Kitchen Exhaust Ductwork Cost: Budgeting for New and Replacement Runs

Duct Material Choices and Their Price Differences

The type of duct material is the first major cost driver. Rigid metal duct, typically galvanized steel or aluminum, is the standard for kitchen exhaust because it is smooth, durable, and resists grease buildup. For a typical 6-inch round run, expect to pay $2 to $4 per linear foot for the duct itself. Flexible aluminum duct, while easier to install, costs a bit more per foot and is not always permitted by local codes for kitchen exhaust due to its corrugated interior, which can trap grease.

Stainless steel duct sits at the top of the price range, often $8 to $12 per linear foot. It is used in commercial-style kitchens or when the duct is exposed as a design feature. For a typical residential run of 15 to 25 feet, the material cost alone might range from $50 to $300, depending on the metal you choose. The duct size also matters: a 6-inch duct is common for up to 600 CFM range hoods, but higher-capacity hoods require 8- or 10-inch duct, which costs 20% to 40% more per foot.

Do not overlook the small fittings. Elbows, transition pieces, and roof or wall caps add $10 to $50 each. A single 90-degree elbow can cost $15 to $25, and you may need two or three for a complex route. When you add these to the straight sections, the material budget for a typical new run often lands between $150 and $400, before any labor charges.

Labor Costs: What Ductwork Installation Typically Runs

Labor is often the larger half of the total ductwork bill. A professional HVAC contractor or duct installer typically charges $45 to $90 per hour, depending on your region and the complexity of the job. For a straightforward replacement that follows an existing path, you might pay for 2 to 4 hours of labor, or $100 to $350. A new run that requires cutting through cabinets, ceiling joists, or exterior walls can take 4 to 8 hours, pushing labor to $400 to $700 or more.

Some contractors quote a flat fee for ductwork rather than an hourly rate. These quotes often start around $500 for a simple, short replacement and climb to $1,500 or more for a long, complex new installation. The biggest labor drivers are accessibility and the number of stories. A duct that runs straight up through a single-story ceiling and exits through the roof is the least expensive to install. A run that has to snake through a second floor or exit through a side wall with multiple turns will cost noticeably more.

When comparing quotes, ask exactly what is included. A low hourly rate might not cover drywall repair, patching the roof, or disposing of the old ductwork. These ancillary tasks can add $100 to $300 to the final invoice if you need the crew to handle them. Getting three written estimates is a good practice, but make sure each one specifies the same scope of work so you are comparing like for like.

Comparing New Duct Runs vs. Replacing Existing Ductwork

Replacing old ductwork is almost always cheaper than running a brand-new line. The reason is simple: the path already exists. The installer does not have to cut new openings through framing or negotiate obstacles from scratch. For a replacement, you are mainly paying for the material (new rigid duct) and the labor to disconnect the old pieces, fit the new ones, and seal the joints. Expect a replacement to cost 30% to 50% less than an equivalent new run, often landing between $400 and $800 total.

A new run, by contrast, involves creating a path where none exists. That means cutting holes through drywall, possibly notching studs or joists, and installing a new exterior vent cap. The extra material and labor can easily double the price. For a typical 20-foot new run through a finished ceiling, you might pay $800 to $1,200. If the path goes through an unconditioned attic, you will also need to insulate the duct, which adds $1 to $2 per linear foot for insulation wrap.

There is a middle ground: reusing the existing exterior vent location but replacing the internal sections. This is common when a homeowner upgrades from a recirculating hood (which has no duct) to a vented one. In that case, you are effectively installing a new run, but the wall or roof penetration may already exist if there was once an old vent. Confirm this with your contractor, as it can save you several hundred dollars in cutting and patching labor.

Hidden Factors That Move the Final Price

Several less obvious variables can swing your ductwork budget by a few hundred dollars. The distance between the range hood and the exterior wall or roof is the most significant. A short, straight run of 10 feet is cheaper than a 30-foot run that requires a booster fan to maintain airflow. If the run is unusually long or has many turns, the contractor may need to increase the duct diameter to keep static pressure low, which raises material costs.

The type of roof or wall you have also matters. Metal roofs are harder to cut and require special flashing, adding $50 to $150 to the job. Masonry walls (brick or block) need a core drill, which costs more than a standard hole saw and can add an hour of labor. If you have a conditioned attic, you will need to seal and insulate the duct to prevent condensation and heat loss, which adds a bit to both material and labor.

Local building permits are another cost that is easy to overlook. Many municipalities require a permit for new ductwork, especially if it involves cutting into the building envelope. Permit fees range from $50 to $250. While a permit adds to your upfront cost, it also means the work will be inspected for safety and code compliance, which can prevent expensive problems down the line. Always ask your contractor if the quote includes permit fees or if they are separate.

How to Budget Accurately for Your Specific Kitchen

Start by measuring the straight-line distance from the top of your range hood to the nearest exterior wall or roof, then add 20% to account for bends and fittings. This gives you a rough linear footage estimate. Multiply that by the per-foot material cost for the duct type you prefer, and add $50 to $100 for fittings. This material estimate is usually between $150 and $400 for most homes.

For labor, call two or three local ductwork specialists and ask for a flat-rate quote for the exact job. Give them the same details for each call: the duct size, the route, the number of stories, and whether you have drywall or plaster walls. This way, the quotes are directly comparable. As a rule of thumb, budget $500 to $1,200 for a typical replacement, and $800 to $1,800 for a new run, including parts and labor.

Set aside an extra 10% to 15% as a contingency for surprises. Old houses often hide wiring or plumbing inside walls that only become apparent once the drywall is open. If you are doing the work as part of a larger kitchen remodel, it is wise to have this buffer available so a ductwork surprise does not stall the whole project. With a realistic range in mind, you can make an informed decision about whether to repair, replace, or reconfigure your exhaust ducting.