What this covers
A whole-home dehumidifier removes moisture from the air of the entire house, or from a crawlspace or basement, instead of one room. The technician measures the space and the moisture load, chooses a unit sized for it, and mounts it where it can be serviced: hung from joists in a crawlspace, set on a stand in a basement, or in a mechanical room. It is ducted on its own or tied into the air handler so dried air reaches the living space, drained to a floor drain or condensate pump, and wired to a humidistat or a thermostat that reads humidity. Careful work seals the space first, because a dehumidifier in a crawlspace with open vents is fighting the weather.
When to call
- Musty smells, damp air or condensation on windows and cold pipes.
- A crawlspace or basement that stays humid even after drainage repairs.
- Air conditioning that cools the house but leaves it feeling clammy.
- A newly encapsulated crawlspace that needs moisture control.
What to expect
- MeasureHumidity readings and the size of the space set the unit capacity and location.
- InstallThe unit is mounted, ducted and tied to a drain or condensate pump.
- ControlA humidistat is set and wired so the unit runs only when the air needs drying.
- CheckAirflow, drainage and readings are verified, and you are shown how to change the filter.
Get a certified company
Look up a certified company by ZIP code. Every company's license, insurance and trades are verified before it is listed, and placement is never paid.
Questions people ask
How is it different from a portable dehumidifier?
A whole-home unit moves far more air, drains on its own instead of filling a bucket, and is ducted so it dries the whole house or the whole crawlspace rather than one room.
Does it work with the air conditioner?
Yes. Many are tied into the air handler. The air conditioner removes some moisture while it cools, and the dehumidifier handles the humid days when it is cool enough that the air conditioner barely runs.
Where does the water go?
Into a drain line to a floor drain, a sump, or a small condensate pump that lifts it to a drain. The line is routed so it cannot back up into the unit.
Related: Whole-home air purification · Crawlspace encapsulation · Ductwork installation and repair · All heating, cooling and air quality
This page describes what the service involves. The company you hire sets the scope, the schedule and the price, and your contract is with that company. We verify credentials and collect reviews from real jobs. We do not guarantee any company's workmanship. Safety steps are general guidance. When in doubt, leave the home and call 911.