Air conditioning failures can happen when you least expect them, and while your vehicle may still be drivable, the experience becomes far less comfortable especially in hot or humid conditions.
Your car’s air conditioning system does more than just cool the cabin. It filters out pollutants and airborne particles, providing clean, odourless air. This is particularly beneficial for passengers with respiratory conditions or allergies.
Because of these health and comfort benefits, it’s essential to keep your car’s air conditioning system in good working order. Like all mechanical components, however, it’s not immune to wear and tear.
Let’s take a closer look at the top 5 most common causes of car air conditioning failures.
5 Common Causes of Air Conditioning Failure In a Car
Leaking or Depleted Refrigerant
Every air conditioning system needs a refrigerant. The most common and widely used is CFC-12 or R-22, more popularly known as Freon. Freon is a chlorofluorocarbon (CFC) that has been linked to depleting ozone levels.
Due to environmental impacts and health concerns, safer refrigerants have been introduced, for example, HFC-134a.
Refrigerants absorb the heat and produce cool air.
In your air conditioning unit, there are compressors and coils. The compressor adds pressure to the refrigerant
As the refrigerant circulates through the condenser or coils, it condenses to a liquid state. It then absorbs heat from the air outside and converts it into cool air. This cycle is responsible for the cooling effect in your car, and when disrupted, it can lead to car air conditioning failures.
For an air conditioning unit to function properly, it requires refrigerant. When there is a malfunction or leak related to the refrigerant, the air conditioner stops working effectively.
Refrigerant leakage can be caused by loose connection or corrosion of the heat pump.
Your air conditioner can lose 10 to 15 percent of the refrigerant over a year. Over five years, that is at least 50% loss of refrigerant.
Coils and Condenser Failure
The function of the condenser is to cool the highly pressurised refrigerant vapours coming from the compressor. The condenser is made up of a system of coils and fans. If the condenser becomes damaged or clogged, it can restrict the cooling process and contribute to car air conditioning failures.
The air conditioner coils or condensing system may become blocked by dust or grime. They can also become rusty and may leak.
This causes the air conditioning unit to overheat , as it constantly tries to expel hot air.
Malfunctioning Fan or Blower System
The condenser system fan circulates the air through the coils. If the condenser system fan fails, the air flow will stay warm, which is one of the common causes of air conditioning failures.
Freezing or Faulty Evaporator
Failure may happen if the air conditioner starts blowing hot or warm air, and then suddenly switches to cold air. A faulty evaporator will cause your air conditioner to repeatedly switch between hot and cold, which is a typical symptom of air conditioning failures.
Just as the condenser creates cool air, the evaporator will create warm air. Please check out our article on how the air conditioner of a car works for better understanding of this part.
Additionally, the evaporator can freeze as it is in direct contact with the refrigerant.
If an evaporator is covered in ice, it cannot cool air properly. The system will have to wait till the ice melts before it can circulate cold air again.
Bad Expansion Valve and Orifice Tube
The expansion valve and orifice tubes are core components of a car’s air conditioning.
If insufficient refrigerant flows, the evaporator can overheat; and if too much refrigerant flows, the evaporator can freeze. A noticeable sign of this is icy air coming out of the air vent, which may indicate underlying air conditioning failures.
Conclusion
If you feel your air conditioner is faulty, it could be a malfunction of any of these components.
At Sandgate Auto Electrics, we understand the importance of a well-functioning air conditioning system—especially when dealing with air conditioning failures. If you need further advice, or for a certified technician to assess your vehicle’s air conditioning, call us on (07) 3269 3158 or book a job using the button below. We are located 113 Connaught Street Sandgate QLD 4017. Feel free to visit us at any time.