Thanks for the info on intake/exhaust ratios. I'm not sure how much drag the reducer's going to add either but I don't think all that much with the low flow fan. The fan is 4" diameter and I plan to mount it straight to the coupler, thinking that would be the least amount of backpressure?

Yes the intakes have light traps and the closet door will be shut all times as well, unless I'm actually looking in on the plant. Wasn't planning on the exhaust having one as there's no windows or anything in the attic, just a small vent about 50' away that never really get's direct sun.

The shoplights are just an idea, I can toss smaller CFLs on the sides instead if you think heat might be better controlled that way. The colors can be changed, I was planning on throwing them in for flowering.
redtails Reviewed by redtails on . Input needed Ok, so let me preface this by saying I live in an urbanized desert, where the temps can be unstable and typically high(even with A/C), as well as avg humidity <20%. Also the components I've listed in the pic are what I already have. I'm trying to make it work with what's available, as I'm on a limited budget, so please don't start recommending something unnecessarily too expensive for this sized grow like a 400w cooled HPS with a 6" vortex fan. I'm trying to rework the ventilation system Rating: 5