RESNET Publication No. 001-16

Procedures for Certifying
Residential Energy Efficiency
Tax Credits
RESNET Publication No. 001-16
May 16, 2016

Published by:

Residential Energy Services Network, Inc.
P.O. Box 4561
Oceanside, CA 92052-4561
http://resnet.us/

©Residential Energy Services Network, 2013. All rights reserved.

Procedures for Certifying
Residential Energy Efficiency Tax Credits
RESNET Publication No. 001-16
May 16, 2016
1.

Purpose

This publication provides procedures for certifying residential energy efficiency tax
incentives, including the certification of verification professionals and the verification
and accreditation of software tools used for calculating home energy savings for the
certification of highly efficient new homes for federal tax credits and for the certification
of energy savings resulting from improvements to existing homes through home energy
retrofits.
2.

Scope

This procedure applies to the certification of residential energy savings for tax incentive
qualification for all new and existing single family dwellings and all new and existing
multifamily dwellings that are three stories or less above grade level. This procedure
employs a set of standard operating conditions representative of typical residences. As
such, it may not accurately reflect the energy use of residences that depart from these
standard operating conditions. This procedure does not apply to multifamily dwellings
that are greater than three stories above grade.
3.

Procedures for Certification of Eligibility for Tax Credits

3.1 Standard for Inspection of Homes
To be eligible for the federal tax credits for homes every home shall be independently
field tested to verify the energy performance of the home. To comply with the law, field
verification of a qualifying home’s energy performance shall be conducted in accordance
with the Mortgage Industry National Home Energy Rating System Standards. These
standards are posted online at http://www.resnet.us/standards/mortgage.
3.2

Procedures for Certifying Individuals

Individuals authorized to certify a home’s qualification for tax credits must be trained and
certified in accordance with the procedures contained in the Mortgage Industry National
Home Energy Rating System Standards.

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4.

Procedures for Verification of Software Programs

4.1 New Homes
Since the credits for new homes are based on performance as compared with Section 404
of the 2006 IECC, computer software modeling is required. In order to ensure the
accuracy of computer tools, software programs seeking accreditation as tax credit
qualification tools shall comply with Sections 4.1.1 and 4.1.2.
4.1.1 Reference Home Rule Set. The technical specifications defined in Appendix A
of this document shall serve as the rule set for configuration of the Reference and
Qualifying Homes for determination of tax credit qualification.
4.1.2 Suite of Software Verification Tests. RESNET has defined a series of software
test suites that shall be used to verify the accuracy of software programs for tax credit
computation. To become accredited as a New Home Tax Credit qualification tool,
software shall be subjected to verification testing in accordance with Sections 4.1.2.1
through 4.1.2.4.
4.1.2.1 ANSI/ASHRAE Standard 140-2011, Class II, Tier 1 Tests. ASHRAE
Standard 140, Class II Tests were developed from the HERS BESTEST1 for testing
the accuracy of simulation software for predicting building loads. The
ANSI/ASHRAE Standard 140-2011, Class II, Tier 1 test procedure has been adopted
by RESNET and is a requirement for all software programs to be accredited.
Acceptance criteria for this suite of tests shall be as specified in Appendix B.
4.1.2.2 Auto-generation of the Reference Home – This test verifies the ability of the
software tool to automatically generate the tax credit Reference Home. See Appendix
C for the test cases and acceptance criteria for the auto-generation test suite.
4.1.2.3 RESNET HVAC Tests – RESNET has developed a series of tests that test
the consistency with which software tools treat HVAC equipment, including furnaces,
air conditioners, and air source heat pumps. See Appendix D for the test cases and
the established acceptance criteria for this test suite.
4.1.2.4 Duct Distribution System Efficiency Tests – This test measures the accuracy
with which software tools calculate air distribution system losses. ASHRAE
Standard 152 results are used as the basis for the test suite acceptance criteria. See
Appendix E for the test cases and acceptance criteria for this test suite.

1

R. Judkoff and J. Neymark, 1995, “Home Energy Rating System Building Energy Simulation Test (HERS
BESTEST), Volume 1, Report No. NREL/TP-472-7332a, National Renewable Energy Laboratory, Golden,
Colorado. (online at: http://www.nrel.gov/docs/legosti/fy96/7332a.pdf)

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4.2 Existing Homes
Energy improvements to existing homes shall be based on the projected change in wholehome energy use attributable to the installed energy improvements considering all
standard energy end uses in the existing home.
4.2.1 Software Accreditation. Since the original configuration of the home serves as
the baseline for this energy use comparison, there is no requirement for the Reference
Home auto-generation test suite as is required for new homes. However, because the
comparison is based on all of the energy end uses of the home, there are additional
software verification and accreditation requirements. To become accredited as an
Existing Home Tax Credit qualification tool, software shall be subjected to verification
testing in accordance with Sections 4.2.1.1 through 4.2.1.4.
4.2.1.1 ANSI/ASHRAE Standard 140-2011, Class II, Tier 1 Tests. ASHRAE
Standard 140, Class II Tests were developed from the HERS BESTEST for testing
the accuracy of simulation software for predicting building loads. The
ANSI/ASHRAE Standard 140, Class II, Tier 1 test procedure has been adopted by
RESNET and is a requirement for all software programs to be accredited. Acceptance
criteria for this suite of tests shall be as specified in Appendix B.
In addition to the Tier One HERS BESTEST, one additional test case shall be
required for verification and accreditation of software for existing homes. This test
case is a combination of HERS BESTEST cases L120A and L130A and has been
named case L125A. See Appendix G for the specifications for this test case and for
the established acceptance criteria for this test case.
4.2.1.2 RESNET HVAC Tests – RESNET has developed a series of tests that test
the consistency with which software tools treat HVAC equipment, including furnaces,
air conditioners, and air source heat pumps. See Appendix C for the test cases and
the established acceptance criteria for this test suite.
4.2.1.3 Duct Distribution System Efficiency Tests – This test measures the accuracy
with which software tools calculate air distribution system losses. ASHRAE
Standard 152 results are used as the basis for the test suite acceptance criteria. See
Appendix D for the test cases and acceptance criteria for this test suite.
4.2.1.4 Service Hot Water System Tests – This test measures the accuracy with
which software tools calculate the hot water use in dwellings as a function of the
entering water temperature, the daily hot water use and the labeled efficiency of the
service hot water system. See Appendix E for the test cases and the established
acceptance criteria for this test suite.
4.2.2 Energy Savings Determination. Energy savings for existing home retrofits shall
be determined by comparing a Baseline Home with an Improved Home in accordance
with Sections 4.2.2.1 through 4.2.2.4.

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4.2.2.1 Baseline Home. The Baseline Home model for the purposes of determining
the energy savings of an existing home retrofit shall be the original configuration of
the existing home, including the full complement of lighting, appliances and residual
miscellaneous energy use as specified by Tables 303.4.1.7.1(1) and 303.4.1.7.1(2) of
the Mortgage Industry National Home Energy Rating Systems Standards, effective
November 15, 2011. The energy use of these end uses in the Baseline Home shall be
based on the original home configuration following the provision of Section
303.4.1.7.2 of the Mortgage Industry National Home Energy Rating Systems
Standards, effective November 15, 2011.
4.2.2.1.1 Where multiple appliances of the same type exist in the original
configuration of the existing home, the same number of those appliance types
shall be included in the Baseline Home model.
4.2.2.1.2 Where a standard appliance as defined by Tables 303.4.1.7.1(1) and
303.4.1.7.1(2) of the Mortgage Industry National Home Energy Rating Systems
Standards, effective November 15, 2011, does not exist in the original
configuration of the existing home, the standard default energy use and internal
gains as specified by Table 303.4.1(3) of the Mortgage Industry National Home
Energy Rating Systems Standards, effective November 15, 2011, for that
appliance shall be included in the Baseline Home model.
4.2.2.2 Improved Home. The improved home model for the purpose of determining
the energy savings of an existing home retrofit shall be the existing home’s
configuration including all energy improvements to the original home and including
the full complement of lighting, appliances and residual miscellaneous energy use
contained in the home after all energy improvements have been implemented.
4.2.2.2.1 Where an appliance has been upgraded but the existing appliance is not
removed from the existing home property, both the new and existing appliance
shall be included in the Improved Home model.2
4.2.2.2.2 Where a standard appliance as defined by Tables 303.4.1.7.1(1) and
303.4.1.7.1(2) of the Mortgage Industry National Home Energy Rating Systems
Standards, effective November 15, 2011, does not exist in the improved
configuration of the existing home, the standard default energy use and internal
gains as specified by Table 303.4.1(3) of the Mortgage Industry National Home
Energy Rating Systems Standards, effective November 15, 2011, for that
appliance shall be included in the Improved Home model.
4.2.2.2.3 Improvements in lighting and appliance energy use in the Improved
Home model shall be calculated in accordance with Section 303.4.1.7.2 of the
Mortgage Industry National Home Energy Rating Systems Standards, effective
November 15, 2011.
2

For example, if a refrigerator is upgraded to a more efficient model and the original refrigerator is kept on
property for potential use as a second refrigerator; both refrigerators shall be included in the Improved
Home energy model.

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4.2.2.3 Standard Operating Conditions.
4.2.2.3.1 Both the Baseline Home and Improved Home shall be configured and
modeled in accordance with the Qualifying Home specifications of Appendix A
except that the Baseline Home shall not violate the input constraints specified in
Table 4.2.2.3(1) below.
Table 4.2.2.3(1) Baseline Home Input Constraints
Equipment Constraints*
Min Value
Forced-air furnace, AFUE
72%
Hot water / steam boiler, AFUE
60%
Heat Pump, HSPF
6.5
Heat Pump, SEER
9.0
Central air conditioner, SEER
9.0
Room air conditioner, EER
8.0
Gas-fired storage water heater, EF
0.50
Oil-fired storage water heater, EF
0.45
Electric storage water heater, EF
0.86
Enclosure Constraints (including air film conductances)
Max U-factor
Wood-frame wall
0.222
Masonry wall
0.250
Wood-frame ceiling with attic (interior to attic space)
0.286
Unfinished roof
0.400
Wood-frame floor
0.222
Single-pane window, wood frame
0.714
Single-pane window, metal frame
0.833
* Exception: Where the labeled equipment efficiency exists for the specific piece
of existing equipment, the labeled efficiency shall be used in lieu of these
minimum input constraints.
4.2.2.3.2 Air Distribution Systems
4.2.2.3.2.1 In cases where the air distribution system leakage is not measured
in the original Baseline Home, the ducts shall be modeled in the spaces in
which they are located and the air distribution system leakage to outdoors at
25 Pascal pressure difference shall be modeled in both the Baseline Home and
the Improved Home as 0.10 times the conditioned floor area of the home split
equally between the supply and return side of the air distribution system with
the leakage distributed evenly across the duct system.
Exception: If the air handler unit and a minimum of 75% of its duct
system are entirely inside the conditioned space boundary, the air
distribution system leakage to outdoors at 25 Pascal pressure difference
shall be modeled in both the Baseline Home and the Improved Home as
0.05 times the conditioned floor area of the home split equally between the
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supply and return side of the air distribution system with the leakage
distributed evenly across the duct system.
4.2.2.3.2.2 In cases where the air distribution system leakage is measured in
the Baseline Home, the following shall apply:
4.2.2.3.2.2.1 For the Baseline Home, the ducts shall be modeled in the
spaces in which they are located and the air distribution system leakage to
outdoors at 25 Pascal pressure difference shall be modeled as the lesser of
the measured air distribution system leakage to outdoors at 25 Pascal
pressure difference in the original Baseline Home or 0.24 times the
conditioned floor area of the home, either split evenly between the supply
and return side of the air distribution system or as measured separately
with the leakage distributed evenly across the duct system.
4.2.2.3.2.2.2 For the Improved Home, the ducts shall be modeled in the
spaces in which they are located and the air distribution system leakage to
outdoors at 25 Pascal pressure difference shall be set equal to the
measured air distribution system leakage to outdoors at 25 Pascal pressure
difference in the Improved Home, either split evenly between the supply
or return side of the air distribution system or as measured separately with
the leakage distributed evenly across the duct system.
4.2.2.3.2 Both the Baseline Home and the Improved Home shall be subjected to
the operating conditions specified by Section 303.5.1.4.2 of the Mortgage
Industry National Home Energy Rating Systems Standards, effective November
15, 2011.
4.2.2.4 Total Energy Savings Calculation.
4.2.2.4.1 Energy units used in the calculation of energy savings shall be units of
Equivalent Electric Energy using the Reference Electricity Production Efficiency
for fossil fuels. Equivalent electric energy use shall be calculated using Equation
4.2.2.4-1, below.

kWheq = kWhelec +

Btufossil *0.40
3412

(Eqn. 4.2.2.4-1)

4.2.2.4.2 Energy savings shall be calculated as the difference between the wholehouse projected equivalent electric energy use of the Baseline Home and the
whole-house projected equivalent electric energy use of the Improved Home.
4.2.2.4.3 The energy savings percentage of the retrofit shall be calculated as the
whole-house equivalent electric energy savings as determined by clause 4.2.2.4.2
above divided by the whole-house equivalent electric energy use of the Baseline
Home.

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4.3 Process for Accrediting Software Programs
In states that have laws regulating home energy rating software tools and required
procedures for verification of software tools used for energy codes, the state may add
additional state requirements to these national requirements.
The RESNET accreditation process provides a suite of verification tests to certify that
rating software tools conform to the verification criteria for each test. The software
developer shall be required to submit the test results, test runs, and the software program
with which the tests were conducted to RESNET. This information may be released by
RESNET for review by any party, including the Treasury Department and competing
software developers. This process is expected to result in compliance without a costly
bureaucratic review and approval process.
4.4 Process for Software Developers to Apply to if Their Programs Cannot Meet
the Test Verification Requirements
RESNET has established an appeals process that software developers may use if their
software or tax credit qualification programs are so unique that they cannot be accurately
tested through the RESNET software testing procedures. The elements of this appeal
process are:




The provider’s documentation of how the software or qualification program
meets or exceeds the criteria established in the RESNET procedures for tax
credit qualification.
The software developer’s justification and documentation as to why the
software or qualification program is so unique that it cannot comply with the
RESNET testing protocols.
Independent evaluation of the software tool or qualification program by
RESNET in collaboration with independent individuals with appropriate
expertise. Based upon the results of the evaluation, RESNET may certify that
the software tool or qualification program meets or exceeds the performance
criteria of RESNET’s procedures for tax credit qualification programs.

4.5 References
ASHRAE, Standard 152-2004, “Method of Test for Determining the Design and
Seasonal Efficiencies of Residential Thermal Distributions Systems.” American
Society for Heating, Refrigerating and Air Conditioning Engineers, Atlanta, GA.
ASHRAE Standard 140-2011, “Standard Method of Test for the Evaluation of Building
Energy Analysis Computer Programs.” American Society of Heating,
Refrigerating, and Air Conditioning Engineers, Atlanta, GA, 2012.
ASTM Standard C-1549-2009, “Standard Test Method for Determining Solar
Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer,”
ASTM International, West Conshohocken, PA.

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ASTM Standard E-1918-2006, “Standard Test Method for Measuring Solar Reflectance
of Horizontal and Low-Sloped Surfaces in the Field.” ASTM International, West
Conshohocken, PA.
ASTM C1371 - 04a(2010)e1, “Standard Test Method for Determination of Emittance of
Materials Near Room Temperature Using Portable Emissometers.” ASTM
International, West Conshohocken, PA.
CRRC-1, 2008. “Method #1: Standard Practice for Measuring Solar Reflectance of a Flat,
Opaque, and Heterogeneous Surface Using a Portable Solar Reflectometer.” Cool
Roof Rating Council, Oakland, CA.
ICC, 2006, “2006 International Energy Conservation Code.” International Code Council,
500 New Jersey Avenue, NW, Washington, DC.
RESNET, January 2013, Mortgage Industry National Home Energy Rating System
Standards. Residential Energy Services Network, Oceanside, CA.

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Appendix A

Appendix A
Proposed Software Tool Certification and Rule Set Standard
For New Home Federal Tax Incentive Qualification
Introduction
This proposed software tool certification and rule set standard consists of three principal
sections: Section 1 provides recommended standards for the certification of software
tools used for tax credit qualification; Section 2 specifies the method by which energy
savings are determined; and Section 3 (the “rule set”) provides recommended standards
for the configuration, simulation, analysis and testing (where applicable), of the
Reference Home and the Qualifying Home.
1 Software Tools for Tax Incentive Qualification
1.1 Minimum software tool capabilities. Calculation procedures used to qualify
homes for tax incentives shall be computer-based software tools capable of
calculating the annual energy consumption of all building elements that differ
between the Reference Home and the Qualifying Home and shall include the
following minimum capabilities:
1. Computer generation of the Reference Home using only the input for the
Qualifying Home. The calculation procedure shall not allow the user to
directly modify the building component characteristics of the Reference
Home.
2. Calculation of whole-building, single-zone sizing for the heating and cooling
equipment in the Reference Home in accordance with ASHRAE Handbook
of Fundamentals or equivalent computational procedures.
3. Calculations that account for the indoor and outdoor temperature
dependencies and the part load performance of heating, ventilating and air
conditioning equipment based on climate and equipment sizing.
4. Listing of each of the Qualifying Home component characteristics
determined by the analysis to provide qualification along with their
respective performance rating (e.g. R-Value, U-Factor, SHGC, HSPF,
AFUE, SEER, EF, etc.).
1.2 Minimum reporting requirements. Tax incentive qualification software tools
shall generate reports that, at a minimum, document the following information:
a. Address of the Qualifying Home;
b. Documentation of all building component characteristics of the Qualifying
Home . Such documentation shall also give the estimated annual energy

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A-1

Appendix A
consumption for heating and cooling for both the Reference Home and the
Qualifying Home;
c. Name and signature of individual certified to complete the qualification
report;
d. Name and version of the certified tax credit qualification software tool used
to perform the qualification analysis.
1.3 Software tool certification. Tools approved by RESNET shall be based on
verification for certification in accordance with Sections 1.3.1 through 1.3.4.
1.3.1 ANSI/ASHRAE Standard 140, Class II, Tier 1 Tests. ASHRAE
Standard 140, Class II Tests were developed from the HERS BESTEST3
for testing the accuracy of simulation software for predicting building
loads. The ANSI/ASHRAE Standard 140, Class II, Tier 1 test procedure
has been adopted by RESNET and is a requirement for all software
programs to be accredited. Acceptance criteria for this test suite shall be as
specified in Appendix B.
1.3.2 Reference Home Auto-generation Tests. This test suite determines the
ability of software tools to automatically generate the tax credit Reference
Home. Verification criteria shall be as specified in Appendix C of this
publication.
1.3.3 RESNET HVAC Tests. This test suite determines the ability of software
tools to account for indoor and outdoor temperature dependencies and the
part load performance of heating, ventilating and air conditioning
equipment based on climate. Verification criteria shall be as specified in
Appendix D of this publication.
1.3.4 Distribution System Efficiency (DSE) Tests. This test suite determines
the ability of software tools to account for air distribution system losses.
Verification criteria shall be as specified in Appendix E of this
publication.

3

R. Judkoff and J. Neymark, 1995, “Home Energy Rating System Building Energy Simulation Test (HERS
BESTEST), Volume 1, Report No. NREL/TP-472-7332a, National Renewable Energy Laboratory, Golden,
Colorado. (online at: http://www.nrel.gov/docs/legosti/fy96/7332a.pdf)

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Appendix A
2

Computation of Energy Savings
2.1 The energy loads for heating and cooling in the Qualifying Home shall be
normalized to account for the differences in improvement potential that exist
across equipment types using the following formula:4
nMEUL = REUL * (nEC_x /EC_r)
where:
nMEUL = normalized Modified End Use Loads (for heating or cooling) as
computed using accredited simulation tools.
REUL = Reference Home End Use Loads (for heating or cooling) as computed
using accredited simulation tools.
EC_r = estimated Energy Consumption for Reference Home’s end uses (for
heating, including auxiliary electric consumption, or cooling) as
computed using accredited simulation tools.
and where:
nEC_x = (a* EEC_x – b)*(EC_x * EC_r * DSE_r) / ( EEC_x * REUL)
where:
nEC_x = normalized Energy Consumption for Qualifying Home’s end uses (for
heating, including auxiliary electric consumption, or cooling) as
computed using accredited simulation tools.
EC_r = estimated Energy Consumption for Reference Home’s end uses (for
heating, including auxiliary electric consumption, or cooling) as
computed using accredited simulation tools.
EC_x = estimated Energy Consumption for the Qualifying Home’s end uses
(for heating, including auxiliary electric consumption, or cooling) as
computed using accredited simulation tools.
EEC_x = Equipment Efficiency Coefficient for the Qualifying Home’s
equipment, such that
EEC_x equals the energy consumption per unit load in like units as the load,
and as derived from the Manufacturer’s Equipment Performance Rating
(MEPR) such that
EEC_x equals 1.0 / MEPR for AFUE or COP ratings, or such that
EEC_x equals 3.413 / MEPR for HSPF, EER or SEER ratings.
DSE_r = REUL/EC_r * EEC_r

4

Source: Fairey, P., J. Tait, D. Goldstein, D. Tracey, M. Holtz, and R. Judkoff, "The HERS Rating
Method and the Derivation of the Normalized Modified Loads Method." Research Report No. FSEC-RR54-00, Florida Solar Energy Center, Cocoa, FL, October 11, 2000. Available online at:
http://www.fsec.ucf.edu/bldg/pubs/hers_meth/

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Appendix A
For simplified system performance methods, DSE_r equals 0.80 for
heating and cooling systems. However, for detailed modeling of
heating and cooling systems, DSE_r may be less than 0.80 as a result of
part load performance degradation, coil air flow degradation, improper
system charge and auxiliary resistance heating for heat pumps. Except
as otherwise provided by these Standards, where detailed systems
modeling is employed, it must be applied equally to both the Reference
and the Qualifying Homes.
EEC_r = Equipment Efficiency Coefficient for the Reference Home’s
equipment, such that EEC_r equals the energy consumption per unit
load in like units as the load, and as derived from the Manufacturer’s
Equipment Performance Rating (MEPR) such that
EEC_r equals 1.0 / MEPR for AFUE or COP ratings, or such that
EEC_r equals 3.413 / MEPR for HSPF, EER or SEER ratings.
REUL = Reference Home End Use Loads (for heating or cooling) as computed
using accredited simulation tools.
and where the coefficients ‘a’ and ‘b’ are as defined by Table 2.1 below:
Table 2.1. Coefficients ‘a’ and ‘b’
Fuel type and End Use
a
Electric space heating
2.2561
Fossil fuel* space heating
1.0943
Biomass space heating
0.8850
Electric air conditioning
3.8090
Electric water heating
0.9200
Fossil fuel* water heating
1.1877
*Such as natural gas, LP, fuel oil

b
0
0.4030
0.4047
0
0
1.0130

2.2 Following normalization of the heating and cooling energy consumptions for the
Qualifying Home as specified in section 2.1 above, the Reference Home’s total
reference end use loads for heating and cooling (REULtot) shall be compared
with the Qualifying Home’s total normalized modified end use loads for heating
and cooling (nMEULtot) using the following formula to determine the % Energy
Reduction:
% Energy Reduction = [(REULtot – nMEULtot) / (REULtot)] * 100

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Appendix A
3

Rule Set for Configuration of the Reference Home and Qualifying Homes
3.1 General. Except as specified by this Section, the Reference Home and
Qualifying Home shall be configured and analyzed using identical methods and
techniques.
3.2 Residence Specifications. The Reference Home and Qualifying Home shall be
configured and analyzed as specified by Table 3.2(1).
Table 3.2(1) Specifications for the Reference and Qualifying Homes
Building Component
Above-grade walls:

Conditioned basement
walls:

Floors over
unconditioned spaces:

Crawlspaces:

Ceilings:

Reference Home
Type: wood frame
Gross area: same as Qualifying
Home
U-Factor: from Table 3.2(2)
Solar absorptance = 0.75
Emittance = 0.90
Type: same as Qualifying Home
Gross area: same as Qualifying
Home
U-Factor: from Table 3.2(2) with
the insulation layer on the
interior side of walls
Type: wood frame
Gross area: same as Qualifying
Home
U-Factor: from Table 3.2(2)
Type: vented with net free vent
aperture = 1ft2 per 150 ft2 of
crawlspace floor area.

U-factor: from Table 3.2(2) for
floors over unconditioned
spaces
Type: wood frame
Gross area: same as Qualifying
Home
U-Factor: from Table 3.2(2)

RESNET Publication No. 001-16 (2016)

Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home

Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as the Qualifying Home,
but not less net free
ventilation area than the
Reference Home unless an
approved ground cover in
accordance with IRC 408.1
is used, in which case, the
same net free ventilation
area as the Qualifying
Home down to a minimum
net free vent area of 1ft2
per 1,500 ft2 of crawlspace
floor area.
Same as Qualifying Home

Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home

A-5

Appendix A
Table 3.2(1) Specifications for the Reference and Qualifying Homes
Building Component
Roofs:

Reference Home
Type: composition shingle on
wood sheathing
Gross area: same as Qualifying
Home
Solar absorptance = 0.75

Emittance = 0.90

Attics:
Foundations:

Doors:

Glazing: (a)

Type: vented with aperture = 1ft2
per 300 ft2 ceiling area
Type: same as Qualifying Home
Gross Area: same as Qualifying
Home
U-Factor / R-value: from
Table 3.2(2)
Area: 40 ft2
Orientation: North
U-factor: same as fenestration
from Table 3.2(2)
Total area(b) =
(a) The Qualifying Home glazing
area; where the Qualifying
Home glazing area is less than
18% of the conditioned floor
area
(b) 18% of the conditioned floor
area; where the Qualifying
Home glazing area is 18% or
more of the conditioned floor
area
Orientation: equally distributed to
four (4) cardinal compass
orientations (N,E,S,&W)

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Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Values from Table 3.3 shall be
used to determine solar
absorptance except where
test data is provided for roof
surface in accordance with
ASTM Standards C-1549, E1918, or CRRC Method # 1.
Emittance values provided by
the roofing manufacturer in
accordance with ASTM
Standard C-1371 shall be
used when available. In
cases where the appropriate
data are not known, same as
Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home

Same as Qualifying Home

Same as Qualifying Home

A-6

Appendix A
Table 3.2(1) Specifications for the Reference and Qualifying Homes
Building Component

Skylights
Thermally isolated
sunrooms
Air exchange rate

Mechanical ventilation:

Reference Home
U-factor: from Table 3.2(2)
SHGC: from Table 3.2(2)
Interior shade coefficient:
Summer = 0.70
Winter = 0.85
External shading: none
None
None

Qualifying Home
Same as Qualifying Home
Same as Reference Home (c)

Specific Leakage Area (SLA) (d) =
0.00036 assuming no energy
recovery

For residences that are not
tested, the same as the
Reference Home
For residences without
mechanical ventilation
systems that are tested in
accordance with Section802
of the RESNET Standards
(2013),6 the measured air
exchange rate (e) but not less
than 0.35 ach.
For residences with
mechanical ventilation
systems that are tested in
accordance with Chapter
802 of the RESNET
Standards (2013),5 the
measured air exchange rate
(e)
combined with the
mechanical ventilation
rate,(f) which shall not be
less than 0.01 x CFA + 7.5
x (Nbr+1) cfm.
Same as Qualifying Home

None, except where a mechanical
ventilation system is specified
by the Qualifying Home, in
which case:
Annual vent fan energy use:
kWh/yr = 0.03942*CFA +
29.565*(Nbr+1) (per dwelling
unit)
where:

Same as Qualifying Home
Same as Qualifying Home
Same as Qualifying Home

Same as Qualifying Home

5

RESNET, January 2013, Mortgage Industry National Home Energy Rating System Standards. Residential
Energy Services Network, Oceanside, CA.

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Appendix A
Table 3.2(1) Specifications for the Reference and Qualifying Homes
Building Component

Internal gains:

Reference Home
CFA = conditioned floor area
Nbr = number of bedrooms
As specified by Table 3.2(4)

Internal mass:

An internal mass for furniture and
contents of 8 pounds per square
foot of floor area

Structural mass:

For masonry floor slabs, 80% of
floor area covered by R-2 carpet
and pad, and 20% of floor
directly exposed to room air
For masonry basement walls, same
as Qualifying Home, but with
insulation required by Table
3.2(2) located on the interior
side of the walls
For other walls, for ceilings,
floors, and interior walls, wood
frame construction
Fuel type: same as Qualifying
Home
Efficiencies:
Electric: air source heat pump
with efficiency in accordance
with Table 3.2(1)(a)
Non-electric furnaces: natural
gas furnace with efficiency in
accordance with Table
3.2(1)(a)
Non-electric boilers: natural gas
boiler with efficiency in
accordance with Table
3.2(1)(a)
Capacity: sized in accordance
with Section 303.5.1.4,
RESNET Standards (2013). 6
Fuel type: Electric

Heating systems (h),(i)

Cooling systems (h),(k)

RESNET Publication No. 001-16 (2016)

Qualifying Home

Same as Reference Home,
except as provided by
Section 303.4.1.7.2,
RESNET Standards
(2013).6
Same as Reference Home,
plus any additional mass
specifically designed as a
Thermal Storage Element (g)
but not integral to the
building envelope or
structure
Same as Qualifying Home

Same as Qualifying Home

Same as Qualifying Home
Same as Qualifying Home (i)

Same as Qualifying Home

Same as Qualifying Home

Same as Qualifying Home

Same as Qualifying Home
Same as Qualifying Home (k)

A-8

Appendix A
Table 3.2(1) Specifications for the Reference and Qualifying Homes
Building Component

Thermal distribution
systems:

Thermostat

Reference Home
Efficiency: in accordance with
Table 3.2(1)(a)
Capacity: sized in accordance
with Section 303.5.1.4,
RESNET Standards (2013). 6
A thermal distribution system
efficiency (DSE) of 0.80 shall
be applied to both the heating
and cooling system efficiencies.

Type: manual
Temperature setpoints: cooling
temperature set point = 78 F;
heating temperature set
point = 68 F

Qualifying Home
Same as Qualifying Home
Same as Qualifying Home

As specified by Table 3.2(3),
except when tested in
accordance with ASHRAE
Standard 152-2004(m), and
then either calculated
through hourly simulation
or calculated in accordance
with ASHRAE Standard
152-2004
Type: Same as Qualifying
Home
Temperature setpoints: same
as the Reference Home,
except as provided by
Section 303.5.1.1, RESNET
Standards (2013).6

Table 3.2(1) Notes:
(a) Glazing shall be defined as sunlight-transmitting fenestration, including the area of
sash, curbing or other framing elements, that enclose conditioned space. Glazing
includes the area of sunlight-transmitting fenestration assemblies in walls bounding
conditioned basements. For doors where the sunlight-transmitting opening is less
than 50% of the door area, the glazing area is the sunlight transmitting opening area
shall be used. For all other doors, the glazing area is the rough frame opening area
for the door, including the door and the frame.
(b) For homes with conditioned basements and for multi-family attached homes the
Reference Home glazing area shall be calculated using the following equation:
AF = As x FA x F
where:
AF = Total glazing area
As = The smaller of the Qualifying Home glazing area OR 18% of the
conditioned floor area
FA = (Above-grade thermal boundary gross wall area) / (above-grade gross
thermal boundary wall area + 0.5 x below-grade gross thermal boundary
wall area)
F = (Above-grade gross thermal boundary wall area) / (above-grade gross
thermal boundary wall area + common wall area) or 0.56, whichever is
greater
and where:

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Appendix A

(c)

(d)

(e)

(f)

(g)

(h)

Thermal boundary wall is any wall that separates conditioned space from
unconditioned space or ambient conditions, including the area of band joists
or other inter-floor structure.
Above-grade thermal boundary wall is any portion of a thermal boundary wall
not in contact with soil
Below-grade thermal boundary wall is any portion of a thermal boundary wall
in soil contact
Common wall is the total wall area of walls adjacent to another conditioned
living unit, not including foundation walls.
For fenestrations facing within 15 degrees of due south that are directly coupled to
thermal storage mass, the winter interior shade coefficient shall be permitted to
increase to 0.95 in the Qualifying Home.
Where Leakage Area (L) is defined in accordance with Section 5.1 of ASHRAE
Standard 119 and where SLA = L / CFA (where L and CFA are in the same units).
Either hourly calculations using the procedures given in the 2001 ASHRAE
Handbook of Fundamentals, Chapter 26, page 26.21, equation 40 (ShermanGrimsrud model) or calculations yielding equivalent results shall be used to
determine the energy loads resulting from air exchange.
Tested envelope leakage shall be determined and documented by a Certified Rater
using the on-site inspection protocol as specified in Appendix A under “Blower
Door Test.” Either hourly calculations using the procedures given in the 2001
ASHRAE Handbook of Fundamentals, Chapter 26, page 26.21, equation 40
(Sherman-Grimsrud model) or calculations yielding equivalent results shall be used
to determine the energy loads resulting from air exchange.
The combined air exchange rate for infiltration and mechanical ventilation shall be
determined in accordance with equation 43 of 2001 ASHRAE Handbook of
Fundamentals page 26.24 in combination with the” Whole-house Ventilation”
provisions of 2001 ASHRAE Handbook of Fundamentals, page 26.19 for
intermittent mechanical ventilation.
Thermal storage element shall mean a component not normally part of the floors,
walls, or ceilings that is part of a passive solar system, and that provides thermal
storage such as enclosed water columns, rock beds, or phase change containers. A
thermal storage element must be in the same room as fenestration that faces within
15 degrees of due south, or must be connected to such a room with pipes or ducts
that allow the element to be actively charged.
For a Qualifying Home with multiple heating, cooling, or water heating systems
using different fuel types, the applicable system capacities and fuel types shall be
weighted in accordance with the loads distribution (as calculated by accepted
engineering practice for that equipment and fuel type) of the subject multiple
systems. For the Reference Home, the efficiencies given in Table 3.2(1)(a) below
will be assumed when:
1) A type of device not covered by NAECA is found in the Qualifying Home;
2) The Qualifying Home is heated by electricity using a device other than an air
source heat pump; or
3) The Qualifying Home does not contain one or more of the required HVAC
equipment systems.

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Appendix A

Table 3.2(1)(a). Standard Reference Home
Heating and Cooling Equipment Efficiencies (i) (k) (m) (n)
Qualifying Home
Function
Reference Home Device
Fuel
Electric
Heating
7.7 HSPF air source heat
pump
Non-electric warm
Heating
78% AFUE gas furnace
air furnace or space
heater
Non-electric boiler
Heating
80% AFUE gas boiler
Any type
Cooling
13 SEER electric air
conditioner
(i) For a Qualifying Home without a proposed heating system, a heating system with
the efficiency specified in Table 3.2(1)(a) shall be assumed for both the Reference
Home and Qualifying Home. For electric heating systems, an air-source heat pump
with efficiency in accordance with Table 3.2(1)(a) shall be selected.
(k) For a Qualifying Home without a proposed cooling system, an electric air
conditioner with efficiency specified in Table 3.2(1)(a) shall be assumed for both
the Reference Home and the Qualifying Home.
(m) Tested duct leakage shall be determined and documented by a Certified Rater using
the on-site inspection protocol specified by the Mortgage Industry National Home
Energy Rating Standards, Appendix A under “Air leakage (ducts)”.

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Appendix A

(d, e)

(a)

Slab-on-Grade
R-Value & Depth

Basement Wall
(c)
U-Factor

Floor Over
Unconditioned
Space U-Factor

Frame Wall
U-Factor

Ceiling
U-Factor

Glazed Fenestration
Assembly SHGC

Component Heat Transfer Characteristics for Reference Home

Fenestration and
Opaque Door
U-Factor

Climate Zone

(b)

Table 3.2(2).

1
1.20
0.40
0.035
0.082
0.064
0.360
0
2
0.75
0.40
0.035
0.082
0.064
0.360
0
3
0.65
0.40
0.035
0.082
0.047
0.360
0
4 except
0.40
0.40
0.030
0.082
0.047
0.059 10, 2 ft.
Marine
5 and
0.35
0.40
0.030
0.060
0.033
0.059 10, 2 ft.
Marine 4
6
0.35
0.40
0.026
0.060
0.033
0.059 10, 4 ft.
7 and 8
0.35
0.40
0.026
0.057
0.033
0.059 10, 4 ft.
Table 3.2(2) Notes:
(a) Non-fenestration U-Factors shall be obtained from measurement, calculation, or an
approved source.
(b) Climates zones shall be as specified by the 2004 Supplement to the International
Energy Conservation Code.
(c) For basements where the conditioned space boundary comprises the basement
walls.
(d) R-5 shall be added to the required R-value for slabs with embedded heating.
(e) Insulation shall extend downward from the top of the slab vertically to the depth
indicated.
Table 3.2(3) Default Distribution System Efficiencies for Inspected Systems (a)
Forced Air
Hydronic
Distribution System Configuration and Condition:
Systems
Systems (b)
Distribution system components located in
unconditioned space
0.80
0.95
Distribution systems entirely located in conditioned
space (c)
0.88
1.00
Proposed “reduced leakage” with entire air distribution
0.96
system located in the conditioned space (d)
Proposed “reduced leakage” air distribution system
0.88
with components located in the unconditioned space
“Ductless” systems (e)
1.00
Table 3.2(3) Notes:
(a) Default values given by this table are for distribution systems as rated, which meet
minimum IECC 2000 requirements for duct system insulation.
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Appendix A
(b) Hydronic Systems shall mean those systems that distribute heating and cooling
energy directly to individual spaces using liquids pumped through closed loop
piping and that do not depend on ducted, forced air flows to maintain space
temperatures.
(c) Entire system in conditioned space shall mean that no component of the distribution
system, including the air handler unit or boiler, is located outside of the conditioned
space boundary.
(d) Proposed “reduced leakage” shall mean leakage not greater than 3 cfm to outdoors
per 100 square feet of conditioned floor area and not greater than 9 cfm total air
leakage per 100 square feet of conditioned floor area at a pressure differential of 25
Pascal across the entire system, including the manufacturer’s air handler enclosure.
Total air leakage of not greater than 3 cfm per 100 square feet of conditioned floor
area at a pressure difference of 25 Pascal across the entire system, including the
manufacturer’s air handler enclosure, shall be deemed to meet this requirement
without measurement of air leakage to outdoors. This rated condition shall be
specified as the required performance in the construction documents and requires
confirmation through field-testing of installed systems as documented by a
Certified Rater.
(e) Ductless systems may have forced airflow across a coil but shall not have any
ducted airflows external to the manufacturer’s air handler enclosure.
Table 3.2(4). Internal Gains for Reference Home (a)
End Use /
Sensible Gains (Btu/day)
Latent Gains (Btu/day)
Component
a
b
c
a
b
c
Residual MELs
7.27
0.38
Interior lighting
4,253
7.48
Refrigerator
5,955
168
TVs
3,861
645
Range/Oven (elec) (b)
2,228
262
248
29
(b)
Range/Oven (gas)
4,086
488
1,037
124
Clothes Dryer (elec) (b)
661
188
73
21
(b)
Clothes Dryer (gas)
738
209
91
26
Dish Washer
219
87
219
87
Clothes Washer
95
26
11
3
Gen water use
-1227
-409
1,245
415
Occupants (c)
3716
2,884
Notes for Table 3.2(4)
(a) Table values are coefficients for the following general equation:
Gains = a + b*CFA + c*Nbr
where CFA = Conditioned Floor Area and Nbr = Number of bedrooms.
(b) For Rated Homes with electric appliance use (elec) values and for Rated homes
with natural gas-fired appliance use (gas) values
(c) Software tools shall use either the occupant gains provided above or similar
temperature dependent values generated by the software where number of
occupants equals the number of bedrooms and occupants are present in the home
for 16.5 hours per day.

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Appendix A

Table 3.3 Default Solar Absorptance for Various Roofing Surfaces6
Roof Materials
Composition Shingles
Dark
Medium
Light
Tile/Slate
Dark
Medium
Terra cotta
Light
White
Metal
Dark
Medium
Galvanized, unfinished
Light
Galvalum, unfinished
White

Absorptance
0.92
0.85
0.75

0.90
0.75
0.65
0.60
0.30

0.90
0.75
0.70
0.60
0.35
0.30

Roof Materials

Absorptance

Wood Shingles
Dark
Medium

0.90
0.80

Concrete/Cement
Dark
Medium
Light
White

0.90
0.75
0.60
0.30

Membrane
Dark
Medium
Light
White

0.90
0.75
0.60
0.30

Built-Up (gravel surface)
Dark
Medium
Light

0.92
0.85
0.75

6

Source: Parker, D S, J E R McIlvaine, S F Barkaszi, D J Beal and M T Anello (2000). Laboratory
Testing of the Reflectance Properties of Roofing Material. FSEC-CR670-00. Florida Solar Energy Center,
Cocoa, FL. Available online at: http://www.fsec.ucf.edu/bldg/pubs/cr670/

RESNET Publication No. 001-16 (2016)

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Appendix B

Appendix B
Acceptance Criteria for Building Loads Tests

ANSI/ASHRAE Standard 140, Class II, Tier 1 Tests. The ANSI/ASHRAE Standard
140-2011, Class II, Tier 1 test procedure is a requirement for all software programs to be
accredited. The acceptance criteria for this test suite are developed in accordance with
Annex 22 of ANSI/ASHRAE Standard 140-2011and are as follows:
Annual Heating Loads:
Colorado Springs, CO
Heating
range max
L100AC
79.48
L110AC
103.99
L120AC
64.30
L130AC
53.98
L140AC
56.48
L150AC
71.33
L155AC
74.18
L160AC
81.00
L170AC
92.40
L200AC
185.87
L202AC
190.05
L302XC
90.52
L304XC
75.32
L322XC
118.20
L324XC
80.04

range min
48.75
71.88
37.82
41.82
43.24
40.95
43.53
48.78
61.03
106.41
111.32
52.66
43.91
68.35
44.01

Annual Heating Load deltas:
Colorado Springs, CO
Heating
range max
L110AC-L100AC
28.12
L120AC-L100AC
-7.67
L130AC-L100AC
-5.97
L140AC-L100AC
-4.56
L150AC-L100AC
-3.02
L155AC-L150AC
6.88
L160AC-L100AC
5.10
L170AC-L100AC
17.64
L200AC-L100AC
107.66
L202AC-L200AC
9.94
L302XC-L100AC
14.50
L302XC-L304XC
17.75
L322XC-L100AC
39.29
L322XC-L324XC
38.27

range min
19.37
-18.57
-27.50
-24.42
-12.53
-1.54
-3.72
7.12
56.39
-0.51
-3.30
5.66
15.71
20.21

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Appendix B

Annual Cooling Loads:
Las Vegas, NV
Cooling
range max range min
L100AL
64.88
50.66
L110AL
68.50
53.70
L120AL
60.14
47.34
L130AL
45.26
32.95
L140AL
30.54
19.52
L150AL
82.33
62.41
L155AL
63.06
50.08
L160AL
72.99
58.61
L170AL
53.31
41.83
L200AL
83.43
60.25
L202AL
75.96
52.32
Annual Cooling Load deltas:
Las Vegas, NV
Cooling
range max
L110AL-L100AL
7.84
L120AL-L100AL
0.68
L130AL-L100AL
-13.71
L140AL-L100AL
-27.14
L150AL-L100AL
20.55
L155AL-L150AL
-9.64
L160AL-L100AL
12.28
L170AL-L100AL
-4.83
L200AL-L100AL
21.39
L200AL-L202AL
14.86

range min
-0.98
-8.67
-24.40
-38.68
8.72
-22.29
3.88
-15.74
6.63
2.03

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Appendix C

Appendix C
Reference Home Auto-Generation Test Suite for Verification of
Software Tools Used for Tax Incentive Qualification
Introduction
This report contains recommendations regarding the reference home auto-generation test
suite for tax credit qualification. The Reference Home auto-generation test suite is one
of four minimum test suites that this Standard requires for software tools used for tax
incentive qualification. The test cases in this proposed test suite are designed to verify
that software tools automatically generate accurate Reference Homes given only the
building information for the Qualifying home.

Reporting
Software tools applying for verification shall provide evidence that their software meets
the requirements of this test suite. The software tool provider or software vendor is
responsible for producing the documentation needed to show that the software has been
verified through this test suite. In some cases, the data needed to verify accuracy is of no
interest or value to the end-user of the software, but in any case, the software tool must
generate it.

Minimum Requirements
At a minimum, software tools applying for accreditation must report the following values
for the Reference Home:
1. Areas and overall U-factors (or R-values in the case of slab-on-grade
construction) for all building components, including ceilings, walls, floors,
windows (by orientation) and doors.
2. Overall solar-heat gain coefficient (SHGCo)7 of the windows during heating.
3. Overall solar-heat gain coefficient (SHGCo) of the windows during cooling.
4. Wall solar absorptance and infrared emittance
5. Roof solar absorptance and infrared emittance
6. Total internal gains to the home (Btu/day)
8
7. Specific leakage area (SLA) for the building, by zone or as SLAo , as appropriate
7

The overall solar heat gain coefficient (SHGCo) of a fenestration is defined as the solar heat gain
coefficient (SHGC) of the fenestration product taken in combination with the interior shade fraction for the
fenestration.
8
SLAo is the floor-area weighted specific leakage area of a home where the different building zones (e.g.
basement and living zones) have different specific leakage areas.

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Appendix C
8. Attic net free ventilation area (ft2)
9. Crawlspace net free ventilation area (ft2), if appropriate
10. Exposed masonry floor area and carpet and pad R-value, if appropriate
11. Heating system labeled ratings, including AFUE, COP, or HSPF, as appropriate.
12. Cooling system labeled ratings, including SEER or EER, as appropriate.
13. Thermostat schedule for heating and cooling
14. Air Distribution System Efficiency (DSE).
15. Mechanical ventilation kWh/yr, if appropriate
Software tools must have the ability to recreate or store the test case Reference Homes as
if they were Qualifying Homes such that they also can be simulated and evaluated as
Qualifying Homes.

Auto-generation Test Suite
Test Case1. HERS BESTEST case L100 building configured as specified in the HERS
BESTEST procedures, located in Baltimore, MD, including a total of 3 bedrooms and the
following mechanical equipment: gas furnace with AFUE = 82% and central air
conditioning with SEER = 11.0; a gas range, oven and clothes dryer; all other appliances
are electric.
Test Case 2. HERS BESTEST case L100 configured on an un-vented crawlspace with
R-7 crawlspace wall insulation, located in Dallas, TX, including a total of 3 bedrooms
and the following mechanical equipment: electric heat pump with HSPF = 7.5 and SEER
= 12.0; all appliances are electric.
Test Case 3. HERS BESTEST case L304 in Miami, configured as specified in the HERS
BESTEST procedures, located in Miami, FL, including a total of 2 bedrooms and the
following mechanical equipment: electric strip heating with COP = 1.0 and central air
conditioner with SEER = 15.0; all appliances are electric.
Test Case 4. HERS BESTEST case L324 configured as specified as in the HERS
BESTEST procedures, located in Colorado Springs, CO, including a total of 4 bedrooms
and the following mechanical equipment: gas furnace with AFUE = 95% and no air
conditioning; a gas range, oven and clothes dryer; all other appliances are electric.
Test Case 5. Recreate or store the Reference Homes created in Tests 1 through 4 as
Qualifying Homes and simulate and evaluate them.

Verification Criteria
Test Cases 1 – 4. For test cases 1 through 4 the values contained in Table 1 shall be used as the
verification criteria for software tool accreditation. For Reference Home building components
marked by an asterisk (*), the verification criteria may include a range equal to ± 0.05% of the
listed value. For all other Reference Home components the listed value is exact.

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Appendix C
Table 1. Verification Criteria for Test Cases 1 – 4
Reference Home Building
Component
Above-grade walls (Uo)
Above-grade wall solar
absorptance (α)
Above-grade wall infrared
emittance (ε)
Basement walls (Uo)
Above-grade floors (Uo)
Slab insulation R-Value
Ceilings (Uo)
Roof solar absorptance (α)
Roof infrared emittance (ε)
Attic vent area* (ft2)
Crawlspace vent area* (ft2)
Exposed masonry floor area * (ft2)
Carpet & pad R-Value
Door Area (ft2)
Door U-Factor
North window area* (ft2)
South window area* (ft2)
East window area* (ft2)
West window area* (ft2)
Window U-Factor
Window SHGCo (heating)
Window SHGCo (cooling)
SLAo* (ft2/ft2)
Sensible Internal gains* (Btu/day)
Latent Internal gains* (Btu/day)
Heating system rating and
efficiency
Cooling system rating and
efficiency
Air Distribution System Efficiency
Thermostat Type
Heating thermostat settings
Cooling thermostat settings

Test 1

Test 2

Test 3

Test 4

0.082

0.082

0.082

0.060

0.75

0.75

0.75

0.75

0.90

0.90

0.90

0.90

n/a
0.047
n/a
0.030
0.75
0.90
5.13
n/a
n/a
n/a
40
0.40
67.50
67.50
67.50
67.50
0.40
0.34
0.28
0.00036
55,470
13,807
AFUE =
78%
SEER =
13.0
0.80
Manual
68 F
(all hours)
78 F
(all hours)

n/a
0.047
n/a
0.035
0.75
0.90
5.13
10.26
n/a
n/a
40
0.65
67.50
67.50
67.50
67.50
0.65
0.34
0.28
0.00036
52,794
12,698
HSPF =
7.7
SEER =
13.0
0.80
Manual
68 F
(all hours)
78 F
(all hours)

n/a
n/a
0
0.035
0.75
0.90
5.13
n/a
307.8
2.0
40
1.20
67.50
67.50
67.50
67.50
1.20
0.34
0.28
0.00036
48,111
9,259
HSPF =
7.7
SEER =
13.0
0.80
Manual
68 F
(all hours)
78 F
(all hours)

0.059
n/a
0
0.030
0.75
0.90
5.13
n/a
307.8
2.0
40
0.35
50.02
50.02
50.02
50.02
0.35
0.34
0.28
0.00036
83,103
17,934
AFUE =
78%
SEER =
13.0
0.80
Manual
68 F
(all hours)
78 F
(all hours)

Test Case 5. Test case 5 requires that each of the Reference Homes for test cases 1-4 be
stored or recreated in the software tool as a Qualifying Home and simulated as any other
qualifying home would be simulated. If the resulting Qualifying home is correctly
configured to be identical to its appropriate Reference Home, energy use calculations
arising from normal operation of the software tool should produce virtually identical
energy use for both the Reference Home and the Qualifying Home for this round of tests.

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Appendix C
For test case 5, the energy use e-Ratio shall be calculated separately from the simulation
results for heating and cooling, as follows:
e-Ratio = (Qualifying Home energy use) / (Reference Home Energy Use)
Verification criteria for these calculations shall be ± 0.5% of 1.00. Thus, for each of the
preceding test cases (1-4), the e-Ratio resulting from these software tool simulations and
the subsequent e-Ratio calculations shall be greater than or equal to 0.995 and less than
or equal to 1.005.

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Appendix D

Appendix D
RESNET HVAC Test Suites 1 & 2

Required Capabilities
Tools must be capable of generating HVAC results using system type and efficiency as
inputs. Additional efficiency information is allowable, but must not be required to
operate the tool. Tools must also account for duct leakage, duct insulation levels and the
presence of a programmable thermostat.
System Types

System types that must be supported by all tools:
1. Compressor based air conditioning system
2. Oil, propane or natural gas forced air furnaces
3. Electric resistance forced air furnaces
4. Air source heat pump
Optional system types that may be supported include:
1. Evaporative cooling, direct, indirect or IDEC
2. Ground or water source heat pumps
3. Multiple fossil fuel systems which utilize fuel for backup heating and an electric
air or ground source heat pump for primary heating. An example of this would be
an electric air source heat pump with a fossil fuel furnace as a supplement or
backup.
4. Radiant heating systems including but not limited to hot water radiant floor
systems, baseboard systems and ceiling cable systems.
5. Hydronic systems.
6. Combo systems in which the system supplies both domestic hot water and space
heating.
7. Active solar space heating systems
Capability tests do not currently exist for the optional system types listed above. The
following table lists the efficiency metrics that are reported by manufacturers and must be
used for each system type.

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Appendix D

HVAC Equipment Type

Gas or Fuel Furnaces

Electric Resistance Furnace
Air Source Heat Pump
<65 kBtu/h
Air Cooled Central Air
Conditioner <65 kBtu/h
Air Cooled Window Air
Conditioner

Heating
Efficiency
Metric
AFUE

COP
HSPF

Cooling
Efficiency Comments:
Metric
Includes wall furnaces, floor
furnaces and central forced air
furnaces.
Use COP of 1.0, an HSPF of
3.413 may be equivalent and
acceptable for some tools.
SEER
SEER
EER

PTAC units are included in this
category

Detailed Default Inputs
Where tools use detailed modeling capabilities for HVAC simulation like DOE-2, the
following values should be used as default values in the simulation tool to achieve the
best results.
Default Values for use with Detailed HVAC Simulation Tools
DOE-2 Keyword:
HEATING-EIR

COOLING-EIR
DEFROST-TYPE
DEFROST-CTRL
DEFROST-T (F)
CRANKCASE-HEAT
CRANK-MAX-T
MIN-HP-T (F)

Description (units)

Heat Pump Energy Input Ratio
compressor only, (1/cop)
Air Conditioner Energy Input
Ratio compressor only,
(1/cop)
Defrost method for outdoor
unit, (Reverse cycle)
Defrost control method,
(Timed)
Temperature below which
defrost controls are activated,
(oF)
Refrigerant crankcase heater
power, (kW)
Temperature above which
crankcase heat is deactivated,
(oF)
Minimum temperature at
which compressor operates,

RESNET Publication No. 001-16 (2016)

Value

0.582*(1/(HSPF/3.413))
0.941*(1/(SEER/3.413))
REVERSE-CYCLE
TIMED
40o
0.05
50o
0o

D-2

Appendix D
DOE-2 Keyword:

Description (units)

Value

o

MAX-HP-SUPP-T
MAX-SUPPLY-T
(heating, heat pump)
MAX-SUPPLY-T
(heating, natural gas
furnace)
FURNACE-AUX
MIN-SUPPLY-T
(cooling)
SUPPLY-KW
SUPPLY-DELTA-T
SUPPLY-KW

SUPPLY-DELTA-T
COIL-BF

Other parameters:
Part load performance
curves
Heating system size
Coil airflow
Cooling system size

( F)
Temperature above which
auxiliary strip heat is not
available, (oF)
Maximum heat pump leaving
air temperature from heating
coil, (oF)
Maximum gas furnace leaving
air temperature from heating
coil, (oF)
Natural gas furnace pilot light
energy consumption, (Btu/h)
Minimum cooling leaving air
temperature from cooling coil,
(oF)
Indoor unit standard blower
fan power, (kW/cfm)
Air temperature rise due to fan
heat, standard fan, (oF)
Indoor unit standard blower
fan power, high efficiency fan,
(kW/cfm)
Air temperature rise associated
due to fan heat, high efficiency
fan, (oF)
Coil bypass factor,
(dimensionless)
Compressor part load
performance curves
Installed heat pump size,
(kBtu/h)
Indoor unit air flow, (cfm)
Installed air conditioner size,
(kBtu/h)

50o
105o
120o
100
55o
0.0005
1.580
0.000375

1.185
0.241

Henderson, et.al.9
Determined by Manual J
(specified)
30 cfm/(kBtu/h)
Determined by Manual J
(specified)

9

Henderson, H.I., D.S. Parker and Y.J. Huang, 2000. “Improving DOE-2's RESYS Routine: User Defined
Functions to Provide More Accurate Part Load Energy Use and Humidity Predictions,” Proceedings of
2000 Summer Study on Energy Efficiency in Buildings, Vol. 1, p. 113, American Council for an EnergyEfficient Economy, 1001 Connecticut Avenue, Washington, DC.

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Appendix D
List of Tests
The following test suites represent tests that tools must pass to be accredited. All tests
are to be performed using the L100 building case described by the HERS BESTEST
procedures.10
For each test case, interim acceptance criteria are provided. These interim criteria are
based on preliminary reference results from 5 tools, which are capable of detailed hourly
building simulation and HVAC modeling computations (e.g. DOE-2). The criteria are
established for interim purposes as the 90% confidence interval for the 5 preliminary sets
of reference results. In order to pass a specific test, tools must predict percentage energy
use changes for the specified heating and/or cooling system tests that falls between the
upper and lower acceptance criteria for that test.
Tools that do not model the performance of HVAC equipment in detail must provide for
climate adjusted equipment performance factors in order to fall within the acceptance
criteria for these tests. Methods of adjusting the manufacturer’s nameplate ratings to
account for climate dependent performance have been reported.11
Test Suite 1 – Air conditioning systems: Test to ensure that there is the proper
differential electrical cooling energy consumption by cooling systems when the
efficiency is varied between SEER 10 and a higher efficiency unit, taken to be SEER 13.
For the purposes of this test assume zero duct leakage and all ducts and air handlers are in
conditioned space.
Air Conditioning System Test Specifications
Test #
System Type
Capacity
Air cooled
HVAC1a
38.3 kBtu/h
air conditioner
Air cooled
HVAC1b
38.3 kBtu/h
air conditioner

Location

Efficiency

Las Vegas, NV

SEER = 10

Las Vegas, NV

SEER = 13

Interim Air Conditioning System Acceptance Criteria
Mfg. Equip Performance Low Acceptance
Test #
Rating (MEPR) Change
Criteria
HVAC1a
Base case
--HVAC1b
-23.1%
-20.0%

High Acceptance
Criteria
---18.4%

10

Judkoff, R. and J. Neymark, 1995. "Home Energy Rating System Building Energy Simulation Test
(HERS BESTEST)," Vol. 1 and 2, Report No. NREL/TP-472-7332, National Renewable Energy
Laboratory, Golden, Colorado 80401-3393. (Also available online at http://www.nrel.gov/publications/.)
11
Fairey, P., D.S. Parker, B. Wilcox and M. Lombardi, "Climate Impacts on Heating Seasonal
Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER) for Air Source Heat Pumps."
ASHRAE Transactions, American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc.,
Atlanta, GA, June 2004. (Also available online at http://www.fsec.ucf.edu/bldg/pubs/hspf/)

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Appendix D
Test Suite 2 – Heating Systems: Test to ensure that there is differential heating energy
consumed by heating systems when the efficiency is varied between a code minimum
heating and a higher efficiency unit. The tests will be carried out for both electric and
non-electric heating systems. For the purposes of this test assume zero duct leakage and
all ducts and air handlers in conditioned space. .
Gas Heating System Test Specifications
Test #
System Type
Capacity
HVAC2a

Gas Furnace

56.1 kBtu/h

HVAC2b

Gas Furnace

56.1 kBtu/h

Location
Colorado
Springs, CO
Colorado
Springs, CO

Interim Gas Heating System Acceptance Criteria
Mfg. Equip Performance Low Acceptance
Test #
Rating (MEPR) Change
Criteria
HVAC2a
Base case
--HVAC2b
-13.3%
-13.1%

Electric Heating System Test Specifications
Test #
System Type
Capacity
Air Source
HVAC2c
56.1 kBtu/h
Heat Pump
Air Source
HVAC2d
56.1 kBtu/h
Heat Pump
Electric
HVAC2e
56.1 kBtu/h
Furnace

Location
Colorado
Springs, CO
Colorado
Springs, CO
Colorado
Springs, CO

Interim Electric Heating System Acceptance Criteria
Mfg. Equip Performance Low Acceptance
Test #
Rating (MEPR) Change
Criteria
HVAC2c
Base case
--HVAC2d
-31.0%
-26.0%
HVAC2e
99.2%
47.8%

RESNET Publication No. 001-16 (2016)

Efficiency
AFUE = 78%
AFUE = 90%

High Acceptance
Criteria
---12.6%

Efficiency
HSPF = 6.8
HSPF = 9.85
COP =1.0

High Acceptance
Criteria
---19.1%
63.4%

D-5

Appendix E

Appendix E
RESNET Distribution System Efficiency (DSE) Test Suite
Distribution System Efficiency (DSE) tests are designed to ensure that the impact of duct
insulation, duct air leakage and duct location are properly accounted for in software.
Tables 1 and 2 below describe the test specifications and the bounds criteria for these
important tests.

Test Case Specification
For all tests, assume that the air-handling unit is in conditioned space. If the software tool
being tested has the ability to modify inputs for duct area, assume that the supply duct
area is equal to 20% of the conditioned floor area and the return duct area is equal to 5%
of the conditioned floor area. The duct leakage shall be 250 cfm25 for cases 3d and 3h
with the return and supply leakage fractions each set at 50%. All tests assume a natural
gas forced air furnace and forced air cooling system with efficiencies of 78% AFUE =
78% for the heating system and SEER = 10 for the cooling system.
Furnace and air conditioner heating and cooling capacities should be modified for each of
the duct system efficiency test cases according to the values provided in Tables 1a and
2a. Similarly, the specified heating and cooling coil airflow (cfm) should be altered by
case using a value of 360 cfm/ton (30 cfm/kBtu) of capacity. Also, the exterior air film
resistance of the duct system should be added to the specified duct R-values given in
Tables 1a and 2a to obtain agreement for duct conductance. For non-insulated sheet
metal ducts (R-0) the air film has a resistance of approximately R=1.5 ft2-oF-hr/Btu and
for insulated ducts (R=6) the air film has a resistance of R=1.0 as shown by test results
obtained by Lauvray (1978) at a typical residential duct airflow rate of 530 fpm.12 These
values are currently established for the purposes of duct design calculations by ASHRAE
within the Handbook of Fundamentals (2001, p. 34.15). Thus, unless the software
undergoing test accounts for these film resistances, the uninsulated sheet metal duct (R=0
in Tables 1a and 2a) should be entered as R=1.5 while the insulated ducts (R=6 in tables)
should be entered as R=7.
For the heating comparison test cases (Table 1a), which assume a basement, use the
HERS BESTEST Case L322 home. The basement is to be unconditioned, have a floor
area equal to the main floor area (1539 ft2) and have R11 insulation in the floor joists of
the main floor with a framing fraction of 13%. The basement case has no basement wall
insulation. For the cooling comparison test cases (Table 2a), use the HERS BESTEST
case L100 home.

12

T.L. Lauvray, 1978. “Experimental heat transmission coefficients for operating air duct systems,”
ASHRAE Journal, June, 1978.

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Appendix E
Bounds Criteria
The bounds criteria for these tests were established using ASHRAE Standard 152-04,
using the spreadsheet tool constructed for the U.S. DOE Building America program by
Lawrence Berkeley National Laboratory (LBNL).13 In all cases, the input values for the
Standard 152 calculations assumed the following:










Single story building
Single speed air conditioner/heating system
System capacities as specified in Tables 1a and 2a
Coil air flow = 360 cfm per 12,000 Btu/h
Ducts located as specified in Tables 1a and 2a
Supply duct area = 308 ft2
Return duct area = 77 ft2
Supply and return duct insulation of R=1.5 and R=7 for uninsulated (R=0) and
insulated (R=6) ducts, respectively
Supply and return duct leakage = 125 cfm each, where so specified in Tables 1a
and 2a.

Following the ASHRAE Standard 152 analysis, the resulting DSE values were converted
to a percentage change in heating and cooling energy use (“Target Delta” in Tables 1b
and 2b) using the following calculation:
% Change = 1.0 – (1.0 / DSE)
Bounds criteria were then established as this target delta plus and minus 5% to yield the
values given in Tables 1b and 2b for heating and cooling test minimum and maximum
delta bounds criteria, respectively.

Heating Energy Tests

Test #
HVAC3a
(base case)
HVAC3b
HVAC3c
HVAC3d

13

Table 1a. Heating Energy DSE Comparison Test Specifications
System
System
Duct
Location
Capacity
Duct Location
Type
Leakage
(kBtu/h)
Colorado
Gas
100%
46.6
None
Springs, CO
Furnace
conditioned
Colorado
Gas
100% in
56.0
None
Springs, CO
Furnace
basement
Colorado
Gas
100% in
49.0
None
Springs, CO
Furnace
basement
Colorado
Gas
100% in
61.0
250 cfm25
Springs, CO
Furnace
basement

Duct
R-val*
R=0
R=0
R=6
R=6

See http://www.eere.energy.gov/buildings/building_america/benchmark_def.html

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Appendix E
* Duct R-value does not include air film resistances. For uninsulated ducts, this film resistance is
approximately R=1.5 and for insulated ducts it is approximately R=1.0. If software does not consider
this air film resistance in detail, then these air film resistances should be added.

Test #
HVAC3a
HVAC3b
HVAC3c
HVAC3d
* Delta =

Table 1b. Heating Energy DSE Comparison Test Bounds Criteria
Target Delta* Heating
Minimum Delta*
Maximum Delta*
Energy Relative to
Heating Energy
Heating Energy
HVAC3a
Base case
----26.4%
21.4%
31.4%
7.5%
2.5%
12.5%
20%
15%
25%
% Change in energy use = ((alternative – base case) / (base case)) * 100

Cooling Energy Tests
Table 2a. Cooling Energy DSE Comparison Test Specifications
System
Duct
Duct RTest #
Location
System Type
Capacity
Duct Location
Leakage
val*
(kBtu/h)
HVAC3e
Las Vegas,
Air
100%
-38.4
None
R=0
(base case)
NV
Conditioner
conditioned
Las Vegas,
Air
HVAC3f
-49.9
100% in attic
None
R=0
NV
Conditioner
Las Vegas,
Air
HVAC3g
-42.2
100% in attic
None
R=6
NV
Conditioner
Las Vegas,
Air
HVAC3h
-55.0
100% in attic
250 cfm25
R=6
NV
Conditioner
* Duct R-value does not include air film resistance. For uninsulated ducts, this film resistance is
approximately R=1.5 and for insulated ducts it is approximately R=1.0. If software does not consider
this air film resistance in detail, then these air film resistances should be added.

Test #
HVAC3e
HVAC3f
HVAC3g
HVAC3h
* Delta =

Table 2b. Cooling Energy DSE Comparison Test Bounds Criteria
Target Delta* Cooling
Minimum Delta*
Maximum Delta*
Energy Relative to
Cooling Energy
Cooling Energy
HVAC3e
Base case
----31.2%
26.2%
36.2%
11.5%
6.5%
16.5%
26.1%
21.1%
31.1%
% Change in energy use = ((alternative – base case) / (base case)) * 100

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Appendix F

Appendix F
RESNET Service Hot Water Test Suite
1

Hot Water System Performance Tests

Hot water system tests are designed to determine if software tools accurately account for
both the hot water use rate (gallons per day) and the climate impacts (inlet water
temperatures) of hot water systems. The tests are limited to standard gas-fired hot water
systems and cannot be used to evaluate solar hot water systems, heat pump hot water
systems, hot water systems that recover heat from air conditioner compressors (heat
recovery or de-super heater systems), or other types of hot water systems. In addition,
distribution losses associated with hot water distribution systems are not covered by this
test.
2 Test Description
The following table provides summary specifications for the six required hot water
tests. The tests are segregated into two sets of three tests – one set of cold climate
tests (Duluth, MN) and one set of hot climate tests (Miami, FL).
Table 2-1. Summary Specifications for Standard Hot Water Tests
Test
System
Climate
System
Number of
Number
Type
Location
Efficiency
Bedrooms
DHW-MN-56-2
40 gal, gas
Duluth, MN
EF = 0.56
2
DHW-MN-56-4
40 gal, gas
Duluth, MN
EF = 0.56
4
DHW-MN-62-2
40 gal, gas
Duluth, MN
EF = 0.62
2
DHW-FL-56-2
DHW-FL-56-4
DHW-FL-62-2

40 gal, gas
40 gal, gas
40 gal, gas

Miami, FL
Miami, FL
Miami, FL

EF = 0.56
EF = 0.56
EF = 0.62

2
4
2

Additional specifications used in the creation of the reference results that establish the
hot water system test acceptance criteria are as follows:
2.1 Hot Water Draw Profile
The hot water draw profile is as specified by ASHRAE Standard 90.2, as given in
Table 2-2 below:

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Appendix F
Table 2-2. Hourly Hot Water Draw Fraction for Hot Water Tests
Hour of
Daily
Hour of
Daily
Hour of
Daily
Day
Fraction
Day
Fraction
Day
Fraction
1
0.0085
9
0.0650
17
0.0370
2
0.0085
10
0.0650
18
0.0630
3
0.0085
11
0.0650
19
0.0630
4
0.0085
12
0.0460
20
0.0630
5
0.0085
13
0.0460
21
0.0630
6
0.0100
14
0.0370
22
0.0510
7
0.0750
15
0.0370
23
0.0510
8
0.0750
16
0.0370
24
0.0085
2.2 Inlet Mains Temperature
The cold-water inlet mains temperatures to the hot water system are calculated in
accordance with the following formula:14
Tmains = (Tamb,avg + offset) + ratio * (Tamb,max / 2) * sin (0.986 * (day# - 15 - lag) - 90)
where:
Tmains
= mains (supply) temperature to domestic hot water tank (ºF)
Tamb,avg = annual average ambient air temperature (ºF)
Tamb,max = maximum difference between monthly average ambient
temperatures (e.g., Tamb,avg,july – Tamb,avg,january) (ºF)
0.986
= degrees/day (360/365)
day#
= Julian day of the year (1-365)
offset
= 6F
ratio
= 0.4 + 0.01 (Tamb,avg – 44)
lag
= 35 – 1.0 (Tamb,avg – 44)

2.3 Additional TRNSYS Simulation Parameters
Additional inputs for TRNSYS reference result simulations are as follows:
 Rated Power
40,000 Btu/hr
 Recovery efficiency:
0.78
 Tank UA for EF=0.56 system:
10.79 Btu/hr-F
 Tank UA for EF=0.62 system:
7.031 Btu/hr-F
 Tank set point temperature:
120 F
 Tank space temperature (“loss temp”):
75 F
 Tank stratification:
15 equal nodes
 Simulation time step:
1/16th hour

14

NREL, “Building America Research Benchmark Definition.” National Renewable Energy Laboratory,
Golden, CO, December 29, 2004. May be found online at:
http://www.eere.energy.gov/buildings/building_america/pa_resources.html

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Appendix F
3 Acceptance Criteria
In each of the two sets of three test cases, the first test listed (DHW-xx-56-2) is the
base case and the other two cases are the alternative cases. There are two metrics
used for acceptance criteria a difference metric (delta) and an absolute metric
(MBtu). The delta metric is the % change in energy use for the alternative cases
with respect to the base case, which is determined as follows:
% Change = (alternative - base) / (base) * 100
The absolute metric is the projected hot water energy use given in millions of Btu
(site MBtu). The acceptance criteria given in Table 3-1 below are determined from
reference results from three different software tools – TRNSYS version15, DOE-2.1E
(v.120) as used by EnergyGauge USA version 2.5, and RemRate version 12.
Minimum and maximum acceptance criteria are determined as the 99% confidence
interval for these reference results using the student t-test.
Table 3-1. Acceptance Criteria for Hot Water Systems Tests
Case
MN,0.56,4 (delta)
MN,0.62,2 (delta)
FL,0.56,4 (delta)
FL,0.62,2 (delta)
MN,0.56,2 (MBtu)
FL,0.56,2 (MBtu)
MN-FL (MBtu)

Mean
29.3%
-9.3%
24.1%
-13.6%
20.13
12.69
7.44

RESNET Publication No. 001-16 (2016)

St Dev
0.58%
0.51%
1.02%
1.19%
0.38
0.36
0.40

99%CI
2.85%
2.49%
5.01%
5.87%
1.89
1.76
1.95

Minimum
26.5%
-11.8%
19.1%
-19.5%
18.24
10.92
5.49

Maximum
32.2%
-6.8%
29.1%
-7.7%
22.02
14.45
9.39

F-3

Appendix G

Appendix G
RESNET/HERS BESTEST L125A Test Case
1. Background
Test Case L125A is developed as an additional HERS BESTEST case to examine
potential interactions between home alterations that interact with one another in a way
that causes their combined impact on energy use to be different than the sum of their
individual impacts on energy use. HERS BESTEST Case L120A examines the impact of
adding additional ceiling and wall insulation to the L100A Case (baseline) and Case
L130A examines the impact of adding high performance windows to the L100A Case.
This Case, named L125A combines test Case L120A and Case L130A to examine the
impact of adding both sets of improvements to the L100A Case.
1.1. Test Case L125A Specifications. 15
Case L125A is exactly the same as Case L100A, except that
 An extra layer of R-38 batt insulation has been added to the ceiling, and exterior
walls have 2x6 24" O.C. framing and R-18 batt insulation with R-7.2
polyisocyanurate exterior board insulation; and
 All single-pane windows are replaced with double-pane low-emissivity (low-e)
windows with wood frames and insulated spacers.
1.2. Acceptance Criteria for Test Case L125A
Acceptance criteria for Test Case L125A are developed in the same manner as for all
other HERS BESTEST cases (as detailed in Appendix H of the User’s Manual referenced
above) except that for this test the criteria are developed from six software tools that are
currently used in the marketplace as follows:
 EnergyGauge® USA by Florida Solar Energy Center
 EnergyInsights by Appogee Interactive
 OptiMiser by Energy Logic
 Rem/Rate by Architectural Energy Corporation
 EnergyMeasure ™ Home by Conservation Services Group
 TREAT by PSD Consulting

15

Users are advised to consult the following reference for details: Judkoff, R. and J. Neymark, November
1995. “Home Energy Rating System Building Energy Simulation Test (HERS BESTEST) – Volumes 1,
Tier 1 and Tier 2 Tests User’s Manual.” National Renewable Energy Laboratory, Golden, Colorado,
Report No. NREL/TP-472-7332.

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Appendix G
Results from these six simulation tools were used to determine the acceptance criteria
both for Test Case L125A and for the difference between Test Case L100A and Test
Case L125A. Table 1 presents the software results along with the acceptance criteria
range for Test Case L125A and Table 2 presents the difference results along with
acceptance criteria range for the L100A Case minus the L125A Case.
Table F-1. Absolute Results for Case L125A
Heating Results (L125A)
Cooling Results (L125A)
Software Tool Annual MBtu Software Tool Annual MBtu
Tool A
33.72
Tool A
36.07
Tool B
35.31
Tool B
32.11
Tool C
35.58
Tool C
32.60
Tool D
35.62
Tool D
34.31
Tool E
34.21
Tool E
35.47
Tool F
37.40
Tool F
33.40
Mean
35.31
Mean
33.99
StDev
1.29
StDev
1.58
90% CI
1.16
90% CI
1.42
+ Range
41.40
+ Range
40.07
-Range
29.72
-Range
28.11
Table F-2. Difference Results for Case L100A - L125A
Heating Results (L100ACooling Results (L100AL125A)
L125A)
Software Tool Annual MBtu Software Tool Annual MBtu
Tool A
33.70
Tool A
23.96
Tool B
34.09
Tool B
22.89
Tool C
25.30
Tool C
21.15
Tool D
25.66
Tool D
21.40
Tool E
32.53
Tool E
23.08
Tool F
32.50
Tool F
22.10
Mean
30.63
Mean
22.43
StDev
4.04
StDev
1.07
90% CI
3.64
90% CI
0.97
+ Range
38.09
+ Range
27.96
-Range
21.30
-Range
17.15

RESNET Publication No. 001-16 (2016)

G-2