[Federal Register Volume 75, Number 1 (Monday, January 4, 2010)]
[Proposed Rules]
[Pages 186-218]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-30884]



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Part II





Department of Energy





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10 CFR Part 431



Energy Conservation Program: Test Procedures for Walk-In Coolers and 
Walk-In Freezers; Proposed Rule

  Federal Register / Vol. 75, No. 1 / Monday, January 4, 2010 / 
Proposed Rules  

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DEPARTMENT OF ENERGY

10 CFR Part 431

[Docket No. EERE-2008-BT-TP-0014]
RIN 1904-AB85


Energy Conservation Program: Test Procedures for Walk-In Coolers 
and Walk-In Freezers

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

ACTION: Notice of proposed rulemaking and public meeting.

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SUMMARY: Pursuant to the Energy Policy and Conservation Act, as 
amended, the U.S. Department of Energy (DOE) is proposing test 
procedures for measuring the energy consumption of walk-in coolers and 
walk-in freezers (collectively ``walk-in equipment'' or ``walk-
in(s)''), definitions to delineate the products covered by the test 
procedures, and provisions (including a sampling plan) for 
manufacturers to implement the test procedures. The notice also 
addresses enforcement issues as they relate to walk-in equipment. 
Concurrently, DOE is undertaking an energy conservation standards 
rulemaking for this equipment. Any data gathered through the use of the 
test procedure adopted by DOE will be used in evaluating any potential 
standards for this equipment. Once these standards are promulgated, the 
adopted test procedures will be used to determine equipment efficiency 
and compliance with the standards.

DATES: DOE will hold a public meeting in Washington, DC on Thursday, 
February 11, 2010, beginning at 9 a.m. DOE must receive requests to 
speak at the meeting before 4 p.m., Thursday, January 28, 2010. DOE 
must receive a signed original and an electronic copy of statements to 
be given at the public meeting before 4 p.m., Thursday, January 28, 
2010.
    DOE will accept comments, data, and information regarding this 
notice of proposed rulemaking (NOPR) before or after the public 
meeting, but no later than March 22, 2010. See section V, ``Public 
Participation,'' of this NOPR for details.

ADDRESSES: The public meeting will be held at the U.S. Department of 
Energy, Forrestal Building, Room 8E-089, 1000 Independence Avenue, SW., 
Washington, DC 20585-0121. To attend the public meeting, please notify 
Ms. Brenda Edwards at (202) 586-2945. Please note that foreign 
nationals participating in the public meeting are subject to advance 
security screening procedures, requiring a 30-day advance notice. If 
you are a foreign national and wish to participate in the public 
meeting, please inform DOE as soon as possible by contacting Ms. Brenda 
Edwards at (202) 586-2945 so that the necessary procedures can be 
completed.
    Any comments submitted must identify the NOPR for Test Procedures 
for Walk-in Coolers and Freezers, and provide docket number EERE-2008-
BT-TP-0014 and/or Regulation Identifier Number (RIN) 1904-AB85. 
Comments may be submitted using any of the following methods:
    1. Federal eRulemaking Portal: http://www.regulations.gov. Follow 
the instructions for submitting comments.
    2. E-mail: [email protected]. Include the docket number 
EERE-2008-BT-TP-0014 and/or RIN 1904-AB85 in the subject line of the 
message.
    3. Postal Mail: Ms. Brenda Edwards, U.S. Department of Energy, 
Building Technologies Program, Mailstop EE-2J, 1000 Independence 
Avenue, SW., Washington, DC 20585-0121. Please submit one signed 
original paper copy.
    4. Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department of 
Energy, Building Technologies Program, 950 L'Enfant Plaza, SW., 6th 
Floor, Washington, DC 20024. Please submit one signed original paper 
copy.
    For detailed instructions on submitting comments and additional 
information on the rulemaking process, see section V, ``Public 
Participation,'' of this document.
    Docket: For access to the docket to read background documents or 
comments received, visit the U.S. Department of Energy, Resource Room 
of the Building Technologies Program, 950 L'Enfant Plaza, SW., 6th 
Floor, Washington, DC 20024, (202) 586-2945, between 9 a.m. and 4 p.m. 
Monday through Friday, except Federal holidays. Please call Ms. Brenda 
Edwards at the above telephone number for additional information 
regarding visiting the Resource Room.

FOR FURTHER INFORMATION CONTACT: Mr. Charles Llenza, U.S. Department of 
Energy, Building Technologies Program, EE-2J, 1000 Independence Avenue, 
SW., Washington, DC 20585-0121, (202) 586-2192, 
[email protected] or Mr. Michael Kido, Esq., U.S. Department of 
Energy, Office of General Counsel, GC-72, 1000 Independence Avenue, 
SW., Washington, DC 20585- 0121, (202) 586-8145, 
[email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Authority and Background
II. Summary of the Proposal
III. Discussion
    A. Overall Approach
    1. Basic Model
    2. Approach Option 1: Test the Unit as a Whole
    3. Approach Option 2: Allow Manufacturers To Use Alternative 
Energy Determination Methods (AEDMs)
    4. Proposed Option and Recommendation: Separate Envelope and 
Refrigeration Tests
    B. Envelope
    1. Overview of the Test Procedure
    2. Test Methods
    a. Insulation
    b. Air Infiltration
    c. Steady-State Infiltration Test
    3. Calculations
    a. Energy Efficiency Ratio
    b. Heat Gain Through the Envelope Due to Conduction
    c. Heat Gain Due to Infiltration
    d. Envelope Component Electrical Loads
    e. Normalization
    f. Daily Energy Consumption Coefficients
    C. Refrigeration System
    1. Overview of the Test Procedure
    2. Test Conditions
    3. Test Methods
    4. Measurements and Calculations
    D. Compliance, Certification, and Enforcement
    1. Provisions for Energy Conservation Standards Developed by the 
Department of Energy
    2. Provisions for Existing Design Standards Prescribed by 
Congress
IV. Regulatory Review
    A. Review Under Executive Order 12866
    B. Review Under the National Environmental Policy Act
    C. Review Under the Regulatory Flexibility Act
    D. Review Under the Paperwork Reduction Act
    E. Review Under the Unfunded Mandates Reform Act of 1995
    F. Review Under the Treasury and General Government 
Appropriations Act, 1999
    G. Review Under Executive Order 13132
    H. Review Under Executive Order 12988
    I. Review Under the Treasury and General Government 
Appropriations Act, 2001
    J. Review Under Executive Order 13211
    K. Review Under Executive Order 12630
    L. Review Under Section 32 of the Federal Energy Administration 
(FEA) Act of 1974
V. Public Participation
    A. Attendance at Public Meeting
    B. Procedure for Submitting Requests to Speak
    C. Conduct of Public Meeting
    D. Submission of Comments
    E. Issues on Which DOE Seeks Comment
    1. Test Procedure Improvements
    2. Basic Model
    3. Separate Envelope and Refrigeration Tests
    4. Definition of Envelope
    5. Effect of Impermeable Skins on Long-Term R Value
    6. Measuring Long-Term R Value Using American Society for 
Testing and Materials (ASTM) C1303-08
    7. Infiltration

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    8. Nominal Coefficient of Performance of Refrigeration
    9. Measuring the U Value of glass
    10. Floor R Value
    11. Electrical Duty Cycle
    12. Normalization Factor
    13. Daily Energy Consumption Coefficients
    14. Definition of Refrigeration System
    15. Measurements and Calculations of Energy Use of Refrigeration 
Systems
    16. Impacts on Small Businesses
VI. Approval of the Office of the Secretary

I. Authority and Background

    Title III of the Energy Policy and Conservation Act of 1975, as 
amended (EPCA or the Act) sets forth a variety of provisions designed 
to improve energy efficiency. Part B of Title III (42 U.S.C. 6291-6309) 
provides for the Energy Conservation Program for Consumer Products 
Other Than Automobiles. The National Energy Conservation Policy Act 
(NECPA), Public Law 95-619, amended EPCA to add Part C of Title III, 
which established an energy conservation program for certain industrial 
equipment. (42 U.S.C. 6311-6317) (These parts were subsequently 
redesignated as Parts A and A-1, respectively, for editorial reasons.) 
Section 312 of the Energy Independence and Security Act of 2007 (EISA 
2007) further amended EPCA by adding certain equipment to this energy 
conservation program, including walk-in coolers and walk-in freezers 
(collectively ``walk-in equipment'' or ``walk-ins''), the subject of 
this rulemaking. (42 U.S.C. 6311(1), (2), 6313(f) and 6314(a)(9))
    EPCA defines walk-in equipment as follows:
    (A) In general.--
    The terms ``walk-in cooler'' and ``walk-in freezer'' mean an 
enclosed storage space refrigerated to temperatures, respectively, 
above, and at or below 32 degrees Fahrenheit that can be walked into, 
and has a total chilled storage area of less than 3,000 square feet.
    (B) Exclusion.--
    The terms ``walk-in cooler'' and ``walk-in freezer'' do not include 
products designed and marketed exclusively for medical, scientific, or 
research purposes. (42 U.S.C. 6311(20))
    Walk-ins covered by this rulemaking may be located indoors or 
outdoors. They may be used exclusively for storage, but they may also 
have transparent doors or panels for the purpose of displaying stored 
items. Examples of items that may be stored in walk-ins include, but 
are not limited to, food, beverages, and flowers. DOE notes that any 
equipment that meets the above definition is potentially subject to 
regulation.
    Under the Act, the overall program consists essentially of the 
following parts: testing, labeling, and Federal energy conservation 
standards. The testing requirements for covered equipment consist of 
test procedures, prescribed under EPCA. These test procedures are used 
in several different ways: (1) Any data from the use of these 
procedures are used as a basis in developing standards for covered 
products or equipment; (2) the test procedure is used when determining 
equipment compliance with those standards; and (3) manufacturers of 
covered equipment must use the procedure to establish that their 
equipment complies with energy conservation standards promulgated 
pursuant to EPCA and when making representations about equipment 
efficiency.
    Section 343 of EPCA (42 U.S.C. 6314) sets forth generally 
applicable criteria and procedures for DOE's adoption and amendment of 
such test procedures. That provision requires that the test procedures 
promulgated by DOE be reasonably designed to produce test results which 
reflect energy efficiency, energy use, and estimated operating costs of 
the covered equipment during a representative average use cycle. It 
also requires that the test procedure not be unduly burdensome to 
conduct. See 42 U.S.C. 6314(a)(2). As part of the process for 
promulgating a test procedure, DOE must publish the procedure that it 
plans to propose and offer the public an opportunity to present oral 
and written comments on them. Consistent with Executive Order 12889 and 
EPCA (see 42 U.S.C. 6314(b)), DOE provides a minimum comment period of 
75 days on a proposed test procedure. As to the test procedures for 
walk-in equipment, EPCA prescribes the following requirements:
    (A) In general.--
    For the purpose of test procedures for walk-in coolers and walk-in 
freezers:
    (i) The R value shall be the 1/K factor multiplied by the thickness 
of the panel.
    (ii) The K factor shall be based on ASTM [American Society for 
Testing and Materials] test procedure C518-2004.
    (iii) For calculating the R value for freezers, the K factor of the 
foam at 20 [deg]F (average foam temperature) shall be used.
    (iv) For calculating the R value for coolers, the K factor of the 
foam at 55 [deg]F (average foam temperature) shall be used.
    (B) Test Procedure.--
    (i) In general.--Not later than January 1, 2010, the Secretary 
shall establish a test procedure to measure the energy-use of walk-in 
coolers and walk-in freezers.
    (ii) Computer modeling.--The test procedure may be based on 
computer modeling, if the computer model or models have been verified 
using the results of laboratory tests on a significant sample of walk-
in coolers and walk-in freezers. (42 U.S.C. 6314(a)(9))
    On February 4, 2009, DOE held a public meeting on the framework 
document it issued concerning the DOE rulemaking to evaluate walk-in 
equipment for energy conservation standards. See 74 FR 411 (Jan. 6, 
2009) and 74 FR 1992 (Jan. 14, 2009). Both the framework document and 
meeting discussed the possible test procedures for this equipment that 
DOE was considering at that time, and gave interested parties an 
opportunity to submit comments. Today's notice addresses those comments 
and proposes test procedures for walk-in equipment.

II. Summary of the Proposal

    In today's notice, DOE proposes to adopt new test procedures for 
determining the energy use of walk-in cooler and walk-in freezer 
equipment to address the statutory requirement to establish a test 
procedure by January 1, 2010. (42 U.S.C. 6314(a)(9)(B)) Concurrently, 
DOE is undertaking an energy conservation standards rulemaking for 
walk-in equipment to address the statutory requirement to establish 
performance standards no later than January 1, 2012. (42 U.S.C. 
6313(f)(4)(A)) DOE will use any data resulting from use of the test 
procedure that DOE adopts to evaluate potential performance standards 
for this equipment. Furthermore, once performance standards are issued, 
manufacturers would be required to use the test procedures to determine 
compliance with such standards and for any representations regarding 
the energy use of walk-in equipment they produce. This test procedure, 
once adopted, would serve as the means for ascertaining compliance with 
the appropriate standards in an enforcement action.
    For the reasons described below, DOE proposes to adopt a test 
procedure that contains two separate test methods. This approach is 
necessary because there are typically two manufacturers of walk-in 
equipment: One who manufactures the envelope (i.e., the insulated box 
in which the refrigerated or frozen items are stored) and one who 
manufactures the refrigeration system (i.e., the mechanism that 
provides the means by which to feed chilled air into the envelope). One 
method determines the

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energy consumption of the refrigeration system of the walk-in cooler or 
freezer. The other method determines the energy consumption of the 
envelope, which is the sum of the energy use associated with heat 
transmission through the envelope in the form of conduction through the 
walls and air infiltration through openings, and the power consumed by 
electrical components that are part of the envelope. Each of the two 
components, the refrigeration system and the envelope, is considered 
separately and the energy consumption of each component is calculated 
using the applicable test procedure. DOE believes that the approach is 
consistent with the requirements in EPCA because the results of the two 
tests will represent, in the aggregate, the total energy consumption of 
walk-in coolers and freezers.
    Using this approach, DOE believes that the proposed test procedures 
will adequately measure the energy consumption of walk-in equipment by 
capturing the energy consumption of both components. However, DOE 
requests comment from stakeholders on improvements or changes to the 
proposed test procedures and will consider modifications that improve 
the accuracy, appropriateness for the equipment being tested, 
repeatability of test results for the same or similar units, 
comparability of results for different types of units, burden on 
manufacturers, precision of language, or other elements of the 
procedures. In submitting comments, interested parties should state the 
nature of the recommended modification and explain how it would improve 
upon the test procedure proposed in this NOPR. Commenters should also 
submit data, if any, to support their positions.
    DOE's adoption of the proposed test procedures, which would be 
applicable to all walk-in equipment, would not necessarily mean that 
DOE would adopt a single energy conservation standard or set of 
labeling requirements for all walk-in equipment. In the separate 
rulemaking proceeding concerning energy conservation standards for 
walk-in equipment, DOE may divide such equipment into classes and may 
conclude that standards are not warranted for some classes of equipment 
that are within the scope of today's test procedure. Furthermore, DOE 
may create a separate standard for each class of equipment that 
includes a utility- or performance-related feature that another 
equipment class lacks, and that affects energy consumption.
    DOE also notes that the National Technology Transfer and 
Advancement Act of 1995 (Pub. L. 104-113) directs Federal agencies to 
use voluntary consensus standards in lieu of Government standards 
whenever possible. Consequently, as described in the following 
paragraphs, DOE attempted to incorporate by reference in its test 
procedures generally accepted rules or recognized industry standards 
such as those issued by the Air-Conditioning, Heating and Refrigeration 
Institute (AHRI), the American Society of Heating, Refrigerating, and 
Air Conditioning Engineers (ASHRAE), the American National Standards 
Institute (ANSI), and/or ASTM International (ASTM), that provide either 
specific aspect(s) of the test procedure, or the complete test 
procedure, for the specified equipment.

III. Discussion

    In the following section, DOE describes the overall approach it 
proposes to follow with respect to the adoption of a test procedure for 
walk-ins. This approach results from the characteristics of walk-in 
equipment and is based in part on the basic model definition that DOE 
currently uses to help establish testing requirements for manufacturers 
to follow. The following section also addresses issues raised by 
commenters, which included: Manufacturers (Craig Industries (Craig), 
Manitowoc, Nor-Lake); trade associations (AHRI); utility companies 
(Southern California Edison (SCE), Sacramento Municipal Utility 
District (SMUD), San Diego Gas and Electric (SDG&E)); and advocacy 
groups (Appliance Standards Awareness Project (ASAP), American Council 
for an Energy-Efficient Economy (ACEEE), Natural Resources Defense 
Council (NRDC), Northwest Energy Efficiency Alliance (NEEA)).

A. Overall Approach

    DOE developed today's proposed test procedure to set forth the 
testing requirements for walk-in equipment. In the framework document, 
DOE considered two overall approaches manufacturers could take to 
determine the energy consumption of walk-in coolers and freezers. 
First, DOE considered using a modified version of the Air-Conditioning 
and Refrigeration Institute (ARI) Standard 1200-2006, ``Performance 
Rating of Commercial Refrigerated Display Merchandisers and Storage 
Cabinets'' (ARI 1200-2006), which uses the test method described in the 
American National Standards Institute/American Society of Heating, 
Refrigerating, and Air Conditioning Engineers (ANSI/ASHRAE) Standard 
72-2005, ``Method of Testing Commercial Refrigerators and Freezers'' 
(ANSI/ASHRAE 72-2005). Second, DOE considered allowing manufacturers to 
determine the efficiency of some of their products using alternative 
efficiency determination methods (AEDMs). (An AEDM is a predictive 
mathematical model, developed from engineering analyses of design data 
and substantiated by actual test data, which represents the energy 
consumption characteristics of one or more basic models.)
    DOE received comments on these proposed approaches, many of which 
were opposed to both approaches. The comments DOE received, and DOE's 
responses, are discussed in more detail below. After considering these 
comments and reviewing the matter further, DOE is proposing separate 
test procedures for the envelope (insulated box) and the refrigeration 
system. DOE discusses the details of its proposals and addresses 
manufacturer comments in the following subsections.
1. Basic Model
    Under EPCA, which prohibits the distribution in commerce of covered 
equipment that do not comply with the applicable standard, each model 
of covered equipment is potentially subject to energy efficiency 
testing consistent with the relevant requirements for that equipment. 
However, walk-in manufacturers typically make numerous envelope models 
and, even within a single model, the units are often customized in 
multiple ways. To reduce this potential burden, DOE proposes following 
the approach it has used for other equipment by allowing manufacturers 
to group equipment or models with essentially identical energy 
consumption characteristics into a single family of models, called a 
basic model. This concept has been established both for residential 
appliances and commercial and industrial equipment covered under EPCA. 
(See Title 10 of the Code of Federal Regulations (10 CFR) 430.2, which 
covers 26 products, and 10 CFR 431.12, 431.62, 431.132, 431.172, 
431.192, 431.202, 431.222, 431.262, and 431.292, which cover various 
equipment.)
    Walk-in refrigeration systems are often manufactured according to 
the same basic blueprint design, and any particular model could 
incorporate modifications that do not significantly affect the energy 
efficiency of the system. For example, manufacturers often sell systems 
that are designed to operate at different voltages. This allows them to 
market to customers with different electrical capabilities. The 
operating voltage affects the energy

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efficiency of the system, but very minimally. If manufacturers were 
required to test the efficiency of each model with a different feature, 
the testing burden would be significant, but yield effectively 
redundant results. Therefore, DOE provides for testing of a basic model 
of refrigeration systems that may not be identical, but would not have 
any electrical, physical, or functional characteristics that 
significantly affect energy consumption. Features that may affect the 
energy consumption of walk-in cooler and freezer refrigeration systems 
include compressor size, fan motor type, and heat exchanger coil 
dimensions.
    Walk-in envelopes are often manufactured according to the same 
basic design, but the equipment is so highly customized that each walk-
in a manufacturer builds may be unique, and potentially subject to 
testing as a separate basic model. For instance, changing the size of 
the envelope would affect the energy consumption obtained by the test 
procedure, even if the construction methods and materials were the 
same. To address this possibility, DOE proposes (1) grouping walk-in 
envelopes with essentially identical construction methods, materials, 
and components into a single basic model, and (2) adopting a 
calculation methodology for determining the energy consumption of units 
within the basic model. This methodology would require a manufacturer 
to test one unit of the basic model and then calculate daily energy 
consumption coefficients (DECCs) for that basic model according to the 
test procedure. The manufacturer could then apply those DECCs to other 
units within a basic model even if those units were not identical, to 
obtain the energy consumption of those units. Although units within a 
basic model need not share identical dimensions, finishes, and non-
energy-related features (e.g., shelving or door kick plates), they must 
have been manufactured using substantially the same construction 
methods, materials, and components. A few examples of factors that 
would necessitate a different basic model include changing the type of 
insulating foam, the method of locking together the panels of the walk-
in envelope, or the electrical characteristics of the lighting. 
Examples of factors that may not constitute a different basic model 
include the type of exterior metal finish, the dimensions of the 
envelope, and the number of doors of the same type. The exterior metal 
finish would not have a substantial impact on the efficiency of the 
envelope. Dimensions and number of doors, on the other hand, would be 
accounted for in the energy consumption calculation using the DECCs 
from the unit of the basic model that was tested. (See section 
III.B.3.f for further discussion of DECCs.)
    All of the equipment included in a basic model must be within the 
same equipment class. Components of similar design may be substituted 
in a basic model without requiring additional testing if the 
represented energy consumption measurements continue to satisfy the 
provisions for sampling and testing. Only representative samples within 
each basic model would be tested.
    For walk-ins, DOE is considering adopting the following definition 
of ``basic model:'' ``Basic Model means all units of a given type of 
walk-in equipment manufactured by a single manufacturer, and--(1) With 
respect to envelopes, which do not have any differing construction 
methods, materials, components, or other characteristics that 
significantly affect the energy consumption characteristics. (2) With 
respect to refrigeration systems, which have the same primary energy 
source and which do not have any differing electrical, physical, or 
functional characteristics that significantly affect energy 
consumption.'' DOE requests comment on its proposed basic model 
approach.
2. Approach Option 1: Test the Unit as a Whole
    In the framework document, DOE considered developing a test 
procedure for walk-ins by adapting an existing test procedure for 
commercial refrigeration equipment, such as ARI 1200-2006. This 
approach would require an entire walk-in cooler or freezer to be 
physically tested within a controlled test chamber in order to evaluate 
its energy consumption over a period of time. During the standards 
framework public meeting, DOE requested comments on the feasibility of 
this approach. Interested parties responded with significant 
reservations about using a modified version of the ARI 1200-2006 test 
procedure, citing crucial differences between walk-ins and commercial 
refrigeration equipment.
    In particular, interested parties noted that walk-ins are 
physically different from commercial refrigerators in ways that make a 
full-system test burdensome or impractical. Manitowoc stated that for 
very large walk-ins, around the 3,000-square-foot limit in the EPCA 
definition, manufacturers might not have a large enough test facility 
to make the measurements necessary for the ARI 1200-2006 test procedure 
in a controlled environment. (Manitowoc, Public Meeting Transcript, No. 
15 at p. 59) (In this and subsequent citations, ``Public Meeting 
Transcript'' refers to the transcript of the February 4, 2009, public 
meeting on standards for walk-in coolers and freezers. ``No. 15'' 
refers to the document number of the transcript in the Docket for the 
DOE rulemaking on standards for walk-in coolers and freezers, Docket 
No. EERE-2008-BT-TP-0014; and the page references refer to the place in 
the transcript where the statement preceding appears.) Kason Industries 
also stated that it would be practically impossible to have a large 
enough controlled climate enclosure to test medium to large walk-ins, 
and added that if a walk-in were a free-standing structure, testing it 
as a whole building would not be practical. (Kason, No. 16 at pp. 1, 4) 
(In this and subsequent citations, the document number refers to the 
number of the comment in the Docket for the DOE rulemaking on standards 
for walk-in coolers and freezers, Docket No. EERE-2008-BT-TP-0014; and 
the page references refer to the place in the document where the 
statement preceding appears.) The Air-Conditioning, Heating, and 
Refrigeration Institute (AHRI) stated that the proposed test procedures 
were not practical because it would be costly to physically test walk-
ins. (AHRI, No. 33 at p. 2)
    Commenters also noted that the market for walk-in coolers and 
freezers is structured differently from the market for commercial 
refrigeration equipment, making a direct comparison between these types 
of equipment difficult. Manitowoc stated that the envelope of a 
particular unit of walk-in equipment may be manufactured by one company 
and the refrigeration system by another company. ARI 1200-2006 would 
require the two systems to be integrated before running the test, which 
would place the burden on the installer or someone beyond the 
manufacturer of the subsystems. (Manitowoc, Public Meeting Transcript, 
No. 15 at p. 59) AHRI agreed that the ARI 1200-2006 standard might not 
be the right approach and that DOE would need to separate the 
mechanical system from the envelope. (AHRI, Public Meeting Transcript, 
No. 15 at p. 62)
    In addition to these concerns, commenters identified a deficiency 
in the ARI 1200-2006 test procedure. SCE stated that the majority of 
potential energy savings can be achieved using floating head pressure 
and variable-speed evaporator fans, both of which have varying effects 
depending on the time of day and the regional climate

[[Page 190]]

because the savings associated with each feature can depend on the 
ambient temperature and usage patterns of the walk-in over the course 
of a day. Because ARI 1200-2006 is a steady-state test, it would not 
capture the energy savings from either option. (SCE, Public Meeting 
Transcript, No. 15 at p. 63) AHRI agreed that the test procedure should 
capture savings from a control strategy or variable-speed components, 
both of which could optimize the operation of the walk-in for a variety 
of ambient conditions and usage patterns. An example of optimization 
would be allowing elements of the refrigeration system to turn off or 
reduce their operation at night when the walk-in is not being accessed. 
(AHRI, No. 33 at p. 2)
    After considering these comments, DOE believes that an adapted 
version of ARI 1200-2006 would be inadequate to use as the test 
procedure for walk-in equipment. ARI 1200-2006 contains too many 
limitations and practical difficulties that would make it very 
difficult to effectively implement as a workable test procedure for 
walk-in. Therefore, DOE is no longer considering this approach.
3. Approach Option 2: Allow Manufacturers To Use Alternative Energy 
Determination Methods (AEDMs)
    DOE's framework document also presented an alternative that would 
permit the use of an AEDM when determining walk-in energy consumption 
to help relieve the testing burden on manufacturers. An AEDM is a 
predictive mathematical model, developed from engineering analyses of 
design data and substantiated by actual test data which represents the 
energy consumption characteristics of one or more basic models. After 
confirming the accuracy of an AEDM, the manufacturer would apply the 
AEDM to basic models to determine their energy consumption without 
conducting any physical testing.
    Applying this approach, the manufacturer would confirm the accuracy 
of the AEDM using the following method. First, the manufacturer would 
determine through actual testing the energy consumption of a certain 
number of its basic models that would be selected in accordance with 
criteria specified in the procedure. Second, the manufacturer would 
apply the AEDM to these same basic models. The AEDM would be considered 
sufficiently accurate only if: (1) The predicted total energy 
consumption of each of these basic models, calculated by applying the 
AEDM, is within a certain percentage of the total energy consumption 
determined from the testing of that basic model; and (2) the average of 
the predicted total energy consumption for the tested basic models, 
calculated by applying the AEDM, is within a certain percent of the 
average of the total energy consumption determined from testing these 
basic models. Under this approach, once the manufacturer verifies the 
accuracy of the AEDM, the manufacturer can use the AEDM to determine 
the energy consumption of other basic models without having to test 
those models. DOE requested comments on this approach during the 
framework public meeting, both in terms of how to implement the 
approach and whether such an approach was valid for walk-ins at all. 
DOE received several relevant comments, which are described and 
addressed below.
    Given the unprecedented nature of using an AEDM to rate this type 
of equipment, DOE needed to determine both an appropriate sample size 
for verifying an AEDM and an acceptable minimum accuracy percentage for 
an AEDM. During the framework public meeting, DOE requested comments on 
these two values. AHRI could not provide feedback on how accurate the 
AEDM should be because DOE had not yet determined the test metric to 
apply. (AHRI, Public Meeting Transcript, No. 15 at p. 69) Manitowoc 
agreed that the test methodology needs to be established and 
experiments conducted to collect data that would be used to validate 
AEDMs. (Manitowoc, Public Meeting Transcript, No. 15 at p. 70) In a 
written comment, Kason Industries stated that an AEDM with a minimum 
accuracy of 66 percent would encompass a majority of the wide range of 
walk-in cooler and freezer applications. (Kason, No. 16 at p. 2) No 
commenter provided substantive data that DOE would use in its analysis 
to help support a particular sample size. Accordingly, DOE did not 
receive enough data from stakeholders that could help it determine an 
appropriate sample size or accuracy range to substantiate an AEDM.
    During the public meeting, DOE also requested comments on the 
possibility of allowing manufacturers to take this approach to rate 
their walk-ins. Kason stated that an AEDM procedure would be preferable 
to using a physical test because the majority of walk-ins are custom-
made by size, ambient temperature, and refrigeration demands. 
Therefore, it would be very difficult to create a test procedure that 
encompasses the range of walk-in equipment. (Kason, No. 16 at p. 1) 
Kason suggested that, as an alternative to testing the system as a 
whole, an AEDM could be based on determining efficiencies and 
performance characteristics for the principal components of a walk-in 
considering three factors: insulation and air tightness of the external 
envelope and door, efficiency of the refrigeration system for steady-
state storage load (similar to the efficiency rating system for HVAC), 
and performance of the refrigeration system for removal of process heat 
and equipment-generated heat. (Kason, No. 16 at p. 2)
    Other interested parties commented that allowing manufacturers to 
develop their own calculation methodology or software program as an 
AEDM could be problematic. Owens Corning questioned whether there could 
be a comparison among ratings published by manufacturers that developed 
different AEDMs. (Owens Corning, Public Meeting Transcript, No. 15 at 
p. 64) Craig stated that manufacturers who devise their own test 
procedures could write them in a way that benefits their own company. 
(Craig, Public Meeting Transcript, No. 15 at pp. 68-69) SCE stated that 
allowing manufacturers to develop their own software as an AEDM could 
be unfair to manufacturers with fewer resources, because the software 
is expensive and time-consuming to develop. Instead, SCE suggested that 
it would be better to have a transparent analysis method with the 
algorithms available to all participants and the data in a standardized 
format. (SCE, Public Meeting Transcript, No. 15 at p. 71) Craig replied 
that many manufacturers have sizing programs, which may be proprietary, 
to calculate the total load of the walk-in, accessories, and product 
load, and to size the refrigeration system properly for the energy 
requirements of the envelope. (Craig, Public Meeting Transcript, No. 15 
at pp. 77-78 and No. 22 at p. 4) However, Craig stressed that requiring 
manufacturers to follow the same model developed or approved by DOE, 
would be fair to different manufacturers and provide consistent 
information to end users. (Craig, Public Meeting Transcript, No. 15 at 
p. 94 and No. 22 at p. 5)
    ACEEE asserted that it would be difficult for DOE to work with many 
proprietary models, some of which might be difficult to verify. (ACEEE, 
Public Meeting Transcript, No. 15 at p. 94) NEEA also said that if an 
AEDM were used, the software should be equally available to all 
manufacturers and code officials for the purpose of determining 
compliance. (NEEA, No. 18 at p. 3) Crown Tonka stated that a standard 
configuration and standard test should be developed to create a 
baseline

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for energy usage, with normalizing factors associated with 
configuration changes. (Crown Tonka, No. 23 at p. 1) Owens Corning 
reiterated that a single AEDM should be accepted to keep comparisons 
consistent. (Owens Corning, No. 31 at p. 2)
    DOE had previously understood that manufacturers would develop 
their own AEDMs and would verify their accuracy by testing a small 
number of walk-in models. However, as discussed above, most interested 
parties indicated that allowing manufacturers to develop their own 
rating calculations or software could be problematic, despite the fact 
that the calculations and software would need to be verified. 
Therefore, DOE does not propose to allow manufacturers to develop their 
own AEDMs. Instead, DOE developed its own calculation methodology for 
manufacturers to use in rating similar, but not identical, units of 
walk-in equipment. For further discussion on this methodology, see 
section III.B.3.f.
4. Proposed Option and Recommendation: Separate Envelope and 
Refrigeration Tests
    Both methods described above were predicated on the assumption that 
an entire walk-in unit is manufactured by a single entity, which could 
either test the walk-in as a whole according to ARI Standard 1200-2006, 
or calculate the overall efficiency using an AEDM. In fact, as DOE 
learned, most walk-ins have two main manufacturers: One who 
manufactures the envelope and one who manufactures the refrigeration 
system that cools the interior of the envelope. (Other manufacturers 
may be involved in producing secondary components --such as fan 
assemblies or lighting-- that are then purchased by the main 
manufacturers and incorporated as part of the refrigeration system or 
envelope.) These two parts are manufactured separately, and are often 
assembled together in the field by a third-party contractor who may not 
have been responsible for the manufacture of either part, and who may 
not have testing or evaluation capabilities. Because of this situation, 
DOE developed, and is proposing, a different approach for testing walk-
ins, as described below.
    Specifically, DOE proposes separate test procedures for the 
envelope and the refrigeration system. The envelope manufacturer would 
be responsible for testing the envelope according to the envelope test 
procedure, and the refrigeration system manufacturer would be 
responsible for testing the refrigeration system according to the 
refrigeration system test procedure. Such an approach would be more 
likely to generate usable data in support of standards for both the 
envelope and the refrigeration system during the development of any 
energy conservation standards for walk-in coolers and freezers. The two 
test procedures are described in sections III.B and III.C, 
respectively.
    There are several advantages to this approach. First, having 
separate test procedures would allow individual component manufacturers 
to test their components--the envelope and the refrigeration system. 
These component manufacturers would be more likely to have access to 
the resources, equipment, and personnel needed to conduct the tests. On 
the other hand, the ``manufacturer'' of an entire walk-in system (i.e., 
envelope and refrigeration system combined), could be a third party: A 
contractor who assembles the walk-in from the separate components and/
or installs it in the field. This third-party assembler may even be the 
end-user or owner of the equipment. If a walk-in is assembled in the 
field, testing of the entire assembled system may not be feasible due 
to lack of expertise and the need for additional testing equipment.
    Second, this approach would result in a significantly reduced 
testing burden while ensuring compliance with any standard DOE may 
develop. There are many more assemblers and installers of walk-ins than 
there are component manufacturers. Because EPCA requires manufacturers 
to demonstrate compliance with energy conservation standards, 
interpreting the term ``manufacturer'' to include assemblers and 
installers, who may be contractors or end-users, to demonstrate 
compliance with a standard would impose the compliance burden on 
entities who, more likely than not, may not have participated in the 
design and manufacture (and therefore energy efficiency) of the 
component parts. Furthermore, this approach would create substantial 
difficulties for DOE to enforce any standards it promulgates for walk-
in equipment. While DOE considered the possibility that including 
assemblers and installers as parties involved in the manufacture of 
this equipment could encourage these parties to take steps to ensure 
that compliant equipment is installed, at this time, DOE believes that 
the testing burdens are best met by the envelope and refrigeration 
system manufacturers for the reasons discussed above. Accordingly, 
under today's proposal, only envelope and refrigeration system 
manufacturers would need to demonstrate compliance with any proposed 
standard through the use of the test procedure. (DOE notes that 
possible remedial action for failing to satisfy these requirements 
include civil penalties and injunctive relief to prevent the continued 
sale and distribution of noncompliant equipment.) (42 U.S.C. 6303-6304)
    DOE requests comment on this proposed approach and whether it is 
appropriate for walk-ins.

B. Envelope

    As described earlier, the envelope consists of the insulated box in 
which the stored items reside. The following discussion describes in 
greater detail the test procedure DOE is proposing for the walk-in 
envelope. DOE also addresses issues raised by interested parties.
    This procedure contains the proposed methodology for evaluating the 
performance characteristics of the insulation as well as methods for 
testing thermal energy gains related to air infiltration caused by use 
(door openings) and imperfections in wall interfaces or door gasketing 
material. Heat gain due to internal electrical components is an 
additional consideration.
    The proposed procedure utilizes the data obtained to calculate a 
measure of energy use associated with the envelope. In other words, the 
test procedure calculates the effect of the envelope's characteristics 
and components on the energy consumption of the walk-in as a whole. 
This includes the energy consumption of electrical components present 
in the envelope (such as lights) and variation in the energy 
consumption of the refrigeration system due to heat loads introduced as 
a function of envelope performance, such as conduction of heat through 
the walls of the envelope. The effect on the refrigeration system is 
determined by calculating the energy consumption of a theoretical, or 
nominal, refrigeration system, were it to be paired with the tested 
envelope. Using the same nominal refrigeration system characteristics 
allows for direct comparison of the performance of walk-in envelopes 
across a range of sizes, product classes, and levels of feature 
implementation.
    The test procedure obtains a metric of energy use associated with 
the envelope of a walk-in cooler or freezer, consistent with the 
statutory requirement (42 U.S.C. 6314(a)(9)(B)(i)). For purposes of 
this rulemaking, DOE interprets the term ``energy use'' to describe the 
sum of (a) the electrical energy consumption of envelope components and 
(b) the energy consumption of the walk-in refrigeration equipment that 
is

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contributed by the performance of the envelope.
1. Overview of the Test Procedure
    In accordance with EPCA, DOE is developing test procedures to 
evaluate the energy use associated with the envelope of walk-in coolers 
and freezers. The walk-in envelope includes, but may not be limited to, 
walls, floor, ceiling, seals, windows, and/or doors comprised of single 
or composite materials designed to isolate the interior, refrigerated 
environment from the ambient, external environment. For the purposes of 
developing this test procedure and evaluating potential performance 
standards for walk-in equipment, DOE considers the envelope to also 
include lighting and other energy-consuming components of the walk-in 
that are not part of its refrigeration system (e.g., motors for 
automatic doors, anti-sweat heaters, etc.). DOE is considering the 
following definition for ``envelope,'' which would be inserted into 10 
CFR part 431:
    (1) The portion of a walk-in cooler or walk-in freezer that 
isolates the interior, refrigerated environment from the ambient, 
external environment; and
    (2) All energy-consuming components of the walk-in cooler or walk-
in freezer that are not part of its refrigeration system.
    DOE requests comments on this proposed definition.
    DOE also evaluated several available industry test procedures to 
measure the energy performance of various components of the walk-in 
envelope, but was unable to find a test procedure that would evaluate 
the entire envelope system. Consequently, DOE developed its own 
methodology, including a prescriptive calculation procedure, which 
incorporates specific component tests and allows for an overall energy 
performance value of the envelope to be determined. The proposed test 
measurements and accompanying calculation procedures to ascertain the 
overall energy performance value are described in the following 
sections.
2. Test Methods
    As discussed above, DOE was unable to find a single, existing 
comprehensive test procedure for evaluating walk-in cooler and freezer 
envelopes. However, DOE identified and evaluated many recognized 
industry standards that could be applied to the testing of certain 
components and characteristics of walk-in envelopes. DOE incorporated 
an insulation test and an air infiltration test, with some 
modifications, into the proposed test procedure. The evaluation 
process, the results of the evaluation, and details of the proposed 
test methods are described in the following sections.
a. Insulation
    Insulation comprises a significant component of walk-in units. EPCA 
specifies that ASTM C518-04, ``Standard Test Method for Steady-State 
Thermal Transmission Properties by Means of the Heat Flow Meter 
Apparatus,'' must be used, along with specific foam temperatures for 
freezer or cooler applications specified in EPCA, to determine the R 
value of individual walk-in envelope insulation materials. (42 U.S.C. 
6314(a)(9)(A)) Commenters identified two issues of significance for DOE 
to consider when developing a test procedure for insulation: aging and 
moisture absorption. DOE discusses these issues in the subsections that 
follow.
i. Aging of Foam Insulation
    EPCA requires that the test procedure for walk-ins use an R value 
that shall be the 1/K factor multiplied by the thickness of the panel. 
(42 U.S.C. 6314(a)(9)(A)) The Act does not specify when the R value 
should be calculated, a key issue interested parties raised at the 
framework public meeting. Specifying when the R-value should be 
calculated is a critical consideration because several sources indicate 
that the R-value of certain materials can change over time.
    Craig stated that R values tend to deteriorate over time and that 
different materials exhibit unique rates of deterioration. (Craig, 
Public Meeting Transcript, No. 15 at p. 215 and No. 8 at p. 1) Craig 
expressed concern that using an initial R value (R value as measured 
within two weeks of manufacture) to determine compliance would ignore 
deterioration that occurs in blown foams over time. Craig argued that 
underestimating the energy use of walk-ins would be the likely outcome 
of using initial R-value, that it would be misleading for end-users, 
and that it would be inconsistent with the goals of the EISA 2007 
legislation and the rulemaking process. (Craig, Public Meeting 
Transcript, No.15 at p. 215) A comment submitted jointly by 
representatives of ASAP, ACEEE, and NRDC (hereafter referred to as the 
``Joint Comment'') stated that the test procedures used should account 
for the potential degradation of panel insulation and door seals over 
time. (Joint Comment, No. 21 at p. 2) Craig also recommended that DOE 
develop an accelerated test procedure that represents lifetime energy 
use and can be completed within 6 months. (Craig, No. 8 at p. 1)
    In the context of foam insulation for walk-ins and the building 
industry, long-term thermal resistance (LTTR), described in greater 
detail below, refers to the impact of diffusion on the thermal 
resistance of insulation materials. In other words, the concentration 
of gaseous blowing agents contained in the foam, and which provide the 
foam with much of its insulating value, is reduced by both the 
diffusion of air into the foam and the secondary process of the blowing 
agent diffusing out of the foam. Because air has a significantly lower 
insulating value, the increased ratio of air to blowing agent reduces 
the foam insulation performance (this process is also known as 
``aging''). This diffusion process causes foam to lose insulating 
value, which is represented by its R-value. As a concept, LTTR 
represents the R-value of foam material over its lifetime by describing 
insulating performance changes due to diffusion over time.
    DOE investigated the issue of aging in foam insulation and found 
that it is widely accepted that the material properties of foam 
insulation made with gaseous blowing agents, other than air and 
including HFC-134a, HFC-245fa, HFC-365mfc, cyclopentanes, change over 
time. The amount of degradation can range from roughly 10-35 percent 
within 2 years of manufacture. Because use of ASTM C518-04 reflects the 
properties of a material at the time it is tested, using ASTM C518-04 
to measure the insulating performance of a foam material at the time of 
manufacture would yield a result that differs from that produced by the 
same test conducted at some later point in time. Additionally, research 
has found that the vast majority of diffusion into and out of foam 
materials manufactured with blowing agents other than air occurs within 
the first 5 years of manufacture. Because the rate of diffusion follows 
an exponential curve, the majority occurs within the first year, after 
which the diffusion curve changes very little as it asymptotically 
approaches the equilibrium point.
    DOE found that various methods of ``conditioning'' foam prior to 
measuring its insulating ability with American Society for Testing and 
Materials (ASTM) C518 have been developed in order to test aged 
insulating value, or LTTR. These standards are contained in five foam 
material specifications:
    (1) ASTM C578-09, ``Standard Specification for Rigid, Cellular 
Polystyrene Thermal Insulation;''
    (2) ASTM C591-08a, ``Standard Specification for Unfaced Preformed 
Rigid Cellular Polyisocyanurate Thermal Insulation;''

[[Page 193]]

    (3) ASTM C1029-08, ``Standard Specification for Spray-Applied Rigid 
Cellular Polyurethane Thermal Insulation;''
    (4) ASTM C1126-04, ``Standard Specification for Faced or Unfaced 
Rigid Cellular Phenolic Thermal Insulation;'' and
    (5) ASTM C1289-08, ``Standard Specification for Faced Rigid 
Cellular Polyisocyanurate Thermal Insulation Board.''
    DOE found that since their development in the 1980s, the most 
widely accepted conditioning methods are the 180-day conditioning at 73 
[deg]F or a 90-day conditioning at 140 [deg]F. The goal of the 90-day 
conditioning method was to achieve the same aging result as the 180-day 
method in a shorter period of time. 180-day conditioning is used by 
ASTM C591-08a and ASTM C578-09 and the 90-day condition is typically 
used for ASTM C1089-08 and ASTM C1126-04. By accelerating the 
conditioning, the 90-day test sought to reduce the time and cost 
burdens for manufacturers. Although elevating the temperature of foams 
did achieve a faster rate of aging, subsequent research found that the 
results were not reliable indicators of actual aging because the 
relationship between the diffusion coefficient (a proportionality 
constant that describes the force or rate of diffusion for a given 
substance) and temperature are different for each gas. (Therese 
Stovall, ``Measuring the Impact of Experimental Parameters upon the 
Estimated Thermal Conductivity of Closed-Cell Foam Insulation Subjected 
to an Accelerated Aging Protocol: Two-Year Results,'' p. 1)
    DOE found that efforts to develop an accelerated aging method that 
did not use elevated temperatures resulted in the creation of ASTM 
C1303, which in 1995 introduced the slicing and scaling method, also 
known as the ``thin slicing'' method (a technique used to slice the 
foam so that it ages more rapidly as a function of reduced thickness). 
In contrast to ASTM C578-09, ASTM C591-08a, ASTM C1029-08, ASTM C1126-
04, and ASTM C1289-08, which specify the use of either the 180-day 
conditioning method or 90-day accelerate conditioning method to age the 
foam before measuring its thermal resistance. In contrast, the thin 
slicing method used in ASTM C1303-08 (the most recent version of ASTM 
C1303) was designed specifically to test the aging of foam insulation 
in duration shorter than 180 days, and without the temperature 
elevation methodology used in the 90-day test. (ASTM C1303-08, section 
5.3, at p. 3) By reducing the length of the pathway for diffusion to 
take place, the ``aging'' can be accelerated without the confounding 
effects caused by unique gas properties of the material and blowing 
agent. The results are used to determine the R-value of foam 5 years 
after manufacture, a value that has been shown to correlate strongly 
with the average R-value of foam 15 years after manufacture. (ASTM 
C1303-08, section 5.4, at p. 3)
    In early 2000, the National Research Council Canada and Institute 
for Research in Construction (NRC-IRC) developed CAN/ULC-S770-00. CAN/
ULC-S770-00 incorporated elements of ASTM C1303-95 (the first version 
of ASTM C1303) but altered that standard by clarifying the slicing 
procedure used in ASTM C1303-95, as differing interpretations of the 
previous procedure were thought to be causing variations in the test 
results among third-party testing facilities. These changes sought to 
eliminate inconsistency in the interpretation of the slicing procedure 
and test setup to ensure uniformity across testing labs. In December 
2000, CAN/ULC-S770-00 became the Canadian national mandatory test for 
calculating the LTTR of all foam insulation products (this test has 
since been updated; the most recent version is CAN/ULC-S770-03). 
Members of the U.S.-based Polyisocyanurate Insulation Manufacturers 
Association (PIMA) began to test their products using the same 
procedure on January 1, 2003. The LTTR calculated from this test 
procedure is used for all building insulation product labeling in 
Canada and PIMA products in the United States. Also in 2000, ASTM 
C1303-95 was updated as ASTM C1303-00.
    In a 2005 rule by the U.S. Federal Trade Commission (FTC) in which 
the FTC considered requiring ASTM C1303-00 (the most recent version at 
that time) for product labeling on all foam insulation products, the 
FTC's review process revealed several unresolved issues related to the 
test procedure. (70 FR 31258 (May 31, 2005); 16 CFR Part 460, Labeling 
and Advertising of Home Insulation: Trade Regulation Rule, Final Rule) 
Subsequently, ASTM C1303-00 was updated to address these issues, which 
included foam stack composition, minimum slice thickness and slice 
source, the time between manufacture and test initiation, preparation 
of foam-in-place samples, and other clarifications of the procedure. 
This updated version was published as ASTM C1303-08 and is the most 
recent version of the standard to date.
    Some commenters noted during the framework meeting that the 
application of an impermeable vapor barrier to the surface of the foam 
could reduce the impact of aging. Depending on its end use, foam 
insulation may have facers or skins applied to act as a vapor barrier 
and/or to enhance the bond of construction glues. Kysor stated that 
proper use of skins eliminates aging and the associated reduction of R-
value in polyurethane panels. (Kysor (attachment), No. 29 at p. 1)
    DOE examined this issue and found that foams used in walk-in panels 
are sometimes protected by impermeable barriers designed to prevent 
vapor and/or air exchange into or out of the foam or the interior of 
the walk-in. DOE found research conducted by the National Resource 
Council Canada (NRCC) suggesting that impermeable facers do not 
eliminate aging but may delay the rate of aging and/or the final 
equilibrium of the aged state. (Mukhopadhyaya, P.; Bomberg, M.T.; 
Kumaran, M.K.; Drouin, M.; Lackey, J.; van Reenen, D.; Normandin, N., 
``Long-Term Thermal Resistance of Polyisocyanurate Foam Insulation With 
Impermeable Facers''; Mukhopadhyaya, P.; Bomberg, M.T.; Kumaran, M.K.; 
Drouin, M.; Lackey, J.; van Reenen, D.; Normandin, N., ``Long-Term 
Thermal Resistance of Polyisocyanurate Foam Insulation With Gas 
Barrier''; Mukhopadhyaya, P.; Kumaran, M.K. ``Long-Term Thermal 
Resistance Of Closed-Cell Foam Insulation: Research Update From 
Canada.'') In one of the summary observations of ``Long-Term Thermal 
Resistance of Polyisocyanurate Foam Insulation With Gas Barrier,'' the 
NRCC noted, ``a considerable amount of aging occurred in thin slice 
specimens despite having untouched impermeable facers, as well as a 
glass plate at the bottom of the specimens and edges sealed completely 
with epoxy coating.''
    Additionally, the relationship between the skin and the rate of 
aging in foam depends on preserving the integrity of both the skin 
surface and the bonding between the skin and insulation. Punctures, 
made to allow for the installation of light fixtures, doors, and 
shelving, undermine the integrity of the skin. Walk-in insulation 
panels and their skins also typically separate over time due to 
shrinkage of foam materials after manufacture. While most foam 
materials contract by less than 1 percent of their total volume, 
shrinkage at this level is enough to create significant air gaps. DOE 
found that current methods of conditioning foam materials do not 
account for impermeable facers.
    Finally, like the conditioning standards that are currently in use, 
ASTM C1303-08 is not designed to test impermeably faced foams that may 
be

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used with walk-ins. Significant research has been underway by the NRCC 
but no known test procedure is currently available that accounts for 
the effect of impermeable barriers. DOE requests feedback on this 
issue, including the submission of test results on the impact of 
impermeable skins on long-term R-value. DOE specifically requests that 
interested parties submit or identify peer-reviewed, published data on 
this issue.
    DOE also requests feedback on the use of ASTM C1303-08 with 
impermeably faced foams. DOE may recommend the use of a test procedure 
specifically designed for impermeably faced foam if one is developed.
    As a result of this evaluation, DOE proposes requiring 
manufacturers to use ASTM C1303-08 to determine the LTTR of walk-in 
foam insulation for the purposes of calculating the energy consumption 
of walk-in equipment. DOE requests comments on this proposal.
    DOE is also proposing and seeking comment on the following 
exceptions to ASTM C1303-08:
    (1) Section 6.6.2 of C1303-08 suggests that two standards for 
measuring the thermal resistance may be used. DOE proposes to allow use 
only of ASTM C518-04 (in EPCA, an incorrect form of the date suffix was 
used, e.g., ASTM C518-[20]04), as specified in EPCA. (42 U.S.C. 
6314(a)(9)(A)(ii))
    (2) In section 6.6.2.1, in reference to ASTM C518-04, the mean test 
temperature of the foam during R-value measurement would be -6.7  2 [deg]C (20  4 [deg]F) with a temperature 
difference of 22  2 [deg]C (40  4 [deg]F) for 
freezers and 12.8  2 [deg]C (55  4 [deg]F) with 
a temperature difference of 22  2 [deg]C (40  4 
[deg]F) for coolers. This change replaces the standard mean temperature 
of 75 [deg]F for ASTM C518-04 with the EPCA specified values.
    (3) For the purposes of preparing samples with foam-in-place 
method, section A2 should be followed exactly except for the following 
modifications to accommodate foam-in-place methods that may be used 
during the manufacture of walk-in panels:
     (3.1) Instead of following A2.3, which specifies that the 
foam be sprayed onto a single sheet of wood, the sample shall be foamed 
into a fully closed box of internal dimension 60 cm x 60 cm by desired 
product thickness (2ft x 2ft x Desired thickness). The box shall be 
made of \3/4\ inch plywood and internal surfaces wrapped in 4 to 6 mil 
polyethylene film to prevent the foam from adhering to the box 
material.
     (3.2) Instead of following section A2.4, which specifies 
the spraying of foam layers onto a open sheet of plywood, the cavity 
shall be filled using the manufacturer's typical foam-in-place method 
through a standard injection port or other process typically used to 
foam the product being tested.
     (3.3) In section A2.6, which defines the single surface in 
contact with the board to be the ``surface,'' the definition of the 
foam's ``surface'' shall be the two surface regions in contact with the 
60 x 60 cm sections of the box.
     (3.4) Section A2.8 shall not be followed because the 
prepared sample will not have any ``free rise'' component.
    DOE proposes that manufacturers select foam test thicknesses based 
on design specifications and practice. If a foam's thickness as 
manufactured varies from the tested product thickness, DOE proposes 
that the R-value of that foam at its manufactured thickness may be 
interpolated using the results of ASTM C1303-08, provided that the 
manufactured thickness does not vary from the tested product thickness 
by more than  0.5 inches. For example, if 4-inch and 6-inch 
products were prepared, interpolation between 3.5 and 4.5 inches would 
be allowed for the 4-inch foam and 5.5 and 6.5 inches for the 6-inch 
foam. If the manufacturer determines that final foam thickness should 
be outside of the tested range, then additional testing would be 
necessary to fit the criterion for interpolation. Manufacturers should 
make their sample selections accordingly to avoid the need for 
additional testing. DOE requests feedback on the use of interpolation 
within the specified  0.5 inch range.
    DOE proposes that the results for each of the sample sets of three 
stacks should be reported as specified by ASTM C1303-08. As defined by 
ASTM C1303-08, after thin slices of foam are cut, the slices are 
organized into ``stacks'' of slices to match the original overall 
thickness of the sample. The procedure defines three stack types: (1) 
Stacks comprised of only surface slices of foam, (2) stacks of only 
core slices and (3) a mixture of core and surface slices. A ``surface'' 
slice and a ``core'' slice are defined in ASTM C1303 as ``a thin-slice 
foam specimen that was originally adjacent to the surface of the full-
thickness product and that includes any facing that was adhered to the 
surface of the original full-thickness product'' and ``a thin-slice 
foam specimen that was taken at least 5 mm (0.2 in.) or 25% of the 
product thickness, whichever is greater, away from the surface of the 
full thickness product,'' respectively. The R-value of only the mixed 
stack would be used to calculate the energy performance of walk-ins. 
DOE requests feedback on this approach. ASTM is currently conducting a 
5-year ``ruggedness'' test. Upon completion of the test, DOE may 
consider a rulemaking to modify the required number of stacks and/or 
which stack is best suited for labeling and calculating energy 
performance. DOE requests feedback on the use of the mixed stack R-
value for the purpose of calculating walk-in energy use.
    Additionally, DOE notes that ASTM C1303-08 is specifically intended 
for measuring the LTTR of foam materials. In light of this situation, 
the process contained in this standard would not apply to advanced 
insulation technologies such as vacuum insulated panels (VIPs) or 
aerogels. However, ASTM C518-04 can be used to measure the thermal 
properties of these new technologies, which, as specified in EPCA, is 
the required test for measuring insulating performance. (42 U.S.C. 
6314(a)(9)(A)(ii)) DOE requests feedback on whether non-foam advanced 
technologies, such as VIPs or aerogels, would be likely to be used for 
walk-ins in the next 5 years. If DOE determines that these materials 
may be used in walk-ins in the next 5 years, DOE may consider 
alternative test procedures for capturing the long-term insulating 
value of any non-foam materials.
ii. Water Absorption in Foam
    At the framework public meeting, interested parties raised the 
issue of R-value deterioration in foams due to moisture absorption. 
Craig stated that moisture penetration causes a decline in the R-value 
of foam insulation, at a rate that depends on the type of foam used. 
(Craig, No. 22 at p. 3) As is the case with aging, insulating foams 
exhibit different characteristics in the presence of moisture. 
Polystyrene foam is highly resistant to water absorption, whereas 
polyurethanes and polyisocyanurates are more easily damaged by exposure 
to moisture. In general, the solution to moisture issues involves 
creating an impermeable barrier between the insulation and the moisture 
source. However, Owens Corning asserted that customers routinely 
puncture metal skins to allow for the installation of lighting 
fixtures, shelving, and doors, creating holes that allow moisture to 
enter the insulation. (Owens Corning, Public Meeting Transcript, No. 15 
at p. 61)
    Although vapor permeance and water absorption tests exist, they are 
designed for measuring specific material properties rather than 
measuring system performance of composite structures like walk-ins. For 
a variety of reasons,

[[Page 195]]

these tests would be complex, costly, and time consuming to use because 
several sub-methods would need to be developed to quantify the impact 
of water on walk-ins. For every unique construction method and/or 
combination of materials (e.g., blowing agent, foam type, barriers, 
gasketing materials, panel joint type, and method), the following 
considerations exemplify the challenges inherent in accounting for and 
quantifying insulating performance: (1) The rate at which the walk-in 
envelope collects water over its life must be measured or predicted 
using an accelerated test; (2) a saturation level or maximum 
absorption, if any, must be determined; and (3) a correlation between 
water absorption levels and insulation performance must be quantified. 
At this time, test procedures for each of these considerations are not 
yet recognized by a nationally recognized organization such as ASTM.
    DOE reviewed several methods for testing vapor permeance and water 
absorption in foam insulation materials including ASTM E96, ``Standard 
Test Methods for Water Vapor Transmission of Materials,'' ASTM C209, 
``Standard Test Methods for Cellulosic Fiber Insulation Board,'' ASTM 
C272-01 (2007), ``Standard Test Method for Water Absorption of Core 
Materials for Structural Sandwich Constructions,'' and ASTM D2842-06, 
``Standard Test Method for Water Absorption of Rigid Cellular 
Plastics.'' Each of these standards describes a method for submerging a 
sample in water for a specified amount of time and then measuring the 
amount of water absorbed on a volume or weight basis. However, each one 
specifies significantly different immersion durations (ranging from 2 
to 96 hours) and methods of weighing samples (blotting surfaces before 
measurement or using a buoyancy measurement). DOE believes that using 
the longest test period, 96 hours, would likely result in near worst 
case or maximum water absorption, but it is unclear how this directly 
translates to reduction in insulation performance for various 
materials.
    Additionally, ASTM E96-05 measures vapor permeance under low vapor 
pressure gradient conditions. However, the temperature differentials in 
which walk-ins operate cause a high vapor pressure gradient, which has 
the effect of continuously driving moisture through the envelope. 
Neither ASTM E96-05 nor any other known procedures currently provide a 
methodology to accurately calculate the vapor permeance in walk-ins at 
the pressure gradients typically experienced in the field.
    Some research has been completed, including a major study by the 
Cold Regions Research and Engineering Lab (CRREL). The CRREL study 
developed and applied a method for creating a vapor pressure gradient 
across various materials to quantify the rate at which these materials 
absorb and retain water over time. The insulating performance of the 
materials was also tested at various levels of moisture content to 
develop equations for the purpose of calculating the insulating 
properties at any moisture percentage relative to its dry weight. No 
other testing body has applied CRREL's testing procedures to replicate 
the results and most of CRREL's research was completed nearly 20 years 
ago. One of DOE's national labs has also begun development of 
procedures to evaluate the impact of moisture on insulation R-values, 
but this activity remains incomplete.
    Given the discussion above, DOE does not propose to include the 
impact of water absorption on R-value in the test procedure because no 
well-accepted method has been developed. However, DOE will evaluate 
such a procedure if it is developed in the future.
b. Air Infiltration
    Another major pathway for energy loss in walk-ins is air 
infiltration, or air exchanged into and out of a walk-in while all 
access points are closed or during door-opening cycles (i.e., the 
openings of doors for the removal or stocking of product, or passage of 
customers, personnel, and/or machinery, also referred to as ``door-
opening events''). Compared with other energy consumption factors such 
as conduction losses through insulation, air infiltration may be the 
largest contributing factor to envelope energy losses. Air infiltration 
can occur through steady-state leakage or from door opening events. As 
a result, designs and technologies that reduce infiltration during 
steady-state operation and door-opening events should be considered to 
reduce these losses.
    EPCA includes prescriptive requirements for doors used on walk-ins, 
recognizing that a major portion of energy is lost through door opening 
cycles. All walk-in coolers or freezers ``manufactured on or after 
January 1, 2009, shall (A) have automatic door closers that firmly 
close all walk-in doors that have been closed to within 1 inch of full 
closure, except * * * doors wider than 3 feet 9 inches or taller than 7 
feet; [and] (B) have strip doors, spring hinged doors, or other method 
of minimizing infiltration when doors are open * * *'' (42 U.S.C. 
6313(f)(1)) During the framework public meeting, interested parties 
suggested methods for calculating infiltration from door-opening events 
within the test procedure.
    These two infiltration pathways, steady-state leakage, and air 
losses due to door-opening events, are mitigated using distinct 
methods.
    Steady-state infiltration (the air exchanged between the interior 
and exterior of a walk-in while all doors are closed, also referred to 
as ``leakage'') occurs because of the significant pressure gradient 
caused by the large temperature difference between the refrigerated 
space and the external environment. This pressure differential 
continuously induces air movement from the outside to the inside of a 
walk-in where leakage pathways exist. Leakage typically occurs through 
door frames, door gaskets, wall panel-to-panel interfaces, and wall-to-
floor and wall-to-ceiling junctions. While considered minimal for small 
walk-ins, leakage becomes more significant as the walk-in size 
increases.
    Air infiltration due to door openings is mostly a function of door 
area, opening frequency, duration, and air density. The primary means 
of reducing the amount of infiltration is by the use of active or 
passive infiltration reduction devices and devices that help reduce the 
time that doors are left accidentally ajar. Air curtains and strip 
curtains are good examples of active versus passive devices. The 
sections below describe the methods for testing the effectiveness of 
such devices and procedure for calculating air infiltration's impact on 
energy use in walk-ins.
    Hired Hand recommended that the energy analysis for warehouse 
coolers and freezers include the performance of the door, including the 
number of door-opening cycles each day or week and factoring in 
optional door configurations such as automatic doors with or without 
strip curtains. (Hired Hand, No. 27 at p. 1) Eliason recommended that 
DOE consider average door cycling and door-ajar conditions in its test 
procedure. (Eliason, No. 19 at p. 1) Eliason noted that both of these 
conditions are part of the company's internal life-cycling test and 
represent real-world conditions. (Eliason, No. 19 at p. 1) Hired Hand 
stated that a simple rating for door infiltration performance could be 
based on door-opening cycles per week. (Hired Hand, No. 27 at p. 2) 
Hired Hand also suggested that DOE require consumer labeling to 
indicate the cost per minute of leaving the door open based on door

[[Page 196]]

size and application. (Hired Hand, No. 27 at p. 2)
    Based on stakeholder comments and DOE review of the impact of air 
infiltration on energy use, DOE identified two methods that could be 
used to measure air infiltration in walk-ins: the blower door method 
and the gas tracer method. These methods are described in the following 
subsections.
i. Blower Door Method
    DOE reviewed ASTM E1827-96 (2007), ``Standard Test Methods for 
Determining Airtightness of Buildings Using an Orifice Blower Door,'' 
as a possible candidate test procedure for testing walk-ins. This 
method pressurizes or depressurizes the internal space using a large 
fan, typically placed in a doorway. The infiltration rate of the space 
can be directly calculated by measuring the pressure difference between 
the exterior and interior space and the air-flow rate through the fan.
    After reviewing this test method, DOE identified reasons why the 
test might not be suitable for walk-ins. The blower door method is 
better suited for structures with relatively high rates of 
infiltration, such as buildings and homes, rather than the relatively 
low levels typically observed in walk-ins. In addition, known 
calibration curves for the blower door method require small temperature 
differentials (generally less than 10 [deg]F) between the inside and 
outside of the envelope. However, walk-ins typically operate with a far 
greater differential that is normally greater than 40 [deg]F. Another 
drawback to using this method with walk-ins is that the test setup 
procedure requires blocking a main entrance to the structure with the 
blower door. Because infiltration around the main door is a key source 
of infiltration in walk-ins and would not be measured as part of the 
test, this approach would not adequately capture the majority of the 
infiltration. For these reasons, DOE does not propose the use of the 
blower door method for measuring the air infiltration of walk-ins.
ii. Gas Tracer Method
    DOE also reviewed ASTM E741-06, ``Standard Test Method for 
Determining Air Change in a Single Zone by Means of a Tracer Gas 
Dilution.'' Although not as widely used as the blower door method, the 
gas tracer method has been used for decades by the building industry. 
The test is conducted by injecting a tracer gas, such as carbon dioxide 
or perfluorocarbons, into the internal space and measuring its 
concentration at recorded times. From these measurements, the average 
air change rate can be determined. While manual tools, such as 
syringes, or automated systems can be used to sample the air spaces, 
the test procedure lends itself to automation both for calibration and 
data collection. Depending on the gas and sampling method used, the gas 
concentration can be measured immediately with portable equipment. This 
method is also more accurate than the blower door method because it 
allows for direct measurement of infiltration without modification of 
the design conditions. (ASTM, ASTM E741-06 (2006), ``Determining Air 
Change in a Single Zone by Means of a Tracer Gas Dilution,'' section 
5.6, p. 3)
c. Steady-State Infiltration Test
    For the reasons described above, DOE proposes using the gas tracer 
method described in ASTM-E741-06 for measuring the steady-state air 
infiltration of walk-ins, with the following six exceptions:
    First, DOE proposes using the ``concentration decay method'' 
instead of other available options described in ASTM E741-06. DOE 
considers this method to be the simplest, fastest, most cost efficient, 
and most accurate.
    Second, carbon dioxide (CO2) is the recommended gas 
tracer for all testing because of the few human hazards related to its 
use, and the availability and relative cost of sampling equipment.
    Third, the test would use the ``average air change rate'' method, 
in changes per hour (1/h), rather than the ``average air change flow'' 
method described in ASTM E741-06. The ``air change flow'' method allows 
for the direct measure of the exchange of air in cubic feet per hour 
and does not require measurement of the internal volume of the space 
but requires a more complex test setup and sampling method. In 
contrast, the ``air change rate'' method measures the rate of exchange 
of air per unit of time can be completed using relatively simple 
equipment. However, converting this value to a measurement of the flow, 
e.g., volume of air exchanged per unit time, requires a precise 
measurement of internal volume. Since the precise internal volume of a 
given walk-in is readily available, DOE considers the ``air change 
rate'' method preferable to the ``air change flow'' method because the 
equipment is less expensive and the measurements are easier to obtain.
    Fourth, ASTM E741-06 describes the importance of verifying proper 
gas mixing but does not describe where or how many spatial locations 
should be sampled. DOE proposes that spatial measurements shall be 
taken in a minimum of six locations or one location per 20 square feet 
(ft\2\) of floor area (whichever results in a greater number of 
measurements), at a height of 3 ft  0.5 ft, or a minimum of 
2 ft  0.5 ft from the inside wall of the walk-in envelope, 
to verify that the air space is uniformly mixed.
    Fifth, DOE proposes the test be completed close to operational 
temperature to mimic the thermally induced pressure gradient seen in 
walk-ins. The internal air temperature shall be -23.3 (-10 [deg]F) 
 2 [deg]C (4 [deg]F) for freezers and 1.7 (35 [deg]F) 
 2 [deg]C (4 [deg]F) for coolers. The external air 
temperature should be 24 [deg]C (75 [deg]F)  2.5 [deg]C (5 
[deg]F).
    Sixth, the test should be completed with all doors closed. The 
resulting measurement shall be in units of changes per hour.
    DOE requests feedback on its proposal to use ASTM E741-06 as the 
method for determining air infiltration and on the proposed exceptions 
to the test procedure.
    For the purposes of administering the test, DOE considered the 
following options for the location of the test: (1) Require testing at 
a third-party testing facility. DOE believes that requiring that 
manufacturers to ship every walk-in manufactured, or a representative 
model, to a third-party facility for testing, would place a substantial 
burden on manufacturers; (2) require testing by a third party on site 
at a walk-in manufacturing facility. Completing the infiltration test 
at the manufacturing facility reduces logistical complexity and costs 
associated with testing. Since the equipment used to complete 
infiltration testing was originally designed for testing the 
performance of buildings, the equipment and protocols are designed to 
be mobile.
    DOE believes that the most viable option is allowing testing to 
occur at the manufacturing facility, if preferred by the manufacturer. 
DOE requests feedback on the flexibility of location required for 
completion of any infiltration test.
iii. Door Infiltration Reduction Device Test
    DOE is considering incorporating a door-opening test to quantify 
the impact of technologies such as strip curtains, air curtains, or 
other infiltration reduction devices during door-opening events. Due to 
the limited data available on these devices and the variety of 
technologies, DOE believes a standardized test would provide a more 
comprehensive and accurate picture regarding the effectiveness of these 
devices when compared to simply using effectiveness assumptions.

[[Page 197]]

    DOE proposes a two-part test to account for the effect of the door 
infiltration reduction device. First, measurements should be taken once 
the tracer gas has uniformly dispersed in the internal space using the 
methodology described in ASTM E741-06. Within 3 minutes  30 
seconds, with the infiltration reduction device in place, a door should 
be opened at an angle of 90 degrees over a period no longer than 3 
seconds, then held at 90 degrees in the open position for 5 minutes 
 5 seconds, then closed over a period no longer than 3 
seconds. The gas concentration should be sampled again after the door 
has been closed. Samples should continue being taken until the gas 
concentration is once again uniformly mixed within the walk-in. Second, 
the test should be repeated exactly as described above with the 
infiltration reduction device removed or deactivated.
    Using the measured infiltration with the device in place and 
without the device in place, the infiltration reduction effectiveness 
can be directly calculated:
[GRAPHIC] [TIFF OMITTED] TP04JA10.025

Where:

Vrate,with-device = air infiltration rate, with door open 
and reduction device active, using 4.2, 1/h;
Vrate,without-device = air infiltration rate, with door 
open and reduction device disabled or removed, using 4.2, 1/h.

    This calculation will yield a value between 0 and 100 percent, with 
100 percent meaning that the device prevents all air infiltration when 
the door is open. DOE proposes using this calculated effectiveness for 
every unique door-device combination that a manufacturer may offer. DOE 
requests feedback on the proposed method for measuring the 
effectiveness of an infiltration reduction device.
iv. Infiltration Due to Door Openings
    DOE does not propose to require manufacturers to measure the 
infiltration from all door-opening events. The complexity of testing, 
the variation of walk-in design, and various end-use behavior factors 
would make such a recommendation very difficult to execute. Instead, 
DOE proposes using analytical methods based on equations published in 
the ASHRAE Refrigeration Handbook in combination with assumed door-
opening frequency, and duration of door cycles, to calculate the air 
infiltration associated with each door-opening event.
    ASHRAE recommends using Gosney and Olama's (1975) air exchange 
equations for fully established flow through door openings (Equation 
2). Several key assumptions have the greatest impact on predicated air 
exchange and are related to the calculation of the decimal portion or 
time a doorway is open, Dt. (ASHRAE, Refrigeration Handbook, 
2006, section 13.5)
[GRAPHIC] [TIFF OMITTED] TP04JA10.026

Where:

Dt = fractional door opening,
P = the number of doorway passages (or number of door-opening cycles 
for a given door),
[thetas]p = the door open-close time,
[thetas]o = the time the door stands open, and
[thetas]d = daily time period.

    Dt is important for properly calculating the energy 
impact of air infiltration due to door-opening events. Therefore, the 
assumed values of P, [thetas]p, and [thetas]o 
will drive the result. The daily time period, [thetas]d, is 
simply assumed to be 24 hours.
    For display glass doors, a P of 72 per day, [thetas]p of 
8 seconds per passage, [thetas]o of 0 minutes and 
[thetas]d of 24 hours could be used. P of 72 per day is 
based on comments by Hired Hand and research on cold store 
infiltration. Hired Hand commented that the reach in frequency is 
approximately 400-600 per week (or one passage every 20 minutes 
assuming 18 hours per day per week). (Hired Hand, Public Meeting 
Transcript, No. 15 at p. 154) However, DOE identified a study by A.R. 
East, P.B. Jeffrey, and D.J. Cleland, ``Air Infiltration into Walk-in 
Cold Rooms,'' which suggested that this number should be closer to one 
passage every 10 minutes (assuming 18 hours per day per week). DOE 
suggests that the average of the two values of one passage every 15 
minutes or P of 72 per day could be used. DOE chose the value of 8 
seconds per passage but seeks comment on whether another value may be 
more appropriate.
    For all other door or access types, a P of 60 per day, 
[thetas]p of 12 seconds per passage, [thetas]o of 
15 minutes, and [thetas]d of 24 hours could be used. The 
number of passages reflects that other door types are typically 
accessed less frequently than glass doors. The value of 12 seconds per 
passage was selected based on the assumption that non-glass doors, such 
as those through which forklifts are driven in order to load product, 
will be open for longer periods of time than a typical display door. 
DOE selected the [thetas]o of 15 minutes due to the 
probability that a non-glass door will be propped open accidentally or 
intentionally. If an automatic door opener/closer is used for doors 
larger than 7 feet tall and 3 feet, 9 inches wide, then a 
[thetas]p of 10 seconds should be used.
    DOE recognizes that with the variety of walk-in types and end-
users, the frequency and duration of door-opening events is likely to 
vary significantly. As a result, DOE requests comments on the DOE 
assumed values for P, [thetas]p, and [thetas]o.
3. Calculations
    In this section, DOE proposes a calculation methodology for using 
the results obtained from the measurements in the aforementioned tests, 
along with other known quantities, to calculate an energy use metric 
associated with the envelope. The steps in the proposed methodology are 
explained below.
a. Energy Efficiency Ratio
    EPCA requires that the test procedure ``measure the energy use of 
walk-in coolers and walk-in freezers.'' (42 U.S.C. 6314(a)(9)(B)(i)) 
However, EPCA does not specify the units of measurement or units for 
reporting that are required. Based on a review of commonly used energy 
consumption metrics, DOE recommends the use of kWh/day as this unit is 
commonly recognized by end-users, manufacturers and other interested 
parties. However, a majority of metrics used to describe heat transfer 
losses are in units of British Thermal Units (BTU) per unit time. 
Therefore, to convert the British Thermal Units per hour (BTU/h) 
thermal energy transmission calculation into a measure of electrical 
energy consumed by the refrigeration equipment to remove the heat, DOE 
proposes using an energy efficiency ratio (EER) conversion based on a 
nominal efficiency of an assumed refrigeration system.
    Because an envelope manufacturer cannot control where the 
refrigeration equipment is sited and the EER is intended to provide a 
means of comparison and not directly reflect a real walk-in 
installation, DOE proposes that the EER be 12.4 Btu per Watt hour (Btu/
W-h) for coolers and 6.3 Btu/W-h for freezers. The difference in EER 
for coolers and freezers reflects the relative efficiency of the 
refrigeration equipment for the associated application. As the 
temperature of the air surrounding the evaporator coil drops (that is, 
when considering a freezer relative to a cooler), thermodynamics 
dictates that the system effectiveness at removing heat per unit of 
electrical input energy decreases. DOE requests feedback on the 
relative EERs of refrigeration equipment for a comparison basis.

[[Page 198]]

b. Heat Gain Through the Envelope Due to Conduction
    The energy calculation for all components that comprise the 
external surface area of the walk-in may be determined using the 
measured surface area, the measured foam R-value for the walls and 
ceiling, the R-value (or U-value) for glass doors, the design operation 
temperature, and the average ambient air temperature. Then, the 
associated heat transfer due to conduction can then be directly 
calculated.
i. Conduction Through Glass Display Doors
    The heat conduction through the glass is one of the largest single 
contributors to energy consumption for walk-ins with a high ratio of 
glass surface area to non-glass surface. The thermal conductivity, the 
inverse of thermal resistivity or R-value, is commonly represented by 
the U-value in units of Btu/ft2-[deg]F-h. The thermal 
conductivity for most glass products, such as glass doors and windows 
used in buildings, is certified by a third party organization such as 
the National Fenestration Rating Council (NFRC). After certification, 
the product is granted a NFRC label and thermal conductivity 
performance rating. This rating represents an overall component 
performance including but not limited to the glass and the glass frame. 
However, in the case of glass products manufactured for the use in 
walk-ins, such as display doors, inset window and glass walls, DOE 
believes that glass component manufacturers currently do not 
participate in any third party rating programs nor do they provide 
products with performance labels. In addition, the performance data of 
these products is not readily available able in product literature.
    In order for the thermal conductivity performance of glass products 
be incorporated into the walk-in test procedure, DOE proposes these two 
options: (1) If manufacturers of glass doors used in walk-ins 
participate in the same NFRC rating program, the performance of the 
door shall be simply read from its label and used for calculations in 
this test procedure. If glass door manufacturers do not participate in 
the same NFRC rating program, then (2) DOE would require manufacturers 
to use the free software package Window 5.2 (available here: http://windows.lbl.gov/software/window/window.html), that calculates the U-
value, or thermal conductivity, of a glass door given precise 
specifications such as the size of the door, the number of panes of 
glass, the gas fill between the panes, etc. This tool was developed by 
Lawrence Berkeley National Lab (LBNL) and is known in the glass 
component industry to accurately predict glass door thermal performance 
from the given door characteristics. It has been used for many years 
and has been heavily verified by empirical test data. In order to 
ensure that inputs used to calculate overall door performance are not 
being manipulated by manufacturers, DOE intends to require the walk-in 
manufacturer to report the exact inputs and settings used in Window 5.2 
to represent the door materials and glazing system. This will ensure 
transparency and accuracy by enabling other manufacturers and DOE to 
verify the integrity of the data and calculated performance.
    DOE seeks comment on the availability of performance data on glass 
products used in walk-in applications, glass component manufacturers' 
participation in third party certification programs such as NFRC, and 
the proposed method for predicting the thermal performance of glass 
components using LBNL's Window 5.2 software package.
ii. Conduction Through Floors
    In general, walk-in coolers are installed on top of concrete 
surfaces regardless of the walk-in type. For a walk-in cooler that does 
not have a floor supplied by the manufacturer, the average insulating 
performance of concrete will be assumed for the floor surface of the 
walk-in. Therefore, DOE proposes using an R-value of 0.6 ft\2\- F-h/Btu 
for calculating the energy lost assuming the walk-in cooler are sited 
on 6-inch concrete floors of 150 lb/ft\3\ density (ASHRAE Fundamentals 
Handbook). DOE requests feedback on the use of this R-value for coolers 
that are not shipped with an insulated floor.
    Generally, walk-in manufacturers that sell large freezers do not 
install freezer floors. This task is normally subcontracted by the end-
user before the walk-in is installed to ensure EPCA compliance. 
Therefore, DOE proposes using the minimum R-value specified in EPCA for 
walk-in freezer floors, R-28 ft\2\-F-h/Btu, for energy performance 
calculations if the manufacture does not supply a floor to ensure EPCA 
compliance. (42 U.S.C. 6313(f)(1)(D)) DOE requests comments on the use 
of this proposed R-value for freezer floors.
c. Heat Gain Due to Infiltration
    The amount of embodied energy in an air sample is primarily a 
function of its temperature and density or what is typically referred 
to as the enthalpy in a thermodynamic system such as a walk-in. The 
required amount of energy needed to remove heat from the air is 
calculated as the difference between the enthalpy of air entering the 
refrigerated space and enthalpy of the air inside the refrigerated 
space. This calculation is commonly used when designing walk-ins and 
typically uses dry-bulb and wet-bulb temperatures. The difference, per 
unit mass or volume of air, is calculated using the functional 
relationship between temperature and enthalpy. Using the measured 
infiltration rate from the required steady-state test described above 
or calculated analytical value for air infiltration for door-opening 
events and the calculated internal and external enthalpy, a rate of 
energy lost per hour (Btu/h) due to air exchange can be calculated.
d. Envelope Component Electrical Loads
    Because the energy use of the walk-in refrigeration equipment is 
being analyzed separately from the envelope energy use, DOE is 
considering calculating the electricity consumption of lights, sensors, 
and other miscellaneous electrical devices using name-plate rating and 
assumptions about their daily operation, all of which would be 
incorporated into the evaluation of envelope energy use. In addition, 
because the test procedure for the refrigeration system will not 
include heating loads caused by lighting, heater wires, and other 
miscellaneous components, the thermal load from these components will 
be factored into the envelope calculations. DOE proposes as part of the 
test procedure calculations that 100 percent of the electrical energy 
consumed to operate the devices that are internal located in the walk-
in, will be converted to thermal energy. This assumption is accurate 
since at steady-state, all the input electrical energy is converted 
completely into heat adhering to the physical laws of conservation of 
energy. While some electrical energy, which has been converted into 
light, may escape the controlled space via translucent glass display 
doors, this escaping energy is negligible. The associated thermal 
energy will then be used to calculate an additional compressor load 
that would be required to remove the additional heat generated by these 
components.
    DOE recommends using the following equation to calculate the power 
usage for each electricity-consuming device type, Pcomp, 
(kWh):

[[Page 199]]

[GRAPHIC] [TIFF OMITTED] TP04JA10.027

Where:

Prated,t = rated power of each component,
PTOt = percent time off, and
nt = the number of devices at the rated power.

    DOE proposes that the rated power must be read from each 
electricity-consuming device product data sheet or name plate, and the 
nt is the number of identical devices for which the 
Pcomp calculation is being made.
    DOE further proposes the use of the following equation to calculate 
additional compressor load due to heat generated by electrical 
components, Cload, (kWh):
[GRAPHIC] [TIFF OMITTED] TP04JA10.028

Where:

EER = EER of walk-in (cooler = 12.4 or freezer = 6.3), Btu/W-h
Ptot,int = The total electrical load due to components 
sited inside the walk-in envelope

    The percent time off (PTO) value accounts for the reduction in 
energy use in walk-ins with component control systems installed and to 
specify the possible number of hours for various component types. While 
this value may not reflect behaviorally related energy consumption, 
such as how long an end-user typically leaves the lights on, it will 
provide a means for comparison of walk-in performance. To address the 
wide variety of devices that could be employed in a walk-in unit, DOE 
proposes the following PTO values:
    (1) For lights, DOE proposes a PTO value of 25 percent for systems 
without timers or other auto shut-off systems and 50 percent for 
systems with timers or other auto shut-off systems installed.
    (2) For anti-sweat heaters, DOE proposes a PTO value of 0 percent 
for all systems without direct or indirect relative humidity sensing 
controls. DOE further proposes that a PTO value of 75 percent be used 
for walk-in coolers, and 50 percent for walk-in freezers with these 
controls. (Focus on Energy, BP-3429-0304, ``Anti-Sweat Heater 
Controls,'' 2004, p. 1)
    (3) For electrically powered devices (such as air curtains) that 
mitigate air infiltration but are not actively controlled based on door 
open or closed positions, DOE proposes a PTO value of 25 percent.
    (4) For electrically powered devices that mitigate air infiltration 
that are also actively controlled based on door open or closed position 
for display doors, DOE proposes a PTO value of 99.33 percent.
    (5) For electrically powered devices that mitigate air infiltration 
that are also actively controlled based on door open or closed position 
for all other doors, DOE proposes a PTO value of 99.17 percent.
    (6) For all other devices, DOE proposes a PTO value of 0 percent, 
unless the walk-in manufacturer can demonstrate that the device is 
controllable by a preset control system. If this can be demonstrated, 
then DOE proposes a value of 25 percent for the device in question.
    DOE seeks comments on these assumptions.
e. Normalization
    A single metric would make comparing the energy use of walk-ins 
much more straightforward. DOE proposes using a calculation for energy 
consumption per unit time and a normalization factor to account for 
differences in glass and non-glass external surface area depending on 
the product class. During the framework public meeting and in written 
comments, some interested parties recommended that DOE use volume as 
the normalization factor for performance standards. (Manitowoc, Public 
Meeting Transcript, No. 15 at p. 56; EEI, Public Meeting Transcript, 
No. 15 at p. 116; NEEA, No. 18 at p. 3) Crown Tonka, in a written 
comment, recommended that the test metric be kWh per cubic foot (i.e., 
energy consumption normalized by volume). (Crown Tonka, No. 23 at p. 1) 
The Joint Comment recommended that DOE use surface area as the 
normalization factor. (Joint Comment, No. 21 at p. 2) A comment 
submitted jointly by representatives of SCE, SMUD, and SDG&E (hereafter 
referred to as the Utilities Joint Comment) also stated that DOE should 
use surface area as a normalization factor. (Utilities Joint Comment, 
No. 32 at p. 7)
    Many established metrics use a per-day time scale normalized by 
product volume. However, surface area is the key geometric 
characteristic related to both conduction and infiltration because 
volumetric normalization cannot directly account for the higher 
conduction and infiltration losses associated with glass doors and 
windows. Conduction and infiltration losses through glass become 
particularly important considerations as the ratio of glass door area 
to total wall area increases, as is the case in walk-ins designed for 
customer access. Using surface area as the normalization factor would 
account for these losses through any glass door or window used in a 
walk-in. Therefore, DOE proposes the use of surface area as a 
normalization factor for performance calculations of walk-ins. DOE 
requests comments on this proposed normalization method.
f. Daily Energy Consumption Coefficients
    As discussed in section III.A.1, DOE proposes allowing 
manufacturers to group similar units together into a single ``basic 
model.'' This approach would reduce the testing burden as only one unit 
of each basic model would be subject to testing. However, in the case 
of envelopes, the equipment is so highly customized that each unit a 
manufacturer builds may be unique. For example, units may have 
identical materials, components, or construction methods, but may be 
built to varied dimensions, which could result in different energy 
consumption values being obtained using the proposed test methods.
    In order to compare units that are similar enough to be included in 
the same basic model, but that are not identical, the test procedure 
allows for calculating daily energy consumption coefficients (or 
DECCs), using test results from a particular unit within a basic model, 
and then applying these DECCs to other units within a basic model to 
calculate the energy consumption of the other units. DECCs are 
essentially scaling factors that allow a manufacturer to change certain 
parameters of an envelope and calculate the corresponding change in 
energy consumption. In the case of today's proposed procedure, these 
parameters would be wall surface area, non-glass door surface area, 
glass display door surface area, glass wall and inset window surface 
area, infiltration due to opening of non-display type doors and 
infiltration reduction due to reduction devices in place on non-display 
doors, infiltration due to opening of display type doors and 
infiltration reduction due to reduction devices in place on display 
doors, and electrical energy consumption due to devices including, but 
not limited to, lights, anti-sweat heaters, and motors to drive air 
mixing fans. The expression for daily energy consumption is formulated 
on the assumptions that: (1) Energy consumption due to conduction 
losses

[[Page 200]]

scales linearly with surface area; (2) energy consumption due to 
infiltration scales linearly with the number of doors of each type and 
total wall surface area; (3) energy consumption of anti-sweat door 
heaters scales linearly with total door surface area; and (4) energy 
consumption of other electrical components including lighting and 
stirring fans scales linearly with the interior volume of the envelope.
    Once the DECCs are calculated from a tested walk-in envelope, they 
are combined to provide a linear expression of the daily energy 
consumption of any walk-in envelope of the same basic model as the 
tested envelope (that is, having the same construction methods, 
materials, components, and other energy consumption characteristics as 
the tested envelope), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.029

Where:

DECCnon-glass = DECC for non-glass,
Anon-glass,tot = total non-glass surface area,
DECCglass,door = DECC for glass doors,
Aglass,glass, tot = total glass surface area, and
DECCglass,wall = DECC for glass walls and inset windows,
Aglass,wall, tot = total glass wall and inset window 
surface area, and
DECCinfilt,disp--dr--opn = DECC for opening of display 
type doors,
Adisp--doors = total area of display doors,
DECC disp--dr--device = DECC for infiltration reduction 
device in place for display doors,
ndisp--doors = total number of display doors,
DECCinfilt,non-display--,dr--opn = DECC for non-display 
type doors,
Anon-display--doors = total area of non-display type 
doors,
DECCnon-display--dr--device = DECC for infiltration 
reduction device in place for non-display doors,
nnon-display--doors = total number of non-display doors,
DECClight = DECC for lights,
Vref--space = total enclosed refrigerated volume(ft\3\),
DECCASH = DECC for anti-sweat heaters,
DECCstir--fan = DECC for motors used to drive air mixing 
fans, and
DECCother = DECC for other electricity consuming devices.

    Only applicable DECCs shall be used. For example, if a certain 
basic model did not have glass display doors, DECCs and variables 
pertaining to glass display doors would not be calculated, nor would 
they be included in the equation of energy consumption.
    DOE believes that this approach would reduce the testing burden on 
manufacturers because it would not require manufacturers to test every 
unit produced with slight variations due to customer specification. 
However, by specifying a calculation methodology that manufacturers 
must use, the approach reduces the potential for inconsistency among 
manufacturers' rating methods, a concern that interested parties raised 
about DOE's previous idea to allow each manufacturer to develop its own 
AEDM for rating similar, but not identical, equipment. (See section 
III.A.3 for discussion of comments about this issue.) DOE requests 
comment on the proposed approach of specifying a formula based on 
DECCs, and on the assumptions that DOE made in generating this formula. 
DOE also asks if there are other parameters it should consider when 
calculating DECCs.

C. Refrigeration System

    As previously discussed, a differentiation was made for the 
purposes of this test procedure between the envelope or structure of 
the walk-in cooler or freezer and the mechanical refrigeration system 
performing the physical work necessary to cool the interior space. The 
refrigeration system in this context is further subdivided into three 
categories, consisting of single-package systems containing both the 
condensing and evaporator units, split systems with the condensing unit 
and unit cooler physically separated and connected via refrigerant 
piping, and rack systems utilizing unit coolers, which receive 
refrigerant from a shared loop. The proposed test procedure contains 
separate specific provisions for the standardized testing of each 
refrigeration system type. Later sections provide a general overview of 
the test procedure for refrigeration systems of walk-in coolers and 
freezers and address some of the technical issues pertinent to the 
proposed test procedure. The following section also addresses issues 
raised by interested parties.
1. Overview of the Test Procedure
    In accordance with EPCA, DOE proposes to adopt a test procedure for 
measuring the energy consumption of the refrigeration system of walk-in 
coolers and freezers. (42 U.S.C. 6314(a)(9)(B)(i)) DOE is considering 
adding the following definition for ``refrigeration system'' to 10 CFR 
part 431, subpart R: ``Refrigeration system means the mechanism used to 
create the refrigerated environment in the interior of a walk-in cooler 
or freezer, consisting of an integrated single-package refrigeration 
unit, or a split system with separate unit cooler and condensing unit 
sections, or a unit cooler that is connected to a central rack system; 
and including all controls and other components integral to the 
operation of this mechanism.'' DOE requests comments on this proposed 
definition.
    In the framework document, DOE examined in detail six test 
procedures developed either by AHRI or ASHRAE that relate to the 
measurement of energy consumption of refrigeration equipment to 
determine whether they could apply to walk-in refrigeration systems. 
Although the six procedures collectively covered all of the components 
of the refrigeration systems of walk-in coolers and freezers (i.e., the 
compressor, the condenser, the condensing unit or the unit cooler), 
each of these existing procedures covered only one or some of the 
components, and none applied to the testing of the complete 
refrigeration system. The rating conditions specified in those 
procedures also are generally not representative of typical conditions 
found in walk-in equipment.
    During the framework public meeting and in a written comment, AHRI 
informed DOE that it has begun developing a standard for the 
performance rating of walk-in cooler and freezer refrigeration systems. 
(AHRI, Public Meeting Transcript, No. 15 at p. 50; AHRI, No. 33 at p. 
3) This standard, AHRI Standard 1250P, ``2009 Standard for Performance 
Rating of Walk in Coolers and Freezers,'' was published in September of 
2009. DOE has reviewed the final, published version of AHRI Standard 
1250P and proposes to

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incorporate it by reference into this test procedure.
    The test procedure DOE proposes to adopt covers testing of 
refrigeration systems for walk-in coolers and freezers, including unit 
coolers and condensing units that are sold together as a matched system 
(i.e., paired with each other in a way that optimizes the performance 
of the system), as well as unit coolers and condensing units sold 
separately, including unit coolers connected to compressor racks. The 
procedure describes the method for measuring the refrigeration capacity 
and the electrical energy consumption for the condensing unit and the 
unit cooler, as well as the off-cycle fan energy and the defrost 
subsystem under specified test conditions. The standard test conditions 
specify the dry-bulb and wet-bulb temperatures, the relative humidity 
for both the unit cooler and the condensing unit, and require that the 
system must operate under steady-state conditions. The test procedure 
groups walk-in cooler and freezer systems into four categories by 
distinguishing between indoor and outdoor locations for the condensing 
unit, and between coolers and freezers. The test procedure also 
specifies calculations for the nominal box loads for each of the four 
categories under typical low- and high-load conditions, expressed as a 
function of the ambient air temperature. (The ``nominal box load'' 
refers to the refrigeration load imposed on the system by the walk-in 
envelope. Similar to the way in which the envelope was assumed to be 
paired with a refrigeration system of a given EER to provide a means of 
comparison between different envelopes, DOE assumes that the 
refrigeration system is paired with an envelope of given heat transfer 
characteristics. This assumption is made for comparison purposes. See 
section III.B.3.a for further discussion of this concept.) For systems 
in which the condensing unit is located outdoors, the test procedure 
uses bin temperature data and bin hour data to represent the impact of 
the seasonal variation in outside ambient air temperature on energy 
use. The test procedure computes an annual walk-in efficiency factor, 
or AWEF, for the refrigeration system under a specified thermal load 
profile over a 24-hour operation period.
2. Test Conditions
    DOE received several comments on test conditions. The Utilities 
Joint Comment stated that most of the potential energy savings can be 
achieved using floating head pressure and variable-speed evaporator 
fans, both of which are time-varying and weather dependent, and a 
steady-state test may not capture these savings adequately. (Utilities 
Joint Comment, No. 32 at p. 4) Manitowoc stated that energy usage can 
depend on the heat load in the box consisting of defrost energy and fan 
energy, both of which depend on the refrigeration system control 
strategy. (Manitowoc, Public Meeting Transcript, No. 15 at p. 76) NEEA 
stated that the test conditions should reflect variations in the 
location of the condensing unit, thermal load conditions, and outdoor 
air temperature. (NEEA, No. 18 at p. 3)
    The test procedure DOE proposes specific conditions for both the 
interior and exterior of the walk-in to determine the net refrigeration 
capacity. The interior conditions of the unit cooler are specified as 
nominal temperature and humidity conditions: 2 [deg]C dry-bulb and less 
than 50 percent relative humidity (RH) for coolers, and -23 [deg]C dry-
bulb and less than 50 percent RH for freezers. The proposed test 
procedure would measure both net refrigeration capacity and off-cycle 
fan power at those conditions for the unit cooler. For the condenser, 
the test procedure would specify three different ambient conditions for 
dry-bulb and wet-bulb temperatures: Hot (35 [deg]C/24 [deg]C), moderate 
(15 [deg]C/12 [deg]C) and cold (2 [deg]C/1 [deg]C). The purpose of 
specifying three sets of ambient conditions is to capture the variation 
in capacity under different ambient temperatures.
    For two-capacity condensing units, the test procedure would measure 
the net refrigeration capacity under the same set of ambient conditions 
for the condenser at both the minimum and maximum capacity levels. 
Variable-speed condensing units would also have their refrigeration 
capacities measured at an additional intermediate capacity level. 
Because the test procedure provides for measurement of the compressor 
power and the fan power at two compressor capacity levels for two-speed 
systems and at three capacity levels for variable-speed systems at 
multiple outside ambient air temperature levels, DOE believes that the 
proposed test conditions reasonably reflect the energy savings that may 
be achieved through the control strategies referred to by interested 
parties. Also, as mentioned above, the proposed procedure includes a 
measurement of off-cycle fan power, which would account for energy 
savings due to variable-speed evaporator fans.
    The Joint Comment stated that test procedures should account for 
partial-load conditions as well as maximum loading, and that test 
methods limited to maximum load conditions at steady-state operation 
are insufficient. (Joint Comment, No. 21 at p. 2) ACEEE also stated 
that the efficiency metric of the refrigeration system should reflect 
part-load conditions. (ACEEE, Public Meeting Transcript, No. 15 at p. 
99) In the proposed test procedure, DOE has provided for testing of 
two-capacity and variable-capacity condensing units at the minimum 
capacity level, which would correspond to the appropriate low-load 
level condition for an appropriately sized unit. However, for a single-
capacity unit, low-load conditions would lead to a higher frequency of 
equipment cycling because the equipment would be sized for a much 
larger load; that is, a load consistent with worst-case conditions. For 
single-speed equipment, the proposed test procedures do not capture the 
impact of this cyclic degradation. DOE believes that capturing the 
cyclic degradation is not necessary because, averaged over 
representative locations in the entire country, walk-in coolers may 
operate for many hours at the full-load condition. For instance, the 
daily pull-down-load in typical walk-in cooler and freezer 
installations is met over a period of 5 to 8 hours of full-load 
operation for a properly sized unit. Consequently, the impact of the 
cyclic degradation is not very significant for the walk-in cooler or 
freezer refrigeration system.
    Craig noted that the refrigeration systems of walk-in equipment are 
often oversized to account for the worst weather conditions and 
additional pull-down load (Craig, Public Meeting Transcript, No. 15 at 
p. 97). Nor-Lake stated that its methodology for determining the 
refrigeration load for the walk-in takes into account the worst 
conditions over the typical annual cycle, as well as product load, 
pull-down load, the number of door openings, and duration (Nor-Lake, 
No. 30 at p. 2). The proposed test procedure computes the energy use on 
the basis of a nominal box load, which takes into account product load, 
infiltration load due to door openings, and transmission load through 
the box walls and roof. DOE believes that the values for the nominal 
box loads adequately reflect typical oversizing values. The proposed 
annual energy efficiency metric is based on weather conditions that are 
considered representative of the population-weighted average weather 
conditions of the country as a whole.
3. Test Methods
    The net refrigeration capacity of the system is determined by one 
of the following test methods: (1) DX Dual Instrumentation measures the 
enthalpy change and the mass flow rate of the

[[Page 202]]

refrigerant across the unit cooler using two independent measuring 
systems; or (2) DX Calibrated Box measures the enthalpy change and the 
mass flow rate of the refrigerant across the unit cooler and the heat 
input to the calibrated box. In the first method, the test unit cooler 
and the matched condensing unit are kept inside separate environmental 
chambers. In the second method, the condensing unit is placed inside 
the environmental chamber, while the unit cooler is kept inside a 
calibrated box, which is inside a temperature-controlled enclosure.
    DOE believes the test methods are appropriate for walk-ins because 
they were adapted from AHRI Standard 420-2008, ``Performance rating of 
forced-circulation free-delivery unit coolers for refrigeration,'' and 
ASHRAE Standard 23, ``Methods of Testing for Rating Positive 
Displacement Refrigerant Compressors and Condensing Units,'' and have 
been widely used in the refrigeration industry for many years. 
Furthermore, these test methods were developed and approved by the 
industry and published by the industry trade association as a 
sufficiently adequate means of assessing the net refrigeration capacity 
of equipment that share many functional similarities with walk-ins, 
such as components, materials, and substances (e.g., the refrigerant) 
that provide the mechanical means of refrigeration. The test methods 
DOE is proposing today also account for ways in which walk-in 
refrigeration systems differ from commercial refrigeration equipment; 
as in their operating conditions, configurations, or patterns of use. 
For example, condensing units of walk-in refrigeration systems may be 
located outdoors and experience a wider range of operating temperatures 
than commercial refrigeration, which is generally located indoors; the 
walk-in refrigeration test procedure specifies three different ambient 
temperatures at which to test, in order to approximate actual 
conditions under which the system might operate. Furthermore, DOE's 
proposed methods improve upon previously developed refrigeration test 
methods by accounting for the energy-saving effects of advanced 
technologies such as variable-speed fans and defrost control 
strategies.
4. Measurements and Calculations
    The test procedure DOE proposes to adopt, AHRI Standard 1250P-2009, 
measures certain parameters, including the net refrigeration capacity 
and the off-cycle fan power for both coolers and freezers. The defrost 
power and thermal energy transferred to the defrost drain water are 
measured for a defrost cycle for freezers only. Separate calculation 
procedures for single-capacity, two-capacity, and variable-capacity 
equipment are included in the test procedure. The test procedure 
determines the annual walk-in energy factor, or AWEF, as the ratio of 
the annual net heat removed from the box, which includes the internal 
heat gains from non-refrigeration components but excludes the heat 
gains from the refrigeration components in the box, to the annual 
electrical energy consumption. The final metric determined by this 
procedure is a measure of efficiency. However, DOE is required by EPCA 
to establish ``a test procedure to measure * * * energy use.'' (42 
U.S.C. 6314(a)(9)(B)(i)) In light of this requirement, DOE proposes 
that manufacturers determine both the AWEF and the annual energy 
consumption of their equipment using the test procedure, which will 
enable the test procedure to be consistent with the requirements of 
EPCA to develop test procedures that measure the energy consumption of 
walk-in equipment.
    In the AHRI Standard 1250P-2009 calculations, the annual net heat 
removed from the nominal box is represented as a function of ambient 
temperature surrounding the condenser and the measured net 
refrigeration capacity at the highest test temperature. For 
refrigeration systems consisting of a unit cooler and a dedicated 
condensing unit, the annual net heat removed from the box can be 
calculated from the system capacity and, for systems located outdoors, 
the net heat removed from the nominal box at a given bin temperature 
weighted by the number of hours corresponding to the bin temperature. 
The temperature bin data listed in Table D1 of AHRI Standard 1250P-2009 
has been constructed from the ambient temperatures over a typical 
meteorological year for a specified location, corresponding closely to 
the use cycle parameters prescribed in other DOE standards. For 
refrigeration systems consisting of a unit cooler connected to a remote 
rack, the net heat removed is a function of the unit cooler capacity at 
the test points specified in AHRI Standard 1250P-2009.
    DOE is considering deriving the expressions for the annual net heat 
removed from the box, that is, the numerator of the equations for 
energy consumption, by simplifying the equations in AHRI Standard 
1250P-2009. As an example, the calculation methodology for indoor 
coolers using AHRI Standard 1250P-2009 would be as follows:
    The AWEF, for walk-in cooler systems with dedicated condensing 
units located indoors, is determined by
[GRAPHIC] [TIFF OMITTED] TP04JA10.030

Where [Sigma][BL(tj)] is the annual net heat removed from 
the box over the course of the year, and [Sigma][E(tj)] 
is the annual energy consumption of the system. Thus,
[GRAPHIC] [TIFF OMITTED] TP04JA10.031

AWEF is calculated directly using the test procedure, while 
BL(tj) is calculated by:
[GRAPHIC] [TIFF OMITTED] TP04JA10.032


[[Page 203]]


For indoor units, tj is assumed to be constant; thus, 
nj = 8760, the total number of hours in a year. BLH and 
BLL are given by, respectively,
[GRAPHIC] [TIFF OMITTED] TP04JA10.033

and
[GRAPHIC] [TIFF OMITTED] TP04JA10.034

Where qss(90 [deg]F) is the system steady state 
refrigeration capacity at 90 [deg]F. When terms are combined and the 
expression simplified, the equation for annual energy consumption 
becomes
[GRAPHIC] [TIFF OMITTED] TP04JA10.035

DOE requests comment on using these equations to derive annual energy 
consumption.

D. Compliance, Certification, and Enforcement

    Finally, DOE addresses below compliance, certification, and 
enforcement issues involving walk-ins. At this time, DOE is not 
proposing any specific requirements for this equipment. As discussed 
below, DOE will consider addressing these issues in a separate 
rulemaking. Any data on which a manufacturer relies for the purposes of 
certifying compliance with any applicable standards that DOE 
promulgates for this equipment would be derived from the test procedure 
that DOE adopts. The adopted procedure would also be used by DOE during 
enforcement-related testing.
1. Provisions for Energy Conservation Standards Developed by the 
Department of Energy
    The purpose of establishing compliance, certification, and 
enforcement regulations is to provide reasonable assurance that 
manufacturers appropriately test and accurately represent the 
performance characteristics of commercial equipment. DOE recently 
incorporated the standards prescribed by EISA 2007, including those for 
walk-ins, into 10 CFR parts 430 and 431. 74 FR 12074 (March 23, 2009). 
However, DOE has not yet proposed or issued amended energy conservation 
standards for walk-ins. DOE will consider issuing compliance, 
certification, and enforcement provisions for walk-ins in a future 
rulemaking. Therefore, today's notice proposes no certification, 
compliance, or enforcement provisions for energy conservation standards 
for walk-ins.
2. Provisions for Existing Design Standards Prescribed by Congress
    DOE is responsible for enforcing Federal energy standards, whether 
those standards were developed through a DOE rulemaking pursuant to 
EPCA or prescribed by Congress. In EISA 2007, Congress prescribed 
design standards specifically for walk-ins that took effect on January 
1, 2009. Typically, DOE establishes specific enforcement regulations 
for each product covered by existing standards, which may require 
manufacturers to file documents such as a compliance statement and a 
certification report. In a compliance statement, the manufacturer 
certifies its products meet the requirements. In a certification 
report, the manufacturer provides product-specific information that 
would enable DOE to determine whether the product meets the standard. 
DOE has already established compliance and certification requirements 
for other products.
    Until DOE finalizes regulations that require compliance statements 
and certification reports for walk-ins, manufacturers will not be 
required to report data to DOE, but they must still meet all prescribed 
design standards that went into effect on January 1, 2009. If there is 
a question on compliance with design standards, the manufacturer must 
make a reasonable case that the equipment meets those standards.
    To address concerns about the EISA 2007 design requirements for 
walk-ins, DOE maintains a Frequently Asked Questions page on the DOE 
Web site at http://www1.eere.energy.gov/buildings/appliance_standards/commercial/wicf_faqs.html.

IV. 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 Executive Order 12866, ``Regulatory Planning and 
Review,'' 58 FR 51735 (October 4, 1993). Accordingly, this action was 
not subject to review under that Executive Order by the Office of 
Information and Regulatory Affairs (OIRA) of the Office of Management 
and Budget (OMB).

B. Review Under the National Environmental Policy Act

    In this proposed rule, DOE proposes to adopt test procedures and 
related provisions for walk-in equipment. The test procedures would be 
used initially for the purpose of considering the adoption of energy 
conservation standards for walk-ins, and DOE would require their use 
only if standards were subsequently adopted. The proposed test 
procedures will not affect the quality or distribution of energy and, 
therefore, will not result in environmental impacts. Therefore, DOE 
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 the Department's 
implementing regulations at 10 CFR part 1021. More specifically, 
today's proposed rule is covered by the Categorical Exclusion in 
paragraph A6 to subpart D, 10 CFR part 1021. Accordingly, neither an 
environmental assessment nor an environmental impact statement is 
required.

C. Review Under the Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires 
preparation of an initial regulatory flexibility analysis (IRFA) for 
any rule that by law must be proposed for public comment, unless the 
agency certifies that the rule, if promulgated, will not have a 
significant economic impact on a substantial number of small entities. 
As required by Executive Order 13272, ``Proper Consideration of Small 
Entities in Agency Rulemaking'' (67 FR 53461 (August 16, 2002)), DOE 
published procedures and policies on February 19, 2003, to ensure that 
the potential impacts of its rules on small entities are properly 
considered during the rulemaking process. 68 FR 7990. DOE has made its 
procedures and policies available on the Office of General Counsel's 
Web site, http://www.gc.doe.gov.
    DOE reviewed the test procedures considered in today's notice of 
proposed rulemaking under the provisions of the Regulatory Flexibility 
Act and the procedures and policies published on February 19, 2003. As 
discussed in more detail below, DOE found that because the proposed 
test procedures have not previously been required of

[[Page 204]]

manufacturers, all manufacturers, including small manufacturers, could 
potentially experience a financial burden associated with new testing 
requirements. While examining this issue, DOE determined that it could 
not certify that the proposed rule, if promulgated, would not have a 
significant effect on a substantial number of small entities. 
Therefore, DOE has prepared an IRFA for this rulemaking. The IRFA 
describes potential impacts on small businesses associated with walk-in 
cooler and freezer testing requirements.
    DOE has transmitted a copy of this IRFA to the Chief Counsel for 
Advocacy of the Small Business Administration for review.
1. Reasons for the Proposed Rule
    Title III of the EPCA sets forth a variety of provisions designed 
to improve energy efficiency. Part B of Title III (42 U.S.C. 6291-6309) 
provides for the Energy Conservation Program for Consumer Products 
Other Than Automobiles. NECPA (Pub. L. 95-619) amended EPCA to add Part 
C of title III, which established an energy conservation program for 
certain industrial equipment. (42 U.S.C. 6311-6317) (These parts were 
subsequently redesignated as Parts A and A-1, respectively, for 
editorial reasons.) Section 312 of EISA 2007 further amended EPCA by 
adding certain equipment to this energy conservation program, including 
walk-in coolers and walk-in freezers (collectively ``walk-in 
equipment'' or ``walk-ins''), the subject of this rulemaking. (42 U.S.C 
6311(1), (2), 6313(f) and 6314(a)(9)) The proposed rule would establish 
a test procedure for walk-in coolers and walk-in freezers.
2. Objectives of, and Legal Basis for, the Proposed Rule
    Under EPCA, the overall energy conservation program consists 
essentially of the following parts: Testing, labeling, and Federal 
energy conservation standards. The testing requirements for covered 
equipment consist of test procedures, prescribed under EPCA. The test 
procedures, if adopted, would be used in one of three ways: (1) Any 
data from the use of the test procedure, would be used by DOE as a 
basis for developing standards for walk-in equipment; (2) the procedure 
would be used by DOE when determining equipment compliance with those 
standards; and (3) manufacturers of covered equipment would be required 
to use the procedure as the basis for establishing that their equipment 
complies with the relevant energy conservation standards promulgated 
pursuant to EPCA and when making representations regarding equipment 
efficiency.
    Section 343 of EPCA (42 U.S.C. 6314) sets forth generally 
applicable criteria and procedures for DOE's adoption and amendment of 
test procedures for covered equipment. That provision requires that the 
test procedures promulgated by DOE be reasonably designed to produce 
test results which reflect energy efficiency, energy use, and estimated 
operating costs of the covered equipment during a representative 
average use cycle. It also requires that the test procedure not be 
unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)) Further 
information concerning the background of this rulemaking is provided in 
Section I of this preamble.
3. Description and Estimated Number of Small Entities Regulated
    Small businesses, as defined by the Small Business Administration 
(SBA) for the walk-in cooler and freezer manufacturing industry, are 
manufacturing enterprises with 750 employees or fewer. DOE used the 
small business size standards published on January 31, 1996, as 
amended, by the SBA to determine whether any small entities would be 
required to comply with the rule. 61 FR 3286; see also 65 FR 30836, 
30850 (May 15, 2000), as amended at 65 FR 53533, 53545 (September 5, 
2000). The size standards are codified at 13 CFR Part 121. The 
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. Walk-in cooler and freezer equipment manufacturing is 
classified under NAICS 333415, Air-Conditioning and Warm Air Heating 
Equipment and Commercial and Industrial Refrigeration Equipment 
Manufacturing.
    DOE reviewed AHRI's listing of commercial refrigeration equipment 
manufacturer members and surveyed the industry to develop a list of 
domestic manufacturers. DOE also asked stakeholders and AHRI 
representatives within the industry if they were aware of any other 
small business manufacturers. DOE then examined publicly available 
data, including regulatory databases such as state databases and the 
National Sanitation Foundation (NSF) Section 7 database. DOE identified 
at least 37 small manufacturers of walk-in cooler and freezer 
envelopes, and at least 5 small manufacturers of walk-in cooler and 
freezer refrigeration systems. However, some manufacturers that DOE 
interviewed indicated that there could be many more small business 
manufacturers than were publicly listed. Such unlisted manufacturers 
could be very small (< 50 employees) and serve only a local market. 
They also may not submit any information to state or national 
regulators such as NSF. Therefore, DOE believes there may be more 
affected small entities than it estimated and seeks comment on the 
number of small entities that may be impacted by the test procedure.
4. Description and Estimate of Compliance Requirements
    Potential impacts of the proposed test procedures on manufacturers, 
including small businesses, come from impacts associated with the cost 
of testing. In this test procedure NOPR, DOE proposes measures to 
reduce the financial burden of testing on all manufacturers, including 
small business manufacturers. First, where the procedure gives 
manufacturers options in terms of materials, equipment, or methodology 
to be used in performing the test, DOE proposes to allow manufacturers 
to use the lowest-cost option, where possible. For instance, ASTM E741-
06 allows manufacturers to use any of about 12 tracer gases. DOE 
specifies a tracer gas to ensure that all manufacturers report at the 
same accuracy, but specifies the use of carbon dioxide, which would be 
the lowest cost option. Second, DOE proposes to reduce the total number 
of tests manufacturers would have to perform by allowing them to group 
similar equipment into a single family, or basic model, and only 
requiring them to test one unit of each basic model. (See section 
III.A.1 for a more detailed discussion of the basic model proposal.)
    The proposed test procedure for envelopes would require 
manufacturers to perform testing in accordance with two industry test 
standards: ASTM C1303-08, ``Standard Test Method of Predicting Long-
Term Thermal Resistance of Closed-Cell Foam Insulation,'' and ASTM 
E741-06, ``Standard Test Method for Determining Air Change in a Single 
Zone by Means of a Tracer Gas Dilution.'' DOE spoke with industry 
experts to determine the approximate cost of each test and determined 
that a test using ASTM C1303-08 costs between approximately $5,000 and 
$10,000, and a test using ASTM E741-06 costs between $1,000 and $5,000. 
A typical manufacturer would have approximately 8 basic models, so the 
total cost of compliance would be approximately $84,000.

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    The proposed test procedure for refrigeration systems would require 
manufacturers to perform testing in accordance with a single industry 
test standard: AHRI Standard 1250P-2009, ``2009 Standard for 
Performance Rating of Walk-In Coolers and Freezers.'' Because this test 
was recently developed by the industry and has not yet been widely used 
to test refrigeration systems, DOE could not determine how much the 
test currently costs. However, DOE researched the cost of other, 
similar standards and subsequently estimated that a test using AHRI 
Standard 1250P-2009 would likely cost approximately $5,000. A typical 
refrigeration manufacturer could have approximately 50 basic models, 
making the total cost of compliance approximately $250,000.
    Because the cost of running each test is the same for all 
manufacturers, and because DOE has proposed measures to reduce burden 
on all manufacturers, DOE believes that all manufacturers would incur 
comparable costs as a result of the proposed test procedures. However, 
DOE does not expect that small manufacturers would have fewer basic 
models than large manufacturers, because the equipment is highly 
customized throughout the industry. A small manufacturer could have the 
same total cost of testing as a large manufacturer, but this cost would 
be a higher percentage of a small manufacturer's annual revenues. Thus, 
DOE cannot certify that the differential impact associated with walk-in 
cooler and freezer test procedures on small businesses would not be 
significant.
5. Duplication, Overlap, and Conflict With Other Rules and Regulations
    DOE is not aware of any rules or regulations that duplicate, 
overlap, or conflict with the rule being considered today.
6. Significant Alternatives to the Rule
    DOE considered a number of alternatives to the proposed test 
procedure, including test procedures that incorporate industry test 
standards other than the three proposed standards, ASTM C1303-08, ASTM 
E741-06, and AHRI Standard 1250P-2009, described above. Instead of 
requiring ASTM C1303-08 for testing the long-term thermal properties of 
insulation, DOE could require only ASTM C518-04, ``Standard Test Method 
for Steady-State Thermal Transmission Properties by Means of the Heat 
Flow Meter Apparatus,'' which tests the thermal properties of 
insulation at a certain point in time (i.e., the point of manufacture). 
(Because ASTM C1303-08 incorporates ASTM C518-04, requiring ASTM C1303-
08 is consistent with the statutory requirement for basing measurement 
of the thermal conductivity of the insulation on ASTM C518-04.) (42 
U.S.C. 6314(a)(9)(A)) A test of ASTM C518-04 alone costs approximately 
$500-$1,000. However, DOE is considering ASTM C1303 for other reasons; 
namely, the concern that ASTM C518-04 alone does not capture the 
performance characteristics of a walk-in over the period of its use, 
because it does not account for significant changes in the thermal 
properties of insulation over time. For more discussion on this issue, 
see Section III.B.2.a.
    DOE also considered ASTM E1827-96(2007), ``Standard Test Methods 
for Determining Airtightness of Buildings Using an Orifice Blower 
Door,'' instead of ASTM E741-06, for testing infiltration. ASTM E1827-
96(2007) costs about $300-$500 for a single test. However, DOE believes 
that ASTM E1827-96(2007) is not appropriate for walk-ins because it is 
conducted by placing test equipment in the door, and thus does not 
account for in infiltration through the door, which is a major 
component of infiltration in walk-ins. In addition, it is not intended 
for testing envelope systems, such as a walk-in, that have a large 
temperature difference between the internal and external air. 
Therefore, to complete a blower-door test, the walk-in would not be 
able to be tested at or close to operational temperatures, resulting in 
a test that does not accurately reflect its performance. For more 
discussion on this issue, see Section III.B.2.b.
    In the framework document, DOE considered adapting an existing test 
procedure for commercial refrigeration equipment, such as ARI Standard 
1200-2006, ``Performance Rating of Commercial Refrigerated Display 
Merchandisers and Storage Cabinets,'' as an alternative to AHRI 
Standard 1250P-2009. The two tests are based on a similar methodology 
for rating refrigeration equipment in general, but ARI Standard 1200-
2006 requires testing at only one set of ambient conditions, whereas 
AHRI Standard 1250P-2009 requires testing at 3 sets of ambient 
conditions for refrigeration systems with the condensing units located 
outdoors. The additional time required to test the system at 3 sets of 
conditions would incur additional cost and could make AHRI Standard 
1250P-2009 more burdensome than ARI Standard 1200-2006. However, DOE 
believes that AHRI Standard 1250P-2009 is more appropriate for testing 
walk-ins than ARI Standard 1200-2006. A test procedure based on ARI 
Standard 1200-2006 would require the entire walk-in to be tested as a 
whole, but manufacturers might not have a large enough test facility to 
make the measurements necessary for the ARI 1200-2006 test procedure in 
a controlled environment. Also, the refrigeration system is often 
manufactured separately from the insulated envelope. In this case, 
whoever assembled the two components would bear the burden of 
conducting ARI 1200-2006; this party might not be the manufacturer of 
the refrigeration system. In contrast, AHRI 1250P-2009 tests only the 
refrigeration system. It does not require a larger test chamber than 
other, similar tests, and can be conducted by the manufacturer of the 
refrigeration system. Furthermore, because AHRI 1250P-2009 requires the 
system to be tested at 3 ambient temperatures, it captures energy 
savings from features (for example, floating head pressure) that allow 
the system to use less energy at lower ambient temperatures. For more 
discussion on this issue, see Section III.A.2.
    DOE requests comment on the impacts to small business manufacturers 
for these and any other possible alternatives to the proposed rule. DOE 
will consider any comments received regarding impacts to small business 
manufacturers for all the alternatives identified.

D. Review Under the Paperwork Reduction Act

    Today's proposed rule contains no record-keeping requirements. 
Therefore, today's notice of proposed rulemaking would not impose any 
new reporting requirements requiring clearance by OMB under the 
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The Department 
recognizes, however, that if it adopts standards for walk-in coolers 
and walk-in freezers, once the standards become operative, 
manufacturers may become subject to record-keeping requirements 
associated with compliance with the standards. Therefore, the 
Department will comply with the record-keeping requirements of the 
Paperwork Reduction Act if and when energy conservation standards are 
adopted.

E. Review Under the Unfunded Mandates Reform Act of 1995

    Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) (UMRA) requires each Federal agency to assess the effects of Federal 
regulatory actions on State, local, and tribal governments and the 
private sector. With respect to a proposed regulatory

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action 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 (adjusted annually for inflation), section 202 of UMRA requires 
a Federal agency to publish estimates of the resulting costs, benefits, 
and other effects on the national economy. (2 U.S.C. 1532(a), (b)) UMRA 
also requires a Federal agency to develop an effective process to 
permit timely input by elected officers of State, local, and tribal 
governments on a proposed ``significant intergovernmental mandate,'' 
and requires an agency plan for giving notice and opportunity for 
timely input to potentially affected small governments before 
establishing any requirements that might significantly or uniquely 
affect small governments. On March 18, 1997, DOE published a statement 
of policy on its process for intergovernmental consultation under UMRA 
(62 FR 12820) (also available at http://www.gc.doe.gov). The proposed 
rule published today does not provide for any Federal mandate likely to 
result in an aggregate expenditure of $100 million or more. Therefore, 
the UMRA does not require a cost benefit analysis of today's proposal.

F. 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 proposed 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.

G. Review Under Executive Order 13132

    Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 4, 1999) 
imposes certain requirements on agencies formulating and implementing 
policies or regulations that preempt State law or that have federalism 
implications. The Executive Order requires agencies to examine the 
constitutional and statutory authority supporting any action that would 
limit the policymaking discretion of the States and 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 today's proposed rule and 
has determined that it does not preempt State law and does 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) No further action is required by Executive Order 13132.

H. Review Under Executive Order 12988

    With respect to the review of existing regulations and the 
promulgation of new regulations, section 3(a) of Executive Order 12988, 
``Civil Justice Reform'' (61 FR 4729, February 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, and (3) provide a clear legal 
standard for affected conduct rather than a general standard and 
promote simplification and burden reduction. Section 3(b) of Executive 
Order 12988 specifically requires that Executive agencies make every 
reasonable effort to ensure that the regulation (1) Clearly specifies 
the preemptive effect, if any; (2) clearly specifies any effect on 
existing Federal law or regulation; (3) provides a clear legal standard 
for affected conduct while promoting simplification and burden 
reduction; (4) specifies the retroactive effect, if any; (5) adequately 
defines key terms; and (6) addresses other important issues affecting 
clarity and general draftsmanship under any guidelines issued by the 
Attorney General. Section 3(c) of Executive Order 12988 requires 
Executive agencies to review regulations in light of applicable 
standards in section 3(a) and section 3(b) to determine whether they 
are met or it is unreasonable to meet one or more of them. DOE has 
completed the required review and determined that, to the extent 
permitted by law, this proposed rule meets the relevant standards of 
Executive Order 12988.

I. Review Under the Treasury and General Government Appropriations Act, 
2001

    The Treasury and General Government Appropriations Act, 2001 (44 
U.S.C. 3516, note) provides for agencies to review most disseminations 
of information to the public under guidelines established by each 
agency pursuant to general guidelines issued by OMB. OMB's guidelines 
were published at 67 FR 8452 (February 22, 2002), and DOE's guidelines 
were published at 67 FR 62446 (October 7, 2002). DOE has reviewed 
today's notice under the OMB and DOE guidelines and has concluded that 
it is consistent with applicable policies in those guidelines.

J. 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 the 
Office of Information and Regulatory Affairs (OIRA), Office of 
Management and Budget, a Statement of Energy Effects for any proposed 
significant energy action. A ``significant energy action'' is defined 
as any action by an agency that promulgated or is expected to lead to 
promulgation of a final rule, and that (1) Is a significant regulatory 
action under Executive Order 12866, or any successor order; and (2) is 
likely to have a significant adverse effect on the supply, 
distribution, or use of energy; or (3) is designated by the 
Administrator of OIRA as a significant energy action. For any 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 is not a significant regulatory action under 
Executive Order 12866. Moreover, it would not have a significant 
adverse effect on the supply, distribution, or use of energy. The 
Administrator of OIRA also did not designate today's action as a 
significant energy action. Therefore, it is not a significant energy 
action, and DOE has not prepared a Statement of Energy Effects.

K. Review Under Executive Order 12630

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

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L. Review Under Section 32 of the Federal Energy Administration (FEA) 
Act of 1974

    Under section 301 of the Department of Energy Organization Act 
(Pub. L. 95-91), DOE must comply with section 32 of the Federal Energy 
Administration Act of 1974, as amended by the Federal Energy 
Administration Authorization Act of 1977. (15 U.S.C. 788) Section 32 
provides in part that, where a proposed rule contains or involves use 
of commercial standards, the rulemaking must inform the public of the 
use and background of such standards. The rule proposed in this notice 
incorporates testing methods contained in the following commercial 
standards: ASTM C1303-08, ``Standard Test Method of Predicting Long-
Term Thermal Resistance of Closed-Cell Foam Insulation;'' ASTM E741-06, 
``Standard Test Method for Determining Air Change in a Single Zone by 
Means of a Tracer Gas Dilution;'' and AHRI Standard 1250P, ``2009 
Standard for Performance Rating of Walk in Coolers and Freezers.'' The 
Department has evaluated these standards and is unable to conclude 
whether they fully comply with the requirements of section 32(b) of the 
Federal Energy Administration Act, i.e., whether they were developed in 
a manner that fully provides for public participation, comment, and 
review. As required by section 32(c) of the Federal Energy 
Administration Act, of 1974, as amended, DOE will consult with the 
Attorney General and the Chairman of the Federal Trade Commission 
before prescribing a final rule concerning the impact on competition of 
requiring manufacturers to use the methods contained in these standards 
to test walk-in equipment.

V. Public Participation

A. Attendance at Public Meeting

    The time, date, and location of the public meeting are provided in 
the DATES and ADDRESSES sections at the beginning of this document. 
Anyone who wants to attend the public meeting must notify Ms. Brenda 
Edwards at (202) 586-2945. As explained in the ADDRESSES section, 
foreign nationals visiting DOE headquarters are subject to advance 
security screening procedures.

B. Procedure for Submitting Requests To Speak

    Any person who has an interest in the topics addressed in this 
notice, or who is a 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 between 9 a.m. and 4 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 Program, 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 
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 that those persons who are scheduled to speak submit a 
copy of their statements at least one week prior to the public meeting. 
DOE may permit any person who cannot supply an advance copy of this 
statement to participate, if that person has made alternative 
arrangements with the Building Technologies Program in advance. When 
necessary, the request to give an oral presentation should ask for such 
alternative arrangements.

C. Conduct of Public Meeting

    DOE will designate a DOE official to preside at the public meeting 
and may also employ a professional facilitator to aid discussion. The 
public meeting will be conducted in an informal, conference style. The 
meeting will not be a judicial or evidentiary public hearing, but DOE 
will conduct it in accordance with section 336 of EPCA (42 U.S.C. 
6306). Discussion of proprietary information, costs or prices, market 
share, or other commercial matters regulated by U.S. anti-trust laws is 
not permitted.
    DOE reserves the right to schedule the order of presentations and 
to establish the procedures governing the conduct of the public 
meeting. A court reporter will record the proceedings and prepare a 
transcript.
    At the public meeting, DOE will present summaries of comments 
received before the public meeting, allow time for presentations by 
participants, and encourage all interested parties to share their views 
on issues affecting this rulemaking. Each participant may present a 
prepared general statement (within time limits determined by DOE) 
before the discussion of specific topics. Other participants may 
comment briefly on any general statements. At the end of the prepared 
statements on each specific topic, participants may clarify their 
statements briefly and comment on statements made by others. 
Participants should be prepared to answer questions from DOE and other 
participants. DOE representatives may also ask questions about 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 procedures needed for the 
proper conduct of the public meeting.
    DOE will make the entire record of this proposed rulemaking, 
including the transcript from the public meeting, available for 
inspection at the U.S. Department of Energy, 6th Floor, 950 L'Enfant 
Plaza, SW., Washington, DC 20024, (202) 586-2945, between 9 a.m. and 4 
p.m., Monday through Friday, except Federal holidays. Anyone may 
purchase a copy of the transcript from the transcribing reporter.

D. Submission of Comments

    DOE will accept comments, data, and information regarding the 
proposed rule no later than the date provided at the beginning of this 
notice. Comments, data, and information submitted to DOE's e-mail 
address for this rulemaking should be provided in WordPerfect, 
Microsoft Word, PDF, or text (ASCII) file format. Interested parties 
should avoid the use of special characters or any form of encryption, 
and wherever possible, comments should include the electronic signature 
of the author. Absent an electronic signature, comments submitted 
electronically must be followed and authenticated by submitting a 
signed original paper document to the address provided at the beginning 
of this notice. Comments, data, and information submitted to DOE via 
mail or hand delivery/courier should include one signed original paper 
copy. No telefacsimiles (faxes) will be accepted.
    According 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 two copies: One copy of the document including 
all the information believed to be confidential, and one copy of the 
document with the information believed to be confidential deleted. DOE 
will make its own determination as to the confidential status of the 
information and treat it according to its determination.
    Factors of interest to DOE when evaluating requests to treat 
submitted information as confidential include (1) A description of the 
items, (2) whether and why such items are customarily

[[Page 208]]

treated as confidential within the industry, (3) whether the 
information is generally known by or available from other sources, (4) 
whether the information has previously been made available to others 
without obligation concerning its confidentiality, (5) an explanation 
of the competitive injury to the submitting person which would result 
from public disclosure, (6) a date upon which such information might 
lose its confidential nature due to the passage of time, and (7) why 
disclosure of the information would be contrary to the public interest.

E. Issues on Which DOE Seeks Comment

    DOE is particularly interested in receiving comments on the 
following issues:
1. Test Procedure Improvements
    DOE requests comments on improvements in the test procedures that 
it should consider. In submitting comments, interested parties should 
state the nature of the recommended modification and an explanation of 
how it improves upon the test procedure proposed in this NOPR. See 
section II for details.
2. Basic Model
    Because walk-in equipment tends to be highly customized, DOE is 
considering allowing manufacturers to group similar walk-in equipment 
under a single ``basic model'' and only subjecting one unit of each 
basic model to testing. DOE will use the term ``basic model'' to 
represent a single family of walk-in equipment, consisting of walk-in 
equipment or models of equipment that do not have any differentiating 
electrical, physical, or functional features that significantly affect 
energy consumption characteristics. DOE requests comments on the 
proposed basic model approach. See section III.A.1 for details.
3. Separate Envelope and Refrigeration Tests
    For any walk-in, two different manufacturers may make the two main 
components: The envelope, or insulated box, and the refrigeration 
system. In this notice, DOE proposes separate test procedures for the 
envelope and the refrigeration system. The envelope manufacturer would 
be responsible for testing the envelope according to the envelope test 
procedure, and the refrigeration system manufacturer would be 
responsible for testing the refrigeration system according to the 
refrigeration system test procedure. The purpose of this provision is 
to accurately reflect the structure of the walk-in market and assign 
testing responsibilities to the equipment manufacturers. DOE requests 
comments on the proposed approach to develop separate test procedures. 
See section III.A.4 for details.
4. Definition of Envelope
    DOE requests comments on the following definition of ``envelope:'' 
``(1) a piece of equipment that is the portion of a walk-in cooler or 
walk-in freezer that isolates the interior, refrigerated environment 
from the ambient, external environment; and (2) all energy-consuming 
components of the walk-in cooler or walk-in freezer that are not part 
of its refrigeration system.'' See section III.B.1 for details.
5. Effect of Impermeable Skins on Long-Term R-Value
    DOE received many comments on the framework document regarding 
long-term R-value. After researching the issue, DOE determined that the 
R-value of insulating foams diminish after manufacture at rates that 
vary by material type and environmental conditions. Diffusion of gases 
and moisture infiltration are the key mechanisms of R-value decline. 
Many manufacturers seek to prevent or delay diffusion and moisture 
infiltration by sealing the foam in a ``skin,'' typically a metal 
material. DOE received comments suggesting that these skins can be made 
fully impermeable while other comments argued that full impermeability 
cannot be achieved due to imperfect sealing at panel joints, imperfect 
adherence of foam to metal during manufacture, deliberate punctures for 
fixtures and shelving, and/or inadvertent punctures that typically 
occur in the field. DOE requests feedback on this issue, including the 
submission of test results on the impact of impermeable skins on long-
term R-value. Specifically, DOE requests that interested parties submit 
or identify any peer-reviewed, published data pertaining to the 
efficacy of skins in preventing or delaying R-value decline. See 
section III.B.2.a for details.
6. Measuring Long-Term R-Value Using American Society for Testing and 
Materials (ASTM) C1303-08
    DOE proposes accounting for R-value decline due to diffusion of 
gases by requiring manufacturers to condition their foam prior to 
testing. DOE proposes requiring manufacturers to condition foam using 
ASTM C1303-08, which conditions foam using an accelerated aging method 
prior to testing its R-value. Because ASTM C1303-08 uses ASTM C518-
2004, using ASTM C1303-08 would be consistent with EPCA. (42 U.S.C. 
6314(a)(9)(A)(ii)) DOE requests feedback on the proposal to require 
conditioning and testing foam using ASTM C1303-08. DOE recognizes that 
ASTM C1303-08 is designed for unfaced and permeably faced foams rather 
than the impermeably faced foams typical of walk-ins. DOE requests 
feedback on the use of ASTM C1303-08 for foams that will be impermeably 
faced.
    DOE is considering several exceptions and clarifications to ASTM 
C1303-08 to satisfy requirements of EPCA and to make the test procedure 
more applicable to walk-ins. DOE requests feedback on the number of 
samples and sample thicknesses, the use of interpolation of results for 
foam thicknesses within the specified 0.5 inch range, and 
the use of the core stack R-value out of a sample size of three stacks 
for the purpose of calculating walk-in energy use.
    Lastly, ASTM C1303-08 cannot be used for non-foam materials, but 
DOE is not aware of any non-foam materials currently being used as 
insulation in walk-in coolers or freezers. DOE requests comment on 
whether non-foam technologies, such as vacuum insulated panels or 
aerogels, are likely to be commercially available for walk-ins within 
the next 5 years. See section III.B.2.a for details.
7. Infiltration
    Air infiltration causes a substantial amount of heat gain through 
the envelope. After evaluating several methods of testing and measuring 
the air infiltration, DOE proposes requiring ASTM E741-06, also 
referred to as the gas tracer method, as the test procedure for 
measuring steady-state infiltration and the effectiveness of 
infiltration reduction devices (for air infiltration unrelated to door 
opening events). Because door opening also contributes to infiltration, 
DOE proposes accounting for this infiltration pathway. DOE does not, 
however, propose to require manufacturers to individually measure the 
infiltration from door opening events, due to the complexity of this 
type of testing and the availability of accurate analytical models, 
which would make a test procedure very difficult to implement. DOE 
proposes using analytical methods based on ASHRAE fundamentals as well 
as assumed door-opening frequency and duration and the measured 
infiltration barrier effectiveness to calculate the air infiltration 
associated with each door-opening event. DOE requests comments on the 
proposed test method for steady-state infiltration. DOE requests input

[[Page 209]]

and feedback on the calculations and assumptions proposed for 
determining infiltration from door-opening events. See section 
III.B.2.b for details on the proposed analytical methods.
8. Nominal Coefficient of Performance of Refrigeration
    In developing a test procedure for the envelope alone, without a 
refrigeration system, DOE had to determine the energy consumption 
associated with heat gain through the envelope due to conduction and 
infiltration. DOE proposes to assume a nominal EER for the 
refrigeration system to convert the heat gain through the box into a 
measure of the energy consumption of a theoretical refrigeration system 
that would be removing this heat from the box. For comparison purposes, 
DOE recommends that the EER be 12.4 Btu per watt hour (Btu/Wh) for 
coolers and 6.3 Btu/Wh for freezers because these are typical EER 
values. DOE requests comments on this proposal and on the assumed value 
for the EER. See section III.B.3.a for details.
9. Measuring the U-Value of Glass
    Because conduction through glass components can be a significant 
source of heat transfer through walk-in envelopes, DOE seeks to order 
to account for improvements in glass performance in the test procedure. 
DOE proposes two options for manufacturers: (1) If manufacturers of 
glass doors used in walk-ins participate in the NFRC rating program, 
the performance of the door shall be simply read from its label and 
used for calculations in this test procedure. If glass door 
manufacturers do not participate in the NFRC rating program, then (2) 
DOE proposes to require manufacturers to use the LBNL's publicly 
available Window 5.2 software package to calculate glass door 
performance. DOE seeks comment on the availability of performance data 
on glass products used in walk-in applications, glass component 
manufacturers' participation in third party certification programs such 
as NFRC, and the proposed method for predicting the thermal performance 
of glass components using Window 5.2. See section III.B.3.b for more 
information.
10. Floor R-Value
    EPCA does not require walk-in cooler floors to meet a specific R-
value. In many instances, walk-in coolers are shipped without 
additional insulating floors and are simply placed on top of an 
existing surface, such as a concrete slab. Since concrete is the floor 
surface most commonly used with floorless walk-in coolers DOE is 
considering using the R-value of 6-inch concrete to calculate energy 
lost through these floors. DOE proposes using an R-value of 0.6 ft\2\-
[deg] F-hr/Btu for 6-inch concrete. Since walk-in freezers are required 
to have a floor insulation of R-28, DOE will assume this R-value for 
purposes of calculating the energy loss through walk-in freezer floors 
if the manufacturer does not provide any additional insulating surface. 
DOE requests comments on these assumptions. See section III.B.3.b for 
details.
11. Electrical Duty Cycle
    As part of the envelope test procedure, DOE recommends calculating 
the electricity consumption of lights, sensors, and other miscellaneous 
electrical devices not considered part of the refrigeration equipment 
using name-plate rating and an assumed daily operation. DOE 
incorporates assumed duty cycles of lights, anti-sweat heaters, and 
other devices based on whether they are controlled by a preset control 
system. While these assumptions may not reflect the actual behaviorally 
related energy consumption, they will provide a means for comparison. 
DOE requests comments on whether the duty cycle assumptions are 
appropriate. See section III.B.3.d for details.
12. Normalization Factor
    For the envelope test procedure, DOE proposes to normalize the 
energy consumption by a certain factor related to the size of the walk-
in so that manufacturers of larger walk-ins and walk-ins with glass 
doors are not unfairly penalized. DOE believes that the surface area of 
the envelope is an appropriate normalization factor, because surface 
area is the key geometric characteristic related to both conduction and 
infiltration and is particularly important as the ratio of glass door 
area to wall area increases. DOE requests comments on the proposal to 
normalize the energy consumption by the surface area of the walk-in. 
See section III.B.3.e for details.
13. Daily Energy Consumption Coefficients
    In order to compare envelopes that are similar enough to be 
included in the same basic model but are not identical, the test 
procedure allows for calculating Daily Energy Consumption Coefficients, 
or DECCs, using test results from a particular envelope within a basic 
model, and then applying these DECCs to other envelopes within a basic 
model to calculate the energy consumption of the other units. DECCs are 
essentially scaling factors that allow a manufacturer to change certain 
parameters of an envelope and calculate the corresponding change in 
energy consumption. DOE believes that this approach would reduce the 
testing burden on manufacturers because it would not require 
manufacturers to test every unit produced with slight variations due to 
customer specification. DOE requests comment on this rating 
methodology. For formulas and more information, see section III.B.3.f.
14. Definition of Refrigeration System
    DOE requests comments on the following definition of 
``refrigeration system:'' ``the mechanism used to create the 
refrigerated environment in the interior of a walk-in cooler or 
freezer, consisting of an integrated single-package refrigeration unit, 
or a split system with separate unit cooler and condensing unit 
sections, or a unit cooler that is connected to a central rack system; 
and including all controls and other components integral to the 
operation of this mechanism.'' See section III.C.1 for details.
15. Measurements and Calculations of Energy Use of Refrigeration 
Systems
    The test procedure DOE proposes to adopt, AHRI Standard 1250P-2009, 
determines the annual walk-in energy factor, or AWEF, which is a 
measure of the efficiency of a walk-in's refrigeration system. However, 
DOE is required by EPCA to establish ``a test procedure to measure * * 
* energy use.'' (42 U.S.C. 6314(a)(9)(B)(i)) In light of this 
requirement, DOE proposes that manufacturers determine both the AWEF 
and the annual energy consumption of their equipment using the test 
procedure, which will enable the test procedure to be consistent with 
the requirements of EPCA to develop test procedures that measure the 
energy consumption of walk-in equipment. DOE is considering satisfying 
the statutory requirement by deriving the energy consumption of the 
walk-in refrigeration system from data obtained when the test procedure 
is performed. DOE's derivation process, and further information, can be 
found in section III.C.4.
16. Impacts on Small Businesses
    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires 
preparation of an initial regulatory flexibility analysis (IRFA) for 
any rule that by law must be proposed for public comment, unless the 
agency certifies that the rule, if promulgated, will not have a 
significant economic impact on a

[[Page 210]]

substantial number of small entities. Upon examination of this NOPR, 
DOE could not certify that the rule, if promulgated, would not have a 
significant economic impact on a substantial number of small entities; 
therefore, DOE prepared an IRFA for this rule. DOE requests comment on 
the number of small businesses affected by the proposed rule, and seeks 
comment on impacts to small business manufacturers for any possible 
alternatives to the proposed rule. More information, along with the 
text of the IRFA, can be found in section IV.C.

VI. Approval of the Office of the Secretary

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

List of Subjects in 10 CFR Part 431

    Administrative practice and procedure, Confidential business 
information, Energy conservation, Reporting and recordkeeping 
requirements.

    Issued in Washington, DC, on December 14, 2009.
Cathy Zoi,
Assistant Secretary, Energy Efficiency and Renewable Energy.
    For the reasons stated in the preamble, DOE proposes to amend part 
431 of chapter II of title 10, of the Code of Federal Regulations, to 
read as set forth below.

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

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


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

    2. Section 431.302 is amended by adding, in alphabetical order, 
definitions for ``Basic model,'' ``Envelope,'' ``Refrigeration 
system,'' and ``Walk-in equipment'' to read as follows:


Sec.  431.302  Definitions concerning walk-in coolers and walk-in 
freezers.

    Basic Model means all units of a given type of walk-in equipment 
manufactured by a single manufacturer, and--
    (1) With respect to envelopes, which do not have any differing 
construction methods, materials, components, or other characteristics 
that significantly affect the energy consumption characteristics.
    (2) With respect to refrigeration systems, which have the same 
primary energy source and which do not have any differing electrical, 
physical, or functional characteristics that significantly affect 
energy consumption.
    Envelope means (1) the portion of a walk-in cooler or walk-in 
freezer that isolates the interior, refrigerated environment from the 
ambient, external environment; and (2) all energy-consuming components 
of the walk-in cooler or walk-in freezer that are not part of its 
refrigeration system.
    Refrigeration system means the mechanism used to create the 
refrigerated environment in the interior of a walk-in cooler or 
freezer, consisting of an integrated single-package refrigeration unit, 
or a split system with separate unit cooler and condensing unit 
sections, or a unit cooler that is connected to a central rack system; 
and including all controls and other components integral to the 
operation of this mechanism.
* * * * *
    Walk-in equipment means either the envelope or the refrigeration 
system of a walk-in cooler or freezer.
    3. Section 431.303 is amended by adding new paragraphs (b)(2), 
(b)(3), and (c) to read as follows:


Sec.  431.303  Materials incorporated by reference.

* * * * *
    (b) * * *
    (2) ASTM C1303-08, Standard Test Method of Predicting Long Term 
Thermal Resistance of Closed-Cell Foam Insulation, approved September 
15, 2008, IBR approved for Sec.  431.304.
    (3) ASTM E741-06, Standard Test Method for Determining Air Change 
in a Single Zone by Means of a Tracer Gas Dilution, approved October 1, 
2006, IBR approved for Sec.  431.304.
    (c) AHRI. Air-Conditioning, Heating, and Refrigeration Institute, 
2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, (703) 600-0366, 
or http://www.ahrinet.org.
    (1) AHRI Standard 1250P-2009, 2009 Standard for Performance Rating 
of Walk-In Coolers and Freezers, approved September 2009, IBR approved 
for Sec.  431.304.
    (2) Reserved.
    4. Section 431.304 is revised to read as follows:


Sec.  431.304  Uniform test method for the measurement of energy 
consumption of walk-in coolers and walk-in freezers.

    (a) Scope. This section provides test procedures for measuring, 
pursuant to EPCA, the energy consumption of walk-in coolers and walk-in 
freezers.
    (b) Testing and Calculations.
    (1) Determine the energy consumption of walk-in cooler and walk-in 
freezer envelopes by conducting the test procedure specified in 
Appendix A to this subpart.
    (2) Determine the U-value of glass components from the product 
label in compliance with the National Fenestration Rating Council's 
Product Certification Program, PCP-2007, or by using the Window 5.2 
software to calculate the performance of the glass.
    (3) Determine the Annual Walk-in Efficiency Factor of walk-in 
cooler and walk-in freezer refrigeration systems by conducting the test 
procedure set forth in AHRI Standard 1250P-2009 (incorporated by 
reference, see Sec.  431.303).
    (4) Determine the energy consumption of walk-in cooler and walk-in 
freezer refrigeration systems by:
    (i) For refrigeration systems with the condensing unit located 
inside a conditioned space, performing the following calculations for 
coolers and freezers, respectively:
[GRAPHIC] [TIFF OMITTED] TP04JA10.036

Where qss (90 [deg]F) is the steady state net refrigeration 
capacity measured at an ambient condition of 90 [deg]F, and the Annual 
Walk-In Efficiency Factor is calculated from the results of the test 
procedures set forth in

[[Page 211]]

AHRI Standard 1250P-2009 (incorporated by reference, see Sec.  
431.303).
    (ii) For refrigeration systems with the condensing unit located 
outdoors, performing the following calculations for coolers and 
freezers, respectively:
[GRAPHIC] [TIFF OMITTED] TP04JA10.037

Where qss (95 [deg]F) is the steady state net refrigeration 
capacity measured at an ambient condition of 95 [deg]F; tj 
and nj represent the outdoor temperature at each bin j and 
the number of hours in each bin j, respectively, for the temperature 
bins listed in Table D1 of AHRI Standard 1250P-2009 (incorporated by 
reference, see Sec.  431.303); and the Annual Walk-In Efficiency Factor 
is calculated from the results of the test procedures set forth in AHRI 
Standard 1250P-2009 (incorporated by reference, see Sec.  431.303).
    (iii) For refrigeration systems consisting of a unit cooler 
connected to a rack system, performing the following calculations for 
coolers and freezers, respectively:
[GRAPHIC] [TIFF OMITTED] TP04JA10.038

Where qmix,evap is the net capacity of the evaporator coil, 
determined by testing the unit cooler at the 25 [deg]F suction dewpoint 
for a cooler and the -20 [deg]F suction dewpoint for a freezer, at the 
maximum evaporator fan speed, according to AHRI standard 1250P-2009 
(incorporated by reference, see Sec.  431.303); and the Annual Walk-in 
Efficiency Factor is calculated from the results of the test procedures 
set forth in AHRI Standard 1250P-2009 (incorporated by reference, see 
Sec.  431.303).
    5. Appendix A is added to subpart R of part 431 to read as follows:

Appendix A to Subpart R of Part 431--Uniform Test Method for the 
Measurement of Energy Consumption of the Envelopes of Walk-In Coolers 
and Walk-In Freezers

1.0 Scope

    This appendix covers the test requirements used to measure the 
energy consumption of the envelopes of walk-in coolers and walk-in 
freezers.

2.0 Definitions

    The definitions contained in Sec.  431.302 are applicable to 
this appendix.

2.1 Additional Definitions

    (a) Unless explicitly stated otherwise, the surface area for all 
measurements is the area as measured on the external surface of the 
walk-in.
    (b) A device or control system that ``automatically'' opens and 
closes doors without direct user contact (i.e., a motion sensor that 
senses when a forklift is approaching the entrance to a door, opens, 
and then closes after the forklift has passed).
    (c) Unless explicitly stated otherwise, all calculations and 
test procedure measurements shall use the temperature and relative 
humidity data shown in Table A.1. For installations where two or 
more walk-in envelopes share any surface(s), the ``external 
conditions'' of the shared surface(s) should reflect the internal 
conditions of the neighboring walk-in.

         Table A.1--Temperature and Relative Humidity Conditions
------------------------------------------------------------------------
                                                          Value   Units
------------------------------------------------------------------------
           Internal Conditions (cooled space within envelope)
------------------------------------------------------------------------
Cooler:
    Dry Bulb Temperature...............................      35       F
    Relative Humidity..................................      60       %
Freezer:
    Dry Bulb Temperature...............................     -10       F
    Relative Humidity..................................      60       %
------------------------------------------------------------------------
          External Conditions (space external to the envelope)
------------------------------------------------------------------------
Freezer and Cooler:
    Dry Bulb Temperature...............................      75       F
    Relative Humidity..................................      40       %
------------------------------------------------------------------------

3.0 Test Apparatus and General Instructions

3.1 Conduction Heat Gain

3.1.1 Glass Doors

    (a) All dimensional measurements for glass doors include the 
door frame and glass.
    (b) Calculate the individual and total glass door surface area 
(Aglass) as follows:

[[Page 212]]

[GRAPHIC] [TIFF OMITTED] TP04JA10.039

Where:

i = index for each type of unique glass door used in cooler or 
freezer being tested,
ni = number of identical glass doors of type i,
Wglass,i = width of glass door (including door frame), and
Hglass,i = height of glass door (including door frame).

    (c) Calculate the temperature differential(s) 
[Delta]Ti for each unique glass door ([deg]F) as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.040

Where:

i = Index for each type of unique glass door used in cooler or 
freezer being tested,
TDB,int,i = dry-bulb air temperature inside the cooler or freezer, 
[deg]F
TDB,ext,i = dry-bulb air temperature external to cooler or freezer, 
[deg]F

    (d) Calculate the conduction load through the glass doors, 
(Qcond-glass,door):
[GRAPHIC] [TIFF OMITTED] TP04JA10.041

Where:

ni = number of identical glass doors of type i;
Uglass,i = thermal transmittance, U-value of the door, of type i, 
Btu/h-ft\2\-[deg]F;
Aglass,i = total surface area of all walk-in glass doors of type i, 
ft\2\; and
[Delta]T1 = temperature differential between refrigerated and 
adjacent zones, [deg]F.

3.1.2 Wall Glass and Doors With Inset Glass

    (a) Calculate the individual and total glass surface area 
(Aglass,wall), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.042

[GRAPHIC] [TIFF OMITTED] TP04JA10.043

Where:

i = index for each type of unique glass door used in cooler or 
freezer being tested,
ni = number of identical glass walls or insets of type i,
Wglass,wall,,i = width of glass wall (including glass framing)
Hglass,wall,i = height of glass wall (including glass framing)

    (b) Calculate the temperature differential(s) 
[Delta]Tglass,wall,i for each unique glass wall ([deg]F), 
as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.044

Where:

i = Index for each type of unique glass door used in cooler or 
freezer
TDB,int,glass,wall,i = dry-bulb air temperature inside the cooler or 
freezer, [deg]F
TDB,ext,glass,wall,i = dry-bulb air temperature external to cooler 
or freezer, [deg]F

    (c) Calculate the conduction load through the glass walls and 
glass insets, (Qcond-glass,wall), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.045

Where:

ni = number of identical glass walls or insets of type i;
Uglass,wall,i = thermal transmittance, U-value of the glass wall, of 
type i, Btu/h-ft\2\-[deg]F;
Aglass,wall,i = total surface area of all walk-in glass walls and 
insets of type i, ft\2\; and
[Delta]Tglass,wall,i = temperature differential between refrigerated 
and adjacent zones, [deg]F.

3.1.3 Non-Glass Envelope Components

    (a) Calculate the total surface area of the walk-in non-glass 
envelope (Anon-glass,tot), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.046


[[Page 213]]


Where:

i,j,k,l = number of identical surface area regions of walls, floors, 
ceilings and non-glass doors, respectively, comprised of the same 
thickness and underlying materials and temperature differential--for 
example, if a walk-in has wall sections that are of two different 
thickness or of two different foam insulation products, i=2;
Awalls,i = area of walls, of thickness and underlying materials of 
type i;
Afloor,j = area of floor, of thickness and underlying materials of 
type j;
Aceiling,k = area of ceiling, of thickness and underlying materials 
of type k; and
Anon-glass door,l = area of doors, of thickness and underlying 
materials of type l.

    (b) Determine the R-value (Thermal resistance) of the walls, 
ceiling, and floor foam per 4.1, as follows:
    (c) Calculate the conduction or transmission load through all 
non-glass components (Qcond-non-glass), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.047

Where:

Rnon-glass,wall, i = R-value of foam used in wall panels, of type i, 
h-ft\2\-[deg]F/Btu;
Rnon-glass,floor, j = R-value of foam used in floor panels, of type 
j, h-ft\2\-[deg]F/Btu;
Rnon-glass,ceil, k = R-value of foam used in ceiling panels, of type 
k, h-ft\2\-[deg]F/Btu;
Rnon-glass,door, l = R-value of foam used in non-glass doors, of 
type l, h-ft\2\-[deg]F/Btu;
Awalls,i = area of wall, of thickness and underlying materials of 
type i;
Afloor,j = area of floor, of thickness and underlying materials of 
type j;
Aceiling,k = area of ceiling, of thickness and underlying materials 
of type k; and
Anon-glass door,l = area of doors, of thickness and underlying 
materials of type l.
[Delta]Ti = dry bulb temperature differential between internal and 
external air, of type i, [deg]F
[Delta]Tj = dry bulb temperature differential between internal and 
external air, of type j, [deg]F
[Delta]Tk = dry bulb temperature differential between internal and 
external air, of type k, [deg]F
[Delta]Tl = dry bulb temperature differential between internal and 
external air, of type l, [deg]F

3.1.4 Total Conduction Load

    (a) Calculate total conduction load, Qcond, (Btu/h), 
as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.048

Where:

Qcond-non-glass = conduction load through non-glass components of 
walk-in, Btu/h; and
Qcond-glass,wall = total conduction load through walk-in glass walls 
and inset windows, Btu/h.
Qcond-glass,door = total conduction load through walk-in glass 
doors, Btu/h.

3.2 Infiltration Heat Gain

3.2.1 Steady State Infiltration Calculations

    (a) Convert dry-bulb internal and external air temperatures from 
[deg]F to Rankine ([deg]R), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.049

Where:

TDB-int,R = the dry-bulb temperature of internal walk-in air, 
[deg]R; and
TDB-ext,R = the average dry-bulb temperature of air surrounding the 
walk-in, [deg]R.

    (b) Calculate the water vapor saturation pressure for the 
external air and the internal refrigerated air, as follows:
    (1) If TDB,R < 491.67 [deg]R (32 [deg]F), using 
following equation to calculate water vapor saturation pressure 
(Pws in psia):
[GRAPHIC] [TIFF OMITTED] TP04JA10.050

Where:

TDB,R = dry-bulb temperature in Rankine (for the internal or 
external air),
C1 = -1.0214165 E+04,
C2 = -4.8932428 E+00,
C3 = -5.3765794 E-03,
C4 = 1.9202377 E-07,
C5 = 3.5575832 E-10,
C6 = -9.0344688 E-14, and
C7 = 4.1635019 E+00.

    (2) If TDB,R > 491.67 [deg]R (32 [deg]F), use the 
following equation to calculate water vapor saturation pressure 
(Pws in psia):
[GRAPHIC] [TIFF OMITTED] TP04JA10.051

Where:

TDB,R = dry-bulb temperature (for the internal and external air), 
[deg]R;
C8 = -1.0440397 E+04;
C9 = -1.1294650 E+01;
C10 = -2.7022355 E-02;
C11 = 1.2890360 E-05;
C12 = 2.4780681 E-09; and
C13 = 6.5459673 E+00.

    (c) Calculate the absolute humidity ratio, [omega], as follows:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.052
    
Where:

RH = relative humidity in decimal format (e.g., 0.40 for 40 percent) 
(for the internal or external air), and
Pws = water vapor saturation pressure.

    (d) Calculate air specific volume, [nu], (ft\3\/lb), as follows:

[[Page 214]]

[GRAPHIC] [TIFF OMITTED] TP04JA10.053

Where:

TDB,R = dry-bulb temperature (for the internal or external air), 
[deg]R, and
[omega] = absolute humidity ratio.

    (e) Calculate air density, air density (lb/ft\3\), as follows:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.054
    
Where:

[nu] = specific volume of air, ft\3\/lb.

    (f) Calculate the enthalpy for the internal and external air, h, 
(Btu/lb), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.055

Where:

TDB,F = dry-bulb temperature (for the internal or external air), 
[deg]F; and
    [omega] = absolute humidity ratio.

    (g) Measure the steady-state infiltration rate per 4.2., 
Vrate(1/h)
    (h) Convert Vrate to V, (ft\3\/h), as follows:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.056
    
Where:

Vref-space = the total enclosed volume of the walk-in, ft\3\
Vrate = the infiltration rate per 4.2, 1/h

    (i) Calculate the total infiltration load due to steady-state 
infiltration, Qinfilt, (Btu/h), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.057

Where:

V = the infiltration rate measured from 4.2, ft\3\/h;
[rho]int = internal air density, lb/ft\3\;
[rho]ext = external air density, lb/ft\3\;
hint = internal air enthalpy, Btu/lb; and
hext = external air enthalpy, Btu/lb.

3.2.2 Door Opening Infiltration Calculations

    (a) Calculate the portion of time each doorway is open, 
Dt, as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.058

Where:

i = index for each unique door. A unique door must be of the same 
geometry, underlying materials, function, and have the same 
temperature difference across the door
P = number of doorway passages (i.e., number of doors opening 
events);
[thgr]p = door open-close time, seconds per opening P;
[thgr]o = time door stands open, minutes; and
[thgr]d = daily time period, h.

    (1) Number of doorway passages: For display glass doors, P = 72, 
and all other doors, P= 60
    (2) Door open-close time: For display glass doors, 
[thgr]p = 8 seconds. For non-glass doors, if an automatic 
door opener/closer is used, [thgr]p = 10 seconds and all 
other doors, [thgr]p = 15 seconds.
    (3) Time door stands open: Display glass doors, 
[thgr]o = 0 minutes and all other doors, 
[thgr]o = 15 minutes.
    (4) Daily time period: All walk-ins, [thgr]d = 24 
hours.
    (b) Calculate the density factor, Fm, for each door, 
as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.059

Where:

i = index for each unique door
[rho]int,i = internal air density, of door type i, lb/
ft\3\; and
[rho]ext,i = external air density, of door type i, lb/ft\3\.

    (c) Calculate the infiltration load for fully established flow 
through each door, qi (Btu/h), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.060

Where:

i = index for each unique door
Ai = doorway area, of door type i, ft\2\;
hint,i = internal air enthalpy, of door type i, Btu/lb;
hext,i = external air enthalpy, of door type i, Btu/lb;
[rho]int,i = internal air density, of door type i, lb/ft\3\;
[rho]ext,i = external air density, of door type i, lb/ft\3\;
Hi = doorway height, of door type i, ft;
Fm,i = density factor, of door type i, and
g = acceleration of gravity, 32.174 ft/s\2\.

    (d) Calculate the doorway infiltration reduction device 
effectiveness, E (%), at the same test conditions as described in 
steady-state infiltration section, as follows:
    (1) A sample set must be taken once the tracer gas has uniformly 
dispersed in the internal space using the methodology described in 
4.2.
    (2) The test should be repeated exactly as described with the 
infiltration reduction device removed or deactivated.
    (3) Calculate the infiltration reduction effectiveness:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.061
    
Where:

Vrate,with-device = air infiltration rate, with door open and 
reduction device active, using 4.2, 1/h;
Vrate,without-device = air infiltration rate, with door open and 
reduction device disabled or removed, using 4.2, 1/h.
(e) Calculate the total door opening infiltration load for a single 
door, Qopen, (Btu/h), as follows:

[[Page 215]]

[GRAPHIC] [TIFF OMITTED] TP04JA10.062

Where:

q = infiltration load for fully established flow, Btu/h;
Dt = doorway open-time factor;
Df = doorway flow factor, 0.8 for freezers and coolers (from ASHRAE 
Fundamentals);
E = effectiveness of doorway protective device, as measured by gas 
tracer test, %; and
ni = number of doors (of the type i being considered in 
calculation).

    (f) Calculate the total load due to door opening infiltration 
for all doors, Qopen, (Btu/h), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.063

3.3 Energy Consumption Due To Total Heat Gain

    (a) Calculate the total thermal load, Qtot, (Btu/h), 
as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.064

Where:

Qinfilt = total load due to steady-state infiltration, Btu/h;
Qcond = total load due to conduction, Btu/h; and
Qopen= total load due to door opening infiltration, Btu/h.

    (b) Select Energy Efficiency Ratio (EER), as follows:
    (1) For coolers, use EER = 12.4 Btu/Wh
    (2) For freezers, use EER = 6.3 Btu/Wh
    (c) Calculate the total daily energy consumption due to thermal 
load, Qtot,EER, (kWh/day), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.065

Where:

Qtot = total thermal load, Btu/h; and
EER = EER of walk-in (cooler or freezer), Btu/Wh.

    3.4 Energy Consumption Related To Electrical Components. 
Electrical components contained within a walk-in could include, but 
are not limited to: heater wire (for anti-sweat or anti-freeze 
application); lights (including display door lighting systems); 
control system units; and sensors.

3.4.1 Direct Energy Consumption of Electrical Components

    (a) Select the required value for percent time off for each type 
of electricity consuming device, PTOt (%)
    (1) For lights without timers, control system or other demand-
based control, PTO = 25 percent. For lighting with timers, control 
system or other demand-based control, PTO = 50 percent.
    (2) For anti-sweat heaters on coolers (if required): Without 
timers, control system or other demand-based control, PTO = 0 
percent. With timers, control system or other demand-based control, 
PTO = 75 percent. For anti-sweat heaters on freezers (if required): 
Without timers, control system or other auto-shut-off systems, PTO = 
0 percent. With timers, control system or other demand-based 
control, PTO = 50 percent
    (3) For active infiltration reduction devices: Without control 
by door open or closed position, PTO = 25 percent. With control by 
door open or closed position for display doors, PTO = 99.33 percent. 
With control by door open or closed position for other doors, PTO = 
99.17 percent.
    (4) For all other electricity consuming devices: Without timers, 
control system, or other auto-shut-off systems, PTO = 0 percent. If 
it can be demonstrated that the device is controlled by preinstalled 
timers, control system or other auto-shut-off systems, PTO = 25 
percent.
    (b) Calculate the power usage for each type of electricity 
consuming device, Pcomp,t, (kWh), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.066

Where:

t = index for each type of electricity consuming device with 
identical rated power;
Prated,t = rated power of each component, of type t, kW;
PTOt = percent time off, for device of type t, %; and
nt = number of devices at the rated power of type t.

    (c) Calculate the total electrical energy consumption, Ptot, 
(kWh), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.067

[GRAPHIC] [TIFF OMITTED] TP04JA10.068

Where:

t = index for each type of electricity consuming device with 
identical rated power;
Pcomp,int, t = the energy usage for an electricity consuming device 
sited inside the walk-in envelope, of type t, kWh.
Pcomp,ext, t = the energy usage for an electricity consuming device 
sited outside the walk-in envelope, of type t, kWh.

3.4.2 Total Indirect Electricity Consumption Due to Electrical Devices

    (a) Calculate the additional compressor load due to thermal 
output from electrical components contained within the envelope, 
Cload, (kWh), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.069

Where:

EER = EER of walk-in (cooler=12.4 or freezer=6.3), Btu/Wh;
Ptot,int = The total electrical load due to components sited inside 
the walk-in envelope.

3.5 Total Normalized Energy Consumption

3.5.1 Total Energy Load

    (a) Calculate the total energy load of the walk-in envelope per 
unit of surface area, Etot (kWh/ft\2\), as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.070


[[Page 216]]


[GRAPHIC] [TIFF OMITTED] TP04JA10.071

[GRAPHIC] [TIFF OMITTED] TP04JA10.072

Where:

Qtot,EER = the total thermal load, kWh;
Ptot = the total electrical load, kWh;
Anon-glass,tot = total surface area of the non-glass envelope, 
ft\2\;
Aglass,tot = total surface area glass envelope, ft\2\.
Cload = additional compressor load due to thermal output from 
electrical components contained within the envelope, kWh.

4.0 Test Methods and Measurements

4.1 R-Value Testing and Measurements

4.1.1 Measuring R-Value of Insulating Foam

    (a) Follow the test procedure in ASTM C1303-08 exactly, except 
for these exceptions, (incorporated by reference, see Sec.  
431.303):
    (1) Section 6.6.2, where several types of hot plate methods are 
recommended, ASTM C518-04, (incorporated by reference, see Sec.  
431.303), must be used for measuring the R-value
    (2) Section 6.6.2.1, in reference to ASTM C518-04, the mean test 
temperature of the foam during R-value measurement must be:
    (i) For freezers: - 6.7  2 [deg]C (20  4 
[deg]F) with a temperature difference of 22  2 [deg]C 
(40  4 [deg]F)
    (ii) For coolers: 12.8  2 [deg]C (55  4 
[deg]F) with a temperature difference of 22  2 [deg]C 
(40  4 [deg]F)
    (b) At least one sample set must be prepared, comprised of three 
stacks, while adhering to all preparation methods and uniformity 
specifications described in ASTM C1303-08, (incorporated by 
reference, see Sec.  431.303).
    (c) The value resulting LTTR for the foam shall be reported as 
Rfoam, but for the purposes of calculations in this test 
procedure calculations, it will be converted to 
Rnon-glass, as follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.073

Where:

Rfoam = R-value of foam as measured by ASTM C1303-08, h-ft\2\-
[deg]F/Btu-in.

4.1.2 Determining R-Value of Concrete Floors

    (a) For walk-ins in which the floor is concrete instead of 
insulated panels and has not been supplied by the walk-in 
manufacturer:
    (1) Coolers: Use an R-value of 0.6 for floors of walk-in 
coolers.
    (2) Freezers: Use an R-value of 28 for floors of walk-in 
freezers.

4.2 Steady State Infiltration Testing

    (a) Follow the test procedure in ASTM E741-06 exactly, except 
for these changes and exceptions to the procedure, (incorporated by 
reference, see Sec.  431.303):
    (1) Concentration decay method: The ``concentration decay 
method'' must be used instead of other available options described 
in ASTM E741-06.
    (2) Gas Tracer: CO2 must be used as the gas tracer 
for all testing.
    (3) Air change rate: Measure the air change rate in ft\3\/h, 
rather than the air change flow described in ASTM E741-06, 
(incorporated by reference, see Sec.  431.303).
    (4) Spatial measurements: Spatial measurements must be taken in 
a minimum of six locations or one location/20 ft\2\ of floor area 
(whichever results in a greater number of measurements) at a height 
of 3 ft  0.5 ft, at a minimum distance of 2 ft  0.5 ft from the walk-in walls or doors.
    (b) The internal air temperature for freezers and for coolers 
shall be  2 [deg]C (4 [deg]F) of the values shown in 
Table A.1.
    (c) The external air temperature must be 24 [deg]C (75 [deg]F) 
 2.5 [deg]C (5 [deg]F) surrounding the walk-in.
    (d) The test must be completed with all reach or walk-in doors 
closed.
    (e) For testing the effectiveness ASTM E741-06 will be used, 
with the following changes or exceptions to the procedure:
    (1) Within 3 minutes  30 seconds, with the 
infiltration reduction device in place, a hinged door should be 
opened at an angle greater than or equal to 90 degrees. The elapsed 
time, from zero degrees position (closed) to greater than or equal 
to 90 degrees (open) must be no longer than 5 seconds. The door must 
then be held at an angle greater than or equal to 90 degrees for 5 
min 5 seconds and then closed over a period no longer 
than 5 seconds. For non-hinged doors, the door must reach its 
maximum opened position, be held open, and reach a fully closed 
position for the same elapsed time as described above for hinge-type 
doors.
    (2) The gas concentration must be sampled again after the door 
has been closed. Samples should continue being taken until the gas 
concentration is once again uniform within the walk-in.

5.0 Calculation of Daily Energy Consumption Coefficients (DECC)

    The calculation procedures described in this section are based 
on the test measurements and other performance parameters discussed 
and described in the previous sections. The Daily Energy Consumption 
Coefficients are each combined to provide a linear expression of the 
daily energy consumption of any walk-in system with the construction 
features or component design parameters of a tested walk-in design 
with similar components and features. The DECC figures established 
using measurements on the test unit may be used to derive the daily 
electrical energy consumption of other walk-in systems in the same 
class constructed with similar components of construction as 
follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.074

Where:

    DECCnon-glass = DECC for non-glass,
    Anon-glass,tot = total non-glass surface area,
    DECCglass,door = DECC for glass doors,
    Aglass,glass, tot = total glass surface area, and
    DECCglass,wall = DECC for glass walls and inset windows,
    Aglass,wall, tot = total glass wall and inset window surface 
area, and
    DECCinfilt,disp_dr_opn = DECC for opening of display type doors,
    Adisp_doors = total area of display doors,
    DECCdisp_dr_device = DECC for infiltration reduction device in 
place for display doors,
    ndisp_doors = total number of display doors,
    DECCinfilt,non-display_,dr_opn = DECC for non-display type 
doors,

[[Page 217]]

    Anon-display_doors = total area of non-display type doors,
    DECCnon-display_dr_device = DECC for infiltration reduction 
device in place for non-display doors,
    nnon-display_doors = total number of non-display doors,
    DECClight = DECC for lights,
    Vref_space = total enclosed refrigerated volume (ft\3\),
    DECCASH = DECC for anti-sweat heaters,
    DECCstir_fan = DECC for motors used to drive air mixing fans, 
and
    DECCother = DECC for other electricity consuming devices.

    (a) Calculate DECCnon-glass as follows:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.075
    
    [GRAPHIC] [TIFF OMITTED] TP04JA10.076
    
    [GRAPHIC] [TIFF OMITTED] TP04JA10.077
    
Where:

Qcond,non-glass = conduction load due to non-glass surface area,
Qcond,glass,wall = conduction load due to glass wall and inset 
window surface area,
Qcond,glass,door = conduction load due to glass door surface area,
Qinfilt = load due to steady-state infiltration,
Anon-glass,tot = total non-glass surface area,
Aglass,wall,tot = total glass wall and inset window surface area,
Aglass,door,tot = total glass door surface area,
EER = energy efficiency ratio for freezer or cooler, as described 
3.3(b)

    (b) Calculate DECCglass,door as follows:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.078
    
    [GRAPHIC] [TIFF OMITTED] TP04JA10.079
    
    [GRAPHIC] [TIFF OMITTED] TP04JA10.080
    
Where:

Qcond,non-glass = conduction load due to non-glass surface area,
Qcond,glass,wall = conduction load due to glass wall and inset 
window surface area,
Qcond,glass,door = conduction load due to glass door surface area,
Qinfilt = load due to steady-state infiltration,
Anon-glass,tot = total non-glass surface area,
Aglass,wall,tot = total glass wall and inset window surface area,
Aglass,door,tot = total glass door surface area,
EER = energy efficiency ratio for freezer or cooler, as described 
3.3(b)

    (c) Calculate DECCglass,wall as follows:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.081
    
    [GRAPHIC] [TIFF OMITTED] TP04JA10.082
    
    [GRAPHIC] [TIFF OMITTED] TP04JA10.083
    
Where:
Qcond,non-glass = conduction load due to non-glass surface area,
Qcond,glass,wall = conduction load due to glass wall and inset 
window surface area,
Qcond,glass,door = conduction load due to glass door surface area,
Qinfilt = load due to steady-state infiltration,
Anon-glass,tot = total non-glass surface area,
Aglass,wall,tot = total glass wall and inset window surface area,
Aglass,door,tot = total glass door surface area,
EER = energy efficiency ratio for freezer or cooler, as described 
3.3(b)


[[Page 218]]


    (d) Compute DECCglass in an identical manner to DECCglass,door, 
described above.
    (e) Compute DECCinfilt,disp_dr_opn and DECCdisp_dr_device as 
follows:
[GRAPHIC] [TIFF OMITTED] TP04JA10.084

[GRAPHIC] [TIFF OMITTED] TP04JA10.085

Where:

Qopen,disp_dr = total infiltration load calculated for display door-
opening events, and
EER = energy efficiency ratio for freezer or cooler

    (f) Determine DECCdisp_dr_device as follows:
    (1) For passive infiltration reduction devices (e.g., strip 
curtains), the DECCdisp_dr_device is zero.
    (2) For active infiltration reduction devices (e.g., air 
curtains), DECCdisp_dr_device = Pcomp where Pcomp is determined as 
in section 3.4.1 using the appropriate PTO (percent time off)
    (g) Compute DECCinfilt, non-display_dr_opn and DECC non-display_
dr_device in the same manner as DECCinfilt, disp_dr_opn and 
DECCdisp_dr_device above.
    (h) Compute DECCASH in the following manner:
    [GRAPHIC] [TIFF OMITTED] TP04JA10.086
    
Where:

Pcomp,ASH = total energy consumed by anti-sweat heaters (per section 
3.4.1), and
Adisp-door = total surface area of display doors.


    (i) Compute DECCstir_fan, for stirring (non-evaporator) fans in 
the following manner:
[GRAPHIC] [TIFF OMITTED] TP04JA10.087

Where:

Vref_space = total volume of the refrigerated space (ft \3\), and
Pcomp,stirring_fan = total energy consumed by stir fan(s) (per 
3.4.1).

    (j) Compute DECCother for all other electricity consuming 
devices: For all lights and other electrical loads, Pcomp,j is 
determined per the provisions of the section 3.4.1 and the DECCother 
is obtained by dividing the respective Pcomp,j by Vref_spac.

[FR Doc. E9-30884 Filed 12-31-09; 8:45 am]
BILLING CODE 6450-01-P