Silencers are designed to suppress noise in electric and pneumatic duct fans. The built-in silencers reduce the noise of the fans by about 22dB, which reduces the nuisance of working in underground conditions.
 

Acoustic silencers are usually used in two cases:

• in the installation network of flow devices in order to reduce the noise level emitted by these devices (e.g. fans),

• for insulating openings in partitions requiring air flow.

One of the typical examples of acoustic silencers are duct fans noise silencers.

Silencers are shaped in such a way that the outer jacket has a double wall and the inner surface of the jacket is properly perforated. The cylindrical insert is made of perforated sheet. Double outer wall and the cylindrical insert are filled with a damping compound. Installing the mufflers  reduces the noise level of the fans by about 22dB.