Despite the fact that the noise from a ventilation fan has no positive effect on fan performance but it causes nuisance to the system end user. Optimum designs consider low noise fans/equipments to avoid noise complaints. However, the demand of incresed performance make it challenging to satisfy the both airflow and noise requirements at same time. Origin of fan noise Fan noise can be contribution of several sources. For instance, Aerodynamic noise can be the result of turbulence caused by the blades of a rotating fan. Frequency and magnitude of noise gerenration is directly proportional to speed of ventilation fan. Vibrations can ……….. Practical methods of controlling fan noise
Aircoustics suggest following simple methods of
reducing noise from fans:
- Using damping—layer damping and constrained
layer damping; - Modification of supports to avoid obstacles before and after the fan
- Lining ductworks with foam or fiberglass;
- Changing fan speed controllers to reduce speed for
axial or centrifugal flow fans;
to be continue……….
