1. Purpose

AMCA Publication 201 includes general information about how fans are tested in the laboratory and how their performance ratings are calculated and published. It also reviews some of the more important reasons for a decrease in fan performance that may occur when the fan is installed in an actual system. Allowances, called system effect factors (SEF), are also given. The SEF must be taken into account by the system design engineer if a reasonable estimate of fan/system performance is to be determined. It must be appreciated that the SEF given in this manual are intended as guidelines and are, in general, approximations. Some have been obtained from research studies. Others have been published previously by individual fan manufacturers, and many represent the consensus of engineers with considerable experience in the application of fans.

2. Scope

ANSI/AMCA Standard 210 offers the system design engineer guidance as to how the fan was tested and rated. AMCA Publication 201 helps provide guidance as to what effect the system and its connections to the fan have on fan performance. Recognizing and accounting for losses that affect the fan’s performance in the design stage will allow the designer to predict the installed performance of the fan with reasonable accuracy. Fans of different types and even fans of the same type, but supplied by different manufacturers, will not necessarily react with the system in the same way. It will be necessary, therefore, to apply judgment based on actual experience in applying the SEF. The SEF represented in this manual assume that the fan application is generally consistent with the method of testing and rating by the manufacturer. Inappropriate application of the fan will result in SEF values inconsistent with the values presented. Mechanical design of the fan is not within the scope of this publication.