How to cool a Co2 Enriched grow room?

Do you feel that the Co2 is worth it in this case? I mean even though it slowly leaks out?

It's 20.00 for a refill, that's pocket change in this business. I grow for 6 patients total. 2 are cancer patients. So anything I can do for a better yeild is worth it to me and my patients.

Also this is my 1st run with co2. So far (end of wk 6) it's looking like a better yeild so far.