it depends on how fast you want the air to clean figure out how many cubic feet you have in your shop L X w X h this will tell you how many cubic feet you have so lets use a simply number lets say you have 1200 cubic feet if the filter you are looking at runs a 600 cfm you probably want 2 of the units if it runs a 1200 cfm one will do. but keep in mind that these filters well not keep the air clean while your working they should be left running for a few hours after you leave the shop.
just in case i wasn't clear enough you need just as many CFM as you have cubic feet.
just in case i wasn't clear enough you need just as many CFM as you have cubic feet.
