Restaurants: Sizing the Dining Room Separately From the Open Kitchen

Key takeaways

• An open kitchen concept doesn't mean the dining room and kitchen should share one sizing calculation
• Size the dining room independently using its own floor area and ceiling height
• Exhaust ventilation, not filtration, is the primary tool for cooking smoke and heat in the kitchen
• Filtration in the kitchen area supplements exhaust for odour that escapes the hood, not as a replacement
• Coordinate both zones under one restaurant-wide plan rather than two separate vendor relationships

Why an Open Kitchen Concept Blurs the Boundary Between Two Zones

Many restaurants in Singapore now run open kitchens as a design feature, letting diners watch food being prepared. It's a popular layout, but it makes air quality planning less obvious than in a restaurant with a fully enclosed back-of-house kitchen. Smoke, steam and cooking odour drift across the boundary between the two zones far more freely than in a sealed layout.

This leads some operators to treat the whole floor as a single space and buy one purifier sized to the combined square footage. That approach misses an important distinction: the kitchen's biggest air quality problem, smoke and heat from active cooking, is not something filtration is designed to solve at the source. The dining room's biggest concern, general comfort and lingering food odour for seated guests, is a different problem with a different fix.

Separating the two zones for sizing purposes, even when they share one physical space, gives a more accurate picture of what each actually needs.

Applying the CADR Formula to the Dining Room Independently

The dining room should be sized on its own floor area and ceiling height, using the same formula as any commercial space: required CADR in cubic metres per hour equals floor area in square metres multiplied by ceiling height in metres multiplied by target air changes per hour. Restaurants typically fall into the commercial range of four to five air changes per hour, similar to an office, though a smaller or higher-turnover dining room may warrant sizing toward the upper end.

A dining room between 31 and 54 square metres generally sits in Classic 400S range, while a larger dining floor moves toward Pro 800S coverage. Run your actual dining room dimensions, not the whole restaurant footprint, through the Air Purifier Size Calculator to get an accurate figure rather than guessing from total floor space.

What the Kitchen Area Needs on Top of Its Exhaust System

A commercial kitchen exhaust hood exists to remove smoke, grease particles and heat directly at the cooking source, and it should remain the primary defence in any kitchen, open or enclosed. It is designed and regulated for that job in a way a standalone air purifier is not.

Where filtration adds value is downstream of the hood, catching the smoke and odour that drift into the open kitchen area and toward the dining room despite the exhaust running. An activated carbon layer is particularly useful here for absorbing cooking odour compounds that a HEPA stage alone would pass through. This is a supplementary layer, not a substitute for a properly functioning exhaust system, and it should be sized and positioned to catch spillover, not to replace extraction at the cooktop itself.

Coordinating Both Zones Under One Restaurant-Wide Plan

Sizing the dining room and kitchen area separately doesn't mean running two unrelated systems. Once each zone has its own correctly sized unit, servicing, filter changes and any WiFi monitoring can sit under one restaurant-wide plan so front-of-house and back-of-house aren't tracked by different processes.

This also keeps the budget conversation clear when presenting to ownership: one line for dining room comfort, another for kitchen-area supplementary filtration, rather than a single blended figure that's hard to justify against actual usage. If the restaurant later renovates the kitchen layout or extends the dining floor, only the affected zone's sizing needs revisiting.

Getting a Survey Before the Next Inspection Cycle

Restaurants generally face periodic reviews of their premises, and having an air purification plan already documented and in place tends to be more reassuring than scrambling once a review date is confirmed. A room-by-room survey ahead of time also gives a more accurate sizing than estimating from a floor plan alone, since actual airflow and layout vary between kitchens even at similar square footage.

AIRE offers a free room-by-room Air Report with no upfront cost, covering both the dining room and kitchen-area filtration separately. Businesses can compare buying outright against renting, where filters and servicing are bundled into the rental rate, which suits a restaurant that expects to renovate or expand seating in the future.

Next step

Start with the Air Purifier Size Calculator using your actual dining room dimensions, then request a free room-by-room Air Report to cover the kitchen area's supplementary needs alongside it.

Frequently asked

Should the dining room be sized independently from an open kitchen?

Yes. Even in an open-concept layout, the dining room should be sized on its own floor area and ceiling height using the CADR formula, separate from the kitchen area, because the two zones face different air quality problems and need different fixes.

What does the kitchen area need beyond its exhaust system?

The exhaust hood remains the primary tool for removing cooking smoke and heat at the source. Filtration in the kitchen area adds a supplementary layer, particularly activated carbon, to address odour that drifts past the hood, not a replacement for proper extraction.

Can both zones be coordinated under one restaurant-wide plan?

Yes. Once the dining room and kitchen area are each sized correctly, servicing, filter changes and monitoring can be managed under one restaurant-wide plan rather than treated as two separate, unrelated arrangements.

Related reading

• Commercial Air Purifier Rental in Singapore