Is the co2 making your room hot? I'm kind of confused by that statement I guess. If those are the only plants you have, you probably don't need additional c02. If you could point the fan at an upward angle towards the light, and then pull the hot air at the top of your grow space out, that'll probably help. Depending on ambient temps in your, house, you may need to get an a/c.My rooms getting to hot and fucking with the co2..
"It raises the temperature in my room about 10 degrees. Its kinda bad but when you are in a co2 enriched environment the plant actually does better at higher temps. 85*+." - widow maker
here is the link to the whole deal
https://www.rollitup.org/newbie-central/937-how-grow-marijuana-2.html