Great question. Per the installation manual, page 11 states the following: "Likewise, it is important to keep the outdoor coil clean. Dirt, leaves, or debris could also restrict the airflow. If cleaning of the outdoor coil becomes necessary, hire a qualified servicer. Inexperienced people could easily puncture the tubing in the coil. Even a small hole in the tubing could eventually cause a large loss of refrigerant. Loss of refrigerant can cause poor operation and/or severe equipment damage." If you have any further questions or need further assistance, please feel free to reach out to one of our experienced customer service representative and they would be happy to assist you. Thank you and have a wonderful day.Installation Manual