Low Frequency Noise Reduction for Fan Hum

Example: a low frequency (62 Hz) noise hum 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 hum 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 hum was to use an engineering noise abatement technique.  This was highly successful, reducing the low frequency noise hum 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 engineering 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 engineering 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 noise control for a fan hum on how to reduce low frequency fan noise.

Attenuating sound on this industrial fan, large cyclone and duct
A solution to control low frequency roof extractor fan noise

Comments on low frequency noise reduction for fan hum & machines

It is particularly difficult to control and reduce low frequency sound. 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 hum, drone 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.

Reduce Noise for Vibratory Bowl Feeder, Linear Vibrating Feeder

Although fans are the most common cause of low frequency hum sounds, other types of machine and equipment also generate high levels of low frequency noise.  Our solutions are highly effective for reducing low frequency hum sounds on industrial machines, boilers and other equipment as well as fans. The vibratory bowl feeder in the photo is another example of our low frequency noise reduction successes. We have over 35 years’ experience of successfully suppressing low frequency noise all types fan and industrial machine in food, pharmaceutical and all other types of factory.

You can see more details of our advanced noise solutions for nuisance caused by other types of industrial machine, boiler etc. on reduce low frequency industrial noise.

How to get our help with low frequency noise reduction for a fan hum & machine sound

To find out how we can help you reduce a low frequency hum noise on a fan or industrial machine :

For help with a noise problem contact us
or call us on 01727 864667

Note the photos on this page are illustrative only and not the fans described in this low frequency noise reduction example.