How to Dampen Window Air Conditioner Compressor Noise

Window air conditioner compressors are one of the most important parts of your AC unit. The compressor is responsible for circulating refrigerant through the system, and it is what helps to cool the air in your home.

If your compressor is not working properly, then your AC unit will not be able to effectively cool your home. There are a few different signs that you can look for that indicate that your compressor may be having issues. One of the most common signs is if your AC unit is making strange noises.

If you hear rattling, grinding, or any other unusual noise coming from your AC unit, then it is likely that there is an issue with the compressor. Another sign that there could be a problem with your compressor is if your AC unit is not blowing cold air.

If the air coming from your AC unit is not as cool as it should be, then it is possible that the compressor is not working properly. If you notice any of these signs, then you should contact a professional to have your compressor checked out and repaired if necessary.

After inspection, you discover that the noise problem is something completely unrelated to the compressor; you could easily fix this problem by following my guide on air conditioner noise reduction.

  • Clicking sound
  • Banging sound
  • Buzzing sounds
  • Screeching/squealing sound
  • Hissing sound

Loud Clicking Noise

The clicking sound could be caused by different components of the AC and not only the compressor.

It all depends on the source of the noise problem:

  • If you only hear the clicking sound once you start the AC (but it doesn’t start), that could indicate a problem with the capacitor, thermostat, or compressor.
  • But if you only hear the clicking sound once the AC is running, don’t freight as it’s likely that small objects have nestled on the blower fan.

Banging Sounds

The most probable culprit, in this case, is the compressor. It’s responsible for circulating refrigerant that highly contributes to cooling your home.

The compressor components can become loose because of wear and tear, resulting in loud banging sounds as they bang against each other inside the compressor.

In most cases, the compressor unit needs to be replaced as there isn’t a way you can open the compressor without damaging the outer shell as it’s hermetically sealed.

Buzzing Sounds

There are several reasons why your window air conditioner could be producing buzzing noises.

While buzzing noises could indicate that you have a malfunctioning compressor, they are also an indicator of other problems that need troubleshooting.

Such problems include:

  • Loose wiring
  • Failing motor
  • Broken capacitor
  • Arcing

Screeching/Squealing Noise

Three culprits could be responsible for the loud screeching or squealing noises from your window air conditioner. They include:

  • Bad fan motor
  • Faulty blower motor
  • Faulty compressor

If the loud screeching noises coming from the outside unit, you will likely have a bad compressor.

When the motor inside the compressor goes bad, it can result in loud screeching noises.

If you hear the screeching noises from the inside of your home, then it’s likely that the blower fan motor is to blame.

Over time the bearings on the fan motor can wear out, resulting in screeching/squealing noises.

Hissing Sounds

A hissing sound is a sign of a refrigerant leak.

In normal operation, the refrigerant operates in a closed-loop inside the AC system.

However, the copper lines and coils that carry the refrigerant often leak over time, resulting in a loss.

How to Fix Window Air Conditioner Compressor Noise

Now that you’re aware of why a compressor for your window air conditioner could be making noise, it’s time we figured ways to fix the compressor noise.

However, it’s highly important to take precautions when dealing with AC compressors as a slight mistake could be fatal, as is the case with these two mechanics who died while repairing AC compressors. (Source)

Check the Installation

While it’s easier to install a window air conditioner than it is to install through the wall air conditioner, there are some guidelines that you must follow to make sure it’s well established.

 The ac should be level from side to side and slightly tilted to the back to help prevent moisture from pooling.

You should also reinforce the brackets if the wall isn’t solid and ensure that the AC is installed per the manufacturer’s instructions.

Make sure that both the top and the side closure panels are in place and well fastened. Use acoustic caulking to fill small cracks and if you notice adjacent windows rattling, tighten the screws and, if possible, apply caulking to cancel vibration noises.

If the problem isn’t with the installation, here’s what you can do next.

Clean Dirty Condenser Fan

While the condenser fan noise is not related to compressor noise, optimal maintenance will help prevent foreseeable problems with the compressor.

First, turn off power to your unit at the breaker box (or remove the fuse if you have individual fuses).

– Next, unplug your machine from the power supply. Sometimes there are screws on both sides near where the cords enter the machine.

Carefully remove these screws and set them aside so they can be re-installed later when you’re done cleaning the unit.

– Now, you want to take a broom or a paintbrush and gently sweep any loose debris from the front grille of your air conditioner.

Take special care that nothing falls into the fan blades, which are right below where you’re standing.

You should then vacuum out this area with a small attachment (a crevice tool will work great) on your vacuum cleaner to get rid of any dust bunnies that may have accumulated there over time.

– Lastly, use an all-purpose household cleaner like Fantastik Heavy-Duty All-Purpose Cleaner mixed about half and half with water (about 2 cups of cleaner mixed with 2 cups of water).

Spray this mixture into the back grille of your unit, and then use a damp cloth to gently wipe down all debris that’s gathered there.

Now, turn the power on at the breaker box (or replace the fuse) and plug in the air conditioner so it can run for about 5 minutes or so.

You’ll notice that any loose dirt is likely to be blown out of the front grille. If you don’t see any dust coming out, repeat these steps until you do.

Inspect The AC Compressor

You can try opening up the back cover or removing the front grille to take a look at your compressor for signs of damage.

If you notice that there are burn marks, debris in the fins, oil leaks, loose wires, etc.

Then this may be due to tampering by somebody who doesn’t know enough about air conditioners and should never have been inside in the first place.

If it looks like somebody has tampered with your unit when you open it up to take a look, turn off power at the breaker box (or remove the fuse), unplug your team from the power supply, and call in an HVAC professional to inspect it before turning on again.

Buy AC Compressor Cover

While a soundproof window air conditioner compressor cover will help reduce the noise from your compressor, it won’t completely eliminate it. If you’re looking for complete silence, you’ll need to look into other options, such as an acoustic enclosure or soundproofing your entire home.

Second, a soundproof window air conditioner compressor cover can actually make your unit less efficient. That’s because the cover will trap heat inside, causing your unit to work harder and use more energy.

Third, if you live in an area with extreme temperatures, a soundproof window air conditioner compressor cover can actually be dangerous. That’s because the cover can trap heat inside, causing your unit to overheat and potentially catch fire.

So, while a soundproof window air conditioner compressor cover has its benefits, it’s important to weigh those benefits against the potential risks before making a purchase.

Soundproof Against Window Air Conditioner Compressor Noise

Even at its regular operation, an air conditioner is bound to make noises that will no doubt disturb your quiet living at home.

If that’s the case with you, then you can soundproof your air conditioner using affordable soundproofing materials that help block out noise.

Firstly, you need to insulate around the window frame with sound dampening materials such as acoustic foam panels or mass-loaded vinyl.

The idea is to reduce noise that comes from the outside unit from leaking into your window.

You can follow my guide on soundproofing a window to learn of the different materials and methods to help prevent noise, both impact and airborne, from leaking into your space.

Soundproof Box for Air Conditioner

Making a soundproof box for your air conditioner is a great way to reduce the noise it makes. There are many different ways to do this, but the most effective method is to use soundproofing material.

  • There are two main types of soundproofing materials: acoustic foam and mass loaded vinyl. Acoustic foam is the more popular choice because it is more effective at absorbing sound. Mass loaded vinyl is also effective, but it is more expensive and not as easy to work with.
  • To make a soundproof box for your air conditioner, you will need:
  • Soundproofing material (acoustic foam or mass loaded vinyl)
  • Scissors
  • Tape measure
  • Ruler or straight edge
  • Pencil
  • Sharp knife or box cutter
  • Marker
  • Glue (optional)

Measure the air conditioner unit and add 2 inches to all sides. This is the size of your soundproof box.

Cut the soundproofing material to the correct size using scissors or a sharp knife. Make sure the edges are straight and even.
Tape the soundproofing material to the air conditioner unit, making sure there are no gaps. You can optionally glue the material in place for a more permanent solution.

Trim any excess material from around the edges of the unit using scissors or a box cutter.

Your soundproof box is now complete! Enjoy the peace and quiet.


Above are some of the best methods to help fix window air conditioner compressor noise.

Even though window AC’s make some noise, the noises could sometimes be an indicator of an underlying problem that needs maintenance.

If the normal AC noise is still a bother to you, you could try to soundproof the AC itself to help reduce the noise to manageable levels.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.