Kansas City has been feeling the heat, and it’s only getting hotter! The last thing you expect to find in this kind of weather, is frost on your condenser unit. And of course, on a 90 degree day or higher, it’s the last thing you want to see. So let’s say you didn’t get a professional in to service your AC before summer started (don’t worry, we do our very best to provide SAME DAY service to our valued customers here at Blue Heating and Cooling, so just give us a call!), and now you’ve got ice where it doesn’t belong. Why is it happening and what do you do?
How does it work?
First of all, air conditioning works by removing and transferring latent heat from the inside of your house to the outside, effectively cooling the interior. The heat is transferred through a refrigerant called Freon (for more information on Freon, see our blog post here). The Freon expands in the evaporator coil, causing the coil to cool quickly. Air is blown over the cold coils and the heat from the air is transferred to the Freon. The cold air is then blown through the ducts throughout the house, and the Freon moves outside to the condenser where it is forced to release the heat. And then the cycle repeats.
Wondering if you have ice – even if you don’t see it?
It’s not always visible on your condenser, but if there’s a full drip pan, or the sound of ice chunks falling, those are both red flags. It’s normal to see some water dripping, but an excess is a sign that it’s time to call a technician, and turn off your AC right away.
What could go wrong?
If you’re finding ice or frost on you unit, either the evaporator coils are getting too cold, or heat isn’t transferring to the Freon. There are a number of issues that could cause this, so let’s look at a few.
- The outside temperature is too low. This is probably the least likely cause, but during very mild weather, especially when its still spring, nighttime temps can dip below the 62 degree mark that air conditioners are not designed to operate at. If you notice the evenings are still a bit chilly, be sure to turn off your AC at night as an easy way to prevent this.
- Restricted airflow through the unit. Air needs to be able to move through the system effectively in order to keep the process going. A blockage in the airflow reduces the temperature and can cause the unit to freeze up. Blockages or restrictions can be caused by anything from dirt and debris in the lines, to closed vents, to dirty air filters, to even leaks or clogs in the ductwork.
- Low refrigerant level. Obviously if your refrigerant is low, this is going to cause problems. If a leak has caused a lowered amount of Freon in the system, the Freon will expand too much in the air conditioner’s evaporator coil, which will lower temperatures to freezing and cause ice to form.
- Dirty evaporator coil. A dirty evaporator coil restricts air flow, and that in turn causes ice to form. A dirty coil can also cause extensive damage to the compressor, meanwhile using extra electricity and providing ineffective cooling.
- Last but not least: mechanical failure. Your air conditioner can freeze up due to a blocked drain, a damaged blower fan, broken valves, or kinked refrigerant lines.
How can I fix it?
Now we know some of the things that can go wrong with your AC unit, but how do we go about fixing the problem? As always, an ounce of prevention is worth a pound of cure! But if you’ve already got ice, changing your air filter is a good first step in troubleshooting. Cleaning the ductwork and repairing any air ducts, as well as making sure all the air vents are open can also be helpful. It’s good to make a habit of cleaning the evaporator coil regularly, but if it’s been a while, a professional cleaning is in order. If you think this is the culprit, shut the unit off until a technician can come and clean it or let you know if it simply needs replacing. And we can’t say it enough, regular professional maintenance can catch these problems before they pop up, and prevent you from having to shut down your AC on a sweltering day while you try to figure out your icy problem, or wait for a technician to arrive!
