Why is There Ice on My Air Conditioning Unit?

Are you finding an unwelcome layer of ice forming on your air conditioner? Don't be alarmed: it's a common problem usually caused by restricted airflow or low refrigerant. In fact, it's often one of the most straightforward air conditioning repair jobs for a professional to handle. Here is what you need to know about both issues.

Restricted Airflow: Causes and Fixes

Your air conditioner's evaporator coil is responsible for helping cool the air in your home. It works by absorbing heat from the air as air passes over the coil. The heat is then pushed outside, and the resulting cool air is circulated through the house. When this airflow becomes slowed or blocked, however, the coils can freeze because there is not enough warm air around them to keep the refrigerant inside in liquid form.

The most common causes of restricted airflow include blocked ducts or vents, a dirty air filter, an undersized system, or a failing blower motor that can't push enough air. To prevent this, make sure to check and change your air filters regularly according to the manufacturer’s recommendations. Typically, this is every one to three months, depending on the type of filter and how often you're running your air conditioner.

It's also important to check for blockages in the ducts and vents that could cause airflow restriction. In particular, look for leaves, debris, or other buildup.

Low Refrigerant: Causes and Fixes

Your air conditioner's refrigerant is responsible for absorbing heat from the air in your home and then releasing it outside. This ultra-cold liquid does this by circulating through the evaporator coils and related systems, absorbing heat as it goes. Once directed outside, the heat is released, removing warmth from inside the house and releasing it outdoors.

If there's insufficient refrigerant, this process won't happen efficiently and can cause ice to form on your air conditioner's coils. This is because not enough heat is absorbed and released, causing the coils to get too cold and freeze. Low refrigerant causes include a system leak, improper installation, or a faulty condenser unit.

Air conditioners use freon as a refrigerant, which is highly toxic and should not be handled by anyone but professionals specializing in air conditioning repair. To fix this problem, you will need to contact a technician to inspect your system, locate any leaks or faulty parts, and replace the refrigerant as needed.