Dear OP-
You know that if a warehouse is getting unreasonably high energy costs that yields a search warrent for police? Talking about a warehouse grow operation online is not a smart thing to do; even if starting small, still never a good idea. I would stick with a room or 2, nothing more...
Sup bro.
I had a small gnat problem and I bought two CP's (carnivorious Plants), a Sundew and a pitcher plant. The problem was taken care of in one day. Sundews are helpful for spider mites and pitcher plants more so for gnats. If the problem persist, I would buy some spray but do research...