Low Frequency Noise Reduction
Low frequency noise is a very common cause of nuisance for residents living close to an industrial factory. It is also the hardest type of sound to reduce, and it is difficult to achieve a high noise reduction using common noise control techniques. We have a range of specialist low frequency noise reduction solutions that suppress the noise at source, which means they provide very high noise reduction – as well as being low cost to install. Here are a few examples of our highly effective low frequency noise solutions:
Low Frequency Noise Reduction for Fan Hum
Fan hums and drones are the most common source of industrial low frequency noise nuisance. Example: a low frequency noise hum (62 Hz) from several cooling fans at a food factory caused nuisance complaints. Because the sound attenuation of silencers is very poor at low frequencies, a standard silencer would have been able to reduce the hum sound 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 for a fan hum on low frequency fan noise control.
How to achieve Low Frequency Noise Reduction for Fan Hum
It is particularly difficult to control and reduce low frequency sound. This is because the performance of common types of noise control product such as a silencer, enclosure, screen, barrier, etc. is poor at low frequencies. So the best method of low frequency noise attenuation and cancellation 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 noise reduction. Often, it completely eliminates the low frequency fan hum, drone or whine sound, such that it is no longer audible. Consequently, there are many cases where our advanced sound reduction solution has succeeded in resolving a 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 hum sounds, other types of machine and equipment also generate high levels of this type of 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 40 years’ experience of successfully suppressing 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.
Low Frequency Noise Reduction Techniques for Fans and Machines
Because low frequency noise is so difficult to reduce using normal sound control products, special methods are needed. The best low frequency fan noise reduction technique is usually one that uses advanced technology to suppress the noise at source by smoothing out turbulence in the air flow. Alternative techniques include specialist silencers that are specifically designed to suppress low frequency fan noise.
The best low frequency noise reduction technique for machines depends on whether the noise is airborne or structure-borne. We use sophisticated noise and vibration analysis and measurement equipment to diagnose the main noise transmission path. Once we have done that we determine the optimum solution that provides the noise reduction needed at minimum cost. If the main transmission path is structureborne, the best low frequency noise control technique is often to install a high performance type of vibration isolation material. There is an example of this on compressor low frequency noise reduction (see compressor noise control for an office).
How to get help with low frequency noise reduction – machine & fan hum
We have over 40 years’ experience in reducing industrial noise for all types of machine in all types of factory throughout the UK. Our specialist solutions often provide both higher sound reduction and large cost savings compared with other sound control methods. Due to their exceptionally high noise reduction, our low frequency noise specialist solutions often solve noise nuisance problems after other methods from other companies’ have been tried and failed to provide enough sound reduction. 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.