Air pressure in the grow room

[9KtuFK]

I noticed itâ??s extremely hard to have a perfect balance of air coming in from outside and air getting out. Iâ??m especially afraid of the negative air flow condition (more is coming in and less going out) as it will disperse the smell trough out the house.

So I was thinking of trying to get a little more air going out than coming in to make sure the smell stays in the grow room. Is this a bad idea and if so, how can I get the exact pressure/ratio (in to out) ?

Thanks

[BlueBear]

Generally you want to have more CFM's on the exhaust than on the intake. What is your set up like now. You are right, you will end up pushing some smell into your house.
Adieu

[9KtuFK]

There is more air getting out than getting in at the present moment and the walls (black/white) seems to be taking it OK.

I guess it's the best way to go ... RIGHT ?

Could this affect my babyâ??s in a negative way ?

[TheGreenFog]

More suction out than in will create the negative pressure condition. In my thread, the method used is active exhaust with passive intake. If you have seen the pics in the thread, you will have noticed the black plastic/mylar doors on the growroom. When they are shut, they are sucked in and you can SEE the negative pressure condition. This is good, but not TOO much.

The way to set it up...ONE way...is to hook up your active exhaust and drill holes for your passive intake. If you need a little more intake, drill another hole...or make the existing hole larger until you somewhat balance out the intake and exhaust. In 'our' rubbermaid flowering box. We have set up the same system: a small fan as exhaust and 6 small holes at the bottom as passive intake. Works like a frickin' charm. ;)

P.S. My opinion, always exhaust at the top of space (where the warmer air rises) and intake from the lower-most point (where the cool air is, of course). I've seen some opposing opinions on this, but I don't understand why you wouldn't do it like this. If you set it up this way, you are also sucking cool air past, over and around your plants, and therefore helping keep the temp down. :D

Takes a deep breath... Whoa that air is pure...I need a toke. ;)

RastafarI. :rasta:

TGF

[BlueBear]

Fog you are right about placing the exhaust at the top and the intakes at the bottom. Hot air rises, so you are able to pull it all out from the top, and suck the cool air from the outer room in from the bottom.
Adieu

[MegaOctane12]

I noticed itâ??s extremely hard to have a perfect balance of air coming in from outside and air getting out. Iâ??m especially afraid of the negative air flow condition (more is coming in and less going out) as it will disperse the smell trough out the house.

So I was thinking of trying to get a little more air going out than coming in to make sure the smell stays in the grow room. Is this a bad idea and if so, how can I get the exact pressure/ratio (in to out) ?

Thanks

If you look around there are forumlas for the exact amount of air that should be exchanged.