Centrifugal fan units provide an inherently low noise characteristic which makes this design preferred for most installations that require low sound levels. If the standard LSTB sound pressure level is not quiet enough for certain applications, the sound levels can be further reduced by adding fan intake and discharge sound attenuators. EVAPCO also recommends the use of Variable Frequency Drives (VFD) or two speed motors for reduced fan speed when operating at less than design load for additional noise reduction.

Fan Inlet Attenuation
Reduces sound radiated through the air intake. It consists of baffled panels to change the path of the air entry and to capture the radiated noise, thus reducing the overall sound levels generated. The attenuator is self-supporting and does not require structural steel support.

Discharge Attenuation
The discharge attenuation hood features a straight sided design with insulated baffles to reduce the overall sound levels of the discharge air. The discharge attenuator incorporates a large access panel to allow entry to the drift eliminators and water distribution system. If a higher discharge velocity is required, a tapered discharge hood that provides minimal sound attenuation is available.