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.
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.