You've used your air conditioner to keep your home comfortable while the outside temperatures continued to climb. However, recently, your air conditioner just hasn't provided as much cooling to your home as it once did—even though you've replaced your air filter and had your refrigerant charged by a professional. In such a case, it's likely your evaporator coil is dirty. Clean it by following these steps:
Gain Access To Your Evaporator Coil
Many homeowners have difficulty differentiating their air conditioner's evaporator coil from their condenser coil. Your condenser coil is housed in your outdoor unit, while your evaporator coil is housed in your indoor unit. Remove the screws that hold your indoor unit's access door in place and pull the door off your unit to reveal your evaporator coil and drain pan.
Blast Away Loose Debris
As large volumes of air pass through your evaporator coil, small amounts of airborne debris will become trapped in your coil's fins. After several years of use, a large amount of debris can collect on your coil and reduce its efficiency.
Use a gas duster or air compressor to blast the loose debris out of your coil's fins. If your air compressor or duster is fairly powerful, then hold the nozzle several inches away from your coil to avoid bending the delicate fins.
To ensure the airborne debris doesn't resettle on your coil, use a vacuum in tandem with your compressor or duster to suck up the loose debris. Simply placing your vacuum's hose inside your evaporator coil housing will suffice—if you guide your vacuum hose over your coil fins, you risk bending them.
Use A Foaming Cleaner
There are several specialized evaporator coil cleaning agents on the market, but foaming cleaners are the most effective. The lifting power of a foaming cleaner will remove stubborn debris from the depths of your coil fins and allow you to perform a more thorough cleaning. You can purchase a foaming coil cleaner from your local hardware or home improvement store.
Always follow the instructions listed on your foaming cleaner while applying it to your evaporator coil. Typically, the instructions will have you apply a moderate amount of cleaner to each side of your coil and wait a few minutes while the foam begins to rise.
Some cleaners will require you to rinse the coil with room temperature water to remove the debris and foam. If your cleaner requires you to rinse your coil, then use your air compressor or gas duster afterward to dry your coil and avoid corrosion damage.
If your cleaner does not require you to manually rinse your coil, then activate your air conditioner while your foaming cleaner continues to clean your coil. Once your air conditioner sends icy refrigerant through your coil, condensation will collect on the coil fins and slowly rinse the foam off the coil.
However, the foam dripping off your coil may cause your drain pan to overflow. If you suspect that your drain pan will overflow, then keep the access door off your unit and soak up any overflowing foam with an old rag or towel.
Perform Preventative Routine Maintenance
Clean your evaporator coil prior to every summer season to make sure it doesn't become coated in a thick layer of debris in the future. In addition to preventing your coil from freezing, regular cleanings will allow your air conditioner to provide greater cooling power to your home.
If you have trouble at any point during the cleaning process, or if you simply don't have the time or tools to clean your evaporator coil by yourself, then contact a local heating and cooling technician to perform the cleaning for you. A professional technician will clean your coil and inform you of any signs of damage that may indicate a more serious problem with your system.