This July turned out to be a really hot month. Even though by meteorologists’ standards definite heat starts from +35°C, the current weather is enough to justify all means of cooling, and the air conditioner becomes an indispensable “friend.” But, of course, our ancestors had no such opportunity. Read this article to know how people escaped heat and swelter before the advent of the air conditioner and who invented this wonderful device.
Secrets of Ancient Civilizations
Our forefathers were quite inventive. Early ventilation systems had already been in use in Ancient Egypt. Back then the Egyptians already knew how to create air circulation in the room. For example, in the pyramid of Cheops there were special air ducts that moved air perfectly for many millennia until there were so many tourists that it was necessary to integrate additional means of ventilation.
In ancient Rome, people wrapped up in wet cloth and did the same thing with jugs. The evaporating moisture thus cooled down their beverages.
In affluent homes, small pools were located right in the center of the dwelling, while citizens with modest wealth went to public terms to cool down. The Hindus wetted their grass mats with water and placed them on the window sills. Russians sought to spend hot hours near water bodies, for example, to do their laundry. Large pieces of ice were delivered to the rich homes of the nobility that melted slowly to cool down the room.
Fans were invented quite early in China which were considered a subject of luxury and an indicator of wealth.
There was even a special code that defined who was entitled to which fan. The emperor’s family had a fan adorned with gold and nephrite. Mandarins owned silver or ivory fans. An unprepossessing fan of waxed paper was invented for commoners. In the mid-16th century, Portuguese merchants brought overseas goods to the countries of the Old World. The novelty was appreciated by ladies of noble descent. The collection of Catherine Medici, which has more than 900 fans of skillfully designed fans, is well known. Aristocrats’ fans were so luxurious that they could even be pledged in a bank if the owner was short on money.
The system of natural air movement in ducts and pipes was described meticulously by Mikhail Vasilyevich Lomonosov in his work On Free Air Movement Noted in Mines. In addition to the theory, the first design of an instrument that recorded the speed and direction of airflow was created. The first mechanical fan in history, driven by a steam engine was installed in 1735 in the Houses of the English Parliament. This giant and unwieldy invention was also called a fan. In 1795 Wilhelm Christian Friebe summed up scientific considerations on the intensity of air exchange in a heated room through doors and windows, thus giving birth to the neutral zone theory.
A Race of Inventions
With the scientific basis barely described, the inventors set to work. In 1810, a ventilation system was installed for the first time in a London hospital. Five years later, it was patented by the French entrepreneur Jean Chabannes who called the method “the conditioning of buildings.” The meaning of the word “to condition” was then slightly different and meant “to bring into conformity.” While the French were filing their paperwork, the British were thinking about how to improve the apparatus.
This was when the British physicist Michael Faraday made an important discovery: while experimenting with ammonia the scientist found that this substance absorbs heat when evaporated. So the principle of refrigeration was discovered that formed the basis of all refrigerators and air conditioners of our time. The dual system was designed as follows: the substance was evaporated and absorbed heat in one section while condensing back into liquid state and releasing heat into the environment in the other section. These were the kind of scientific tricks involving transformation of substance. Image Caption
Having made the first steps toward creating a mechanical ventilating device, researchers were willing to experiment in an attempt to refine the installation. In 1830, the American James Baron received a patent for a mechanical fan driven by a suspended load. Another inventor from the United States, practicing physician John Gorrie, decided to cool the hospital wards, and in 1844 created a machine to make artificial ice. However, the air conditioner was still far away.
The first successful centrifugal fan (the well-known snail-shaped fan) was invented in the Russian Empire in 1832 by the military engineer A.A. Sablukov. In 1835, the model was applied to ventilate the Chagir mine in Altai. Sablukov’s fans were also popular in sugar and leather factories. The inventor also proposed to use them for ship holds to promote drying and evaporation. However, axial fans did not attain their modern form until 1906 when N.E. Zhukovsky came up with the vortex wing theory, according to which lift occurs at the wing due to the application of an attached vortex to the main flow.
Adapting to the Room
In the late 1860s, the first ceiling fans driven by mechanical energy of water came into use in the United States. The design was as follows: a two-blade fan was connected to a belt system driven by a water wheel. Despite the complexity of the design, it had its advantage: such a system could drive multiple units at once. The first workspace-adapted fans became very popular in offices, shops and restaurants. Rare representatives of this design can still be found in Southern states.
In 1882, Philip Diehl, a German-born American, improved the ceiling fan and replaced its mechanical gear with an electric drive. He quickly encountered competitors, and the idea had to be improved. The industrious inventor turned the ceiling fan into a “Diehl chandelier.” The invention embodied the “two-in-one” principle: the light fixtures compensated for the occlusion of light as blades rotated and provided additional lighting. By 1920 one could hardly surprise people with ceiling fans. The product entered the international market.
In 1892, Paul Mortier, a French engineer, designed a diametral fan featuring a drum-like wing with vanes folded forward as its main component. Mortier fans were popular in mines, albeit only for a short time. They were replaced quickly with new electric models designed by the famous American Thomas Alva Edison.
Freshness and Coolness
In 1902, Willis Carrier manufactured the first sample of a machine that not only ventilated but also cooled air. The novel invention was installed at one of the printing offices in Brooklyn. The goal was not to care for employees, but to improve production. It was necessary to reduce the air humidity, as ink dried slowly on wet paper. However, the cool environment turned out to benefit entrepreneur in many ways: workers became less tired, and printing output was boosted dramatically. In 1924, the first air conditioner appeared in a Detroit department store, tripling its revenues. After such excellent success stories, air conditioners were installed in banks, cinema and even public toilets. In 1928 the American Congress finally became air-conditioned, and in 1929 the turn came for the U.S. Senate.
In the same year, General Electric released the first room air conditioner – the predecessor of the modern split system. The compressor and condenser were mounted outdoor because ammonia was used in the product. Despite manufacturers’ effort to safeguard buyers, there were often accidents when ammonia exploded. In 1931, the problem was solved by switching to a new refrigerant, Freon. Moreover, all parts of the invention were assembled in a single unit, and a window conditioner was born.
In the late 1950s, American inventors competed with the Japanese who sold their Daikin household air conditioners on the global market. The devices could not only cool but also heat the room. Toshiba accepted the challenge of their compatriots and improved the model: the noisy compressor was taken outside, and the device itself could be installed in any part of the room regardless of the windows location. In the early 1980s, an inverter-controlled air conditioner was launched with the ability to maintain a set room temperature, saving up to 45% electricity. In 1982, Daikin struck back with new type of air conditioner, a variable refrigerant volume (VRV) design. Upon reaching the required temperature, the air conditioner did not reduce the engine speed but adjusted the amount of Freon. The idea was picked up by other manufacturers who changed the already patented name to VRF (variable refrigerant flow).
And how did things develop in our country?
Meanwhile, in the USSR in 1975, the production of household air conditioners was established in Baku in cooperation with the Japanese firm Hitachi. They were known for their trademark acronym BK, meaning “household air conditioner” in Russian. The product fell short of providing a high level of comfort: it was noisy, only suitable for mounting in a window opening and was terribly expensive. But despite everything, it was very popular. Products from Baku were exported to Cuba and even Australia. After a while, it was revealed that Freon directly contributed to the formation of ozone holes. In 1987, the Montreal Protocol was signed by economically developed countries requiring manufacturers of air conditioners had to switch to new refrigerants, gradually displacing Freon.
So hard was the story of air conditioner design. The design of an object we can hardly imagine living without through summertime heat.
The article is based on open sources.