Example: a low frequency (62 Hz) noise drone from several cooling fans at a food factory caused nuisance complaints. Because the low frequency sound attenuation of silencers is very poor, a standard silencer would have been able to reduce the low frequency noise drone by only 3 dB. This is such a small noise reduction that residents would not have noticed any difference in the fan sound.
We decided the best solution to reduce the low frequency fan noise was to use an advanced noise abatement technique. This was highly successful, reducing the low frequency noise drone by a massive 19 dBA. This solution achieved such a large sound reduction that it made the fans completely inaudible at the nearest house. It completely resolved the noise nuisance problem - and at low cost.
In addition, our advanced noise control solution improved fan performance. It meant that 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 different type of low frequency noise control solution been selected. Because they often increase the resistance to airflow, common noise reduction solutions such as a silencer often reduce fan performance, or increase energy consumption due to the fan speed being increased to compensate.
Our advanced low frequency noise control solution had another advantage over other sound reduction methods. It was made of steel only. This meant that the company could continue 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.
There are more examples of low frequency fan noise control onhow to reduce low frequency fan noise.
Low frequency sound / noise is particularly difficult to control and reduce. This is because the performance of common types of noise control solution such as a silencer, enclosure, screen, barrier, etc. is poor at low frequencies. So the best low frequency noise reduction solution is usually one that uses advanced technology to suppress the sound. Because it involves suppression of the sound generating mechanism at source, an advanced noise control solution can provide a much higher low frequency noise reduction. Often, it completely eliminates the low frequency fan drone, hum or whine sound. Consequently, there are many cases where our advanced sound reduction solution has succeeded in resolving a low frequency noise nuisance problem where other sound solutions have been tried but failed to provide enough sound reduction.
Although fans are the most common cause of low frequency sound, other types of machine and equipment also generate high levels of low frequency noise. Our solutions are highly effective for reducing low frequency sound on industrial machines, boilers and other equipment as well as fans.
You can see more details of our advanced noise solutions for nuisance caused by other types of industrial machine, boiler etc. onreduce low frequency industrial noise.
To find out how we can help you find a solution to a low frequency noise nuisance problem, please ring the number below orcontact us.
Note the photos on this page are illustrative only and not the fans described in this low frequency noise reduction example.