While A/C service technicians are dispatched to homes for many different reasons, frozen evaporator coils have to be close to the top of the list. When the evaporator coil freezes up in the inside component of your central A/C, your system won't cool your home, and may stop working altogether. If the coil keeps freezing up, it could cause long-term damage to your air conditioner. Keep reading for ways to resolve the issue.
Poor Airflow
Not enough airflow across the evaporator coil is probably the primary reason for frozen evaporator coils. An air conditioner provides indoor cooling when pressure is reduced on refrigerant in the evaporator coil. This cools down the refrigerant, turning it into a gas. When this happens, the refrigerant extracts heat energy from the air, which results in cool air. If insufficient air is flowing across the coil, it won't absorb adequate heat. The refrigerant will continue cooling, causing the coil to freeze. Airflow may be constrained for a variety of reasons, including a clogged air filter or a dirty evaporator coil.
Low Refrigerant
If the refrigerant level is low, this can cause the evaporator coil to freeze up. With less refrigerant expanding into a gas in the evaporator coil, the cooling process accelerates, and results in airborne moisture freezing on the coil. A professional HVAC technician should address any issues related to refrigerant.
Overworked A/C
If your air conditioner is being overworked in order to lower indoor temperature by a large amount, for example, if the thermostat is set to 64 when it's 94 outside, this can lower pressure in the cooling system and cause frozen evaporator coils. Overwork also can damage the compressor and air handler motor. Avoid making unreasonable demands on your A/C.
A variety of mechanical issues can result in frozen coils, including a refrigerant line that has kinked and a malfunctioning blower fan, among others.
If you turn off the A/C until the coil has thawed, or tried some of the methods suggested above, and that fails to address the issue, contact us at Hartman Brothers Heating & Air Conditioning.
Our goal is to help educate our customers in New Haven, Indiana and surrounding Fort Wayne area about energy and home comfort issues (specific to HVAC systems). For more information about evaporator coils and other HVAC topics, download our free Home Comfort Resource guide.
Credit/Copyright Attribution: “chrisdorney/Shutterstock”