R-404A, Transport, Refrigeration, DR-34, Compressor discharge temperature
A primary reason R-404A has become the preferred refrigerant for commercial refrigeration over the last two decades is its low compressor discharge temperature which provides excellent protection for compressors and significantly improves their operability and durability. However, R-404A with a 100 year global warming potential (GWP) of 3943 is also one of the highest GWP refrigerants in use today and has been targeted by various regulatory agencies for potential phase-down or phase-out. Several reduced GWP options have been proposed using blends of HFCs and hydrofluoroolefins (HFOs) that are around 1300 GWP. However, these blends have increased compressor discharge temperature and in some applications may require external compressor cooling. A new non-flammable refrigerant DR-34 has been developed which has a compressor discharge temperature only 1-3K higher than R-404A and closely matches all other properties and performance. DR-34 has a GWP of 1945 and is designed to meet GWP limits in the European F-Gas regulation. This refrigerant will be particularly suitable for transport refrigeration where compressor cooling is difficult to manage under a wide range of ambient conditions. The properties of DR-34 including thermodynamic properties, lubricant miscibility, as well as system testing will be presented.