ANSI/AMCA Standard 208 Calculation of the Fan Energy Index



Throughout 2019, Air Movement and Control Association (AMCA) International Inc. is making ANSI/AMCA Standard 208, Calculation of the Fan Energy Index, available for download at no cost in its online store.

The ratio of the electrical power of a reference fan to the electrical power of an actual fan, both calculated at a given airflow and pressure duty point, FEI “levels the playing field,” enabling meaningful comparisons of many different fan types. It was developed by AMCA and its members to replace fan efficiency grade (FEG), the metric introduced in 2010 in ANSI/AMCA Standard 205, Energy Efficiency Classification for Fans.

“FEI is superior to FEG because it includes motors and drives, not just the bare-shaft fan, which is consistent with regulations covering pumps and air compressors,” AMCA Senior Director of Global Affairs Michael Ivanovich said. “It will help to save energy by taking efficient motors and drives into account.

“Additionally, FEI will be easier to enforce because the sizing/selection window needed for FEG is eliminated, and, unlike with FEG, FEI ratings are direct indicators of fan energy use,” Ivanovich continued. “FEG ratings remained consistent with fan size, so inherently inefficient smaller fan sizes had disproportionately high FEG ratings.”

Addendum AO to ANSI/ASHRAE/IES 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, which contains FEI requirements proposed for Standard 90.1, is nearing completion and is expected to be considered for publication by ASHRAE in June. Additionally, a proposal to replace FEG with FEI in the 2021 edition of the International Energy Conservation Code is in place, and FEI is being considered by the California Energy Commission for California’s Title 20 appliance-efficiency regulation.

To learn more about FEI, visit AMCA’s FEI microsite at To browse AMCA publications and standards in AMCA’s online store, visit