Temperature/Cabinet Concerns

is your vented light setup a sealed light setup. Any pics would help.

:thumbsup: Cactusman I attached a photo of the setup. It is sealed but only by gravity and weight. The glass slides into an opening on one side and has a metal tab that swings down to hold in place. There is 4" flexible duct going into one of the vents and the same size coming out. Then the duct goes to the active exhaust where I have had a 80 cfm and a 240cfm fan. Still the same temps???? Also there is a 6" passive intake going into the cab with two other active exhaust going out. I have each of them with 80cfm duct fans sucking as well. If you are facing the cab the lower right side has the intakes and the top left side is where all the exhaust are located.

Is your hood drawing air in from the cab or is it connected to an intake that draws in air from outside the box?

are y'all having this problem with the ballast nearby? those suckers get hot. I have a cabinet that is smaller than the ones listed here, and my temps never go higher than 85, even when I cover the top where the light is with a towel so light doesn't leak out the window. my ballast doesn't effect the temperature because it doesn't share air with the grow area. I have a segregated area that I was going to use for dark teatments so I lined it with black foam. but it currently houses the ballast and temps in there are around 90, but the grow shelf stays around 80. not bad for only being separated by a wall of plastic

Yeah I added my 400watt hps yesterday to my cab and my temps are at about 90 when the light is on and 74 in the dark. I moved the ballast to outside of the box and it didn't seem to help that much. I'm getting a new exhaust fan tomorrow so that should help alot...at least I hope.

I was just reading about similar problems in another thread. From what I just learned you maybe getting false readings by having the thermometer directly in the light.
Try making a small cover for your thermometer out of cardboard. Place the thermometer so it is at the level of the plant canopy with the cover keeping it shaded from the direct light. See if the reading drops any.

Hope this helps.