Air conditioning was invented to "save you"? Wrong! The truth is...

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, what’s interesting is 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, do you feel that life is as fragile as paper? The story begins in a factory in New York, USA in the early 20th century .

Sackett-Wilhelms printing and publishing company's printing plant. Image source: Carrier official website

This is a printing plant in Brooklyn owned by Sackett-Wilhelms Lithographic Printing and Publishing Company.

Here, workers use the method of multi-color printing to make magazine covers: there are as many printing plates as there are colors in an image. After printing the first color part on the first plate, they go to the second plate to print the second color...

Everything was going well, but in the summer of 1902 the workers ran into 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 levels?

In this fog of inspiration, Willis Carrier came up with a brilliant idea:

He made an airtight box, first sucked the outside air into the box, and then sprayed cold water into the air. The air in the box turned into mist, that is, air with 100% humidity. At this time, Willis Carrier added an appropriate amount of dry air into the box. Once the two were mixed, he could mix air of any humidity.

This principle sounds a bit like "add water if there is too much flour, add flour if there is too much water", which is very simple, but very effective. And this is the prototype of the world's first air conditioner . The inventor of this device, Willis Carrier, was only 25 years old at the time.

Based on the prototype, Willis Carrier submitted a new design on July 17, 1902. The new scheme can directly reduce the temperature of indoor air to control humidity. The principle is also very simple - if steam can be passed through the room through the pipe, it can make the room warmer, then letting cold water do the same action can achieve the opposite purpose? This machine finally effectively solved the humidity problem in the printing workshop.

Initially, the cooling water came from a nearby deep well. The following spring, he began using an ammonia compressor to further cool the water. This allowed the printing workshop to maintain a relative humidity of 55% year-round. Modern air conditioning was born, and July 17 is 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, and factory owners in industries such as textiles and pharmaceuticals quickly adopted the new equipment. In 1903, the newly built New York Stock Exchange trading floor became the first building to be air-conditioned for temperature control reasons .

Willis Carrier was delighted by such a huge success. However, he was not satisfied with it. Instead, 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 founded the company named "Carrier Engineering Company" after himself. 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.

Image 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!"

Author: Wang Jiangshan, Xu Lai

Review｜Qin Zongmin Member of China Refrigeration Society Senior Engineer

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

The cover image and the images in this article are from the copyright gallery. The image content is not authorized for reprinting.