Daikin has developed a new refrigerant blend, which the Japanese company says is a more efficient alternative to R1234yf in electric vehicle HVAC systems.

The new development gas, D1V140, is designed to reduce the energy draw of the heating and cooling systems in electric vehicles and thus improve the vehicles’ range.

Unlike conventional internal combustion engined vehicles, in winter electric vehicles cannot use the engine waste heat for heating the interior and must draw the power from the battery. Previous research has shown that the capacity of a R1234yf vehicle heat pump system reduces by up to 40% when the ambient temperature drops from 0℃ to -10℃. This is recognised as a significant problem in colder climates by motor manufacturers.

The new Daikin refrigerant blends R1234yf with 23% of a new hydrofluoro-olefin refrigerant HFO1132(E). Not very much is known of HFO1132(E) but it is thought to possess a GWP of 3. Daikin maintains it is less than 1.

Initial evaluations, however, are said to have shown that the refrigerant provides good performance for heat pump function in electric vehicles in cold regions and good cooling performance in warm climates.

Daikin is said to be working with the Society of Automotive Engineers to confirm safety and performance of the new D1V140 blend and both the blend and HFO1132(E) were submitted last month for registration to ASHRAE34. They are both expected to be designated as an A2L.

A number of patents have been registered by Daikin for HFO1132(E), for both its production and its application in a variety of different blends, including D1V140.

HFO1132(E) is one of three possible forms, or isomers, of the chemical difluoroethylene. All possess the same chemical composition, but are differentiated by their arrangement of atoms. The others are HFO1132(Z) and R1132a, a refrigerant recently registered with ASHRAE by Koura.