Air Conditioner Problem: Squealing Noise

Central air conditioning systems are made up of different moving parts. There are pistons and motors in their compressors, moving fans in their air handlers, and other mechanical parts that are essential to not only cooling air but also distributing it inside the areas that they are supposed to cool. The movement of these parts usually gives off different sounds that are normal.

But squealing noises? Those are not normal air conditioner noises and are usually an indication of air conditioner problems. Here are some of the things that may be causing your air conditioner to produce squealing noises.

A malfunctioning compressor motor

An air conditioner's compressor motor is the part that powers the process of turning a low-pressure refrigerant gas into a high-pressure gas. This is an important step in the system's operations since pressurizing the refrigerant gas is necessary to facilitate the change of the refrigerant from a gaseous state to a liquid state.

This process of pressurizing the refrigerant gas involves a lot of moving parts. Therefore, if the motor's bearings are worn-out, if there is a lubricant loss, or if there are any bent parts – all of which can cause different moving parts to rub together abnormally– the compressor will produce a squealing noise.

When this happens, it is advisable that you shut your system and have a contractor inspect it. This is important because, if the system is left running, the increase in friction due to worn-out bearings or lack of lubrication will accelerate the rate at which the compressor's parts wear out. Continued system operation can literally damage the whole compressor unit.

A malfunctioning air handler

The air handler is the other part of a central air conditioning system that heavily relies on a motor to do its job. Its motor has bearings that can wear out. It has fan blades that can bend. And there is the fact that handling incoming air usually leaves it susceptible to dirt accumulation. All these things increase the likelihood of an air handler being the source of squealing noises.

Squealing caused by bent fan blades are easy to detect. Simply turning the fans, when the system is off, and noting whether the blades knock on any parts should be enough to tell if they are to blame. If the blades are not to blame, the next step should be to clean the air handler. And if that doesn't work, try lubricating any moving parts. And if that still doesn't get rid of the squealing, replace the motor's bearings.

If you need help with these steps, consider contacting an air conditioning service for assistance.