Air cooler: An air cooler is any device for cooling the air inside a building, room, or vehicle. Air coolers are used in thermally insulated casings to form refrigerators and are also used in buildings to cool rooms. In buildings they are only required when the building itself is not constructed so that it is able to dissipate enough heat. The cooling of air can be done by 3 devices: air-conditioning, evaporative cooling and fans.