Here are 10 easy-to-apply, affordable noise-reduction methods that can be used right across industry.
Typically used in applications such as chutes, hoppers, panels and tanks, damping usually uses two techniques: layer damping, in which a layer of bitumastic damping material is stuck to a surface, and constrained layer damping, which is more rugged and involves construction of a laminate.
Maxideck and Maxiboard from Sound Reduction Systems (SRS) can help with soundproofing for floors. Maxideck, an acoustic-flooring solution, can be used in kitchens and bathrooms. It offers high levels of airborne and impact insulation when used on timber. It can be used to comply with the Building Regulations Approved Document E (2003), is easy to install and is only 28mms thick.
Maxiboard for ceilings and floors can also help meet Part E Regulations and can be used to form enclosures and independent structures. It takes screws and nails direct, and is extremely durable, yet only 17mms thick.
2 Fan installations
Curiously, when fans operate at peak efficiency, they're at their quietest. Common noise-reduction features are bends close to the fan and dampers. To cut down on up to 12 dB, ensure at least 2-3 duct diameters of straight duct between any feature that may disturb the flow and the fan itself.
Typically used in extraction, ventilation and cooling, ductwork involves openings in walls and enclosures. Instead of fitting silencers, it is often possible to achieve a 10 - 20 dB reduction in airborne noise from a duct or opening by lining the last bend in the ductwork with foam or fibreglass, or constructing an absorbent, lined right-angled bend to fit on the opening.
SRS has two products that can be used. Acoustic Socket and Service Boxes are made from two layers of 10mm-thick high-density gypsum-based board and will ensure the acoustic integrity of any metal or timber-framed separating wall containing sockets and/or services. Meanwhile, Soundstop 5 is a multi-purpose acoustic barrier that's ideal for ceiling voids or within partition walls. It reduces room-to-room noise by up to 46dB.
4 Fan speed
In axial or centrifugal flow fans, you can reduce noise simply by changing control systems or pulley sizes and resetting dampers.
5 Pneumatic exhausts
Pneumatic exhaust noise can be reduced by up to 30dB by fitting silencers. For back pressure, fit a larger coupling and silencer; for clogging, you need a straight-through silencer, while multiple exhausts can be manifolded into a single, larger diameter pipe.
6 Pneumatic nozzles
Pneumatic nozzles are often used for cooling, drying and blowing. You can usually replace the existing nozzles for quiet, high-efficiency units that can reduce noise by up to 10 dB.
7 Vibration isolation pads
Typically used on machine feet, pumps and mezzanine installations, vibration isolation pads are usually made of rubber or bonded cork and reduce vibration and noise pollution.
SRS's Acoustilay system is ideal for beneath washing machines. It improves the sound-insulation performance of timber floors and substantially reduces impact noise through concrete and timber floors. Acoustilay is simply laid under most floor finishes and can replace conventional carpet underlay.
8 Existing machine guards
In an open set of machine guards, halving the 'gap' open area can reduce noise pollution by 3 dB. Reducing the openings, such as flexible seals, by 90% can reduce noise by 10 dB.
Maxiboard with Coustifoam lining is ideal for this. Coustifoam is an acoustic lining to soffits or walls, or can be laid over the back of open-cell suspended ceilings. Its flexibility allows it to be easily formed around penetrations or contours.
9 Chain and timing-belt drives
Quieter timing belts with different tooth profiles aimed at limiting noise can replace noisy chain drives. A new type of belt for noise-critical applications uses a chevron tooth pattern that can cut noise by up to 20 dB.
10 Electric motors
The electric motors that drive fans and pumps can be replaced by general-duty motors that are up to 10 dB quieter. These can be phased into the system over a period of time.