The expansion valve setting for R-1234yf refrigerant is different compared to R-134a. Changing from R-1234yf to R-134a refrigerant may result in a system with incorrect refrigerant flow and heat exchanger mal-distribution which may cause a loss of cooling performance or durability concerns.
Still, the answer is an emphatic, “No.” Not only would a retrofit of this type negate the environmental benefits of R-1234yf, but it would also be a violation of Federal Law under Section 203 of the Clean Air Act: “tampering” with a vehicle's emissions control device.
R-134a and R-1234yf systems have unique fittings so they can only be used with the appropriate corresponding refrigerants and equipment. R-1234yf is very expensive. This has led to end-users trying to replace the refrigerant in vehicles originally containing R-1234yf with R-134a, in an attempt to save money.
The cooling capacity of R1234yf used as a drop-in replacement in a R134a refrigerant facility is about 9% lower than that presented by R134a in the test range. This difference in the values of cooling capacity obtained with both refrigerants decreases when the condensing temperature increases and when an IHX is used.
The ACX universal flushing unit is designed for refrigerants R134a and R1234yf. A proper flush of the air conditioning system is one of the most important tasks to be carried out during repairs and after the replacement of a compressor.
HFO-1234yf (R-1234yf ) has a global warming impact value of 1 versus 1300 for R-134a. It breaks down chemically in the atmosphere in only 11 days versus 13 years for R-134a! While R-1234yf oils are backwards compatible with R-134a systems, R-134a PAG oils are not compatible with R-1234yf systems.
Most vehicles have a label or sticker under the hood that indicate whether the refrigerant used is R-134a or R-1234yf.
Switching to R1234yf refrigerant is a step towards a greener future, but it comes with higher costs due to advanced equipment, stringent regulations, and specialized training.
You cannot mix refrigerant types, and putting the wrong refrigerant in your car will cause damage to the air conditioning system! If you're not sure which kind of refrigerant your vehicle takes, DIY A/C charging may not be for you.
However when the condensing temperature gets lower, R1234yf outperformed R134a. Over the range of operational conditions tested, the maximum difference in terms of cooling capacity is less than 5% and the COP is less than 10%.
Technically yes, as the pressures are similar. In fact an empty R1234yf system could even be recharged with R134a and still work - this is why they changed the connectors again, and in part why the R1234yf recovery machines are designed to sense if the refrigerant is contaminated with R134a and abort.
The best way to recover contaminated or unfamiliar refrigerants is to dedicate a recover-only unit to impure refrigerants. Some equipment manufacturers also offer recover-only units designed to remove these refrigerants. Some refrigerants might be contaminated with flammable substances such as propane and butane.
In with the new
The new refrigerant type uses ND-oil 12, also a PAG 46 oil but with additives specifically for the R1234yf type refrigerant.
Vehicles with R-1234yf have different service fittings than R-134a vehicles to prevent cross-contamination with different refrigerants. Also, it's illegal to put R-134a or any other refrigerant into a car originally equipped with R-1234yf.
Refrigerant types are not to be mixed. The usage of dyes and sealants is discouraged.
In the United States, vehicles produced after 2021 no longer contain R-134A in the air conditioning system. In other parts of the world, including the United States, there are restrictions around using 1,1,1,2-tetrafluoroethane. Specifically, in California, retailers can deny selling customers canned R-134a.
There are three refrigerants that can be used to replace R-134a: R-1234yf, R-152a, and R-744.
R-1234yf is used in almost every new car sold in the U.S., but the EU is discussing a ban and the industry is investigating alternatives like CO2 and propane.
Please remember that using the wrong type of refrigerant for your system can create a hazard or cause serious damage so it is very important to get it right. Don't worry though, as AC Avalanche recharge hoses can only work on systems of their respective type, eliminating the risk of using the wrong type.
An AC leak will lead to warmer air from your vents over time. In most cases this can be fixed with a proven stop leak additive to seal up any leaks. When it's time for an AC recharge, turn to AutoZone.
If you are purchasing less than 2 pounds of either R-134a or R-1234yf, you are not required to have a license to purchase either refrigerant. However, if you are working with 10- and 25-pound single-use recyclable cylinders you will need Section 608 Technician Certification.
Most cars hold between 28 and 32 ounces of refrigerant (or about 2—3 12oz cans), however larger vehicles and those with rear A/C will likely hold more. Check your vehicle manual for the system capacity for your specific vehicle.