Because of their place below the grade, basements are vulnerable to leaks and excess moisture. That's why it's a good idea to run a dehumidifier in the basement, especially if you—or your off-season storage—spend a lot of time down there. Over time, excess moisture leads to mold growth, warped wood or paper, rust, and peeling paint. A dehumidifier allows you to control the indoor humidity level, and take extra water out of the air. You can choose from a small, portable dehumidifier or a whole-house system depending on your needs.