An ultrasonic humidifier uses ultrasonic vibrations to convert water into mist. Inside the device is a small, vibrating metal or ceramic plate that oscillates at a very high frequency. These ultrasonic vibrations are so fast that they atomize the water in the tank of the humidifier into tiny droplets. These microscopic water droplets are then released into the air as a fine mist. The mist increases the humidity in the room without noticeably changing the temperature.
In an evaporative humidifier, also known as a steam humidifier, water is brought to the boil, creating steam. This process uses a heating unit inside the appliance to heat the water in the reservoir. As soon as the water boils, it evaporates and the resulting steam is released into the room.
This steam mixes with the dry room air and thus increases the humidity. As the steam is hot when it is produced, this type of humidifier also has the side effect of slightly warming the air, which can be particularly pleasant in colder months.
Vaporizers are efficient and hygienic, as boiling the water kills most bacteria and microorganisms before the steam is released into the room air. However, they can consume more energy than other humidifiers as they need to heat water to boiling point.
In an atomizing humidifier, often referred to as a nebulizer, the water is forced through a nozzle that atomizes it into fine droplets. This type of humidifier uses a pump to feed water at high pressure through one or more fine nozzles. As the water exits through the nozzles, it is broken down into a fine mist. This fine mist can then be released into the room air, where it evaporates and thus increases the humidity.
In contrast to humidifiers that work with ultrasound, atomizer technology is based on mechanical pressure. They are particularly effective in producing a very fine mist and can therefore also be used in larger rooms or even in industrial environments to regulate humidity.