Home & Garden

What size dehumidifier do you need?

Right-size the pint-size for your humid dwelling.

What size dehumidifier do you need? Credit: Ivation

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With summer on the way, it’s time to get prepared for what it brings: humidity.

Yes, those sweaty days of summer are almost here—or maybe you just have a basement that always smells damp and musty. Either way, you need a good dehumidifier if you want to enjoy clean, dry air.

However, one common question when shopping for this tool is what size will be most efficient for your home. Here are our tips for getting the right style and size of dehumidifier for your needs.

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Different styles of dehumidifiers

Desiccant dehumidifiers
Credit: Ivation

Desiccant dehumidifiers work best in small rooms.

The two main types of dehumidifiers—desiccant and refrigeration—have different strengths and understanding how they work can help you buy the right one for your situation.

In short, desiccant dehumidifiers are best for smaller areas that need fairly consistent dehumidification, like basements or laundry rooms. They don’t use that much energy, so you can leave them running all the time.

Refrigeration dehumidifiers, on the other hand, are better for larger rooms that need occasional dehumidifying on very humid days, but they can use a lot of energy.

Choosing the right dehumidifier size

The 'size' (or 'rating') of a dehumidifier is measured in pints. It's usually prominent in the product name.

Dehumidifiers are usually rated by a single number: the amount of water, in pints, that they can extract from the air in a day. A small dehumidifier might be able to manage 5 to 10 pints per day, while a larger model could manage 60 or 70 pints. Industrial models designed to clear out flooded properties can grab hundreds of pints a day.

These numbers are only an estimate, though—how much the dehumidifier will extract for you will depend on the level of humidity, the temperature and other factors.

Measure your room

The first step is to figure out how much space you want the dehumidifier to cover. To this end, you'll want to measure the room in your house where you're going to put the device and calculate the square footage.

If you plan to use it in a space where two rooms connect—such as a living room and dining room with an open arch—treat the two rooms as one, as the air will flow from one to the other.

Consider the humidity level

The right dehumidifier size for your home depends on both the size of the room and the humidity level, which can range from a mildly clammy feel to water dripping down the walls (rarely a good sign).

For rooms that just feel a little humid, you can get away with about 1 pint per 10 square feet of floor space. For rooms that are seriously damp, such as after a flood, you're going to need something that can suck more moisture out of the air—at least 3 pints per 10 square feet.

Here’s a cheat sheet to figure it out. Find your room size and typicaly humidity levels that you see in that room, then look for a dehumidifier with the suggested rating:

What Size Dehumidifier Should You Buy?
Room Size
How humid is the room right now? 100 sq ft 150 sq ft 200 sq ft 250 sq ft 300 sq ft 400 sq ft 500 sq ft 600 sq ft
Mildly clammy 10* 15 20 25 30 40 50 60
Very clammy 14 21 29 36 43 57 71 86 Water on floor 20 30 40 50 60 80 100 120 Dampness on walls 50 75 100 125 150 200 250 300 Water on walls 100 150 200 250 300 400 500 600
* recommended size, as measured in pints

Don't forget to get rid of the water

The amount of water that a dehumidifier can extract from the air isn’t the end of the story, though. That water has to go somewhere.

Most dehumidifiers include a tray that can hold water, but it needs to be emptied periodically. If you're in a very damp area and the dehumidifier has a small tray, you may have to empty it several times a day. For this reason, many dehumidifiers include a pipe and a pump that can be used to dump the water out into a sink or a drain. You may want to set up this type of drain if you're dealing with serious humidity.

With the right size dehumidifier, you'll be able to enjoy all summer has to offer—without overbearing humidity in your home.

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