Washing machine: hamilton smith, inventor of washing machine. 1858, hamilton smith made the world's first washing machine in Pittsburgh, USA.
Air conditioning: The first air conditioning system was designed and installed by American inventor Willis haviland Kelly 1902. The air conditioning system was designed for a printer in new york, USA. He found that the change of temperature would cause the deformation of paper, which would lead to the imbalance of color ink. Carrier registered the patent 1906.