Blowers/006 Blowers Vibration Isolation of blowers.pdf
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Index: Blowers
Subject: (6) Vibration Isolation of Blowers
Date: May 8, 2009
All plenum and housed blowers will be mounted with some type of vibration isolation to prevent vibration transmission to the unit base. If springs are required, the factory order will specify the spring type and deflection that is to be used. If springs are not specified, then rubber-in-shear isolators shall be used to mount the blowers. Rubber-in-shear isolators have a specified load, just like springs, and the project engineer must call out the proper number of isolators to support the weight of the blower, frame, motor and accessories. The blower must also be isolated from the blower bulkhead. For plenum blowers, a foam gasket is used around the inlet flange perimeter. On housed blowers (forward curved and backward inclined), ventglas is used to connect the blower outlet flange to the bulkhead. Springs should not be used under the blower on any unit that will be mounted on a spring isolation curb, as this can create harmonics that will increase vibration transmission.
EXCEPTION: Direct drive blowers for regeneration in desiccant units are hard mounted to the side of the unit for exhaust directly through the unit panel.