aiight thanks, i appreciate the advice, you said you had the fans running through an ATX power supply? I set mine up with 12v adapter's, a few 3 speed fans, right now im waiting on getting a decent cutting instrument to put holes all over my cab, though in the same boat, no temp gauge, so im kinda messing with the fans to see what speed gets the best airflow, i thought fast, though i'm afraid it might blow too hard and hurt the plants, who know's i just gotta try everything i guess, i was thinking of adapting my plan a lil bit more and adding another fan in the top of the grow cab...a sort of cool air intake, since this cab is located just under a window, which has a great view, of the underside of the porch, i was thinking i would exhaust through the window, and also take some of the colder air, from outside and vent that in, seeing as it is getting to be winter round here, any idea if it might be detrimental, having the cold air coming in? maybe i should just keep it all room temp? what do you think?