Low frequency noise reduction at a food factory
A low frequency (62 Hz) noise drone from several cooling fans at
a food factory caused a noise nuisance complaint. Because the low
frequency performance of silencers is very poor, a standard silencer
would have reduced the low frequency noise drone by only 3 dB. This
is such a small noise reduction that residents would not have noticed
Using an advanced noise abatement technique, we reduced the low
frequency noise drone by 19 dBA. This corresponds to a massive 99%
reduction in noise energy. The solution achieved such a large noise
reduction that it made the fans completely inaudible at the nearest
house. Furthermore, it resolved the noise nuisance problem at low
The advanced noise control solution also improved fan performance.
Consequently, the fans needed to operate less often to maintain
the required temperature. This reduced energy consumption. This
would not have been the case had a common type of noise control
solution been selected. Because they often increase the resistance
to airflow, common types of noise reduction solution such as a silencer
often reduce fan performance, or increase energy consumption due
to the fan speed being increased to compensate.
The advanced low frequency noise control solution had another advantage
over common types of solution. It was made of steel only. This meant
that the company could continue the practice of cleaning each fan
and duct with water jets. This would not have been possible had
silencers been fitted. This is a very important consideration in
the food industry because of their strict hygiene requirements.
General comments on low frequency noise reduction
Low frequency noise is particularly difficult to control and reduce.
The reason is that the performance of common types of noise control
solution such as a silencer, enclosure, screen, barrier, etc. is
poor at low frequencies. Because it involves suppression of, or
breaking up the noise generating mechanism at source, an advanced
noise control solution can provide a high noise reduction at any
frequency. Often, it completely eliminates the low frequency noise
drone, hum or whine. Consequently, there are many cases where an
advanced noise reduction solution has succeeded in resolving a low
frequency noise nuisance problem where other types of solution have
Some more examples of low frequency noise control solutions are
shown on the Industrial Noise Control - Noise
Nuisance page of this web site with costs.
To find out how we can help you find a solution to a low frequency
noise nuisance problem, or to receive our company brochure or a
quotation, please click on contact us about low frequency noise reduction.
Advanced Noise Solutions Ltd : 01727 864667
could help you save £ thousands on low frequency noise solutions