How to Quiet a Noisy Window Air Conditioner

Having a noisy window air conditioner is no way to enjoy your time at home in the summer. It’s annoying and quite frankly it disturbs everyone’s peace.

So, how can you make a noisy window air conditioner quieter?

The first thing you need to know is why your window air conditioner’s noisiness is a problem. Besides the fact that it irritates you, there’s some other reasons for why you’ll want to quiet your noisy window air conditioner as soon as possible. 

In this article we’ll be looking not just at how to quiet your noisy window air conditioner, but also at the causes of air conditioner noise. 

Why a noisy air conditioner is a problem

AC noise can be irritating but it could be more serious than that.

If your air conditioner is making a lot of noise, it could mean that it’s starting to deteriorate and that its internal parts are loosening.

So, the noise your air conditioner is making could be an indication that it’s getting damaged.

How To Quiet Your Window AC 

  1. Make sure it’s been installed properly

If your window air conditioner hasn’t been mounted correctly it’ll make noise. So, the simple solution to that is to try and mount it properly.

Go through the installation guide and make sure that all the installation procedures have been followed correctly. Make sure that you pay attention to the gaskets. 

When you are re-mounting the air conditioner, make sure it’s level. You can use a level to do this. After air conditioner maintenance, improper installation is the biggest cause of AC noise.

  1. Buy a better unit

You’ll probably want to do this as a last resort. The fact of the matter is that some units are louder than others. Buying a window air conditioner that’s specifically made to be quiet might be a better option for you. 

  1. Soundproof your window air conditioner

A window air conditioner allows a lot of outside noise to enter inside your home. You can fix this by blocking the paths that the noise is entering through. If your window air conditioner has a super light frame, it’s going to let in a ton of noise. 

So, the first thing you need to do is buy some foam insulation (this can be found in your local hardware store). You’ll need to measure the window frame and cut your insulation foam just slightly too large. You can then squeeze it into place. 

Foam insulation also works well in a pinch to soundproof an existing drywall.

This doesn’t look that great though. If you would prefer a fix that looks more pleasing to the eye, you go to an acrylic supplier. You’ll need to take along the exact measurements of your window frame. Ask them to cut an upside down ‘U’ and then voila! You can fit it around your window air conditioner. 

  1. Tighten anything that might be loose

Make sure that there’s nothing loose on the outside or inside of your air conditioner. 

  1. Check the coil fins

You can only access the cooling coils if you can take the back of your air conditioner off. If you can, give them a light dusting. Make sure that they aren’t bent. If they are, just run a comb down cooling coils to straighten them. 

  1. Reposition any parts that might be too close to one another

You’ll want to be careful that you don’t damage your air conditioner with this one. If you see any parts that might be bumping against each other, try to gently move them apart. 

  1. Check for damaged parts

Sometimes your air conditioner can make a noise simply because there’s a part that’s not working anymore or it’s damaged. Use our guide above to see what that noise your window air conditioner is making could mean. If the part is badly damaged, you’ll want to replace it. This will help your air conditioner run more smoothly. 

  1. Check the rubber vibration pads

Anti-vibration pads can reduce noise but they need to be in good condition to do their job properly. Make sure that the rubber vibration pads are still moving easily. You’ll need to replace the pads if the rubber is split, cracked, or dried out.

But don’t run off to go check what’s happening inside your air conditioner just yet. Before you can identify what’s wrong with your air conditioner, you need to know all the possible causes for the noise. 

Causes Of Air Conditioner Noise

Before you make your window air conditioner quieter you need to know what that AC noise is being caused by.

  1. Unknown debris

If you happen to have a window air conditioner, the chances are that something may have fallen into it (leaves, animals, etc.). If your window air conditioner starts to make funny, loud noises, make sure that you unplug it before checking inside. You can open up the grill and you’ll probably need a flashlight since it can get pretty dark in there. 

  1. Using a small air conditioner to cool a large house

A small air conditioner that’s being used for a big house will need to work overtime to reach the desired temperature. This means that your air conditioner’s units are going to wear out quickly and the overall efficiency of your air conditioner will be affected. If your air conditioner deteriorates, this can be a cause for the noise. But the noise also stems from how hard the air conditioner has to work. 

  1. Damaged fan blades

Debris can damage your fan blades if it falls inside of the window unit. If the debris finds its way to the blades, the chances are that your fan blades will bend. There is a solution to that though. You can just use a pair of pliers to straighten the blades out. 

  1. Lack of lubrication

The air conditioner’s fan motor needs to be properly lubricated. If it’s not, your air conditioner will make a whole lot of unwanted noise. You can lubricate the fan motor yourself, but it’s difficult to reach the motors. This is a good tip to keep your air compressor quiet too.

  1. Feel the vibrations

Nope, these are not good vibrations. They’re the kind that can drive you crazy. A window unit air conditioner needs to sit in the frame of the window, as you probably know.

But it’s incredibly important that it’s mounted properly. If it’s not, that’s most likely the cause of the noise your air conditioner is making. This is a good thing to check to keep your ceiling fan quiet too.

Noisy window air conditioner

Different noises could mean different things

Whistling noise

A leaf, debris, a loose part, or belt can cause a whistling sound. 

Squealing noise 

If your air conditioner makes a constant squealing sound, it usually means that a fan or blower motor, the blower wheel or housing is failing. But it could also mean that the bearing is worn.


There are two reasons for why your air conditioner would make a screeching sound. It could be the compressor or there could be a leaf stuck in the fan blades. A compressor normally screeches when there’s a build-up of pressure. 


You’ll hear a crackling noise if there’s dirt or debris that’s been caught in the unit. If you have a faulty condenser, your air conditioner could have an ice-build up. This will also make a crackling noise. 


A humming noise can be an indication that there’s electrical problems. But it can also mean that there’s an issue with the motor. The humming can be caused by loose wiring too. 


The fact that your air conditioner is making a pulsating sound does not always mean something is wrong. But if you hear it from inside the house it could mean that a part inside the air conditioner has come loose and it may need to be replaced. Fan motors and blades are known to be parts that come off easily.


A clanking noise indicates pretty much the same thing as the pulsating noise. But if your air conditioner is making a clanking noise, it could mean that the outdoor or indoor blower fan is hitting against something. 

Popping sound

Your window air conditioner should not sound like popcorn. This is actually one of the more serious sounds you need to listen out for.

When it makes that popping popcorn sound, it could be the humidity condensing or it could mean that the coils are being iced up. A more serious reason for your air conditioners noise is that there’s a leak in the housing and this means that water might be seeping in. 

Buzzing noise 

A buzzing noise may be the result of your air conditioner’s parts being loose, having an unbalanced fan or a loose fan. What’s more serious, is that its motor could be failing.

You’ll want to check that there’s no coolant leak as well. It’s a possibility that the filter or condenser coils might need a clean too. 

Beeping noise 

If your unit beeps quite often, it may mean that the power supply is failing. It could also be that an internal relay is faulty. 

How to keep your air conditioner running smoothly and quietly

The better your window air conditioner’s condition, the better it’ll run. So, we need to know what to do to keep it looking and working efficiently. Here’s 6 ways that you can do this: 

Keep the filter clean 

Once a month, take the filter out and soak it. You only have to keep it soaking for 5 minutes. Wipe it down and let it dry before you put it back in. If it’s way too dirty, you might want to look into replacing it. 

Take care of the coils

Your coils can get pretty dirty. Take your window air conditioner off the frame and take off the front and back panels too. You can spray a soapy solution onto the coils. After waiting for a few minutes, you can wipe them down. You need to wipe the coils downwards. You can do this annually and at the beginning of the season. 

Straighten the fins

If there are any fins that are misplaced, straighten them. You can gently run a comb downwards along the fins. 

Wipe The Fan Blades

Make sure that you wipe down the fan blades and get rid of any dust.  

Keep the drainage clean

If your drain pan gets too full, the condensation can remain inside the air conditioner. You need to drain the pan down the sink and just give it a quick clean (you can wipe it down) if it’s needed. 

Take care of your air conditioner when you’re not using it

It’s easy to dump your window air conditioner down somewhere when you don’t need it. Instead, place it in a cool dry space, inside a box when you don’t need to use it. Don’t use it again until winter is over. 

How to install a window air conditioner properly to reduce noise

An improper installation of your window air conditioner can be a major cause for noise, like we’ve discussed. So, here’s a guide to installing a window air conditioner properly: 

  1. The unit needs to not only be able to fit the window, but it also needs to be big enough to cool the space you’re wanting it to cool. Make sure that you read all of the installation instructions, before you start the installation. 
  1. You need to mark the window opening you’re going to use for the air conditioner. Make sure it’s close to an electrical outlet. 
  1. Open and prepare the window and opening as per instructions. Once again, it’s really important to follow the instructions. Once you’ve opened and prepared the window, you’ll need to fasten the side or top panels. Then, insert the unit into the window opening. You might want to have someone else around to help.
  1. Close the window onto the A/C. This will secure it in place. You can then focus on fastening all the brackets. Extend the side or top panels. This will ensure that the animals, insects and even the weather will be kept out. If your window air conditioner came with foam or insulation pads, install them. You can then plug in the unit. And that’s it! You can now enjoy your window air conditioner.

An explanation of the different parts in your window air conditioner

Window Air Conditioner Parts

The indoor parts of your air conditioner are your cooling coil, fan blower, capillary tube, operation panel, filter drier and drain pan. 

The cooling coil has an air filter mounted on it. The cooling coil allows heat exchange to happen between the refrigerant in the system and the air inside the room it’s cooling. 

The fan blower is a centrifugal evaporator blower. It’s used to discharge the cool air to the room.

A Capillary Tube is an expansion device. This is one of the parts that can cause noise. If its installed too close to the evaporator it can be quite loud. 

An Operation Panel controls the temperature and speed of the blower fan. 

The Filter Drier is used to remove the moisture from the refrigerant.

A Drain Pan contains the water that condensates from the cooling coil. The water gets discharged through gravity. 

A window air conditioner’s outside parts include the compressor, condenser coil, propeller fan and fan motor. 

The compressor compresses the refrigerant (a refrigerant is a working fluid). 

A Condenser Coil rejects heat from the refrigeration to the outside air.

The Propeller Fan is located inside the air-cooled condenser. It helps to move the air molecules over the surface of the condensing coil.

The fan motor works with the indoor blower and outdoor propeller fan, which are connected together.

A window air conditioner’s noise is not too difficult to fix. You don’t have to spend lots of money, and it won’t take up much of your time to sort out the noise they might make.

Don’t worry about calling in a professional unless you really don’t know what to do. First try and locate the problem and see if you can sort it out. 

Also, take note of what sounds your window air conditioner is making so that you can identify the problem more quickly. 

We really hope that the solutions mentioned in the article for quieting your noisy window air conditioner have helped.