The VFD and motor models used for this calculation are based on constant volts per hertz ratio operation. In practice, other control settings are sometimes adopted to improve energy efficiency or to better match VFD output to actual fan operating conditions. This document does not provide selection guidance. Users shall ensure that selected components have sufficient capacity and are configured to produce the desired results. The purpose is to provide a consistent calculation procedure for comparing a pool of competing fan systems when actual test data are not available.