Attenuating Extractor Fan Noise Nuisance for Industry
Attenuating low frequency extractor fan hums and drones can be very difficult. Fitting standard silencers and attenuators into the ductwork usually only achieves a small noise reduction at low frequencies. A specialist, advanced technology type of solution can provide much higher reductions in low frequency extractor fan noise. This type of solution can attenuate low frequency hum and drone sounds by over 20 decibels.
The above picture shows an example where this specialist type of solution has been used for attenuating the sound from two cooling extractor fans in the food industry. These blowers were producing a very loud hum sound that caused considerable annoyance to local residents over a wide area around the factory. The food company first tried attenuating their combustion air supply fan by fitting a silencer to the intake. This did not reduce the sound at the houses. So they asked us to help.
Our survey quickly identified which fans generated the annoying hum. It also found that a large noise reduction was needed because the fan hum was very loud and the food factory operates at night. We designed a high performance fan noise attenuating solution. This was highly successful, attenuating the fan hum by 27 decibels – making the hum completely inaudible at the houses even at night.