Dehumidifiers have only a few components, and operate on the same principle as a refrigerator, freezer, or air-conditioner.
Residential dehumidifiers have a cooling system made up of these primary components:
- The compressor is the quiet motor (engine) of the cooling system. It's the black, football-size component at the bottom of your dehumidifier. The compressor runs as long as the dehumidifier humidistat (the humidity-sensor) calls for a reduction in the humidity.
- The condenser is a series of finned tubes, similar to a radiator. It's usually near the circulating fan.
- The evaporator is located near the back of the dehumidifier, right above the water-collection container. It also resembles a radiator or a coiled-up set of tubes. When the dehumidifier's humidistat senses increased humidity, it cycles on, which starts the compressor and circulating fan.
- The circulating fan circulates the air over the evaporator and condenser coils.
When the unit runs, the circulating fan and compressor also run. The fan continually draws room air over the evaporator coils, which are cold, and then over the condenser coils, which are warm. Because the evaporator coils are cold, the moisture in the room collects on them--just as the outside of a glass of icy liquid "sweats" on a warm, humid day. When the moisture on the coils increases, it drips off of the coils into the collection container.
The air then flows over the warm condenser coils and out into the room. This process removes water from the air and, because of the heat from the fan motor and compressor motor, the exiting air is somewhat warmer, as well as dryer.