. 2013-00483 Filed 1-10-13; 8:45 am]
BILLING CODE 6450-01-P