I was called to a home to perform maintenance on an air conditioner. The customer reported that the air conditioner was running well, but they needed a new filter. I inspected the unit and found that the filter was dirty and needed to be replaced. I removed the old filter and replaced it with a new one, ensuring that it was properly installed and secured. I also added refrigeration to the unit to improve its cooling performance. After completing the maintenance, the customer was satisfied with the results and thanked me for my service.