I was called to a home to perform preventative maintenance on an Amana AC system. The customer had noticed that the unit was not cooling as efficiently as it had been in the past. I inspected the unit and found that the coils were dirty and needed to be cleaned. I also checked the refrigerant levels and found that they were low. I added more refrigerant and performed a leak test to ensure that the system was sealed properly. After the maintenance was complete, the customer noticed a significant improvement in the cooling performance of the unit.