HCFC refrigerant R409A is a blend of R-22, R-142b, and R-124, intended for retrofitting R-12 refrigeration systems. The pressure and system capacity match R-12 when the blend is running in a 10F to 20F evaporator, and there is typically 13F temperature glide in the evaporator.
Direct expansion refrigeration and air conditioning systems designed for R-12 or R-500; good success in any size system, minor adjustment of controls needed. Discharge pressure and temperature increases compared to R-12, which may be a problem in very hot ambient conditions. Capacity holds well into lower application temperatures (-30F). R-409A mixes well with mineral oil down to 0F. As a result it may not be necessary to change oil in systems which do not run colder than 0F in the evaporator (below that alkylbenzene should replace some mineral oil).