DeadlyFruit
New member
I put a filtered register in between my grow room and the next room to allow air to come in. Push air out high up in one wall and allow it to come in at ground level in another wall. Since it is a register I can close it but if I restrict air i get so much suction it pulls in the Mylar. To be honest I should have a second incoming register so the incoming capability matches the calculated outgoing CFM. If you are interested, somewhere on GWE there is a calculation for how big the incoming air hole has to be to match an x CFM exhaust fan.