Exhaust vent location

[Scratch]

I have a 40x63 shop that I setup a 16’x12’x8’ room to use for sandblasting and painting, now I need to put an exhaust fan in there. I used to paint cars and I know the downdraft system is the best for dust management. Ideally you’d want the air to come in from the center top, go around the car and underneath it pulling the fumes with it.

I can setup the incoming air to come in anywhere on the ceiling pretty easily, but I can’t cut the concrete so no go on the floor vent. I would “think” the next best option would be to have it vent out on the side wall of the booth, nearest the floor, so in the middle of the 16’ wall, at the floor.

Any input?