You need to use Polyolester (POE) oil with R-407C.
R-407C is entirely immiscible with mineral oil, so a complete oil change to POE will be necessary when retrofitting an R-22 installation. After changing the oil, it pairs well with R22. If you prefer not to change the oil, M099 is a suitable alternative, though you might experience up to a 10% reduction in capacity.
Yes, R-407C must always be charged into the system as a liquid. Because it is a zeotropic blend of three different refrigerants (HFC-32, HFC-125, and HFC-134a), charging it as a vapor will cause the blend to separate (fractionation), ruining the ratio of the mixture and altering the system's performance.
No, R-407C is not compatible with mineral oil.
POE lubricant is recommended for use with Freon™ 407C. In order to achieve equivalent miscibility to R-22/oil, the residual oil should be about 5 wt% or less of the total lubricant used in the system. In larger systems, this amount of residual mineral oil can be achieved by using a flushing technique.
R-407C is primarily compatible with Polyolester (POE) oil. While R-22 systems often use Mineral Oil (MO) or Alkylbenzene (AB), R-407C requires POE to ensure proper miscibility and oil return to the compressor. When retrofitting an R-22 system, the oil must be changed to POE, with recommended residual MO levels below 5%.
Putting too much PAG oil in an A/C compressor leads to a phenomenon called oil overcharge, which compromises both cooling performance and hardware integrity. An excess of oil coats the inside of A/C lines, displacing refrigerant and creating a variety of system-level issues.
The general observed trend was a drop in both capacity and efficiency and also in suction and discharge pressures. It was due to a loss ofR32 which is the highest pressure component in the mixture. Flammability issue may have to be considered for vapor leaks due to the higher percentage of R32 in the leaking vapor.
Yes, R-407C is being phased out. Under the US EPA AIM Act, production and use of high-Global Warming Potential (GWP) refrigerants, including R-407C, are strictly restricted.
R22 uses mineral oil. R407C requires POE oil. Mixing them prevents oil circulation, starves the compressor, and causes mechanical failures.
R407C refrigerant requires Polyolester (POE) oil for system lubrication. POE oil is miscible with R407C, meaning it mixes well and circulates through the system to return to the compressor, whereas standard mineral oil (used with older refrigerants like R-22) will cause sludge and compressor failure.
R-407C operating pressures depend heavily on the ambient temperature. Generally, the suction (low side) pressure runs between 50 to 80 psig, while the discharge (high side) pressure runs between 240 to 320 psig in typical AC operation.
Opteon™ XP20 (R-449C) refrigerant is a hydrofluoroolefin (HFO) option that replaces R-22 and R-407C in residential and commercial air conditioners, as well as direct expansion chillers. It has similar performance and properties to R-22 and R-407C and can be used in both retrofit and new equipment.
R407C is an efficient and well-proven refrigerant that performs well in air conditioning and heat pump systems. Its biggest advantage is its similarity to R22, making it a convenient replacement in retrofits. However, due to its high GWP, it requires responsible use and compliance with environmental regulations.
R407C won't work with R410A as the discharge pressure, power consumption is also not the same. The popular recommended Freon that is compatible with R410A is R-32 and it has significantly less amount of GWP than R410A. For R407C, R134A, R125, and R32 are compatible and can go together in the natural environment.
To avoid fractionation, R-407C should be removed from the cylinder as a liquid, and charged into the suction line during equipment operation. This can be done with a liquid charging adapter, which causes the liquid refrigerant to flash to a vapor prior to entering the system.
R407C requires synthetic polyolester (POE) oil rather than the mineral oil used in many older R22 systems. This means converting to R407C often involves a complete oil change and flushing of the system to remove all traces of mineral oil.
As of January 1, 2020, the United States banned the use of the R22 refrigerant, commonly known as Freon.
A 30-pound cylinder of R-22 refrigerant is generally worth between $500 and $1,200 to purchase wholesale, and up to $2,400 to $4,500 if bought directly from a service company during a home repair.
You need at least Type II or Universal certification to buy or handle most HVAC refrigerants such as R410A, R407C, R22, etc.
R-22 refrigerant typically costs between $𝟗𝟎 and $𝟐𝟓𝟎 per pound. Because R-22 has been phased out, the supply is dwindling, which causes prices to continuously climb.
A2L refrigerants, the new refrigerants for 2026, will replace R-410A in new systems. A lot about A2L refrigerants is explained in their name: The “A” means low toxicity. The “2L” is a safety classification, indicating it is mildly flammable.
The lubricant that is currently used with R-22 is either Mineral Oil (MO) or Alkylbenzene (AB). The retrofit procedure to R-407C, recommended by manufacturers, requires a lubricant change to Polyol Ester (POE) since the solubility and miscibility of R-407C in either MO or AB are much lower than in POE.
While R-407C is the closest match to R-22 in terms of pressures and cooling capacity, it is not a true "drop-in" replacement. You cannot simply pour it into an existing R-22 system without professional modifications and a full evacuation.
For an R-407C air conditioning or refrigeration system running under normal conditions (around 80°F to 95°F ambient temperature), expect a suction pressure of 70 to 85 psig and a discharge pressure of 200 to 260 psig.