[Federal Register Volume 75, Number 174 (Thursday, September 9, 2010)]
[Proposed Rules]
[Pages 55068-55108]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-21364]
[[Page 55067]]
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Part III
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. 174 / Thursday, September 9, 2010 /
Proposed Rules
[[Page 55068]]
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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: Supplemental notice of proposed rulemaking.
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SUMMARY: The U.S. Department of Energy (DOE) previously published a
notice of proposed rulemaking to adopt test procedures for measuring
the energy consumption of walk-in coolers and walk-in freezers,
pursuant to the Energy Policy and Conservation Act (EPCA), as amended.
DOE is continuing to consider those proposals, but is now soliciting
comments on several alternative proposed options. Once any final test
procedure is effective, any representation as to the energy use of
walk-in equipment must reflect the results of testing that equipment
using the test procedure. Concurrently, DOE is undertaking an energy
conservation standards rulemaking for this equipment. If DOE receives
data in this test procedure rulemaking that are pertinent to the
development of standards, it will use that data in evaluating potential
standards for this equipment. Once these standards are promulgated, the
adopted test procedures will be used to determine compliance with the
standards.
DATES: DOE will accept comments, data, and information regarding this
supplemental notice of proposed rulemaking (SNOPR) no later than
October 12, 2010. See section V of this SNOPR for details.
ADDRESSES: Any comments submitted must identify the SNOPR for Test
Procedures for Walk-In Coolers and Walk-In 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, 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 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, 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]; Mr. Michael Kido, U.S. Department of Energy,
Office of General Counsel, GC-71, 1000 Independence Avenue, SW.,
Washington, DC 20585-0121, (202) 586-8145, [email protected]; or
Ms. Elizabeth Kohl, U.S. Department of Energy, Office of General
Counsel, GC-71, 1000 Independence Avenue, SW., Washington, DC 20585-
0121, (202) 586-7796. E-mail: [email protected].
SUPPLEMENTARY INFORMATION:
I. Authority and Background
II. Summary of the Proposal
III. Discussion
A. Overall Issues
1. Definition of Walk-In Cooler or Freezer: Temperature Limit
2. Testing and Compliance Responsibility
3. Basic Model of Envelope
4. Basic Model of Refrigeration Systems
B. Envelope
1. Heat Conduction Through Structural Members
2. Use of ASTM C1303 or EN 13165:2009-02
3. EN 13165:2009-02 as a Proposed Alternative to ASTM C1303-10
4. Version of ASTM C1303
5. Improvements to ASTM C1303 Methodology
6. Heat Transfer Through Concrete
a. Floorless Coolers
b. Pre-Installed Freezer Floor
c. Insulated Floor Shipped by Manufacturer
7. Walk-in Sited Within a Walk-In: A ``Hybrid'' Walk-In
8. U-Factor of Doors and Windows
9. Walk-In Envelope Steady-State Infiltration Test
10. Door Steady-State Infiltration Test
11. Door Opening Infiltration Assumptions
12. Infiltration Reduction Device Effectiveness
13. Relative Humidity Assumptions
C. Refrigeration System
1. Definition of Refrigeration System
2. Version of AHRI 1250
3. Annual Walk-In Energy Factor
IV. Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the National Environmental Policy Act
C. Review Under the Regulatory Flexibility Act
1. Reasons for the Proposed Rule
2. Objectives of and Legal Basis for the Proposed Rule
3. Description and Estimated Number of Small Entities Regulated
4. Description and Estimate of Compliance Requirements
5. Duplication, Overlap, and Conflict With Other Rules and
Regulations
6. Significant Alternatives to the Rule
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. Submitting Public Comment
B. Issues on Which DOE Seeks Comment
1. Upper Limit of Walk-In Cooler
2. Basic Model of Envelope
3. Basic Model of Refrigeration
4. Updates to Standards
5. Heat Conduction Through Structural Members
6. Alternatives to ASTM C1303-10
7. Improvements to ASTM C1303 Methodology
8. Conduction Through Floors
9. ``Hybrid'' Walk-Ins
10. U-Factor of Doors and Windows
11. Envelope Infiltration
12. Relative Humidity Assumptions
13. Definition of Refrigeration System
14. Annual Walk-In Energy Factor
15. 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, in context, ``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),
[[Page 55069]]
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,'' ``walk-ins,'' or ``WICF''), the
subject of this rulemaking. (42 U.S.C 6311(1), (20), 6313(f), and
6314(a)(9))
At its most basic level, the term ``walk-in equipment'' encompasses
enclosed storage spaces of under 3,000 square feet that can be walked
into and are refrigerated to specified temperatures--above 32 degrees
Fahrenheit ([deg]F) for coolers and at or below 32 [deg]F for freezers.
(42 U.S.C. 6311(20)(A)) The term does not include equipment designed
and marketed exclusively for medical, scientific or research purposes.
(42 U.S.C. 6311(20)(B))
Walk-ins that meet this definition 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.
Under the Act, the overall program consists of three parts:
testing, labeling, and Federal energy conservation standards. The
testing requirements consist of test procedures prescribed under the
authority of EPCA. These test procedures are used in several different
ways: (1) DOE uses them to aid in the development of standards for
covered products or equipment; (2) manufacturers of covered equipment
must use them to establish that their equipment complies with standards
promulgated under EPCA and when making representations about equipment
efficiency; and (3) DOE must use them to determine whether equipment
complies with applicable standards.
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. (42 U.S.C. 6314(a)(2)) As part of the process for promulgating
a test procedure, DOE must publish a proposed procedure and offer the
public an opportunity to present oral and written comments in response
to that procedure. DOE solicited comments on the notice of proposed
rulemaking (``NOPR'') setting forth proposed test procedures, published
on January 4, 2010 (``the January NOPR''). 75 FR 186. DOE also held a
public meeting to discuss the January 2010 NOPR on March 24, 2010. DOE
is now soliciting further comment through this SNOPR.
The January NOPR and the March 2010 meeting provided interested
parties an opportunity to submit comments on the proposals. Interested
parties raised significant issues and suggested changes to the proposed
test procedures. DOE determined that some of these comments warrant
further consideration. In today's notice, DOE addresses those comments
and proposes adjustments to the initial test procedures proposed for
walk-in equipment in the January 2010 NOPR.
II. Summary of the Proposal
DOE is proposing several changes to the proposal presented in the
January NOPR. These changes involve:
(1) Definition of walk-in cooler and walk-in freezer.
(2) Testing and compliance responsibility.
(3) Versions of standards incorporated by reference.
(4) Basic model for envelope.
(5) Basic model for refrigeration system.
(6) Conduction through structural members.
(7) Alternatives to ASTM C1303.
(8) Heat transfer through concrete.
(9) U-factor of glass and non-glass doors.
(10) Steady-state infiltration through panel interfaces and doors.
(11) Door opening infiltration assumptions.
(12) Infiltration reduction device effectiveness.
(13) Relative humidity assumptions.
(14) Definition of refrigeration system.
(15) Annual walk-in energy factor.
Concurrently, DOE is undertaking an energy conservation standards
rulemaking to address the statutory requirement to establish
performance standards for walk-in equipment no later than January 1,
2012. (42 U.S.C. 6313(f)(4)(A)) DOE will use the test procedure in the
concurrent process of evaluating potential performance standards for
the equipment. After performance standards become applicable,
manufacturers must use the test procedures to determine compliance with
the standards, and DOE must use the test procedure to ascertain
compliance with the standards in any enforcement action. Moreover, once
any final test procedure is effective, any representation as to the
energy use of walk-in equipment must reflect the results of testing
that equipment using the test procedure.
III. Discussion
This section addresses issues raised by interested parties in
response to the January NOPR and provides detail regarding DOE's
proposed changes to the test procedure. Interested parties include
trade associations (American Chemistry Council/Center for the
Polyurethanes Industry (ACC/CPI), AHRI); manufacturers of the covered
equipment (Craig Industries, Metl-Span, Nor-Lake, Carpenter, Master-
Bilt, American Panel Corporation, Arctic Industries, Amerikooler,
Kason, Hill Phoenix, TAFCO/TMP (TAFCO), International Cold Storage
(ICS), ThermalRite, Manitowoc, Kysor Panel, HeatCraft, and Crown
Tonka); suppliers of components used in the covered equipment
(Honeywell, BASF, Dyplast, ITW Insulation, Owens Corning, HH
Technologies (Hired Hand), Dow Chemical, and Schott Gemtron); utilities
(Southern California Edison (SCE), San Diego Gas and Electric (SDGE),
and the Sacramento Municipal Utility District (SMUD)); and energy
efficiency advocates (American Council for an Energy-Efficient Economy
(ACEEE)).
A. Overall Issues
1. Definition of Walk-In Cooler or Freezer: Temperature Limit
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))
During the public meeting on the January NOPR and in written
comments, several interested parties stated that DOE should clarify
this definition with respect to temperature limits and exclusions.
Multiple interested parties commented that DOE
[[Page 55070]]
should set an upper temperature limit for walk-ins. Three temperature
limits were proposed: (1) 40 or 41 [deg]F; (2) 45 [deg]F; and (3)
between 31 [deg]F and 55 [deg]F. Kysor stated that DOE should align
with the National Sanitation Foundation (NSF) definition of 41 [deg]F
as the maximum high temperature for food storage. (Kysor, Public
Meeting Transcript, No. 1.2.010 at p. 85) ICS agreed with Kysor but
cautioned that this temperature could be different from the temperature
set by the customer. (ICS, Public Meeting Transcript, No. 1.2.010 at p.
86)
In written comments, Kysor also suggested 40 [deg]F as the upper
limit because NSF/ANSI Standard 7, ``Commercial Refrigerators and
Freezers'' uses such a requirement. See NSF/ANSI Standard 7,
``Commercial Refrigerators and Freezers,'' Section 6.10.1,
``Performance (``Storage refrigerators and refrigerated food transport
cabinets shall be capable of maintaining an air temperature of 40
[deg]F (4 [deg]C) or lower in the interior.'') (Kysor, No. 1.3.035 at
p. 1) Craig and Hired Hand both indicated that 45 [deg]F or 41 [deg]F
would be an acceptable upper limit. (Craig, Public Meeting Transcript,
No. 1.2.010 at p. 86; Craig, No. 1.3.017 at p. 1 and Public Meeting
Transcript, No. 1.2.010 at p. 19; Hired Hand, Public Meeting
Transcript, No. 1.2.010 at p. 88) A comment submitted jointly by SCE,
SDGE, and SMUD, hereafter referred to collectively as ``the Joint
Comment,'' recommended that DOE develop a definition to clarify that
walk-in coolers operate at temperatures between 55 [deg]F and 32
[deg]F. (Joint Comment, No. 1.3.019 at p. 17) SCE pointed out that
California's building energy standards consider 55 [deg]F and below to
be refrigerated. (SCE, Public Meeting Transcript, No. 1.2.010 at p. 85)
TAFCO agreed that DOE should impose an upper limit of 55 [deg]F because
this is the highest temperature at which most refrigeration systems
will operate. (TAFCO, No. 1.3.022 at p. 1) Craig disagreed with a 55
[deg]F limit because this temperature is the typical holding
temperature for wine coolers, but the walk-in wine cooler might be
rated at a lower temperature. (Craig, Public Meeting Transcript, No.
1.2.010 at p. 86) DOE infers from the comment that Craig was concerned
that the energy consumption of a wine cooler at the test procedure
rating temperature might not represent the energy consumption at the
actual holding temperature. Hired Hand stated that air conditioning is
the first stage of cooling for walk-ins inside air-conditioned
warehouses, which echoed the concerns of other commenters that the
complete absence of an upper temperature limit might inadvertently
include a wider variety of conditioned spaces than contemplated. (Hired
Hand, Public Meeting Transcript, No. 1.2.010 at p. 87)
EPCA defines walk-in equipment, in part, as meaning a space that is
``refrigerated,'' and as having a ``chilled storage area.'' (42 U.S.C.
6311(20)) DOE proposes clarifying the term ``refrigerated'' within the
statutory definition to distinguish walk-in equipment from air-
conditioned storage spaces. DOE could not find a consensus among the
industry for the definition of ``refrigerated'' or ``chilled storage.''
However, the Joint Comment, SCE, and TAFCO suggested that 55 [deg]F
represented a boundary between ``refrigerated space'' and ``conditioned
space'' as refrigeration systems typically do not operate above 55
[deg]F, and air-conditioning systems typically do not operate below
this limit. DOE found that preparation rooms, wine coolers, and storage
coolers for most fruits and vegetables are considered refrigerated
spaces and are typically cooled to temperatures between 45 [deg]F and
55 [deg]F. DOE proposes adopting a clarifying definition that would set
an upper limit of 55 [deg]F for walk-in equipment. DOE believes that
using the upper limit of food storage temperatures (i.e., 40 [deg]F or
45 [deg]F) to define walk-in equipment, as suggested by some
commenters, would exclude some equipment that is ``refrigerated'' and
has a ``chilled storage area.'' Such an approach would, in DOE's view,
exclude from coverage equipment that falls within the statutorily-
prescribed scope of EPCA's walk-in definition. The space in which a
walk-in is located (e.g., a grocery store, warehouse, or other
conditioned space) would not itself be considered a walk-in unless it
meets the statutory definition of a walk-in and DOE's proposed
clarifying definition that would set an upper limit on the temperature
range. DOE requests comment on its proposal of clarifying
``refrigerated'' to mean at or below 55 [deg]F.
2. Testing and Compliance Responsibility
In responding to comments received on the framework document, the
January NOPR detailed DOE's proposal to create separate test procedures
for the envelope and the refrigeration system, the two discrete systems
that comprise a walk-in. 75 FR 191. These two systems may or may not
each be manufactured by a separate manufacturing entity. Additionally,
other manufacturers may be involved in producing secondary components--
such as fan assemblies or lighting--that are then incorporated as parts
of the refrigeration system or envelope.
In the January NOPR, DOE proposed that 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. 75 FR 191. DOE believed that the
manufacturers of the envelope and refrigeration systems--as parties
most likely to be intimately familiar with the design and operation of
their own equipment--would be more likely than installers to have the
resources, equipment, and trained personnel needed to conduct the tests
necessary to certify WICF equipment as compliant with any energy
conservation standards that DOE develops. 75 FR 191.
However, interested parties commented that DOE's concept of a
single envelope manufacturer may not align with the actual market.
Commenters suggested that the panel manufacturers, whom DOE assumed
would serve as the envelope manufacturers for purposes of testing
compliance, did not necessarily control the design of the walk-in
envelopes for which their panels were used. Many of the comments from
interested parties suggested that DOE should assign compliance testing
responsibility to parties involved in the physical assembly (e.g.,
installers) and/or design-level specification (e.g., general
contractors) of the walk-in envelope because actions taken by these
parties could have a significant effect on walk-in performance over its
lifetime. Some commenters suggested various forms of joint
responsibility between the manufacturer(s) of the envelope components
and the parties responsible for the physical assembly and/or design-
level specification of the envelope. Other interested parties commented
that these options would not constitute a viable approach and that DOE
should focus on the panel manufacturers for compliance testing because
they would be more likely to have the proper equipment and expertise to
test the panels.
Likewise, interested parties commented that DOE's concept of a
single refrigeration system manufacturer may be inaccurate because the
condensing unit and unit cooler of a single refrigeration system may be
manufactured by separate entities and the whole system may be
manufactured from these separate parts by a third manufacturer.
Commenters generally suggested assigning joint responsibility between
the manufacturer(s) of the unit
[[Page 55071]]
cooler and condensing unit and the manufacturer of the system as a
whole. Others suggested that DOE break a refrigeration system down into
its individual components (e.g., compressor, coils) and regulate each
component separately.
DOE believes that many of the comments concerning compliance
testing responsibility stem from the definition of the term
``manufacture,'' which EPCA defines as ``to manufacture, produce,
assemble or import.'' (42 U.S.C. 6291(10)) Several interested parties
requested clarification of the definition of ``manufacture'' and the
implications of that role. DOE generally requires a single party, whose
role falls under the term ``manufacture,'' to assume compliance
responsibility for a given appliance or equipment; typically, the party
responsible for demonstrating compliance would conduct the necessary
testing or arrange for testing to be conducted by a third party (e.g.,
a testing lab). DOE recognizes that the walk-in envelope and
refrigeration system markets rely on multiple supply chain scenarios in
which several distinct parties could serve different roles that may
fall under the term ``manufacture.'' In the case of both walk-in
envelopes and refrigeration systems, DOE recognizes that assigning
compliance responsibility to a single entity that may not be involved
in all aspects of the design and construction of these systems may
present certain logistical issues. Accordingly, DOE plans to further
address these issues during the standards rulemaking when developing
the required efficiency levels and when developing certification and
compliance responsibilities.
3. Basic Model of Envelope
Although often manufactured according to the same basic design,
many walk-in envelopes can be highly customized. To address this
possibility, DOE proposed the following approach in the January NOPR:
(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. For walk-in envelopes, DOE
proposed to define a ``basic model'' as ``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.'' 75 FR
189.
Master-Bilt, BASF, ACC/CPI, Craig, Kason, and ThermalRite supported
the concept of the basic model for WICF envelopes. (Master-Bilt, No.
1.3.009 at p. 1; BASF, No. 1.3.003 at p. 3; ACC/CPI, No. 1.3.006 at p.
2 and No. 1.3.028 at p. 1; Craig, Public Meeting Transcript, No.
1.2.010 at p. 102; Kason, No. 1.3.037 at p. 1 and Public Meeting
Transcript, No. 1.2.010 at p. 124; and ThermalRite, No. 1.3.031 at p.
1) Craig supported an approach consisting of a single basic model test
on a baseline model and adding component loads. (Craig, Public Meeting
Transcript, No. 1.2.010 at p. 123) Kason stated that the basic model
test should include provisions at the component level, where
manufacturers could pick new components as long as the components were
certified to exceed the performance of the old components. (Kason,
Public Meeting Transcript, No. 1.2.010 at p. 124) Kysor and Nor-Lake
both believed that the concept of the basic model may not be realistic
if envelope components such as doors and lights were not purchased or
installed by the panel manufacturers; in that case, Kysor and Nor-Lake
stated that component manufacturers should be responsible for rating
individual components. (Nor-Lake, No. 1.3.029 at p. 2; Kysor, No.
1.3.035 at p. 2) Arctic proposed expanding the basic model concept to
eliminate testing for units using the same materials and construction
methods as a previously certified model, adding that it would be
impractical and infeasible for them to test every kind of equipment
they manufacture because of the great variety of box dimensions.
(Arctic, No. 1.3.012 at p. 1) BASF and Kason also stated that
manufacturers must be able to reduce the number of models to test to
ensure minimal manufacturer burden. (BASF, No. 1.3.003 at p. 3 and
Kason, No. 1.3.037 at p. 1)
Other interested parties disagreed with the proposed basic model
approach. Bally stated that the company produces tens of thousands of
basic models, making basic model testing infeasible. (Bally, Public
Meeting Transcript, No. 1.2.010 at p. 132) Hill Phoenix believed that
use of a basic model for testing would not accurately represent the
energy usage of most walk-ins because of equipment variability, that an
energy usage calculation program would have to be created and
maintained and be consistent across the industry, and that basic model
testing would require costly government oversight. Instead, Hill
Phoenix recommended component-level modeling. (Hill Phoenix, No.
1.3.023 at p. 2)
Several interested parties requested clarification of the proposed
definition of basic model. ACC/CPI and Honeywell recommended that
different types of foam and/or different blowing agents should trigger
different basic models (ACC/CPI, No. 1.3.006 at p. 2 and Public Meeting
Transcript, No. 1.2.010 at p. 43; Honeywell, No. 1.3.020 at p. 1)
Honeywell also recommended that a different facer material should
trigger a new basic model. (Honeywell, No. 1.3.020 at p. 1) Owens
Corning stated that the insulation material should not trigger a new
basic model because the R-value of the insulation is addressed in EISA
and that panel construction (framed or frameless) should be used to
differentiate between basic models. (Owens Corning, No. 1.3.030 at p.
2) ICS stated that different applications should constitute different
basic models: holding storage, quick chilling or freezing, or blast
freezing. (ICS, No. 1.3.027 at p. 1) TAFCO commented that the use of
strip curtains or air curtains should not constitute a new basic model.
(TAFCO, No. 1.3.022 at p. 2)
Other interested parties requested that DOE specify standard
characteristics for a certain basic unit that every manufacturer would
test. American Panel, ThermalRite, and Craig recommended that DOE
specify a standardized basic model size. (American Panel, No. 1.3.024
at p. 2; ThermalRite, No. 1.3.031 at p. 1; Craig, Public Meeting
Transcript, No. 1.2.010 at pp. 102, 106, and 119) Craig suggested a
basic size applicable to the food industry--an 8 foot x 10 foot cooler
and a 6 foot x 8 foot freezer, both with a height of 7 feet 6 inches
tall--and added that size would only be applicable to the infiltration
test because other characteristics could be calculated. (Craig, Public
Meeting Transcript, No. 1.2.010 at p. 105 and No. 1.2.010 at pp. 102,
106, and 119) Kysor suggested that only height could be specified,
arguing that walk-ins cannot be characterized by size. (Kysor, Public
Meeting Transcript, No. 1.2.010 at p. 106)
Finally, interested parties commented on the proposed scaling
methodology associated with the basic model concept. Manitowoc stated
that a scaling methodology based on surface area would not give an
accurate representation of energy use because energy scales not only
with surface area but with other factors as well such as the number of
installed doors and door size. In other words, individual component
loads scale with individual component characteristics. (Manitowoc,
[[Page 55072]]
Public Meeting Transcript, No. 1.2.010 at p. 108) ThermalRite also
questioned whether there is a linear relationship between energy
consumption and WICF size that would allow for scaling. (ThermalRite,
Public Meeting Transcript, No. 1.2.010 at p. 110)
Upon consideration of these comments, DOE believes that the basic
model concept would provide manufacturers with a standardized method of
categorizing their products. However, the definition of basic model
proposed in the January NOPR could make the concept difficult to use as
originally intended to reduce testing burden. Specifically, the phrase
``* * * characteristics that significantly affect the energy
consumption * * *'' could be interpreted inconsistently by
manufacturers. The paragraphs below describe DOE's proposed alternative
approach to defining the term ``basic model''. Additionally, feedback
from interested parties indicated a desire for DOE to specify
prescriptive design characteristics for a basic model. Because EPCA
requires DOE to promulgate performance-based standards for this
equipment, DOE does not intend to specify design characteristics that
do not affect normalized energy consumption, as suggested by ACC/CPI,
Honeywell, Owens Corning, ICS and TAFCO. See 42 U.S.C. 6313(f)
(instructing DOE to set performance-based standards for walk-ins).
DOE is considering adopting a revised definition of the term
``basic model'' that would be consistent with the definition of basic
model used elsewhere in the appliance standards program, improve the
clarity of the definition, and narrow the scope of the basic model
concept. Most notably, this revision would not allow walk-in models to
differ in terms of their normalized energy consumption. Models grouped
within a basic model could still differ in terms of their non-energy
characteristics (e.g., color, shelving, metal skin material type,
exterior finish, door kick-plate) but any change to a characteristic
that affects normalized energy consumption (e.g., panel systems, door
systems, electrical components, and infiltration reduction devices)
would constitute a new basic model.
DOE's proposed revision, while reducing the possibility of
inconsistent interpretation of the term ``basic model'', could increase
the testing burden relative to the burden under the definition of
``basic model'' as proposed in the January NOPR. Some of the burden may
be offset, however, by burden-reducing measures proposed elsewhere in
the test procedure. These measures include incorporating scaling
factors for the infiltration test (section III.B.9), the panel U-factor
test (section III.B.1), and representative doorway sizes for
infiltration reduction device testing. With these measures, DOE
attempts to minimize the number of physical tests that would need to be
performed for the test procedure and instead provide a calculation
methodology that would allow for rating equipment based on physical
tests conducted on other equipment. DOE believes that this approach
would sufficiently address the concerns of BASF, Kason, Arctic, Bally,
and Hill Phoenix regarding the number of basic models to be tested and
the cost of testing. A DOE-specified calculation methodology would also
address Hill Phoenix's recommendation that the energy use calculation
program be consistent across the industry. Regarding Arctic's view that
the basic model concept should be expanded to include similar units
with the same materials and construction methods that have been
previously certified, DOE notes that models with the same
characteristics as previously certified models would be considered the
same basic model only if they met the conditions in the basic model
definition. In other words, the models would need to have the same
manufacturer and not have any differing characteristics that affect
normalized energy consumption.
The proposed test procedure revisions considered in this SNOPR also
rely more heavily on component testing, consistent with the suggestions
made by Craig, Kason, Kysor, Nor-Lake, and Hill Phoenix. This approach
removes the burden of testing an entire walk-in for which only one
component is different from a previously rated walk-in: the test
procedure revisions in this SNOPR would allow for testing the new
component and then using the proposed calculation methodology to obtain
the new rating of the walk-in. Additionally, the proposed component
tests allow for testing one component and then applying those results
to other components that meet certain similar criteria. DOE believes
this method is more accurate than allowing for scaling of the entire
walk-in, because each walk-in could contain many customized parts.
Adopting this method would address the concerns raised by Manitowoc and
ThermalRite that energy may not scale directly with walk-in external
surface area or other size characteristics. For some proposed component
tests, DOE specifies characteristics of the part that must be
physically tested (i.e., the geometry of a panel test sample), instead
of specifying characteristics of the tested walk-in unit as a whole as
suggested by American Panel, ThermalRite, Craig, and Kysor, because (1)
complete walk-in units may be very different from one another even if
they use similar components, and (2) the scaling calculations are more
accurate on the component level than on the level of the entire walk-
in, which supports testing certain components as part of the compliance
procedure. For additional details on these proposed component tests,
see section III.B.
With respect to certification, in general, DOE requires that
manufacturers of a covered basic model submit a certification report
providing details, which demonstrate compliance with the applicable
energy conservation standards or design standards prescribed by DOE or
established by Congress. DOE estimates that approximately 50 percent of
the market consists of standardized walk-ins that are produced in large
quantities. For the other half of the market, walk-ins may have custom
features and components that could qualify each as a different basic
model. In this situation, manufacturers could produce many basic models
in a year.
DOE is unsure, however, how burdensome this would be in terms of
the actual number of hours or personnel required to certify additional
basic models under this approach. If requiring a certification report
for each basic model under the approach outlined in today's SNOPR would
impose an unreasonable burden, DOE may consider a compliance
certification approach similar to that taken for distribution
transformers (another case in which some equipment is highly
customized). 10 CFR 431.371(a)(6)(ii). Distribution transformer
manufacturers are required to maintain records on all basic models sold
(or built), but must submit a compliance report to DOE that certifies
only the least efficient basic model within larger groupings that may
encompass many basic models. 10 CFR 431.371(a)(6)(ii). The manufacturer
would certify that every other transformer in the larger grouping is no
less efficient than the certified basic model certified to DOE. Given
the nature of the market, DOE is willing to consider variations on this
approach for walk-ins, such as requiring certification for the least
and most efficient basic models within a larger group. Such an approach
could help address the concern of Hill Phoenix about the cost of an
oversight strategy.
[[Page 55073]]
DOE requests comment on its proposed definition and approach
regarding basic models for envelopes.
4. Basic Model of Refrigeration Systems
In the January NOPR, DOE proposed that the definition of the term
``basic model'' in the context of a refrigeration system would refer to
all units with the same energy source and without any different
electrical, physical, and functional characteristics that affect energy
consumption. DOE then stated during the NOPR public meeting that it was
considering a new definition that would not allow units within a basic
model to differ in energy consumption. DOE also stated during the
public meeting that it would consider the default of including no
provision for a basic model, under which manufacturers would be
required to test every model they manufacture.
AHRI and ACEEE agreed with DOE's proposed approach and definition
of basic model. (AHRI, No. 1.3.032 at p. 2 and Public Meeting
Transcript, No. 1.2.010 at p. 169; ACEEE, No. 1.3.034 at p. 2) Craig
also agreed with the proposed approach given that improvements could be
applied to existing systems. (Craig, Public Meeting Transcript, No.
1.2.010 at p. 172) ICS, Manitowoc, and HeatCraft recommended that the
basic model of refrigeration be allowed to vary minimally (a 5 percent
tolerance) in energy consumption, while HeatCraft also stated that in
Europe, the tolerance is typically 8 percent. (ICS, No. 1.3.027 at p.
1; Manitowoc, Public Meeting Transcript, No. 1.2.010 at p. 159; and
HeatCraft, Public Meeting Transcript, No. 1.2.010 at p. 162) On the
other hand, Master-Bilt expressed concern that too many refrigeration
system combinations may exist for the basic model concept to be applied
effectively. (Master-Bilt, No. 1.3.009 at p. 1) HeatCraft stated that
it was concerned about testing highly variable refrigeration systems
and combinations, and whether they would be able to incorporate new
technologies. (HeatCraft, Public Meeting Transcript, No. 1.2.010 at p.
42) Nor-Lake was also concerned about the potential testing burden
because it has distinct energy efficiency ratio values on over 250
models. It recommended either defining basic model to account for how
many basic models a manufacturer would have or to replace the basic
model approach with a component-based one. (Nor-Lake, No. 1.3.005 at
pp. 2 and 5 and No. 1.3.029 at p. 2) Manitowoc suggested considering a
unit cooler its own basic model (not the combination of unit cooler and
condensing unit), making it unnecessary to test all combinations but
only individual parts of the system. (Manitowoc, Public Meeting
Transcript, No. 1.2.010 at p. 158)
TAFCO identified refrigeration system components that, if changed,
would significantly affect energy consumption. These components include
the compressor, condensing coil, fan motors, head pressure control, and
evaporator coil. (TAFCO, No. 1.3.022 at p. 2) American Panel added that
headmasters (which control pressure) must be included on outdoor
condensing units if the unit will be exposed to low temperatures.
(American Panel, No. 24 at p. 3) Some interested parties discussed
whether DOE should specify certain characteristics of the basic model.
Specifically, HeatCraft stated that the basic model should include some
common parts such as a filter dryer to permit a valid comparison
between manufacturers, but manufacturers should be allowed to add
unique features. (HeatCraft, Public Meeting Transcript, No. 1.2.010 at
p. 162) ACEEE agreed that the basic model should include parts that
have a reasonable probability of affecting energy consumption to
encourage manufacturers to include all necessary components in their
WICF equipment. (ACEEE, Public Meeting Transcript, No. 1.2.010 at p.
168) AHRI disagreed, stating that DOE should not specify design
requirements in defining basic model groups, but rather agreed with
DOE's proposed definition. (AHRI, Public Meeting Transcript, No.
1.2.010 at p. 169) (Although ACEEE did not elaborate further on what it
considers ``all necessary components,'' DOE is interpreting this phrase
as referring to any components that would be needed to have the unit
work in a manner as designed without the addition of aftermarket
components that would impact the equipment's energy usage.)
As with envelopes, DOE must ensure that all refrigeration systems
are accurately rated and comply with the standard. To avoid differing
interpretations of what a ``significant difference'' in energy
consumption might be, DOE believes that it is appropriate to clarify
certain aspects of that definition to eliminate differences in the
measured energy consumption of models belonging to the same basic model
group. Accordingly, DOE proposes a revised definition of basic model of
refrigeration where units cannot differ in electrical, physical, or
functional characteristics that affect energy consumption. DOE
recognizes that the components identified by TAFCO affect the energy
consumption of the refrigeration system. Nevertheless, DOE believes
that listing only certain components where changes would constitute a
new basic model could overlook changes to other components that affect
energy consumption. In addition, the question of significance would
remain under such an approach. DOE believes that the definition
proposed here is sufficient to define basic model--a basic model would
necessarily have to include all components that affect energy
consumption.
DOE also acknowledges the concerns of interested parties,
specifically Master-Bilt, HeatCraft, and Nor-Lake, that a manufacturer
could produce many condensing unit and unit cooler combinations--i.e.,
many basic models --and that testing could be burdensome. DOE notes
that the proposed refrigeration system test procedure, AHRI 1250-2009,
allows for testing the condensing unit and unit cooler separately and
then, using the calculation methodology in AHRI 1250-2009, determining
the performance of the combined system, similar to the approach
suggested by Manitowoc. Under this approach, each combination would not
have to be tested, which would decrease the number of physical
equipment tests, even though each different combination would be
considered a different basic model and would receive a different
rating.
At this time, DOE does not intend to incorporate a tolerance into
the definition of basic model, as suggested by ICS, Manitowoc, and
HeatCraft, in order to ensure that the rating applying to each basic
model is as accurate as possible. DOE notes that one potential issue
with introducing a tolerance approach may be that neither DOE nor the
eventual purchaser of the equipment could expect that the rating of a
particular model would be equal to that model's actual energy
consumption. It is unclear to DOE how significant this issue may be if
such an approach were adopted.
DOE acknowledges, however, that units within a basic model are
expected to differ slightly as a result of manufacturing and materials
variations. As a result, DOE may consider accounting for these
variations in sampling plans used for compliance testing and developed
as part of any future certification and enforcement rulemaking. DOE's
existing compliance and certification regulations, developed for
certain other commercial equipment, provide that when a random sample
of equipment is taken for determining compliance with the standard for
commercial refrigeration equipment,
[[Page 55074]]
represented values of estimated energy consumption of a basic model
shall be no less than the higher of the mean of the test sample or the
upper 95 percent confidence limit of the true mean divided by 1.10. 75
FR 652, 666-71 (Jan. 5, 2010), codified at 10 CFR 431.372. This rule
also provides that, in enforcement proceedings, DOE's determination
that a basic model complies with the standard is based on a confidence
limit which accounts for statistical variation within a basic model. 75
FR 674, codified at 10 CFR part 431, Appendix D to Subpart T.
These sampling provisions are only intended to reduce the burden on
manufacturers associated with certification and enforcement.
Manufacturers would still be required to use the test procedure to rate
their equipment and, once energy conservation standards take effect, to
determine whether each basic model of the equipment they manufacture
complies with the standard.
As discussed above for envelopes, DOE could consider a compliance
certification approach similar to that taken for distribution
transformers (another case in which some equipment is highly
customized) to reduce the burden while ensuring that the energy
conservation standards are being met. 10 CFR 431.371(a)(6)(ii). DOE
describes this approach in detail in section III.A.3.
DOE requests comment on the definition of and approach to basic
model of refrigeration systems.
B. Envelope
The envelope consists of the insulated box in which items are
stored and refrigerated. To meet one element of the statutory
requirement that the DOE test procedure ``measure the energy use'' of
walk-ins (42 U.S.C. 6314(a)(9)(B)(i)), DOE had proposed to incorporate
a metric for the energy use associated with the envelope of a walk-in
cooler or walk-in freezer. Under the applicable EPCA definition of
``energy use''--the amount of energy directly consumed by a piece of
equipment at the point of use (42 U.S.C. 6311(4))--DOE has tentatively
determined that the energy use of a walk-in envelope is the sum of (1)
the electrical energy consumption of envelope components and (2) other
energy consumption of the walk-in equipment resulting from the heat
transfer performance of the envelope.
The proposed envelope test procedure contains methods for
evaluating the performance characteristics of insulation, testing
thermal energy gains related to air infiltration and determining direct
electricity use and heat gain due to internal electrical components.
The proposed procedure uses data obtained from these methods to
calculate a measure of energy use associated with the envelope by
calculating the effect of the envelope's characteristics and components
on the energy consumption of the walk-in as a whole. These
characteristics and components would include 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 would be determined by calculating the energy
consumption of a theoretical or ``nominal'' refrigeration system if it
were paired with the tested envelope. The test procedure uses the same
nominal refrigeration system efficiency for all tested envelopes to
allow for direct comparison of the performance of walk-in envelopes
across a range of sizes, product classes, and levels of feature
implementation.
1. Heat Conduction Through Structural Members
In the January NOPR, DOE proposed that the long-term thermal
resistance (LTTR) value of the insulating foam after 5 years of
equivalent aging be determined using ASTM C1303-08, ``Standard Test
Method for Predicting Long-Term Thermal Resistance of Closed-Cell Foam
Insulation.'' This value would be used as the R-value for all non-glass
envelope sections constructed with foam insulation, for purposes of
calculating the energy consumption of the walk-in. Other components of
the panel, such as structural members, were not included in the
conduction calculations of the test procedure.
Craig, Owens Corning, and American Panel pointed out that
conduction through structural members must be considered when
determining the R-value of a composite walk-in insulation panel.
(Craig, No. 1.3.036 at p. 3 and Public Meeting Transcript, No. 1.2.010
at pp. 20 and 61; Owens Corning, Public Meeting Transcript, No. 1.2.010
at p. 56; and American Panel, No. 1.3.024 at p. 3) The Joint Comment
recommended that the current R-value requirement for the foam be
converted to an overall U-factor requirement for the assembled panel.
(Joint Comment, No. 1.3.019 at p. 11) (U-factor is a measure of heat
transmission, including conduction and radiation. A lower U-factor
indicates a lower rate of heat transmission.) Metl-Span, BASF, Kysor,
and ACC/CPI agreed with the approach of determining the performance of
the panel as a whole and recommended that DOE use ASTM C1363-05,
``Standard Test Method for Thermal Performance of Building Materials
and Envelope Assemblies by Means of a Hot Box Apparatus,'' for
evaluating the fully assembled panel. (Metl-Span, No. 1.3.004 at p. 1;
BASF, No. 1.3.003 at p. 2; Kysor, No. 1.3.035 at p. 2; ACC/CPI, No.
1.3.006 at p. 2)
In view of these comments, DOE proposes to account for conduction
through structural members, as urged by Craig and American Panel, by
measuring the overall U-factor of fully assembled panels as recommended
by the Joint Comment. All panels (walls, ceiling, and floor) would be
tested using ASTM C1363-05 for measuring the overall U-factor of fully
assembled panels, as stated by Metl-Span, BASF, Kysor, and ACC/CPI. The
resulting composite panel U-factor from ASTM C1363-05 would then be
corrected using the LTTR results from ASTM C1303-10, if foam is used as
the primary insulating material. See section 3.1.6 of Appendix A for
details. DOE believes using the results from ASTM C1363-05 modified by
ASTM C1303-10 best captures the effect of structural members and long-
term R-value of foam products.
DOE recognizes the burden involved when testing an entire
representative walk-in using ASTM C1363-05; i.e., requiring a
representative walk-in composed of 18 panels to be tested 18 times. DOE
also notes that testing a single representative panel would be less
burdensome but very inaccurate. Panels are often manufactured in
dimensions close to 8 feet long by 4 feet wide, but panel geometry
frequently deviates from this size as walk-ins are made larger. In
addition, structural members are normally placed in the perimeter of
panels (if used at all). Therefore, the heat transfer of a given panel
is most closely related to the ratio of perimeter structural materials
to non-perimeter core panel materials.
If DOE were to require an ASTM C1363-05 test using only one panel
size, the test would be representative of only this single perimeter-
to-core ratio. If a walk-in were constructed of panels that deviated
from this representative size in either extreme (i.e., much smaller or
larger), the resulting energy calculations could be inaccurate. To
balance the competing interests of minimizing burden while ensuring
measurement accuracy, DOE is proposing to specify two test regions of a
pair of representative panels. At one test region, the tester would
measure the U-
[[Page 55075]]
factor of the perimeter and panel-to-panel interface area (``Panel
Edge''), while at the other region the tester would measure the U-
factor of the core area of the panel (``Panel Core''). The details of
this procedure are described in section 4.1.1 of Appendix A.
DOE seeks comment on the use of ASTM C1363-05 for this portion of
the test procedure.
2. Use of ASTM C1303 or EN 13165:2009-02
In the January NOPR, DOE proposed using ASTM C1303-08, ``Standard
Test Method of Predicting Long Term Thermal Resistance of Closed-Cell
Foam Insulation,'' to determine the long-term R-value of foam
insulations used in walk-ins. 75 FR 194. (That test method has since
been updated to ASTM C1303-10, which, as discussed in section III.B.4,
DOE is now proposing to adopt as part of this test procedure. All
references to ASTM C1303 in today's notice refer to the ASTM C1303-10
version of the protocol.) As discussed later in section III.B.3, DOE
also proposes, in the alternative, the use of EN 13165:2009-02 (a
European-developed material standard), and seeks comment on the use of
these procedures.
DOE recognizes that R-value decline occurs over time in unfaced and
permeably faced foams. In the published January NOPR, DOE cited a body
of research indicating that R-value decline also occurs in foams with
impermeable facers because the metal skins delay, but do not prevent,
R-value decline because the panel edges are unprotected. DOE recognized
that using ASTM C1303-10 would require testing foams without their
metal facers because the test procedure was designed for unfaced or
permeably faced foams. In the published NOPR and at the NOPR public
meeting, DOE requested that interested parties submit data related to
using ASTM C1303-10 for walk-ins.
DOE received many comments related to ASTM C1303-10. Supporting
documents submitted during the comment period are listed in the table
below and identified with reference numbers. DOE conducted further
research and identified additional documents that provide information
on the use of ASTM C1303-10. These are also listed in the table below
with reference numbers preceded by ``DOE.''
Table III.1--Research Cited by Interested Parties and by DOE
----------------------------------------------------------------------------------------------------------------
Commenter Paper Citation Ref. No.
----------------------------------------------------------------------------------------------------------------
ACC/CPI.................................................... SPI Polyurethane Division k Factor 1
Task Force, ``Rigid Polyurethane
and Polyisocyanurate Foams: An
Assessment of Their Insulating
Properties,'' Proceedings of the
SPI 31st Annual Technical/
Marketing Conference, Oct. 18-21,
1988 Philadelphia, PA. pp. 323-327.
ACC/CPI, Carpenter, Honeywell.............................. Wilkes, K. E., Yarbrough, D.W., 2
Nelson, G. E., Booth, J. R.,
``Aging of Polyurethane Foam
Insulation in Simulated
Refrigerator Panels--Four-Year
Results with Third-Generation
Blowing Agents'', The Earth
Technologies Forum, Washington,
DC, April 22-24, 2003.
ACC/CPI, Honeywell......................................... Norton, F.J., ``Thermal 3
Conductivity and Life of Polymer
Foams'', Journal of Cellular
Plastics, 1967, pp. 23-37.
ACC/CPI, Honeywell......................................... Shankland, I. R. ``Blowing Agent 4
Emissions from Insulation Foam'',
Polyurethanes World Congress 1991
pp. 91-98.
Dow........................................................ Oertel, Dr. Gunter, Polyurethane 5
Handbook, p. 256.
Dow........................................................ Ottens et al., ``Industrial 6
Experiences with CO2 Blown.
Polyurethane Foams in the
Manufacture of Metal Faced
Sandwich Panels,'' Polyurethane
World.
Congress '97'......................
Dow........................................................ Bertucelli et al., ``Phase-Out of 7
Ozone Depleting Substances in the
Manufacture of Metal Faced
Sandwich Panels with Polyurethane
Foam Core,'' Utech Asia '99'.
Owens Corning.............................................. The Role of Barriers in Reducing 8
the Aging of Foam Panels by Leon
R. Glicksman.
Dow........................................................ European standard EN 13165......... 9
DOE........................................................ Wilkes, K. E., Yarbrough, D. W., DOE 1
Nelson, G. E., Booth, J. R.,
``Aging of Polyurethane Foam
Insulation in Simulated
Refrigerator Panels--Four-Year
Results with Third-Generation
Blowing Agents,'' The Earth
Technologies Forum Conference
Proceedings, 2003.
DOE........................................................ Paquet, A., Vo C., ``An Evaluation DOE 2
of the Thermal Conductivity of
Extruded Polystyrene Foam Blown
with HFC-134a and HCFC-142b,''
Journal of Cellular Plastics,
Volume 40, May 2004.
DOE........................................................ Federal Trade Commission, DOE 3
``Labeling and Advertising of Home
Insulation: Trade Regulation Rule;
Final Rule,16 CFR Part 460,''
Federal Register/Vol. 70, No. 103/
Tuesday, May 31, 2005.
DOE........................................................ Roe, Richard, ``Long-Term Thermal DOE 4
Resistance (LTTR): 5 Years Later''
RCI-057-Interface, March 2007.
DOE........................................................ Stovall, Therese, ``Measuring the DOE 5
Impact of Experimental Parameters
upon the Estimated Thermal
Conductivity of Closed-Cell Foam
Insulation Subjected to an
Accelerated Aging Protocol: Two-
Year Results, Journal of ASTM
International, Vol. 6, No. 5 Paper
ID JAI102025, April 2009.
DOE........................................................ Kalinger, P., and Drouin, M. (Johns DOE 6
Manville), ``Closed Cell Foam
Insulation: Resolving the issue of
thermal performance,'' October/
November 2001.
DOE........................................................ Mukhopadhyaya, P., Bomberg, M. T., DOE 7
Kumaran, M. K., Drouin, M.,
Lackey, J., van Reenen, D., and
Normandin, N., ``Long-Term Thermal
Resistance of Polyisocyanurate
Foam Insulation with Impermeable
Facers ,'' Insulation Materials:
Testing and Applications: 4th
Volume, ASTM STP 1426, A. O.
Desjarlais, Ed., American Society
for Testing and Materials, West
Conshohocken, PA, 2002.
[[Page 55076]]
DOE........................................................ Mukhopadhyaya, P., Bomberg, M. T., DOE 8
Kumaran, M. K., Drouin, M.,
Lackey, J., van Reenen, D., and
Normandin, N., ``Long-term Thermal
Resistance of Polyisocyanurate
Foam Insulation with Gas
Barrier,'' IX International
Conference on Performance of
Exterior Envelopes of Whole
Buildings, Clearwater Beach,
Florida, Dec. 5-10, 2004, pp. 1-10.
DOE........................................................ Mukhopadhyaya, P.; Kumaran, M.K., DOE 9
``Long-Term Thermal Resistance of
Closed-Cell Foam Insulation:
Research Update From Canada,'' 3rd
Global Insulation Conference and
Exhibition, Oct. 16-17, 2008,
Barcelona, Spain, pp. 1-12, NRCC-
50839.
DOE........................................................ Bomberg, M., Branreth, D., DOE 10
``Evaluation of Long-Term Thermal
Resistance of Gas-Filled Foams:
State of the Art,'' Insulation
Materials, Testing and
Applications, ASTM STP 1030, ASTM,
Philadelphia, 1990, p. 156-173.
DOE........................................................ H. Macchi-Tejeda, H. Opatova, D. DOE 11
Leducq, Contribution to the gas
chromatographic analysis for both
refrigerants composition and cell
gas in insulating foams--Part I:
Method, International Journal of
Refrigeration, Volume 30, Issue 2,
March 2007, Pages 329-337.
DOE........................................................ H. Macchi-Tejeda, H. Opatova, J. DOE 12
Guilpart, Contribution to the gas
chromatographic analysis for both
refrigerants composition and cell
gas in insulating foams--Part II:
Aging of insulating foams,
International Journal of
Refrigeration, Volume 30, Issue 2,
March 2007, Pages 338-344.
----------------------------------------------------------------------------------------------------------------
ACC/CPI, in reference to paper [1], stated that the Task Force
found that polyurethane foam encased in and adhered to impermeable
facers does not age significantly. (ACC/CPI, No. 1.3.006 at p. 3) In
reference to [2], Honeywell stated that Wilkes et al. concluded that
``the increment of thermal conductivity of foams with facers is less
than those of enclosed foams'', and regarding that, ASTM C1303-08 is
likely to underestimate the aged thermal insulation value of panel
foams with facers. (Honeywell, No. 1.3.020 at p. 3) Honeywell suggested
that ``DOE consider adapting the aging prediction methodology
presented'' in either [3] or [4]. (Honeywell, No. 1.3.020 at p. 2) Dow
stated that [5], [6], and [7] indicated that change in thermal
conductivity due to aging is limited in blown polyurethane foams. (Dow,
No. 1.3.026 at p. 2) In reference to [8], Owens Corning stated that the
study showed that blowing agent can diffuse under metal skins, that it
migrates to the surface and that it can permeate out even underneath an
air-impermeable surface. (Owens Corning, No. 1.2.010 at p. 256) Dow
noted that [9] ``provides methods for evaluating the aged lambda
([lambda]) or R-values for both exposed foam and faced foam using an
accelerated procedure. The standard uses safety factors depending on
thickness and blowing agent used in the foam and also uses incremental
factors for exposed foams versus foams with facings.'' However, Dow
also noted that ``even though the standard and the procedure apply to
foams with and without impermeable facings,'' the aging factor is four
times higher for exposed foam than it is for impermeably faced foam.
(Dow, No. 1.3.026 at p. 1)
With regard to papers cited by interested parties, DOE makes the
following observations (the numbering refers to the paper reference
number in Table III.1).
1. On p. 325 of paper [1], the SPI Polyurethane Division k Factor
Task Force states ``* * * thermal performance changes little with time
if the foam is protected against gas diffusion by a non-permeable facer
that adheres well to the foam.'' However, immediately following this
statement SPI says, ``The literature emphasizes that not only the foam
but the entire package or composite must resist gas diffusion.'' This
statement supports DOE's position that it is critical to ensure that
all of the foam is encapsulated by an impermeable barrier to prevent
diffusion of gases, not just the face of the material. However, the
study also provides a number of studies that suggest that aging is
delayed on the order of three to nine years rather than two to three
years as DOE previously suggested.
2. In paper [2], Wilkes et al. measured the LTTR of 2-inch-thick
foam samples faced with either Acrylonitrile Butadiene Styrene (ABS) or
High Impact Polystyrene (HIPS) plastic. The edges of the samples were
covered with aluminum foil tape to reduce lateral diffusion through the
panel edges. The samples were aged for 4 years in 90 [deg]F, 40 [deg]F,
and -10 [deg]F environments. In conclusion, Wilkes et al. found that
for ``both ABS and HIPS plastics, the conductivity increases after four
years were less than those predicted for unenclosed full-thickness
core-foam, showing that the plastic liners reduce the rate of aging.
The panels with HIPS sheets showed average increases of [thermal
conductivity] of 19 percent to 28 percent with aging at 90 [deg]F, 12
percent to 23 percent at 40 [deg]F, and 3 percent to 8 percent at -10
[deg]F. The panels with ABS sheets showed smaller increases of 14
percent to 21 percent at 90 [deg]F, 10 percent to 17 percent at 40
[deg]F, and 2 percent to 5 percent at -10 [deg]F.'' (p. 10). The
results demonstrate that facers reduce the rate of aging. However, the
plastic facers used, with the exception of the foil around the edges,
are gas permeable. In addition, Wilkes et al. specifically attempted to
eliminate lateral diffusion with the foil tape on the edges of the
samples, which is not representative of actual walk-in panels.
3. Honeywell suggested that DOE adopt aging methodology presented
by the Norton article [3], which was one of the key citations for the
development of ASTM C1303-10. Norton completed much of the original
research in the field of foam insulation aging. Therefore, DOE is
proposing to adopt a test procedure, ASTM C1303-10, which already
incorporates Honeywell's suggested methodology.
4. The Shankland paper [4] proposes an analytical approach to
calculating lateral gas diffusion through foam panels with open edges.
A similar methodology is proposed in [DOE 8] and [DOE 9], but
researchers have had difficulty modeling and predicting blowing agent
diffusion coefficients. [DOE 8] has found that direct analytical
approach is not possible, but numerical computer simulation to predict
lateral gas diffusion rates may be viable in a few years.
5. The Oertel paper [5] describes research conducted to predict the
amount of blowing agent that permeates through building walls after
being
[[Page 55077]]
released from the underlying foam insulation. The researcher notes,
``if the rigid foam is faced with a diffusion barrier, the
equilibration process cannot occur. The original composition of the
cell gas remains unchanged and the low initial thermal conductivity is
maintained. This was proven when impermeable facing materials were
used. Only metallic surfaces are impermeable.'' This section does not
cite research confirming this claim, but as previously mentioned, DOE
agrees that metal facers, particularly ones used in WICF panels, are
gas impermeable. However, because the metal skins used in WICF panels
do not fully encapsulate the foam in a contiguous manner (i.e., metal
skin on the panel face and all edges), gas diffusion may still occur
laterally through the panel edges.
6. DOE notes that the Ottens study [6] is one of two of which DOE
is aware that has been completed on polyurethane foam-in-place panels,
with open edges intended to simulate metal skinned walk-in panels. This
paper summarizes studies completed by IMA (Materialforschungs- und
Anwendungstechnik Dresden GmbH, translation: Materials and Applications
Research) as requested by Arbeitsgemeinschaft Industrieller Forschung
(translation: Association of Industrial Research) to assess the long-
term insulating behavior of sandwich elements. In particular, this
paper cites data on carbon dioxide (CO2) blown foams as an
alternative to other blowing agents. On page 30 of the study, Figures 4
and 5 show aging results for both core and edge regions of test panels.
The areas greater than approximately 12 inches from the edge exhibit 2
to 3 percent aging after 6 months at a temperature of approximately 160
[deg]F. Regions within 12 inches of the edge show 5 to 17 percent
aging, with the highest rate of aging occurring at the panel corners.
Dow noted in its reference to this paper that CO2 ``has
higher diffusion speeds, [therefore] the aged thermal conductivity
would be even better for the HFC blown foams used in many walk-in
applications.'' DOE agrees with Dow that CO2 exhibits a
faster rate of diffusion than hydrofluorocarbon (HFC) blowing agents
typically used in foams, which indicates that the study is likely more
representative of a worst case aging scenario. This study clearly
demonstrates that lateral gas diffusion occurs in metal faced panels
with open edges. DOE also notes that the majority of aging has occurred
at the panel perimeter, which is an expected result because the rate of
diffusion should decay exponentially with increased distance (or
thickness of foam) from the exposed edge as described in ASTM C1303-10.
The authors did not note the aging period that their test, which was
conducted over 6 months at an elevated temperature, was intended to
simulate, but because elevated temperature dramatically increases gas
diffusion rates, the tests are likely representative of panels aged for
at least 5 years.
7. The Bertucelli paper [7], other than [5], is the only one that
DOE has reviewed that directly tests aging of actual walk-in panels.
Bertucelli et al. state that, ``in practice, for metal faced sandwich
panels the diffusion phenomena can only take place through the open
sides of the panels. The initial thermal conductivity value remains for
a long time practically unchanged for the largest part of the panel due
to the long path for diffusion.'' (p. 2) Again, this research supports
DOE's claim that significant lateral diffusion occurs through open
edges of panels. This statement appears to be based on data shown on
page 17 that are very similar to data shown in [6] for CO2
blown foams. However, this test was on a 4 foot by 8 foot panel aged at
room temperature for a year. Close to the geometric center of the
panel, the thermal performance has aged by 2 to 5 percent from its
initial value. Measurements approximately 20 inches from the edges
range from 2 to 6 percent. These data are similar to data submitted by
Carpenter (see Table III.2) which were also from a panel aged at room
temperature but with an HFC blowing agent. The Bertucelli paper also
notes that EN 13165, a European material standard that was developed in
Germany but certified by the European Committee for Standardization
(CEN), provides certified aging values for various blowing agents used
in metal faced sandwiched foam-in-place panels. The researchers also
note that the certified aging value for water-blown foams, HCFC-141b
and pentane is 10 percent.
8. The Glicksman paper [8] found that the effectiveness of
impermeable facers is highly dependent on adhesion of the foam to the
facer. Slight separation allows gas diffusion to occur perpendicularly
to the barrier and laterally between the barrier and the foam, which
permits more rapid aging than if the diffusion is forced through the
foam material only in the lateral direction. This research supports
DOE's assertion that delamination is a major contributing factor to
aging of panels.
9. EN 13165 is a material standard for ``factory made rigid
polyurethane foam (PUR) products.'' Dow noted that this standard has
provisions for accelerated aging of panels. This is one of the material
standards that uses the aging factor described in [7]. DOE was
previously unaware that the CEN had established aging factors for
insulated panels and believes that this standard may serve as an
alternative to ASTM C1303-10 (see section III.B.3 for more details).
In addition to comments on specific papers submitted by
stakeholders, DOE received many general comments on the use of ASTM
C1303. DOE addresses these additional comments below.
BASF stated that there was insufficient evidence to support DOE's
assertion that the diffusion as a result of delamination, holes drilled
for shelves, and gaps at windows and doors causes a dramatic decrease
in insulation performance of the panel, and that DOE should publish and
make available any supporting data. (BASF, No. 1.3.003 at p. 3-4)
Honeywell stated that ASTM C1303 was inappropriate because the data
used to select it were based on foil-faced board stock rather than
metal-faced panels. (Honeywell, No. 1.3.002 at p. 1) BASF proposes to
delay a decision on modifying ASTM C1303 to apply to impermeably
skinned panels due to a lack of data, and instead proposes that DOE
first test and compare (1) panels from the field that are at a known
age that is greater than 5 years, (2) newly manufactured panels
measuring the R-value at different points in the panels, and (3) newly
manufactured panels that are sliced and aged according to the methods
in ASTM C1303-10. (BASF, No. 1.3.003 at p. 4)
Carpenter submitted data, shown in Table III.2, of panels that had
been in the field for one year. These data suggest that R-value
decreases approximately 3.1 to 4.3 percent within 1 year. (Carpenter,
No. 1.3.007a at p. 3) Dow stated that ASTM C1303-10 states that it is
not to be used with impermeably faced foams, and that industry
literature states that metallic, impermeable surfaces will prevent
blowing agent diffusion. (Dow, No. 1.3.026 at p. 1) Owens Corning
submits that research has shown that an effective barrier can
substantially reduce the rate of foam aging. In its view, to be
effective, the barrier must have a low permeability and the foam/
barrier interface must not allow lateral gas flow. However, all
cellular foams have some amount of lateral gas flow. (Owens Corning,
No. 1.3.030 at p. 1) In addition, Owens Corning referenced a
Massachusetts Institute of Technology study on insulation with metal
skins using dye to observe the diffusion of blowing agent. The study
showed that blowing agent
[[Page 55078]]
can diffuse under metal skins, that it migrates to the surface, and
that it can permeate out even underneath an air-impermeable surface.
(Owens Corning, No. 1.2.010 at p. 256)
Table III.2--Tested Data Submitted by Carpenter
----------------------------------------------------------------------------------------------------------------
R-value ft\2\ hr[deg] F/Btu in
-----------------------------------------------------------------------
20[deg] F 55[deg] F
Sample ID -----------------------------------------------------------------------
11/2008 11/2008
(initial) 01/2010 (aged) (initial) 01/2010 (aged)
----------------------------------------------------------------------------------------------------------------
Panel middle............................ 7.89 7.63 7.00 6.78
Panel edge.............................. 7.89 7.54 7.00 6.70
----------------------------------------------------------------------------------------------------------------
In response to BASF's comment that DOE should publish and make
available any supporting data for the use of ASTM C1303-10, DOE lists
all papers in Table III.1. Most of these papers were already described
in detail in January NOPR, but DOE welcomes further comment on these
studies.
In response to Honeywell's comment regarding foil facers, DOE
recognizes that foil faced foams may not have identical characteristics
to metal skins, but believes that foils would serve as a reasonable
proxy for general aging behavior.
With regard to BASF's comment that DOE should collect field data on
panels older than 5 years of age, DOE believes that the data submitted
by Carpenter support DOE's assertion that significant aging occurs over
the 15 to 20 year life of a panel and that the diffusion is occurring
laterally because aging of 3-4 percent occurred within about 1 year,
with the edge samples aging more than the core. DOE welcomes additional
data on this issue from panel manufacturers and other interested
parties.
As to Dow's comments regarding the scope of ASTM C1303-10, although
DOE agrees with Dow that ASTM C1303-10 states that the test does not
apply to impermeably faced foams, DOE has not proposed the use of ASTM
C1303-10 on panels themselves. Instead, DOE has proposed that the
procedure be followed when testing the underlying unfaced foam as a
proxy for the actual aging provisions outlined in the NOPR that
describe how the unfaced foam samples are prepared for testing by ASTM
C1303-10. See section 4.1.2 of Appendix A for details.
With regard to Owens Corning's comments that an effective barrier
can substantially reduce the rate of foam aging, DOE agrees that
impermeable facers affect the diffusion pathway of gases through foam.
However, DOE believes that impermeable facers delay aging, rather than
eliminate it as Dow and ACC/CPI suggest. In addition, the International
Institute of Refrigeration (IIR), which serves as an international body
with 61 member countries to ``promote knowledge of refrigeration
technology and all its applications in order to address today's major
issues, including food safety and protection of the environment,''
states that the thermal properties of insulation can change over time:
``It is well known that thermal conductivity can increase in plastic
foams in which gaseous blowing agent has been used * * * with such
materials, there will inevitably be a deterioration of insulation
properties over time due to the diffusion of the blowing agent.''
(Insulation and Airtightness of Cold Rooms, 2002 Edition, IIR, p.154)
Because walk-in panel perimeters are not protected by gas impermeable
materials such as the metal skins, gas diffusion can still occur
laterally through the panel. DOE notes that Owens Corning's second
comment regarding the Massachusetts Institute of Technology study on
diffusion of blowing agents points to data that suggest the lateral
flow of gas occurs at the foam surface to metal skin interface due to
poor adhesion of the foam to metal.
In addition to the data presented above, DOE presents aged R-values
of a number of foam types in Table III.3. These results are based on
CAN/ULC S-770, the Canadian thin slicing method that is based on
various versions of ASTM C1303. Each data point is an average of dozens
of tests at the thicknesses shown.
Table III.3--Foam Thin-Slicing Test Results, Source: Canadian Laboratory
------------------------------------------------------------------------
5-Year Long Term Thermal Resistance, CAN/ULC S-770, @
75[deg] F mean temperature
------------------------------------------------------
Permeably Faced Extruded Spray-in-Place
Product Polyisocyanurate Polystyrene Polyurethane
Board Thermal Board Thermal Foam Thermal
Resistivity Resistivity Resistivity
[deg]F-ft [sup2]- [deg]F-ft [sup2]- [deg]F-ft [sup2]-
h/Btu-in. h/Btu-in. h/Btu-in.
------------------------------------------------------------------------
Thickness Thermal Thermal Thermal
Resistivity Resistivity Resistivity
------------------------------------------------------------------------
(mm) ([deg]F.ft\2\.h/ ([deg]F.ft\2\.h/ ([deg]F.ft\2\.h/
Btu.in ) Btu.in ) Btu.in )
------------------------------------------------------------------------
100 6.178 5.607 6.197
------------------------------------------------------------------------
75 6.127 5.490 5.958
------------------------------------------------------------------------
50 6.028 5.339 5.703
------------------------------------------------------------------------
25 5.880 5.019 ................
------------------------------------------------------------------------
[[Page 55079]]
These data address concerns raised by various interested parties
that the thin slicing method would unfairly predict that polyurethane
would perform at a lower level than extruded polystyrene and, in some
cases, would perform at a level as low as expanded polystyrene.
Instead, these data appear to predict that polyurethane products would
continue to outperform extruded polystyrene on a per inch basis. It is
also important to note that if DOE were not to propose the use ASTM
C1303-10, DOE would still be indirectly accounting for aging in one of
two classes of foams: Board stock foams such as extruded polystyrene.
Because board-stock insulation is manufactured at one location, stored
for a period of time, and then shipped to WICF panel manufacturers, the
foam is exposed to ambient temperatures and unprotected by metal skins
for a significant period of time prior to its installation in a WICF
envelope. Therefore, before board stock based foams are even laminated
into WICF panels, significant aging has already occurred. DOE believes
that all of the above factors tend to support the use of a test
procedure that, as accurately as possible, will uniformly represent
aging of all foam classes.
In light of the research and data submitted by interested parties,
and the German data regarding the use of aging factors specifically for
foam-in-place metal faced panels, DOE continues to maintain that (1)
foam aging occurs in WICF panels, (2) the aging is possible, even with
metal facers, due to the gas permeable edges of panels, and (3) R-value
degradation is significant enough, over the life of a walk-in cooler or
freezer, to warrant a long-term foam aging test. DOE continues to urge
manufacturers and interested parties to submit R-value data for panels
aged 5 or more years to support their particular claims. While DOE
believes there are enough indirect and direct data to incorporate aging
into the WICF test procedure, DOE is interested in ensuring, to the
extent possible, that it incorporates manufacturer-submitted data as
part of its analysis.
DOE requests comments from interested parties regarding the
proposal to use ASTM C1303-10 to measure the long-term R-value decline
in WICF foam insulation. DOE requests that interested parties consider
in their comments the research and papers provided by DOE and other
commenters.
3. EN 13165:2009-02 as a Proposed Alternative to ASTM C1303-10
As noted in the previous section, Germany has developed a test
procedure (that was certified as a European standard by the CEN) and
calculation methodology to determine the aged R-value of metal skin
panels. EN 13165:2009-02, Thermal insulation products for buildings--
Factory made rigid polyurethane foam (PUR) products--Specification
describes two alternatives in Annex C, the fixed increment procedure
and the accelerated aging procedure for determining aged R-value. An
overview of the two alternatives is shown in Figure 1 below:
BILLING CODE 6450-01-P
[[Page 55080]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.030
BILLING CODE 6450-01-C
The alternative procedures--the fixed increment procedure and the
accelerated aging procedure--are selected based on certain criteria and
availability of historical data as defined in EN 13165:2009-02. In
summary, the fixed increment procedure determines if a facing or panel
construction is ``gas diffusion tight'' by subjecting it to an elevated
temperature for 60 days and determining whether there is any decrease
in the R-value. If the panel is found to be gas tight and the test
material is also made with blowing agents of known characteristics,
then the LTTR of the foam is determined using assumed increments of R-
value loss. The assumed aging values have been certified by Germany
through testing. Otherwise, the accelerated aging procedure must be
used to determine the LTTR. The accelerated aging procedure subjects
the panel to an elevated temperature for 180 days and determines the
decrease in the R-value.
Like EN 13165:2009-02, which is a standard for polyurethane
products, a similar standard exists for extruded polystyrene: EN
13164:2009-02 Thermal insulation products for
[[Page 55081]]
buildings--Factory made products of extruded polystyrene foam (XPS)--
Specification. Annex C of EN 13164:2009-02 also provides a methodology
for determining the LTTR of impermeably faced or ``gas tight''
products. DOE proposes, as an alternative to ASTM C1303-10, the use of
the test procedures of these respective standards for determining the
LTTR of walk-in polyurethane and extruded polystyrene products. DOE
proposes to directly rely on the methods described in EN 13164:2009-02
and EN 13165:2009-02 with two exceptions: (1) The initial R-value must
be measured at the EPCA defined mean test temperatures (instead of the
specified ~75 [deg]F) of 55 [deg]F for coolers and 20 [deg]F for
freezers and (2) the final R-value must also be measured using the EPCA
defined mean test temperatures. Using the initial and final R-values, a
calculated foam ``derating'' factor would be used in place of the
similar calculation using results from ASTM C1303-10. DOE seeks comment
on the use of EN 13164:2009-02 and EN 13165:2009-02 for determining the
LTTR of walk-in panels made from extruded polystyrene or polyurethane,
respectively.
DOE also seeks comment on the proposed use of CEN's certified aged
values as an alternative to requiring testing using ASTM C1303-10.
4. Version of ASTM C1303
As indicated earlier, DOE initially proposed that the test
procedure incorporate ASTM C1303-08. 75 FR 194. Nor-Lake pointed out
that a more recent version of this testing method was published in
2009, ASTM C1303-09a. (Nor-Lake, No. 1.3.005 at p. 3) DOE then
determined that an even more recent version has recently been
published, ASTM C1303-10. To address these comments, DOE compared ASTM
C1303-08, ASTM C1303-09a and ASTM C1303-10 and found no substantive
differences between them that would appreciably affect the accuracy or
manner in which to measure a given foam's R-value. In light of this
finding, DOE is revising its proposal to adopt the most recent version,
ASTM C1303-10.
DOE invites comment on this proposed approach.
5. Improvements to ASTM C1303 Methodology
In the January NOPR, DOE proposed several exceptions to ASTM C1303-
08 related to sample preparation of foam-in-place products. 75 FR 194.
Specifically, DOE proposed that, rather than requiring that foam be
sprayed onto a single sheet of wood in accordance with section A2.3 of
ASTM C1303-08, the sample ``shall be foamed into a fully closed box of
internal dimension 60 cm x 60 cm by desired product thickness (2 ft x 2
ft x desired thickness). The box shall be made of \3/4\ inch plywood
and internal surfaces are wrapped in 4 to 6 mil polyethylene film to
prevent the foam from adhering to the box material.'' DOE had intended
for this proposed approach to minimize manufacturer burden while
ensuring uniform sample preparation.
In reference to this proposal, Honeywell stated that the sample
preparation method is too prescriptive for foam-in-place products and
argued that DOE should not dictate materials for building the sample
mold or dimensions of the mold. Rather, it recommended that foam-in-
place samples be prepared in a fashion that represents the average foam
properties (or bulk foam properties) of the commercial panel.
(Honeywell, No. 1.3.020 at p. 3) ACC/CPI stated that the sample
preparation methods of polyurethane foam are too prescriptive when
describing mold materials that must be used, and instead recommended
adopting a modified version of section 3.1 of ASTM C1303-10 to account
for a product manufacturer's typical method of panel cavity
preparation, foam injection and cure time. (ACC/CPI, No. 1.3.006 at p.
5)
DOE agrees that spatial variation during foam injection is a
relevant concern. To represent foam properties more closely for various
manufacturers, DOE proposes the following changes:
1. Mold/Sample Panel Geometry
a. A panel must be prepared following the manufacturer's injection,
curing and assembly methods. The width and length of the panel must be
48 inches 1 inch and 96 inches 1 inch,
respectively.
b. As proposed in the January NOPR, the panel thickness shall be
equal to the desired test thickness. 75 FR 194.
2. Materials
The panel should be identical to panels sold by the manufacturer,
with one key exception: The inner surfaces must be lined with a
material, such as 4 to 6 mil polyethylene film, to prevent the foam
from adhering to the panel internal surfaces. (This ensures that when
the panel metal skin is removed for testing, the underlying foam is not
damaged.)
3. Sample Preparation
a. After the foam has cured and the panel is ready to be tested,
the facing and framing materials must be carefully removed to ensure
that the underlying foam is not damaged or altered.
b. A 12-inch x 12-inch square (x desired thickness) cut from the
exact geometric center of the panel must be used as the sample for
completing ASTM C1303-08.
These additions will allow for more representative samples while
maintaining consistency across manufacturers. DOE also believes, based
on its analysis of the likely impacts from the adoption of this
procedure, that these proposed modifications will not lead to any
appreciable deviations from the measured energy use of the envelope.
DOE invites comments from interested parties on the reasonableness of
this prediction.
Certain interested parties raised specific concerns as to the
applicability of ASTM C1303 to ``bun stock'' foam. ``Bun stock'' foam
is foam formed in large cylindrical tubes or ``buns.'' Dyplast, ACC/
CPI, Honeywell, and ITW all stated that DOE should not consider ASTM
C1303 because ASTM C1303 specifically states that the test method does
not apply to rigid closed-cell bun stock foams. (Dyplast, No. 1.3.008
at p. 1; ACC/CPI, No. 1.3.006 at p. 3; Honeywell, No. 1.3.020 at p. 2;
and ITW, No. 1.3.013 at p. 1) Dyplast mentioned that this was due to
the non-homogenous nature of the bun stock foams. (Dyplast, No. 1.3.008
at p. 1) ITW further stated that ASTM C1303 would not be applicable
because it is not possible to determine a consistent initial time for
the test and because sheets may be cut from bun stock in different
orientations, resulting in different form morphology. (ITW, No. 1.3.013
at p. 1)
DOE recognizes that bun stock foam is different from other types of
foam used in WICF equipment. The foam resembles the wood grain found in
trees and has cells that vary in size and density by location. When the
buns are cut into board stock of various dimensions, the foam
morphology varies from one board to another as the boards may be cut
from the bun stock in different orientations.
DOE specified in the January NOPR that manufacturers must use the
prescriptive method defined in ASTM C1303 (Part A: The Prescriptive
Method), but as noted by interested parties, the prescriptive method is
not applicable to bun stock foam. 75 FR 193. However, in addition to
Part A of ASTM C1303, Part B: Research Method allows for testing of
bun-stock or other non-
[[Page 55082]]
homogenous foams. DOE believes that the research method in Part B is
appropriate and applicable for testing of bun-stock foams. Therefore,
to address the comments from Dyplast, ACC/CPI, Honeywell, and ITW, DOE
proposes that the research method of ASTM C1303-10, Part B be used for
testing the LTTR for bun stock foam only.
6. Heat Transfer Through Concrete
In the January NOPR, DOE proposed the use of the following equation
to calculate the heat transfer through the floor of both insulated and
uninsulated WICF. 75 FR 213. That equation, along with its defined
variables, is as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.034
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,
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, and
[Delta]Tl = dry bulb temperature differential between internal and
external air, of type l, [deg]F.
To complete the calculation, DOE proposed temperature assumptions
for the internal cooled air and the surface temperature of the floor.
The cooled air temperature was selected based on WICF type: 35 [deg]F
and -10 [deg]F for coolers and freezers, respectively. DOE also assumed
that the finished subfloor surface material was made of concrete.
Additionally, DOE proposed a 55 [deg]F subfloor surface temperature for
all walk-ins. The temperature difference across the floor ([Delta]T)
could be calculated using the 55 [deg]F subfloor surface temperature
and the internal cooled air assumption. With a known floor area
(Afloor), [Delta]T, and floor R-value, the heat transfer through the
floor could be readily calculated. However, the specific floor R-value
was incorporated into the calculation based on certain conditions.
These conditions are described in greater detail below.
Floorless Coolers: For the scenario of uninsulated (``floorless'')
coolers, DOE proposed a concrete R-value of 0.6 ft\2\ - [deg]F - h/Btu,
based on typical concrete density and thickness as reported in the 2009
ASHRAE Fundamentals Handbook.
Pre-Installed Freezer Floor: For the scenario where (1) a
manufacturer does not provide a freezer floor; and (2) an insulated
floor has been installed on-site by the end-user, DOE proposed that
manufacturers use R = 28 ft\2\ - [deg]F - h/Btu for completing the heat
transfer calculations. This R-value is the same as the EPCA-prescribed
minimum requirement for freezer floors. BASF, ThermalRite, and American
Panel supported using an assumption of R-28, while Nor-Lake stated that
a value of R-20 would be more appropriate but did not specify why.
(BASF, No. 1.3.003 at p. 4; ThermalRite, No. 1.3.031 at p. 2; American
Panel, Public Meeting Transcript, No. 1.2.010 at p. 263; Nor-Lake, No.
1.3.029 at p. 4) DOE, however, continues to hold the view that its
proposed approach best reflects the statutory framework set out by
Congress because R-28 is the minimum freezer floor R-value required by
EISA 2007. See 42 U.S.C. 6313(f)(1)(D).
Insulated Floor Shipped by Manufacturer: For both coolers and
freezers, if a manufacturer provided the floor, DOE proposed in the
January NOPR that the floor R-value (as measured by the test procedure)
be used for the heat transfer calculations. 75 FR 198.
Between the publication of the January NOPR and the public meeting,
DOE completed additional finite element model (FEM) computer
simulations of floorless coolers. Based on FEM simulation results, DOE
described a new equation during the public meeting for calculating heat
transfer through floorless coolers:
[GRAPHIC] [TIFF OMITTED] TP09SE10.035
Where:
If Afloor <= 750 ft\2\, qfloor = 33.153 x
Afloor-0.364,
If Afloor > 750 ft\2\, qfloor = 0.0002 x
Afloor + 2.84,
qfloor = heat flow correction factor,
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,
Aceiling,k = area of ceiling of thickness and underlying
materials of type k,
Anon-glass door,l = area of doors of thickness and
underlying materials of type l,
Afloor = area of floor, ft\2\,
[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, and
[Delta]Tl = dry bulb temperature differential between
internal and external air, of type l, [deg]F.
The FEM simulations demonstrated that using 60 [deg]F and 65 [deg]F
would result in more accurate energy calculations. DOE indicated at the
NOPR public meeting that it was considering modifying the surface
temperature assumptions for freezers and coolers to 60 [deg]F and 65
[deg]F, respectively, and sought comment from interested parties on
these revised temperatures.
Several manufacturers recommended that DOE maintain the original
assumption of 55 [deg]F for sub-floor surface temperature. ThermalRite
requested that
[[Page 55083]]
55 [deg]F be retained because it believed that the equations were based
on solid engineering principles and data. (ThermalRite, No. 1.3.031 at
p. 2) Nor-Lake agreed that 55 [deg]F would be more appropriate. (Nor-
Lake, No. 1.3.029 at p. 4) Kysor and TAFCO preferred 55 [deg]F because
it would be consistent with industry assumptions. (Kysor, Public
Meeting Transcript, No. 1.2.010 at p. 270 and TAFCO, No. 1.3.022 at p.
3) ICS recommended that 55 [deg]F be maintained as the assumption for
both coolers and freezers because a walk-in with an insulated floor
would not have an effect on sub-floor temperature regardless of WICF
temperature. (ICS, No. 1.3.027 at p. 2) In light of this general
support and the absence of any comments explaining why use of a 55
[deg]F temperature assumption would be inappropriate, DOE proposes
continuing to apply its 55 [deg]F assumption for all WICF for three
reasons: (1) 55 [deg]F is the general industry accepted value; (2)
using a single assumption simplifies calculations; and (3) using a
single temperature avoids the complexity of accounting for various
field installation variations (such as concrete thickness and proximity
to building walls).
Regarding the heat transfer calculations for floorless coolers,
Nor-Lake supported using Eq. 1 as proposed in the January NOPR. (Nor-
Lake, No. 1.3.029 at p. 4) Master-Bilt and Nor-Lake recommended that
DOE consider using the minimum thickness of 3.5 inches rather the 6
inches as proposed in the January NOPR for calculating the concrete R-
value, because the building industry uses 3.5 inches. (Master-Bilt, No.
1.3.009 at p. 2 and Nor-Lake, No. 1.3.005 at p. 4)
In this SNOPR, DOE proposes different equations for calculating
heat transfer through floor panels, non-floor panels (i.e., wall and
ceiling panels), and non-glass doors. Although Nor-Lake supported using
Eq. 1 as proposed in the January NOPR, the equations proposed in this
SNOPR allow greater flexibility in calculating heat transfer through
the envelope because they are able to account for unique temperature
differences across each component. See section III.B.7 for a more
detailed description of the equations in the SNOPR. The equation for
floor heat transfer incorporates the results of FEM simulation by using
the values for the heat flow correction factor (qfloor) that
appear in Eq. 2 above. In performing the FEM simulation, DOE assumed 6-
inch-thick concrete despite Master Bilt and Nor-Lake's comments,
because that is the recommended floor thickness in the ASHRAE Handbook
of Fundamentals (ASHRAE Fundamentals 2005). However, DOE will continue
to consider other values if they are more appropriate for the
application and asks for comment on a more appropriate value.
7. Walk-In Sited Within a Walk-In: A ``Hybrid'' Walk-In
In the January NOPR, the calculation procedure provided a means of
rating all walk-ins, including the scenario where a freezer is sited
inside a cooler or where a cooler and freezer share a common wall.
Modifications described in this SNOPR ensure that the rating of
these walk-in cooler/freezer hybrids is properly captured. For example,
every panel or door may have a unique temperature differential across
the material to reflect either a panel that divides a cooler and
freezer or a door that may open from freezer temperatures to cooler
temperatures. See section 3.1 of Appendix A for details. In the event
an individual non-floor panel, floor panel or door spans two
temperature regimes, the lower temperature must be used for the purpose
of calculating the heat transfer across that component. For example, if
a floor panel spans a section of the floor, where 80 percent of the
panel is exposed to cooler temperatures and the other 20 percent is
exposed to freezer temperatures, the heat transfer calculation through
the floor panel must use only the freezer temperature.
DOE believes the equations shown in section 3.1 of Appendix A
provide an accurate means of testing a given walk-in cooler, freezer or
hybrid walk-in. DOE seeks comment on the equations and their accuracy,
particularly for hybrid walk-ins.
8. U-Factor of Doors and Windows
Conduction heat gain through doors and windows contributes to the
energy load of the envelope. To account for this fact, DOE proposes to
measure heat gain through doors (with and without glass) and any other
glass surfaces such as windows, as well as through the framing
materials used for doors and windows. In the January NOPR, DOE proposed
measuring heat gain through doors and windows using one of the
following options: (1) For doors with a National Fenestration Rating
Council (NFRC) rating, thermal performance would have been determined
from the NFRC label; or (2) for doors without an NFRC rating, thermal
performance parameters would have been determined using Window 5.2, a
computer program developed by Lawrence Berkeley National Laboratory. 75
FR 198. (The NRFC is a non-profit, public-private partnership of the
window, door, and skylight industry.) In either case, DOE proposed
using the thermal performance parameters as inputs for calculations
specified in the Test Procedure NOPR.
DOE's proposed method was supported by BASF, Master-Bilt, and Nor-
Lake. (BASF, No. 1.3.003 at p. 4; Master-Bilt, No. 1.3.009 at p. 2;
Nor-Lake, No. 1.3.005 at p. 4) Kason agreed that using third-party
software (such as Window 5.2) to evaluate window performance is
reasonable. (Kason, No. 1.3.037 at p. 4) However, NFRC recommended
using a standard size door for all calculations to ensure a full rating
that includes frame effects and allow for accurate reporting. (NFRC,
Public Meeting Transcript, No. 1.2.010 at p. 280) Furthermore, Schott
Gemtron pointed out that the standard glass door in Window 5.2 is not
the same as a typical glass door used in walk-ins. (Schott Gemtron,
Public Meeting Transcript, No. 1.2.010 at p. 284) ACEEE stated that the
manufacturers of doors with glass surfaces should use NFRC rating
methods to certify performance. (ACEEE, No. 1.3.034 at p. 2)
In response to the comment from Schott Gemtron, the Window 5.2
program does not incorporate WICF-specific doors at this time because
NFRC, the primary user of Window 5.2, has never rated WICF doors. To
remedy this situation, the typical WICF door geometries would simply
need to be added to the Window 5.2 database. Because use of the NFRC
ratings would avoid the need for DOE to prescribe specific geometries
or testing scenarios, however, DOE proposes in this SNOPR that instead
of using Window 5.2, manufacturers shall rate the total thermal
transmittance (known as U-factor) of doors and windows, including their
framing materials, using the test procedure NFRC 100-2010-E0A1,
``Procedure for Determining Fenestration Product U-Factors.'' NFRC 100-
2010-E0A1 specifies a test procedure but does not specify test
conditions, which depend on the product. Details of proposed test
conditions may be found in section 4.1.3 of Appendix A. DOE welcomes
comments on improvements that could be made to Window 5.2, however, and
would consider allowing use of Window 5.2 provided that such
improvements led to results as consistent as those achieved with the
NFRC rating.
In addition, DOE proposes applying the provisions in section 5.2 of
NFRC 100-2010-E0A1, which would provide a uniform and reasonably
accurate method of measuring the thermal transmittance of the door and
window components installed in a walk-in. The section contains
reference methods for
[[Page 55084]]
determining heat transfer properties for specific side-hinged exterior
door systems, to all doors (i.e. doors without any glass, doors with
glass windows, glass display doors, etc.) and glass walls. Doors, as
defined in Appendix A 2.1(b) of these proposed regulations, includes
the user movable components and the framing components that support the
door hinges such as the center mullions in display doors or door plugs
found commonly in passage doors. The complete assembly must be tested
to find the door U-factor.
NFRC 100-2010-E0A1 provides a means of testing representative door
geometry that can then be extrapolated to other doors of similar
materials and geometry. This approach is less costly but generally
results in more conservative test results. However, if a door
manufacturer or other party responsible for testing would prefer to
perform the complete physical test described in NFRC 100-2010-E0A1 for
all doors (i.e. not rely on NFRC's extrapolation methodology), the
testing entity may do so.
DOE seeks comment on the proposal requiring windows and doors,
including their framing materials, to be rated using NFRC 100-2010-
E0A1. As stated above, DOE also seeks comment on improvements to the
Window 5.2 program that would make its use in the test procedure
appropriate.
9. Walk-In Envelope Steady-State Infiltration Test
In the January NOPR, DOE noted two air exchange pathways for walk-
in envelopes: (1) Air exchange (``infiltration'') occurring during door
opening events, the extent of which depended on door opening area and
the frequency of door opening, and (2) infiltration during ``steady-
state'' conditions. DOE defined steady-state as the period of time when
all access methods, such as doors, were in the closed position. During
steady-state conditions, infiltration could occur via cracks in door
sweeps, bi-directional pressure relief valves, and panel-to-panel
interfaces. Infiltration during door opening events accounts for the
majority of infiltration into the envelope, but steady-state
infiltration could be significant as well. Because air infiltration
plays a role in determining the overall efficiency of a given WICF and
the likely energy consumption in keeping its refrigerated areas cool,
DOE proposed using ASTM E741-06, ``Standard Test Method for Determining
Air Change in a Single Zone by Means of a Tracer Gas Dilution,'' for
testing the steady-state air infiltration of walk-in coolers and walk-
in freezers. DOE detailed a number of requirements, such as internal
and external temperatures during testing, sampling methods, and gas
tracer calculation type.
In comments on the January NOPR, interested parties noted the role
that pressure relief valves play with respect to infiltration testing.
These valves are standard equipment with walk-in envelopes and are
designed to ensure the proper operation of a WICF unit by relieving
pressure changes that accompany rapid cooling of warm air after door
opening events. Craig stated that the standard pressure relief valve on
walk-ins could interfere with infiltration testing, and Kason added
that WICF manufacturers use pressure relief ports that allow gas to
move through the envelope and further suggested that these ports would
need to be blocked to test infiltration. (Craig, No. 1.3.017 at p. 2
and Kason, No. at p. 3)
Because bi-directional pressure relief valves are considered
standard equipment for all walk-in freezers, today's notice clarifies
that they should be included in the general steady-state infiltration
test if they are part of the walk-in being tested. In addition, because
valves contribute to steady-state infiltration, it is necessary to
measure their contribution. The duration of the steady-state test is
long enough to ensure that the average valve operation time is
accurately represented. In addition, properly sited and designed valves
should not be opening and closing frequently, if at all, during steady-
state conditions. Because these valves are intended to relieve large
pressure swings caused by rapid cooling of warm air that has entered
during door opening events, the pressure differential across the valve
should be low enough that it remains closed during steady state
operation.
In the January NOPR, DOE also proposed to reduce testing burden by
allowing manufacturers to test the infiltration of a limited number of
envelopes and then scale those results to all other envelopes
manufactured. Interested parties agreed with DOE's approach to reduce
the testing burden but suggested that it was necessary for DOE to
provide detailed requirements of how the test units should be
constructed. Craig, American Panel, and ThermalRite stated that DOE
must specify the basic unit to be tested in terms of size and certain
components, which would be standardized across all manufacturers.
(Craig, No. 1.2.010 at pp. 102-103; American Panel, No. 1.3.024 at p.
2; ThermalRite, No. 1.3.031 at p. 1)
DOE agrees with this approach and proposes that with respect to the
steady-state infiltration test, the techniques, materials, and final
assembly must be identical to units that are shipped to customers. The
unit must be assembled following the instruction manual supplied by the
manufacturer. Details may be found in section 4.2 of Appendix A.
DOE seeks comment on the modifications to the steady-state
infiltration testing.
10. Door Steady-State Infiltration Test
In the January NOPR, DOE proposed testing steady-state infiltration
on fully assembled envelopes using the gas tracer method described in
ASTM E741-06, ``Standard Test Method for Determining Air Change in a
Single Zone by Means of a Tracer Gas Dilution.'' The NOPR proposed an
additional series of tests, using ASTM E741-06, under certain
conditions, and would have required testing of all possible
combinations of panels and doors.
Interested parties recommended several alternatives for DOE to
consider. The Joint Utilities recommended the NFRC rating method for
determining infiltration related to doors, in part because this method,
in their collective view, provides a means to test and sample products
that would assure that the sold product matches the quality of the
tested sample. (Joint Utilities, No. 1.3.019 at p. 12-13) Hired Hand
recommended ASTM E330-97, ``Standard Test Method for Structural
Performance of Exterior Windows, Doors, Skylights and Curtain Walls by
Uniform Static Air Pressure Difference,'' or ASTM E283-92, ``Standard
Test Method for Determining Rate of Air Leakage Through Exterior
Windows, Curtain Walls, and Doors Under Specified Pressure Differences
Across the Specimen.'' (Hired Hand, No. 1.3.033 at p. 5)
In this SNOPR, DOE is proposing measuring steady-state infiltration
through panels and doors using separate tests for each rather than
using a single test for both as proposed in the January NOPR. DOE is
considering this modification to reduce testing burden; the January
NOPR proposed to require a new test for each unique panel and door
configuration, which could be overly burdensome to test because of the
many possible configurations. For all doors, DOE is considering NFRC
400-2010-E0A1, ``Procedure Determining Fenestration Product Air
Leakage.'' NFRC 400-2010-E0A1 is based on ASTM E283-04, the most recent
version of ASTM E283-92, one of the test methods recommended by Hired
Hand. This test method is appropriate for this
[[Page 55085]]
application because it was specifically designed to measure the air
leakage through doors and fenestration products. DOE adapted NFRC 400-
2010-E0A1 for use with doors on walk-in envelopes by establishing
standard assumptions for the pressure differences, in Pascals (Pa),
across cooler and freezer doors and requiring the infiltration at these
pressures to be determined using a pressure-infiltration relationship
determined through testing. Section 4.4.2 of proposed Appendix A
contains the assumptions and the method for finding the pressure-
infiltration relationship. DOE does not intend to incorporate ASTM
E330-97, ``Standard Test Method for Structural Performance of Exterior
Windows, Doors, Skylights and Curtain Walls by Uniform Static Air
Pressure Difference,'' as suggested by Hired Hand because this
procedure measures structural performance, which does not impact
efficiency; but DOE invites Hired Hand to submit further justification
in support of this standard. DOE seeks comment on the proposal to test
steady-state infiltration through doors separately from steady-state
infiltration through panels and using NFRC 400-2010-E0A1 for both
tests. DOE seeks comment on the proposed assumptions for the pressure
differential across cooler doors (1.5 Pa) and freezer doors (3.5 Pa).
DOE seeks comment on the proposal to determine infiltration across
cooler and freezer doors using tests of infiltration and exfiltration
at 10 Pa to 60 Pa to establish a pressure-infiltration relationship
with which to extrapolate the infiltration occurring across cooler and
freezer doors.
11. Door Opening Infiltration Assumptions
In the January NOPR, DOE proposed to incorporate several
assumptions from the ASHRAE Handbook of Fundamentals 2009 related to
door opening infiltration that would be used to calculate the portion
of time each doorway is open, Dt:
[GRAPHIC] [TIFF OMITTED] TP09SE10.036
Where:
P = number of doorway passages (i.e., number of doors opening
events),
[thgr]p = door open-close time (seconds/P),
[thgr]o = time door stands open (minutes), and
[thgr]d = daily time period (h). 75 FR 197.
For glass display doors and all other doors, DOE specified P = 72
and 60, respectively. Required values for [thgr]p: (1)
reach-in glass doors, [thgr]p = 8 seconds; (2) all other
doors, [thgr]p = 15 seconds; and (3) if an automatic door
opener/closer is used, [thgr]p = 10 seconds. DOE required
glass display doors [thgr]o = 0 minutes and all other doors,
[thgr]o= 15 minutes.
Hired Hand proposed revised parameters for the number of door
openings (P), steady-state time, and all other parameters in the
equation for infiltration due to door openings both for doors with
automatic door closures and manually closed larger doors, because, in
its view, the proposed parameters are adequate for display cases and
small walk-ins but insufficient for evaluating large retail supermarket
applications (storage warehouse coolers and freezers where door entry
width is greater than 4 feet and serviced by employees only). (Hired
Hand, No. 1.3.033 at p. 3) Schott Gemtron stated that DOE needs to
distinguish between glass display doors and service doors because
service doors are not opened as often. (Schott Gemtron, Public Meeting
Transcript, No. 1.2.010 at p. 314) Hired Hand also stated that DOE
should clarify the coverage of doors because they believe the intent of
EISA 2007 was targeted mainly at retail applications with doors smaller
than 45 inches in width. (Hired Hand, No. 1.3.033 at p. 1)
DOE agrees with Hired Hand and Schott Gemtron that additional
refinement to assumptions can be made to differentiate between glass
display, passage (or service), and freight doors. In addition, to
reflect the benefit from the use of automated doors, DOE proposes to
modify the value of [thgr]o when a sensor and automated
open/close system is included. Therefore, DOE proposes to define
``glass display door'' as a door designed for the movement and/or
display of product rather than the passage of persons, ``passage door''
(or ``service door'') as an opaque door that is less than or equal to a
45-inch width and designed for the passage of persons, and ``freight
door'' as an opaque door that is greater than 45-inch width. DOE cannot
specifically exclude doors wider than 45 inches if they are used on a
walk-in cooler or walk-in freezer that is not excluded from coverage by
EISA 2007, as suggested by Hired Hand.
The new assumptions regarding doors are reflected in Table III.4.
Table III.4--Assumptions to Differentiate Door Types
--------------------------------------------------------------------------------------------------------------------------------------------------------
[thgr]p,w [thgr]o,w/
Door type P [thgr]p sec sensor sec [thgr]o min sensor min [thgr]d hrs Note
--------------------------------------------------------------------------------------------------------------------------------------------------------
Glass Display........................ 72 8 -- 0 -- 24 Proposed in NOPR.
Passage.......................... 60 15 10 15 -- 24
Freight.......................... 60 15 10 15 -- 24
Glass Display........................ 72 8 -- 0 -- 24 SNOPR.
Passage.......................... 60 15 10 30 10 24
Freight.......................... 120 60 30 60 20 24
--------------------------------------------------------------------------------------------------------------------------------------------------------
DOE seeks comment on this alternative approach and modified
assumptions.
12. Infiltration Reduction Device Effectiveness
DOE discovered an error in Eq. 3-25 after the January NOPR was
published. DOE notified stakeholders of the error and correction at the
public meeting.
DOE proposes to use the corrected Eq. 3-25 in the final rule.
ThermalRite supported the infiltration reduction device (IRD)
effectiveness test methodology, but stated that manufacturers of IRDs
should perform the testing. (ThermalRite, No. 1.3.031 at p. 2) DOE
acknowledges that it may be more appropriate for a third party to test
an IRD by itself, whether that third party is the IRD manufacturer or a
different entity, because IRD effectiveness is largely independent of
other envelope characteristics. Therefore, DOE proposes several
modifications to the IRD effectiveness test that it initially proposed.
These modifications would permit testing to be done by the IRD
manufacturer, the envelope manufacturer, or another entity. The
modifications that DOE is considering as alternatives to its initially
proposed approach may be found in section 4.3 of Appendix A.
[[Page 55086]]
Hired Hand stated that DOE should include an assumed performance
value for IRDs that are subject to degradation and do not perform
consistently over time. (Hired Hand, No. 1.3.033 at p. 5 and Public
Meeting Transcript, No. 1.2.010 at p. 310) DOE believes it is
reasonable to incorporate assumed performance values because an
established body of research supports these values. While the
assumptions do not reflect all real-world WICF door use scenarios or
applications, it is necessary for DOE to assume values to ensure a
uniform testing method to rate walk-ins. These assumptions are stated
in section 4.3 of proposed Appendix A to this SNOPR.
DOE seeks comment on this alternative approach.
13. Relative Humidity Assumptions
In the January NOPR, DOE proposed the assumption of an internal
walk-in relative humidity of 45 percent. This value was selected to
match AHRI-1250 test dry-coil conditions. However, these conditions do
not necessarily reflect general walk-in humidity conditions; rather,
the conditions were chosen to test refrigeration systems when there is
little or no frost load on the evaporator coil. DOE recognizes that, in
practice, the relative humidity (RH) varies significantly depending on
the product stored within a walk-in.
In order to reflect higher RH values experienced in practice, DOE
proposes a new assumption of 75 percent RH for both freezer and cooler
internal conditions. This RH level is within the 65-85 percent range of
humidity levels used in practice for products from canned beverages
such as beer to packaged fruits and vegetables. DOE seeks comment on
this assumption in addition to assumptions found in proposed Appendix
A, section 2.1(e).
C. Refrigeration System
As previously discussed, DOE is proposing for the purposes of this
test procedure to draw a distinction between the envelope or structure
of the walk-in cooler or walk-in freezer and the mechanical
refrigeration system performing the physical work necessary to cool the
interior space. The refrigeration system itself could be one of three
types: (1) Single-package systems containing the condensing and
evaporator units; (2) split systems with the condensing unit and unit
cooler physically separated and connected via refrigerant piping; or
(3) rack systems utilizing unit coolers, which receive refrigerant from
a shared loop. The following section addresses issues raised by
interested parties that prompted DOE to consider other options in
addition to those proposed in the January NOPR.
1. Definition of Refrigeration System
During the NOPR public meeting, DOE stated that it was considering
the following changes to the definition of refrigeration system:
substituting ``integrated single package refrigeration unit'' with ``a
packaged system where the unit cooler and condensing unit are
integrated into a single piece of equipment'' in order to clarify the
term and substituting ``central rack system'' with ``multiplex
condensing system'' because the latter is a more inclusive term and may
be more technically accurate.
Thermal-Rite and Nor-Lake expressed support for the revised
definition of refrigeration system. (Thermal-Rite, No. 1.3.031 at p. 1;
Nor-Lake, No. 1.3.029 at p. 2) ACEEE stated that the definition
proposed in the January NOPR seemed appropriate and seems to recognize
the varieties serving the marketplace. (ACEEE, No. 1.3.034 at p. 2)
Master-Bilt, BASF, and Kason all stated that they agreed with the
definition but did not specify which version they supported. (Master-
Bilt, No. 1.3.009 at p. 2; BASF, No. 1.3.003 at p. 5; Kason, No.
1.3.037 at p. 4) On the other hand, Craig stated that the definition of
refrigeration system should include a temperature limit and suggested
45 [deg]F as the upper limit. (Craig, No. 1.3.036 at p. 84) A person
affiliated with Gonzaga Law also viewed the proposed definition of
refrigeration equipment as too inclusive but did not specify how DOE
could improve it. (William Gray, Gonzaga Law, No. FDMS 0003 at p. 1)
HeatCraft stated that DOE should have an exemption for refrigeration
equipment that serves loads other than walk-ins. (HeatCraft, Public
Meeting Transcript, No. 1.2.010 at p. 92)
Regarding the above comments, DOE believes that adding a
temperature limit to the definition of refrigeration system, as
suggested by Craig, is unnecessary because DOE is already proposing to
add a temperature limit to the definition of walk-ins that will cover
both envelopes and refrigeration systems. To address HeatCraft's
concern, DOE has included the term ``multiplex equipment'' in the
definition to refer to refrigeration equipment serving loads other than
walk-ins. DOE's revised definition includes unit coolers connected to
multiplex systems, meaning that only the unit cooler is covered in any
refrigeration system that incorporates a multiplex system. The
multiplex systems themselves would not be covered.
Consistent with its discussions at the public meeting, DOE is also
proposing to revise its proposed definition of the term ``refrigeration
system'' with respect to WICF equipment. DOE requests comment on the
proposed alternative definition.
2. Version of AHRI 1250
In the January NOPR, DOE proposed to incorporate the industry
standard AHRI 1250P-2009, ``Standard for Performance Rating of Walk-In
Coolers and Freezers,'' into the test procedure. The January NOPR
inadvertently referred to the preliminary version of this standard,
while the final published version is AHRI 1250-2009, which was
published in September 2009. DOE found no significant differences
between the preliminary version and the final version; nevertheless,
DOE proposes to incorporate the most recent version, AHRI 1250-2009,
into the final test procedure.
3. Annual Walk-In Energy Factor
DOE is required by EPCA to establish a test procedure to measure
the energy use of walk-in coolers and walk-in freezers. (42 U.S.C.
6314(a)(9)(B)(i)) AHRI 1250-2009 determines the annual walk-in energy
factor (AWEF) as its final metric, 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 energy consumption.
Because AWEF is essentially a measure of efficiency, DOE proposed in
the January NOPR to develop equations to derive energy consumption from
AWEF. 75 FR 202-203. DOE also proposed to require manufacturers to
report both AWEF and energy consumption and asked for comment on this
approach. 75 FR 202-203.
Nor-Lake agreed with the proposed method of measuring and
calculating the energy use of refrigeration systems (Nor-Lake, No.
1.3.005 at p. 4) but also cautioned that both the methodology for
deriving annual energy consumption from AWEF and the reporting
requirements should be consistent across all manufacturers. (Nor-Lake,
No. 1.3.029 at p. 5) Manitowoc, on the other hand, stated that AWEF is
a more useful metric than energy consumption because the calculated
energy consumption may not be an accurate representation of actual
energy consumption in the field as the load profile in the test
procedure is arbitrary. Rather, AWEF can be used to easily estimate
actual energy consumption if the actual load is known, and AWEF
[[Page 55087]]
also allows for comparisons between higher and lower efficiency
systems. (Manitowoc, Public Meeting Transcript, No. 1.2.010 at p. 375)
Arctic suggested that DOE could develop software to assist businesses
with calculating energy consumption. (Arctic, Public Meeting
Transcript, No. 1.2.010 at p. 392)
Because EISA requires that the test procedure measure energy use,
as explained above, DOE continues to propose that manufacturers measure
and report both AWEF and the measure of energy use derived from AWEF as
determined by the test procedure. The calculation methodology and
reporting requirements will be consistent across manufacturers as
suggested by Nor-Lake.
DOE notes that in the course of performing the test procedure and
determining AWEF, the annual energy use of a walk-in refrigeration
system may be found as an intermediate result or easily derived from
AWEF or other intermediate results. Thus, DOE proposes to simplify the
method by which energy use is determined by introducing revised
calculations in the rule language. DOE requests comment on the
simplified calculations.
DOE does not intend to develop software for calculating energy use,
as suggested by Arctic, because this is outside the scope of the
rulemaking. The proposed test procedure contains all the necessary
calculations for determining AWEF and energy use, and manufacturers may
develop or use their own software that assists them in performing these
calculations if they choose.
IV. Regulatory Review
A. Review Under Executive Order 12866
The Office of Management and Budget (OMB) has determined that test
procedure rulemakings do not constitute ``significant regulatory
actions'' under Executive Order (E.O.) 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 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 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 DOE's implementing regulations at 10 CFR part 1021.
More specifically, today's proposed rule is covered by the categorical
exclusion in paragraph A5 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 E.O. 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 supplemental
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
manufacturers, all manufacturers, including small manufacturers, could
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
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 (SBA)
for review. This SNOPR includes changes made to the IRFA in light of
comments from interested parties on the January NOPR, specifically
regarding the number of small entities regulated and the potential
testing burden. The revised IRFA also considers the burden of new tests
that DOE is proposing in this SNOPR.
1. Reasons for the Proposed Rule
The reasons for this proposed rule are discussed elsewhere in the
preamble and not repeated here.
2. Objectives of and Legal Basis for the Proposed Rule
The objectives of and legal basis for the proposed rule are
discussed elsewhere in the preamble and not repeated here.
3. Description and Estimated Number of Small Entities Regulated
DOE uses the SBA small business size standards published on January
31, 1996, as amended, 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. 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.
In the January NOPR, DOE classified walk-in cooler and freezer
equipment manufacturing under NAICS 333415, ``Air-Conditioning and Warm
Air Heating Equipment and Commercial and Industrial Refrigeration
Equipment Manufacturing,'' which has a size standard of 750 employees.
75 FR 204. After reviewing industry sources and publicly available
data, 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 that met this criterion.
In comments on the January NOPR, both American Panel and Kysor said
that virtually all panel and walk-in manufacturers are small businesses
under this standard. (American Panel, Public Meeting Transcript, No.
1.2.010 at p. 379; Kysor, No. 1.3.035 at p. 3) Craig said that it was a
small business under this standard. (Craig, Public Meeting Transcript,
No. 1.2.010 at p. 17) Schott Gemtron stated that over 90 percent of the
membership of the trade association of North American Food Equipment
Manufacturers (NAFEM)
[[Page 55088]]
was under $12 million in sales. (Schott Gemtron, Public Meeting
Transcript, No. 1.2.010 at p. 389) Several commenters listed sources
DOE could use to identify small businesses: Nor-Lake recommended the
NSF Standard 7 listings, Arctic recommended the NAFEM database, and ICS
recommended the central contractor registry. (Nor-Lake, No. 1.3.029 at
p. 5; Arctic, Public Meeting Transcript, No. 1.2.010 at p. 388; and
ICS, Public Meeting Transcript, No. 1.2.010 at p. 390)
In light of these comments and additional research conducted by
DOE, the industry can be characterized by a few manufacturers that are
subsidiaries of much larger companies (who would not be considered
small businesses) and a large number of small companies as categorized
by NAICS code 333415. Furthermore, more than half of small walk-in
manufacturers have 100 or fewer employees. DOE acknowledges the sources
provided by Nor-Lake, Arctic, and ICS and will consider these sources
in its characterization of the industry in the final regulatory
flexibility analysis (FRFA).
4. Description and Estimate of Compliance Requirements
In the NOPR, DOE described potential impacts of the proposed test
procedures. DOE received comments from manufacturers regarding the
estimated impacts. Arctic stated that potential impacts of the proposed
test procedures on manufacturers, including small businesses, come from
impacts associated with the cost of testing. (Arctic, No. 1.3.012 at p.
1) ICS commented that burden would come both from testing cost and
length of time required to perform the tests. (ICS, No. 1.3.027 at p.
2) BASF commented on specific tests, stating that ASTM C1303-08 is more
expensive than ASTM C518-04 and that ASTM E741-06 and AHRI 1250-2009
were even more expensive. (BASF, No. 1.3.003 at p. 5) Master-Bilt,
American Panel, and Hill Phoenix all commented that the test procedure
would be particularly burdensome to small businesses. (Master-Bilt, No.
1.3.009 at p. 3; American Panel, No. 1.3.024 at p. 4; Hill Phoenix, No.
1.2.023 at p. 3) Craig asserted that the cost of testing could be up to
$1 million and would be likely to put small companies out of business
or force them to sell noncompliant products. (Craig, No. 1.3.017 at p.
1; No. 1.3.036 at p. 4; and Public Meeting Transcript, No. 1.2.010 at
p. 18)
Envelope Manufacturer Testing Impacts
In the January NOPR, DOE proposed to require envelope manufacturers
to test their equipment 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'' (ASTM C1303-08 has since been updated
to ASTM C1303-10, but the updated version contains no substantive
changes that would affect the testing cost). 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.
Therefore, in the January NOPR, DOE estimated that the cost of testing
for one walk-in would range from $6,000 to $15,000. Also, DOE estimated
that a typical manufacturer would have approximately 8 basic envelope
configurations that would need to be tested, so the total cost of
compliance due to testing would be approximately $84,000 (ranging from
$48,000 to $120,000). This estimated total cost only includes the cost
of one test on each basic configuration, and does not include
additional testing on the same basic model that may be required as part
of a sampling plan. DOE may consider development of a sampling plan in
a future rulemaking.
The revisions to the proposed test procedure that are proposed in
this SNOPR for envelope manufacturers would require testing in
accordance with the two tests mentioned above as well as an additional
test: ASTM C1363-05, ``Standard Test Method for Thermal Performance of
Building Materials and Envelope Assemblies by Means of a Hot Box
Apparatus.'' The SNOPR would also require the measurement of heat gain
through doors (with and without IRD and including glass doors) to be
tested using NFRC procedures, rather than allowing for use of either
the NFRC procedures or the Window 5.2 program. DOE determined that a
test using ASTM C1363-05 costs between $1,000 and $3,000, and NFRC
testing cost varies between $1,000 and $10,000 for all doors and IRDs
depending on product lines. However, NFRC has reduced fees for small
businesses, which it defines as companies with less than $1 million in
sales.\1\ These reduced fees are 50 percent of members' annual fees and
product line fees (33 percent of non-members' annual fees and product
line fees), and a waiver of label fees. DOE realizes that this
definition differs from the SBA size threshold set out for walk-in
envelope manufacturers but believes that some entities that are small
businesses pursuant to SBA's size threshold could also qualify for
these reduced fees.
---------------------------------------------------------------------------
\1\ http://www.nfrc.org/documents/ProgramCostsFactsheet.pdf.
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To address the comments from Arctic, ICS, BASF, Master-Bilt,
American Panel, Hill Phoenix, and Craig regarding testing costs, DOE
notes that provisions in the January NOPR and revisions to the proposed
test procedure that are considered in this SNOPR allow manufacturers to
test a limited number of models and model components and then calculate
the performance of other models from the test results. Measurements
incorporating these revisions include heat transfer through panels (see
section III.B.1), steady state infiltration through the envelope (see
section III.B.9), and door and IRD performance (see section III.B.12).
DOE estimates that a typical envelope manufacturer could be required to
perform ASTM C1303-10 on between 1 and 2 types of foam; ASTM C1363-05
on 1 to 2 types of panel pairs; ASTM E741-06 on 1 to 2 envelopes; and
NFRC testing on 1 to 3 types of doors and 1 to 3 types of IRD. The
total cost of one test on each type of walk-in or component listed
could range from $8,000 to $46,000. This estimated cost could vary
significantly depending on the number of unique components incorporated
into a particular manufacturer's walk-ins. Furthermore, the estimated
total cost only includes the cost of one test on each item listed. DOE
may consider developing a sampling plan in a future rulemaking to
determine how many tests need to be performed on the same type of
envelope or component, to ensure the test results are repeatable and
statistically valid. Therefore, DOE welcomes comment on this estimate.
Refrigeration System Manufacturer Testing Impacts
The proposed test procedure for refrigeration systems would require
manufacturers to perform testing in accordance with a single industry
test standard: AHRI Standard 1250-2009, ``2009 Standard for Performance
Rating of Walk-In Coolers and Freezers.'' Because this test was
recently developed by the industry and has not
[[Page 55089]]
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 estimated in the January NOPR
that a test using AHRI Standard 1250-2009 would likely cost
approximately $5,000. DOE has not received evidence to the contrary and
thus maintains this estimate for the SNOPR for a single test. In the
January NOPR, DOE estimated that the total testing cost for a typical
refrigeration manufacturer could be approximately $250,000, based on an
estimate of 50 basic models, but it could be higher for manufacturers
of more customized equipment. For instance, a manufacturer with 200
basic models would incur a testing cost of approximately $1 million.
Master-Bilt stated that they sell over 160 models of condensing units
and 130 models of evaporators, with over 1500 combinations. (Master-
Bilt, No. 1.3.009 at p. 3) (DOE notes that Master-Bilt is not
considered a small business because it has more than 750 employees
including its parent company.) In comments on the January NOPR, Craig
stated that under DOE's estimated cost of $250,000, small manufacturers
would be forced to discontinue assembling their own refrigeration
systems and instead purchase units from large manufacturers, making
them less competitive. (Craig, No. 1.3.017 at p. 2) DOE further notes
that the estimated testing cost does not include cost of the tested
equipment and asks whether manufacturers could sell equipment that had
been tested, thus reducing this cost.
To address these concerns, DOE is proposing burden-reducing
measures for refrigeration system manufacturers similar to those for
envelope manufacturers. The test procedure proposed in the January
NOPR, AHRI 1250-2009, which DOE continues to propose in this SNOPR,
allows for rating the condensing unit and the unit cooler separately
and then calculating their combined efficiency; this would reduce
testing burden by not requiring every combination to be tested.
Allowing for the use of such a calculation would significantly decrease
the number of tests.
DOE recognizes the particular burden of the envelope and
refrigeration tests on small manufacturers. Because the cost of running
each test is the same for all manufacturers, both small and large, and
because DOE has proposed measures to reduce burden on all such
manufacturers, manufacturers would likely incur comparable absolute
costs as a result of the proposed test procedures. However, Kason
stated that the burden of testing will be greater on small
manufacturers because they will sell fewer units per type of basic
model. (Kason, No. 1.3.037 at p. 4) Indeed, 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, the
differential impact associated with walk-in cooler and walk-in freezer
test procedures on small businesses may be significant even if the
overall testing burden is reduced as described above. DOE requests
comment on quantitative differential impacts and will consider
presenting such impacts in the FRFA.
To further address concerns about costs, DOE notes that for both
envelopes and refrigeration systems, DOE may consider development of a
sampling plan to determine how many units must be tested to establish
compliance and enforcement requirements. In such a rulemaking, however,
DOE could also consider additional methods to reduce the testing burden
on manufacturers. For example, DOE could consider allowing
manufacturers to rely on component suppliers for test results, and
manufacturers could then use these values in their calculations of
energy consumption of the walk-in. DOE could also allow manufacturers
to group basic models into a ``family'' of models and only require the
lowest-efficiency basic model in the family to be certified. DOE could
also consider allowing manufacturers to use validated alternative
efficiency determination methods, or AEDMs, which could consist of a
calculation or computer program, to rate their equipment. DOE will
consider the impacts to small businesses of future certification,
compliance, and enforcement provisions for walk-in coolers and freezers
in a later rulemaking.
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 to $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.
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 $300-$ to 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 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 could not be
tested at or close to operational temperatures, resulting in a test
that does not accurately reflect its performance.
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 1250-2009. 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 1250-2009 requires testing at three sets of ambient
conditions for refrigeration systems with the condensing units located
outdoors. The additional time required to test the system at three sets
[[Page 55090]]
of conditions would incur additional cost and could make AHRI Standard
1250-2009 more burdensome than ARI Standard 1200-2006. However, DOE
believes that AHRI Standard 1250-2009 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 1250-2009 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. Because AHRI 1250-2009 requires the system to be
tested at three ambient temperatures, it captures energy savings from
features (e.g., floating head pressure) that allow the system to use
less energy at lower ambient temperatures.
DOE requests comment on the impacts to small business manufacturers
for these and any other possible alternatives to the proposed rule.
D. Review Under the Paperwork Reduction Act
DOE recognizes that if it adopts standards for walk-in coolers and
walk-in freezers, once the standards become operative, manufacturers
would become subject to record-keeping requirements associated with
compliance with the standards. Such record-keeping requirements would
require OMB approval pursuant to the Paperwork Reduction Act, 44 U.S.C.
3501, et seq. DOE will comply with the 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 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 before establishing any requirements that might significantly or
uniquely potentially affect small governments. On March 18, 1997, DOE
published a statement of policy on its process for intergovernmental
consultation under UMRA. 62 FR12820. (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 E.O. 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 E.O. 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 E.O. 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 E.O. 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 E.O. 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. Both OMB's and
DOE's guidelines were published. 67 FR 8452 (February
[[Page 55091]]
22, 2002) and 67 FR 62446 (October 7, 2002), respectively. 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), OMB, a Statement
of Energy Effects for any proposed significant energy action. A
``significant energy action'' is defined as any action by an agency
that promulgated or is expected to lead to promulgation of a final
rule, and that is (1) a significant regulatory action under E.O. 12866,
or any successor order; and (2) likely to have a significant adverse
effect on the supply, distribution, or use of energy; or (3) 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 E.O. 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 E.O. 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 U.S. Constitution.
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.'' DOE
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. Submitting Public Comment
DOE will accept comments, data, and information regarding the
supplement to 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. 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 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.
B. Issues on Which DOE Seeks Comment
DOE is particularly interested in receiving comments on the
following issues:
1. Upper Limit of Walk-In Cooler
EPCA defines walk-in cooler or walk-in freezer as ``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.'' (42 U.S.C.
6311(20)(A)) DOE proposes clarifying the term ``refrigerated'' within
the definition of walk-in cooler or walk-in freezer to distinguish
walk-ins from conditioned storage spaces. DOE proposes an upper limit
of 55 [deg]F because this is a generally accepted boundary between
``refrigerated space'' and ``conditioned space.'' DOE requests comment
on this proposal. For details, see section III.A.1.
2. Basic Model of Envelope
Although often manufactured according to the same basic design,
walk-in envelopes are so highly customized that each walk-in a
manufacturer builds may be unique. To address this possibility, DOE
proposed the following in the January NOPR: (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. 75 FR 189.
Upon further consideration, DOE proposes in this SNOPR that a basic
model of walk-in envelope should include equipment with the same design
features, components, manufacturing method, etc., such that
[[Page 55092]]
units within the basic model are the same with respect to the
normalized energy consumption as determined by the test procedure
(i.e., the energy consumption divided by square feet of surface area.)
DOE believes that this definition of basic model will ensure that all
equipment is accurately rated and complies with the standard.
DOE recognizes this revised definition of ``basic model'' is
narrower than the definition proposed in the January NOPR. However, the
increase in test burden resulting from the narrower definition could be
offset by the burden-reducing measures proposed elsewhere in the test
procedure. Additionally, this definition would be consistent with the
definition of basic model elsewhere in the appliance standards program.
The proposed definition would provide a way of distinguishing walk-ins
that differ in energy consumption from walk-ins that differ only in
cosmetic or non-energy-related features. DOE requests comment on the
proposed definition. For details, see section III.A.3.
3. Basic Model of Refrigeration
Interested parties commented that the definition proposed in the
January NOPR was ambiguous; thus, DOE proposes to clarify the
definition.
As with envelopes, DOE must ensure that all refrigeration systems
are accurately rated and comply with the standard. Therefore, DOE
proposes a definition for basic model of walk-in refrigeration such
that units within the basic model must be the same with respect to
energy consumption as determined by the test procedure. To relieve
potential testing burden of many combinations of equipment, the
proposed test procedure provides for rating a refrigeration system's
condenser and evaporator separately and then calculating the system
energy consumption. DOE requests comment on the revised approach and
definition of basic model of refrigeration. For details, see section
III.A.4.
4. Updates to Standards
After the NOPR was published, DOE learned that two of the standards
incorporated by reference had been updated. DOE proposes to incorporate
the updated versions in the final rule. For details, see sections
III.B.4 and III.C.2.
5. Heat Conduction Through Structural Members
Interested parties commented that DOE's proposed test procedure did
not account for heat conduction through structural members of the
envelope such as a wood frame. Therefore, in this SNOPR, DOE proposes
that panels (walls, ceilings, and floors) made with foam insulation are
tested using ASTM C1363-05, ``Standard Test Method for Thermal
Performance of Building Materials and Envelope Assemblies by Means of a
Hot Box Apparatus,'' for measuring the overall U-factor of fully-
assembled panels. The resulting composite panel U-factor found by ASTM
C1363-05 will then be corrected using the LTTR results from ASTM C1303-
10. DOE believes that using the results from ASTM C1363-05 modified by
ASTM C1303-10 best captures the impact of structural members and long-
term R-value of foam products. DOE requests comment on this approach.
For details, see section III.B.1.
6. Alternatives to ASTM C1303-10
DOE proposes the use of alternative test methods found in Annex C
of EN 13165:2009-02 and EN 13164:2009-02 for determining the long term
thermal resistance (LTTR) of walk-in panels made using foam insulation.
For details, see section III.B.3.
7. Improvements to ASTM C1303 Methodology
DOE proposes several modifications to the ASTM C1303 methodology to
address sample preparation and applicability to certain types of foam
used in walk-ins and requests comment on these modifications. For
details, see section III.B.5.
8. Conduction Through Floors
In the January NOPR, DOE proposed an equation to calculate the heat
transfer through the floor of both insulated and uninsulated WICF, and
proposed assumptions for subfloor temperature and floor R-value (where
the floor is provided separately from the panels). Between the
publication of the January NOPR and the public meeting, DOE completed
additional finite element model (FEM) computer simulations of floorless
coolers. Based on FEM simulation results, DOE described a new equation
during the public meeting for calculating heat transfer through
floorless coolers. In light of this modeling and additional comments
from interested parties, DOE is proposing a new method for calculating
the heat transfer through certain floors. See section III.B.6 for more
details.
9. ``Hybrid'' Walk-ins
In the January NOPR, the calculation procedure provided a means of
rating all walk-ins including the scenario when a freezer is sited
inside a cooler or a cooler and freezer share a wall. Modifications
described in this SNOPR ensure that the rating of these walk-in cooler/
freezer hybrids is properly captured. DOE seeks comment on these
modifications and the accuracy of the new equations. See section
III.B.7 for details.
10. U-Factor of Doors and Windows
DOE proposes to base the calculation of U-factor of doors and glass
windows on NFRC 100-2010-E0A1, ``Procedure for Determining Fenestration
Product U-Factors'' and requests comment on this proposal. For details,
see section III.B.7.
11. Envelope Infiltration
DOE proposes modifications to its calculations and methodology for
determining steady state infiltration rate through panel-to-panel and
door-to-panel interfaces. DOE also modified its proposed assumptions
for door opening infiltration and effectiveness of infiltration
reduction devices. DOE requests comment on its approach and assumptions
related to infiltration. For details, see sections III.B.9, III.B.10,
III.B.11, and III.B.12.
12. Relative Humidity Assumptions
In the January NOPR, DOE proposed the assumption of an internal
walk-in relative humidity of 45 percent to be consistent with dry-coil
conditions in the proposed refrigeration system test. DOE recognizes
that in practice the relative humidity (RH) varies significantly
depending on the product stored within a walk-in. Therefore, in order
to reflect higher RH values experienced in practice, DOE proposes a new
assumption of 75 percent RH for both freezer and cooler internal
conditions. DOE seeks comment on this assumption. See section III.B.7
for details.
13. Definition of Refrigeration System
In the January NOPR, DOE proposed a definition of refrigeration
system and then presented a revised definition at the NOPR public
meeting. In light of comments from interested parties, DOE is proposing
to incorporate its revised definition with some modification. DOE
requests comment on the revised definition and whether any previously
proposed versions of the definition are preferable. See section III.C.1
for details.
14. Annual Walk-In Energy Factor
DOE is required by EPCA to establish a test procedure to measure
the energy use of walk-in coolers and walk-in freezers. (42 U.S.C.
6314(a)(9)(B)(i)) AHRI 1250-2009 determines the annual walk-in energy
factor (AWEF) as its final metric, which is the ratio of the annual
[[Page 55093]]
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 energy consumption.
In the course of performing the test procedure and determining AWEF,
the annual energy use of a walk-in refrigeration system may be found as
an intermediate result or easily derived from AWEF or other
intermediate results. Thus, DOE proposes to simplify the method by
which energy use is determined and require manufacturers to determine
both energy use and AWEF. DOE requests comment on the simplified
calculations in the rule language. For details, see section III.C.3.
15. Impacts on Small Businesses
In the January NOPR, DOE prepared an initial regulatory flexibility
analysis (IRFA) as required by the Regulatory Flexibility Act (5 U.S.C.
601 et seq.) because it could not certify that the rule, if
promulgated, will not have a significant economic impact on a
substantial number of small entities. DOE received comment from
interested parties on the number of small entities and the expected
economic impact of the proposed test procedure on small entities and
has revised the IRFA accordingly. DOE continues to request comment on
impacts to small business manufacturers, particularly differential
impacts to small and large businesses. More information, along with
revisions to 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 supplement
to the proposed rule.
List of Subjects in 10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Energy conservation, Incorporation by reference, Reporting
and recordkeeping requirements.
Issued in Washington, DC, on August 23, 2010.
Cathy Zoi,
Assistant Secretary, Energy Efficiency and Renewable Energy.
For the reasons stated in the preamble, DOE proposes to revise 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 the definitions for ``Basic
Model,'' ``Envelope,'' ``Refrigerated,'' ``Refrigeration system,'' and
``Walk-in equipment'' in alphabetical order to read as follows:
Sec. 431.302 Definitions concerning walk-in coolers and walk-in
freezers.
Basic model means--
(1) With respect to envelopes, all units manufactured by a single
entity, which do not have any differing features or characteristics
that affect normalized energy consumption.
(2) With respect to refrigeration systems, all units manufactured
by a single entity, which do not have any differing electrical,
physical, or functional characteristics that 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.
Refrigerated means held at a temperature at or below 55 degrees
Fahrenheit using a refrigeration system.
Refrigeration system means the mechanism (including all controls
and other components integral to the system's operation) used to create
the refrigerated environment in the interior of a walk-in cooler or
freezer, consisting of:
(1) A packaged system where the unit cooler and condensing unit are
integrated into a single piece of equipment,
(2) A split system with separate unit cooler and condensing unit
sections, or
(3) A unit cooler that is connected to a multiplex condensing
system.
* * * * *
Walk-in equipment means either the envelope or the refrigeration
system of a walk-in cooler or freezer.
3. In Sec. 431.303, add new paragraphs (b)(2), (b)(3), (b)(4),
(b)(5), (c), (d), and (e) to read as follows:
Sec. 431.303 Materials incorporated by reference.
* * * * *
(b) * * *
(2) ASTM C1303-10, Standard Test Method of Predicting Long Term
Thermal Resistance of Closed-Cell Foam Insulation, approved 2010, IBR
approved for Sec. 431.304.
(3) ASTM C1363-05, Standard Test Method for Thermal Performance of
Building Materials and Envelope Assemblies by Means of a Hot Box
Apparatus, approved 2005, IBR approved for Sec. 431.304.
(4) ASTM E283-04, Standard Test Method for Determining Rate of Air
Leakage Through Exterior Windows, Curtain Walls, and Doors Under
Specified Pressure Differences Across the Specimen, approved 2004, IBR
approved for Sec. 431.304.
(5) 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 1250-2009, 2009 Standard for Performance Rating
of Walk-In Coolers and Freezers, approved September 2009, IBR approved
for Sec. 431.304.
(2) [Reserved].
(d) CEN. European Committee for Standardization (French: Norme or
German: Norm), Avenue Marnix 17, B-1000 Brussels, Belgium, Tel: + 32 2
550 08 11, Fax: + 32 2 550 08 19 or http://www.cen.eu/.
(1) EN 13164:2009-02, Thermal insulation products for buildings--
Factory made products of extruded polystyrene foam (XPS)--
Specification, approved February 2009, IBR approved for Sec. 431.304.
(2) EN 13165:2009-02, Thermal insulation products for buildings--
Factory made rigid polyurehane foam (PUR) products--Specification,
approved February 2009, IBR approved for Sec. 431.304.
(e) NFRC. National Fenestration Rating Council, 6305 Ivy Lane, Ste.
140, Greenbelt, MD 20770, (301) 589-1776, or http://www.nfrc.org.
(1) NFRC 100-2010-E0A1, Procedure for Determining Fenestration
Product U-factors, approved June 2010, IBR approved for Sec. 431.304.
(2) NFRC 400-2010-E0A1, Procedure for Determining Fenestration
Product Air Leakage, approved June 2010, IBR approved for Sec.
431.304.
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
[[Page 55094]]
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.
(i) Determine the Annual Walk-in Energy Factor of walk-in cooler
and walk-in freezer refrigeration systems by conducting the test
procedure set forth in AHRI Standard 1250-2009 (incorporated by
reference, see Sec. 431.303).
(ii) Determine the annual energy consumption of walk-in cooler and
walk-in freezer refrigeration systems:
(A) For systems consisting of an integrated single-package
refrigeration unit or a split system with separate unit cooler and
condensing unit sections, where the condensing unit is located
outdoors, by conducting the test procedure set forth in AHRI Standard
1250-2009 (incorporated by reference, see Sec. 431.303) and recording
the annual energy consumption term in the equation for annual walk-in
energy factor in section 7:
[GRAPHIC] [TIFF OMITTED] TP09SE10.037
where tj and n 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 1250-2009
(incorporated by reference, see Sec. 431.303).
(B) For systems consisting of an integrated single-package
refrigeration unit or a split system with separate unit cooler and
condensing unit sections, where the condensing unit is located in a
conditioned space, by performing the following calculation:
[GRAPHIC] [TIFF OMITTED] TP09SE10.038
where BLH and BLL for refrigerator and freezer systems are defined
in section 6.2.1 and 6.2.2, respectively, of AHRI Standard 1250-2009
(incorporated by reference, see Sec. 431.303) and the annual walk-
in energy factor is calculated from the results of the test
procedures set forth in AHRI Standard 1250-2009 (incorporated by
reference, see Sec. 431.303).
(C) For systems consisting of a unit cooler connected to a rack
system, by performing the following calculation:
[GRAPHIC] [TIFF OMITTED] TP09SE10.039
where BLH and BLL refrigerator and freezer systems are defined in
section 7.9.2.2 and 7.9.2.3, respectively, of AHRI Standard 1250-
2009 (incorporated by reference, see Sec. 431.303) and the annual
walk-in energy factor is calculated from the results of the test
procedures set forth in AHRI Standard 1250-2009 (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) Steady-state: The condition where the average internal
temperature changes less than 1[deg]C (2 [deg]F) from one hour
period to the next.
(b) Door: An assembly installed in or on an interior or exterior
wall; that is movable in a sliding, pivoting, hinged, or revolving
manner of movement; and that is used to produce or close off an
opening in the walk-in. For walk-ins, a door includes the door
panel, glass, framing materials, door plug, mullion, and any other
elements that form the door or part of its connection to the wall.
(1) Passage door: A door designed for human passage or movement
of product through the walk-in. A passage door may accommodate a
hand cart or equivalent.
(2) Freight door: A door designed for human passage or movement
of product through the walk-in. A freight door may accommodate a
forklift or equivalent.
(3) Display door: A door designed for the movement and/or
display of product rather than the passage of persons
(4) Glass door: A door comprised of 50 percent or more glass,
irrespective of intended use.
(c) Surface area: Unless explicitly stated otherwise, the
surface area for all measurements is the area as measured on the
external surface of the walk-in.
(d) Automatic door opener/closer: A device or control system
that ``automatically'' opens and closes doors without direct user
contact (e.g., a motion sensor that senses when a forklift is
approaching the entrance to a door, opens, and then closes after the
forklift has passed).
(e) Rating conditions: Unless explicitly stated otherwise, all
calculations and test procedure measurements shall use the
temperature and relative humidity data shown in Table A.VI.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.VI.1--Temperature and Relative Humidity Conditions
------------------------------------------------------------------------
Value Units
------------------------------------------------------------------------
Internal Conditions (cooled space within envelope)
------------------------------------------------------------------------
Cooler:
Dry Bulb Temperature................................ 35 [deg]F
Relative Humidity................................... 75 %
Freezer:
Dry Bulb Temperature................................ -10 [deg]F
Relative Humidity................................... 75 %
------------------------------------------------------------------------
External Conditions (space external to the envelope)
------------------------------------------------------------------------
Freezer and Cooler:
Dry Bulb Temperature................................ 75 [deg]F
Relative Humidity................................... 52 %
------------------------------------------------------------------------
Subfloor Temperature
------------------------------------------------------------------------
Freezers & Coolers:
Temperature......................................... 55 [deg]F
------------------------------------------------------------------------
[[Page 55095]]
3.0 TEST APPARATUS AND GENERAL INSTRUCTIONS
3.1 Conduction Heat Gain
3.1.1 Glass Area
(a) All dimensional measurements for glass doors include the
door frame and glass.
(b) Calculate the individual and total glass door surface area,
Aglass door, as follows, ft\2\:
[GRAPHIC] [TIFF OMITTED] TP09SE10.040
[GRAPHIC] [TIFF OMITTED] TP09SE10.041
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 door,i = width of glass door (including door
frame), ft; and
Hglass door,i= height of glass door (including door
frame), ft.
(c) Calculate the glass wall individual and total glass surface
area, Aglass,wall, as follows, ft\2\:
[GRAPHIC] [TIFF OMITTED] TP09SE10.042
[GRAPHIC] [TIFF OMITTED] TP09SE10.043
Where:
i = index for each type of unique glass wall used in cooler or
freezer being tested;
ni = number of identical glass walls of type i;
Wglass,wall,i = width of glass wall (including glass
framing), ft; and
Hglass,wall,i= height of glass wall (including glass
framing), ft.
(d) Calculate the total combined glass door and glass wall area,
Aglass,tot, as follows, ft\2\:
[GRAPHIC] [TIFF OMITTED] TP09SE10.044
Where:
Aglass door, tot= total glass door area, ft\2\; and
Aglass wall, tot= total glass wall area, ft\2\.
3.1.2 Temperature Difference Across Glass Areas
(a) Calculate the temperature differential(s)
[Delta]Tglass door,j for each unique glass door as
follows, [deg]F:
[GRAPHIC] [TIFF OMITTED] TP09SE10.045
Where:
j= index for each type of unique glass door temperature differential
used--for example if a freezer glass door opens into a cooler
internal conditioned temperature and a freezer glass door opens into
external temperature, j=2;
TDB,int,glass door,j = dry-bulb air temperature inside
the cooler or freezer where the door is located, [deg]F;
TDB,ext,glass door,j = dry-bulb air temperature external
to the door of type j, [deg]F.
(b) Calculate the temperature differential(s)
[Delta]Tglass,wall,j for each unique glass wall, as
follows ([deg]F):
[GRAPHIC] [TIFF OMITTED] TP09SE10.046
Where:
j = index for each type of unique glass wall temperature
differential used;
TDB,int,glass,wall,j = dry-bulb air temperature inside
the cooler or freezer, [deg]F; and
TDB,ext,glass,wall,j = dry-bulb air temperature external
to cooler or freezer, [deg]F.
3.1.3 Non-Glass Area
Calculate the individual and total surface area of the walk-in
non-glass envelope components Anon-floor panel edge,i,
Anon-floor panel edge,tot,
Anon-floor panel core,i,
Anon-floor panel core,tot,
Afloor panel edge,i, Afloor panel edge,tot,
Afloor panel core,i, Afloor panel core,tot,
Anon-glass door,i, and Anon-glass door,tot, as
follows (ft\2\):
[[Page 55096]]
(a) Anon-floor panel edge,i, ft\2\, (see
Figure 2 to help visualize the area calculations)
[GRAPHIC] [TIFF OMITTED] TP09SE10.031
[GRAPHIC] [TIFF OMITTED] TP09SE10.047
Where:
i = index for each type of unique non-floor panel--for example, if a
walk-in is constructed of non-floor panels that are of two different
thicknesses or manufactured using two different foam insulation
products but panel dimensions are all identical, i=2 or, if a walk-
in is constructed of non-floor panels that are all of identical
thicknesses and identical materials but of non-floor panels of 15
different dimensions, i=15;
ni = number of identical panels of type i;
Xedge test region = Panel Edge Test Region width, as
shown in Figure 3, ft;
Wnon-floor panel,i = non-floor panel width, of thickness
and underlying materials of type i, ft; and
Lnon-floor panel,i = non-floor panel length, of thickness
and underlying materials of type i, ft;
(b) Anon-floor panel edge,tot, ft\2\
[GRAPHIC] [TIFF OMITTED] TP09SE10.048
Where:
i = index for each type of unique non-floor panel; and
Anon-floor panel edge, i= non-floor panel edge area, of
thickness and underlying materials of type i, ft\2\.
(c) Anon-floor panel core,i, ft\2\
[GRAPHIC] [TIFF OMITTED] TP09SE10.049
Where:
i = index for each type of unique non-floor panel;
ni = number of identical panels, of thickness and
underlying materials of type i;
Anon-floor panel edge,i= panel non-floor edge area, of
thickness and underlying materials of type i, ft\2\;
Wnon-floor panel,i = non-floor panel width, of thickness
and underlying materials of type i, ft; and
Lnon-floor panel,i = non-floor panel length, of thickness
and underlying materials of type i, ft;
(d) Anon-floor panel core,tot, ft\2\
[[Page 55097]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.050
Where:
i = index for each type of unique non-floor panel; and
Anon-floor panel core, i= non-floor panel core area, of
thickness and underlying materials of type i, ft\2\;
(e) Afloor panel edge,i, ft\2\
[GRAPHIC] [TIFF OMITTED] TP09SE10.051
Where:
i = index for each type of unique floor panel;
ni = number of identical panels, of thickness and
underlying materials of type i;
Xedge test region = Panel Edge Test Region width, as
shown in Figure 3, ft;
Wfloor panel,i = floor panel width, of thickness and
underlying materials of type i, ft; and
Lfloor panel,i = floor panel length, of thickness and
underlying materials of type i, ft;
(f) Afloor panel edge,tot, ft\2\;
[GRAPHIC] [TIFF OMITTED] TP09SE10.052
Where:
i = index for each type of unique floor panel; and
Afloor panel edge, i= floor panel edge area, of thickness
and underlying materials of type i, ft\2\.
(g) Afloor panel core,i, ft\2\
[GRAPHIC] [TIFF OMITTED] TP09SE10.053
Where:
i = index for each type of unique floor panel;
ni = number of identical panels, of thickness and
underlying materials of type i;
Afloor panel edge,i= floor panel edge area, of thickness
and underlying materials of type i, ft\2\;
Wnon-floor panel,i = floor panel width, of thickness and
underlying materials of type i, ft; and
Lnon-floor panel,i = floor panel length, of thickness and
underlying materials of type i, ft;
(h) Afloor panel core,tot, ft\2\
[GRAPHIC] [TIFF OMITTED] TP09SE10.054
Where:
i = index for each type of unique floor panel; and
Afloor panel core, i= floor panel core area, of thickness
and underlying materials of type i, ft\2\.
(i) Anon-glass door,i, ft\2\
[GRAPHIC] [TIFF OMITTED] TP09SE10.055
Where:
i = index for each type of unique non-glass door;
ni = number of identical glass doors, of thickness and
underlying materials of type i;
Wnon-glass door,i = non-glass door width, of thickness
and underlying materials of type i, ft; and
Hnon-glass door,i = non-glass door height, of thickness
and underlying materials of type i, ft.
(j) Anon-glass door,tot, ft\2\
[[Page 55098]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.056
Where:
i = index for each type of unique non-glass door; and
Anon-glass door,i= non-glass door area, of thickness and
underlying materials of type i, ft\2\.
(k) Anon-glass tot, ft\2\
[GRAPHIC] [TIFF OMITTED] TP09SE10.057
Where:
Anon-floor panel edge, tot= non-floor panel edge total
area, ft\2\;
Anon-floor panel core, tot= non-floor panel core total
area, ft\2\;
Afloor panel edge, tot= floor panel edge total area,
ft\2\;
Afloor panel core, tot= floor panel core total area,
ft\2\; and
Anon-glass door,tot= non-glass door total area, ft\2\.
3.1.4 Temperature Difference Across Non-Glass Areas
Calculate the temperature differential(s)
[Delta]Tnon-floor panel,j,
[Delta]Tfloor panel,j, and
[Delta]Tnon-glass door,j, [deg]F, as follows:
(a) [xutri]Tnon-floor panel, j, [deg]F
[GRAPHIC] [TIFF OMITTED] TP09SE10.058
Where:
j = index for each type of non-floor panel temperature differential;
TDB,int, non-floor panel,j = dry-bulb air internal
temperature, [deg]F. If the panel spans both cooler and freezer
temperatures, the freezer temperature must be used; and
TDB, ext, non-floor panel, j = dry-bulb air external
temperature, [deg]F.
(b) [xutri]Tfloor, j, [deg]F
[GRAPHIC] [TIFF OMITTED] TP09SE10.059
Where:
j = index for each type of floor panel temperature differential;
TDB, int, floor panel, j = dry-bulb air internal
temperature, [deg]F. If the panel spans both cooler and freezer
temperatures, the freezer temperature must be used; and
TDB, ext, floor panel, j = 55[deg] F, as defined in Table
A.VI.1.
(c) [xutri]Tnon-glass door, j, [deg]F
[GRAPHIC] [TIFF OMITTED] TP09SE10.060
Where:
j = index for each type of non-glass door temperature differential;
TDB, int, non-glass door, j = dry-bulb air internal
temperature, [deg]F. If the panel spans both cooler and freezer
temperatures, the freezer temperature must be used; and
TDB, ext, non-glass door, j = dry-bulb air external
temperature, [deg]F.
3.1.5 Conduction Heat Load Across Glass Areas
(a) Calculate the conduction load through the glass doors,
Qcond-glass, door, as follows btu/h:
[GRAPHIC] [TIFF OMITTED] TP09SE10.061
Where:
i = index for each type of unique glass door;
j = index for each type of glass door temperature differential;
ni, j = number of identical glass doors of type i with
temperature differential j;
Uglass door, i = thermal transmittance, U-factor of the
door, of type i, as rated by NFRC see section 4.4.1, Btu/h-ft\2\-
[deg]F;
Aglass door, i = total surface area of all walk-in glass
doors of type i, ft\2\; and
[xutri]Tglass door, j = temperature
differential between refrigerated and adjacent zones of type j,
[deg]F.
(b) Calculate the conduction load through the glass walls,
(Qcond-glass, wall), btu/h, as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.062
Where:
i = index for each type of unique glass wall;
j = index for each type of glass wall temperature differential;
[[Page 55099]]
ni, j = number of identical glass walls of type i with
temperature differential j;
Uglass, wall, i = thermal transmittance, U-factor of the
glass wall, of type i, as rated by NFRC see section 4.4.1 Btu/h-
ft\2\-[deg]F;
Aglass, wall, i = total surface area of all walk-in glass
walls of type i, ft\2\; and
[xutri]Tglass, wall, j= temperature differential between
refrigerated and adjacent zones of type j, [deg]F.
3.1.6 Panel Long Term Thermal Transmittance
(a) Calculate the foam degradation factor, (DFi),
unitless, as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.063
Where:
i= index each type of unique foam used in the walk-in envelope--for
example if a walk-in uses one foam type for non-floor panels and
another foam type for floor panels, i=2;
RLTTR, i = the R-value, from ASTM C1303-10, per 4.1.2 of
foam type i, h-ft\2\-[deg]F/Btu; and
R0, i = the R-value of foam used for determining EPCA
compliance of foam type i, h-ft\2\-[deg]F/Btu.
(b) Calculate the long term thermal transmittance,
(ULT, non-floor panel core, i), Btu/h-ft\2\-[deg]F, as
follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.064
Where:
i= index each type of unique foam used in the walk-in envelope;
Unon-floor panel core, i = the U-factor, per 4.1.1 of
foam type i, Btu/h-ft\2\-[deg]F; and
DFi = the degradation of foam type i, unitless.
(c) Calculate the long term thermal transmittance,
(ULT, floor panel core, i), Btu/h-ft\2\-[deg]F, as
follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.065
Where:
i= index each type of unique foam used in the walk-in envelope;
Ufloor panel core, i = the U-factor, per 4.1.1 of foam
type i, Btu/h-ft\2\-[deg]F; and
DFi = the degradation of foam type i, unitless.
3.1.7 Conduction Heat Load Across Non-Glass Areas
Calculate the conduction heat load through all non-glass
components: Qcond-non-floor panel,
Qcond-floor panel, Qcond-non-glass door and
Qcond-non-glass, as follows btu/h:
(a) Qcond-non-floor panel, btu/h,
[GRAPHIC] [TIFF OMITTED] TP09SE10.066
Where:
i = index for each type of unique component of type i;
j = index for each unique temperature differential of type j;
ni,j = number of identical non-floor panels of type i
with temperature differential;
[Delta]Tnon-floor panel,j = temperature differential
across the non-floor panels of type i, [deg]F;
Unon-floor panel edge,i = U-factor for panel edge area
type i, per 4.1.1, Btu/h-ft\2\-[deg]F;
ULT,non-floor panel core,i = Long term thermal
transmittance of foam type i, per section 4.1.1, Btu/h-ft\2\-[deg]F;
Anon-floor panel edge,i = area of non-floor panel edge of
type i, ft\2\; and
Anon-floor panel core,i = area of non-floor panel core of
type i, ft\2\.
(b) Qcond-floor panel, btu/h,
[GRAPHIC] [TIFF OMITTED] TP09SE10.067
Where:
i = index for each type of unique component of type i;
j = index for each unique temperature differential of type j;
ni,j = number of identical floor panels of type i with
temperature differential j;
[Delta]Tnon-floor panel,j = temperature differential
across the floor panels of type i, [deg]F;
Ufloor panel edge,i = U-factor for panel edge area type
i, per 4.1.1, Btu/h-ft\2\-[deg]F;
ULT,floor panel core,i = Long term thermal transmittance
of foam type i, per 4.1.1, Btu/h-ft\2\-[deg]F;
Afloor panel edge,i = area of floor panel edge of type i,
ft\2\; and
Afloor panel core,i = area of floor panel core of type i,
ft\2\.
(1) Exception to Qcond-floor panel: If the walk-in is
at cooler temperature and has an uninsulated floor, then
Qcond-floor panel, btu/h, is as follows:
(i) If Afloor <= 750 ft\2\, then
[GRAPHIC] [TIFF OMITTED] TP09SE10.068
(ii) If Afloor > 750 ft\2\, then
[[Page 55100]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.069
Where:
Afloor = total area of the floor, as measured from the
walk-in architectural drawing, ft\2\.
(2) Exception to Qcond-floor panel: If the walk-in is
at freezer temperature and an insulated floor has not being shipped
with the walk-in, then Qcond-floor panel, is as follows
btu/h:
[GRAPHIC] [TIFF OMITTED] TP09SE10.070
Where:
Afloor = total area of the floor, as measured from the
walk-in architectural drawing, ft\2\.
[Delta]Tfloor = temperature differential across the
freezer floor as defined in 3.1.4(b), [deg]F
Rfreezer floor = 28 ft\2\-[deg]F-h/Btu, as required by
EPCA.
(c) Qcond-non-glass door, btu/h,
[GRAPHIC] [TIFF OMITTED] TP09SE10.071
Where:
i = index for each type of unique component of type i;
j = index for each unique temperature differential of type j;
ni,j = number of identical non-glass doors of type i with
temperature differential j;
[Delta]Tnon-non glass door,j = temperature differential
across the floor panels of type i, [deg]F;
Unon-glass door,i = U-factor for panel edge area type i,
per 4.4.1, Btu/h-ft\2\-[deg]F; and
Anon-glass door,i = area of floor panel edge of type i,
ft\2\.
(d) Total conduction load for non-glass areas,
Qcond-non-glass, as follows btu/h:
[GRAPHIC] [TIFF OMITTED] TP09SE10.072
Where:
Qcond-non-floor panel = conduction through non-floor
panels, btu/h;
Qcond-floor panel = conduction through floor panels, btu/
h; and
Qcond-non-glass door = conduction through non-glass
doors, btu/h.
(1) Exception: If calculating Qcond-non-glass for an
uninsulated cooler or for a freezer where an insulated floor is not
part of walk-in, calculate as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.073
Where:
Qcond-non-floor panel = conduction through non-floor
panels, btu/h;
Qcond-floor panel = conduction through floor, as found in
3.1.7(b)(1) or (2) btu/h; and
Qcond-non-glass door = conduction through non-glass
doors, btu/h.
3.1.8 Total Conduction Load
(a) Calculate total conduction load, Qcond, as
follows btu/h:
[GRAPHIC] [TIFF OMITTED] TP09SE10.074
Where:
Qcond-non-glass = total conduction load through non-glass components
of walk-in, Btu/h;
Qcond-glass,wall = total conduction load through walk-in glass
walls, Btu/h; and
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] TP09SE10.075
[GRAPHIC] [TIFF OMITTED] TP09SE10.076
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), use the
following equation to calculate water vapor saturation pressure
(Pws in psia):
[[Page 55101]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.077
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, psia:
[GRAPHIC] [TIFF OMITTED] TP09SE10.078
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, w, as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.079
Where:
RH = relative humidity in (for the internal or external air), and
Pws = water vapor saturation pressure, psia.
(d) Calculate air specific volume, v, (ft\3\/lb), as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.080
Where:
TDB,R = dry-bulb temperature (for the internal or external air),
[deg]R; and
v = specific volume of air, ft\3\/lb.
(e) Calculate air density, air density, lb/ft\3\, as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.081
Where:
v = specific volume of air, ft\3\/lb.
(f) Calculate the enthalpy for the internal and external air, h,
as follows btu/lb:
[GRAPHIC] [TIFF OMITTED] TP09SE10.082
Where:
TDB,F = dry-bulb temperature (for the internal or external air),
[deg]F; and
w = absolute humidity ratio, unitless.
(g) Calculate the total crack length, CL,(ft), using
the architectural drawing of the walk-in,
(h) Calculate the steady state infiltration rate of the walk-
in,Vj, ft\3\/h:
[GRAPHIC] [TIFF OMITTED] TP09SE10.083
Where:
j = index of type cooler or freezer;
VL = the normalized infiltration rate per section 4.2 of this
document using the architectural drawing of the walk-in, ft\3\/h-ft;
and
CL = total crack length, ft.
(i) Calculate the total infiltration load due to steady-state
infiltration, (Qinfilt panel), Btu/h, as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.084
Where:
j = index of cooler or freezer temperature;
Vj = the infiltration rate measured at test temperature j, per
section 4.2, ft\3\/h;
[rho]int,j = internal air density, lb/ft\3\;
[rho]ext,j = external air density, lb/ft\3\;
hint,j = internal air enthalpy, Btu/lb; and
hext,j = external air enthalpy, Btu/lb.
3.2.2 Door Steady-State Infiltration Calculations
(a) Calculate the steady-state infiltration associated with
doors as follows, Vdoor steady,i\3\/h:
[GRAPHIC] [TIFF OMITTED] TP09SE10.085
Where:
i = index of each unique door geometry and temperature
differential combination;
ni = number of identical doors of type i, unitless;
and
Vdoor1Q = door steady state infiltration as found
following section 4.4.2, ft\3\/h.
(b) Calculate the total infiltration load due to steady-state
infiltration through doors, Qdoor steady, btu/h, as
follows:
[[Page 55102]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.086
Where:
i = index of type cooler or freezer temperature;
Vdoor steady,i = total door steady-state infiltration, ft\3\/h;
[rho]int,i = internal air density, as found in 3.2.1 above, lb/
ft\3\;
[rho]ext,i = external air density, as found in 3.2.1 above, lb/
ft\3\;
hint,i = internal air enthalpy, as found in 3.2.1 above, Btu/lb; and
hext,i = external air enthalpy, as found in 3.2.1 above, Btu/lb.
3.2.3 Door Opening Infiltration Calculations
(a) Calculate the portion of time each doorway is open,
Dt, unitless, as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.087
Where:
i = index for each unique door--for example 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 door opening
events);
[thetas]p = door open-close time, seconds per opening P;
[thetas]u = time door stands open, minutes; and
[thetas]d = daily time period, h.
(1) Number of doorway passages: For display glass doors, P = 72,
for passage doors, P = 60 and for freight doors, P = 120.
(2) Door open-close time: For display glass doors,
[thetas]p = 8 seconds, for passage doors,
[thetas]p = 15 and for freight doors,
[thetas]p = 60.
(3) Door open-close time if an automatic door opener/closer is
used: For passage doors, [thetas]p = 10 and for freight
doors, [thetas]p = 30.
(4) Time door stands open: Display glass doors,
[thetas]o = 0 minutes, for passage doors
[thetas]o = 30 minutes and for freight doors
[thetas]o = 60 minutes.
(5) Time door stands open if an automatic door opener/closer is
used: For passage doors [thetas]o = 10 minutes and for
freight doors [thetas]o = 20 minutes.
(6) Daily time period: All walk-ins, [thetas]d = 24
hours
(b) Calculate the density factor, Fm, for each door,
as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.088
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] TP09SE10.089
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/sec.\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) Calculate the infiltration reduction effectiveness:
[GRAPHIC] [TIFF OMITTED] TP09SE10.090
Where:
i = index for each unique doorway size of type small, medium or
large;
j = index for each unique infiltration reduction device (IRD) of
type i;
Vrate,with-device i,j = air infiltration rate, with door open and
reduction device active, 4.3, 1/h, if a device j is not used with
the doorway i, Vrate,with-device i,j = Vrate,without-device i,j ;
and
Vrate,without-device i,j = air infiltration rate, with door open and
reduction device disabled or removed, using 4.3, 1/h.
(e) Calculate the total door opening infiltration load for all door-
IRD combinations, Qdoor open, (Btu/h), as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.091
Where:
i = index for each unique combination of doorway size,
temperature difference and Dt, of type i--for example, if
the walk-in has a small, medium and large door, i = 3, or if the
walk-in has ten identical dimensioned display doors and one passage
door all with the same temperature differential, i = 2;
j = index for the effectiveness of IRD type j;
ni = number of doorways of type i being considered in the
calculation;
qi = infiltration load for fully established flow, Btu/h;
Dt,i = doorway open-time factor as calculated for each unique door
way, unitless;
Df = doorway flow factor, 0.8 for freezers and coolers (from ASHRAE
Fundamentals), unitless;
Ei,j = effectiveness of doorway type i with IRD type j, as measured
by gas tracer test, %.
3.3 Energy Consumption Due to Total Heat Gain
(a) Calculate the total thermal load, Qtot, (Btu/h),
as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.092
[[Page 55103]]
Where:
Qinfilt panel = total load due to steady-state infiltration, Btu/h;
Qcond = total load due to conduction, Btu/h;
Qdoor steady = total load due to door steady-state infiltration,
Btu/h; and
Qdoor open = 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] TP09SE10.093
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/day), as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.094
Where:
u = index for each type of electricity consuming device sited inside
the walk-in envelope and/or sited external the walk-in envelope,
inside, u=int, external, u=ext;
t = index for each type of electricity consuming device with
identical rated power;
Prated,u,t = rated power of each component, of type t,
kW;
PTOu,t = percent time off, for device of type t, %; and
nu,t = number of devices at the rated power of type t,
unitless.
(c) Calculate the total electrical energy consumption,
Ptot, (kWh/day), as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.095
[GRAPHIC] [TIFF OMITTED] TP09SE10.096
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/day; and
Pcomp,ext, t = the energy usage for an electricity consuming device
sited outside the walk-in envelope, of type t, kWh/day.
3.4.2 Total Indirect Electricity Consumption Due to Electrical Devices
(a) Calculate the additional compressor load due to thermal
output from electrical components sited inside the envelope,
Cload, (kWh/day), as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.097
Where:
EER = EER of walk-in (cooler=12.4 or freezer=6.3), Btu/Wh; and
Ptot,int = The total electrical load due to components sited inside
the walk-in envelope, kWh/day
3.5 Total Energy Consumption and Normalized Energy Consumption
3.5.1 Total Energy Consumption
Calculate the total energy load of the walk-in envelope per unit
of surface area and non-normalized total energy consumption,
Etot,non-glass,norm, Etot,glass,norm,
Etot,electrical,norm, and Etot,(kWh/ft\2\/
day), as follows:
(a) Etot,non-glass,norm, kWh/ft\2\/day,
[GRAPHIC] [TIFF OMITTED] TP09SE10.098
(b) Etot,glass,norm, kWh/ft\2\/day,
[[Page 55104]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.099
(c) Etot,electrical,norm, kWh/ft\2\/day,
[GRAPHIC] [TIFF OMITTED] TP09SE10.100
(d) Etot, kWh/day,
[GRAPHIC] [TIFF OMITTED] TP09SE10.101
Where:
Qtot,EER = the total thermal load, kWh/day;
Ptot = the total electrical load, kWh/day;
Anon-glass,tot = total surface area of the non-glass
envelope, ft\2\;
Aglass,tot = total surface area glass envelope,
ft\2\; and
Cload = additional compressor load due to thermal
output from electrical components contained within the envelope,
kWh/day.
4.0 TEST METHODS AND MEASUREMENTS
4.1 Conduction Performance Testing and Measurements
4.1.1 Measuring Panel and Floor U-factors using ASTM C1363-05
(a) Test Sample Geometry Requirements
(1) Two (2) panels, 8' 1'' long and 4' wide 1'' must be prepared.
(2) The panel edges must be joined using a given manufacturer's
panel interface joining system (i.e. camlocks).
(3) Panel Edge Test Region must be cut from the joined panels
such that X = 2' 0.25'' and Z = 7' 0.5''.
(See Figure 3)
(i) Exception: Walk-in panels that utilize vacuum insulated panels
(VIP) for insulation, X = 2' 2''. The wider tolerance is
meant to allow the cutting line, when preparing the Panel Edge Test
Region, to match the VIP junctions such that VIP will not lose
vacuum by being pierced by the cutting device.
(4) Panel Core Test Region must also be cut from one of the two
panels such that Y = 2' 0.25'' and Z = 7'
0.5''. (See Figure 3)
(i) Exception: As above, walk-in panels that use VIP for insulation,
Y = 2' 2''.
[GRAPHIC] [TIFF OMITTED] TP09SE10.206
(b) Testing Conditions
(1) The air temperature on the ``hot side'' of the box should be
maintained at 75 [deg]F 1 [deg]F.
(i) Exception: When testing floors, the air temperature should be
maintained at 55 [deg]F 1 [deg]F.
(2) The temperature in the ``cold side'' of the envelope should
be maintained at 35 [deg]F 1 [deg]F for the panels used
for walk-in coolers and -10 [deg]F 1 [deg]F for panels
used for walk-in freezers.
(3) The air velocity should be maintained as natural convection
conditions as described in ASTM C1363-05 (incorporated by reference,
see Sec. 431.303). The test must be completed using the masked
method and with surround panel in place as described in ASTM C1363-
05.
(c) Required Test Samples
(1) Wall and Ceiling Panels
(i) Cooler conditions, Panel Edge Region U-factor:
Unon-floor panel edge,cooler
(ii) Cooler conditions, Panel Core Region U-factor:
Unon-floor panel core,cooler
(iii) Freezer conditions, Panel Edge Region U-factor:
Unon-floor panel edge,freezer
(iv) Freezer conditions, Panel Core Region U-factor:
Unon-floor panel core,freezer
[[Page 55105]]
(2) Floor Panels
(i) Cooler conditions, Floor Panel Edge Region U-factor:
Ufloor panel edge,cooler
(ii) Cooler conditions, Floor Panel Core Region U-factor:
Unon-floor panel core,cooler
(iii) Freezer conditions, Floor Panel Edge Region U-factor:
Ufloor panel edge,freezer
(iv) Freezer conditions, Floor Panel Core Region U-factor:
Ufloor panel core,freezer
4.1.2 Measuring R-Value of Insulating Foam
(a) Follow the test procedure in ASTM C1303-10 exactly, with
these exceptions (incorporated by reference, see Sec. 431.303):
(1) Mold/Sample Panel Geometry
(i) A panel must be prepared following typical manufacturer
injection, curing and assembly methods. The width and length of the
panel must be 48 inches 1 inch and 96 inches 1 inch, respectively.
(ii) The panel thickness shall be equal to the desired test
thickness.
(2) Materials
(i) The panel materials should exactly mimic a commercially viable
panel; that is, the panel should be exactly identical to panels sold
by the manufacturer, with one key exception: The inner surfaces must
be lined with a material, such as 4 to 6 mil polyethylene film, to
prevent the foam from adhering to the panel internal surfaces. (This
ensures that when the panel metal skin is removed for testing, the
underlying foam is not damaged).
(3) Sample Preparation
(i) After the foam has cured and the panel is ready to be tested,
the facing and framing materials must be carefully removed to ensure
that the underlying foam is not damaged or altered.
(ii) A 12-inch x 12-inch square (x desired thickness) cut from the
exact geometric center of the panel must be used as the sample for
completing ASTM C1303-10.
(4) Section 6.6.2, where several types of hot plate methods are
recommended, use ASTM C518-04 (incorporated by reference, see Sec.
431.303), for measuring the R-value. In section 6.6.2.1 of ASTM
C1303-10, in reference to ASTM C518-04, the mean test temperature of
the foam during R-value measurement must be 20 +/- 4 [deg]F (-6.7 +/
- 2 [deg]C) with a temperature difference of 40 +/- 4 [deg]F (22 +/-
2 [deg]C) for freezers and 55 +/- 4 [deg]F (12.8 +/- 2 [deg]C) with
a temperature difference of 40 +/- 4 [deg]F (22 +/- 2 [deg]C) for
coolers.
(5) 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 C1303-10 (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 RLTTR, as
follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.102
Where:
Rfoam = R-value of foam as measured by ASTM C1303-10, h-
ft\2\-[deg]F/Btu.
4.1.3 U-Factor of Doors
(a) All doors must be tested using NFRC 100-2010-E0A1.
(b) Internal conditions:
(1) Air temperature of 35 [deg]F (1.7 [deg]C) for cooler doors
and -10 [deg]F (-23.3 [deg]C) for freezer doors.
(2) Mean inside radiant temperature same as shown in (b)(1)
above.
(c) External conditions
(1) Air temperature of 75 [deg]F (23.9 [deg]C).
(2) Mean outside radiant temperature same as shown in (c)(1)
above.
(d) Direct solar irradiance = 0 W/m2 (0 Btu/h-ft2).
(e) The average convective heat transfer coefficient on both
interior and exterior surfaces of the door should be based on
``natural convection'' as described in section 4.3 of NFRC 100-2010-
E0A1 (incorporated by reference, see Sec. 431.303).
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 or SF6 must be used as
the gas tracer for all testing.
(3) Air change rate: Measure the air change rate in 1/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 +/- 4 [deg]F (2 [deg]C) of the values shown in Table
A.VI.1.
(c) The external air temperature must be 75 [deg]F (24 [deg]C)
+/- 5 [deg]F (2.5 [deg]C) surrounding the walk-in.
(d) The test must be completed with the walk-in door closed.
(e) Number of tests:
(1) One unit must be tested at freezer conditions with an
insulated floor in place.
(2) One unit must be tested at cooler conditions.
(f) Geometry of standard walk-in test unit:
(1) External dimensions:
(i) Width = 12 ft 6''
(ii) Length = 18 ft 6''
(iii) Height = 8 ft 6''
(2) Rectangular Shape (see Figure 4)
[[Page 55106]]
[GRAPHIC] [TIFF OMITTED] TP09SE10.207
(g) Equipment Specifications
(1) One Passage Door (see Figure 4)
(i) Width = 36 inches 2 inches
(ii) Height = 78 inches 4 inches
(2) At freezer temperature, a pressure relief valve must be in-
place and operational during testing.
(i) Valve flow rate > 8 cubic ft per minute @ 1 inch of
H2O (250 Pa))
(3) Prescribed wall and ceiling panel geometry
(i) Wall panels
1. Width < 4 ft 1 inch
2. Height < 8 ft 1 inch
(ii) Ceiling panels
1. Width < 4 ft 1 inch
(h) Test Procedure Requirements
(1) The unit must be assemble following instructions provided in
the standard panel manufacturer installation instructions that are
normally provided with a shipped walk-in.
(2) The unit may be tested only after it has reached a steady-
state condition, normally greater than 24 hours after the
refrigeration system has been activated.
(3) The infiltration measurement period must be over a duration
greater than one hour
(4) The standard unit internal volume must be empty and
unoccupied except for items necessary for testing or for cooling the
test unit (such as test equipment or evaporator fans).
(i) Test Results
(1) At cooler conditions, the result following ASTM E741-06, is:
(i) First, correct the result to standard test conditions per ASTM E
283.
(ii) The final and corrected infiltration rate,
Vrate,cooler, (1/h)
(2) At freezer conditions,
(i) First, correct the result to standard test conditions per ASTM E
283.
(ii) The final and corrected infiltration rate,
Vrate,freezer, (1/h)
(j) Calculations
(1) Convert Vrate,freezer and Vrate,cooler to
Vfreezer and, Vcooler, (ft\3\/h), as follows:
[GRAPHIC] [TIFF OMITTED] TP09SE10.103
and
[GRAPHIC] [TIFF OMITTED] TP09SE10.104
Where:
Vref-space = the total enclosed volume of the walk-in, of the test
unit shown in Figure 4, ft\3\; and
Vrate,cooler= the infiltration rate from the cooler test,
1/h
Vrate,freezer= the infiltration rate from the cooler
test, 1/h
(2) Using the architectural drawing of the test unit, calculate
total effective crack length, CL,wall,
CL,door-wall, CL,ceiling-floor and
CL,(ft), as follows:
(i) CL,wall, ft:
[GRAPHIC] [TIFF OMITTED] TP09SE10.105
Where:
i = index for walls from 1 to 3, i = 1: wall of length 18' and
height 8', i = 2: other wall of length 18' and height 8' and i = 3:
wall opposite of the door of width 12' and height 8';
H = height of the walk-in unit per Figure 4, ft; and
Npanels,i = number of panels used to build wall of type i.
(ii) CL,door-wall, ft:
[GRAPHIC] [TIFF OMITTED] TP09SE10.106
Where:
H = height of the walk-in unit per Figure 4, ft; and
Npanels,door-wall = number of panels used to build the door wall
(iii) CL,ceiling-floor, ft:
[GRAPHIC] [TIFF OMITTED] TP09SE10.107
[[Page 55107]]
Where:
W = width of the walk-in unit per Figure 4, ft;
Npanels,ceiling = number of panels used to build the door wall, ft;
Pfloor = external perimeter of the floor, ft; and
L = length of the walk-in unit per Figure 4, ft.
(iv) CL, ft:
[GRAPHIC] [TIFF OMITTED] TP09SE10.108
Where:
CL,wall = the total crack length of the non-door walls,
ft;
CL,door-wall = the total crack length of the door wall,
ft; and
CL,ceiling-floor = the total crack length of the ceiling
and floor, ft;
(3) Calculate the infiltration per unit crack length for the
freezer, Vfreezer-ft and cooler, Vcooler-ft,
tests, (ft\3\/h-ft), respectively as follows:
(i) Vfreezer-ft, ft\3\/h-ft:
[GRAPHIC] [TIFF OMITTED] TP09SE10.109
Where:
CL = the total crack length of the test unit as shown in
Figure 4, ft; and
Vfreezer-ft = infiltration rate from the freezer test,
ft\3\/h.
(ii) Vcooler-ft, ft\3\/h-ft:
[GRAPHIC] [TIFF OMITTED] TP09SE10.110
Where:
CL = the total crack length of the test unit as shown in
Figure 4, ft; and
Vcooler = infiltration rate from the cooler test, ft\3\/
h.
4.3 IRD Effectiveness Testing
4.3.1 IRD Test Alternatives
(a) The following IRD effectiveness assumptions may be used:
(1) Strip Curtains Effectiveness: E = 0.5
(2) Air Curtains Effectiveness: E = 0.3
(b) If an IRD is tested and found to have a higher performing
effectiveness than the default values proposed above, that value may
be used in the energy calculations.
(c) All non-strip curtain and non-air curtain IRD's must be
tested following the test procedure below.
4.3.2 Doorway Testing Geometry
(a) IRD effectiveness tests must use the following door sizes:
(1) The testing must be completed for each device at the correct
representative size for small, medium and/or large doorways.
(2) For doors with width <= 48 inches and height <= 84 inches,
the small door test opening size may be used (``small test''): width
= 48 inches 0.5 inch and height = 84 inches 0.5 inch
(3) For doors with width <= 96 inches and height <= 144 inches,
the medium door test opening size may be used (``medium test''):
width = 96 inches 0.5 inch and height = 144 inches
0.5 inch
(4) For doors of any width or height, the large door test
opening size may be used (``large test''): Width = 144 inches 0.5 inch and height = 180 inches 0.5 inch.
(5) For the small door test, a test volume of dimension and
construction and door location shown in Figure 4 must be used.
(6) For all medium and large door tests, the width and height of
the test unit must be increased in size, directly proportional to
the increased door size over the small door test. For example since
the medium doorway width is twice the size of the small door, the
test unit must be twice as wide as shown in Figure 4.
4.3.3 IRD Test Procedure Requirements
(a) Use ASTM E741-06 (incorporated by reference, see Sec.
431.303), with the following exceptions to the procedure:
(1) Within 3 minutes +/- 30 seconds of achieving gas
concentration uniformity, with the infiltration reduction device in
place, a hinged door should be opened at an angle greater than or
equal to 90 degrees.
(2) The elapsed time, from zero degrees position (closed) to
greater than or equal to 90 degrees (open) must be no longer than 5
seconds.
(3) 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 in the same elapsed time as described above for hinge-type
doors.
(4) 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 spatially within the walk-in.
(5) A gas concentration sample set must be taken once the tracer
gas has uniformly dispersed in the internal space using the
methodology described in 4.2.
(i) Following ASTM E741-06, the calculated result is Vrate,with-
device i,j
(6) The test should be repeated exactly as described with the
infiltration reduction device (IRD) removed or deactivated.
(i) Following ASTM E741-06, the calculated result is Vrate,without-
device i,j
4.4 NFRC Door Testing
4.4.1 Door Conduction Testing
(a) All doors, as defined in section 2.1(b), must be tested
using NFRC 100-2010-E0A1 (incorporated by reference, see Sec.
431.303).
(1) Internal conditions:
(i) Air temperature of 35 [deg]F (1.7 [deg]C) for cooler doors and -
10 [deg]F (-23.3 [deg]C) for freezer doors.
(ii) Mean inside radiant temperature same as shown in (1)(i) above.
(2) External conditions.
(i) Air temperature of 75 [deg]F (23.9 [deg]C).
(ii) Mean outside radiant temperature same as shown in (2)(i) above.
(iii) Direct solar irradiance = 0 Btu/h-ft\2\ (0 W/m\2\).
(iv) The average convective heat transfer coefficient on both
interior and exterior surfaces of the door should be based on
``natural convection'' as described in section 4.3 of NFRC 100-2010-
E0A1.
4.4.2 Door Infiltration Testing
(a) All doors must be tested using NFRC 400-2010-E0A1
(incorporated by reference, see Sec. 431.303).
(b) Number of tests:
(1) One door system of representative sizes of ``small,''
``medium,'' and ``large'' as defined in 4.3.2(a), that have
identical construction (i.e. only differ in dimensional size) may be
used for extrapolating the infiltration of other doors that only
differ in size as described in 4.3.2(a).
(c) Testing must be completed at six pressure differentials for
both positive and negative pressure (exfiltration and infiltration):
(1) 0.0401 in-H2O (10 Pa).
(2) 0.0803 in-H2O (20 Pa).
(3) 0.1204 in-H2O (30 Pa).
(4) 0.1606 in-H2O (40 Pa).
(5) 0.2007 in-H2O (50 Pa).
(6) 0.2409 in-H2O (60 Pa).
(d) At each of the six pressure differentials described above,
the airflow rate must be measured.
(e) Using the six pressure differentials and measured flow rates
(in both directions) the values for Ci and ni,
must be found using log-linear regression equation below:
[GRAPHIC] [TIFF OMITTED] TP09SE10.111
Where:
i = index corresponding to the exfiltration or infiltration test;
VdoorQ = the airflow rate, ft\3\/h (m\3\/s);
[Delta]P = the differential pressure, in-H2O (Pa);
Ci = coefficient determined based on goodness of fit to
test data of type i; and
ni = exponent determined based on goodness of fit to test
data of type i.
(f) Find the average C and n:
[GRAPHIC] [TIFF OMITTED] TP09SE10.112
[GRAPHIC] [TIFF OMITTED] TP09SE10.113
Where:
Cinfiltration = coefficient determined using log-linear
regression of infiltration test;
Cexfiltration = coefficient determined using log-linear
regression of exfiltration test;
[[Page 55108]]
ninfiltration = exponent determined using log-linear
regression of infiltration test; and
nexfiltration = exponent determined using log-linear
regression of exfiltration test.
(g) If n is found to be less than 0.5 or greater than 1.0 the
test is considered invalid and the infiltration and exfiltration
tests must be repeated until valid value for n is determined.
(h) Using the valid n, corresponding C and the equation below,
determine,VdoorQ, the infiltration for the corresponding
pressure differentials (m\3\/s) for both cooler and freezer
application:
(1) Coolers: 0.006 in-H2O (1.5 Pa).
(2) Freezers: 0.014 in-H2O (3.5 Pa).
[GRAPHIC] [TIFF OMITTED] TP09SE10.114
Where:
VdoorQ = the airflow rate, ft\3\/h (m\3\/s);
[Delta]P = the differential pressure, in-H2O (Pa);
C = coefficient determined based on goodness of fit; and
n = exponent determined based on goodness of fit.
(i) Using the resulting VdoorQ for coolers and
freezers, calculate the normalized infiltration rate per length of
``operable crack perimeter,'' Vdoor normQ, as defined in
ASTM E-283-04 (ASTM E-283-04 section 12.3.1) (incorporated by
reference, see Sec. 431.303) must be calculated.
[GRAPHIC] [TIFF OMITTED] TP09SE10.115
Where:
VdoorQ = the airflow rate, ft\3\/h (m\3\/s); and
Pdoor crack = door operable crack perimeter, ft.
(j) Vdoor normQ, for the corresponding representative
door test size, may be used for calculating the infiltration rate of
doors with differing operable crack perimeter.
(k) If a testing entity desires such, VdoorQ may be
found for all doors instead of calculating an infiltration rate
based on Vdoor normQ.
[FR Doc. 2010-21364 Filed 9-8-10; 8:45 am]
BILLING CODE 6450-01-P