Can I Mix HVAC Refrigerants?

Refrigerants are a critical part of your air conditioning system—they’re the substance that can turn hot air cool. As a result, refrigerant leaks are problematic and one of the more frequently diagnosed issues with an HVAC system. But if your A/C runs on an older or discontinued type of refrigerant, you may wonder if the solution is as simple as “recharging” it with a different type of refrigerant. Below, we discuss a few key facts about refrigerants and what you should know about the different types available.

Can I Mix Refrigerants?

Unlike many HVAC-related questions, the answer to this is an unequivocal no. This is true even if a product is advertised as mixable or even if a technician tells you it’s OK to mix!

Different refrigerants use different oils to lubricate the system, and these oils don’t mix. What’s more, different refrigerants operate at different pressures and mixing them makes it all but impossible to predict how they will perform. This can make it very difficult to diagnose problems later, and poses a risk to any technician who must later make repairs. Trying to blend refrigerants can also cause premature compressor failure and can impact how well the system cools your home.

Why is Mixing Refrigerants So Tempting?

Several years ago, one of the most ubiquitous and popular refrigerants, R22 (aka Freon) was phased out. But while R22 is no longer produced in or imported to the U.S., the supply that existed when it was outlawed will continue to be used until it is depleted. The result is a simple matter of supply and demand: while recovered and recycled R22 remains available, the price of this substance continues to rise as it becomes harder to get.

R22 uses mineral oil, while most refrigerants manufactured today use polyolester (POE) oil. As suggested above, these oils don’t mix well together, and before R22’s phaseout, technicians who suggested blending refrigerants would face ridicule from their peers.

But when homeowners are faced with an air conditioner that still uses R22 and has a refrigerant leak, they have a tough choice: replace the entire unit, purchase R22 at a premium price, or mix R22 with a “drop in” refrigerant. This third option can seem like the obvious one from a financial standpoint—at least until you realize that mixing refrigerants will accelerate the death of your current air conditioner.

What Should Homeowners Understand About Refrigerants?

One common misconception about refrigerants is that they’re consumed by the unit. A refrigerant circuit is a closed system. Unless it has a leak, it should never need to be refilled with refrigerant. This means that if your unit does require a refrigerant recharge, simply refilling it isn’t enough—you also need to detect and repair the leak.

It’s also important to understand that R22 is an old technology that was phased out to be replaced by more eco-friendly refrigerants. This means if you have an HVAC system that still uses R22, it’s likely nearing the end of its natural life anyway and it no longer makes financial sense to invest a lot of money in repairs.

While blending refrigerants is never advised, some owners opt to do so to extend their HVAC unit’s life by a few months—knowing it will likely accelerate its ultimate end. Bearing in mind the potential pitfalls before you take this step is of the utmost importance since there’s no coming back after you’ve mixed R22 with something else.

Who Should I Call?

If you need help with a refrigerant leak or want to investigate your replacement options, give the skilled technicians at North East Air Conditioning, Heating & Plumbing a call at (210) 658-0111 or visit our website to set up an appointment. We’ll work with you to find the best solution for your needs and budget.

Header photo by Alex Kondratiev on Unsplash


Call: 210-658-0111