The "outside condenser unit" is the big box with the large fan in it located on the side of your house or building. This unit is where heat from the inside of your house is pushed to the outside (which is why the fan blowing air above the unit feels warm). Inside of the box are coils of pipe that are surrounded by thousands of thin metal "fins". These fins give the coils more surface area for exchanging heat.

Cleaning the outside condenser unit involves four activities. Before doing any of these activities, be absolutely sure to shut off power to the unit and consult your owner's manual regarding discharging the capacitor and proper maintenance procedures for your unit. If you have any questions about how to do this, seek professional maintenance help.

Remove leaves, debris, spider webs, etc. from the outside of the unit. Be careful to push debris away from the fins, not pushing debris into the fins.

Remove leaves, debris, etc. from the inside of the unit (after ensuring that power is shut off to the unit). After you remove the cover grille, you can use a garden hose to spray the coils from the inside of the unit.

If any of the fins are bent, you can use a special tool called a "fin comb" to straighten and clean them.

The motor which drives the fan typically has ports which allow lubricating oil to be added (check your owner's manual).