Why is My Air Conditioner So Loud? A Florida HVAC tech explains

May 05, 2016

This a common question but it can be a difficult one to answer without actually inspecting the unit. It’s also difficult because what is “loud” to one person may not be loud to another.

But if the noise from your air conditioner is uncomfortable or inconvenient to you or your neighbors, there’s a good chance it’s too loud.

First ask yourself “Is my AC making a strange noise all of a sudden? Has its volume suddenly increased?”

If so, it’s most likely a sign that something is wrong (or is about to go wrong). To help you determine and fix the issue, check out our list of 6 loud AC noises and their causes. If you know there is a serious issue already, visit our air conditioning repair page, to see what is all entailed. We will diagnose the issue for you, immediately.

But if your AC has always been loud, it could be one of these 3 common causes:

  1. Your AC unit is too big for your home
  2. Your home has poor duct design
  3. Your AC unit is just an older (noisy) unit

Let’s look at each of these causes and explore solutions that can give you a quieter AC.

Reason #1: Your AC unit is too big for your home

The noise: When the AC kicks on, air sounds loud and forceful in the ducts and it becomes difficult to hear others talking in the same room. You may also notice some whistling.

What you’re hearing: An air conditioner that is too large will force more air through your ducts than they can handle. So whenever the air conditioner turns on, you’ll hear a large volume of air making its way through the ducts.

Accompanying issues: You’ll know this is the problem, if you also have the following problems:

  • AC turns on and off frequently
  • High levels of humidity in your home
  • Quick, short blasts of cold air
  • Hot and cold spots throughout the house

Solution: You likely need someone to replace the system with a smaller, correctly sized AC to get rid of the noise.

Make sure you hire a technician to do a heat-load calculation first, though. This home inspection takes a look at many factors (size of your home, amount of windows, insulation levels, etc.) to determine the correct size AC that you need.

Reason #2: Your home’s ducts are poorly designed or undersized

The noise: Similar to an oversized AC, you’ll hear loud, rushing air in the ducts. You may also hear a hissing, whistling noise coming from the vents.

What you’re hearing: Undersized ducts or too many sharp angles or bends in the duct design increases air velocity. And high air velocity increases noise. Vents can also become noisy when the duct design pushes too much air through them.

Accompanying issues: You can tell that your ducts are the problem (compared to AC size), because rather than an air conditioner that shuts on and off frequently, you’ll likely have:

  • Stuffy air
  • Mold growth (usually on vents)
  • Doors slamming by themselves

Solution: If you think your home may have a faulty duct design, have a technician inspect your air duct system. They’ll be able to determine if you will need a complete redesign or just a quick repair somewhere.

Reason #3: You have an older, outdated AC unit (and it’s just loud)

The noise: Whenever your outdoor unit runs, it’s particularly loud. The roaring makes it difficult to hear your TV or conversations inside.

What you’re hearing: Old units have little or no noise-reducing features and so are louder to begin with. And with age, they just continue to get louder as parts wear out.

Accompanying issues: Signs of an old unit include:

  • SEER rating of 10 or less (See: What is a SEER rating?)
  • Your AC still uses R-22 refrigerant
  • High energy bills

Solution: Depending on the age of your air conditioner, you may want to replace your old unit with a quieter, more efficient model.

But if your unit has a few years of life left in it and you’re not quite ready to replace it, here are some tips on how you can reduce the noise coming from your outdoor unit.

  • Install a mounting pad. These rubber pads are placed between the outdoor unit and its concrete base to prevent noise caused by vibrations.
  • Build a sound-blocking fence. A fence built around your outdoor unit helps reduce noise by deflecting it away from your home. Just make sure it’s at least 3 feet away and doesn’t interfere with your unit’s airflow.
  • Invest in a compressor blanket. These “blankets” cover the noisy compressor (located inside the outdoor unit) and help muffle noise.

Let us help you quiet that AC

If you can’t take the loudness of your air conditioner any longer, contact us. We can help you pinpoint the problem and find the right solution for your needs and budget.

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