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portable air conditioner making noise

Why Is My Portable Air Conditioner Making Weird Noises? & What To Do?

Compared to other air conditioners, portable air conditioners tend to be noisier. It could be even more distracting and unbearable whenever it starts to make weird noises. 

So, why is your portable AC making loud noises? It is hard to give a single clear-cut answer. These noises, however, are more likely to be caused by loose parts, obstructed airflow, unbalanced fan blades, incorrect placement, or improper window installation.

Because there are various kinds of noises, I’ll break down these causes by noise type so you know what to do if you hear a specific noise coming from your portable air conditioner.

Your portable air conditioner is making a rattling noise 

The rattling noise is quite frightening and gives us the impression that our device is about to fail. Sometimes, it is true. 

  • When the compressor or the fan motor fails, it will emit a rattling or banging noise. If your machine is aging, it has a higher likelihood of failure.
  • Other loose parts and debris accidentally getting into the case can cause noise. 
  • Aside from that, a rattling noise may occur when the surface is too hard or uneven. If you have changed its placement recently, you should think about it. 
  • The window installation can also cause noise. You should walk to the window and check if it is the source of the noise.


After unplugging the machine, you can disassemble it, clean out the debris inside, and tighten all the loose screws and nuts with a screwdriver. You can also move your portable AC to another place or adjust the window panel assembly fits.

If none of these methods work, the fan motor or compressor may need to be repaired or replaced, which should be done by an HVAC professional.

As a side note, the compressor is the heart of your portable AC, which is expensive. If your machine is relatively old, purchasing a new unit may be a better choice.

See also: Why is my air conditioner making a rattling noise?

Your portable air conditioner is making loud buzzing noises

Buzzing noises can be caused by a few different reasons. Sometimes, it is hard to identify.

  • Electrical arcing. If your portable AC has been used for years, the wires inside may wear out, leading to electrical arcing, which can produce a buzzing sound.
  • The condensate pump used to drain water can also be the culprit when it is clogged or breaks down. 
  • The fan blades are another part you should take a look at. When there is a crack in the blade, it can give off a buzzing noise when the blades spin. 
  • The evaporator coil can vibrate and make a wired noise when coated with ice.


If you see the ice on the evaporator coil, you can let the ice thaw and test the machine after that. 

If you doubt the problem is caused by other reasons, you should make a call to a certified technician. 

See also: Why is my air conditioner making a buzzing noise?

Your portable air conditioner is making a whistling noise

The main cause of a whistling noise in your portable AC is reduced airflow. Usually, it is due to the dirty air filter or something that has blocked the air vents. 


Cleaning the air filter is a simple solution to the problem. Simply removing it from your portable air conditioner and rinsing it under running water should do the trick. Remember to let it dry before reinstalling it.

You should also remove any furniture or fabrics that may obstruct airflow.

See also: Why is my air conditioner making a whistling noise?

Your portable air conditioning is making a beeping noise

Some portable air conditioners will make a beeping noise to alert you that something is wrong.

It often indicates that an electrical component is faulty or that the voltage is too high or too low.

When the water bucket is full, your portable air conditioner will also beep.


The first thing you can do is dump the water. If the beeping sound doesn’t stop, you can flip the breaker on to restart your machine. 

When these two methods are useless, you should hire a technician.

See also: Why is my air conditioner making a beeping noise?

Your portable air conditioning is making a clicking noise

It is normal to hear a click when the machine is turning on or off. If the clicking sound shows up when the machine is running, it may be caused by loose parts or fan obstruction. 


If you have the expertise, you can disassemble your portable AC to remove the grimes and debris on the fan motor and blades and use a screwdriver to tighten up the loose part.

See also: Why is my air conditioner making a clicking noise?

Your portable air conditioning is making a humming noise

When you set the fan speed too high, your portable will make some noises when it is running at full capacity.

When a fan motor fails but still receives power, it can produce a humming sound when attempting to spin the blade. This may also result in a pulsing sound.

The bent fins will also produce a similar noise, but the fins are not easy to bent in a portable AC.


Lowering the fan speed to medium or low should reduce the decibel level.

Examine the fins and straighten them with a fin comb. If they are not bent, the cause is most likely the fan motor. A technician should decide whether to replace or repair the fan motor.

See also: Why is my air conditioner making a humming noise?

Your portable air conditioning is making a hissing noise

Nine times out of ten, the hissing noise comes from a refrigerant leak. Because the refrigerant in the coil is pressurized, it will make a hissing sound when it escapes from a small hole in the coil. 

A refrigerant leak is more likely to happen in an older machine because the coils will become rusted and corroded with time. The refrigerant usually smells like chemicals or sweet.


You are not allowed to recharge the refrigerant on your own because it is dangerous for both your health and the environment. The HVAC expert has the tool to locate the leaks and can recharge your portable AC properly. 

See also: Why is my air conditioner making a hissing noise?

Your portable air conditioning is making a squealing noise

When the weather is too cold, the lubricating oil will become thicker, making the compressor require more time to warm up. In this process, the portable AC will make a squealing noise. 


The noise should stop when the machine is turned on for a while. If you hear the noise constantly, it may be caused by the fan motor, which should be replaced or repaired by a pro.


A portable air conditioner can make different kinds of noises. You can troubleshoot your machine by tracing the source of sounds. 

Sometimes, you can fix it by yourself by cleaning the debris or grime on the filter, motor, or blades. Please take safety precautions. 

Other tasks, such as recharging your AC, and changing the fan motor, should be done by an expert. 

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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 more than 150 products in person, including 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.

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