A wise engineer once told me that “lubrication is the secret to life” and that is certainly the case when it comes to AC system compressors. Design and development engineers strive to find the proper balance between adequate oil charge to lubricate the internals of a compressor and having too much oil in the system. Too much oil will degrade AC system performance by inhibiting heat transfer in the condenser and evaporator. Overcharging a system with oil can also cause problems with variable displacement compressors that use mechanical control valves. When it comes to oil in an AC system more is not better.
My colleague, Richard Hawkins, from the 1-800-Radiator & A/C technical support group reviewed the topic of “A/C System Lubrication System Issues & Concerns” at the 2020 MACS Conference in Nashville, TN. Some lubrication and service issues are summarized in these slides from his presentation at the conference.
MACS members can find Richard’s entire presentation at:
https://www.macsw.org/web/MACS/MACS_Member_Only_Content/Training_Event_Archives