Why is Your A/C Freezing Up?

An Air Conditioning System is designed to run in a particular way, so if anything within that system gets out of balance, things can go wrong. If something causes the Freon in the system to expand more than usual, which will make the coils colder than usual, or if something preventing air flow over the coils, then the evaporator coil will drop below freezing and the system will begin to ice up. Often there is a feedback where more ice increases the problem causing the ice, and eventually the whole thing will be frozen up. If this happens too often, it can damage the system.

One common cause of air conditioners freezing up is when the system is low on Freon. Less Freon will expand more because there is less pressure, and more expansion means a cooler temperature. Eventually the temperature will drop below freezing and then moisture in the air that contacts the coil will begin to freeze and form ice on the coil. One important step in determining why the air conditioner might be freezing is to check the levels of Freon. If it’s low, it will need to be filled up.

Another common cause is insufficient flow of air over the coil. The air conditioning system is designed to draw warm air from inside the house across the coil to cool the air, then return that cooled air into the house. This transfers heat back to the coil, preventing it from dropping its temperature too low. However, if the airflow is blocked or restricted, then not enough warm air will flow over the coil, with not enough heat transfer, which will cause a drop in temperature which will eventually cause the moisture to form ice. The most common cause of this restricted air flow is a clogged filter, so be sure to change your filters regularly. On the other hand, sometimes there might be a leak in the ductwork or some kind of obstruction that is restricting the air flow.

Sometimes mechanical failures can cause problems. Kinks in refrigerant lines might restrict the Freon, or a faulty blower fan might change the airflow. Additionally, running the air conditioner in outside temperatures below 62 or so degrees can cause the refrigeration system to drop in pressure and then run colder than it should. A qualified service technician should inspect the system for any mechanical or related problems.

If your air conditioner starts freezing up, or if you have any questions or problems with your own air conditioner system, be sure to contact All Day Air Cooling and Heating at (239) 357-0727 today to speak with our knowledgeable and experienced staff.