They use refrigerant, which freon is a type of. For the cooling mechanism of a refrigeration machine, a compressor pushes the liquid coolant out and into the expansion evaporator. The evaporator uses the cool temperature from the coolant and uses the forced air from a fan (example for AC or fridge) and into an expansion valve that regulates its flow to the next step. It then goes to a condenser where it goes back into a fluid from gas form and back to the compressor. I left a few steps out (it's been a while).
You would take a black dot at the top right of the y axis and dray it to the the far right of your x axis. hope this helps have a nice day and God bless
