How to Choose an Industrial Hood and Kitchen Ventilation

Why can't a hood be selected independently of the equipment?

A grill, fryer, range, oven and dishwasher don't produce the same amount or type of load. High-load equipment producing greasy smoke has different filter, exhaust and fire-risk needs than steam-only equipment. Hood calculation should therefore be based on the final equipment list and layout.

If a grill or fryer is added later, the existing hood's size, filter surface, duct and fan capacity may fall short. A menu change is also a technical-project change.

What determines capture and containment performance?

Hot air rises, dragging surrounding air with it and forming a plume. The hood must capture this plume without it escaping the edges and direct it to the filters. Overhang beyond the equipment footprint, correct mounting height and side panels that reduce edge effects all directly affect performance.

• Cooking equipment's heat and grease load
• Hood type, size, height and overhang
• Filter angle, surface and placement
• Cross-drafts from doors, windows, HVAC vents and fresh-air jets
• Pressure loss in the exhaust duct and the fan's operating point
• Pressure balance between the kitchen and neighbouring areas

How are hood types classified?

Wall-type hoods are used when the cooking line sits against a wall; island-type hoods when equipment is in the middle — island applications are more exposed to ambient air movement, so capture conditions can be harder. Low-level or specialised capture systems are assessed for specific equipment and manufacturer conditions.

Greasy cooking lines need suitable grease filters, safely removable/washable filters and grease-collection details. Condensate-type applications are designed mostly around steam load. It's the fit for purpose, not the system's name, that matters.

Why is fresh air as important as exhaust?

When a large amount of air is removed from the kitchen without controlled replacement, doors can become hard to open, uncontrolled air and dust can enter, hood capture can be disrupted, and combustion appliances can be affected. Fresh air isn't just about completing the flow rate — it's used to manage air movement.

A fresh-air jet blown directly at the hood mouth or over hot food can disrupt the plume. Diffuser type, speed, temperature and location should be chosen with both comfort and capture performance in mind.

How are ductwork, fan and fire safety handled?

The greasy exhaust duct is designed on as short, cleanable and sealed a route as possible. Elbows, cross-section changes and long horizontal runs increase pressure loss and grease build-up. Access panels must be reachable; the fan and roof outlet should be solvable for safe maintenance-crew access.

The cooking line's fire load, duct penetrations through the building, suppression-system needs, and gas/electrical cutoff scenarios are assessed with relevant fire regulation and competent project teams. The hood alone is not a fire-safety system.

What checks happen at commissioning?

• Fan direction, belt, vibration and access check
• Measuring exhaust and fresh-air flow rates
• Filters fitted in the correct type with no gaps
• Observing edge leaks and cross-draft effects with a smoke test
• Checking door operation and odour transfer to neighbouring areas
• Noise, vibration, condensation and drainage checks
• Accessibility of cleaning panels and suppression elements
• Recording final settings in a measurement report

Common ventilation mistakes

• Choosing the hood based only on cooking-line length
• Increasing exhaust flow while neglecting fresh air and building pressure
• Placing an HVAC vent opposite the hood at high speed
• Leaving duct-cleaning panels behind a suspended ceiling or fixed cabinet
• Selecting the fan without a duct pressure-loss calculation
• Skipping flow and smoke testing after installation