My can filter was just purchased, brand new. I could exhaust it out of my air tight panda film barrier, but I'd still have my other exhaust which is sucking air off my fan, pumping stink out. I have quite the vacuum in my room with the one forced exhaust and passive intake, I'd imagine that would increase alot with two exhausts. Also, in my grow room is a small crawl space to my bathroom, wouldn't I smell it permeate through that/my panda film and door before they got it through the walls? The only time it does stink is when the door is open, not when I have it shut and can running inside. Meh, and absolutely no signs of bud yet. The smell is so wonderful though.