IAC Acoustics rectangular and cylindrical duct attenuators provide effective, predictable noise reduction at substantial savings over other noise reduction methods because IAC products are laboratory-developed and tested under controlled conditions. Moreover, we manufacture duct silencers to specific metal tolerances and with controlled acoustic infill flow resistances to achieve consistent results.
Should none of our standard range of silencers meet your requirements we will develop one for you. If you have a special requirement, please contact us and our specialist team will be able to provide you with a bespoke solution.
IAC Acoustics Duct Attenuator Range of Products
We design and manufacture duct attenuators in response to specific requirements from acoustical consultants, consulting engineers, owners and contractors. Our duct silencers provide the most economical choice for solving the wide diversity of noise control problems encountered in HVAC engineering.
IAC standard rectangular duct attenuator cross sections range from 150 mm x 150 mm (6 in. x 6 in.) to 1200 mm x 1200 mm (48 in. x 48 in.). For small mains, branches and duct run outs there are module sizes to fit every need. When large silencer banks are required, multiple-module assemblies can be arranged to provide almost limitless dimensional flexibility.
Duct Attenuator Design
All of the duct attenuators manufactured by IAC Acoustics are of the passive design because they do not require mechanical or electrical means to function. They do their job very simply by providing a trouble free static means for the dissipation of sound energy by converting it into very minute quantities of heat. Many of the original air conditioning attenuators developed by IAC in 1950 are still in use today.
Active duct attenuators operate electronically by means of microprocessors, loudspeakers and microphones. They cancel sound by feeding back an additional noise source that is 180 degrees out of phase with the original noise. In theory, noise reduction is effective for low frequencies, usually below 300 Hz. Initial research to develop a commercial product was particularly strong in Great Britain but, today, research goes on throughout the world.
HVAC noise control requirements are rarely confined to a narrow low frequency range. The broad band low and high frequency attenuation capabilities of typical passive attenuators are practically always required.
Cross section through typical IAC Quiet-Duct Silencer
Forward and Reverse Flow
In 1972, IAC developed silencer Dynamic Insertion Loss and Self-Noise ratings both under FORWARD FLOW (+) and REVERSE FLOW (-) conditions for Rectangular and Cylindrical Duct Attenuators.
Since attenuation values are generally higher in the first five octave bands in the Reverse Flow (-) mode compared to the Forward Flow (+) mode, more economical silencer selections can often be made on return air systems. These phenomena are illustrated below.
IAC duct silencers are rated under operating conditions in the most advanced aero-acoustic research and development laboratory available. Regardless of their size or configuration, they are developed, tested and rated in accordance with the most current industry standards. There is no guesswork with hit-or-miss empirically-developed calculations or otherwise inaccurately-rated silencers.
For many companies, noise control in conjunction with the discharge of gases into the atmosphere is a priority. It is essential that all installations have the necessary noise control systems, as this ensures that the factory meets the relevant noise criteria.
Ventilation and exhaust silencers reduce the noise caused by the release of pressurized gases, such as air, steam or other gases, such as nitrogen and oxygen, into the atmosphere.
IAC Acoustics is a manufacturer of ventilation and exhaust silencers. Ventilation / deflation silencers from IAC meet all conceivable market requirements, whether they are customized or meet more general customer needs. Our team of skilled engineers works with a modern selection of software to find the best solution for you, both in terms of acoustic performance and price.
Process applications and market areas include:
Features ventilation / blow-off silencer
IAC has a wide range of standardized and tailor-made silencers designed to reduce the noise of exhaust air, steam or other gases into the atmosphere. All our mufflers are designed, manufactured and manufactured in accordance with standards and can guarantee a noise reduction of up to 75 dB (A).
Our ventilation and exhaust silencers are designed according to international standards and offer:
In addition, our ventilation / exhaust silencers have the following features: