Central air conditioning is a method of structural cooling in which a centralized unit cools and dehumidifies air before circulating it throughout a building. This is in direct contrast with systems that rely on individual units in rooms or suites of rooms. Central air, as it is also known, is often bundled with a heating system, as both rely on similar amounts of electrical power and ductwork to distribute cooled or heated air. This type of air conditioning is generally seen in large structures, or in homes in extremely hot, humid climates.