Foundation Vent Replacement?

[lbperry]

I'm in a 50 year old brick home on a crawlspace. It has the typical 8" x 16" vents around the foundation. They are manually operated cast aluminum. They have worked well but are at the point of needing replacement.
My pest control company has been trying to sell me some auto-adjusting vents.
My reservations about going to the automatic ones, other than price, is my concern regarding the ability of a bimetallic actuator to properly open and close them, particularly after they've gotten a few years weathering on them.
Could you guys give me your experiences and recommendations on the automatic operating ones? I would want metal ones since I don't believe plastic/poly would be long term durable enough.
I'd appreciate any comments/brand recommendations/alternatives that you might have.
Thanks, Lawrence Perry

 

[Pontiac787]

I have no experience specificity with these vents but I would tend to think manual would be the way to go. I doubt the automatic would function without issue for the next 50 years.

 

[Jeepster04]

Its hard to recommend floor vents at all. The auto ones will open when its hot and humid out, and close when its cold and dry out.... It seems so odd to let hot humid air under your house all summer long.

I keep all of my vents closed except for one to allow some air movement under my floor. Otherwise I have plastic down and a dehumidifier under there. If I were going to do it properly, I would seal the plastic to the block, seal the vents off completely, and have a fan pulling air from under the plastic. But, I dont feel like doing all of that.