Our customers trust our professionally trained HVAC technicians to give them quality advice when it comes to their cooling systems, and rightfully so. One of the questions our technicians often receive is whether or not they should ever see ice forming on the indoor coil of an AC system while it is running during the summer.
We understand why you may think this is a common occurrence. After all, chilled air is coming from the vents, so ice should be a natural part of the coolin process, right? One of the ways to rig up a simple cooling system is to place a bowl of ice in front of a fan, so shouldn’t an AC work similarly?
The short answer is no, this isn’t normal. Allow us to explain why.
Freezing is Not Part of the Cooling Process
Unfortunately, ice on an AC coil is a symptom of a potentially major problem that requires professional repairs. There is no point in the cooling process in which your air conditioner uses ice or frost. It shouldn’t be a byproduct of the cooling process, either. Your air conditioner is a type of heat pump, which means it pumps heat from one area to another.
In this case, it removes heat from inside your home and moves it outside. It does this through the circulation of a chemical refrigerant blend, which evaporates and condenses in a heat exchange cycle. Although the refrigerant in the indoor evaporator coil is extremely cold, it shouldn’t trigger the creation of ice because it warms up as it absorbs heat from the air.
So, Why Do I See Ice on my Indoor Coil?
There are a few possible reasons you may see ice on the indoor coil of your air conditioner:
- Your air filter might be clogged. This is one of the various reasons that you should keep up on changing the air filter—every 1 to 3 months. If insufficient warm air is drawn over the coil, it will remain too cold, and moisture will begin to freeze along it.
- The coil might be dirty. This is another byproduct of a clogged air filter, but not the only cause. Dirt and grime serve as an insulating barrier over the coil, inhibiting its ability to absorb heat. This leaves the refrigerant too cold, and will again start to cause moisture to freeze along the coil.
- You might have a refrigerant leak. This is the most serious problem you can have out of the three mentioned here. A drop in refrigerant level creates a change in pressure throughout the system, eventually damaging the compressor. The reduced refrigerant also restricts heat absorption on the coil, leaving the remaining refrigerant too cold, and again, leading to freezing along the coil.
An important thing to remember about ice on your air conditioner is that it takes a professional to remove it and to resolve the problem that caused it to begin with. Attempting to chip away or thaw the ice on your own can do more harm than good to your cooling system.