The best fan noise reduction solution is one that makes fans inaudible and provides large cost savings. This type of solution uses advanced technology to cancel the fan noise at source.
Due to their exceptionally high sound reduction, advanced fan noise control solutions often solve noise nuisance problems after products from other companies have been tried but failed to reduce the sound sufficiently. An advanced solution normally provides much higher noise reduction than other options like an acoustic enclosure, barrier / screen or silencer. It can also save thousands of pounds on the cost of fan noise suppression.
As soon as a company installed two new dust extract fans outside their wood-working factory, nearby residents started to complain about the noise, saying it was very loud and asking for fan soundproofing to be installed. The company fitted acoustic enclosures over the two fans at a cost of £6,000 (2003 prices). Noise nuisance complaints continued. The company then spent £8,000 installing an acoustic screen. Still, the complaints continued.
Then the company asked for our help. We designed an advanced fan sound reduction solution to suppress the noise at source. This achieved such a large noise reduction that the fans could no longer be heard at the nearest house. Complaints stopped immediately.
Our fan noise control solution cost a small fraction of the £14,000 that had been spent on the noise reducing enclosures and screen. Had they chosen our advanced solution first, the company would have saved £14,000 because the acoustic enclosures and screen were not needed.
When faced with complaints about a low frequency fan hum that residents found very loud and highly annoying, a food company fitted an exhaust silencer onto the air outlet. Complaints continued and residents said the noise was no quieter.
Then we were consulted. Our advanced fan noise solution decreased the fan hum by a massive 27 dB, and was so successful that the noise hum was completely inaudible at the houses - even at night.
Due to their large benefits, advanced solutions have proved highly popular and we have used them successfully to decrease fan noise on numerous extractors and dust extraction systems for many industrial companies and factories throughout the UK.
There are many more examples below for reducing noise from industrial fans, blowers, coolers, air conditioners, etc.
Companies often waste large amounts of money by choosing solutions that fail to provide enough sound reduction to solve the fan noise problem. Our experience and knowledge can help avoid this and enables us to determine the best and lowest cost solution. We use a range of specialist solutions to decrease fan noise that provide much higher noise reductions than other techniques, and which are not available from other companies.
Some companies treat the wrong fan, blower or noise source. This means they waste substantial time and money on fan noise mitigation measures that provide no sound reduction. We avoid this by carrying out a diagnostic noise survey to establish the main noise sources. Our diagnostic surveys use very sophisticated noise measurement equipment plus our considerable expertise to identify precisely which fans / blowers are causing the noise nuisance and how much sound reduction is needed for each. This enables us to tailor the fan noise suppression treatment precisely, which can provide considerable cost savings.
Our diagnostic tests also determine the main noise radiating surfaces within a fan or extraction system. This helps avoid wasted spending. For example, when faced with a noise problem, companies often fit an acoustic enclosure over the fan. Sometimes this provides no noise reduction. Our diagnostic tests can determine in advance whether an acoustic enclosure would provide a worthwhile sound reduction - or if there is a better solution that provides higher noise reduction at lower cost. An acoustic enclosure can cost £5,000 - £6,000 or more for a relatively small fan. So, our diagnostic tests can save companies thousands of pounds by helping them to avoid fitting an unnecessary acoustic enclosure. To maximise the cost savings, ask for our help before purchasing any fan sound mitigation products.
A large bakery company started receiving noise nuisance complaints from several local residents annoyed by a very loud low frequency hum. The hum fluctuated considerably in loudness, making it highly annoying. The bakery identified their bread oven as the source and fitted a silencer to the combustion air fan. This had no effect on the sound at the houses, so the bakery asked us how to decrease the fan noise. The bread oven has 11 fans. Using basic information about each fan and detailed frequency analysis of the sound, we quickly identified the source of the hum.
We found the source was not the combustion fan to which the bakery had fitted a silencer, but two small cooling extractor fans, nearby. Our advanced solution was applied to reduce the fan noise - it was designed specifically to silence the fan hum sound. This was so successful that it made the oven extractor fans inaudible at the houses, even at night - reducing the low frequency fan hum by 27 dB (a huge reduction). There have been no noise nuisance complaints since. Residents were so relieved the highly annoying hum was no longer audible that several wrote to thank the bakery company. Our solution had no effect on fan performance or oven cooling, so the company continued producing perfect loaves of bread!
Low frequency fan hums / drones are a very common cause of noise nuisance complaints. Usually the best method for this type of sound is to use a specialist fan noise reduction technique that uses advanced technology to cancel the hum / drone. This is because other fan noise suppression methods like an acoustic enclosure, screen or silencer provide very little reduction at low frequency, so they often fail to reduce hums or drones sufficiently.
Our advanced fan noise control solution has been installed on numerous extraction systems and has been highly successful, reducing low frequency fan hums by as much as 30 dB (which is a huge reduction). It usually eliminates the fan hum completely, making it inaudible. It also provides very large cost savings by avoiding the need to fit more expensive products such as a sound enclosure, screen, duct silencer, fan soundproofing, etc.
Our high performance fan noise solutions have proved successful on all types of industrial fan and blower, from small transport fans to large extractor fans, ventilation air handling units (AHU), HVAC units and everything in between. They have also been highly successful in commercial companies including hotels, offices - e.g. for computer cooling systems, gyms, etc.
.... or continue reading to see more benefits of our high performance solutions and more examples of how to reduce fan noise in factories and other industrial and commercial companies.
Below are more examples of how to reduce industrial fan noise and blower sound in a variety of applications. Some are case studies where industrial fans were causing noise nuisance to nearby residents (in some cases a noise abatement notice had been served). Some are examples where we have decreased fan sound for workers to comply with the Control of Noise at Work regulations. Many of the examples illustrate the major benefits that can result from using our advanced solutions, namely large cost savings and higher noise reductions than other sound attenuating methods like fan noise enclosures, screens and duct silencers.
A manufacturing company wanted to reduce workplace noise from an
airveyor system used to convey plastic bottles around a factory that manufactures product for the food industry. The conveying system uses a series of fans to transport the bottles. The company received a quote for £130,000 for acoustic enclosures to encase the conveying system. They then asked for our advice. Our diagnostic noise tests found the transport fans were the main noise source. Our fan sound reduction measures were applied, reducing the air conveyor noise by 6 dBA such that sound levels fell below the 85 dBA target. The total cost was about £2,500, so our fan noise suppression solution achieved the desired noise reduction while saving the company about £127,000.
A printing company wanted to reduce the noise from a paper waste extraction blower. The blower was annoying local residents who asked the factory to install fan soundproofing. The company went to an acoustic product manufacturer who installed an acoustic enclosure around the blower. However noise nuisance complaints continued - so the noise enclosure was not only expensive but unsuccessful. The factory then asked our industrial fan noise reduction company how to reduce the blower noise. We found that the problem was caused by a very loud and annoying low frequency tone (
hum) emanating from the blower. We designed an engineering noise cancellation modification targeted specifically at suppressing the noise tone (
hum). This was highly successful, achieving a 19 dB reduction in the noise tone such that it was no longer audible. Complaints stopped immediately. Had our high performance fan noise solution been fitted first, it would have saved the company several thousands of pounds because an acoustic enclosure would not have been needed.
A sawdust waste extract system was causing noise nuisance to residents in a nearby housing estate. First, the company fitted a steel acoustic enclosure over the large main extractor fan in an attempt to solve the noise problem. Complaints continued. So they fitted a large wooden fence around the extraction system. Complaints continued. Then the company found us and asked us how to decrease the extractor fan noise.
Our diagnostic noise survey found that sound reducing measures were needed for both the large extract fan plus the small transfer fan. These centrifugal fans emitted a loud whine and hum, which were the cause of the nuisance problem. We designed an advanced solution for both fans using noise cancelling methods. This noise suppressing treatment was very successful, reducing the whine from the large fan by 25 dB and the hum from the small transfer fan by 20 dB. Our high performance fan noise solution made both fans inaudible at the housing estate. Complaints ceased immediately.
Following complaints from nearby residents about the noise from a smoke scrubbing extraction system, the company contacted the equipment supplier who fitted noise insulation muffling around the extractor fan. Complaints continued, so the company installed a tall fence to form an acoustic barrier around the fan, the exhaust stack and scrubber. Complaints continued, so we were asked how to reduce the blower noise.
Our measurements showed that it was necessary to suppress the low frequency fan hum and also decrease the overall fan sound level by at least 15 dBA. Our silencing solution achieved this and was so successful that it made the fan inaudible at the houses - in fact it could only be heard when standing close to the fan and scrubber.
Had they used our solution first, the company could have avoided spending money on the fence and fan muffling material that failed to solve the problem. This would have saved them a considerable amount of money.
Nearby residents were being kept awake by a loud whine sound from an industrial extractor fan that expelled air to the exterior through the wall of a sweets manufacturing factory. Because the centrifugal fan operated all night, a very large sound reduction was needed. A standard duct silencer / attenuator would have been able to decrease the whine sound by only about 10 dB, which was nowhere near enough. So we designed a high performance exhaust silencer. Our silencing method was highly successful, reducing the fan whine by a huge 25 dB such that it was no longer even audible at the nearest house. Our fan silencer was designed for very low airflow resistance as well as high noise attenuation and had negligible effect on the fan's extraction performance.
A manufacturing factory wanted to install soundproofing on a coater machine that was exposing workers to high sound levels within the factory. Due to the high cost, they consulted our fan noise reduction company first. Our diagnostic survey found that the main noise source was a pair of axial fans used for cooling the coater machine drier. We purpose-designed a small, compact duct silencer to suppress the axial fan sound. Our silencing solution was highly successful. It managed to reduce the fan noise by 14 dBA, to well below the 85 dBA legal limit in the noise at work regulations. It cost considerably less than soundproofing the entire coater machine.
A low frequency drone from several roof mounted axial extraction fans prompted complaints from nearby residents. The axial fans operate all day and night to provide cooling and ventilation in the food industry. The cooling fan exhausts radiated most of the sound. Fitting exhaust silencers in the duct-work would not have worked because they provide little sound attenuation at low frequencies - a standard fan silencer / duct attenuator would have provided only 3 dB reduction, a barely detectable difference. Also, the hygiene requirements of the food industry meant the extraction system had to be cleaned with high pressure water jets. This would have soaked and damaged the noise absorbing material inside a silencer, making it even more ineffective. The problem was how to reduce the fan noise drone without using a silencer/duct attenuator.
We designed an engineering solution to cancel out the fan drone sound. This provided a huge 19 dB reduction in the low frequency drone, making the cooling fans completely inaudible at the nearest house. As well as achieving 16 dB higher sound reduction, our solution cost less to install than a fan silencer. Because our fan noise mitigation modification was entirely made from steel, it could withstand high pressure water cleaning without being damaged and with no loss of sound reduction. Fan noise suppression using an engineering solution can provide large benefits compared with duct silencers.
A low frequency cooling fan drone (100 Hz) was causing nuisance to local residents at night. Normal fan exhaust silencers would have provided little noise attenuation at this low frequency. We designed fan noise mitigation modifications for the outlet duct. This converted the duct into a silencer tailored to suppress the 100 Hz low frequency. This specialist silencing technique was very effective, reducing the low frequency fan drone by 14 dB such that it was inaudible to local residents - silence !
A cardboard manufacturer asked for our help. Their cardboard trim waste extract fan was exposing nearby workers to 89 dBA. We solved the problem by fitting a simple fan noise suppression solution to the intake of the existing ducting. This silencing method achieved an 8 dBA reduction, lowering workers' noise levels to 81 dBA for very low cost.
We designed specialist fan muffling treatment for a centrifugal blower that blows air onto the product to clean it. This silencing method was very successful, reducing the noise by 9 dBA. The resulting noise level was 81 - 82 dBA at nearby workers, well below the legal limit for noise at work. We also used advanced technology to design a noise cancellation modification to reduce a loud, highly annoying whine that was emitted by the blower. This achieved a massive 32 dB reduction, making the blower whine inaudible.
A large, well-known UK manufacturer of white goods asked us for a fan noise control solution after local residents complained about noise nuisance. Our diagnostic noise survey found the main cause of the annoyance was a pair of centrifugal extract fans, one large and one small. We designed an advanced solution for cancelling the fan hums that were annoying the neighbours. This specialist fan noise reduction technique decreased the fan hums by 11 and 14 dB respectively. There were no further noise nuisance complaints.
A company wanted to reduce the noise from a large furnace fume extractor fan at a manufacturing factory. They decided against installing an industrial fan noise enclosure due to the high cost. We designed fan soundproofing measures using specialist sound-deadening materials that were applied to the exterior of the centrifugal fan casing. This lowered the sound level by 12 dBA, which was more than sufficient to achieve the 85 dBA noise at work limit.
A manufacturing company was considering fitting expensive soundproofing to some extractor blowers when they discovered us and asked us how to reduce industrial fan noise. Using detailed narrow band frequency analysis, our diagnostic noise measurements showed that worn bearings were the cause of the high noise levels. Renewing the bearings decreased the sound from 87 dBA to 83 dBA, easily achieving the 85 dBA target for nearby workers - a very low cost fan noise control method !
An industrial blower on a drier was causing noise nuisance and annoyance to local residents. Our diagnostic survey showed that the main cause of the nuisance was a loud low frequency drone from the blower, which residents found highly annoying. We designed an advanced fan sound abatement solution to cancel out the drone. This was highly successful, reducing the drone by a huge 22 dB with no loss of blower performance. Afterwards, the blower was inaudible at the houses.
Our industrial fan noise reduction specialists designed small airflow noise mitigation measures to attenuate the sound from some paint booth ventilation extractor fans. These lowered the noise to 75 dBA (a 6 dBA sound attenuation), easily achieving the company's 80 dBA target for nearby workers. There were no installation costs - our fan sound control solution merely required small adjustments to be made by the company's maintenance workers at negligible cost.
An industrial extract fan used for ventilation was exposing workers to 85 dBA. We were able to reduce the noise to 79 dBA with just a bucket of water - an extremely low cost fan sound control method!
A low frequency hum sound was annoying local residents. We used specialist survey equipment to measure the noise then analyse it. This showed that the source of the hum was a very large scrap extraction fan located outside the factory. A very high sound reduction was needed because the fan operates all night.
Our noise abatement solution used advanced technology to cancel out the fan hum, and was so successful that the hum became inaudible at the nearest house. A 19 dB attenuation in the hum sound was achieved. This was considerably higher than could have been provided by fitting a fan exhaust silencer / duct attenuator. Our noise cancellation solution was entirely made from steel, so could withstand all kinds of weather including any rain water that entered the fan via the exhaust stack. There was no loss in extraction performance.
The above examples show that our fan noise control solutions can provide exceptionally large sound reductions and considerable cost savings compared with other fan noise mitigation methods such as acoustic enclosures, screens, barriers, fan soundproofing, silencers etc. Another benefit of our specialist fan noise solutions is that they do not restrict airflow, so there is no loss of suction or extraction performance. This contrasts with some types of silencer, which can reduce fan and extraction performance due to their high airflow resistance.
Where the air is very dusty or dirty a duct silencer can become clogged, which can considerably impair the sound reduction achieved. Our advanced / engineering fan noise reduction solutions do not clog and are completely unaffected by dust or dirt in the airflow.
Silencers can be unacceptable in the food, drinks and pharmaceutical industries for hygienic reasons, due to the risk of contamination from the silencer absorption material. Our advanced noise control solutions are fully hygienic and contain no material that could contaminate food, drink or pharmaceutical products.
Where our advanced fan noise control techniques cannot be applied and a very high sound reduction is needed, we often purpose-design a high performance fan silencer that combines very high attenuation with negligible resistance to airflow.
However, in some applications a standard commercial attenuator is the best and lowest cost option (attenuator is another name for a silencer). There are many different types and sizes of attenuator, each with a different noise reduction. When selecting a duct attenuator, it is important to choose a type, size and specification that provides the necessary noise reduction. If an attenuator is selected at random, there is a high risk that it won't provide enough noise reduction. This happens often, wasting time and money. To avoid this, when selecting a duct attenuator it needs to be matched carefully to the noise characteristics of the fan. We can advise on suitable fan attenuators for any particular application.
Our specialist fan noise suppression company offers high performance sound attenuation solutions to manufacturing, industrial / commercial companies and factories throughout the UK. Companies can benefit from much higher noise reductions and save thousands of pounds by choosing our advanced fan noise reduction techniques instead of more expensive, less effective options like acoustic enclosures, screens and barriers.
For a costing, or to find out how our specialist fan noise reduction company can help you suppress industrial extractor fan or blower sound on AHU (air handling units), HVAC ventilation units, air conditioner systems, etc., contact us or ring the 'phone number below.
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