Can You Use Purified Water in a Humidifier?

Air and water are the two elements that are vital for the existence of humanity. Indoor air that we breathe in constantly is usually too dry and might irritate various body parts such as the skin and respiratory system. Moreover, dry air creates perfect conditions for bacteria and viruses to spread and travel which might cause serious health problems. 

A humidifier is a device that adds moisture to the air preventing all the abovementioned inconveniences and filling your indoor area with healthy air to breathe. Since you will be breathing in the water that you put into the humidifier it is important to have a high-quality water supply. 

Purified water can and should be used in a humidifier. It will help you to breathe clean air and prolong the humidifier’s life. Distilled water is the cleanest type of purified water so it’s the best ideal water type to use.

In this article, we will cover all of the questions that concern water for humidifiers including various types of water and its influence on the device and quality of air, and tips for getting the best out of your experience when using one.

Therefore, if you own or plan to obtain this air cleaning device then keep on reading as this article is about all that you need to get informed on how to get the best results from the humidifier by using the right type of water. 

Why Should You Avoid Using Tap Water in Your Humidifier?

Untreated tap water is full of harmful contaminants. According to the Water Quality Association usually tap water contains elements such as pesticides, chloramine, fluoride, bacteria and viruses, and many more. Imagine what negative effects breathing in such contaminants might have on the sensitive respiratory system.

Related: Does Kirkland Water Have Fluoride?

Furthermore, tap water contains a number of heavy metals, sediment, and other particles. The latter can clog and damage the pipes and ways of your humidifier, thus decreasing its longevity and high-quality work productivity.

Also, the specialists of the Mayo Clinic states that the bacteria and viruses present in tap water will result in the growth of mold in the tank of your humidifier which will then be released into the air you breathe in. 

What is the Best Water for a Humidifier?

Since we have briefly covered the downside of using tap water in your humidifier, the following paragraph will show detailed information and evaluation of each type of water that you can use for your device to find out which one is the best.

Tap Water

As mentioned above tap water in most cases is hard and is full of harmful contaminants such as chloramine, fluoride, lead, pesticides, and even bacteria and viruses. Also, many other particles can be found in tap water like sediment or heavy metals which will clog and damage your humidifier device.

With all that in mind, it is hard to find at least one positive thing about using tap water for humidifiers but if we have to then it would be its accessibility, yet at what cost. Therefore, it is best to choose any other option listed below.

Purified Water – Distilled Water 

Distillation is the most common way of water purification – a mechanical process that eliminates contaminants and minerals from your water. Purified or distilled water contains no calcium, chlorine, sulfate, ammonia, heavy metals, or carbon dioxide making it clean from any harmful contaminants that might damage your humidifier and get into the air you breathe.

Moreover, distilled water is the type of water that’s been used in food and beverage manufacturing, laboratories, and health institutions which signifies its safety. All in all, distilled water is the best type of water for your humidifier.

Megahome water distiller

Megahome distiller to produce water for a humidifier

We have an article about the Best Water Distillers so check it out to find more options.

Filtered Water 

There are many types of water filtration systems that differ depending on the type of filtration and the outcome it creates. Reverse osmosis is the type of water filtration that removes all harmful contaminants and impurities leaving you with 99% pure water.

Carbon block filters do a perfect job eliminating harmful contaminants as well yet it is not so effective when dealing with heavy metals. Ionization is another filtration method that treats water yet in some cases it has been found to be not so effective when dealing with bacteria compared to RO or carbon block systems.

In any case, filtered water is a great option to use for your humidifier yet it depends on the filtration system you have since the presence of heavy metals and bacteria might still damage your device and be precarious.

iSpring RCC7AK Reverse Osmosis under sink filtration system

Can You Use Purified Water in a Humidifier?

Boiled Water

Most of us think that by simply boiling the water we make it healthy and harmless to consume. The truth is that treating the water at a high temperature only eliminates the germs. Therefore, all of the harmful contaminants are still in place.

Even more so, boiling reduces the volume of water, and in that case the concentration of harmful contaminants increases. Samely as with tap water, boiled water is not treated properly and remains harmful both, for your health and the humidifier. 

Bottled Water

Contaminants would rarely be found in bottled water as The Food and Drug Administration has set the standards that must be followed before releasing it to the market. Although this means that bottled water is perfectly safe to use in your humidifier there is something to keep in mind.

Most of the bottled water comes in plastic bottles and synthetic polymer particles (microplastic) can be found released into the water. These particles are highly dangerous for the human body to consume and of course, it would damage your humidifier. 

Related: Does Reverse Osmosis Remove Microplastics?

Demineralized Water

With demineralization, almost all salts, minerals, and impurities are being removed from the water. This means that demineralized water is free from contaminants like calcium, sulphate, chloride, magnesium, sodium, etc.

The disadvantage that comes with demineralized water is simply that together with harmful minerals it also removes beneficial ones which might cause a mineral shortage in the body and influence its functions.

Moreover, this type of water purification does not eliminate viruses, bacteria, and organics, which will have a significant negative effect on your humidifier and the cleanness of your air. 

Type of WaterAdvantagesDisadvantages
Tap waterEasy accessFull of harmful contaminants, bacteria, viruses. Will damage the humidifier
Purified (distilled) waterNo harmful contaminants, healthyNone
Filtered water99% pure water (RO), perfect for a humidifierCertain types of filtration leave heavy metals, bacteria
Boiled waterNo gemsFull of contaminants in increased concentration
Bottled waterTreated according to FDA standardsHas microplastic particles
Demineralized waterFree from salts and mineralsHas viruses, bacteria, organics

Hot VS. Cold Water in a Humidifier

The effects of your humidifier also depend on the temperature of the water that you fill your humidifier tank with. When using hot water your humidifier will release hot mist which can be perfect for those who are in need of treating conditions of the respiratory system, cold or flu.

However, if your humidifier is not suitable for releasing hot mists it might damage it severely. Moreover, hot water creates a perfect environment for bacteria and mold to grow which is definitely something that you want to avoid. Using hot water might also be dangerous for the younger members of your household or pets as it might cause burns if spilled.

On the contrary, using cold water in a humidifier would not put any physical danger and has less dissolved minerals.

Also, cold mist might be more comfortable to breathe in rather than the hot one. If in doubt, simply choose neutral room temperature water or obtain a humidifier that automatically sets the temperature of the mist. 

Can You Use Hard Water in a Humidifier?

Hard water is the type of water that contains increased amounts of dissolved minerals. When using hard water in a humidifier it might create a byproduct of those minerals called white dust. The latter is the result of a humidification process when small mineral particles are being released into the air.

Although in most cases white dust simply settles on various surfaces it is also inevitable that it will mix with the air of the space. Breathing air mixed with white dust for long periods might result in respiratory problems. 

How Often Should You Change Water in a Humidifier?

It is important to change the water in a humidifier everyday and more importantly to empty it immediately if not in use. The reason for that is because moist and dark places are favorite for bacteria to grow. Therefore, to avoid this growth of bacteria or even algae it is essential to change the water regularly when in use and empty it when not.

Also, be informed about what type of treatment your humidifier needs and follow the instructions provided by the manufacturer.

Remember that your humidifier can be beneficial for your health as well as unhealthy and that all the contaminants and the bacteria that sits inside of your humidifier will be released into the air you breathe in. Take care of your humidifier and enjoy clean and healthy air!

Read more about Brita water in humidifiers.


This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

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