Air Conditioner Making Noise? 3 Ways To Quiet Annoying AC Sounds

Air Conditioning

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We often hear that “if there’s smoke, there’s fire.” That also goes for a noisy air conditioner. If it makes strange noises, there is often a problem with it that requires looking into. But some sounds are less serious than the others..

On the other hand, there are certain sounds that an air conditioner normally makes as part of its operating process. 

Is your air conditioner making noise? How do we know if there’s a problem? If it is a normal noise, what can we do about it?

Here are some common reasons why an air conditioner produces certain noises.

air conditioner making noise

Air Conditioner Makes Buzzing Noise When Starting

If your air conditioner makes a loud noise when turning on, the AC could be having electrical issues.

When the AC is signaled by the thermostat that there is a need to lower the room’s temperature, its startup is accompanied by a clicking or ticking sound. The sound is made by the electrical components waking up to initiate the cooling cycle. You may also hear the same sound upon shutdown.

If it is an electrical issue, it’s often the compressor, contactor or capacitor creating the buzzing noise or causing other components to have difficulty starting and producing noise.

Since electrical systems in air conditioners can be very dangerous to work on, your best choice is to have the air conditioner serviced by a professional.

But keep in mind that some noise on startup is normal. Some air conditioners even produce a squealing sound upon startup. If the sounds are brief, these buzzing, clicking, ticking, or squealing sounds are normal.

Air Conditioner Making Loud Buzzing Noise

Just like a buzzing noise when an air conditioner starts, constant buzzing noises tend to be electrical.

But it could also be caused by loose or unbalanced parts.

An air conditioning system has numerous intricate components. Some are designed to move as part of the chilling process and others are meant to stay put. 

If the latter parts somehow got loose or broken, it could produce a banging, buzzing, or clanking sound. The parts that are most susceptible to being loose-fitting are the grills, side panels and electrical access panel. Another cause for a buzzing sound is the copper lines rubbing against something or each other.

Air Conditioner Makes Whooshing Noise

Whenever someone has asked me about a whooshing noise from their air conditioner, 9 times out of 10 they are talking about a heat pump. The same is true when someone notices an air conditioner making noise when off.

In both cases, this tends to be a normal part of operation.

It’s easy to mistake an air conditioner and heat pump. They look exactly the same from the outside.

If you’re hearing the whooshing noise during the summer season, there is a malfunction that needs immediate attention. And if you don’t have a heat pump but instead do have an air conditioner, it should never make a whooshing noise.

If you have a heat pump, a whooshing noise is common when the unit goes into defrost mode during the heating season. This mode is built into the heat pump to remove ice that forms on the outside of the unit.

Air Conditioner With Unbalanced Components

If the moving parts of the air conditioner did not break off but for some reason became unbalanced, it could generate a clanking sound.

For example, if the indoor blower, outdoor fan, and the fan blades become lopsided, it may hit the casing, or worse, it may hit and damage the other parts of the unit.

The compressor itself could also be loose at times which creates disturbing noises. Since the compressor is one of the major parts of the AC, this could mean a more expensive repair by a professional.

Dirty Air Conditioner

If your air conditioner starts to generate a buzzing sound, it could be the condenser coil is overdue for a cleaning. The same is true if your air filters have a dust buildup that needs to be washed, cleaned, or replaced if it is the disposable filter type.

At other times, you might hear a rattling sound. The first place to check is if there are twigs, leaves, or small trash that got inside the system. Some tiny animals could have also made their way inside the mechanism and could produce strange noises and, not to mention, foul odor.

Why Should You Be Concerned With HVAC Noises?

What noise?” you might ask at first. With all the cool comfort and the good feeling it brings you, you might not even be bothered by the sounds your AC has been generating.

True, all machines—especially the big ones—produce some kind of sound as they operate. And since an air conditioning system is no small device, some kind of mechanical resonance is expected. Right?

Many models of air conditioners are producing a sound of an average of 70 to 80 decibels. How noisy is that? It is in the same level of noise in a business office, or a regular conversation, or a working vacuum cleaner, and almost like listening to chamber music.

Realizing the need for less noisy AC units, modern manufacturers take advantage of new technology to make it possible to create quieter cooling units. Unfortunately many technologies to lower noise levels also makes the AC more complicated and more likely to have repair issues.

But how can you, as a private homeowner, prevent your AC from emitting troublesome noises for you and your neighbors? 

Air Conditioner Noise Reduction Blanket

One annoying sound that is normal is when an air conditioner is making a pulsating noise. This can be a normal sound from a compressor.

The good news is that there is a solution that helps.

A reliable and common way to block noise the air conditioner makes is to install a sound blanket. Also known as the acoustic blanket or sound curtain, a sound blanket is usually made of fiberglass covered with vinyl. 

These compressor noise reduction blankets go around the compressor within the air conditioner. As its name suggests, a sound blanket will help cover and absorb the air conditioner compressor sounds such as loud vibrations and pulsating noise.

Besides putting the soundproofing blanket inside the AC unit itself, you can also install it on a wall nearest to it and the fence close to your neighbor’s wall. This step can reduce up to 40% of the compressor noise. It is best to pick a soundproofing product that can be painted over and can last for many years against the elements.

Does the air conditioner sound blanket really work? If done correctly and with the appropriate material, a sound blanket could reduce the noise by 30% to 50%.

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