I am in the process (nearly completed) of building a stealth grow closet: However I am having serious heat issues. Right now I am using a 75CFM computer fan to pull air out, but the bottom of my box is getting over 100F with a 400W HID. Event when running my LED+CFL It still gets up to 82F. This is with a fan blowing at my intake holes. I have 3X 2.5" intake holes in the side that feed up into a 4" hole in the bottom of the grow area. In the top I have a 4" duct that is pulling in air with no carbon filter. I can feel a good amount of suction from the top duct. Any suggestions?
For that size tent if you have the money get a 4" inline fan. A computer fan isn't nearly enough,and for a 400w hps you will need a 6" and cool tube. Or it'll be way to hot in that space.