I had a simlar problem in a box that was 5' tall, 30" across and 28" deep. Had a 250w hps and a daytona 150cfm fan. Temps soard into the 90's. First I made sure that the box wasn't pushed up against a wall. This helped giving more free flowing cool air, but still the temps were mid to upper 80's. So then I got an idea. I screwed a couple furing strips just below the lamp, and dropped a piece of clear tempered glass in there. I wasn't a tight fit, and you don't want it to be so you get good air circulation around the plants... but it isolated the lamp and the ballist enough that my temps dropped down to the mid 70's then.

Just a suggestion....

Jaxxx
Jaxxxom Reviewed by Jaxxxom on . Temperature/Cabinet Concerns :) The cabinet is 3x3x5 or 45 cubic feet. The lamp is a 430 hps with cool vents. I have a 240 cfm fan hooked up to the lamp. I also have two 80 cfm to vent out the cab. I have passive intakes for both the lamp vent in and the cabinet vent in(one each). The duct work comes out of the passive intakes and connects to a "y" which then goes to a single duct tube which then goes to the outside to draw the air into the box. Even though it is a nice 65-70 degrees outside the temps in the box are Rating: 5