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How to Fix That Noisy Air Conditioner That’s Driving You Crazy


Employee frustrated by hvac noise from air conditioner

Do you remember the episode of Mad Men where Ginsberg is literally driven insane by the constant, brain-numbing racket of the computer? If you’re working in an office with a noisy air conditioner, you may be concerned that you, or someone sitting near you, is headed for a similar fate.

If you’ve been stuck working at home due to the pandemic, dealing with an HVAC noise problem can be even more frustrating. You probably don’t have an office maintenance guy to complain to, or anywhere to go to escape from the distracting racket coming from your air conditioner.

Before that noisy air conditioner leads to a meltdown, it’s time to take control of the situation and find out how to quiet your noisy air conditioner for good.

First things first: you need to get to the bottom of the source of the noisy air conditioner.

Identifying the source of the noisy air conditioner

A wide variety of underlying issues could be causing your noisy air conditioner. To begin troubleshooting, pay attention to what the noise sounds like and where it’s coming from. Then find your HVAC noise on the list below to learn about the possible causes and what to do.

NOISY AIR CONDITIONER: Running constantly

If your air conditioner sounds normal but never seems to turn off, or if it cycles on and off continuously, there are several causes for concern:

  • Wasted energy. When your noisy air conditioner runs constantly, it’s also running up your electric bill.
  • Wear and tear on the parts. If the constant running is straining your sanity just imagine the toll it’s taking on your air conditioner’s parts.
  • Impending breakdown warning! According to Air Conditioning, Heating and Refrigeration NEWS, a noisy air conditioner is a sign that something is going wrong or about to go wrong. Something is not working right, and the problem will get worse if you don’t take care of it. Eventually the noise will stop, but so will your air conditioning.

Here are a few of the possible reasons your noisy air conditioner is running constantly:

  • Coils need to be cleaned
  • Air filters are clogged
  • Refrigerant is leaking
  • Controls are faulty
  • Blower motor or fan speed
  • Ducts have holes
  • Evaporator coil is frozen

If your air conditioner is blowing warm air as well as running constantly, you probably have frozen coils. In that case, turn off the system completely and call a qualified HVAC repair professional immediately to prevent further damage to the system. Otherwise it’s not an emergency, and a service visit should be able to take care of other issues quickly and easily.

Related article: Your AC Running Constantly Is Trying to Tell You Something.

NOISY AIR CONDITIONER: Volume cranked to the max

If your air conditioning system has always been too loud, you may have chosen the wrong unit. It could be a lower cost unit that lacks noise reduction technology, or the unit could be too large for the space.

In this case, you need to bring in an HVAC design professional to evaluate your system design. Here are some of the changes you might need to make to stop air conditioner noise:

  • Locate the equipment as far as you can from offices, classrooms, and restaurant dining rooms.
  • Create buffer zones between the noisy equipment and areas that you need to keep quiet. These could be printing rooms or storage areas.
  • Put mechanical rooms near roadways or noisy areas outside to absorb more sound.
  • Design ductwork so that air travels in a smooth, even flow. Certain ductwork patterns create a turbulent flow that requires bigger and louder fans.
  • Use duct air returns instead of air return louvers. The latter cause air to move from room to room, carrying equipment noise and even conversations throughout the building.

NOISY AIR CONDITIONER: Whistling and whining

Those ghostly noises that seem to come from everywhere can be pretty unnerving. Not to mention distracting when you’re on the phone or trying to conduct a meeting. The good news is, the cause is nothing “unnatural” after all, but rather air flow and air pressure issues with your HVAC system:

  • Clogged filters
  • Leaky ducts
  • Inadequate ventilation design
  • Fan motor speed

Fixing air flow problems requires some detective work, but can often be accomplished by simple measures like repairing ducts or adjusting fan motors. It’s all about correcting and controlling the flow of air, something your qualified HVAC professional is well-equipped to handle.

Related article: HVAC Troubleshooting: Surprising Symptoms of HVAC Problems.

NOISY AIR CONDITIONER: Rattling and Shaking

What’s important here is listening to where the rattle is coming from. Is it the vent or return in a specific room? Or does it seem to be originating from the air conditioner unit itself?

If it’s the air conditioner, you may have worn bearings in the fan motor, or the fan motor blades may be damaged. It’s also possible that the unit itself needs to be stabilized on the surface it sits on. Don’t try to fix this yourself! That noisy air conditioner has high voltage electrical components and hazardous refrigerant chemicals. Let the experts take care of this.

Another possibility is loose ducts or an object rattling around in the ducts. An inspection should be able to find the cause and fix it.

NOISY AIR CONDITIONER: Squeaking and squealing

If your air conditioner has not been serviced in a while, your noisy air conditioner could have maintenance issues, including:

  • The blower belt is failing. The belt that drives the blower motor may have developed a problem. It may have slipped, come loose or it may be worn and needs to be replaced. During an HVAC preventative maintenance inspection, this would have been fixed long before it developed that annoying squeal.
  • Motor shaft bearings need oiling. Again, this is a problem that is easily preventable with regular maintenance. Your air conditioner’s moving parts need to be oiled every so often so they continue to work efficiently and quietly.

Peace and quiet is only one of the many costs of failing to regularly maintain your HVAC equipment. Poor maintenance also costs your business in many ways that you may not realize. Want to learn more? Grab a copy of our helpful guide to Calculating the Hidden Costs of Poor HVAC Maintenance.

Get the guide to understanding your HVAC System's hidden costs.