How to Check Air Ducts for Leaks

How to Check Air Ducts for Leaks

The best thing about living in the modern age is having centralized heating and cooling. We can be comfortable all year long, and in Texas, that means we can endure hot, humid summers without feeling like we’re dying from the weather. It’s lovely, but it only works because of effective HVAC systems.

Unfortunately, any system is going to suffer from disrepair over time. One of the most common problems to arise is the presence of leaks in the air ducts. Leaks hurt efficiency, and they can ultimately prevent your system from functioning correctly.

So it’s important to be able to find leaks. There are four different techniques you can use, and when you employ them correctly, you can find even the smallest HVAC leaks. Plugging those leaks helps your system work better and last longer, so here is your tutorial on these four methods.

Visual Inspection

The first and easiest step to take on this journey is to try a visual inspection. You can look with your eyes at any ducts you can see. This may require you to get in a crawlspace or your attic, and if you are in the attic, be careful to only step on secure cross beams. With a visual inspection, you’re looking for obvious holes, gaps, or other signs of a leak that you can see with the naked eye. It is worthwhile to plug major gaps as you go. One of the best methods is to simply seal them with duct tape upon inspection. You can go back and provide a stronger seal once you’re done with the whole inspection.

Generally speaking, you can find the largest and most impactful leaks with a simple visual inspection.

Going by Feel

If the visual inspection doesn’t completely solve the mystery, you can look for subtler leaks by using your hands. This method is exactly as you would guess. Turn the HVAC system to the highest blowing settings. With it blowing as hard as possible, run your hand along the ductwork and try to feel for leaks. If you feel the movement of air at any point, you found the source of a leak.

Pay special attention to joints when you do this method. That’s where most leaks occur, especially when you see duct tape. Duct tape is not a permanent seal, and if that’s the extent of the repair that was done before, there’s a good chance that the same spot is leaking again.

Smoke Test

You’ve done a visual inspection and felt for leaks. You also sealed up (at least temporarily) the leaks that you found. Still, the system isn’t functioning quite up to your expectations. It’s time to find subtler leaks, and for that, you can use the smoke test.

You still want the HVAC system to be running. You’re going to use a source of smoke to help identify air currents where they are not supposed to be. Any source of safe smoke is fine, but incense is the most common. Run the smoke under the HVAC system. If you see it swirl, you found a leak. Mark it so you can seal it after the test is done.

Fog Machine

The last test is like a smoke test on steroids. Before you conduct this test, it’s important that you plug all of the leaks you found with other methods. Even if you only taped them for now, that should be enough.

This test involves using a fog machine. You’re going to place it right by the blower intake fan. Let the fan blow fog all the way through the system. Follow along the ductwork and look for leaking fog. Mark what you find.

If you do this while you have a major leak, you’re going to find that your attic or crawlspace fills with fog very quickly. It will render the test moot, and that is why this test is only for finding subtle leaks after major holes have been plugged.

When you’ve marked all of your leaks, you have a few options. Duct tape is a great temporary fix, but you ultimately need a permanent seal. If you don’t feel comfortable doing that part, you can get professional help. If you can’t find all of the leaks, or you want to skip the whole hassle, Metro Express Service in Carrollton is here for you. Contact us today for ductwork inspections and repairs in Dallas/Fort Worth. We can identify and resolve leaks quickly in order to ensure that your HVAC system is working at peak efficiency. We can do a full inspection, handle routine maintenance, and make recommendations for improved performance and longevity. Whatever your system might need, we’re ready and able to supply it.