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.
Samuel Cleland Davidson
Sir Samuel Cleland Davidson, KBE (18 November 1846 – 18 August 1921) was an Irish inventor and engineer. Through his career in the tea import business he invented and patented a number of industrial machines and developed the earliest air conditioning systems. He founded the Sirocco Works in Belfast in 1881.