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.)
It was an engineering victory over one of the human race's oldest and most tenacious nemeses: extreme heat. Efforts to stay cool probably date to mankind's first consciousness of the sweat bead.
Ancient Chinese, Persians, and Romans all are credited with developing cooling devices. In Rome, aqueduct water was piped through the walls to cool some homes.
Modern systems are basically refrigerators that chill rooms instead of milk and butter, and the United States would become the undisputed capital of artificial cooling in the 20th century. In 1902, a cooling system was installed in the New York Stock Exchange, and four years later, Boston Floating Hospital became the nation's first air-conditioned hospital.
The following year, Willis Carrier was granted a patent for a mechanism that controlled both indoor temperature and humidity, or "dew point." It was a sensation in humidity-sensitive factories, including those in which chocolate and chewing gum were made, according to Gail Cooper, a Lehigh University professor and author of Air-Conditioning America.
While Carrier's companies helped popularize the technology, it was another engineer, Stuart Gardner, who came up with the term air conditioner.
It may be hard to imagine today, but Cooper points out that the concept of a man-made climate in a sealed environment was almost unimaginable in the early 20th century.
Movie theaters created a giant new market during World War I and the 1920s, and by the '30s Frigidaire was selling room and central-air units for houses.
But the home-cooling concept was slow to catch fire, and World War II interrupted production. In 1947, according to the air-conditioning society, a mere 42,900 window units were sold. In 1953, that number jumped to 1,075,000.
Now, the hot new market for cooling power is the computer, said Alfonso Ortega, engineering professor at Villanova University, and the ever-growing numbers of data centers, such as the Philadelphia Technology Park at the Navy Yard site, that power them.
Ortega said that with the demand for more and more computing power, the industry is turning to those centers for security and protection against outages.
In a typical office, Ortega said, "if the ventilating system fails, we say, 'Sorry, we have to send everybody home.' You can't stop a data center. Bank transactions cannot experience failure.
"Stop and think about our dependence on the Internet," he said. "Most people take it for granted."
The United States has at least 850 data centers, including 12 in the Philadelphia region, according to Data Center Map, a Danish company.
The Environmental Protection Agency says that by next year, data centers alone may require the building of 10 new power plants.
Despite the widespread and intense heat, evidently, the major power companies have avoided meltdowns so far this summer. It wasn't for nature's lack of trying.
PJM Interconnect, the 13-state power consortium that includes Pennsylvania, New Jersey, and Delaware, set an all-time high for power use during the June-July period.
With air conditioners on full hum this week, PJM expects a new high for the meteorological summer, June through August.
Said spokeswoman Paula Dupont-Kidd: "It's certainly looking like record numbers for energy consumption."
Contact staff writer Anthony R. Wood at 610-313-8210 or email@example.com.