A restaurant owner called me last August, three weeks before his soft open, panicking. His kitchen hood had failed the fire marshal's inspection twice. The Ansul nozzles weren't aimed right. The duct ran past a wood-framed soffit with less than 18 inches of clearance. No access panel within the required spacing on the horizontal run. His mechanical contractor had taken the deposit and gone quiet. The owner was facing a month of delay, $4,800 in rent on an empty building, and missing the Labor Day weekend he had built his entire marketing push around.
I've done about 30 restaurant fit-outs over the years. Roughly a third included hood work. The pattern is always the same — owners and even experienced GCs underestimate the commercial kitchen hood installation cost, underestimate the inspection rigor, and pick the wrong subcontractor. This is what I've learned about getting these jobs right the first time.
Type I vs Type II — Get This Wrong and Nothing Else Matters
Before you talk dollars, you have to know which hood you actually need. Inspectors don't negotiate on this.
Type I hoods handle grease-laden vapor. Anything with an open flame, a fryer, a flat-top grill, a charbroiler, a wok station, a salamander, a pizza oven with direct flame — that's Type I. The hood, the ductwork, and the fan have to be UL 710 listed, the duct has to be welded liquid-tight 16-gauge minimum, and the whole system needs a UL 300 wet chemical fire suppression system (Ansul R-102 is the most common). NFPA 96 governs this top to bottom.
Type II hoods handle steam, heat, and odor. Dishwashers, steam tables, pasta boilers, some convection ovens, coffee roasters. No grease, so no Ansul required and the duct can be galvanized. Type II hoods are about half the cost of Type I — sometimes less.
Where I see the mistake: a chef adds a small flat-top to what was supposed to be a Type II zone. Or the layout shifts during construction and a fryer ends up under a Type II canopy. The fire marshal walks in, looks at the equipment, and tells you the entire hood has to be re-listed as Type I — meaning a new hood, new duct, new suppression. I've watched this cost an owner $40,000 because the kitchen layout drifted two feet during framing.
Lock the equipment schedule before the hood is ordered. In writing. Signed by the chef, the owner, the kitchen designer, and you. Then build to it.
Real-World Commercial Kitchen Hood Installation Cost Ranges
Here's what I've actually seen these jobs run in the last three years, in real money on real jobs. Pricing varies by region — coastal markets and union jurisdictions run 25-40% higher than the numbers below.
Small Type II hood (4-6 feet, single canopy over a dishwasher or steam table): $6,000 to $12,000 installed. That includes the hood, a short straight-up duct, a small inline fan, and electrical. No suppression needed. This is the simplest version of the work.
Mid-size Type I hood with makeup air (8-12 feet, single canopy over a 6-burner range and fryer): $18,000 to $35,000. Now you have a UL 710 hood, welded 16-gauge duct, an upblast roof fan, a tempered makeup air unit to replace the exhausted air, an Ansul R-102 system with the nozzles aimed and listed, gas shut-off solenoids tied to the suppression, and the electrical interlocks. This is the most common scope for a small independent restaurant.
Full island hood plus Ansul plus ducting through 3 floors of a mixed-use building: $55,000 to $95,000 and sometimes more. Shaft-building through occupied space, permits on multiple floors, access panels every 12 feet, a 2-hour grease duct enclosure, and a 5-ton tempered makeup air unit on the roof. I bid one in 2024 for a downtown gastropub on the ground floor of a 4-story building. Hood and Ansul: $42,000. Shaft, panels, fire dampers, roof penetration: $38,000. Makeup air: $22,000. Total $102,000 before the gas line upgrade.
I always tell owners: if you're spending less than $20,000 on hood work for a Type I scope, somebody is cutting corners that will get flagged. Use a tool like the construction cost estimator to build the line item realistically into your buildout budget from day one — don't let it be the surprise at month three.
The NFPA 96 Mistakes That Get Flagged Every Time
This is the part most GCs miss. NFPA 96 is the code that governs commercial cooking ventilation, and inspectors know it cold. The same five or six failures show up over and over. Here's what gets flagged:
Duct clearance to combustibles
NFPA 96 requires 18 inches of clearance from grease duct to combustible construction, unless you wrap the duct in a listed enclosure (3M Fire Barrier Duct Wrap is the most common — usually two layers, 1.5 inches each). I've watched countless installs where the mechanical guy ran duct two inches from a wood stud wall and called it done. Inspectors don't miss this. Either you build a non-combustible chase or you wrap the duct with a listed product. There is no third option.
Access panel spacing
You need an access panel within 3 feet of any change in direction and at intervals no greater than 12 feet on horizontal runs. Panels have to be the same gauge as the duct, gasketed, and labeled. I once inherited a job where the previous contractor put panels every 20 feet. Failed. We cut 6 new openings and re-pressure-tested. Two extra weeks on the schedule.
Drain pan slope and grease cup placement
Hood plenums drain to a grease cup that has to be accessible and removable without tools. I see installs where the cup is wedged behind a ceiling tile. Fail.
Ansul nozzle aim
This fails more commercial kitchen hood installation jobs than any other code item. Every appliance under the hood needs Ansul nozzles aimed at it per the UL 300 listing for that specific appliance. A 6-burner range gets a different nozzle pattern than a flat-top. If the chef swaps a 36-inch flat-top for a 48-inch after the Ansul tech has been there, the system isn't UL 300 compliant. The tech has to come back, re-position, re-test, re-tag. Lock the equipment.
Fire damper and shaft penetration details
When grease duct passes through a fire-rated assembly, you can't use a standard fire damper — they're not allowed in grease duct. You need a grease duct enclosure of the right rating, properly firestopped at every penetration with a UL-listed system, photo-documented before it gets covered. Cover it without photos and inspectors will make you cut it back open. Done it. Hated it.
Makeup air balance
Type I hoods exhaust 200-400 CFM per linear foot. Throw that out without replacing it and you depressurize the kitchen, pull combustion air backward through gas appliances, and create a CO hazard. Your makeup air has to replace at least 80% of the exhaust volume (some jurisdictions require 100%). I've seen kitchens so negative the front door wouldn't close.
Sequencing the Work So You Don't Pay Twice
A restaurant fit-out has maybe 15 trades on site. The hood install touches almost all of them. Here's the sequence I run:
- Lock the equipment schedule. Chef, owner, kitchen designer, hood contractor, GC all sign off before anything gets ordered.
- Hood contractor does a site survey with shop drawings showing hood, duct path, roof penetration, makeup air location, gas line route, and electrical interlocks. Submit to the AHJ for permit.
- Rough framing accommodates the duct chase before drywall. Build the chase oversized — duct wrap is bulkier than the duct itself.
- Hood and duct rough-in before drywall. Pressure-test the duct with a halogen light leak test while it's exposed.
- Ansul rough-in with cylinders, nozzle network, gas solenoid, and pull stations. Don't pressurize yet.
- Drywall, ceiling, and finishes around the hood. Access panels installed flush.
- Equipment delivery and final placement, then Ansul final aim and pressurization with actual equipment in place. Ansul tech tags the system.
- Pre-occupancy inspection with the fire marshal. Bring everything — UL 710 listing, UL 300 listing, duct pressure test report, firestop photos, makeup air balance report.
Restaurant fit-outs are one of the highest-margin commercial scopes a small GC can take on, and the restaurant build-out market is one of the most underrated specialties for crews that want repeat work. For benchmark numbers on the full buildout, the restaurant construction cost data showing $380/sf averages gives you a sanity check on where the hood line should fall.
What to Look for in a Hood Subcontractor
Not every mechanical contractor does hood work, and not every hood contractor does it well. My checklist:
- UL 710 and UL 300 certified — both the company and the techs on your job
- Current Ansul or Amerex certification for the suppression brand they're installing
- A portfolio of NFPA 96 jobs in your jurisdiction in the last 12 months
- Shop drawings signed and sealed if your jurisdiction requires it
- They handle the permit and inspection coordination themselves
- Duct pressure test and balance report included in the bid
- Written guarantee of inspection pass on the first walk-through, or they come back at no charge
The cheapest bid on hood work is almost always the most expensive bid by the time the job is done. I'd rather pay $4,000 more upfront for a contractor I know will pass first time than spend three weeks chasing punch items with a low-bid guy.
Frequently Asked Questions
What is the average commercial kitchen hood installation cost?
A simple Type II hood runs $6,000-$12,000 installed. A typical Type I hood with makeup air for a small restaurant runs $18,000-$35,000. Larger installs with island hoods, multi-floor duct runs, or rooftop makeup air units can run $55,000-$95,000 or more. Regional pricing, union labor, and code complexity push these numbers higher on the coasts and in major metros.
Do I need an Ansul system on every hood?
Only Type I hoods (over grease-producing equipment) require a UL 300 wet chemical suppression system like Ansul R-102 or Amerex KP. Type II hoods (over steam, heat, or odor sources without grease) don't require fire suppression. The line is whether the appliance produces grease-laden vapor — fryers, grills, charbroilers, and woks always require Type I. Dishwashers and steam tables are Type II.
How long does a commercial hood install take?
For a typical Type I scope in a new restaurant, the hood and duct rough-in is 3-5 days, Ansul rough-in is 2 days, makeup air is 2-3 days, and final commissioning is 1-2 days. Real-world calendar time from order to inspection is usually 6-10 weeks because of equipment lead times (hoods are often 4-8 week lead, makeup air units 6-12 weeks) and inspection scheduling. Start the hood permit application the day you sign the buildout contract.
What's the most common NFPA 96 inspection failure?
In my experience, Ansul nozzle aim is the most common failure — usually because equipment changed after the suppression was installed. Duct clearance to combustibles is a close second. Access panel spacing on long horizontal runs and firestop documentation at floor penetrations round out the top failures. All of these are preventable if the hood contractor knows the code and the GC sequences the work correctly.
Does a hood contractor handle the makeup air unit?
Most full-service hood contractors design and install the makeup air as part of their scope because it has to be balanced against the exhaust. Some HVAC contractors handle the makeup air separately. Either approach works, but the two scopes have to be coordinated — the hood and the makeup air are a single system from a code and a comfort standpoint. If you split them, make sure one party owns the balance report.
Can a hood pass inspection without a fire damper in the grease duct?
Yes — and in fact, fire dampers are prohibited in grease ducts under NFPA 96. Grease duct penetrations through fire-rated assemblies are handled with a listed grease duct enclosure (typically a UL-rated wrap or a shaft with the correct hourly rating), not with a damper. Inspectors flag this if your mechanical contractor specs the wrong protection.
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