The 2019 edition of ANSI/ASHRAE/IES 90.1, “Energy Standard for Buildings Except Low-Rise Residential Buildings (ASHRAE 90.1),” adopts a new fan efficiency metric, Fan Energy Index (FEI). FEI replaces the Fan Efficiency Grade (FEG) used in the 2013 and 2016 editions of Standard 90.1.

ES White paper