dust collector

[cbg]

I am setting up a woodworking shop in my garage, and would like to soundproof the dust collection unit.  It's essentially a big vacuum run by a very noisy (85 db) motor.  My plan is to build, behind the garage, a separate enclosure to house the dust collector.  The enclosure will need to be at least 3'w x 2'd x 6'h.  There will be a 5" pvc pipe running from the garage to the enclosure.  I will need to vent air from the enclosure (the vacuum sucks air and wood chips from the machines in the garage and into a device that separates the chips and filters dust, and then the filtered air is vented either back into the garage or outdoors).  The outside surface of the enclosure will need to be wood clapboard to match the garage, but other than that I am free to use whatever materials I like. 

Any suggestions?