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.
Rider-Ericsson Engine Company
In his patent of 1759, Henry Wood was the first to document the powering an engine by the changing volume of air as it changed temperature. George Cayley was the first to build a working model in 1807. The Reverend Robert Stirling is generally credited with the "invention" of the hot air engine in 1816 for his development of a "regenerator" which conserves heat energy as the air moves between the hot and cold sides of the engine. Technically, not all hot air engines utilize regenerators, but the term hot air engine and Stirling engine are sometimes used interchangeably.