I read the wikipedia page and asked my dad – but I am honest: I don’t understand it.
In: Engineering
Fridges don’t make things cold, they move heat around.
They cool the main box by taking heat from the inside and putting it on the outside, specifically the back of the fridge. Fridges can get hot on the back.
HOW they move heat is the hard part. Essentially they use a trick that you might not have heard of or understand fully.
It takes energy to heat something, but it takes a very large amount of energy to break the threshold and turn a material from liquid to gas, from gas to liquid, etc.
This is why you cool down very fast when you sweat. The evaporation process requires very large amounts of heat, and that heat leaves your body with the evaporating liquid.
Fridges abuse this “trick”, and have a substance inside that is a liquid or a gas at just the right temperatures they want. They move it around the fridge and change the temperature and pressure so that it’s a liquid sometimes, and a gas at other times in the cycle. Hooking a system like this up correctly allows the substance to take heat from one part of the cycle and give it to the other part of the cycle. One half is hooked to the cold box, one to the outside of the fridge.
The exact process is somewhat complicated, so I encourage research on the topic. Technology connections has great YouTube videos on appliances such as this explaining them in more detail.
You would also further understand the topic with physics courses. A refrigerator is the opposite of an engine, and is a little like a steam engine in reverse.
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