In the technical service group we are regularly asked if an alternative refrigerant can be used in existing R-22 systems without changing the mineral oil. There is no single answer to the question as there are so many alternative refrigerants in the marketplace and many applications to consider. The most widely accepted alternative refrigerants include NU-22B, MO99, R-422D and R421A. Each include as part of the “blend” hydrocarbon (HC) components and carry A1 safety designation. Using HCs to improve oil return dates back several decades in refrigeration applications meaning the industry has data to understand how it performs in real world applications. The bottom line is this: HC’s are not miscible with mineral oil so the use of alternate refrigerants must be avoided.
If you have any questions please don’t hesitate to contact our technical services group and we’d would be glad to evaluate your specific application.
