How to Install a Crawl Space Dehumidifier: A Simple 5 Step Guide

Due to their location, crawl spaces tend to be damp, musty, and sometimes home to rodents and other animals looking for shelter. If you avoid your crawl space because you dislike the environment down there, why not install a crawl space dehumidifier?


You may even be able to install it yourself!

Like many home improvement projects, all you need are the right tools and a little advice. Read our guide and explore the five steps you can take to make your crawl space healthier and less creepy.

1. Location Location Location

You might think you don’t have much of a choice when it comes to the location where you install the crawl space dehumidifier. After all, it’s a small space, and who will see it anyway?

You’re partially correct—not many visitors will ask to take a look in your crawl space.


That said, you do need to install the dehumidifier in an area where it can discharge airflow without anything in the way. You’ll also want to make sure you can get to the unit easily since you will need to adjust the humidistat and perform seasonal maintenance (filter changes and cleaning).

2. Create a Level Foundation

Level is the keyword when deciding where to place the dehumidifier. Since many crawl space floors are not level, you may need to prepare a foundation for the unit.

Concrete blocks often make the most sense, but you can create a base from anything that assures stability. Leveling is also essential to ensure you don’t allow water to stand in the drain pan.

3. What About Crawl Space Dehumidifier Ducting?

Not all crawl spaces are identical. You may have one with a divider or an unusual shape, making it necessary to install a ducting kit.

Duct kits direct air discharged from the dehumidifier further away from the unit, preventing local air sampling. The longer distance also creates a cross current. This helps the unit dry the entire space more efficiently and aids in crawl space mold prevention.


You may also want to use an insulated flex duct to help with noise control. Check with the dealer where you purchase your unit for suggestions about ducting.

4. Where Will the Water Go?

Since a dehumidifier pulls excess water from the air, you must have a way to drain the water it collects. The most common way to deal with water from your dehumidifier is to utilize gravity draining in a crawl space.

Most units for basements and crawl spaces come with gravity draining capability, but you’ll still need to attach the drainage hose or PVC pipe to the unit’s drain fitting. Then, you’ll run the hose either to a floor drain or sump pump.

5. Set Up a Hygrometer

While your new crawl space dehumidifier is self-sufficient, it’s not an install-it-and-forget device. Monitoring crawl space humidity is essential to maintaining humidity levels between 50-60%

If you use a wireless hygrometer, you won’t need to enter the crawl space unless you need to perform other crawl space maintenance.


Place the data logger in the crawl space, set it to record temperature and humidity at various time intervals, and then connect the logger to your computer to retrieve the information.

Ready to Transform Your Crawl Space?

Now that you know the steps needed for crawl space dehumidifier installation, you can put your DIY skills to work! You may have other questions not answered in this guide, and we’re here with the answers.

Whether you need help with installation, crawl space maintenance, or assistance with crawl space damage repair, our team can help. Reach out to us today!