Home Energy Rating System Guidelines

[[Page 15736]]

DEPARTMENT OF ENERGY

10 CFR Part 437

Office of Energy Efficiency and Renewable

[Docket No. EE-RM-95-202]

RIN 1904-AA74

Home Energy Rating System Guidelines

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

Energy.

ACTION: Proposed rule; Notice of limited reopening of the comment

period.

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SUMMARY: On July 25, 1995, the Department of Energy (DOE) published a

notice of proposed rulemaking to establish voluntary guidelines for

home energy rating systems that provide residential building energy

efficiency ratings and were developed in consultation with the Home

Energy Rating Systems Council. The purpose of this document is to

reopen the comment period for 30 days in order to solicit

recommendations from the Board of Directors of the Home Energy Rating

Systems Council, and comments from all interested persons, with respect

to new policy options and technical data that DOE is considering in

preparation for final guidelines. These options respond to comments

concerning three components of the guidelines: air infiltration levels

for the reference and the rated home; heating, air conditioning and hot

water equipment for the reference home; and the phased-in compliance

levels.

DATES: Written comments ([10] copies) on the issues presented in this

document must be received on or before May 9, 1996.

ADDRESSES: Comments should be addressed to: U.S. Department of Energy,

Office of Energy Efficiency and Renewable Energy, EE-33, Docket No. EE-

RM-95-202, 1000 Independence Avenue, S.W., Washington, D.C. 20585, 202-

586-3012.

Public Reading Room: Supporting information used to develop this

notice and the written comments received are contained in the Public

Rulemaking File, Docket No. EE-RM-95-202. This Docket is available for

examination in DOE's Freedom of Information Reading Room. 1E-090,

Forrestal Building, 1000 Independence Avenue SW., Washington, D.C.

20585, 202-586-6020, between 9 a.m. and 4 p.m., Monday through Friday,

except Federal holidays. The supporting information used to develop

this notice is also available on the internet at URL#: http://

www.eren.doe.gov or from the Energy Efficiency and Renewable Energy

Clearinghouse at 1-800-DOE-EREC (1-800-363-3732).

FOR FURTHER INFORMATION CONTACT:

John Reese or Robert Mackie, Buildings Division, EE-432, U. S.

Department of Energy, Room 1J-018, 1000 Independence Avenue SW.,

Washington, D.C. 20585, (202) 586-7819.

Diana Dean, Office of General Counsel, GC-12, U.S. Department of

Energy, Room 6B-231, 1000 Independence Avenue SW., Washington, D.C.

20585, (202) 586-7440.

SUPPLEMENTARY INFORMATION:

I. Introduction

This notice to reopen the comment period is part of an ongoing,

Congressionally mandated rulemaking to establish voluntary home energy

rating system guidelines that are required by section 271 of the

National Energy Conservation Policy Act (Act), as amended by the Energy

Policy Act of 1992. 42 U.S.C. 8236. The background for this rulemaking

is discussed in detail in the Supplementary Information section of the

notice of proposed rulemaking. 60 FR 37949 (July 25, 1995).

Since the close of the 60-day comment period on the notice of

proposed rulemaking, DOE has been reviewing the comments. As directed

by the Act, DOE has consulted with the Home Energy Rating Systems

(HERS) Council and sought its views on issues that emerged from the

comments. With respect to comments claiming that the proposed reference

home infiltration rate is too high and that the proposed reference home

heating, air conditioning and hot water equipment produced unexpected

rating anomalies, the Technical Committee of the HERS Council made

recommendations that are discussed in detail later in this notice. The

HERS Council Board did not take a position on these recommendations and

sent these issues back to the Technical Committee for further review.

Consistent with its obligation to promulgate final guidelines, DOE

has independently reviewed the HERS Technical Committee's

recommendations, and today makes available for public comment DOE's

technical evaluations. These evaluations are entitled ``Climate

Sensitive Air Change Rate Study'' and ``Analysis of Heating, Air

Conditioning, and Water Heating Equipment Adjustment Factors.'' They

have been added to the public file in DOE's Freedom of Information

Reading Room and may be obtained from the information contact for this

rulemaking or through the internet as described above. DOE is now

considering whether to modify the proposed guidelines accordingly.

In addition, adverse comments on the advisability of DOE's proposed

distinction between ``basic compliance'' and ``full compliance'' for

the two years following promulgation of the guidelines have prompted

DOE to consider an alternative approach to phasing in compliance that

was not discussed in the notice of proposed rulemaking. Later in this

notice, DOE's tentative approach to resolving these issues is set forth

for public comment.

DOE requests that the HERS Council Board respond to this notice by

filing comments that include recommendations regarding the policy

options DOE is considering. DOE also would welcome the comments of

other interested members of the public.

II. Discussion of New Policy Options

A. Infiltration

DOE originally proposed guidelines assuming a level of 0.67 air

changes per hour (ACH) for the reference home to which the subject

rated home is compared. The 0.67 ACH was based on the Council of

American Building Official's Model Energy Code (MEC), 1994 amendments.

Although one comment endorsed the proposed level, most comments

were critical. There were two major concerns. One was that the proposed

0.67 ACH results in a reference home that is too energy inefficient

when compared to newly constructed houses that typically have

infiltration rates below 0.50 ACH. Another concern was that a single

national air change rate was not valid for all climate conditions.

Some of the critics suggested substituting a 0.50 ACH level

provided for in the 1995 MEC. Others favored reliance on the

infiltration and ventilation consensus standards of the American

Society of Heating, Refrigerating, and Air-Conditioning Engineers

(ASHRAE): ASHRAE Standard 119-1988 establishes minimum air leakage

levels and provides a method for establishing a normalized leakage

area, producing a consistent measure of building tightness; ASHRAE

Standard 136-1993 establishes a calculation method for effective air

change and provides weather factors that, when applied to a normalized

leakage area, produce an effective air change rate for various

locations across the country; and

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ASHRAE Standard 62-1989 sets minimum standards for ventilation.

The HERS Council Technical Committee supported use of the ASHRAE

standards. They suggested that the guidelines should provide a base

level value for the normalized leakage area of 0.57 to be adjusted for

weather using the ASHRAE factors. The 0.57 normalized leakage area base

level increases the reference home's energy efficiency (in comparison

to the level under the proposed guidelines), yielding a level

appropriate for most regions when adjusted for weather conditions. For

the vast majority of the sites, the reference home would be between

0.57 ACH and 0.40 ACH. Furthermore, with a 0.57 normalized leakage, the

Technical Committee believed that no weather adjusted air change rates

would fall below the 0.35 ACH minimum ventilation rate set by ASHRAE

Standard 62.

The suggestion to use the single point set by the Model Energy Code

overlooked an important shortcoming. This approach, is not sensitive to

the variation in air change rates due to climatic variations. DOE has

decided that, with two minor modifications, the Technical Committee's

recommendation to use ASHRAE standards has sufficient merit to be

considered for inclusion in the final guidelines. The first

modification is to incorporate in the guidelines the minimum 0.35 ACH

for the reference house. This is necessary because two of the 213 sites

nationwide examined by the Technical Committee are in fact slightly

below the 0.35 level. The second modification is a conforming change to

the treatment of the rated house. That change would involve adjustment

of the ACH using the weather factors in ASHRAE Standard 136-1993.

Addition of this approach to the proposed guidelines may provide a

nationally recognized method for setting air change rates sensitive to

different climate conditions and consistent with recommended minimum

ventilation rates.

DOE also solicits comment on establishing a minimum allowable air

change rate. DOE is now considering as a policy option for the final

guidelines setting 0.35 ACH as the minimum allowable air change rate on

which energy savings may be calculated for the rated home. The 0.35 ACH

coincides with the rate currently specified by ASHRAE Standard 62 for

minimum ventilation. Lowering the level of the air change rate any

further should not result in a higher HERS rating.

B. Heating, Air Conditioning, and Hot Water Equipment

The proposed guidelines provided for a computerized comparison of

the rated home to a reference home using the same energy source as the

rated home. Consistent with the recommendations of the HERS Council

Board, the proposed guidelines further provide for estimated energy

consumption at the home for the rated and reference homes.

After the comment period ended, the HERS Technical Committee

identified some anomalous rating results that the foregoing approach

produced when it was assumed that an identical energy efficiency

improvement (e.g., a new air conditioning system) was made to two rated

homes. These two rated homes differ only in the fuel used for heating,

air conditioning, and hot water. Improvements to fossil fuel homes

tended to rate higher than electric homes in climates with large

heating loads. The relationship reversed for climates with large

cooling loads.

The problem occurs because the end use loads of the reference and

rated homes are divided by the seasonal performance coefficients of the

heating, cooling, and hot water equipment to arrive at the consumption.

The impact of other efficiency changes is then based on energy

consumption. Consequently, the same improvements have different impacts

in homes of different fuels.

To achieve an equal treatment of efficiency improvements, the HERS

Technical Committee recommended that an adjustment factor be used. This

factor would adjust the consumption of the reference and rated homes

for the purposes of the rating point score. It normalizes load so that

efficiency improvements can be measured equally regardless of fuel

type. This is achieved by setting one profile of equipment as the basis

from which equipment utilizing other fuels is specified. The base fuel

could be any fuel. The Technical Committee selected a profile of

electric equipment as the basis because it is widely available for

heating, cooling, and hot water purposes. Fossil fuel cooling systems,

for example, are much less common.

The HERS Council had originally developed a table of efficiencies

for heating, cooling, and hot water equipment and included them in

their guidelines. This information was incorporated in section 437.103,

Tables 2 and 4, of the proposed guidelines and served as the basis for

efficiency of equipment in the reference home. Rather than using those

tables as the basis for developing the adjustment factor, the Technical

Committee reduced the tables by combining classes and sizes of

equipment. Because Table 2 did not include a minimum efficiency level

for biomass heating or gas cooling, the Technical Committee used

professional judgement to set levels for these technologies.

DOE has reviewed the HERS Council Technical Committee's

recommendations and believes they may have merit. However, reducing,

the information in Tables 2 and 4 to the extent recommended

oversimplifies the range of equipment options. Therefore, additional

equipment options from Tables 2 and 4 are presented below with the

adjustment factors and the accompanying equation. Table 2A presents

factors for gas cooling and biomass heating. DOE is particularly

interested in comments on these two values for which no standards

exist.

Table 2

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Adjustment

Type Units Rating factor \1\

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Heating equipment:

Gas or Oil Warm Air Furnace.................. AFUE 0.78 0.39

Gas Boiler (water)........................... AFUE .80 .40

Gas Boiler (steam)........................... AFUE .75 .37

Oil Boiler (water or steam).................. AFUE .80 .40

Electric Air Source Heat Pump................ HSPF 6.80 1.00

Cooling equipment:

Electric Central Air Conditioner............. SEER 10.00 1.00

Heat Pump.................................... SEER 10.00 1.00

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1. The adjustment factor is created by dividing the seasonal

performance coefficient of the alternative fuel device (eg. natural

gas, fuel oil, biomass, etc.) by the seasonal performance coefficient

of the equivalent electric device. The seasonal performance

coefficients for electric heating and cooling devices have units of

Btu/W. To convert HSPF and SEER to seasonal performance coefficients

they must be divided by 3.413 Btu/W, yielding seasonal performance

coefficients of 1.99 and 2.93 for the standard HSPF of 6.80 and SEER of

10.0, respectively. For water heaters, EF is used for all fuel types.

EF and AFUE are already unitless seasonal performance coefficients, so

they do not require any modification.

Gas Cooling...................................... N/A \2\ 0.75 0.26

Biomass Heating.................................. N/A .70 .35

2. No standard efficiencies exist for these technologies. The HERS

Technical Committee recommended these levels for consideration.

Table 4

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Water heating Rated storage capacity (gallons) and adjustment factor

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30 gallon 40 gallon 50 gallon 60 gallon

Type -------------------------------------------------------------------------------------------------------

EF AF EF AF EF AF EF AF

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Gas............................................. 0.56 0.61 0.54 0.60 0.53 0.60 0.51 0.59

Oil............................................. .53 .58 .53 .59 .50 .57 .48 .55

Electric........................................ .91 1.00 .90 1.00 0.88 1.00 0.87 1.00

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EF = Energy Factor. AF = Adjustment Factor.

The adjustment factors in the Tables 2, 2A and 4 are used in the

equation:

ER=((EH x EUH + EC x EUC + EW x

EUW) + EM)

Where:

ER=Adjusted energy consumption for point calculation.

EH = Rated home estimated energy purchased for heating.

EC = Rated home estimated energy purchased for cooling.

EW = Rated home estimated energy purchased for water heating.

EUH,C,W = Equipment utilization factors from Tables 2, 2A & 4

The point score is then determined using the following equation:

Point score = 100-((ER/EC)/.05)

Where--

ER=Estimated purchased energy consumption for heating, cooling, and

water heating of rated home (Btu).

EC=Estimated purchased energy consumption for heating, cooling, and

water heating of reference home (Btu).

DOE has performed an analysis of the HERS Technical Committee

recommendations. A copy of that analysis has been placed in the public

rulemaking file and is available upon request or through the internet.

The analysis shows that the reduction in consumption by the same

efficiency improvements, in homes of different fuels, can vary by 3% to

4%. This difference can benefit electric homes or fossil fuel homes.

The adjustment factor is shown to eliminate this variation.

On the basis of this analysis, DOE is considering adopting the HERS

Technical Committee recommendations with the modifications described

above. Interested members of the public, including the HERS Council

Board, are invited to comment on the analysis as well as the general

suitability of the recommendations.

C. Phased-in Compliance Period

The proposed guidelines allow for phased-in compliance over a two

year period. HERS providers would have one year to come into ``basic

compliance'' by meeting a specific set of guideline provisions, and two

years to come into ``full accreditation'' by meeting all the guideline

provisions.

This provision generated a wide range of comments. Some advised the

total elimination of the section. One argued for an additional one year

grace period for meeting the ``basic compliance'' level. The two level

approach was criticized by those who felt that allowing an intermediate

level would undermine the value of ``full accreditation.''

DOE thinks that accreditation is a legitimate subject to address in

the guidelines and that failure to include suitable non-binding

guidance would irresponsibly leave a crucial implementation subject

uncovered. The comments revealed that nearly all HERS providers would

have to make adjustments and lending institutions have indicated that

they are willing to deal with applicants on an individual basis during

an interim period before full compliance is required. Therefore, DOE is

considering modifying the proposed guidelines by eliminating the

``basic compliance'' level and allowing two years for development of

accrediting procedures and for HERS providers to meet all components

and become accredited under the guidelines. DOE invites, particularly

financial institutions, to comment on this possible policy.

Issued in Washington, D.C. on April 3, 1996.

Christine A. Ervin,

Assistant Secretary, Energy Efficiency and Renewable Energy.

[FR Doc. 96-8782 Filed 4-8-96; 8:45 am]

BILLING CODE 6450-01-P