If you've done any research on refrigerants and/or new air conditioning units you have probably heard about a new-ish 'alternate' refrigerant by Dupont called ISCEON M099. Now, this refrigerant is advertised as being very similar to R-22, which will be completely phased out by 2020. Companies have found a way around this R-22 phase out by producing new units that come pre-charged with Nitrogen instead of R-22 called 'dry units'. When a dry unit is installed, it then needs to be charged with refrigerant.
There are some perks to getting M099 refrigerant, such as cheaper cost and easy retrofitting. M099 is much more similar to R-22 than R-410A when it comes to system pressure temperatures. However, issues have arisen dealing with the mineral oil used as lubrication in all dry charged units. I have come across a lot of websites that claim M099 is fine to use with the mineral oil lubricants, but Lennox has issued official warnings about using M099 in dry charged units. They have stated that:
- "Just as oil and water are not compatible, neither are alternate refrigerants and mineral oil. Use of alternate refrigerants with mineral oil can have detrimental effects on the unit. The use of an alternate refrigerant in systems containing mineral oil as their lubricant voids the manufacturer and compressor warranties."