Comparative performance analysis of HFO1234ze/HFC134a binary mixtures working as a drop-in of HFC134a in a domestic refrigerator

The aim of the investigation has been to register and to evaluate the energetic performances of HFO1234ze binary mixtures with HFC134a, working as a drop-in refrigerant in a domestic refrigerator. A number of different tests have been conducted in order to establish, firstly, the optimal charge through pull-down tests and, once found, to evaluate energy consumptions during 24-h tests. The experimental investigation follows the prescriptions of the UNI-EN-ISO 15502. The results collected demonstrate that a binary mixture HFC134a/HFO1234ze (10/90% weight) is characterised by a lower environmental impact in terms of global warming despite employing HFC134a. Indeed, both the indirect and the direct contribution to global warming are reduced. The direct contribution depends on the GWP of the refrigerant fluid that for the mixture is lower than 150 according to UE regulation 517/2014. The indirect contribution depends on the energy consumptions and the energy saving with HFC134a/HFO1234ze mixture is around 14%.