[Federal Register Volume 62, Number 85 (Friday, May 2, 1997)]
[Proposed Rules]
[Pages 24164-24209]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-10922]
[[Page 24163]]
_______________________________________________________________________
Part II
Department of Energy
_______________________________________________________________________
Office of Energy Efficiency and Renewable Energy
_______________________________________________________________________
10 CFR Part 435
Energy Efficiency Code For New Federal Residential Buildings; Proposed
Rule
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed
Rules
[[Page 24164]]
DEPARTMENT OF ENERGY
Office of Energy Efficiency and Renewable Energy
10 CFR Part 435
[Docket No. EE-RM-96-300]
RIN 1904-AA53
Energy Efficiency Code for New Federal Residential Buildings
AGENCY: Office of Energy Efficiency and Renewable Energy, DOE.
ACTION: Notice of proposed rulemaking, public hearing, and request for
public comment.
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SUMMARY: The Department of Energy today proposes a rule that would
establish minimum energy-efficiency building standards for new Federal
residential buildings, including single-family and multi-family low-
rise housing, pursuant to the requirements of the Energy Conservation
and Production Act of 1976, as amended. The proposed rule would cover
all aspects of residential building thermal envelopes, including
foundations, crawl spaces, floors, walls, fenestration, roof/ceilings,
and attics. The proposed rule would also cover the heating,
ventilation, and air-conditioning systems design, service water heating
systems, radon control, air infiltration, and electrical power and
lighting systems. The proposed rule would revise the current Federal
residential standards to conform generally with the format and language
of the Council of American Building Officials Model Energy Code, 1992.
The proposed rule is, on the average, 11 percent more energy-efficient
than the Model Energy Code, 1992 for single-family residences and 26
percent more energy-efficient than the Model Energy Code, 1992 for
multi-family residences for heating and cooling.
DATES: Written comments on the proposed rule (ten copies and, if
possible, a computer disk containing the electronic file of these
comments) must be received on or before July 14, 1997. A public hearing
will be held in Washington, D.C., on June 5, 1997, beginning at 9:30
a.m. at the address listed below. Requests to speak must be received by
the Department on or before June 3, 1997. Ten copies of the statement
to be given at the public hearing must be received by the Department by
4:00 p.m., June 3, 1997.
ADDRESSES: Written comments on the proposed rule (ten copies), as well
as requests to speak at the public hearing, requests for copies of the
technical support documents and requests for speaker lists should be
addressed to: U.S. Department of Energy, Energy Efficiency Code for
Federal Residential Buildings, Docket Number EE-RM-96-300, Office of
Codes and Standards, Office of Energy Efficiency and Renewable Energy,
U.S. Department of Energy, Room 1J-018, 1000 Independence Avenue, S.W.,
Washington, D.C. 20585-0121, (202) 586-7574.
Fax comments will not be accepted. The public hearing will be held
at the U.S. Department of Energy, Forrestal Building, Room 1E-245, 1000
Independence Avenue, S.W., Washington D.C. 20585-0121. Copies of the
transcripts of the public hearings and written public comments received
may be read at the Department of Energy's Freedom of Information
Reading Room, U.S. Department of Energy, Forrestal Building, Room 1E-
190, 1000 Independence Avenue, S.W., Washington, D.C. 20585-0121, (202)
586-6020, between the hours of 9:00 a.m. and 4:00 p.m., Monday through
Friday, except Federal holidays. The reference standards are also
available from the sources listed in Subpart H of the proposed rule.
For more information concerning public participation see section IX.
Public Comment Procedures.
FOR FURTHER INFORMATION CONTACT:
Stephen P. Walder, Office of Codes and Standards, EE-43, U.S.
Department of Energy, Office of Energy Efficiency and Renewable Energy,
Room 1J-018, 1000 Independence Avenue, S.W., Washington, D.C. 20585-
0121, (202) 586-9209;
Francine B. Pinto, Esq., Office of General Counsel, GC-72, U.S.
Department of Energy, Room 6E-042, 1000 Independence Avenue, S.W.,
Washington, D.C. 20585-0103, (202) 586-7432.
SUPPLEMENTARY INFORMATION:
I. Introduction
A. Authority
B. Background
1. Model Energy Code, 1992
2. The Current Federal Standards
3. Standard 90.2-1993
II. Relationship Between the Proposed Rule, the MEC, 1992, the Current
Federal Residential Standards, Standard 90.2-1993, and Other Federal
Initiatives
A. General
B. Relationship Between the Proposed Rule and the MEC, 1992
C. Relationship Between the Proposed Rule and the Current Federal
Residential Standards
D. Relationship Between the Proposed Rule and Standard 90.2-1993
E. Relationship to Other Federal Initiatives
III. Description of the Proposed Rule and Differences Between the
Proposed Rule and the Model Energy Code, 1992
A. Subpart A: Administration and Enforcement
1. Sections 435.102.1.2 and 435.102.1.3: Building Envelope
Insulation and Insulation Installation
2. Section 435.102.3: Fenestration Product Rating,
Certification, and Labeling
3. Section 435.104: [Reserved]
4. Section 435.105: [Reserved]
5. Section 435.106: [Reserved]
6. Section 435.107: Precedence
7. Section 435.108: Life-Cycle Cost Analysis
B. Subpart B: Definitions
C. Subpart C: Design Conditions
D. Subpart D: Design by Systems Analysis; Design Utilizing Renewable
Energy Sources
1. Section 435.402.1: Energy Analysis
2. Section 435.402.1.1: Input Values/Assumptions for Group R
(Single Family and Multi-family Low Rise) Buildings
3. Section 435.403.3: Passive Solar Design Analysis
E. Subpart E: Design by Component Performance Approach
1. Major Revisions from the Model Energy Code, 1992 that are
Contained in Subpart E of the Proposed Rule
a. Section 435.502: Building Thermal Envelope Requirements
b. Section 435.502.2.1.1.2: Metal Framing
c. Section 435.502.2.1.5: Crawl Space Walls
d. Section 435.502.3.3: Recessed Lighting Fixtures
e. Section 435.503.2: Mechanical Equipment Efficiency
f. Section 435.503.3.1.1: Heating and Cooling Equipment Capacity
g. Section 435.503.5.7.2: Duct Sealing
h. Section 435.503.5.9.1: Backdrafting Test
i. Section 435.504.2: Service Water Heating Equipment
j. Section 435.504.4: Heat Traps
2. Miscellaneous Revisions that are Contained in Subpart E of
the Proposed Rule, Not in the MEC, 1992
F. Subpart F: [Reserved]
G. Subpart G: Radon Control
H. Subpart H: Standards
IV. Consultation
V. Energy and Economic Impacts
VI. Technological Feasibility and Economic Justification
VII. Measures Concerning Radon and Other Indoor Air Pollutants
VIII. Findings and Certification
A. Review Under the National Environmental Policy Act
B. Environmental Protection Agency Review
C. Regulatory Planning and Review
D. Federalism Review
E. Review Under Executive Order on Metric Usage in Federal
Government Programs
F. Review Under Executive Order on Civil Justice Reform
G. Review Under the Regulatory Flexibility Act
H. Paperwork Reduction Act Review
[[Page 24165]]
I. Review Under Section 32 of the Federal Energy Administration
Authorization Act
J. Unfunded Mandates Reform Act Review
IX. Public Comment Procedures
A. Participation in Rulemaking
B. Solicitation of Public Comments
C. Written Comment Procedures
D. Public Hearings
1. Procedure for Submitting Requests to Speak
2. Conduct of Hearings
I. Introduction
A. Authority
The Department today proposes a rule that would establish Federal
building energy-efficiency standards for new Federal residential
buildings pursuant to section 305(a) of the Energy Conservation and
Production Act (ECPA), as amended by the Energy Policy Act of 1992
(EPACT), 42 U.S.C. 6834(a). In developing this proposed rule, the
Department is directed to consult with other Federal agencies as well
as private and state associations and other appropriate persons.
Section 305(a)(1) of the ECPA requires the Department to establish
Federal building energy standards that include those energy-efficiency
measures that are technologically feasible and economically justified.
The standards must contain energy saving and renewable energy
specifications that meet or exceed the energy saving and renewable
energy specifications of the Council of American Building Officials
(CABO) Model Energy Code (MEC), 1992. Section 305(a)(2)(A).
Section 305(a)(2)(B) requires that to the extent practicable, the
proposed standards use the same format as the appropriate voluntary
building energy code, in this case, the MEC, 1992. Furthermore, Section
305(a)(2)(C) requires that the proposed rule be established in
consultation with the Environmental Protection Agency (EPA) and other
Federal agencies and, where appropriate, contain measures with regard
to radon and other indoor air pollutants.
The current energy performance standards for new Federal buildings
remain in effect until the standards established under subsection (a)
become effective. Section 305(d). These current standards are found in
10 CFR Part 435, Subpart C.
Section 306 addresses Federal compliance. Each Federal agency and
the Architect of the Capitol must adopt procedures to assure that new
Federal buildings will meet or exceed the Federal building energy
standards proposed here. Section 306(a). Section 306(b) bars the head
of a Federal agency from expending Federal funds for the construction
of a new Federal building unless the building meets or exceeds the
appropriate Federal building energy standards established under Section
305.
B. Background
There are currently three building energy codes that address low-
rise residential buildings in all parts of the United States \1\: the
Model Energy Code (MEC); 10 CFR Part 435, Subpart C, Mandatory
Performance Standards for New Federal Residential Buildings; and the
American Society of Heating, Refrigerating and Air Conditioning
Engineers (ASHRAE), Inc., Standard 90.2-1993, Energy-Efficient Design
of New Low-Rise Residential Buildings. All three bear on today's
proposed rule. The MEC contributes format, substance, and technical
improvements to the proposal. The Federal residential standards first
introduced the concept of cost-effectiveness in building standards and
tools to analyze the economic justification of energy-efficiency
requirements in building standards. Tools that evolved from the
development of the current Federal residential standards were used to
determine the economic justification for the requirements contained in
the proposed rule. ASHRAE Standard 90.2-1993 also provides substantive
technical improvements to the proposal.
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\1\ There are other building energy codes that are state-
specific or regional that are not considered.
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1. Model Energy Code, 1992
Currently, the MEC is the most widely accepted and used residential
energy-efficiency code in the United States. Seventeen states have
adopted the MEC, or modified versions of the MEC, as their energy code.
Approximately 20 percent of new home loans are issued or guaranteed by
the Department of Housing and Urban Development, the Department of
Veterans Affairs, and the Rural Economic and Community Development
group of the Department of Agriculture. Such loans or loan guarantees
require compliance with the MEC, 1992. The MEC has been promulgated
jointly by the three model code organizations: the Building Officials
and Code Administrators International; the International Conference of
Building Officials; and the Southern Building Code Congress
International under the auspices of the Council of American Building
Officials. The MEC is provided as a model and intended for adoption by
state and local jurisdictions.
The provisions of the MEC, 1992 regulate the design of building
envelopes for adequate thermal resistance and low air leakage and the
design and selection of mechanical, electrical, service water-heating
and illumination systems and equipment which will enable effective use
of energy in new building construction. The MEC provides flexibility to
permit the use of innovative approaches and techniques to achieve
efficient utilization of energy. These provisions are structured to
permit compliance with the intent of the code by any one of the
following paths of design: (1) A systems analysis approach for the
entire residential building and its energy-using subsystems, including
buildings which utilize renewable sources (Chapter 4), (2) a building
design by component performance approach (Chapter 5) and, (3) building
design by acceptable practice (Chapter 6).
2. The Current Federal Standards
On August 25, 1988, the Department published standards for new
Federal residential buildings (53 FR 32536). It established building
energy-efficiency standards for the design and construction of Federal
residential buildings.
The current Federal standards require that Federal agencies use
software to create project-specific compliance forms that are then
completed by prospective builders to demonstrate compliance with
minimum energy-efficiency requirements. The process must be undertaken
for each project. The micro-computer software program, Conservation
Optimization Standard for Savings in Federal Residences (COSTSAFR),
uses local construction, maintenance and replacement costs, local
climate data, and local fuel costs to determine an energy-efficient and
cost-effective energy usage goal for any of nine residential building
unit types addressed in the COSTSAFR program data base. COSTSAFR
calculates project-specific minimum energy-efficiency requirements and
presents these requirements in compliance forms known as ``the point
system.'' The use of COSTSAFR eliminated the need for performing
lengthy calculations or making uninformed choices regarding the
selection of energy-efficiency measures. COSTSAFR is designed so that
implementing officials, designers, and builders can easily tell if a
proposed combination of measures will result in energy-efficiency
levels that meet or
[[Page 24166]]
exceed the COSTSAFR required level for cost-effective energy-efficiency
in a building.
The Department decided not to use COSTSAFR as the basis for this
new Federal proposed rule because it cannot always be assured of
complying with the new legislative requirements. In particular,
COSTSAFR can generate energy-efficiency requirements that do not meet
the MEC, 1992 energy-efficient levels specified by EPACT. The software
would have to be reconfigured to eliminate this possibility.
3. Standard 90.2-1993
Standard 90.2-1993, Energy-Efficient Design of New Low-Rise
Residential Buildings, is a standard for residential construction
published by the American Society of Heating, Refrigerating and Air
Conditioning Engineers (ASHRAE), Inc. Standard 90.2-1993 is the next
generation residential component of ASHRAE's earlier Standard 90 (1975)
and Standard 90A-1980, which specified design requirements for energy-
efficient commercial and residential buildings. Standard 90.2-1993 sets
criteria for the building envelope, heating equipment and systems, air-
conditioning and systems, and provisions for overall building design
alternatives and trade-offs.
II. Relationship Between the Proposed Rule, the MEC, 1992, the Current
Federal Residential Standards, Standard 90.2-1993, and Other Federal
Initiatives
A. General
The Department has decided to develop a proposed rule similar in
format to the MEC rather than modify the current Federal residential
building standards. Currently, construction professionals are more
familiar with the MEC, 1992 format and content than the Federal
standards. This familiarity with the MEC requirements and format is
likely to reduce costs associated with the development and use of
building specifications consistent with those of the MEC. The
consistency of the proposed rule with industry-wide practice will
facilitate implementation by Federal agencies of the final rule.
Currently, 10 CFR Part 435 contains standards for Federal commercial
buildings (Subpart A), a reserved section that was intended for
voluntary standards for new non-Federal residential buildings (Subpart
B), and standards for Federal residential buildings (Subpart C). On
August 6, 1996, the Department proposed to remove Subpart A from Part
435 and republish it as a new Part 434 in the Code of Federal
Regulations. (61 FR 40882). In today's proposed rule, Subparts B and C
would be removed and Part 435 would be revised to establish standards
for Federal residential buildings only.
B. Relationship Between the Proposed Rule and the MEC, 1992
The proposed rule would adopt portions of the Model Energy Code,
1992 verbatim. There are, however, some requirements in the proposed
rule that exceed the MEC, 1992 resulting in increased energy-
efficiency. Many of the provisions improving energy-efficiency are
found in the 1993 and 1995 versions or the 1994 amendments to the MEC,
1993. Those aspects of the proposed rule that exceed the MEC, 1992
resulting in increased energy-efficiency are: (1) more stringent
thermal envelope requirements, (2) insulating of crawl space walls, (3)
sealing recessed light fixtures, (4) heating and cooling equipment
capacity requirements, (5) air distribution system construction, and
(6) heat traps.
The proposed rule would also make revisions to the Model Energy
Code, 1992, that are consistent with current building construction
practice. These include requirements for: (1) insulation inspection,
(2) window and door thermal performance ratings, (3) improved
performance path specifications, (4) metal framing construction and,
(5) radon and other indoor air pollutants. The requirements referenced
in (1)-(4) above, do not save energy but help ensure that energy
savings are achieved. Requirements concerning radon and other indoor
air pollutants are consistent with health and safety needs.
Further, the Department has made miscellaneous minor changes to the
MEC, 1992 to improve the clarity and useability of the rule. These
miscellaneous changes are not expected to have any impact on the
agencies or their contractors.
The proposed rule is on the average, 11 percent more energy-
efficient than the Model Energy Code, 1992 for single-family residences
and 26 percent more energy-efficient than the Model Energy Code, 1992
for multi-family residences for heating and cooling.
C. Relationship Between the Proposed Rule and the Current Federal
Residential Standards
There are significant differences and similarities between the
proposed rule and the current standards. The current standards have a
point system related to energy cost that permits tradeoffs among
energy-efficiency measures, while the proposed rule has an overall U-
value that permits tradeoffs in envelope measures. The use of
microcomputer software is necessary to determine the requirements of
the current standards, whereas, the requirements of the proposed rule
are contained in a hardcopy publication. Both have a similar whole
building energy usage analysis compliance approach.
The current Federal standards will not always assure the user of
meeting or exceeding the requirements of the MEC, 1992. The Department
has demonstrated that residential buildings designed using COSTSAFR
will have a less stringent level of thermal performance than those
buildings designed using the requirements of the proposed rule.
D. Relationship Between the Proposed Rule and Standard 90.2-1993
A number of features from Standard 90.2-1993 are included in
today's proposed rule. These provisions address feasible residential
design features not presently or adequately addressed by the MEC, while
providing the potential for further energy savings in the proposed
rule. They include heating and cooling equipment sizing limitations;
default thermal performance data for metal frame walls; and heat traps
on water heaters for potable water.
Standard 90.2-1993 has been put into code format providing a
similar structure for both the standard and the proposed rule. Both
also have three alternative compliance paths of similar nature.
Standard 90.2-1993 however, has more complexity than the respective
compliance options of the proposed rule. The Department believes that
this greater complexity of Standard 90.2-1993 would make it more
difficult to adopt, use, and enforce than the MEC, which is the basis
for the proposed rule. The Department also believes that the complexity
and differences between Standard 90.2-1993 and the MEC would have made
it difficult for the Department to have assured the user of meeting the
minimum energy-efficiency requirements of the MEC, 1992. The Department
determined that the necessary cost and resources to revise Standard
90.2-1993 as the proposed Federal residential rule and that would meet
or exceed the MEC, 1992 would not be warranted. The proposed rule looks
to the broad recognition and penetration enjoyed by the MEC within the
community of residential designers, builders and enforcement officials
to facilitate its implementation by the Federal sector.
[[Page 24167]]
E. Relationship to Other Federal Initiatives
The proposed rule would establish the minimum level of energy-
efficiency for new Federal buildings. The rule works in conjunction
with two related Federal initiatives designed to encourage cost-
effective efficiency improvements for new buildings beyond the minimum
requirements of the proposed rule. First, Executive Order on Energy
Efficiency and Water Conservation at Federal Facilities, Executive
Order No. 12902 (59 FR 11463, March 8, 1994), specifically requires
that, ``Each agency involved in the construction of a new facility--
shall: (1) design and construct such facility to minimize the life
cycle cost of the facility by utilizing energy efficiency, water
conservation, or solar or other renewable energy technologies.''
Section 306(a) of Executive Order 12902. It also requires agencies to
``ensure that the design and construction of facilities meet or exceed
the energy performance standards applicable to Federal residential or
commercial buildings as set forth in 10 CFR Part 435, local building
standards, or a Btu-per-gross square-foot ceiling--whichever will
result in a lower life cycle cost over the life of the facility.''
Section 306(a)(2) of Executive Order 12902. In addition, Federal
agencies shall increase, to the extent practicable and cost-effective,
purchases of products that are in the upper 25 percent of energy
efficiency for all similar products, or products that are at least 10
percent more efficient than the minimum level that meets Federal
standards. Section 507(a)(2) of Executive Order 12902. This latter
provision is being implemented through the Department's ``Procurement
Challenge Program'' that notifies Federal agencies of the availability
and performance of these high-efficiency options. This ``Procurement
Challenge Program'' is being coordinated with the EPA ``Energy Star''
product specification activities. In addition, the Department's Office
of Building Technologies, State and Community Programs provides
detailed technical information on state-of-the-art energy-efficiency
equipment for new buildings. These sources of technical assistance can
help Federal agencies specify highly-efficient equipment for new
Federal residential buildings.
Second, section 435.108 of today's proposed rule references the
requirements of 10 CFR Part 436 governing life-cycle cost analysis for
Federal energy investments. The life-cycle cost analysis provisions
found in 10 CFR Part 436 allow agencies to determine when additional or
alternate energy-efficiency measures would provide net benefits in the
form of energy cost savings to ensure that measures selected are cost-
effective to the Federal government. This is especially relevant in
areas where energy costs are higher than presumed for the analysis
supporting today's proposal, and for innovative technologies and
specifications that cannot be readily incorporated into the proposed
rule. The microcomputer program entitled ``ARES'' (Automated
Residential Energy Standard) can be used for evaluating the life-cycle
cost-effectiveness of various thermal envelope energy-efficiency
measures (EEMs) that can be more energy-efficient than the requirements
of the proposed rule. The Department is currently conducting life-cycle
cost analysis that would identify energy-efficiency measures that are
economically justified in specified circumstances and exceed the
minimum requirements of the proposed rule. The Department will provide
the results of this analysis to the Federal agencies to assist them in
the design and construction of energy-efficient Federal residential
buildings.
III. Description of the Proposed Rule and Differences Between the
Proposed Rule and the Model Energy Code, 1992
This section describes the proposed rule and the differences
between the proposed rule and the Model Energy Code, 1992. Those
sections of the proposed rule not specifically addressed here have been
adopted from the MEC, 1992. Minor language and citation changes will
not be noted. The discussion below corresponds to the subparts,
sections, paragraphs, and subparagraphs in the proposed rule. The
sections identified as reserved are discussed briefly.
A. Subpart A: Administration and Enforcement
This subpart describes the scope and general requirements of the
rule, the requirements concerning the identification and maintenance
information on building materials and equipment, the use of alternate
materials, the application of the proposed rule if sections are in
conflict, and the requirement for a life-cycle cost analysis.
Proposed sections 435.101-108 contain changes from the MEC, 1992,
as discussed below. The Department believes that the provisions
discussed below are technologically feasible, and are of such minimal
cost that the benefits of such requirements make them economically
justified.
1. Sections 435.102.1.2 and 435.102.1.3: Building Envelope Insulation
and Insulation Installation
The sections require that insulation installed in the building be
clearly marked so that the ``R-value'' of the insulation can be easily
verified. The blown or sprayed attic insulation ``depth'' marker
requirement is contained in the MEC, 1995 but not in the MEC, 1992. The
insulation depth markers will help ensure that the claimed thickness of
the loose-fill ceiling insulation can be verified. Verification of the
ceiling insulation assures that the designed energy-efficiency
performance of the building ceiling can be achieved at a minimal cost
to the government. The associated costs are minimal compared to the
possibility of installing insulation that is less than the required
designed thickness and thereby loses energy. The use of depth markers
is technologically feasible because a marker is a simple ruler
graduated in one-inch increments and affixed to the roof/ceiling
framing.
2. Section 435.102.3: Fenestration Product Rating, Certification, and
Labeling
Section 121 of EPACT requires the Secretary of Energy to make a
determination, within one year of enactment, on whether a window energy
rating and labeling program established by the National Fenestration
Rating Council (NFRC) meets the objectives of the legislation. If not,
the Department is to develop a mandatory rating program. The
Secretary's provisional determination concluded that the NFRC voluntary
national window rating program meets the requirements of EPACT.
(September 23, 1994, 59 FR 48865, 48868). The Department supports the
NFRC efforts to establish a uniform, national rating, certification and
labeling program through incorporation of the NFRC program in Federal,
state and local government and national voluntary codes and standards.
The verification of window and door assembly U-values is a
significant element in determining the overall U-value or thermal
performance of the building envelope, which is a key factor in
achieving compliance with the proposed rule. Section 435.102.3 of the
proposed rule requires that when Federal agencies purchase fenestration
products, the U-value (conductive heat transfer) for that fenestration
product (window, door, and skylight) shall be assigned. If the product
has been tested in accordance with NFRC 100-91 (Procedure for
Determining Fenestration
[[Page 24168]]
Product Thermal Properties), the NFRC U-value shall be used. The rating
procedure tests the fenestration products to determine the conductive
heat transfer properties and/or characteristics of the product.
If fenestration products are not tested in accordance with NFRC
100-91, a default U-value will be assigned, using Tables 102.3.1 and
102.3.2 located in the Appendix of the proposed rule. The default
values represent a conservative energy-efficiency performance potential
of a product based on characteristics of the product which are
verifiable by visual inspection. The NFRC 100-91 rating procedure and
the default U-value tables for non-tested products in the proposed rule
are those found in the MEC, 1995.
There is no standard for rating the energy-efficiency (U-values) of
window and door assemblies in the MEC, 1992. The inclusion of the
requirement to assign U-values to fenestration products will
potentially save energy costs by eliminating inaccurate U-values or
ratings that do not reflect the total window or door assembly thermal
performance. Thus assigning U-values or default U-values helps to
ensure that the claimed thermal performance of fenestration products
will actually be achieved in housing construction.
The NFRC procedure provides a fair and accurate rating of window
and door thermal performance. Over 22,000 products have been rated by
the NFRC. The ratings of window and door thermal performance are
recognized by at least six states in their building code provisions
regarding energy-efficiency.
Windows and doors that are rated in accordance with NFRC 100-91 may
result in an expenditure by the product manufacturer. However, NFRC
100-91 is set up so that every window or door unit need not be tested
individually. The results of a few actual tests are extrapolated by
computer modeling to the manufacturer's entire product line. Thus the
per unit cost of receiving a NFRC rating is relatively small.
Alternatively, a fenestration product manufacturer can elect not to
test and save the associated costs, and receive the default U-value
rating.
Assigning a U-value according to the new rating procedure can
change the rating received by particular windows. A model that was
previously rated at 0.4 might, for example, be rated under the new
system at 0.5. As a result, there may be situations in which agencies
would change the window selected in order to keep with the code's U-
value requirements. That change could result in higher purchase prices,
but would reduce building energy use as well. The use of energy-
efficient windows is becoming standard building construction practice
in most regions of the nation, particularly in the northern tier
states, indicating their general cost-effectiveness in today's building
markets. Given the nominal cost per unit for NFRC testing and rating
and the general cost-effectiveness of energy-efficient windows, the
Department has determined that the assigning of U-values in accordance
with NFRC 100-91 or default U-values in the proposed rule is
economically justified. See the Technical Support Document, section
6.7, page 6.6.
3. Section 435.104: [Reserved]
The proposed rule does not include the section entitled, ``Plans
and Specifications'' from the MEC, 1992.
4. Section 435.105: [Reserved]
The MEC, 1992 has requirements concerning the inspection by the
building official of construction or work for which a building permit
is required. Federal agencies have various procedures concerning the
inspection of construction. Section 435.105 is reserved in the proposed
rule to allow Federal agencies the flexibility of using their own
requirements concerning the inspection of residential construction.
5. Section 435.106: [Reserved]
The proposed rule does not include the section entitled,
``Validity'' from the MEC, 1992.
6. Section 435.107: Precedence
The Model Energy Code, 1992 contains no statement addressing the
order of precedence between potentially conflicting requirements of the
proposed code and those of a reference standard. Section 435.107.1 of
the proposed rule clarifies which requirements that shall apply.
7. Section 435.108: Life-Cycle Cost Analysis
The MEC, 1992 contains no requirements related to life-cycle costs.
The proposed rule would require building design(s) of Federal
residential buildings to be evaluated consistent with Subpart A of 10
CFR Part 436, which specifies methodologies and procedures for life-
cycle cost analyses of Federal buildings.
B. Subpart B: Definitions
This subpart includes definitions for all relevant words or phrases
that have a specific meaning within the context of the rule. In
accordance with the proposed rule, new definitions not in the MEC, 1992
have been added and unneeded definitions have been removed. For
example, definitions related to the radon control requirements have
been added and definitions related to non-residential HVAC systems and
components not regulated by this rule have been deleted. Appendix D in
the Technical Support Document identifies those definitions that have
been added or removed.
C. Subpart C: Design Conditions
This subpart gives sources for heating and cooling degree-day data,
establishes design conditions for the sizing of the heating,
ventilating, and air-conditioning system, and provides reference
standards for mechanical ventilation criteria. Other than identifying
cooling degree-days and providing more specific information on where
one may obtain weather data, this section is unchanged from the MEC,
1992.
D. Subpart D: Design by Systems Analysis; Design Utilizing Renewable
Energy Sources
This subpart contains a compliance approach that may be used as an
alternative to Subpart E. Subpart E contains the minimum energy-
efficiency requirements for the thermal performance of new Federal
residential buildings.
Subpart D requires that the user conduct an annual energy analysis.
It defines the general methodology and rules for this energy
comparison. A proposed building complies with this rule if its
calculated annual energy usage is less than or equal to the energy
usage of a similar building (referred to as the ``standard design'')
designed in accordance with Subpart E. The annual energy analysis
methodology is equivalent to that in Chapter 4 of MEC, 1992 but
provides more direction and specific detail on how the annual energy
analysis shall be conducted, as discussed below.
1. Section 435.402.1: Energy Analysis
A critical parameter for performing any comparative energy analysis
is defining the space heating, air conditioning, and service water
heating equipment and the efficiency or performance levels of that
equipment for the ``standard'' design.
As in the MEC, 1992, the proposed rule would require that the
standard and the proposed design be compared utilizing the ``same
energy source(s) for the same functions.'' These energy sources are
determined by the Subpart E provisions governing the selection of
equipment. This energy consumption provision is similar to the
provision in
[[Page 24169]]
section 402.1 contained in the MEC, 1992 and 1993. The only substantive
difference between the proposed rule and the earlier versions of the
MEC that relate to this section is the application of life-cycle cost
requirements.
In order to comply with Subpart D, a proposed design must be at
least as life-cycle cost-effective as the standard design and use no
more energy than the standard design. In the event that the proposed
design utilizes more than one energy source and increases the
consumption of one energy source and decreases the consumption of the
other energy source, then the overall energy consumption, measured at
the site, must be less than or equal to the standard design. Because
the energy sources in the standard and proposed design must be the
same, changes in energy consumption that affect more than one energy
source would be limited to variations in equipment efficiency and types
and building thermal envelope efficiencies.
Because methods for consistently measuring and comparing the energy
performance of new technologies take time to develop, the proposed
design may utilize newer equipment types not covered using current
Department test procedures. The Department is requesting comment on
methods of addressing newer equipment technologies for which a
recognized means of evaluating and comparing energy performance have
not yet been fully developed.
2. Section 435.402.1.1: Input Values/Assumptions for Group R (Single-
Family and Multi-family Low Rise) Buildings
This proposed rule specifies input values/assumptions for certain
energy-related building parameters that must be used in the whole
building energy analysis comparison. These values were taken from the
MEC, 1995. In contrast, the MEC, 1992 does not provide specification of
these values. For example, if the builder or designer chooses to use
the annual energy analysis approach, the thermostat set points that
must be assumed are given in Table 402.1.1-4, whereas the MEC, 1992
provides no information.
The specification of input values/assumptions performs two
functions. First, it eliminates the time and effort that each user
needs to set these values/assumptions individually. Second, it
establishes ground rules that ensure consistency among different whole
building annual energy analyses and helps prevent misuse of this
approach.
The Department has determined that specifying the input values/
assumptions to annual energy analyses comparisons is technologically
feasible because it is consistent with current building energy usage
analysis practice and is the only way to verify consistency in
analytical results across the different analytical tools. The
specification of input values is also economically justified since
failure to specify such input values could result in the approval of
noncomplying or unrealistic building designs and unnecessary energy
cost increases. The introduction of erroneous data would add
unwarranted time, effort, and cost to the project.
The Department has included many new annual energy analysis input
values/assumptions in the proposed rule. See the Technical Support
Document, section 6.8, page 6.8.
3. Section 435.403.3: Passive Solar Design Analysis
The MEC, 1992 and 1995 do not include direction on methodologies
for measuring the energy impacts of solar space conditioning. This
section of the proposed rule allows for the optional use of
``BuilderGuide,'' a software program that calculates heating and
cooling loads for solar technologies. ``BuilderGuide'' was produced by
the Department in partnership with the Passive Solar Industries Council
and the National Renewable Energy Laboratory. The resulting
``BuilderGuide'' package is specific to some 2400 United States
locations, and uses a methodology that is based on 15 years of solar
energy research. The Department has determined that ``BuilderGuide'' is
a well developed, widely distributed and recognized software program.
Other reliable tools for calculating energy usage of solar technologies
or other new energy-efficiency measures can be used. The Department
recognizes that designs using renewable energy sources for space
conditioning or water heating may be economically justified. The
Department is promoting ways to further stimulate the use of renewable
sources of energy. The Department welcomes additional suggestions on
approaches for crediting measures that use renewable sources of energy.
E. Subpart E: Design by Component Performance Approach
Sections 435.501-505 contain the minimum energy-efficiency
requirements for the thermal performance of building envelope
components, building mechanical systems and equipment, service water
heating, and electrical power and lighting. Compliance with the
requirements of Subpart E is required unless the optional compliance
approach prescribed in Subpart D is used.
The building envelope requirements apply to the building components
enclosing conditioned space, including: roof/ceilings, above grade
walls, slab-on-grade floors, floors over unconditioned spaces, basement
walls, crawl space walls, doors, windows, and skylights. The proposed
rule also contains requirements limiting air infiltration through the
building envelope.
The mechanical systems and equipment performance requirements set
heating and cooling equipment load capacity (sizing) limits,
temperature and humidity control requirements, distribution system
construction and insulation requirements, and backdrafting testing
requirements. The requirements relating to electrical power and
lighting systems apply only to multi-family residences. The mechanical
equipment section does not require mechanical equipment efficiencies
that exceed current Federal minimum standards.
Sections 435.501-505 of the proposed rule in Subpart E revise and
update the requirements contained in Chapter 5 of the MEC, 1992.
Subpart E contains two separate building envelope compliance
approaches. The two approaches are: (1) The individual component
performance approach and, (2) the whole building performance approach.
The individual component performance approach (section 435.502.2.1)
gives maximum U02 requirements for the floor over
unheated spaces, wall, and roof/ceiling. The different elements of the
wall (insulation, windows, doors, opaque wall), the floor (insulation,
type of floor), or the roof/ceiling (insulation, skylights, type of
ceiling) may be varied to achieve the U0. The whole building
performance approach (section 435.502.2.2) defines the maximum
U0 requirement for the entire building. The user can then
tradeoff among the requirements for the walls, floors, and roof/
ceilings as long as the maximum U0 for the entire building
is not exceeded.
---------------------------------------------------------------------------
\2\U0 = the area-weighted average thermal
transmittance of an area of the building envelope; i.e., the
exterior wall assembly including fenestration and doors, the roof
and ceiling assembly, and the floor assembly (British thermal unit/
(hour x square feet x degrees Fahrenheit).
---------------------------------------------------------------------------
1. Major Revisions From the Model Energy Code, 1992 That Are Contained
in Subpart E of the Proposed Rule
The major substantive changes from the MEC, 1992 as found in
Subpart E are described below.
a. Section 435.502: Building thermal envelope requirements. The
tables
[[Page 24170]]
found in proposed section 435.502, and Figures 1 through 6 in the
Appendix contain the building thermal envelope requirements. These
requirements are significantly changed from the MEC, 1992 and generally
are more stringent than the MEC, 1992, except for the requirements for
crawl space walls which are essentially the same as those in the MEC,
1992. The requirements that are more stringent than the MEC, 1992
consist of maximum U0-values for above-grade walls including
windows and doors, roof/ceilings, floors over unheated spaces, basement
walls, and minimum R-values for slab-on-grade perimeters. When
describing the thermal performance of a building component, consider
that the lower a U0-value, the more energy-efficient the
component and the higher a R-value, the more energy-efficient the
component.
The Department conducted a life-cycle cost economic analysis, as
specified at 10 CFR Part 436, to analyze these thermal envelope
requirements so as to minimize life-cycle costs to the Federal
government. The assessment was conducted using the ARES computer
software analyzing information such as the average Federal cost of
energy, expected energy price increases, and typical costs for
installation and maintenance of proposed measures. The economic
analysis considered construction-related costs and space heating and
cooling energy costs for 881 cities and eight types of common heating
fuel/equipment types. See the Technical Support Document (chapters 2
thru 5) for a detailed description of the analysis to establish the
building thermal envelope requirements.
b. Section 435.502.2.1.1.2: Metal framing. The proposed rule
includes a detailed new table (Appendix Table 502.2.1.1.2) to provide
users with the correction factors for the thermal-performance values of
wall assemblies framed with metal studs. Table 502.2.1.1.2 does not
appear in the MEC, 1992 but is in the MEC, 1995 and Standard 90.2-1993.
This table provides a standardized treatment of heat loss through walls
framed with metal studs. The thermal performance requirements of such
walls are the same as those for wood-framed walls. Metal framing is
technologically feasible. Metal wall assemblies have become more
popular over the last several years due in part to the price increase
of wood. Metal framing is not required by the rule and need not be
specified where not cost-effective or otherwise not preferred.
c. Section 435.502.2.1.5: Crawl space walls. Section 435.502.2.1.5
of the proposed rule requires floors above crawl spaces vented to
outdoors to be insulated. This requirement is contained in the MEC,
1995, but is not in the MEC, 1992. In the MEC, 1992 insulating the
crawl space wall was not dependent on whether the crawl space was
ventilated. Wall insulation for vented crawl spaces is ineffective
because outside air will enter the crawl space through the vents.
Increased energy usage results from the uninsulated heat transfer path
through the floor above. Crawl space wall insulation in the proposed
rule is an option only if the crawl space is not vented. The Department
has determined that the insulation of floors over vented crawl spaces
is technologically feasible since it is part of current standard
building construction practice.
Further, the requirement is economically justified. See the
Technical Support Document, section 6.3, page 6.2.
d. Section 435.502.3.3: Recessed lighting fixtures. Recessed
lighting fixtures, when installed in the building envelope, must be
properly sealed to prevent unwanted ceiling air leakage. The
requirement is contained in the MEC, 1995. Without this requirement,
recessed lighting fixtures can be a significant source of energy loss
due to air leakage into the attic space. The MEC, 1992 has no
requirements relating specifically to recessed lighting fixtures.
The Department has determined that the insulation and sealing of
recessed lighting fixtures are technologically feasible. These
practices are used in current building construction practice. The
requirement is economically justified because the incremental cost for
installing well-sealed recessed light fixtures is less than the cost of
the energy that would otherwise be lost over the 25-year analysis
period. See the Technical Support Document, section 6.6, page 6.5.
e. Section 435.503.2: Mechanical equipment efficiency. Section
435.503.2 addresses the selection of heating and cooling equipment with
attention to the use of life-cycle cost principles. The primary
difference between the MEC, 1992 and the proposed rule regarding this
section is that the proposed rule includes provisions addressing the
life-cycle cost of the installed equipment. The MEC, 1992 has no
requirements concerning life-cycle cost principles. In the proposed
rule when selecting among equipment options that are minimally
compliant with Federal performance standards, that option with the
lowest life-cycle cost is to be selected. The proposed rule allows for
the selection of equipment that exceeds Federal minimum efficiency
standards under Subpart E providing the equipment is at least as life-
cycle cost effective as equipment that is minimally compliant with
Federal standards. Agencies are encouraged through the Procurement
Challenge program and other Federal initiatives to consider more
energy-efficient equipment.
Given the large range of heating and cooling equipment types and
efficiencies available, this section provides a simplified method for
incorporating life-cycle cost principles into equipment selection. Two
options are provided for: the first option requires Federal agencies to
select the most cost-effective equipment that is minimally compliant
with Federal standards. For central heating and cooling equipment
systems for multi family dwellings that service multiple rather than
individual dwelling units, minimum equipment efficiencies found in the
codified version of ASHRAE Standard 90.1-1989 are used. This approach
is consistent with the overall rule, which sets building envelope
efficiency requirements at a level that is cost-effective on average
when equipment at minimum Federal efficiency levels is used. The second
option allows for the use of any other equipment available, provided
that it is at least as cost-effective as the heating and cooling
equipment identified under the first option. This second option allows
for the use of more efficient versions of equipment that are subject to
minimum Federal standards and would allow use of equipment, such as
natural gas heat pumps or ground source heat pumps, that are not
covered by the Federal standards.
It is anticipated that for most buildings, an informal comparison
of local costs and fuel availability will identify a few systems as the
most likely to be the most cost-effective; these systems can then be
compared in more detail to identify the system that has the lowest
life-cycle cost under the first option. If any other equipment is
preferred, a single additional calculation will establish whether it is
more cost-effective than the system identified in the first option.
f. Section 435.503.3.1.1: Heating and cooling equipment capacity.
The Department has included limits on equipment capacities in section
435.503.3.1.1 of the proposed rule. These requirements are taken from
the codified version of Standard 90.2-1993. The MEC, 1992 has no
requirements relating to the sizing of heating and cooling equipment.
Oversizing of heating and cooling equipment results in increased energy
usage since the equipment cycles on and off more frequently and,
therefore, runs at a
[[Page 24171]]
lower average efficiency than properly sized equipment. Furthermore,
oversized cooling equipment is less able to remove moisture from the
air and, therefore, is less able to control humidity. Also, oversized
heating, ventilating, and air-conditioning equipment also generally
costs more to purchase than properly sized equipment. The Department
believes that the requirement is technologically feasible and
economically justified based on the discussion above. See the Technical
Support Document, section 6.2, page 6.2. However, in very well
insulated homes, equipment sizing could be such that the smallest
available size of intended equipment might not meet the proposed sizing
requirement. The Department would appreciate comments on what designers
should do if unable to obtain equipment within the equipment capacity
requirements.
g. Section 435.503.5.7.2: Duct sealing. The proposed rule would
contain duct sealing requirements that are more stringent than those in
the MEC, 1992. A requirement that all low-pressure air ducts be sealed
with mastic with fibrous backing tape was added as section
435.503.5.7.2 of the proposed rule. This requirement is also in the
MEC, 1995.
Leaking supply and return ducts decrease heating and cooling
equipment efficiency and increase energy usage while not meeting
resident comfort requirements. Many studies of actual houses have
revealed leaky ducts to be a major source of energy loss. One study
showed leaks of 15 percent can reduce air conditioner efficiency by
33--50 percent. See the Technical Support Document, section 6.4, page
6.4. To address these problems, the proposed rule requires all low-
pressure supply and return ducts outside the conditioned space to be
sealed with mastic with fibrous backing tape. In contrast, the MEC,
1992 requires only that the supply ducts are sealed and allows any type
of tape.
Current construction practice allows the use of duct tape to
``seal'' cracks and crevices in supply and return air ducts. Duct tape
however, is not a sealant. A clean surface and a tight fit are required
to produce a ``seal'' at installation and neither of these conditions
is routinely met. If a ``seal'' is obtained at installation, however,
the tape degrades over time as a result of deterioration of the glue.
Properly installed duct tape ``seals'' often will leak within a year or
two. Repairing leaking ducts after construction can be costly or
impractical because ducts are often in inaccessible locations or they
are wrapped with insulation that must be removed and replaced.
Mastic is a permanent sealant. It does not degrade over time, and
is expected to last for the life of the home. Installation is
uncomplicated, with several methods of application from which to
choose. Mastic has excellent adhesive and cohesive properties, even on
typically dirty or oily surfaces found at the construction site. The
cost of sealing ducts in existing housing is estimated to range from
$50 to $300 when the installer has unrestricted access to the ducts
without making it necessary to remove the finished material that may
cover the ducts. The cost will clearly be lower during construction in
new housing. This requirement is technologically feasible because
mastic and tape sealing are found in current building construction
practice. The requirement is economically justified because the cost of
the energy saved over the 25-year analysis period would exceed the cost
of the additional labor and materials that would be used to comply with
this section. See the Technical Support Document, section 6.4, page
6.4.
h. Section 435.503.5.9.1: Backdrafting test. The Department has
included requirements relating to the prevention of backdrafting of
fossil-fuel-burning appliances in the proposed rule. The MEC, 1992 has
no requirements relating to this potential health hazard. Chimney
backdrafting in fossil-fuel-burning appliances such as oil or gas-fired
water heaters, gas-fired clothes driers, fireplaces, or wood stoves is
a potential threat to occupant health in residential buildings. Chimney
backdrafting can occur when exhaust gases are drawn into a building
through the chimney or vent because air pressure is lower inside the
building than outside. Chimney backdrafting can cause serious health
problems and even death can occur from exhaust gases containing or
leading to the formation of carbon monoxide. Infants are particularly
at risk because their respiratory systems are not fully developed, and
they are susceptible to health effects at lower concentrations than are
safe for most healthy adults. Sulfur dioxide and carbon dioxide also
circulates in occupant breathing spaces as a result of backdrafting.
These gases can cause long-term health effects such as chronic
respiratory illness, or short-term health effects such as discomfort,
shortness of breath, and respiratory irritation.
The Department has determined that tests for potential backdraft
problems should be performed in all homes with fossil-fuel-burning
appliances that do not obtain exhaust combustion air directly from the
outside. These tests shall be performed because the potential for
chimney or venting failure exists in all homes and especially in all
well sealed, poorly ventilated homes with combustion equipment. Tight
building envelopes can cause stack-effect-induced depressurization and
powered exhaust fans can exacerbate the problem.
The test specified in the proposed rule is taken from the Canadian
spillage test developed by the Canadian General Standards Board. The
test measures the inside/outside pressure differential across a
building shell with a micromanometer under best-case and worst-case
scenarios. The test then compares the measurements to depressurization
limits for combustion appliances in the house. When depressurization
measurements exceed limits, remedial action is required before the
house can pass the spillage test and comply with the rule. The
Department has reviewed the Canadian spillage test and determined that
it is technologically feasible and has included it in the proposed
rule. See Technical Support Document, section 8.0, page 8.1.
The cost to perform a backdrafting test is estimated to be between
$50 and $100, depending on factors such as: the complexity of the
house, the number of houses in a given area to be tested, and local
weather conditions. This cost range does not include remedial measures.
The Department has determined that there is a potential risk of
backdrafting which justifies the inclusion of this requirement which is
consistent with health and safety needs. See the Technical Support
Document, section 8.0 for more information. The Department requests the
public to comment on whether carbon monoxide alarms should be required
in Federal residences.
i. Section 435.504.2: Service water heating equipment. Section
435.504.2 addresses the selection of service water heating equipment
with the application of life-cycle cost requirements. As with space
heating and cooling equipment, Federal agencies may either (1) select
the most cost-effective domestic water heating equipment that minimally
complies with Federal standards or (2) select any other equipment that
is at least as life-cycle cost-effective. More efficient equipment may
be selected under Subpart E. Agencies are encouraged through the
Procurement Challenge program and other Federal initiatives to consider
more energy-efficient equipment.
j. Section 435.504.4: Heat traps. Heat traps are one-way valves or
pipe configurations that prevent thermal diffusion or thermal siphoning
of
[[Page 24172]]
potable water from the hot water heater in the house through the water
distribution system, thus needlessly dissipating heat. Section
435.504.4 of the proposed rule requires that water heaters with
vertical pipe risers have heat traps. This requirement is not in the
MEC, 1992 and was taken from the codified version of Standard 90.2-
1993. Heat traps are also technologically feasible because they are
part of current water heater manufacturing practice. The use of heat
traps is a low-cost method of reducing water heating energy use already
installed on many commercially available water heaters. Therefore, heat
traps are economically justified because the net annual savings over
the lifetime of the water heater exceeds the initial first cost of the
additional hardware. See the Technical Support Document, section 6.5,
page 6.5.
2. Miscellaneous Revisions That Are Contained in Subpart E of the
Proposed Rule, Not in the MEC, 1992
The proposed rule includes the following additional requirements
that are not part of the MEC, 1992. Section 435.502.1.4 contains a
clarification to the MEC, 1992 in that access openings, which are
considered part of the thermal envelope element, must be evaluated as
part of the overall building thermal envelope element (e.g., floors,
walls, roof/ceiling, etc.,). The Department believes this is
technologically feasible because access openings are commonly insulated
in colder climates and are economically justified because it imposes no
additional cost to the building. See the Technical Support Document,
section 6.9, page 6.10.
Section 435.502.1.5 contains a requirement for the insulation of
foundations supporting masonry veneer. The Department has determined
that the requirement is technologically feasible because it reflects
current building construction practice. Although some energy would be
lost, the energy loss would be small and economically justified when
weighed against the costs that would be incurred by damage to the
masonry veneer. Damage can occur due to settling of the masonry as the
insulation is compressed. The technical justification for this
requirement may be found in the Technical Support Document, section
6.10, page 6.10.
Section 435.502.2.1.3 contains an equation to calculate the total
floor heat loss of the proposed building. The equation requires that
all floors of different construction (in aggregate) must meet the
U0 requirements for floors over unheated spaces. The
Department has determined that the requirement is technologically
feasible. The technical justification for this requirement may be found
in the Technical Support Document, section 6.11, page 6.10. The
equation is economically justified because the use of the equation to
determine the U-value requirement for floors over unheated spaces is
cost-effective. Variations in floor configurations are not required by
this proposed rule.
Section 435.502.2.1.4 contains a clarification of acceptable slab
insulation placement which reflects current building construction
practice. The Department has determined that the requirement is
technologically feasible because it reflects current standard building
construction practice. The technical justification for this requirement
may be found in the Technical Support Document, section 6.11, page
6.11. The clarification is economically justified because it imposes no
additional slab insulation requirements. There is a potential for
installation cost savings due to the flexibility offered by the
proposed requirement.
Section 435.502.3.2 simplifies language on caulking and sealing
requirements for typical air sealing measures. The Department has
determined that the requirement is technologically feasible because the
simplified language generally reflects the requirements contained in
the MEC, 1992. The technical justification for this requirement may be
found in the Technical Support Document, section 6.13, page 6.12. The
simplified language is economically justified because it imposes no
additional costs to the construction of the building.
Section 435.502.3.1 refers to updated reference standards for
allowable infiltration rates for windows and doors. This section
reflects current manufacturing standards for air-tightness of pre-
fabricated windows and doors. The Department has determined that the
requirement is technologically feasible because current manufactured
windows and doors are built to the updated referenced standards. The
updated reference standards are economically justified because the
proposed rule imposes no additional cost or requirements on
manufacturing quality or performance. The technical justification for
this requirement may be found in the Technical Support Document,
section 6.15, page 6.14.
F. Subpart F: [ Reserved ]
Subpart F is reserved for a simplified compliance approach the
Department is developing. This approach will make it easier to
determine compliance with this rule. This revised simplified compliance
approach would be different from that contained in the MEC, 1992, 1993,
and 1995. This approach is expected to be similar to the Department's
``MECcheck'' tables which display pre-calculated configurations in
compliance with the MEC, 1992, 1993 or 1995. The Department is planning
to produce a ``Federal'' version of MECcheck.
G. Subpart G: Radon Control
Subpart G provides the minimum requirements for the control of
radon from the ground and from construction materials associated with
Federal residential buildings. The application of requirements for
radon control apply in addition to the provisions of Subpart D or E.
The ECPA, as amended, directs that the Federal residential building
energy standard ``consider, in consultation with the Environmental
Protection Agency and other Federal agencies, and where appropriate
contain, measures with regard to radon and other indoor air
pollutants.'' 42 U.S.C. 6834(a)(2)(C). The intent is for the Department
to address health concerns related to air quality in Federal buildings.
The Department has determined that radon is a potential health
hazard in residential buildings and that the proposed rule should
address radon testing and mitigation requirements. Radon is a gas that
exists naturally in many soils and enters a building through the
foundation. Radon concentrations in soil vary widely across the United
States and even within a small region, such as a county. If high
concentrations of radon are present in the soil below a building, then
measures to control radon are needed. Approximately 6 percent of
existing single-family homes in the United States or 5.8 million homes
in 1990 have average radon levels greater than 4 pCi/L per year, the
threshold level determined by the EPA to require corrective action.
Approximately 0.7 percent of existing single-family homes in the
country have average radon levels greater than 10 pCi/L per year. The
EPA estimates that indoor radon causes between 7,000 and 30,000 lung
cancer deaths per year. This range is based on the uncertainty inherent
in the many factors contributing to the risk of radon exposure and on a
national residential radon survey estimate of an average level of 1.25
pCi/L per year. The EPA's best estimate is that 14,000 lung cancer
deaths per year result from residential radon exposure.
[[Page 24173]]
In this proposed rule the Department would be accepting EPA's
determination that radon-resistance control measures should only be
required in zones (counties) of high radon potential. Such zones are
defined by the EPA ``U.S. Map of Radon Zones'' or local data if
available. The proposed rule specifies the EPA ``U.S. Map of Radon
Zones'' as the default source designating counties where the proposed
requirements apply. Table 702.2 in the Appendix of the proposed rule
lists the applicable counties. The EPA ``U.S. Map of Radon Zones'' is
not always sufficient to predict radon concentrations accurately. There
may be instances where specific locations will be assigned to an
inappropriate radon potential zone in the EPA ``U.S. Map of Radon
Zones''. To accommodate for such inaccuracies, the proposed rule allows
considering appropriate evidence and ``overruling'' the EPA ``U.S. Map
of Radon Zones.''
Consideration of non-EPA data is justifiable given that studies on
radon concentrations in many Federal installations are already
available or are underway.
The proposed rule uses the following approach for addressing radon
when radon-resistant construction is necessary:
(1) Foundation sealing with passive (non-mechanical) venting of
soil gas to the outside;
(2) Long-term and short-term post-occupancy radon testing to verify
occupant safety;
(3) Mitigation, if the tests reveal high radon concentrations; and
(4) Post-mitigation testing for radon and potential backdrafting to
ensure safety.
Each of these four approaches is described in further detail below.
The proposed radon requirements are technologically feasible because
the techniques used are part of current standard building construction
practice in many areas of the U.S. and are consistent with the EPA
Model Standards and Techniques for Control of Radon in New Residential
Buildings (EPA 402-R-94-009, March 1994). The Department is accepting
EPA's analysis of the costs and benefits of radon control. See RS-34,
pages ES-1-ES-4. The Technical Support Document (Chapter 7.0) provides
construction specifications and technical justifications for the
proposed rule. The proper initial abatement approach in areas of
potentially high radon concentrations is to seal potential sources of
air leakage in the foundation and vent the soil gas below the
foundation. Such venting uses a pipe that extends from the foundation,
through the house, and out the roof. This approach is consistent with
the approach in the EPA Radon Mitigation Standards (EPA 402-R-93-078,
October 1993). It cannot be conclusively determined before construction
that a radon source exists that is strong enough to raise indoor
concentrations above the EPA action level. Therefore, it would be
fiscally imprudent initially to require measures beyond foundation
sealing and the ``passive'' vent pipe. If elevated radon levels are
found after construction and these initial measures were not installed,
the cost of the retrofit would be much higher than the cost during
initial construction.
The radon concentration within a residence can only be determined
after the residence is built and occupied. This is due to the
interaction of radon sources with construction characteristics of the
house and the indoor pressure-driven air flow that is influenced by
heating, ventilating and air-conditioning equipment under occupant
control. Because short-term tests are not adequate to obtain annual
average radon concentrations, the proposed rule requires long-term
post-occupancy testing of residences built in specified locations. The
long-term test requires between 6 months and 1 year and is the most
accurate measure of chronic radon levels an occupant will encounter. A
short-term test which lasts between seven and 60 days, is also proposed
to ensure that occupants are not exposed to radon levels in excess of
20 pCi/L while the long-term test is in progress. Testing procedures
and devices must conform to the EPA Protocols for Radon and Radon Decay
Measurements in Homes (EPA 402-R-93-003, June 1993).
Testing may show that sealing the foundation and installing the
passive vent are not sufficient to control the radon level. In such
cases, the proposed rule requires that a fan be installed and operated
in the foundation vent system to lower radon concentrations. Vent fans
must be activated when the long-term test reveals radon concentrations
greater than the EPA action level of 4 pCi/L or if the first short-term
test and a second short-term confirmatory test reveals radon levels in
excess of 20 pCi/L. The EPA Radon Mitigation Standards offer guidance
on installing the fan.
Follow-up tests are required to ensure that the vent fan is
successful at lowering indoor radon levels. Additionally, because the
foundation vent fan may under certain circumstances cause fossil-fuel-
burning appliances to tend to backdraft, both the proposed rule and the
EPA Radon Mitigation Standards require testing for backdrafting of
chimney and combustion vents. Section 435.503.5.9.1 of the proposed
rule, referenced in Subpart G, specifies the test procedure to be used
to check for potential backdrafting.
The Department departs from the EPA ``Radon Mitigation Standards''
in several respects. First, the proposed rule allows data on radon
concentrations at Federal facilities to take precedence over the EPA
``U.S. Map of Radon Zones'' for determining whether radon-resistant
construction is required. Second, if the housing is located in a high
radon zone, the proposed rule requires testing and, if necessary,
mitigation and further post mitigation testing. Third, many sections of
the EPA Radon Mitigation Standards that are unenforceable, including
discussions, explanations, or recommendations, have been deleted.
Fourth, the Department provides more detail in some construction
specifications so that the required measures can be more easily
verified. Fifth, the Department did not explicitly include the EPA
requirements for sealing the above-grade structure to help limit air
infiltration through the foundation. This was because similar
requirements are already included in section 435.502.3 of the proposed
rule.
The Department has thus followed the general approach outlined in
the EPA Radon Mitigation Standards. Radon-resistant construction is
only required in locations with high radon potential and a phased
approach to control is specified. Control should be based on a sealed
foundation, passive venting of soil gas and radon testing after
occupancy. Only if necessary should a fan be added to the vent system.
The Department consulted and provided to the EPA draft copies of the
proposed rule (including radon requirements) and the Environmental
Assessment supporting the proposed rule. The EPA has provided extensive
comments on the requirements for radon in the proposed rule and the
Department has incorporated many of those comments in Subpart G.
H. Subpart H: Standards
This section provides a list of all the standards referenced in the
proposed rule. This section has been updated from the MEC, 1992 because
some requirements contained in this proposed rule are not contained in
the MEC, 1992 reference standards. Also, some referenced standards have
been updated to newer versions since 1992.
[[Page 24174]]
IV. Consultation
In developing today's proposal, the Department has consulted with
outside parties, including state and local code officials, private
sector representatives, and other Federal agencies, as required by
section 305(a)(1) of ECPA.
In addition, the Department continues to work with the relevant
private sector organizations and the states to analyze potential
improvements to the MEC and to facilitate the adoption of such
improvements in both the public and private sectors. Adoption of the
MEC format in today's proposal provides a ready basis for the
incorporation of future code improvements as they are developed and
approved through the standard process for model code change proposals.
Finally, the Department will specifically provide Federal agencies
with information regarding the availability of energy-efficiency
equipment and emerging developments that improve building envelopes.
This support will help keep Federal agencies current regarding energy-
efficiency opportunities between the updates of this rule.
V. Energy and Economic Impacts
Section 305(a)(2)(A) of ECPA requires that the proposed rule meet
or exceed the MEC, 1992. The proposed rule is based on the MEC, 1992,
with the additions described in Section III above. Overall, the
proposed rule, if adopted would reduce energy use by approximately 11
percent for single-family residences and 26 percent for multi-family
residences, as compared to the MEC, 1992.
The energy estimates reported here are based on the minimum
specifications required in Subpart E of the proposed rule. Additional
cost-effective energy-efficiency improvements in new Federal
residential buildings are facilitated by this rule through Subpart D,
which provides a means of documenting the energy savings and cost-
effectiveness of more energy-efficient building designs.
The Department has prepared a Technical Support Document that
includes an economic analysis. It concludes that there are no
significant adverse economic effects from adopting the proposed rule.
The proposed rule, when compared to the MEC, 1992, will result in a
positive net flow of benefits from energy savings that more than
offsets higher capital construction and other costs at estimated
Federal costs of energy.
The national net effect of the proposed rule is a cumulative
savings of $870,000 for the approximately 3,000 Federal housing units
constructed each year. These net effects are based on the net present
value of energy savings and capital costs over a 25-year period. See
the Economic Analysis at page 6.
VI. Technological Feasibility and Economic Justification
The standards proposed today are technologically feasible and
economically justified to the Federal government as required by Section
305(a)(1) of ECPA.
The Department used the life-cycle cost methodology reflected in
the microcomputer program entitled ``ARES'' for evaluating the life-
cycle cost-effectiveness of various thermal envelope EEMs. Only those
EEMs the Department judged technologically feasible were reviewed.
The life-cycle cost analysis compares the cost and benefits of all
the EEMs. The HVAC equipment performance efficiencies are specified at
current minimum EPCA levels. See 10 CFR Part 430. These are the same
levels found in the MEC, 1993. Given a set of fuel prices, financial
and economic parameters, and EEM costs for a specific location, ARES
identifies the life-cycle cost resulting from any given set of EEMs.
Energy costs and discount rates reflect estimated Federal costs of
energy and the Federal discount rate established annually by the
Federal Energy Management Program for the life-cycle cost analysis
required by 10 CFR Part 436. The present value of the total costs for
several EEMs are compared, and the results are used to set the code to
energy-efficiency measure levels that achieve the lowest energy-related
total cost for construction, operation and maintenance for each
location studied. The resulting thermal-envelope-component values are
presented as a function of heating degree-days.
The technical feasibility of the EEMs contained in the ARES energy
data base was assessed by determining that they were technologically
verifiable, commercially available, and in common construction
practice. Construction features that cannot be analyzed by ARES because
the technical or economic data has not been well established, or
features that have small additional costs but significant potential for
energy savings, have been analyzed by practicable architectural,
engineering, or economic judgment.
VII. Measures Concerning Radon and Other Indoor Air Pollutants
Section 305(a)(2)(C) of the ECPA requires the Department to
consider, where appropriate, measures with regard to radon and other
indoor air pollutants. The Department has proposed a set of radon
requirements concerning the control and mitigation of radon in Federal
residences. These requirements draw heavily from the EPA Radon
Mitigation Standards, EPA 402-R-93-078, April 1994. As part of these
proposed requirements, post-occupancy testing is proposed for locations
with high radon potential to discover whether radon concentrations
within the residences are acceptable. The proposed Federal rule also
includes requirements for addressing the potential for backdrafting of
combustion by-products, such as carbon monoxide, from fossil-fuel-
burning appliances.
VIII. Findings and Certification
A. Review Under the National Environmental Policy Act
The Department has completed an Environmental Assessment (EA), see
Environmental Assessment of the Impacts on Building Habitability and
the Outdoor Environment Resulting from the Proposed Federal Residential
Code, in support of the proposed rule, pursuant to the implementing
regulations of the Council on Environmental Quality (CEQ) (40 CFR Parts
1500-1508), the ``National Environmental Policy Act of 1969, as
amended,'' (NEPA) (40 U.S.C. 4221 et seq.), the Department's NEPA
Implementing Procedures, (10 CFR Part 1021), and the Secretarial Policy
on the National Environmental Policy Act (June 1994). Section V.B.2. of
the Secretarial Policy requires, wherever possible, that the Department
provide an opportunity for interested parties to review environmental
assessments prior to the Department's formal approval of such
assessments. The written public comment procedures for this EA are
discussed below in section IX.
The draft EA addresses the possible incremental environmental and
indoor habitability effects attributable to the application of the
proposed rule. The analysis in the draft EA demonstrates that the
potential environmental effects from the proposed rule would be
limited. The only impacts would be a decrease in outdoor air pollutants
resulting from decreased fossil fuel burning and temporary increases in
formaldehyde concentrations in the Federal residences.
B. Environmental Protection Agency Review
As required by the Federal Energy Administration Act of 1974, 15
U.S.C. 766(a)(1), a copy of this proposed rule
[[Page 24175]]
was submitted to the Administrator of the Environmental Protection
Agency for comments on the impact of the proposed rule on the quality
of the environment.
C. Regulatory Planning and Review
This regulatory action has been determined to be a significant
regulatory action under Executive Order No. 12866, 58 FR 51735 (October
4, 1993), but not economically significant. Accordingly, today's action
was subject to review under the Executive Order by the Office of
Information and Regulatory Affairs (OIRA) and OIRA has completed its
review.
D. Federalism Review
Executive Order 12612, 52 FR 41685 (October 30, 1987), requires
that regulations, rules, legislation, and any other policy actions be
reviewed for any substantial direct effects on states, on the
relationship between the Federal government and the states, or in the
distribution of power and responsibilities among various levels of
government. If there are substantial effects, then the Executive Order
requires preparation of a federalism assessment to be used in all
decisions involved in promulgating and implementing a policy action.
The proposed rule would establish energy-efficiency requirements
solely applicable to new Federal residential buildings. It does not
impose any requirements on state governments. Therefore, the Department
finds that today's proposed rule, if finalized, will not have a
substantial direct effect on state governments, therefore, a federalism
assessment has not been prepared.
E. Review Under the Executive Order on Metric Usage in Federal
Government Programs
Section 5164(b) of the Omnibus Trade and Competitiveness Act of
1988, 15 U.S.C. 205b, which amended the Metric Conversion Act of 1975,
designates the metric system of measurement as the preferred system of
weights and measures for trade and commerce. This law requires Federal
agencies by the end of fiscal year 1992 and to the extent economically
feasible, to use the metric system in U. S. procurements, grants, and
other business-related activities, except to the extent that such use
is impractical or likely to cause significant inefficiences or loss of
markets to U.S. firms. The Omnibus Trade and Competitiveness Act of
1988 also requires Federal agencies to establish guidelines and to
report as part of its annual budget submission on the actions it plans
in order to implement fully the metric system of measurement. This
policy is also stated and amplified by Executive Order 12770 of July
25, 1991, ``Metric Usage in Federal Government Programs.''
This rule is the first use of a dual metric/English (soft metric
conversion) system of measurement in a Federal building energy
regulation. The metric system of measurement is followed by the English
system in parentheses. In using this dual system, the Department is
facilitating the goal of 15 U.S.C. 205b to promote competitiveness by
relating Federal energy standards to the international measurements
that United States companies must use to meet world demand for building
components. The rule retains reference to English system measurements
for those companies that do not have the ability to readily translate
between metric and English units. The use of this dual system of
measurement does not change the requirements of the proposed rule and
has no substantive impact on the users of the proposed rule.
F. Review Under Executive Order on Civil Justice Reform
Section 3 of Executive Order 12988, 61 FR 4729 (February 7, 1996),
instructs each agency to adhere to certain requirements in promulgating
new regulations. These requirements, set forth in Section 3(a) and (b),
include eliminating drafting errors and needless ambiguity, drafting
the regulations to minimize litigation, providing clear and certain
legal standards for affected legal conduct, and promoting
simplification and burden reduction. Agencies are also instructed to
make every reasonable effort to ensure that the regulation describes
any administrative proceeding to be available prior to the judicial
review and any provisions for the exhaustion of administrative
remedies. The Department has determined that today's regulatory action
meets the requirements of section 3(a) and (b) of Executive Order
12988.
G. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act of 1980, 5 U.S.C. 601-612, requires
that an agency prepare an initial regulatory flexibility analysis and
that it be published at the time of publication of general notice of
proposed rulemaking for the rule. This requirement does not apply if
the agency ``certifies that the rule will not, if promulgated, have a
significant economic impact on a substantial number of small
entities.'' 5 U.S.C. 605.
The proposed rule only imposes requirements on the Federal
government for the construction of new Federal residential buildings.
Therefore, the Department certifies that this rule, if promulgated,
would not have a significant economic impact on a substantial number of
small entities.
H. Paperwork Reduction Act Review
This proposed rule was examined with respect to the Paperwork
Reduction Act, 44 U.S.C. 3501 et seq., which directs agencies to
minimize Federal information collection and reporting burdens imposed
on individuals, small businesses, and state and local governments.
This proposed rule would establish requirements for the design of
new Federal residential buildings. It does not impose requirements for
the collection or reporting of information to the Federal Government.
Accordingly, clearance under the Paperwork Reduction Act of 1980 is not
required by the Office of Information and Regulatory Affairs of the
Office of Management and Budget.
I. Review Under Section 32 of the Federal Energy Administration
Authorization Act
Pursuant to Section 301 of the Department of Energy Organization
Act (Pub. L. 95-91), the Department is required to comply with Section
32 of the Federal Energy Administration Authorization Act of 1974, as
amended by section 9 of the Federal Energy Administration Authorization
Act of 1977. The findings required of the Department by Section 32
serve to notify the public regarding the use of commercial standards in
a proposal and through the rulemaking process. It allows interested
persons to make known their views regarding the appropriateness of the
use of any particular commercial standard in a notice of proposed
rulemaking. Section 32 also requires that the Department consult with
the Attorney General and the Chairman of the Federal Trade Commission
concerning the impacts of such standards on competition.
Today's proposed rule adopts, in significant part, the MEC, 1992,
1993 and 1995 and the relevant reference standards (RS) contained in
the MEC, 1992, 1993, and 1995. The reference standards can be found in
Subpart H of the proposed rule designated as RS-1--RS-34. In addition,
the proposed rule adopts certain requirements from Standard 90.2-1993.
The Department has evaluated the promulgation of the above
standards with regard to compliance with Section
[[Page 24176]]
32(b). The Department is unable to conclude whether these standards
fully comply with the requirements of Section 32(b), i.e., that they
were developed in a manner which fully provided for public
participation, comment, and review. Therefore, the Department now
invites public comment on the appropriateness of incorporating these
industry standards in its final rule. As required by Section 32(c), the
Department will consult with the Attorney General and the Chairman of
the Federal Trade Commission concerning the impact of these standards
on competition, prior to issuing a notice of Final rulemaking.
J. Unfunded Mandates Reform Act Review
Title II of the Unfunded Mandates Reform Act of 1995 (the Act),
enacted as Pub. L. 104-4 on March 22, 1995, requires each Federal
agency, to the extent permitted by law, to prepare a written assessment
of the effects of any Federal mandate in a proposed or final agency
rule 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) in any one year. The
requirements do not apply if the rule incorporates regulatory
requirements that are specifically set forth in law. 2 U.S.C. 1531,
1532.
Furthermore, section 204(a) of the Act, 2 U.S.C. 1534(a), requires
the Federal agency to develop an effective process to permit timely
input by elected officers (or their designees) of state, local, and
tribal governments on a proposed ``significant intergovernmental
mandate.'' A ``significant intergovernmental mandate'' under the Act is
any provision in a Federal agency regulation that: (1) would impose an
enforceable duty upon state, local, or tribal governments (except as a
condition of Federal assistance); and (2) may result in the expenditure
by state, local, and tribal governments, in the aggregate, of $100
million (adjusted annually for inflation) in any one year. Section 203
of the Act, which supplements section 204(a), provides that before
establishing any regulatory requirements that might significantly or
uniquely affect small governments, the agency shall have developed a
plan that, among other things, provides for notice to potentially
affected small governments, if any, and for a meaningful and timely
opportunity to provide input in the development of regulatory
proposals. 2 U.S.C. 1533.
The rule proposed today would establish building energy-efficiency
standards for new Federal residential buildings pursuant to section
305(a) of the Energy Conservation and Production Act, as amended. 42
U.S.C. 6834(a). It does not include any Federal requirements that would
result in the expenditure of money by state, local, and tribal
governments. Therefore, the requirements of the Unfunded Mandates
Reform Act of 1995 do not apply to this rulemaking.
IX. Public Comment Procedures
A. Participation in Rulemaking
The Department encourages the maximum level of public participation
in this rulemaking. Representatives of Federal agencies, utilities,
state and local governments, building code organizations, and builder
associations, building owner associations, as well as individuals,
architects, engineers, builders, building owners, consumers, and others
are urged to submit written statements on the proposed rule. The
Department also encourages interested persons to participate in the
public hearing to be held in Washington, D.C., at the time and place
indicated in this Notice.
The Department of Energy has established a comment period of 90
days following publication for interested persons to comment on this
proposed rule. All comments will be available for review in the
Department's Freedom of Information Reading Room.
B. Solicitation of Public Comments
The Department welcomes comments on any aspects of the proposed
rule and supporting documentation, including the draft EA. In
particular, the Department is seeking comments on those specific issues
described below. The Department requests that comments of a technical
nature be supported by substantive data.
In particular, the Department requests comments addressing the
quantitative and methodological basis for setting specific ventilation
requirements in energy codes that relate to Federal residential
construction. Ventilation can help mitigate indoor air pollutants and
moisture problems in many situations. Excessive ventilation, however,
can increase energy use but not necessarily mitigate the health effects
of some indoor air pollutants. The Department is interested in comments
on how best to set ventilation requirements to achieve adequate indoor
air quality without incurring unnecessary construction or energy costs.
Second, the Department seeks comments on whether all residences
with fuel-burning devices requiring a vent pipe or chimney should be
required to undergo testing for depressurization-induced chimney
failure (backdrafting). The Department has included this requirement in
the proposed rule because of the health hazard of backdrafting.
Third, the Department specifically requests comments regarding the
treatment of equipment efficiency for space heating and cooling and
water heating. The proposed rule incorporates the existing Federal
minimum appliance standards, while relying on other Federal initiatives
to encourage the identification and use of more efficient equipment
where economically justified.
The Department would have to establish the economic benefits and
technological feasibility of any equipment efficiency specifications
that would be included in this rule that exceed the Federal minimum
requirements.
Fourth, the Department requests comments concerning the
technological feasibility and economic justification relative to the
heating and cooling equipment sizing provisions contained in the
proposed rule.
Fifth, the Department requests comments concerning suggestions on
approaches for crediting measures that use renewable sources of energy.
Sixth, the Department requests comments on the appropriateness of
the approach identified in section 435.402.1.6 of the proposed rule for
dealing with equipment efficiencies under the whole building energy
analysis compliance path in Subpart D.
Seventh, the Department requests comments on whether carbon dioxide
alarms should be required in Federal residences.
Eighth, the Department requests comment on how this proposed rule
could address equipment technologies for which a means of evaluating
and comparing energy performance has not yet been fully developed.
Finally, as previously stated, the Department of Energy requests
public review and comments on the draft EA.
C. Written Comment Procedures
Interested persons are invited to participate in this proceeding by
submitting written data, views, or comments with respect to the
proposed rulemaking.
Written comments (ten copies) shall be submitted to the address
indicated in the ADDRESSES section of this notice. The copies must be
received by the date indicated in the DATES section of this notice.
Comments should be identified on both the outside of the envelope and
on the documents themselves with the
[[Page 24177]]
designation, Energy Efficiency Code for New Federal Residential
Buildings (Docket No. EE-RM-96-300). In the event any person wishing to
provide written comments cannot provide ten copies, alternative
arrangements can be made in advance with the Department.
All comments received on or before the date specified at the
beginning of this proposed rule and other relevant information will be
considered by the Department before final action is taken on the
proposed rule. All written comments will be available for examination
in the Rule Docket File in the Department's Freedom of Information
Office Reading Room at the address provided at the beginning of this
document before and after the closing date for comments. In addition, a
transcript of the proceedings of the public hearings will be filed in
the docket.
Pursuant to the provisions of 10 CFR 1004.11, any person submitting
information that is believed to be confidential, and which may be
exempt by law from public disclosure, should submit one complete copy,
and two copies from which the information believed to be confidential
has been deleted. The Department will make its own determination of any
such claim and treat it according to its determination.
D. Public Hearings
1. Procedure for Submitting Requests To Speak
To have the benefit of a broad range of public viewpoints in this
rulemaking, the Department will hold a public hearing at the time and
place indicated in the DATES and ADDRESSES sections of this notice. Any
person who has an interest or who is a representative of a group or
class of persons that has an interest in the proposed rule or the
associated environmental assessment may request an opportunity to make
an oral presentation. A request to speak at the public hearing must be
mailed to the address or telephoned to the number indicated in the
ADDRESSES section of this notice and received by the time specified in
the DATES section of this notice.
The person making the request should briefly describe his or her
interest in the proceedings and, if appropriate, state why that person
is a proper representative of the group or class of persons that has
such an interest. The person should also provide a telephone number
where he or she may be contacted during the day. Each person selected
to be heard will be notified by the Department as to the approximate
time he or she will be speaking. Ten copies of the speaker's statement
must be submitted at or before the hearing. In the event any person
wishing to testify cannot meet this requirement, alternative
arrangements can be made in advance with the Department.
2. Conduct of Hearings
The Department reserves the right to schedule persons to be heard
at the hearing, to schedule their representative presentations, and to
establish procedures governing the conduct of the hearing. The length
of each presentation is limited to 15 minutes or otherwise based on the
number of persons requesting an opportunity to speak.
A Department official will preside at the hearing. This will not be
a judicial or evidentiary-type hearing. It will be conducted in
accordance with 5 U.S.C. 553 and Section 501 of the Department of
Energy Organization Act, 42 U.S.C. 7191. At the conclusion of all
initial oral statements, each person who has made an oral statement
will be given the opportunity to make a rebuttal or clarifying
statement. The statements will be given in the order in which the
initial statements were made and will be subject to time limitations.
Questions may be asked only by those conducting the hearing. Any
interested person may submit to the presiding official written
questions to be asked of any person making a statement at the hearing.
The presiding official will determine whether the question is relevant
or whether time limitations permit it to be presented for a response.
Any further procedural rules needed for the proper conduct of the
hearing will be announced by the presiding official at the hearing.
A transcript of the hearing will be prepared by the Department and
made available as part of the administrative record for this
rulemaking. It will be on file for inspection at the Department's
Freedom of Information Reading Room as provided at the address
indicated at the beginning of this document.
If the Department must cancel the public hearing, the Department
will make every effort to publish an advance notice of such
cancellation in the Federal Register. The hearing date may be canceled,
for example, in the event no member of the public requests the
opportunity to make an oral presentation.
List of Subjects in 10 CFR Part 435
Buildings, Energy conservation, Energy efficiency, Engineers,
Federal buildings and facilities, Housing.
Issued in Washington, DC, on April 1, 1997.
Brian T. Castelli,
Chief of Staff, Energy Efficiency and Renewable Energy.
For the reasons set forth in the preamble, Part 435 of Chapter II
of Title 10 of the Code of Federal Regulations is proposed to be
revised as set forth below:
PART 435--ENERGY EFFICIENCY CODE FOR NEW FEDERAL RESIDENTIAL
BUILDINGS
435.100 Explanation of numbering system for this part.
Subpart A--Administration and Enforcement
435.101 Scope and general requirements.
435.102 Materials and equipment.
435.103 Alternate materials'method of construction, design, or
insulation systems.
435.104 [Reserved].
435.105 [Reserved].
435.106 [Reserved].
435.107 Precedence.
435.108 Life-cycle cost analysis.
Subpart B--Definitions
435.201 Definitions.
Subpart C--Design Conditions
435.301 Scope.
435.302 Thermal design parameters.
435.303 Mechanical ventilation criteria.
Subpart D--Design by Systems Analysis; Design Utilizing Renewable
Energy Sources
435.401 Scope.
435.402 Systems analysis.
435.403 Renewable energy source analysis.
Subpart E--Design by Component Performance Approach
435.501 Scope.
435.502 Building thermal envelope requirements.
435.503 Building mechanical systems and equipment.
435.504 Service water heating.
435.505 Electrical power and lighting.
Subpart F--[Reserved]
Subpart G--Radon Control
435.701 General.
435.702 Scope.
435.703 Compliance.
435.704 Alternative systems.
435.705 Conflict with other standards, codes, or regulations.
435.706 Qualification of testers and installers.
435.707 Design and construction requirements.
Subpart H--Standards
435.801 Reference standards.
435.802 Abbreviations and acronyms used in reference standards.
[[Page 24178]]
Appendix to Part 435 Figures and Tables
Authority: 42 U.S.C. 6831-6832, 6834-6836; 42 U.S.C. 8253-54; 42
U.S.C. 7101, et seq.
Sec. 435.100 Explanation of numbering system for this part.
100.1 General. For the purposes of this part, a derivative of two
different numbering systems will be used.
100.1.1 For the purpose of designating a section, the numbering
system employed in the Code of Federal Regulations (CFR) will be
employed. The number ``435'' which signifies part 435, Chapter II of
Title 10, Code of Federal Regulations, is used as a prefix for all
section headings. The suffix is a three digit number. For example, the
life-cycle cost analysis section of this part is designated
Sec. 435.108.
100.1.2 Within each section, a numbering system common to many
national voluntary consensus model codes is used. A decimal system is
used to denote paragraphs and subparagraphs within a section. For
example, 435.502.1.2 refers to subparagraph 2 of paragraph 1 of
Sec. 435.502.
100.2 The hybrid numbering system is used for two purposes:
100.2.1 The use of the Code of Federal Regulation numbering system
allows the researcher using the CFR easy access to this part.
100.2.2 The use of the second system allows the builder, designer,
architect or engineer easy access to the technical provisions because
they are familiar with the numbering system and its format generally
conforms to existing building codes. This system was chosen because of
its commonality among the buildings industry.
Subpart A--Administration and Enforcement
Sec. 435.101 Scope and general requirements.
101.1 Title. This part shall be known as the Energy Efficiency
Code for New Federal Residential Buildings and is referred to herein as
``this part.''
101.2 Purpose. The provisions of this part provide minimum
standards for energy efficiency for the design of new Federal
residential buildings. The performance standards are designed to
achieve the maximum practicable cost-effective improvements in energy
efficiency and increases in the use of non-depletable sources of
energy. It is intended that these provisions provide flexibility to
permit the use of innovative approaches and techniques to achieve
efficient utilization of energy. This part also establishes minimum
requirements for the control of radon in new Federal residential
buildings.
101.3 Compliance. This part requires:
101.3.1 Use of a systems approach for the entire building and its
energy-using subsystems which may utilize renewable sources as
established in Subpart D or use of a component performance approach for
various building elements and mechanical systems and components as
established in subpart E; and
101.3.2 Compliance with the radon requirements is established in
subpart G.
101.4 Scope. This part provides design requirements for building
envelopes for adequate thermal resistance and low air leakage and the
design and selection of mechanical, electrical, service water-heating
and illumination systems and equipment which will enable efficient use
of energy in new Federal residential building construction. It applies
to the design and construction of all new Federal residential buildings
that are three stories or less above grade that are not subject to
state or local building codes. Federal residential buildings more than
three stories above grade and all Federal nonresidential buildings must
comply with the Energy Code for Federal Commercial and Multi-Family
High-Rise Residential Buildings.
101.4.1 Radon control. This part also establishes requirements for
control of radon for certain new Federal residential buildings. The
applicability of those requirements is established in section 702.
101.4.2 Building types.
101.4.2.1 Group R Federal residential buildings. For the purposes
of this part, Group R residential buildings include:
(a) Type A-1--Detached one and two family dwellings, and
(b) Type A-2--Other residential buildings, three stories or less in
height.
101.4.2.2 Other buildings. Any buildings and structures not
included in section 101.4.2.1 are not covered by this rule.
101.4.3 Exempt buildings. The building types that are exempt are
as follows: assembly, health, and
101.4.3.1 Buildings and structures or portions thereof whose peak
design rate of energy usage is less than 1.0 W (3.4 Btu/h) or 10.8 W/
m\2\ (1 W/ft\2\) of floor area for all purposes.
101.4.3.2 Buildings and structures or portions thereof which are
neither heated nor cooled.
101.4.4 Application to existing buildings.
101.4.4.1 Additions to existing buildings. Additions to existing
buildings or structures may be made to such buildings or structures
without making the entire building or structure comply. The new
addition shall conform to the provisions of this part as they relate to
new construction only.
Sec. 435.102 Materials and equipment.
102.1 Identification.
102.1.1 General. Materials and equipment shall be identified on
the building plans and specifications in a manner that will allow for a
determination of their compliance with the applicable provisions of
this part.
102.1.2 Building envelope insulation. Building envelope insulation
shall have a thermal resistance (R) identification marker on each piece
of building envelope insulation 0.3048 m (12 in.) or greater in width.
Alternatively, a signed and dated certification for the insulation
installed in each element of the building envelope shall be provided,
listing the type of insulation, the manufacturer, and the R-value. For
blown-in or sprayed insulation, a certification shall be provided that
identifies the initial installed thickness, the settled thickness, the
coverage area, and the number of bags of insulation installed. The
certification shall be posted in a conspicuous place on the job site.
102.1.3 Insulation installation. Roof-ceiling, floor, and wall-
cavity insulation shall be installed to permit inspection of the
manufacturer's R-value identification mark. Alternatively, the
thickness of roof-ceiling insulation that is blown in or sprayed shall
be identified by thickness markers that are labeled in meters (inches)
and installed at least one every 27.9 m2 (300
ft2) of attic space. The markers shall be affixed to the
roof trusses or ceiling joists and marked with the minimum installed
thickness and minimum settled thickness using numbers 25.4 mm (1 in.)
or greater in height. Each marker shall face the attic access opening.
The thickness of installed insulation shall meet or exceed the minimum
installed thickness shown by the marker.
102.2 Maintenance information. Required regular maintenance
actions shall be clearly stated on a readily accessible label. Such
label may be limited to identifying, by title or publication number,
the operation and maintenance manual for that particular model and type
of product. Maintenance instructions shall be furnished for equipment
which requires preventive maintenance for efficient operation.
[[Page 24179]]
102.3 Fenestration product rating, certification, and labeling.
Fenestration products (windows, doors, and skylights) purchased by the
Federal government shall have assigned U-values. If tested for U-value,
the U-values of fenestration products (windows, doors, and skylights)
shall be determined in accordance with RS-1, by an accredited,
independent laboratory. The tested U-value of the fenestration product
shall be certified and the certified U-value shall be labeled on a
conspicuous place on the product. Such certified and labeled U-values
shall be accepted for purposes of determining compliance with the
building envelope requirements of this part.
102.3.1 Exception. Where a fenestration product has not been
assigned a U-value in accordance with RS-1 for a particular product
line, that product shall be assigned a default U-value in accordance
with Appendix Tables 102.3.1 and 102.3.2. Product features must be
technically verifiable for the product to qualify for the U-value
associated with those features. Where the existence of a particular
feature cannot be determined with reasonable certainty, the product
shall not receive credit for that feature. Where a composite of
materials from two different product types are used, the product shall
be assigned the higher U-value.
Sec. 435.103 Alternate materials--method of construction, design, or
insulation systems.
103.1 The provisions of this part are not intended to prevent the
use of any material, method of construction, design or insulating
system not specifically prescribed herein, provided that such
construction, design or insulating system has been approved as meeting
the intent of this part.
Sec. 435.104 [Reserved]
Sec. 435.105 [Reserved]
Sec. 435.106 [Reserved]
Sec. 435.107 Precedence.
107.1 When different sections of this part, or a section of this
part and a section of a referenced standard from section 801 of this
part, specify different materials, methods of construction, or other
requirements, the more stringent or restrictive requirement shall
govern. Whenever there is a conflict between a general requirement and
a specific requirement, the specific requirement shall govern.
Sec. 435.108 Life-cycle cost analysis.
108.1 The proposed building design(s) shall be evaluated in
accordance with the requirements of the Federal Energy Management
Program described in subpart A of 10 CFR part 436 to determine its
life-cycle cost.
Subpart B--Definitions
Sec. 435.201 Definitions.
For the purposes of this part, certain abbreviations, terms,
phrases, words and their derivatives shall be set forth in this
section.
Accessible (as applied to equipment). Admitting close approach; not
guarded by locked doors, elevation, or other effective means (see
``Readily accessible'').
Addition. Increase in conditioned floor area.
Air film. Air immediately adjacent to surfaces of building
materials which helps to inhibit heat flow through those materials.
Air transport factor. The ratio of the rate of useful sensible heat
removal from the conditioned space to the energy input to the supply
and return fan motor expressed in consistent units and under the
designated operating conditions.
Attic. A space directly underneath the roof sheathing and directly
above or adjacent to the interior surfaces of the topmost story of a
building that satisfies all of the following conditions:
(1) The structural members comprising the roof are separate and
distinct rafters and ceiling joists or truss assemblies;
(2) The space is ventilated in accordance with the requirements of
the applicable building code;
(3) The clear height from the top of the ceiling joists to the
highest point of the underside of the rafters is greater than 0.762 m
(30 in.); and
(4) The space is provided with a readily accessible access in
accordance with the requirements of the applicable building code.
Automatic. Self-acting, operating by its own mechanism when
actuated by some impersonal influence, as, for example, a change in
current strength, pressure, temperature or mechanical configuration
(see also ``Manual'').
Basement wall. The opaque portion of a wall which encloses one side
of a basement and is partially or totally below grade.
Building code. The legal instrument which is in effect in a state
or unit of general purpose local government, the provisions of which
must be adhered to if a building is to be considered to be in
conformance with law and suitable for occupancy and use.
Building envelope. The elements of a building which enclose
conditioned spaces through which thermal energy may be transferred to
or from the exterior or to or from spaces located in buildings exempted
by the provisions of section 101.4.2.
Comfort air conditioning. The process of treating air so as to
control simultaneously its temperature, humidity, cleanliness, and
distribution to meet requirements of the conditioned space.
Comfort envelope. The area of a psychrometric chart enclosing all
those conditions described in Figure 1 in Standard RS-2 listed in
section 801 as being comfortable.
Conditioned floor area. The horizontal projection of that portion
of interior space which is contained within exterior walls and which is
conditioned directly or indirectly by an energy-using system.
Conditioned space. Space within a building which is provided with
heated and/or cooled air or surfaces and, where required, with
humidification or dehumidification means so as to be capable of
maintaining a space condition falling within the comfort zone set forth
by Standard RS-2 listed in section 801.
Cooled space. Space within a building which is provided with a
positive cooling supply.
Crawl space wall. The opaque portion of a wall which encloses a
crawl space and is partially or totally below grade.
Deadband. The temperature range in which no heating or cooling is
used.
Degree day, cooling. A unit, based upon temperature difference and
time, used in estimating fuel consumption and specifying nominal
cooling load of a building in summer. For any one day, when the mean
temperature is greater than 18.3 deg.C (65 deg.F), there exists as
many degree days as there are Celsius (Fahrenheit) degrees difference
in temperature between the mean temperature for the day and 18.3 deg.C
(65 deg.F).
Degree day, heating. A unit, based upon temperature difference and
time, used in estimating fuel consumption and specifying nominal
heating load of a building in winter. For any one day, when the mean
temperature is less than 18.3 deg.C (65 deg.F), there exists as many
degree days as there are Celsius (Fahrenheit) degrees difference in
temperature between the mean temperature for the day and 18.3 deg.C
(65 deg.F).
Drain tile loop. A continuous length of drain tile or perforated
pipe extending around all or part of the internal or external perimeter
of a basement or crawl space footing.
Dwelling unit. A single housekeeping unit comprised of one or more
rooms providing complete independent living
[[Page 24180]]
facilities for one or more persons, including permanent provisions for
living, sleeping, eating, cooking and sanitation.
Efficiency, HVAC system. The ratio of useful energy output (at the
point of use) to the energy input in consistent units for a designated
time period, expressed in percent.
Energy. The capacity for doing work taking a number of forms which
may be transformed from one into another, such as thermal (heat),
mechanical (work), electrical and chemical in customary units, measured
in kilowatt-hours (kWh) or Kilojoules [British thermal units (Btus)].
Energy source. Electricity, natural gas, propane gas or fuel oil
that is available at a residential building for space heating, space
cooling, service water heating and lighting. See also ``Renewable
energy sources.''
Equipment type. HVAC system equipment or service water heating
equipment that (1) performs a specific function(s) (e.g., space heating
or space heating and service water heating), (2) uses a specific energy
source(s) (e.g., electricity or a ``dual-fuel'' furnace that can use
electricity or natural gas), and (3) employs a specific operational
principle (e.g., direct combustion, heat rejection to air, heat
extraction from ground water). Example: A heat pump water heater is a
different equipment type from an electric resistance water heater.
Exterior envelope. See ``Building envelope.''
Federal agency. Any department, agency, corporation, or other
entity or instrumentality of the executive branch of the Federal
government, including the United States Postal Service, the Federal
National Mortgage Association, and the Federal Home Loan Mortgage
Corporation.
Federal residential building. Any detached one- or two-family
residential dwelling or other residential building or structure, three
stories or less in height, to be constructed or developed for
residential occupancy by, or for the use of, any Federal agency that is
not legally subject to state or local building codes or similar
requirements.
Furnace, duct. A furnace normally installed in distribution ducts
of air conditioning systems to supply warm air for heating and which
depends on a blower not furnished as part of the duct furnace for air
circulation.
Furnace, warm air. A self-contained, indirect-fired or electrically
heated furnace that supplies heated air through ducts to spaces that
require it.
Glazing area. Interior surface area of assemblies that enclose
conditioned space and that contain glazing, such as windows, sliding
glass doors, and skylights, including the frame, sash, curbing,
muntins, and other framing element.
Grade. The finished ground level adjoining the building at all
exterior walls.
Gross area of exterior walls. The normal projection of the building
envelope wall area bounding interior space which is conditioned by an
energy-using system, including opaque wall, window and door area. The
gross area of exterior walls consists of all opaque wall areas,
including between floor spandrels, peripheral edges of floors, window
areas including sash, and door areas, where such surfaces are exposed
to outdoor air, unconditioned spaces, or spaces exempted by section
101.4.2, and where such spaces enclose a heated or mechanically cooled
space, including interstitial areas between two such spaces. For each
basement wall with an average below-grade area less than 50% of its
total wall area, including openings, the entire wall, including the
below-grade portion, is included as part of the gross area of exterior
walls. Nonopaque areas (windows, doors, etc.) of all basement walls are
included in the gross area of exterior walls.
Gross floor area. The sum of the areas of the several floors of the
building, including basements, cellars, mezzanine and intermediate
floored tiers and penthouses of headroom height, measured from the
exterior faces of exterior walls or from the center line of walls
separating buildings, but excluding:
(a) Covered walkways, open roofed-over areas, porches and similar
spaces.
(b) Pipe trenches, exterior terraces or steps, chimneys, roof
overhangs and similar features.
Group R Federal residential buildings. For the purpose of this
part, Group R Federal residential buildings include:
(a) Type A-1--Detached one and two family dwellings; and,
(b) Type A-2--Other Federal residential buildings, three stories or
less in height.
Heat. The form of energy that is transferred by virtue of a
temperature difference or a change in state of a material.
Heat trap. An arrangement of piping connecting to a hot water
heater such that the piping makes an inverted ``U'' just before
connecting to the heater fittings. Any other arrangement, including a
commercially available heat trap, which effectively restricts the
natural tendency of hot water to rise also qualifies as a heat trap.
Heated slab. Slab-on-grade construction in which the heating
elements or hot air distribution system is in contact with or placed
within the slab or in the subgrade.
Heated space. Space within a building which is provided with a
positive heat supply. Finished living space within a basement with
registers or heating devices designed to supply heat to a basement
space shall automatically define that space as heated space.
Humidistat. A regulatory device, actuated by changes in humidity,
used for automatic control of relative humidity.
HVAC. Heating, ventilating and air conditioning.
HVAC system. The equipment, distribution network, and terminals
that provide, either collectively or individually, the processes of
heating, ventilating, or air conditioning to a building.
HVAC system components. HVAC system components provide, in one or
more factory-assembled packages, means for chilling and/or heating
water with controlled temperature for delivery to terminal units
serving the conditioned spaces of the building. Types of HVAC system
components include, but are not limited to, water chiller packages,
reciprocating condensing units and water source (hydronic) heat pumps
(see ``HVAC system equipment'').
HVAC system efficiency. See ``Efficiency, HVAC system.''
HVAC system equipment. HVAC system equipment provides, in one
(single package) or more (split system) factory-assembled packages,
means for air circulation, air cleaning, air cooling with controlled
temperature and dehumidification, and, optionally, either alone or in
combination with a heating plant, the functions of heating and
humidifying. The cooling function may be either electrically or heat
operated and the refrigerant condenser may be air, water or
evaporatively cooled. Where the equipment is provided in more than one
package, the separate packages shall be designed by the manufacturer to
be used together. The equipment may provide the heating function as a
heat pump or by the use of electric or fossil-fuel-fired elements. (The
word ``equipment'' used without modifying adjective may, in accordance
with common industry usage, apply either to HVAC system equipment or
HVAC system components.)
Infiltration. The uncontrolled inward air leakage through cracks
and interstices in any building element and around windows and doors of
a
[[Page 24181]]
building caused by the pressure effects of wind and/or the effect of
differences in the indoor and outdoor air density.
Life-cycle cost. The total discounted cost of owning, operating,
and maintaining a building or piece of equipment over its useful life
(including its fuel, energy, labor, and replacement components)
determined on the basis of a systematic evaluation except that in the
case of leased buildings, the life-cycle cost shall be calculated over
the effective remaining term of the lease.
Manual. Capable of being operated by personal intervention (see
``Automatic'').
Multi-family dwelling. A building containing three or more dwelling
units.
Opaque areas. All exposed areas of a building envelope which
enclose conditioned space, except openings for windows, skylights,
doors and building service systems.
Outdoor air. Air taken from the outdoors and, therefore, not
previously circulated through the system.
Packaged terminal air conditioner. A factory-selected wall sleeve
and separate unencased combination of heating and cooling components,
assemblies or sections intended for mounting through the wall to serve
a single room or zone. It includes heating capability by hot water,
steam, or electricity.
Packaged terminal heat pump. A packaged terminal air conditioner
capable of using the refrigeration system in a reverse cycle or heat
pump mode to provide heat.
pCi/L. The abbreviation for ``picocuries per liter,'' which is used
as a measure for radon concentrations in air. A picocurie is one-
trillionth (10-12) of a curie. A ``curie'' is a commonly
used measurement of radioactivity.
Positive cooling supply. Mechanical cooling deliberately supplied
to a space such as through a supply register. Also, mechanical cooling
indirectly supplied to a space through uninsulated surfaces of space-
cooling components, such as evaporator coil cases and cooling
distribution systems which continually maintain air temperatures within
the space of 29.4 deg.C (85 deg.F) or lower during normal operation.
To be considered exempt from inclusion in this definition, such
surfaces shall comply with the insulation requirements of this part.
Positive heat supply. Heat deliberately supplied to a space by
design, such as a supply register, radiator or heating element. Also,
heat indirectly supplied to a space through uninsulated surfaces of
service water heaters and space heating components, such as furnaces,
boilers and heating and cooling distribution systems which continually
maintain air temperature within the space of 10 deg.C (50 deg.F) or
higher during normal operation. To be considered exempt from inclusion
in this definition, such surfaces shall comply with the insulation
requirements of this part.
Proposed design. A building design submitted in response to a
request for proposals for the construction of a new Federal residential
building.
Readily accessible. Capable of being reached quickly for operation,
maintenance, removal, or inspection, without requiring the need to
climb over or remove obstacles or to resort to portable ladders or
chairs (see ``Accessible'').
Renewable energy sources. Sources of energy (excluding minerals)
derived from incoming solar radiation, including natural daylighting
and photosynthetic processes; from phenomena resulting therefrom,
including wind, waves and tides, lake or pond thermal differences; and
from the internal heat of the earth, including nocturnal thermal
exchanges.
Reset. Adjustment of the set point of a control instrument to a
higher or lower value automatically or manually to conserve energy.
Roof assembly. All components of the roof/ceiling envelope through
which heat flows, thus creating a building transmission heat loss or
gain, where such assembly is exposed to outdoor air and encloses a
heated or mechanically cooled space. The gross area of a roof assembly
consists of the total interior surface of such assembly, including
skylights exposed to the heated or mechanically cooled space.
Sash crack. The sum of all perimeters of all window sashes, based
on overall dimensions of such parts, expressed in meters (feet). If a
portion of one sash perimeter overlaps a portion of another sash
perimeter, only count the length of the overlapping portions once.
Sensible capacity. The maximum sensible load for which a piece of
equipment is designed to remove or add sensible heat.
Sensible load. The cooling or heating load to remove or add the
sensible heat that causes a temperature change.
Service systems. All energy-using systems in a building that are
operated to provide services for the occupants or processes housed
therein, including HVAC, service water heating, illumination,
transportation, cooking or food preparation, laundering or similar
functions.
Service water heating. Supply of hot water for purposes other than
comfort heating.
Slab-on-grade floor insulation. Insulation around the perimeter of
the floor slab or its supporting foundation when the top edge of the
floor slab perimeter is above the finished grade or 0.305 m (12 in.) or
less below the finished grade.
Soil gas. The gas, present in soil, which may contain radon.
Soil gas retarder. A continuous membrane or other comparable
material used to retard the flow of soil gas into a building.
Solar energy source. Source of natural daylighting and of thermal,
chemical or electrical energy derived directly from conversion of
incident solar radiation.
Standard design. A building designed to exactly meet but not exceed
all requirements in Subpart E of this part.
Submembrane depressurization system. A system designed to achieve a
lower air pressure beneath the soil gas retarder in a crawl space,
relative to crawl space air pressure, resulting in air withdrawal from
under the soil gas retarder either passively (relying on the upward
convective flow of air) or actively (by use of a fan-powered vent).
Subslab depressurization system (active). A piping system that
connects the subslab area with outdoor air, is routed through the
conditioned space of a building, and uses a fan-powered vent to draw
air from beneath the slab.
Subslab depressurization system (passive). A piping system that
connects the subslab area with outdoor air, is routed through the
conditioned space of a building, and relies on the convective flow of
air to draw air from beneath the slab.
Supplementary heater operation. The auxiliary electric resistance
heating device that provides heat which contributes to the operation of
the heat pump when the temperature is too low for the heat pump to
operate independently.
System. A combination of central or terminal equipment or
components and/or controls, accessories, interconnecting means, and
terminal devices by which energy is transformed so as to perform a
specific function, such as HVAC, service water heating or illumination.
Technically verifiable. To visually, physically, or through testing
determine the physical characteristics or specifications of an element,
material, or object.
Terminal element. The means by which the transformed energy from a
system is finally delivered; i.e., registers, diffusers, lighting
fixtures, faucets and similar elements.
Thermal conductance. Time rate of heat flow through a body
(frequently per unit area) from one bounding surface to
[[Page 24182]]
the other for a unit temperature difference between the two surfaces,
under steady conditions (W/m2 deg.C) [Btu/
(hft2 deg.F)].
Thermal resistance (R). The reciprocal of thermal conductance
(m2 deg.C/W)
[(hft2 deg.F)/Btu].
Thermal transmittance (U). The coefficient of heat transmission
(air to air). It is the time rate of heat flow per unit area and unit
temperature difference between the warm side and cold side air films
(W/m2 deg.C) [Btu/
(hft2 deg.F)]. The U-value applies to
combinations of different materials used in series along the heat flow
path, single materials that comprise a building section, cavity air
spaces and surface air films on both sides of a building element.
Thermal transmittance, overall (Uo). The overall
(average) heat transmission of a gross area of exterior building
envelope (W/m2 deg.C) [Btu/
(hft2 deg.F)]. The Uo value
applies to the combined effect of the time rate of heat flow through
the various parallel paths such as windows, doors and opaque
construction areas, comprising the gross area of one or more exterior
building components, such as walls, floors or roof/ceilings.
Thermostat. An automatic control device actuated by temperature and
designed to be responsive to temperature.
Unitary cooling and heating equipment. One or more factory-made
assemblies which include an evaporator or cooling coil, a compressor
and condenser combination, and may include a heating function as well.
Where such equipment is provided in more than one assembly, the
separate assemblies shall be designed to be used together.
Unitary heat pump. One or more factory-made assemblies which
include an indoor conditioning coil, compressor(s) and outdoor coil or
refrigerant-to-water heat exchanger, including means to provide both
heating and cooling functions. When such equipment is provided in more
than one assembly, the separate assemblies shall be designed to be used
together.
Ventilation. The process of supplying or removing air by natural or
mechanical means to or from any space. Such air may have been
conditioned.
Ventilation air. That portion of supply air which comes from
outside (outdoors) plus any recirculated air that has been treated to
maintain the desired quality of air within a designated space. (See
Standard RS-3 listed in section 801 of this part, and definition of
``Outdoor air''.)
Walls. Those portions of the building envelope which are vertical
or tilted at an angle of 30 deg. or less from the vertical plane.
Zone. A space or group of spaces within a building with heating
and/or cooling requirements sufficiently similar so that comfort
conditions can be maintained throughout by a single controlling device.
Subpart C--Design Conditions
Sec. 435.301 Scope.
301.1 General. The criteria of this subpart establishes the design
conditions for use with Subparts D and E of this part.
Sec. 435.302 Thermal design parameters.
302.1 Exterior design conditions. The following design parameters
from table 302.1 shall be used for calculations required under this
part.
Table 302.1
[Exterior design conditions]
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Winter \1\............................. Design Dry-bulb..................... deg.C ( deg.F).
Summer \1\............................. Design Dry-bulb..................... deg.C ( deg.F).
Design Wet-bulb..................... deg.C ( deg.F).
Degree days, heating \2\
Degree days, cooling \2\
----------------------------------------------------------------------------------------------------------------
\1\ The outdoor design temperature shall be selected from the columns of 97.5% values for winter and 2.5% values
for summer from tables in Standard RS-4 listed in section 801. Adjustments may be made to reflect local
climates which differ from the tabulated temperatures, or local weather experience.
\2\ The degree days, heating [base 18.3 deg.C (65 deg.F)] and cooling [base 18.3 deg.C (65 deg.F)] shall be
selected from NOAA Annual Degree Days to Selected Bases Derived from the 1961--1990 Normals, Standard RS-4
listed in section 801, data available from adjacent military installations, or other sources of local data.
302.2 Interior design conditions.
302.2.1 Indoor Design Temperature. Indoor design temperature shall
be 22.2 deg.C (72 deg.F) for heating and 25.6 deg.C (78 deg.F) for
cooling.
302.2.2 Exception. Other design temperatures may be used for
equipment selection if it results in a lower energy usage.
Sec. 435.303 Mechanical ventilation criteria.
303.1 Ventilation. Ventilation air shall conform to Standard RS-3
listed in section 801. The minimum column value of Standard RS-3 for
each type of occupancy shall be used for design. The ventilation
quantities specified in section 6 of Standard RS-3 are for 100% outdoor
air ventilating systems.
303.1.1 Exception. If outdoor air quantities other than those
specified in Standard RS-3 are used or required because of special
occupancy or process requirements, source control of air contamination,
health and safety or other standards, the required outdoor air
quantities shall be used as the basis for calculating the heating and
cooling design loads.
Subpart D--Design by Systems Analysis; Design Utilizing Renewable
Energy Sources
Sec. 435.401 Scope.
401.1 General. This subpart establishes design requirements based
on a systems analysis of total energy use by a new Federal residential
building, including all of its systems. These design requirements may
be applied as an alternative to the component performance requirements
established in subpart E.
Sec. 435.402 Systems analysis.
402.1 Energy analysis. Compliance with this subpart requires an
analysis of the annual energy usage, hereinafter called an annual
energy analysis. The proposed building shall utilize a design that is
demonstrated, through technically valid and documented calculations, to
have equal or lower annual energy use and equal or lower life-cycle
costs than the standard design.
(a) A building designed in accordance with this subpart complies
with this part if the calculated annual energy usage and life-cycle
costs are not greater than a similar building (defined as a ``standard
design'') with building thermal envelope components and mechanical
systems and equipment used to provide heating, ventilating, and air-
conditioning designed in accordance with subpart E.
[[Page 24183]]
(b) For a proposed building to be considered similar to a
``standard design,'' the proposed building shall have the same
conditioned floor area, ratio of thermal envelope area to conditioned
floor area, exterior design conditions, occupancy, climate data, and
usage operational schedule.
(c) The proposed design shall use the same energy source(s) for
space heating, space cooling, and domestic water heating as the
standard design (identified in subpart E).
402.1.1 Input values for Group R buildings. The input values/
assumptions from tables 402.1.1a through 402.1.1g shall be used in
calculating the annual energy usage.
Table 402.1.1a
[Glazing systems]
------------------------------------------------------------------------
Input Assumptions
-------------------------------------------------------------------------
Design Parameter Standard Design Proposed Design
------------------------------------------------------------------------
Glazing Orientation.............. Window area of Window area
proposed house, 25% oriented as
on North, South, proposed
East, and West design.
Exterior walls..
Shading.......................... Draperies shall be Any exterior
assumed to be shading
closed during provided by
period of proposed
mechanical air design.
conditioner
operation..
------------------------------------------------------------------------
Table 402.1.1b
[Heat storage (thermal mass)]
------------------------------------------------------------------------
------------------------------------------------------------------------
Internal mass.................. 39.0 kg/m\2\ (8 lb/ft \2\)
Structural mass................ 17.1 kg/m\2\ (3.5 lb/ft \2\)
------------------------------------------------------------------------
Table 402.1.1c
[Building thermal envelope--surface areas and volume]
------------------------------------------------------------------------
Design parameter Input assumptions
------------------------------------------------------------------------
Floor, walls, ceiling.................. The floor, walls, and ceiling
areas for both the standard
and proposed design(s) shall
be equal.
Foundation and floor type.............. The foundation and floor type
for both the standard and the
proposed design(s) shall be
equal.
Glazings, including skylights.......... The area of glazing in the
standard design shall not be
greater than the area of
glazing in the proposed
design(s). The glazing U-value
of the standard design shall
be selected to permit
calculated Uo-wall compliance
of the standard design.
Glazing area in the standard
design shall not be provided
with extra shading beyond
shading that is provided by
typical construction
practices--such as roof
overhangs. Energy performance
impacts of added shading for
glazing areas may be accounted
for in the proposed design(s)
for a specific building.
Results from shading
calculation on one proposed
building shall not be used for
groups of buildings.
Doors of A-1 structures................ The standard design shall have
at least 3.7 m \2\ (40 ft \2\)
of door area.
Building Volume........................ The volumes of both the
standard and proposed
design(s) shall be equal.
------------------------------------------------------------------------
Table 402.1.1d
[Thermostat (constants)]
------------------------------------------------------------------------
Design parameter Input value
------------------------------------------------------------------------
Heating Set Point..................... 20.0 deg.C (68 deg.F).
Cooling Set Point..................... 25.6 *C (78 *F).
Night Set Back........................ 15.6 *C (60 *F).
Set Back Duration..................... 7 hours.
Number of Set-back Periods............ 1 (night time).
Maximum number of zones............... 2.
Number of thermostats per zone........ 1.
------------------------------------------------------------------------
Table 402.1.1e
[Internal Sensible Heat Gains (Constants)]
------------------------------------------------------------------------
Unit type Input value
------------------------------------------------------------------------
A-1 Units.......................... 440 W (1,500 Btu/h)
A-2 Units.......................... 879 W (3,000 Btu/h)
------------------------------------------------------------------------
Table 402.1.1f
[Domestic Water Heater (Constant, Calculation)]
------------------------------------------------------------------------
Design parameter Input value
------------------------------------------------------------------------
Temperature set point.................. 49 deg.C (120 deg.F)
Daily hot water consumption............ Liters=113.7 x n-units+(37.9 x
n-bedrooms); [Gallons=(30 x n-
units)+(10 x n-bedrooms)]
------------------------------------------------------------------------
Note:
n-units=number of living units in proposed design(s)
n-bedrooms=number of bedrooms in each living unit.
Table 402.1.1g
[Distribution System Loss Factors]
------------------------------------------------------------------------
Duct Location
-------------------------------------------------------------------------
Mode Outside Inside
------------------------------------------------------------------------
Heating.............................................. 0.75 1.00
Cooling.............................................. 0.80 1.00
------------------------------------------------------------------------
402.1.2 If the proposed design takes credit for reduced air
changes per hour levels, documentation of measures providing such
reduction, or results of a post-construction blower-door test shall be
demonstrated using Standard RS-5 listed in section 801.
402.1.3 Passive solar building designs shall have fixed external
shading, operable internal or external shading or other shading
technologies to limit excessive summer cooling energy gains to the
building interior.
402.1.4 Passive solar buildings shall utilize at least 919 kJ/
deg.C (45 Btu/ deg.F) of additional thermal mass, per m2
(ft\2\) of added glass area, when added south-facing glass area exceeds
33% of the total glass area in walls.
402.1.5 Site Weather Data (constants).
402.1.5.1 The typical meteorological year (TMY), or its ``ersatz''
equivalent, from the National Oceanic and Atmospheric Administration
(NOAA), or an approved equivalent, for the closest available location
shall be used.
402.1.6 The HVAC System Efficiency, for heating and cooling mode,
as identified in 10 CFR part 430 shall be proportionally adjusted for
those portions of the ductwork located outside or inside the
conditioned space using the values shown above, in accordance with
equation 402.1a and table 402.1g:
(Equation 402.1.6a)
[[Page 24184]]
Total Adjusted System Efficiency=Equipment Efficiency x Distribution
Loss Factor x percent of ducts outside+Equipment Efficiency x
Distribution Loss Factor x percent of ducts inside.
402.1.7 Air infiltration. Air changes per hour for the standard
design is 0.5 (for purposes of calculation only).
402.2 Design. The energy usage of the standard design and the
proposed design shall be compared as follows:
(a) The comparison shall be expressed as joule per square meter
(Btu input per square foot) of gross floor area per year at building
site.
(b) If the proposed design results in an increase in usage of one
energy source and a decrease in another energy source, even though
similar sources are used for similar purposes, the difference in each
energy source shall be converted to equivalent energy units for
purposes of comparing the total energy used.
(c) The different energy sources shall be compared on the basis of
energy use at the site where: 1 kWh=3,413 Btu.
402.3 Analysis procedure. The analysis of the annual energy usage
of the standard design and the proposed design(s) shall meet the
following criteria:
(a) The building heating/cooling load calculation procedure used
for annual energy usage analysis shall be detailed enough to evaluate
the effect of factors specified in section 402.4.
(b) The calculation procedure used to simulate the operation of the
building and its service systems through a full-year operating period
shall evaluate the effect of system design, climatic factors,
operational characteristics, and mechanical equipment on annual energy
usage. Manufacturer's data or comparable field test data shall be used
when available in the simulation of systems and equipment. The
calculation procedure shall be based upon 8,760 hours of operation of
the building and its service systems and shall utilize the design
methods specified in Standards RS-4, -6, and -7 listed in section 801.
402.4 Calculation procedures. The calculation procedure shall
cover the following items:
(a) Design requirements--Environmental requirements as required in
subpart C.
(b) Climatic data--Coincident hourly data for temperatures, solar
radiation, wind and humidity of typical days in the year representing
seasonal variation.
(c) Building data--Orientation, size, shape, mass, air, moisture
and heat transfer characteristics.
(d) Operational characteristics--Temperature, humidity,
ventilation, illumination, control mode for occupied and unoccupied
hours.
(e) Mechanical equipment--Design capacity, part load profile.
(f) Building loads--Internal heat generation, lighting, equipment,
number of people during occupied and unoccupied periods.
402.4.1 Use of approved calculation tool. The same calculation
tool shall be used to estimate the annual energy usage for space
heating and cooling of the standard design and the proposed design(s).
402.5 Documentation. Proposed design(s) shall have an energy
analysis comparison report providing technical detail on the data used
in and resulting from the comparative analysis to verify that both the
analysis and the designs meet the criteria of section 401 of this part.
402.6 Exception. Proposed design(s) for one and two family
dwellings and multifamily buildings having a conditioned floor area of
465 m\2\ (5,000 ft\2\) or less are exempted from performing an analysis
on a full-year (8760 hours) basis as described in section 402.3(b).
However, comparison of heating, cooling, and service water heating
equipment energy usage between the proposed design(s) and the standard
design shall be provided in accordance with the remaining provisions of
section 402 of this part.
Sec. 435.403 Renewable energy source analysis.
403.1 General. A proposed building utilizing solar, geothermal,
wind or other renewable energy sources for all or part of its energy
source shall meet the requirements of section 402 of this part, except
such renewable energy may be excluded from the total annual energy
usage allowed for the building by that section.
403.1.1 To qualify for this exclusion such renewable energy must
be derived from a specific collection, storage and distribution system.
The solar energy passing through windows shall also be considered as
qualifying if such windows are provided with:
(a) Operable insulating shutters or other devices which, when drawn
or closed, shall cause the window area to reduce maximum outward heat
flow rate to that specified in section 502.3.1; and
(b) The window areas are shaded or otherwise protected from direct
rays of the sun during periods when mechanical cooling is required.
403.1.2 Exclusion shall also be granted for solar energy passing
through windows provided:
(a) The glass is double or triple pane insulating glass with a low-
emittance coating on one or more airspace surfaces of the glass, or
with a low-emittance plastic film suspended in the airspace, and
(b) The glass areas are shaded from direct solar radiation during
periods when mechanical cooling is required.
403.1.3 Other criteria covered in section 402 shall apply to the
proposed design(s) utilizing renewable sources of energy.
403.2 Documentation. An annual energy analysis comparison shall be
prepared comparing the proposed design(s) and the standard design as
specified in section 402. The report shall provide technical detail on
the building and system design(s) and on the data employed in the
comparative analysis sufficient to verify that both the analysis and
the proposed design(s) meet the criteria of sections 402 and 403 of
this part.
403.2.1 The energy derived from renewable sources and the
reduction in conventional energy requirements derived from nocturnal
cooling shall be separately identified from the overall building energy
use. Supporting documentation on the basis of the performance estimates
for the renewable energy sources or nocturnal cooling shall be
demonstrated in the building plans and specifications.
403.2.2 Energy usage must be calculated in accordance with the
design conditions and methods specified in this part.
403.3 Exception. Proposed design(s) for buildings of less than
464m2 (5,000 ft2) of conditioned floor area that
derive a minimum of 30% of their total annual energy usage from
renewable sources or from nocturnal cooling are exempt from performing
the analysis on a full-year (8,760 hours) basis as described in section
402.3(b). However, comparison of heating, cooling, and service water
heating equipment energy usage between the proposed design(s) and the
standard design shall be provided in accordance with the remaining
provisions of sections 402 and 403 of this part.
403.4 Passive solar design analysis. Proposed design(s) using
passive solar heating strategies, such as south window placement
coupled with thermal mass, attached greenhouses or sunspaces, or Trombe
walls, can be analyzed for annual heating and cooling loads using RS-8.
Other methods for analysis of solar design strategies and equipment are
permitted. Note that use of RS-8 provides information on building loads
only; actual energy consumption depends on the equipment
[[Page 24185]]
proposed for installation in the building.
Subpart E--Design by Component Performance Approach
Sec. 435.501 Scope.
501.1 General. This subpart establishes design requirements based
on component performance for new Federal residential buildings. The
design requirements established in subpart D may be applied in lieu of
these requirements.
Sec. 435.502 Building thermal envelope requirements.
502.1 General. The building thermal envelope shall meet the
requirements of table 502.1a. Compliance with these requirements shall
be demonstrated in accordance with section 502.2. To demonstrate
compliance, calculation procedures and information contained in RS-4,
or laboratory test measurements obtained from test methods RS-9, -10, -
11, or -12, or other documented procedures or information, shall be
used.
502.1.1 The proposed design may include the use of thermal mass in
the exterior walls when determining energy use. If the use of thermal
mass is considered appropriate in the design of the exterior walls then
the required UW for exterior walls, covered by section
502.2.1.1 and having a heat capacity greater than or equal to 123 kJ/
m2 deg.K (6 Btu/ft2 deg.F),
shall be less than or equal to the U-value determined by the applicable
heating degree-days and low-mass-wall UW in tables 502.1b,
502.1c, or 502.1d. The column headings in tables 502.1b through 502.1d
are the UW's, as determined by using equation 502.2a and
Appendix Figure 1, for low-mass-walls; wall constructions having a heat
capacity of less than 123 kJ/m2 deg.K (6 Btu/
ft2 deg.F), as determined by equation 502.1a. The
heat capacity of the wall shall be determined by using equation 502.1a
below:
(Equation 502.1a)
HC=w x c
where:
HC=heat capacity of the exterior wall, based on exterior surface area,
W/(m2 deg.K) [Btu/(ft2 deg.F)].
w=mass of the wall, based on exterior surface area, kg/m2
(lb/ft2).
c=specific heat of the exterior wall material, kJ/(kg deg.K)
[Btu/(lb deg.F)].
The specific heat values shall be permitted to be obtained from
Chapter 22 of Standard RS-4.
Table 502.1a \1\
----------------------------------------------------------------------------------------------------------------
Element Mode Type A-1 buildings Type A-2 buildings
----------------------------------------------------------------------------------------------------------------
Walls............................ Heating or cooling....... Uo Uo
Roof/Ceiling..................... Heating or cooling....... Uo Uo
Floors over unheated spaces...... Heating or cooling....... Uo Uo
Heated slab on grade 2 5......... Heating.................. R R
Depth in.\6\ Depth in.\6\
Unheating slab on grade 3 5...... Heating.................. R R
Depth in.\6\ Depth in.\6\
Basement wall 4 5................ Heating or cooling....... U U
Crawl space wall 4 5............. Heating or cooling....... U U
----------------------------------------------------------------------------------------------------------------
\1\ Values shall be determined by using the graphs (Figures 1, 2, 3, 4, 5 and 6) contained in the Appendix of
this part using heating degree days as specified in section 302.
\2\ There are no insulation requirements for heated slabs in locations having less than 278 Celsius heating
degree days (500 Fahrenheit HDD).
\3\ There are no insulation requirements for unheated slabs in locations having less than 1,389 Celsius heating
degree days (2,500 Fahrenheit HDD).
\4\ Basement and crawl space wall U-values shall be based on the wall components and surface air films. Adjacent
soil shall not be considered in the determination of the U-value.
\5\ Typical foundation wall insulation techniques can be found in Standard RS-13.
\6\ Depth of burial measured as described in section 502.2.1.4.
Table 502.1b.--Required Uw for Wall With a Heat Capacity Equal To or Exceeding 123 kJ/(m2 deg.K) [6 Btu/(ft2 deg.F)] With
Insulation Placed on the Exterior of the Wall Mass
--------------------------------------------------------------------------------------------------------------------------------------------------------
UW required for walls with a heat capacity less than 123 kJ/(m2 deg.K) [6 Btu/(ft2
deg.F)] as determined by using equation 502.2a and appendix figure 1
Heating degree days 18.3 deg.C (65 deg.F) -----------------------------------------------------------------------------------------------------------
base 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22
(0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0-1111...................................... 1.59 1.47 1.30 1.19 1.02 0.90 0.73 0.62 0.45
(0-2000).................................... (0.28) (0.26) (0.23) (0.21) (0.18) (0.16) (0.13) (0.11) (0.08)
1112-2222................................... 1.53 1.42 1.24 1.13 0.96 0.85 0.73 0.56 0.45
(2001-4000)................................. (0.27) (0.25) (0.22) (0.20) (0.17) (0.15) (0.13) (0.10) (0.08)
2223-3056................................... 1.42 1.30 1.19 1.02 0.90 0.79 0.62 0.51 0.39
(4001-5500)................................. (0.25) (0.23) (0.21) (0.18) (0.16) (0.14) (0.11) (0.09) (0.07)
3056-3611................................... 1.30 1.19 1.07 0.96 0.85 0.68 0.56 0.45 0.34
(5501-6500)................................. (0.23) (0.21) (0.19) (0.17) (0.15) (0.12) (0.10) (0.08) (0.06)
3612-4444................................... 1.24 1.07 0.96 0.85 0.73 0.62 0.51 0.39 0.28
(6501-8000)................................. (0.22) (0.19) (0.17) (0.15) (0.13) (0.11) (0.09) (0.07) (0.05)
>4445....................................... 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22
(>8001)..................................... (0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 24186]]
Table 502.1c.--Required Uw for Wall With a Heat Capacity Equal To or Exceeding 123kJ/(m2 deg.K) [6Btu/(ft2 deg.F) With Insulation
Placed on the Interior of the Wall Mass
--------------------------------------------------------------------------------------------------------------------------------------------------------
Uw required for walls with a heat capacity less than 123 kJ/(m2 deg.K) [6 Btu/(ft2
deg.F)] as determined by using equation 502.2a and appendix figure 1
Heating degree days 18.3 deg.C (65 deg.F) -----------------------------------------------------------------------------------------------------------
base 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22
(0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0-1111...................................... 1.42 1.24 1.13 0.96 0.85 0.68 0.51 0.39 0.22
(0-2000).................................... (0.25) (0.22) (0.20) (0.17) (0.15) (0.12) (0.09) (0.07) (0.04)
1112-2222................................... 1.36 1.19 1.07 0.90 0.79 0.68 0.51 0.39 0.22
(2001-4000)................................. (0.24) (0.21) (0.19) (0.16) (0.14) (0.12) (0.09) (0.07) (0.04)
2223-3056................................... 1.30 1.19 1.07 0.90 0.79 0.62 0.51 0.39 0.22
(4001-5500)................................. (0.23) (0.21) (0.19) (0.16) (0.14) (0.11) (0.09) (0.07) (0.04)
3056-3611................................... 1.24 1.13 0.96 0.85 0.73 0.62 0.51 0.34 0.22
(5501-6500)................................. (0.22) (0.20) (0.17) (0.15) (0.13) (0.11) (0.09) (0.06) (0.04)
3612-4444................................... 1.19 1.07 0.96 0.79 0.68 0.56 0.45 0.34 0.22
(6501-8000)................................. (0.21) (0.19) (0.17) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)
>4445....................................... 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22
(>8001)..................................... (0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 502.1d.--Required Uw for Wall With a Heat Capacity Equal To or Exceeding 123kJ/(m2 deg.K) [6Btu/(ft2 deg.F) With Integral
Insulation (Insulation and Mass Mixed, Such as a Log Wall)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Uw required for walls with a heat capacity less than 123 kJ/(m2 deg.K) [6 Btu/(ft2
deg.F)] as determined by using equation 502.2a and appendix figure 1
Heating degree days 18.3 deg.C (65 deg.F) -----------------------------------------------------------------------------------------------------------
base 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22
(0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0-1111...................................... 1.59 1.42 1.30 1.13 0.96 0.85 0.68 0.51 0.39
(0-2000).................................... (0.28) (0.25) (0.23) (0.20) (0.17) (0.15) (0.12) (0.09) (0.07)
1112-2222................................... 1.53 1.36 1.24 1.07 0.96 0.79 0.62 0.51 0.34
(2001-4000)................................. (0.27) (0.24) (0.22) (0.19) (0.17) (0.14) (0.11) (0.09) (0.06)
2223-3056................................... 1.47 1.30 1.19 1.02 0.90 0.73 0.62 0.45 0.34
(4001-5500)................................. (0.26) (0.23) (0.21) (0.18) (0.16) (0.13) (0.11) (0.08) (0.06)
3056-3611................................... 1.36 1.19 1.07 0.96 0.79 0.68 0.56 0.45 0.28
(5501-6500)................................. (0.24) (0.21) (0.19) (0.17) (0.14) (0.12) (1.10) (0.08) (0.05)
3612-4444................................... 1.24 1.13 1.02 0.85 0.73 0.62 0.51 0.39 0.28
(6501-8000)................................. (0.22) (0.20) (0.18) (0.15) (0.13) (0.11) (0.09) (0.07) (0.05)
>4445....................................... 1.13 1.02 0.90 0.79 0.68 0.56 0.45 0.34 0.22
(>8001)..................................... (0.20) (0.18) (0.16) (0.14) (0.12) (0.10) (0.08) (0.06) (0.04)
--------------------------------------------------------------------------------------------------------------------------------------------------------
502.1.2 The design shall not create conditions of accelerated
deterioration from moisture condensation. For frame walls, floors, and
ceilings not ventilated to allow moisture to escape, an approved vapor
retarder having a maximum perm rating of 57.4 ng/
Pasm2 (1.0 perm), when tested in
accordance with Standard RS-14, Procedure A, shall be installed on the
warm-in-winter side of the thermal insulation.
502.1.3 Exceptions.
502.1.3.1 Buildings are exempt from the requirements of section
502.1.2 in construction where moisture or its freezing will not damage
the materials.
502.1.3.2 Buildings are exempt from the requirements of section
502.1.2 in hot and humid climate areas where the following conditions
occur:
(a) 19.4 deg.C (67 deg.F) or higher wet-bulb temperature for
3,000 or more hours during the warmest six consecutive months of the
year, and/or
(b) 22.8 deg.C (73 deg.F) or higher wet-bulb temperature for
1,500 or more hours during the warmest six consecutive months of the
year.
502.1.4 Access openings. Access doors, hatches, scuttles, pull-
down staircases and similar constructions separating a conditioned from
an unconditioned space shall be weatherstripped along the surfaces that
seal to the surrounding fixed frame. The access opening shall be
insulated to a level equivalent to the insulation of the surrounding
floor, wall, and ceiling.
502.1.4.1 Exception. If the access opening is uninsulated, the U-
value of the surrounding floor, wall, and ceiling shall be decreased in
accordance with equations 502.2a, 502.2b, 502.2c, or 502.2d, as
appropriate.
502.1.5 Masonry Veneer. When insulation is placed on a foundation
wall, and part of the foundation wall supports a masonry veneer for the
exterior wall, the horizontal portion of the foundation supporting the
veneer need not be insulated.
502.2 Heating and cooling criteria.
502.2.1 Compliance by performance on an individual component
basis. Each component of the building envelope shall meet the
provisions of table 502.1a as provided in sections 502.2.1.1--
502.2.1.6.
502.2.1.1 Walls.
502.2.1.1.1 Conventional framing. The combined thermal
transmittance value (UO) of the gross area of exterior walls
shall not exceed the value given in table 502.1a. Equation 502.2a shall
be used to determine acceptable combinations to meet this requirement.
[[Page 24187]]
[GRAPHIC] [TIFF OMITTED] TP02MY97.000
where:
Uo=the average thermal transmittance of the gross area of
exterior walls.
Ao=the gross area of exterior walls.
Uw=the combined thermal transmittance of the various paths
of heat transfer through the opaque exterior wall area.
Aw=area of exterior wall that is opaque.
Ug=the thermal transmittance of the area of all windows
within the gross wall area as determined in accordance with section
102.3 of this part.
Ag=the area of all windows within the gross wall area.
Ud=the thermal transmittance of the area of all doors within
the gross wall area as determined in accordance with section 102.3 of
this part.
Ad=the area of all doors within the gross wall area.
When more than one type of wall, window, or door is used, the U x
A term for that item shall be expanded into sub-elements as:
UwAw = (Uw1Aw1) +
(Uw2Aw2) + (Uw3Aw3) + ...
(etc.)
502.2.1.1.2 Metal framing. When exterior walls are framed with
metal studs, calculate the value of Uw used in equation
502.2b as follows:
where:
Rs=the total thermal resistance of the elements, in series
along the path comprising the wall assembly of heat transfer, excluding
the cavity insulation and the metal stud.
Rins=the R value of the cavity insulation
Fc=the correction factor listed in Appendix table
502.2.1.1.2.
[GRAPHIC] [TIFF OMITTED] TP02MY97.001
502.2.1.1.3 Any vertical glazing assemblies or vertical walls that
form part of a roof assembly that bounds conditioned space, such as
clerestories and dormers, shall be treated as part of the exterior wall
area for purposes of complying with this part.
502.2.1.2 Roof/ceiling. The combined thermal transmittance value
(UO) of the gross area of the roof or ceiling assembly shall not exceed
the value given in table 502.1a. Equation 502.2c shall be used to
determine acceptable combinations to meet this requirement.
[GRAPHIC] [TIFF OMITTED] TP02MY97.002
where:
Uo=the average thermal transmittance of the gross roof/
ceiling area.
Ao=the gross area of the roof/ceiling assembly.
UR=the thermal transmittance of all elements of the opaque
roof/ceiling area.
AR=area of the opaque roof/ceiling assembly.
Us=the thermal transmittance of the area of all skylight
elements in the roof/ceiling assembly as determined in accordance with
section 102.3 of this part.
As=the area (including frame) of all skylights within the
roof/ceiling assembly.
When more than one type of roof/ceiling or skylight is used, the U
x A term for that item shall be expanded into its sub-elements, as:
UR x AR = (UR1 x
AR1) + (UR2 x AR2) + ...etc.
502.2.1.2.1 When return air ceiling plenums are employed, the
roof/ceiling assembly shall:
(a) For thermal transmittance purposes, not include the ceiling
proper nor the plenum space as part of the assembly and, b) For gross
area purposes, be based upon the interior face of the upper plenum
surface.
502.2.1.3 Floors over unheated spaces. The combined thermal
transmittance value (UO) of the gross area of floors over
unheated spaces shall not exceed the value given in table 502.1a. The
thermal transmittance requirement of this section does not apply to
floors over unvented crawl spaces and basements if the requirements of
section 502.2.1.5 and/or 502.2.1.6 are met. For floors over outdoor
air, e.g., overhangs, the UO value shall meet the same
requirement shown for roofs in table 502.1a. Equation 502.2d shall be
used to determine acceptable combinations to meet this requirement.
[GRAPHIC] [TIFF OMITTED] TP02MY97.003
where:
UO=the combined thermal transmittance of the different floor
assemblies.
AO=the gross area of all floor assemblies.
U1,...,n=the thermal transmittance of the various heat
transfer paths through the first (or nth) floor assembly.
Af1,...,fn=the area of the first (or nth) floor assembly.
502.2.1.4 Slab-on-grade floors. For slab-on-grade floors, the
thermal resistance of the insulation around the perimeter of the floor
shall not be less than the value given in table 502.1a. Insulation
shall be placed on the outside
[[Page 24188]]
of the foundation or on the inside of the foundation wall. In climates
below 3,333 annual Celsius heating degree days (HDD) (6,000 annual
Fahrenheit HDD), the insulation shall extend downward from the top of
the slab for a minimum distance of 0.610 m (24 in.) or downward to at
least the bottom of the slab and then horizontally to the interior or
exterior for a minimum total distance of 0.610 m (24 in.) and shall be
designed for ground contact. In climates equal to or greater than 3,333
annual Celsius heating degree days (HDD) (6,000 annual Fahrenheit HDD),
the insulation shall extend downward from the top of the slab for a
minimum of 1.22 m (48 in.) or downward to at least the bottom of the
slab and then horizontally to the interior or exterior for a minimum
total distance of 1.22 m (48 in.). In all climates, horizontal
insulation extending outside of the foundation shall be covered by
pavement or soil a minimum of 0.254 m (10 in.) thick. If the insulation
is placed to the inside of the foundation wall, there must be
insulation placed between the slab and the foundation wall. The top
edge of the insulation installed between the exterior wall and the edge
of the interior slab shall be permitted to be cut at a 45 deg. angle
away from the exterior wall.
502.2.1.5 Crawl space walls. If the floor above a crawl space does
not meet the requirements of section 502.2.1.3 and the crawl space does
not have ventilation openings that communicate directly with outside
air, then the exterior walls of the crawl space shall have a thermal
transmittance value not exceeding the value given in table 502.1a.
Where the inside ground surface is less than 0.305 m (12 in.) below the
outside finish ground level or the vertical wall insulation stops less
than 0.305 m (12 in.) below the outside finish ground level, crawl
space wall insulation shall extend vertically and horizontally a
minimum total distance of 0.610 m (24 in.) linearly from the outside
finish ground level (see RS-13).
502.2.1.6 Basement walls. The exterior walls of basements below
uninsulated floors shall have a thermal transmittance value not
exceeding the value given in table 502.1a from the top of the basement
wall to a depth of 3.05 m (10 ft) below the outside finish ground
level, or to the level of the basement floor, whichever is less.
502.2.2 Compliance by whole building performance. The stated
UO, U, or R value of an assembly may be increased or
decreased, provided the total heat gain or loss for the entire building
does not exceed the total resulting from conformance to the values
specified in table 502.1a.
502.3 Air leakage.
502.3.1 Window and door assemblies. Window and door assemblies
installed in the building envelope shall comply with the maximum
infiltration rates allowed in RS-15, -16, -17, -18, and -19.
502.3.1.1 Exception. Site-constructed windows and doors shall be
sealed in accordance with section 502.3.2.
502.3.2 Caulking and sealants. Joints, openings, and penetrations
in the building envelope that are sources of air leakage shall be
sealed with caulking, gasketing, weather-stripping, house wrap, or
other materials compatible with the construction materials, location,
and anticipated conditions. Sealants used in joints between dissimilar
materials shall allow for differential expansion and contraction of
such materials.
502.3.3 Recessed lighting fixtures. When installed in the building
envelope, recessed lighting fixtures shall meet one of the following
requirements:
(a) Type IC rated, manufactured with no penetrations between the
inside of the recessed fixture and the ceiling cavity, and sealed or
gasketed to prevent air leakage into the unconditioned space.
(b) Type IC or non-IC rated, installed inside a sealed box
constructed from a minimum 0.013-m (\1/2\-in.) thick gypsum wallboard,
a preformed polymeric vapor barrier, or other air-tight assembly
manufactured for this purpose. The fixture shall maintain a 0.013-m
(\1/2\-in.) minimum clearance from combustible material and 0.064 m (3
in.) minimum clearance from insulation material.
(c) Type IC rated in accordance with RS-15 with no more than 0.944
L/s (2.0 cfm) air movement from the conditioned space to the ceiling
cavity. The fixture shall be tested at 75 Pascals or 1.57 psf pressure
differential and shall be labeled.
Sec. 435.503 Building mechanical systems and equipment.
503.1 General. This section covers mechanical systems and
equipment used to provide heating, ventilating, and air-conditioning
functions.
503.2 Mechanical equipment efficiency. Mechanical equipment used
to provide heating and air-conditioning functions shall be selected
pursuant to the following:
503.2.1 Detached one and two family dwellings. Heating and air-
conditioning equipment selection shall comply with section 503.2.1.1 or
section 503.2.1.2.
503.2.1.1 Minimum federal standards. The installed equipment type
shall have the lowest life-cycle cost of all the applicable equipment
included in table 503.2, when those equipment types have been evaluated
at the minimum equipment performance efficiency allowed under Federal
standards as specified in 10 CFR part 430.
503.2.1.2 Alternative approach. Any equipment that is at least as
life-cycle cost-effective as the equipment identified in section
503.2.1.1 may be installed.
503.2.1.3 When either the selected equipment or the equipment
identified in table 503.2 to which it is compared provides both heating
and cooling, the life-cycle cost comparison shall be based on the
combined life-cycle cost of providing heating and cooling services.
Otherwise, separate heating and cooling life-cycle cost comparisons
shall be made.
503.2.1.4 All such equipment shall be installed in accordance with
the manufacturer's instructions.
Table 503.2.--Mechanical Equipment Regulated by Federal Law
------------------------------------------------------------------------
Heat pump \1\ or air conditioner;
air, water or evaporatively cooled <70,320 kw=""><240,000 btu/h)="" ------------------------------------------------------------------------="" packaged="" terminal="" air="" conditioner="" or="" all="" capacities.="" heat="" pump.="" warm="" air="" furnaces,="" gas="" and="" oil-fired.="" all="" capacities.="" boilers,="" gas-and="" oil-fired...........="" all="" capacities.="" ------------------------------------------------------------------------="" \1\="" does="" not="" include="" ground-water="" source="" heat="" pumps.="" 503.2.2="" central="" heating="" and="" air-conditioning="" units="" for="" multiple="" dwelling="" units="" in="" multi-family="" low="" rise="" dwellings.="" heating="" and="" air-="" conditioning="" equipment="" selection="" shall="" comply="" with="" section="" 503.2.2.1="" or="" section="" 503.2.2.2.="" 503.2.2.1="" equipment="" covered="" by="" rs-20.="" the="" installed="" equipment="" type="" shall="" have="" the="" lowest="" life-cycle="" cost="" of="" all="" the="" applicable="" equipment="" included="" in="" table="" 403.1="" of="" rs-20,="" when="" those="" equipment="" types="" have="" been="" evaluated="" at="" the="" minimum="" equipment="" performance="" efficiency="" allowed="" by="" table="" 403.1="" of="" rs-20="" for="" the="" capacity="" required.="" 503.2.2.2="" alternative="" approach.="" any="" equipment="" that="" is="" at="" least="" as="" life-cycle="" cost-effective="" as="" the="" equipment="" identified="" in="" section="" 503.2.2.1="" may="" be="" installed.="" 503.2.2.3="" when="" either="" the="" selected="" equipment="" or="" the="" equipment="" identified="" [[page="" 24189]]="" in="" table="" 403.1="" of="" rs-20="" to="" which="" it="" is="" compared="" provides="" both="" heating="" and="" cooling,="" the="" life-cycle="" cost="" comparison="" shall="" be="" based="" on="" the="" combined="" life-cycle="" cost="" of="" providing="" heating="" and="" cooling="" services.="" otherwise,="" separate="" heating="" and="" cooling="" life-cycle="" cost="" comparisons="" shall="" be="" made.="" 503.2.2.4="" all="" such="" equipment="" shall="" be="" installed="" in="" accordance="" with="" the="" manufacturer's="" instructions.="" 503.3="" hvac="" systems.="" 503.3.1="" load="" calculations.="" heating="" and="" cooling="" system="" design="" loads="" for="" the="" purpose="" of="" sizing="" systems="" and="" equipment="" shall="" be="" determined="" in="" accordance="" with="" the="" procedures="" described="" in="" rs-4,="" or="" an="" equivalent="" computation="" procedure,="" using="" the="" design="" parameters="" specified="" in="" section="" 302="" of="" this="" part.="" design="" loads="" shall="" account="" for="" infiltration.="" 503.3.1.1="" heating="" and="" cooling="" equipment="" capacity.="" 503.3.1.2="" heating="" equipment.="" the="" capacity="" of="" the="" equipment="" shall="" not="" exceed="" 170%="" of="" the="" design="" load.="" 503.3.1.3="" exception.="" power="" burner="" and="" induced-draft="" burner="" fossil="" fuel="" heating="" equipment.="" 503.3.2="" cooling-only="" equipment.="" equipment="" capable="" of="" providing="" only="" cooling="" shall="" be="" selected="" so="" the="" sensible="" capacity="" of="" the="" equipment="" is="" not="" less="" than="" the="" calculated="" total="" sensible="" cooling="" load="" but="" not="" more="" than="" 125%="" of="" the="" design="" sensible="" load="" or="" the="" closest="" available="" size="" provided="" by="" the="" manufacturer.="" the="" corresponding="" latent="" capacity="" of="" the="" equipment="" shall="" not="" be="" less="" than="" the="" calculated="" latent="" load.="" 503.3.3="" heat="" pump="" equipment.="" heat="" pump="" sizing="" shall="" be="" based="" on="" the="" cooling="" design="" requirements="" and="" shall="" not="" exceed="" 125%="" of="" the="" cooling="" load="" at="" design="" conditions.="" for="" variable-speed="" or="" multiple-speed="" units,="" the="" cooling="" capacity="" at="" the="" lowest="" speed="" shall="" not="" exceed="" 125%="" of="" the="" cooling="" load="" at="" design="" conditions.="" alternatively,="" where="" these="" data="" are="" not="" available="" for="" design="" temperatures,="" the="" capacity="" at="" the="" design="" heating="" temperature="" may="" be="" determined="" by="" interpolation="" or="" extrapolation="" of="" manufacturers'="" performance="" data.="" the="" auxiliary="" electric="" resistance="" heat="" capacity="" shall="" not="" exceed="" 120%="" of="" the="" design="" heating="" requirement.="" 503.3.4="" central="" electric="" furnace.="" central="" electric="" furnaces="" shall="" be="" installed="" within="" the="" conditioned="" space="" unless="" they="" are="" specifically="" designed="" for="" use="" outside="" the="" conditioned="" space.="" such="" furnaces="" greater="" than="" 12="" kw="" (3.42="" tons)="" shall="" be="" divided="" into="" at="" least="" two="" stages.="" an="" electric="" heat="" pump="" or="" an="" off-peak="" electric="" heating="" system="" with="" thermal="" storage="" shall="" be="" installed="" in="" conjunction="" with="" the="" furnace="" for="" locations="" with="" 111="" hdd,="" base="" 18.3="" deg.c="" (200="" hdd,="" base="" 65="" deg.f)="" or="" more.="" 503.4="" temperature="" and="" humidity="" controls.="" 503.4.1="" system="" controls.="" each="" dwelling="" unit="" shall="" be="" considered="" a="" zone="" and="" be="" provided="" with="" thermostatic="" controls="" responding="" to="" temperature="" within="" the="" dwelling="" unit.="" each="" heating="" and="" cooling="" system="" shall="" include="" at="" least="" one="" temperature="" control="" device.="" where="" a="" dwelling="" unit="" is="" served="" by="" more="" than="" one="" system,="" the="" thermostatic="" controls="" of="" each="" system="" shall="" prevent="" simultaneous="" operation="" in="" different="" modes.="" 503.4.2="" thermostatic="" control="" capabilities.="" where="" used="" to="" control="" comfort="" heating,="" thermostatic="" controls="" shall="" be="" capable="" of="" being="" set="" locally="" or="" remotely="" by="" adjustment="" or="" selection="" of="" sensors="" down="" to="" 12.9="" deg.c="" (55="" deg.f)="" or="" lower.="" 503.4.2.1="" where="" used="" to="" control="" comfort="" cooling,="" thermostatic="" controls="" shall="" be="" capable="" of="" being="" set="" locally="" or="" remotely="" by="" adjustment="" or="" selection="" of="" sensors="" up="" to="" 29.4="" deg.c="" (85="" deg.f)="" or="" higher.="" 503.4.2.2="" where="" used="" to="" control="" both="" comfort="" heating="" and="" cooling,="" thermostatic="" controls="" shall="" be="" capable="" of="" providing="" a="" temperature="" range="" or="" deadband="" of="" up="" to="" 5.6="" deg.c="" (10="" deg.f)="" or="" more="" within="" which="" the="" supply="" of="" heating="" and="" cooling="" energy="" is="" shut="" off="" or="" reduced="" to="" a="" minimum.="" 503.4.2.2.1="" exception.="" thermostats="" that="" require="" manual="" changeover="" between="" heating="" and="" cooling="" modes.="" 503.4.3="" heat="" pump="" supplementary="" heater.="" the="" heat="" pump="" shall="" be="" installed="" with="" controls="" to="" prevent="" supplementary="" heater="" operation="" when="" the="" operating="" load="" can="" be="" met="" by="" the="" heat="" pump="" alone.="" supplementary="" heater="" operation="" is="" permitted="" during="" transient="" periods,="" such="" as="" start-="" ups,="" following="" room="" thermostat="" set-point="" advance,="" and="" during="" defrost.="" 503.4.4="" humidistat.="" humidistats="" used="" for="" comfort="" purposes="" shall="" be="" capable="" of="" being="" set="" to="" prevent="" the="" use="" of="" fossil="" fuel="" or="" electricity="" to="" reduce="" relative="" humidity="" below="" 60%="" when="" reducing="" moisture="" or="" to="" increase="" relative="" humidity="" above="" 30%="" when="" adding="" moisture.="" 503.5="" distribution="" system="" construction="" and="" insulation.="" 503.5.1="" piping="" insulation.="" all="" hvac="" system="" piping="" shall="" be="" thermally="" insulated="" in="" accordance="" with="" table="" 503.5.1a.="" 503.5.1.1="" exceptions.="" (a)="" factory-installed="" piping="" within="" hvac="" equipment="" tested="" and="" rated="" in="" accordance="" with="" section="" 503.2.="" (b)="" piping="" that="" conveys="" fluids="" which="" have="" a="" design="" operating="" temperature="" range="" between="" 12.8="" deg.c="" (55="" deg.f)="" and="" 48.9="" deg.c="" (120="" deg.f).="" (c)="" when="" the="" heat="" loss="" and/or="" heat="" gain="" of="" the="" piping="" without="" insulation="" does="" not="" increase="" the="" energy="" requirement="" of="" the="" building.="" (d)="" when="" the="" piping="" is="" installed="" in="" basements,="" cellars,="" or="" unventilated="" crawl="" spaces="" having="" insulated="" walls.="" (e)="" when="" additional="" insulation="" or="" vapor="" barriers="" have="" been="" specified="" to="" prevent="" condensation.="" table="" 503.5.1a.--minimum="" pipe="" insulation="" [thickness="" in="" meters="" (inches)]="" \3\="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" pipe="" sizes="" \2\="" -----------------------------------------------------------------------------------="" fluid="" temperature="" range,="" 0.032="" to="" piping="" system="" types="" deg.c="" (="" deg.f)="" run="" outs="" 0.025="" m="" (1="" 0.051="" m="" 0.064="" to="" 0.127="" to="" 0.203="" m="" (8="" 0.051="" m="" (2="" in.)="" and="" (1.25="" to="" 2="" 0.102="" m="" (2.5="" 0.152="" m="" (5="" in.)="" and="" in.)\1\="" less="" in.)="" to="" 4="" in.)="" to="" 6="" in.)="" larger="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" heating="" systems="" steam="" and="" hot="" water="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" high="" pressure/="" temperature..............="" 152.2-232.2...............="" 0.038="" 0.064="" 0.064="" 0.076="" 0.089="" 0.089="" (306-450).................="" (1.5)="" (2.5)="" (2.5)="" (3)="" (3.5)="" (3.5)="" medium="" pressure/="" temperature............="" 121.7-151.7...............="" 0.038="" 0.051="" 0.064="" 0.064="" 0.076="" 0.076="" (251-305).................="" (1.5)="" (2)="" (2.5)="" (2.5)="" (3)="" (3)="" low="" pressure/="" temperature..............="" 93.9-121.1................="" 0.025="" 0.038="" 0.038="" 0.051="" 0.051="" 0.051="" (201-250).................="" (1)="" (1.5)="" (1.5)="" (2)="" (2)="" (2)="" low="" temperature.........................="" 48.9-93.3.................="" 0.013="" 0.025="" 0.025="" 0.038="" 0.038="" 0.038="" [[page="" 24190]]="" (120-200).................="" (0.5)="" (1)="" (1)="" (1.5)="" (1.5)="" (1.5)="" steam="" condensate="" (for="" feed="" water).......="" any.......................="" 0.025="" 0.025="" 0.038="" 0.051="" 0.051="" 0.051="" ..........................="" (1)="" (1)="" (1.5)="" (2)="" (2)="" (2)="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" cooling="" systems="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" chilled="" water...........................="" 4.4-12.8..................="" 0.013="" 0.013="" 0.019="" 0.025="" 0.025="" 0.025="" (40-55)...................="" (0.5)="" (0.5)="" (0.75)="" (1)="" (1)="" (1)="" refrigerant,="" or="" brine...................="" below="" 4.4.................="" 0.025="" 0.025="" 0.038="" 0.038="" 0.038="" 0.038="" (40)......................="" (1)="" (1)="" (1.5)="" (1.5)="" (1.5)="" (1.5)="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" \1\="" runouts="" not="" exceeding="" 3.66="" m="" (12="" ft)="" in="" length="" to="" individual="" terminal="" units.="" \2\="" for="" piping="" exposed="" to="" outdoor="" air,="" increase="" insulation="" thickness="" by="" 0.0127="" m="" (0.5="" in.).="" \3\="" insulation="" thicknesses="" are="" based="" on="" insulation="" having="" thermal="" resistivity="" in="" the="" range="" of="" 27.7="" to="" 31.9="" (m="" \2\.="" deg.c)/w="" per="" meter="" [4.0="" to="" 4.6="" h.ft="" \2\.="" deg.f/btu="" per="" inch]="" of="" thickness="" on="" a="" flat="" surface="" at="" a="" mean="" temperature="" of="" 23.9="" deg.c="" (75="" deg.f).="" 503.5.1.2="" for="" materials="" with="" thermal="" resistivity="" greater="" than="" 0.81="" (4.6),="" the="" minimum="" insulation="" thickness="" may="" be="" reduced="" as="" determined="" by="" equation="" 503.5.1.2a:="" [graphic]="" [tiff="" omitted]="" tp02my97.004="" 503.5.1.3="" for="" materials="" with="" thermal="" resistivity="" less="" than="" 0.71="" (4.0),="" the="" minimum="" insulation="" thickness="" shall="" be="" increased="" as="" determined="" by="" equation="" 503.5.1.2b:="" [graphic]="" [tiff="" omitted]="" tp02my97.005="" 503.5.2="" [reserved]="" 503.5.3="" [reserved]="" 503.5.4="" [reserved]="" 503.5.5="" [reserved]="" 503.5.6="" duct="" system="" insulation.="" all="" supply="" and="" return="" air="" ducts="" and="" plenums="" installed="" as="" part="" of="" an="" hvac="" air="" distribution="" system="" shall="" be="" insulated="" to="" provide="" a="" thermal="" resistance,="" excluding="" film="" resistances,="" to="" that="" value="" determined="" by="" equation="" 503.5.6a:="" [graphic]="" [tiff="" omitted]="" tp02my97.006="" where="">t= the design temperature difference between the air in
the duct and the temperature of the ambient air in contact with the
exterior duct surface.
503.5.6.1 Exceptions. Duct insulation, except as required to
prevent condensation, is not required in the following cases:
(a) When t is 13.9 deg.C (25 deg.F) or less.
(b) When supply-or return-air ducts are installed in basements,
cellars, or unventilated crawl spaces having insulated walls in one-and
two-family dwellings.
(c) When the heat gain or loss of the ducts, without insulation,
will not increase the energy requirements of the building.
(d) Within HVAC equipment.
(e) Exhaust air ducts.
503.5.6.2 For buildings with uninsulated roofs over attics
containing ducts, the air temperature shown in table 503.5.6.2 shall be
used.
Table 503.5.6.2.--Attic Temperatures
------------------------------------------------------------------------
Seasonal conditions Temperature
------------------------------------------------------------------------
Summer conditions:
Roof slope:
5 in 12 and up........................ 54.4 deg.C (130 deg.F).
3 in 12 to 5 in 12.................... 60.0 deg.C (140 deg.F).
less than 3 in 12..................... 65.6 deg.C (150 deg.F).
Winter conditions all slopes.............. 5.56 deg.C (10 deg.F)
above outdoor design.
------------------------------------------------------------------------
503.5.7 Duct construction. Ductwork shall be constructed and
erected in accordance with Standards RS-6, RS-21, RS-22, RS-23, or RS-
24 listed in section 801 of this part or in accordance with the
construction documents.
503.5.7.1 Duct testing. High-pressure and medium-pressure ducts
shall be leak tested in accordance with the applicable standards in
section 801 of this part with the rate of air leakage not to exceed the
maximum rate specified in that standard.
503.5.7.2 Duct sealing. All low-pressure supply and return air
ducts, including those that are created within stud bays or joist
cavities by covering with sheet metal, shall be sealed using mastic
with fibrous backing tape installed according to the manufacturer's
specifications. Other sealants may be specified if their
[[Page 24191]]
performance can be demonstrated to equal or exceed that of mastic with
fibrous backing tape. For fibrous glass ductwork, pressure-sensitive
tape may be used if installed in accordance with RS-24. Duct tape is
not permitted as a sealant on any ducts.
503.5.8 Mechanical ventilation. Each mechanical ventilation system
(supply and/or exhaust) shall be equipped with a readily accessible
switch or other means for shutoff or volume reduction and shutoff when
ventilation is not required. Automatic or gravity dampers that close
when the system is not operating shall be provided for outdoor air
intakes and exhausts.
503.5.9 Combustion air. Each combustion device shall be properly
installed and provided with a sufficient air supply to meet the air
flow requirements for that device. For any fuel-burning equipment
installed in the dwelling unit, combustion zone depressurization shall
not exceed the equipment's depressurization limit.
503.5.9.1 Backdrafting test. Dwelling units that have installed
combustion appliances requiring a vent pipe or chimney (including gas
clothes dryers, water heaters, furnaces, fireplaces, and wood stoves)
shall be tested for depressurization-induced chimney failure
(backdrafting) in accordance with RS-25. If backdrafting occurs, the
cause of insufficient make-up air shall be identified and corrected
before occupancy. Testing is not required if the combustion air is
supplied directly from the outdoors to the combustion chamber via a
sealed passageway, and the products of combustion are exhausted
directly outdoors through an independent sealed vent.
503.5.9.2 Combustion air supplies. Any duct, pipe, screened
opening or other construction feature which serves to provide
combustion air to fossil-fuel burning appliances, including service
water heaters, shall be prominently labeled in a readily accessible
location directly on or immediately adjacent to the construction
feature. The label shall contain the following statement, or words
conveying a similar intent:
Warning: This pipe [duct, vent, etc.] has been installed to
provide combustion air for an appliance that burns natural gas,
propane gas, fuel oil, or any solid fuel. It should not be modified
or obstructed in any way, without first consulting a qualified HVAC
contractor or your local building department. Obstruction or
improper modification may cause toxic combustion products to be
drawn into the living space of the home.
503.5.10 Transport energy. The air transport factor for each all-
air system shall be not less than 5.5 when calculated in accordance
with equation 503.5.10a. The factor shall be based on design system air
flow. Energy for transfer of air through heat recovery devices shall
not be included in determining the factor.
[GRAPHIC] [TIFF OMITTED] TP02MY97.007
503.5.10.1 For purposes of these calculations, Space Sensible Heat
Load Removal Rate is equivalent to the maximum coincident design
sensible cooling load of all spaces served for which the system
provides cooling. Fan Power Input is the rate of energy delivered to
the fan prime mover.
503.5.10.2 Air and water, all-water and unitary systems employing
chilled, hot, dual-temperature or condenser water-transport systems to
space terminals shall not require greater transport energy (including
central and terminal fan power and pump power) than an equivalent all-
air system providing the same space sensible heat removal and having an
air transport factor not less than 5.5.
503.5.11 Balancing. The HVAC system design shall provide means for
balancing air and water systems. Components for balancing include
dampers, temperature and pressure test connections, and balancing
valves.
Sec. 435.504 Service water heating.
504.1 General. The purpose of this section is to provide criteria
for design and equipment selection that will produce energy savings
when applied to service water heating. Water supplies to ice-making
machines and refrigerators shall be taken from a cold-water line of the
water distribution system.
504.2 Performance efficiency. Mechanical equipment used to provide
residential service water heating functions shall be selected pursuant
to the following:
504.2.1 Detached one and two family dwellings. Service water
heating equipment selection shall comply with section 504.2.1.1 or
section 504.2.1.2.
504.2.1.1 Minimum federal standards. The installed equipment type
shall have the lowest life-cycle cost of all the applicable equipment
included in section 430.32(d) of 10 CFR part 430, Subpart C, when those
equipment types have been evaluated at the minimum equipment
performance efficiency allowed under Federal standards as specified in
10 CFR part 430.
504.2.1.2 Alternative approach. Any equipment that is at least as
life-cycle cost-effective as the equipment identified in section
504.2.1.1 may be installed.
504.2.1.3 When either the selected equipment or the equipment
identified in section 403.32(d) of 10 CFR part 430, Subpart C to which
it is compared provides heating or cooling to the conditioned space of
the building, in addition to service water heating, the life-cycle cost
comparison shall be based on the combined life-cycle cost of providing
service water heating and the heating or cooling service. Otherwise,
separate life-cycle cost comparisons shall be made.
504.2.1.4 All such equipment shall be installed in accordance with
the manufacturer's instructions.
504.2.2 Service water heating units for multiple dwelling units in
multi-family low rise dwellings. Service water heating equipment
selection shall comply with section 504.2.2.1 or section 504.2.2.2.
504.2.2.1 Equipment covered by RS-20. The installed equipment type
shall have the lowest life-cycle cost of all the applicable equipment
included in table 404.1 of RS-20, when those equipment types have been
evaluated at the minimum equipment performance efficiency allowed by
table 404.1 of RS-20.
504.2.2.2 Alternative approach. Any equipment that is at least as
life-cycle cost-effective as the equipment identified in section
504.2.2.1 may be installed.
504.2.2.3 When either the selected equipment or the equipment
identified in table 404.1 of RS-20 to which it is compared provides
heating or cooling to the conditioned space of the building, in
addition to service water heating, the life-cycle cost comparison shall
be based on the combined life-cycle cost of providing service water
heating and heating or cooling service. Otherwise,
[[Page 24192]]
separate life-cycle cost comparisons shall be made.
504.2.2.4 All such equipment shall be installed in accordance with
the manufacturer's instructions.
504.3 Combination service water heating and space heating
equipment. Equipment shall not be used to serve both space heating and
service water heating unless: the annual space heating energy is less
than 50% of the annual service water heating energy; the energy input
or storage volume of the combined space heating equipment and water
heater is less than twice the energy input or storage volume of the
smaller of the separate space heating equipment or water heaters
otherwise required; or the input to the combined equipment is less than
43.95 kW (150,000 Btu/h).
504.4 Heat traps. Water heaters with vertical pipe risers shall
have a heat trap installed on both the inlet and outlet of the water
heater unless the water heater has an integral heat trap or is part of
a circulating system.
504.5 Automatic controls. Service water-heating systems shall be
equipped with automatic temperature controls capable of maintaining a
pre-selected temperature. The control shall be preselected to a
temperature of 60 deg.C (140 deg.F) or less.
504.6 Shutdown. A separate switch shall be provided to permit
turning off the energy supplied to electric service water-heating
systems. A separate valve shall be provided to permit turning off the
energy supplied to the main burner(s) of all other types of service
water-heating systems.
504.7 Pump operation. Circulating hot-water systems shall be
arranged so that the circulation pump(s) can be conveniently turned
off, automatically or manually, when the hot-water heater is not in
operation.
504.8 Pipe insulation. For recirculating systems, piping heat loss
shall be limited to a maximum of 5.13 W (17.5 Btu/h) per linear foot of
pipe by insulating in accordance with table 504.8a. Table 504.8a is
based on a design temperature external to the system piping of 18.3
deg.C (65 deg.F) minimum. Lower design temperatures shall require
recalculation of the required piping insulation to limit heat loss to
the above amount.
504.8.1 Exception. Piping insulation is not required when the heat
loss of the piping, without insulation, does not increase the annual
energy requirements of the building.
Table 504.8a.--Minimum Pipe Insulation \2\
[Thickness in meters (inches)]
----------------------------------------------------------------------------------------------------------------
Pipe sizes \1\
---------------------------------------------------------------
Noncirculating Circulating mains and runouts
Service water heating temperatures deg.C ( runouts -----------------------------------------------
deg.F) ----------------
Up to 0.025 m Up to 0.032 m 0.038-0.051 m Over 0.051 m
(1 in.) (1.25 in.) (1.5-2 in.) (2 in.)
----------------------------------------------------------------------------------------------------------------
76.7-82.2 (170-180)............................. 0.013 (0.5) 0.025 (1.0) 0.038 (1.5) 0.051 (2.0)
60.0-71.1 (140-160)............................. 0.013 (0.5) 0.013 (0.5) 0.025 (1.0) 0.038 (1.5)
37.8-54.4 (100-130)............................. 0.013 (0.5) 0.013 (0.5) 0.013 (0.5) 0.025 (1.0)
----------------------------------------------------------------------------------------------------------------
\1\ Nominal iron pipe size and insulation thickness.
\2\ See footnote 3 from table 503.5.1a.
Sec. 435.505 Electrical power and lighting.
505.1 Electrical energy consumption. Each separate dwelling unit
of multifamily residential buildings shall be individually metered.
505.1.1 Exception. Transient facilities such as dormitories and
bachelors' quarters are exempt from the requirements of section 505.1.
505.2 Lighting power budget. The lighting system of the non-
dwelling portion of multi-family residences, such as common stairwells
and corridors, shall meet the applicable lighting provisions of RS-20.
Subpart F--[Reserved]
Subpart G--Radon Control
Sec. 435.701 General.
This subpart provides minimum requirements for the control of radon
from the ground and from construction materials associated with
buildings. This subpart does not provide requirements for the control
of radon from ground water or drinking water.
Sec. 435.702 Scope.
702.1 Building types. These radon control provisions apply to new
Federal residential buildings, additions to the foundations of such
buildings, and renovations to such buildings where the foundation wall
will be exposed.
702.1.2 Exception. Three story multifamily residential buildings
that have dwelling units only on the third floor are exempt from the
requirements of this subpart.
702.2 Building locations. This subpart applies to any new
construction located completely or partially in Zone 1 on the U.S. Map
of Radon Zones as specified in Appendix table 702.2. This subpart shall
also apply when locally available data, or a radon potential map
derived from non-local data, indicate a particular site may have a
radon potential commensurate with that in Zone 1, although not listed
in Appendix table 702.2 as being in Zone 1.
702.2.1 Exception. Where measured data collected at or near to the
proposed construction site, or a radon potential map derived from non-
local data, indicate the construction site does not have a radon
potential commensurate with that in Zone 1, the provisions of this
subpart shall not apply.
Sec. 435.703 Compliance.
703.1 General. Buildings located in areas classified as Zone 1 as
defined in section 702.2 shall comply with the design and construction
requirements provided in section 707.
703.2 Long-term testing. Starting within 30 days after occupancy,
the building shall be tested for an integration period no less than six
months in accordance with RS-26. If the radon level is at or above 4
pCi/L, the radon ventilation system shall be activated in accordance
with RS-27 within one month of the completion of testing.
703.3 Short-term testing. Short-term testing shall be performed
and concluded within 30 days of occupancy for an integration period no
less than 7 days in accordance with RS-26. If the radon level is at or
above 20 pCi/L, a second short-term test shall be performed for a
minimum of 7 days beginning at the conclusion of the first short-term
test. If the average of the two
[[Page 24193]]
tests exceeds 20 pCi/L, the radon ventilation system shall be
activated.
703.4 Follow-up testing.
703.4.1 Radon testing; short-term. If the ventilation system has
been activated in response to long-term or short-term testing,
additional radon testing shall be completed within 10 days of system
activation for a minimum integration period of two days. If the test
results exceed 4 pCi/L, additional radon mitigation measures shall be
performed. After mitigation, any further testing shall be performed.
703.4.2 Radon testing; long-term. If the results of short-term
testing performed under section 703.4.1 are 4 pCi/L or less, the long-
term testing required under section 703.2 shall be re-initiated upon
conclusion of the short-term test for an integration period no less
than 6 months. If the test results exceed 4 pCi/l, additional radon
mitigation shall be performed. After mitigation, any further testing
shall be performed.
703.4.3 Backdrafting testing. If the ventilation system has been
activated in response to long-term or short-term testing, additional
backdrafting testing shall be performed, in accordance with the
provisions of section 503.5.9.1, within 30 days of system activation.
703.5 Reporting of test results. All radon test results shall be
reported to the Deputy Assistant Secretary for Building Technologies
(EE-40) at the U.S. Department of Energy, Washington, DC 20585.
703.6 Ventilation fan alarm. If the radon ventilation fan has been
activated in response to testing under this section, a visual
indication of fan operation, or an alarm indicating fan failure, shall
be installed within the living space of the dwelling unit.
Sec. 435.704 Alternative systems.
The requirements of this subpart are not intended to preempt,
preclude, or restrict the application or use of alternative materials,
systems, or construction practices. Alternative materials, systems, or
methods of construction shall be acceptable when they can be shown to
yield radon control equivalent to that required herein. To be
considered equivalent, a radon level below 4 pCi/L shall be
demonstrated through long-term testing conducted on a similar building
(design with similar environmental conditions and operational
schedules) located in the same radon potential zone, using the proposed
alternative approaches. Any alternative system is still subject to the
testing and reporting requirements of section 703.
Sec. 435.705 Conflict with other standards, codes, or regulations.
The provisions of this subpart are not intended to conflict with
other health and safety provisions of any other applicable standards,
codes, or regulations. When a conflict occurs, the requirement with the
greater positive impact on the health and safety of the building
occupants shall prevail.
Sec. 435.706 Qualification of testers and installers.
Active radon control systems shall be designed and installed by
individuals who are state-certified as radon mitigation contractors or
by an individual listed in the EPA Radon Contractor Proficiency
Program. All radon testing shall be performed or supervised by
individuals who are state-certified as radon measurement contractors or
are listed in the EPA Radon Contractor Proficiency Program.
Sec. 435.707 Design and construction requirements.
707.1 Slab-on-grade foundations and slab-below-grade floor
assemblies.
707.1.1 Subfloor preparation. A 0.089 m (4-in.) thick layer of
clean graded sand overlain by a continuous layer or strips of
geotextile drainage matting designed to allow the lateral flow of soil
gas, or clean aggregate passing through a 0.051-m (2-in.) sieve and
retained on a 6.4 mm (\1/4\-in.) sieve, shall be placed under all
concrete slabs and other floor systems (such as treated-wood floors on
ground) that directly contact the ground and are within the walls of
the living spaces of the building.
707.1.2 Sub-slab membrane.
707.1.2.1 Application. A 6-mil (or 3-mil cross-laminated)
polyethylene or equivalent flexible sheeting material shall be placed
on top of the subfloor prior to casting the slab or placing the floor
assembly. The sheeting shall cover the entire floor area with separate
sections of sheeting overlapped at least 0.305 m (12 in.). The sheeting
shall extend to within 13 mm (\1/2\ in.) of all pipes, wires, or other
penetrations of the material.
707.1.2.2 Sealing. All seams, lap joints, penetrations, punctures,
tears, and other disturbances of the continuity of the sub-slab
membrane shall be sealed with mastic or tape compatible with the
membrane material. Paper or cloth tape shall not be used. Where
additional pieces of membrane material are used for sealing, the piece
shall overlap the discontinuity a minimum of 12 inches on all sides and
shall be sealed with mastic or tape.
707.1.3 Concrete floor slabs. Concrete floor slabs shall be
designed, mixed, placed, reinforced, consolidated, finished, and cured
in accordance with RS-28.
707.1.3.1 Stakes. The use of grade or support stakes which
penetrate the subslab membrane shall be avoided. Permanent and/or
temporary concrete blocks or screed chairs may be used. Where stakes
are used to support plumbing pipes, electrical conduits, or other
objects which penetrate the slab, they shall be sealed to the slab in
accordance with section 707.1.4. These stakes shall be solid or have
the upper end sealed tightly by installation of an end cap designed to
provide a gas-tight seal. Support stakes shall be of non-porous
material resistant to decay, corrosion and rust.
707.1.4 Sealing of floor slabs.
707.1.4.1 Openings. Openings through concrete slabs, wood, or other
floor assemblies which provide a direct path to exposed soil (such as
spaces around bathtub, shower, or toilet drains) shall be filled or
closed with non-shrink mortar, grout, expanding foam, polyurethane
caulk, elastomeric sealant, or other similar material designed for such
application that adheres to the surrounding material and remains
flexible. Where large work spaces are formed into a slab, such as
beneath a bath tub drain, the exposed soil shall be fully covered with
a solvent-based plastic roof cement or other material, to a minimum
depth of 1 inch.
707.1.4.2 Penetrations. Gaps around pipe, wire, or other objects
that penetrate concrete slabs, wood, or other floor assemblies shall be
made airtight with an elastomeric joint sealant as defined in RS-29 and
applied in accordance with RS-30 and the sealant manufacturer's
installation instructions.
707.1.4.3 Joints. All control joints, isolation joints,
construction joints, and other joints in concrete slabs or between
slabs and foundation walls shall be sealed. A continuous formed gap
(for example, a ``tooled edge''), which allows for the application of a
sealant that will provide a continuous, airtight seal, shall be created
along all joints. When the slab has cured, the gap shall be cleared of
loose material and filled with an elastomeric joint sealant as
described in section 707.1.4.2.
707.1.4.4 Cracks. Cracks in the field of a slab with widths greater
than 1.59 mm (\1/16\ in.) shall be routed to a recess with minimum
dimensions of 6.35 mm (\1/4\ in.) by 6.35 mm (\1/4\ in.) and sealed
with an approved sealant.
707.1.5 Foundation walls.
707.1.5.1 Concrete and masonry. Below-grade concrete and masonry
foundation walls shall be water-proofed. Where basements are
constructed with
[[Page 24194]]
hollow block masonry, the exterior walls shall be covered with 6-mil
minimum polyethylene sheeting, extending from the finished grade to
cover the joint with the footing. Hollow block masonry walls shall be
constructed with one continuous course of solid masonry, masonry that
is grouted solid, or a solid concrete beam; the continuous course shall
be located at or above finished grade. Where a brick veneer or other
masonry ledge is installed, the course immediately below that ledge
shall be sealed in the same manner.
707.1.5.2 Wood. Pressure-treated wood foundations shall be
constructed, installed, and water-proofed in accordance with RS-31.
707.1.5.3 Joints and penetrations. Joints, cracks, or other
openings around all below-grade penetrations or wall ties shall be
sealed airtight with an elastomeric sealant on both the inside and
outside surfaces of the foundation wall.
707.2 Crawl spaces.
707.2.1 Openings. Openings around all penetrations of those
building assemblies that separate crawl spaces from habitable space
shall be sealed to prevent air leakage. Means of egress and ingress
between habitable spaces and crawl spaces, such as hatches or access
doors, shall be sealed or gasketed to prevent air leakage.
707.2.2 Ventilation. Crawl spaces shall be provided with at least
0.0929 m\2\ (1 ft\2\) net free area of ventilation openings for each
27.9 m\2\ (300 ft\2\) of crawl space area. Such vents shall be through
the exterior wall and be of noncloseable design.
707.2.3 Ground cover. The soil in crawl spaces shall be cleaned of
all vegetation and organic matter and covered with a continuous layer
of 6-mil thick polyethylene sheeting or an equivalent membrane
material. The sheeting shall be lapped at least 0.305 m (12 in.) at
joints. All seams, joints, penetrations, punctures, and tears in the
ground cover membrane shall be sealed in accordance with section
707.1.2.2. The membrane shall fully cover the floor and abut to the
foundation walls or footings.
707.3 Vent system.
707.3.1 Passive sub-membrane depressurization system for crawl
space construction. One continuous, uninterrupted vent pipe, sealed
permanently gas-tight at joints, at least 0.064 m (3 in.) in diameter,
and meeting the provisions of RS-32 or RS-33 shall be provided to vent
the soil in the crawl space. The vent pipe shall be connected to a
plumbing ``T'' fitting and inserted between the membrane and the soil
such that the ``T'' fitting rests on the ground and its openings are
completely below the membrane. A minimum of five feet of perforated
drain pipe of three inches minimum diameter shall join to and extend
from each opening of the ``T.'' The pipe perforations shall be parallel
to the plane of the ground and shall not be capped at the ends. The
``T'' and its perforated extensions shall be located at least 1.52 m (5
ft) and no more than 5.49 m (18 ft) (measured in a horizontal plane)
from the exterior perimeter of the crawlspace area. The vent pipe shall
terminate above the roof as required in section 707.3.4. The vent pipe
shall have a maximum of 3 elbow or tee fittings between the sub-
membrane fitting and the roof termination.
707.3.2 Passive sub-slab depressurization system for basement
floor and slab-on-grade foundation construction. A minimum of one
continuous, uninterrupted vent pipe, sealed permanently gas-tight at
joints, at least 0.64 m (3 in.) in diameter, and meeting the provisions
of RS-32 or RS-33 shall be provided to vent the soil below the floor
slab. The vent pipe shall have a plumbing ``T'' fitting of the same
diameter at one end that shall be placed into the subslab aggregate or
other permeable material before the slab is poured. The ``T'' fitting
openings shall be completely below the sub-slab membrane. Each subslab
termination of the vent pipe shall serve no more than 232 m\2\ (2500 ft
\2\) of slab floor area. The ``T'' fittings shall be located at least
five feet and no more than 5.49 m (18 ft) (measured in a horizontal
plane) from the exterior perimeter of the foundation. The pipe shall
terminate above the roof as required in section 707.3.4. The vent pipe
shall have a maximum of 3 elbow or tee fittings between the sub-slab
fitting and the roof termination.
707.3.2.1 Multiple suction points. Where a single residence has
multiple floor slabs, floor slabs in excess of 232 m\2\ (2500 ft \2\),
or floor slabs that are provided and separated by interior footings or
other barriers to the lateral flow of subslab soil gas, additional vent
pipes shall be installed to ensure that all subslab areas are
ventilated. Such pipes shall run independently and terminate as
required in section 707.3.4 or shall be manifolded in an accessible
location and connected to a single vent terminating above the roof as
required in section 707.3.4. Each vent pipe, even if manifolded, shall
have a maximum of 3 elbow or tee fittings between the sub-slab fitting
and the corresponding roof termination.
707.3.2.2 Exceptions. A sealed slab sump exposed to the sub-slab
aggregate, or internal drain tile loops that are stubbed up through the
slab, either of which is in turn connected to a vent pipe extending
vertically and terminating above the roof as required in section
707.3.4, are exempt from the requirements of section 707.3.2.
707.3.3 Combination construction. In combination basement/crawl
space or slab-on-grade/crawl space construction, the vent systems
required by sections 707.3.1 or 707.3.2 shall be separate systems or
manifolded in an accessible location and connected to a single vent
terminating above the roof as required in section 707.3.4.
707.3.4 Vent pipe termination. The vent pipe shall run through the
conditioned part of the house to the greatest extent possible and shall
not be located within an external wall. A portion of the vent pipe
shall be accessible in the attic or other area outside of the habitable
space. The vent pipe shall be labeled ``RADON REDUCTION SYSTEM'' in
0.051-m (2-in.) high black letters on a yellow band on each floor level
where the vent pipe(s) is exposed and visible. The vent pipe shall be
installed with a minimum slope of 3.18 mm (\1/8\-in.) per 0.305 m (ft)
to drain rainwater or condensate by gravity to the soil. The vent pipe
shall terminate in a vertical section that extends at least 0.305 m (12
in.) above the surface of the roof. The termination point shall be at
least 3.05 m (10 ft) away from any window or other opening into the
building's conditioned space that is less than 0.610 m (2 ft) below the
termination point. The termination point shall be at least 3.05 m (10
ft) from any adjoining or adjacent buildings.
707.3.5 Electrical service. An approved electrical junction box
rated for a 20 amp feed to an external device shall be installed within
20 feet of that portion of the vent pipe in the attic or other area
outside of the habitable space identified in section 707.3.4.
707.4 Plumbing system interconnections.
707.4.1 Drains. Floor drains shall be trapped and connected to the
building's sanitary drain system. Condensate drains serving cooling
coils shall terminate outside the building to daylight or to a floor
drain, plumbing fixture, sump, or other approved location.
707.4.2 Sumps. Sumps open to soil or serving as the termination
point for subslab or exterior drain tile loops shall be tightly
covered. When serving as a floor drain, the sump lid shall be equipped
with a trapped inlet.
707.5 HVAC system interconnections.
[[Page 24195]]
707.5.1 Air-handling units. Air-handling units shall not be
located in crawl spaces or other areas exposed to soil gas.
707.5.1.1 Exception. When the air-handler is sealed so as to
preclude the circulation of air from the area exposed to soil gas.
707.5.2 Ducts. Air-handling ducts exposed to soil gas shall be
made permanently airtight by sealing in accordance with section
503.5.7. Ducts shall not be installed beneath slabs.
707.5.3 Plenums. Air circulation plenums shall not be located in
crawl spaces or in other construction assemblies directly exposed to
soil gas. Any plenum assembly shall be made permanently airtight by
sealing in accordance with section 503.5.7.
Subpart H--Standards
Sec. 435.801 Reference standards.
801.1 The standards, and portions thereof, which are referred to
in various sections, paragraphs, and subparagraphs of this part shall
be considered a part of this part.
------------------------------------------------------------------------
Code standard No. Title and source
------------------------------------------------------------------------
RS-1................... National Fenestration Rating Council 100-91,
Procedure for Determining Fenestration Product
Thermal Properties, National Fenestration
Rating Council, 1300 Spring St., Suite 120,
Silver Spring, MD 20910.
RS-2................... ANSI/ASHRAE 55-1992, Thermal Environmental
Conditions for Human Occupancy, American
Society of Heating, Refrigerating, and Air-
Conditioning Engineers Inc. 1791 Tullie
Circle, N.E., Atlanta, GA 30329-2305.
RS-3................... ANSI/ASHRAE Standard 62-1989, Ventilation for
Acceptable Indoor Air Quality, American
Society of Heating, Refrigerating, and Air-
Conditioning Engineers, Inc. 1791 Tullie
Circle, N.E., Atlanta, GA 30329-2305.
RS-4................... 1993 ASHRAE Handbook of Fundamentals, American
Society of Heating, Refrigerating, and Air-
Conditioning Engineers, Inc., 1791 Tullie
Circle, N.E., Atlanta, GA 3 0329-2305.
RS-5................... ASTM E 779-87, Standard Test Method for
Determining Air Leakage Rate by Fan
Pressurization, American Society for Testing
and Materials, 1916 Race Street, Philadelphia,
PA 19103.
RS-6................... 1992 ASHRAE HVAC Systems and Equipment
Handbook, American Society of Heating,
Refrigerating, and Air-Conditioning Engineers,
Inc., 1791 Tullie Circle, N.E., Atlanta, GA
30329-2305.
RS-7................... ASHRAE, Energy Calculations I: Procedures for
Determining Heating and Cooling Loads for
Computerizing Energy Calculations, Algorithms
for Building Heat Transfer Subsystems, 1975,
American Society of Heating, Refrigerating,
and Air-Conditioning Engineers, Inc., 1791
Tullie Circle, N.E., Atlanta, GA 30329-2305.
RS-8................... BuilderGuide Energy Analysis Software for
Homebuilders, Passive Solar Industries
Council, Passive Solar Industries Council,
1511 K. Street N.W., Suite 600, Washington, DC
20005.
RS-9................... ASTM C 177-85, Standard Test Method for Steady-
State Heat Flux Measurements and Thermal
Transmission Properties by Means of the
Guarded-Hot-Plate Apparatus, American Society
for Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103.
RS-10.................. ASTM C 518-91, Standard Test Method for Steady-
State Heat Flux Measurements and Thermal
Transmission Properties by Means of the Heat
Flow Meter Apparatus, American Society for
Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103.
RS-11.................. ASTM C 236-89, Standard Test Method for Steady-
State Thermal Performance of Building
Assemblies by Means of a Guarded-Hot-Box,
American Society for Testing and Materials,
1916 Race Street, Philadelphia, PA 19103.
RS-12.................. ASTM C 976-90, Standard Test Method for Thermal
Performance of Building Assemblies by Means of
a Calibrated Hot Box, American Society for
Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103.
RS-13.................. 1988 Builder's Foundation Handbook. U.S.
Department of Energy, Office of Scientific and
Technical Information, P.O. Box 62, Oak Ridge
TN 37831-9939.
RS-14.................. ASTM E 96-94, Standard Test Methods for Water
Vapor Transmission of Materials, American
Society for Testing and Materials, 1916 Race
Street, Philadelphia, PA 19103.
RS-15.................. ASTM E 283-91, Standard Test Method for
Determining the Rate of Air Leakage Through
Exterior Windows, Curtain Walls and Doors
Under Specified Pressure Differences Across
the Specimen, American Society for Testing and
Materials, 1916 Race Street, Philadelphia, PA
19103.
RS-16.................. ANSI/NWWDA I.S.2-87, Industry Standard for Wood
Window Units, National Wood Window and Door
Association, 1400 Touhy Ave., Des Plaines, IL
60018.
RS-17.................. ANSI/AAMA 101-93, Voluntary Specifications for
Aluminum and Poly (Vinyl Chloride) (PVC) Prime
Windows and Glass Doors, American
Architectural Manufacturers Association, Des
Plaines, IL 60018.
RS-18.................. ASTM D 4099-93, Standard Specification for PVC
Prime Windows/Sliding Glass Doors, American
Society for Testing and Materials 1916 Race
Street, Philadelphia, PA 19103.
RS-19.................. NWWDA I.S.3-88, Industry Standard for Wood
Sliding Patio Doors, National Wood Window and
Door Association, 1400 Touhy Ave., Des
Plaines, IL 60018.
RS-20.................. Energy Code for Commercial and High-Rise
Residential Buildings--Codification of ASHRAE/
IESNA 90.1-1989, Energy Efficient Design of
New Buildings Except Low-Rise Residential
Buildings, American Society of Heating,
Refrigerating, and Air-Conditioning Engineers,
Inc., 1791 Tullie Circle, N.E., Atlanta, GA
30329-2305.
RS-21.................. SMACNA, Installation Standards for Residential
Heating and Air Conditioning Systems, Sixth
Edition, 1988, Sheet Metal and Air
Conditioning Contractors Nat'l Assoc., 4201
Lafayette Center, Dr., Chantilly, VA 22021-
1209.
RS-22.................. SMACNA, HVAC Duct Construction Standards--Metal
and Flexible, First Edition, 1985, Sheet Metal
and Air Conditioning Contractors Nat'l Assoc.,
4201 Lafayette Center, Dr., Chantilly, VA
22021-1209.
RS-23.................. SMACNA Fibrous Glass Duct Construction
Standards, 6th Edition, Washington, D.C.,
1992, Sheet Metal and Air Conditioning
Contractors Nat'l Assoc. 4201 Lafayette
Center, Dr., Chantilly, VA 22021-1209.
RS-24.................. NAIMA Fibrous Glass Duct Construction
Standards, 1989 Edition, North American
Insulation Manufacturers Assoc., 44 Canal
Center Plaza, Suite 310, Alexandria, VA 22314.
RS-25.................. CGSB, The Spillage Test. CAN/CGSB-51.71-94,
Canadian General Standards Board, 222 Queen
Street, Suite 1402, Ottawa, Ontario, Canada
K1A 1G6.
RS-26.................. EPA 402-R-92-003, Protocol for Radon & Radon
Decay Product Measurements in Homes, United
States Environmental Protection Agency,
Washington, DC 20460.
RS-27.................. EPA 402-R-93-078, Radon Mitigation Standards,
United States Environmental Protection Agency,
Washington, DC 20460.
RS-28.................. ACI Standard 302.1R-89, Guide for Concrete
Floor and Slab Construction, American Concrete
Institute, P.O. Box 19150, Redford Station,
Detroit, MI 48219.
[[Page 24196]]
RS-29.................. ASTM C 920-94, Standard Specification for
Elastomeric Joint Sealant, American Society
for Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103.
RS-30.................. ASTM C 1193-91, Standard Guide for Use of Joint
Sealants, American Society for Testing and
Materials, 1916 Race Street, Philadelphia, PA
19103.
RS-31.................. Permanent Wood Foundation Design and
Construction Guide, Southern Pine Council,
Southern Pine Council, P.O. Box 641700,
Kenner, LA 70064.
RS-32.................. ASTM D 2665-94, Standard Specification for PVC
Plastic Drain, Waste, and Vent Pipe and
Fittings, American Society for Testing and
Materials, 1916 Race Street, Philadelphia, PA
19103.
RS-33.................. ASTM D 2661-94A, Standard Specification for ABS
Plastic Drain, waste, and Vent Pipe and
Fittings, American Society for Testing and
Materials, 1916 Race Street, Philadelphia, PA
19103.
RS-34.................. Analysis of Options for EPA's Model Standards
for Controlling Radon in New Homes, United
States Environmental Protection Agency,
Washington, DC 20460.
------------------------------------------------------------------------
Sec. 435.802 Abbreviations and acronyms used in reference standards.
AAMA American Architectural Manufacturers Association
ACI American Concrete Institute
ACCA Air Conditioning Contractors of America
ANSI American National Standards Institute, Inc.
ARI Air Conditioning and Refrigeration Institute
ASHRAE American Society of Heating, Refrigerating, and Air-
Conditioning Engineers, Inc.
ASTM American Society for Testing and Materials
CABO Council of American Building Officials
CGSB Canadian General Standards Board
OSTI U.S. Department of Energy
EPA United States Environmental Protection Agency
NWWDA National Wood Window and Door Association
NAIMA North American Insulation Manufacturers Assoc.
NFRC National Fenestration Ratings Council
PSIC Passive Solar Industries Council
SMACNA Sheet Metal and Air Conditioning Contractors Nat'l Assoc.
SPC Southern Pine Council
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[FR Doc. 97-10922 Filed 4-29-97; 8:45 am]
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