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.
Dave Lennox
David Lennox (April 15, 1855 – February 15, 1947) was an American inventor and businessman. A furnace manufacturing business he founded in 1895 in Marshalltown, Iowa evolved into what is today known as Lennox International, a global corporation specializing in air conditioning, heating, and commercial refrigeration. Lennox helped to develop what has been described as the first riveted-steel furnace in 1895. His contributions to furnace design have been described as significant steps forward in durability and efficiency from the cast iron furnaces commonly in use near the end of the 19th century.