The air conditioner (AC) condenser is responsible for getting rid of the heat that the AC extracts from the house. Thus, the AC's cooling efficiency will suffer if the condenser is malfunctioning. Below are some condenser problems that can trigger inefficient cooling.
The condenser has a coil that circulates hot refrigerant to dissipate heat. Damage to the coil can cause the refrigerant to leak. Coil damages, from physical impact or corrosion, are typical causes of refrigerant damages. Cooling efficiency reduces and the risk of AC damage increases if the coil loses too much refrigerant.
The condenser has an electrical motor that drives the fan and the compressor. The condenser fan circulates air over the coils to aid heat dissipation. The compressor motor raises the temperature and pressure of the compressor to facilitate heat exchange. An electrical failure, for example, due to an overheated motor, will affect both functions.
Fan Damage or Blockage
As mentioned above, the AC needs the condenser fan to help it dissipate heat to the outside air. Anything that interferes with the running of the fan leads to impaired cooling. An example of such an issue is if a foreign object, say a toy, is trapped inside the fan housing and blocks the blades. Another example is if something damages the fan blades, causing them to lose their aerodynamic shapes and move less air than usual.
A capacitor is an electronic device capable of storing and discharging huge amounts of electricity. Several parts of the AC that require a lot of energy draw their power from capacitors. The condenser motor is one of these parts.
Thus, the condenser motor might not run if its capacitor has failed. The capacitor might even switch off on its own if its capacitor is failing and cannot provide an adequate charge. Overheating, overvoltage, and aging are common causes of capacitor failure.
Lastly, physical damage to the condenser can also interfere with your AC's cooling capacity. The condenser coil comprises of thin metal that a physical impact, say from hailstones or other windblown debris, can easily damage. Damage to the coils interferes with airflow through the condenser. Such damage also reduces the surface areas of the fins through which can dissipate. Both issues result in reduced cooling capacity.
Note that your AC should not struggle to cool your house. An overworking AC can suffer catastrophic damage. Contact an AC technician to figure out what is wrong with the condenser, and fix it before further damage occurs. Look for someone who provides local air conditioning services.