Commercial Kitchen Ventilation and Hood Systems in Ontario

The kitchen exhaust and ventilation system is the single most expensive and complex component of a restaurant renovation. It is also the most regulated. Getting it wrong delays your opening, fails inspection, and can cost tens of thousands of dollars to fix. This guide covers what you need to know before starting a restaurant build-out in Ontario.

Types of Commercial Kitchen Hoods

Type I Hood (Grease Hood)

Required over any cooking equipment that produces grease-laden vapours: fryers, grills, charbroilers, woks, and solid-fuel cooking equipment. Type I hoods have grease filters, a fire suppression system, and exhaust ductwork that terminates through the roof.

Type I hoods are the most expensive to install because they require:

• Listed and labelled hood, filters, and ductwork
• ULC-listed fire suppression system (wet chemical)
• Dedicated exhaust fan on the roof
• Make-up air system to replace the exhausted air
• Grease duct that is welded and wrapped to fire-rated specifications

Budget $25,000-60,000 for a Type I hood system in a typical restaurant, depending on the hood length and rooftop access.

Type II Hood (Condensate Hood)

Required over equipment that produces steam, heat, or odour but not grease: dishwashers, steam tables, ovens (non-grease-producing), and pizza ovens. Type II hoods are simpler and less expensive because they do not require grease filters or fire suppression.

Budget $8,000-20,000 for a Type II hood system.

Make-Up Air

Every cubic foot of air exhausted through a kitchen hood must be replaced with conditioned make-up air. Without adequate make-up air, the kitchen operates under negative pressure, which causes:

• Doors that are difficult to open (suction effect)
• Cold drafts in winter as unconditioned air is pulled through any available opening
• Poor hood capture (the hood cannot contain grease vapours if the building pressure is wrong)
• Increased energy costs

Make-up air systems can be integrated into the hood (direct-fired make-up air units) or provided as a separate HVAC system. Either way, the make-up air volume must match the exhaust volume. This is a code requirement, not optional.

Grease Interceptors

Ontario municipalities require grease interceptors on the sanitary drain serving any commercial kitchen. A grease interceptor prevents fats, oils, and grease from entering the municipal sewer system.

There are two types:

• Passive grease interceptors (grease traps): Small units installed under or near sinks. Suitable for low-volume kitchens and some fast-casual restaurants.
• Gravity grease interceptors: Large in-ground or below-slab units sized based on the kitchen's flow rate. Required for full-service restaurants.

The sizing and type depend on the municipality and the kitchen's projected flow. Toronto, Mississauga, and Brampton each have specific bylaws governing grease interceptor requirements.

Budget $3,000-8,000 for a passive interceptor installation and $8,000-25,000 for a gravity interceptor (including excavation and concrete work if below-slab).

Exhaust Duct Routing

The grease exhaust duct from a Type I hood must run to the roof and terminate at a listed exhaust fan. The duct must be:

• Welded 16-gauge or 18-gauge steel (no screwed joints)
• Wrapped in a fire-rated enclosure where it passes through occupied spaces
• Sloped to drain back to the hood (to prevent grease accumulation)
• Accessible for cleaning at required intervals

Duct routing is one of the most challenging aspects of a restaurant renovation, especially in multi-tenant buildings. The duct needs a clear path to the roof, and the landlord must approve the roof penetration and fan location. In some buildings, the available duct route adds significant cost because of the distance or the number of fire-rated enclosures required.

Permit and Health Department Requirements

A restaurant build-out with a commercial kitchen requires:

1. Building permit from the municipality (covers structural, mechanical, electrical, plumbing)
2. Health department review (Toronto Public Health or the applicable regional health unit)
3. Fire department review (fire suppression system in the hood)
4. TSSA registration if gas-fired equipment is involved (Technical Standards and Safety Authority)

The health department review covers the kitchen layout, handwashing stations, food storage, washroom facilities, and ventilation. This review runs in parallel with the building permit but is a separate approval.

Common Mistakes

1. Undersizing the make-up air system. This is the most common ventilation mistake and causes operational problems from day one.
2. Not confirming rooftop access before signing the lease. If you cannot route a grease duct to the roof, you cannot operate a commercial kitchen.
3. Skipping the grease interceptor sizing calculation. An undersized interceptor will fail and result in municipal fines.
4. Assuming the landlord's base building HVAC is sufficient. It almost never is for a restaurant use.

VNG handles the full kitchen ventilation scope on restaurant renovations, from hood procurement through duct installation, make-up air, and grease interceptor. Request a quote for your restaurant build-out.