Fine Homebuilding Project Guides

Wiring

How-To

Installing a Range Hood

Learn how to mount, vent, and wire the hood over a cooktop.

Safety Alert: Most hoods aren’t heavy but they’re unwieldy, so get help installing one.

Range hoods are typically screwed to the underside of a cabinet or mounted directly to a wall. A typical hood is mounted between 24 and 30 inches above the range, though it’s best to check the installation manual and your local building codes for specific requirements. The ducting that vents a hood should exit the house as directly as possible. As you plan your duct route, use a stud finder to locate studs in the wall behind the stove or through ceiling joists above. The duct run should exit through the siding or the roofing. To locate the hole for the ductwork, level the hood and center it over the range.

Mounting and Ducting a Range Hood

Cut a hole in the wall or ceiling and insert a thimble—a specialized fitting that creates an opening through a wall or ceiling into which the duct fits. If there already is a thimble in place, insert the duct from the range hood up into the thimble 3 in. to 4 in. above its final position 1. Friction should hold the duct in place.

PRO TIP: A well-sized hood should extend about 3 in. beyond the range on both ends.

Level the hood, center it over the range, and bolt it to the wall 2. Mount the hood in at least two points: If the studs behind the hood are 16 in. o.c., you may have to bolt one side of the hood to a stud 3 and secure the other side of the hood with a toggle bolt. After the hood is mounted, slide the duct down over the takeoff atop the hood 4. Tape all of the joints with self-adhering metal tape.

1) Slide the duct into the thimble.	2) Level, center, and mount the hood.
3) Bolt at least one side of the hood to a stud.	4) Lower the duct over the hood takeoff and seal the joint with metal tape.

Wiring a Range Hood

Many range hoods have discrete electrical junction boxes with knockouts into which you insert cable clamps and cables. In the example shown here, the shroud that encloses the duct doubles as a junction box. The lead wires from the fan and light emerge through a bushing on the top of the hood and attach to wires in a Romex supply cable, which emerges from the wall cavity.

Strip and splice like wire pairs using wire connectors. Splice the ground wires first—be sure there’s a grounding pigtail to the hood itself—then neutral wires, and then hot wires 1.

To minimize weight and avoid marring shiny trim pieces, many pros install the fan filters, trim, and other trappings after the hood shell is mounted. Most of the parts simply snap into place—just follow the instructions provided 2. Then, if your hood has a bottom casing, screw it into place 3. Finally, fit the shroud over the ducting and the wire connection—they’re usually held in place with one pair of screws at the top and another pair at the bottom 4.

1) Splice the grounds, then neutrals, and then hot wires.	2) Snap on the fans, filters, and trim pieces.
3) Attach the bottom casing onto the hood.	4) Use screws to secure the shroud in place.