Calculation of the power of the kitchen hood

When choosing a ventilation device, people often pay attention only to the design of the unit or brand. But they forget about the most important parameter - this is the power of the kitchen hood (performance). Without the correct selection of this parameter, even the most beautiful unit of a well-known company will not be able to cope with its task - to effectively clean the air in the room. The performance indicator determines how much polluted air a device can pass through itself in a certain time, it is measured in meters.³/ h

Recommended power

The higher the power of the unit, the faster the air in the kitchen will be cleaned. Performance can be quickly calculated from the table below.

At a minimum, industrial devices for ventilation of kitchen premises have a capacity ranging from 200 to 300cubic meters per hour. The cost of such models is low, and they cope with their task with difficulty. Install low-power devices can only be in small rooms, provided that you do not cook very often. With frequent cooking it is recommended to use standard installation (capacity - about 600 cubic meters per hour), or with a reinforced pumping volume - about 1000 m³/ h Accordingly, the price of such devices is higher.

Power calculation

To calculate the exhaust performance, you first need to understand what functions the instrument should perform. According to the instructions, this device should clean or clean the polluted air in the kitchen. According to sanitary standards, 12 air replacement cycles must take place within one hour. That is, it should change in the room 12 times in 1 hour. Now you know where the coefficient “12” comes from in the formulas for calculating performance.

The formula itself looks like this: Q = S * H ​​* 12, where:

• Q is the power of the unit, which is measured in m3 / h;
• S is the area of ​​the room for which ventilation is needed;
• H - room height;
• 12 - the coefficient meaning cycles of replacement of air in the room.

For example:

• the area of ​​the room is 12 m²;
• height - 2.7 m;

Substitute the values ​​in the formula: Q = 12 * 2.7 * 12 = 388.8 m3. Based on this calculation, the device will produce such a volume, only using the maximum performance. Such a mode it will not survive for a long time and can fail.

To reduce the load, it is recommended to add about 15% to the calculated value.

This creates a small power reserve for the kitchen hood, facilitating the operation of the device. And for you it is possible to turn on the maximum mode only during a large smoke-filled room, for example, on the eve of holidays when a large number of dishes are being cooked.

It should be noted that all these calculations in terms of the volume of air exchange have averaged figures, since this does not take into account the various nuances:

• type of hob;
• hood type;
• room layout.

Type of hob

It depends on the type of stove what amount of pollutants can get into the air when cooking. And its updating, accordingly, should occur more often or less often. The update factor should also be changed. Power calculation for the kitchen at using electric stove differs from the standard one, since no combustion products enter the air, except for the fumes from the prepared food. The coefficient for such plates can be increased from 12 to 15, and the formula will look like this: Q = S * H ​​* 15.

Hood over the electric stove

When are you going use gas hob, then the coefficient should be increased to 20. This is done so that in addition to the fumes from the prepared food, a large amount of harmful products of gas combustion enters the atmosphere. In this case, the formula is written as: Q = S * H ​​* 20.

Hood over the gas stove

Type of hood

The units differ in the mode of operation, namely, where the air is diverted. There are 2 types of devices:

• vent;
• recycling.

Ventilation (flow) type device implies connecting it to ventilation channel in the house, for the discharge of exhaust gases to the outside. But before calculating the power, the channel capacity must be taken into account. If the house is old and the ventilation shaft is clogged, then even if you buy a powerful hood (according to calculations), it will not be able to take the air out at full capacity.And neighbors in the riser waste gases from your kitchen will be blown into the room. In such cases, you can do separate exit for ventilation outside by making a hole in the wall.

Recirculation type device contains in design filter system and does not require connection to the ventilation shaft. In most cases, cleaning takes place in 2 stages. First, large particles are absorbed by the first filter: steam, grease and fumes. Then the air passes through a carbon filter, which removes all odors, and enters back into the room.

Filters can create some resistance when pumping, which also needs to be taken into account when calculating the performance of the hood. The recommended increase in this value for such devices is approximately 30 - 40%.

Room layout

When calculating the performance of ventilation should take into account the layout of the kitchen. If, for example, an arch is installed instead of a door, or you are used to not closing the door, then the volume of the adjacent room should be taken into account in the calculations.

If kitchen combined with dining room or the living room, the requirements for calculating the performance of the device increase significantly, due to the rapid spread of odors that need to be effectively removed.

Noise level

Now, when using the above recommendations, you have made calculations of the required hood power for your kitchen, you should think about the noise that it will produce. When you choose a device in a store, you are unlikely to appreciate the device noise due to the large size of the room or other noise in the sales area. Properly assess this figure will help instructionwhich is attached to the unit.

The more powerful the device, the stronger the sound that it makes.

The manual should look at the sound parameters at maximum load and in the normal mode of the device. If the noise level is in the range of 30 to 45 decibels in the standard mode, then the operation of the device will not cause you discomfort. Such hoods can be called practically noiseless. When operating at maximum, the sound should not exceed 55 decibels. If this indicator is exceeded, then such a device may be suitable only for large rooms. Otherwise, a loud sound will cause discomfort.

Following the above recommendations, you can choose the right power hood for the kitchen. And this, in turn,will contribute to the creation of a pleasant indoor climate and well-being during cooking.