Humidifiers are useful for keeping the air moist when winter approaches and humidity levels start to drop. They help cure and prevent a myriad of illnesses associated with cold. However, one common occurrence that can affect the humidifier performance is mold.


Molds usually occur in humidifiers that people do not properly clean and maintain. They spread into the air alongside the mist and cause several nasal infections. With proper cleaning, you can, however, eliminate mold from the humidifier completely. 

How does mold form? 

Mold is a type of fungus that grows or thrives in wet and enclosed environment. You will find them near water or moist environment as white, black, green or brown patches. This makes a humidifier, an enclosed tank, an ideal environment for its growth.

You may ask what can a few molds cause? However, as they multiply the humidifier starts to spread them into the air all over the house and this can cause several ailments to the body.

One of such is a deadly condition called humidifier lung. It occurs when you breathe in contaminated air from your humidifier. Some of its symptoms are chill, coughing, fever, shortness of breath, lung inflammation etc.

They can also cause illnesses for people that are allergic or result in asthma attack.  The good thing is that you can easily cure it by treating its causative, dirty humidifiers.

How to Prevent Mold from Forming 

You can prevent and destroy molds, though unsightly and annoying substances in humidifiers, with the following tips 

1) Regular Cleaning 

This is the first and essential step to fighting molds. You should change the water every day to prevent deposits from forming due to dirty water. 

Clean the tank of the humidifier thoroughly once a week to remove deposits or mold spores that usually start to form at the bottom. You can use boiling water to melt off residue while cleaning especially in cool mist humidifiers.

2) Use additives such as Vinegar 

Vinegar is also a potent material that you can use in killing off mold and mold spores while cleaning. It is antibacterial and antimicrobial which means it will last long in preventing spores from forming in the tank.

Remove the foam belt and also wash thoroughly with vinegar. You should do this weekly rather than monthly as the foam belt is an easy target for mold growth. 

You can also use other additives such as humidifier tablets, bleach, tea tree oil, and hydrogen peroxide. Humidifier tablets are specifically designed to kill molds but they are costlier than using homemade products like vinegar.

Chlorine bleach though works well to eliminate molds should be used sparingly. They can destroy the humidifier hose when exposed to the bleach during continuous use. 

3) Use distilled water rather than tap water 

Asides cleaning regularly, you should take extra measures to prevent mold from forming in the first place. Tap water is hard water filled with mineral contents that aid and accelerate the growth of mold spores.

Filling your tank with distilled water instead will ensure your humidifier produces fewer mold spores and other microbes that can be deadly to the lungs when inhaled. 

3) Change the filters periodically 

The filters that come with the humidifier though work to separate microbes from clean air, can also be inhabitants of microbes.

You should change the filters at least once in three months or at the end of a winter season. Or better yet, you can opt for filterless humidifiers that do not require replacement and will not house molds. 

3) Store in a dry environment 

When moisture levels start to increase and the air seems more breathable you start to use your humidifier less and even turn it off entirely. The machine wasn’t exactly designed to work all year long so no worries. However, storing your humidifier is another factor important to mold prevention. 

Before you keep it away, clean all the parts thoroughly and air dry for days till there’s no moisture left in the humidifier. When dry, place a baking soda pack into the tank before closing the lid.

This will absorb all moisture left and prevent mold from growing as they thrive in a moist environment. This way your humidifier will be fresh and ready to use during the winter or cold season. 

4) Follow manufacturers instruction

Every humidifier comes with a guide manual from the manufacturer. It is paramount that you follow the guidelines included for proper maintenance of the device. If the manual says you should not include essential oils or any other oil into the humidifier, you should adhere.

Tools included or cleaning procedure outlined in the manual should also be considered while cleaning your device for best results and a long-lasting humidifier.


The easiest way to prevent mold is by daily cleaning, especially if you use a small-sized humidifier. Changing the water, scrubbing the tank with a light brush, and using distilled water can help prevent the growth of mold in your humidifier. 

In addition, you should also follow the other tips highlighted for clean and bacteria-free air in your office or home. 

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