When the summer heat is at its hottest, everyone hopes their air conditioning will work its best at the flick of a switch. While AC units are generally reliable devices, some occasional maintenance is required to maximize their efficiency and lifespan. One of these tasks is cleaning the coils. These critical parts are what transfer the heat out of your home, but they accumulate dirt and grime over time, insulating them and making it harder for your AC unit to do its job. By setting aside an hour for the relatively simple job of cleaning your AC coils, you can get the most out of this important seasonal appliance.
Tools and supplies
- Coil brush
- Fin brush (optional)
- Garden hose
- Foaming coil cleaner (see step 4)
You’ll first need to access your AC unit’s coils. These are usually found on the exterior portion of window- or wall-mounted units or behind a removable panel (typically secured with screws) on central units. Refer to your owner’s manual if you’re unclear on where the coils are or how to properly access them.
Check the coils for any large debris such as leaves, sticks, clods of dirt or spider webs. Remove any foreign objects you find, then use a coil brush to dust off the coils. Also known as a soil brush, this tool can be found at most large hardware stores or air conditioning shops. Lightly brush with the bristles parallel to the fins of the coils to avoid bending them. Your goal is to simply knock away loose dust and other material, not to perform a deep scrub.
Step 3 (optional)
If there are any bent fins on your AC unit, now is a great time to fix them. Using a fin brush (also available from hardware stores and AC shops), slowly run the bristles parallel to the line of fins to straighten them out. Putting the fins back into alignment will help restore the efficiency of the unit by maximizing the exposed surface area for the coils.
Step 4 (optional)
Prior to cleaning, it’s helpful to rinse down central AC units by spraying them with water from a garden hose. Water can enter your home when attempting to rinse out window- or wall-mounted units, so skipping this step and using a somewhat pricier “no-rinse” cleaner in step 5 may be preferable.
Shake your can of foaming coil cleaner, and spray it directly into the coils so that all of them are covered. The cleaner should foam up to fill the space between the coils. This foaming action lifts away the dirt and grime that accumulates between the fins. Allow the cleaner to work for five to 10 minutes or according to its instructions.
If the cleaner’s instructions specify, rinse off the agent with a hose. Good water pressure and slow, back and forth passes are recommended to ensure all the cleaner is flushed out. Since window- or wall-mounted units are best cleaned with no-rinse cleaner, simply running the unit is enough to flush out the cleaner with the condensation that forms.
Clean your AC coils once a year, ideally in spring before you make heavy use of the unit, and you’ll help get peak performance and the maximum lifespan from your climate control appliance.