Tang dynasty
The inventor Ding Huan (fl. 180 AD) of the Han dynasty invented a rotary fan for air conditioning, with seven wheels 3 m (10 ft) in diameter and manually powered. In 747, Emperor Xuanzong had a "Cool Hall" built in the imperial palace, which the "Tang Yulin" () describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains. During the subsequent Song dynasty, written sources mentioned the air conditioning rotary fan as even more widely used.
Nash Motors
Using its Kelvinator refrigeration experience, the automobile industry's first single-unit heating and air conditioning system was introduced by Nash in 1954. This was a compact, affordable system for the mass market with controls on the dash and an electric clutch. Entirely incorporated within the engine bay, the combined heating and cooling system had cold air for passengers enter through dash-mounted vents. Competing systems used a separate heating system and an engine-mounted compressor with an Evaporator in the car's trunk to deliver cold air through the rear package shelf and overhead vents. The alternative layout pioneered by Nash "became established practice and continues to form the basis of the modern and more sophisticated automatic climate control systems."