R-401b

A blend of R-22, R-152a, and R-124 intended for retrofitting R-12 in lower temperature refrigeration systems. The pressure and system capacity match R-12 when the blend is running below 0°F in the evaporator. The B version can also be used in R-500 air conditioning systems. The 8°F temperature glide in the evaporator may result in changes to control settings. Discharge pressure increases compared to R-12, as well as an increase in discharge temperature. The R-152a content, an HFC, hurts the miscibility with mineral oil. It is recommended to change some of the oil to alkylbenzene, especially at lower evaporator temperatures.