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The basement is the most common location for a dehumidifier — and the toughest too. "Between the extreme humidity levels and often chilly temperatures, these below-grade spaces are a real torture test for dehumidifiers," says Dan DiClerico, director of the Home Improvement & Outdoor Lab at the Good Housekeeping Institute.
After testing more than a dozen dehumidifiers from leading brands over the past year, these are our recommendations for the best basement dehumidifiers.
Our top picks:
High humidity in the basement can affect the rest of the house, like condensation on windows, pipes and toilet tanks. Not only do the moist conditions feel gross, they can also make your home a more welcome environment for black mold, mildew and other allergens. The best dehumidifiers can drop your basement's relative humidity down below 60%, the threshold at which bacteria, microbial agents and bad odors thrive. Dehumidifiers work by pulling moisture out of the air through a series of heat exchangers and a condenser that drops the temperature of the air below its dew point and then collects the resulting condensation in a tank.
When determining the best dehumidifiers for basements, we gave preference to high-capacity units with more "suction power" to pull the moisture from the air. We also looked for models with bigger tanks, which means you have to empty it less frequently.
After reading our reviews, you can find expert advice on what to consider when shopping for a dehumidifier at the bottom of this guide, along with details on how dehumidifiers work and how we test dehumidifiers. Looking for more ways to breathe easy? Check out our guides on the best air purifiers and the best humidifiers.
How we test dehumidifiers
Products experts and analysts at the Good Housekeeping Institute continuously survey the marketplace and manufacturers to identify the models that consumers nationwide are most likely to find in stores and online. For this report, we singled out reliable brands for testing across different size categories to cover every need and budget.
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 dehumidifier collects in a 48-hour time period. Our engineers also use a decibel meter to assess how loud each machine is when running on its highest fan speed. Usability is another important part of our evaluation; it happens in the Lab, as well as in the homes of consumer testers, allowing us to test the dehumidifiers under real-world conditions.
We look at such factors as portability, how intuitive the display and controls are and ease of cleaning, including how easy it is to wash the filter and empty the water reservoir. Finally, we evaluate each brand's customer service by contacting their help lines with a pretend problem and seeing how quickly it is remedied by the representative.
What to look for when shopping for dehumidifiers for the basement
Here are a few things to keep in mind when looking 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. Dehumidifiers are sized based on how many pints of water they can remove in a day. The colder the space, the less water the unit pulls since colder 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 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: Things like easy-access reservoirs and filter indicators can make it easier to maintain your machine. Auto-humidistats can sense the moisture in the air and turn off when a desired level is reached. Basements tend to be colder, so you might want to check for a low temperature setting or auto-defrost function to help ensure the unit runs properly in cooler spaces.
How does a dehumidifier work?
Dehumidifiers are a system of two heat exchangers and a condenser. Air from the room is pulled into the first heat exchanger by its fan and exchanges heat with a refrigerant in the heat exchanger. 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 in the process 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 hotter than the air that enters, as work is required to run the system.
Why trust Good Housekeeping?
This guide was written by Abigail Bailey, who spent hours studying the Good Housekeeping Institute's dehumidifier testing data and poring over recent user reviews online.
She also consulted GH Institute Lab Assistant Nikolas Greenwald, who led our latest round of dehumidifier testing. Before joining GH in 2022, Nikolas worked on projects ranging from chemical inventory and reporting to the development of bioassays in the labs of the Massachusetts Institute of Technology and Regeneron Pharmaceuticals. He holds a degree in chemical engineering from Northeastern University.
This article was reviewed by Home Improvement & Outdoor Lab Dan DiClerico who oversees our in-Lab dehumidifier testing and has spearheaded numerous investigative reports on the topic of indoor air quality, working closely with outside experts from the government, industry and the home services space. He also oversees our continuous in-home, survey-based consumer testing for dehumidifiers, which allows us to evaluate these devices in real-world conditions.
Abigail (she/her) covers everything from kitchen gear to mattresses and smart blinds for the Institute, as well as assisting the General Manager in any number of projects. She graduated from Louisiana State University with a B.A. in creative writing, as well as earning her M.S. in publishing digital and print media from New York University. Before GH, she worked at LSU Press and The Southern Review literary magazine. In her free time you can find her quilting, cross-stitching or trying to figure out how to squeeze one more bookshelf in her tiny apartment.
As the lab assistant at the Good Housekeeping Institute, Nik (he/him) works with all of our Labs to develop testing protocols and manage data collection and analysis. Before joining Good Housekeeping in 2022, Nik worked in the labs of MIT and Regeneron, working on projects ranging from chemical inventory and reporting to the development of bioassays. He holds a degree in chemical engineering from Northeastern University.
Having written thousands of product reviews and how-to articles on all aspects of home ownership, from routine maintenance to major renovations, Dan (he/him) brings more than 20 years of industry experience to his role as the director of the Home Improvement & Outdoor Lab at the Good Housekeeping Institute. A one-time roofer and a serial remodeler, Dan can often be found keeping house at his restored Brooklyn brownstone, where he lives with his wife and kids.
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