Keep Your AC in Top Shape by Cleaning Your Evaporator Coil

A little spring cleaning can go a long way toward keeping your air conditioner in great shape. Unfortunately, too many homeowners overlook the things they can't readily see. Hidden away within the AC plenum, your evaporator coil often ends up being missed. The following shows why and how you should give your AC system's evaporator coil the TLC it needs to help it survive another sweltering summer.

Why Coil Cleaning Is Often Necessary

Although your AC air filter catches the vast majority of dust and debris floating around, there's still some that manages to escape. This is the sort of stuff that winds up being stuck between the evaporator coil's thin aluminum fins. Blockages can make it difficult or even impossible for air to flow through the coil. Without steady airflow, the coil can't absorb latent heat from the surrounding air. That means your AC system won't work properly unless the coil's cleaned.

There's another good reason why you should keep your evaporator coil clean. As mold spores and mildew bacteria settle on the coil, the damp, dark, and relatively cool conditions inside the plenum can easily allow mold and mildew to grow on the coil unchallenged. This doesn't just put a dent in your AC system's performance or energy efficiency—it can also drag down the overall quality of your home's indoor air when the spores are blown into your home. Certain types of mold and mildew have also been known to trigger allergy and severe asthma in children and older adults.

How to Clean the Coil

As mentioned before, the evaporator coil is located within the AC cabinet's plenum, which usually sits on top of the cabinet (this part of the AC unit is inside the home). Once you've opened up the plenum, you have a couple of common approaches to consider when cleaning the coils.

You can manually scrub the coils with a soft-bristle brush. You'll need to use a 50/50 mixture of warm water and mild dish detergent inside of a plastic spray bottle. Spray the solution onto the coil and gently scrub away any dirt and debris you see. Be mindful not to bend the fragile aluminum fins lining the coil, as it could take a lot of time and effort to undo the damage.

There's also a noncontact method of cleaning the evaporator coil. All you need is a foaming, no-rinse cleaner specifically formulated for use on HVAC coils. Spray the foaming cleaner on the evaporator coil according to the instructions listed on the can. This product will eventually work its way through any debris or mold buildup it encounters. After a few minutes, much of the residue will drain harmlessly off the evaporator coil and into the drip pan below.

While you're at it, it's also a good idea to clean the condensate drip pan and drain line. It'll help keep the debris from your evaporator coil cleaning from clogging up the drain. Drain clogs can cause the drip pan to overflow with condensate and create flooding problems. As with the evaporator coil, you can use mild detergent and warm water to clean the pan. Drain clogs can be easily removed with a small plumber's snake or the suction from a wet/dry shop vacuum.

How Often It Should Be Cleaned

There's no definite word on how often you should check and clean your evaporator coil. The US Department of Energy recommends checking it on an annual basis and cleaning whenever necessary. Regular air filter changes can help reduce the need to constantly clean the coil. Also, if you'd prefer not to clean your evaporator coil on your own, most HVAC contractors are willing to do the work for you as a part of their annual AC service. To schedule an appointment or for further information about your evaporator coil, contact a representative from a company like R & B Heating & Air Conditioning.