1902 is believed to be the year of the air conditioner’s inception, when Willis Carrier, an American engineer, designed a hitherto unknown device for a printing office in New York. Structurally, it was a genuine air conditioner, except it was designed to reduce humidity, because it was bad print quality, rather than cool down the room.
It was in the mid-1920s that first tentative steps in that direction were made, when an air conditioning system was installed in a supermarket in Detroit. However, in those days an air conditioner was ab unaffordable rarity, and it had to be tailored to a particular type of building.
In the mid-1940s, when first compact one-room devices were designed, the technology began its pace around the world. The production of so-called window air conditioners (AC) was first launched in the USA and, later, in Europe and Japan. That was a tremendous move forward. Installation process is unabashedly simple, and it does not require professional background or expensive tools. Plus, Freon, which is used as a coolant, will not freeze even at extremely low temperatures. All that spurred the AC boom, sending prices down to a generally affordable level.
The Middle East oil boom fueled the expansion of the air conditioning industry, because Middle East countries joined the list of major AC users along with the USA and Japan, as early as in the 1970s. Today, window AC units are still popular, except in warmer climates they are installed in thin walls rather than in windows.
Besides, the Europeans have their own kind of device – a portable AC, which does not need to be mounted and can be carried from one room to another. Italy is the main manufacturer of this kind of AC.
Manufacturers of central air conditioning systems that cool down large rooms and even whole buildings, have done a good job too.