An evaporative humidifier is a device designed to increase the moisture content in a room or building. It achieves this by drawing dry air across a wetted filter, pad, or belt. As the air passes, water evaporates into the airstream, raising the relative humidity. The process is self-regulating; drier air allows for more evaporation, while already humid air inhibits further moisture absorption. A typical unit consists of a water reservoir, a wick or filter to draw water upwards, and a fan to circulate air through the moistened material.
Maintaining adequate humidity levels offers several advantages, including mitigating dry skin, reducing static electricity, and preventing damage to wooden furniture and musical instruments. Historically, methods of humidification ranged from simple pots of water placed near heat sources to more sophisticated mechanical systems. Evaporative models represent a relatively energy-efficient and affordable solution compared to other humidification technologies, as they generally consume less power than steam-based alternatives and do not produce potentially irritating white dust associated with ultrasonic units.
