Fan Outlet Silencers

“Outlet Silencers are a Must in Industrial Facilities”

Outlet Silencer on an FRP Blower

Industrial FRP fan with an FRP discharge silencer

Fan and blower outlet silencers are utilized in most industrial applications where the fan outlet is not ducted, or the fan outlet duct or exhaust stack is directed to or in the vicinity of a noise sensitive area. When evaluating fan noise issues, it is important to consider if there are multiple fans in proximity. Two fans with the same noise level will produce a three dBA increase in sound pressure level and a noticeable increase in sound loudness.

When designing the outlet silencer, noise data from the fan manufacturer is vital. Existing plant noise level is also important to document, as are any regulations or codes that need to be met. As a standard, fan manufacturers generate data for sound power levels, which is essential for determining the size of the silencer. Important factors that determine the silencer size, in addition to CFM and static pressure, should include:

  • Fan connection size
  • Fan total sound power (dB)
  • Fan noise criteria level (sound level @ X feet away)
  • Noise criteria position (IE Position 3 90 degrees from silencer opening)
  • Fan location (indoors/outdoors)


Once the silencer is selected, silencer construction options are available in galvanized, carbon, and stainless steel along with FRP. Boltable flanges are standard, but slip-fit connections are available.

Outlet Silencer on a Ventilation Fan

Upblast industrial fan with outlet silencer