Home & Garden

Ask Angie: Who should be hired to install a whole-house dehumidifier?

Angie Hicks
Angie Hicks MCT

Dear Angie: What kind of service provider should I hire to install a whole-house dehumidifier? We're tired of dumping the reservoir on the small one we have now.

— John R, Williamsport, Md.

Dear John: For this kind of work, you should hire a licensed HVAC contractor who regularly installs dehumidifiers. These pros typically place whole-house dehumidifiers in basements, attics or mechanical closets.

It's important to manage your home's humidity, as too much is associated with discomfort and mold, health and other problems. Ideally, the relative humidity in your home should be 45 to 50 percent. You can buy an indoor monitor, with many models costing less than $20, to determine the precise relative humidity.

Smaller portable dehumidifier units may work well for one room or a small area, but they can fill up quickly during the humid months and shut off when you need them most. A whole-house dehumidifier continues to work right along with your heating and air conditioning system. Some can dehumidify an area as large as 3,000 square feet.

An air handler, such as a furnace, doesn't simply pump out hot or cold air; it also sucks the room-temperature air, and its moisture, back through air returns. This is where a dehumidifier comes into play. Technicians typically connect a whole-house unit to a home's HVAC system, tying it into a main return. It removes moisture and allows the dry air to cycle back to the air handler.

Installations generally cost from $3,000 to $5,000, unless your home is so large it requires more than one unit.

As with your heating and air conditioning system, a whole-house dehumidifier should be sized to your house and specific situation. Unit sizes are based on how much water they can remove from the air in a day. Whole-house dehumidifiers can remove, on average, 90 to 150 pints, depending on their size, and drain the water through your home's plumbing system.

Some service providers told us that sizing a dehumidifier is more an art than a science. The HVAC contractor must factor in the normal humidity where you live, how much humidity your home's air conditioning system already dissipates and whether you have a basement or crawl space that holds moisture.

Plan to get multiple estimates from contractors who are appropriately licensed, insured and bonded, and who have positive consumer reviews and experience installing whole-house dehumidifiers.

Angie Hicks compiles the best advice from the most highly rated service pros on Angieslist.com to answer your questions. Ask Angie your question at askangie@angieslist.com.