How to Inspect Your Ductwork For Energy and Money-Wasting Leaks

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Small leaks in your ductwork can cause 15-30% loss in your energy efficiency.

If you have hot and cold rooms in your home, you likely have leaks in your ductwork somewhere.

But not all leaks can be found simply by looking at your ductwork.

Here’s how to find those trickier small ones:

1. Get a Smoke Pencil or Incense Stick

Yes. This sounds odd at first. But trust us, it makes your job easy.

On a calm, non-windy day, light your smoke pencil or incense stick. Make sure your HVAC system is running. Now, hold the smoke pencil or incense stick near your ductwork.

Make sure you do this on all sides. And do this up and down the entire length of your ductwork.

If you see the smoke or incense quickly move in a different direction, you’ve found a leak.

It’s extremely difficult to find these same leaks using your eyes or hands alone.

2. It’s Possible (But Not Easy) To Find Leaky Ductwork in Your Walls

Even HVAC pros have a difficult time isolating leaky ductwork found in your walls.

If you want to give it a try, find your HVAC’s air handler. Use a piece of cardboard to partition the supply side from the return side. Tape the cardboard in place with masking tape.

Use a blower door and pressure pan to take a reading at each register in your home. Your ductwork’s supposed to be a closed system, so you should get a reading close to zero.

If you find an unusual reading, you’ve likely found a leak.

Finding (And Repairing) In-Wall Leaks May Be Best for the Pros, But…

Because finding leaks in the ductwork in your walls is so challenging, even many HVAC pros can’t do it.

To find an HVAC pro who can do it consistently with ease, simply ask them,”How would you go about finding a ductwork leak in my walls?”

Their answer will reveal their competence. If they give you a vague non-answer that’s hard to understand, you know to talk to someone else. If they rattle off a detailed process, you know you’ve found the right person for the job.