Crawlspace ventilation

[A. Seth Teicher]

I have a 16 x 30 addition with a filled block insulated foundation. The crawlspace has no vents on the exterior walls and a good vapor barrier, and in 7 years I've had no moisture problems. There are 2 large openings, into the basement, on the interior wall for ventilation. We recently had a mouse infestation, with some of them apparently coming in through the openings. I've purchased a Tjernlund VD2 for one of the openings, and will screen the other. Is this an acceptable way to ventilate the crawlspace?

Thanks

[Raymond Wand]

Why not just cover each opening with screens on wood frames?
You have passive ventilation currently and you have no problems with moisture so why do you feel you need a power vent?

Find any exterior holes and pack them with steel wool and caulk over. Mice do not eat through steel wool.

[Gunnar Alquist]

I have a 16 x 30 addition with a filled block insulated foundation. The crawlspace has no vents on the exterior walls and a good vapor barrier, and in 7 years I've had no moisture problems. There are 2 large openings, into the basement, on the interior wall for ventilation. We recently had a mouse infestation, with some of them apparently coming in through the openings. I've purchased a Tjernlund VD2 for one of the openings, and will screen the other. Is this an acceptable way to ventilate the crawlspace? Thanks

Seems to me with only one vent opening and a fan, either the crawlspace will be experience positive pressure (pushing air from the crawl into the house) or negative pressure (pulling air from the house into the crawl). Neither sounds good.