Hood and extraction in a pro kitchen: pick the right setup
Extraction rate, filters, flue, fresh-air make-up: everything to size a pro kitchen ventilation correctly.
Extraction rate is calculated against the thermal power installed under the hood. Rule of thumb: 600 to 900 m³/h per kW thermal for flame appliances (gas), 400 to 600 m³/h per kW for electric appliances (hob, oven, fryer). For a 30 kW gas line, plan a 18,000 to 27,000 m³/h extraction box, sized with a 20 % margin.
Grease filters are the first line of defence. Favour stainless baffle filters (or stainless cassettes), tool-free removable and dishwasher-safe. Activated charcoal filters only make sense without a flue (recirculation hood), a configuration to avoid in a pro kitchen since it rarely meets DTU 24.1.
The evacuation flue must be stainless, airtight, thermally insulated and discharge above the ridge of the building. Its section must match the planned flow (8 to 12 m/s velocity in the flue). Mandatory yearly sweeping is logged in the maintenance book. In a condominium, using the existing flue is rarely allowed for catering: plan a dedicated flue.
Fresh-air make-up is often overlooked. Extract 15,000 m³/h without bringing back fresh air and you create a depression that slams doors, disturbs wood-oven or boiler draft, and reverses odour flow. A motorised supply diffuser must deliver 80 to 90 % of the extracted flow, ideally pre-heated in winter to avoid cold drafts.
Frequently asked questions
Which hood for a 60 m² kitchen with a 25 kW cooking line?
Central or wall-mounted double-cassette hood, 2.40 to 3 m long, 15,000 to 22,000 m³/h extraction box, removable stainless filters and 12,000 to 18,000 m³/h fresh-air make-up.
Must I sweep the extraction flue of a pro kitchen?
Yes, yearly sweeping by a professional is mandatory (decree of 25 June 1980 on ERP buildings). A sweeping certificate must be available during safety commission visits.
What if the existing flue is undersized?
Either create a dedicated insulated stainless flue to the roof, or install a molecular filtration box with activated charcoal and UV to allow facade discharge. The second option costs 3 to 5 times more in investment and upkeep.