Vented vs Unvented Crawls

A recent study on two homes in our area done by ORNL, for all you crawlspace geeks.
Every areas of the country is different. What works here may not work in your region.
Encapsulation did not save any money, it did however reduce overall humidity.

Good stuff & thanks for sharing. I would have liked to see this same study with the ductwork in the crawl though.

Keep in mind the south is different and you are in Ohio.

Paper to the People does not apply everywhere.

Both houses were built to above code at the time. They both used heat pumps and with no ducts it would be a lower return. The house with the sealed crawlspace had a warmer floor. This is something people with small children have noticed right away after a retrofit. The follow up on the two homes shower about 1600 KWH less consumption in the home with the sealed crawlspace. In an already efficient house that’s a fair amount saved. Might not all be because of the crawl but it does show that efficiency, comfort, and durability can all be improved.

More Info here … Enjoy… Roy Crawl spaces[1].pdf

The problem with the perception that people take away from surveys is that they often just focus on one aspect of the situation.Encapsulating a crawlspace is not just about saving energy. It’s not just about increasing comfort (warm floor).

The comparison should encompass all changes that occur between the two construction techniques.

“For every action, there is a reaction”!

What is the reaction to encapsulating the crawlspace?

How does it affect radon infiltration.?

How does it affect moisture infiltration?

How does it affect mold infiltration?

How does it affect air leakage of the duct system located in the encapsulated crawlspace?

How does it affect floor and wall penetrations (connected to the crawlspace)?

I come across contractors that do all kinds of stupid things attempting to create this “conditioned crawlspace”. They have many reasons explaining why they’re trying to accomplish this, few of them address the important points.

I still can’t seem to get it through to real estate agents who tell their clients to close the crawlspace ventilator in the winter and open it in the summer here in Tennessee.

Then they become infuriated when we have to discuss why organic substances are eating the floor joists, radon levels are high, termites are crawling about and there are drafts coming under the kitchen cabinets were the HVAC supply is panned to the floor.

Got to love both crawlspaces have mold at the end of the study. So both crawlspaces failed. :roll:

I guess a dehumidifier is needed?!!??!?!