One of the easiest, most cost-effective green things you can do for your building energy efficiency is to have your HVAC system condenser and evaporator coils inspected yearly and cleaned as necessary. Dirty coils force compressors to run longer and work harder than required, increasing energy usage and utility costs while decreasing component life and occupant comfort According to the U.S. Environmental Protection Agency (EPA), the U.S. Department of Energy (DOE), major utilities, and other experts, dirty condenser and evaporator coils can significantly increase HVAC energy usage and associated utility costs. The U.S. DOE says that a dirty condenser coil can increase compressor energy consumption by 30 percent.  A dirty evaporator coil decreases airflow, resulting in reduced heat transfer and a degradation of the dehumidification process. These can cause overall air quality to decline and systems to fail, and decrease the life expectancy of motors due to increased heat while running.n

Pacific Gas & Electric (PG&E) suggests an annual coil cleaning to its commercial customers as part of its ongoing efforts to promote energy-efficient HVAC-system operations. Once the system has been properly charged with refrigerant and has good airflow across the indoor coil, and assuming there is no damage to the duct system, only basic service, such as changing filters and cleaning the outdoor unit annually, should be needed to maintain the system operation at peak performance levels, says PG&En