Dehumidifier Buying Guide

We test dehumidifiers in three categories based on capacity, a claimed measurement of the amount of water each model can remove from the air—a claim we test. Here’s how we categorize the models in our current dehumidifier ratings:

Small: Claimed to remove 20 to 25 pints of moisture per day.

Medium: Claimed to remove 30 to 35 pints per day.

Large: Claimed to remove 40 or more 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 set at 60° 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. For our convenience rating, we evaluate how often you’ll have to empty the tank. We also measure and judge 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 each dehumidifier. 

Some older dehumidifier boxes say 30-pint, 50-pint, or 70-pint, referring to the amount of water the dehumidifier can remove within 24 hours at 80° F and 60 percent relative humidity. 

But you’ll also see more and more dehumidifiers labeled 20-, 30-, or 45-pint, which is what’s in our ratings now. It doesn’t mean these models remove less water; it’s just that they were tested in a condition where less moisture needs to be removed. 

Dehumidifiers are typically used in basements, and the Department of Energy changed its test standard by lowering the room temperature by 15° F to 65° F, to better reflect basement conditions. There’s less water to remove in cooler air, which is why the number of pints of water drops. The humidity level in both the old and new test is 60 percent. 

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, check out "How to Get the Most From Your Dehumidifier."

Consider Where It Will Go 
Noise can be a concern in living spaces. Our measurements from 3 feet away range from 58 decibels to 67 decibels for the dehumidifiers in our current ratings. 

Normal conversation is around 60 decibels, and a washer is about 70 decibels, according to the Centers for Disease Control and Prevention.