Idk if ppl already do this but I was trying to figure out how to hang fans in my grow tents i moved out of the closet grows while back. So I got ubolts and a piece of board. Drilled out holes in board and ran u bolts through. wing nuts would be nice make it easier to move. Can also use offset pipe flange. It works really well for an adjustable place to mount fans can even mount the big 16 inch oscillating fans. Board should be 1/4 or 1/2 inch thick 6 inch wide. Alot of table top fans also have screw mounts on the bottom so if dont need a big wall mount fan can use table! I would use a bolt with a screw head with a nut on back to slide the fan on don’t want regular screws have point sticking out can tare and poke holes. I have set like this in my 5×5 and 2×4 since there’s no good clip fans. Secret jardin has one but there like 80$ now hopefully this helps someone!!! #DGC For life!