Tips for Buying and Using Dehumidifiers

Save your sinuses, your home, and your money by controlling humidity levels with a dehumidifier.

Image: Robert F. Clayton

Ah, summer chores! There’s a lawn to mow, paint to touch up, a grill to clean. But there are summer maintenance concerns inside, too; namely, taming your home’s No. 1 enemy — moisture.

Summer’s higher temps raise humidity levels in your home, and all that moist air can wreak havoc on interior walls and flooring. Too-high humidity promotes the growth of mold, mildew, and other allergensthat take a toll on homeowners, too — especially asthma and allergy sufferers.

Related: 10 Tips to Prevent Mold in Your Home

How Do I Know If My Home is Too Humid?

The EPA recommends keeping your home’s humidity under 60% during the summer and between 25% to 40% in the winter. You can pick up a hygrometer at your local hardware store for less than $25; it’ll measure the air’s moisture content.

But your own comfort — or discomfort — is one of the best indicators of off-kilter humidity. Coughing, sneezing, and clammy hands can all be signs that the air is too humid.  

Your home has a few ways of telling you, too:

  • Wonky wood: Hard-to-open wooden window frames and creaky, buckling hardwood floors are signs of swollen wood caused by too much moisture in your home.
  • Funky smells: A musty odor can indicate growth of moisture-loving mold and mildew.
  • Damaged walls: Peeling wallpaper, blistering paint, and dark spots on walls or the ceiling are all symptoms of excess humidity.
  • Constant condensation: Basic household activities like cooking and showering put moisture into the air, but if you’re seeing condensation on your windows long past bath time, your humidity level is probably too high.

Related: What’s the No. 1 Thing People Want in Their Bathroom?

What Are My Options for Dehumidifiers?

A dehumidifier pulls in wet air, removes moisture, and then exhausts the drier air back into your home. 

There are two types of dehumidifiers: portable and whole-house. The type of dehumidifier that’s best for the job depends on the size of the space you want to dry out and how often you need to.

Portable Dehumidifiers

For one specific space, like a kitchen or a bedroom, a portable dehumidifier ($100 to $350) should do the trick. You can move it from room to room as needed during the months when moisture is a problem.

Some larger models (those with 30+ pint capacities) can be bulky to move, and with a portable you’ll have to empty the water tank each time it’s full. Fortunately, you don’t have to worry about overflow; most new models come with an automatic shutoff if the water tank gets full. Some units also have humidistats, timers, remote controls, and built-in wheels.

Tip: Use the greywater your dehumidifier collects to water your houseplants. 

Operating a portable dehumidifier will add to your energy bill — about 160 kilowatt hours (kWh) per month, or roughly $19 per month. That’s more than your refrigerator uses, but less than the average air conditioner, which eats up about 300 kWh per month.

FYI: Speaking of your AC, yes, running your air conditioner can lower humidity in your home, but more effectively when temps are in the 80s or above. On days when the temps are in the 70s, your AC won’t be running enough to pull any significant amount of moisture out of the air. Without a dehumidifier, the air may still feel sticky even if temperature in your home is at a comfortable level.

This chart from the Association of Home Appliance Manufacturers (AHAM) can help you determine the size (pint capacity) of the dehumidifier you should use based on existing conditions and the size of the space. The values indicate the number of pints collected in a 24-hour period.

Condition without dehumidification during warm and humid outdoor conditions

500  sq. ft.

1000 sq. ft.

1500 sq. ft.

2000 sq. ft.

2500 sq. ft.

Moderately damp — Space always feels damp and has musty odor only in humid weather.1014182226
Very damp — Space always feels damp and has musty odor. Damp spots show on walls and floor.1217222732
Wet — Space feels and smells wet. Wall or floors sweat, or seepage is present.1420263238
Extremely wet — Laundry drying, wet floor, high load conditions.1623303744

*Dehumidification variables also include such other factors as climate, laundry equipment, number of family members, number of doors and windows, and degree and intensity of area activity. Chart data via AHAM.

Whole-House Systems

If you live in a climate where controlling humidity levels is a year-round battle, or you find yourself using multiple portable units, it may be time to install a whole-house system ($1,500 to $2,800), which can be integrated right into your HVAC.

“While a portable dehumidifier can be effective in certain areas, its range is very limited. A whole-house system utilizes a home’s existing duct system for heating and cooling to treat the entire house,” says Andrew Parra, a consultant at Deljo Heating and Cooling in Chicago.

Plus, there’s no tank to empty; a plastic tube and a run of PVC pipe carries water into a basement drain. No basement? A condensate pump will route water outside or to another drain, often in a laundry room or bathroom. You’ll need a pro to install a whole-house dehumidifier. 

Parra recommends installing the system’s humidistat on a central, inside wall of your home, away from doors and windows, to ensure a more accurate read.

Low-Tech DIY Options to Dehumidify

Or maybe you want to DIY — dry-it-yourself. You can dehumidify with some common household items, including:

  • Chalk
  • Kitty litter
  • Charcoal briquettes
  • Rock salt

These DIY solutions work best in small spots like closets or crawlspaces. Some do double duty, removing funky odors in addition to moisture.