Willis Carrier, Air Conditioning, and His Contribution to Mechanical Engineering and HVAC Systems

Welcome to this special edition of the SoftInWay blog! While we at SoftInWay are known for helpful articles about designing various machines, retrofitting, and rotor dynamics, we believe it is also important to examine the lives of some of the men and women behind these great machines.

Commonly listed among the greatest mechanical engineering inventions of the 20th Century, the air conditioning system has gone from basic use in refrigeration to a staple of living in many countries. Locales that were previously borderline uninhabitable for people sensitive to heat or poorer air quality, became available, thanks to this device that could be installed in homes and businesses. But who invented the air conditioning system?

A portrait photograph of Willis Carrier in 1915

Willis Haviland Carrier (1876-1950) was born on November 26th, 1876 in Angola, a small town in Upstate New York just outside of Buffalo. Carrier was the inventor of modern air conditioning as we know it. While other forms of air conditioning had been around for millennia, what Carrier invented was utterly life-changing for those who were able to use it, and work/live in air-conditioned environments.  His work has been so influential on modern HVAC engineering and the world in general, that his legacy company has a website in his honor.

Carrier grew up in the greater Buffalo area, attending the Angola Academy, and later Buffalo High school, where his class’s graduation can still be found in a newspaper clipping from the Buffalo Evening News in June 1897.

It seemed from graduating high school that Carrier was destined for great things. A later clipping from the Buffalo Evening News in October of 1897 states that Carrier was awarded a scholarship to Cornell University to study engineering. By 1901, he graduated with a Master’s Degree in Engineering and got to work almost immediately at Buffalo Forge.

Early Attempts

In 1902, a Brooklyn-based company called the Sackett & Wilhelms Lithography and Printing Company was having trouble with the quality of their prints. According to Willis Carrier’s legacy website, a consulting engineer working on behalf of Sackett & Wilhelms visited Buffalo Forge’s Manhattan office in the spring of 1902 to visit J. Irvine Lyle, who was responsible for Buffalo Forge’s sales in New York. The consulting engineer stated that the humidity of New York’s climate was causing problems with Sackett & Wilhelms’ printing quality. As a result, there was excessive scrap, as well as poor print quality and lost production time. The consulting engineer, Walter Timmis, had ideas on how to address it, but wanted to gauge the interest of Buffalo Forge in taking on the job.

Buffalo Forge was a “respected supplier of forges, fans, and hot blast heaters”. Lyle knew that engineers had a way to control heat and humidity in the air, and had a specific engineer in mind for this project that Buffalo Forge would take on – Willis Carrier. Carrier had worked on several projects including “designs for a dry heating plant, a lumber dry kiln and a coffee dryer, among others” according to his legacy website.

Carrier took the challenge head on, starting with a simple apparatus that made use of burlap and calcium chloride brine. According to his legacy site, the system was effective for controlling humidity, but it added heat, an odor, and salt to the air which wasn’t going to work for this application. He had to try something new.

His next design was a game-changer. Starting with heating coils, Carrier replaced the typical stream that flowed through these coils with cold water and worked on moving air through these coils to lower the temperature, and in turn, the dew point temperature.  This movement meant the ambient air was cooler as well as the relative humidity. Carrier worked on this through the spring and summer of 1902, and by late summer, Carrier’s cooling system was installed at Sackett & Wilhelms.

The blueprints of Carrier's first air conditioning system
The blueprints of Carrier’s first air conditioning system, image courtesy of Willis Carrier’s website.

The coils were put in place as well as “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 1902 to meet the demands of the first full summer of operation.” By October 1903, Lyle reported to Buffalo Forge’s office Upstate that Carrier’s system had worked. Carrier’s website states, “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.” Through this project, Willis Carrier created the first air conditioning system. According to Gothamist, another building that used this kind of system in 1902 was the New York Stock Exchange. Instead of needing to control the humidity and temperature for production, it was done purely for worker comfort, demonstrating that air conditioning was going to become popular in a wide variety of applications.

The Next Big Step

While standing on a Pittsburgh train platform one foggy night in the fall of 1902 , Carrier realized, “if I can saturate the 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.”

Strange as it may seem, this concept was sound. By 1903, Carrier had a working prototype that brought this idea to life and made a “spray-type air conditioning system able to both wash and humidify or dehumidify the air. Modern air conditioning now had its fundamental building block.”

Going forward, Carrier worked with his team at Buffalo Forge to create air washers and other devices that would control the dew-point, which according to Carrier and company, were “the greatest single factor in modern air conditioning”. Brochures from Buffalo Forge were said to be “prophetic”, as Carrier foresaw the air conditioning systems becoming commonplace in public areas like theaters, churches, restaurants, and other common areas where people would gather, and want to be comfortable.

In 1907, the Buffalo Forge won international business and sold an air conditioning system to the Fuji Silk Spinning Company based in Yokohama Japan. I was their first step in conducting business globally, and far from the east coast of the United States.  Buffalo Forge’s management created a subsidiary company, the Carrier Air Conditioning Company of America. It wasn’t long until the new Carrier company was winning new business and taking on new challenges in every application possible; everything from climate control in a neonatal ward of a hospital, to new movie theaters and tobacco companies as well as a contract with the Gillette company to prevent their new razors from rusting prematurely.

Unfortunately for Carrier, the eruption of what would become World War I in Europe interrupted his business, and Buffalo Forge closed the Carrier Air Conditioning Company. By pulling together his best engineers from Buffalo Forge, and partnering with his old colleague J. Irvine Lyle, Carrier founded his independent business, called Carrier Engineering Corporation on June 26th, 1915. Almost immediately, they began to get business from companies supporting the war effort that was in need of climate control in their factories.

Carrier Engineering Corporation

There was no shortage of business for the new Carrier Engineering Corporation, as they had their first business with the American Ammunition Company based out of New Jersey. This company and another 9 were loading fuses into ammunition for the war effort, and these factories needed dry, cool working conditions to ensure these fuses and primers would be reliable. The Carrier Engineering Corporation had more firsts in the next few years, including designing and installing the first climate control systems for use in meatpacking and dairy applications. Carrier Engineering ended up being a critical asset in the war effort, as they would provide air conditioning for 16 of 18 fuse-loading plants in the U.S. and Canada. Carrier and his team were the go-to for all things air conditioning.

Inventing an Industry Standard

In 1922 Carrier introduced the world to his most influential invention, which is still a mainstay of air conditioning and turbomachinery – the centrifugal refrigeration machine, or chiller.

The famed picture of the Carrier Centrifugal Chiller
The famed picture of the Carrier Centrifugal Chiller, courtesy of Williscarrier.com

We covered this amazing machine and 100 years of chiller technology in another blog not so long ago. Thanks to this large-scale machine, every kind of large public building had air conditioning from department stores and banks to the increasingly popular movie theaters, which became a refuge from the sweltering summer days and evenings.

This renaissance of climate control system installations would popularize the term “comfort air conditioning”. Whereas the original installations of Carrier’s air conditioning systems were necessary for the preservation of manufactured products, these subsequent installations were completed simply because it made buildings more comfortable on hot, humid days!

comfort air conditioning would see demand from small businesses and residential applications as well, and in May of 1926, the first home air conditioner was introduced by the Carrier Corporation. By 1928, small air conditioning units for shops were made available and could be used to refrigerate rooms and shops that did not have the need for large-scale centrifugal chiller machinery.

An illustration of the Carrier Unit Air Conditioner
An illustration of the Carrier Unit Air Conditioner, courtesy of Williscarrier.com

At this point, Carrier was the byword for climate control and air conditioning. Carrier’s machines were found everywhere from Macy’s, to Congress, to onboard US Navy ships including the USS Wyoming and inside the engine rooms of other ships. Despite the economic hardship of the Great Depression, and the industrial hurricane brought on by World War II, Carrier’s team held steady.

Following a merger, and being renamed the Carrier Corporation, Willis Carrier was given an honorary doctorate degree from Alfred University, based in Alfred, New York. As he led the Carrier Corporation through new contracts to install air conditioning systems in skyscrapers being constructed in New York City, he also contributed to the post-war housing boom in the American southwest and other parts of the country that were previously inhospitable due to the hot summers.

His Legacy

On October 7th, 1950, Willis Carrier passed away at the age of 76. In his 76 years, he completely changed what the world knew about heating, ventilation, and air conditioning. A system that was originally designed to preserve products that were heat/humidity sensitive, turned out to completely change how we live.

Entire areas of the country were drastically less populated because the heat in the summer was just too oppressive. Working in a Manhattan building in mid-July during a heatwave while wearing a suit was miserable. Fast forward to today, and air conditioning is a staple of American households, and of commercial buildings and homes across the world. The name “Carrier” is still a byword for air conditioning and comfort. In fact, I even have Carrier units cooling my home!

When it's hitting 90 Fahrenheit with high humidity here in New York, you can bet I'm grateful for Willis Carrier's work, and the products of his legacy company.
When it’s hitting 90 Fahrenheit with high humidity here in New York, you can bet I’m grateful for Willis Carrier’s work, and the products of his legacy company.

Do you design air conditioning systems? See how the AxSTREAM platform can be used to do everything from simulating refrigeration cycles to conceptual designs of the compressors, as well as perform rotor dynamics, simulate thermal flows, and get these results in a few hours. Learn more here


  1. http://www.williscarrier.com/index.php#
  2. https://gothamist.com/arts-entertainment/did-you-know-the-first-air-conditioner-ever-was-installed-in-brooklyn

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