lol yeah i always wanted a sealed room for years finally got it almost figured out. what ac unit are you talking about that recirculates and also how much elec is it gonna run. cheaper to run the fans or the ac. .. the timers annoy me, what do you guys think about either an environmental controller or just a co2 regulator with a sensor an keep using timers for exhaust? what brands of controllers shoul i use and which brand is the ac?