Commercial kitchens generate heat, moisture, grease, and odours that must be effectively managed. Proper ventilation keeps kitchens comfortable, maintains air quality, meets regulations, and protects the building fabric.
Ventilation Requirements
Commercial kitchens need both extract and supply air:
Extract Ventilation
Removes heat, steam, grease, and cooking odours at source. Canopy hoods over cooking equipment capture contaminants before they spread through the kitchen.
Supply Air
Replaces extracted air and provides fresh air for kitchen staff. Without adequate supply, kitchens develop negative pressure, causing doors to slam, draughts through gaps, and poor extract performance.
Makeup Air
Specifically tempered air to replace extract. Prevents uncomfortable conditions from cold outside air flooding into the kitchen.
Design Considerations
Heat Load Calculation
Cooking equipment generates significant heat. Extract rates must match heat generation to maintain acceptable temperatures. Under-designed systems leave kitchens uncomfortably hot.
Capture Velocity
Extract hoods must capture rising plumes from cooking. Insufficient capture velocity lets grease and odours escape into the kitchen. Canopy design and extract rate work together for effective capture.
Grease Filtration
Grease must be removed from extract air before it reaches ductwork. Baffle filters, mesh filters, or cartridge filters in canopy hoods capture grease. Regular cleaning is essential.
Fire Safety
Kitchen extract systems present fire risk from grease accumulation. Design must include fire suppression, appropriate materials, and access for cleaning. Compliance with insurance and regulatory requirements is mandatory.
Odour Control
Kitchen exhausts can cause nuisance to neighbours. Carbon filtration, UV treatment, or ESP (electrostatic precipitation) systems may be required depending on location and cooking type.
Energy Recovery
Kitchen exhaust contains significant heat. Recovery systems can capture this energy, though grease contamination requires robust equipment designed for kitchen applications.
Air Handling for Kitchens
Kitchen supply air needs differ from standard comfort ventilation:
Tempered Makeup Air
Supply air must be heated in winter to avoid cold draughts. Dedicated makeup air units condition air specifically for kitchen replacement.
Air Distribution
Supply air distribution must avoid disrupting canopy capture. Poorly positioned supply creates cross-draughts that prevent effective extract.
Balancing Supply and Extract
Kitchen pressure balance affects the whole building. Slight negative pressure keeps odours contained but excessive negative pressure causes problems. Careful balancing during commissioning is essential.
Regulations and Standards
Building Regulations
Part F (Ventilation) and Part B (Fire Safety) both apply to commercial kitchen ventilation. Designs must demonstrate compliance.
Gas Safety
Kitchens with gas appliances need adequate combustion air and safety interlocks. Gas Safe regulations apply.
DW/172
BESA’s specification for kitchen ventilation systems provides industry-standard guidance on design and installation.
Insurance Requirements
Insurers often have specific requirements for kitchen extract systems, particularly regarding fire suppression and duct cleaning access.
Maintenance Requirements
Kitchen ventilation systems need regular maintenance:
Filter Cleaning – Grease filters require frequent cleaning, often weekly in busy kitchens.
Duct Cleaning – Extract ductwork accumulates grease and must be cleaned periodically. Frequency depends on usage and cooking type.
Fan Maintenance – Extract fans handling greasy air need regular inspection and cleaning.
Fire Suppression – Suppression systems require regular inspection and testing.
Our Kitchen Ventilation Solutions
i-Flow designs and manufactures air handling equipment for commercial kitchen applications. We work with kitchen designers and contractors to deliver integrated ventilation solutions. Contact us to discuss your kitchen project.
