The original post: /r/diy by /u/tfoster16 on 2024-12-22 19:23:06.

I have 4 unused 42" direct drive drum fans (Strongway direct drive 42in 3/5 HP, 17473 CFM) and was thinking about using one to make an air filter for a warehouse space (20k sqft) to run at night on weekends. I would create a cube frame to hold 20x20x4 merv 10 filters (probably 2" lumber) with 4 filters on each face and some foam insulation and tape to seal the fan to the cube. The Glasfoss filters on Amazon state they have a Merv 8 air flow (1390 CFM) so I would need filters on 4 sides of the cube ($192). Has anyone tried making a fan filter this large and did it work? Would I be better off making several standard size box fan filters instead?

https://preview.redd.it/dfzjy4ojag8e1.jpg?width=1407&format=pjpg&auto=webp&s=d4deabae0e3d4671a44111f9c0b27349d0ad393d