if your going to be using HID lights(MH or HPS) you will probably need a air intake; I have a grow box in my closet with a 400 MH or HPS(depending on veg or flower) I needed an air intake from outside air to get the box cool enough. temps were 85-90f before and 75-80 after. I even had to put a peice of tempered glass seperating the plant from the light as it was still hot.

if you send me a pic I can make some suggestions.

J