ARLINGTON HEIGHTS, Ill. — Air Movement and Control Association (AMCA) International Inc. announces the revision of ANSI/AMCA Standard 204, “Balance Quality and Vibration Levels for Fans.”

Covering fans with rigid rotors generally found in commercial-building HVAC, industrial-process applications, mine/tunnel ventilation, and power-generation applications, ANSI/AMCA Standard 204 underwent minor revisions, including:

•           Reformatting to adhere to current style;

•           Changes to definitions for alignment with other standards;

•           A new suggested frequency range for overall vibration measurement;

•           Updates to the latest version of referenced standards; and

•           Inclusion of an example showing a typical calculation of overall vibration level from a vibration signature captured using a fast-Fourier-transform (FFT) analyzer.

The cost of ANSI/AMCA Standard 204-20 is $45 for AMCA members and $90 for non-members. To purchase, visit AMCA’s online store at