Why can we make heat without expunging cold, but not the inverse (make cold without expunging heat)?
In: Physics
To make heat is easy, you just need fire. You light wood or natural gas or something on fire. Or even without fire, you take an element and run a lot of electricity through it and it heats up.
Cold doesn’t work that way. You can’t burn something to make cold. You can’t light something on cold. So the way we do it is by using a very cold substance (refrigerant). Refrigerant acts like a heat exchanger.
A pump pumps the refrigerant through coils. The refrigerant then makes the coils super cold. Air is blown past the coils which makes the air cool down. But at the same time, the heat from the air is getting absorbed by the refrigerant. So we continue to pump it until it gets to a radiator and we run air over it to let it release it’s heat. Then pump it back into the coils. It’s a bit more complex than that, because the pump actually compresses the refrigerant and the expansion of the refrigerant is what makes it super cold. Kinda like when you spray a canned duster for a long time and it gets super cold and causes ice to form.
But ultimately, there is nothing natural that causes things to be cold, except the weather.
Interesting thing to note. While most homes do not have these, most business use what is called a heat pump to manage temperatures. A heat pump works on the same principal as an AC. Except in the winter when it’s cold outside and you want to heat up the inside so people are comfortable, they run it in reverse. So the hot “exhaust” is used to heat the building and the cold air is blown outside.
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