The evaporator coil's primary function is to capture the heat from your home's indoor air. While the evaporator coils do their job, the condenser coils (also commonly called the fan coils) release the trapped heat into the air around the outdoor unit. Both coils are typically made of copper and are encased by multiple aluminum fins that help improve the transfer of heat. They are located in separate areas of the HVAC system - condenser coils are in the outdoor cabinet of your system while the evaporator coils are located inside your home in the indoor air handling unit.
Evaporator coils play a vitally important role in the performance of the cooling function of your AC system by providing the cooling that is necessary to generate the cold air that keeps the indoor air of your home or business comfortable, even during the hottest of temperatures. They also play a role in the dehumidification that your HVAC system provides. Water condenses onto the coils as they become cooler, which is then removed from your indoor air. This water is then collected in the drain pan, safely flowing away from the system.
The effectiveness and performance of these two vital functions is greatly reduced when the evaporator coils get dirty. The coils are typically damp from the dehumidification process, so the dust, pollen and other particulates in the air will stick to the coils as the air passes by them. If the air filter is dirty, or no air filter is used at all, this can also increase the amount of contaminants that come in contact with the coil. When all of these factors come into play, enough dirt and dust can collect on the coils to affect their performance in a relatively short amount of time.
Problems that occur when the condenser and evaporator coils get dirty:
- Ice buildup on coil
- Increased wear on the system (leading to damage and malfunctions)
- Lowered cooling capacity
- Lowered heat transfer
- Higher energy consumption
- Higher temperatures and operating pressures
Dirty coils use up to 40% more energy than air conditioning units with clean coils, as well as reducing the cooling function by an estimated 30% or more. Not only will your AC unit continue to lose performance and efficiency, but your monthly utility bills will continue to sky-rocket if dirty coils are left to wreak their havoc. Evaporator coils should be checked regularly and cleaned as needed. Sometimes coils can be prone to easily collecting dirt and debris, therefore monthly cleaning may be necessary. A typical system, however, usually needs to be cleaned every 3 months during cooling season and at the very least annually during scheduled HVAC maintenance.