The Air Movement and Control Association (AMCA) has published ANSI/AMCA Standard 208-18, Calculation of the Fan Energy Index. ANSI/AMCA Standard 208 defines the calculation method for fan energy index (FEI), an energy-efficiency metric for fans inclusive of motors and drives. This metric provides a standardized and consistent basis for comparing fan energy performance across fan types and sizes at a given fan duty point.

ANSI/AMCA Standard 208-18 is available for purchase at the AMCA online bookstore.

According to AMCA, FEI has several uses. Fan specifiers can use it to understand and communicate fan-efficiency design intent, while legislative and regulatory bodies can use it to define energy-efficiency requirements of fans. The standard has been written to support the fan industry's entrance into energy and construction codes and standards and to support utility rebate programs.

FEI is a replacement for fan efficiency grade (FEG), a metric currently referenced in model energy codes and standards such as ASHRAE 90.1, ASHRAE 189.1, and IECC and in federal regulations in several Asian countries. FEI will replace FEG as it is adopted through change proposals as part of routine revision cycles. AMCA will expand its Certified Ratings Program to cover FEI later in 2018.