I was called to a home in Tucson, Arizona, to perform summer maintenance on a 4-year-old Ameristar split system. The customer had noticed that the air conditioner was not cooling the house as well as it had in the past. Upon inspection, I found that the evaporator coil was dirty and needed to be cleaned. I used a specialized cleaning solution to remove the dirt and debris from the coil, and then I reinstalled it. After cleaning the coil, I checked the refrigerant levels and found that they were low. I added more refrigerant to the system and then tested it again. The air conditioner now cooled the house much better than before. The customer was very happy with the results, and I was able to provide them with a quote for future maintenance services.