I live with asthma, which makes me sensitive to dust and pollen. Dry air also causes me breathing difficulties, so I use a humidifier in my home.
If you’re like me, you’ve probably asked yourself, “Does a humidifier clean the air?”
It doesn’t. Although humidifiers can improve air quality through moisture, they aren’t designed to clean the air. For that, you need an air purifier.
In this guide, I will explain in detail how a humidifier works and what you can do to humidify and clean your home air.
How Humidifiers Work and Their Benefits
I like humidifiers because of their simplicity. The devices increase moisture levels in dry indoor air by turning water into a vapor or mist and dispersing it into your home.
Different types of air humidifiers vaporize water in different ways. Warm mist humidifiers use boiling water to create steam — just like a kettle.
Cool mist humidifiers use various methods to turn water into a refreshing mist or a cloud of droplets. The two most common humidifier types are evaporative and ultrasonic humidifiers.
An evaporative humidifier sucks water into a wicking filter and evaporates into your home’s air either naturally or with the help of a fan. An ultrasonic humidifier (my favorite type) uses a vibrating disc called a diaphragm to break water into a cooling mist.
Whichever kind of humidifier you use, it can benefit you in many ways:
- Reduce Congestion: Dry air, whether from weather or air conditioning, can irritate your nasal passages and increase snot and mucus production. Adding moisture to the air can loosen the mucus and clear your nose of congestion, especially in winter.
- Soothe Asthma and Sinus Issues: Dry air can be a particular problem for people — like me — who suffer from sinus issues or asthma symptoms. A humidifier can help you control breathing symptoms and provide relief, as long as you use it correctly.
- Alleviate Cold and Flu Symptoms: I always go the extra mile to protect my family when the dreaded flu season hits. Some studies show that humidity levels above 40% rapidly deactivate flu and common cold viruses. A humidifier designed for reducing sinus problems can help you avoid getting sick and soothe symptoms like sore throat and coughing. (1)
- Help with Dry Skin: Low humidity can dry out your skin, causing it to crack and itch. Increasing indoor humidity levels can moisturize the skin to prevent itching and provide help for skin conditions like psoriasis.
- Keep Hair and Scalp Healthy: In the cold winter months, your hair can become brittle and dry, causing it to break or split. A humidifier can help add moisture to your hair, which expedites growth and keeps your locks looking luscious. My wife loves the volume higher humidity levels give to her hair.

Does a Humidifier Clean the Air?
Humidifiers do not clean air in the indoor environment. I appreciate them for their amazing health benefits, but home humidifiers simply are not built to filter or clean the air.
Most humidifiers, like evaporative humidifiers, pass air through a filter as they create moisture. The filter may catch a little bit of dust, but most humidifier filters aren’t fine enough to trap air pollutants
They only reduce the amount of hard water being pushed through the system. Additionally, most humidifiers don’t draw in enough air from the indoor environment to affect contaminant levels.
A humidifier can reduce the number of viruses by adding moisture to the room. Some viruses cannot survive humidity levels of 40-60% as the humidity breaks down their structure. This is one of the most important ways a humidifier can help reduce common cold and flu symptoms. (2)
You may notice that humidifier air is easier to breathe, but that doesn’t mean the unit is cleaning the air. Humidity simply reduces irritation in your airway and on your skin, making you more comfortable in your home.
If you want to decrease the number of contaminants in the air, I recommend getting a large, whole-house air purifier.
Differences Between Air Purifiers and Humidifiers
Comparing a humidifier to an air purifier is a bit like comparing apples to oranges. They are superficially similar (both machines improve indoor air quality and both round fruits grow on trees) but they are completely different in purpose and function.
Air purifiers function by drawing in air and passing it through one or more filters. Filters on air purifiers can range from HEPA filters to advanced high-end filters that may even neutralize dangerous viruses, like the COVID-19 virus.
As air passes through the purifier, dust, allergens, pet dander, mold spores, volatile organic compounds, and other particles become trapped in the filter. The air purifier removes these harmful airborne pollutants and makes indoor air healthier to breathe, particularly if you suffer from allergies or asthma as I do.
Humidifiers — as I mentioned — aim to increase the relative humidity of the air. These devices produce water vapor or a cool mist through various methods, depending on the type of air humidifier. Higher humidity can provide relief to people dealing with dry skin or nose, sinus problems, or asthma symptoms.
The similarities between air purifiers and humidifiers include:
- Both devices improve indoor air quality.
- Both can relieve symptoms of colds, asthma symptoms, and other respiratory ailments.
- Both can offer an affordable solution for making the air in your home easier to breathe.
The key differences between air purifiers and humidifiers are:
- Air purifiers can’t add moisture to the air, while humidifiers are fantastic at it.
- Humidifier doesn’t produce cleaner air, although higher humidity can destroy certain viruses and pathogens.
In summary, both an air purifier and a humidifier can improve the air quality in your home. They simply do it in different ways and offer different benefits.
An air purifier is designed to trap allergens and airborne particles floating in the air to make it safer and healthier to breathe. Humidifiers make the air more humid, and the increased air moisture eases skin conditions, cold symptoms, and symptoms from chronic respiratory conditions.
Can I Use an Air Purifier and Humidifier Together?
You can use an air purifier and a humidifier at the same time and in the same room. I do it all the time.
Using them together can solve your problems with both dry air and airborne allergens. However, you must place them correctly to make sure you can improve your home’s air quality.
I recommend placing the air purifier and humidifier at the opposite ends of a room. The moisture from the humidifier could decrease the effectiveness of the air purifier filter — or even cause it to get moldy.
As long as you keep the devices as far away from each other as possible, you can enjoy the best indoor air quality all year round!
The Risks Involved When Using Humidifiers
- Too Much Moisture: Maintaining a humidity level of 30 to 50% is ideal for your home. Higher humidity can cause mold growth and increased dust mites, which are among the leading causes of allergies and asthma. Ensure you have the proper settings on your humidifier and use a hygrometer to monitor indoor humidity.
- Spills and Leaks: Don’t overfill your humidifier and place it on a stable, hard platform at least two feet off the floor (unless you’re using a large or non-portable humidifier). Leaking or spilled water can soak into carpets or other soft surfaces and create a breeding ground for mold and bacteria.
- Poorly Cleaned Humidifier: You must clean your humidifier’s water tank and filters regularly. A poorly cleaned humidifier can grow mold or bacteria and spread them around your entire house. Don’t try letting your humidifier run for a longer time by combining it with an air purifier — a purifier is not a substitute for a good, thorough cleaning!

FAQs
Can humidifiers cause pneumonia?
Humidifiers do not cause pneumonia. They can alleviate cold and flu-like symptoms and relieve coughing and wheezing, as long as you clean your humidifier regularly.
Should a humidifier run all night?
You can run a humidifier all night (or all day) as long as you ensure it doesn’t run out of water or make your indoor air too humid.
How do you dehumidify a room quickly?
To quickly dehumidify a room, you should use a dehumidifier. Many dehumidifiers can remove up to 50 pints of moisture per day from the air.
Do humidifiers make the room wet?
A humidifier should not make your rooms wet or damp if you set the humidistat to an appropriate setting. If your room does become uncomfortably humid, you have either set the machine too high or are using an oversized humidifier in too small a room.
Conclusion
As much as I hate to disappoint you, humidifiers don’t clean the air. They can improve air quality by adding humidity to your home, but that doesn’t significantly reduce pollutant levels in the air.
For the highest possible air quality, I recommend using your humidifier with a high-quality air purifier. You can then breathe easy, knowing you’re protected from both dry air and airborne contaminants.
Resources:
1) https://www.medicalnewstoday.com/articles/322228#types-of-humidifiers
2) https://www.hsph.harvard.edu/news/hsph-in-the-news/op-ed-humidity-can-aid-in-the-fight-against-covid-19/