24164 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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.

SUMMARY: The Department of Energy

today proposes a rule that would

establish minimum energy-efficiency

building standards for new Federal

residential buildings, including singlefamily 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 24165

1There are other building energy codes that are

state-specific or regional that are not considered.

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 costeffectiveness 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.

1. Model Energy Code, 1992

Currently, the MEC is the most widely

accepted and used residential energyefficiency 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 microcomputer 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 energyefficiency 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
24166 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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 singlefamily 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.
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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 energyefficiency 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 lifecycle 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 costeffectiveness 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 energyefficient 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 energyefficiency 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 Uvalue 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
24168 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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 Uvalue 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 costeffectiveness in today’s building

markets. Given the nominal cost per

unit for NFRC testing and rating and the

general cost-effectiveness of energyefficient windows, the Department has

determined that the assigning of Uvalues 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 airconditioning 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 24169

2U0 = 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).

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 lifecycle 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 (SingleFamily and Multi-family Low Rise)

Buildings

This proposed rule specifies input

values/assumptions for certain energyrelated 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, slabon-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

U0

2 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.

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
24170 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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 lifecycle 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 thermalperformance 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 costeffective 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 lifecycle 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 energyefficient 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 costeffective 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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-effectinduced 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 energyefficient 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
24172 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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 airtightness 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.
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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 postoccupancy 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 postoccupancy 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 radonresistant 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. Radonresistant 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.
24174 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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 singlefamily 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 costeffective 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-envelopecomponent 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, postoccupancy 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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
24176 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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.
24178 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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.

§ 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 § 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 § 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

§ 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 costeffective 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 energyusing 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 HighRise 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/m2 (1 W/ft2) 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.

§ 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. Roofceiling, 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.
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 24179

102.3 Fenestration product rating,

certification, and labeling. Fenestration

products (windows, doors, and

skylights) purchased by the Federal

government shall have assigned Uvalues. If tested for U-value, the Uvalues 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 Uvalue 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 Uvalue 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 Uvalue.

§ 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.

§ 435.104 [Reserved]

§ 435.105 [Reserved]

§ 435.106 [Reserved]

§ 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.

§ 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

§ 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 °C (65 °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 °C (65

°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 °C (65 °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 °C (65

°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
24180 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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 roofedover 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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 lifecycle 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 °C (85 °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 °C (50 °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
24182 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

the other for a unit temperature

difference between the two surfaces,

under steady conditions (W/m2·°C) [Btu/

(h·ft2·°F)].

Thermal resistance (R). The reciprocal

of thermal conductance (m2·°C/W)

[(h·ft2·°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·°C) [Btu/

(h·ft2·°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·°C) [Btu/(h·ft2·°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° 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

§ 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.

§ 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 ........... °C (°F).

Summer 1 .......................................................................................................................................... Design Dry-bulb ........... °C (°F).

Design Wet-bulb .......... °C (°F).

Degree days, heating 2

Degree days, cooling 2

1The 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. 2The degree days, heating [base 18.3°C (65°F)] and cooling [base 18.3°C (65°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°C (72°F) for heating and 25.6°C

(78°F) for cooling.

302.2.2 Exception. Other design

temperatures may be used for

equipment selection if it results in a

lower energy usage.

§ 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

§ 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.

§ 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.
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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 proposed house, 25% on North, South, East, and West

Exterior walls..

Window area oriented as proposed design.

Shading ............................... Draperies shall be assumed to be closed during period of mechanical

air conditioner operation..

Any exterior shading provided by proposed design.

TABLE 402.1.1b

[Heat storage (thermal mass)]

Internal mass 39.0 kg/m2 (8 lb/ft 2)

Structural

mass.

17.1 kg/m2 (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 Uvalue 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.

TABLE 402.1.1c—Continued

[Building thermal envelope—surface areas and

volume]

Design parameter Input assumptions

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 °C (68 °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 °C (120 °F)

Daily hot

water consumption.

Liters=113.7×nunits+(37.9×n-bedrooms);

[Gallons=(30×nunits)+(10×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/°C (45 Btu/°F) of

additional thermal mass, per m2 (ft2) of

added glass area, when added southfacing 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)
24184 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

Total Adjusted System

Efficiency=Equipment Efficiency ×

Distribution Loss Factor × percent

of ducts outside+Equipment

Efficiency × Distribution Loss

Factor × 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 fullyear 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 m2 (5,000

ft2) 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.

§ 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 24185

proposed for installation in the

building.

Subpart E—Design by Component

Performance Approach

§ 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.

§ 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·°K (6

Btu/ft2·°F), shall be less than or equal to

the U-value determined by the

applicable heating degree-days and lowmass-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 lowmass-walls; wall constructions having a

heat capacity of less than 123 kJ/m2·°K

(6 Btu/ft2·°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×c

where:

HC=heat capacity of the exterior wall,

based on exterior surface area, W/

(m2·°K) [Btu/(ft2·°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·°K) [Btu/(lb·°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≥

Depth ≥ in.6

R≥

Depth ≥ in.6

Unheating slab on grade 3 5 ....................................... Heating ...................................................................... R≥

Depth ≥ in.6

R≥

Depth ≥ in.6

Basement wall 4 5 ....................................................... Heating or cooling ..................................................... U≤ U≤

Crawl space wall 4 5 .................................................... Heating or cooling ..................................................... U≤ U≤

1Values 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. 2There are no insulation requirements for heated slabs in locations having less than 278 Celsius heating degree days (500 Fahrenheit HDD).

3There are no insulation requirements for unheated slabs in locations having less than 1,389 Celsius heating degree days (2,500 Fahrenheit

HDD). 4Basement 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. 5Typical 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 · °K) [6 BTU/

(FT2 ·°F)] WITH INSULATION PLACED ON THE EXTERIOR OF THE WALL MASS

Heating degree days

18.3 °C (65 °F) base

UW required for walls with a heat capacity less than 123 kJ/(m2 · °K)

[6 Btu/(ft2 · °F)] as determined by using equation 502.2a and appendix figure 1

1.13

(0.20)

1.02

(0.18)

0.90

(0.16)

0.79

(0.14)

0.68

(0.12)

0.56

(0.10)

0.45

(0.08)

0.34

(0.06)

0.22

(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)
24186 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

TABLE 502.1C.—REQUIRED Uw FOR WALL WITH A HEAT CAPACITY EQUAL TO OR EXCEEDING 123KJ/(M2·≥K) [6BTU/

(FT2· ≥F) WITH INSULATION PLACED ON THE INTERIOR OF THE WALL MASS

Heating degree days

18.3°C (65°F) base

Uw required for walls with a heat capacity less than 123 kJ/(m2 · °K) [6 Btu/(ft2 · °F)] as determined by using equation

502.2a and appendix figure 1

1.13

(0.20)

1.02

(0.18)

0.90

(0.16)

0.79

(0.14)

0.68

(0.12)

0.56

(0.10)

0.45

(0.08)

0.34

(0.06)

0.22

(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 · ≥K) [6BTU/

(FT2·°F) WITH INTEGRAL INSULATION (INSULATION AND MASS MIXED, SUCH AS A LOG WALL)

Heating degree days

18.3°C (65°F) base

Uw required for walls with a heat capacity less than 123 kJ/(m2 · °K) [6 Btu/(ft2 · °F)] as determined by using equation

502.2a and appendix figure 1

1.13

(0.20)

1.02

(0.18)

0.90

(0.16)

0.79

(0.14)

0.68

(0.12)

0.56

(0.10)

0.45

(0.08)

0.34

(0.06)

0.22

(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/

Pa·s·m2 (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 °C (67 °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 °C (73 °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.
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 24187

U

U A U A U A

A o

w w g g d d

o

= ( ) + ( ) + ( ) (Equation 502.2a)

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 × A term

for that item shall be expanded into subelements 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.

U

R R F w

s ins c

= + × ( )

1 (Equation 502.2b)

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.

U

U A U A

A O

R R S S

O

= ( ) × + × ( ) (Equation 502.2c)

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 × A

term for that item shall be expanded

into its sub-elements, as:

UR × AR = (UR1 × AR1) + (UR2 × 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.

U

U A U A U A

A O

f f f f fn fn

O

= ( ) 1 1 2 2 × + × ( ) +L ( ) (Equation 502.2d)

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
24188 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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° 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. Siteconstructed 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.

§ 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 airconditioning 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 Heat

Pump.

All Capacities.

Warm Air Furnaces,

Gas and Oil-Fired.

All Capacities.

Boilers, Gas-and OilFired.All Capacities.

1 Does not include ground-water source heat

pumps.

503.2.2 Central heating and airconditioning 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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 lifecycle 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 °C (200 HDD, base 65 °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 °C (55 °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 °C (85 °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 °C (10 °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 °C (55 °F) and 48.9

°C (120 °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

Piping system types Fluid temperature

range, °C (°F)

Pipe sizes 2

Run outs

0.051 m (2

in.)1

0.025 m (1

in.) and less

0.032 to

0.051 m

(1.25 to 2 in.)

0.064 to

0.102 m (2.5

to 4 in.)

0.127 to

0.152 m (5 to

6 in.)

0.203 m (8

in.) and

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
24190 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

TABLE 503.5.1A.—MINIMUM PIPE INSULATION [THICKNESS IN METERS (INCHES)] 3—Continued

Piping system types Fluid temperature

range, °C (°F)

Pipe sizes 2

Run outs

0.051 m (2

in.)1

0.025 m (1

in.) and less

0.032 to

0.051 m

(1.25 to 2 in.)

0.064 to

0.102 m (2.5

to 4 in.)

0.127 to

0.152 m (5 to

6 in.)

0.203 m (8

in.) and

larger

(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.

2For 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.°C)/W per meter [4.0 to 4.6 h.ft 2.°F/

Btu per inch] of thickness on a flat surface at a mean temperature of 23.9°C (75°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:

0 81 4 6 503 3 31 . ( . ) . . . Thickness

Actual Resistivity m Thickness (Equation 503.5.1.2a) × = Table New Minimu

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:

0.71 (4.0) Table 503.5.1a Thickness

Actual Resistivity m Thickness (Equation 503.5.1.2b) × = New Minimu

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:

R m K W h ft F Btu Equation 5 = ⋅ = ⋅ ⋅° ∆ ∆ t t

15 03.5.6a) 47 3

2 2

. / / (

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 °C (25 °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 °C (130 °F).

3 in 12 to 5 in 12 60.0 °C (140 °F).

less than 3 in 12 65.6 °C (150 °F).

Winter conditions all

slopes.

5.56 °C (10 °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 lowpressure 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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.

Air Transport Factor = Space Sensible Heat Load Removal Rate

) Power Input 03.5.10a)

in watts (Btu/h).

1

1

1

Supply turn Fan(s Equation 5

Expressed 

+ Re (

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.

§ 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 multifamily 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,
24192 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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 °C

(140 °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 °C (65 °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)]

Service water heating

temperatures °C (°F)

Pipe sizes 1

Noncirculating

runouts Circulating mains and runouts

Up to 0.025 m

(1 in.)

Up to 0.032 m

(1.25 in.)

0.038–0.051

m (1.5–2 in.)

Over 0.051 m

(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.

2See footnote 3 from table 503.5.1a.

§ 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

§ 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.

§ 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.

§ 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
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules 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 reinitiated upon conclusion of the shortterm 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.

§ 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.

§ 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.

§ 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 statecertified as radon measurement

contractors or are listed in the EPA

Radon Contractor Proficiency Program.

§ 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 treatedwood 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 nonporous 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
24194 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

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

m2 (1 ft2) net free area of ventilation

openings for each 27.9 m2 (300 ft2) 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 submembrane 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 m2 (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

m2 (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 subslab 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.
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707.5.1 Air-handling units. Airhandling units shall not be located in

crawl spaces or other areas exposed to

soil gas.

707.5.1.1 Exception. When the airhandler 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

§ 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.
24196 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules

Code standard

No. Title and source

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.

§ 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

BILLING CODE 6450–01–P
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Appendix to Part 435—Figures and Tables
24198 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
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24200 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
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24202 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
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24204 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
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24206 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
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24208 Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
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[FR Doc. 97–10922 Filed 4–29–97; 8:45 am]

BILLING CODE 6450–01–C