Can You Mix Different Refrigerants in Your HVAC Unit?

Discover the potential risks and consequences of mixing different refrigerants in your HVAC unit. Trust Sandium for expert advice.

Updated on Oct 22, 2023
5 min read
Can You Mix Different Refrigerants in Your HVAC Unit?

Many Bay Area homeowners wonder whether they can mix different types of refrigerants in their air conditioning system with the R22 phase-out almost complete. The direct answer is that different refrigerants should not be mixed. Keep reading to learn more about when an unscrupulous contractor may recommend this and the things that can go wrong.

When Do Contractors Recommend Mixing Refrigerants?

There are a few reasons why a contractor or technician may mix refrigerants in your air conditioning system. The foremost reason is because of the cost. A regular jug of R22 costs almost 3 – 4 times more as compared to other types of refrigerants. Another common reason is that the technician is misinformed. Amateur contractors may not realize that they cannot ‘top off’ using a different type of replacement refrigerant.

The correct way is to fully recover, evacuate, and replace the refrigerant completely when using replacement refrigerant. Make sure you ask the AC contractor about the refrigerant they would be using before you agree to the repair.

Impact of Mixing Refrigerants in an AC System

Mixed AC refrigerants can result in changing temperatures and increased system pressure that can prove to be bad for your system. Your air conditioner may suffer from ineffective compressor cooling, metering device malfunction, ineffective cooling, and possible compressor damage.

It is common knowledge that different refrigerant types are not meant to be mixed. Every refrigerant has a specific pressure–temperature chart that is used for reaching the correct charge levels. There is no given charge that can be referred to when different refrigerants are mixed together. This means the refrigerant will not be charged properly, which can result in reduced system lifespan and efficiency and overheating.

These are a few things that can potentially go wrong when you mix refrigerants in your air conditioning unit:

1. The system may overheat

Different types of refrigerants have different pressure and sitting temperatures. You may inadvertently cause the unit to overheat. Different refrigerants don’t mix like oil and water don’t mix. This will cause different temperatures to cycle through the system, which can result in a burnt motor in the air conditioning system. This is a costly repair and one you don’t want.

2. Inefficient running

Your HVAC system will need to work harder to cool the home where there are different refrigerants in it. This will result in a loss of efficiency and an increase in energy costs.

3. Compressor damage

An air conditioner is susceptible to potential damage with mixed refrigerants. This includes damage to the compressor as a result of unpredictable pressures and temperatures. There is also a potential loss of adequate oil return to the compressor, which adds to the compressor strain. Different pressure points can push against the coils causing them to become misshapen and burst.

Mixing Refrigerants is Against the Law

Another reason to not mix refrigerants is that it is illegal because of the phasing out of R22. While it is highly unlikely that the EPA would persecute you for this, it is still not a judicious idea. Refrigerants that aren’t mixed can be reclaimed and reused. However, once mixed, the refrigerant has to be incinerated. Mixed refrigerants are not just hazardous to the environment, but also to technicians.

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