Yes, it is possible to over-dehumidify a house by removing too much moisture from the air. This can create an overly dry environment that negatively affects those with respiratory or skin issues, and may cause your skin, hair, and sinuses to feel dry. However, this is unlikely to happen with most modern dehumidifiers, as they are equipped with moisture sensors and adjustable settings. These features allow the unit to pause automatically when the desired humidity level is reached, preventing the air from becoming uncomfortably dry. In contrast, older or more basic dehumidifiers left running for too long could potentially over-dry the air. To avoid this, aim for a balance between removing excess moisture and maintaining a comfortable environment. You can often monitor your home's humidity levels using a modern thermostat for guidance.

Damp proofing and waterproofing are both methods to help keep your basement dry. Damp proofing keeps soil moisture from entering your basement, which is helpful since your basement is underground. Waterproofing, however, keeps both soil moisture and liquid water out of the basement, which is essential, especially if you live in a wet environment. Because it’s more protective, waterproofing typically costs more than damp proofing.

The best ventilation for a crawl space is a fully encapsulated crawl space with its own separate ventilation system. If you go this route, ensure you have the proper crawl space code requirements done and dusted before encapsulating your crawl space with a moisture barrier and installing appliances that may not be up to the proper specs.

Most houses will have vents in the crawl space. This allows for air passage and energy retention, which in many ways can help control the temperature inside the home. If you are able to consider the cost of a crawl space encapsulation, you may not need your crawl space vents at all.