What Causes an Air Conditioner to Freeze Up?

In the summer, there’s nothing as refreshing as a glass of ice water. Although ice in your drink is a good thing, if it forms on your air conditioner, you could experience a full breakdown. The good news is that, in many cases, there are easy fixes to a frozen air conditioner. Keep reading this guide to better understand what causes this condition and what you can do to prevent and fix it.

1. Dusty Evaporator Coil

Before air is pushed through your home by your blower fan, it moves over a component called the evaporator coil. This coil is made up of a single metal pipe that bends back and forth dozens of times. Since a long length of pipe is compressed into a small space, the refrigerant in the tube can remain in this space for a long time.

Therefore, as air blows over this tube, the refrigerant removes heat and humidity from the air to make it more comfortable on your skin. Unfortunately, if your evaporator coil becomes dusty, the humidity that condenses on the metal tube won’t fall away. Instead, it will remain for a long period, which will give the cold refrigerant time to freeze the water, resulting in less-efficient cooling and potentially causing damage to your system.

2. Refrigerant Leak

Another problem you may encounter with your system is a low refrigerant level. The refrigerant in your system, typically a chemical called R410A, is cooled and heated by the various components in your air conditioner. Ultimately, it will take your home’s heat through vents to the outside where it can be expelled into the air.

To do this efficiently, a precise volume of refrigerant is necessary, depending on the size of your air conditioner. If this volume changes, the refrigerant won’t be able to cool down and heat up as efficiently, which can cause the system to freeze up when the other components can’t do their jobs properly. Typically, low refrigerant level is caused by a small hole in your refrigerant line. This will have to be detected and patched by a technician before your system can resume normal operation.

3. Malfunctioning Blower Fan

Your blower fan is the component that’s responsible for moving both hot and cold air throughout your home. During the summer, when your air conditioner is running, the blower fan pulls in air through the return vents and then sends that air over the evaporator coil.

However, if the blower fan is malfunctioning, it will reduce the volume of air that moves over the coil. Since the coil depends on incoming warm air to regulate its temperature, a lack of air can cause the coil to become supercooled, resulting in a frozen system that needs immediate attention.

4. Blocked Ducts

In the same way that healthy veins and arteries are crucial to your health as they carry oxygen-rich blood throughout your body, healthy and clean ducts are crucial to the health of your air conditioner as they carry air throughout your home. A blocked duct, either on the supply end or the output end, can cause your air conditioner to freeze up.

Freezing on the supply end is typically caused by a restriction in the volume of air flowing over the evaporator coil. On the output end, problems can result when there are blockages in the ducts that result in the system producing too much cold air, which can cause the coil to become too cool.

Most of the time, blocked ducts are caused by an accumulation of dust and dirt. However, ducts can sometimes collapse if something in the structure around them changes. In any event, if you’re having issues with your air conditioner freezing and you can’t find another cause, it’s a good idea to have a technician inspect your ducts.

We Know Your System Inside and Out

For over 40 years, Barker's Heating & Cooling has been serving the community in College Station with professional and knowledgeable service. When you call us with an air conditioner repair need, we’ll work hard to diagnose the problem until we track down the root cause.

We apply this same attention to detail to all of the services we perform. If you need maintenance or repairs for a furnace or air conditioner, we can take care of that. If you need a new HVAC system installed, we can do that, too. We can also make ductwork modifications, install geothermal systems, and design and install indoor air quality systems to make your home as comfortable as possible.

If you’re ready for service in College Station, give us a call at Barker's Heating & Cooling today.