Air Conditioning is the process of controlling the humidity and cooling the air inside a building.
Air conditioning units often use a fan to draw in air and, after it has been conditioned, distribute it back into the occupied parts of a building. Air conditioning and refrigeration are provided through the removal of heat. Heat can be removed through radiation, convection, or conduction. Refrigeration conduction mediums such as water, air, and ice are referred to as refrigerants. A refrigerant is employed either in a heat pump system in which a compressor is used, or in a free cooling system which uses pumps to circulate a cool refrigerant.