I'm wondering the same thing actually, my closet is a bit smaller though. more like 2' deep x 6' wide x 8' tall. I could leave it open if I need to for heat, but I am running a 6" 400cfm inline fan for exhaust at the moment, however that would go onto a cooltube perfectly if I get one, and I could switch to a 4" inline for exhaust of the room. right now ambient room temp is probably 65-70 since it's fall where I'm at.
any input? I think I'm gonna buy the cooltube just in case, but hopefully I won't need it.