How to Clean Outdoor AC Units: Expert Guide

Spring is on its way and with that comes spring cleaning to prepare for summer. 

Just like cleaning your kitchen and bathroom are key parts of a homeowner’s duties, cleaning your outdoor AC unit is an important maintenance task that can help improve its performance and extend its lifespan. 

If you want to get started to make sure your unit is ready for summer, here’s our expert, step-by-step guide on how to clean an outside AC unit.

1. Turn off the power

Like most electrical appliances, if you’re wondering how to clean an outside AC unit, start by turning off your unit’s power supply. This will protect you and your unit from harm. 

You can do this by switching off the circuit breaker or using the disconnect switch, if available.

2. Remove any debris

Begin to clean your outdoor AC unit by carefully inspecting it and using your hands or a brush to remove any loose debris, such as leaves, grass, or sticks that may have accumulated on or around the unit. Be gentle and avoid bending or damaging the fins of the condenser coil.

Next, use a vacuum cleaner or a blower to remove debris that’s stuck or wedged in hard-to-reach places. Use the soft brush attachment on your vacuum cleaner to clean the fins of the condenser coil, being careful not to damage them.

Alternatively, you can use a blower or compressed air device to blow away debris from the coil, fins, and other parts of the unit.

3. Clean the condenser fins

The condenser fins are located on the outside of the AC unit, typically covered by a metal or plastic grille. Remove the grille or access panel to gain access to the condenser fins. 

If the fins are clogged with dirt or debris, you can use a fin comb to straighten them. 

Once you have access to the condenser fins, inspect them for dirt, dust, or grime. Clogged fins can reduce airflow and decrease the efficiency of your AC unit.

Now you can use a fin brush or a soft brush to clean the condenser fins, but be careful not to bend or damage them, as they are delicate and affect the AC unit’s airflow.

Clean the condenser fins carefully: 

  1. Use a soft brush, such as a nylon bristle brush or a fin comb, to gently brush the fins in an up-and-down or side-to-side motion. This can help dislodge dirt and debris from the fins.
  2. Use compressed air to blow away dirt and debris from the fins. Be careful not to use too much pressure, as it can bend or damage the fins. Hold the nozzle of the compressed air nozzle a few inches away from the fins and blow in the opposite direction of the airflow.
  3. You can also use a gentle spray from a water hose to clean the condenser fins. However, avoid using a high-pressure water setting as this can cause damage. Spray water from the inside out, to wash away dirt and debris.
  1. Finally, clean the surrounding area. As you clean the condenser fins, be sure to clean the surrounding area, including the grille, access panel, and the ground around the AC unit, to remove any dirt, dust, or debris that may have accumulated.

4. Clean the condenser coils

The condenser coils are located inside the AC unit and are responsible for transferring heat. To clean them, you can use a coil cleaner. These are available at most hardware or HVAC supply stores.

When cleaning an outdoor AC unit, follow the manufacturer’s instructions on the coil cleaner for the best results. Typically, you spray the coil cleaner onto the coils, let it sit for a few minutes, and then rinse it off with water.

Be sure to rinse thoroughly and avoid getting water on any electrical components. If you are unsure how to clean an outside AC unit, contact a local professional who can assist you.

5. Check the drain line

Your air conditioner unit has a drain line that allows condensation to drain away.

Locate the drain line

The drain line is typically a PVC pipe that runs from the indoor unit of your AC system to the outside of your home. It is usually located near the indoor air handler or furnace.

Inspect the drain line

Check the drain line for any signs of blockage or clogs. Look for standing water or moisture around the drain line, which may indicate that the line is not draining properly. If you notice any visible debris or buildup, such as dirt, algae, or mold, they may be causing a blockage in the drain line.

Clear the drain line

If you find blockages in the drain line, you can try to clear them using any of the following:

  • Use a wet/dry vacuum: Attach a wet/dry vacuum to the end of the drain line and turn it on to create suction. This can help remove debris from the drain line.
  • Use a drain line cleaning tool: There are specialized drain line cleaning tools available, such as drain line cleaning brushes or air pressure blowouts, that can help clear clogs in the drain line. Follow the manufacturer’s instructions for proper use.
  • Use a bleach solution: Mix a solution of 50/50 water and bleach, and pour it into the drain line. The bleach can help kill any algae or mold growth and clear minor clogs. Allow the solution to sit for about 15-30 minutes, then flush the drain line with water.

Test the drain line

Once you have cleared any blockages, pour a small amount of water into the drain line and observe if it is draining properly. The water should flow smoothly without any backup or standing water.

It’s recommended to check and clean the drain line of your AC unit at least once per year, preferably before the cooling season begins, and more frequently if you notice any signs of clogs or water backup.

Some steps may be trickier than others so if you don’t know how to clean an outside air conditioning unit or test it on your own, contact an HVAC professional. 

6. Reassemble the AC and restore the power

Once you’ve cleaned the AC unit, carefully reassemble any components that were removed. Make sure everything is properly secured. Then, restore power to the AC unit by turning on the circuit breaker or reconnecting the disconnect switch.

7. Trim any overgrown vegetation around the unit 

When homeowners attempt to clean outdoor AC units, they often forget about the unit’s surroundings. Make sure there is no tall grass, weeds, or other vegetation growing too close to your AC unit as this could cause blockages and hinder airflow.

Don’t know how to clean your outdoor AC unit? Let us help. 

To keep your outdoor AC unit clean and well-maintained, it’s recommended to perform regular cleaning and maintenance tasks, such as cleaning or replacing air filters, keeping the area around the unit clear, and most importantly, scheduling professional HVAC maintenance at least once a year.

An HVAC professional is trained to catch the things you miss and will let you know if anything needs replacing. Call Anderson Air to schedule your annual maintenance visit today.

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