Editing Humidifier (section)

===Impeller humidifiers ===
[[Impeller]] humidifiers (a type of cool mist humidifier) are usually noisier than others.  It uses a rotating disc to fling water at a diffuser, which breaks the water into fine droplets that float into the air. The water supply must be kept scrupulously clean, or there is a risk of spreading bacteria or mold into the air.