More explanation on how it could be deadly would be appreciated Loc Nar. RacerX, would a portable air conditioner with a vent hose exchange the air or would a window unit be necessary? Which units dont exchange air is my main question. A window unit would be much louder in my situation so a portable would be best. I now vent my window unit into my garage which is partitioned with my growing area. Do the controllers work directly with the air conditioner thermostat. I would think that if the controller would just turn the power of the AC on and off the temp would be reset. I'm a little confused on this. I have been using excellofizz in my 10 X 5 area with great success. Peace