Foundation Vents

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So I need to replace the foundation vents around the house most of the louvers are gone and the metal frame is cracking and most of the screen in them is gone, the one in the phone is the best one.

They are a odd size and seems like my options are limited.
Screenshot_20190731-090735.png
The biggest the opening can possibly be is 14.5" wide x7.5"tallx 8" deep.

I found these which seems pretty decent and will also allow me to shut them in the winter, but seeing if anyone else has any options before I spend $30 a pop on 8 vents.
Screenshot_20190731-085944.png
 
Some thoughts, assuming your foundation is a crawlspace:

1. If your floor is insulated, then all you're trying to do is reduce moisture retention. An open vent (screened to keep critters out, of course) is most efficient, because it allows unrestricted air movement all the time. The trade off is a (minor) loss of energy from the crawlspace drawing heat or cooling through the floor from the interior space.

2. Operable (automatic opening/closing) "save energy" by opening when it's hot and humid (hot air holds more moisture, so if it's trapped in your crawlspace...bad for water reasons), allowing moisture out, while also bringing in cooler air to reduce cooling load. In cold weather, when the air holds less moisture, vents close, making the crawlspace a dead air space that helps keep heat in at a time when there's less moisture in the trapped air.

3. The problem with auto-operable vents is they're likely to eventually stop working automatically. The problem with manually operable ones is that we usually forget to open or close them (unless the problem has already occurred).

4. If there's another source of water/moisture in the crawlspace -- wet location, spring under house (I've seen it), etc., then that should be addressed first, by either sealing & conditioning the crawlspace ($$$) or full-time, maybe even fan-assisted venting.

5. My personal opinion (YMMV) is that auto-operable vents aren't really worth it. My strategy would be to crawl under the house, assess the status of the insulation, replace wet & sagging insulation/upgrade insulation for energy saving, and go with el cheapo screens for vents.

But I have not seen your crawlspace, so I recommend a large crystal of organic, natural, solar-evaporated sea salt be taken with this post.
 
Foundation vents in the south are nothing but trouble.
Seal the crawl space, eliminate those lousy vents and condition the area.
 
Foundation vents in the south are nothing but trouble.
Seal the crawl space, eliminate those lousy vents and condition the area.
I sealed mine...love it!
 
For you guys that have sealed, who did you use and what was the cost per sqft (or however you think makes sense). I got an estimate that was over $10 per sqft so the project is on the back burner.
 
In general I agree closed crawls are far better than vented, but you have to make sure there are no existing water problems, elevated radon (esp if you are near granite outcrops, like around Rolesville), natural draft furnace/water heater, etc.

First rule of home upfits: Do no harm.
 
encapsulated mine myself...conditioned and dehumidified too.....was a PITA....do not buy 12' wide plastic if it is cheaper...unrolling and unfolding between all the piers was impossible ...
 
For you guys that have sealed, who did you use and what was the cost per sqft (or however you think makes sense). I got an estimate that was over $10 per sqft so the project is on the back burner.
Did it myself when I was younger and more limber. :rolleyes:

Biggest cost was the vapor barrier. Sealing the vents was relatively inexpensive.
 
encapsulated mine myself...conditioned and dehumidified too.....was a PITA....do not buy 12' wide plastic if it is cheaper...unrolling and unfolding between all the piers was impossible ...
I agree. As I recall, I calculated the pier widths from the blueprints and ordered accordingly. Also installed a monster dehumidifier.
 
Only cheap solution is diy
Did it myself when I was younger and more limber. :rolleyes:

Biggest cost was the vapor barrier. Sealing the vents was relatively inexpensive.

I waited too long to DIY, it would most likely irritate my lower back and put me out of commission for months, probably before the job was finished.

IIRC this is where i bought the supplies from, lots of good how to vids on there too

https://crawlspacerepair.com/
Thanks! While I can’t DIY it, it’s good to understand the process and predict where the contractor will be cutting corners on both labor and materials.
 
I also did mine myself. I got liner and dehumidifier from CrawlSpace Care Technologies out of Greensboro. Great folks, and I believe they also train a dealer/installer network so they should be able to provide you with at least one local reference for installation.
 
X2 on sealing the crawlspace and leaving vents open.

Leaving the vents open would be counter productive.... The main point of sealing a crawl is to keep out humid outside air while cutting off soil moisture at the same time.

Vents could be open in the winter, but then you lose some of the energy benefits of the sealed crawl.
 
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