Refrigeration system

One of the things that caught my attention in the video was how the refrigeration system was invented as a way of using the cold to human benefits. People started using ice for keeping the food till the mid of 1750s when refrigeration system was introduced. The idea of refrigerator was introduced by William Cullen, he used a pump to make a partial vacuum over a container of diethyl ether and resulted in which boiled and got heat from the surrounding air, and created some ice. To follow his lead Oliver Evans came up with the vapor compression refrigeration. Until it reached to Michael Faraday who used liquefied ammonia and he was using high pressure with low temperatures. It took decades till Alexander Twining built the first vapor compression refrigeration system. The refrigerator we have uses a compressor which raises the pressure pushes it to the coils, and when the hot gas meets the cooler air around, it becomes liquid. At high pressure during the liquid form the refrigerant cools down and goes into the coils. The liquid ammonia goes to gas then the cycle starts. It all started with a pump and a vacuum and the same concept went on until we have got the refrigeration system we have today.

https://en.wikipedia.org/wiki/Refrigerator

https://www.realsimple.com/food-recipes/tools-products/appliances/how-does-refrigerator-work