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 10°F to 20°F evaporator, and there is typically 13°F temperature glide in the evaporator. Applications: 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 (-30°F). R-409A mixes well with mineral oil down to 0°F. As a result it may not be necessary to change oil in systems which do not run colder than 0°F in the evaporator (below that alkylbenzene should replace some mineral oil).