What’s New in ASHRAE/IES Standard 90.1-2022—Mechanical Updates, Part II Mechanical System Performance Rating Method

ASHRAE/IES Standard 90.1-2022 introduces a new system performance approach—the Mechanical System Performance Rating Method—as a new pathway for HVAC compliance. This method and the metric developed to express the efficiency of the HVAC system—the total system performance ratio (TSPR)—are discussed.