The Best Dehumidifiers for Basements That Actually Last

Product analysts and test engineers at the Good Housekeeping Institute Home Improvement & Outdoor Lab continuously survey the marketplace and manufacturers to identify basement dehumidifiers that consumers nationwide are most likely to find in stores and online. For this report, we selected reliable brands for testing across various size categories to cater to every need and budget. Our four winners were chosen from more than a dozen tested models.

Hands-on testing begins in our Lab under controlled humidity and temperature conditions (similar to how other home air equipment is tested, including humidifiers and portable air conditioners). The key performance-based test measures how much water each unit removes over a 48-hour period under consistent conditions.

Our engineers also use a decibel meter to measure the sound level of each machine when running at its maximum fan speed. Usability is another important aspect of our evaluation, which occurs both in the Lab and in the homes of consumer testers, who used the units in real basement conditions and shared feedback on day-to-day performance.

Our pros also assess factors such as portability, the intuitiveness of the model's display and controls, and ease of cleaning, including how easy it is to wash the dehumidifier's filter and empty the water reservoir. Finally, we evaluate each brand's customer service by contacting their helplines with a pretend problem and tracking response time, helpfulness, and resolution quality.

Here are a few factors to keep in mind when searching for a dehumidifier for your basement:

✔️ Size: If you have a large basement (or a particularly damp one), you're going to want a bigger unit that can process more air. If you have a smaller space, you might want a smaller unit. Dehumidifiers are sized by how many pints of water they can remove per day. The colder the space, the less water the unit pulls since cold air contains less moisture than warm air. Here's a little guide to get you started:

• A small humidifier removes 20 to 25 pints of moisture at 65°F, or 30 to 40 pints at 80°F (about 400 to 600-plus square feet).
• A medium humidifier removes 30 to 35 pints of moisture at 65°F, or 50 to 60 pints at 80°F (about 800 to 1,000-plus square feet).
• A large humidifier removes 40 to 55 pints of moisture at 65°F, or 70 to 90 pints at 80°F (about 1,200 to 1,500-plus square feet).

✔️ Hoses and pumps: Some large-capacity dehumidifiers come equipped with a hose connection (pictured), so you don't have to empty the machine regularly. A pump can send water to a sink or other place to siphon off, and many can move the water up to 15 feet.

✔️ Features: Look for easy-access reservoirs and filter indicators that make it easier to maintain your machine. Also consider auto-humidistats, which can sense air moisture and turn off when the desired level is reached. Because basements tend to be cold, you might want to check for a low-temperature setting or auto-defrost function to help ensure the unit runs properly in cool spaces.

A dehumidifier consists of two heat exchangers and a condenser. Air from the room is pulled into the first heat exchanger by its fan, where it exchanges heat with the refrigerant. This heat exchange causes the air to drop below its dew point (the temperature at which condensation starts to form).

The resulting condensation is then deposited into the dehumidifier's tank. The evaporated coolant then flows into a condenser, where it's returned to its liquid form, and the heat it produced is absorbed back by the air. This way, cold air isn't coming off the dehumidifier. The air that leaves a dehumidifier will always be slightly warmer than the air that enters, since the system requires work to run.

While a dehumidifier cannot get rid of mold, it can help prevent it by removing moisture from the air that mold spores need to thrive, according to the U.S. Environmental Protection Agency. Though you're never going to get rid of every last spore in the home, using a dehumidifier to keep humidity below 55% will make it difficult for mold outbreaks to reach levels that start causing health problems.

Dan DiClerico has spearheaded numerous investigative reports on indoor air quality, working closely with external experts from government, industry, and the home services space. In his role as Home Improvement & Outdoor Lab director at the Good Housekeeping Institute, he oversees our continuous in-home, survey-based consumer testing for dehumidifiers, which allows us to evaluate these devices in real-world conditions.

GH Institute Data Engineer Nikolas Greenwald led our latest round of dehumidifier testing. Before joining GH in 2022, Greenwald worked on projects ranging from chemical inventory and reporting to bioassay development in the labs of the Massachusetts Institute of Technology and Regeneron Pharmaceuticals. He holds a degree in chemical engineering from Northeastern University.