How Long Does It Take to Install a Range Hood Duct?

Quick Answer

Installing a range hood duct takes 3–6 hours for a typical residential installation with a direct path through an exterior wall or up through the roof. Complex installations involving long duct runs, multiple elbows, or routing through finished ceilings can take 8–12 hours or more. If you are also installing the range hood itself, add 1–2 hours to the total.

Time Estimates by Installation Type

Installation Scenario	Time	Difficulty
Through exterior wall (first floor)	3–4 hours	Moderate
Through roof (single story)	4–6 hours	Moderate–Hard
Through roof (two story, from first floor)	6–10 hours	Hard
Island range hood (ceiling duct)	6–12 hours	Hard
Replacing existing ductwork	2–4 hours	Moderate
Professional installation	3–5 hours	N/A

Tools and Materials Needed

Tools

• Reciprocating saw or jigsaw
• Drill with hole saw (4" or 6")
• Tin snips for cutting duct
• Foil HVAC tape (not standard duct tape)
• Caulk and caulk gun
• Stud finder
• Level
• Safety glasses and dust mask

Materials

• Rigid or semi-rigid duct (6" diameter is standard for most range hoods)
• Wall or roof cap with damper
• Elbows (90-degree and 45-degree as needed)
• Foil HVAC tape and/or clamps
• Fire-rated sealant (if penetrating a fire-rated assembly)
• Duct transitions if range hood outlet size differs from duct size

Step-by-Step Installation

Step 1: Plan the Duct Route (30–60 minutes)

This is the most important step. The shortest, straightest path to the exterior wins. Every 90-degree elbow adds the equivalent of 5–8 feet of straight duct in terms of airflow resistance. Aim for a total equivalent duct length under 30 feet.

Check for obstructions: framing members, electrical wiring, plumbing pipes, gas lines, and HVAC ducts. Use a stud finder and, if available, an inspection camera to verify the path is clear.

Step 2: Cut the Exterior Penetration (30–60 minutes)

For a wall exit, drill a pilot hole from inside to outside, then cut the hole from outside using a reciprocating saw or hole saw. For roof penetrations, work from the attic side. The hole should be slightly larger than the duct diameter.

This step takes longer for masonry, brick, or stucco walls, which may require a masonry blade or core drill.

Step 3: Install the Wall/Roof Cap (20–30 minutes)

The exterior cap includes a built-in damper that prevents backdrafts. Apply exterior-grade caulk around the flange before securing with screws. For roof installations, slide the cap flashing under the shingles above and over the shingles below to prevent leaks.

Step 4: Run the Ductwork (1–3 hours)

Assemble duct sections working from the range hood outward to the exterior cap. Key guidelines:

• Use rigid metal duct whenever possible. It provides the best airflow and meets code in most jurisdictions.
• Semi-rigid aluminum duct is acceptable for short runs but should not be used for runs longer than 8 feet.
• Flexible vinyl duct is prohibited by most building codes for range hoods due to fire risk and should never be used.
• Orient seams up to prevent grease from leaking at joints.
• Seal every joint with foil HVAC tape. Standard cloth duct tape fails over time from heat and grease.

Step 5: Connect to the Range Hood (30–45 minutes)

Attach the duct to the range hood outlet using a duct connector or transition piece. Secure with foil tape and a hose clamp. If the hood outlet is round and the duct is rectangular (or vice versa), use an appropriate transition fitting.

Step 6: Test and Seal (15–30 minutes)

Turn on the range hood at maximum speed. Check all joints for air leaks by holding a tissue near each connection — it should be pulled toward the duct, not blown away. Verify the exterior damper opens and closes freely. Seal any gaps around the wall or ceiling penetration with fire-rated caulk.

Common Mistakes to Avoid

• Using flexible vinyl duct: This is a fire hazard and violates building code
• Too many elbows: Each 90-degree turn reduces efficiency by 25–30%
• Terminating in an attic or crawl space: The duct must exhaust to the building exterior to prevent moisture and grease buildup
• Undersizing the duct: Match the duct diameter to the range hood outlet. Never reduce the duct size below the hood specification.
• Using screws on interior duct joints: Sheet metal screws catch grease and create turbulence. Use foil tape and clamps instead.

When to Hire a Professional

Consider hiring a professional if:

• The duct must pass through a fire-rated wall or floor assembly
• You have a two-story home and the range hood is on the first floor
• The installation involves masonry or brick penetration
• Local code requires a permit and inspection (common for kitchen ventilation work)
• The range hood requires a dedicated electrical circuit

Professional installation typically costs $300–$800 for the ductwork alone, not including the range hood.