Installing a crawl space dehumidifier protects your home from mold, wood rot, and musty smells. You can do it yourself in a few hours with basic tools. Here's how:
Why Your Crawl Space Needs a Dehumidifier
Your crawl space holds moisture from the ground and humid outdoor air. This dampness rises through your floors into your living space and allows for the growth of mold.
Up to half of your home's air starts in your crawl space. High humidity below means problems throughout your entire house. You'll notice musty odors, increased allergies, and higher energy bills.
A dehumidifier keeps humidity between 30-50%, which is what you want when asking what should crawl space humidity be. This stops mold growth and prevents structural damage before it starts.
What You Need Before Installing
Tools and Materials:
- Drill with bits
- Level
- Measuring tape
- Drain hose (usually included)
- Concrete blocks or platform (optional)
- GFCI outlet nearby
Prep Your Space: Go through your crawl space and remove any debris or stored items. Check for standing water or active leaks. You must fix water problems before installing a dehumidifier.
| Choose Your Dehumidifier: Top 5 Best Crawl Space Dehumidifiers |
Install a vapor barrier if you don't have one. This plastic sheeting blocks ground moisture and makes your dehumidifier work better.
Step 1: Choose the Right Location
Place your dehumidifier near the center of your crawl space. Central placement distributes dry air evenly throughout the space.
Keep the unit at least 12 inches away from walls and obstructions. Air needs to flow freely around all sides of the machine.
Avoid placing the unit directly under bedrooms. The vibration and noise can travel through floor joists into living areas above.
Step 2: Create a Level Platform
Set your dehumidifier on concrete blocks or a platform. Raise it 6 inches off the ground to protect it from potential flooding.
Use a level to make sure the platform sits completely flat. An uneven surface causes condensation to pool instead of draining properly.
The platform also improves air intake from all directions. This helps your unit run more efficiently.
Step 3: Set Up Drainage
Most crawl space dehumidifiers drain automatically through a hose. Connect the drain hose to the outlet on your unit.
Route the hose to your sump pump, floor drain, or outside. The hose must slope downward for gravity drainage to work.
Some units include a condensate pump that pushes water upward. These give you more flexibility with drain placement.
Step 4: Connect to Power
Plug your dehumidifier into a GFCI-protected outlet. Never use extension cords or adapters with crawl space dehumidifiers.
The outlet should be within 9 feet of the unit. If you don't have a nearby outlet, hire an electrician to install one.
Make sure nothing blocks access to the power cord. You'll need to unplug the unit for maintenance.
Step 5: Configure Your Settings
Set your target humidity to 50% or slightly below. This level prevents mold growth without wasting energy.
Enable the auto-restart feature if available. This ensures your dehumidifier turns back on after power outages.
Check that the unit sits level one more time before turning it on. An unlevel dehumidifier won't drain properly.
| PDF Instructions: Dehumidifier Installation Checklist |
Maintenance Tips
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Every Month: Check the drain hose for clogs or kinks. Make sure water flows freely to the drain point.
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Every 3-6 Months: Clean or replace the air filter according to your model's instructions. A dirty filter reduces efficiency.
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Twice Per Year: Inspect the unit for mineral buildup. Use a descaling solution if recommended by the manufacturer.
Monitor your crawl space humidity with weather station. Your dehumidifier should keep levels between 30-50% consistently.
Protect Your Crawl Space with Quality Products
In spite of what a crawl space dehumidifier does, it works best alongside other moisture control solutions. Proper ventilation, vapor barriers, and sealed access points create a complete system.
Check out our crawl space doors, vent covers, and waterproofing products to keep moisture out for good. Together, these solutions protect your home's foundation and improve air quality throughout your house.