1820 Inventor Michael Faraday makes the same discovery in England when he compresses and liquifies ammonia.
1830s At the Florida hospital where he works, Dr. John Gorrie builds an ice-making machine that uses compression to make buckets of ice and then blows air over them. He patents the idea in 1851, imagining his invention cooling buildings all over the world. But without any financial backing, his dream melts away.
1881 After on July 2, naval engineers build a boxy makeshift cooling unit to keep him cool and comfortable. The device is filled with water-soaked cloth and a fan blows hot air overhead and keeps cool air closer to the ground. The good news: This device can lower room temperature by up to 20 F. The bad news: It uses a half-million pounds of ice in two months… and President Garfield still dies.
1902 Willis Carrier invents the Apparatus for Treating Air for the Sackett-Wilhelms Lithographing and Publishing Co. in Brooklyn, N.Y. The machine blows air over cold coils to control room temperature and humidity, keeping paper from wrinkling and ink aligned. Finding that other factories want to get in on the cooling action, Carrier establishes the Carrier Air Conditioning Company of America.
1906 Stuart Cramer, a textile mill engineer in North Carolina, creates a ventilating device that adds water vapor to the air of textile plants. The humidity makes yarn easier to spin and less likely to break. He's the first to call this process "air conditioning."
1914 Air conditioning comes home for the first time. The unit in the Minneapolis mansion of Charles Gates is approximately 7 feet high, 6 feet wide, 20 feet long and possibly never used because no one ever lived in the house.
1931 H.H. Schultz and J.Q. Sherman invent an individual room air conditioner that sits on a window ledge—a design that's been ubiquitous in apartment buildings ever since. The units are available for purchase a year later and are only enjoyed by the people least likely to work up a sweat—the wealthy. (The large cooling systems cost between $10,000 and $50,000. That's equivalent to $120,000 to $600,000 today.)
1939 Packard invents the coolest ride in town: the first air-conditioned car. Dashboard controls for the a/c, however, come later. Should the Packard's passengers get chilly, the driver must stop the engine, pop open the hood, and disconnect a compressor belt.
1942 The United States builds its first "summer peaking" power plant made to handle the growing electrical load of air conditioning.
1947 , "The greatest contribution to civilization in this century may well be air-conditioning—and America leads the way." Yet somehow people still say a brilliant new idea is "the best thing since sliced bread."
1950s In the post-World War II economic boom, residential air conditioning becomes just another way to keep up with the Joneses. More than 1 million units are sold in 1953 alone.
1970s Window units lose cool points as central air comes along. The units consist of a condenser, coils, and a fan. Air gets drawn, passed over coils, and blasted through a home's ventilation system. R-12, commonly known as Freon-12, is used as the refrigerant.
1994 Freon is linked to ozone depletion and banned in several countries. Auto manufacturers are to the less harmful refrigerant R134a by 1996. Brands like Honeywell and Carrier develop coolants that are more environmentally friendly.
2003 In "," Andre 3000 raps, "What's cooler than being cool? Ice cold!" They aren't talking about air conditioning.