I made a tent with that light proof panda material. For exauhst ventilation I have a Squrile cage fan running 131 cfm, vented to the side of my 150w HPS hood. Now with that and a 9 volt pc fan for an intake, I don't really have a negative pressure going. So my question is, can I put like a small fan for another exauhst on to gain negative pressure? Perhaps mounted like on top, facing up or maybe on the side? Oh and do you think that tthis may cause a smell to be able to leak? I have a carbon filter on the big fan, but will it still work for eliminating the smell? Just please give this some thought, this is the one thing that is pullin me down.
Ok wow I did it up near the hole on the side by the ducting for the big fan. I put a 12 dcv on there and boy did it give me negative pressure. But now my thing that I call a door, like sucks in... I changed the intake pc fan wiring from 9 to 12 volts, but that didnt help much. I guesse I just need to do something about my door. Make it stiff or something.
Quite often, if your intake fan is too small, it will actually restrict how much air can get in the hole. You want enough air to get in your intake so that your exhaust fan doesn't suck your door open. Slight negative pressure is all you need. If you can't get it to work with one intake hole, you may need to add a second.