Informational Guide

How to Quiet a Noisy Window AC

We look at how to quiet a noisy window air conditioner and provide useful tips about checking the decibels of your unit and how to soundproof it.

by Josh M

A little bit of white noise from a window air conditioner is completely normal, but if your unit is excessively noisy, it can be disruptive and annoying. Also, it could be an indicator of a potential problem that needs to be addressed.

This is a common problem with window air conditioners, whether you have a large unit or a smaller sized window AC, but thankfully, there are some things you can try to quiet the noise.

In this article, we’ll be looking at how to quiet a noisy window air conditioner and provide useful tips about checking the decibels of your unit, how to soundproof it, and how to know when it’s time for a replacement.

Laptop with LEDIn order to work out if there is a problem with your window air conditioner, you first need to work out how loud the noise actually is.  To do this, you can take a decibel measurement for your unit when it is switched on. Learning about how window air conditioners work is also recommended as you will understand which parts are making noise.

Decibels are measured using a logarithmic system. This means that each addition of 10 decibels doubles the loudness of a noise. For example, if your air conditioner emits a 60-decibel noise,  it is 2x as loud as one that emits a 50-decibel noise.

The average air conditioner makes around 40 decibels of noise. Some air conditioners can be as quiet as 25 decibels or as loud as 55 decibels.

Although window air conditioners can sometimes be at the top end of this range, if your air conditioner is making noise that exceeds 50-60 decibels, it could be an indication that something isn’t quite right with your unit.

Measuring the decibel level of your air conditioner is pretty easy. You can download smartphone apps that do it for you. Here are some examples of apps you could use:

Most Common Loud AC Noises & Their Causes

  • Banging and Clanking Sounds
    Banging or clanking usually indicates that there is a loose part within the system. Identifying which part is loose can be a little tricky without contacting a professional. Banging sounds could mean a loose rod or piston, and clanking could be caused by a loose or faulty compressor.
  • Clicking Sounds
    A little clicking sound from your aircon here and there is nothing to worry about, but if it is making a clicking sound regularly, then it could be a sign that there is a fault. Usually, clicking sounds mean there is a problem with the thermostat.
  • Humming Sounds
    Humming is a fairly common sound for air conditioners to make, and all window air conditioners will hum quietly while turned on. However, if the hum is louder than usual, it could be a sign that there is a loose part in the unit or that there is an electrical issue.
  • Rattling Sounds
    Loud rattling sounds coming from the air conditioner are a cause for concern and should be addressed as soon as possible. They are usually a sign that wear and tear is causing parts to become loose or that the internal fan is hitting other parts within the unit.
  • Screaming Sounds
    Screaming or whistling sounds from window air conditioners are extremely common, and the most likely cause is a refrigerant leak. Refrigerant leaks can be quite dangerous, so it’s a good idea to discontinue use until you can get it fixed by a professional.
  • Popping Sounds
    Popping sounds coming from your window AC unit could be due to condensation or ice forming on the coils. This may be because the thermostat is set too low. It could also be caused by a drainage issue.
  • Water Sounds
    Water sounds coming from inside your air conditioning unit are usually nothing to worry about. Air conditioners remove the moisture from the warm air drawn in from the outside as they cool it. This water is then collected and evaporated, but as it evaporates, you may hear sloshing or splashing noises.
  • Squealing Sounds
    When you first turn your air conditioner on, a slight squealing sound is normal. However, if this persists, it could indicate a motor issue or a problem with the blower.

Does Your Window Air Conditioner Let in Outside Noise?

Although there can be a variety of reasons your AC unit is making noise, it could be the case that the noise you are hearing is actually coming from outside the window through the aircon unit.

Think about it, if you took out any style window air-con unit, what would you be left with? A great big hole that noise can easily pass through.

Window air conditioners with light frames are notorious for letting in outdoor noises. If you suspect the noise is coming from outside your home rather than inside your unit, there are some things you can do.

Firstly, you could try covering the frame around the unit with insulated foam. Squeezing the foam into any gaps around the unit will help to reduce the outdoor noise being let in. Additionally, you can cover the unit itself with insulating foam to reduce noise that is seeping in through the unit itself.

However, both of these methods only work when the AC is off. When you have the AC running, the foam will need to be removed so that the unit can access the air from the outside properly.

How To Quiet A Noisy Window Air Conditioner (Soundproofing Tips)

A noisy air conditioner doesn’t have to be the end of the world, and if you just want a good night’s sleep, there are some things you can try to rectify the problem. Aside from the foam panel option we mentioned above, here are some steps you can take to try and quiet a noisy window air conditioner.

Check the Installation

If you want to know how to quiet a noisy air conditioner, the first step you should take is to check the unit installation. Poor installation can cause noise to leak in from outside, but it can also cause unwanted vibrations and rattling. Use a spirit level to check if the unit is level and also check if there are any gaps unnecessary gaps.

Another way to reduce any rattling or squeaking sounds is to tighten the screws on the air conditioner unit. You can tighten the screws using a screwdriver, but be careful not to over-tighten them, as this can cause damage to the window frame.

Add Foam Insulation

If you do find gaps between the unit and the window, then you may want to consider filling the gaps with small strips of foam insulation. This is an easy way to soundproof a noisy air conditioner while still being able to switch it on and use it.

It won’t block out all the noise from outside, but it should help to reduce noise caused by the unit moving around or noise coming in from outside.

Clean and Vacuum the Air Conditioner

Built-up dirt and grime inside the air conditioner can cause the airflow to be noisier than usual. To rectify this, remove the front panel and use a vacuum cleaner and cloth to remove any dust and dirt from the inside of the unit.

Ensure that the unit is fully switched off before you open it up. Also, avoid the electrical components if you’re using cleaning products, steam, or water to remove dirt.

You should be able to clean your AC without removing it.

Vacuum Cleaner
Get the Air Conditioner Looked at by a Professional

If none of the above steps helped reduce the noise, the best thing to do is contact an HVAC professional. They will know exactly how to quiet a noisy air conditioner and will be able to tell you if there is a problem with some of the parts, or whether the unit is just old and cheaply made, and therefore noisy.

Also, they will be able to complete maintenance tasks like oiling the bearings and greasing brackets and joints, which can help reduce noise.

Hang a Blanket and Consider Rearranging the Space

As a temporary solution for how to soundproof a window air conditioner, you could try hanging a thick blanket in front of the unit. Hang the blanket around 4 feet away from the unit. This should help to reduce the sound while still allowing the unit to cool the room effectively.

If you have a window air conditioner in a large room, another option is to rearrange your furniture so that you are sleeping or relaxing further away from the unit. This way, the noise will be less disruptive.

Is It Worth Buying a Quieter Window AC Unit?

If you find that your window AC unit is still too loud after you’ve tried the above steps, and you’ve had it for a while, it might be time to put it out to pasture.

Air conditioning systems aren’t supposed to be noisy – at least not if they’re well made – so if yours is making a lot of noise, it’s probably past its prime. Sometimes, there’s just no fixing a noisy old unit.

Benefits Newer Models

Here are some benefits of buying a newer, quieter window AC unit that make it worth the investment.

  • Greater energy efficiency.
    Well-built units are made with high-quality fans, compressors, and other components, making them more energy-efficient than cheaper units, so they don’t need to use as much energy to cool your home.
  • More comfortable home.
    Newer models of window ACs aren’t just quiet; they’re also more effective at cooling your home.
  • Happy neighbors.
    Noisy AC units don’t just affect the people in your household; they affect those around you too. If you want to be a good neighbor and keep the folks next door happy, it might be worth buying a newer model.
Specs to Look For When Buying a Quiet Model

Aside from the dB rating, there are some other features that give you a good indication of how quiet an AC unit is. Here are some of the most important specs to look for when you’re shopping around.

  • Variable-speed fan.
    Being able to adjust a unit’s fan speeds means you can run it at a quiet speed when you want to keep the noise down.
  • Noise-reducing fan blades.
    Modern units often come with specially-designed fans that reduce noise
  • Compressor insulation.
    This covers the compressor and helps to muffle the unit’s noise.
  • Insulated base pan.
    This sits underneath the air conditioner and helps to reduce noise levels.

To save you time, you can also take a look at our list of the best, quietest window ACs on the market.

People Also Ask (FAQ)

Why is my window air conditioner spitting water?

Water spitting from the outside of the air conditioner is completely normal. However, if it’s spitting inside your room, this means the unit and filter need to be cleaned. It could also mean that the unit has been installed at an incorrect angle, and leveling the unit may help.

How can I quiet my Frigidaire window air conditioner?

All of the steps above may help you to quiet a Frigidaire window air conditioner. If they don’t help, you should contact an HVAC specialist.

Will an AC compressor make noise if low on Freon?

Yes, it’s quite normal for AC compressors to make noise if the refrigerant level is low. However, it could also be a problem with the compressor clutch.

How do I stop my neighbor’s AC from making noise?

You could try talking to them and offering them the advice in this article. Alternatively, consider soundproofing your own home and installing double-glazed windows to reduce noise levels from outside.

Conclusion

So there you have it, everything you need to know about how to quiet a noisy window air conditioner. You may be able to reduce the noise from your window air conditioner with a few simple DIY steps, but if not, it’s worth getting professional help or upgrading your unit.

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.

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