Air conditioning
Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by US inventor Willis Carrier. The introduction of residential air conditioning in the 1920s helped enable the great migration to the Sun Belt in the United States.
Ding Huan
Ding Huan (丁緩) was a Chinese engineer, inventor, and craftsman who lived in the first century BC during the Han dynasty. Among the inventions attributed to him is an air conditioning system based on evaporative cooling.