I have a fresh air supply. Both cool air intake and hot air exhaust from two '6' inch blowers. It didn't fix the tempature issue. The problem is coming from using a 1000 watt light, converted into a 600 watter in a 3 x 3 1/2 closet space. There is plenty of fresh air, just way too much heat coming off of the light, even when I use a blower to cool it down it is still hot to the touch.

I know nothing about Co2. Maybe I should look into that.