The CO2 system is small, only 40oz of compressed CO2 at most. Small case that is sealed well doesn't need a large CO2 tank. The CO2 would also be used for an automatic fire suppression system which would also trigger a master electric switch for the grow case.

It needs to stay clandestine from outsiders, friends and the girlfriend lol. I guess the biggest thing to be worried about is the smell, as you mentioned, Emilya. Is it really that difficult to neutralize the odor from 1 plant? I know of this one company that makes compact CFLs which have a coating on the glass which neutralizes odors. I was thinking of using that inside the case as a supplemental grow light and also use a carbon filtration system.

I've thought of all safety issues and I assure you I will not burn the house down lol. My biggest drive to do this is to make something that is just way out there and works really well... I guess I could do that with a tomato plant, but you can't smoke tomatoes lol.