[Creative Cultivation Program] Did I invent the air conditioner to save you? Wrong, I invented it to save paper!

Author: Wang Jiangshan, Xu Lai

Audit expert: Qin Zongmin, member of the Chinese Society of Refrigeration, senior engineer

In the hot summer, air conditioners have become a must-have item in the eyes of many people. The inventor of air conditioners, American engineer Willis Carrier, has also become the target of many people's praise. Some netizens even jokingly called him "Carrier Bodhisattva" and said that their lives "are all given by this person"...

However, it is interesting that Willis Carrier's original intention in designing and manufacturing air conditioners was not to "give life to netizens in hot summer weather". He originally designed air conditioners for "paper" - after reading this, will you feel that "life is thinner than paper"? The story begins in a factory in New York, USA in the early 20th century.

(Photo of the printing plant of Sackett-Wilhelms Offset Printing and Publishing Company: Carrier official website)

This is a printing plant of Sackett-Wilhelms Lithographic Printing and Publishing Company in Brooklyn. Here, workers use the process printing method to produce magazine covers: an image contains as many colors as there are printing plates. After printing the first color on the first plate, the second color is printed on the second plate... Everything was fine, but in the summer of 1902, the workers encountered big trouble.

The summer of that year was particularly hot and muggy, especially in the printing workshop. Because of the high humidity, the printing paper constantly absorbed moisture from the air, causing the fibers that made up the paper to swell and deform. As a result, when printing, the corresponding positions between different colors were not so accurate, and the success rate of printing was greatly reduced.

There were problems, but the work could not stop. So the factory owner found Buffalo Forge Company, hoping that the engineers there could help him solve the problem. A young engineer from the company accepted the task. You must have guessed it, he was Willis Carrier.

At first, he planned to follow the idea of ​​a previous engineer and use concentrated salt water to solve the humidity problem - the reason is simple, concentrated salt water will absorb moisture from the air and reduce the concentration. However, this method is not easy to use. It is not possible to directly absorb the moisture in the air, so the only way is to change the idea and lower the indoor temperature. When the temperature is low, the air humidity will naturally drop.

In that era, people had invented many ways to reduce the temperature. In 1889, in New York, Carnegie Hall installed a special ventilation system: ice and huge blowers allowed the audience to enjoy the music in a cool environment. But this was not a good solution for the printing workshop. How to solve the problem?

But a problem is a problem, and Willis Carrier had no idea. Fortunately, he never gave up, but continued to think about it for several weeks, until one day, he stood on the platform and saw a steam locomotive roaring and spewing a lot of water vapor. His mind suddenly became clear: Isn't fog just air with 100% humidity? As long as you determine what is 100% humidity, then wouldn't it be easy to determine other humidity?

In this fog of inspiration, Willis Carrier came up with a brilliant idea: he made a sealed box, sucked the outside air into the box, and then sprayed cold water into the air. The air in the box turned into fog, that is, air with 100% humidity. At this time, Willis Carrier added an appropriate amount of dry air to the box. Once the two were mixed, air of any humidity could be prepared. This principle sounds a bit like "add water if there is too much flour, and add flour if there is too much water." Very simple, but very effective. And this is the prototype of the world's first air conditioner. Willis Carrier, who invented this equipment, was 25 years old.

Based on the prototype, Willis Carrier submitted a new design on July 17, 1902. The new scheme can directly reduce the temperature of the indoor air to control the humidity. The principle is also very simple - if steam can be passed through the room through the pipe to warm the room, then can't cold water do the same thing to achieve the opposite purpose? This machine finally solved the humidity problem in the printing workshop. At first, the cooling water came from a deep well nearby. In the spring of the following year, he began to use ammonia compressors to further cool the water. The printing workshop was able to maintain a relative humidity of 55% throughout the year. Air conditioning in the modern sense was born, and July 17 is also widely accepted as the "birthday" of air conditioning - yes, air conditioning just celebrated its 120th birthday.

Initially, Willis Carrier's invention was used to control humidity. Factory owners in industries such as textiles and pharmaceuticals soon used this new equipment. In 1903, the newly built New York Stock Exchange trading floor became the first building to install air conditioning for temperature control reasons. Such a huge success made Willis Carrier very happy. But he was not satisfied with this. He keenly saw the application prospects and value of air conditioning and continued to study and optimize his design concepts. In 1906, he established the "Law of Continuous Dew Point Reduction" and designed the first automatic air conditioner based on this principle. In 1911, he found the "Rational Humidity Formula" and set standard specifications for the entire air conditioning industry. During this period, in 1915, Willis Carrier and his friends opened a company named "Carrier Engineering Company" with their own names. Until now, this company still plays an important role in the field of heating, air conditioning and ventilation systems.

Today, air conditioning is used in most public facilities and many homes, and the basic principle of the air conditioning we use today is still the same as that invented a hundred years ago. The wind of inspiration that started with a piece of printed paper eventually blew the whole world.

The great thing about Willis Carrier is that he did not stop at the level of completing an invention, but studied the principles behind it and discovered broader regularities, thus promoting the development of other industries and even disciplines. In addition, his continued research also reduced the size and price of air conditioners, making them accessible to the public. This is an invention that has entered thousands of households.

Willis Carrier's original purpose of inventing air conditioning was not to cool people, but to keep paper from deforming. In fact, in the history of science and technology, there are many examples of inventions with very different original intentions and final applications, just like "unintentional planting of willows that will eventually produce a shade". But what really made Willis Carrier achieve greater success and make greater contributions was not just the initial burst of inspiration, but his continued exploration and long-term efforts after his first success. After unintentional planting of willows, you also need to be intentional to produce shade.

(Source: Carrier official website)

Maybe Willis Carrier just "saved people" when he "saved paper" at first, but thanks to his half-century work in the field of air conditioning, when we sit leisurely in an air-conditioned room with a book in our hands, we should really say "Thank you Carrier!"

References:

[1]https://www.newyorker.com/tech/annals-of-technology/an-apparatus-for-treating-air-the-modern-air-conditioner

[2]https://en.wikipedia.org/wiki/Willis_Carrier

[3]https://en.wikipedia.org/wiki/Air_conditioning

This article is produced by the Science Popularization China-Creation Cultivation Program. Please indicate the source when reprinting