ASHRAE-90.1-2022- - Page 356
Extracted Content
(This appendix is not part of this standard. It is merely informative and does not contain requirements necessary for conformance to the standard. It has not been processed according to the ANSI require- ments for a standard and may contain material that has not been subject to public review or a consen- sus process. Unresolved objectors on informative material are not offered the right to appeal at ASHRAE or ANSI.)
INFORMATIVE APPENDIX I USING OTHER METRICS IN CONJUNCTION WITH APPENDIX G PERFORMANCE RATING METHOD WHEN APPROVED BY THE RATING AUTHORITY
I1. GENERAL
This informative appendix describes changes to Section 3, Section 4, and Normative Appendix G for using metrics other than energy cost—including site energy, source energy, and carbon emissions—that may be adopted by the rating authority for the Normative Appendix G Performance Rating Method . It also provides methodology for determining building performance factors (BPFs) that should be used in conjunction with custom energy conversion factors other than the national average defaults in Table I5-1.
I2. CHANGES TO SECTION 3
Replace references to “annual energy cost” with the reference to the selected metric in the definitions of baseline building performance and proposed building performance .
I3. CHANGES TO SECTION 4
a. Replace all references to “ energy cost” in Section 4.2.1.1 with “ site energy,” “source energy,” or “carbon
emissions,” as appropriate, throughout. b. Replace all references to “Performance Cost Index” in Section 4.2.1.1 with “Performance Index (Site
Energy),” “Performance Index (Source Energy),” or “Performance Index (Carbon Emissions),” as appropriate throughout. c. For site energy, replace Table 4.2.1.1 with Table I3-1. d. For carbon emissions, replace Table 4.2.1.1 with Table I3-2. e. For source energy, replace Table 4.2.1.1 with Table I3-3.
I4. CHANGES TO NORMATIVE APPENDIX G
a. Replace references to “ energy cost” with references to “ site energy,” “source energy,” or “carbon emis sions” as appropriate in Sections G1.2.2, G1.3.2, G2.1, G2.4.2, and G2.5 section headings. b. Remove the first sentence and informative note in Section G2.4.2, and replace it with the conversion fac tors from Table I4-1 for the selected metric. c. Add an exception to Section G2.4.2 to allow using alternative conversion factors as appropriate for
building location and as approved by the adopting authority .
I5. METHODOLOGY FOR BPF ADJUSTMENT TO ACCOUNT FOR LOCALIZED CONVERSION FACTORS
The BPF values in Table 4.2.1.1, based on energy cost, and the values in Tables I3-1, I3-2, and I3-3, are based on the coefficients in Tables I5-2 through I5-4 and the electricity and fossil fuel conversion factors in Table I5-1. The values in Table I5-1 represent U.S. national average values. The U.S. national conversion factors may not be appropriate for all locations, and some jurisdictions may want to adopt custom conversion factors other than those shown in Table I5-1. When energy conversion factors other than those specified in Table I5-1 are used, the BPFs should also be updated in accordance with Equation I-1.
BPF i,j = (EC + Ai,j × GC)/( Bi,j × EC + Ci,j × GC) (I-1)
Ai,j, Bi,j, Ci,j = coefficients from Tables I5-2, I5-3, and I5-4 for building area type i and climate zone j
EC = custom electricity conversion factor expressed using the units shown in Table I5-1 for the selected metric
GC = custom natural gas conversion factor expressed using the units shown in Table I5-1 for the selected metric
354 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)