A humidifier is used to alleviate discomfort caused by dry skin, allergies, asthma and stuffy sinuses by increasing the moisture content (humidity) in the air. A warm mist humidifier heats water to produce steam that humidifies the air. A cool mist humidifier releases tiny water droplets into the air.

Comparison chart

Cool Mist Humidifier versus Warm Mist Humidifier comparison chart
Edit this comparison chartCool Mist HumidifierWarm Mist Humidifier
Cost Cheaper to operate Heating element requires more energy
Operation Noisier Silent
Ease of use Cleaning is easier Cleaning is hard
Hazards Suspended material such as microorganism and mineral in the water are diffused into the air by impeller and ultrasonic humidifiers. Hot water and heating element may cause scalding. Risky with children around.


Both cool-mist and warm-mist humidifiers offer relief for allergies and asthma. If a person can breathe well in a sauna then a warm mist humidifier is suitable. If a person finds it difficult to breathe in a sauna then a cold mist humidifier is suitable.

In this video Dr. Ari Brown explains the uses of a humidifier in a baby’s room.

Types of Humidifiers

Types of Cool Mist Humidifiers

Types of Warm Mist Humidifiers

A buying guide for various types of humidifiers that outlines the symptoms, size and benefits:

Humidifier Buying Guide (click to enlarge)
Humidifier Buying Guide (click to enlarge)

Humidity levels

Humidifiers are required to maintain the moisture content of a room. 35 to 50% humidity level is considered to be healthy. A low humidity level results in dry and itchy skin or chapped lips. Humidity level greater than 50% results in growth of mold spores, bacteria and dust mites. 40% humidity is required for musical instruments to prevent their crazing or cracking of finish.

Optmimum humidity level for the flu virus

The flu virus thrives best when humidity is either over 98% or between zero and 50%. So Dr. Linsey Marr, a researcher at Virginia Tech, recommends keeping humidity levels around 50% (but not over 60%, because that can cause mold buildup) to give the flu virus the least chance of survival.[1]

Pros and Cons

Advantages of Cool Mist Humidifiers

Disadvantages of Cool Mist Humidifiers

Advantages of Warm Mist Humidifiers

Disadvantages of Warm Mist Humidifiers


All humidifiers require maintenance. Here are some steps you can take to keep a humidifier in good shape:


Products on the list of best selling humidifiers on Amazon usually range from $30 to $80, with some high-end humidifiers priced at as much as $170.


Share this comparison:

If you read this far, you should follow us:

"Cool-mist vs Warm-mist Humidifier." Diffen.com. Diffen LLC, n.d. Web. 7 Nov 2018. < >