How To Fix A Noisy Portable Air Conditioner

All air conditioners produce noise unavoidably when they operate. The only difference is the loudness and sound that they will create. Do you know why your air conditioning unit makes a sound while running? In this post, we'll give you well-screened answers to why and how to fix them.

There are numerous reasons why portable air conditioners get so noisy. That makes keeping an eye on your portable system even more critical. Generally, there are two options for fixing the noise problem: repairing or replacing your AC.

In this post, we'll cover everything you need to know about portable air conditioners and what makes them so noisy. We will also include some tips and tricks to keeping the noise levels down so you can get back to enjoying the cold air. With that said, let's get right into it!

Portable air conditioner in a blue light room, How To Fix A Noisy Portable Air Conditioner


Why Is My Portable Air Conditioner Noisy?

A noisy portable air conditioner typically happens because it's been turned off for a while. For example, if you stored your AC away during the wintertime, you may notice it being louder than usual when you first power it back on.

Another factor is the air conditioning unit's parts. They may be too old, overused, or even misaligned from their original location. This is when you should reach out to the manufacturer about getting a replacement piece.

Air conditioner portable

What Are The Causes For A Noisy Portable Air Conditioner?

There are numerous kinds of sounds a portable air conditioner makes. The most common include rattling, buzzing, clanking, pulsating, and whistling.

Furthermore, when you hear one of these strange sounds, this means that something could be wrong with your portable AC system.


In general, rattling doesn't mean something seriously wrong with your portable air conditioner. This will usually happen due to a misaligned fan blade, loose screws, or a faulty motor.

Misaligned Fan Blade

This problem is due to poor installation. The fan in the condenser coil and the blower fan in the air handler must be misaligned. Thus, it produces vibrations that lead to rattling.

Loose Screws/Panel

Screwdriver screw in metal steel plate bolt

This is, by far, the easiest to fix. The panel door is enclosed thinly by a metal foil that bumps against the whole unit if it is not correctly attached. If the screws are not secured and tightened enough, it will cause a strange rattling sound.

Faulty Motor

The motor provides power to the compressor as well as propels the fans. So, if you hear a rattling noise, it means it is damaged. One thing to note, you want to be careful and turn off your fan entirely before repairing its motor, as this can be dangerous.

How To Fix

Fixing the rattling sound is somehow easy since you will have to realign parts of the air conditioning unit and screw the panel screws. However, if it is a faulty motor, you will need to call a professional because this requires an immediate replacement.


Another common noise from a portable AC is buzzing. Luckily, this can usually be traced down to the capacitor, refrigerant, fan blades, contactor, or compressor.


Checking air compressor capacitor

If the capacitor of your air conditioner is poor, its power delivery to the fan won't be constant as it should be. It will then create a large wave of sending power to the fan, which will create a buzzing sound.


Vacuum pump measuring equipment for filling air conditioners

If your refrigerant is leaking, the air conditioning unit will freeze up. This malfunction can lead to a constant buzzing sound coming from your air conditioner.

Fan Blades

A buzzing sound can exist when the fan blade of the air conditioner is damaged.


If the air conditioner's contactor is malfunctioning, expect the compressor to not power appropriately. And if the voltage is high enough, an electric jump may happen.

That jump will cause the compressor to start every few minutes. Hence, it will lead to a buzzing sound.


Dislocated or damaged isolating legs of a compressor are two possible causes of a buzzing sound.

How To Fix

You can resolve the problems above with only one option. That is to replace the parts where the noise lies.

Replace the capacitor and buy a new fan. Replace the malfunctioning contactor so the compressor will receive a stable flow of electricity again. You see, you can execute the fixing yourself, as it only requires a few technical skills.

However, there is one exempted case. And that is the replacement of the refrigerant leak. Replacing it is not as easy as it seems. So, to fix it the appropriate way, you badly need to hire a professional.


Loose or broken air conditioner parts are what cause a clanking sound. It may include a damaged indoor fan, faulty motor, or even compressor.

How To Fix

To fix this noise, check the indoor fan, motor, or compressor to diagnose the part where the malfunctioning lies. It's not easy to inspect them one by one, that is why we suggest calling a professional.


Check if the compressor of the portable air conditioner insulates correctly. If not, fix it immediately to avoid further problems. Look over the compressor because sometimes it pulsates or vibrates on the surface from where it rests.

Another cause is the refrigerant line which may be whirring and vibrating against the wall. If so, try changing its position or moving the hose until you notice the sound stop.

How To Fix

Inspect the area where the compressor lies. If it is a plastic platform, there's a possibility it will crack and start pulsating. You can replace the plastic with a plank of wood. As a result, it will lessen the vibration and stop the pulsating sound.

If you want additional support, use rubber isolation pads to end the shaking compressor of your portable air conditioner. It will also work for window-type air conditioners.

Although they already have built-in isolation feet, you still need to check if it's missing or damaged. Additionally, you can tighten the screws of the compressor to ensure that it's accurately built.

If you can hear the pulsating noise from the air conditioner's refrigerant, try to keep it away from the things near it. It will create a pulsating sound if you let it hit itself against anything.

Check out these rubber pads on Amazon.


Lack of airflow causes a whistling sound to come from a portable air conditioner. If the whistling emerges, it means there is a high air pressure happening inside the air conditioner. Your unit is working forcefully to pull enough air from inside your home through its system.

If objects like furniture, windows, or a couch block the air conditioner's air intake, this can also cause your system to whistle, so keep that in mind.

How To Fix

You have to clean your air filters. If it is full of moisture, it will lessen the airflow. And cleaning them means increasing the airflow of the air conditioner once again.

It will also normalize as before. In addition, doing this will end any noise coming from your AC. As we said, make sure to move the furniture or any blockage that limits the airflow to your air conditioner.

Why Is It Important To Fix A Noisy Portable Air Conditioner?

air conditioner on wood flooring

When it comes to why fixing a noisy portable air conditioner is important, this comes down to the functionality of your system. Considering that nobody wants to deal with strange noises coming from their air conditioners, getting your cooling system looked at can only be a good thing.

That is why many professionals advise us to maintain our air conditioning unit to prevent future damages and part issues. Aside from saving us repair costs, it will also grant us maximum energy efficiency.

To Wrap Up

No air conditioning unit runs silently. Nevertheless, it's an appealing idea to acknowledge the strange noises that it creates since they can signify a problem.

This is especially true if noises continue to come from your portable AC system. Again, it's best to have a professional take a look at your air conditioner as soon as possible to prevent further damage from happening.

Made it to the end? Check out these helpful related HVAC posts below!

Air Conditioner Fan Not Running – What Could Be Wrong?

How To Clean An Air Conditioner Coils

This Post Has 2 Comments

  1. Vivian Black

    Thanks for pointing out that because of the noise my AC makes, it could be because of old parts. It is actually quite old and has never been maintained. I will call for an air conditioning expert tomorrow.

  2. Amanda Riley Richmond

    My water full light will come on and the unit will shut down. I have to do a power reset to get the red light to cut off. My water is not full.

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