buy some kd (knock down) rigid duct from home depot, and remember every 90 degree elbow is like running 30 feet of straight duct. more 90s, more static pressure build up, fan has to work harder. would not recommend dryer vent at all. put damper (or fan controller)in supply so u can regulate negative pressure in room. if using co2 put backdraft damper in supply so no air escape through supply and electric damper on exhaust so it will open and shut when fan comes on and off. just my 2 cents, but don't trust me i have only been doing hvac for 11 years.
armbar Reviewed by armbar on . Calling SpaceNeedle. HVAC question. I was told to search you out because my question wasn't getting answered in my thread here: http://boards.cannabis.com/indoor-growing/125263-ventalation-fans-fans-fans-fans.html Ultimately my question boils down to this: (from the thread) I guess I just wanted to know where in an 18 foot run of duct that has a light in the middle of the run, would you place a 275 cfm and a 175 cfm fan to get the best cooling possible. Forget all that other stuff, if someone could just answer that it Rating: 5