Once a luxury, air-conditioning these days has a cooling hand in almost everything from hospital operating rooms to chocolate factories, to Internet movies, to the office windows you can't open, to the baseball updates posted on all those handheld mobile devices.
Air-conditioning is life support for computer systems that make so many applications possible. These days, computers use as much power to cool themselves as they do to operate, said Jim Weller, an executive involved in the new Philadelphia Technology Park in South Philadelphia.
While cooling technology has advanced and units are becoming more efficient, fully 20 percent of all U.S. power is consumed by air-conditioning, Gordon Holness, retired president of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, said last week.
"It puts major stress on our utility grid," he added, and air-conditioning is even a suspect in global warming. Regardless, in essence America has developed an air-conditioning dependency, Holness said.
The hum of cooling machines has become as much a part of summer as the sounds of cicadas, crickets, and katydids, a proliferation that represents a remarkable evolution.
In 1960, an era of rotating bedroom fans and screen-defying mosquitoes, 14 percent of U.S. housing units had air-conditioning of any kind; only 2 percent had central, according to the Census Bureau. By last year, air-conditioning was in 84 percent of all the nation's homes; in the Philadelphia region, more than 90 percent.
The National Academy of Engineering ranked cooling technology in the top 10 of 20th-century inventions, ahead of spacecraft, highways, lasers, and the Internet. (Electricity topped the list; the automobile was second.)
