Crawl Space Ventilation

Perhaps nothing in the home is more misunderstood than crawl space ventilation. Most people, if asked, will tell you to close crawl space vents in the winter and open them in the summer. That is utterly backward advice in the Ohio River Valley area. Since the only reason for having vents is to promote drying out the crawl space, consider the following:

Winter air is naturally dry in a relative sense, so a small amount of ventilation may be beneficial. (Too much ventilation is likely to make floors feel cold, put plumbing at risk of freezing, add to utility bills, etc., and these issues probably contribute to the widespread misunderstandings about crawl space ventilation.)

What happens when hot, humid summer air is allowed into a crawl space? It cools down. That’s especially true if ductwork is in the crawl space. Condensation will occur at typical temperatures found in crawl spaces. In fact, since cool air settles, the entire crawl space may be below the temperature that supports condensation. So water droplets form, leading to moldy surfaces.

Here is a statement to remember: “You can’t ventilate your way out of a wet crawl space in the summer.” The more you try, the worse things will become. Crawl space ventilation in the Ohio River Valley area is a bad idea. Regarding crawl space dampness, research has shown that there is actually more evaporation of water taking place from damp soil than there is from standing water. This is believed to be the result of there being more exposed surface area within and around the soil, which encourages evaporation as the water is “wicked up” to the top surface. Even dry-appearing soil or gravel in a crawl space is capable of allowing many gallons of water to evaporate into the crawl space every day, and ultimately into the home, where it adds to comfort issues and sometimes even mold problems. On average, an uncovered floor in a crawl space will produce ten times the moisture in the home that a family of four will produce through daily living.

If you know or suspect that you have a wet crawl space and don’t know what to do about it, you should consider getting Jack Frost to help you. We are not aware of any other company in the area that has knowledge to fix these problems, simply because other heating and air-conditioning companies do not know how to identify the problems and their causes in the first place.