ANSI/ASHRAE/IES Standard 90.1- 2019 Energy Standard for Buildings Except Low-Rise Residential Buildings (I-P Edition)

The 2019 edition includes various modifications and clarifications to improve internal consistency and to standardize the structure and language of the document. Significant changes to requirements include the following

• New commissioning requirements in accordance with ASHRAE/IES Standard 202

• Combined categories of “nonmetal framed” and “metal framed” products for vertical fenestration
• Upgraded minimum criteria for SHGC and U-factor across all climate zones
• Revised air leakage section to clarify compliance
• Refined exceptions related to vestibules, added new option and associated criteria for using air curtains

• Modified lighting power allowances for Space-by-Space Method and the Building Area Method
• New simplified method for lighting for contractors and designers of renovated office buildings and retail buildings up to 25,000 ft2 (2300 m2).
• Updated lighting control requirements for parking garages to account for the use of LEDs
• Updated daylight responsive requirements, added definition for “continuous dimming” based on NEMA LSD-64-2014
• Clarified side-lighting requirements and associated exceptions
• Mechanical
• New requirements to allow the option of using ASHRAE Standard 90.4 instead of ASHRAE Standard 90.1 in computer rooms that have an IT equipment load larger than 10 kW
• Added pump definitions, requirements, and efficiency tables to the standard for the first time
• New equipment efficiency requirement tables and changes to existing tables
• Replaced fan efficiency grade (FEG) efficiency metric with fan energy index (FEI)
• New requirements for reporting fan power for ceiling fans and updated requirements for fan motor selections to increase design options for load-matching variable-speed fan applications
• New energy recovery requirements for high-rise residential building
• New requirement for condenser heat recovery for acute care inpatient hospitals
Energy Cost Budget (ECB) Method (Section 11)
• Numerous changes to ensure continuity
• Set baseline for on-site electricity generation systems
Performance Rating Method (Appendix G)
• Clarified Appendix G rules and corresponding baseline efficiency requirement when combining multiple thermal zones into a single thermal block
• New explicit heating and cooling COPs without fan for baseline packaged cooling equipment
• New rules for modeling impact of automatic receptacle controls
• Set more specific baseline rules for infiltration modeling
• Clarified how plant and coil sizing should be performed
• Updated building performance factors
Both Compliance Paths
• Clearer, more specific rules for treatment of renewables
• New updates to rules for lighting modeling