When your air conditioner is running properly, it should be nearly silent and should not have any frost or ice present. However, if you pay attention to your system, you have very likely seen part of it icing up at times. Learn what causes these ice-ups and whether it is something that should concern you with this simple guide provided by Island Heating & Air Conditioning in Oak Harbor.

How Air Conditioners Work

Before digging into what causes air conditioners to freeze, you should understand how they work. Your air conditioner circulates refrigerant between the outdoor condensing unit and the indoor evaporator coil. It cools your home by absorbing the heat from the air moving through your HVAC system and venting it outside.

To accomplish this, the system must regulate the pressure of the refrigerant. When the pressure goes down, the refrigerant gets cold. When the pressure increases, the refrigerant gets hot.

The refrigerant at the evaporator coil should be low, making it cold and allowing it to absorb the most heat. Then, the compressor increases the pressure, allowing it to effectively transfer the heat to the air moving through the condensing coil. If the pressure cannot be regulated or if the air is not moving through effectively, your system may experience a freeze. Here are the four most common causes of an AC freeze-up.

1. Dirty Coils

As air moves through your system, it deposits airborne contaminants on the evaporator coil. Eventually, these particles restrict the flow of air moving through the coil. The dust particles create an insulating effect on the coils.

In both cases, the refrigerant cannot absorb the proper amount of heat, which keeps the evaporator coil too cold. This lack of heat leads to freezes in the coil and areas farther down the refrigerant line. To deal with these contaminants, your system should be carefully cleaned annually during routine maintenance.

2. Clogged Air Filters

Your air filters are critical to keeping these particles out of the system and protecting them from excessive buildup. However, it is also the gateway to your system for the air needed to circulate. If the filters are clogged, then air cannot flow through the system properly, leading to the same issue as dirty coils.

Plan to check your filter regularly to keep air flowing freely. Most experts recommend changing your filter about every three months, depending on filter type and air quality. However, you can extend the life of your filter by checking it monthly and gently vacuuming the intake side.

3. Ineffective Circulating Fan

Your circulating fan is responsible for drawing air into your system, through the coil, and pushing it back out. Like the evaporator coil and air filter, contaminants settle on the fan wheel, reducing how much air it moves.

In addition to collecting these contaminants, the fan motor itself can also cause an issue. As the motor ages and nears the end of its service life, it may not spin as rapidly. This again reduces the amount of air it draws into the system.

4. Refrigerant Leaks

Your system must have a certain amount of refrigerant circulating to operate correctly. If it is too little, the compressor cannot create the pressure needed. This causes the pressure in the lines leading to the compressor to drop, leading to a freeze.

A leak is what causes the refrigerant level to be too low. These leaks may be minor and will build over time, or they may be major and very noticeable. Either way, they both result in the same frozen system.

What to Do Next

If you suspect you have a freeze in your system, turn it off and allow it time to thaw. While it is thawing, double-check your air filters to be sure they are clean. Then consider calling a qualified technician to troubleshoot your problem.

Preventing these issues is the best way to protect your system, and you do that with annual routine maintenance. During a maintenance visit, a technician will clean your coils and fan, check your refrigerant level, and test each component. Once the maintenance is completed, you will know your system is ready to handle all that summer throws at it.

Island Heating & Air Conditioning has been the trusted name for air conditioning maintenance and repair around Oak Harbor for over 35 years. Our technicians are also experts in indoor air quality and heating installation, repair, and maintenance. Call to schedule your air conditioning maintenance or repair appointment with one of our expert technicians today.


May 19, 2021 9:53 pm