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.
Carrier Corporation
Willis Carrier is credited with inventing modern air conditioning in 1902. In 1915, Carrier and six other engineers pooled $32,600 to form the Carrier Engineering Corporation. They purchased their first factory in 1920, in Newark, New Jersey.