Have been doing this for awhile and am making the switch to CO2 and a closed or semi closed room. I have 2 fans a 6" and a 8" can fan, as well as a big huge can filter, dont know the # but is very large, 100lbs?. I am picking up a co2 burner with digi controller, 3 lumatek 1000w ballasts with cool tubes, and a can 150 carbon filter. My set up is a room within a larger room of the house, which I use for trimming curing storage and so on. I was just sucking air into my room from the outer room, scrubbing it and dumping it outside. So my plan now is to put the big filter in my outer room, run into the cooltubes and dump outside, creating negative pressure within the outer room so no smell escapes. The inner room is 8 feet high I was going to hang the can150 filter and 6inch fan at the top of the room dumping outside, hooked to a thermostat set for 85deg. Co2 sinks, heat rises, leave the co2, dump the heat. I will have to get ac in the summer but it is 5 deg celsius at night here right now. Does this sound like it will work? ANy suggestions would be very appreciated.