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.
David Boswell Reid
Prof David Boswell Reid MD FRSE FRCPE (1805 – 5 April 1863) was a British physician, chemist and inventor. Through reports on public hygiene and ventilation projects in public buildings, he made a reputation in the field of sanitation. He has been called the "grandfather of air-conditioning".