Why Does an Air Conditioner Freeze Up?

Why Does an Air Conditioner Freeze Up?


In Singapore, having an air conditioner that works is one of the greatest pleasures, especially during the heat of the day. However, one of the most annoying things can happen when the aircon gets too cold and ices over. As a result, cooling performance deteriorates and enduring the heat becomes more difficult.


So, what is going on? How is it possible for ice to form on the parts of your air conditioning system while it is hot outside?


Our experts share the most common causes for ice to form on your units.


Inadequate airflow causes an air conditioner to freeze up

air conditioner filter


An essential part of your aircon is the evaporator coil. As the last stage in the air cooling cycle, it is responsible for storing the cooled liquid refrigerant circulating in your system. During evaporation, air passes over the coil, absorbing cool gas and carrying it through your system so you can enjoy cold air in your room.


In the event that the coil cannot eliminate this cool air due to diminished airflow, the temperature around it gradually drops. When the air gets too cold, it will condense into liquid and leading to a buildup of ice on your unit.


And what are the possible reasons for inadequate airflow in your system? They can happen due to:

  • Filters clogged with dirt prevent air from returning to the indoor unit
  • A failure in the motor of the fan prevents the indoor unit from drawing enough air
  • Debris and dust cover evaporator coils and prevent them from absorbing heat


There are some to-dos you can try to solve or prevent the issues. You need to clean your air filters regularly and schedule a professional aircon cleaning to clean evaporator coils and fix malfunctions in your unit.


Your aircon is low on refrigerant

aircon gas refill


You cannot have cool air without refrigerant. It turns from liquid to gas during the cooling process and back again as it moves in your aircon system. Pressure drops when your aircon is low on refrigerant, and the coils get abnormally cold as a result. 


As such, humidity from the air beads up on the coil freezes when returning air passes through it. This continues until all the moisture around the coil becomes ice.


And the most common reason for an inadequate amount of refrigerant in your system is a refrigerant leak. A refrigerant leak is dangerous and must be handled by a licensed technician. Certified aircon contractors can inspect your system, fix the leak, and refill the refrigerant.


Broken parts in your aircon

how often should you perform aircon cleaning


A number of things can go wrong with your air conditioner. For example, your drain line may be clogged, your fan may be broken, or your refrigerant lines might be cracked. All these can lead to ice forming on your system.


You can prevent clogged drain lines with regular aircon cleaning. On the other hand, if you think there is a broken part in your aircon, it would be better to reach your aircon contractor and ask for an inspection.


What you should do if there is an ice buildup on your aircon


In case you see ice forming on the surface of your aircon, you should do this as soon as possible:

  • Turn off your aircon
  • Let the ice thaw naturally
  • Ensure no objects are blocking the front of your indoor or outdoor unit
  • Clean the air filters of your aircon


What if the freezing continues although your filter is clean?


You should address the problem as soon as possible. Ignoring the issue for a long time can cause strain on your unit and damage the compressor in your system. In other words, you will end up paying more to fix it.


That is why it is better to schedule an appointment with your aircon contractor if ice keeps forming on your unit. They can send a team to inspect your aircon system.


For over 20 years, Purer Fresher Air has offered aircon servicing (including cleaning), aircon chemical wash, and aircon gas top-up to homeowners and businesses in Singapore.


At our company’s core, we strive to serve our customers with utmost integrity, be transparent in our pricing and diagnosing issues, and recommend only what will benefit you as a customer without unnecessary upselling.


You can tap the floating WhatsApp button to talk with us, schedule an aircon service appointment, or call us at +65 9830 8224.

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