Calculate exhaust and supply airflow for commercial kitchen canopies from cooking equipment type and canopy dimensions per AS 1668.2.
Select cooking type and enter canopy dimensions to calculate airflow.
Based on AS 1668.2 exhaust rates. Rates are per linear metre of cooking equipment. Supply air = 85% of exhaust. Always confirm with an HVAC engineer and health authority requirements.
AS 1668.2 (The use of ventilation and air-conditioning in buildings — Ventilation design for indoor air contaminant control) covers commercial kitchen ventilation in NZ and Australia. The standard specifies minimum exhaust rates by cooking equipment type and category, and requires makeup (supply) air of typically 85–90% of exhaust volume.
AS 1668.2 recommends a minimum 150 mm overhang beyond the cooking equipment on all sides exposed to the kitchen. For high-output equipment like wok ranges or commercial deep fryers, 300 mm or more overhang is recommended. Insufficient overhang allows cooking effluent to escape the capture zone and reduces ventilation effectiveness.
Type I hoods are designed for grease-laden air from cooking processes (fryers, grills, woks) and require grease filters, grease drip trays and fire suppression systems. Type II hoods handle non-grease-laden heat and moisture (dishwashers, combi ovens, bain-maries) and have simpler construction. NZ health regulations and building codes require the correct type for each application.