What’s That Sound? Common Air Conditioning System Noises Explained

Every home is full of equipment making some type of noise, such as your running refrigerator or dishwasher. These noises are something that we tend to get used to, and the same can typically be said for our HVAC systems. Because of this familiarity, it’s easy to tell when something sounds “off”. Our HVAC systems tend to make many different sounds depending on the task that it’s completing, but there’s some sounds that could indicate a significant and costly issue. In this article, we will discuss some common, yet concerning noises you might hear from your HVAC system, and how you should proceed if you do. 

Where is the noise coming from? 

The location of the bothersome noise often exposes the problem at hand. Most of the sounds you notice coming from your HVAC system will either be located in the outdoor compressor, air handler, or the ductwork. 

In this blog, I will refer to various parts and equipment terms associated with your HVAC system. If there’s any confusion on this terminology, refer to our previous blog, “How Does Your Home’s HVAC System Actually Work?” 

Compressor Noises 

The compressor is the large unit located outside of the home. Its main job is to cool the air and send it throughout the house. Considering that this unit is outside, it is prone to experiencing a range of issues. 

● Screeching: Usually this noise is a sign of a significant problem, such as a hazardous amount of internal pressure building up inside the compressor. It is important to eliminate power to your system immediately and contact us so we can assess the issue. 

● Banging: This sound can be associated with a loose part. 

● Hissing: This noise is typically accompanied by bubbling noises if you listen closely, and this often means that there may be a refrigerant leak. 

● Buzzing: Typically indicates that your AC has a poor connection or a faulty contactor. 

● Clanking: The compressor itself or a part within may be loose. 

● Humming: Often indicates that there are complications with the motor or that a new capacitor may be needed.

Air Handler Noises 

Irritating noises from the air handler are often noticed quicker than condenser noises as the air handler is located within the home. 

● Buzzing: Usually means that an electrical component of the air handler is wearing out. You most likely need a relay switch or electrical work done on the circuit breaker. 

● Clanking: Often indicates that some hardware may have come loose or there is a faulty compressor. 

● Hissing: Most likely a sign of a refrigerant leak. 

● Ticking: Debris has probably gotten stuck in the fan blade. 

Ductwork Noises 

Ductwork is used to distribute air throughout the home, meaning that sound can be distributed through the ducts as well. Air ducts are actually known to amplify these sounds, either coming from the ducts themselves or a different part of the HVAC system. 

● Hissing: This indicates that there is likely air leaking out of the ductwork. ● Rattling: Usually a faulty blower or fan. 

● Whistling: This noise is often not a concern as ductwork contracts as air moves through it. 

If you notice an abnormal noise coming from your HVAC system, it’s important to contact Crows Heat & Air as soon as possible to make sure everything is operating as it should be. If these sounds are ignored, it’s likely that a minor concern can turn into a major expense. The simplest way to avoid a noisy air conditioner and costly repairs is to schedule routine maintenance for your systems. If you have any questions or concerns regarding the noise of your home’s HVAC system or necessary maintenance, give us a call at 972-548-1323.