Atlanta, Georgia — ASHRAE released its latest version of its energy efficiency standard, ANSI/ASHRAE/IES Standard 90.1-2022, Energy Efficiency Standard for Sites and Buildings Except Low-Rise Residential Buildings.
The latest version of 90.1-2022 includes an expanded scope for building sites and major additions appearing for the first time in a minimum-efficiency U.S. model energy standard or code.
“We have identified some ambiguity in the standard by offering guidance on regulating only buildings and not sites. Examples include exterior and parking lot lighting, which, if not provided through the main electric panel in the building, were not within the scope of Standard 90.1 previously,” said Don Brundage, ASHRAE standing standard project committee 90.1 chair.
Major additions to Standard 90.1-2022 include a minimum prescriptive requirement for onsite renewable energy. This change is representative of a more widely adopted shift to renewable energy, an optional mechanical system performance path, allowing HVAC system efficiency trade-offs based on the new total system performance ratio (TSPR) metric, and new requirements to address the impacts of thermal bridging, according to ASHRAE.
Additional highlights include new energy credit requirements for a customized approach to improving energy efficiency, new informative guidance for using carbon emissions, site energy, or source energy as alternative performance metrics to the current energy cost metric, and significant efficiency increases in IEER for commercial rooftops and a new SEER2/HSPF2 metric for less than 65K sized air-cooled heat pumps.
“Including sites also clarifies that onsite renewables could count as credits towards energy usage across the entire building project, even if located in a parking lot or other onsite location, not only within the footprint of the building,” said Brundage. “We are continuing to improve efficiency and reduce energy use through updates to Standard 90.1, meeting the needs of the design community and keeping Standard 90.1 pertinent as demand grows for reduced energy use and carbon emissions.”
Brundage also added that efficiency increases in IEER for commercial rooftop units provide substantial cost-effective energy savings and, as a side benefit, encourage variable speed operation, which helps improve dehumidification performance in humid climates.