Ventilation Duct Silencers

The duct silencers protect the inhabitants from excessive noise transmitted by the ventilation system, which impacts the comfort of staying indoors. What is the cause of the noise in the ductwork? The most common causes are HVAC equipment like AHUs, fans or simply air travelling through ducts. 

In order to attenuate the ventilation system, duct silencers should be installed – made of galvanized, aluminium, stainless steel or plastics (see chemically resistant sound attenuators). Ventilation silencers are fitted with non-compatible mineral wool. Depending on the type of ventilation ducts we can divide sound attenuators into:

• circular duct silencers
• rectangular duct silencer with attenuating baffles (splitters) 

Circular sound attenuators can be equipped with a pod (round baffle) or vertical baffles for better-attenuating properties– especially in diameters of 630 mm and larger.

In case when there is no free space available or it is very limited, it is possible to use elbow silencers (BSIL) or circular duct silencer in the low-profile rectangular casing, while flexible silencers, the shape and position of which is much more easily adaptable, can be used in complicated systems. 

How to select a duct silencer?

We recommend using our free selection software AlnorSILENT to easily find the best attenuation solution by entering parameters of the HVAC equipment, like a fan, that generates the noise. Download it HERE.