Abstract
With the effort to find alternative refrigerants with lower global warming potential (GWP), challenges have arisen due to the flammability risk for many of the alternatives. One of the new alternatives is R-452B, which is recommended as a replacement for R410A. R-452B is classified as a mildly flammable refrigerant (A2L) by ANSI/ASHRAE Standard 34. This paper summarizes a computational fluid dynamic (CFD) simulation study of a leak incident of R-452B from a 3-ton packaged unit which serves a 167 m2 residence. The R-452B leak is assumed to be downstream of the evaporator coil. The simulated residence has four rooms and a hallway. The packaged unit distributes the conditioned air through a supply duct system delivering the air through registers. The dispersion of R-452B is characterized for two scenarios: one with underfloor supply air ducts and another with ceiling supply air ducts. The mass flow rate of R-452B exiting the duct outlets is quantified and the refrigerant volume fraction is monitored inside the residential space.
