Refrigeration revolutionized human society by allowing foods to be stored longer. To this date, refrigerators operate on a continuous cycle with four steps: compression, absorption, expansion and condensation.
The first step in the refrigeration cycle is compression, where the system forces vapors into a small space and causes them to heat up.
After the compression finishes, coils absorb heat from the vapors, reducing their temperature.
Once the vapor temperature decreases, a throttling device further removes heat and applies pressure until the vapor becomes liquid.
Finally, the fluid evaporates and once again becomes gas. The cold temperature is directed to the refrigerated area, while the remaining gas is cycled back into the system, starting the process once again.