We test dehumidifiers in three categories based on capacity, which refers to the amount of water they’re claimed to remove from the air—a claim we test.

Small: Claimed to remove 30 to 35 pints of moisture per day.

Medium: Claimed to remove 50 pints per day.

Large: Claimed to remove 60 to 70 pints per day.

Our water-removal tests measure a dehumidifier’s ability to remove moisture from the air (the number of pints of water per day, as claimed by the manufacturer) in our test chamber at 80° F and 60 percent relative humidity. The humidistat accuracy test determines how closely each dehumidifier can reach and maintain a set humidity level.

For energy efficiency, our engineers calculate the amount of energy it takes to remove 1 pint of water from the air, and our cool-room performance test judges a model’s water removal and efficiency performance in a room at 50° F and 60 percent relative humidity (a good indicator of performance in a cold, wet basement). We also evaluate noise levels. 

These lab test results, along with brand reliability and owner satisfaction data from our CR member survey, are incorporated into an Overall Score for the dehumidifiers we test. 

Most dehumidifier boxes say 30-pint, 50-pint, or 70-pint, referring to the amount of water the dehumidifier can remove within 24 hours, which is what you’ll see in our dehumidifier ratings. But as these models sell out, you’ll start to see dehumidifiers labeled 20-, 30-, or 45-pint. 

“It doesn’t mean they remove less water, it’s just that they were tested in a condition where less water had to removed,” says John Banta, who leads CR’s tests of dehumidifiers. They’re typically used in basements, and the Department of Energy changed its test standard by lowering the room temperature to better reflect basement conditions. There’s less water to remove in cooler air, which is why the number of pints of water drops. We’ll test these dehumidifiers when more become available in stores and online.

Consider Where It Will Go
Noise is a concern in living spaces. Our measurements from 3 feet away typically range from about 50 decibels (approximately the sound of a refrigerator running) to 67 decibels (about as loud as a box fan set to high) for the dehumidifiers we test.

Large or Wet Spaces
Typically, the damper the space, the more capacity you’ll need in a dehumidifier. The best large-capacity models remove moisture quickly and efficiently in the toughest situations, such as an especially wet basement.

Small or Damp Spots
A large-capacity dehumidifier will help dry a smaller space quickly, but a medium-capacity model will probably do it with less cycling on and off, according to manufacturers.

Fix Existing Problems


Even the best dehumidifier might not work effectively if too much outside moisture seeps into your home. Unclogging gutters and making sure downspouts are directing rainwater at least 5 feet from the house can help. For more tips, see "How to Get the Most from Your Dehumidifier."