How to Install a Range Hood: A Step-by-Step Ducting and Mounting Checklist

Before You Start: Gather Tools and Verify Your Setup

Installing a range hood is a weekend project that requires careful preparation. Begin by confirming the hood’s size matches your cooktop width—typically 24, 30, or 36 inches—and that the duct route from the ceiling or wall to the outside is clear of obstructions. Measure the vertical distance between the cooktop and the hood’s underside; most manufacturers recommend 24 to 30 inches for gas stoves and 20 to 24 inches for electric, but check the manual for your specific model.

Your tool checklist should include a stud finder, level, drill with hole saw and spade bits, screwdriver, tape measure, pencil, safety glasses, and work gloves. If your duct run is longer than 30 feet, include additional elbows and metal duct tape. For the electrical side, have a voltage tester, wire strippers, and a junction box on hand. Never skip the voltage tester—even with the breaker off, confirm the circuit is dead before touching wires.

Before cutting any holes, inspect the wall or ceiling for studs, joists, and potential obstructions like plumbing or electrical lines. Use a stud finder and mark the centerline of the cooktop, then transfer that line to the wall. This centerline ensures the hood is perfectly aligned with the burners, which is critical for proper capture of smoke and grease. If you have a ductless model, skip the exterior venting, but you still need to route the recirculating filter and charcoal filter properly.

Plan the Duct Run: Choose the Shortest Path with Minimal Bends

The duct run is the backbone of your range hood’s performance. The ideal route is straight up through the ceiling or out the wall behind the hood, using rigid metal ductwork—never flexible plastic or foil, which can trap grease and restrict airflow. Measure the total length of the run, including elbows, and aim for no more than 25 to 30 equivalent feet. Each 90-degree elbow adds about 15 feet, and each 45-degree adds 7 feet, so plan accordingly to stay within the fan’s capacity.

For a wall-mounted hood, you’ll typically cut a hole through the exterior wall at the height of the hood’s exhaust outlet. For an under-cabinet or island hood, the duct runs through the ceiling. Use a hole saw slightly larger than the duct diameter—usually 6 or 8 inches—and cut from the outside in to avoid chipping the interior drywall. Wear a dust mask and safety glasses during this step, and have a shop vacuum ready to remove debris.

When connecting duct sections, slide the crimped end of one piece into the next and secure with sheet metal screws. Wrap every joint with metal foil tape, not duct tape, which dries out and fails. For a cleaner seal, apply a bead of silicone caulk around the exterior wall opening before installing the vent cap. The vent cap should have a backdraft damper that closes when the fan is off, preventing outside air from entering your kitchen.

Run the Electrical Wiring and Install a Dedicated Circuit

Range hoods draw anywhere from 3 to 10 amps, so a dedicated 15-amp circuit is recommended, though many local codes allow a shared circuit if the load is low. Start by turning off the power at the main breaker and testing the existing wiring with a voltage tester. If you’re not comfortable working with live wires, hire a licensed electrician—this is one step where safety outweighs DIY confidence.

Install a new metal junction box near the hood’s location, either in the ceiling or behind the wall. Run 12/2 or 14/2 non-metallic cable from the breaker panel to the box, leaving at least 6 inches of wire inside. Connect the black wire to the hood’s black lead, white to white, and green or bare copper to the grounding screw. Use wire nuts and wrap the connections with electrical tape for extra security.

If your hood has a built-in outlet, you may need to install a duplex receptacle instead of hardwiring. Check your local code—some areas require a GFCI-protected outlet if the hood is within 6 feet of a sink. Once wired, secure the cable with a strain-relief clamp where it enters the box, and attach the box cover. Turn the power back on and test the fan and light before mounting the hood permanently.

Mount the Hood: Align, Level, and Secure to Studs

With the duct and wiring in place, you’re ready to mount the hood. Hold the hood against the wall and mark the mounting hole locations through the keyhole slots or brackets. Use a level to ensure the marks are perfectly horizontal—a tilted hood will cause grease to pool and reduce performance. Most hoods have a template in the manual; tape it to the wall and mark the screw holes.

Drill pilot holes into the studs using a 1/8-inch bit, then drive the lag screws or heavy-duty toggle bolts. For drywall without studs, use hollow-wall anchors rated for at least 50 pounds, since the hood plus ductwork can weigh 30 to 60 pounds. Hang the hood by hooking the back lip over the screws, then tighten them gradually, checking level as you go. For under-cabinet models, secure the top screws to the cabinet’s underside before tightening the wall screws.

After the hood is snug, connect the duct from the hood’s exhaust outlet to the rigid pipe you ran earlier. Slide the hood’s collar over the duct and secure with a hose clamp or sheet metal screws. Seal the joint with foil tape. If your hood has a telescoping chimney, slide it up to the ceiling and lock it in place with the provided screws. Finally, install the baffle filters and test the fan for airflow—hold a piece of paper near the hood; it should stick firmly when the fan is on high.

Finish with Sealing, Testing, and a Final Checklist

A proper installation ends with a thorough check. Turn on the fan and feel for air leaks around the duct joints and the vent cap—leaks reduce suction and let conditioned air escape. Use foil tape or mastic sealant to close any gaps, and check that the backdraft damper moves freely. Also verify that the hood’s lights are bright enough to illuminate the cooktop, and adjust the light bulb direction if possible.

Inspect the exterior vent cap from outside: it should be clear of debris, leaves, and bird nests, and the flap should open when the fan runs. If you have a recirculating model, replace the charcoal filter according to the manufacturer’s schedule, typically every 6 to 12 months. Clean the metal baffles or mesh filters monthly—they collect grease and reduce airflow when clogged.

Keep the manual and warranty information in a drawer near the hood. Record the installation date and filter replacement dates on a sticker inside the cabinet. If you encounter any issues like excessive noise or weak suction, re-check the duct for kinks or blockages, and confirm the fan speed settings are correct. For complex problems or gas appliance venting, consult a professional—a mistake here can affect indoor air quality and fire safety.