Quieting a Noisy Window Air Conditioner: A Quick Guide

Window AC buttons not working

Air conditioners are a godsend, but man can they be noisy! As someone who’s suffered from a rattly old window air conditioner for a summer, I vowed to never go through that again.

To keep a window air conditioner quiet, check the internal components for any loose parts. Keep fans and coils dusted, and gently adjust any bent or disjointed parts. To fix vibrations, tighten all panel screws and use weatherseal to cushion against any rattling of the window or frame.

But there’s more than that. Let’s look at each type of solution in more detail together.

Quieting a Noisy Window Air Conditioner

While this is quite a big list, I’ve written it with the most common problems first. By checking each one in order, you should (hopefully) find your answer to quiet your air conditioner.

  • Check the Installation. While Window AC’s can be installed by anyone, getting it right is a little more tricky. Make sure that the unit is still securely connected to the window frame. A quick test is to push on different parts of the unit/frame/window, and see if it has an affect on the noise.
  • Check the Panel. The panel of the unit may have come loose – make sure the screws are still secured tightly. When the machine’s running, try putting your hand on different places and applying pressure. That might give you an idea of where to start.
  • Check the Fan Blades 1. There’s two main suspects in a noisy ac fan. First is a bent or crooked blade – this may be whacking itself off another part of the unit. The other common issue is loose insulation or some other foreign object that’s attached itself to the fan blade. Just have a general check over, and give the fan a light dusting down.
  • Check the Fan Blades 2. Next up, we want to make sure the fan blades are clean. Give them a wipe down to remove any dust and debris that could be grinding against something else within the machine.
  • Check the Motor. If you’ve had the AC for a good few years, the lubrication within the motor may not be up to scratch anymore. If you’re able to access the motor via a lubrication port, try adding a touch of oil by taking off the caps and (carefully!) letting a few drops of oil in there and on the motor shaft. Note that this often isn’t possible on newer models.
  • Check the Coil Fins. The back of your air conditioner contains the cooling coils. If you can take the back off the window air conditioner, give the coils a light dusting down. A gentle spray of water works too – just don’t apply too much pressure with the water.
  • Try Repositioning. If you spot anything loose or clashing with another part, you can try to gently move these apart, or stop the noise by adding a type of cushion.
  • Try Reinforcing. If you’re convinced it’s the window frame that’s causing the noise, and you’ve tightened the unit’s screws, you can go a step further by adding foam weatherstripping around the frame to cushion the vibrations.

Stuck with an Older Model? Consider a Modern One.

If your noise issue is due to the air conditioner itself (say, a super loud compressor), there may not be much you can do. For sanity’s sake you might want to consider a modern replacement. Recent models are much quieter – not to mention much less demanding on your electricity bill.

Soundproofing a Window AC from Outside Noise

This point deserves a whole topic on it’s own.

A major downside of window ac’s is the outside noise they let in. If you were to remove the panels and filters, you’d just have an open window to the outdoors! As much as we all love listening to car horns and sirens – there are ways to help this.

So let’s fix it. All we need to do is re-block the paths that the noise is getting in.

First, we need to cover up the window frame.

For air conditioners like the one below, these super-light frames let in a ton of noise. Cover them up with some foam insulation from your local hardware store (just 1-2″ thick will do). If you measure carefully and cut it just slightly too large, it should hold its place by being squeezed in. For a less crude looking option, take your exact measurements to an arcylic supplier and have them cut an upside down ‘U’ to fit around the AC.

Second is the air conditioner itself.

Same tactic.

Cut out some insulation to affix in front of the main panel. Although crude, it’s 10x more effective at blocking out noise.

Obviously you can only keep this on when your ac is off. There’s no real way to block out the noise when the AC is on – since it needs access to that outside air in order to work. There are some DIY solutions, but we don’t recommend them as you may damage your unit. Instead, it’s best to contact a professional.

How to Keep A Window Air Conditioner Running

The best way to keep an appliance quiet is to look after it properly. Especially with something like an air conditioner, there’s a few easy steps we should be doing regularly. They take can take less than 10 minutes to do, but can keep your air conditioner working for over 10 years!

Here’s how to keep your window air conditioner running quietly:

  1. Keep Your Filter Clean! Around once a month during the hot season, take the filter out and give it a good soak. After 5 minutes, give it a good wipe down and leave it out to dry before replacing it. If it’s become way too dirty, you can always grab a new one.
  2. Look After Your Coils. Your AC has both evaporator coils (in the room) and condenser coils (outside). These can both get clogged up with dust and dirt, but just take minutes to wipe down. You need to take the Window AC off the frame and take off the front and back panels. Then spray some soapy solution on the coils, wait a few minutes, and gently wipe them down. *Only* wipe downwards, in the direction of the fins. While this can be a pain, you only need to do it annualy; at the start of the season.
  3. Straighten The Fins. While you’re busy with the above, make sure to also gently straighten any misplaced fins. Just gently run a comb downwards along them.
  4.  Wipe The Fan Blades. With the housing off, make sure to also wipe down the fan blades to get rid of any dust and clutter that’s attached to them.
  5. Don’t Dirty The Drainage. Make sure to keep an eye on your drain pan – if this gets too full then the condensation can get stuck inside the air conditioner. All you need is to drain it down your sink and give it a quick wipe down whenever’s needed.
  6. Keep It Cosy. When you don’t need them, it’s tempting to just chuck a window air conditioner into any old storage spot. Instead, make sure you look after them! Take them down, place inside a box, and keep it in a dry, cool space. Allow a full winter’s hibernation before you wake it back up!


Window air conditioners can be a fantastic solution to a hot summer.

They’re an inexpensive way to keep cool and ‘chilled’ even while it’s roasting outside. But a noisy unit can drive anyone insane. I hope these few tips have given you some ideas to try and help solve any air conditioner noise you are hearing.

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Thank you for reading, and have a great day! -Craig

I've been helping homeowners with appliance repair since 2016. Starting out as an enthusiastic amateur, I've since worked with many Appliance, HVAC, and DIY experts over the last 7+ years. My mission is to help fix your appliances and prevent future issues - saving you stress, time, and money. Visit my author page to learn more! Read more