How to Install a Crawl Space Dehumidifier: A Comprehensive Guide

Excess moisture in your crawl space can lead to a host of problems, including mold growth, structural damage, and compromised indoor air quality. Installing a crawl space dehumidifier is a smart solution to maintain a dry and healthy environment beneath your home. In this guide, we’ll walk you through the step-by-step process of how to install a crawl space dehumidifier. By following these instructions, you can protect your home from moisture-related issues and improve overall air quality.

Section 1: Assessing Your Crawl Space

Before you dive into the installation process, it’s crucial to evaluate your crawl space to determine the size, condition, and existing moisture levels. This step helps you select the right dehumidifier and understand the specific needs of your space.

  1. Measure the Crawl Space: Measure the dimensions of your crawl space to ensure you choose an appropriately sized dehumidifier.
  2. Check for Moisture Issues: Look for signs of moisture, such as damp surfaces, water stains, or mold. This assessment will help you decide on the capacity of the dehumidifier needed.

Section 2: Choosing the Right Dehumidifier

Selecting the right dehumidifier is crucial for effective moisture control. Factors to consider include:

  1. Capacity: Choose a dehumidifier with the capacity to handle the volume of your crawl space. Most models indicate their coverage area in square feet or cubic feet per minute (CFM).
  2. Energy Efficiency: Opt for an energy-efficient model to save on electricity costs over time.
  3. Type: You can choose between portable or whole-house dehumidifiers. Your crawl space’s size and specific needs will help you make this decision.

Section 3: Gathering Necessary Tools and Materials

Before installation, ensure you have the following tools and materials ready:

  1. Dehumidifier unit
  2. Plastic drain hose
  3. Condensate pump (if needed)
  4. Measuring tape
  5. Screwdriver
  6. Drill
  7. Ventilation pipes (if required)
  8. Hose clamps
  9. Sealing tape
  10. Safety equipment (gloves, goggles)

Section 4: Installation Steps

Now, let’s go through the installation process:

  1. Positioning the Dehumidifier: Place the dehumidifier in a central location within your crawl space to ensure even moisture removal.
  2. Drainage Setup: Connect the plastic drain hose to the dehumidifier’s drainage outlet. If your crawl space has a low point, you may need a condensate pump to facilitate drainage.
  3. Ventilation (if necessary): Some crawl spaces benefit from additional ventilation. Install ventilation pipes to ensure proper airflow.
  4. Secure the Dehumidifier: Use screws to fasten the dehumidifier to the floor or wall, ensuring stability.
  5. Sealing Gaps: Use sealing tape to cover any gaps or openings in the crawl space, preventing outside air from entering.

Section 5: Maintenance and Monitoring

After installing the dehumidifier, it’s essential to perform regular maintenance and monitoring to keep your crawl space dry and your dehumidifier working efficiently.

  1. Regular Cleaning: Clean or replace the air filter and check the water bucket or drain hose for blockages regularly.
  2. Adjust Settings: Monitor humidity levels and adjust the dehumidifier’s settings as needed to maintain your desired humidity level.
  3. Check for Issues: Regularly inspect the dehumidifier for signs of wear, damage, or leaks.


Installing a crawl space dehumidifier is a proactive step toward maintaining a dry, mold-free, and healthy space beneath your home. By carefully assessing your crawl space, choosing the right dehumidifier, and following the installation steps, you can ensure a clean and dry environment. Regular maintenance and monitoring will help keep your crawl space in optimal condition, ultimately benefiting the overall health and longevity of your home.