Crawl space dehumidifier installation
In a Middle Tennessee summer, a sealed crawl space needs something pulling water out of the air. A crawl space dehumidifier is built for exactly that.
A crawl space dehumidifier keeps the air under your house dry once the crawl space has been sealed. For Murfreesboro homeowners, contractors install new units, replace failed ones, and set up the drain line, controls and filters so the system runs without anyone having to check on it.
How is it different from a basement or room dehumidifier?
A crawl space unit is built to run in a low, cool space, sit on a liner or hang from joists, and drain continuously through a hose or condensate pump. A room unit with a bucket isn't designed for that and won't keep up in a Middle Tennessee July.
How big does it need to be?
The City of Murfreesboro uses the 2024 International Residential Code, which lists dehumidification as one way to condition an unvented crawl space and sizes it at 70 pints of moisture removal per day per 1,000 square feet of crawl space floor. A contractor will also look at how tight the space is and how much moisture the ground and walls give off.
Signs your existing unit needs help
- The humidity reading stays high or the unit never shuts off
- The musty smell has come back
- Water is pooling around the unit or the drain line is clogged
- The condensate pump is failing or alarming
- The unit is noisy, icing up or showing error codes
Repair, replace or upgrade?
Clogged filters, kinked hoses and failed pumps are inexpensive fixes. A dead compressor or an undersized unit that runs constantly usually means replacement. If the crawl space was never fully sealed, sealing it may help the dehumidifier more than buying a bigger one.
What affects the cost?
- Unit capacity and features
- How the condensate drains
- Whether a new outlet or circuit is needed
- Access and where the unit can be placed
- Any sealing or liner work needed first
Pricing comes from the contractor after an inspection.
Common questions
Can I use a dehumidifier without sealing the crawl space?
It will run, but in a vented crawl space it's fighting outdoor air. A dehumidifier works much better in a sealed crawl space.
How is a crawl space dehumidifier sized?
The 2024 IRC dehumidification option uses 70 pints of moisture removal per day for every 1,000 square feet of crawl space floor. Contractors adjust for the specific space.
What maintenance does a crawl space dehumidifier need?
Regular filter cleaning or replacement and a check of the drain line or pump. Follow the manufacturer's schedule.
Where this service is available
Related services
- Crawl space encapsulation
- Crawl space drainage and sump pumps
- Crawl space mold cleanup
- Sagging floor repair
Background on Tennessee licensing, the city code and the limestone under Rutherford County is in the Rutherford County crawl space guide.
Water on the rock, a musty house, or a floor that dips?
Call and we'll put you in touch with an independent crawl space contractor who works in Murfreesboro and across Rutherford County.