How Many Hours a Day Should You Run a Dehumidifier?

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Have you recently purchased a dehumidifier? By now, you probably already know it can prevent mold growth and respiratory issues. However, you might still be clueless about how long you should run this household appliance. 

You can run a dehumidifier constantly for 24 hours when necessary. The ideal runtime depends on your specific needs, though. Leaving the dehumidifier on for a day is beneficial for very humid rooms, but it’s not always recommended. 

Below, we’ll cover the factors to consider before setting the dehumidifier to run for 24 hours. We’ll also answer your frequently asked questions about using the device. 

How Many Hours a Day Should You Run a Dehumidifier?

You can run a dehumidifier constantly for 24 hours if you want to. Doing so removes excess moisture in the room and prevents different problems. These include mold growth, allergens, musty odors, and damage to furniture. 

However, you don’t need to run your dehumidifier non-stop because it costs a lot of money. There is also a risk of over-drying the air. That leads to another set of problems, such as dry skin, nosebleeds, and irritated sinuses.

So, how many hours is the ideal duration to operate a dehumidifier? You can safely run the appliance for 12 hours a day. This is enough time to extract moisture from the air, especially during more humid seasons. The result is safe and comfortable indoor air quality. 

That said, it’s always best to adjust the runtime based on several factors. We’ll take a look at some of them below.

Current Humidity Level

Current Humidity Level

First, you must consider the existing humidity level in your home. It can largely how long to run your dehumidifier.

For example, if your home is humid or you live near the sea, you need to run the unit for longer periods. But if the climate is usually dry, you can keep operation to a minimum. You can even avoid using the dehumidifier altogether.

Another thing to consider is the type of room where you intend to place the device. Basements, bathrooms, and laundry rooms usually have higher relative humidity levels than other areas in the house. As such, you must continuously run the dehumidifier to remove excess water.

Do you have cracks in the walls, windows, and doors? These also require you to operate the device longer because excess humidity can seep through these areas.

Target Humidity Level

You must also ask yourself, “What is my target humidity level?” 

The Occupational Safety and Health Administration (OSHA) suggests relative humidity levels between 30% and 60%. Anything lower or higher than that can cause discomfort and other issues.

If you want to reach a 40% humidity level, but your home is closer to 60%, you must run your dehumidifier longer. However, if the current humidity level is already near 40%, you can use the device for a few hours without a problem. 

Dehumidifier Size

Finally, the size of the dehumidifier can affect its runtime.

Using a smaller dehumidifier in a large room can take longer for the air to achieve optimal humidity levels.

In contrast, a large unit in a tiny area can quickly remove excess humidity. 

Always check the capacity of the dehumidifier before buying one. Look for its PPD or Pints Per Day rating to give you an idea of how much water it can remove from the air.

Is It Safe to Leave a Dehumidifier On All Night?

Is It Safe to Leave a Dehumidifier On All Night

Yes, you can safely leave a dehumidifier running all night long. Doing so actually offers several benefits.

First, it can eliminate mold and dust mites, which thrive in humidity. These contaminants increase allergen count. Since the dehumidifier reduces relative humidity, it can alleviate symptoms of asthma and other respiratory problems.

Second, the device can make the air feel cool, ensuring a more comfortable sleep at night. Say goodbye to waking up hot and sweaty.

Leaving the dehumidifier overnight can also prevent musty odors. So, don’t hesitate to turn the appliance on if you smell something foul in your bedroom. It might be the solution to get rid of the scent once and for all.

Finally, running your dehumidifier overnight can help protect your valuables, whether it is your prized teak furniture or your books. The appliance prevents humid air from causing different problems.

Should a Dehumidifier Run Constantly?

It’s possible to use a dehumidifier constantly for 24 hours and seven days a week. However, continuous operation isn’t recommended for many reasons.

Safe Humidity Levels

The primary purpose of a dehumidifier is to maintain a comfortable and safe indoor humidity level. This figure ranges between 30% and 60%. 

You don’t need to run the device for too long unless your house has consistently high humidity levels. Running the dehumidifier constantly can lead to very dry air. This makes it difficult to breathe and move around your home. It can also result in dry skin, cracked lips, and eye irritation. Plus, low humidity can cause damage to your belongings.

Increased Electricity Cost

Running a dehumidifier non-stop can significantly increase your electric bill. The device can consume up to 200 watts per hour, depending on its capacity and PPD rating.

If you want to use the dehumidifier for long periods (not necessarily 24 hours), check its energy efficiency first. Go to the Energy Star website and review the online ratings for your preferred model.  

Constant Water Container Removal

You must also consider the task of emptying the water collected in the dehumidifier. Remember that the appliance extracts moisture from the air. This extra water goes into a bucket or container, which you must remove regularly. 

This task can be cumbersome because some models only take a few hours to reach full capacity.

And, if you’re not around to empty the bucket, the dehumidifier may cause the water tank to overflow. It can lead to unexpected and unwanted flooding in your room. 

Those planning to run their dehumidifier constantly must choose one with a draining hose. It allows water to drain continuously without the need to empty the bucket manually.

Frequent Maintenance

The last thing to consider is the maintenance required when you run your dehumidifier constantly. 

The unit can remove a lot of moisture from the air. It can also draw in dust and dirt, which gets stuck in the filter. Regular filter cleaning is a must to ensure the dehumidifier is working properly.

Continuous use can also mean frequent repairs. Since you’re running it more often, you increase the risk of damaging the internal components. Fixing these problems can cost you a lot of money in the long run. 

When Should You Turn Off the Dehumidifier?

You can switch off the dehumidifier once it reaches your desired humidity level. Choose a model with a built-in humidistat to help you see the current humidity level. 

You must also turn the unit off if the water tank is full. As previously mentioned, you must drain this water regularly to keep the dehumidifier working properly.

You must also stop usage to clean the filters. Ideally, you want to wash them every week to prevent debris from accumulating. But if you don’t have time, you can opt to clean filters once a month.

The change of season is also a sign for the dehumidifier to take a rest. For example, the transition to winter from summer means the air is cooler and dryer. The dehumidifier may be unnecessary during this time. 

How Much Does It Cost to Run a Dehumidifier 24 Hours a Day?

How Much Does It Cost to Run a Dehumidifier 24 Hours a Day

The total cost of running a dehumidifier for 24 hours daily depends on several factors. These include the efficiency and wattage rating of the unit as well as the electricity cost per kilowatt-hour (kWh). 

To calculate the cost yourself, you must first determine the daily usage. Multiply the wattage of the dehumidifier by 24 hours. 

Then, multiply the daily usage (in kilowatt-hours) by your electricity rate per kWh. The result is the daily cost of running the device. 

Let’s have a 300-watt dehumidifier as an example. Meanwhile, the electricity cost per kWh is at $0.16. 

  • Daily Usage: 300 watts x 24 hours = 7,200 watt-hours or 7.2 kWh
  • Daily Cost: 7.2 kWh x $0.16 per kWh = $1.152

So, using this example, running the dehumidifier for 24 hours costs around $34.56 per month.


Dehumidifiers are essential for improving indoor air quality by reducing excess moisture. You can run your dehumidifier for as long as 24 hours or as short as a few hours. The ideal runtime depends on the current and target humidity levels as well as the unit size. Most homeowners use the device overnight (8 up to 12 hours) to prevent mold, furniture damage, and respiratory problems.

Do you have more questions about dehumidifiers? We’d love to hear from you! Feel free to send your queries via our contact page.

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