Performed AC cool check. Checked electrical, mechanical, safety, and performance of the system. System was low on refrigerant. Leak check was performed but no leak was found. Mold and mildew were found inside air handler. Drain line cleared and treated. Condenser coil cleaned. Options for repair were presented to customer and they chose to have the system charged with refrigerant and to install our Breathe Easy Package - Stage 3. System was charged with refrigerant and is now operating at 10 degrees of sub cooling. Breath Easy Stage 3 has been installed. Electrical disconnect confirmed in and on. System was running at the time of departure.