Off topic maybe but who better to ask than an HVAC pro.

I have a really nice, tight (no windows) half basement in my house and have been using a dehumidifier down there in the summer -- works great.

I've been concerned about fresh air getting to the basement and it just so happens that the guy who built the place installed a very robust aluminum vent (opening is about 12 x 8) and this is mounted at the top of the basement wall, goes through ground outside and then vents a few feet above ground in a nice rainproof fashion.

I have a couple of questions --

When I opened it, (I had it sealed), I immediately felt warm outside air coming into the basement, which solves the fresh air problem BUT sure doesn't help the humidity situation.

I read somewhere that if you actually create a vent that pulls air from the basement floor, that this can then act as a dehumidifier ? true?

It would be easy to extend this to the basement floor and it would be nice to save the electricity on the humidifier. but ?