Exhaust/Venting a growbow...newbie question

Hey all!

Vegging 24hrs in a closet right now with the door open most of the day, and a window in the room open, so lots of fresh air and air exchange right now. But, I'm moving everything into a closed box as soon as I finish it. Dimensions roughly 2 x 2 x 4.5 or so.

With respect to venting/exhaust and getting the old are out of the box...I am not sure if I am on the right track. It seems like this would be too simple and I want to make sure it will work before I rig it up. Right now I am planning on using computer fans, about 4 total, plus maybe one hooked up to my light fixture (6x CFLs) full time to cool lights.

1) Fan in the side of the box at the bottom simply blowing fresh air into the box.
2) Fan in opposite bottom corner of box moving air up to top of box (and across plants).
3) Two fans next to one another mounted in a closed, sealed box of their own, blowing outside the box. I'm going to use a short piece 3" flexi duct on the inside of the box as an intake and also to help keep light from entering/exiting. The fans will be directly on the outside of the box blowing out. Noise/visibility aren't a concern and I will add a charcoal filter when the time comes.

I guess my main question is this: Will the two fans at the top blowing out create draw? Or do I need to actually use fans that are "sucking in" rather than "blowing out"......is it the same thing? Will my idea work?

Any advice appreciated! I realize I could buy a bathroom fan for about $20 but I am not sure how I would get it wired to run on an outlet. Is it just like stripping and splicing for a PC fan as long as I match the voltage properly? Thanks for your time!

As long as the exhaust fan is bigger than the intake fan.

Yep, you are about there. You need to be extracting more than inlet to create negative pressure so that all the air is pulled through the charcoal filter (when you get one). Also, a cheap variable 12v transformer will give some control over temps.

cues said:

Yep, you are about there. You need to be extracting more than inlet to create negative pressure so that all the air is pulled through the charcoal filter (when you get one). Also, a cheap variable 12v transformer will give some control over temps.

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So 1 fan down bottom and 2 up top should do the trick then, since I would effectively be doubling the output versus the input?

And the two fans up top "blowing out" the side are going to create a "sucking" scenario at my intake duct?

Thanks again for any input. It all makes sense in my head..."heat rises...fans up top will push out...new, cooler air will rise to take place...repeat". At least thats how I'm seeing it

ndeehel said:

So 1 fan down bottom and 2 up top should do the trick then, since I would effectively be doubling the output versus the input?

And the two fans up top "blowing out" the side are going to create a "sucking" scenario at my intake duct?

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you don't need an intake fan just the exhaust (if you prefer) it's what is known as passive intake. You need to be careful not to cut your intake hole too big. You want that negative pressure like cues said, but you don't want to stress your fans too much and burn out the motors. good luck stay high

shrxhky420 said:

you don't need an intake fan just the exhaust (if you prefer) it's what is known as passive intake. You need to be careful not to cut your intake hole too big. You want that negative pressure like cues said, but you don't want to stress your fans too much and burn out the motors. good luck stay high

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So maybe for an intake hole at the bottom just cut something about quarter sized or a bit bigger with some panty hose over it? The drawing action of the fans up top will drag air in (albeit with less force) through the intake hole?

Makes sense

Thanks all!

ndeehel said:

So maybe for an intake hole at the bottom just cut something about quarter sized or a bit bigger with some panty hose over it? The drawing action of the fans up top will drag air in (albeit with less force) through the intake hole?

Makes sense

Thanks all!

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Yes you could start off small and make hole bigger as needed not too big you don't want air to escape out your intake, and yes put some sort of a screen over your intake. good luck stay high