How to Clean an Outside AC Unit

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Things You'll Need

  • Shop vacuum

  • Clean cloth(s)

  • Water

  • Motor oil (if necessary)

Cleaning the outdoor air conditioner unit will help improve overall performance

Many homes and businesses use an air conditioning unit comprised of an outdoor unit and an indoor unit or thermostat in order to provide cooler air during warmer months. While most air conditioners can be expected to work well, this performance can be improved or maintained with some basic cleaning on a regular basis. Cleaning the outdoor air conditioner unit will help keep the unit running smoothly and efficiently and can reduce overall energy costs. Always unplug and turn off the air conditioner before cleaning the outdoor unit.


Step 1

Remove the outer case from the outdoor unit. Use a shop vacuum to carefully clean the outside of the air conditioner, focusing on the condenser fins, which look like pieces of light aluminum. Be careful not to bend the fins. Remove any debris, weeds or grass that may be stuck in the sides of the air conditioner.


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Step 2

Unscrew the grille on the top of the unit and lift up to remove, moving carefully as the fan may lift up as well. Wipe the fan clean and apply one or two drops of electric motor oil into the lubrication ports near the base of the fan. These will appear as small holes. Note that not all fans have lubrication ports and therefore do not need to be oiled.


Step 3

Restore the fan and the top grille. Turn the indoor thermostat to "Off" and allow the unit to sit for 24 hours.

Step 4

Restore power and turn the thermostat to a cool temperature. Listen to the air conditioner for noises that may indicate that damage has occurred. Pull back the insulation on the pipe that extends from the outdoor unit and feel the pipe. It should feel cool or cold and the other pipe should feel warm.


Step 5

Contact a service professional if the air conditioner is making unusual sounds or the pipes do not feel warm and cold as described in step 4.


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