Fan hums / drones are a common cause of noise nuisance affecting residents living near factories and other commercial companies. These hums / drones are usually at a low frequency. Normal fan silencers only provide a small noise reduction at low frequencies, which means they often fail to reduce the noise sufficiently to prevent noise nuisance complaints. Our specialist duct silencer provides very high noise reduction at low frequencies so has solved numerous noise nuisance problems where normal industrial silencers had failed to resolve the problem. Our duct silencer usually makes hums / drones inaudible at the nearest houses to the factory / commercial company.
Our specialist silencer usually imposes negligible pressure loss, so has no noticeable effect on fan performance. In contrast, to achieve a high noise reduction, a standard industrial silencer often imposes a high pressure loss and this can cause an unacceptable loss of fan performance, suction or extraction.
We have two types of specialist duct silencer. One is designed to target fan hums, drones or whines and provides a very high reduction in the hum, whine or drone sound. This type of silencer is extremely popular because most fans and blowers produce a loud hum / drone or whine, which frequently causes noise nuisance. It is suitable for industrial fans and most other types of fan. There are many examples where this type of attenuator has provided a very high noise reduction for a fan hum / drone / whine on our main fan noise control page: reducing fan noise.
Fan hums / drones / whines produce a large noise peak at a single frequency. So our specialist silencer is designed to provide a very high noise reduction at that frequency. On some fans, a hum / drone / whine is not the dominant feature of the sound, and noise reduction is needed over a wide range of frequencies. In such cases and where a standard industrial silencer cannot provide sufficient noise reduction, we purpose-design a special duct silencer that provides high noise reduction over a wide range of frequencies. We design this type of attenuator in such a way as to provide a very high noise reduction combined with a very low (negligible) pressure loss, i.e. very low resistance to airflow. So, there is little or no loss of suction, extraction or airflow rate.
This specialist duct silencer has been highly successful on many different types of fan / blower and in most types of industry and factory. We design our industrial silencers according to the noise reduction needed. A noise reduction of 15 - 17 dBA is typical for this type of extraction fan silencer, but in some cases has been as high as 25 dB where a very high noise reduction is needed. Where a lower noise reduction is sufficient, we design a smaller attenuator. This minimises the cost. With a smaller, lower cost silencer, the typical noise reduction is in the region of 8 - 10 dBA.
Noise from a sweets factory fan outlet was causing nuisance to local residents and keeping them awake at night. This produced a loud whine that was highly annoying and disturbing residents' sleep. A very large reduction was needed. A standard exhaust silencer would only reduce the whine by about 10 dB, which would have been insufficient to avoid further noise nuisance. So we purpose-designed a specialist fan exhaust silencer. This was highly successful, providing a 25 dB reduction in the whine sound, making the fan inaudible at the houses. We designed the exhaust silencer with very low airflow resistance so it had no noticeable effect on the extraction performance. This contrasts with some types of fan exhaust silencer that reduce the airflow substantially due to their high resistance.
Our specialist extract fan silencer has provided high noise reduction on many different types of industrial fan, including extract, supply and exhaust fans as well as axial and centrifugal fans and blowers. Although we specialise in industrial silencers for factories, our specialist duct silencer can be used on any type of fan or in any environment, and for commercial companies - not just in an industrial factory.
To find out how we can help you with a high performance fan silencer for a noise problem (industrial or commercial), please contact us or ring us on the number below.
Please note: our specialist duct silencer is most suitable for industrial fans and blowers at manufacturing companies or in medium or large commercial firms.
For more information on our fan noise cancelling technique, see cancel fan noise drone or hum.
Note: the above photos are illustrative only and do not show the exhaust fan described in the sweets factory example.