You need to rely on your air conditioning during the summer months to keep your home cool and comfortable. Depending on where you live, the spring and fall could also produce days warm enough to need air conditioning. You might rely on your cooling system for a significant part of the year, so you'll want to ensure that it functions correctly. It can be frustrating and uncomfortable if you suddenly find yourself in an overly warm house because your AC is frozen up.

An AC has frozen up if the unit appears to be covered in a layer of ice. Specifically, frost may be built upon the refrigerant lines and evaporator coil. The appearance can range from a thin layer of frost to a block of ice. If you have ever had to ask, "Why is my HVAC covered in ice?" you understand the problems that this can cause. There are many reasons why this might happen, from dirty air filters to low refrigerant levels to improper drainage. Let's look at why ice may be forming on your AC unit.

One of the most common reasons your HVAC system might be freezing up is poor airflow. Usually, this is also one of the easiest problems to fix. Your air conditioner needs adequate air flowing through the system to function correctly. Air conditioners work by expanding refrigerant inside the evaporator coil to cool down. The refrigerant is converted from gas to liquid and back again very quickly. When the refrigerant is sent to the evaporator coil, it is converted to gas and cools the indoor coil. Your blower fan moves air across the coil, absorbing heat and humidity and cooling the air. Without adequate airflow, the system will get too cold and freeze over.

Poor Airflow

Poor airflow could result from dirty air filters, dirty evaporator coils, closed vent registers, or a faulty fan motor. One of the simplest solutions is to check your air filters and vents. You should always keep your vents open and change your air filters regularly. Additionally, routine HVAC service will ensure that your outdoor unit stays clean and unrestricted. If you have ruled out all of these issues, you may need to check the fan motor.

Low Refrigerant Levels

An adequate level of refrigerant in your AC system is just as important as good airflow. Improper refrigerant levels can cause your equipment to malfunction and freeze up. When you have a refrigerant leak, the evaporator coils will become too cold, and water condensation will form a layer of ice on the equipment. You will need a Denver air conditioning repair technician to examine your system to repair the leak and add additional refrigerant. It is also important to note that ignoring this issue could damage your coils and air compressor. Once more extensive damage is done, you will face expensive repairs or even the need for a replacement unit.

Poor Drainage

During the normal cooling process, your equipment produces a good bit of water condensation. If you experience a problem with drainage, the condensed water will remain inside the unit and will eventually freeze. Frozen coils can further prohibit the drainage problem and create a major ice issue. You must routinely check the condensate line to ensure that your unit is draining correctly. 

Regular HVAC service will also help maintain system drainage.

Heating and cooling systems incorporate complex equipment and processes to deliver comfortable temperatures to your home. When problems arise, the entire system can be impacted. A frozen unit can be the result of a few problems inside the outdoor unit or elsewhere in the system. Regular HVAC maintenance before each cooling season will help ensure the health of all components, prevent an issue with ice forming, and ensure that your system lasts beyond the 20-year life span.