HVAC & Refrigeration Daily

AMCA Develops New Fan Efficiency Metric That Saves Energy and Eases Compliance

On Monday, Feb. 3 at 10:30 a.m., Air Movement and Control Association is hosting an educational seminar entitled: Fan Energy Index (FEI) as a Rating Metric and Design Tool in room W331H. Conducted by Michael Ivanovich, AMCA International Senior Director of Global Affairs, and Tim Mathson, AMCA International Principal Engineer, the session will instruct attendees how to use FEI to meet ASHRAE/IES 90.1-2019 provisions for variable-air-volume and constant-volume systems. The session will award 1 PDH credit

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) metric used in the 2013 and 2016 editions of Standard 90.1. FEI also is replacing FEG in the 2020 edition of ANSI/ASHRAE/USGBC/IES 189.1, “Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings (ASHRAE 189.1),” and the 2021 editions of the International Energy Conservation Code (IECC) and International Green Construction Code (IgCC).


FEI beats FEG for saving energy because it is a system-level metric that includes the efficiency impacts of motors and drives. It was mathematically derived to encourage right-sizing. FEG ratings for a fan model remain unchanged across fan sizes, thus requiring a “sizing/selection” window to nudge fan selections to larger diameters that are more efficient. This window is not needed by FEI — it’s built into the metric.


Simpler enforcement: Because there is no sizing/selection window requiring fans to be sized within 15 percentage points of peak total efficiency, code officials need only to check submittals and labels for FEI ratings and the engineer’s selected duty point.

Clarity for buyers and specifiers: FEI ratings are true to the actual efficiency of a fan or fan system, and the sizing/selection window needed for FEG is not needed for FEI.

Flexible application: For given duty points and FEI code requirements, manufacturer software may offer compliant fans of different types, sizes, motors, and drives. Engineers can then apply other project requirements, such as size, acoustics, budget, and availability for the fan selection.

Tremendous lifecycle benefits: The FEI metric and other changes to the fan efficiency sections in ASHRAE 90.1 and IECC Fans will save energy by right-sizing fans, increase designer flexibility and ease compliance checking. Right-sizing fans increases service life and improves acoustics, resulting in additional benefits to building owners and occupants

AMCA CERTIFIES FEI RATINGS                                                                                            

The AMCA Certified Ratings Program is certifying manufacturers FEI ratings for specific fan models, and sizing/selection software that supports FEI ratings. Because multiple fan models and motor/drive combinations can lead to compliant FEI-rated fan selections, manufacturer software is the most efficient way to access FEI ratings for design projects. Code compliance can be accomplished by comparing submittal documents with the energy code requirement.


  • Visit Booth #4852 for more information and an issue brief on FEI.
  • For hyperlinks to online FEI training modules, peer-reviewed technical papers describing FEI, PowerPoint presentations and other resources, visit www.amca.org/fei.   
  • For links to AMCA-certified manufacturer software supporting FEI, visit www.amca.org/certify and search by license type: FEI.

ASHRAE 90.1-2019 is now available at www.ashrae.org/bookstore.

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