Came out to call for a system not cooling well. Customer stated that the system doesn’t keep up with desired temp. Customer had father in law meet me at home. System was set at 75 and it was 73 in the home when I checked the thermostat. Checked system over and found condenser operational but the coil plugged with debris. System needed a thorough cleaning before I could address anything else. Cleaned the condenser coil thoroughly and cycled unit on from thermostat. Checked amps, temperatures and pressures of condenser. Systems pressures were below recommended range. Discussed with customer about possible leak in system and options moving forward. Customer chose to not do a leak search on the system and just add refrigerant at this time. Stated she believes they had to add some last year or the year before. Told her I couldn’t guarantee how long the refrigerant would last in system, but unit wasn’t too far out of range. Customer approved adding a pound for now and see how the unit does.