410A v. NU22 systems

[flagship1]

The new R410a systems and all others that us the POE oils do have risks that the end user should be aware of, that being the highly hygroscopic nature of this refrigerant oil.
When POE oil is exposed to the atmosphere it quickly absorbs the moisture in the air which forever changes the oil into a highly acidic/caustic substance that destroys copper, aluminum and just about anything else it comes into contact with, unlike the old fashioned R22 mineral oil that returns to its original pristine state when you boil off the moisture with a vacuum.
This can result in the necessity to actually replace every inch of copper lines, every evaporator/fan coil, the expansion valve, accumulators, filter direr, compressor and all components exposed to the caustic oil, which can be very problematic, time consuming as well as expensive.
Of course in Fantasy Land this is never a problem because every technician if fully versed and prepared to deal with this, but even so, in the event of a refrigerant leak you will need to yank the compressor and hold it upside down for 24 hrs to remove the old oil and flush the entire system before replacing the oil and recharging.
At Flagship Marine we prefer living in the real world and strive to make equipment as "sailor proof" as possible. These oils are not in keeping with our strict adherence to the KISS principle (Keep It Simple Stupid), so we continue to use mineral oil with the new environmentally friendly R22 replacements such as NU22, AKA R422b which are readily available and over the counter and will be so for a long time to come.

Tom Martland
Flagship Marine, Inc.
Stuart, FL 2/4/12