What Type Of Water To Use For A Humidifier?

This article discusses the best type of water to use for your humidifier. 

You might be tempted to just use tap water for your humidifier. We don’t recommend this as tap water contains various contaminants that could have a disastrous effect on your skin, respiratory system, and health in general. 

But with so many types of water to use for humidifiers available, from purified, to distilled, to filtered, to bottled, and more, it can be tough to make the most worthwhile choice. 

Put simply, the best type of water to use for a humidifier is distilled water. Distilled water is completely free of all contaminants, microbes, and irritants, but also eliminates minerals, heavy metals, and the like.  

Still, other types of water for humidifiers also have their advantages. We use our experience to compare the different choices and help you choose the best one for you. 

Keep reading for more information about the best type of water to use for your humidifier.  

What Type Of Water To Use For A Humidifier?

If you want a quick recommendation for the best type of water for humidifiers, just go with distilled water. It is easily the best choice for your humidifier, as it is free of all contaminants, minerals, heavy metals, and anything else that might affect your health or your surroundings. 

It will be the most expensive option, and you might have to go out of your way to source it. But distilled water is by far the best type of water to use for your humidifier.

Why The Type Of Water Used In A Humidifier Matters

Imagine living in an area that is close to heavy industry. The air quality will probably be much lower than other places that aren’t as close to industrial areas. 

The lower quality air will be harder to breathe. It will also cause various respiratory diseases, from breathlessness and coughing to asthma and lung disease. 

The same is true for the type of water to use for humidifiers. If you don’t fill the unit with high quality water that is free of contaminants, irritants, and germs, it will cause many health problems. 

Additionally, it will even have an effect on your surroundings, as the same mist that you breathe in will also settle on your furniture, walls, pets, and food.

The Different Types Of Water 

There are actually many different types of water that people use day-to-day for various purposes. 

The major differences between all of them have to do with the type of filtration processes they went through, and how many contaminants they hold. 

Here’s a quick introduction to just a few different types of water for humidifiers. 

Tap Water

Tap water is just that; water from your tap. It’s what you use in your kitchen, your bathroom, and anywhere else around the house. Tap water originates from lakes, rivers, and even groundwater, deep below the surface. 

It is treated at various treatment facilities before making its way to our homes, where we drink it, shower with it, wash our cars with it, and so much more. Tap water still contains a fair bit of minerals, and the taste takes some getting used to due to the chemicals used to treat tap water. 

That said, not all tap water is safe to drink. Some parts of the world get tap water that is not fit for human consumption, or indeed using in a humidifier. 

Purified Water

Purified water and tap water often get confused for each other, since both are treated and don’t contain any contaminants. However, they could not be more different. 

The processes used to filter and treat the two are very different from one another, and purified water contains significantly less contaminants than tap water. Purified water still retains a high mineral content, but it is perfectly safe to drink. 

Purified water is free of dust particles, germs, microbes, and any irritants that could harm you. 

In fact, it is often recommended by doctors to patients who need the highest quality drinking water possible. And at the end of the day, purified water is actually a good type of water for humidifiers. 

Distilled Water

Distilled water, like purified water, is water that does not contain any contaminants, microbes, germs, or dust. But distilled water takes it a step further by also eliminating minerals and heavy metals from its composition. 

It is made by a process called ‘distillation’, wherein water is boiled and the resulting steam collected and converted back to water. Distillation of water removes all of the contaminants, minerals, and heavy metals. 

This makes distilled water the purest water you can get. It is perfectly safe to drink, though it may taste a bit bland due to the absence of minerals that contribute to the flavor. 

The process of distillation is also more expensive than purification, making distilled water more expensive to buy than other types. 

Hard Water

Hard water is water that has a very high mineral content. This is usually untreated water that you might get from your tap in some regions. 

Hard water is generally safe to drink, and won’t make you sick like some people think. But it will taste very different because of how high the mineral content is. In fact, it will taste a bit unpleasant, especially if you’re used to drinking other types of water. 

Which Types Of Water Are Safe To Use For Humidifiers

While all the different types of water we’ve mentioned are safe for human consumption, it’s a different story when it comes to using them in your humidifier. 

Here’s why the different types of water are or aren’t safe for use in humidifiers. 

Can You Use Tap Water In A Humidifier? 

Tap water is not recommended for use in a humidifier. It has a pretty high mineral content, and isn’t as pure as purified water, meaning it still contains a fair bit of contaminants. 

Another thing to consider is that no matter how well the tap water is treated at the treatment facility, it still gets to your house in pipes, and is then probably stored in a tank. It is possible for tap water to get contaminated when it is in these pipes and tanks, making it unsuitable for use in a humidifier. 

If used in a humidifier, contaminated tap water could cause problems with the diffuser, the nozzle, or any number of other sensitive internal components. 

Can You Use Purified Water In A Humidifier?

On the other end of the spectrum, purified water is actually perfectly safe for use in a humidifier. This is because it does not contain any contaminants whatsoever. It undergoes more comprehensive filtration and purification than tap water, so there is no chance of contamination. 

Purified water is safe for use in a humidifier, but it does contain a fair bit of minerals. These minerals are what give purified water its unique taste. 

But if you regularly use purified water in your humidifier, it could require you to clean the tank more often. Minerals from the purified water can easily get deposited in the tank, where they may even cause mold if neglected for longer periods. 

This isn’t really a problem if you are keeping up with the maintenance and cleaning of your humidifier. To reiterate, purified water is perfectly safe to use in a humidifier. 

However, if you aren’t cleaning the tank or replacing the filter on a regular basis, mineral deposits are something to keep in mind. 

Can You Use Distilled Water In A Humidifier?

Distilled water is easily the best type of water to use for a humidifier. Unlike purified water, it filters out minerals and heavy metals in addition to filtering out contaminants. 

Distilled water is water, and nothing else. It is the best type of water to use for a humidifier as it does not pose the risk of mineral deposits in the humidifier’s water tank. Additionally, it does not cause any issues with the diffuser, the nozzle, or any of the humidifier’s other internal components. 

You will have to pay a bit more for distilled water, but it is well worth it. 

Can You Use Hard Water In A Purifier?

Hard water is easily the worst type of water to use in a humidifier. The mineral-rich composition means the chances of mineral deposits in the water tank are much higher. 

In fact, the mineral content of hard water is so high that the minerals could very easily be released into your surroundings. Here, they could even cause mold to form, which poses a serious health risk. 

Can You Use Filtered Water In A Humidifier?

A lot of people like to use filtered water for their humidifier. 

Filtered water is essentially just tap water that goes through an extra stage of filtration after coming out of the tap. You may have a filter installed at your house, which you use for the water you drink. 

And while filtering tap water removes most of the contaminants such as dust, dirt, and other irritants, not all filters are capable of removing finer minerals and heavy metals from the water. 

That is why we don’t recommend using filtered water for your humidifier. 

Can You Use Bottled Water In A Humidifier?

Using bottled water in a humidifier is a big no-no. 

This is because most bottled water companies leave the minerals and heavy metals in the water when purifying or filtering it. In fact, some companies may even add minerals after they’ve already filtered the water. 

These minerals are perfectly healthy for human consumption, but could cause a variety of problems, as we’ve discussed above. 

So we don’t recommend using bottled water in a humidifier. 

Can You Use Hot Water In A Humidifier?

Warm mist from a humidifier can have a ton of benefits for your health. Not to mention, it just feels a bit cozier on cold days!

But warm mist humidifiers use extra components such as a heating element, which can be pricey. A budget-friendly alternative is to use hot water in your humidifier. And as long as the water you’re in your humidifier is purified or distilled, it doesn’t matter if it’s hot or cold. 

So yes, you can use hot (purified or distilled) water in your humidifier. 

Can You Use Boiled Water In A Humidifier?

You might think that since hot water is safe to use in a humidifier, the same goes for boiling water. But it’s not that simple. 

The fact is that humidifiers have a lot of sensitive internal components. These components are not necessarily designed to withstand extreme heat, such as from boiling water. 

Really, whether or not you can use boiling water in your humidifier will depend on the exact make and model of your unit, and how much heat it is designed to withstand. 

And if you’re curious about that, we recommend consulting the user manual that came with your humidifier, or asking the manufacturer to be sure. 


To sum up, distilled water is the best type of water to use for a humidifier. It is free of all the minerals and contaminants that could potentially be a problem for you, your humidifier, and your surroundings. 

Purified water is still a close second, and if you are willing to clean your humidifier more frequently, it’s also a solid choice. It also provides a cheaper alternative to distilled water, which can be a bit pricey. 

And if you want to reap the benefits of warm mist from a humidifier, you can use hot water, but using boiling water at extremely high temperatures might not be the best idea. 

Finally, hard water and tap water are totally unsafe for use in a humidifier, owing to their high mineral content. 

Even filtered water still contains a ton of minerals, and most bottled water companies actually add minerals to their water, making it unsuitable for use in a humidifier.


Shawn Willis is all about humidifiers. After working for some of the biggest names in the industry, he started HumidifierGuys with Scott Dawson. Now, the dynamic duo helps others figure out what they need in their next humidifier.

Shawn is an avid sports fan, motorcycle enthusiast, and has two dogs named Whiskey and Boba.