As the weather cools down and you start thinking about cozy fall nights indoors, it’s easy to forget about your air conditioner. But the start of fall is actually one of the best times to give it some attention.
After months of heavy use, your AC may be clogged with dust, dirt, and debris—and if you don’t clean it now, you could face higher energy bills, reduced efficiency, and even surprise breakdowns next summer. As Keith Wortsmith, the president of DASH Heating & Cooling, puts it: “Dirt is what kills the system, not even age. AC parts overheat, choke on dust, and run longer than they are supposed to—this is what makes those parts break."
By now you might be wondering how to clean an air conditioner, and which parts of the job you can handle yourself. Good news—you don’t have to be a professional to tackle the basics. With a few simple steps, you can keep your system cleaner, more efficient, and ready to keep you cool when summer rolls back around.
How to Clean an Air Conditioner
Start with the basics—replace or wash your filter, clear away debris around the unit, and give the outdoor condenser coil a gentle rinse with a garden hose. Wortsmith also recommends pouring a cup of plain white vinegar into the drain line every couple of months to prevent clogs. "Find the little T-shaped vent or cap on the PVC pipe near your indoor unit, pop it open, and slowly pour the vinegar in to kill the algae and mildew before it completely clogs the line," he notes.
How Often Should You Change Your Air Filter?
Filters are your AC’s first line of defense and the easiest thing for homeowners to manage. Wortsmith explains that lifestyle makes a big difference: “In a dusty home with pets, filters can need changing as often as every month. In cleaner households, you may be able to go two or three months.” A clogged filter reduces airflow, forces the system to run longer, and can even lead to coil damage over time.
How to Clean a Window Air Conditioner
If you use a window unit, the cleaning steps are a little different but just as important. Start by removing the front panel and rinsing the filter with warm, soapy water—just let it dry fully before putting it back. Vacuum dust from the coils and fins with a soft brush attachment, and wipe out the drip tray to prevent mold. Finally, check the back of the unit for leaves or debris and give it a gentle rinse with a hose. A quick cleanup like this helps your window unit cool better and last longer.
Do You Need to Clean the Outdoor Unit?
Yes. The outdoor condenser coil collects grass, leaves, pollen, and dirt all season. Wortsmith recommends rinsing it off with a garden hose at least once a year, and more often if you live near cottonwood trees or mow frequently. Skipping this step makes the system work harder than it should, which shortens its life and wastes energy. Be gentle—avoid pressure washers that can damage the delicate fins.
Can Cleaning Your AC Really Lower Energy Bills?
Yes—cleaning really can make a noticeable difference. “You’re paying higher electric bills because the unit has to run twice as long to do the same job if it’s dirty,” Wortsmith says. When your filters and coils are clean and airflow is open, your system doesn’t have to struggle to cool your home. This not only saves money month to month but also prevents unnecessary wear and tear that can lead to costly repairs. A little effort now—especially in the fall—can save you time, money, and stress down the road.
Tierney McAfee is a freelance writer and Country Living and The Pioneer Woman contributor who covers entertainment, holiday & entertaining, food & drinks, design ideas, DIY, and more.
