Industrial Kitchen Ventilation System Design

What are the design inputs?

Type, power, fuel and operating duration of cooking equipment
Hood geometry, mounting height and layout
Kitchen volume, ceiling height and neighbouring areas
Doors, windows, service openings and lift connections
Duct route, roof/facade exit and maintenance access
Fresh-air, heating-cooling and heat-recovery approach
Fire safety and local permit/environmental conditions

Without this data, choosing a fan based on floor area alone cannot guarantee capture performance. Whenever the equipment list changes, the air calculation must be revisited.

How are local exhaust and general ventilation separated?

The hood is local exhaust, capturing heat and pollutants at the source. General ventilation manages residual heat, humidity and air quality in the space. A shortfall in one can't always be compensated by overworking the other.

If cooking plume escapes the hood, examine overhang, load class, mounting height and cross-drafts rather than simply enlarging the fan.

Why is air balance and pressure critical?

If air removed from the kitchen isn't replaced in a controlled way, the building draws it from doors and gaps instead — causing hard-to-open doors, dust ingress, odour transfer and problems with combustion appliances.

In most projects the kitchen is kept at a controlled negative pressure relative to clean neighbouring areas to reduce odour spreading to the dining room — but excessive negative pressure isn't desirable either. Pressure stages between restroom, waste area, dish room and dining room should be assessed as part of the whole building system.

How are fresh air and HVAC positioned?

Fresh air should be distributed to occupied areas at low speed and evenly. High-velocity diffusers can disrupt the hood's capture zone. Air temperature matters too — overly cold air affects staff comfort and can cause condensation.

A split air conditioner only changes air temperature; it doesn't provide the fresh air needed or the kitchen's exhaust balance on its own. HVAC capacity, hood load and fresh-air conditioning should be calculated together.

How are ductwork and fan selection made?

Duct cross-section is chosen together with air velocity, grease build-up, noise and available building space. Elbows, contractions, filters, silencers and long runs create pressure loss. A fan is selected not just by free airflow but by its operating point against total system resistance.

Sealing and cleanability are essential for greasy exhaust ducts. Access panels should be placed at elbows and critical sections, with a safe service platform considered for the roof fan.

How is energy efficiency improved?

Hood sized to the equipment load, not oversized
Fan speed control within safe limits based on variable use
Low-pressure-loss duct routing and clean filters
Fresh air conditioned to actual need
Heat recovery, where contamination and fire risk have been assessed and it's appropriate
Operating hours and automation matched to real operation

Important: heat recovery on greasy exhaust requires expert design and suitable equipment due to fouling, cleaning, fire and cross-contamination risks.

Commissioning and performance verification

Verify equipment and hood positions against the project.
Measure exhaust and fresh-air flow rates and compare to design values.
Check correct filter placement and pressure loss.
Observe capture and spillage with a smoke test under cooking load.
Measure the pressure relationship between kitchen and dining/corridor.
Check door operation, odour transfer, noise, vibration and condensation.
Report final fan settings, measurements and maintenance points.

Common mistakes in holistic design

Designing the hood and HVAC as two independent systems
Increasing fan flow without accounting for fresh air and building pressure
Not testing the cross-draft created when a service door opens
Leaving no access for duct cleaning and roof-fan maintenance
Not reflecting an equipment change in the ventilation project
Accepting the system without post-installation measurement

Frequently Asked Questions

Should the kitchen be at negative pressure?

A controlled pressure relationship is needed to reduce odour spreading to clean areas, but excessive negative pressure can cause door, comfort and combustion-safety issues. The value should be calculated and measured together with the building system.

Does air conditioning meet the fresh-air requirement?

A standard split unit mostly recirculates indoor air and doesn't supply fresh air. The air replacing kitchen exhaust must be designed separately.

Should the hood fan always run at full speed?

Variable speed can be possible depending on load and control system, but minimum safe capture, building pressure and fire scenarios must be preserved.

Is an odour problem solved just by changing filters?

Odour can stem from capture leakage, duct leaks, wrong exhaust location, pressure imbalance or process sources. Filter maintenance matters, but the whole system should be examined.

Plan your project the right way from day one

Arlinoks designs equipment layout around workflow, temperature control, cleaning access and measurable operation points.

Get in touch with Arlinoks

Sources

Regulations, local authority requirements and technical standards can change over time. Verify current requirements with the relevant authority, project author and specialists before implementation.