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.
Paul Elbridge Wright
Wright was responsible for the development of the first thermoelectric air conditioner with a coefficient of performance of greater than two. He was responsible for the first fossil-fuel, silicon germanium thermoelectric generator. Under Wright's direction, a magnesium-mercuric oxide battery was developed which exhibited an energy density of watt-hours per pound. During this time, Wright was also instrumental in developing technology for weather and other satellites. Some inventions at ATL were less successful, such as the video disc player and the bulls-eye UPC scanner.