Conference Year



DR-55, R410A Alternatives, Flammability, Safety, R-452B


Today air conditioning product and applications designers, as a result of climate change contribution concerns for high direct global warming potential (GWP) refrigerants, are being asked to consider lower GWP refrigerants with various degrees of flammability. In recent year, the HVACR industry has been actively investigating the safety of flammable refrigerants by determining their risks, potential occurrences and severity of events. Today R410A is used to cover most air conditioning applications and all lower GWP alternatives presented to date have some degree of flammability with most being ASHRAE 34 flammability class 2L.  A novel R410A alternative refrigerant blend, R452B or DR55, has recently been studied in a 4 ton RTU to determine the potential for compositional fractionation in various modes of operation. In addition, the ASHRAE flammability process needed to classify refrigerant flammability and flammability classification data for R452B will be presented in this paper. The unit compositional data and the ASHRAE classification process and data will be compared and contrasted to show differences in potential flammability interpretations and design safety implications.