I keep mine on the exhaust. Mine blows into the filter - seems to work best this way and also is more dampened making it more quiet.

I guess I never thought to suck air through it...

__________________
Check out my MM grow journal - part aero/hydro and part soil grow. * OG Kush - Herrajuana - Pitbull *http://www.rollitup.org/grow-journal...door-grow.html