The 6 Best Dehumidifiers for Garages

1. How We Picked

We did not run six dehumidifiers through a winter in a test garage, and we will not pretend otherwise. This guide is built from manufacturer specification sheets, ENERGY STAR records and retailer listings that repeat the manufacturer's figures. Every capacity, temperature and electrical number on this page is attributed to its source, and where listings disagree, which they often do with this kind of equipment, we say so and plan around the more conservative figure.

A garage is a harder job than a basement, and that shaped every pick. Garages are colder, dustier and dirtier, they swing in temperature and humidity every time the door opens, and many have no floor drain. So the first thing we looked for was a published minimum operating temperature, because a household dehumidifier that stops working at 41°F is useless in a garage that sits at 38°F all winter. Units that publish a low-temperature floor ranked above those that do not.

Second, we looked at drainage. A garage dehumidifier that needs its bucket emptied twice a day will not get emptied twice a day. Built-in pumps or a gravity drain to a floor drain or the driveway are close to essential, and four of our six picks have a pump. Third, we looked for rugged construction, because a garage dehumidifier will get bumped, covered in sawdust and splashed with salt water off the cars.

If your problem is a basement rather than a garage, our basement dehumidifier guide is the better starting point, and if the whole house is humid, our whole house dehumidifier guide covers ducted systems.

2. Why Garages Need a Different Dehumidifier

Most household dehumidifiers are refrigerant units: a fan pulls air across a cold coil, water condenses on the coil and drips into a bucket. That works well at room temperature. As the air cools, the coil gets colder, and below a certain point the condensate freezes on the coil instead of dripping off. The unit then has to stop and defrost, and it spends more and more of its time defrosting as the temperature falls. Many household units list a floor around 41°F, and below roughly 50°F their real capacity drops sharply.

Low-grain refrigerant, or LGR, units are refrigerant designs engineered to keep working at lower temperatures and humidity. The AlorAir Sentinel and Storm and the Dri-Eaz Revolution are this kind, and their listings give operating floors around 33 to 34°F. They still use a cold coil, so they still slow down near freezing, but they keep pulling water long after a household unit has given up.

Desiccant dehumidifiers work differently. They pass air over an absorbent material, usually a rotating wheel, which soaks up moisture, then heat the material to drive the water off into a collection tank. Because nothing gets cold, nothing freezes, and listings for the Ebac DD200 give a minimum of minus 4°F. The price is electricity: a desiccant unit uses a heater, so it draws far more power than a refrigerant unit for the same water removed in warm conditions.

So the right type depends on how cold your garage gets. Above about 50°F year-round, a household unit is fine. Between freezing and 50°F, an LGR unit is the sweet spot. If the garage regularly drops below freezing, a desiccant unit is the only one that keeps removing water reliably.

3. Our 6 Picks

Every figure below comes from a manufacturer specification sheet, an ENERGY STAR record or a retailer listing repeating the manufacturer's rating, and we note where sources disagree. We researched these units from published specs; we did not lab-test them.

4. Sizing for a Garage

Garage dehumidifiers are rated the same way as every other dehumidifier, in pints per day at 80°F and 60 percent relative humidity. That test condition is even further from reality in a garage than in a basement. A garage in shoulder season might sit at 45°F and 80 percent humidity, where a refrigerant unit removes a fraction of its rating. So buy more capacity than the square footage alone suggests, and prefer units that publish a saturation figure or a low-temperature figure.

As a rough guide, a damp one-car garage or workshop corner can be handled by a small desiccant like the Ivation in a cold climate, or a 35 to 50 pint household unit if it stays warm. A typical two-car garage is a good match for a 55-pint LGR like the AlorAir HDi65S. A three-car garage, a detached shop or a garage that floods with meltwater from cars every winter is where the 80 to 85 pint units, the Dri-Eaz Revolution and AlorAir Storm, earn their size.

Remember what is driving the moisture. Cars bring in snow and slush that melts on the floor, which can add gallons of water on a bad day. An uninsulated slab condenses humid summer air. A dryer vent or a chest freezer in the garage adds heat and moisture of its own. If you can cut the source, for example with a floor squeegee and a drain or by sealing the slab, you can buy a smaller unit and run it less.

Measure before you buy. A hygrometer left in the garage for a couple of weeks tells you how high humidity climbs and how cold it gets, which is exactly the information you need to choose between household, LGR and desiccant. Our dehumidifier sizing guide explains the general method in more detail.

5. Drainage: Pumps, Hoses and Freezing Lines

Drainage is the make-or-break detail in a garage. A bucket that fills in a few hours will overflow or shut the unit off, and a full bucket of water in a cold garage can freeze. So plan for continuous drainage from the start. If the garage has a floor drain, a gravity hose is the simplest answer. If not, a unit with a built-in pump can push water to a utility sink, out through the wall or down the driveway.

Four of our six picks have built-in pumps, and their listed lift heights cover most garages: the AlorAir HDi65S up to 19.6 feet per listings, and the Midea Cube more than 16 vertical feet per Midea. Our guide to dehumidifiers with pumps covers how to route a pump hose and what goes wrong with them.

In a cold garage, protect the drain line. A hose that runs along an outside wall or out onto the driveway can freeze solid on a winter night, which will either trip the unit's float switch or, on some units, back water up into the cabinet. Keep the line short, run it inside the heated envelope where you can, and slope it so water does not sit in low spots. If it must run outside, end it where it can drip freely rather than into a puddle that freezes over the outlet.

Desiccant units handle water differently. Many collect condensate in a small tank, and some can run a gravity drain hose, but not all can pump. Check what your version supports before you buy, because a desiccant unit with a small tank in a damp garage will need emptying often.

6. Placement and Running It Well

Put the dehumidifier where air can circulate around it, away from where cars park and off the floor if snowmelt pools there. A few inches of clearance on every side is the minimum, and more is better for the intake and exhaust. Units with casters or carry handles are easier to move out of the way when you need the floor.

Keep the garage door closed while it runs. Every time the door is open, the dehumidifier is trying to dry the neighborhood. If you work in the garage with the door open, switch the unit off and let it catch up afterward. The same logic applies to gaps around the door: a worn bottom seal lets humid air and water in, and fixing it reduces the load on the dehumidifier.

Set the humidistat to about 50 percent. Below that you are spending electricity for little benefit, and above about 60 percent rust, mildew and that musty garage smell set in. Most of the units here have a built-in humidistat, and the Dri-Eaz Revolution's runs from 30 to 90 percent in five-percent steps, which is plenty of control for a garage.

Think about heat as well. A small amount of heat in a cold garage helps a refrigerant dehumidifier enormously, because it keeps the coil above freezing. If you are already planning a garage heater for a workshop, keeping the space a little warmer can let a household or LGR unit do the job instead of a power-hungry desiccant.

7. Running Cost

The running cost of a garage dehumidifier depends mostly on its type. Refrigerant units are efficient in warm conditions: the Dri-Eaz Revolution lists 4.8 pints per kilowatt-hour at the AHAM point, and the AlorAir Storm 2.44 liters, or about 5.2 pints, per kilowatt-hour. The AlorAir Storm draws 5.62 amps at 115 volts, which works out to roughly 650 watts while running.

Desiccant units use more. The Ebac DD200 is listed at about 800 watts. If it runs eight hours a day for 120 cold days, that is about 768 kilowatt-hours, or roughly $130 a season at 17 cents per kilowatt-hour. The heat it gives off is not entirely wasted, because it warms the garage slightly, but it is still the most expensive type to run in mild weather.

For your own estimate, multiply the unit's wattage by the hours it actually runs and by your electricity rate. A dehumidifier on a humidistat runs far less once the garage is dry than it does on day one. Our guide to how much electricity a dehumidifier uses walks through the math with worked examples.

Do not forget filters. Garages are dusty, and a clogged filter cuts airflow and capacity. Check it monthly at first, rinse or replace it as the manual directs, and you will keep the unit close to its rated performance and away from an early repair.

8. Maintenance in a Dirty Space

Garage dehumidifiers live a harder life than basement units. Sawdust, road salt and fine dust from the driveway all end up on the filter and, if the filter is torn or missing, on the coil. Clean or replace the filter regularly and inspect the coil each season. A dirty coil cannot transfer heat properly, which lowers capacity and can make the unit run constantly without drying the space.

Flush the drain line and pump once a season. A pump reservoir that sits with stagnant water grows slime, and slime clogs pumps. A cup of diluted bleach or a manufacturer-approved cleaner through the drain path, followed by clean water, keeps it moving. Check the float switch still trips the unit off if the drain blocks.

If the unit sits idle over summer, dry it out before storing it. Run it with the fan only for a while if it has that setting, empty the tank or pump, and cover it against dust. A unit stored wet will smell of mildew next season, and a pump left with water in a garage that freezes can crack.

Finally, keep it off the floor if water pools there, and keep it away from the car's path. Restoration-grade units like the Storm and Revolution shrug off knocks, but a household Midea in a busy garage is safest on a sturdy shelf or a raised platform near a drain.

9. Match a Pick to Your Garage

For most garages that are cold but not freezing, the AlorAir Sentinel HDi65S is the one to buy: a 33.8°F floor per AlorAir, a built-in pump and a size that fits a typical two-car garage. If your garage is larger, wetter or doubles as a workshop, step up to the AlorAir Storm LGR Extreme or the Dri-Eaz Revolution, which move more water and are built to take abuse.

If your garage regularly falls below freezing, buy a desiccant. The Ebac DD200 is listed down to minus 4°F and suits a full garage, while the Ivation 13-pint unit covers a one-car garage or workshop corner for much less money. Both use more electricity than refrigerant units, which is the cost of drying air that cold.

If your garage is attached and stays reasonably warm year-round, a household unit is enough, and the Midea Cube with a built-in pump is a tidy, affordable choice. Just do not move it into an unheated detached garage in winter and expect it to keep up, because household units are not built for that.

And if the dampness is coming from the house rather than the garage, look upstream. Our basement and crawl space guides cover the two most common sources of whole-house humidity, and our whole house versus portable comparison explains when one big unit beats several small ones.