How long does it take for a dehumidifier to work?

Maintaining the ideal relative humidity in any area is important. High levels of moisture content in the air and environment lead to plentiful problems. Thankfully, dehumidifiers are wonder workers that help us to extract excess water. But, the question here is, ‘How long does it take for a dehumidifier to work?’.

How quickly do dehumidifiers work?

Those who are new to using a dehumidifier, often find themselves caught with the thought that the longer you have a dehumidifier unit put to work, the better it will remove moisture from the humid room. This is such an assumption. Most dehumidifiers lose effectiveness when not being used correctly.

‘How long does it take for a dehumidifier to work?’ This is a common and good question.

The answer is, there is more than one important factor that will play a role. Fewer people are aware of the fact that how much water is collected in the water tank is not a reflection of a dehumidifier running on full power. At the same time, one must remember before you use a dehumidifier to be aware of the following pointers as to the general rule.

1. Size of the room

room capacity

How quickly can a dehumidifier fill the tank or how long does it take for a dehumidifier to work to extract moisture from a room; depends not just on the dehumidifier capacity, but also depends on the size of the room.

Larger rooms require larger dehumidifiers and will also fill their tank slower. If the level of humidity in such rooms is high, it might require the dehumidifier to work and run continuously. A small room, like a laundry room, crawl spaces, or bathroom is easier to have its moisture levels maintained.

‘How long does it take for a dehumidifier to work’ depends on the surface area of the space, level of humidity, dampness level, and dehumidifier capacity.

If you simply buy the most commonly used capacities, without thinking over the room size, you are going to waste money on energy costs and spend long hours for the dehumidifier to work. To reduce humidity in a large room buy a higher capacity dehumidifier, and for a smaller room, an average dehumidifier unit with a minimum required capacity.

2. Dehumidifier capacity

Size of the dehumidifier

A few things that have a big impact on how much excess moisture from the air is removed and how faster the ideal level of relative humidity is maintained is the dehumidifier capacity.

The extraction rate of the dehumidifier depends on its in-built capacity. How quickly a dehumidifier works and how much water is collected in the tank depends largely on the pint capacity. Hence, a high capacity dehumidifier running for even a short time on full power in a room will remove more moisture is the general rule.

However, the same amount of water vapor can be removed and humidity level can be maintained even by a small dehumidifier unit; at an appropriate level of time and quantity to suit the room it is placed in.

Removing moisture from a large or small surface area also creates an impact on the tank capacity. If you have dehumidifiers with a small tank size, you are going to have to empty the tank constantly. Many dehumidifiers come with the auto shut-off feature. Certain models even have an LED light indicator to instantly warn you of an impending overflow and then they auto shut off.

Getting a large water bucket allows more space for the unit to hold water and even run continuously without the fear of an overflow. Nevertheless, you must drain the bucket once every few days to avoid mold growth.

3. Room dampness level

The dampness level of the room is a huge factor that determines how long does it take for a dehumidifier to work. Excess moisture can get trapped in the furniture, walls, and other areas of the room.

When excess moisture is locked in more than one place in the room, the relative humidity levels of the room will be naturally high. The amount of time that will take for a dehumidifier to take in moist air and give out drier air for a room with high relative humidity levels will be longer.

Most dehumidifiers or any average dehumidifier unit will take close to 5 to 7 hours to start removing the excess moisture. However, if the humidity level is quite high, a minimum required capacity unit is not going to help. You must have the dehumidifier run continuously for the recommended 12 hours and have a unit that can operate to give the best results with high dampness level capacity.

For a smaller room with more moisture, buying dehumidifiers with the same surface area that removes moisture and maintains humidity with limited potential is not going to help. Rather than buying dehumidifiers with the same surface area as the room, get larger dehumidifiers to tackle the room with high humidity levels.

‘How long should a dehumidifier run’, before it starts to have an impact on the dampness level and humidity is thus explained.

4. Room design

A humid room with poor air quality, filled with dust mites is sometimes due to poor ventilation and more people in the area. If a small room has many people in it, it is natural for the humidity level to shoot up.

Poorly ventilated rooms will also have high relative humidity levels. Small dehumidifiers lose effectiveness when placed in a room with high humidity. They cannot remove the dust mites, improve air quality, give out dry air or even maintain the relative humidity. For a room that has a natural design to trap excess moisture, it will take longer for the dehumidifier to work.

Integrating dehumidifiers into a refrigeration system like HVAC, and remembering to open windows whenever possible will help to improve the efficiency of the dehumidifier to reduce the level of humidity.

5. Season

Summer and warm air will hold more water or moisture. Hence the unit running time during these seasons in a room with warm air will give the best results from your dehumidifier.

6. Placement of dehumidifier

Placement of the dehumidifier in a room also determines how long does it take for a dehumidifier to work. Based on the levels of relative humidity that exists in a room, one might have to try different areas to place dehumidifiers. Humidity levels are better controlled when the high-capacity dehumidifier is placed close to the problem area.

Placing the dehumidifier next to the source that shoots the level of humidity is always the best option. Sometimes it might require integrating the dehumidifier into the refrigeration system like HVAC, or keeping a portable unit in the laundry room that builds the humidity levels, etc.

Discuss with your energy company or certified professional to find the right placement for dehumidifiers to get the best results.

Ensure that dehumidifiers or air movers or any device that deals with air is kept a few feet away from the wall to prevent blockage of air. Improving air quality by removing dust mites and giving you dry air will be affected by improper placement.

Placement also plays a role in how long it will take for a dehumidifier to work. How quickly can a dehumidifier fill the tank will directly influence how much liquid water you must empty.

Should a dehumidifier run always?

dehumidifier adjust

Is it necessary that a dehumidifier should run all the time?

This is one of the many questions that will instantly cross a new homeowners’ mind when they buy a dehumidifier. The level of humidity, size of the room, its dampness level of water vapor content in the area, and things decide how long does it take for a dehumidifier to work.

It is such an assumption that a dehumidifier should run continually. Most commonly used capacities will function as required for their potential. A large room or small room with a high humidity level will take close to 12 hours to hit the ideal level.

However, basements or garages, or places post water damage might take even up to a few days to reach the expected humidity levels. Energy costs that result from using the dehumidifier can be calculated with your utility company in advance.

What Is The Best Time To Run A Dehumidifier?

A few things that homeowners are cautious about while using dehumidifiers is the time they use a dehumidifier. Running the unit before humidity levels can rise is always best. You can assess when the moisture levels rise in your home. Mostly in the crawl spaces, basements, after a shower, post laundry, etc.

Keeping humidity levels under check and preventing high energy costs is possible. The best time to use a dehumidifier is between 10 pm to 7 am. Energy costs are charged at their lowest during these hours, and the humidity level will be lesser before you begin the daily activities.

Does a dehumidifier work better in a warm room?

Yes! Warmer temperatures and higher humidity levels are the best work areas for dehumidifiers.
The ideal humidity level should be between 30 % to 50 %. Humidity higher than this and a warm area will have higher moisture levels also. Since warm air can hold more moisture.

A warm environment (like summer) has increased dampness level capacity and hence a dehumidifier is most effective here.

Will a dehumidifier always collect water?

Most dehumidifiers will always collect water that will be stored in the water tank. But, if your dehumidifier does not collect water it could be the level of humidity is low and hence there is not enough moisture left in the area.

Size of the room and type; basements or crawl spaces will have high humidity most times. A dehumidifier kept here will always collect water. This might not be the case with a dehumidifier kept in the bedroom, where removal of moisture can happen quicker.

Certain models, like the Desiccant dehumidifier, will not collect water in a reservoir. It has a different dehumidification process.

FAQ Section

1. Should I Run A Fan With A Dehumidifier?

Air movers and fans used along with a dehumidifier is a good idea.

These amplify air movement and help the dehumidifier to take in moist air and give out drier air. Using fans also ensures you don’t get extremely dry air, but rather a cool one.

Keeping the windows open while the unit is running is recommended since the air from outside might tamper with the process.

Using fans will also have an influence on how long does it take to dry the air.

2. Is it OK to leave dehumidifier on overnight?

Yes! It is absolutely safe to use a dehumidifier overnight if your bedroom has high relative humidity continuously.

Many dehumidifier units are available with silent operation, which will not disrupt sleep. Using the dehumidifier will keep the space free from dust mites and allergens to give you sound sleep.

You might have minor problems like dry skin and throat if you sleep close to the device, however, this can be handled. Also, make sure the water tank is emptied or automatic shut off is turned ON before you go to sleep.

3. Should you run a dehumidifier with the windows open?

As aforementioned, it is recommended not to open windows when the dehumidifier is ON.
You can keep the windows open when the dehumidifier is not operating to reduce humidity naturally. Summer is the best time to practice this.

4. When should you stop using a dehumidifier?

Do not let the dehumidifier run any further if the desired relative humidity level has been achieved.

A low humidity level will be hit faster by a higher capacity dehumidifier. If you notice more water in the water tank than usual, or if you suspect that the tank size is smaller or larger for the area; stop the dehumidifier and restart it when the issue is sorted.

Do not let the device extract moisture any higher than essential. This may result in dry skin and eyes, poor air circulation, etc.

5. Can you use a dehumidifier with the heating on?

Yes, you can use your dehumidifier with the heater ON. But, this is not going to improve the comfort of the environment.

6. How long does it take for a dehumidifier to dry basement?

As aforementioned, a basement will have a higher relative humidity level than a bedroom and it might take longer for the dehumidifier to work there.

Depending on the water content trapped in the area, it can take anywhere from a few hours to a few days to dry the space thoroughly.

Wrapping Up

With this we have reached the end of the article, ‘How long does it take for a dehumidifier to work?’. We hope you found it helpful. Let us know in the comments below how long does it take for a dehumidifier to work in your home to achieve the ideal relative humidity.


About The Author

Olivia — a self-confessed air quality addict — is a home climate enthusiast, fresh air advocate, and someone with deep personal experience and knowledge about mold extermination. Her work was mentioned in countless notable humidity publications. Previously she was an editor at Mold Remediation.