You probably already know this, but for anyone else reading - it's more than just compressing and decompressing - it's changing phase between liquid and solid!

You probably already know this, but for anyone else reading - it's more than just compressing and decompressing - it's changing phase between liquid and solid! It takes a lot of extra energy to go from a liquid to a gas - think about how when boiling water, it doesn't all immediately turn into steam when it hits 100 degrees. It takes a long time to boil it down to nothing, even on a really hot stove. That's because switching from liquid to gas takes more energy than just getting hotter. The refrigerants used in ACs and heat pumps take advantage of this behavior to maximize how much heat they can move - much more than if they stayed as a gas