I have needed an air filtration system for some time and like most of you did not want to pay the high cost for one. I went to a lot of A/C companies but had no luck in finding a squirrel cage style blower. They all told me they hit the junk pile as soon as they come in. So I went to a pawn shop and was able to pick up an air blower that is rated to move 1600 CFM’s. This is the type of blower unit you would use on a wet floor or carpet. With help from crank49 he helped me determine I needed 3 air intakes for this amount of CFM’s. I built a cube that would hold 3, 16×20 pleated filters, one on each side. I will replace the current switch with a timmer. I pleased to say this is really working well.