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Are Dehumidifiers Safe?

Updated on July 18, 2023
Written by
Danny Ashton
Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.

Our verdict

Generally speaking, dehumidifiers are very safe to use. That said, there are a few risks to be aware of.

Running a dehumidifier is a great way to ensure that your home remains at a comfortable temperature while also protecting your furniture and the structural integrity of your home.

There are also some common questions and concerns that consumers have about dehumidifiers, so let’s address those concerns and go over the risks associated with dehumidifiers, so that you can operate your dehumidifier safely.

🤔 Can You Run a Dehumidifier Constantly?

You can, but there are a few reasons why it’s not a good idea:

  • You run the risk of the air in your home becoming too dry, which is just as bad as having too much humidity. The idea is to have an optimal level of relative humidity (RH) which is between 30% and 50%. You can measure the RH of a room by using a hygrometer.
  • Dehumidifiers are electronic appliances that can potentially overheat if left on for long periods of time, and this can pose a fire risk. 

Dehumidifiers usually include an auto-defrost feature that is specifically designed to prevent these sorts of fires from occurring. Nevertheless, if your unit is constantly, you run the risk of the auto-defrost freezing its coils.

Pro tip: Wondering how to fix a dehumidifier that has frozen up? Check out our thorough guide with tips on what to do when dehumidifier ices up.

🤔 Can You Leave a Dehumidifier on Overnight?

Yes. Leaving your dehumidifier running overnight shouldn’t be a problem, especially if your device has auto-defrost in case of overheating and an auto-off function in case of tank overflows. Most modern dehumidifiers will have both of these features, so you should be perfectly fine to leave your dehumidifier running when you go to sleep. 

That said, it’s important that you check a few things before turning in for the night:

  1. If your dehumidifier has a tank, make sure it’s empty. You don’t want to risk waking up floating on water like Jack and Rose.
  2. Make sure your unit is clean and well maintained.
  3. Make sure your unit is in a sensible position. Don’t go tripping over it in the dark.

🤔 Is a Dehumidifier a Fire Risk?

Because dehumidifiers are electrical, it’s impossible to rule out the risk of one causing a fire. It is incredibly rare for a dehumidifier to cause a fire, but it can happen. In almost all cases, fires caused by dehumidifiers can be attributed to one of two factors, either a manufacturer defect or improper use. 

  • If there is a manufacturer defect, then it may be impossible to detect the problem or prevent the fire from occurring. However, each dehumidifier is rigorously tested before being sold to the consumer, and as such, the odds of there being a manufacturer defect leading to fire is extremely low. 
  • A dehumidifier might cause a fire due to improper use. For example, if you place a large dehumidifier in a small space, then it’s possible that the device may not have sufficient air to cool off and may overheat. 

If in doubt, buy a dehumidifier with an auto-defrost feature, keep on top of cleaning and maintaining your unit, and make sure it’s the right size unit for the room.

🤔 Will a Dehumidifier Dehydrate Me?

No, absolutely not. Dehumidifiers only pull moisture out of the air and cannot affect the moisture in your body in any way. This is something you definitely don’t need to worry about. 

🤔 Are Dehumidifiers Safe for Pets?

In almost all cases, dehumidifiers are safe to use around your pets, especially cats and dogs. If you have birds or reptiles, then be sure to give them a cool misting once or twice a day if you are running a dehumidifier around them. 

🤔 Is It Safe to Clean a Dehumidifier? 

Most definitely, YES! It’s perfectly safe to clean your dehumidifier. In fact, it’s a very good idea to clean your water tank and the exterior of the device regularly. You should always empty the tank when not in use and clean it often to prevent mold from building up inside the unit. 

Pro tip: Does your dehumidifier need a clean? Follow our step by step guide packed with practical advice on how to clean a dehumidifier in a safe way.

🤔 Is It Safe to Drink Dehumidifier Water?

Most definitely, NO!. Once the water has been collected in your dehumidifier, it comes in contact with the chemicals inside the coils, which is hazardous. The water inside your dehumidifier is greywater that is unsafe to drink even when boiled. You should never drink water from your dehumidifier unless you are confident that no mold could grow in the tank.

Pro tip: Want to learn more about why it is not recommended that you drink dehumidifier water? We dug deep in our ultimate guide “Can you drink dehumidifier water?”, in which I drank water from our test unit for science.

How Dehumidifiers Can Be Good For Your Health 

Now that we’ve addressed the main risks and concerns associated with operating a dehumidifier let’s go over some of the health benefits you’ll enjoy when running a dehumidifier in your home, spoiler alert, there are quite a few of them.  

1. Prevention of mold and mildew

Mold and mildew are perhaps the biggest health risks associated with having high levels of humidity in your home. They can severely damage your respiratory system and can even cause death if left unchecked. 

As dehumidifiers reduce the relative levels of humidity in your home, they essentially deprive mold and mildew of the conditions that they need to grow and thrive. This can prevent mold from forming in the first place or limit its ability to spread if you already have mold, potentially saving you thousands of dollars in repairs and possible hospital bills.

2. Fewer headaches

As a result of having cleaner air in your home, you’ll be much less likely to suffer from headaches, especially if you routinely have headaches made worse by muggy humid air in your home. 

3. Fewer issues with allergies 

By removing mold and mildew from the home, dehumidifiers that contain an air filter can help relieve some allergies. If you suffer from allergies triggered by dust, pollen, and/or pets, we would recommend using an air purifier that contains stronger filters specifically designed to remove those allergens from the air. 

4. Elimination of dust mites

Dust mites are another potential hazard associated with high levels of humidity in your home. In the same way that dehumidifiers deprive mold and mildew of the conditions they need to thrive, they can prevent dust mites from spreading, which can help you breathe better and prevent you from getting skin rashes and blemishes often caused by dust mite infestations. 


Dehumidifiers are almost always safe to own and operate, as long as you use them properly. All you need to do is follow a few simple guidelines to minimize the risk of any harm:

✔️ DO use the right dehumidifier for the space. If the unit is too small for the space, it will be overworked. If it’s too big, it might not have enough ventilation.

✔️ DO find a unit that has an auto-defrost function. This will keep your unit at the correct temperature and will automatically shut the machine off in the event of overheating.

✔️ DO clean and maintain your dehumidifier on a regular basis.
DON’T run your dehumidifier constantly. As with any electrical device, if it’s overworked, it won’t be as effective.

DON’T run your unit overnight without doing some simple checks first (see above).

DON’T drink the water collected by your dehumidifier. The water can become contaminated by the chemicals contained in the coils inside your device, which is toxic to humans.

Assuming that you follow this advice, your dehumidifier will be perfectly safe to use and can even bestow a number of health benefits, including cleaning the air in your home, reducing the risk of mold and mildew, preventing dust mites, helping to prevent headaches, and eliminating allergy symptoms. Pretty handy to have around the home we say.

About the author

Danny Ashton

Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.