Who would’ve thought that Buffalo, NY – a city famous for its bitterly cold and snowy winters – is the home of the modern air conditioner? But a man in this Northeastern city was tasked to solve a problem for a Florida company, and so began the modern man vs. nature battle to control temperature extremes. Before we get to Willis Carrier’s invention, let’s take a look at how humans have fought the battle to master their environment, as well as the man vs. man race to control the rights to their discoveries.
Cross-Cultural Methods to Keep Cool
Many worlds and lifetimes away from Buffalo, NY, the early Egyptians, Romans, and Chinese developed methods to cool their buildings. An early Egyptian window unit consisted of hanging reeds, kept damp with trickling water, covering the openings to homes. When air passed through, the evaporating water cooled the room, and added humidity to the dry environment. Is duct work so new? Not really. The Romans circulated the water pumped from aqueducts through their walls to keep cool. A Chinese invention used huge rotary fans with 10-foot wheels to move air. In addition, water fountains provided spray that helped reduce the temperature of the moving air in a cool room. What all these cultures had in common: the desire to keep the upper class comfortable and the inspiration to move air and water to do so.
Early Protected Air Conditioning IP
Fast-forward to the late-18th and 19th centuries. As inter-continental communication became possible, awareness of inventiveness and competition for monetization increased. The U.S. Patent Act of 1790 officially recognized the value of intellectual property (IP). Before that, in Europe and Australia, inventors were issued “patents letters” for their work, but that was mainly an avenue for the governing body to tax them. There hadn’t been a cohesive system for issuing patents in Colonial America, and the U.S. Patent Act offered inventors some protection at the colony level. Beginning in the last decade of the 18th century, inventors began realizing ownership of “any useful art, manufacture, engine, machine, or device, or any improvement therein not before known or used” with the US Patent Act .
Coming a long way from reeds in the windows and giant fans, the efforts to control ambient temperature continued. The key ingredients for some time remained water and air movement. Industrial progress required mechanization beyond the manual efforts of earlier times. Then, scientific advances placed chemistry in the mix. Benjamin Franklin performed early work introducing chemicals as a means of reducing temperature. In 1758, his experiments “confirmed that evaporation of highly volatile liquids (such as alcohol and ether) could be used to drive down the temperature of an object past the freezing point of water”. In England in 1820, scientist and inventor Michael Faraday concluded that compressed and liquefied Ammonia, when evaporating, cooled the air. Neither innovator sought patents for these ideas, and they were freely available for others to apply in the field.
A relevant development emerged in the late-1840s, as an inventor in Florida, Dr. John Gorrie, needed a way to make ice. The mechanism he developed to do so was a compressor powered by movement from animal, air, water, or steam. Dr. Gorrie received a patent for his ice machine in 1851. 
Figure 1: Gorrie’s ice maker
What does the ice maker have to do with air conditioning? Well, the real problem Dr. Gorrie was addressing was wellness. He believed high temperatures caused many ailments and needed to quickly and cost-effectively bring ice to his hospital to cool the rooms to make patients more comfortable and aid recovery. Gorrie’s idea was the first in mechanized artificial room cooling and his vision expanded beyond cooling buildings to regulating entire cities. He received the patent, but wasn’t able to profit from it or see his idea materialize because he lost his financial backing.  Still, the IP was established and protected, and laid the foundation for expansive air conditioning systems.
And this brings us back to Buffalo, NY in the early 20th century. There, the issue was not human comfort or health, but manufacturing processes. Willis Carrier was an engineer with the Buffalo Forge Company. A publishing client of theirs, in Brooklyn, NY, struggled with wrinkled pages and unstable ink during NY’s humid summers. Carrier had to figure out how to reduce temperature and humidity to ensure high quality printing.
Using what he already knew about heating objects with steam by sending air over hot coils, Carrier altered the process by filling the coils with cold water to produce cool air. This was an electrical method of evaporation that re-invented the strategies of the ancient Egyptians and Chinese. It also circulated and cleansed the air. He revealed this innovation in 1902 and installed it in the mill. The patent for Apparatus for treating air was granted in 1906.
Figure 2: Apparatus for treating air 
Meanwhile, Stewart W. Cramer had his own manufacturing problem to solve, needing to add moisture to the air in a textile mill in Charlotte, NC. In 1906, he gave us the phrase, “air conditioning” when he combined moisture with the ventilation system. Further, Cramer broadened the scope of air conditioning to methodize not only humidifying and air cleansing, but also heating and ventilation. The Humidifying and air-conditioning apparatus was granted a patent in 1907 .
Figure 3: Humidifying and air-conditioning apparatus 
However, Cramer’s novel terminology – that bit of IP – was adopted by another inventor. Carrier quickly associated the phrase, “air conditioning” with his own developments and began the Carrier Corporation, specializing in air conditioning and refrigeration.
Despite these early applications in industry, serious adoption of air conditioning first occurred, again, for human comfort, allowing movie theaters in the South to stay open all year, rather than close for the summer. Businesses and factories began fully utilizing air conditioning in the 1930s and 40s. The 1950s saw the miracle of home cooling. Since then, progress through the 20th and into the 21st centuries has shifted to energy efficiency and clean energy.
Even with our brutal winters we’re grateful to Carrier and Cramer, and appreciate improvements to their established IP.
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