the American developer of the formulae and equipment that made air conditioning possible. The 'Apparatus for Treating Air' (U.S. Pat# 808897) granted in 1906, was the first of more than 80 patents awarded to Carrier. In 1911, he described his basic Rational Psychrometric Formulae, which to this day is the basis of fundamental calculations for the air conditioning industry. He and six other engineers formed the Carrier Engineering Corporation in 1915. Today it stands as the largest air conditioning corporation in the world. In 1921, Carrier patented the centrifugal refrigeration machine used to condition large spaces. In 1928 he developed the first residential 'Weathermaker', an air conditioner for private home use.