One important issue associated with unencapsulated crawl spaces that you may never have known about is high electric bills. As a matter of fact, unencapsulated crawl spaces can cost up to 15-25% more than encapsulated crawl space in energy bills, even if you factor a dehumidifier into the equation, which is a tool you may need to bring your crawl space back down to a normal humidity level.
Why is this? There are a number of reasons unencapsulated crawl spaces can be so much more energy-dense than encapsulated ones. Moist air is more difficult to condition, so your air conditioner may have to work harder with high-moisture air than with low-moisture air. Additionally, crawl space vents and other places that air can get out also allows your air-conditioned air to get out, which means you’re basically pumping air-conditioned air into the world.