How Long Does it Take for a Dehumidifier to Work?

Dehumidifiers are increasingly gaining popularity, particularly in countries with high temperatures and higher humidity. If you have just bought one, you might be wondering: how long does it take for a dehumidifier to work?

Like all machines, dehumidifiers come with many complicated constituent parts and components. When it’s activated for the first time, a dehumidifier might take up to 12 hours to work. But once it’s been broken in, a good dehumidifier won’t take longer than 15 to 20 minutes to reduce the humidity of the room it’s placed in.

That being said, your dehumidifier’s performance depends upon a number of factors. We’ve discussed them below to help you get better acquainted with your new air machine.

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How Do Dehumidifiers Work?

There are two ways in which a dehumidifier might be programmed to work: absorption or refrigeration. In the case of absorption, the machine is fitted with some sort of dry material that will suck in the moisture out of the air and dispose of it.

In terms of a refrigeration system, the air is cooled and made drier by the dehumidifier. The collected moisture (from either system) is then stored in a small container, which must be emptied periodically.


As you can imagine, this is quite a complex process. This is why some dehumidifiers take a longer time than others to clear the air of moisture.

How Long Does It Take For A Dehumidifier To Work?

As mentioned above, a brand new dehumidifier activated for the first time might take up to 12 hours to properly do its job. While some of the higher-priced models might start working instantly out of the box, this is rare.

However, after its first run, your air machine will start up much quicker and lower the moisture levels in its appointed room in as low as 20 minutes. The following factors play a part in the performance of your dehumidifier.

The Dehumidifier’s Capacity

Dehumidifiers come in varying capacities, ranging from 25 pints to 90 (or more). The capacity indicates how much moisture the machine can remove from the air in 24 hours. So, the higher the machine’s capacity, the more water/moisture it can extract.

Depending on humidity levels and your dehumidifier’s capacity, it can take varying amounts of time to clear the air.

For example, a 22-pint dehumidifier might take up to 34 minutes to clear out a room with 90%-40% humidity and 15 minutes for 80%-50% humidity. On the other hand, a 50-pint machine can take 10 minutes or 5 minutes respectively for the same humidity levels.

The Size of the Dehumidifier’s Tank

As we mentioned above, every dehumidifier comes with a tank in which extracted water and moisture are stored. The tank size also plays a part in determining how much time the machine will take to clear the air of the room it’s placed in.

As you can imagine, if the dehumidifier’s tank is filled all the way, the machine will be unable to take in any more water. With smaller tanks, you’ll have to empty them sooner rather than later if you want your dehumidifier to continue running smoothly.

One easy solution to this problem is investing in a dehumidifier with a continuous drain feature. Such a dehumidifier gives you the option to connect the unit via a pump directly to a sink or other water outlet.

Moisture Levels

This is pretty obvious, but the amount of time it takes a dehumidifier to work depends on how much moisture it’s dealing with. This is called the moisture level, measured using a moisture meter.

Some dehumidifiers come with their own humidity detectors, alerting you to the right time to turn the machine on and also indicating how long the operation might take.

Here’s an overview of the appropriate dehumidifier capacity for each room size and moisture level.

Moisture Level Dehumidifier Capacity (pints)

Moisture Level

Dehumidifier Capacity (pints)


10 – 26


12 – 32


14 – 38

Very Wet

16 – 44

How Long Should a Dehumidifier Run Per Day?

The ideal duration for a dehumidifier to operate is 12 hours. That means, as a rule, you should aim to keep it on for at least 12 hours every day, mainly if you live in a very humid or moist climate.

However, this is not gospel. The right amount of time to keep your dehumidifier running depends on the extant conditions.

For example: the room’s design, size, temperature, the positioning of the dehumidifier, geographical location, and course, the time of day.

Wait, is there an ideal time during which the dehumidifier should run? Yes!

Best Time of Day to Use a Dehumidifier

Understandably, electricity bill concerns might come up if you’ve got a new dehumidifier. As such, you might be wondering at which point during the day it’s best to use the machine.

Of course, it depends on the weather. Undoubtedly, daytime hours are the hottest, so you might be tempted to turn the dehumidifier on then. However, these are peak hours for electricity usage in most places. Consequently, we would suggest turning the machine on only at night, around 10pm, or early in the morning, like 7am.

Alternatively, you can choose to stagger the dehumidifier’s running times. So, let’s say you keep it on for 4-5 hours in the morning, then 5-6 hours again in the night. Remember to use a timer and monitor the dehumidifier’s tank closely as well.

Final Words

We hope we’ve given you a comprehensive answer to how long does it take for a dehumidifier to work. As we’ve seen, it depends on a variety of factors, so remember to keep those in mind. We wish you clean, fresh, and easy to breathe air!