Just completed an air filtration system for my workshop. We had to replace our air conditioner and heater system earlier this summer so I kept the furnace blower fan for future use. I used the mobile air cleaner cart built by Jay Bates as the basis for my build https://jayscustomcreations.com/2016/05/mobile-air-cleaner-cart/. My overall dimensions are 21"D x 29"W x 39"H and uses four 20" x 20" filters. I've got it sitting on top my garage refrigerator so as to hopefully pull the air up high.