A homeowner sitting on her couch, smiling as she looks at and rests her feet on a dehumidifier

If you’ve used a dehumidifier before, you know it can take some time to remove all that moisture from the air.

But, just how long should you expect to wait?

How Long Does It Typically Take To Dehumidify a Room?

The fact of the matter is: dehumidifiers take a while to work.

It is much harder to take moisture out of the air than it is to put moisture into the air. So while your home can build humidity quickly on a summer day, it can take some time to get rid of it.

Dehumidifiers can take a few days, even up to a week, to completely clear your home of excess moisture.

Factors Involved in Dehumidifying a Room

As mentioned, a few factors are involved in how quickly a room gets wholly dehumidified. 

Dehumidifiers come in two different types—refrigerator coil and desiccant

Refrigerator coil dehumidifiers are the most common. They work by using cold copper coils to turn the moisture in the air into liquid. 

Desiccant dehumidifiers use silica gel or another absorbent substance to trap moisture as the air continually passes through the device. 

Illustration demonstrating how a desiccant dehumidifier functions
Courtesy of Appidi Technology

Dehumidifiers also come in a wide range of sizes to adjust to any room size. There are dehumidifiers for every sized space, from small portable ones to industrial sizes. 

These factors (and a few others) impact how fast a dehumidifier works. It’s also essential to keep in mind that many of these variables are interconnected.

Room Size

Smaller, closed-off spaces will be easier to dehumidify than large spaces. So single rooms (like bathrooms) will be easier for a portable unit to dehumidify quickly.

However, many homes today have an open floor plan with multiple interconnected rooms. This layout makes for a lot of extra work on a small dehumidifier. These units were meant to serve a smaller space and may struggle when placed in an open area.

No matter what size room you’re working in, you should expect it to take at least a few days.

That being said, you should notice an improvement in the air quality within a day of continuously running it. If not, you may need a larger unit or something could be wrong with the one you have.

How Often You Are Running the Dehumidifier

You’ll get quicker results if you leave the dehumidifier on full time for a few days to a week, but sometimes these units can be loud and disruptive, especially at night.

So if you have to turn the unit off, expect it to take longer to remove the moisture from the room.

Each time you shut off the device, moisture is recollecting inside the air. That means when you turn the dehumidifier back on, it has to work extra hard to start things up again.

Essentially, the more you run your dehumidifier, the faster it can remove the moisture from the air.

Dehumidifier Size

The size of the room may be the most critical factor, but the size of the unit also plays a considerable role.

As mentioned, dehumidifiers come in a range of sizes.

Portable models are made to remove moisture from one room, and you will often need one in each room to completely dehumidify a house.

If you are just looking to dehumidify certain areas (for example, a basement) you may need to invest in two units. Luckily, these portable dehumidifiers are often inexpensive and can be found at most home and hardware stores.

The living room of a home with a dehumidifier on the floor and homeowner resting up against the couch with her cat in front

There are also industrial-size units, most often used in cases where water damage has occurred because of a bad leak, hurricane, or another natural disaster.

Unfortunately, these dehumidifiers are very loud and expensive, so they aren’t the first choice for residential homes.

If you need to remove humidity from your entire home, a whole-house dehumidifier is likely your best option. These connect to your central HVAC system and can affect the air throughout your home.

These systems are quite a bit more expensive than the ones you find at the home goods store but they work on your entire home.

Dehumidifying with a whole-house model takes significantly less time, and the humidity levels stay consistent no matter where you are in the house. The biggest downside is the installation costs and the need for an HVAC professional.

Dehumidifier Type

As mentioned, you can choose between desiccant dehumidifiers and refrigerant coil dehumidifiers. 

In general, desiccant dehumidifiers take more time than coil dehumidifiers because they don’t pull quite as much moisture out of the air with each cycle through. 

However, desiccant dehumidifiers involve less maintenance since you aren’t dealing with a drip tank or draining hose.

The table below summarizes the important information you need to know when choosing between refrigerant coil and desiccant dehumidifiers.

Dehumidifier TypeCapacity (Pints Per Day)Suitable Room Size (SF)
Refrigerant Coil30 to 70500 to 4,000
Desiccant15 to 30Up to 1,200
Whole-house90 to 150Varies
Table 1: Comparison between refrigerant coil, desiccant, and whole-house dehumidifiers.

The Type of Climate You Live In

The final major factor determining how long it will take to dehumidify a room is your climate.

If you live in a highly-humid area, your house will take on that high amount of humidity. 

In places such as South Florida, it may take a few weeks to completely dehumidify your house, even if you are continually running it. 

Photo of our first net-zero house in Florida
Our first Net-Zero house in Florida

It probably won’t take long to get your house feeling comfortable if you happen to live in a more mild to moderately humid climate.

Room Temperature

Suppose you have equally-sized rooms at the same indoor humidity level, their indoor temperature is another factor that will affect how long the dehumidifier takes to dehumidify.

It’s worth noting that the higher the temperature, the more the water vapor the air can hold, and vice versa.

Based on this understanding, it can be challenging for your dehumidifier to reach the desired humidity level on a warmer day.

This is because it has to work hard to remove more water from the air.

Two Quick Tips to Reduce the Dehumidification Time

Luckily, there are ways to enhance your dehumidifier’s efficiency and aid in reducing the duration it takes to achieve the desired humidity level.

  • Use an air conditioner: Air conditioners are excellent in lowering indoor humidity. Like dehumidifiers, AC units have coils that condense the water vapor in the air into liquid and remove it. AC units can remove between 5 and 20 gallons (18.93 and 75.71 liters) of water from the house depending on humidity levels.
  • Turn on your fans: Besides enhancing indoor air circulation, ceiling fans also lower indoor moisture. You should also use your bathroom fan when showering and the exhaust fan when cooking to prevent the accumulation of moisture indoors. Too much indoor moisture means that the dehumidifier will take longer to achieve the desired humidity.

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