Performing semiannual air conditioning maintenance tune-ups on two AC systems in a residential home. Programming thermostat, changing air filters, testing safety controls/detectors, balancing airflow, assessing ductwork, taking vital readings, and evaluating HVAC system performance. Recommending contactor, capacitor, UV coil treatment, and compressor saver. Installing REME Halo UV light. Systems are cooling and ready for Summer weather.