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.
Guillaume Amontons
Guillaume Amontons is also the inventor of the hot air engine. In 1699 he built his first engine, means over one century before the well-known Stirling Engine. This engine, named by Amontons "FIre Mill" was following a new thermodynamic cycle, that later became the Stirling cycle.