Most histories are boring, and no one including me, was interested the subject growing up. However, we have made the history of refrigeration quite interesting for you. How, you ask?
Consider this, did you know that lager beer would not be so popular if not for refrigeration? To know similar cool facts, read on.
Also, this post is meant for light reading, that’s why we have not covered many engineering aspects of the history.
Table of Contents
How People Kept Things Cold Before Refrigerators
Answer is simple. Ice.
Chinese were one of the first to use ice, around 3,000 years back! They cut out ice from frozen rivers and lakes and filled empty cellars for religious ceremonies.
Ancient Persians mastered the art of storing ice more than 2500 years back. They used to make ice in winter and store them in cold houses called Yakhchals. These structures were so effective that they could store ice all round the year.
Greek, Romans and Hebrews used snow to cool beverages (chilled beer?). People in Europe had easy access to ice in winters. They would cut big blocks of ice from lakes and rivers and store them in their sheds. This ice could be used for most part of the year.
Things began to change when US began ice trading.
In early 19th century, US began cutting ice from lakes and ponds and exporting to several parts of the country. Within few years, they were sending ice to countries even as far as India!
This was possible because lot of ice stacked together slows down melting of ice. This, along with strong insulation from sawdust did the trick. This ensured that many countries now had year-round access to ice. And this led to invention of first refrigerators.
First refrigerators for home used to have at least two compartments. One was for storing ice and the other had food inside it. Cool air and water from the ice compartment would cool the food in the adjacent compartment(s).
However, it had several drawbacks, which meant that they were not fit for mass use. Constant melting of ice would lead to mold formation and cleaning the ice off the sawdust (meant for insulation) was time taking and unhygienic.
But this ice was came as a blessing for large industries. And guess what, one of the first industries to transform because of this ice trade was the beer industry. And that too lager beer. This is because method of making lager-style beers is different from ale-style beers. Basically, the yeast used in both of them is different. Why is this important? Because yeast used in lager beer requires low temperature for beer production.
Famous beer brand Miller was one of the first brands to make ice year round with the help of ice cut from lakes and rivers in the US.
Next industry to get revolutionized was the meat industry. Earlier, the concept of meat export was very limited. But availability of ice made sure that meat could be transported over long distances without fear of meat getting spoilt.
Cities that were near the lakes became important because of easy access to ice. In fact, Chicago became meat packaging center of the world. All due to effective transportation and refrigeration.
The demand for ice became so huge that natural ice was not enough. This meant that there was lot of experimenting to produce machines that could produce ice.
Big breakthrough came when an American inventor designed a refrigerator based on compression cycle (basically, lot of things were similar to refrigeration process that we have today). After further improvement in this design, these machines were installed in beer and meat industry. And guess what these machines used to do? Make more ice! Since these machines were quite big, they were unfit for home use.
One of the reasons for slow growth of mechanical refrigeration was unavailability of good refrigerant (gas used in refrigeration). A good refrigerant has very low boiling point (some refrigerants used today even boil at room temperature) and should be able to transfer heat easily among other things. It was tough to find good refrigerants.
For example, one refrigerator was invented with ammonia as a refrigerant. Ammonia is a poisonous gas and its accidental leakage was so dangerous that its production was stopped in very short time ( even though ammonia is used today in large freezing and refrigeration plants).
This also meant that the technology was understood, but the search for best refrigerant was still on. Scientists had realized that there was no natural gas that can be used a refrigerant for mass production. Basically, naturally occurring refrigerants were either too flammable or highly toxic.
Birth of Freon
Scientists created a new gas to meet the criteria of a good refrigerant- Freon. This gas had all the things required in a good refrigerant and was cheap to produce as well. It was world’s first non-flammable refrigerants, which meant it was extremely safe for home use.
Soon, Freon became the most popular refrigerant by a huge margin and ruled the AC industry for several decades, until it was discovered that it causes ozone depletion.
Freon was one of the important inventions that brought refrigeration in home appliances such as ACs and refrigerators (another reason being World War II).
Interestingly, some of the early home refrigerators would have cold box in the kitchen, while the mechanical parts, motor, compressor were installed in adjacent room or basement. Needless to say, they took quite a good amount of space.
Refrigeration technology has come a long way from its early days of ice and saw dust. Now most modern refrigerators come with advanced features, temperature control etc.
However, Frost free technology and digital inverter compressors were two most important inventions that further revolutionized the refrigeration industry. Frost free refrigeration made refrigerators extremely convenient by removing the process of manual defrosting.
Inverter compressors allowed refrigerators to consume lesser energy, produce lesser noise and have long lifespan.
IOT enabled refrigerators (although their convenience is debatable) have gone one step ahead and come with large LED screens and phone-based operating system. You can use them just like smartphones to watch videos (cooking videos?), listen to music and even play few games.
That’s about it. Now you know the history of refrigeration. Next time to take out water from the refrigerator and you get a déjà vu feeling, don’t blame us :).