A blend of R-125, R-134a and R-600 (butane), intended for retrofitting R-22 air conditioning and refrigeration systems. Runs slightly lower suction pressure and lower discharge pressure than R-22.
There will also be a drop in discharge temperature compared to R-22. Lower pressures can affect valve operation or selection of orifice tube. The blend will produce lower capacity than R-22, especially at lower suction temperatures.
Addition of hydrocarbon to the blend improves oil return with mineral oil and alkylbenzene oil, however the lubricant may still separate from the refrigerant. In some applications polyol ester (POE) lubricants may be needed.