What Does An Ionizer Do In A Humidifier? Do You Need It?

A humidifier is a lifesaver for many people, especially those who live in an arid or semi-arid area or suffer from asthma and cough. This industry is competitive, and many manufacturers strive to offer more features to customers. Such as, you can find a humidifier that includes an ionizer on the market now.

What does an ionizer do in a humidifier? Do you need to overpay for this feature? I will answer all of the important questions related to this subject in the post. 

Understanding the mechanism of an ionizer can take some time, but I will explain it as simply as possible. 

What is a humidifier ionizer? 

what is humidifier ionizer

As the name suggests, a humidifier ionizer is a small ionizer integrated into the humidifier. When you pressure the “ION” button on the humidifier, it will release negative ions into the air

The humidifier ionizer is similar to the ionizer in an air purifier, which helps to improve the indoor air quality further.

What does a humidifier ionizer do?

A humidifier ionizer works based on the “Lenard effect.” In case you don’t know, the Lenard effect (also known as the waterfall effect) is a phenomenon where negative air ions (NAIs) are generated when water molecules collide with each other or a wetted solid. 

The negative ions are released through thunderstorms, fog, and mist in nature. But the ionizers disperse charged molecules by means of artificial corona discharge.

When the negative air ions get into the air, they will attract the positive ions and bind each other together. In this way, contaminants will accumulate together and turn to be larger particles. Eventually, it will land on the sofa, furniture, or ground which you can clean up easily.

The ionizer could also help kill bacteria and mold spores floating in the air. It is because the NAIs can destroy the protein structure of these microorganisms. 

Benefits of using a humidifier with an ionizer?

People can benefit a lot from using a humidifier or an ionizer separately. Using an appliance that combines these two machines could be even more powerful. 

Prevent molds and bacteria in the air

As a humidifier owner, you should clean it regularly. Otherwise, the stagnant water will become the breeding ground of molds and bacteria, releasing bad smells and posing risks to your health, such as allergies and even lung infections. 

If you happen to have an ultrasonic or evaporative cool mist humidifier, keeping the humidifier clean is even more crucial since there is no heat to kill germs. 

The ionizer in a humidifier can help to ease the problem. The negative ions can kill the germs just released into the air to some extent. I don’t find any evidence to show how effective it is, but it is better than nothing.

Aside from that, it can help to kill dust mites. While a humidifier can make you feel comfortable by improving the humidity, it could also boost the growth of dust mites when the humid level exceeds 50%. With an integrated ionizer, the dust mites can’t thrive as quickly as they used to be.

Improve sleep quality

Using a humidifier can improve sleep quality by increasing your overall comfort and easing your itchy throat

When a humidifier comes with an ionizer, it can make you sleep even better. This is due to the fact that the negative air ions can regulate sleep patterns and decrease stress. 

If you are suffering from sleeplessness, leave the appliance on all night and test if it works for you.

Increase immune function

The level of humidity will affect our immune system. The low humidity level can dry out mucous membranes, inhibiting our immune function from defending against airborne germs.

Using a humidifier can maintain the condition of our mucous membranes, allowing us to fight viruses. 

An added ionizer can remove the virus in the air, reducing the likelihood of getting a cold. 

Who needs a humidifier with an ionizer?

Many of us have a busy life and live in small spaces. If you live in a humid and poorly ventilated apartment, purchasing a humidifier with an ionizer is sensible. 

It can improve the indoor air quality and let you have a good rest. It would be beneficial for those who struggle to commit to regular cleanliness as well.

People with a poor immune system will also like it since it kills the virus and protects our mucous membranes.

However, a humidifier would not work wonders just by adding an ionizer function. If you are on a budget, buying a humidifier without such a feature is totally fine.

Should you use a humidifier ionizer if you suffer from asthma?

humidifier ionizer and asthma

There has long been a debate regarding whether or not you should use an ionizer as a solution for allergy and asthma sufferers. But many studies have shown that you shouldn’t do that.

The ionizer, even though it is a small unit in a humidifier, can emit ozone that can cause chest pain and shortness of breath. In addition, it is not good at removing large particles such as pet dander.

Therefore, using an ionizer is terrible for these suffers. If you already have a humidifier with an ionizer, you can just turn this function off and continue to use it as a humidifier.


Identifying the features of humidifiers could be a daunting task. When seeing a humidifier with an ionizer, you might not know if it is the one you need. 

The ionizer can create negative air ions, and these charged molecules can trap germs in the air and kill viruses and bacteria. That being said, it can improve the air quality.

Meanwhile, since humidifiers could produce bacteria and molds in the air, an integrated ionizer can help to alleviate the issue. 

Generally speaking, you can feel more comfortable when these two features are on.

Note that ionizers can’t reduce large airborne particles and will emit some ozone, making it not a solution for people with asthma or allergy. But people who suffer from sleeplessness can have a try as it will help to improve sleep quality.

About The Author

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested dozens of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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