Who invented the air conditioner and when?

The air conditioner was invented by Willis Haviland Carrier in 1902. Carrier, an American engineer, designed the first air conditioning system to control the temperature and humidity in a printing plant in Brooklyn, New York. His system used refrigeration to cool air and regulate the moisture, which improved the quality of printing. Carrier’s invention revolutionized the way businesses and homes managed indoor climates, and it later expanded into the residential market, becoming essential for comfort in hot climates and contributing to the development of modern architecture.