March 31, 2017
So, your AC stopped blowing cold air and after investigating, you found ice on your AC unit’s refrigerant lines. And now you’re wondering if that’s normal.
Unfortunately, ice anywhere on your AC unit is definitely not normal. Now, ice build-up on your unit can happen if you happen to be running your AC in sub 65-degree weather, but we’ll assume you aren’t.
So, if you have ice building on your AC refrigerant lines, you have one of the following 2 problems:
Not sure which problem you have? Don’t worry. We’ll explain both of these problems, why they lead to a frozen AC and what you can do to fix the problem.
When your AC doesn’t “breathe” in enough air, the part that actually cools the air (the evaporator coil) gets too cold and eventually freezes over.
Here’s why: The evaporator coil is basically a large web of refrigerant coils. And the refrigerant inside those coils can reach temperatures as low as 10-20 degrees Fahrenheit. Now, normally, there’s enough warm unconditioned air passing over those coils to prevent ice or frost build-up.
But when there’s not enough warm air passing over your evaporator coils, the evaporator will quickly ice over (and ice will travel along the refrigerant lines). And the ice builds even faster as humid air hits the coils, condenses and freezes.
Problems that can lead to restricted airflow include:
What to do:
Clean filter (left) vs dirty filter (right)
Your AC uses a special chemical called refrigerant to absorb heat from inside your home and transfer that heat outdoors. But if refrigerant levels drop, the refrigerant pressure inside your evaporator coil drops as well. And when the pressure drops so does its temperature. Eventually, the low refrigerant temperatures cause ice to form on evaporator coils.
Only one thing causes your AC’s refrigerant levels to drop: a refrigerant leak.
You see, your refrigerant is housed inside a closed circuit of copper coils and unlike gas in a car, refrigerant never gets “used up”. So, if you have low refrigerant levels, the only explanation is that refrigerant has found a way to escape (i.e., via a hole in your refrigerant coils).
Signs of a refrigerant leak include:
What to do:
Note: Beware contractors who recharge your system without repairing the leak first. If they don’t first repair the leak, you’ll find yourself paying for another refrigerant recharge very soon (and refrigerant is pricey).
Need help determining what’s causing your AC to freeze up? We can help. Just contact us and we’ll send an experienced tech over right away. We provide expert air conditioning repair in Denver and the surrounding areas, including: Arvada, Aurora, Boulder, Castle Rock, Highlands Ranch, Littleton, Longmont, Thornton, Wheat Ridge, and more.
For your convenience, you can request an appointment in one of two ways: