Can you exhaust down instead of up?

[Guest]

I want to put a cabinet in a closet but don't want to tear into the ceiling to vent into the attic.

Can I vent under the house? This closet has the hatch door for the crawlspace. I was wondering if I could run ducting through the hatch and under the house? Like a cold air return in the closet or the cabinet?

The second question is, could I pull cold air from the crawlspace from one duct up into the cabinet for cool air in the winter and suck it back out of the cabinet through the carbon filter and exhaust to a different end of the crawlspace?

So basically build a replacement hatch door with 2 4 inch holes up into the cabinet. One stopping at the bottom of the cabinet for letting air into the cab and one going to the to for the exhaust.


So would crawlspace air be worse for the cab than room air? I figure I can put the fan in a box in the crawlspace too. Just trying to work out any crawlspace woes or heat/air movement.

Thanks

 

[Raistlin Majere]

i vent down under my house, and it works just fine
but i dont pull air in from there, we have central air that works just fine
if you do pull air in from your crawl space make sure you filter it, lots of bugs could come in that way

 

[hoosierdaddy]

You should be able to use the crawlspace just fine.
I like your idea of a box for the fan down there.

Keep in mind that crawlspaces are semi-exposed to the outside, so critters and bugs need to be addressed. Nothing some intake filtering can't take care of though.

Make sure that you consider the oder controls. I would plan on a carbon scrubber before the exhaust. You can then pipe the exhaust out one of the crawlspace openings through a dryer vent or something. That way the intake won't be taking back hot exhaust air.

The air down there will the coolest ambient air you can find.

Good luck!

 

[00420]

i did it a long time ago and only prob i had and did not see it tell about a week after it was set up was late one night i got home and could see this orange glow from under the house out the vents on the side. man did it ever look like it was on fire glad no one else seen it..... now that i think about it i was pulling air in from under and out my attic...
either way watch for a glow hehe... smell might be something to worry about to my house has 12 of them vents it can exit anyone of them hope its not the one by the front door

 

[Guest]

Thanks for all the fast responses!


My first design had the entire grow down there with a "Great Escape" tunnel trolley to the far end of the crawlspace but figure it was over kill and I didn't want to be under the house every night.

I was thinking about putting the fan down there but also thought it might be nice to put the carbon filter down there as well so I could save cabinet height. I've read its better to suck through a carbon filter rather than exhaust through one as the end of the chain.... any truth to that? The fan box will be made out of 3/4 MDF for sound deadening and on a speed controller.

I thought about light, noise etc under there and figure I can staple black poly to the joists as a baffle for sound etc. I only have 5 vents from the crawlspace to outside and they are covered with screen. Maybe some form of pantyhose on the intake would keep the bugs out.

So if I could put all that crap down there, then I can have a short, CFL sog cabinet in there since the bulk will be outside the cabinet. The closet is 2x4 and 8 feet high and I only need 6-8 oz per cycle (90days???) as the most I would need. So this is looking pretty doable soon.