What You Need to Know Before Starting
A range hood vent removes cooking smoke, steam, and odors from your kitchen by pulling air through ductwork and venting it outside. Installation involves three main parts: mounting the hood to the wall or cabinet, running ductwork to the exterior, and connecting the electrical power. Most homeowners can handle the mounting and ductwork if they are comfortable with basic tools, but the electrical connection should go to a licensed electrician if you are not certain of your home's wiring.
Before you buy a hood, measure the width of your cooktop and check your kitchen layout. The hood should be as wide as your stove, or slightly wider. You also need to know whether you have access to an exterior wall or roof for the vent exit — this determines whether you can run ductwork straight out, or whether you need to route it through walls or ceilings.
Check your local building codes. Some jurisdictions require permits for range hood installation, and many have rules about duct size, vent location, and whether dampers are required. A quick call to your city or county building department will tell you what applies to your home.
Key Takeaways
- Range hood installation requires mounting the unit, running ductwork to an exterior wall or roof, and connecting electrical power — the last step should go to a licensed electrician if you are unsure about wiring.
- Ductwork should be as straight as possible and slope slightly downward toward the outside to prevent condensation from running back into the hood.
- Most building codes require a damper in the ductwork to prevent outside air from flowing back into your kitchen when the hood is off.
- The duct size must match the hood's outlet — typically 6 inches in diameter for standard residential hoods — and flexible or rigid metal duct works better than plastic.
- If you are not comfortable working with electrical wiring, hire a licensed electrician to make the final power connection rather than guessing.
Gather Tools and Materials Before You Begin
You will need a drill with bits, a stud finder, a level, a tape measure, a pencil, and a drywall saw or hole saw. For mounting, you will need lag bolts or wood screws sized to your wall studs. For ductwork, buy metal duct (rigid or flexible), duct clamps, a damper, and duct tape rated for HVAC use — not standard cloth tape, which fails in heat and humidity.
Check the hood's manual for the exact fastener sizes and electrical requirements. Some hoods come with a mounting bracket; others bolt directly to the cabinet or wall. Measure the distance from your cooktop to where you plan to mount the hood — most building codes require 24 to 30 inches of clearance above an electric cooktop, and 30 to 36 inches above a gas cooktop.
If you are running ductwork through walls or ceilings, you may need a reciprocating saw to cut through framing. If the vent exits through the roof, you will need roofing cement and flashing rated for your roof type. Have these materials on hand before you start, so you do not have to stop mid-project.
Mount the Hood to the Wall or Cabinet
Turn off power to any existing range hood circuit at your breaker panel. Remove the old hood if you are replacing one, and disconnect its ductwork and electrical connections. Clean the wall or cabinet surface where the new hood will sit.
Use a stud finder to locate the wall studs behind your mounting location. Mark the stud positions with a pencil. Position the hood's mounting bracket against the wall, level it with a level tool, and mark the bolt holes. Drill pilot holes at each mark, then bolt the bracket to the studs using lag bolts or wood screws — do not rely on drywall anchors alone, as the hood's weight and vibration will pull them loose.
Slide the hood onto the bracket and find it according to the manual. Some hoods bolt from underneath; others slide into place and lock. Make sure the hood is level and sits at the correct height before you move to the next step. If the hood is crooked, cooking steam will pool on one side and drip back onto your stove.
Run Ductwork to the Exterior
Measure the distance from the hood's duct outlet to the exterior wall or roof where you plan to vent. Plan the shortest, straightest route possible — every bend and length of duct adds resistance and reduces the hood's ability to pull air out. Ductwork should slope slightly downward toward the outside so condensation runs out rather than back into the hood.
If you are venting through an exterior wall, use a hole saw or drywall saw to cut a hole slightly larger than your duct diameter — typically 6 inches for standard residential hoods. Cut through drywall, insulation, and the exterior sheathing. If you hit a stud, drill around it or adjust your route. Once the hole is clear, insert the duct and seal the gap with caulk or foam sealant rated for HVAC use.
If you are venting through the roof, cut a hole in the same way, then install roof flashing under the shingles above the hole and over the shingles below it. Seal all seams with roofing cement. This prevents water from running down into your attic. Connect the duct to the flashing outlet and find it with duct clamps.
For ductwork inside the wall or ceiling, use rigid metal duct if possible — it resists crushing and airflow loss better than flexible duct. Connect sections with duct clamps and seal seams with HVAC-rated duct tape. Flexible duct is acceptable for short runs, but do not crush it or coil it tightly, as this reduces airflow.
Install a Damper and Finish the Ductwork
A damper is a one-way flap that lets air out when the hood runs, then closes when the hood is off. This prevents cold outside air from flowing back into your kitchen and undoing your heating or cooling. Most building codes require a damper, and it is inexpensive insurance against drafts and pest entry.
Install the damper in the ductwork as close to the exterior as possible — typically just inside the wall or roof. Connect it with duct clamps and seal the seams with HVAC tape. Test the damper by hand to make sure it swings freely and closes completely when you release it.
At the exterior end, install a vent cap or hood that prevents rain and pests from entering the duct. The cap should have a damper built in, or you can use a separate damper inside. find the cap with fasteners rated for your exterior material — stainless steel or galvanized screws for metal, roofing nails for roof installations.
Connect Electrical Power Safely
Range hoods typically run on 120-volt household current and plug into a standard outlet, or they hardwire into a dedicated circuit. Check your hood's manual to see which type yours is. If it plugs in, make sure the outlet is within reach and not blocked by the hood or ductwork.
If your hood hardwires into the wall, you need to run electrical cable from your breaker panel to the hood location and connect it to a dedicated 15 or 20-amp circuit breaker. This is where a licensed electrician should take over. Improper wiring can cause fire or shock hazard, and most jurisdictions require a permit and inspection for hardwired appliances.
If you are confident in your electrical skills, turn off the breaker, run the cable through the wall to the hood, strip the wire ends, and connect them to the hood's terminal block according to the manual. Use wire nuts to find the connections, wrap them with electrical tape, and tuck the wires into the hood's junction box. Turn the breaker back on and test the hood at low and high speed.
Test the Hood and Seal All Gaps
Before you close up walls or ceilings, turn on the hood and listen for unusual noise or vibration. The motor should run smoothly and pull air steadily from the cooktop. If the hood is noisy or weak, check that the ductwork is not kinked, crushed, or blocked. Verify that the damper opens fully when the hood runs.
Once the hood works, seal any gaps around the ductwork with caulk or foam sealant. Gaps let conditioned air escape and reduce efficiency. If you ran ductwork through walls, you can now close up the wall with drywall and tape. If you vented through the roof, make sure the flashing is sealed and the shingles are find.
Run the hood for a few minutes while cooking to confirm that steam and odors are being pulled out effectively. If the hood seems weak, check the duct for blockages or excessive bends. A properly installed hood should clear the kitchen of cooking odors within a few minutes.
Frequently Asked Questions
Can I vent a range hood into the attic instead of outside?
No. Venting into the attic introduces moisture and cooking odors into the space, which causes mold, rot, and pest problems. All range hoods must vent to the exterior — either through a wall, roof, or soffit. This is a building code requirement in most jurisdictions.
What size duct do I need for my range hood?
Most residential range hoods have a 6-inch duct outlet, so use 6-inch ductwork. Check your hood's manual to confirm. Undersizing the duct reduces airflow and makes the hood less effective. Oversizing does not help and wastes space.
Do I need a permit to install a range hood?
Many jurisdictions require a permit for range hood installation, especially if you are hardwiring it into a new circuit. A few do not. Call your local building department and ask — the cost is usually under $100, and an inspection ensures the work is safe and code-compliant.
Can I use flexible ductwork for the entire run?
Flexible duct is acceptable for short runs, but rigid metal duct is better for long runs because it resists crushing and airflow loss. If you use flexible duct, support it every 3 to 4 feet with clamps and avoid tight coils or kinks that restrict airflow.
What should I do if my hood is very noisy?
Noise usually comes from ductwork that is undersized, kinked, or blocked. Check that the duct diameter matches the hood outlet, that there are no sharp bends, and that the damper moves freely. Vibration noise may mean the hood is not mounted securely — tighten all bolts and check that the mounting bracket is level.