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Can You Mix R134a with R1234yf?

Air conditioning is not a luxury but a necessity in today’s world. Whether it’s our homes, vehicles, or offices, our comfort level is largely thanks to these coolants that keep us comfortable during the hottest days. However, the question arises with multiple refrigerants in the market: Can you mix R134a with R1234yf? Let’s dive deep into this intricate matter.

Can You Mix R134a with R1234yf?

No, you should not mix R134a with R1234yf. Mixing these two refrigerants can cause serious problems, including system damage, reduced cooling efficiency, and increased risk of leaks.

R134a and R1234yf are different refrigerants with different properties. R134a is a hydrofluorocarbon (HFC) refrigerant, while R1234yf is a hydrofluoroolefin (HFO) refrigerant. HFC refrigerants have higher global warming potentials (GWPs) than HFO refrigerants.

Why Would Anyone Consider Mixing?

The rising costs and the phased-out approach to some refrigerants might tempt some individuals or professionals to consider mixing to either extend their existing coolant’s life or transition smoothly. However, the question remains: is it safe and efficient?

What Happens if You Mix R134a with R1234yf?

Mixing R134a and R1234yf can cause the refrigerant to become unstable and form sludge. This sludge can clog the compressor and other components in the system, leading to system failure.

In addition, mixing R134a and R1234yf can reduce the system’s cooling efficiency. This is because the two refrigerants have different boiling points. When the refrigerant mixture boils, it can form bubbles that can reduce the refrigerant flow through the system.

Finally, mixing R134a and R1234yf can increase the risk of leaks. This is because the two refrigerants have different solubility properties. When the refrigerant mixture leaks, it can separate into its component parts. This can lead to the formation of a layer of R1234yf on top of the R134a. This layer of R1234yf can be difficult to remove, and it can lead to further leaks.

If you need to recharge your refrigeration or air conditioning system, use only the correct type of refrigerant. If your system uses R134a, you should only use R134a refrigerant. If your system uses R1234yf, you should only use R1234yf refrigerant.

Economic Impact of Mixing R134a with R1234yf?

On the surface, mixing might seem like a cost-saving measure. However, in the long run, it could be far more expensive. The risks of compressor failures, system inefficiencies, or even entire system replacements can cost significantly more than a proper refrigerant replacement or upgrade.

Transitioning the Right Way

For those considering transitioning from R134a to R1234yf or vice versa, the right way is a complete refrigerant evacuation, followed by a system check and then a refill with the intended refrigerant. Always ensure you are working with professionals who understand the intricacies of these systems.


In the ever-evolving world of refrigerants and air-conditioning, it’s easy to get swayed by shortcuts or perceived cost-saving measures. However, the real value lies in understanding the nuances and making informed decisions. As with many things in life, cutting corners in the short run can lead to significant pitfalls in the future.