A dehumidifier is a device that reduces the level of humidity in the air by removing excess moisture. It is often used in homes, offices, and other indoor spaces to improve air quality and reduce the risk of mold and other types of moisture-related damage. Dehumidifiers work by drawing in air from the surrounding environment, passing it over a cooled coil, and collecting the condensed water in a reservoir. The cooled, dehumidified air is then returned to the room. Dehumidifiers are available in various sizes and models, and they can be used to dehumidify a single room or an entire house.