Science and technology of the 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" (唐語林) 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.
Walter P. Chrysler Jr.
In 1934, Chrysler founded the Airtemp division of Chrysler Corporation, which developed the first automotive air-conditioning system. After establishing worldwide distribution, he transferred the patent to the parent company but remained a director. In the following year he became president of the Chrysler Building; he continued in that position until 1953.