Upon arrival homeowner informed me of unit freezing outside and having to be shut off. Started unit up and inspected outdoor unit and found low on r22. Quote r22 recharge was approved, add 3lbs r422D r22 substitute. Unit is back cooling with 230psi-16°/63psi-17° Unit is 20 years old, coil is deteriorating outside. Unit should be considered for replacement soon. Homeowners also potentially interested in mini split addition to 2nd floor due to lack of cooling capacity upstairs.