Quote Originally Posted by xcrispi
you'll get 40% more air flow using hard galvanized ductwrk too verses the foil sliky garbage also . your gonna go buy sweet hurricane fans n then go cork em up w/ cheap ass flexable ductwork is defeating your purpose .
just my 2 c worth
An expensive fan still pulls more then a cheap fan, crappy ducting or not. 90 degree elbows seem to make a difference...however to be honest...ive never found that much of a difference, especially with straight sections. I noticed no temp difference or airflow difference, but it looks sweeter and its a lot quieter.

I pull 2 hoods with 1 8" fan (750cfm) always and I feed the room with just passive air and some circulating fans or a smaller diameter and cfm intake fan. This keeps the room around 70 degrees all the time, but thats largely dependent on the intake charge temp.

If you can afford all the fans and noise, the most efficient way to cool your room will be to pull cold air from outside the room, through both lights, and out the grow room to a difference area then the intake. Then have a 1 large fan pulling air out of the grow room (if its sealed) or the large exhaust and a smaller intake fan pulling air in the grow room...and run that on intervals with recirculating fans always going on inside. This would enable you to take advantage of CO2 without loosing it and without getting the room to hot when you turn off the room vent. Make sense?

Or just get a portable A/C and be done with your problems.