Already 4,000 years ago, the population of Mesopotamia dug pits, where they kept ice and snow from the mountains, to store food. Snow and ice were long the only way for humans to cool or freeze their food and drink. If stored in the soil properly and in the right place it may last for several months. Running water, cavities in the ground and cellars. We humans have long known that cold is a superior way of preserving food.
In the 19th century, the industrial revolution came, with it cities were growing and become more in numbers. Food needed to be transported to the cities, from increasingly distant places. Meat could be transported for a few days with ice-cold railway wagons, but for longer shifts and for storing food, an improved cooling technique was needed. The artificial cooling technique was already available in the early 19th century, but had many childhood diseases. The appliances were large and clumsy, often extra spaces for the engine and compressor were required in addition to the cabinet itself. Also, they were dangerous. The machinery, which contained several moving parts, often had leakage. The refrigerants used were ammonia and sulfur dioxide which are toxic.
The earliest refrigerators were thus not suitable for private households. Instead, it became more common in the 19th century with Iceboxes cooled by natural ice. The ice was chopped out of lakes, stored under insulating sawdust and distributed to the growing upper and middle class by ice-men with horse and cart. Frederic Tudor, a Boston businessman, became known as the Ice-King. He exported ice from the lakes of New England to Cuba and India. He earned incredible money and created a business of over 90,000 employees who saw, packed, loaded, shipped and sold ice. Also from Norway, much ice was exported, especially to England. Special ice-cold trams made it possible to provide the population with fresh foods. With the lucrative ice industry and a rapidly growing demand for chilled goods, renewed interest in artificial cold was also awakened.
Engineers and technicians in both Europe and the United States began to develop the technology. The American company Frigidaire became the first to launch a refrigerator adapted for private households. Frigidaires refrigerator began to be sold in 1921 and became popular in well-off homes. However, it was terribly expensive and the cost was comparable to a T-Ford. In addition, the potential customers were also restricted by another factor: Frigidaires and other former manufacturers’ refrigerators were based on compression technology. This required access to electricity, which was not particularly common in residential buildings at this time.
Two young technology students in Stockholm began experimenting with a method that did not require compression. As early as 1859, Frenchman Ferdinand Carré had patented an ice machine designed according to the so-called absorption technique. But the KTH (Royal Instute of Techniology in Stockholm) students Baltzar von Platen and Carl Munters further developed the technology and eventually managed to construct a functional refrigerator for the home. A crucial innovation was that they supplied hydrogen to facilitate the refrigerant’s transition from liquid to gas. The experiments they performed mostly took place in their student flat. Von, Platen, in his memoirs, explains that they used to work on their ideas at night and instead taking lectures during the day they slept. However, they still managed their studies and in 1922 they were able to present their master thesis: a self-circulating cooling system without moving parts. Electrolux’s foresighted founder Axel Wenner-Gren immediately understood the potential of the product. He bought the rights to the fridge and hired the two young engineers. In 1925, Electrolux began mass production of the so-called absorption refrigerator, which soon became a world success. The fridge was run with heat, so you did not need electricity, but could in stead use gas that was available in most households. Absorption refrigerators dominated the market in Europe until the 1950s.
Successively, households began to gain access to electricity and then compression technology came back. By that time, the technology had developed so that compression fridges became both safer and cheaper. The compression technique is also about ten times more efficient than the absorption technique of creating cold. One of the changes that contributed to making both compression and absorption refrigerators more safe and secure, was that ammonia as a refrigerant from the late 1920s was replaced by significantly more stable substances – freons.
In the 1970s, the drawback with using freon was discovered, that it affected the ozone layer. In 1987 an international agreement was signed, the Montreal Protocol, with intention of phasing out the freons. It was not easyy for the refrigerator manufacturers to switch from freon to alternatives more difficult to handle. However, in the early 1990s the switch began to accelerate, probably with good help by Greenpeace actions. In 1993, Electrolux became the first manufacturer to launch the refrigerator completely without CFC, the most harmful of freons.
Of course, the industry is focusing on making the refrigerator even more energy efficient. Today a good refrigerator consumes 70% less energy than a normal 15 year old refrigerator.