World's First Air Conditioner: The Invention That Changed the World

What was the invention?

It’s thought that the first cooling of buildings was engineered by the Romans, who ran aqueducts through the houses of the upper class to cool them.

In Cairo, during the middle ages, many homes used ventilators to move air through houses. Then, during the 19th century, there were several advances in cooling through evaporation. But it wasn’t until 1902 that all of these concepts were put together.

This 1902 schematic drawing shows the likely air-conditioning system installed at Sackett & Wilhelms, a Brooklyn, New York, printing company desperate to find a solution to the humidity problems plaguing its printing processes.

In 1902, with human comfort the last thing on his mind, Willis Haviland Carrier, a talented young mechanical engineer, was working for the Buffalo Forge heating company after graduating from Cornell University.

Working on 10 dollars a week, he completed the schematic drawings for what will be the first successful air-conditioning system. This new design was different — so novel, in fact, that it would not only help to solve a problem that had long plagued printers, but would one day launch a company and create an entire industry essential to global productivity and personal comfort.

The 1902 installation marked the birth of air conditioning because of the addition of humidity control, which led to the recognition by authorities in the field that air conditioning must perform four basic functions:

• Control temperature
• Control humidity
• Control air circulation and ventilation
• Cleanse the air

After several more years of refinement and field-testing, on January 2, 1906, Carrier was granted U.S. Patent 808,897 for an Apparatus for Treating Air, the world's first spray-type air conditioning equipment. It was designed to humidify or dehumidify air, heating water for the first function and cooling it for the second.

Why was Carrier assigned this task?

In this artist's conceptualization, Willis Carrier starts the engine that will drive the world's first modern air-conditioning system, installed in the summer of 1902 at the Sackett & Wilhelms printing plant in Brooklyn, New York. This illustration appeared in the August 1954 edition of Steelways magazine which noted, thanks to Carrier, that "air conditioning spread through the industry like a cool breeze."

The problem began with paper. In the spring of 1902, consulting engineer Walter Timmis visited the Manhattan office of J. Irvine Lyle, the head of Buffalo Forge's sales activities in New York. Timmis' client, Sackett & Wilhelms, found that humidity at its Brooklyn plant wreaked havoc with the color register of its fine, multicolor printing.

Ink, applied one color at a time, would misalign with the expansion and contraction of the paper stock. This caused poor quality, scrap waste and lost production days, Timmis said. Judge magazine happened to be one of the important clients whose production schedule was at risk. Timmis had some ideas about how to approach the problem but would need help.

One of Lyle's great skills was his ability to assess new business opportunities, and he grasped this one immediately. He knew that engineers had long been able to heat, cool and humidify air. Sometimes, as a result of cooling, they had also been able to reduce humidity. But precise control of humidity in a manufacturing environment—that was something entirely new.

Lyle also had an innate ability for sizing up people. In this case, he believed he knew the engineer who could tackle this problem, a recent Cornell University graduate who had already impressed many people at Buffalo Forge. So, Lyle accepted Timmis' challenge and sent the problem to Willis Carrier, the first step in a long and prosperous collaboration.

Carrier was passionate about solving engineering problems, so much so that he would forget everything else when he would be consumed by one. He once packed his suitcase for an outstation trip, only to discover later that he had merely put his handkerchief in it. This was a challenge he wasn’t going to back down from. Energized by the puzzle, Carrier immediately grasped the issues and began his investigation by means of rigorous testing and intensive data gathering, hallmarks of his long career.

His first test was recommended by Timmis and involved a roller towel with loosely woven burlap saturated with a solution of calcium chloride brine. While the apparatus removed humidity, it added heat, salt and odor to the air, none being acceptable in the printing process.

When did Carrier figure out what to do?

The lightbulb moment

• Sometimes, the greatest ideas happen at the most random moments. For Willis Carrier, that “lightbulb” moment occurred on a foggy train platform in Pittsburgh in 1902. On that day, he was looking through the mist and figured out that he could dry the air simply by having it go through water to create fog. This would make it possible to create air that contained a specific amount of moisture. Later that year, he would finish his creation that controlled humidity. This was the moment that modern air conditioning was born.

• Carrier then tried his own experiment, replacing steam with cold water flowing through heating coils, balancing the temperature of the coil surface with the rate of airflow to pull the air temperature down to the desired dew point temperature. Even as he worked, Carrier knew that every part of the process — from metal coils prone to rust, to inexact Weather Bureau tables — could be improved. Nonetheless, he and his team moved steadily forward, completing drawings and sending them to Lyle to be implemented.

• The first set of coils was installed at the Sackett & Wilhelms plant late in the summer of 1902 along with fans, ducts, heaters, perforated steam pipes for humidification, and temperature controls. Cooling water was drawn from an artesian well that first summer and supplemented by an ammonia compressor in the spring of 1903 to meet the demands of the first full summer of operation. This system of chilled coils was designed to maintain a constant humidity of 55 percent year-round and have the equivalent cooling effect of melting 108,000 pounds of ice per day.

Lyle's bet paid off. On October 21, 1903, he reported in a letter to his home office that, "The cooling coils which we sold this company have given excellent results during the past summer." This confirmed his faith in both the opportunity, and in the exceptional talent of the young engineer who had directed the project. Willis Carrier had demonstrated the intellect, creativity and vision to assemble everything that had gone on before him, improve upon it, and create something entirely new.

Where did Carrier contribute to the future of AC?

As Carrier had predicted, air conditioning soon became more important for the comfort it provided than for the industrial processes that it made possible. Air conditioning began to appear in theaters and concert halls and in the skyscrapers that were beginning to appear in New York City and Chicago.

• In 1911 Carrier was invited to give a lecture to the American Society of Mechanical Engineers, a high honor for someone so young. His invitation to the meeting recognized air conditioning as a formal branch of engineering and turned 35-year-old Carrier into an internationally recognized leader in the field.

• Carrier's lecture, published with the unpromising title of "Rational Psychrometric Formulae," became the basis upon which the air conditioning industry was founded.

• Carrier's psychometric formulas describe the different combinations of temperature and humidity that are possible for air at a given pressure, and are still in use today. It became known as the "Magna Carta of Psychrometrics."

• Using the formulae, an engineer can design an efficient air conditioner that is capable of converting air at one temperature and humidity into air at a second, presumably lower, temperature and humidity.

Note: Psychrometrics is used to describe the field of engineering concerned with the determination of physical and thermodynamic properties of gas-vapor mixtures.

Who did Carrier partner with?

With the onset of World War I in late 1914, the Buffalo Forge Company, where Carrier had been employed for 12 years, decided to confine its activities entirely to manufacturing. It was then that Carrier, Lyle (his boss) and five fellow engineers pooled together their life savings of $32,600 to form the Carrier Engineering Corporation in New York on June 26, 1915.

Despite the development of the centrifugal refrigeration machine and the commercial growth of air conditioning to cool buildings in the 1920s, the company ran into financial difficulties, as did many others, as a result of the Wall Street Crash in October 1929.

In 1930, Carrier Engineering Corp. merged with Brunswick-Kroeschell Company and York Heating & Ventilating Corporation to form the Carrier Corporation, with Willis Carrier named Chairman of the Board.

The Great Depression slowed residential and commercial use of air conditioning. Willis Carrier's ‘igloo’ in the 1939 New York World's Fair gave visitors a glimpse into the future of air conditioning, but before it became popular, World War II began. During the post-war economic boom of the 1950s, air conditioning began its tremendous growth in popularity.

Carrier passed away on October 7, 1950 without seeing the boom period of personal air-conditioning. Carrier Corporation was acquired by United Technologies in 1979. Today, it is a $13 billion company with over 43,000 employees serving customers in 170 countries on six continents.

How was incremental value added to AC after 1902?

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).

1939: Packard invents the coolest ride in town: the first air-conditioned car. Dashboard controls for the a/c, however, come later. Should Packard's passengers get chilly, the driver must stop the engine, pop open the hood, and disconnect a compressor belt.

1950s: In the post-World War II economic boom, residential air conditioning becomes indispensable.

1970s: Window units lose popularity as central air comes along.

As time passed, concepts such as energy efficiency and green technology became important. But air-conditioning ranks right at the top with the Steam Engine as one of the inventions that changed the world for good.