Science & Technology

On the Shoulders of Giants: From Farm Boy to Mad Scientist

Note: This article is hosted here for archival purposes only. It does not necessarily represent the values of the Iron Warrior or Waterloo Engineering Society in the present day.

Today’s column is about Willis H. Carrier, a genius who can justly be called the “Father of Air Conditioning”. Born on a farm near Buffalo, New York in 1876, Carrier’s early life was basically the good old American Dream. A typical day for him was getting up at 5 am to milk cows, and delivering the milk to the nearest town, all before school. But his family was poor and he could not afford higher education. For several years, he worked a variety of jobs – lawn mower, high school teacher, waiter – while trying to apply for university. Finally in 1897 he received a scholarship for Cornell University. In 1901, he graduated in Electrical Engineering, and despite forge and turbomachine manufacturing not being his field, took a job offer with Buffalo Forge Company.

As soon as he got to his new job, Carrier began questioning why the company made boilers the way they did. Naturally his bosses weren’t too pleased. But Carrier was determined to look for better solutions, even doing unpaid work after hours to improve boiler efficiency. One day, he walked into the owner’s office, and announced that he had something worth more to the company than three years’ of anyone else’s work. (Author’s Note: I wish I had his confidence and brilliance …) By the summer of 1902, just one year after he started working at Buffalo Forge, Carrier was the head of a newly-created R&D department.

In the winter that year, Carrier had his Eureka moment. While waiting for a train, he noticed that as the air got colder, there was more fog. It was then when he realized he could use the fact that cold air holds less water than hot air to his advantage – by mixing saturated air of a certain temperature with the air in a room, he could control both temperature and humidity.

Back at the company, his team did a series of experiments which showed that wet-bulb temperature remained constant if air was adiabatically humidified. This meant that you could figure out the humidity and enthalpy in a room by simply measuring the dry and wet bulb temperatures and looking up numbers in a steam table.

In 1904, Buffalo Forge made its first sale of Carrier’s air conditioning system. Soon, AC was being used in department stores, in factories, and even in Broadway theatres. In 1914, Carrier and his team formed their own independent company. He continued being obsessed with making his inventions better. His creativity with finances also helped – once, when his company was running short on money, he ran experiments while fixing the ducts at a client’s factory without telling them, so they’d be on the hook for the bill. By the time of his death in 1950, air conditioning was ubiquitous in North America.

In front of his peers at the 1911 meeting of the ASME (American Society of Mechanical Engineers), Carrier gave a lecture where he announced a number of humidity and temperature formulas, and unveiled the psychrometric chart – where you could easily look up the humidity, temperature, enthalpy, or density of air for a given state. To this day (and I’m speaking as someone who just wrote an exam on these topics), these formulas and charts are still being used.

Every hot summer, when you walk into a building and get that amazing cool feeling, or every time you step into a bathroom to hear a whirring fan dehumidifying the room, you’re experiencing Carrier’s legacy. Besides residential uses, facilities from breweries to ice rinks often require a particular temperature or humidity, and air conditioning is used to provide it. Through time, Carrier’s invention has become an essential part of today’s society.

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