Attenuate Fan Noise at Low Frequency
How best to attenuate fan noise where the main problem is a low frequency hum or drone causing nuisance to nearby residents? The common solution is to fit an attenuator into the duct and install acoustic enclosures, screens or acoustic louvres. However these noise solutions usually only achieve a small reduction in low frequency noise. Most companies are unaware that there is a specialist type of solution available that uses advanced technology to provide a much higher reduction in low frequency fan noise.
This specialist type of solution usually attenuates low frequency fan hum and drone sounds by such a large amount that it makes them completely inaudible to residents living near the factory or industrial building where the fans are located. In contrast, common types of solution usually achieve some reduction in low frequency noise from the fan, but often not enough to stop local residents complaining.
Using this technologically advanced type of solution we have solved numerous noise nuisance problems after other companies’ attempts using other noise control techniques failed to provide sufficient noise reduction to solve the nuisance problem.
Time and Cost Savings for Companies and Environmental Health Officers
Due to their exceptionally high noise reduction, our specialist solutions usually solve noise nuisance problems immediately. This can save time and money for the company that operates the noisy fan by avoiding the need for repeated attempts at reducing the noise, as can occur when less effective sound attenuation techniques are installed.
It can also save the time of the Environmental Health Officer at the local Council. If residents continue to complain to the Council after a sound attenuation product has been installed and failed to provide enough noise reduction, the Environmental Health Officer will have to contact the company making the noise and ask for further noise reduction. This can entail another visit to the complainant’s property to re-assess the noise and decide if it still constitutes a nuisance. By solving the noise problem at a stroke our specialist solutions minimise the time that Environmental Health Officers spend resolving the complaint.
Example of Bakery Fan Sound Attenuation
The above picture shows an example where our specialist technologically advanced type of solution was used to attenuate fan noise nuisance from a bakery in the food industry. Residents were complaining about a very loud low frequency hum which caused considerable annoyance at houses spread over a wide area around the factory. The loudness of the fan hum oscillated up and down considerably and repeatedly over a short interval, which made it highly annoying. The bakery operates 24 hours and some residents reported that the fan hum kept them awake at night.
The local Environmental Health Officer told the bakery that he had received numerous noise nuisance complaints and asked the food company to reduce the fan noise. The bakery realised that the loud hum was caused by a fan in their oven area. The company first tried to attenuate their oven combustion air supply fan by fitting a silencer to the intake. This did not reduce the sound at the houses at all. So the bakery asked us to help.
There are 11 fans within the bakery oven area so we used a detailed diagnostic noise survey and analysis to identify the cause of the fan noise nuisance. We very quickly found that the highly irritating hum causing the nuisance was created not by the combustion fan as suspected by the bakery, but by two cooling fans located on top of the bakery oven. These are shown in the above photo.
We also found that a very large noise reduction was needed because the fan hum was very loud at nearby houses and the food factory operates at night. Our specialist advanced technology solution was used to attenuate the fan noise. This was highly successful, reducing the fan hum by a very large 27 dB, making the hum completely inaudible at all the houses, even at night.
Afterwards residents were so relieved that the highly annoying fan hum had gone that many of them wrote to the Environmental Health Officer saying they could no longer hear the noise and thanking him and the bakery. He passed these thanks onto the bakery company.
How to get our Help to Attenuate Fan Noise
Our advanced technology, high performance noise solutions can be applied to all types of industrial fan and blower and in all types of factory and medium to large sized commercial company. For more information and examples on how to attenuate fan noise and low frequency hums, see cancelling fan noise.
To find out how we can help you attenuate fan noise nuisance and low frequency hums and drones, contact us as shown below: