How to Clean an Air Conditioner

When summer is in full swing, scorching hot days become the norm. That means your air conditioner has been working overtime, especially if you like to keep cool by staying inside. And if you always want cool air blasting from your portable air conditioner, you definitely need to learn how to keep your air conditioner clean.

Whether you have central air or a window unit, here's how to clean an air conditioner like a professional. Plus, check out these air conditioning maintenance tips and tricks you can easily do to protect yourself from the summer heat.

How Often to Clean an Air Conditioner

Window AC

Air conditioning units need to be cleaned regularly. "I would recommend cleaning [a window AC unit] every two weeks," says Giacomo Calzavara, Managing Director of JMATEK North America, a licensee of Honeywell portable cooling products.

Central Air

As for a central AC unit, it's a good idea to have a professional inspect and clean your system once a year. They can make sure the coolant levels are on target, check for leaks, and clean the coils.

Considerations Before You Get Started

There are two primary areas to focus on when cleaning a window AC unit: filters and coils.

Filters remove the dust from the air and when they're clogged, they force your AC unit to work harder and use up more energy to cool your home—that costs more for you without delivering results.
Coils help move the hot and cold air, so make sure they're not clogged with dirt and dust.

Of course, for some air conditioning systems (like central AC), it's best to have a professional HVAC contractor inspect the unit, check the ductwork, and ensure it's operating efficiently.

"Companies like ours should come out and do the heavy maintenance on it, but in between, there are air conditioning maintenance tips people can follow themselves," says Dave Mejean, HVAC manager at B&W Plumbing and Heating Co., Inc., an Angi vendor. "It's like a car: You have to have your mechanic tune it up, but there are still things you can do to make sure it's running too."

What You'll Need

Materials

Window AC Unit

Screwdriver
Cloth
Soft brush
Spray bottle
Mild dish soap or mild detergent

Central AC Unit

Screwdriver
Cloth
Vacuum
Hose

Instructions

How to Clean a Window AC Unit With Mild Dish Soap

Turn Off the Unit

Turn off the unit. For safety purposes, it's always a good idea to turn off the power and unplug the cord before working on an electrical unit.
Remove and Clean the Cover
- Depending on your unit, there will be a front cover that is fastened with tabs, knobs, or screws.
- Consult your air conditioner's manual to confirm removing the front cover and opening your unit.
Remove and Clean the Filter
- Find the filter, which is typically located in the front of the unit. Check your manual if you're struggling to find it.
- Dust the filter with a cloth.
- Rinse it with lukewarm water and mild soap.
- Let the filter dry completely before placing it back in the unit.
Locate and Clean the Coils

Most window air conditioners will have two sets of coils: the evaporator coils in front (inside) and the condenser coils in the back (outside).
- Brush away dirt from the coils with a soft brush or cloth.
- Clean away any additional dirt with a spray bottle filled with slightly soapy water.
- Try putting a little mild detergent or dish soap in the bottle if the debris is hard to remove—but not so much soap that it gets too sudsy.
- Dry with a clean cloth.
Dry Thoroughly

Make sure all parts of the unit are dry. Then replace the front cover. Turn the unit back on.

How to Clean a Central AC Unit With a Hose and Water

Turn Off Unit

Turn off your AC and locate the vent. Depending on the construction of your home, your central AC vent may be located on the walls, under windows, in the ceiling, or on the floor.
Remove the Vent Cover

Depending on how your vent cover is secured, you may need to use a screwdriver to unscrew the cover or simply use push tabs to open it.
Remove and Clean the Filter

You should find the filter right behind the vent cover.
- If you have a washable filter in your AC vent, follow the steps above (under How to Clean a Window AC Unit) to clean it.
- If you don't have a reusable filter, simply swap out the old filter for a new one, making sure any arrows on the filter are facing the right direction.
Turn off the Outdoor Unit

To do this, you must find the breaker switch outside—which is usually located under a flip-up lid near the condenser unit.
Remove the Top of the Condenser Unit

After the top is removed, use a vacuum to remove any leaves, grass, dirt, or other debris in or around the unit.
Spray Down Unit

With a hose, carefully spray down the unit to remove the remaining dirt, making sure not to get the electrical box wet. (Use a hose, not a power washer—as it can damage the fins.)
Allow to Dry

Wait 30 - 60 minutes to let the condenser unit dry completely before turning it back on.

Seasonal Upkeep and Maintenance Tips

Change the Filters

For central AC units, Mejean recommends checking the filter every 30 to 60 days to see if it's dirty or dusty—lifestyle makes a big difference, since people who have kids or pets might have to change it every month, while those who don't have too many visitors or animals might only need to swap it out every two to three months.

According to a home survey by American Standard Heating & Air Conditioning of 2,000 American homeowners, only 36% of homeowners swap out their air filters. "We often tell our clients that simple preventative measures like this can take just minutes to do but can help ensure your system is working efficiently and can help save money in the long run," Brian Kleinschmidt, home improvement expert and American Standard Heating & Air Conditioning partner, says.
Clean the Condenser Unit

Cleaning the condenser unit outside is another important part of central AC maintenance. This typically only needs to be done once a year, but may need to be done more often depending on the location of your unit and if it is prone to lots of debris.

"It's important to keep the area surrounding [your condenser unit] clean and debris-free," Mika Kleinschmidt, home improvement expert and American Standard Heating & Air Conditioning partner, says. "A good rule of thumb is not to let any plants or other wildlife grow within a 2-foot radius of your air conditioner."
Remove Blockages

Make sure nothing is blocking the unit. "Airflow is so critical to cooling systems, so make sure there aren't any beds, dressers, clothes, books, or other items blocking the unit vents," Mejean says. For your central air conditioner's outdoor unit, Mejean suggests leaving at least a 12-inch clearance around it.
Regularly Check for Common Issues

Constantly check for common problems like weak airflow, icy coils, and leakages in all types of units. They could indicate either a blockage in your air conditioner or a clogged filter.
Know When to Call a Pro

Central air systems can be complicated. "If your air conditioner or other HVAC system can't maintain consistent temperatures, a technician is the best person to investigate the issue," Brian Kleinschmidt says. "If your utility bills increase but your overall usage remains the same, one or more components of your system may not be working as they should."

Mika Kleinschmidt also suggests listening closely for any strange noises when your system starts. "If you hear any, call a technician to inspect the problem more closely," she says.