Short answer: Las Vegas restaurant kitchen ventilation must comply with the International Mechanical Code (IMC) as adopted by Clark County, NFPA 96 for grease-laden exhaust, and the Southern Nevada Health District (SNHD) plan review requirements. Type I exhaust hoods over cooking equipment that produces grease or smoke must provide 150-500 CFM per linear foot of hood depending on equipment type and hood style, with UL 300-listed fire suppression, baffle-type grease filters, and code-compliant make-up air. Clark County requires mechanical permits, fire department plan review, and health district approval before any commercial kitchen can operate. Violations result in immediate closure orders — the SNHD does not issue warnings for ventilation deficiencies.
Learn about our commercial HVAC services including kitchen ventilation design and installation.
Why Kitchen Ventilation Is the Most Regulated System in Your Restaurant
If you are opening a restaurant in Las Vegas, remodeling an existing kitchen, or adding cooking equipment to a food service operation, the ventilation system will determine your timeline, your budget, and whether you open on schedule. Kitchen ventilation is not an afterthought — it is typically the single most complex mechanical system in a restaurant, and it touches three separate regulatory agencies in Clark County.
A restaurant that fails ventilation inspection does not open. And in Las Vegas, where the Southern Nevada Health District conducts plan review before construction and field inspection before opening, there is no workaround, no temporary exception, and no grace period. Get the ventilation right from the start, or plan for delays.
This guide covers the specific requirements for Las Vegas and Clark County, including the code editions currently adopted, hood sizing calculations, make-up air design, grease management, fire suppression integration, and the permit sequence that every restaurant operator needs to understand.
Applicable Codes and Regulatory Agencies
Las Vegas restaurant kitchen ventilation is governed by multiple overlapping codes and regulatory bodies. Understanding which agency reviews what — and in what order — prevents the most common project delays.
Clark County Building Department
Clark County enforces the International Mechanical Code (IMC), currently the 2021 edition with local amendments. The building department reviews and permits the mechanical design, including:
- Exhaust hood sizing and CFM calculations
- Ductwork material, gauge, and routing
- Make-up air system design
- Exhaust fan specifications and roof penetrations
- Energy code compliance for ventilation systems
Clark County Fire Prevention Bureau
The fire prevention bureau reviews fire suppression and fire safety aspects under NFPA 96 (Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations). Their review covers:
- UL 300-listed fire suppression system design and coverage
- Clearances between exhaust hoods and combustible materials
- Access for fire suppression system inspection and maintenance
- Grease duct fire-resistance ratings and enclosures
- Ansul or similar system installation compliance
Southern Nevada Health District (SNHD)
The SNHD conducts plan review for all food service establishments. For kitchen ventilation, they review:
- Hood coverage over all cooking equipment
- Adequate ventilation to prevent grease and smoke migration into dining areas
- Dishwasher and warewashing ventilation
- Condensation control
- Pest exclusion at make-up air intakes
Critical sequencing note: The SNHD requires architectural and mechanical plans before they will issue a health permit to operate. Many restaurant operators submit building permit applications before SNHD plan review, then discover the health district requires design changes that force permit revisions. Submit to SNHD first or simultaneously with Clark County.
Type I vs. Type II Exhaust Hoods
The IMC classifies kitchen exhaust hoods into two types based on the cooking equipment underneath.
Type I Hoods (Grease-Laden)
Required over any equipment that produces grease-laden vapors, smoke, or flue gases:
- Charbroilers, grills, and griddles
- Fryers (deep fat and shallow)
- Ranges, woks, and cook tops
- Ovens (convection, pizza, rotisserie, and wood-fired)
- Broilers and salamanders
- Tandoori ovens and solid-fuel cooking equipment
Type I hoods require:
- Listed grease filters (baffle type — mesh filters are not code-compliant for Type I applications)
- UL 300-listed fire suppression system
- Grease-rated ductwork (minimum 16-gauge carbon steel or 18-gauge stainless steel, continuously welded, with a minimum 2% slope to drain)
- Grease drip trays and cups
- Minimum 18-inch clearance from the bottom of the hood to the cooking surface (varies by hood type)
Type II Hoods (Heat and Moisture)
Required over equipment that produces heat, steam, or moisture but not grease:
- Dishwashers (commercial rack type and conveyor type)
- Steam tables and bain-maries
- Pasta cookers and steamers
- Some bakery ovens (when producing only heat and moisture, not grease)
Type II hoods require:
- Condensate-rated ductwork
- No fire suppression required
- Standard filters acceptable (mesh or baffle)
- Lower exhaust rates than Type I hoods
Common mistake: Installing a Type II hood over equipment that produces grease. If a restaurant adds a griddle under a Type II hood, the entire hood, ductwork, and fire suppression system must be upgraded — often at a cost of $15,000-$30,000. Plan for the final menu, not the opening menu.
Hood CFM Calculations: Sizing Exhaust for Las Vegas Kitchens
Exhaust hood airflow requirements depend on hood style, equipment type, and cooking volume. The IMC specifies minimum exhaust rates in CFM per linear foot of hood.
Wall-Mounted Canopy Hoods (Most Common)
Wall-mounted canopy hoods are installed against a wall with the back of the hood sealed to the wall surface.
| Equipment Type | Minimum CFM per Linear Foot |
|---|---|
| Light duty (ovens, steamers) | 200 CFM/ft |
| Medium duty (ranges, griddles <3 ft) | 300 CFM/ft |
| Heavy duty (charbroilers, woks, fryers) | 400 CFM/ft |
| Extra-heavy duty (solid fuel, wood-fired) | 550 CFM/ft |
Island (Center) Canopy Hoods
Island hoods are not against a wall and must capture from all four sides. Airflow requirements increase significantly.
| Equipment Type | Minimum CFM per Linear Foot |
|---|---|
| Light duty | 250 CFM/ft |
| Medium duty | 300 CFM/ft |
| Heavy duty | 500 CFM/ft |
| Extra-heavy duty | 700 CFM/ft |
Proximity (Backshelf) Hoods
Low-profile hoods mounted closer to the cooking surface. These hoods have lower CFM requirements but limited applicability.
| Equipment Type | Minimum CFM per Linear Foot |
|---|---|
| Light duty | 150 CFM/ft |
| Medium duty | 200 CFM/ft |
| Heavy duty | Not recommended |
Example Calculation
A 12-foot wall-mounted canopy hood over a cooking line consisting of a 36-inch charbroiler (heavy duty), a 36-inch griddle (medium duty), and a 6-burner range (medium duty):
The charbroiler determines the duty classification for the overlapping section. Because charbroilers generate the highest grease and smoke load, the entire hood must be rated for heavy-duty exhaust when a charbroiler is present:
- 12 linear feet x 400 CFM/ft = 4,800 CFM minimum exhaust
Las Vegas adjustment: The IMC calculations provide minimums. In Las Vegas, where kitchen temperatures can start at 85-90 degrees F ambient during summer (even with air conditioning), experienced designers typically add 10-15% to calculated exhaust rates to maintain capture velocity at the hood edge. A hood that marginally captures at 72 degrees may spill smoke and grease at 88 degrees because higher ambient temperatures reduce the thermal plume's buoyancy relative to the surrounding air.
Make-Up Air Requirements
This is where most Las Vegas restaurant projects run into problems. Every cubic foot of air exhausted through the hood must be replaced by make-up air — otherwise, the kitchen operates under negative pressure, entrance doors suck inward, back doors do not close, and the hood loses capture effectiveness.
The Balance Equation
- Exhaust air volume (hood CFM + bathroom exhaust + any other exhaust) must be balanced by supply air (make-up air unit + HVAC system supply + transfer air from dining room)
- IMC requires that make-up air provide 80-100% of the exhaust volume
- The balance should create a slight negative pressure in the kitchen relative to the dining room (to prevent cooking odors from migrating into dining areas)
Make-Up Air Unit Types
Direct-fired make-up air units: Gas-fired units that temper outdoor air before delivering it to the kitchen. The most common choice for Las Vegas restaurants because they handle the extreme temperature range — heating outdoor air in winter and tempering 115-degree summer air to a manageable 85-90 degrees. Direct-fired units do not cool the air to comfort levels; they prevent the introduction of extremely hot outdoor air.
Indirect-fired units: Similar to direct-fired but with a heat exchanger that separates combustion gases from the supply air. Required when the make-up air is delivered directly into the hood cavity.
Untempered make-up air: Code allows a percentage of make-up air to be untempered (unconditioned outdoor air). In Las Vegas, untempered make-up air during summer means introducing 110-115 degree air directly into the kitchen. This is code-compliant but creates brutal working conditions. Most restaurants temper at least 80% of make-up air.
The Las Vegas Make-Up Air Challenge
Outdoor design temperature in Las Vegas is 111 degrees F (ASHRAE 0.4% cooling design). A kitchen exhausting 5,000 CFM needs 4,000-5,000 CFM of replacement air. If that replacement air enters at 111 degrees, the kitchen HVAC system must overcome that heat load in addition to cooking equipment heat, body heat, and solar gain through the building envelope.
The practical solution is a combination approach:
- Direct-fired or indirect-fired make-up air unit delivering 60-70% of replacement air, tempered to 85-90 degrees F
- HVAC system supply providing 20-30% as conditioned air
- Transfer air from the dining room providing 10-15% (this also helps maintain slight negative pressure in the kitchen)
Budget impact: A make-up air unit for a 5,000 CFM exhaust system in Las Vegas typically costs $12,000-$25,000 installed, including gas piping, ductwork, roof curb, and electrical. This is often the line item that surprises first-time restaurant operators.
Grease Filtration and Duct Requirements
Grease Filters
Type I hoods must use listed baffle-type grease filters. Key requirements:
- UL 1046 listed
- Removable for cleaning (dishwasher-safe stainless steel baffle filters are standard)
- Installed at a 45-degree angle minimum for proper grease drainage
- No gaps between filters (grease will bypass through any gap)
- Grease drip trough with removable grease cups at each end
Filter cleaning frequency: In a high-volume Las Vegas restaurant, baffle filters should be cleaned nightly in the dishwasher or degreasing sink. Weekly is the absolute minimum for any commercial kitchen. Grease-saturated filters reduce exhaust airflow by 15-30%, degrade capture performance, and create a fire hazard.
Grease Duct Construction
Grease-laden exhaust ductwork must meet specific construction standards:
- Material: 16-gauge carbon steel (black iron) or 18-gauge stainless steel (Type 304 or 316)
- Joints: Continuously welded — mechanical joints, screws, and rivets are prohibited because they create grease leak points
- Slope: Minimum 2% slope back toward the hood for grease drainage (duct running 20 feet horizontally must drop at least 5 inches)
- Cleanout access: Access panels every 12 feet on horizontal runs and at every change of direction
- Clearance: Minimum 18-inch clearance to combustible materials, unless enclosed in a rated shaft
- Enclosure: Grease ducts passing through occupied spaces must be enclosed in a 1-hour fire-rated shaft (2-hour if the duct passes through a fire-resistance-rated assembly)
Rooftop Exhaust Fan
The exhaust fan for a Type I hood system must be:
- Located on the roof (upblast type is most common in Las Vegas)
- Hinged for access to the duct interior for cleaning
- Equipped with a grease drain and grease containment cup
- Capable of withstanding 700 degrees F for 15 minutes (fire-rated)
- Properly curbed and sealed to prevent roof leaks
- Minimum 40 inches above the roof surface (check Clark County amendments)
Las Vegas rooftop consideration: Exhaust fans on Las Vegas rooftops are exposed to extreme UV radiation and temperatures exceeding 150 degrees F on the roof surface during summer. Specify UV-resistant fan housings and belt materials rated for high-ambient-temperature operation. Standard belts can stretch and slip in extreme heat, reducing exhaust volume when it is needed most.
Fire Suppression Integration
NFPA 96 requires automatic fire suppression in all Type I exhaust hood systems. The most common system is a wet chemical system (typically UL 300-listed systems marketed as Ansul R-102, Kidde, or Amerex).
System Coverage Requirements
- Every cooking appliance under the hood must have nozzle coverage
- Duct nozzles at the entrance to the grease duct
- Plenum nozzles within the hood plenum
- Fuel shutoff: the fire suppression system must automatically shut off gas supply to all cooking equipment under the hood upon activation
- Electrical shutoff: the system must automatically shut off electrical power to cooking equipment and the exhaust fan upon activation
Inspection and Maintenance
- Semi-annual inspection by a licensed fire protection contractor (Clark County Fire Prevention Bureau requirement)
- Annual system service including nozzle inspection, agent level check, and functional test
- After any activation: Complete system recharge, inspection, and re-certification before resuming cooking operations
Cost context: A fire suppression system for a typical restaurant kitchen (10-14 foot hood with 4-6 appliances) costs $3,000-$6,000 installed. Semi-annual inspections cost $200-400 each. These costs are non-negotiable — operating without a current inspection certificate is a closure violation.
The Permit and Approval Sequence
For a new restaurant or major kitchen remodel in Las Vegas, the approval sequence typically proceeds as follows. Allow 8-16 weeks for the entire process.
Step 1: Design Phase (2-4 Weeks)
Engage a mechanical engineer or an experienced commercial kitchen designer to produce:
- Kitchen equipment layout with hood sizing calculations
- Exhaust and make-up air CFM calculations
- Mechanical plans showing ductwork routing, fan locations, and make-up air unit placement
- Fire suppression system layout (usually prepared by the fire suppression contractor)
- Energy code compliance documentation
Step 2: Simultaneous Submittals (4-8 Weeks Review)
Submit plans to all three agencies at the same time to run reviews in parallel:
- Clark County Building Department: Mechanical permit application with full mechanical plans
- Clark County Fire Prevention Bureau: Fire suppression plans and hood/duct layout
- SNHD: Full architectural and mechanical plans as part of the food establishment plan review
Each agency may issue comments or correction requests. Expect at least one round of revisions.
Step 3: Construction and Installation
Once permits are issued:
- Install ductwork and hood (mechanical contractor)
- Install fire suppression system (fire protection contractor)
- Install make-up air unit and connect to controls
- Install HVAC system if new or modified
- Coordinate gas piping and electrical connections
Step 4: Inspections and Final Approval
- Clark County mechanical rough-in inspection (before concealing ductwork)
- Clark County final mechanical inspection
- Fire department inspection of fire suppression system
- SNHD pre-opening inspection
All three agencies must sign off before you can operate the kitchen. Missing any one inspection holds up your opening.
Common Violations and How to Avoid Them
Based on the most frequent violations cited by Clark County and SNHD in restaurant inspections:
- Insufficient hood coverage. The hood must extend at least 6 inches beyond the cooking equipment on all open sides. Equipment placed partially outside the hood coverage area is a violation.
- Missing or non-functional make-up air. Exhaust without adequate make-up air is both a code violation and a performance problem.
- Expired fire suppression inspection. Semi-annual inspections must be current. Expired tags result in immediate correction orders.
- Grease filter gaps. Any gap between baffle filters allows grease-laden air to bypass filtration. This is both a fire hazard and a code violation.
- Blocked cleanout access. Storing equipment or supplies in front of duct cleanout panels prevents required maintenance access.
- Improper grease duct material. Flex duct, PVC, or standard galvanized ductwork is never acceptable for Type I grease exhaust.
- Modified cooking equipment without hood update. Adding a charbroiler under a hood designed for a steamer requires a complete hood redesign for the higher exhaust rate and duty classification.
The Cooling Company: Commercial Kitchen HVAC and Ventilation
The Cooling Company works with restaurant owners, general contractors, and kitchen designers on commercial kitchen HVAC and ventilation projects across the Las Vegas Valley. We handle make-up air unit installation, kitchen HVAC systems, and coordination with hood and fire suppression contractors to ensure the entire system works as a unit.
We understand Las Vegas code requirements, the Clark County permit process, and the practical realities of keeping a commercial kitchen at workable temperatures when it is 115 degrees outside. Call (702) 567-0707 to discuss your restaurant project.
Frequently Asked Questions
How much does a commercial kitchen ventilation system cost in Las Vegas?
A complete commercial kitchen ventilation system in Las Vegas — including exhaust hood, grease ductwork, rooftop exhaust fan, make-up air unit, fire suppression, and installation — typically costs $35,000-$80,000 for a standard restaurant kitchen. The make-up air unit alone is $12,000-$25,000 installed. Fire suppression adds $3,000-$6,000. The wide range depends on hood length, equipment duty classification, ductwork routing complexity, and whether the building has existing infrastructure from a previous restaurant tenant.
Can I open a restaurant in Las Vegas without a Type I exhaust hood?
Only if your menu uses exclusively equipment that does not produce grease-laden vapors — such as microwave-only, cold prep, or steam-only operations. Any cooking that generates grease, smoke, or flue gases requires a Type I hood with fire suppression. Some food concepts (juice bars, sandwich shops with no cooking, salad-focused restaurants) can operate with Type II hoods or no hood at all. The SNHD plan review will determine whether your specific menu and equipment require Type I ventilation.
How often must restaurant grease duct cleaning be performed in Las Vegas?
NFPA 96 requires grease duct cleaning frequency based on cooking volume: monthly for high-volume operations like 24-hour restaurants and charbroiler-heavy kitchens, quarterly for moderate-volume restaurants, semi-annually for low-volume operations, and annually for seasonal or limited-use kitchens. Clark County Fire Prevention enforces this schedule. A licensed hood cleaning contractor must provide a certificate of inspection after each cleaning. Many Las Vegas restaurants that operate long hours with heavy grease cooking need monthly cleaning to remain compliant.
What happens if my restaurant fails a ventilation inspection in Las Vegas?
The consequences depend on which agency identifies the violation. The Southern Nevada Health District can issue immediate closure orders for ventilation deficiencies that affect food safety or air quality — they do not issue warnings for ventilation issues. Clark County Building can issue stop-work orders during construction or correction notices for operating businesses. The Fire Prevention Bureau can shut down cooking operations for fire suppression deficiencies. In all cases, the kitchen cannot operate until the violation is corrected and re-inspected, which can take days to weeks depending on the nature of the repair.
Do I need a make-up air unit for my restaurant in Las Vegas?
Almost certainly yes. Any kitchen exhaust system removing more than a few hundred CFM needs replacement air. Without a make-up air unit, the kitchen operates under severe negative pressure — doors are difficult to open, the hood loses capture effectiveness, and the HVAC system cannot maintain temperatures. In Las Vegas, a make-up air unit is especially critical because untempered outdoor air at 110-115 degrees creates dangerous working conditions. Code requires that make-up air provide 80-100% of the exhaust volume, and practical kitchen operation in Las Vegas demands tempered make-up air.
Neighborhoods We Serve for Commercial Kitchen HVAC
We work with restaurants and food service businesses across Downtown Las Vegas, Summerlin, Spring Valley, Enterprise, Paradise, Henderson, North Las Vegas, Centennial Hills, Silverado Ranch, Green Valley, and the Las Vegas Strip corridor.
Why Restaurant Owners Trust The Cooling Company
- Serving Las Vegas since 2011
- 55+ years combined experience
- Licensed, EPA-certified technicians
- 100% satisfaction guarantee
- BBB A+ rated
- Lennox Premier Dealer
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Related reading: See our complete commercial HVAC guide for system types and costs. Learn about commercial HVAC maintenance to keep your restaurant systems running efficiently.
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Call (702) 567-0707 or visit commercial HVAC services, commercial installation, or commercial repair for details.