? about venting from crawlspace to attic

If a person wanted to set up a 4' X 5' flowering room, using a 1000W HPS (w/ cooltube) would they be able to bring in "fresh" air from underneath the house, from the 2ft crawlspace, through the cool tube, and up to the attic? The reason I ask is b/c the air under most houses is kinda stale, but it is very cool, just wondering if you start moving the air if it would start becoming more "fresh". There is also concern with a little bit of moisture from under there, which they are trying to get fixed at the moment. This person is also considering doing it with this fan from HD

8 In. 110VAC 500FM In-Line Duct Fan - 3012 at The Home Depot

its actually a 500cfm fan.

No problem at all. Use a dehumidifier to control humidity if youhave to.

you could maybe run it through a can filter before bringing it into the room. that'll clean it and pull out some of the moisture too i imagine.
don't know much about that stuff...but just a thought

I would be concerned with pathogens that are under your house. Is this a mobile home, or is the 'crawlspace' actually a shallow cellar with concrete floor and walls?
Bringing in outside air is a good way to introduce pests and disease if it is not filtered correctly. Usually, the air within your house is preferable, as it is at the correct temperature already, and as a bonus, has elevated levels of CO2 from the human inhabitants... :D

you should be fine with using the air from underneath the house.
as it will be ventilated from vents around the house and will give you a steady supply of clean fresh air.:thumbsup:

Its a peer and beam house and there are vents at the north and south end of the house. I figured it would be ideal b/c of the coolness from under there, so I wouldn't have the 500cfm fan pulling a lot of my cool air from my house to the attic. I may go with the vent from my crawlspace to the cool tube as it shouldn't even "touch" the plants, it would just go through the cool tube and right out of the attic. I may have to use another vent for my plants CO2 levels though and just use the air from inside my house. I guess I wouldn't have to have as big of a fan for that.

What about the fan from Home depot though? Thanks guys

please ignore my last post.
i am a builder of houses and also a noob grower and thought i could point you in the right direction.but stinky has pointed out some valid points that i wasnt thinking of as a grower. :sorry1:

If you are just running it to cool your lights, as a weird kind of closed system (weird because it's essentially open to the Great Outdoors on both ends lol), you don't have to worry about pathogens at all.
The air around your PLANTS should be exchanged from within the home, though, unless you plan to filter it.