How to calculate the power of the hood for the kitchen? Expert Advice

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If you are tired of constantly airing the kitchen, and the question of air purification remains unresolved, then it's time to get a powerful exhaust hood of the desired model. Before buying, you need to make sure that you take into account all the nuances - from functionality to decorative features. And for this it is necessary to familiarize yourself with the characteristic qualities of the most common models available for sale, as well as calculate their power.

Among the huge range of cooker hoods, you can choose models of any size and shape. Many buyers primarily choose a beautiful design or a famous brand. But the appearance of these devices is much less important than their technical parameters - the power and volume of air pumped per unit time.

An improperly selected hood for this room will not be able to effectively clean the air in it. The indicator of its productivity, measured in m³/ h, affects how much polluted air it can let in for an hour. Using special calculations using a simplified formula, you can independently choose the most suitable exhaust technology for your kitchen. A more accurate calculation can only be done by a competent engineer.

What is the difference between hoods and ventilation

The ventilation system is a network of channels built into the walls with access to the outside of the building for the discharge of exhaust air from the room. The influx of fresh air in this case occurs through the door and window openings in a natural way.

This air exchange system according to sanitary standards should be installed in all residential premises. But it is not very efficient and all the more it is not able to localize and remove odors, fumes, soot and other "charms" of life. To prevent them, forced ventilation is installed - an exhaust hood. She collects all the fumes from the hob, through the duct directs them to the ventilation system.

Hood device

By the principle of action, they are all similar to a vacuum cleaner, but with other functions. Modern exhaust devices come in different designs, depending on the purpose - they only remove the contaminated air, while others filter it and return it to the already cleaned one. According to the cleaning method, they are divided into flowing, recirculating and combined, which combine both options.

• Flow hoods equipped with metal or plastic pipes (round, square, corrugated) for connection to the ventilation system, which are rigid or flexible. The lower parts of the device consist of filters (grease catchers) that trap soot and fat. They disguise themselves behind decorative panels. Inside are fans and special engines. Behind them is an air duct connected to the ventilation.
• Recirculation They work autonomously, without connecting to ventilation, therefore they do not have pipes, which makes them look more aesthetically pleasing. Inside their housings after the fans are replaceable, very thin carbon filters. For rough cleaning filters are made of durable aluminum, they can simply be washed with detergents. Outwardly, the principle of the structure of the buildings is the same as that of flowing ones.

The exhaust system is powered by an electric network. Everything is very simple - it plugs into the outlet, the button with the selected mode is pressed (indicated by numbers 1-3), the engine is gaining momentum. The most convenient for connecting hoods are with touch screens or with remote control (using the remote control or voice commands).

Types of exhaust systems in shape and placement methods

According to the structural features of the hull, there are several varieties:

• Flat - the most compact, without additional installations. Suitable for small rooms. But they have a short life, they must be replaced periodically. Among the flat ones there is a kind of sloping, angled to the hob and having small dimensions.
• Dome - powerful and functional, well clean large rooms. They are quite overall and have the shape of hemispheres or pyramids.
• Also available cylindrical (height adjustable) square, cone-shaped, round and other non-standard forms.
• Recessed models differ from previous ones in the possibility of disguising them in furniture, ceiling, niche in the wall.

According to the peculiarities of placement there are hoods:

• outboard - mounted to a wall or ceiling in any area of ​​the kitchen;
• island - are attached to the ceiling in the center of the room;
• angular - are installed at two adjacent walls for more rational use of space.

Requirements for exhaust devices and their installation in the kitchen

To ensure efficient and safe operation of these devices, several installation rules must be observed:

• The dimensions of the intake opening must be larger than the cooking surface.
• The distance from the surface of the plate to the hood should be at least 70-80 cm to avoid overheating.
• Its capacity should be such as to ensure complete replacement of air at least 10 times per hour.
• If the kitchen does not have access to a special ventilation shaft, then it is better not to connect it to an ordinary one, so as not to disrupt its operation, and even better - install a recirculation model.

How to calculate the power and performance of a kitchen hood depending on the area of ​​the room

The higher the extraction power, the faster air purification will occur. The required performance for this room can be found in the table, where the kitchen area and its height are taken as the basis for the calculations. Lowest performance for cheap models, approximately 200-300 m³/ h They can be installed only in small kitchens and provided that cooking on the stove is not very frequent. If the hob is used frequently, the power must be at least 600 m³/ h

Formula for calculating the power of a kitchen hood

Calculations can be done using a simplified formula yourself:

Q = S × H × 12

Q - exhaust power (m³/ h);

S - area of ​​the kitchen;

H - the height of the kitchen;

12 - coefficient (number of air change cycles per hour)

According to sanitary standards, 10-15 cycles of air replacement should occur within an hour. Coefficient 12 is the selected average.

For example, S = 10 m2, H = 2.5 m2

With these values ​​it turns out:

Q = 10 × 2.5 × 12 = 300 m3 / h.

Other factors to consider

Calculations according to the formula are of average importance, because you must also take into account other nuances:

• Type of hob. For an electric stove, the coefficient reading can be up to 15, because in addition to fumes from products, no other substances enter the air. But with a gas stove, harmful substances from burning gas also enter the air. In this case, the coefficient is taken from 20.
• Type of hood. When flowing, it is necessary to take into account the throughput of the existing ventilation shaft. With recirculation, this factor does not matter.
• The layout of the room. If there is an open entrance to the next room or the door often opens there, then you need to take into account the large area of ​​the room when calculating.

Cooker hood selection

If funds allow you, choose a model that works in two modes - combined (read more here). This is a more convenient option. On sale there are already models that work almost silently - with a level of no more than 40 dB. An alternative to one powerful engine is a system with two but less power, which produce much less noise. An important role in the operation of exhaust devices has fans. The maximum loads withstand tangential and diametrical loads. The hood must be larger than the hob so that steam and dirt do not get on the ceiling.

Video: rules for calculating the required hood performance 

Among the abundance of models presented for sale in stores, it is difficult to immediately navigate and make the right choice. The correct calculation of the power of the exhaust system, the selection of a model of a suitable size and method of functioning will allow you to create a healthy microclimate and safe conditions in the house.