As the weather starts getting warmer and contractors are finding older equipment that use R-22 refrigerant that appear to be low on charge or have some other refrigerant issue, the question has been coming up, “What ALTERNATIVE refrigerant should I be using since R-22 is so expensive and is being phased out?”
As you may already know, the EPA began to limit the amount of R-22 that can be made (see post on Refrigerant – R-410A vs R-22). These reductions have already started to show up in the form of higher costs for R-22. As a result, contractors want to know what an approved alternative refrigerant for R-22 is to keep their customer’s cost down and still maintain existing operating equipment.
I have been doing a lot of research on this and I’ll let you know what I have found out. First of all, if you are doing refrigeration, you probably have been using alternatives like R-421A or COOL 50, or Dupont’s MO99 (R-438A) for some time now. Most of these have been approved by the compressor manufacturers for use in refrigeration applications.
However, Copeland and other compressor manufacturers have NOT approved these for A/C applications. Because of this, if you use any of the alternative refrigerants, you will void the warranty on that compressor.
What Copeland is saying: These refrigerants are not approved for use in any air conditioning system using Copeland Compressors.
They further state: A number of these refrigerants with properties similar to R-22 have been introduced in the service market that include R-417a, R-422A/B/D, R-434A, R-438a and R-421A. The capacity and efficiency of most of these refrigerants are lower than R-22, while the GWP values are significantly higher. In addition to the performance loss, sufficient AIR CONDITIONING SYSTEM testing of these service refrigerants has not been done to understand their oil return characteristics and therefore, their long-term reliability.
So, if you don’t want to “get into trouble” down the road with warranty, the recommended service replacement for R-22 is R-407C and POE oil. Keep in mind, since the alternative refrigerants have lower capacity and efficiency, are you really doing your customer a favor if it costs them more in the long run in energy consumption? And, if you care about the environment and Global Climate Change, these alternate refrigerants have a higher GWP (global warming potential) than R-22.
One last thing — you should check with your system manufacturer to understand the implications of field retrofitting refrigerants. I do know some manufacturers are approving alternative service refrigerants so be sure to check with them to see what they are approving and for what equipment..
Ultimately — though I neither condone nor condemn this — if the system is out of warranty, you pretty much can do what you feel is in the best interest of your customer when it comes to using alternate service refrigerants. Be sure to follow the refrigerant manufacturer’s recommendations for using these alternate service refrigerants and what you need to do in regards to the existing lubricant (oil) in the system, which may require the addition of POE oil as well as other measures. Just remember — though they do cost less and that could be a benefit to your customer, they also are less efficient and do have the higher GWP — You should discuss it with your customer, educate them, and give them the option.
Attached are 2 bulletins from Copeland which provided some of the information for this post. Be sure to look them over completely. I also highlighted some passages for your quick reference.