Ventilation options for 32x32 tent

Whats up guys, I would like some input on my set up as i am trying to run it at 400w but i just cannot figure out why temps shoot up to 86-87.No signs of heat stress though, to provide more information on the setup, i have a 32x32x63 tent with a 6" filter >>>hood>>>>400 cfm 6" fan>>> out through a window. To make sure no hot air would get back to the room, i followed a "stealth" exhaust write up that i found using a wicker blind and some foam.

I have been running it at 250w ( dimmable ballast) and the temps are pretty steady at 80. The tent is kept in a spare bedroom and the room temp in there hovers from 74-78 with central ac set to 77. I have a extra 4" inline fan that i am thinking of cooling the hood with an additional fan and have it vent out outside as well. Any feedback on how can i lower my temps running it at 400w?

You have a few options. you can run a inline fan and pull air from outside into your tent which would obviously be colder depending on your enviorment. Thats a pretty small tent I use to have the same one and had the same problem with heat. the only thing you can do is force air ether into the tent or out using pressure from fans. I need to know a little bit more about the enviroment your in and your situation as in what temps ar elike outside and outside of the tent itself because these are all important factors. Use your carbon filter to take air out and then run a hose outside to pull air in. thats really all you can do and that only works if its colder outside then inside the tent. or just use the a/c. i wouldnt even have the carbon filter hooked up until flower.