Timeline of United States inventions (1890–1945)
Air conditioning is the cooling and de-humidification of indoor air for thermal comfort. Using a system of coils as a solution to cool and remove moisture from muggy air in a printing plant that was wrinkling magazine pages, Willis Carrier invented and manufactured the world's first mechanical air conditioning unit in 1902. Carrier's invention – encompassing the first system to provide man-made control over temperature, humidity, ventilation and air quality, was first installed as a solution to the quality problems experienced at a Brooklyn printing plant, Sackett-Wilhelms Lithographing and Publishing Company. Air conditioning not only spawned a company and an industry, but also brought about profound economic, social and cultural changes.
Warren S. Johnson
Warren Seymour Johnson (November 6, 1847 – December 5, 1911) was an American college professor who was frustrated by his inability to regulate individual classroom temperatures. His multi-zone pneumatic control system solved the problem. Johnson’s system for temperature regulation was adopted worldwide for office buildings, schools, hospitals, and hotels – essentially any large building with multiple rooms that required temperature regulation. To manufacture and market his system, Johnson established the Johnson Electric Service Company which eventually became Johnson Controls.