Should There Be Ice on My AC’s Evaporator Coil?

Living in Minnesota means getting used to ice. We deal with it a lot during a significant stretch of the year. We get so accustomed to seeing it, that when it appears on an air conditioner during the summer, we might assume it’s normal.

For people who aren’t HVAC professionals and don’t know the details about how an air conditioner works, it makes some sense for ice to appear on an AC’s evaporator coil. During the summer, the air conditioner sends out chilled air; why wouldn’t there be ice associated with that?

But You Shouldn’t See Ice on Your AC’s Coil!

Even if you can make sense of a frozen evaporator coil with some twists in logical, the simple fact is ice on an air conditioning is abnormal. It’s a sign of something wrong with the air conditioner. If you see ice on your AC, you need to call for air conditioning repairs in Woodbury, MN from our technicians.

Let’s start with some Air Conditioning 101. How does an AC provide cooling for a building? It’s through a process called heat exchange, which means the AC isn’t generating cold air, it’s removing the heat from the air. It does this through refrigerant, a chemical blend that easily transitions between liquid and gas form. The refrigerant evaporates in the indoor coil to absorb heat from the air, which warms up the cold refrigerant. In the outdoor coil, the warm refrigerant condenses, releasing the heat. You don’t need ice for this process: it’s moving heat from one place to another.

What Doe Ice on the Coil Mean?

It points toward a number of possible problems. Essentially what is occurring is that the refrigerant in the evaporator coil is remaining cold rather than warming up through heat absorption. If the temperature of the coil stays below freezing, the moisture along the surface of the coil that collects during evaporation will change to ice.

A common reason for ice on the coil is a loss of refrigerant due to leaks. It may sound odd that losing refrigerant would create ice, but remember that refrigerant is a heat transference fluid, not just “something cold.” If there’s less refrigerant in the evaporator coil, it will not absorb enough heat to raise the temperature of the remaining refrigerant above freezing—and so trigger ice development. Refrigerant loss is a serious malfunction for an air conditioner and must have expert repairs done as soon as possible.

Other reasons for the frost to appear on the coil include a dirty air filter preventing sufficient warm air from entering the AC and dirt and grime collection along the coil, creating an insulating layer.

Don’t attempt to figure out the cause of the iced coil yourself. And please don’t try to “fix” the problem by scraping off the ice on your own. This won’t solve the actual cause of the frost (which is a symptom, not the disease) and it might damage the coil. You need professional air conditioning repairs to target the actual malfunction and then defrost the coil without harming it. Our technicians are here to help restore your AC, no matter the trouble.