performed a leak search, tech found a small leak at the indoor evaporator coil on the bottom right front. Tech educated homeowner on a system upgrade and would like to set up an appointment with a field supervisor, costumer is not looking forward to keep replacing evaporator coils. Costumer wanted to charge system with refrigerant to keep it from freezing up and cool better. Tech charged system with 2lbs of R410a, delta T improved and evaporator is not freezing up, indoor saturation temp above freezing point. System is cooling as of now.