A review of refrigerant R1234ze(E) recent investigations

• This paper reviews the most relevant research on R1234ze(E) (pure and mixture).
• Property, heat transfer, pressure drop and system performance studies are collected.
• R1234ze(E) properties are well-defined and allow precise calculations.
• R1234ze(E) two-phase HTC is similar to that of R134a (and higher pressure drop).
• R1234ze(E) mixtures are good lower-GWP alternatives.

Climate change is demonstrated through global surface temperatures increase in the last century. To stop this phenomenon, new regulations that ban or tax greenhouse gas fluids (HFC among them) have been approved. In the medium term, only low-GWP refrigerants will be permitted in developed countries. HFO fluids and most used HFCs as refrigerants in HVACR systems possess similar thermophysical properties. Among them, one of the most promising is R1234ze(E). This refrigerant presents good environmental properties and can be used in most of HVACR applications, pure or mixed with HFC or natural refrigerants (mainly CO2). This paper collects the most relevant research about R1234ze(E) thermophysical and compatibility properties, heat transfer and pressure drop characteristics, and vapor compression system performance; separating those works that consider R1234ze(E) pure or blended. Once the available literature is analyzed, it can be concluded that pure R1234ze(E) is a good option only in new HVACR systems. Nevertheless, if it is combined with other refrigerants, the final GWP value is also considerably reduced, maintaining efficiency parameters at levels that allow them to replace R134a, R404A or R410A in existing systems with minor modifications.