How to Clean Air Conditioner Fins

When your air conditioner merely groans and pushes warm air around you'll wish you took the time to clean it before you installed it in your window.

Rear condenser finsRear condenser fins
In addition to cleaning or replacing the filter, open up your unit to thoroughly clean the fan, grills, evaporator fins, and condenser fins. Not only will you have a comfortable summer, you'll have a lower electric bill.

Remove the front grill from the air conditioner by gently pulling it forward and pushing down at the same time. Sometimes, the grill is mounted with screws, so if it cannot be removed easily, look for hidden screws. They may be on the top edge of the grill or around the control panel.

With the screwdrivers and socket wrench, remove all of the screws that mount the metal cover to the air conditioner. Then lift the metal cover straight up, taking care not to let the sharp edges hit the inner parts.

Cover the motor with cloth rags to protect it when you clean and rinse the fins.

Use the paintbrush or vacuum cleaner to remove dirt and debris from the surface of the evaporator front fins. Brush in the direction of the fins (up and down) and not side to side. The fins are made of soft aluminum and will bend easily.

Spray the fins thoroughly with the degreasing cleaner and wait 15 minutes (or as instructed on the can) to allow the dirt to loosen.

Slowly pour warm water into the fins to rinse off the cleaner and remove the dirt. Then drain the runoff. Keep the water and runoff away from the motor, electrical components and connections.

Straighten any bent fins with a fin comb. Doing so will increase the airflow through the evaporator coils and improve the overall cooling effect.

Repeat Steps 4 through 7 for the condenser rear fins.

Wipe off any excess water and runoff, then let the air conditioner dry out for a few hours.

When the air conditioner is completely dry, plug it in to test its performance. If it works properly, the air conditioner can be reassembled.

Things You Will Need

  • Phillips-head screwdriver
  • Flat-head screwdriver
  • ΒΌ inch socket head and socket wrench
  • Heating, Ventilation and Air Conditioning (HVAC) cleaner, spray detergent or other degreaser
  • Fin comb
  • Paintbrush (or vacuum cleaner with soft brush)
  • Cloth rags


  • While the air conditioner is apart, take the opportunity to oil the motor, and to clean the fan blades and grill assembly.


  • Do not use high-pressure water to clean and rinse the fins. Doing so may damage the fins and is highly dangerous, because the coils are pressurized with refrigerant.

About the Author

Dwight Romulo Valdez, M.A., FAAA, has been writing health and technology articles since 2008. His articles have appeared on and Valdez has been in the hearing health care profession since 1983 and currently runs an audiology practice in New Hampshire.