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Kitchen ventilation

Kitchen ventilation is the branch of ventilation specialising in the treatment of air from kitchens. It addresses the problems of grease, smoke and odours not found in most other ventilation systems.

Kitchen ventilation equipment includes an extractor hood or canopy, and a filtering system. The system's fan may be located in the kitchen or in its ducts

History

Commercial kitchen ventilation design has evolved significantly since the mid-20th century due to stricter fire codes and workplace safety regulations. The introduction of stainless steel canopies and electrostatic precipitators marked key advancements in reducing airborne contaminants.

Requirements

An adequate kitchen ventilation system should:

  • Remove cooking fumes at the source, i.e. as close as possible to the cooking equipment.
  • Remove excess hot air and introduce cool clean air, maintaining a comfortable environment. Inadequate ventilation can cause stress, contributing to unsafe working conditions and high staff turnover.
  • Ensure that air movement in the kitchen does not cause discomfort.
  • Provide sufficient air for complete combustion at fired appliances, and prevent the risk of carbon monoxide accumulation.
  • Be easy to clean (intermittent e.g., manually, or continuously e.g. using ozone) so that fat residues do not accumulate in the hood and ducts and block air inlets, leading to loss of efficiency and increasing fire risk.
  • Be quiet and vibration-free.

Kitchen ventilation design

The design of an effective kitchen ventilation system is determined by:

  • The kitchen's workload
  • The amount, type and power of cooking equipment
  • The kitchen's layout and shape
  • The number of kitchen staff
  • The need for easy cleaning and maintenance
  • Energy efficiency

Hot air from cooking is usually vented externally through a chimney system. When this is not possible, recirculating cooker hoods are used that clean the air and direct it back into the kitchen.

Airflow and ventilation rates

Kitchen ventilation guidelines are typically based on airflow capacity, measured in cubic feet per minute (CFM). For residential range hoods, the Home Ventilating Institute (HVI) recommends a rate of 100 CFM per linear foot of cooktop width when mounted against a wall, and 150 CFM per linear foot for island installations. In absolute terms, a 30‑inch (2.5 ft) wall-mounted hood should deliver 250–300 CFM, with island hoods requiring approximately 375 CFM for equivalent coverage.

Commercial kitchens require much higher airflow. Broan‑NuTone recommends 100 CFM per 10,000 BTU of stove output, meaning a 50,000 BTU range would need around 500 CFM.

ASHRAE Standard 62.2 also specifies a minimum of 100 CFM** for vent-capture range hoods in residential settings and calls for **5 air changes per hour (ACH) if alternative exhaust methods are used.

Hood capture effectiveness improves with larger hoods and proper positioning—extending 3 inches beyond cooktop edges and mounting at the recommended height (20–30 inches above) ensures effective smoke and grease removal.

Grease filters

The most common types of grease filters used in professional kitchens are:

References