Why Does Your Air Conditioner Freeze in the Summer?

While having an air conditioner freeze may seem like a catastrophic event, in reality, the causes could be easy and inexpensive to fix. The first is inadequate air blowing over the coil, and the second is a low refrigerant level. Although the causes are simple, the ramifications of a frozen coil can be serious if the system continues to run.

Inadequate Airflow

When the cold refrigerant enters the evaporator coil, it absorbs the heat from the air flowing over it and returns the warmed refrigerant to the outdoor condenser where it loses the heat. If there isn’t enough airflow, the refrigerant stays too cold, and frost can form on the outside the coil. The returning refrigerant to the condenser will be too cold, and it can harm the compressor, which is an air conditioner’s most expensive part.

The two primary causes of weak airflow include an overly dirty air filter for the air handler or a dirty coil. It’s important to check the filter monthly during the peak of the cooling season. Ask your HVAC contractor about cleaning the coil during the annual maintenance visit to prevent an accumulation of dirt, mold or biofilms on the coil that will make the air conditioner freeze.

Low Refrigerant

Whether your system lacked refrigerant from its installation date, or leaks have formed over time, low refrigerant will freeze the A/C coil over.

What to Do

When you discover the coil is frozen, turn the system off immediately. While you wait for the coil to thaw, check the air filter. Replace if it’s dirty. If the filter is fine, call your HVAC contractor who will measure and adjust the refrigerant level. Letting a frozen A/C run drives up energy consumption and won’t cool your home. It could also result in a serious breakdown.

The conditions that make an air conditioner freeze over are preventable through maintenance.

For more information contact Sobieski Services, Inc. We want to help customers in Delaware, Maryland, New Jersey and Pennsylvania learn more about energy and home comfort to save money and live in more comfortable and healthier homes.

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