Have you ever noticed ice forming on your air conditioner? While it may look harmless, ignoring ice on your AC is a big mistake. Ice formation is a sign that something isn’t working right and could be causing damage to your system. Here’s why ice forms on an air conditioner and what to do if it happens.
Why Ice Forms on Air Conditioners
When ice or frost forms on an air conditioner, it’s almost always on the evaporator coil (the coil located indoors). Your system’s blower blows hot indoor air over the evaporator coil. Meanwhile, the refrigerant in the evaporator coil absorbs heat from that indoor air, making it cooler. Below are the three most common reasons why ice forms on air conditioners and evaporator coils.
Lack of Air Flow. When air isn’t circulating properly, your AC’s evaporator coil can become too cold. This causes condensation on the coil to freeze, resulting in a layer of frost or ice. Dust-clogged air filters are the most common culprits behind poor airflow.
Low Refrigerant Levels. It may seem counterintuitive, but a low refrigerant level can cause the evaporator coil to freeze. In a nutshell, if the refrigerant in an air conditioner is low, the pressure in the system will be low—which also means the temperature in the system will be low. Condensation can freeze on the evaporator coil if the temperature drops below freezing.
Dirty Evaporator Coil. If your evaporator coil is clogged with dirt and debris, it won’t be able to absorb heat from the air efficiently. When the evaporator coil cannot absorb heat effectively, the coil gets extremely cold, and the condensation collecting on it freezes.
Why You Shouldn’t Ignore Ice on Your Air Conditioner
A layer of ice may not seem like a big deal, but it’s important to look at how this affects your air conditioner’s ability to function. Once a layer of ice forms on the evaporator coil, that coil has a harder time absorbing heat from your indoor air. Consequently, the coil will get even colder, and more ice will form. The thicker the ice gets, the more it will restrict the warm air trying to move through the coil, worsening the problem.
Additionally, this freezing affects refrigerant’s movement through your AC system, impacting its ability to change back and forth between liquid and gas. That change in state from liquid to gas and vice versa is crucial—not just for your AC to work but for it not to break down. If liquid refrigerant makes its way to the compressor (which is very expensive to replace), the compressor can be irreversibly damaged.
