A dehumidifier is basically a household appliance which effectively reduces the level of humidity in the air, promoting health and fitness. Dehumidifiers are also used in industrial climatic chambers to control relative humidity within certain rooms to stay at levels for better processing of products. Dehumidifiers help prevent excessive sweating and also an outburst of moths, fleas, cockroaches, woodlice and dust. Air conditioners also act as dehumidifiers when they chill the air. Amongst the most common type of dehumidifiers include mechanical and refrigerative dehumidifiers.