It's hot. Too hot to ride your bike or play outside. So hot it
makes you tired. What do you do? Go in your house, go to the mall,
or go to a movie where it's nice and cool - thanks to air
Air conditioning celebrated its 100th birthday last month. On
July 17, 1902, Willis Haviland Carrier installed the first air
conditioner at a printing plant in Brooklyn, N.Y. It wasn't to help
the workers at the factory, though. It was to keep the paper cool
and dry so it wouldn't curl in the midsummer heat and humidity. That
way, the printing presses could apply the ink evenly.
Mr. Carrier started a revolution. Air conditioning allowed cities
to develop in deserts. It changed the design of houses and
skyscrapers. It's what allows us to go to work - or to school - year-
How did people keep cool before AC?
Ancient Egyptians were probably the first to discover that hot,
dry breezes became moist and cool as they blew through dampened mats
or past porous clay pots full of water. Ancient Greeks, Romans, and
people living in India also used this principle to cool their
Roman emperors, meanwhile, commanded that snow be brought down
from the mountains to cool their summer gardens. In the eighth
century, Caliph Al-Mahdi of Baghdad (in modern-day Iraq) had slaves
fan blocks of ice to create cool breezes. He also had snow packed
into the space between the double walls of his summer house.
People in many warmer climes designed houses that promoted good
air circulation. Their homes had high ceilings, deep porches, and
large windows and doors positioned so that breezes could blow
straight through. They planted trees for shade. Fountains and pools
were also cooling. (Swimming pools didn't become popular until the
Carriage air conditioning
My favorite cooling-down invention was called the All-Weather
Eye. It was invented by William Whiteley in 1884. He put blocks of
ice in a holder under horse carriages and then attached a fan to the
axle. As the wheels turned, the fan blew air across the ice and up
into the passenger compartment.
Fans have been used for thousands of years to cool off. Slaves
fanned Egyptian pharaohs with huge lotus leaves. The pleated
(folded) fan was probably modeled after the way a bat folds its
wings. It first appeared in Japan around AD 700. Handheld fans were
ornamental as well as practical. (Have you ever made a fan by
pleating a piece of paper? You can feel a lot cooler by moving the
The first electric fan - a two-bladed desk version - was produced
commercially by the Crocker & Curtis Electric Motor Co. in 1882. The
first oscillating (waving back and forth) electric fan, which could
cool a larger area, was produced in 1908. Electric fans became
important accessories in 20th-century office buildings.
Within 20 years of Carrier's first machine being installed in
Brooklyn, movie theaters in Chicago, New York, and Los Angeles began
to install air conditioners. Remember, these were large buildings
that had to be totally dark - no sunlight or streetlights - to show
a movie. It's hard to let air in without letting in light, too.
Before air conditioning, you couldn't show movies in the summer when
it was too hot because the theaters would be stifling inside.
Department stores were quick to adopt the new cooling technology,
too. Big stores advertised, "Come on in, it's cool inside." Office
buildings were important laboratories for air-conditioning advances.
The modern glass-walled skyscraper is possible only because the
inside climate can be carefully controlled. With summer sunlight
streaming through all that glass, the temperature inside would be
An updated version of ancient Egypt's solution
In the late 1930s, the "swamp cooler" or evaporative cooler
arrived. It works on the same principle that the wet mats of ancient
Egypt did: As water evaporates, it absorbs heat. …