Ventilation of Industrial Kitchens

We can describe industrial kitchens as a set of planned works that enable businesses involved in the out-of-home food production sector to produce and serve their commercial products, semi-finished products or raw materials at high capacity and within certain norms.

It is not enough to perceive industrial kitchens as places where food production can only be established by cooks, architects, operators or equipment manufacturers.

Industrial kitchens are designed in accordance with the rules of gastronomy science, the architectural details of the building where they are established, the operating structure of the enterprise and environmental emission values. It includes all areas and equipment that allow the production and service of high capacity food and beverage. These areas and equipment cover the places where foodstuffs are stored, prepared and cooked, as well as the social areas of the personnel, changing rooms, toilets, the areas where the infrastructure of the devices required by the production processes and the equipment where the products are served.

Industrial kitchens are technological kitchens used in businesses such as cafes, restaurants, factories, hotels, canteens and catrings. Industrial kitchens have the necessary equipment to meet all the needs that may arise in a kitchen.

In industrial kitchen ventilation systems, there should be hood, flame, smoke and odor filter systems, air ducts, exhaust fan, fresh air system and fire extinguishing system. While designing the system, the work environment and the fire safety of the building should be prioritized.

When planning the ventilation of industrial kitchens, it is one of the high priority issues to calculate and design the hoods that collect the pollutants such as soot, smoke, odor, and oil that occur during cooking and then evacuate them to the atmosphere after passing them through the filter system. Appropriate models and sizes of hoods should be selected, taking into account the capacity, number and size of the cooking units, as well as the variety and density of the pollutants formed. While making the selection, it should be kept in mind that the calculated hood model and cross section directly affects the exhaust fan and filter system capacities.

The hood selection should be made in minimum sizes that will allow the exhaust channels to transfer all the pollutants rising from the cooking surface to the chimney. The closed edges between the hood and cooking units will positively affect the fan capacity. A hood of the same size may differ up to 100% only on the number of closed sides, fan capacity and filter system capacity. If the sides of a hood of the same size and the cooker unit are closed, a lower capacity fan and filter group is used, while if the sides of the same hood with the cooking unit are open, you will need to use a higher capacity fan and filter group. This difference will cause unnecessary installation and usage costs.

In kitchens where it is not possible to manufacture exhaust air ducts from welded stainless steel material, attention should be paid to the fact that they are manufactured from welded DKP material and that there are intervention covers and oil pockets for cleaning. Fire dampers should not be placed in kitchen exhaust ducts.

Kitchen ventilation duct systems should be designed individually and should not be combined with the air ducts of different units and should be connected to the chimney at the shortest distance.

While designing the hood of industrial kitchens, hot water to be obtained by an air-to-water heat exchanger to be installed in the hood can be put into use in the kitchen. The heat exchanger to be placed in the hood will provide hot water free of charge by taking advantage of the hot air thrown into the atmosphere. This application will provide high savings in the energy used for hot water supply.

Existence of flame-repellent filters in hoods, fire extinguishing system, fire resistance of the chimney shaft for at least 1 hour, testing the duct joints and impermeability, having intervention covers are the leading fire precautions to be considered.

Ash and soot that is produced as a result of the combustion of hydrocarbon fuels such as wood and coal in the grills accumulate in the air channels over time. There are unburned fuel powders in the accumulation. These pollutants combined with oil cause narrowing in the cross sections of the exhaust ducts, adversely affecting the evacuation of the smoke and may cause a fire.

The factors that cause fire are the accumulation of pollutants that occur in the grills and stoves using solid fuel and have flammable properties in the air ducts by mixing with oil, disrupting the duct and system cleaning, using inappropriate ducts and selecting an unsuitable fan flow.

At high cooking temperatures, more oil vapor occurs. When the oil vapor cools, it becomes solid again. These oil residues that accumulate in the channels are flammable. The ignition temperature of oil residues is slightly lower than the initial ignition temperature. This situation brings with it the risk of fire in hoods and ducts.

To prevent fires that may occur in industrial kitchens;

Cooker hood and outside hood oil filters should be used. An electrostatic filter system should be used to filter smoke, and a carbon filter system should be used to filter odor. There should be oil drains inside the hood. The hood and air ducts should be cleaned daily. There should be sufficient number and size of covers on the exhaust channels for cleaning. It should have an automatic fire extinguishing and gas detection system. In places where natural gas, SPG or flammable materials are operated, the fan and ventilation motors should be explosion and spark safe ex-proof type and chimney grounding should be done. Necessary training should be given to the kitchen staff regarding the operation of the ventilation and automatic fire extinguishing system. What to do in an emergency should be specified with instructions. The inside of the hood, ducts, chimney and filter system should be cleaned regularly by authorized companies.

İlker KURAN

Alperen Ltd Şti.