Willis Carrier
Willis Haviland Carrier (November 26, 1876 – October 7, 1950) was an American engineer, best known for inventing modern air conditioning. Carrier invented the first electrical air conditioning unit in 1902. In 1915, he founded Carrier Corporation, a company specializing in the manufacture and distribution of heating, ventilation, and air conditioning (HVAC) systems.
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.