Tips for Detecting and Sealing Leaky Ductwork

The Energy Star program states that 20 to 30 percent of conditioned airflow in the average home is lost through holes and leaks in faulty ductwork. If you’re curious as to why some rooms in your home are stuffier and more humid than others, there’s one easy way to find out. Keep reading to see how you can detect and seal leaky ductwork.

Detecting Ductwork Leaks

Ductwork in the typical Martin County home is located in the attic or crawlspace. As such, some ductwork will be concealed or too difficult to reach. To start, only look for leaks in accessible ductwork. Here’s how to perform the job:

You’ll need a hard hat, a respirator, protective clothing, a flashlight and incense sticks.
Holes, dented ducts and disjointed ducts are easy to spot, while smaller leaks are not.
With your HVAC running, hold a lit incense stick to all duct joints. If the smoke swirls erratically or is sucked in, you’ve found a leak.
Dirt streaks on ductwork are also a sure sign of a leak.
Listen for rattling and clamoring. This may indicate that a connection of two duct portions are knocking together, which may be another leak.
Make sure to check the dampener at the main trunk and air handler for tears and holes.

Sealing Leaky Ductwork

The tools needed for sealing leaky ductwork are fairly simple. You’ll definitely need metal tape (i.e. not cloth “duct” tape), fiberglass mesh, mastic paste and the same protective wear. Here’s what to do:

Damaged, dented or tangled ducts may need to be replaced if you cannot straighten them. It’s not worth the energy loss if a duct connection can’t be sealed tightly.
Holes can be sealed with fiberglass mesh and mastic, and then once dry, wrapped with metal tape. To apply the mastic, it’s best to use a disposable paint brush. Mastic is very messy.
Loose, rattling and fallen duct connections can be wrapped with metal tape with mastic applied on top of that.
Lastly, check your registers for leaks and seal with mastic and tape as needed.

For more tips on sealing leaky ductwork, contact NisAir Air Conditioning and Heating in Palm Beach today.