Best dehumidifiers for mold-prone homes, and the humidity target

Does a dehumidifier prevent mold?

A dehumidifier helps prevent mold by keeping the air dry enough that mold can’t get started on damp surfaces. It does not kill mold or remove growth that is already there.

The target numbers come from the agencies. EPA says to keep indoor relative humidity below 60%, ideally between 30% and 50%. CDC recommends no higher than 50%. A practical setting for most homes is 45% to 50%.

Before you buy, fix the source. A dehumidifier can’t keep up with a leaking pipe, a wet foundation or a crawl space with standing water. If mold already covers more than about 10 square feet, EPA suggests hiring a professional to remove it first. Our guides to preventing mold and mold in the basement cover the moisture side. If a recent leak soaked the area, how fast mold grows explains why the first 24 to 48 hours matter.

How are dehumidifier pints rated now?

Capacity is listed in pints of water removed per day. The test behind that number changed in June 2019.

According to ENERGY STAR, the Department of Energy now tests portable units at 65°F instead of 80°F. That is closer to real basement conditions. Cooler air holds less water, so the same machine posts a lower number under the new test. New models began showing the new ratings around early 2020.

Source: ENERGY STAR. These are rough correlations and vary by model.

So a “50-pint” unit sold today is a large portable. It is not a step down from an old 70-pint machine. Whole-home and crawl space units often list both numbers. The ENERGY STAR database shows the DOE “Appendix X1” figure for every certified model.

How much capacity do you need? ENERGY STAR does not publish a sizing formula. It says only that larger, wetter rooms need higher-capacity units. It also notes that if you are replacing an older dehumidifier, a new one with a smaller number on the box may still do the same job. Coverage claims on product pages are not standardized. One manufacturer page we checked listed two different coverage figures for the same model. Treat square-foot claims as rough, and judge the result with a hygrometer instead.

What features matter for mold control?

ENERGY STAR. A dehumidifier may run for months. ENERGY STAR ratings use Integrated Energy Factor (IEF), which counts the power the unit uses even when it has cycled off. Check the exact model number in the ENERGY STAR product data. Similar-looking models can differ.

A humidistat you can set. The unit should hold a target, such as 50%, and cycle on and off on its own. Built-in sensors measure air at the machine, so check the room with a separate hygrometer.

Continuous drainage. A full bucket shuts the unit off. A gravity drain hose works when a floor drain is lower than the unit. A built-in pump pushes water up into a sink or out a window.

Operating temperature. Standard compressor units lose capacity in cool air. If the space runs cool, pick a model that publishes a low-temperature rating.

Auto-restart. After a power outage, the unit should turn back on with its settings.

Noise. Published figures range from about 40 to 55 dBA among the models below. That matters if the unit sits near bedrooms.

Five models worth a look

The models below are widely sold and currently available. Specs come from each manufacturer’s page and the ENERGY STAR database as of 2026-10-19. We did not test them. Product links follow our advertising disclosure.

The three portables are close on capacity and efficiency. The real differences are drainage, published low-temperature performance and noise.

Two gaps are worth noting. Midea’s and LG’s pages do not publish an operating temperature range, so check the manual before putting either in a cool basement. The Santa Fe Compact70 was not in the ENERGY STAR database when we checked, which is common for crawl space units built to different test conditions. Before buying any model, look up its exact number in the ENERGY STAR product data, since similar model numbers can have different ratings.

Portable, whole-home or crawl space unit?

Portable (50-pint). Right for most single basements, garages and damp rooms. It plugs in, rolls into place and drains to a hose or pump. If one unit can’t hold your target humidity, the space may need a bigger fix.

Whole-home ducted. These connect to ductwork or sit in a basement or sealed crawl space and handle a larger area. ENERGY STAR says it is important that a whole-home unit is sized and installed correctly by a professional. The cost is higher, but there is no bucket and efficiency ratings are better.

Crawl space units. Built low and designed for cooler air. They work only if the crawl space is sealed, has a vapor barrier and is free of standing water. Fix drainage first.

If water damage caused the humidity, dry the structure before you rely on a dehumidifier. The difference between mitigation and restoration explains what professional drying involves.

How to run a dehumidifier to keep mold away

Set the humidistat to 45% to 50%, within EPA’s 30% to 50% ideal range and CDC’s 50% ceiling. Place a separate hygrometer across the room and check it for the first week.

Keep doors to the space closed so the unit isn’t trying to dry the whole house. Leave several inches of clearance around the intake and exhaust. Clean the filter on the schedule in the manual. If you use a drain hose, check that it runs downhill and isn’t kinked.

If humidity stays above 60% with the unit running all the time, the problem is bigger than the machine. Look for a leak, a gutter or grading problem, or an HVAC issue. For more on keeping mold out of your home, return to the mold hub.