The gas used in an R12 system is dichlorodifluoromethane (often known by the genericized brand name Freon-12).
When finding an R12 compatible refrigerant, the best choice depends on whether you are doing a full system conversion (retrofitting) or looking for a direct "drop-in" substitute. Here are the primary options:
You shouldn't use the same oil for both R12 and R134a systems without proper conversion, as the oils are not compatible and can cause compressor failure. "R12 systems use mineral oil. R134a systems use PAG oil."
RS-24 is an easy-to-use Drop-in replacement for R12, There is no need to change the existing lubricant in the system, thereby avoiding a costly retrofit.
No, you cannot use R22 instead of R12.
R600a (isobutane) is refrigerant grade isobutane used as a replacement for R12 and R134a in a variety of refrigeration applications. R600a (isobutane) is a hydrocarbon that is becoming increasingly popular due to its low Global Warming Potential (GWP).
Yes, R32 is not only currently available, but it is the primary EPA-approved replacement for older refrigerants like R410A in new ductless and mini-split air conditioning systems.
While the production of new R12 is banned, it is not illegal to sell or use R12. In fact, many of the cylinders and cans of Freon R12 sold for decades throughout the United States are still around today.
Freon™ Hot Shot-2 (R-417C) is a non-ozone depleting A1 refrigerant that can be used as a direct replacement into existing systems that are still operating with R-12, R-134a, or R-500.
RS-24 is a “Drop-in” alternative for R12 which also provides a long term solution at the same time.
Converting an R12 air conditioning system to R134a is possible, but it requires a full retrofit. Because R134a operates at higher pressures and uses different oil, you must evacuate the old refrigerant, flush the system, replace the O-rings, install a new receiver-dryer, change the oil, and add service port adapters.
Cars manufactured before 1994 originally use R12 refrigerant (also known as Freon). This includes iconic classics, muscle cars, and daily drivers from the 1960s, 70s, and 80s, such as the 1985 Chevy Cavalier, classic Porsche 911s, and older Buick Reattas. Production of R12 is banned, so many of these vehicles have been retrofitted to use R134a.
When converting an R12 A/C system to R134a, you should initially charge it with 75% to 85% of the original R12 capacity. Do not simply top off the system; R134a is not a direct "drop-in" replacement and must be carefully converted to prevent compressor failure.
Adding R12 to an R134a system will cause severe chemical reactions, leading to compressor failure. It will damage internal rubber seals, ruin the compressor's lubrication, and create highly corrosive acidic byproducts. Mixing these refrigerants can also form a high-pressure, non-recyclable gas mixture.
R-12 (technically dichlorodifluoromethane) is a colorless, non-toxic, and non-flammable chlorofluorocarbon (CFC) gas, historically best known by the brand name Freon. It was heavily used for decades as a refrigerant in automotive air conditioning, home refrigerators, and aerosol spray propellants.
Using pure propane (R-290) in an automotive R-12 air conditioning system is not recommended and is illegal in the United States. While propane has similar thermodynamic properties, it is highly flammable. Federal EPA laws strictly prohibit venting or using hydrocarbon replacements in motor vehicle AC systems.
The most common and practical replacement for R12 (Freon) in automotive and stationary systems is R134a. However, switching from R12 to R134a requires retrofitting, which involves replacing the system's O-rings, accumulator/drier, and flushing the old mineral oil out for a compatible PAG or POE synthetic oil.
Never mix R12 with any other refrigerant. Mixing refrigerants creates unpredictable operating pressures, reduces cooling efficiency, and can cause a chemical reaction that creates destructive acids. Attempting to mix can permanently ruin a compressor and makes the refrigerant impossible to reclaim.
The price for R12 will be higher than the price for R11 or R113. This equates to the amount available in the market, as well as the equipment still in use throughout the country that rely on these old CFCs.
He said that a lot of people look to buy it and it could be well worth over $1000.
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.
No, you cannot use R22 instead of R12.
Yes, R-32 is generally considered better than R-410A due to its higher energy efficiency, lower global warming impact, and use of a single compound. However, because it is mildly flammable (A2L classification), it requires dedicated HVAC systems rather than a direct replacement.
No, you generally cannot legally buy R-32 refrigerant in the US without a license. The EPA restricts the sale of almost all regulated refrigerants and their substitutes.
Yes, R-410A is actively being phased out. Production and import of new HVAC systems using R-410A are banned in the U.S.. While the refrigerant is no longer used in new equipment, it remains legal to service and repair existing units using reclaimed or recycled supplies.