The condensing unit portion of your central air conditioner sits outside your home on a concrete slab. The unit contains several vital parts to the cooling process including a motorized compressor, which compresses gas refrigerant; a set of condensing coils, which change that refrigerant into a liquid; and a set of refrigerant supply lines that take the liquid refrigerant inside your house to the air handler to finish the cooling.
The condensing unit also contains a motor-driven fan that promotes airflow, which is critically important for the function of your HVAC unit. A few different airflow issues can impair the condensing unit and require the assistance of an appliance repair service to have your cooling system in proper operation again.
Loss of Coil Efficiency
The condenser coils have a carefully calibrated design that allows the coils to take in gas refrigerant, convert that gas to a liquid, and then pass that liquid along through the system. If the calibration changes for any reason, the coils can fail to convert the entire supply of gas refrigerant to liquid. Subsequent passes of the refrigerant through the system can lead to less and less liquid refrigerant production until your system's cooling efficiency starts to suffer.
The calibration change can happen due to a problem with the coils such as surface dirt buildup or a crack that allows refrigerant to leak out into the ambient air. Or the problem can stem from a malfunctioning fan, which will fail to keep the coils properly cooled during the conversion process.
Yes, condenser coils become hot during the phase change, but they need to avoid becoming too hot or the change won't occur properly. If your coils look clean and you are losing efficiency, you might want to check the health of the fan.
Condenser coils can overheat to the point that the system will shut down to prevent any potential damage related to that heat. Overheating happens more due to impaired air circulation than due to dirty coils because of the severity of the heat issue.
You will know overheating is occurring if your air conditioning unit suddenly starts shutting down shortly after starting for no other clear reason. Rule out a run capacitor issue first. The run capacitor is an electrical storage device that ensures the compressor stays running smoothly. If the capacitor fails, the compressor can start up normally but then shut down unexpectedly.
If you're experiencing either of these issues, contact an appliance repair service like Complete service US for assistance.