R-245fa (1,1,1,3,3-pentafluoropropane) is a hydrofluorocarbon (HFC) refrigerant widely used in industrial and energy-recovery applications. Known commercially as Genetron 245fa, it serves as a drop-in replacement for CFC-11 in centrifugal chillers and Organic Rankine Cycle (ORC) systems, making it ideal for waste-heat recovery and high-power installations. With a boiling point around 15.1°C and a critical temperature of 154 °C, R-245fa provides efficient thermodynamic performance under a wide range of conditions. It is non-ozone depleting (ODP = 0) but has a global warming potential (GWP) of about 1,030. R-245fa is classified as ASHRAE B1 (non-flammable, low toxicity) and is compatible with synthetic (POE) lubricants.