If we wish to know the sound power transmitted through a fan and ducting system, it is preferable to take measurements ‘induct’ in accordance with ISO 5136. Sometimes, however, it is necessary to know the noise around the fan, which may have broken out through its casting and local ducting or been emitted through an open inlet and/or outlet. This document is available only in English.
Eurovent 8/17: Presentation of acoustical data of industrial fans
