How to Clean Your Air Conditioner So It Runs All Summer Long

Kelly Weimert
Written by Kelly Weimert
Updated April 12, 2023
neat bedroom with ac unit
Photo: Evrymmnt / Adobe Stock

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Warm weather means your air conditioner is ready to come out of hibernation, and so is all the dust and grime that set up camp inside your unit over the winter. Can you say spring cleaning?

While you should hire an HVAC contractor near you to service your air conditioner at the start of the season, you can usually clean it on your own as long as you’re comfortable opening up your unit. So before the hot weather comes sweeping in, take a moment to sweep the dust and grime out of your AC unit to enjoy that sweet, cool air. 

Why Should You Clean Your AC Unit?

After a while, dust, dirt, and other debris accumulate on an AC unit's coils and filters, making it less efficient and spreading allergens and other air pollutants throughout your home. Cleaning your AC unit will keep it running efficiently, minimizing future breakdowns and improving your indoor air quality

When to Clean Your Air Conditioner 

The right time to clean your air conditioner depends on your unit, household, and environment. It's typically best to clean it at least once per year, usually in the spring before the summer heat rolls around. However, if you live in a home with pets or use the unit quite a bit throughout the year, you'll likely need to clean it more often. When in doubt, check with your manufacturer for cleaning frequency recommendations. 

How to Clean Your Air Conditioner 

Cleaning an air conditioner is a fairly straightforward project that you can take on yourself with a few supplies and a free afternoon. So whether it's time for your annual maintenance or your unit isn't quite as efficient as it used to be, roll up your sleeves and get ready to make your air conditioner sparkle.

Cleaning Your Central Air Conditioner 

You can clean most air conditioners in 30 minutes to an hour. Be sure to gather your gloves, cleaner, and a soft brush, before you begin.

1. Cut the Power

Start by turning off your air conditioning unit. Cleaning a standard HVAC system while it’s running is dangerous—both for you and your air conditioner. There’s usually a shut-off box somewhere near the condenser unit (the portion of the AC system located outside your home). Unless you know what you’re doing, it’s best to switch off the main breaker. Use a flashlight or other light source to get a good look.

2. Clean Debris From the Outdoor Condenser Unit

Outdoor condensers can collect all kinds of debris, from grass clippings to decaying leaves. Peer into the protective grille around your unit and look for debris in the fan (at the top of the unit) and fins (around the unit). Use a garden hose to rinse away the debris or remove it with your hands. You can scrub dirt on the protective grille with a cloth and soapy water. Do not get the electrical box wet under any circumstances.

3. Clean the Condenser Coils

There are two types of air conditioner coils that need cleaning: the condenser coils and the evaporator coils. If rinsing wasn’t enough to remove stubborn debris, clean the condenser coils and fins by hand. Remove the protective grille (or side panels) around your unit using a screwdriver. 

Then, do the following:

  • Gently brush the AC coils and fins using a soft brush.

  • Cover electrical components with a plastic bag to protect them from moisture.

  • Spray no-rinse coil cleaner on the condenser coils. 

  • Use a hose to spray off the cleaner after a few minutes (optional).

Make sure electrical components don’t come into contact with coil cleaner or water. Be careful not to touch the coil cleaner with bare hands since it can cause irritation.

4. Straighten the Fins and Cover Your Condenser

If any fins bend out of shape during the cleaning process, brush them with a fin comb to straighten them out. Put the protective cover back on your AC, and head inside to clean the rest of your HVAC system.

5. Change the Air Conditioner Filter

change air conditioner filter
Photo: Proxima Studio / Adobe Stock

The more you run your system, the more dirt and debris will clog up your filter. Change your air conditioner filter at least every three months. Since dirty air ducts will muck up the cleanest air conditioning units, hire a local air duct cleaner if you notice any signs of dirty ducts, including:

  • A need to change your filter more frequently

  • Debris built up along your air vents

6. Clean the Evaporator Coils

Evaporator coils are located on the indoor portion of your AC system. In a standard HVAC unit, they’re usually in a box attached to the furnace or inside your air conditioner air handler. You can reach the coils through an access panel, which opens using a knob or by unscrewing screws. Once you open the panel:

  • Remove dust from the coil with a soft brush.

  • Spray coil cleaner evenly on the evaporator coils.

  • Remove any remaining grime with a soft brush (optional).

7. Clean the AC Drain Pan 

If your coil cleaner is working, it should be dripping into your air conditioner’s drain pan, taking the dust and grime with it. This means you’ll also need to clean your drain pan. Use a soapy solution and wipe the drain pan down with a cloth. If the pan isn’t draining normally, you may need to call in a professional to remove a clog.

8. Close the Access Panel and Give Your AC a Test Run

man closing ac filter cover
Photo: Ekaterina / Adobe Stock

When you’re done cleaning your unit, close the access panel. Make sure your AC unit has fully dried before turning on the power. If you cleaned your AC unit because of a problem—like poor performance or a weird smell—give it a test run. If the problem persists, consider hiring a local HVAC repair specialist.

Cleaning Your Window AC Unit 

Even if you have a window AC unit, you should clean it at least once per year to ensure its efficiency. But the process is a little different—and usually faster—than cleaning central AC systems. 

1. Turn Off the AC Unit

Before you get started, make sure to turn off your AC unit to avoid any potential hazards. Start by turning off the unit using the power switch or button, then unplug it from the wall. If the unit is warm to the touch, wait a few minutes for it to cool down before proceeding to the next step.  

2. Remove and Clean the Front Cover

The front cover of an AC unit tends to collect dust, dirt, and debris, which can reduce its efficiency. Locate the screws or clips that secure it to the unit, then carefully remove them and detach the cover. Use a damp cloth to wipe any dirt from the cover, then let it completely dry. Don't reattach it until after you’ve finished cleaning the whole unit, as you'll need to access the area behind the cover in the following steps. 

3. Remove and Clean the Filter

Your window AC unit's filter traps dust and other particles, improving your indoor air quality. But over time, these filters inevitably get too dirty to work properly, making your unit less efficient. To clean the filter, simply remove it from the unit and rinse it with warm water. If the filter is especially dirty, you can soak it in a mixture of water and gentle soap to remove buildup. 

4. Vacuum the Interior

Grab a hand vacuum or a vacuum with a brush attachment and use it to remove dust and dirt from the unit's interior. Pay close attention to the fan blades, as these tend to collect the most debris. 

5. Clean the Coils

An AC unit's coils also get dirty over time, so you'll want to spend some time cleaning them, too. You can usually find the coils behind the unit or behind the front cover. To clean them, use a soft brush to remove dust and debris gently. You might want to use a commercial coil cleaner for very dirty coils that the brush can’t quite tackle.

6. Replace All the Parts

Once you've cleaned each part, it's time to put your unit back together. Start by reinserting the filter. Then grab the screws or clips you removed from the front cover, and use them to reattach it. Finally, plug your unit back in, turn it on, and let it run for a few minutes to ensure it's back in working order. 

Tips to Maintain Your Air Conditioner 

In addition to cleaning your AC unit, there are several other steps you can take to maintain and prolong the lifespan of your unit. 

  • Change the air filter at least every three months, but more frequently if you have pets.

  • Remove any obstructions, like furniture, from the vents to promote airflow.

  • Schedule professional maintenance at least once per year before you start using the unit frequently again.

  • Keep the outdoor unit free of debris and vegetation.

  • Keep an eye on your monthly energy bills. If you notice any unusual increases, inspect the unit for problems that might lead to inefficiencies, like a dirty air filter. 

DIY vs. Hire a Pro

repairman fixing/ cleaning ac unit in home
Photo: goodluz / Adobe Stock

Though handy homeowners may be happy to clean out their AC unit, not everyone wants to delve into the dirt and dust. If you’re not comfortable opening up your AC system, leave it to a professional. It’s a great idea to bundle the cleaning of your unit into the regular maintenance that a professional will need to handle anyway. Maintenance by an HVAC professional can cost $60 to $200, depending on the type and size of your unit.

Mariel Loveland contributed to this piece.

Frequently Asked Questions

You should clean your air conditioner at least once per year, but you may need to clean your whole HVAC system (including the air ducts) more often. According to the National Air Duct Cleaners Association, you may need to clean them more frequently depending on factors like whether you smoke, have pets, or have allergies.

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