I run the Phat filter 4" model IGSPF124 paired with Active Air in-line duct fan
4" model ACDF4.
http://boards.cannabis.com/closet-ca...criticism.html

I cannot tell you about smell but I can tell you that you will definatley notice the sound of a setup like this coming from your closet. mine is the garage and that makes the perfect place for it. it sound like one of these fans.
Lasko Products 2220 20 High Velocity Floor Fan