6. Acoustic installation effect

6.1 Definitions, causes and examples

The installation effects, or system effects, of fans form a significant part of the studies carried out on fans, due to their practical importance. When a fan is integrated into a circuit, be it a ventilation duct or a machine, its aeraulic and acoustic (or even vibratory) characteristics can sometimes be very different, most of the time unfavorably, from those recorded on a standardized test circuit. In other words, a fan may be less noisy than others when tested alone, but noisier when integrated.

It is therefore important to understand, anticipate and seek to reduce these differences in performance, in order to correctly select and size the fan to suit the circuit. If system effects are not taken into account, there...