Chillers are core components in air conditioning and process cooling systems. They operate on the refrigeration cycle principle: a refrigerant evaporates at low pressure, absorbing heat from the medium to be cooled. It is then compressed, raising both pressure and temperature. In the condenser, the refrigerant releases the absorbed heat to a cooling medium and condenses. After expansion, the cycle restarts. A distinction is made between compression chillers (electrically driven) and absorption chillers (heat-driven). The Coefficient of Performance (COP) indicates how much cooling power is generated per unit of drive energy consumed. Modern chillers use environmentally friendly refrigerants with low global warming potential.