600 hps 5ft tall 3 by 3 box hooded with inline fan and 6 inch fents for intake and outake boxes fan has 4 inch in and out connected them to bigger vent to have 1 main in and out... with everything set up my in and out comming from outside on a nice cool night around 59.. my box is climbing to 90 its at 88 now but it's going up the hour... idk what more i can do or what i'm not thinking of but this box isn't getting any cooler
600w is a shit load of light for a box that small. thats your first problem. Its overkill and now its actually fucking your shit up. your going to need to get an A/C pumped in there or put a 400w in it. Is your ballast inside the box? It might be your ventilation system also...needs to be efficient. heat rises. so put your exhaust fans at the highest point possible and your intake at the lowest point possible. what is your CFM rating on the inline fan? does the air that runs through your light vent outside of the box?
^Yes, I agree I got confused on this part: Que? It sounds like somewhere in your ventilation system your air passageway is 4", in which case your entire ventilation system is no more efficient than 4" can be. No matter how wide some other parts of the airflow may be, it's like a chain being only as strong as its weakest link. I also am not clear if you are venting the grow space at all with all venting going from intake straight to an air-cooled straight to exhaust, or what. Please describe. Also Teapot gives good advice above, though I believe a 600w can be managed in that space if your are using an air-cooled hood, which I'm not sure from your description is the case or not. And even with an air-cooled hood, you will need more than a 4" capacity vent system to keep the temps under control.