BO-75-06-2 -- Fan Selection and Installation PDF

This paper covers selection and installation of ventilating fans and some guidelines for the attenuation of fan noise. The purpose is to give the airhandling system design engineer typical fan noise values for estimating the noise a fan will radiate to a ventilating system. The types of fans considered are centrifugal and axial fans of the type normally used with duct systems in central station air-conditioning systems and industrial ventilating systems.

Fan noise is reported in terms of sound-power levels and is calculated from noise measurements taken in a semi-reverberant room using a calibrated reference sound source and the substitution technique. The present code does not cover field measurements. The fan industry reports fan noise in terms of sound power level re 10-12 watt in the 8 octave bands with center frequencies of 63, 125, 250, 500, 1000, 2000, 4000, 8000 Hz. Laboratory fan noise measurement techniques are specified by the Air Moving and Conditioning Association (AMCA Bulletin 300-67, Standard Test Code for Sound Rating Air Moving Devices).