The restaurants and hotels that have installed cooking elements are obliged to extract the fumes derived from the cooking by law. It is possible thanks to an installation formed by chimney and extractor fan; both of them adapted to the currently regulation for kitchens.
Industrial kitchens are only classified as special risk although they must meet specific basic requirements that are regulated in the CTE inside the Basic Fire Safety Document. At the beginning, industrial kitchens are classified as a place of special risk. This classification could be modificated depending the installation or if there is or not automatic extinction (or the extinguisher for cooking). However, they must meet specific requirements which are regulated by the CTE in the Basic Fire Safety Document, called as DB SI.
Kitchens for industrial use (such as local and special risk areas) will be classified as high, medium or low risk according to the criteria which is written in table 2.1 of the CTE DB SI, section SI 1, internal propagation, paragraph 2. For the specific kind of kitchens, it depends of the installed power. For the determination of the installed power, shall be considered only those devices which are directly planned for cooking food and they can origin combustion.
Except for hospital and public residencial uses, there is no special risk in kitchens which protected appliances with automatic fire extinguishing system. In chapter 1 of the section SI4 of this DB we have known that mentioned system must always if its installed power is over 50 kW. However, fume systems must meet these special requirements even if they have a automatic fume extinguishing system:
Exhaust hoods must be separated at least 50 cm from any material witch it’s not done by material A1.
Air pipes must be independent of any other ventilation and they must be exclusive for each kitchen too. They must have register controls for inspection and cleaning with change of direction which angles are bigger than 30º and each 3 horizontal meters maximum.
Air pipes which run through inside of the building will have an EI 30 classification (this requirement will be met for air pipers which run through external facades less than 1,50 meters away from other areas except EI30 or balconies, terraces or user holes with EI 30 classification).
It’s no possible to have fire doors into these kind of air pipes, so they have to run through fire compartmentation elements hoy is indicated by section 3 of this Section 1 of the DB SI.
Filters must be separated from heat sources more than 1.20 meters if they are grill or gas types (in case of these filters are for other things must be separated more than 0,50 meters). They must be easily accessible and removable for cleaning. Also the must have an inclination over 45º and have fat collection with a closed container for throwing them and with a capacity less than 3 liters.
fume systems must comply with the specifications of standard UNE-EN 12101-3: 2002 “Specifications for mechanical fume and heat extractor”. They must have a F400 90 classification.