How to Vent a Gas Cooktop in an Island

Install the Ductwork

• 1

  Measure the shortest distance from the ceiling directly above the cooktop to the roof.

• 2

  Push a straightened wire through the ceiling directly above the cooktop.

• 3

  Go to the floor or attic directly above the kitchen and look for the wire. You might need to remove flooring to access the joists below.

• 4

  Cut out a 6-inch circle from the kitchen ceiling around the wire, using a piece of ductwork as a guide.

• 5

  Trim two 2-by-4 boards to snugly fit on either side of the hole between the joists, and nail or screw them into place. These provide support for the ductwork.

• 6

  Push the female end of a straight piece of duct through the hole into the kitchen with 3 to 4 inches of duct visible in the kitchen.

• 7

  Attach a 90-degree angle duct to the straight duct. Continue to connect straight or angled ducts as needed to reach the roof or a side wall.

• 8

  Cut out a 6-inch wide hole in the wall or roof.

• 9

  Attach the roof or wall vent cover to the roof with roofing nails or wall with long wood or masonry screws.

• 10

  Insert the end of the duct into the back of the vent cover. Seal the joints along the ductwork with self-tapping sheetmetal screws and covering them with metallic duct tape.

Install the Hood

• 11

  Screw the hood frame to the ceiling joists.

• 12

  Shut off the power to your home and attach a branch wire to a nearby junction box in the attic. Pull the wire down the side of the hood frame to power the fan.

• 13

  Attach another piece of 6-inch straight duct from the bottom of the existing duct to just inside the base of the frame for the vent. Connect the ducts with self-tapping sheetmetal screws and metallic duct tape.

• 14

  Install the frame cover according to the manufacturer’s instructions if your hood included one.

• 15

  Get one or two people to hold up the hood while you attach it to the frame with the screws included in the installation kit.

• 16

  Strip off 6 to 8 inches of the cover from the branch circuit to expose the wires.

• 17

  Connect the wires for the hood to the branch circuit, matching like colored wires to each other using the wire nuts from the hood's junction box. Close the hood's junction box, screwing it into place, if required.

• 18

  Turn on the power and test the fan on the hood.