How to Clean AC Coils
How to Clean AC Coils


For comfort creatures, warmer weather and air conditioning have gone hand in hand since Willis Carrier invented the modern air conditioner in 1902. But it's definitely not cool when the air conditioner stops working unexpectedly, leaving the entire household in a sweltering scenario. Like any machine, basic cleaning and air conditioner maintenance is necessary for appliance longevity.

There are two types of coils involved in the operation of your air conditioning system: evaporator and condenser coils, each serving a different function. The evaporator coil absorbs heat and humidity from your home, and is located on the interior portion of the appliance. The condenser coil is located on outdoor units (thus making it more susceptible to accumulating dirt), and is intended to release excess heat to the outside. These coils tend to be made of copper, and are generally surrounded by a set of aluminum fins for helping to improve heat transfer.

Air conditioner condenser coils capture heat from the air inside your home, and tend to collect dirt and debris easily when in regular use. This buildup can force the fans and compressors to work harder, increasing the temperature of the unit and reducing cooling efficiency.

Less efficiency means higher energy costs, and increased risk of system breakdowns resulting from overworked components. This can lead to service calls, component replacement, and the potential need to replace the entire system.

Knowing how to clean AC coils is a money-saving DIY skill, an easy way to maintain efficiency and save on energy costs. Regular, bi-monthly coil cleaning with Simple Green All-Purpose Cleaner during warmer months will keep your AC unit in great working order for years to come. These steps can also be used to clean compressor coils in the outside cabinet of your AC.

Directions for Cleaning AC Coils:

If your AC unit is still under warranty, check the warranty document to make sure self-cleaning doesn't void the warranty.

  1. Turn off the AC at the thermostat and shut off power to the condensing unit.
  2. Remove outer case and caging. Remove the bolts that are attaching the lid to the rest of the condenser, avoiding the bolts that hold the fan to the lid. If your air conditioner's fan assembly is at the top of the unit, be careful not to stretch or damage any wires. If you can't proceed without doing this, contact a professional.
  3. Clear out debris and broken fins. Remove any broken aluminum fins (aluminum fins improve heat transfer) as well as leaves, dirt or dead insects that have gotten into the unit. This helps prevent corrosion and increases airflow.
  4. Spray out the unit. Use a hose to spray out your AC unit, without spraying the disconnect or the electrical components inside the access panel.
  5. Spray the coils down with Simple Green All-Purpose Cleaner. Cover the condenser coils entirely with the cleaner. Let the Simple Green sit 10-15 minutes to penetrate heavier soils, and then hose it down again. After the coil cleaner has dripped off the coils, examine the coil surfaces for any areas that may need another application, and repeat this step as necessary.
  6. Rinse and dry your AC. Spray rinse water from the inside outward, clearing away any remaining residue. Dry off with a clean cloth or paper towel.
  7. Inspect coil fins for damage: Carefully straighten any bent coil fins.
  8. Reassemble the air conditioner: Reassemble your air conditioner now that your coils are clean, and reconnect power to the condensing unit.


Sign Up For Our Newsletter

Join Our Mailing List