AC Keeps Freezing Up: How Using The Wrong Thermostat Setting Affects The Evaporator Coil

Depending on where you live in the United States, some areas may be hotter in the summer than other locations. If you are in the southern portion of the U.S., you may turn your cooling system's thermostat down very low to keep the home comfortable. But by doing so, you may be the cause of your AC freezing up. The indoor unit uses different parts to turn hot air into cold air, including the evaporator coil. If the home reaches a certain low temperature inside, it may place too much stress evaporator coil, causing it to freeze over. In this case, you need to repair your air conditioner. Here's how the wrong thermostat setting may cause two AC parts to freeze up and break down.

How Does the Evaporator Coil Freeze Up?

Most sources recommend that you set your thermostat to about 78 ┬░Fahrenheit, then lower it one degree at a time to find the perfect temperature for you. But if you're like some people, you may not find comfort unless you lower the thermostat to somewhere in the 60s. Now, your home may be too cold for the evaporator coil to work properly. 

The evaporator coil is the triangular-shaped equipment in the air handler or indoor unit. The coil turns heated air into cold air once it passes through it, then releases the cold air back into the home through air registers, ducts and vents. Because only cold air passes through your evaporator coil, ice may develop inside the metal fins that cover it.

At this point, the evaporator coil can't warm up enough to melt the ice. The ice may rapidly spread to the copper line that transports water out of the AC. The copper line also freezes up, which may create problems in every area of the air handler. 

If you feel comfortable enough, you may try to de-ice the evaporator coil yourself by turning off the unit and allowing the ice to melt. However, you may need to perform other steps that include cleaning off the coil's fins and adding refrigerant to the unit. It's a better idea that you have your AC repair technician de-ice the evaporator coil manually to restore its functions.

In addition, if the fins on the coil bent or broke when you try to de-ice it, you may need to replace your evaporator coil altogether. You can try to avoid these issues by simply making some changes in how you keep cool.

What Can You Do to Stay Comfortable Without Damaging Your Evaporator Coil?

You may want to readjust your home's temperature to fit your needs by turning on a ceiling or circulating fan during the day if it's too hot for you. The fan may push the heated air up toward the ceiling, which makes the lower half of the home or flooring feel cooler.

Running a dehumidifier in your bedroom at night may remove some of the moisture and heat. The air may seem drier to you, which may help you sleep more comfortably. 

If you have questions about how and why your AC keeps freezing up, contact an HVAC contractor like Cape Fear Air Conditioning & Heating Co., Inc. for more information.