Simply rinsing the outdoor coils thoroughly will help with removing dirt and grass from the coils. Keeping the coils clean is very important in maintaining proper air flow across the coils that directly effects the system efficiency and capacity. Dirt and debris on the coils will prevent the necessary heat exchange for proper system operation. The painted metal surfaces can be washed and waxed to prevent metal corrosion. Clear Comfort can provide you with some cleaner that is easy to apply and use. Consider using Clear Comfort to keep your system clean and running as designed.