Crawl Space Dehumidifier Installation
Crawl space dehumidifiers cost $1,000–$3,000 installed. Size one by square footage and code (70 pints per 1,000 sq ft in Henrico, VA), then get quotes.
- Full encapsulation typically $5,000–$15,000, average $5,500 (Angi)
- Vapor barrier installed $2–$4 per sq ft (HomeGuide)
- Dehumidifier installed $1,000–$3,000 (HomeGuide)
- Free quotes from independent local contractors
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Typical national cost$5,000 – $15,000Cost guide →About Crawl Space Dehumidifier Installation
A crawl space dehumidifier is a sealed, ducted or freestanding unit made to run in an encapsulated space and drain its own condensate. HomeGuide prices the unit at $300–$2,000 and installation at $1,000–$3,000. Angi's dehumidifier article shows a $7,000 average, but that figure assumes encapsulation is included. For an already-sealed space, Angi says about $3,000.
Size is where most quotes differ. Angi's market table runs from 30–50 pints for spaces up to 1,500 sq ft to 120+ pints above 3,500 sq ft. Codes set their own floor. NC R409.5.1 requires a permanently installed unit rated at least 15 pints/day, with a drain and an outlet. Where the IRC dehumidifier option is adopted, as in Henrico County, VA, the unit must remove 70 pints/day per 1,000 sq ft. EPA advises keeping indoor relative humidity below 60%, ideally 30–50%.
Common Jobs We Route
- New dehumidifier in an encapsulated crawl space (installed $1,000–$3,000)
- Replacement of a failed unit (removal $40–$200 per HomeGuide; repairs $70–$400)
- Tie-in to HVAC ducting (labor $700–$1,000)
- Condensate pump or drain line to daylight (required by NC R409.5.1)
- Alternative drying: supply air (NC 1 cfm per 30 sq ft; IRC 1 cfm per 50 sq ft) or exhaust fan
What Affects the Price
Providers quote their own work — these are the factors that consistently move the number.
- Capacity in pints/day: installed 50-pint $1,000–$2,500, 60-pint $1,200–$2,700, 70-pint $1,500–$3,000
- Refrigerant (~$1,500) vs desiccant (~$2,000) (Angi)
- New circuit or outlet and drain routing (both trigger permits in NC)
- Running cost: $10–$30/month (HomeGuide) or $300–$500/year (Angi)
Cost Guides
Crawl Space Dehumidifier Installation FAQs
What size dehumidifier do I need for my crawl space?
Angi's table: up to 1,500 sq ft, 30–50 pints; 1,500–2,500 sq ft, 50–70; 2,500–3,500 sq ft, 70–120. Where the IRC dehumidifier option applies, code requires 70 pints/day per 1,000 sq ft.
Can I use a regular basement dehumidifier?
HomeGuide notes portable units cost $50–$500, but codes call for a permanently installed unit with a drain (NC R409.5.1). Ask the installer about rated operating temperatures.
Do I still need a dehumidifier after encapsulation?
HomeGuide says yes in humid climates. Code requires some drying method in a sealed crawl space: a dehumidifier, or a supply of conditioned air from the HVAC system. Without one, a sealed space can still hold moisture.
What humidity should a crawl space be?
EPA's guidance for indoor spaces is below 60% relative humidity, ideally 30–50%.
Crawl Space Dehumidifier Installation by Area
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