Year of Invention: 1902
What Is It? A machine that cools and dehumidifies (removes moisture from)
the air in a room or building.
Who Invented It? Willis Carrier (in Buffalo, New York)
Air conditioning has revolutionized industrial plant design and operation, commercial building design (especially skyscraper design), and residential building design. Affordable residential air conditioning made possible the population explosion in Florida and across the American Southwest beginning in the 1950s. Automobiles, restaurants, airplanes, houses, schools, and every other facet of our lives are now designed around air conditioning. We live, work, play, eat, and sleep in air-conditioned spaces.
People used to design buildings to take advantage of prevailing breezes or to create their own air currents and circulation. They built thick exterior walls to help block out the heat.
Ancient Romans knew that water vapor cooled a person. The rich sprayed fine mists to keep themselves comfortable. They also built underground cellars that stayed far cooler than the scorching surface. Greeks brought ice down from the mountains in winter and stacked it in underground rooms that were insulated with a thick padding of straw. The rooms stayed comfortably cool through most of the summer.
Born and raised in upstate New York, Willis Carrier trained as a mechanical engineer. Carrier was 26 years old and working for the Buffalo Forge Company when, in 1902, John Sackett-Williams, a Brooklyn print shop owner, came to him with a problem. Sackett-Williams’s color printing (a new process for printers) wasn’t working. Each page had to pass through a printing press four times for a color print. However, changes in shop temperature—and especially in humidity—made his paper expand or contract between runs. As a