A dirty furnace coil restricts air flow and reduces household comfort. Airflow is the lifeblood of a central heating, ventilation and air conditioning system. Among the first items an HVAC technician will check on a service call for insufficient heat is the system airflow. It impacts not only the amount of warm air emitting from registers in living spaces of the home, but it affects the quality and degree of heat. Furnace heat exchangers are designed with particular airflow specifications. If the volume of air passing through the furnace drops below that parameter, heat exchange is diminished and overall heating effectiveness suffers. While the most obvious cause of insufficient airflow is simply a dirty air filter, other suspects range from a defective blower fan to leaky ductwork. Another possible source of reduced airflow is the evaporator coil located inside the furnace plenum. Air Conditioner Coil in the Furnace Forced air furnace/air conditioner combination systems feature a single indoor unit comprising the furnace burner or electric heating coils and, installed in the furnace plenum, the evaporator coil that receives refrigerant from the A/C compressor in the outdoor unit.

In cooling mode, the refrigerant extracts heat from air pushed through small passages in the coil by the blower fan. This cooled air is conveyed into the supply duct and distributed throughout the house. cost of ac coil cleaningIn heating mode, the gas burner or electric coils activate and a heat exchanger warms air pushed through the furnace by the blower fan. can air purifiers make you coughIn a clean, well-maintained system, this heated air flows through the passages in the evaporator coil and is conveyed into supply ducts. best laser lens cleaner dvdDirt and Dust Often called an A-coil because of its shape, the coil in the furnace plenum is composed of hundreds of tiny air passages. Any restriction in these passages reduces airflow and diminishes effectiveness of the heating and cooling function.

The most frequent cause of a restricted A-coil is an accumulation of dust or dirt. Often a consequence of neglecting maintenance such as regular filter changes, dust and dirt may plug small coil passages and reduce downstream airflow. This degrades the effectiveness of heating throughout the home. It also increases heating costs as the furnace must run longer to meet thermostat settings, wasting gas or electricity. A severely obstructed A-coil may obstruct airflow to the point that the system overheats, tripping a safety high temperature switch and automatically shutting down the furnace. Home for Mold Another potential obstruction in the evaporator coil is mold. In cooling mode, warm air entering the cold passages of the coil condenses. The dark, wet environment forms a perfect breeding ground for mold. Airborne mold spores drawn into the return ducts infiltrate the coil and spawn a thriving mold colony, restricting the flow of air through the coil. During heating season, dried mold residue clogging the coil air passages may substantially reduce airflow and degrade the effectiveness of the furnace.

Don't Do It Yourself Cleaning the furnace A-coil is a job for an HVAC professional. Most coils are enclosed units sealed inside the furnace plenum and not readily accessible from the exterior. A technician may use compressed air, soft brushes and special coil cleaning solvents to clean the coil and restore heating and cooling performance. Biocides to kill mold inside the coil and at nearby locations such as the condensation drain pan also may be applied to prevent recurrence. References InspectApedia: Hot Air Heating Furnace Basic Operating Steps Troubleshooting & Repair GuideInspectApedia: Dirty Or Blocked Air Conditioning Cooling Coil Or Evaporator Coil Photo Credits Jupiterimages/Comstock/Getty Images Suggest a CorrectionThe requested URL /discuss/duboard.php?az=view_all&address=287x9356 was not found on this server.DetailsSUPCO FCR6 Heating and AC Fin Comb 8 x 2.5 x 2.5 inches #9,265 in Home Improvements (See top 100) #267 in Automotive > Car Care > Exterior Care > Cleaners

This is the PERFECT cleaner spray that you can buy. It works as it should. Foams better than others. It worked really good. This stuff really cleans your unit coils. I had a professional spay some before to clean my unit & told me that regular citizens couldn't buy coil cleaner, only professionals. Didn't work to well on my coils. The position of my coils are upward and the rinsing made a mess. Too much of a mess for little results. I have brought these from lowes and homedepot in the past to clean coil. these cleans ok,but not great. Seems that it works OK and removes some grime, but it is extremely difficult to determine whether it actually does any good. Wasn't enouh to clean entire condenser. I'd recommend buying 2 cans. Otherwise coil was clean where the product actually came in contact with it. Really does clean well! Nu-Calgon 417175 Evap Foam SUPCO FCR6 Heating and AC Fin Comb Outland Air Conditioner Pan Cleaner Tablets See and discover other items: a/c machine, air conditioner condenser

You'll need five tools to clean the evaporator coils on your AC unit: a screwdriver, a stiff brush, a large hand mirror, household bleach and wire. Once you have these tools, make sure you know where the evaporator coils are located. You'll find the evaporator for a central air system located directly above the furnace in the plenum (main duct). Your AC unit may have a plenum that is sealed shut. If so, don't try to open it; it means you don't have an AC unit you can clean yourself. Assuming you can open your AC unit's plenum, the first thing you want to do is remove the foil-wrapped insulation at the front of the plenum. This insulation is likely taped in place, so remove this tape carefully. You will have to put it all back. Behind the insulation is an access plate. Take your screwdriver and remove the screws holding the plate in place. Once the screws are out, remove the access plate. How to Remove Glue Spots How to Remove Contact Cement Spots How to Remove Dirt and Mud Stains