Humidifier Buyer's Guide  View Models >>

Humidifiers - Comparisons, Ratings, and Reviews

Why use a humidifier?

Why do we want to add humidity to our homes and what is humidity? Humidity is the amount of moisture or water vapor in the air. People tend to feel more comfortable when the relative humidity is within a certain range (between 35-55 percent). If the humidity is too low, people may be left with physical discomforts such as a dry nose, throat, lips, and skin. In addition, low humidity may also wreak havoc on your home causing static electricity, cracks in furniture, flooring, cabinetry, paint, and peeling wallpaper. High levels of humidity cause a room to feel stuffy and create an environment in which biological contaminants can thrive. Moisture is often added or removed from indoor air to make a room feel more comfortable.

View our Humidifier Comparison Chart.

Types of Humidifiers

Cool Mist and Warm Mist Humidifiers

One gives out a warm mist, the other gives out a cool mist. One is cool, the other is warm. Need more explanation? Well, imagine being in a greenhouse that is how a warm mist feels. People who like warm mists generally live in colder parts of the USA or like to put a warm mist humidifier into a baby's room. Conversely, people who like cool mists live in warmer climates, the last thing they want is to warm the place up a few degrees.


Often referred to as a "vaporizer," a steam humidifier boils water and releases the warm steam into the room. This is the simplest, and therefore the least expensive, technology for adding moisture to the air.


In this humidifier, a rotating disc flings water at a comb-like diffuser. The diffuser breaks the water into fine droplets that float into the air. You normally see these droplets as a cool fog exiting the humidifier.

Ultrasonic - An ultrasonic humidifier uses a metal diaphragm vibrating at an ultrasonic frequency, much like the element in a high-frequency to create water droplets. An ultrasonic humidifier is usually silent, and also produces a cool fog.

Sunpentown ultrasonic cool mist humidifier

Features To Consider When Purchasing

Noise Level: This is a matter of personal choice, but everyone dislikes very noisy appliances. Be very clear about one thing, all appliances of this kind have some degree of noise attached to them. TheSlant Fin warm mist model humidifiers are basically the quietest around.

Automatic Shut Off: The Bemis models all have an auto shut off feature that will shut the unit off when the water is empty or humidity level has been reached.

Built In Humidistat: This allows you to set the actual % you want your humidity set at.

Room vs. Whole House Humidifier: Most smaller models are only meant to humidify a single room. If you have a larger area, or need to take care of an entire house, you will want to go with one of our Bemis whole house humidifiers.

Germ Free Protection: Slant Fin humidifiers offer ultraviolet light and radiation protection to remove harmful bacteria that can be distributed in the air during use.

General Humidifier Information You Need To Know

  • Steam vaporizers can be dangerous around children because they can cause burns. They also have the highest energy costs. However, there are no bacterial or mineral concerns with this technology.
  • The quality of water used in the humidifier will have a large impact on the pollutants spouted into the air. Distilled water is ideal, but whatever you use, remember that any pollutants in the water softener (dissolved minerals and metals) will end up in the air. This is why it is important to clean the tank regularly and refill it with clean water when you haven't been running it. Many high-end ultrasonic units therefore have antibacterial features built in. Some units use ultraviolet light to kill bacteria. Cool mist and ultrasonic units have the capability of releasing most of the pollutants found in the water into the air. Many ultrasonic models feature a demineralization cartridge that filters minerals out of the water to prevent the dust. Steam and warm mist units release far less of the biological pollutants, dissolved minerals and metals but they are still capable of releasing chemical contaminants such as chlorine or volatile chemicals produced by biological contaminants living in the humidifier water.

Overall, many humidifiers have incorporated safety features to help kill harmful bacteria that may be spread into the air such as the ultraviolet Slant Fin humidifiers that use ultraviolet light to kill bacteria. Also, keep in mind that you should not let water stagnate in them if they are not in use, and your humidifier should be cleaned regularly as well to maintain optimal working efficiency.