Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
Put the "fart fan" on the top and a few holes on the bottom with a some kind of filter on them.That will make the air move throughhttp://www.homedepot.com/p/Broan-70-CFM-Ceiling-Wall-Exhaust-Fan-671/202905936#
Looking at the screens as they are almost dry....The emulsion seems thin. I coated 1/1....made sure I had full contact with the coater....Should I be feeling and seeing the mesh on the screens?
What about the light that gets through the fart fan?
That's why sucking air out is better than blowing air in, unless you go full on clean-room style with positive pressure, filtered air.