How to Clean a Window Air Conditioner

Keeping your window air conditioner clean is one of the most important maintenance tasks. A clean air conditioner not only improves efficiency and cooling performance, but also lasts longer. Dust, dirt, mold and grime can build up quickly and hamper airflow, force the air conditioner to use more energy, and even lead to breakdowns.

Cleaning your window AC unit regularly saves you money on energy bills and repairs. It also provides cleaner, healthier air for you and your family. Follow this comprehensive guide to learn how to thoroughly clean a window air conditioner in 9 simple steps.

Why You Should Clean Your Window AC Unit

Here are some key reasons why cleaning your window air conditioner is so important:

  • Improves Efficiency – Dust and dirt accumulation reduces airflow and insulates the cooling coils, forcing your AC to work harder to produce cool air. Cleaning removes buildup and allows it to run more efficiently.
  • Saves Money – More efficient operation means lower energy consumption. You can save up to 15% on electricity costs by cleaning the AC.
  • Enhances Cooling – With maximum airflow across the coils, cooling performance improves dramatically. Removing debris allows cold air to flow freely into the room.
  • Extends Lifespan – Regular cleaning prevents strain on internal components and corrosion due to moisture buildup. Your window AC will last longer.
  • Reduces Repairs – Dust and dirt lead to clogged drains, ice formation, etc. which requires expensive repairs. Cleaning minimizes breakdowns and malfunctions.
  • Improves Air Quality – Dust particles, mold, mildew and bacteria buildup gets circulated into the room air. Cleaning provides healthier indoor air.
  • Prevents Mold – Moisture and dirt encourage mold growth. Regular cleaning inhibits mold formation inside the AC.

Now that you know why cleaning the air conditioner is recommended, let’s look at the cleaning process step-by-step:

How to Clean a Window Air Conditioner

Follow these 9 easy steps to thoroughly clean your window mounted AC unit:

Step 1: Turn Off & Disconnect the Unit

  • Press the ‘Power’ button to switch off the AC.
  • Unplug the power cord from the outlet. Disconnecting from power prevents accidental shocks.
  • Never spray water or cleaning solutions into a connected AC to avoid electrical hazards.

Step 2: Remove the Front Grill

  • Remove the front grill cover of the AC which protects the air filter.
  • Look for screws or clips on the grill and loosen them using a screwdriver. The grill should come off easily.
  • Some units have grills that slide off. Pull hard to disengage the grill from the grooves.

Step 3: Take Out the Filter

  • The filter is usually located right behind the front grill. Slide it upwards and out.
  • Check for a second filter behind the main filter in some models. Remove that out as well.
  • Also take out any foam insulation material surrounding the filter.

Step 4: Clean the Filter

  • Use a vacuum cleaner with a soft brush attachment to remove loose debris. Vacuum both sides of the filter.
  • Alternatively, take the filter outside and spray it down using a garden hose. Allow it to air dry completely before putting it back.
  • If the filter is very dirty, soak it in warm water and mild detergent for 15-20 minutes. Rinse thoroughly until the water runs clear.

Step 5: Clean the AC Coils

  • Locate the condenser coils behind the filter compartment. Coils appear like thin metal fins.
  • Use a stiff brush with long bristles or a coil comb to brush between each fin opening. This removes embedded debris.
  • Wipe down the coils using a clean cloth to clear dust. Take care not to bend the fragile coil fins.

Step 6: Remove Debris & Clean Drip Pan

  • Use a wet/dry vacuum cleaner to extract dust, dirt and debris from the inner chamber.
  • Remove the bottom drain pan and rinse thoroughly to clear out mold, slime and grime buildup.
  • Wipe all accessible surfaces inside the unit using a microfiber cloth.

Step 7: Hose Down the AC Exterior

  • Take the AC unit outside and place it on a flat, stable surface. Make sure the electrical parts don’t get wet.
  • Use a garden hose set to a strong spray to rinse down the cabinet exterior. This washes away grime.
  • Areas around the vents and cooling coils tend to accumulate most dirt. Concentrate on these spots.

Step 8: Dry the AC Completely

  • Use an old towel to wipe down the wet air conditioner exterior.
  • Allow the unit to dry completely before restarting. Water should not drip out when tilted.
  • Remove any accumulated moisture using a hairdryer on the cool setting. Prevent moisture inside electrical parts.

Step 9: Reinstall Filter & Grill

  • Replace the clean filter, foam insulation and drain pan in their correct positions.
  • Attach the front grill cover and tighten the screws or engage the clips to secure it.
  • Connect the power cord and switch the AC back on. The cleaned unit is now ready to use!

Follow this routine every 2-4 weeks during summer to keep your window air conditioner in the best condition. Now let’s look at some frequently asked questions about cleaning window ACs:

FAQs About Cleaning Window Air Conditioners

How often should you clean a window air conditioner?

  • Cleaning every 2-4 weeks is recommended for regular maintenance. Clean more frequently if the AC is exposed to substantial dirt and dust.

What’s the best way to clean AC coils?

  • Use a stiff bristle brush or coil cleaning comb. Avoid damaging the fragile coil fins. A powerful vacuum cleaner also works well.

How do you clean the AC drain?

  • Mix equal parts vinegar and water. Pour the solution into the drain tube until it overflows from the outside. This will clear debris and dissolve mineral deposits clogging the drain.

What should you not clean AC coils with?

  • Avoid abrasive materials like steel wool. Do not use detergents or bleach. This can erode and damage the coil surface. Use only warm water and mild soap if required.

How do you clean window AC filters?

  • Rinse under tap water or use a mild detergent soak. For deeper cleaning, use vacuum and brush attachments. Allow the filter to dry fully before reinstalling.

Should I hose down my window AC?

  • Yes, using a garden hose is an effective way to rinse and clean the cabinet exterior. Just ensure no water gets into interior electrical parts. Completely dry the unit before restarting.

How can I sanitize my AC?

  • Sanitizing the evaporator coil removes mold and bacteria. Use a commercial evaporator coil cleaner or a DIY solution of hydrogen peroxide or tea tree oil mixed with water.

Why does my AC smell musty?

  • Bad odors are usually caused by mold, mildew and bacteria buildup inside the unit. Cleaning the filter, coils and drip pan inhibits microbial growth and eliminates smells.

Why is AC not blowing cold air?

  • Lack of cold air is most commonly caused by dirt or debris blocking the condenser coils. Thorough cleaning improves airflow and cold air delivery.


Cleaning a window mounted air conditioning unit is a relatively quick and simple process that does not require special tools or skills. Follow the steps above to remove dust, debris and grime from the various components and keep the AC operating at peak efficiency.

The key steps are removing the filter, brushing the coils, eliminating drain clogs, hosing down the exterior and drying properly before restarting. Perform this maintenance routine every 2-4 weeks during summer to maximize performance, cut energy consumption and extend the appliance lifespan. With regular cleaning, your window AC will continue providing cool relief for many more years!