How Do Dehumidifiers Work?

Fan to Draw In Air

The first step to dehumidifying air is through the fan. The fan on a dehumidifier draws warm air from the room in. The constant pulling of warm air into the dehumidifier allows for the moisture in the room to be collected efficiently. The warm air then passes over the cold coil.

Cold Coil

The cold coil is essentially the same concept as an air conditioner to cool the air. The ability for air to hold moisture is lost when the air is cooled. When the warm air touches the cold coils, the water in the air condenses and forms on the coils. The water then falls into a collection bucket. This is the same concept when you leave a glass of ice water outside on a hot humid day. The cold glass collects the moisture from the warm air onto the glass surface.

Hot Coil

Finally, the cooled air runs across the hot coils, bringing the air back to room temperature. This is the differentiating aspect between an air conditioner and dehumidifier. A dehumidifier is not meant to change the temperature of the air in the room, only to remove the moisture. An air conditioner will dehumidify a room when operating, thus a dehumidifier is not needed when an air conditioner is present.