How to Quiet a Noisy Air Conditioner! (Full Guide)


Air conditioners are lifesavers both in hot and cold weather. But the cost we sometimes have to pay for using them is excessive noise. In this article we will be discussing everything you need to know about how to quiet your noisy air conditioner.

1. How to Make a Window Air Conditioner Quieter

Most of the noise coming from a window AC unit has to do with the gaps left around the unit itself. These gaps introduce noises coming from outside.

To fix this problem, you have to work towards blocking off all spaces that sound can come in through.

How to Soundproof a Window Air Conditioner

Frames around window AC units are usually light and cannot block off sounds effectively, and there is often a need to reinforce them with materials that can block sound more effectively.

Consider placing Insulating Foam of about one or two inches thickness around the AC frame. This method of soundproofing is easy to install and remove if you ever need to remove the AC unit.

Another method is to cut an acrylic sheet into the exact measurement of the AC opening. The acrylic insert helps the AC unit to sit flush against the space. You can also opt for a custom-made acrylic window insert. It has tubings on all four sides that will press against the window frame to block out all sounds. Acrylic sheet is a better soundproofing material than glass.

Additional things you can do to quiet a window air conditioner include:

  1. Push on the AC unit to see if it is still tightly fitted into its frame. Some screws may have come off, making it unstable and vibrating more against the frame. Make sure that those loose screws are tightened back to ensure a firm fitting.
  2. Check to see if the fan’s blade works appropriately and isn’t bent (hitting other parts of the unit).
  3. Check to see if there’s no foreign object or dust stuck on the fan blade that may be causing any noise. The dirt can cause an imbalance in the bearing of the fan.
  4. Check to see that the fan’s motor is well lubricated. This check is vital if you’ve had the AC for a long time.
  5. The coil fin at the back of the AC may be covered in dust. Dust it off to lessen the noise caused by the AC.

2. How to Reduce Noise From an Indoor Air Conditioner

Noise from an indoor AC can hinder productivity in many ways. It can also affect your quality of life, such as disrupting your sleep patterns.

One of the main causes of noise in indoor AC is the blower fan motor. This fan is responsible for pulling the warm air in the home into the AC and releasing the cooled air back into the house.  Indoor noise can also emanate from the off and on switching sounds of the compressor –– the part that is responsible for circulating the gas or liquid that cools the home- Refrigerant.

When installing a new air conditioner, the location is vital. Consider installing the AC in areas that are further away from frequently used rooms. This placement goes a long way in curbing the noise from the unit. The farther you are from the AC compressor, the better it is for indoor quietness.

To limit noise in the apartment, you will want to consider installing the AC unit in areas far from air ducts. Air ducts are pipes are used to carry air into a house. Fixing an AC far from an air duct will help to reduce echo to the barest minimum.

Soundproofing Option for Indoor AC Noise

A way to block off indoor noise from the AC compressor compartment installed outside the house is to add a layer of soundproofing material such as Mass Loaded Vinyl (MLV) to the wall. The MLV is an easy-to-install soundproofing option on an existing wall. MLV can also be painted, so that it blends nicely with the other surfaces in the apartment.

3. How to Reduce Noise From an Outdoor Air Conditioner

The noise coming from the part of the AC unit installed outside the house is usually a cause of concern not just to the AC owners but their neighbors too. This noise usually comes from the compressor or the cooling fan attached to the compressor unit of the air conditioner. The disturbance can be categorized generally into those relating to electrical malfunctioning or structural issues.

4. Electrical Issues That Cause Noises

Electrical faults are typically fixed by removing the damaged part with a new one. In some cases however, the entire AC unit requires a replacement. But hopefully it’s not that bad! Some examples of common electrical issues are:

  • A completely bad compressor giving a loud screeching sound while working.
  • A faulty capacitor, loose wiring, etc. causing buzzing sounds in the system.
  • Screeching sound coming from the fan set to cool the heat coming from the compressor.
  • Banging sounds are caused by a bent fan blade coming in contact with other body parts.
  • Some hissing sounds coming from parts like the air filter that is not correctly fixed, or a leaking refrigerant.

5. Structural Issues That Cause Noise

Some noise issues in an AC are related to how the unit is arranged or installed. These structural issues give rise to problems relating to echoes and vibrations. A significant improvement in the feature of newer AC models is in their better insulated compressors, which makes them quieter. The speed of the blower fans in these more recent models can also be varied. This means that the AC can be set to work at high or low speed, which translates to more quietness.

So now that we’ve mentioned the things that are specific to different AC units depending on the location, let’s check out other sound blocking methods that are sure to help:

Eliminate Vibrations Caused by Irregular Surfaces

When an AC unit outside the house is fixed on an irregular surface that causes partial contact with the wall or ground, it causes a sort of vibration whenever it’s working. This issue can be rectified by readjusting the placement or re-fixing it in a steadier place. You can also use some anti-vibration pads or Feet Vibration Damper to cushion some of the vibrating effects caused by the AC unit by placing it in between the unit and the surface.

Soundproofing With a Blanket

AC Soundproofing Blanket


As mentioned earlier, the older models of air conditioners don’t have enough padding to support their units’ compressors; therefore, they make some vibrating noise while working. One way to reduce this noise is by making use of a Soundproofing Blanket. Some advantages of using a sound blanket are listed below:

a) Functionality and Cost:

The blanket is a versatile, functional, and inexpensive method of soundproofing because it can conveniently work with different models of compressors.

b) Easy installation:

They are straightforward to install and remove when the need arises due to the hook and loop closures on them.

c) Noise reduction capacity:

They help to reduce noise from compressors up to about 40%.

d) Durability:

The blanket can last for a very long time.

Build a Noise Barrier

A noise barrier can be achieved by creating an enclosure for the air conditioning unit. This helps to keep the noise away and adds to the general aesthetic. The enclosure can be about 8 ft tall. Basically, anything can do the job, as long as the material used is suitable for blocking sound. We recommend plywood, Panel Enclosure, or an outdoor AC fence, as shown in this video:

To ensure proper airflow in and around the AC unit and curb overheating, leave about 3ft space between the barrier and the AC.

Soundproofing the AC Fence/Cover

After building the cover, as shown in the video, you need to soundproof it with some other materials to ensure effective noise reduction. These are the required steps:

  1. Attachment of Mass Loaded Vinyl (MLV) to the inside of the barrier with the help of acoustic adhesives.
  2. Seal the seams with acoustic caulk. This step will further block off all openings that the sound from the AC can escape through.
  3. Paint the barrier to blend with the house color and add to the general aesthetic.
  4. You can decorate with shrubs and other plants around the barrier. This will further add to the aesthetics and also absorb some of the noise given off by the AC.

Generally, when the barrier is properly built and installed, it can reduce noise up to 95%. Though it takes a bit of effort, it’s worth the time spent on it—the MLV and acoustic sealant help contain the sounds made by the AC in the compartment can block the sound to an impressive degree.

Reconsider the Present Location

This may not apply to everyone looking for solutions to a noisy AC but where it is possible, try to consider installing your AC in some of the areas listed below:

  1. Away from rooms that people tend to spend a lot of time in, e.g., living rooms, bedrooms, study, etc.
  2. Away from opposite facing walls and narrow corridors to minimize echoes and noise amplification.
  3. Away from air ducts to also minimize echo.

Channel The Water Leaking From the Air Conditioner

Another unsettling noise for some people is the dripping sound of water coming off an AC unit. Faulty air conditioners fixed on platforms, windows, or walls (raised from the ground) are sources of noise caused by water leakage. Many factors cause AC leakage and dripping, such as:

  • Air Leakage
  • Dirty AC filter
  • Malfunctioning of the condensation pump of the AC due to dirt accumulation.
  • Improper Installation
  • Poor maintenance of the AC
  • Cold weather causing the AC to freeze.

You can sort this out by getting a hose to channel the dripping water into a container. This temporary fix will considerably lower the dripping noise.

Check With Your Maintenance Professional

Check to be sure your AC unit doesn’t go off and on too frequently. This usually adds to the noise level. If this is a problem you have noticed, discuss it with your maintenance professional to know what is wrong and to get it fixed as soon as possible.

5 Tips For Taking Care of Air Conditioners to Maintain Quietness

When an air conditioner is constantly checked and properly maintained, it will sound better, work more effectively, and last longer. Here are steps you can take to ensure the constant running of the AC:

  1. Dust off specks of dirt on the fan’s blade to avert a build-up. The build-up of dirt can cause the fan to malfunction.
  2. Periodically take the AC filter out to clean. If it needs to be changed, you can consider that too. There are newer models of AC filters that are Bluetooth-enabled and easy to use. Filters help to protect against allergens and toxins.
  3. The evaporator and condenser coils of the AC can be clogged up in dust. Wipe down the specks of dirt on the coils in the direction of the fins to remove them.
  4. Make sure to monitor the drain pan. If it gets too full, it can become problematic. Regularly drain off the water from the drain pan into the sink to maintain a good working order.
  5. Whenever the air conditioner is not in use for a long time, dismount it to store in a cool and dry place.

On a Final Note

Many people find it unbearable to live without an air conditioner (myself included!), but the noise that emanates from a faulty or mispositioned AC can be frustrating as you’re well aware.

If all the above explained measures have been tried and there is still no considerable improvement, it means that it has exceeded its life span and needs replacement. Hopefully a quieter model as well!

When getting a new AC, be sure to get a quiet model of the right size for the space you have. This will ensure that the AC does not switch off and on frequently.

We are looking forward to hearing about your AC quieting project in the comment section below. Good luck!

Luka Baron

Soundproof expert and a staunch opponent of noise. This website is a free source of information on how to 'keep it down a notch'. I update the content regularly to keep up with advancements in the soundproofing industry.

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