A condenser coil should be cleaned at least once a year to ensure your air conditioner is blowing cold air, is running efficiently and extend the overall life of your air conditioning unit.
Keeping your condenser coil clean will help keep your air conditioner running at maximum efficiency. A clean condenser coil is one of the easiest ways to save energy while increasing the efficiency of your HVAC system. A clean coil will also allow your compressor to run cooler and extend its life. The images below show the exterior of a condesner unit before and after cleaning.
Monster Vac recommends cleaning the condenser coil at least once a year. Generally the beginning of the warm months is the best time. Over the course of the summer and throughout the year, the condenser coil collects a lot of debris such as grass clippings, dirt and leaves. With exposure to these elements a condenser coil can become dirty and inefficient within a short period of time.