KITCHEN EXTRACT

Kitchen extract poses a specific fire risk due to the presence of combustible contaminants, namely grease. 

Kitchen extract ducts that pass through multiple fire compartments on their way to the outside, are at risk of being exposed to a fire in those compartments. This is outside the kitchen compartment itself. The concern is that a fire will reach the kitchen ductwork that passes through the compartment and cause the grease inside the duct to ignite.

The protection offered by compartmentation is no longer certain as the fire may cascade along the route of the kitchen extract ductwork. The grease in question, due to the process of oxidation, has a low flash point of 180°C. The fire can spread back to the kitchen and all compartments enroute. 

Thor Duct® is a solution, based on the latest EN1366-1 requirements, tested with Insulation to delay a temperature rise of 180°C inside the ductwork.

Includes testing ducts under “Type A” fire, with measuring devices (thermocouples) surface mounted inside the ductwork, inside the furnace, tested to the fire curve EN1363-1.

The insulated ductwork is examined to measure how many minutes it can maintain the duct temperature below 180°C on any one thermocouple, or below 140°C as a mean average of all thermocouples.

Thor Duct® Kitchen Extract is insulated using a calcium magnesium silicate blanket which maintains the duct temperature below 180°C and prevents grease igniting and causing fire to spread throughout the building. This insulation was tested as a combined system (ductwork + Insulation) and evidenced by way of test reports and classification to the standard EN13501-3.

Thor Duct® Cleaning Doors have been tested to EN 1366-1 and are suitable for kitchen extracts. Cleaning doors are required every 2 linear meters. We strongly recommend a routine cleaning regime by specialist contractors.