Refrigeration

Did you know that there is no such thing as cold? You're just feeling the absence of heat. A refrigerator takes away heat and pumps it out the back and that's why the back of a refrigerator is so hot.

First, the compressor squeezes the refrigerant hydrochlorofluorocarbons (HCFCs) so they release heat. The molecules release heat because they are losing kinetic energy and making friction. Then the HCFCs go into the External Heat Exchange Coil and the heat dissipates and the gas cools. Then they flow through the expansion valve to the Internal Heat Exchange Coil. Here they have more room to move so they absorb heat energy and turn it into kinetic energy. Then the molecules flow back to the compressor and it starts all over again.

Below is a model of the refrigeration system that I made using Google SketchUp.