Multi-Year Evaluation of R-449A as a Replacement for R-22 in Low Temperature and Medium Temperature Refrigeration Applications

The search for replacements for the HCFC based refrigerants such as R-22, being phased out globally due to stratospheric ozone depletion issues, initially led to a series of HFC blend alternatives, such as R-407C and R-404A. While these refrigerants have no ozone depletion potential (ODP), they do in some cases have similar, or even higher, global warming potential (GWP) than the fluids they replaced. The global HVACR industry is now searching for a new generation of low GWP and zero ODP refrigerants that have similar operational characteristics and favorable energy efficiency compared to the HCFC predecessors. The Hydrofluoro olefins (HFOs), and HFO blends have recently emerged as a potential new class of low GWP, zero ODP refrigerant fluids. R-449A (XP40) is an HFO-based refrigerant blend that was initially developed as a replacement for high GWP HFCs like R-404A/507, but now is being investigated as a potential R-22 alternative in refrigeration applications as well. This paper will report the results of an extensive study investigating the performance of R-449A relative to R-22 in both low temperature and medium temperature refrigeration applications. Data presented will include results of constant compressor displacement thermodynamic cycle models, compressor calorimeter testing at various operating conditions, display case freezer testing in temperature and humidity controlled environmental chambers, and real world field system data from operating supermarkets in the United States. Operational and energy performance data for the various systems will be compared to baseline operation on R-22.