Performed AC cool check. Checked electrical, mechanical, safety, and performance of the system. Replaced Aprilaire media filter. Found the system to be low on refrigerant. I performed a leak check and found a leak in the evaporator coil. No other major issues were found. Options for repair were presented to the customer and they chose to have refrigerant added today. I added 2.5 lbs of R-410A refrigerant and the system was running at the time of departure.