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Why Ice Might Form on Your AC’s Coil

frost-patternHere’s a common misunderstanding people often have about air conditioning systems: it’s normal for ice to appear on them, because it means the AC is doing an extremely good job of cooling the air.

Nothing about this is true. Air conditioners should never create ice as they operate, the same way that you shouldn’t see ice forming inside a modern freezer (unless you specifically put water in it to turn into ice). When you see ice developing on your AC, it will appear along the indoor coil, the evaporator coil, and that sends a warning that something is wrong with the air conditioner. Not only is a problem present in the AC, but the ice will cause the air conditioner to provide less cool air, not more. In most cases, ice on the coil means you need to call for AC repair in Flushing, MI.

The Basic Problem That Causes Ice on the Coil

If you know the rudiments of how your AC works, you’ll know that cold refrigerant moves through the indoor coil. As the blower pushes warm air around the coil, the cold refrigerant evaporates and absorbs heat from the air, lowering the air’s temperature and raising the refrigerant’s temperature above freezing. As a side effect of evaporation, moisture condenses along the coil, then drips down into a condensate pan.

However, if the refrigerant in the coil isn’t able to absorb enough heat from the air, the refrigerant will remain below freezing. The moisture on the coil won’t drip off; instead, it will freeze on the coil. This ice will further restrict the coil from absorbing heat, and even more ice will grow. If ice completely covers the coil, the AC won’t be able to cool the air at all.

Why the Coil May Lose Heat Absorption

What might interfere with the evaporator coil’s job that will lead to ice growth? These are the possible underlying problems you’ll need to address:

  • Clogged air filter: Yes, clogged HVAC air filters are the source of numerous problems—and this is one of the worst. The trouble is that a clogged filter prevents the blower from sending enough warm air around the coil to allow the refrigerant to warm up. Please replace the filter every one to three months to prevent this. 
  • Dirty evaporator coil: The evaporator coil can collect dust and grime, or mold can start to grow on it, and this will make it harder for the coil to absorb heat—the grime layer insulates it. You should leave the job of cleaning the coil to professionals to avoid potentially damaging it.
  • Loss of refrigerant: This is one of the most serious problems that can cause coil freeze. Although it sounds backward that losing refrigerant would create a colder coil, what is happening is that the lower amount of refrigerant reduces heat absorption, leaving the remaining refrigerant too cold. Leaking refrigerant will eventually cause the entire AC to break down—you must have HVAC professionals seal the leaks and restore the proper amount of refrigerant.  

First Choice Heating & Cooling serves Fenton, Linden, Holly, and the surrounding areas. If your home had a voice … it would call First Choice!

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