*waves HIGH!* depending upon the distances and # of turns/bends in your ducting...
use a squirrel cage on the output side....and IF you need it for the input, then an in line fan is what you want. Run pairs of 600's with a 465cfm squirrel cage on the output side (with about 10 feet of 4" duct) and about six foot of duct on the input. Have no need for the inline blower in my case. okies? *waves bye* Akiko
one 180cfm squirrel cage on my 400W Mh. Bolted directly to the ceiling and venting out of the top of the reflector. My closet never gets over 77*F or below 68*F. :smile:
PS- the shorter you can keep your ducts the less powerful of a fan you will need.
a inline is the way to go if you have alot of ducting, a carbon scrubber, have concern about elec use and/or noise.. blowers will get the job done for less $$ upfront..