The problem is that when i start to use co2 i need to have a controled ventilation process so im not wasting it, so i need to block in ways air can enter. thats why i need input on how much fresh air is needed to keep my room cool, i know it will be cooler once i air cool my lights, but im not sure if it will keep my temp low none the less. here is a picture i drew of what i was thinking about doing. tell me what you think, thanks------click on picture