How to Clean a Window AC Unit: A Step-by-Step Guide

by Kim Causey
WHite Frigidaire air conditioner being wiped clean

Cleaning a Window AC Unit at a Glance

  • Tools and materials: An extra person, screwdriver, fin comb, scrub brush, rags, AC coil cleaner, electric motor oil, all-purpose cleaner
  • Step 1: Remove unit from window
  • Step 2: Straighten fins
  • Step 3: Clean coils
  • Step 4: Wipe fan motor
  • Step 5: Wash or replace filter
  • Step 6: Replace unit

Window air conditioning units can be a lifesaver during hot summers. They pump cool air into living areas that would otherwise reach uncomfortable temperatures. But did you know that your window AC unit needs to be regularly cleaned? Just like a whole-house HVAC system, their filters need to be cleaned and replaced, too. Great, you might be thinking. Yet another thing to keep clean. In reality, cleaning your window unit might be worth the hassle.

This May Also Interest You: How to Clean Your AC Filter in 7 Simple Steps

Buying a window air conditioner is an investment. Keeping your unit clean will help protect that investment, ensuring that your unit will be in good shape to cool your home when you need it. A clean AC unit also translates to cleaner air and lower utility bills. Here’s how to clean yours.

What Is a Window Air Conditioning Unit?

A window air conditioning unit is a smaller, simplified version of a central AC system. They are installed on your window so they can vent warm air outside. Because they’re so small, they’re typically used to cool just the room they’re in. They work well for apartments and other rental properties in addition to single-family homes. Window units may also function as fans, dehumidifiers or heaters.

Components of a Window AC Unit

A window air conditioner has the same basic components as a central air system, just wrapped up in a smaller package. Its parts are housed neatly in a metal enclosure that sits partly inside and partly outside of your window. These are some of the main components:

  • Face Panel: The face panel is the part you see on the front of the unit. It also houses the thermostat and controls.
  • Evaporator Coil: This coil stays cool. It’s where the heat exchange takes place between the refrigerant and heat in the room.
  • Refrigerant: Refrigerant is the chemical that cools the air. Depending on the age of your window unit, this may be Freon or Puron.
  • Compressor: This compresses the refrigerant.
  • Fan or Blower: This blows cool air over the evaporator coil and out to the room.
  • Condenser Coil: This coil gets hot and is used to reject the heat from the refrigeration process, spitting it outside from the portion of your unit that hangs out of the window.
  • Condenser Fan: This fan blows air over the condenser coil.
White window-unit air conditioner being wiped clean -------------------------------------------

How to Clean Your Window AC Unit

Most people assume that when their air conditioning unit starts blowing hot air, it’s because the system is low on refrigerant or needs to be repaired — but that’s not always the case. Many times, a good cleaning is all the unit needs.

Here’s what you’ll need to clean your unit:

  • An extra person
  • Screwdriver
  • Fin comb
  • Scrub brush
  • Rags
  • Gloves
  • Vacuum
  • AC coil cleaner
  • Electric motor oil
  • All-purpose cleaner

According to The Family Handyman, here’s how to clean your window AC unit:

1. Prep the Unit

Start by unplugging your window AC unit from the outlet. Never try to clean with the unit still plugged in. Then, remove the plastic filter holder and front panel.

Window AC units can be heavy, so you’ll want to grab someone to help you remove the unit from the window. If the unit has a mounting frame and case screws, pay attention to where these are upon removal as they will need to go back in the same spot when you reinstall the unit.

2. Comb Out the Fins

You may want to wear gloves for this step. Straighten the bent cooling fins with a fin comb. You can find fin combs online or at home repair stores. Match the end of the fin comb to the spacing on your coils. Then, insert the fin comb and pull it up to straighten the fins.

3. Clean the Coils

Vacuum out all the buildup from both the condenser and evaporator coils. This may include spider webs, dirt or dust. Spray AC coil cleaner over the entire surface of both coils. Let the foam sit on the surface to break down the gunk, then wipe it clean with a rag. If the coils are especially dirty, you can use a scrub brush to get rid of the buildup. Make sure to brush in the direction of the fins, or you’ll have to straighten them again.

4. Wipe the Fan Motor

Wipe down the fan blades with a rag and some all-purpose cleaner. If the fan motor has capped oiling ports, you can take those off and squeeze in a few drops of electric motor oil.

5. Clean the Air Filter

The final step is to wash or replace your air filter. Find more detailed steps for washing your filter below. Your filter should be replaced at least every three months to ensure unrestricted airflow and maintain the performance of your unit. If you are replacing the filter, simply put the new filter in and throw away the old one.

6. Replace the Unit

When you’re done cleaning all the parts of your unit and have replaced the air filter, you can now put your window unit back in the window. Make sure you have someone help you with the heavy lifting. Plug your unit back in and enjoy the cool air.

If you are still noticing issues with your window AC unit, you may have a larger problem that will need to be serviced by a professional.

Can I Clean my Window AC Unit Without Removing It?

Yes. If you don’t have someone to help you get your unit out of the window, or if you simply don't want to remove it, you can still clean it to some extent. Make sure you unplug the unit before you start cleaning. You can follow the steps outlined above. You will likely only be able to clean the evaporator coils from the inside of your house. If you can reach your window unit from outside (i.e., it’s on a first-floor window), you can take the back cover off and clean the condenser coils, too.

How to Clean AC Filters

You’ll need:

  • Spray bottle
  • Bucket of water
  • Hydrogen peroxide
  • Detergent
  • Dry towel
  • Water

Here’s what to do:

1. Remove the Filter

First, you’ll want to check the filter. Take the panel off the front of the unit. You may have to remove a few screws or tabs in order to do so. The filter should be located in a slot within your unit and be seen easily. When you find it, take it out.

2. Clean the Filter

Dip a towel into a solution of tap water and detergent and use it to wipe the filter. Then, place them under running tap water to finish cleaning them. If you notice your filter has an odor, you can add a little baking soda mixed with water to help remove it. Be careful not to tear or damage your filter while cleaning it.

If there is a lot of dust, hair or other debris, you can go in with a vacuum first. Make sure you use a brush attachment. Alternatively, if the filter is extremely dirty, it may be time to replace it.

3. Dry

Allow the filter to dry completely before you put it back inside the unit. Putting it back in when it is wet can damage your unit.

4. Replace

If your filter is too worn out or grimy to clean, simply replace your filter and throw the old one away.

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How Can I Clean an AC Unit Quickly?

You should give your AC Unit a good wipe down every month or so. According to CNET, you can spray your unit with hydrogen peroxide in between deep cleanings. This will help stop mold growth. Make sure you turn off and unplug the unit before you spray it. Wipe the excess off with a rag and allow the unit to dry. It is important that your unit dries completely before you turn it on, so it’s a good idea to spray it in the evening and let it dry overnight.

Benefits of Cleaning Your AC Unit

Lifespan

Everyone wants to keep their appliances running as long as possible. By keeping your AC unit clean and serviced, you can prolong its lifespan.

Fresher Air

Your AC unit is meant to keep you cool, but it can also keep your air cleaner. If your unit is dirty, it can become a breeding ground for bacteria, mold and fungi. When air blows out of the unit, it then pushes these particles around your home and, potentially, into your lungs.

Savings

Keeping your unit clean will ensure that it is running efficiently. Efficiency equals savings on your monthly utility bill.

How Long Do Window Units Last?

Window air conditioner units have a typical lifespan of 10 to 25 years with the right cleaning and maintenance. The actual lifespan depends on usage, maintenance, location and efficiency.

Signs Your Unit Needs Cleaning

Your unit may need to be cleaned if it’s showing any of these telltale signs:

  • Blowing warm air
  • Little to no air is coming out
  • The thermostat on the unit is not accurate
  • It’s loud when it runs
  • It smells
  • Your house feels humid
  • You notice water or refrigerant leaking
  • Your electric bill is higher than usual

If your unit is showing signs of malfunction after you clean it, you should think about hiring a professional to repair it.

Since we’re all home now more than ever, being prepared for unexpected home repairs with a plan from HomeServe is important. Having a plan in place gives you peace of mind knowing that you can simply call our 24/7 repair hotline for covered breakdowns. See what plans are available in your neighborhood.

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