Conversion of a direct to an indirect HFC134a/CO2 cascade system is analysed experimentally. Refrigeration system supplies cooling needs of two cabinets (2 and −20 °C) inside a climatic chamber. A decrease between 1.9 to 3.5 K of the evaporating temperature of the high temperature cycle has been measured. When using propylene-glycol/water mixture (40% vol.) as secondary fluid energy consumption increases from 7.6 to 14.0% regards the direct system. When using Temper −20 as secondary fluid energy consumption varies from −0.3 to 11.1% regards the direct system.