Please Enlighten Me With What To Do With My Crawl Space Vents. (insurance, houses)

[Charlton Dude]

I have read many articles on what to do with crawl space vents in this area, given the temps and moisture we have during the summer. They will claim one of the following 2 things:

• Always leave vents open during the summer to vent the crawl space, allowing the moisture to escape.
• Always keep the vents closed during the summer, to keep the outside moisture out and to prevent a wicking effect into the house.

So the experts claim 2 completely different things, yet they both make sense. What do I do?

[TuborgP]

Originally Posted by Charlton Dude

I have read many articles on what to do with crawl space vents in this area, given the temps and moisture we have during the summer. They will claim one of the following 2 things:

• Always leave vents open during the summer to vent the crawl space, allowing the moisture to escape.
• Always keep the vents closed during the summer, to keep the outside moisture out and to prevent a wicking effect into the house.

So the experts claim 2 completely different things, yet they both make sense. What do I do?

I have been convinced to be of the leave them open year round thread. I have read and discussed and the insurance answer seems to be leave them open. But I understand the two schools of thought are sure they are right. When I sold my old house up North I had to have Radon Abatement done. The guy who did it was like a guru of Radon Abatement and had published on the topic. He told me when I got here to leave them open year round as a constant air flow was important to prevent a number of buildups in your crawl space including mold.

[Charlton Dude]

Originally Posted by TuborgP

He told me when I got here to leave them open year round as a constant air flow was important to prevent a number of buildups in your crawl space including mold.

Then what about the other side that says 2 things will happen:

1. The hot air will ride over the cooler crawl space floor and create moisture, making things worse.
2. That all this moisture will wick up into the house, as they have discovered the airflow is always UP into the house, versus out the other crawl space vent.

[TuborgP]

Originally Posted by Charlton Dude

Then what about the other side that says 2 things will happen:

1. The hot air will ride over the cooler crawl space floor and create moisture, making things worse.
2. That all this moisture will wick up into the house, as they have discovered the airflow is always UP into the house, versus out the other crawl space vent.

Yup it's a crap shoot. I had to select one or the other so I went with the builder recommendation which was the same as the inspector and my realtor. Believe my I was in the same which is it mindset you were. But I had to choose. However with people planting shrubs in front of vents and putting those metal water guards to stop ground water from getting in and blocking air circulation I wonder if it makes a difference?
http://www.askthebuilder.com/543-Cra...ce-Vents.shtml

[Andy64]

Mine have been sealed closed, but I've also added a dehumidifer all for the sake of termite coverage, but thats a whole other issue/story. I believe if you close them you need the dehumidifier.

[Starglow]

You can install thermal crawl space vents that open or close by themselves.

Here's just one example:

temp vents, Temp Vents, TEMP VENTS, crawl space vents, Crawl Space Vents, CRAWL SPACE VENTS, thermo vents, Thermo Vents, THERMO VENTS, temperature controlled vents, Temperature Controlled Vents, TEMPERATURE CONTROLLED VENTS

[NYer]

Well, when our radon test was done, it was important that the house was thouroughly sealed up so that if radon was present, it could build up. So when the engineer said to leave the vents open, that made sense to me.
In 3 years we have not had problems with moisture wicking up. We have 5 1/2 foot crawlspace, covered by a vapor barrier.

[VickiR]

I have heard both ways but in the last few years, all the inspectors that I deal with say the same thing...leave the crawl space vents open year round unless there is going to be 5 days of below freezing weather.

Vicki

[sacredgrooves]

Closed, year around, end of discussion. Anyone saying otherwise (this is region specific not nationwide) is incorrect. The humidity in our area pulled in through the vents during the summer months wreaks HAVOC on the crawlspace environment. You do not have to take my word on it, I only own a company that mitigates crawlspace issues, and inspected 7,000 of them with our home inspection biz.
Try Advanced Energy and see what they have to say....they are actual house scientists with a fantastic study performed on this very subject in our region with 6 identical houses.
Close your vents, especially in the summer.

[Sayantsi]

I've always heard to keep them closed as well, unless you get moisture in there, then open them only while venting it out, and use fans to help with that.