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Finding, Checking, And Repairing Your AC Evaporator

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Your home's split-unit air conditioning system contains many vital components located in both your outdoor condenser unit and in your home, generally near your furnace or air handler. Although the compressor is the part of any system that most homeowners are most familiar with, it is far from being the only critical element. Keeping your home comfortable requires every part of your air conditioning system to be working efficiently, and this includes your evaporator coil. As a homeowner, it is essential to know the location of this unit and to recognize potential signs of trouble.

The Role of the Evaporator

Your AC system is essentially a large pump that moves refrigerant through a closed-loop system. This system contains two crucial coils: the condenser coil, found in the outdoor condenser unit, and the evaporator coil, located inside. If your home uses forced-air heating, then your evaporator coil will be located near your furnace and air handler. The role of this coil complements the role of the condenser coil. Outside, the condenser coil allows warm refrigerant to release its heat into the atmosphere. Inside, the evaporator coil uses cold refrigerant to absorb heat from your home's air and transport it outside.

Checking and Maintaining Your Evaporator Coil

Although often ignored, your evaporator coil is not necessarily a maintenance-free item. Like your condenser coil, it relies on direct contact with the surrounding air to successfully exchange heat with the refrigerant that it carries. Metals such as copper or aluminum are used to construct evaporator coils since these materials are especially good at conducting heat. If the exterior of the coils becomes contaminated, however, then their efficiency may be reduced. Imagine covering yourself with a thick blanket on a cold night; the extra layer of insulation prevents the easy exchange of heat between your body and the much colder air in the room.

Unfortunately, it's usually not an easy task to check your evaporator unit yourself. In most AC systems, the evaporator can be found inside the air handler unit since the blower must be able to direct air directly over the coils. This position means that it does not accumulate dust rapidly, but contaminants can sometimes make their way into the air handler unit due to dirty filters or improper seals. An HVAC technician should check your evaporator as part of an annual maintenance call.

Repairing Bad Evaporator Coils

Evaporator coil issues are usually solvable with a good cleaning, but these components do sometimes fail. Leaks are the most common mode of failure. Any loss of refrigerant will result in reduced efficiency and may ultimately cause the evaporator to freeze over. If you suspect that your system may be leaking, an air conditioning repair contractor will check your refrigerant pressure, refill, and locate the source of the problem. If your evaporator is found to be the culprit, it will usually require replacement.