My Air Conditioner Makes Noise

Written by lee morgan
  • Share
  • Tweet
  • Share
  • Pin
  • Email
My Air Conditioner Makes Noise
Air conditioners make strange, sometimes disconcerting noises. (air conditioner vent image by Tammy Mobley from

In most homes you can tell if the air conditioner is running without placing your hand in front of the vents to feel the cool air. This is because the system typically makes a variety of noises. While some noises are perfectly normal for all types of air-conditioning units, there are other noises that should be cause for concern. Learn to identify these sounds to determine whether you need to investigate them or can write them off as the usual noises associated with your type of air-conditioning unit.


Regardless of the type of air conditioner you have, a squeal is not a normal occurrence. It is a sure sign that something needs repair. Luckily, the problem is simple to diagnose if you know the type of set-up you own.

A squealing noise from an air conditioner is likely to be caused by one of two sources. If you have a belt-driven motor in the system, squeal is probably the result of a loose or worn-out belt that is squealing as it turns. Replace any squealing belt and avoid quick fixes like belt dressing, as this could cause further breakdown of the belt, according to the Home Tips website.

Unless you have an older model, it is unlikely that the system is belt-driven. Direct drive motors are more common today and squealing in this type of system is typically caused by bad bearings. The noise could be accompanied by a grinding sound as well. A technician will need to replace the bearings to stop the motor from incurring more damage over time.


If you hear popping sounds coming from the vents in your home while the air is blowing, or shortly after it shuts off, the air ducts are probably the culprit. This isn't a major concern, but it could become annoying. The noise is caused by the expansion and contraction of the ducts as the temperature changes within them.

Homeowners can reduce the popping noise by making a small dent in the large pieces of sheet metal where the popping originates. This adds rigidity to the surface to reduce popping during use.

Noise You Should Expect

Some noises are just part of the normal operation of an air conditioner. The sudden thump and buzzing sounds of the system turning on and the fan starting up are normal and are usually unnoticeable after the system gets up and running. The "whoosh" sound of air passing through the ducts and through the registers inside the home are minor and should be expected.

Car AC Noises

If the air-conditioning noises you hear come from your car's cooling system, the sounds can tell you the problem. Much like a home air conditioner, the drive belt or the clutch bearings in the compressor generally cause a squealing sound. Buzzing noise coming from the compressor can mean the system is overcharged with refrigerant. Meanwhile, a knocking sound could mean that the bolts holding the different components of the system in place have come loose and are flapping around. Tightening these bolts will solve the problem.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.