How Does A Cool Mist Humidifier really Work?


If you suffer from a dry throat and accompanying cough, your eyes are dry and itchy, you have trouble breathing in dry air, or you have dry, itchy, and flaky skin, the answer to your problems might come in the form of a cool mist humidifier.

You’ve probably heard of warm mist and hot steam humidifiers, which make sense, because after all, when you heat water up, it evaporates into the air.

That said, the way in which a cool mist humidifier functions is a bit different, because as the name implies, they do not use heat to create humidity. So, how do cool mist humidifiers work, what are their benefits, and are they right for you?

The Two Types of Cool Mist Humidifiers

The first thing you should know is that there are in fact types of cool mist humidifiers, and they work to create mist in different ways.

The two main types are ultrasonic cool mist humidifiers and cooling mist evaporative humidifiers. Let’s take a quick look at both.

Keep in mind that both of these types of humidifiers can be found for purchase in a variety of locations including furniture and home improvement stores, and online as well.

Evaporative Cool Mist Humidifiers

The first main type of cool mist humidifier is the evaporative kind. These are very simple as they use a wick or a filter to hold water. This water then evaporates into the air. This kind of humidifier generally uses an air fan to help the water evaporate quicker and to disperse a cool mist into the air.

Evaporative cool mist humidifiers are generally larger, bulkier, and heavier than ultrasonic cool mist humidifiers. They can be small, but are usually a bit chunky. They need to have a wick to hold the water, which can take up a good amount of space.

Moreover, the air fan, as well as the filter, is going to take up space. Although you can find fairly small and portable evaporative models, they are usually always bigger than the ultrasonic option.

Keep in mind that the air fan used by evaporative cool mist humidifiers can create a good deal of noise; this type of humidifier is not overly silent. Also keep in mind that the fan used in evaporative models requires energy to function. Evaporative humidifiers generally draw more energy to function, thus making the more costly to run.

Evaporative cool mist humidifiers usually always feature filtration. The point here is to filter the water to remove as many bacteria, allergens, and other contaminants. On one hand, this is a good thing if you are looking to produce humidity in a clean way which will not negatively impact your breathing. On the other, having to change or clean a filter on a regular basis is not overly convenient.

Ultrasonic Cool Mist Humidifiers

Ultrasonic cool mist humidifiers are quite different in terms of how they function. Instead of allowing water to evaporate, these models use special vibrating plates and a mechanism to create high-frequency sound vibrations. This intense vibration is enough to turn liquid water into an air-based mist. These may use air fans to disperse the mist more efficiently, although most do not.

In terms of size, ultrasonic humidifiers tend to be the far smaller of the two; because they don’t come with wicks, they generally don’t have fans, and have fewer components to them. They are quite small and portable, and usually come in the shape of a teardrop.

Some of them are so small that they can be placed in a glass of water. If you are looking for something small and portable, it’s the ultrasonic humidifier that you want to go for.

Also, due to the fact that most ultrasonic cool mist humidifiers do not have air fans, they tend to be much quieter and less noticeable than evaporative cool mist humidifiers. On that same note, due to having fewer moving components, ultrasonic cool mist humidifiers tend to be more energy efficient than their evaporative counterparts.

Something which you may like about ultrasonic cool mist filters is that they may or may not come with a filter. Many models do not come with any kind of filtration, which can be a good thing if you don’t want to have to pay attention to changing and cleaning filters.

On the other hand, due to not featuring any filtration, most ultrasonic cool mist humidifiers do not clean the water as it is released, and this can cause allergy and breathing issues for some people.


Cool mist humidifiers are great humidifiers to go with, and this goes for both the ultrasonic and the evaporative types.

The reason for this is because just like hot steam humidifiers, they still humidify a room, but they do not produce heat, something which is often an issue with warm mist or hot steam humidifiers.

Now that you know the differences between ultrasonic and evaporative cool mist humidifiers, you are one step closer to making a final purchasing decision.

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