DCM2 service 2 of 2 AC completed changed (1) 16x20x1 (1) 16x25x1 filter, tested system operation’s everything is operating properly with upstairs system main floor charge readings look low roughly 1-2 pounds of R22. R22 is no longer in production and is discontinued as of 2020. Adding refrigerant will only provide temporary comfort and will not fix leak. System is 29 years old average lifespan is 10-15 years due to age and condition would recommend replacement. Attached is AC maintenance checklist.