Conference Year



air conditioning, DR-55, XL55, DR-5A, XL41


R-410A is one of the most widely used fluids for small and mid-sized air conditioning systems globally. While R-410A has many positive attributes for cooling, it is the subject of valid criticisms regarding its high direct global warming potential (GWP) and environmental impact.  Although no single refrigerant fluid has yet been developed that meets every proposed requirement for use in conventional R-410A type stationary air conditioning system designs, blended HFO-based refrigerant compositions have been developed and optimized to provide improved overall safety and performance, while retaining significant environmental sustainability properties versus the legacy refrigerants. This paper discusses two potential alternative fluids, DR-55 and DR-5A, that have been developed to most nearly meet the most often cited sets of environmental, physical and performance properties for air conditioning. DR-55 and DR-5A are optimizations of GWP, flammability, and performance while retaining compatibility with existing R-410A system designs to enable an orderly transition to low GWP.  Data presented will include thermodynamic properties, performance test results, thermal stability, lubricant miscibility, and materials compatibility compared to the existing refrigerant. Performance will be evaluated in a residential air conditioning system designed for R-410A with minimal equipment modifications at both standard air conditioning and high ambient temperature operating conditions. These new refrigerant blends provide useful options to help maintain the quality of life and health benefits from air conditioning and refrigeration, but in an energy efficient, cost effective, and environmentally sustainable manner.