Noise Control - Profit from Best Practice to Minimise Costs
Innovations and new technology in occupational and environmental noise control provide 50% - 80% cost savings over conventional techniques such as acoustic enclosures, silencers, lagging...
Our reputation as the major UK provider of innovative, engineering noise control techniques is a reassuring guarantee that we can solve your noise control problems in the most practical and cost effective manner possible. Many of our solutions are accepted as defining current noise control "best practice" - particularly where maintenance, access, hygiene and productivity are important. In fact there are many examples of companies actually making a profit by implementing our recommendations through increased productivity and reduced down-time. Click below to select case studies of specific interest.
 Self - Financing Noise Control - profit from noise control that pays for itself...
 Occupational Noise Control Audit - cost your options using current best practice as required by the regulations
 Buy Quiet noise purchasing policy - template buying policy and training that cuts the cost of quiet new plant
 More Sound Solutions - engineering noise control at source case study database
 Fan Noise Control + Quiet Fan technology - lower cost, increased efficiency, no maintenance
 Hygienic Noise Control - food, pharmaceutical, electronics and other clean industries where hygiene is critical
 Dynamic Vibration Absorbers - bolt-on vibration dampers to reduce noise and vibration
Burner and Combustion Noise Control at Source - the only known yoghurt based noise attenuation technology
 Impact Noise Control - rugged, quiet and dramatically lower cost impact noise attenuation
 Environmental Noise Control - examples of the same technology used in environmental noise reduction projects
Occupational Noise Control Best Practice: Step-by-Step Guide
 Contact us to discuss specific items of noisy plant or the results of your noise assessment
We may already have a noise control solution and a similar case study available - or we may be able to provide you with an initial diagnosis free of charge via email at very low cost. More on the Remote Control of Noise >
 Carry out a Noise Control Audit - find out what your options are, the benefits and what they would cost
Our engineering audit provides you with a list of the noise control options with costs and estimates of the noise reduction as the basis for your best practice occupational noise control programme. Available for a single machine or as an update to a conventional noise assessment across a whole site. Download the Noise Control Audit technical note > [280kB pdf]
 Provide detailed noise control recommendations - typically 50% - 80% cost savings, or even self financing
We then develop detailed noise control recommendations for the options selected from the Noise Control Audit. These are provided in a form that can be implemented by any competent engineer (in-house or contractor). The typical cost saving over conventional noise control projects is 50% - 80%. Download the Self Financing Noise Control technical note > [608kB pdf]
 Implement the noise control measures and re-evaluate occupational noise levels
We liaise during implementation to ensure optimum performance of the noise control modifications. Re-assess noise levels and then alter or eliminate your PPE and audiometry requirements.
Contact us to discuss the options to minimise your occupational noise control costs |
Self-Financing Noise Control - Innovation and New Technology
This graphic shows examples of Self-Financing Noise Control projects across a wide range of plant categories. These illustrate not only the cost savings that are often inherent in engineering noise control measures compared with enclosures, silencers etc, but also the estimated pay-back period after which the modifications will generate a profit. In many cases, the noise control modifications can be justified simply on the grounds of increased performance and productivity, with the noise reduction as an additional benefit. Summaries of some of the features of these examples are listed below. Download the self financing noise control technical note > [608kB pdf]
- vibratory feeders: elimination of fatigue, increased product feed rate by 100%
- fans: eliminated silencer losses and down-time
- weighing machines: elimination of acoustic enclosures, improved access for maintenance and cleaning
- burners: conventional noise control measures insufficiently effective to avoid requirement to shut-down plant
- power presses: enclosures eliminated - reduced down-time
Occupational Noise Control Audit
The new occupational Control of Noise at Work Regulations require a seismic shift in attitude to noise management in the workplace. Quoting the guidance - “these regulations are concerned with controlling noise, not measuring it...”. Consequently, companies must now quantify their noise control options rather than simply repeating risk assessments that usually include little or no information on the topic. Moreover, PPE can no longer be used for long term risk management unless it can be proved that noise control is impractical.
We can also provide the audit as part of benchmark noise assessment.
| Instead of paying for unnecessary repeat risk assessments under the new regulations, implement a noise control programme that actually reduces the risks - and potentially pays for itself ... |
The most effective way to meet these regulatory requirements is the INVC Occupational Noise Control Audit - either in place of a repeat risk assessment (saving the associated costs) or appended to a conventional risk assessment update. It is an engineering audit that generates a costed list of the noise control options and associated benefits either for a single machine or for a whole site using the best of current technology. The results not only provide the basis for planning the most practical and cost effective noise control programme possible, they also provide certification for plant where it is shown that noise control is not practical. Download the technical note here>> [280kB pdf]
Buy Quiet Noise Purchasing Policy
Do not let your suppliers waste your money on noise control that is not best practice
Implementing and policing a noise buying policy for new plant can either be the single most cost  effective - or one of the most expensive - long term noise reduction measures that a company can take. The difference lies in the way that the noise buying policy is implemented. As most suppliers have little or no noise control expertise, they tend to purchase off-the-shelf enclosures, silencers and materials which they then mark-up and sell-on instead of using an effective diagnostic process to determine why the machine is noisy. In some cases, suppliers have been known to continue selling enclosures (even when they know there are cheaper and more effective engineering alternatives) - simply because they are more profitable...
As the objective is to achieve an installed noise level of <80dB(A) (de-regulation) or <85dB(A) (advisory PPE, no audiometry), the target noise level for an individual machine has to be set lower than these figures to allow for the additive effect of multiple machines. The measurement used is the highest ( Leq) noise level at any point 1m from the plant at a height of 1.5m and at any operator position(s) under realistic operating conditions.
The fact that this vibratory grader generated 99dB(A) was picked-up by a company using our noise buying policy. The supplier was suggesting additional screens and guards at high cost and with no guarantee as to the final noise level. One of our engineers carried out diagnostic tests during proving trails at the supplier and the company purchased the line subject to implementation of the recommended engineering noise control at source measures. These reduced the noise to 85dB(A) at a cost of a few £hundred as against the £several (with access and hygiene issues) previously suggested.
Any suggested noise control measures must be justified by supporting evidence based on source diagnosis and ranking. If this information is not available, then the noise reduction techniques are based on guesswork and are highly unlikely to constitute best practice - with consequent implications re cost and productivity. If the supplier does not have the necessary expertise, then an expert engineering evaluation of the options must be carried out (our engineers regularly provide this technical support) and the plant purchased subject to implementation of agreed best practice noise control measures.
Contact us to discuss Buy Quiet noise purchasing policy template and technical support options and Buy Quiet training.
More Sound Solutions - Noise Control Database
More Sound Solutions is a large collection of low cost engineering noise control case studies that do not involve enclosures (continuing the above theme). This is the ideal starting point for anyone with a noise problem as it provides a showcase for
current “best practice” in noise control - as illustrated by the examples below.
Back to top   Contact us for more information on minimising your occupational noise control costs 
SAMPLE NOISE CONTROL CASE STUDIES
Quiet Fan Technology (QFt) - Fan Noise Control without silencers 
This is a unique noise control technology we have developed that sidesteps conventional noise control techniques completely. It permanently eliminates tonal noise at source for the life of the fan at a fraction of the cost of conventional silencers, enclosures and lagging - and without reducing fan efficiency (unlike conventional silencers). Applications include: extract fans, ID fans, chillers,
air conditioning, process and ventilation fans...
More details and extensive case studies on innovative fan noise reduction
Download the fan noise reduction technical note > [460kB pdf]
Scrap Fan Occupational and Environmental Noise Control
High levels of tonal noise from scrap can fans were causing both occupational and   environmental noise problems. Instead of fitting conventional noise control measures in the form of silencers, enclosures and lagging at a potential cost of £30k or more per system, our bespoke Quiet Fan technology (QFt) was fitted inside the fan casings in a matter of hours to give an overall noise reduction of 22dB(A) at an installation cost of c £200/fan.
 Unlike silencers, the noise control modifications had no effect on fan efficiency, are unaffected by the passage of scrap cans and will last the lifetime of the fans without maintenance. This picture is of a modified fan showing no visible sign that it now generates less than 1% of the previous noise level...
.. and this noise signature illustrates the reduction in tonal noise achieved.
Quoting the client "!?@!*%$ amazing!". We could not have put it better ourselves!.
Noise Control on Induced Draught Fans
CMB asked the INVC to determine what constituted the Best Available Technology (BAT) in noise control to minimise the noise from a new regenerative thermal oxidiser plant. The result was a set of precisely targeted modifications to reduce each of the components contributing to the subjective impact instead of conventional noise control measures consisting of large silencers, enclosures and an earth berm.
QFt removed the tones; one fan was slowed by 100rpm to remove "beating"; damper type and position changed to improve flow; modest conventional attenuators added to reduce broadband noise. These modifications removed all noise "features" and reduced the overall noise by 15dB(A) making the plant virtually inaudible - and at a fraction of the cost and hassles associated with the conventional noise control package.
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Hygienic / Clean Noise Control - pharmaceutical, electronic, food and confectionery...
"Clean" industries where hygiene and cleanliness are paramount (food and drink, pharmaceutical. electronics...) have, until now, been caught in something of a cleft stick with respect to noise control as conventional solutions can cause hygiene and maintenance problems. However, new, high-tech materials coupled with innovative engineering source control techniques are revolutionising noise control in these clean industries.
The Perfect Combination...
The innovation of coupling the new acoustic materials and systems with engineering source control technology is re-defining what constitutes noise control best practice in clean industries. By their very nature, clean or hygienic areas abound with hard, reflecting surfaces that actually amplify sound. Introducing sound absorbing material on walls, ceilings and inside covers reduces noise levels, but conventional acoustic materials (foam, fibreglass, rockwool) pose an unacceptable hygiene problem. However, the new generation of sound absorbent systems developed by Ecophon are suitable for use in GMP (Good Manufacturing Practice) and high care areas, and will withstand aggressive cleaning regimes, including pressure washing.
Installing these new materials can provide substantial reductions in area noise levels without affecting normal operation, access or maintenance and can even simplify cleaning processes. However, in many cases, noise hot-spots will often remain near noisy plant or processes. These can be tackled via engineering techniques to reduce the noise at source. We have invested heavily in diagnosis and the development of new techniques specifically for hygienic applications in clean industries. They can usually be implemented quickly and painlessly - often as an extension to a maintenance schedule - and with very little down-time. These noise control techniques are ideal for the pharmaceutical, electronic and food and confectionery industries where hygiene is a critical requirement. Download the hygienic noise reduction technical note > [660kB pdf]
Weighing Machine Noise Control 
Weighing machines often generate noise levels of 90 - 100dB(A). The conventional approach is to fit partial or full enclosures round each machine. These often produce a noise reduction of only c5dB(A) (and even an increase at the operator in some cases...) at a cost of the order of £6000 - £15000 per machine - and with the associated access and cleaning problems. We have developed source control techniques that reduce noise levels by 10 - 12dB(A) (typically) with no effect on normal operation, cleaning, hygiene or access - and at a small fraction of the cost of enclosure. Successful applications range from confectionery to pharmaceuticals to meat product processing.
Die-Header / Tablet Machine Noise Reduction 
The noise from die header machines used to manufacture hard sweets and other products such as tablets is often 95 - 101dB(A). The conventional approach is to fit them with high cost acoustic enclosures that cause serious access problems and also makes cleaning difficult. Even where enclosures are fitted, noise levels are often still close to 100dB(A) or more. In this case, our solution was based on a precise diagnosis of the source of the noise. This allowed us to more than halve the noise by developing a re-designed cam - which also extended the life of the cam significantly and reduced operating costs. Coupled with hygienic close shields, this has reduced noise levels by 10dB or more at low cost.
Reducing Noise from Air Transport Fans
Noise levels in a pharmaceutical manufacturing area were 95-100dB(A). A hygienic absorption system could be used to reduce the average noise level by 5-10dB(A), but would leave hot-spots of up to 95dB(A) near the air transport fans. As strict hygiene requirements ruled out conventional silencers, novel inserts were fitted inside the fan casings to reduce the tonal noise from these units by close to 20dB with no hygiene or performance implications over the life of the fans. With the local fan noise eliminated, the combined performance would be to reduce operator exposures to below 85dB(A), allowing PPE to be made advisory.
Noise Control for Vibratory Hoppers, Feeders, Conveyors, Separators ...
The noise from dozens of vibratory feed hoppers in a pharmaceutical plant generating 95 - 99dB(A) was reduced by 22dB by designing retro-fit modifications to the geometry and introducing sophisticated damping. There were also other benefits as the modifications substantially improved product feed and eliminated persistent fatigue cracking. The cost was not only a tiny fraction of the c £100000 required to fit conventional enclosures, but there was no effect on normal operation or access and productivity was actually significantly improved. A similar approach has also been successfully applied to noise control on vibratory bottle feeders to give an 8dB(A) reduction at a cost of c£500 and with substantially improved performance and productivity.
Clean NoiseControl in Vibratory Feeder / Vibratory Grader Areas
Typical local noise levels from these types of plant in the food industry are often in the range 90 - 100dB(A). In many cases, it is possible to avoid the use of costly acoustic enclosures (with their attendant access and cleaning problems) via a combination of the new "clean" acoustic absorbent (wall or ceiling systems) coupled with engineering modifications to the plant. Projects include:- multiple vibratory feed hoppers - area de-regulated without spending the £100,000 quoted for enclosures, with improved productivity and the elimination of fatigue cracking; vibratory feeders - area de-regulated and throughput doubled by improving vibrator efficiency; vibratory graders - area de-regulation via source control and replacement of existing enclosure lining.
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Dynamic Vibration Absorbers for Noise and Vibration Control 
We have developed and applied the same technology used to solve the Millennium Bridge sway to control noise and vibration for industrial applications with great success. The solution involves attaching small dynamic vibration absorbers (or dynamic vibration dampers) to the structure that cancel the vibration at the point of attachment. On the famous bridge, these add a virtual stiffness equivalent to large concrete piers (spoiling the ride...). Our industrial noise control uses include 10 - 20dB of noise and vibration control on power presses, grinders, gearboxes, dynamometers and pipe-work.
Power Press and Draw Bench Noise Control - via vibration dampers 
The noise from this 115T Bliss power press was reduced by 90% (10dB) by analysing the flywheel vibration and then bolting £15 worth of small steel blocks mounted on gasket springs at specific points. These tuned dynamic vibration dampers cancel out the flywheel vibration, fit inside the existing guards and were installed in a few hours.
Compare this with the cost and access problems associated with the only alternative noise control measure - a high cost conventional acoustic enclosure.
Similar dynamic vibration dampers fitted to the main gear wheels on a wire draw bench reduced the overall noise by 5dBA - again with no effect on normal operation, access or maintenance and at a cost saving of c £13000.
Burner and Combustion Noise Control at Source
Conventional noise control techniques such as stack silencers and converting buildings into acoustic enclosures involve costs that would make a hardened accountant weep! Our new technology can often reduce the noise from these sources at a fraction of the cost of traditional noise control measures and with virtually no disruption or down-time.
Yoghurt - Based Dual Fuel Burner Noise Control
The cause of complaints about environmental noise levels was traced to this dual fuel burner on a Heinz site. The company contacted us to assess the noise control options. The source was diagnosed as a 116Hz low frequency "drone" - a very common type of burner noise control problem - with a stunning simple solution. The conventional palliative noise control techniques for this sort of problem involve fitting large silencers into the stack and converting the boiler house into an acoustic enclosure - eye-wateringly expensive with extensive down-time (which would have caused serious production problems).
Our alternative solution was a set of aerodynamic modifications fitted inside the combustion head. The initial trials were conducted using an adapted yoghurt pot fitted  inside the combustion head - the only known yoghurt-based noise control application.... This reduced the drone by 16dB, completely eliminating the problem. The cost? Less than £2k with a down-time of a few hours. This new approach and technology is an incredibly cost effective solution to many burner or combustion noise problems.
Impact Noise Control - chutes, bins, conveyors, hoppers....
We have developed a suite of new impact noise control techniques that typically provide 10-20dB reductions and are more effective than conventional technology.
- Applications: chutes, hoppers, conveyors, bins, recycling plant, scrap yards, train/truck loading/unloading, quarries ...
- Benefits: rugged (often harder wearing than the untreated surface); low cost; hygienic
Scrap Impact Noise Control
.. £250 000 cost saving on environmental noise control...
We saved a scrap recycling company over £250 000 on noise barriers by controlling the scrap impact noise at source. This is new technology that can reduce the impact noise from crushers in quarries, dump trucks, shredders, trains, manual handling etc by up to 15dB(A). Compared with conventional noise control techniques, the cost is miniscule, it is incredibly rugged and has no effect on plant operation, maintenance or access.
Additional Noise Control Examples
We have a host of other engineering noise control applications across a wide range of industries - contact us to discuss particular plant or machinery in detail.
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Direct Links
noise control audit - digital noise assessment - noise competency training - noise training - product noise control - fan noise control - VWF (Vibration White Finger) - Hand-Arm Vibration (HAV) assessment - HAV competency training - HAV database (HAV-Base) - Whole Body Vibration (WBV) measurement - environmental noise control - noise nuisance - environmental noise monitoring - production line testing (noise and vibration) - noise nuisance / annoyance recorders - frequency analyser and noise analyser software
Industrial Noise & Vibration Centre
889 Plymouth Road, Slough Berks SL1 4LP
Tel: 01753 698800 Fax: 01753 567 988
email:consult@invc.co.uk
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