AC performance tune up times one system. Inspect blower, evaporator and ductwork. System is a Zone with two thermostats. Treated drain line with white vinegar. Cast temperature drop. That was 18 degrees and we are looking for a 16 to a 20. Test thermostats for proper operations. Check outdoor unit. Refrigerant level good at this time. Test capacitor and contactor. Wash condenser coil. System operating at manufacturer specs at this time.