How to Vent a Downdraft Ductwork

Turn off the power to the existing range hood's electrical circuit at the home's distribution panel. Confirm the power is off by trying to turn the fan on.

Remove the screws that fasten the range hood to the wall and pull the hood off.

Locate the framing members in the wall with a stud finder and mark their location. Determine which two studs the vent ductwork runs in between by lining up the duct opening with the center of two framing members.

Cut along the inside of the wall studs with a drywall saw from the bottom of the cabinetry to the floor. Pull the drywall from this area with your hands.

Determine the height the duct outlet needs to be, from the floor, for your particular downdraft stove. This information is located in the stove's owner's manual.

Extend the existing ductwork down to this level by securing additional sections of four-inch ductwork to the existing outlet. Each section is pushed into the one above and secured with three or four self-taping screws through one another.

Fasten the duct elbow on the bottom straight section using the same method. The elbow should be be pointing out the wall. This elbow is where the stove is connected. Wrap the joints between each duct section with aluminum foil tape.

Fasten a new section of drywall over the opening by screwing it into the framing members on either side. Plaster the joints and allow to dry overnight. Sand the plaster smooth and paint the wall to match the existing wall color.