Air conditioning
In 1902, the first modern electrical air conditioning unit was invented by Willis Carrier in Buffalo, New York. After graduating from Cornell University, Carrier found a job at the Buffalo Forge Company. There, he began experimenting with air conditioning as a way to solve an application problem for the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, New York. The first air conditioner, designed and built in Buffalo by Carrier, began working on 17 July 1902.
Franz San Galli
San Galli's claim as "the" inventor of the heating radiator is disputed. It appears that he is one of several people who contributed to the development of the heating innovation. San Galli received a radiator patent in 1857, while American Joseph Nason developed a primitive radiator in 1841 and received a number of U.S. patents for hot water and steam heating. Nason's patent for tapered pipe threads in particular is cited by 1930s writer Ara Marcus Daniels as the key development in the birth of the radiator.