The Basement workshop is 34x34x7, and 2/3 to 3/4 of that square footage is actual woodworking workspace. 5 slider Basement windows and a Screen Door for the Bilco Door . That helps to provide fresh outside air. Got a couple of box fans that I also run to keep the air moving. Jet and Sears 650 CFM Dust Collectors. One Man workshop , only run one tool at a time Mostly the Lathe, Spindle Sander , Belt Sander , Band Saw , Miter Saw. Any clue as to how big of an Air Filtration System would be needed to handle that square footage , taking into account the outside air movement from the windows and screen door?