Why coil freezes up

The air from the fan will help melt the ice on the compressor. You can also use a hairdryer to help melt the ice faster. These issues will need to be addressed by an AC technician. Clogged air filters are one of the main reasons why AC evaporator coils freeze up. Replacing the air filter could solve the issue.

Make sure your air conditioner is draining properly. If there is a drain pan, see if ice accumulation on the coil extends beyond the drip pan beneath the air handler.

Nic Rardin February 21, Warmer weather will be here before you know it, and your air conditioner will be working hard to keep your home cool and comfortable. Over cooling season, you may run into a common air conditioner repair issue — a frozen coil. Learn why air conditioning coils freeze up, their signs, and what to do to solve this problem and restore cooling to your home. If your air conditioner is running low on refrigerant due to a possible leak, it can freeze up.

This happens because the refrigerant in the evaporator coils can no longer absorb the heat needed for the coils to warm up. The more the refrigerant has to expand, the cooler it makes the temperature. If the temperature of the expander coil drops below freezing, the moisture outside will freeze when it comes into contact with it. This process works to quickly cool the air, which the blower fan then sends throughout your home. In simpler terms, the coils hold the cold refrigerant and remove the heat from the air as it passes over them.

For heating, the process is essentially reversed, creating heat from the air and pushing it into your home instead of removing it. As stated above, the evaporator coils work by absorbing heat from the air. Low airflow can be caused by dozens of problems within the AC system, such as a malfunctioning blower fan, dirty air filters, or even damaged ductwork.

A dirty air filter creates the same airflow problem mentioned above, preventing the evaporator coils from absorbing the necessary amount of heat from the air to function properly.

Dirty air filters can also can spread dirt and clog up other parts of your system, including the coils themselves. If your evaporator coils collect too much dirt or debris, the heat exchange process can become obstructed. Dirty coils will be unable to properly absorb the heat from the air, causing the condensation to become too cold and freeze. Ironic though it may seem, having low refrigerant in your system can actually lead to frozen evaporator coils. Low refrigerant causes the system to overwork, which can lead to the condensation on the coils freezing.

Therefore, if you have low refrigerant, the problem is either a refrigerant leak in your system or an insufficient charge. Similar to how the coils freeze when there is restricted airflow, they can also freeze if the air temperature is too low that your system is trying to cool. Since the coils work by absorbing heat from the air, lack of such heat can lead to the condensation on the coils freezing over. Condensation forming on the evaporator coils is a natural part of how they function.