How to Find a Leak in a Flex Duct

Flexible ducts provide a simple alternative to rigid metal and PVC ductwork in residential homes, because they do not require the installation of elbows and other fittings. These ducts are commonly used for dryer and kitchen hood vents. However, these ducts can tear easily, which can reduce efficiency. Locating a leak in a flexible duct is a straightforward task that requires few tools and supplies.

Things You'll Need

• Spray bottle
• Duct tape

Show More

Instructions

1. • 1

     Visually inspect the flexible duct to identify tears. Vibration from air flowing through the duct typically makes larger tears easy to spot.

   • 2

     Fill a spray bottle with water. Spray the outside of the duct with water and look for bubbles, which indicate air escaping from the duct.

   • 3

     Allow the duct to dry. Apply duct tape to small holes and tears to prevent air from escaping. You may need to replace the flexible duct if it has a tear larger than 1 or 2 inches.