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Do Humidifiers Cause Mold and Excessive Moisture?

Yes! Humidifiers have the tendency of causing mold. But there is more to why, and how this can happen.

Mold! Mold! Mold! 

I’ve heard the word so often. What comes to your mind when you hear the word? I bet it strikes fear into your mind, just like it does to me. 

Now tell me who wouldn’t be scared of such tiny yet dangerous microorganisms that can cause serious health problems. Also, tell me if you won’t go to a great length to prevent the build-up of this deadly fungus in your environment. 

There are countless ways you can prevent the growth of molds, but using a humidifier is one stand-out method because of the machine’s effectiveness in curbing the growth of fungi in the environment. 

Ironically, this effective weapon against this microorganism can also be its most fertile breeding ground…, why?

This article will provide you why a humidifier can cause mold and how it can be appropriately used to prevent the accumulation of molds. 

What is a Mold?

A Mold is a type of fungus that consists of small organisms found almost everywhere. They can be black, white, orange, green, or purple. Outdoors, molds play an essential role in nature, breaking down dead leaves, plants, and trees.

Mold can be found in damp building materials; it usually appears like stains and comes in various colors. If you allow mold to grow in your houses or offices, it can cause poor air quality around your surroundings. Some molds are dangerous and destructive, e.g., Dry Rot Fungus, Serpula lacrymans, and so many others. 

What Causes Growth Of Molds In Homes 

Before I tell you what can cause or contribute to the growth of molds in your homes, I will outline the necessary conditions needed by this fungus to grow well. The requirements are as follows:

  • Moisture (e.g., water leaks, humidity)
  • A food source such as drywall, cotton, etc. 
  • Darkness 
  • Warmth (mold can’t survive freezing temperatures )
  • Oxygen
  • Mold spores

Furthermore, most molds can begin to grow within 24-48 hrs, mainly if the conditions are right. Also, you must note that moisture is the critical factor that can contribute to the growth of this dangerous fungus in your homes. 

Below are eight things that can cause mold in our homes and offices:

  • Leaking pipes 
  • Humidifier 
  • Wet clothes 
  • Flooding 
  • Damp basement 
  • Leaking roofs 
  • Poor ventilation 
  • Condensation 

How a Humidifier Can Contribute To The Growth Of Mold 

As you’re reading this article, you’re probably asking yourself whether a humidifier can cause mold or not…. Unfortunately, the answer is yes. And this will be discussed in the paragraphs below. 

For instance, if the weather’s been very humid and it begins to rain for a few days consecutively, you will start to observe the growth of mold in your home. You will find it common to start seeing mold on benches, walls, and other surfaces because of the moisture. 

Additionally, this fungus can thrive under an environment with a certain level of humidity (mold starts growing at humidity levels above 55%). So If the moisture in your house or office is above the required standard, then you shouldn’t be surprised to have mold growth in your home or office as a recurring issue.

However, I’ve found out that a lot of people who use humidifiers in their homes go above the required humidity levels, This can lead to excessive moisture or wetness which can cause mold to start overgrowing on porous surfaces such as walls, window stills, etc.

Another way humidifiers can cause mold is through lack of proper maintenance. Most people are too lazy to clean their humidifiers as specified in the manufacturer’s manual. 

Well, If you happen to be among this group of lazy fellows, well congrats to you for making your humidifier a playing ground for the molds and other dangerous microbes. Also, once mold grows inside of a humidifier and you use it, it contaminates the air quickly, thereby putting you and your family at high risk.

Using Humidifier Properly To Prevent Against Mold 

Since you can use a humidifier fight against mold and other microbes, if you don’t use it properly, it can lead to the opposite effect. 

Below are ways you can use humidifiers properly:

#1. Proper Maintenance and regular cleaning of the humidifier

Although humidifiers are useful, if your humidifier is dirty, you may not find it as helpful as it should be. Dirty filters and reservoirs can help in the build-up of molds, germs, and bacteria. These harmful microorganisms can be released into the air when using your humidifier.

So you must ensure to properly Wash, rinse, and sanitize your humidifier’s interior, tank, and filter. Also, you must remember to ensure the moist components of your humidifier are correctly dried. 

#2. Monitor the humidity levels of your room 

As stated earlier in this article, molds can grow well under any humidity levels that are higher than 55%. So common sense will tell you when using your humidifier at home, to always ensure you maintain the humidity levels far below 55%.

Anything from 30% to 50% is the recommended relative humidity level for your homes and offices. Also, you must get a digital hygrometer to monitor the humidity level inside of your office and your home. 


Mold is a tiny spore that can be harmful to your health when inhaled. They thrive well under a moist environment, such as the tank of a humidifier.

You must pay maximum attention to the maintenance of your humidifier to prevent the growth of this dangerous spore, which can sometimes be invincible. 

Lastly, always ensure to maintain a constant humidity level of 30%-50% to prevent the growth of molds. Using your humidifier correctly will not only make you enjoy its benefits but would also protect you and your family from dangers.