New Refrigerants and Oils – System and Component Material Compatibility Issues
Posted on Wed, Jan 18, 2012
by Ed Eisermann, Sr GEA Associate
This is the final posting in our multiple segment blog "Six Keys To A Successful Refigerant Transition" series ran in recent months (see part 1)
Recent blogs have discussed the topics of the rapid changes in refrigerant compounds to reduce global warming and protect the environment for future generations. The one topic that has not been covered in depth has been the compatibility of these refrigerants and refrigerant blends on the many materials and components within an air conditioning system.
Early in my career, HCFC 123 became a key refrigerant for large tonnage Centrifugal products as a replacement for R-11. R-11 had been used for decades and many did not anticipate the substitution of the HCFC 123 compound for R-11. Plastic and rubber products reacted differently with HCFC 123 than they did with R-11. When in contact during the refrigerant cycle certain materials swelled and adhesives used for spliced vulcanized O-ring joints failed just to mention two.
No one anticipated the impact of changing to HCFC123. The manufactures of O-rings, valves and sensors did not study the impact of their components and potential effect or consequences to the HVAC products using them. Laboratory testing somehow did not uncover the problems resulting from extended exposure to HCFC123.
I write this blog post to alert the audience of the potential issues. My recommendations to readers are the following:
- Keep your material and component suppliers in the loop to redesigns that will use new refrigerants and oil bends.
- Understand what non-metallic materials are in their valves, distributors etc. that have the potential of being impacted by these refrigerants and oils.
- Work with your suppliers of refrigerants and oils to determine whether they have done long term studies on the effect of their products on the material used by your HVAC component suppliers.
- Make sure that during your transition period there is control of items such as O-rings and components if there is any Form-Fit or Function impact.
- If there is a “FFF” impact, ensure that service literature is revised to highlight the importance of component interchangeability. A “Service Alert” may be warranted.
- Alert the service industry to be prepared for segregation and management of the current and new refrigerant and oils that will be in the new product versus the current installed product.
- Lastly, remember that refrigerants and oils are not always compatible in an HVAC system. As new refrigerant compounds are developed, it is important to understand their long term compatibility with the HVAC products .