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By Lindsay Lafreniere published 20 April 22

Knowing how to clean your humidifier is key for ensuring you have healthy air in your home

Purchasing a humidifier is one thing, but knowing how to clean your humidifier is quite another. The best humidifiers bring with them a range of benefits, from helping to relieve the symptoms of a common cold to easing sore throats and coughs, but keeping your humidifier clean is key to reaping these rewards.

Humidifiers work by pumping more moisture into the often dry air circulating in homes, helping to sooth health issues and providing more water to houseplants. Yet, what you may not realize is that dirty humidifiers can actually make you sick, breeding mold and bacteria that can cause lung infections and flu-like symptoms.

The good news is, learning how to clean your humidifier is nowhere near as complex as it might sound. A few steps is all it takes to get the job done and you’ll find that taking a few moments out of your day once or twice a week to show your humidifier a little tender loving care will ensure that you enjoy all the health perks these devices can offer.

Below, we talk you through exactly how to clean your humidifier, including some helpful tips on how to maintain it and why using your humidifier correctly is so important. If you’re interested in controlling the air quality in your home as well as the humidity level, the best air purifiers are well worth considering.

Tap water is not sterile. Waterborne germs can live and grow in home pipes and our devices that use water, such as humidifiers. This happens especially in places where water sits stagnant and is not flowing or changed often. These germs in water can be harmful and make people sick, including stomach illnesses, like vomiting or diarrhea, or illnesses of the lungs, brain, eyes, or skin. 

According to the Centers for Disease Control and Prevention (CDC), preventing waterborne germs at home is incredibly important, and because humidifiers are a prime breeding ground for these, cleaning them on a regular basis is vital for your health and wellbeing. Young children, elderly people and those with lung diseases or respiratory allergies are particularly susceptible to airborne pollutants. While humidifiers help with allergies, they need to be clean in order to be effective. 

Although cleaning your humidifier is a fairly straightforward process, it’s important to avoid humidifier disinfectants. These are often used by people in their humidifier water tanks as a way of preventing the growth of microorganisms, bacteria, and molds. But recent studies published in the journal of Science of the Total Environment and the International Journal of Environmental Research and Public Health have shown that humidifier disinfectants are associated with lung injuries in children and pregnant women. 

First off, always check the cleaning instructions that come with the model of the humidifier purchased, which should outline the proper use and maintenance of the device. If the paper copy of the instructions is lost, manuals can be downloaded online by searching the make and model. 

The Mayo Clinic recommends cleaning home humidifiers every three days with a three percent hydrogen peroxide solution. First, unplug the humidifier before cleaning, then remove mineral deposits and film with solution. Some manufacturers recommend using chlorine bleach. Ensure the tank is fully rinsed before using. 

Some humidifiers come with filters to clean the air. These should be changed regularly, especially if they’re dirty. Depending on how often you’re using your humidifier, we recommend you pop a fresh filter in every one to three months.

Properly maintaining a home humidifier can not only keep it cleaner but also keep the air in the home clean and safe. 

Using tap water in a humidifier can cause the minerals inside the water to create deposits that promote bacterial growth, states the Mayo Clinic. These minerals are released into the air and can be breathed in or appear as white dust on furniture and other belongings. 

Distilled or demineralized water should be used in humidifiers as each has lower mineral content. Previously boiled and cooled water can also be used, although water should be changed often to prevent the build-up of deposits or film. The CDC states that germs can live in humidifiers and be spread through the mist created when it’s turned on. 

Where possible, empty the humidifier tank daily and dry the inside surface before refilling with clean water to completely stop the spread of bacteria. This is especially true if using cool mist or ultrasonic humidifiers. 

If you’ve been holding onto the same humidifier unit for decades, the build-up inside of it may be too great, so investing in a new one may be the best course of action. Mineral deposits can become difficult, if not impossible, to clean over time, causing bacteria to continue to grow. Once a humidifier is past its use, consider replacing it with a newer, and cleaner, model. 

Humidifiers are often used in specific seasons, such as the cold dead winter with its dry air. If you’re not using it all year round, make sure your humidifier is drained and cleaned before storing it away.

Used filters and cartridges should be replaced before using it again. Once the humidifier is removed from storage for the next season, give it a good clean to ensure that fresh moisture is being pumped into the air. 

There are dangers to increasing the humidity in the home too much. Excess moisture, from the climate or humidifiers, leads to the growth of biological organisms, such as mold and dust mites, according to the United States Environmental Protection Agency. 

Monitor the area around a humidifier to check for signs of extra moisture, especially on windows, drapes, carpeting, and other home textiles. Excess moisture can cause bacteria and other molds to grow.  If these signs of dampness are visible, the humidifier should be turned down or its use reduced in time. 

Lindsay Lafreniere is a freelance writer, editor, and podcast producer. She is particularly interested in writing about healthcare, science, travel, and culture. 

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