How Can I Tell if My Air Ducts Are Leaking? A Florida Tech Explains.

October 06, 2016

According to Energy Star, most homes lose anywhere from 20 to 30 percent of conditioned air to leaky air ducts.

That’s a lot of wasted air.

So how do you know if this is happening in your home?

Well, signs of leaking ducts include:

  • Higher-than-average utility bills
  • Uneven cooling/heating throughout the house
  • Excessive amounts of dust in your home
  • Visual confirmation that air is leaking from your ducts

Now let’s take a closer look at each of these signs and what you should do if you think you have leaky ducts.

Higher-than-average utility bills

If you have leaky ducts, your HVAC system has to work harder and longer to reach and maintain your desired temperature. And that means higher utility bills.

Let us explain how that  works in more detail.

Think of your HVAC system as a living, breathing thing. One one side of the system (the return side), your system breathes in air from inside your home. On the other side (the supply side), it exhales conditioned air back into your home.

Duct leakage can happen on both sides of the system:

Leakage on the return side means hot air from your attic is getting sucked into your ductwork. And the more air your ducts suck in from your attic, the less air it needs to suck in from inside your home. Over time, that means your system gets “unbalanced”, meaning it’s blowing more air into your house than it’s taking out. This is called “positive pressure”. But if there’s too much positive pressure, it pushes conditioned air outside the home through tiny gaps in windows, doors, etc.

Leakage on the supply side means your ducts are blowing cool air into spaces that don’t need it (attic or basement). So all that conditioned air that you’ve already paid for is wasted and your HVAC system struggles to cool or warm your home.

Uneven cooling/heating throughout the house

Leaky ducts can lead to stuffy rooms or specific areas of the house that can’t be cooled or heated.


Well, your ductwork branches throughout your entire home, delivering conditioned air to different areas of your house. But if one of those branches is leaking, less conditioned air will reach the room that that branch serves.


Excessive amount of dust in your home

If there are holes or leaks on the return side of your ductwork, it will pull in the dust and air pollutants from your attic or basement. And once that dust and dirt enters your ductwork, it will inevitably end up into your home.

You’ll notice that no matter how much you clean, you can’t get rid of the unusual amount of dust in your home. That’s because every time you turn your HVAC system on you pull in more dust.

Visual confirmation

If you’re still not sure if you have leaky ducts, there’s nothing like some good ‘ol fashioned investigating.

Once you locate and can visually inspect your ductwork, look for:

  • Loose duct connections
  • Kinks in flexible ducts
  • Holes in ducts

A loose duct connection. Source:

ny and all of these signs indicate that you’re wasting some amount of conditioned air.

Note: It can be hard to visually inspect ductwork, especially if your ducts are located in an attic or crawlspace. Unless you know what you’re doing and looking for, we suggest having a professional inspect your ductwork for leaks.

See the signs? Consider duct sealing.

If you’ve noticed some signs of duct leakage, you can fix the problem by having your ducts sealed.

If you’re interested in learning more about how duct sealing can save you money and increase comfort, contact us today.