damn. i might have my fan on backwardsYou should have negative air pressure. If anything the walls of your tent should be sucked in because your exhaust fan should be moving that air out so many times a minute.
In my grow room my door was held shut by negative air pressure.
thx yall.. i got it right, she sucked in now. I had my fan on the wrong way.Also depends on where you put filter, inside tent, air drawn through filter and put out the top, or suck from the top of tent, the fan blowing into filter top. First way works better and is more quiet, second way gives more tent height/room.
Yes, your walls should suck in as other say. This negative pressure limits air intake to the inside of the tent, then out nice and de smelled.
I've used it too, I had to have the height in that case. Prefer all inside, but like most things, its a compromise sometimes. Made a little more noise....I could have reduced it. When like the bottom right, my filter was on the floor with fan on top, I think that made it a little louder. When inside, its hanging from bungie cord, I think that makes it more quiet.I used the method on bottom right. I dont like putting anything in my grow room that i dont have too.