Cleaning the condenser coil is the only way to ensure the air conditioner is in good working condition and stays for long. You can do this on your own or find a professional to clean it for you. After some time, the condenser coil gathers debris which prevents it from circulating enough fresh air effectively. The first thing to do is to switch off the air conditioner and put on protective gear to keep yourself away from the dust and other dirt particles.
You can use a brush to remove the dirt from the coil depending on how much dirt the coil has gathered. Make sure you brush all the sides of the coil and do it very well before applying any cleaning solution. A gentle sprayer will come in handy for spraying condenser coil cleaner to the unit and afterwards you can spray the unit with water to rinse.