Kitchen Hood and Grease Duct Upgrades for Houston Restaurants
The kitchen exhaust system is the heart of a commercial kitchen. When a restaurant changes its menu, adds a fryer or charbroiler, takes over a second-generation space or fails an inspection, the hood and grease duct are often the first things that need work.
These projects are more involved than they look from the dining room. They touch the roof, walls, fire protection, electrical, mechanical systems and the health department. This guide walks restaurant owners and landlords through the planning steps. It is general information; your mechanical engineer, hood contractor and general contractor will confirm what applies.
When hood work comes up
- New tenant in a former restaurant space: The existing hood may not fit the new cooking line.
- Menu or equipment changes: Adding heavier cooking equipment can change what the hood must handle.
- Failed inspection: A fire inspection or insurance review may flag the hood, duct or suppression system.
- Grease buildup or leaks: Long-term grease problems can damage the duct, roof and walls.
- Comfort problems: A kitchen that is too hot or a dining room with doors that are hard to open can signal a makeup air problem.
Our guide to second-generation space explains how to evaluate what an existing restaurant space can reuse.
The standard behind the system
Commercial cooking ventilation and fire protection are generally designed, installed and maintained under NFPA 96, the Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations. It covers hoods, grease ducts, clearances to combustibles, exhaust fans and cleaning. Your mechanical designer applies it along with the local building and mechanical codes.
The parts of the system
- Hood: Sized to the cooking line below it.
- Grease duct: A welded, liquid-tight duct from the hood to the exhaust fan, with access for cleaning.
- Enclosure: Where the duct runs through the building, it is typically enclosed with fire-rated construction or a listed wrap.
- Exhaust fan: Usually on the roof, with a curb and a grease containment system.
- Makeup air: Replaces the air the hood pulls out so the kitchen works properly.
- Fire suppression: A system over the cooking appliances, tied to fuel shutoff and the fire alarm where required.
Plan the roof work
Most grease ducts go up through the roof. Plan for:
- A new roof penetration or reuse of an existing one
- A properly built curb and flashing tied into the roof system
- Grease containment so grease does not damage the roof membrane
- Coordination with the roof warranty holder if the roof is under warranty
In the City of Houston, commercial roofing work has its own permit page, and our guide to flat roof options for Houston commercial buildings explains common low-slope roof systems.
Permits and reviews
A hood project usually involves several reviews:
- Building and mechanical: Through the City's commercial permit process for commercial remodels.
- Fire protection: Hood suppression and alarm tie-ins are reviewed through the Fire Marshal's Office.
- Health: Food establishments in the City work with the Houston Health Department, which reviews plans and permits food service operations.
Our restaurant buildout checklist covers how these reviews fit into a full restaurant project.
Electrical and gas
New exhaust and makeup air fans need power and controls, and the suppression system usually ties into gas or electrical shutoff for the cooking line. Electrical work is generally governed by NFPA 70, the National Electrical Code. Coordinate with the gas utility or plumber if the gas line or meter needs changes.
Landlord and tenant roles
In leased spaces, the lease or work letter should say who owns the hood, who pays for roof work and who maintains the system. Our guide to landlord work vs. tenant work letters explains how those responsibilities are usually spelled out.
Downtime
For an operating restaurant, downtime is the biggest cost. Ways to reduce it:
- Fabricate the duct and hood ahead of time.
- Do roof work and curb installation before the kitchen shuts down.
- Schedule the swap during the slowest days.
- Book inspections in advance so the kitchen can reopen as soon as possible.
Cleaning and maintenance
After the work is done, plan for regular hood and duct cleaning and suppression system service, and keep records ready for inspections and insurance.
Questions to ask your designer and contractor
Before you approve a hood project, ask for clear answers on the items that most often cause delays or change orders:
- Can the existing duct route and roof penetration be reused, or does the duct need a new path?
- Does the duct enclosure need new fire-rated construction, and who builds it?
- Is the makeup air unit included, and will it be heated or tempered?
- Who furnishes and installs the fire suppression system, and who ties it into gas shutoff and the alarm?
- What roof work is included, and who coordinates with the roof warranty holder?
- What inspections are needed before the kitchen can reopen, and who schedules them?
- What cleanup, patching and ceiling repair are included in the kitchen and dining room?
Second-generation hood checks
If you are taking over a space with an existing hood, have it evaluated before you sign the lease or finalize the budget. Ask for the hood's listing and labels, the condition of the duct and its access panels, the fan and curb condition, the suppression system service records and whether the system matches your planned cooking line. A hood that looks fine from the kitchen can still need a new duct enclosure, fan or makeup air unit to work with different equipment.
Quick checklist
- Confirm the cooking line and equipment
- Have a mechanical designer size the hood, duct and makeup air
- Plan roof penetration, curb and grease containment
- Coordinate fire suppression and alarm tie-ins
- Line up building, fire and health reviews
- Confirm electrical and gas changes
- Clarify landlord and tenant responsibilities
- Plan the shutdown and inspection dates
- Set up cleaning and service
Planning a kitchen hood replacement or restaurant buildout? BPC Development LLC provides free on-site estimates in Houston, TX. Call (281) 301-4737.