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What Does a Humidifier Do? 4 Benefits Explained

Check out these four life-changing benefits of a humidifier.

It’s recommended to keep the humidity between 30 and 50 percent to create a well-balanced environment (1). However, when the humidity drops below 30, it can cause specific issues like dryness and congestion.

One fantastic option for increasing your home’s humidity is a humidifier. These handy devices are great, especially during winter or flu seasons.

But what does a humidifier do? Can it help with a cold? What are the benefits? We’re here to answer all your quizzical questions about humidifiers.

Key Takeaways

  • Humidifiers work by adding moisture to the air, helping to maintain humidity levels between 30-50% for a comfortable living environment.
  • Benefits of using a humidifier include preventing snoring, protecting wooden furniture, reducing static, and minimizing the spread of airborne viruses.
  • It’s important to regularly clean and maintain your humidifier to prevent mold, bacteria, and other contaminants from spreading in the air.
  • Be cautious of overusing a humidifier, as high humidity levels can cause issues such as dampness, mold, and indoor allergens.

How Does a Humidifier Work?

Humidifiers emit water vapor or steam into the air to increase the moisture level. They’re straightforward devices with a tank to hold the water and a control base.

There are five main types of humidifiers:

1. Ultrasonic Warm or Cool Mist

Cool mist humidifier on table

This humidifier creates a fine mist that is emitted into the air and evaporates soon after. It consists of a small metal diaphragm that vibrates at ultra-sonic speed — hence the name. Consequently, it creates tiny water particles that form the mist.

Depending on the model, some will heat the water to 104 degrees Fahrenheit — creating a warm mist. Others stay cold — creating a cool mist. Some more high-end humidifiers offer the option of warm or cool mist.

2. Vaporizer

Vaporizer on table

These contain a heating element that boils the water to create steam, which is then released into the air. The steam should be cool by the time it reaches you. However, refrain from standing too close to the device while running — and keep children and pets away.

As a bonus, some vaporizers — such as the Vicks — offer the option of adding VapoPads to increase its effectiveness and help with illness.

3. Evaporative Cool Mist

Evaporative Cool Mist humidifier

Evaporative humidifiers draw dry air in over or through a moist wick in the tank. The water within the tank will begin to evaporate, and as the vapor increases, moist air is blown back into the room. During the process, heat is removed from the air, resulting in cooler air being emitted back into the room.

4. Air Washer

Air Washer

These devices work simultaneously to purify the air as well as humidify it. They work by drawing air in and “washing” it using rotating discs or mats.

As the air is scrubbed, large particles of dust, pollen, and other impurities are removed. Air washers produce a clean and cool mist that effectively increases the humidity.

5. Whole-House

A whole-house humidifier can humidify your entire home at one time. There are different types, including evaporative and the more expensive steam model. These are installed directly into your HVAC system.

How Is Humidity Measured?

When measuring humidity, we often use a term called “relative humidity.” The relative humidity is the ratio of moisture found in the air compared to how much moisture the air can hold. Temperature plays a significant role in humidity levels since hot air can hold more moisture compared to cold (2).

A hygrometer is commonly used to measure the relative humidity of a room. There are usually separate devices for indoor and outdoor use. Hygrometers measure the temperature and moisture level to give you exact results, such as 40 percent humidity (3).

What Affects the Humidity Levels?

Three factors can affect the humidity levels within your home:

  • Temperature: As mentioned above, when the air temperature rises, the more moisture it can hold, consequently raising the humidity. On the other hand, as it gets colder, the air cannot hold as much moisture, making it drier.
  • Ventilation: We utilize our HVAC systems to improve indoor air by removing hot air and replacing it with fresh air. Inadequate ventilation can lead to dampness and mold as the humidity and temperature rise.
  • Your house: Both the airtightness and building materials of your home will significantly impact the humidity. Good airtightness enables you to control the temperature and ventilation better. Some building materials, such as reinforced concrete, can make it tricky to control condensation. In comparison, newer materials like wood-based cellulose fiber absorb moisture (4).

What Are the Benefits of Humidifiers?

During the winter, the air tends to be cold and crisp — cue the chapped lips and flaky skin. However, with a humidifier, you can get through winter without feeling moisture-deprived. Here are a few benefits of humidifiers:

Prevents Snoring

Whether you’re the snorer or the person who has to listen to it all night, it can be very frustrating. If you tend to breathe through your mouth while sleeping, you will likely wake up feeling dry.

Run a humidifier at night to help soothe your throat and nose from the dryness. It will help you to sleep more comfortably while also minimizing snoring.

Beneficial to the Home

If you have wooden floors or furniture, keeping the humidity balanced can help the wood last longer. Furthermore, if you have houseplants, these will benefit from a little extra moisture in the air.

Prevents Static

Have you ever noticed how frizzy your hair can get during the winter? Or do you notice static electricity when removing the sheet from your bed? Dry conditions in your home can cause this.

Static electricity isn’t just annoying; it can also be dangerous if it builds up, as it can damage certain electronics. Higher humidity can help to prevent or lessen static.

Helps to Prevent Spreading of Airborne Viruses

Recent studies showed that airborne viruses were least likely to spread when the humidity was at least 43 percent. The study showed that nearly 85 percent of viruses were virtually ineffective in more humid conditions (5).

Moisture can prevent the movement of germs since they drop to the nearest surface when combined with moisture. As a result, it’s more difficult for germs to spread through the air. This gives you a chance to clean and remove them.

What Are the Disadvantages of Humidifiers?

There are many advantages to humidifiers, but they aren’t without flaws.


Although humidifiers are highly beneficial, they can become a breeding ground for mold and bacteria. This isn’t just filthy to look at; it can also cause bacteria and mold to spread through the air. As the water in the tank becomes vapor, so do the contaminants.

Keep In Mind

It’s crucial to clean your humidifier regularly and change the water before using it. Never leave water standing in the humidifier for long periods — always clean and dry the tank before storing it.

High Humidity

If your air is dry, using a humidifier is beneficial. However, if you overuse it, you can create a new problem: high humidity.

According to the EPA, humidity levels of 60 percent and more are considered high. With high humidity levels, dampness and condensation are likely to occur. This can lead to dust mites, mold, mildew, and other indoor allergens (6).

Keep Track

If you’re using a humidifier, you should also have a meter to measure the humidity, such as a hygrometer. Keep track of the humidity levels in your home, and only use the humidifier if necessary.

Does a Humidifier Help With…

A Cold?

This is still up for debate. Many parents use cool mist humidifiers to help ease congestion and stuffy noses. However, research has shown that warm mist humidifiers aren’t as effective in treating cold symptoms (7).


Always use a cool-mist humidifier around children. If they get too close to a steamer or vaporizer, they can get burned.


Although humidifiers can help to ease coughing, they can also trigger asthma. This is due to the risk of dust mites and other indoor allergens thriving in more humid conditions. Furthermore, if the tank has mold or mildew, this could spread through the air, causing you to inhale it (8).

Dry Skin?

As soon as winter hits, many people feel their skin is dry, and lips are chapped. This is because the human body is made up of approximately 50 to 60 percent water. When we’re exposed to dry conditions, the moisture is pulled out of our bodies, leaving us dry, flaky, and chapped.

Run a humidifier to keep the relative humidity at a balanced 50 percent for your body to be comfortable. In addition to the humidifier, drink enough water during the day to compensate for what’s lost.


When you get a bad cough or chest cold, experts advise that taking antibiotics won’t do much. So what can you do? According to the Centers for Disease Control and Prevention, using a clean cool-mist humidifier or vaporizer can help to ease the symptoms (9).


Similar to asthma, common indoor allergens thrive in humid environments. Therefore, by increasing the humidity, you can trigger allergies. Additionally, if mold and mildew are growing within the tank, they will spread through the air (10).

What Humidity Should I Set My Humidifier To?

Humidity levels below 30 are too dry, and above 60 are too high. We recommend setting your humidifier to 40 or 45 percent for optimal humidity.

How Much Does a Humidifier Cost?

Depending on the type, whole-house humidifiers can cost between $100 and $700.

Evaporative humidifiers are less expensive compared to steam humidifiers.

With whole-house humidifiers, you also have to consider installation fees. These can range between $350 and more than $800 (11).

Depending on the model and size, small humidifiers can cost anywhere between $15 and $100.

Cleaning and Maintenance of a Humidifier

Taking care of your humidifier is crucial to prevent air contamination. Daily maintenance includes emptying and refilling the tank. You should flush the tank using white vinegar once or twice a week to remove potential mold or mineral build-up.

You can sanitize the tank using bleach, peroxide, or pure vinegar when needed. Always unplug the humidifier before cleaning or doing maintenance. Never use other chemicals to clean the tank since it can be damaged or cause the chemicals to spread through the air.


How Do You Know If Your House Air is Dry?

You know your house air is dry when you experience a sore nose and throat, and suffer from itcvhy and red eyes. You also feel dehydrated, and you may suffer more easliy with allergies. Another tell-tale sign is increased static electricity.

Where Should I Place My Humidifier?

You should place your humidifier in a central position, elevated at least two feet from the ground. Also, avoid putting it in direct sunlight.

How Close Should a Humidifier be to Your Bed?

Your humidifier should be approximately three feet from your bed. Never place it next to your bed or this will cause brfeathing difficulties during the night and can encourage mold spores to grow.

How Long Does It Take to Humidify a Room?

The time it takes to humidify a room depends on the make, model, and size of your humidifier. Some take three hours, while others can take 24 hours.

Can You Use Tap Water In a Humidifier?

You can’t use tap water in your humidifier because it contains mineral elements and chlorine. When the water evaporates it leaves a white residue on your surfaces. It also contaminates the air you breathe.

Humidifiers Have Their Place

We all hear about people who use humidifiers during the winter to ease congestion and other issues like dry skin. They also prevent snoring, can protect your home, and reduce static.

Although humidifiers are very beneficial, they can do more harm than good if not used properly. It’s crucial to keep your humidifier well-maintained to avoid mold and bacteria from building in the tank. Nonetheless, a humidifier can easily keep your home environment comfortable during the colder months.

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About the Author

Matthew Sullivan

Matthew Sullivan is a technical writer with over 15 years of hands-on experience in the realm of HVAC, humidity, air purification, and mold prevention. With a background rooted in mechanical engineering, Matthew seamlessly blends the intricate world of technicalities with the everyday challenges that homeowners and businesses face. His vast expertise has led him to collaborate with leading HVAC manufacturers, consult on cutting-edge air purification systems, and become a sought-after voice on mold mitigation.