While most modern AC units allow for silent operation, some older ones may be rather noisy. Even so, these sounds should not be too loud and disruptive. Therefore, if your system makes squealing noises, it could be malfunctioning. Neglecting these noises will likely lead to diminished efficiency and premature system failure. Therefore, it is imperative to hire an AC repair technician to assess your unit and resolve the cause of the noises. Read the following factors to learn why your AC is making squealing noises. 

Leaky Ductwork

Your AC uses the ducts to transport conditioned air from the indoor unit to your home through the vents. Over time, the ductwork may bend or sag, leaking air. This is due to constant temperature fluctuation that causes the ducts to expand and contract frequently. In addition, if critters infest these air passages, they may eat away at the duct material and cause leakage. The resulting leaky ducts increase static pressure, causing a high-pitched squealing noise. Thus, you should engage an AC repair professional to clean, patch, and seal the ducts to help prevent energy loss.

Worn Out Condenser Fan Bearings

The fan bearings reduce rotational friction, allowing the blades to operate smoothly. However, the bearings may wear down with time due to poor or no lubrication. As a result, the metallic blower components will grind against each other, causing them to overheat. Subsequently, the bearings will make squealing noises as they attempt to support the axial load. Therefore, it is important that you contact an AC contractor to lubricate your fan bearings to enhance the fan's efficiency in expelling heat.

Misaligned Fan Belt

Whereas new AC units use direct-drive motors, older appliances incorporate belt-drive motors. Over time, the belt may wear out, impeding its effectiveness. Furthermore, foreign substances' infiltration can dislodge the fan belt or cause it to break. Subsequently, a worn-out or misaligned belt will make squealing noises while running. Thus, you need to hire an AC repair expert to replace the belt and ensure optimal tension for effective functioning.

Refrigerant Leak

Your AC utilizes the refrigerant to absorb heat in the evaporator coil and expel it outdoors through the condenser coil. However, the line set may become loose over time due to excessive condenser vibrations and leak the refrigerant. In addition, formic acid in the system can corrode the copper lines, causing the coolant to leak. This may result in squealing noises as the pressurized refrigerant leaks. Because prolonged exposure to the refrigerant is detrimental to your health, it is best to engage an AC expert to repair it.

A noisy AC can disrupt your ambiance and make your home uncomfortable. You should schedule routine tune-ups with an AC repair contractor to service your unit and answer your questions.