The smoke outlet in the restaurant sector

The smoke outlet (the duct responsible for extracting the smoke and vapors generated in a kitchen, running from the extractor hood to the roof of the building) of a restaurant is one of the most delicate points when obtaining the relevant operating license. If you are thinking of opening a restaurant or, as a technician, need to draft a restoration project, we will explain what the current regulations require in this regard.

What does the CTE establish regarding the smoke outlet?

CTE DB HS3 Indoor air quality

According to the CTE DB HS3 Indoor Air Quality, the smoke outlet must be located on the roof, at least 3 meters away from any element whose purpose is to allow the intake of ventilation; and also with respect to any space where people are usually present. In addition, it must have a uniform section, be free of obstacles inside, and have a finish that makes it difficult to get dirty.

CTE DB SI Fire safety

According to the CTE DB SI Fire Safety, the kitchen of a restaurant is a location with a high fire risk, as the power of a gas kitchen with about 6 burners easily exceeds 50 kW. To calculate the power, only appliances intended for food preparation will be taken into account, as they are the ones likely to cause combustion (the extractor hood and plate warmers are excluded from the calculation).

Requirements:

According to the Basic Document, the smoke extraction from the kitchens of these special risk venues must meet the following requirements:

• The extractor hoods must be separated by at least 50 cm from any material not classified as A1 (non-combustible).
• Each of the extraction ducts for the evacuation of smoke must be independent and exclusive to each kitchen.
• Access points must be provided to inspect the installation and clean it at those points where the duct changes direction by an angle greater than 30°. In horizontal sections, access points must be provided at least every 3 meters.
• If the ducts run inside the building or through the facade at a distance of less than 1.50 meters from areas of the facade not classified EI 30 or less than 1.50 meters from balconies, terraces or openings, they must have an EI 30 classification.
• No fire dampers can be inside the ducts.
• For gas kitchens or grills, the filters of the extractor hoods must be separated from the heat sources by at least 1.20 meters. In other cases, the distance cannot be less than 0.50 meters. Additionally, they must be accessible and removable for cleaning and have a grease collection tray.
• Fans, which must have an F400 90 classification, must comply with the UNE-EN 12101-3: 2002 standard "Specifications for mechanical smoke and heat exhaust ventilators."

To learn more about fire regulations and ventilation systems.