crawl space dehumidifier installation

crawl space dehumidifier installation:A Complete Guide


Did you know that improper moisture levels in your crawl space can lead to musty odors, rotting wood, and even mold growth that impacts your home's air quality? Installing a dehumidifier is an effective solution, and this guide will walk you through the process step-by-step.

Why You Need a Crawl Space Dehumidifier

Let's start with a little-known fact: the air you breathe in your home is directly impacted by the conditions in your crawl space. Excess moisture and humidity create the perfect breeding ground for mold, mildew, and other nasty stuff you don't want circulating through your living areas.

A quality crawl space dehumidifier helps regulate humidity levels between 30-50% - the ideal range for preventing moisture issues. Keeping your crawl space dry reduces musty odors, rot, insects, and the potential for structural damage over time.

Preparations Before Starting

Gather Your Tools:

1. Tape measure

2. Drill or screwdriver

3. Screws

4. Level

5. Utility knife (for measuring clearance and approximate fit)

6. Tubing for pump drainage (if needed)

7. Clamps (to secure tubing)

Prep the area:

1. Remove any debris, clutter, or standing water from the crawl space.

2. Fix any leaks from pipes or exterior drainage before installing.

3. If encapsulating, seal vents but leave enough clearance around the dehumidifier for good airflow.

Step-by-Step Crawl Space Dehumidifier Installation

With your crawl space prepped and the right dehumidifier selected, you're ready for installation. Follow these steps carefully for a smooth, effective setup:

Step 1: Determine the Ideal Placement

For maximum effectiveness, your dehumidifier should be placed against the vapor barrier (thick plastic lining the ground) near the center of your crawl space. Avoid setting it directly on dirt and make sure there's enough clearance on all sides for airflow.

Step 2: Install the Drainage System

Most crawl space models use a gravity drain to automatically remove collected moisture. Drill a hole through the rim joist where you'll feed the drain hose to the exterior of your home, angling it slightly for proper drainage flow.

If using a built-in pump, you'll route the hose accordingly and may need a condensate pump depending on the distance.

Step 3: Plug It In and Make Adjustments

With the dehumidifier in place and drainage set up, it's time to plug it into a GFCI-protected outlet or install a dedicated circuit if needed. Power the unit on and use the display to set your target humidity level, typically between 30-50%. Allow a few hours for it to cycle and start dehumidifying the space.

Many models have additional settings like:

Fan Speed: Adjust based on moisture levels or noise preference.

Drain Pump Controls: Customize pump operation if present.

Timers: Set a schedule if you only need dehumidification periodically.

Humidistat: Automatically powers off when desired humidity is reached.

Pro Tips:

1. Replace filters regularly according to manufacturer recommendations.

2. Insulate any exposed ductwork to prevent condensation buildup.

3. Consider adding a dehumidifier drain air gap or condensation pump for easy drainage.

Step 4: Maintain and Monitor

Check on your dehumidifier every few months. Remove any built-up dust or debris from the coils and air filter. Inspect the drain line for clogs or leaks.

Use a humidity monitor to track moisture levels over time and adjust dehumidifier settings as needed throughout different seasons. Proper humidity control helps protect not just your crawl space, but the entire structure of your home.

With these steps complete, your crawl space dehumidifier is ready to begin controlling moisture levels! Be sure to monitor humidity readings periodically and adjust settings as needed.

Maintenance and Troubleshooting

To keep your dehumidifier running in top shape:

Filter Cleaning: Clean the air filter regularly, about every 6-12 months.

Drain Checkup: Inspect the drain line periodically and unclog if needed.

Descaling: Use manufacturer-recommended descaling methods to remove mineral buildup.

If issues arise, consult the manual for common diagnostic codes and troubleshooting tips before calling for service.

Encapsulation vs. Non-Encapsulation

One major decision when installing a dehumidifier is whether to fully encapsulate (seal off) your crawl space or leave it as a non-encapsulated, vented space. There are pros and cons to each approach:

Encapsulated Crawl Spaces

Encapsulation means using thick plastic sheeting to fully seal off the crawl space from any outside air and moisture intrusion. It creates a separate, isolated space.

Pros of Encapsulation:

1. Can achieve very low humidity levels more easily when paired with a dehumidifier

2. Better protection against outside air infiltration containing moisture

3. Prevents cold floors above the crawl space in winter

4. Increases energy efficiency of the home

Cons of Encapsulation:

1. Higher upfront installation costs for labor and materials

2. Requires proper vapor barrier sealing with no gaps

3. May require additional insulation and air sealing

4. Limits storage and access to the crawl space

Non-Encapsulated Crawl Spaces

The more traditional approach leaves crawl space vents open and doesn't fully seal from outside air movement.

Pros of Non-Encapsulation:

1. Lower upfront costs, easier for DIY installation

2. Allows more airflow and access to the space

3. Vents can provide supplemental air intake for HVAC systems

Cons of Non-Encapsulation:

1. Harder to control humidity levels with outside air entering

2. More potential for moisture infiltration from the exterior

3. Cold drafts can make it harder to condition the space

For both approaches, it's crucial to properly size and install a crawl space dehumidifier rated for the square footage. Sealing and insulating ductwork is also recommended.

Some contractors take a hybrid approach, utilizing sealed crawl space liners but leaving a few vents open. This balances air exchange with moisture control.

The best choice depends on factors like the home's age, construction type, climate, budget, and the importance of energy efficiency. Many opt to encapsulate when possible, as controlling humidity is easier.

AlorAir Crawlspace Dehumidifiers

To maintain optimal moisture levels and protect your home from potential damage, consider investing in a high-quality crawl space dehumidifier from AlorAir Crawlspace. Our line of dehumidifiers are specifically designed for crawl spaces and basements, with models like the Sentinel HD55 and the Sentinel HD90 offering powerful moisture removal capabilities.

Visit to explore our product offerings and find the perfect dehumidifier solution for your crawl space needs. With proper installation and maintenance, an AlorAir dehumidifier can provide years of reliable humidity control, safeguarding your home's structural integrity and indoor air quality.