A Cool Glance into the History of Air Conditioning
For as long as humans have existed, we've had to live with extreme temperatures, and there's actually a surprisingly small zone in which we feel “comfortable.” In modern times, we train HVAC technicians to install and repair air conditioning units to keep us at that level of comfort, but we've come a long way through the ages.
HVAC—heating, ventilation, and air conditioning—certainly has a modern ring to it, but even in ancient times, there was a distinct desire to keep cool. Ancient Egyptians used to hang wet reeds in their windows to help cool the breeze coming in. It was among the first rudimentary forms of air conditioning. It wasn't until 1758 that Benjamin Franklin and John Hadley made the official discovery that evaporation is a form of cooling, however.
Despite that discovery (and the things it did for refrigeration), traditional air conditioning didn't come into existence until the early 1900s. An early form of “air treatment” was invented by Willis Carrier for the Sackett-Wilhelms Lithographing and Publishing Co. in Brooklyn, NY. The machine blows air over cold coils to keep the room cool and thereby keep the paper from wrinkling. Not long after, at the World's Fair in St. Louis in 1904, Missouri showed off their fully air conditioned state building.
In 1931, the first window air conditioning unit was invented, but given the financial woes of the time and the cost ($10,000-$50,000 per unit), very few people had them. It wasn't until the 1950s that air conditioning really became popular. Even some cities, namely Las Vegas and Phoenix, owe their rapid growth and sustainability to the advent of air conditioning.
Even air conditioned cars aren't quite as modern as we like to think of them. In 1933, a New York City company installed air conditioning into cars. It was expensive enough that most of their customers were limousine services. However, in 1939, the first car to come with a pre-installed air conditioning unit hit the market. The convenient dashboard controls we're all so familiar with didn't exist yet, though. In order to operate the air conditioner, the driver had to park the car, stop the engine, and disconnect a compressor belt.
Finally, in the 1970s, voila—central air, using Freon-12 as the refrigerant. Of course, it wasn't until the 90s that we realized how harmful freon is to the environment, specifically the ozone layer, and as we go forward, we continue to seek environmentally friendly alternatives.
Air conditioning has always been important in our everyday lives, even before it became so convenient to achieve. It'll continue to be important going forward because no matter how much technology we have—our iPhones and tablets—these things don't regulate the temperature. For that reason, HVAC is a smart field to seek employment in. It's widespread, it's growing, and it'll never diminish. A certification program is all it takes to begin working, taking as little as 40 weeks. For more information, check out http://www.iot.edu/programs/technical/heating-ventilation-air-conditioning.