- 1 How to calculate the power and performance of cooker hoods
- 1.1 Types of hoods for the kitchen and the requirements of the standards
- 1.2 How to calculate the power of the extraction equipment
- 1.3 Choosing a kitchen hood: noise vs performance
- 1.4 Video: how to choose the hood for optimal design and performance
How to calculate the power and performance of cooker hoods
The range of kitchen hoods for plates is huge, the models have different shapes and sizes. But the appearance in this technique is not the main thing. More important are the technical parameters of the power and volume of the air being pumped. Functionality is more important than aesthetics. It is only the competent engineer who is in a position to accurately perform the calculation of the output of the hood for the kitchen. However, in the selection of extraction equipment for apartments and private homes, simplified formulas are often used. Consider how to properly use them and adequately interpret the results of calculations.
Types of hoods for the kitchen and the requirements of the standards
When cooking on the stove, evaporation, soot, unpleasant odors are inevitable. From all this, the kitchen room must be disposed of immediately, otherwise it will be possible to forget about the comfortable microclimate and cleanliness in the kitchen. It will be necessary to spend considerable efforts on washing the hob and walls around from the plaque of fat, and also keep the windows open for airing.
For bakeries and shops for cooking food extractor is a must. In the cottage or apartment its installation is left to the discretion of the owners. By construction standards, residential buildings are equipped with natural or forced ventilation. However, even for a small kitchen of this system, air exchange is often not enough.
Household kitchen hoods consist of:
- the electric motor;
- air purifying filters;
- elements of illumination.
They can work in pulling and recirculation mode. In the first case, room air is sucked out of the room, replaced by a new one from the ventilation system. And in the second, it is pumped through internal carbon filters and returns to the room back already cleaned.
Important! Connecting the hood to existing ventilation ducts can disrupt its operation, not all ducts are designed to increase the load.
For purely extraction equipment, it is necessary to equip the tap in the ventilation duct, which does not always look aesthetically pleasing. Plus, for its effective work requires a continuous flow of fresh air from the outside. Equipment with recirculation is easier to install, but its carbon filters will have to be changed at least once a year.
It should be clearly understood that, regardless of the model and power, the kitchen extractor is designed to clean and remove polluted air exclusively from the surface of the plate. Space under the ceiling is not available to her, so it is so important to choose the ventilation technique according to the size of the hob.
The productivity of the hood is calculated in cubic meters per hour - this is the volume of air that it is capable of pumping through itself. Power is measured in kilowatts, reflecting the amount of electricity consumed during operation. You can not confuse these two values.
Requirements norms! The productivity of the exhaust equipment must be such that in an hour the whole air in the kitchen of an apartment or a private house is renewed at least ten times.
According to SNiPs, during operation, the ventilation equipment, which includes the extractor, must, within an hour, fully update the air in the room several times. For kitchens in apartment houses, this value is determined at 10-15. It depends on the type of plate, the operating mode of the fan and other factors. To simplify the calculations, this coefficient is assumed to be taken as 12.
How to calculate the power of the extraction equipment
The performance of the hood is directly related to its performance. The more it is able to pump air, the more powerful it is the fan, which needs an electric motor to work.
For equipment connected to ventilation ducts operating only in the suction mode, the productivity should be calculated on the basis of the cross-section of the ducts. Do this without engineering knowledge and design of the home is almost impossible. A calculation of the drawing power of the area is suitable only for recirculation models. In contrast to the first option, their capacity does not affect the size of the ventilation ducts.
The simplest formula for calculating the area
The classical calculation of the productivity of a kitchen hood - the multiplication of the square of the kitchen, its height and the coefficient 12. However, the figure obtained is very conditional. It does not take into account many factors.
This formula allows you to calculate the parameters for ideal conditions:
- cooking on an electric stove;
- a kitchen room with closed doors and windows;
- A rectangular kitchen without an abundance of decorative delights.
If a gas stove is used for cooking, the coefficient 12 should be changed without hesitation by 20. In this case, apart from fumes, the hood must remove from the kitchen and products of gas combustion. Plus, in any scenario, it's worth adding 15-20% for the stock.
Another 25-30% of the power must be added to the carbon filter. It creates additional resistance for the passage of air flow.
Important nuance! Calculations of capacity and capacity for drawing should be carried out proceeding from the area of the kitchen and adjoining rooms, if they are not fenced off from the first.
If the door to the kitchen is always open or instead of it an arch, then calculate the parameters of the exhaust technology should be based on the overall quadrature of the adjacent premises. The same applies to corridors, as well as combined living rooms or halls. The absence of barriers increases the volume of treated air, as it constantly circulates between the kitchen and adjacent rooms.
Consideration of additional factors
The above calculation of productivity is designed for extraction with recirculation. If the technique works in the exhaust mode, sending the flow to the ventilation, then its efficiency is strongly influenced by the throughput of the ventilation ducts. Of course, it is possible to increase the volume of air pumped through a narrow shaft due to the increased engine power, but this leads to an increase in noise from the operating fan and overheating of the electric motor.
In most private and multi-apartment buildings, the ventilation ducts do not exceed 125 mm in the section, which allows them to pump through 400 m3/ h air. If you install a hood in the kitchen with more performance, then there will be little use from it. In addition, air ducts often have irregularities, narrowing and turns inside, which further reduces their throughput.
Important! The effectiveness of the kitchen hood depends on the mode of operation and the method of its installation, as well as the cubature of the room, the type of plate and the structural features of the ventilation ducts.
If you follow a simplified calculation, then for a small kitchen area, a low-power hood will suffice. However, formulas are formulas, and common sense never hurts. A small room smells from the plate fill faster, and their concentration in this case is an order of magnitude higher than in a spacious kitchen. For a very small room, where food is prepared, it is necessary to select a technique that is more powerful than the calculated indicators.
Choosing a kitchen hood: noise vs performance
As the power increases, the noise of the exhaust system increases. Excessive noise quickly tiresome housewife, cooked food as a result may turn out to be unsuitable for use.
Household hoods are equipped with asynchronous electric motors, which, unlike power units in vacuum cleaners or drills, work much quieter. However, when they are turned on at full power, the noise becomes noticeable. Only at small and average turns they do not create unpleasant sensations.
Advice! The optimum hood is a model with adjustable power and several modes of operation.
Completely noiseless kitchen appliances do not exist. Manufacturers are doing everything possible to reduce its noise, but they are far from omnipotent. At the same time, the noise intensity depends not only on the power of the electric motor and the fan, but also on the purity of the filters and air ducts. Without regular maintenance, the extractor will bring only a headache instead of comfort.
Video: how to choose the hood for optimal design and performance
Kitchen exhaust is part of the forced ventilation system, so the calculation of its power and capacity should be carried out together with the design of all ventilation. The above formulas will allow you to navigate in the calculated and necessary figures. For most home kitchens this is quite enough. If you want maximum efficiency and stability in your work, then it's better to turn to professionals for accurate calculations.