When it comes to your A/C and heating vents, some noise is to be expected. Popping noises are completely natural and happen during a shift of cold or hot air throughout your home. For example, when you're warming your house, your ductwork will expand from the hot air. The opposite happens with cold air. That popping you hear happens when your ducts begin to shift to accommodate your temperature needs.

However, if you've got an extremely noisy A/C or heating vents that are making strange sounds aside from popping, there's a good chance that something more serious is happening. The experts at Ragsdale explain what causes noisy A/C and heating vents below!

Type of Ducts Affect Noise Level

The type of ducts you have in your home could be causing more sounds. The following characteristics are the biggest influencers of noise level.


Ducts come in three different sizes: round, square, and rectangular. Round ducts are the quietest out of these options, while rectangular ducts are the loudest. If you require silence in your home, speak with an HVAC specialist at Ragsdale to see if they can install round ducts, or use one of the following solutions to help quiet the sound:

  • Wrapping the ducts with fiberglass insulation and rubber pads to prevent rubbing against other materials of your house.
  • Using duct liners to deflect sound.

Gauge Rating

If you have metal ducts, then the metal used in your ducts will have a gauge rating. Lower scores on this gauge indicate that the metal used is thicker and stronger, meaning your ducts will be less likely to expand and pop. If you're hearing more popping than usual, the metal used in your ducts might be weaker.


Your air and heating ducts should match the size of your house. If you have a smaller property like an apartment or condo, your ducts can be smaller as you'll need less heat and cool air to keep you and your family feeling comfortable.

However, if you have small ducts for a larger home, they will have to expand and retract more often to match the temperature of the air, leading to more popping sounds. If you suspect your vents may be improperly sized, reach out to us.

What Causes Noisy A/C and Heating Vents?

Aside from the popping described above, it's important to remember that air ducts don't make noise on their own. If strange sounds are coming from your vents, it has to be something inside the ducts.

Here are the possible causes:

  • Noises sometimes carry through your vents from the furnace or AC unit itself. If you are hearing strange noises and are able to identify it's coming directly from your unit, contact Ragsdale for an inspection.
  • If you have closed off vents, it could be causing more stress on your unit, encouraging it to make more noise as it works harder. Make sure that all of your air vents are open.
  • A big indicator could be that your ducts weren't installed properly. If this is the case, they could be sagging or bent in places, which severely impacts the airflow of your system and could lead to a lot of unnecessary noise.
  • Haven't changed your air filters in some time? Dirty air filters or ducts can lead to a build-up of dust and dirt in your system, leading to strange sounds as it moves through your system. You don't want to hear that, but, more importantly, you don't want to breathe in dirty air. Keep up with changing your air filter and getting your ducts cleaned.

If you have noisy air ducts and aren't sure what to do, reach out to the experts at Ragsdale. We're happy to help!

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