This is not criticism of anyone that uses air filtration for their shop or for the concept itself but I felt sort of silly after installing one of the two units purchased for my 40' x 60' barn/shop. After getting one up and running I looked back at my handiwork and thought how could that little box (3'x2'x2') do much good in a space this large even with 2 of them running. Then I thought why not just open up the overhead door and one or both of the 'Mister Ed' doors along one wall instead and let nature do the work. I think that's what I'll do weather permitting and only use the air filtration units when everything is closed up. And yes, it makes eminently more sense to catch the dust at its source. So I'll be putting more effort into improving that equipment in the future. Sometimes you just have to do something silly to make better sense of the situation.