Refrigerator Heat Pump Cycle (2D)

This 2D diagram traces the vapor-compression refrigeration cycle used in every refrigerator, air conditioner and heat pump: refrigerant particles flow around a loop through the compressor, condenser, expansion valve and evaporator, changing color as they change temperature and pressure at each stage. Drag the compressor speed slider to change how fast refrigerant circulates, and the evaporator/condenser temperature sliders to see how the gap between hot and cold sides governs the coefficient of performance — live readouts show COP, work input, and the heat absorbed from the cold side versus rejected to the hot side, which always differ by exactly the compressor's work input.