Many devices have been used throughout history in attempts to cool the air. Long before the term “air conditioning” was coined by Stuart Cramer in 1906, the Persians built “cool wind towers” that captured the wind coming from any direction to a building, and funneled it down through the building across pools of water, which cooled the air before it was forced upward through the other side of the building and out as the wind continued to force air in. This was about 500 years ago.
Before that, in the 2nd century, the Chinese invented huge fans (almost 10ft. in diameter) which were powered by servants, to blow air in certain rooms of the palace. The rooms also contained fountains that sprayed water upward, causing a mist that was carried by the movement of the air.
Even before the Chinese, wealthy Romans were able to have water from the aquaducts piped through the brick walls of their homes to keep cool.
Each of the ancient inventions applied the fundamental concept of modern day air conditioning . . . displacement of heat. With these types of primitive air conditioning systems having been invented so long ago, it gives us some perspective, and reminds us that we are standing on the shoulders of giants.
Let’s fast forward to 1865 when Thaddeus Lowe invented the ice machine. This was a huge step for us in that the same basic tenet was used when air conditioning was “accidentally” invented by Willis Haviland Carrier in 1906. I use the word “accidentally” because Mr. Carrier wasn’t trying to invent a way to cool the air. Instead, he was inventing a dehumidifier for the lithographer’s shop he worked in.
Now, what’s the difference in what Carrier did and what Stuart Cramer, the man who coined the term air conditioning, did? The main difference is that Cramer developed a humidifier for a textile factory, which could increase the temperature when the weather was cold and dry. He called his process air conditioning.
Since Carrier, on the other hand developed a dehumidifier which cooled the air, his invention ultimately became know as air conditioning.
It just so happens that dehumidification is caused by exposing air to a cold surface. The cold surface draws condensation from the air. If you think of a glass of ice water sitting on the counter, you will understand exactly what I’m saying. The glass seems to sweat after a couple minutes, but we know it’s not really sweating. What it’s doing is drawing water vapor from the air around it. As the water vapor condenses, it forms drops of water which accumulate further before it starts dripping down the side of the glass. This is exactly how a dehumidifier works!
To maximize the humidity drawn from the air, Willis Carrier made a coil with vaporized ammonia running through small tubes that laced back and forth across the coil. Metal fins were attached to the tubes which in turn had the heat drawn from them by the vaporized ammonia as it traveled through the tubes. Ammonia was used because it was able to maintain a liquid state at a lower temperature than water froze, and return to a gaseous state at a lower temperature than water boiled. When it is pressurized, vaporized ammonia becomes much colder than the temperature of the ambient air. This made it the perfect medium to pull heat from the surrounding air.
Thus, the modern day of air conditioning was born, and Willis Carrier was named “The Father of Air Conditioning”. With the new power to control the temperature, many industries flourished. Continuous improvements to the air conditioner paved the way for government buildings and theaters to be air conditioned. Eventually, air conditioning was brought into people’s homes. It’s reminiscent of what Steve Jobs and Bill Gates have done with the computer. It’s now normal for every home to have a computer . . . and an air conditioning unit.