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It is evening, near freezing, and fog blankets the Pittsburgh railroad station. A young industrial engineer walks the platform, his brain roiling with a problem that has obsessed him for months. He has gone to sleep with it, awakened to it and brooded over it while commuting to and from work. Now, while waiting at the station, he paces and paces … and then it strikes — the Archimedean lightning bolt of inspiration. The answer is literally all around him! It is the fog itself!

The solitary thinker’s name: Willis Haviland Carrier. Few other inventors have had such an impact on American life and yet remained so little known. For on that foggy night in 1902, Carrier hit upon the theory that became the basis for modern air-conditioning technology — and air conditioning, in a sense, has become the sine qua non of modern American life. The huge postwar population shift from the Northeast and Midwest to the Sunbelt would scarcely have been possible without air conditioning, and scores of technologies from computers to pharmaceuticals could not exist without it. Yet for most of us, the simple ability to cool our homes amid the summer’s heat is more than enough reason to be grateful for Carrier’s fogbound moment of genius.

Who Was Willis Haviland Carrier?

Carrier, who grew up on a farm near Angola, New York, graduated from Cornell University as a mechanical engineer in June 1901. A month later, he began work for the Buffalo Forge Company, a firm that produced heating and exhaust systems.

The summer of 1901 was torrid. Sackett-Wilhelms Lithographing and Publishing of Brooklyn became exasperated by how the weather impeded operations — ink dried poorly, colors ran, and paper swelled — and early the following year its executives approached Buffalo Forge, asking if some way could be found to regulate the moisture in the air as well as the temperature. The firm turned to the 25-year-old Carrier, whose research on heating coils had already lopped $40,000 off his employer’s winter heating bill.

For centuries, methods for cooling air had occupied thinkers who ruminated upon the irony that man, who had so early learned to turn cold into warmth, had been so frustrated in doing the opposite.

“Heat we have in readiness in respect to fire,” wrote Francis Bacon at the beginning of the 17th century, “but for cold we must stay till it cometh or seek it in deep caves and when all is done we cannot obtain it in a great degree.”

In 1851, two breakthroughs in cooling were achieved: Ferdinand Carré of France designed the first ammonia-absorption refrigerating machine; and in the United States, Dr. John Gorrie patented an ice-making device. Henceforth, the challenge would lay not in lowering temperature but in achieving the second element of the equation: controlling humidity.


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Carrier’s partial solution to Sackett-Wilhelm’s problem involved circulating cold water through coils originally designed for heating and then balancing their temperature with the rate of air flow. It worked, and Carrier had every reason to be satisfied. But, while he had fulfilled most requirements for a modern central air-conditioning system, the problem of “dew point control” remained. It was the solution to this dilemma that came in the Pittsburgh railroad station.

Carrier’s brainstorm was the recognition of a paradox: Air could be dried by being saturated with water. He explained it this way: fog “is air approximately 100 percent saturated with moisture. The temperature is low, so even though it is saturated, there is not much actual moisture. There could not be at so low a temperature. Now, if I can saturate air and control its temperature at saturation, I can get air with any amount of moisture I want in it. I can do it, too, by drawing the air through a fine spray of water to create actual fog.”

In effect, the water spray provides a condensing surface for the hot, soggy air passing through it. The moisture condenses on the droplets and drops out, leaving cooler, drier air behind. The patent for Carrier’s “Apparatus for Treating Air” was granted in the dead of winter, on Jan. 2, 1906.*


Although Buffalo Forge executives promoted Carrier to head their engineering department, they apparently failed to appreciate the gold mine they had just been deeded. When war clouds gathered in 1914, the nervous firm dropped its air conditioning subsidiary. Joined by his friend Irvine Lyle, who was to promotion what Carrier was to technology, the inventor formed his own corporation.

During its first year, the Carrier Corporation received forty contracts for air conditioning systems, and by 1929 it had three factories. The Twenties were years of splendid attention-grabbing achievements. Carrier air-conditioned Detroit’s J. L. Hudson department store in 1924, and in 1928 and ’29 he cooled the U.S. House and Senate chambers. But his biggest opportunity to make a public impact with this new technology came in 1925, when he was approached by the Rivoli Theater in New York City.

In those days, as Carrier later explained, “movies closed during hot weather or showed to such small audiences that they operated at a loss. Even on cool days the inside of the theater was hot if there were many people in the audience. The heat from the people was enormous.” A few other theaters had already installed centrifugal refrigeration, but the Rivoli was Broadway. Success there would lead to recognition and financial rewards.

Carrier personally supervised the installation of the Rivoli’s 133-ton machine and stayed up all night before the scheduled Memorial Day debut. The system was late in starting, and the theater was still hot when the crowd filed in. Among the viewers was the head of Paramount Pictures, Adolph Zukor.

“From the wings we watched in dismay as two thousand fans fluttered,” Carrier recalled. “We felt that Mr. Zukor was watching the people instead of the picture — and saw all those waving fans!”

But the temperature gradually dropped, and the patrons lowered their fans. Carrier went into the lobby to watch Zukor emerge.

“When he saw us, he did not wait for us to ask his opinion. He said tersely, ‘Yes, the people are going to like it.'”

During the next five years, a triumphant Carrier Corporation brought cooling relief to more than 300 theaters.


Although most Americans first encountered the wonders of air conditioning in movie palaces, Carrier himself had developed the new technology for industry. The cooling of offices and homes, where mere people — not valuable products — wilted, remained too expensive. Yet Carrier realized that office air conditioning would be his next logical step. He was convinced “that soon there would be a market for air conditioning tall buildings and that I had better design such a system. Edible fish were in sight, so I went fishing.” The breakthrough came in the late 1930s with Carrier’s Conduit Weathermaster System, by which skyscrapers could be air-conditioned without encroaching upon valuable office space.

The final frontier for air conditioning was in the home, but Carrier failed to capitalize on this potentially lucrative market. Home cooling was possible (Carrier had chilled a millionaire’s mansion as early as 1914), but the price in the 1930s ran at least $1,500. Carrier did test the home market, but his “atmospheric cabinet” proved too large, costly and unreliable. After losing $1.3 million pursuing this venture, he decided to concentrate on industrial and office buildings. Home air conditioning would come in the 1950s, but more consumer-oriented companies such as General Electric and Westinghouse would lead the way.

Carrier did not live to see their success. In September 1950, the holder of more than 80 air-conditioning patents suffered a heart attack that soon proved fatal.

When Carrier died, the press poured out well-deserved encomiums. But to this day, Americans everywhere honor the farm-boy-turned-engineer with even more eloquent praise: their exclamations of pleasure when, escaping the heat, they stand in front of the air conditioner and punch the button marked “Cool.”

* The term “air conditioning” was coined not by Carrier but by Stuart Cramer, another engineer working on the problem of controlling the amount of humidity in the air, in this case in textile mills.

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