Ductless air conditioning systems are a reliable and cost-effective cooling solution for almost any home and have many advantages over more conventional ducted AC systems. However, ductless air conditioners are still vulnerable to some of the mechanical problems that frequently affect other types of AC systems.
Ice accumulating inside your ductless air conditioning system is a problem in and of itself, but it can also be a symptom of a more serious mechanical malfunction. If your home's ductless air conditioning system is frequently freezing up, rectifying the problem as quickly as possible can help you avoid more serious (and expensive) issues further down the road.
Why Is Your Ductless Air Conditioning System Freezing?
Unlike ducted central air systems, ductless AC systems do not funnel cool air from a central compressor unit into your home. Instead, an outdoor condenser compresses refrigerant gases until they become supercooled liquids; this liquid refrigerant is then passed through an evaporator coil inside the indoor blower unit, where it cools the warm air passing through the blower.
If the evaporator coil inside one or more of your indoor units gets too cold, or if air passes over it too slowly, it will start to freeze the water vapor present in the air, causing it to accumulate on the evaporator coil as solid ice. This coating of ice forms a physical barrier which prevents air from coming into contact with the evaporator coil itself.
How Can You Stop Your Ductless Air Conditioner Freezing?
Most modern ductless systems automatically alter the speed at which refrigerant flows through the system to match the speed of the fans located in the blower unit(s). If the AC system's air filters are dirty and clogged, air flow through the blower unit will be reduced even though the blower fan is still functioning normally, causing water vapor to freeze inside the blower as solid ice.
If your ductless AC system is frequently freezing up, exchanging the dirty filter (or thoroughly cleaning and replacing your existing filter) can be a quick and easy way to solve the problem. This is a relatively easy maintenance task that does not require special tools or knowledge, although you should call in professional AC repair service if you do not feel confident handling it yourself.
However, in some cases icing problems are caused by problems with the ductless system's refrigerant supply. A ductless AC system with an insufficient or contaminated refrigerant supply can create excessively cold temperatures inside the blower unit, causing large amounts of ice to accumulate around the evaporator coils. Leaks in refrigerant lines and pipes can also lead to freezing issues.
The refrigerant gases used in air conditioning systems are toxic, dangerous substances and can only legally be handled by specially qualified AC service personnel. If switching out your ductless system's dirty filters does not solve your freezing problems, call in a professional AC services company as soon as possible to check for problems with the system's refrigerant supply.