ASHRAE-90.1-2022- - Page 188
Extracted Content
where EC H02_adj = energy credits achieved for heating efficiency improvement EC H02_base = H02 base energy credit from Section 11.5.3 EI heat = lesser of the percentage improvement (as a fraction) above minimum heating efficiency
requirements or 20% (0.20). Where heating equipment with different minimum efficiencies are included in the building, a heating capacity weighted-average improvement shall be used. Where electric resistance primary heating or reheat is included in the building, it shall be included in the weighted-average improvement with an EI heat of 0. Supplemental gas and electric heat for heat-pump systems shall be excluded from the weighted EI heat . For heat pumps rated at multiple ambient temperatures, use the efficiency at 47 F. Gas-fired boiler systems that are required to meet provisions of Section 6.5.4.8 shall use the minimum system efficiency as defined in Section 6.5.4.8.1. Gas-fired boiler systems that are required to meet provisions of Section 6.5.4.8 shall use the minimum system efficiency as defined in Section 6.5.4.8.1.
For metrics that increase as efficiency increases, EI heat shall be calculated as follows:
EI heat
= ----------------HM des - 1 HM min
where HM des = design heating efficiency metric, part-load or annualized where available HM min = minimum required heating efficiency metric, part-load or annualized where available from Section 6.8.1 or Informative Appendix F Informative Note: An example of an annualized or part-load heating efficiency is AFUE rather than Et or Ec . Where only one efficiency rating is provided for equipment in Section 6.8.1 or Informative Appendix F, use that metric.
11.5.2.2.3 H03: HVAC Cooling Performance Improvement. To achieve this credit, space cooling equipment shall exceed the minimum cooling efficiency requirements by 5% or more than listed in the tables in Section 6.8.1 or Informative Appendix F. For water-cooled chiller plants, heat rejection efficiency shall also exceed the minimum efficiency listed in Table 6.8.1-7 by at least the percentage improvement in the chiller efficiency . The measure energy credit (EC CE ) for cooling efficiency improvement shall be determined as follows:
= EC H03 _ base ------------0.05 -
EC H03 _ adj = EC H03 _ base
EI cool
where EC H03_adj = energy credits achieved for cooling efficiency improvement EC H03_base = H03 base energy credits from Section 11.5.3 EI cool = lesser of the percentage improvement (as a fraction) above minimum cooling efficiency requirements or 20% (0.20). Where cooling equipment with different minimum efficiencies are included in the building, a cooling capacity weighted-average improvement shall be used. Where multiple cooling performance requirements are provided, the equipment shall exceed the annualized energy or part-load requirement. Meeting both part-load and full-load efficiencies is not required. For metrics that increase as efficiency increases, EI cool shall be calculated as follows:
EI cool
= --------------CM des - - 1 CM min
For metrics that decrease as efficiency increases, EI cool shall be calculated as follows:
EI cool
= CM-------------- min - - 1 CM des
where CM min = minimum required cooling efficiency metric, part-load or annualized where available from Section 6.8 or Informative Appendix F CM des = design cooling efficiency metric, part-load or annualized where available
186 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)