Vapor-Compression Refrigerant Cycle
One mechanism from Chapter 12: Cooling Things Down.
flowchart LR Evap["Evaporator: refrigerant boils at 38 to 42 F, absorbs heat from chilled water"] Comp["Compressor: raises pressure and temperature, main energy input"] Cond["Condenser: refrigerant condenses at 100 to 120 F, rejects heat to condenser water"] Exp["Expansion valve: throttles to low pressure, flashes and cools refrigerant"] Evap --> Comp Comp --> Cond Cond --> Exp Exp --> Evap