Why Is My Window Air Conditioner So Loud & How To Quiet It?

Many of my friends have complained that their window air conditioners are too loud, making them restless. 

Some window air conditioners are noisy right out of the box, while others make noise because something is wrong.

If you want to make your window AC quieter, you can try to add insulation, clean out the debris, add lubricant, or straighten the fan blades. Of course, there are more ways to go, depending on the root cause of the noise. 

In the following sections, I will walk you through why a window AC is noisy and how to make it quieter so that you can find a suitable solution to your problem.

Let’s jump into it right now!

Why is my window air conditioner making noise?

It would be terrible to sleep with a noisy window air conditioner on but stopping the noise is not like a walk in the park.

There are so many reasons that can cause a window AC to be loud. Before taking any action, it is critical to determine the source of the noise.

Window air conditioners are naturally louder

If you are sensitive to noise, a window air conditioner might not be the best option for you.

Because all of the components are contained within a small box, it will naturally generate more noise than other types of AC.

For example, both central air conditioning and split air conditioning have a separate outdoor unit that keeps the compressor and condenser noise out of your room. A window AC, on the other hand, cannot achieve this because the compressor and evaporator coil are housed in the same cabinet.

Furthermore, older models are typically louder than newer models.

If your window air conditioner makes a low, steady noise right out of the box, it could be due to normal operation.

The set temperature is too low

I understand how badly you want your air conditioner to cool the room quickly, but setting the temperature too low may be a bad idea.

Your window AC will run at full capacity to achieve the desired temperature. As a result, the compressor and motor will make more noise.

Misaligned fan blades

Even though window air conditioners have an air filter behind the panel, this filter cannot remove all of the dust and dirt in the air.

Part of these contaminants will eventually get into the inner workings and accumulate on the fan blades, causing them to become unbalanced.

Aside from that, mechanical tear and wear can lead to this problem as well.

When the fan blades become misaligned, they make a rattling noise as they strike the case or other parts around them.

Damaged fan motor

The faulty fan motor is another common source of unusual noises. When it malfunctions, it will make a humming or pulsating noise as it tries to spin the blades.

It could be the result of worn-out bearings. A lack of lubricant may also be to blame.

Stuck debris in the condenser coil 

The majority of a window air conditioner is exposed outside, making particles, like twigs, rocks, or feathers, get a chance to enter the machine. 

When debris enters the condenser coil, it can create a knocking sound as the coil vibrates. It can also cause the fins to bend.

Poor installation 

If you just got your window air conditioner and notice it starts to make weird noises, it may be due to a poor installation. When the machine is not securely mounted on the window, it will vibrate and give off noises when operating.

Loose window frames

If your house is relatively old, chances are the window frames are loose and will rattle when the airflow is strong.

When the window AC unit is working, the vibration will transform to the window frame, causing it to shake and make noises. 

Loose parts and panels

After a long time of use, the parts and panels of your window AC can become loose. When the AC is on, it will produce a loud noise.

How to quiet a noisy window air conditioner?

how to quiet a noisy window air conditioner

Now that you understand why your window AC is so loud, let’s look into the methods to make it quieter. Simply put, you can stop the noise by addressing the causes of the noises I mentioned above.

Reinstall your window AC

If your brand-new window AC is shaky and noisy while operating, it is likely that you or the professional you hired failed to install it properly. You should hire a pro to reinstall it.

Repair the window frame

Take a look at the window frames. Maybe the noise doesn’t come from your window AC but from the window frame around it. There are a few ways to repair it, including weatherstripping and caulking. It will also improve the performance of your machine because less hot air will enter your room through the cracks.

Add insulation

Adding insulation is an effective way to stop AC vibration. If there are any gaps between the air conditioning unit and the window frame, you should fill them with foam. When the vibration stops, the loud noise will be reduced as well.

Add lubricating oil 

This task is best performed by an HVAC expert, but if you have repair experience, you can give it a shot. After removing the panel, lubricate the motor and motor shaft with a few drops of lubricant.

Give your window AC a thorough cleaning

As you know, dirt and debris in the coils and fan blades can cause a noisy window AC. As a result, you should clean the inside and outside of your device on a regular basis to keep your AC in tip-top shape.

Tighten up the loose parts

When you clean your AC, don’t forget to tighten up all the screws and bolts in the machine. Usually, a screwdriver will do the trick.

Straighten the fans and fins

You can use a plier and a fin comb to straighten the fans and fins so that these parts will not strike the panel and other components.

Replace your old window air conditioner 

If none of the above methods work, you may need to consider purchasing a new unit. Fortunately, window air conditioners are more advanced and much quieter than in the past.

Moreover, if you have a bit more budget, you can invest in a split or central air conditioner, which typically produces less noise than window air conditioners.

In conclusion

Window air conditioners are supposed to be a bit noisier than other counterparts because everything has been kept in a small cabinet. But the sound it gives off should be acceptable. 

If your window AC starts to make a loud noise, you should check if anything has gone wrong. 

You can use what I said in this post as a guide to find the source of the noise and make your air conditioner quieter. Don’t hesitate to turn off your machine and hire a pro if you don’t have the expertise. 

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.