What is a Cool Mist Humidifier?

There are two types of humidifiers: warm mist humidifiers or vaporizers and cool mist humidifiers. 

What exactly is a cool mist humidifier and how does it work? We discuss cool mist humidifiers including types, benefits, and drawbacks. 

What is a Cool Mist Humidifier?

A cool mist humidifier is a device intended to disperse cool moisture into the air to increase Relative Humidity (RH) levels of a given space. 

There are two different types of cool mist humidifiers: ultrasonic and evaporative. While the end result of using either an ultrasonic or an evaporative humidifier is optimal humidity levels for your home or office space, each machine functions with a different technology. 

Types of Cool Mist Humidifiers

Ultrasonic humidifiers and evaporative humidifiers are two of the most common types of cool mist humidifiers on the market. Both humidifier types are effective in raising RH levels; whether an ultrasonic or evaporative cool mist humidifier is right for you is solely dependent on your personal preference. 

Ultrasonic Humidifier

The ultrasonic humidifier is the most common type of humidifier, widely preferred for its quiet whisper. An ultrasonic humidifier creates ultra-fine water droplets by vibrating a metal diaphragm at sonic speed. These droplets are then fanned from the machine and into the room; the result is increased humidity levels and a cooling sensation. One must take care when using an ultrasonic humidifier as the mist emitted from the unit may carry particles and bacteria into the air. 

Evaporative Humidifier

Evaporative humidifiers typically pose fewer health risks out of the two types of cool mist humidifiers. An evaporative humidifier functions by sucking in air from the room, passing it through a moistened wick or filter to add moisture, and fanning this hydrated air back into the surrounding space.

The Benefits of a Cool Mist Humidifier

Room Temperature

Think about the last time it rained. Do you remember how the air felt after the rain stopped? You may have noticed a “crisp” feeling in the air. A cool mist humidifier has a similar effect to the temperature of your room. As a result, a cool mist humidifier is a great solution during the summer months, especially if you live in a dry, desert climate. This can also be a benefit during colder months when indoor heating makes the air hot and dry. 


Vaporizers or steam-based humidifiers are considered a dangerous device by the American Academy of Pediatrics (AAP) in nurseries or children’s rooms. While the vapor released from warm mist humidifiers is cooled by the time it reaches the various spaces of your room, the device can be hot to the touch. For this reason, if you have an infant, a small child, or even a pet, it is recommended to choose a cool mist humidifier to avoid potential burns. 

Energy Efficiency

Cool mist humidifiers are more energy efficient than their warm mist counterparts. Steam-based vaporizers boil the water from their water tank to create warm vapor, which requires higher levels of energy than an ultrasonic or evaporative cool mist humidifier. This is a particularly important feature if you desire to save money on your monthly electricity bill. 

Drawbacks of a Cool Mist Humidifier

Cool mist humidifiers offer a wide range of benefits with regular use. As with any technology, however, there are a few drawbacks important to note including the potential for white dust and the frequent maintenance requirements to prevent bacteria build-up in your machine.

Potential White Dust

If you have ever used a humidifier and noticed a white layer of residue left behind on the countertop, floor, or any other surface, this is called “white dust.” If you use tap water in the tank of your cool mist humidifier, the mineral content from the water can leave behind mineral deposits. 

Most cool mist humidifiers require the use of distilled water to function properly and reduce the potential for white dust. Canopy humidifiers do not require distilled water to prevent white dust; you can use water from the tap, from your refrigerator, or water from your Brita. Our antimicrobial paper filter and Smart Persistent Airflow (SPA™) technology work in conjunction with embedded UV lights in the water tank to kill 99.9% of bacteria before the hydrated air reaches the room.

Requires Frequent Maintenance

A cool mist humidifier requires more frequent maintenance than a warm mist humidifier. Warm mist humidifiers or vaporizers boil water in the water tank to create vapor; boiling water kills bacteria, viruses, or debris that lives in sitting water. 

In order to ensure safe operation of most cool mist humidifiers, you must perform regular maintenance including wipedown after every use and weekly deep cleaning. Canopy humidifiers, however, require far less maintenance with proprietary anti-mold technology and dishwasher safe parts. 

How Do You Clean a Cool Mist Humidifier?

Cleaning most cool mist humidifiers is required weekly to ensure proper function. For a full, detailed description of how to clean your humidifier, you can visit our blog: How to Clean a Humidifier.

Cleaning your cool mist humidifier consists of 5 simple steps:

  1. Take apart your humidifier and place the pieces on a dry cloth
  2. Fill water tank and water reservoir with vinegar and let sit for 30 minutes 
  3. Using a scrub brush or a sponge, scrub the inside of the water tank and reservoir
  4. Using a vinegar soaked rag, wipe down the outside of your device
  5. Rinse all parts with warm water and let dry

Canopy humidifiers contain machine washable parts, which simplifies the cleaning process so that you can spend time on other activities. Simply place all Canopy parts that touch water in the dishwasher with the rest of your dishes from the day, and you’re done!