[Federal Register Volume 61, Number 69 (Tuesday, April 9, 1996)]
[Proposed Rules]
[Pages 15735-15738]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-8782]
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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
