Vapour absorption system is an attractive method for using the low grade energy directly for cooling simple vapour absorption system consists of an absorber, a pump, a generator and a pressure reducing valve to replace the compressor of vapour compression system. The other components of the system are condenser, receiver, expansion valve and evaporator as in the vapour compression system. In Lithium bromide absorption system, a solution of lithium bromide and water is used. Water is being used as the refrigerant and Lithium bromide acts as an absorbent. Lithium bromide is a hydroscopic salt with high affinity for water vapour due to its very low vapour pressure. This system is generally used in air conditioning systems due to not very low temperature (above 0˚C) requirements. In this... paper the effect of performance parameters on the thermodynamic performances of double effect Li/Br H2O system cascaded by vapour compression refrigeration cycle at -52oC of evaporator temperature have been studied in detailed and it is found that performance of double effect vapour absorption refrigeration system cascaded with vapour compression system using HFO-1234yf ecofriendly refrigerant has 5% to 8% lower thermodynamic performances in terms of overall coefficient of performances, exergetic efficiency) than double effect Li/Br H2O vapour absorption refrigeration system cascaded with vapour compression system using HFC-134a ecofriendly refrigerant.