Flex Duct Installation Instructions

Measure the actual path distance between two spans through which the flex duct is to be installed. This can be done with a tape measure or by running the flex duct for visual alignment. You need to account for any bends or turns that the flex duct requires, so measure the actual path.

Cut the flex duct completely at the required length.

Peel the insulating jacket back from the end of the flex duct and slide at least 1 inch of the flex duct onto the metal collar, which should be on one end of the span you measured. This metal collar should already be present on the air conditioner or attached to a vent. Make sure the flex duct goes past the bead of the metal collar.

Secure the flex duct in place by adding at least two wraps of duct tape over the end of the flex duct and collar.

Add a clamp over the assembly, just past the bead, and tighten down with clockwise turns of a flat-head screwdriver.

Pull the insulating jacket back over the flex duct and wrap two layers of duct tape around the end to secure it in place.

Run the flex duct to the other end of the span you measured.

Add support straps every 5 feet. Do this by running the strap under the duct and nailing the strap ends to support truces or beams. If the duct is run vertically, add support straps every 6 feet.

Repeat the assembly process at the other end of the span you measured.