How to make ventilation for a kitchen hood. Natural ventilation in the kitchen - features and installation

Efficient ventilation in the kitchen - one of the most important conditions comfort. Odors, heat, and moisture released during cooking can easily penetrate rooms if ventilation is not working.

Types of ventilation

There are two main types of ventilation in an apartment in the kitchen:

Natural. The simplest and effective way creating good air exchange in the kitchen is natural ventilation. For it to work, two basic conditions must be met:

• In order for dirty air to easily escape into the mine, you need a supply of fresh, clean air. This condition ceased to be fulfilled properly when the widespread replacement of wooden windows with plastic, sealed, energy-saving ones began. Such windows are effective in retaining heat, but significantly reduce the effectiveness of natural ventilation.
• The ventilation system of a house is developed and calculated during the construction stage of the house and takes into account the area of ​​the premises and other factors. Intervention or change in areas of the ventilation system can significantly reduce the exhaust force or change the direction of air flow. Because of this, not clean air from the windows will enter the kitchen, but polluted air from neighboring apartments or from the toilet.

To improve the outflow of polluted air, special hoods are often installed in kitchens, which are designed to capture dirty air above the stove. The most common mistake when installing ventilation in a kitchen with a hood is that they try to replace natural ventilation with a hood. There is practically no supply of clean air. A powerful hood removes polluted air quite quickly and creates rarefied air in the apartment. If there is no supply air from the street through the windows, then the missing volume is drawn out of the toilet, where the second ventilation hole is located.

Proper organization of ventilation using a hood

Most ventilation ducts in houses built last century are not designed for the use of modern hoods. Air ducts usually have a cross-section of 13x13 cm and pass air with a maximum volume of 180 cubic meters per hour. The power of the hoods is several times higher than this value. When operating such a hood, the functioning of ventilation is disrupted. own apartment and the whole house.

Exhaust ventilation in the kitchen can work effectively if you combine the work of a forced system (hood) and a natural one. To do this, the air duct from the hood must be connected to the ventilation system above the grille.

When the hood is turned off, ventilation occurs naturally; air flows out through the grille. Air flow should be ensured through slightly open windows.

When organizing ventilation in a kitchen with a hood, you need to consider a number of points:

When installing a hood, you need to choose the correct distance from the surface of the stove to the hood hood. This distance is indicated in the documents for the hood. A shorter distance provides better traction, but may cause damage to plastic parts from hot air.

To remove air from the hood above the stove to the ventilation channel, special boxes and pipes made of aluminum and plastic are used. Smooth air ducts have less resistance to passing air than corrugated ones. The fewer bends and turns the box has, the better the traction.

When installing ventilation in the kitchen with your own hands, you can place the air duct in two ways:

• Fits on top cabinets.

• Hides with the help of finishing elements: behind plasterboard linings, behind suspended ceiling. In this case, before sewing the pipe, you need to carefully check the operation of the hood. Once the wall or ceiling is covered, it will be much more difficult to fix the problems. Kinks in the pipe or duct reduce the cross-sectional area and reduce the performance of the hood.

Features of ventilation of a private house

Kitchen ventilation in a private house is based on the same principles as in an apartment. The most frequent mistakes when installing ventilation in the kitchen of the house are:

• Incorrect location of the ventilation grille. The grille should be located at a distance of up to 10 cm from the ceiling.
• One shaft for all rooms of the house. According to sanitary and hygienic standards, a separate shaft must be provided for the kitchen, this will prevent dirty air from entering the room through the shaft from the kitchen.
• Low height of ventilation pipes, which does not create the required pressure difference.
• Lack of natural ventilation. When the electricity supplying the forced ventilation system is turned off, dirty air is not removed.

Ventilation in the kitchen, arranged in accordance with all norms and rules, will ensure the absence of odors and fresh air.

In order to have fresh and clean air in an apartment or house, the kitchen must have very good ventilation. Natural ventilation cannot cope with the task of timely removal of odors during cooking, so they hang them over the stove. special device forced ventilation - kitchen hood. How to install the hood correctly, how to secure it and connect it to the ventilation system - more on that later.

Installing a hood in the kitchen is a wise decision

How to hang a hood over the stove

With the correct size, it is equal in width to or even slightly larger than the width of the slab. To install the hood correctly, you need to place it correctly and secure it. The electric hood is located exactly above the stove. The installation height depends on the type of hob:

• The minimum permissible height for hanging a hood above a gas stove is 75 cm.
• Above the electric value is slightly less - 65 cm minimum.

You determine the exact height yourself - based on the height of the housewife who will cook. The bottom edge of the hood should be slightly higher than her head. Less than minimum distance It’s not worth hanging, but higher is possible. But if you need to hang equipment higher than 90 cm from the level of the stove, you need a unit with increased power so that contaminated air is removed effectively.

The hood is attached depending on the type. Built-in - to a specially ordered cabinet size. Wall hung (flat) and dome (fireplace) - to the wall. The fireplace hoods themselves can consist of two parts - a unit with a motor and filters and a dome. Both parts are attached independently of each other, but so that their outputs coincide.

It is worth mentioning separately about island hoods. They are attached to the ceiling. The kit includes a suspension system and clear instructions on what to do and how to do it.

Installation stages

The entire installation and connection process can be divided into several stages:

If there is an outlet nearby, there will be no problems with connecting to electricity. The other steps are also not very complicated, but let’s look at them in more detail.

Attaching a wall or dome model to a wall

Although these two models differ in appearance, they are attached to the wall. They have four holes on the back wall of the case - two on the left, two on the right. Many manufacturers provide their products with a mounting template on which the locations of the fasteners are marked. All you need to do is lean the template against the wall and move the marks. If there is no template, measure the distance between the holes and transfer it to the wall. If you have an assistant, you can ask them to hold it at the selected height and make the marks yourself.

Then everything is simple: use a drill to make holes of the appropriate size, insert plastic plugs for the dowels, then hang the hood on the dowel-nails. Naturally, we check that the installed equipment is horizontal.

This method is good if the wall is smooth and nothing interferes. Often there is a gas pipe running next to the stove, which makes it impossible to hang the hood close to the wall. In this case, you can nail wooden blocks to the wall, and attach the hood to the bars. This is a simple option, but not a very good one - the bars become covered with soot and are difficult to wash.

The second option to install the hood behind the pipes is to use a hairpin screw (the second name is a plumbing pin). They have a thread for screwing into the wall, a smooth part, which makes it possible to carry the hood some distance from the wall, and a smaller thread with two nuts, which will be used to secure the body. There are these studs in different sizes, choose which one you need, but all the nuts are made for a bit or an octagonal wrench.

This option for mounting the hood is universal, simple to implement, and reliable. It is also more convenient to clean - the metal is usually stainless, and it is easy to clean it from deposits.

Installing a built-in hood in a cabinet

The built-in hood is almost completely hidden in the cabinet made for it. It is attached in exactly the same way as described above - with screws, only they are screwed into the walls. Only in advance it is necessary to make holes for the air duct in the shelves located above. This is done after the hood has been purchased, since the location of the air outlet depends on the company and model.

If the cabinet is hanging, it is better to remove it. In the removed cabinet, install the hood in place, mark the location of the air outlet on the bottom shelf, and cut it out. To do this, it is easier to use a jigsaw and a file with fine teeth. The laminate file leaves almost no chips. If desired, you can seal the cut area with a plastic C-shaped furniture profile. They are rigid and flexible. The flexible one is easy to use - it bends at any angle, the hard ones will have to be heated before installation construction hairdryer. These profiles are “set” with glue; most often “liquid nails” are used. After installation in place, remove any remaining glue (with a damp, clean cloth) and fix it. masking tape to the shelf. We cut off the excess profile with a fine-tooth file and clean the cut. sandpaper with fine grain.

We make holes in the other shelves in the same way. By the way, they may no longer be round, but rectangular - it depends on the cross-section of the air duct you have chosen.

After this, all the shelves are installed in place, the cabinet is hung and secured. A built-in hood is attached to it with screws through holes in the body. Next is the process of connecting the air duct.

How to connect the hood to electricity

Since the power consumption of kitchen hoods rarely exceeds 1 kW, they can be connected to regular sockets. It is desirable that they be grounded. This requirement must be met if you want the warranty to be valid.

If the wiring in the apartment is old, you can install the grounding or grounding wire yourself. Just don’t attach it to water supply or heating pipes. This threatens the possibility of electrical injury or even death for you, members of your group or neighbors.

To reach the ground wire, on the shield, find a busbar with wires attached to it or a pipe to which it is welded/screwed stranded wire. You can also connect your own stranded wire to these devices (without discarding those that are already there). For it to work properly, the cross-section must be 2.5 mm, the conductor must be stranded copper, and a non-flammable sheath is desirable.

Some hoods come with a plug at the end. There are no problems with connecting such models - just plug into the outlet and that’s it. But there are models in which the cord ends with wires. This is not because of the greed of the manufacturer, but so that the consumer himself can decide how best to connect the equipment. If you want, you can connect a plug. This option is not suitable - take the terminal block and connect through it. Another option is Wago terminal blocks. You need to take three of them - according to the number of wires. In one terminal block, identical wires from the hood and from the panel are connected - phase to phase (the colors may be different here), zero (blue or dark blue) to zero, ground (yellow-green) to ground.

Air duct for kitchen hood

One of the stages of installing a hood is the selection and installation of air ducts. Air is removed from the kitchen room temperature, therefore there are no special requirements for air ducts and any can be used. Three types are usually used:

There is also a difference between plastic and corrugated air duct - price. Polymer ones are more expensive. Despite this, if you have the opportunity to install a hood using PVC, install them. With an equal cross-section, they provide more efficient air removal and are also less noisy.

The cross-section of the pipes for the air duct is determined by the size of the outlet opening on the hood. In the case of rectangular pipes, an adapter is used.

Air duct sizes for hoods

Round ducts are available in three sizes: 100 mm, 125 mm and 150 mm. This is the diameter of plastic pipes and corrugated hoses. There are more sections of flat air ducts and they are presented in the table.

How to choose a size? In the case of round pipes, their diameter must match the diameter of the hood outlet. It is very undesirable to install an adapter at the outlet and then use an air duct of a smaller diameter - this will reduce the speed of air purification. And even if the hood is very powerful, it will not cope with air purification.

With the choice of the cross-section of a rectangular air duct - its cross-sectional area should not be less area cross-section of the outlet pipe. And the connection occurs through a suitable adapter.

How to attach corrugation to the hood and ventilation

If you decide to install a hood and use aluminum corrugation for the air duct, you will need to think about how to attach it to the body and to the ventilation. To do this, you will need clamps of the appropriate size. They can be metal or plastic.

To connect the hood to the ventilation system, you will also need a special ventilation grille. It has a hole in the upper part for connecting the air duct pipe. There are holes in the lower part to remove air from the kitchen using natural circulation when the hood is not working.

A grate with a protrusion is suitable for attaching the corrugation - around the hole there is a side of several centimeters, onto which the corrugation is placed, after which it is secured using a clamp of a suitable size.

The corrugated air duct is attached to the hood using the same principle. It has a protrusion on which the corrugation is put. The connection is tightened using a clamp.

How to attach an air duct to walls

For plastic air ducts there are special fastenings in the form of latches. They are first mounted on the wall using dowels. The installation step depends on the curvature of the route, but on average, 1 fastening per 50-60 cm is sufficient. Pipes are inserted into these latches during installation with little effort.

If the air duct needs to be fixed to the ceiling, you can use the same fastenings. But if you need to maintain a certain distance from the ceiling, this type of installation will not work. In such cases, take perforated plasterboard hangers, attach them to the ceiling, and then use small PVC screws to attach an exhaust duct to them.

Corrugated air ducts are attached to the walls using clamps or plastic puffs big size. If necessary, they are also mounted to the ceiling using perforated aluminum hangers.

Where and how to remove the air duct

Most often, the air duct from the hood in the kitchen is connected to vent, through which natural ventilation occurs (due to draft). This is incorrect, since in this case most of the grille is closed by the air duct, and air exchange through the remaining accessible holes will be clearly insufficient.

Correctly connect the air duct to a separate ventilation duct. In this case, the same grille as in the photo above is installed on the hole.

If there is no separate ventilation duct, but there is an external wall nearby, you can take the pipe to the street by placing a grille outside. These are two ways to have normal ventilation and ensure normal operation of the hood.

How to take it outside

To install the hood and lead the air duct into the wall, you need to make a hole in it. And this is the only difficulty. Next, an air duct is inserted into this hole and sealed with mortar. From the outside, the hole is covered with a grill to prevent debris from getting in and birds and small animals from settling in.

To prevent outside air from blowing into the room, install a check valve (in the figure above it is indicated by an oblique line). By the way, it is advisable to install it when connecting the air duct to the ventilation system - so that odors from the pipes do not enter the room.

The check or anti-return air valve is a lightweight plastic or metal plate. It is movably attached in two places to the pipe - at the top and bottom, the petals are supported by a weak spring. While the hood is not working, the valve blocks access to air from outside. When the hood is turned on, the air flow bends the plate forward, pressing the spring. As soon as the hood is turned off, the plate returns to its place using springs. If you install a hood without this valve, it may be too cold in the kitchen in winter - outside air will enter the room without problems.

So that the hood does not interfere with natural ventilation in the kitchen

Using a tee and a check valve, by the way, you can install the hood so that it does not interfere with natural ventilation in the kitchen. You will need a special ventilation grille for connecting hoods, a check valve and a tee. A tee is attached to the ventilation grille, an air duct from the hood is connected to its lower entrance, and a check valve is installed on the free outlet, only so that the petals are locked when air passes from the pipe (pictured below).

How does such a system work? When the hood is turned off, the petals of the check valve are bent, air from the kitchen enters the ventilation duct through the grille and the open outlet of the tee. When the hood is turned on, the air flow from it unfolds the valve plate, and the air flows into the ventilation system. When the hood is turned off, the springs again open air access through the tee.

Externally, such a system does not look very attractive and will have to be disguised in some way. But this is the only way to connect the hood to the only existing ventilation outlet and not reduce air exchange.

Everyone knows that good ventilation in the kitchen is integral element healthy microclimate of an apartment or private house. To assist the traditional natural ventilation system duct located under the ceiling, today it is customary to install a kitchen hood above the stove and/or a kitchen exhaust fan duct opening. However, not everyone understands that ill-designed forced exhaust can not only fail to give the desired effect, but also significantly worsen the functioning of the natural ventilation system. Let's look at how to make a hood in the kitchen of an apartment or house effective and safe.

During the cooking process, various harmful substances. They can be divided into two groups: deadly and simply very harmful.

Comfortable ventilation in the apartment in general and in the kitchen in particular is the key to cleanliness and well-being

Dangerous "kitchen" pollution

• Carbon monoxide (carbon monoxide, CO) is a toxic substance that in high concentrations leads first to poisoning and then to death. Owners of electric stoves have nothing to worry about; such equipment is not a source of CO2.

Carbon monoxide is formed during the combustion of natural or biogas, cooking in traditional wood stove. Carbon monoxide is especially dangerous because it has no odor, a person may not feel its presence and accumulation in the room. Carbon monoxide is not absorbed by carbon filters, and the hood turned on in air filtration mode is useless in the fight against CO.

Carbon monoxide poisoning is very dangerous. More people die from it in their homes than from fires, tsunamis, floods and earthquakes combined

• Every time you turn on a gas burner or water heater, a small amount of unburned fuel enters the room. natural gas. A normally functioning natural ventilation system is designed for a similar level of gas emissions and copes with it quite well.

It’s a different matter if there is a leak from gas equipment or pipelines. Household gas itself has no odor, but a “smelly” fragrance is added to it - ethyl mercaptan. If you smell gas, you should immediately open the windows and call emergency services.

The installation of gas leakage and CO detectors will help to significantly increase the safety of people when using gas equipment. In case of danger, the sensors can emit a piercing signal or control a servo drive, which automatically turns off the gas supply from the main and notifies the emergency service about the problem.

The gas leak sensor is capable of promptly detecting a dangerous concentration of natural gas, propane or butane in the air and signaling it

Harmful contaminants in the kitchen

• Kitchen fumes released when frying foods. It consists of volatile particles suspended in the air, mainly oils and fats. After strong heating in a frying pan, harmless food substances acquire properties harmful to humans, even carcinogenic. IN best case scenario dirt and grime settle on walls, furniture and dishes, and in the worst case, in our lungs.

• Cooking also produces water vapor. It is, of course, practically harmless compared to other types of pollution. But there is no benefit from evaporation; excess moisture does not improve the microclimate in the room.

The fumes generated during cooking are not beneficial to the body.

From the above we can conclude that effective, constantly functioning kitchen ventilation is extremely important. If for owners of electric stoves this is a matter of hygiene and cleanliness in the room, then for those who use a gas stove (stove, wood-burning oven) indoors for cooking, this is a matter of safety.

Owners of gas stoves should pay close attention to the performance of the ventilation system and periodically check the presence of draft in the ventilation duct. If in the kitchen, in addition to the stove, a gas water heater or a heating boiler is installed, the normal functioning of the natural exhaust ventilation acquires more higher value.

Kitchen ventilation systems: natural or forced

Many consumers are wondering: which kitchen hood is better, natural or forced? We answer: both are better. Natural and forced exhaust, although they serve a common purpose, do not replace one another. A natural ventilation system is mandatory for a kitchen in an apartment or private house. Let us repeat, the presence and functionality of a natural ventilation system is of particular importance for rooms with gas appliances.

Forced exhaust ventilation for the kitchen is a good thing, even very good. But optional. It can be argued that natural ventilation provides greater safety, while forced ventilation provides comfort.

Ventilation in the kitchen with a hood is an element of the overall ventilation system in an apartment or house

Let's take a closer look at the possibilities different types ventilation, their structure, advantages and disadvantages.

Natural ventilation in the kitchen

The natural ventilation system is well known to all apartment owners through the channels in the kitchen and bathroom walls leading to the roof of the house. Harmful gases and polluted air are removed through the ventilation duct, fresh air enters through the cracks in the windows or special ventilation valves in the walls or window frames. Warm air heated on the stove, due to its lower density, naturally tends to evaporate from the room upward, to the street, where the temperature is lower.

Natural ventilation in a private house in the kitchen, bathroom, furnace, it removes polluted air through vertical channels to the roof. Fresh comes from the street through windows or valves in the walls

Properly designed ventilation with natural draft removes a relatively small volume of air per unit of time, but does so constantly. The ventilation duct located under the ceiling can cope with even a small leak of natural gas, which is lighter than air and rises to the ceiling.

Carbon monoxide, which is formed in relatively small quantities from the working burners of a gas stove, is also quite successfully removed by natural ventilation. Natural ventilation is somewhat less effective at removing kitchen odors and excess moisture during moderate-intensity cooking.

It is necessary to periodically, at least once a month, check for sufficient draft in the ventilation duct. You can check this without special instruments: if a sheet of paper “sticks” to the hole, there is traction.

What is good and what is bad in such a system:

Advantages of a natural ventilation system

• Ventilation with natural draft functions constantly with rare exceptions (see below, in the “cons”).

• Provides general ventilation of the home in combination with ventilation ducts in the bathrooms.

• Copes with the main types of hazardous contaminants released during cooking. Provides safety in the event of a small gas leak. Natural ventilation adequately removes kitchen odors and excess moisture during moderate-intensity cooking.

• Natural ventilation is “free”. In an apartment or private house built in accordance with building codes, it is available by default. There is no equipment that requires repair. No electricity required.

• Quiet operation.

Disadvantages of natural ventilation

• In hot weather and in the off-season, when the outside air suddenly warms up after prolonged cold weather, the efficiency of the natural ventilation system drops sharply. Under unfavorable circumstances, a reverse movement of air may occur: it will begin to flow through the channel from the street into the room. For a kitchen with a gas stove installed, this can be very dangerous, especially if there is gas water heater. In hot weather and during a sudden thaw, it is recommended to ventilate the room through open windows.

• Natural ventilation removes a relatively small volume of air per unit time. If the owners decide to fry a frying pan full of cracklings, the ventilation system will not cope and the persistent kitchen “aroma” will instantly spread throughout all the rooms.

• Ventilation works normally only if there is a sufficient volume of air flow from outside. Modern plastic windows, adjusted “for winter,” are practically airtight when fully closed. To ensure the outflow of air into the channel, you should open the windows slightly during cooking, at least in micro ventilation mode.

• The ventilation duct may be clogged with snow and debris. Selfish and technically illiterate neighbors above can block the ventilation of the lower residents by creating a niche for the refrigerator in their kitchen by removing the ventilation shaft or part of it.

• It is necessary to regularly check the draft and, if necessary, clean the ventilation ducts.

How to properly create natural ventilation in the kitchen

There is ventilation for the kitchen in an apartment built in accordance with the standards; you just need to check its functionality. But how to properly make natural ventilation in a private house? Ventilation ducts should be located in “dirty” rooms: kitchen, toilet, bathroom, furnace room, utility room, bathhouse. In order to ventilate the entire house, and not just the kitchen, the air flow must come from “clean” rooms: living room, dining room, bedrooms.

Ventilation design, if everything is done in accordance with construction and hygiene standards, involves the calculation of many system parameters. When determining the cross-section of ventilation ducts, the type of installed equipment, volume of premises, building design, and climatic conditions of the area are taken into account.

The calculation is difficult for a non-specialist; those who want to delve into the topic can study SP 60.13330.2012, 54.13330.2011, 62.13330.2012, 131.13330.2012, 7.13130.2011 and SanPiN 2.1.2.2645-10. We will give only basic recommendations, which, in our opinion, are sufficient for installing natural ventilation in most private houses:

• If there are four burners, the volume of air removed must be at least 90 m3/h. To do this, it is enough to bring to the roof a vertical exhaust duct with a cross-section of at least 0.02 m2. This corresponds to the channel round section with a diameter of 16 cm or a square size of 14x14 cm (half a brick). More is possible, less is not possible.

• The entrance to the channel should be located on the wall at a distance of 15-30 cm from the ceiling or on the ceiling itself. The last option can be implemented in a private house.

• In order for the natural draft to be sufficiently stable, the channel must be relatively high. Optimal traction is ensured when the channel height is at least 5 meters. Moreover, it should not be cold. In a channel located outside the building and not insulated, during the cold season the draft will be weak or not at all. In a private house, it is best to place ventilation ducts in the center of the house, closer to the ridge.

Forced exhaust ventilation

A ventilation system where polluted air is removed using a fan is called forced. Kitchen exhaust fans can be installed different ways:

• Mount directly onto the existing vertical natural exhaust ventilation duct leading to the roof.

• Make a hole in the outer wall where the exhaust fan will exhaust polluted air directly from the room.

Modern equipment allows you to drill holes of the required section in external walls quickly and without dust

• You can hang a wall-mounted kitchen hood with a built-in fan above the stove. Route the air duct from the hood into an existing ventilation duct or into an additional hole in the wall.

• Insert a fan into the window vent of a “Soviet-style” window and you will get a simple and cheap window hood.

Advantages and disadvantages of forced ventilation

• When properly designed, forced draft ventilation has high performance and is potentially capable of quickly removing significant volumes of contaminated air during intensive cooking.

• A kitchen hood installed directly above the stove will remove most of the dirt before it enters the room. As a result, cleaning the kitchen will become much easier.

• Polluted air is removed only while the kitchen hood fan is running.

• A forced system costs money: a kitchen fan or a hood with a fan, their maintenance and wasted electricity have their price.

How to properly install an exhaust fan on a natural ventilation duct

When installing the fan, the following points must be taken into account:

• If your kitchen exhaust fan has a check valve that prevents air from the duct from flowing into the room when the fan is not running, the check valve must be removed. Otherwise, the operation of natural exhaust will be disrupted.

• A typical cheap household fan of an axial design is not designed to remove air from a vertical duct. The performance indicated in the passport (the volume of air removed per unit of time) will be realized only if the fan removes air from a horizontal channel, and even then it is not very long.

When connected to natural exhaust inexpensive fan it will be difficult to overcome the resistance of friction and the air column, its performance will noticeably drop in comparison with the declared one. The higher the channel, the greater the fall.

The axial fan is structurally simple and cheap

• There are special household fans of centrifugal design designed to operate in vertical channels. The drop in productivity depending on the height of the channel is not as great for them as for axial ones. Actual performance when working in a vertical channel will be close to the declared one.

Centrifugal exhaust fans for the kitchen can be built-in or overhead. Disadvantages of centrifugal fans: high price (they are five times more expensive than axial analogues) and relatively large dimensions.

The centrifugal exhaust fan in the kitchen has a more complex design than the axial version. An impeller with multiple blades rotated relative to its axis is capable of creating significant air pressure, which makes it possible to overcome resistance when removing air into a high vertical channel with small losses in performance. The maximum performance of centrifugal fans is lower than that of axial fans with a motor of similar power. But in difficult working conditions their capabilities are more fully realized

So, an axial fan is cheap, but it is of little use when installed on a natural ventilation duct. Centrifugal is effective, but expensive. A suitable alternative- install the fan in a horizontal duct leading through the outer wall. In this case, you can use a cheap axial exhaust fan without compromising its performance.

Graph of the performance of household fans with motors of similar power depending on the pressure (height of the vertical channel). On the left is an axial fan, on the right is a centrifugal fan. As can be seen from the graphs, when overcoming a pressure of 40 Pa (approximately corresponding to a channel with a height of 25 m), the performance of an axial fan will drop by 80%, and a centrifugal one by only 20%. That is, in these specific conditions (the second floor of a “nine-story building”), the “centrifugal” is four times more efficient than the “axial”

When ducting through a wall, it is necessary to install a check valve at the outlet from the outside. Unfortunately, it is not always possible to drill a hole in the wall if we are talking about a city apartment. But this is not a problem in a private home.

Features of installing a kitchen hood

We won’t talk about how to install a kitchen hood; this should be described in detail in the instructions for it. Let us only remind you that it is necessary to strictly observe the specified height of its placement relative to the tabletop. We also note that using a hood in recirculation mode (without removing air) coupled with a carbon filter will clean the air only from a portion of aerosol particles, mainly fats. Gas combustion products will remain in the room. In addition, a carbon filter that costs some money gets clogged quite quickly and requires replacement.

The hood should be placed higher above a gas stove than above an electric one.

Let's name the main features that should be taken into account when choosing and connecting a kitchen hood:

• A kitchen hood fan, like a household fan installed on a duct, can also have an axial or centrifugal design. Expensive hoods in which they are used centrifugal fans, they remove air well through a vertical channel, the loss in performance is tolerable.

In cheap hoods, axial fans are often installed; when connected to a vertical duct, they are ineffective. Full operation of the hood with axial fan is achieved only by exhausting air through a short horizontal duct through the outer wall.

• When connecting the hood to a vertical natural ventilation duct, it is recommended to remove the check valve on it, if any. In a horizontal channel, the valve is required at the outlet to the outside. It is better to leave it on the hood.

• The cross-section of the ventilation duct should not be less than the cross-section of the hood outlet. You can go from round pipes for rectangular ones, the main thing is not to narrow the section.

It doesn’t matter what shape the air ducts for connecting the hood will have, the main thing is not to reduce the cross-section of the duct

• When connecting the hood to a vertical duct, it should not interfere normal operation natural ventilation. By the way, many people do not take this requirement into account and, unfortunately, most hoods in our homes are installed incorrectly. We will devote the next section to the question of how to properly connect the hood to the ventilation in the kitchen.

How to properly connect a pipe from a kitchen hood to a natural ventilation duct

From the outlet of the kitchen hood, we need to stretch a pipe of the appropriate cross-section and insert it into the hole in the wall leading into the vertical channel of the natural ventilation system. In practice this is done in different ways:

Sometimes only the pipe supplying air from the hood is connected to the vertical duct, completely closing the opening from the room. It is absolutely forbidden to do this, because the operation of natural ventilation will be disrupted.

An example of how you should never connect a kitchen hood: a room with a gas stove lacks normal natural ventilation. Even if you remember to remove the check valve on the hood, the natural air suction above the stove will be weakened due to the additional resistance to air movement that has arisen. In addition, harmful gases accumulating near the ceiling will not be removed at all.

Many sellers of building materials and finishers recommend connecting the hood to the natural ventilation system through an adapter plate with two holes. One of them is designed to connect the hood, the second opens from the duct into the room. It seems that an exhaust hood was provided and natural ventilation was preserved. Actually this is not true. Firstly, when the hood is operating, almost all of the removed air is returned back into the room. It is much easier for him to exit back through the nearby hole than to go up the channel.

A frequently used connection is the air duct from the hood (1) to the natural ventilation duct (3) through an adapter with two holes. While the hood is not working, air outflows from the room through the second hole (2). But when the hood is turned on, most of the air it removes returns to the room

Secondly, the cross-section of the hole for natural exhaust decreases, unless it is specially expanded. Connection via a two-hole adapter is widely used, but we consider it incorrect due to its very low efficiency.

A widespread but ineffective design for connecting a hood to the duct of a natural ventilation system

So that both natural and forced ventilation from the hood to function fully, two requirements must be met:

• While the hood is operating, the second hole must be closed so that the exhaust air is not thrown back into the room.

• The total cross-section of the grid openings for natural ventilation should not be less than the cross-section of the vertical channel.

This can be achieved by increasing the area of ​​the natural ventilation grille and installing a check valve behind it so that it closes after turning on the hood. The valve must be installed in such a way that the supporting air flow from the hood closes it, and when the hood is turned off, the valve opens automatically.

A check valve (5) was installed on the hole in the wall in the natural ventilation channel (4), which opens with slight air movement, but closes against a noticeable air flow. When you turn on the hood, it blocks the air from escaping back into the room and you have to climb up the vertical duct to the roof

How to select and install an air check valve when connecting a hood to a duct

For our purposes, from many types ventilation valves Only one will do - without a drive, without a spring, with a damper that is not divided into segments and whose axis of rotation is shifted relative to the center of symmetry.

Of the three air valves shown, only the one on the left is suitable for our purposes.

After we have selected and purchased the valve, we will have to tinker with installing it in the desired position. In normal mode, the air valve should work like this: there is no air movement - the damper is closed, the air flow opens it. We need to get the opposite result: while the hood is not working, the valve must be completely open. When the hood is turned on, the air pressure from inside the duct should close it. The relatively weak natural movement of air from the room into the duct should not affect the operation of the valve.

The principle of operation of a check valve when connecting a hood to a natural ventilation duct. The illustration shows a spring-loaded valve with a two-piece flapper. Theoretically, this type of valve can be used for our purposes, but in practice it is not easy to select it so that the closing force and air pressure coincide

In the standard position, such a valve is positioned in a horizontal channel in such a way that the damper mounting axis is positioned horizontally, and the larger (and heavier) segment of the curtain “looks” down. In this case, the valve, if there is no air pressure, will be closed. We need to achieve the opposite, the valve must be open. This can be achieved in two ways:

• Install the valve strictly horizontally so that the mounting axis is rotated at an angle of 5-60º to the vertical, while the larger damper sector should be at the top. The angle of inclination at which the damper will be fully open when the hood is not working will have to be selected experimentally. The force to pull the damper and close the valve must be sufficient; a low-power hood may not provide it.

Installation option air valve with tilt of the damper rotation axis

Once the valve is installed and adjusted, the vent can be covered with a grille.

• Position the valve axis strictly vertically, but tilt the valve itself slightly (about 5º) towards the entrance to the natural ventilation channel. The larger segment of the damper should “look” towards the channel. In this case, it will outweigh and the damper will open under its own weight, just as crookedly hung doors open by themselves. The required force to close the valve will be small; you can use a hood of any power.

The axis of rotation of the air valve is set strictly vertically, but it itself is slightly tilted towards the channel. Notice how the valve was hidden in the cabinet for the built-in hood. Air will enter the cabinet from the hole in the top shelf

From the following video you will learn how to use a non-return air valve to connect a kitchen hood to an existing vertical duct, ensuring its maximum performance and without disturbing natural ventilation:

Centralized forced ventilation systems

It is worth mentioning centralized ventilation systems Oh. Office buildings and hotel complexes often have unified system ventilation serving all areas of the building. In housing, as a rule, ventilation is combined within an apartment or private house.

Centralized forced ventilation can be exhaust, supply and exhaust and supply and exhaust with heat recovery. We are convinced that only the last option is suitable for the domestic cold climate.

A supply and exhaust system with heat recovery is not cheap, but it provides real benefits in the form of savings on heating costs and a favorable microclimate. Options without recovery at lower costs are ineffective in our cold climate.

In the supply and exhaust system, air is removed from “dirty” rooms and supplied to “clean” rooms through a system of ventilation ducts. Exhaust and fresh air “meet” in the recuperator, where thermal energy from the heated air being removed is transferred to the cold air coming from the street. In this case, the air flows do not mix.

Operating principle of a ventilation unit with a plate heat exchanger. Warm exhaust air and cold fresh air pass in opposite directions through a heat exchanger consisting of many plates made of a material with good heat transfer. Warm air, without direct contact with cold air, gives it thermal energy

A properly designed and installed ventilation system with heat recovery ensures the transfer of up to 90% of thermal energy from warm air to cold air, which can significantly reduce heating costs and supply air at a comfortable temperature to the premises.

Supply and exhaust recuperative ventilation systems the best way suitable for modern energy-efficient houses. In Scandinavian countries, this type of ventilation has been mandatory for buildings under construction for many years now, replacing natural exhaust hood.

Centralized device supply and exhaust system ventilation with heat recovery. The exhaust air is collected in “dirty” rooms, and fresh air heated in the heat exchanger is supplied to “clean” rooms.

It is problematic to combine centralized ventilation systems with gas stoves. For a gas stove, you will still have to provide natural ventilation from the room or install complex emergency automation. It is difficult to adequately combine two different ventilation systems (with an exhaust hood - three) in one room. An electric stove does not create such problems.

Local forced ventilation devices (room ventilators)

Local ventilation devices with heat recovery (room ventilator) also deserve mention. Their operating principle is similar to central systems: The outgoing air heats the incoming air. The ventilator provides ventilation in one separate room.

Some models resemble in shape and dimensions indoor units split air conditioners. The illustration shows a MitsubishiElectricLossnay room ventilator. The circulation fan is located on the right side of the case, the paper heat exchanger is on the left. To install it in the outer wall, you need to drill two holes with a diameter of 8 cm

Equipping a house or apartment with local forced ventilation with heat recovery is several times cheaper than installing centralized system. And the level of comfort obtained is not much lower.

Local ventilation with recovery is very good for living rooms. A ventilator in the kitchen wouldn’t hurt either, but natural ventilation and a powerful hood vented horizontally into the wall would be more useful. When choosing local ventilation devices, preference should be given to those models in which the volume of supplied air exceeds the volume of air removed.

A popular and relatively inexpensive “breathing” room ventilator, where the removal and supply of air occurs alternately through one channel. The ceramic recuperator accumulates heat while it passes through warm air and then gives it to the cold one

The procedure for changing the ventilation cycles of a “breathing” ventilator. This device is well suited for living rooms, but not for the kitchen

What type of ventilation to choose for the kitchen in a house or apartment

For those who build a solid Vacation home or equipping an elite apartment, erecting an energy-saving building using “passive house” technology, it is worth paying attention to an expensive, but comfortable and economical system forced supply and exhaust ventilation with heat recovery. In the kitchen you should install a powerful hood with outlet to the wall; it is better (and healthier) to use an electric stove. If the house has a gas boiler, the room where it is installed must be equipped with natural exhaust and independent air flow.

For those who are building their own house on a more modest scale and have a limited budget, we advise that you definitely provide vertical channels for natural ventilation in the kitchen, bathrooms, furnace room, bathhouse, utility room and hallway if clothes are dried there.

Ventilation in a private house in the kitchen should be supplemented by a hood above the stove with a separate air duct. It is best to route the duct for removing air from the hood not to the roof, but through the outer wall to the street. A check valve should be installed outside to prevent cold air from entering inside. A fan on the natural ventilation channel should be installed in the toilet and bathroom; in the kitchen, if there is a hood, this is not particularly necessary.

It is best to route the air duct from the hood outside through the outer wall

For an apartment, we recommend a similar option: natural ventilation (available by default), good hood above the stove, fan in the bathroom. It is advisable to vent the hood through the wall; if this does not work, use the scheme described above with a check valve. In our opinion, an additional kitchen fan is not needed.

Finally, we would like to remind you once again that properly selected and installed hood and a kitchen fan will add comfort, but will not replace natural system ventilation. And incorrect connection of the hood may not only not improve, but also significantly worsen the performance of ventilation. We recommend that you pay attention to the issues of room ventilation Special attention, trust its design, installation, and connection of the hood only to competent craftsmen.

The design of ventilation and exhaust systems for kitchen premises is, in fact, very simple. There are many nuances, ignoring which we have every chance of creating incorrect and ineffective ventilation. Ventilation, which, instead of purifying the air, will literally poison our lives.

Natural kitchen ventilation and the law of conservation of air volume

Long gone are the days when residents of private houses and city apartments were satisfied with a natural ventilation system in the kitchen. Despite the relatively low efficiency of such systems (especially during cooking), the principles of their arrangement will always be relevant. The fact is that the continuous functioning of natural ventilation is possible only if certain conditions are met. Namely: ventilation ducts must ensure unhindered removal of air masses from the room, and the influx fresh air to the kitchen must be carried out continuously.

Effective operation of the ventilation system is only possible when the volume of air leaving the room is equal to the volume of air entering the kitchen.

What to put in for air flow in the kitchen

Compliance with the first condition can be ensured by timely cleaning and maintenance of ventilation ducts. Fulfillment of the second condition will help the simplest supply valve to the kitchen as part of the ventilation system.

Squirrel User FORUMHOUSE

You can always embed a supply valve into the wall, which will enhance natural ventilation.

Just a couple of decades ago, most living spaces were equipped wooden windows. Their tightness, as we know, left much to be desired. Therefore, the question of forced ventilation did not arise: the flow of fresh air into an apartment or house occurred practically without human intervention. Today, when we are dealing with sealed double-glazed windows and powerful kitchen hoods, the supply ventilation valve is built into the design plastic window or built into the wall is not a whim, but a necessity.

The simplest supply and exhaust ventilation with your own hands

If your house or apartment has a natural ventilation system with an exhaust vent in the kitchen, then you are practically not in danger of smelling cakes in the bedroom. If your house is just being built, then it’s time to take care of having such a system. Operating in normal mode, it will constantly refresh the air in the kitchen area, and if its efficiency is insufficient, it can always be improved by equipping it with a small exhaust fan.

If you live in a private house, then a roof fan installed in the ventilation duct will help modernize the design of the system without creating noise during operation.

Andrey Vasiliev,

FORUMHOUSE user, Moscow - Rostov Veliky

If a private house, then the problem can be solved simply by installing a roof fan. Set it up and let it make noise outside.

If you live in an apartment, then a fan installed in the ventilation hole will qualitatively improve the flow of fresh air into the room.

Hel User FORUMHOUSE

When I turn on regular fan, built into the kitchen vent, even when open door the smell goes into the ventilation.

A good solution could be a duct fan that can significantly increase the power of the exhaust flow.

By installing the listed devices, you can turn natural ventilation into a simple supply and exhaust system with your own hands.

Rules for creating air ducts

A natural ventilation system that does not have auxiliary fans can play a cruel joke on you at any time. This is what we're talking about physical phenomenon, as "tipping over thrust". It is observed when, under the influence external factors the exhaust flow loses strength or completely changes its direction (air from the street begins to enter the room through the ventilation shaft). Therefore, it is advisable to place the ventilation duct on the roof, and its height should exceed the height of the ridge. This requirement is relevant both for natural ventilation and for the “forced ventilation” system in the kitchen.

Matilda User FORUMHOUSE

Traction overturning often happens in the off-season, when it is humid and chilly outside. If the ventilation pipe is installed below the ridge, then overturning will become a constant phenomenon and will depend on the direction of the wind.

The pipe and ductwork that will pass through cold areas (the attic and the outside of the building) should be insulated.

A ventilation duct led outside through an ordinary horizontal hole in the wall, due to the absence of a pressure difference inside and outside the building, will perform its function only when the fan is turned on.

Ventilation in the kitchen with a hood

We examined the features of systems that operate continuously and are designed to ensure effective air exchange in the kitchen. Now let's talk about kitchen hoods - devices that come into operation during the hottest hours, forcibly helping us get rid of the smell of food cooking on the stove.

A kitchen hood, unlike a standard ventilation system, helps capture smoke, steam and grease particles that enter the air during cooking. Therefore, the requirement to install an exhaust device in addition to the existing ventilation system is justified.

Arsenal&Natalya User FORUMHOUSE

A hood is needed if you don’t want to do frequent renovations in the kitchen. There are no miracles, and without forced removal of evaporation products to the outside, they settle on walls, ceilings, furniture and people.

You need a hood in the kitchen, let's think about what kind of hood to make.

According to the principle of operation, hoods are divided into two types - flow and recirculation. Flow-through systems remove air from the room to the street, while recirculation systems filter out impurities and supply air back into the room.

It is clear that recirculation exhaust devices are not popular among users of our portal. And there are several reasons for this: the need to frequently replace the filter, low efficiency and the inability to remove excess heat from the room.

Andrey Vasiliev

Such a hood is of little use (in my house it’s only there because I’m too lazy to pull a pipe to the duct). Grease quickly accumulates on the walls and is very difficult to wash off (especially if the house is decorated with wood). If you are concerned about installing a hood, which is very useful (especially if you like fried fish, meat and other grills), then you need to vent it into the ventilation duct (I just don’t recommend going outside through the wall, because the wall will get dirty over time).

Considering all the disadvantages of recirculation units, they should be used only in exceptional, special cases.

A flow hood removes by-products formed during cooking outside the room. By installation method flow hoods There are suspended, built-in, corner, dome and island. Regardless of what type of installation the hood is, the removal of air from the room must be organized according to the same principle. It lies in the fact that the existing hood must be connected only to a separate ventilation duct.

It is prohibited to connect the hood to a common ventilation duct, and even more so to a chimney! In this case, carbon monoxide and exhaust air can flow back into the room.

Matilda

The hood from a kitchen gas stove should never be connected to anything. And the air duct from the stove should go vertically upward.

In houses with outdated types of ventilation systems, there is no insulated duct for connecting the hood. And since it is impossible to vent the hood into a common ventilation shaft, an additional ventilation duct must be made in a separate order. A suitable but ineffective solution in this case would be to purchase a recirculation unit.

If you are not afraid of ruining the facade of your house (apartment) with stains from grease, soot and steam, then you can make a separate horizontal channel in the wall for the hood. The outlet vent will be located directly on the outside surface of the wall. It is advisable to equip such a ventilation device in the kitchen at home with a check valve (if its presence is not provided for in the design of the hood itself) or an inertial grille.

shmendel User FORUMHOUSE

A motorized valve is good, but range hoods have check valves. All that remains is to ensure that air is not blown directly into the air duct.

Do this" reducing ventilation in the wall in the kitchen"
will help inertial gratings or deflectors.

Ideally, the exhaust duct should be created according to the same principles by which other ventilation ducts are created. Namely: in order for the air duct to provide natural cravings when the hood is turned off, it should be brought to the roof of the house (just above the ridge).

Particular attention should be paid to insulating the air duct in the attic and outside, which will prevent the formation of condensation.

Matilda

The air ducts that you will lay through the attic are wrapped in cotton wool.

About ventilation outlets: it is advisable to purchase already finished goods, which in accordance with existing standards are insulated at the manufacturing stage.

Kitchen ventilation rules. Mduct material

The material of the air duct used to connect the kitchen hood must meet the following conditions:

1. Create minimal resistance to air flow;
2. Have high anti-corrosion resistance;
3. Have sufficient internal cross-sectional area.

Taking into account the first condition, a flexible corrugated pipe, the walls of which have a fairly high resistance, is recommended to be used exclusively for connecting the hood to the ventilation duct.

If possible, it is preferable to replace the corrugation with a smooth galvanized pipe of round or square cross-section.

To prevent rust from destroying the air duct, many people seek to introduce plastic sewer pipes with a thick cross-section into its design. But this material tends to accumulate fat deposits, but such pipes cannot be called safe. Their use can lead to a fire (as soon as the oil ignites in a hot frying pan while the hood is running). It is for this reason that the use of sewer pipes should be abandoned in advance.

Matilda

Under no circumstances should plastic be used for exhaust hoods. kitchen stove. Even aluminum is not allowed. Galvanized or stainless steel only.

Here's what our users say about the cross-section of pipes designed to create ventilation ducts.

Smart2305 User FORUMHOUSE

For hoods the connection is 150 mm. The diameter of the pipe along the riser should be 200 mm (choose the square equivalent yourself).

Requirements for exhaust ventilation in the kitchen. Power calculation

When choosing a hood for our own kitchen, each of us thinks about how much power this device should have. In all cases, this indicator depends on the area of ​​the kitchen space. If the area of ​​your kitchen is less than 10 m² (inclusive), and the height is 2.5 - 2.7 m, then a hood that passes through 280–350 m³ of air in one hour may well satisfy your needs. If the kitchen area is larger, then the power of the device should be appropriate.

In principle, this parameter can be obtained from sellers, or you can calculate it yourself using the formula: V=S*H*10*1.3. In it: S and H are the area and height of the room, V is the volume (m³/h).

Regulatory documents require mandatory ventilation of the entire apartment, both living rooms and utility rooms. The kitchen is no exception, as it is the main source of substances that are harmful, and even deadly to the human body, entering the internal atmosphere of the house.

During the cooking process, a whole bunch of dangerous chemicals are released into the air.

Among them are:

• Carbon monoxide (CO), better known as carbon monoxide. An extremely toxic substance, even in small concentrations leading to severe poisoning of the entire body. And when the concentration of CO in a person’s blood reaches 5 ml per liter, almost instantaneous death occurs. Main danger carbon monoxide is that it has neither color nor smell. Therefore, its dangerous concentration can be detected only by a sharply deteriorated state of health - a severe headache accompanied by vomiting. CO is released during any combustion, including when frying food on a stove fire.

Attention! Kitchen hoods equipped with replaceable filters are not able to protect against carbon monoxide. To neutralize it, only a ventilation system that removes polluted air outside is suitable.

• Natural gas (propane, butane, methane) is another dangerous chemical component present in the kitchen. It is commonly used as an energy carrier for gas hobs. But in high concentrations it can not only cause human poisoning, but also cause fire and explosion. Every year, hundreds of people around the world become victims of gas leaks that could easily have been avoided with an effective ventilation system.
• Carcinogens are volatile substances released into the air when foods are fried or fats are burned in a frying pan. This is the same child that stands in the kitchen while preparing food, and then settles on the walls and ceilings of the room with a greasy coating. Carcinogenic substances, although they cannot lead to immediate death of a person, like CO or propane, are capable of accumulating in human body. When these substances enter the liver, kidneys, and lungs, they ultimately cause severe pathologies, including cancer.
• Water vapor is released when cooking soups or boiling a kettle. By itself, it is absolutely harmless to humans. But in high concentrations it condenses on walls and ceilings interior spaces, causing the appearance of fungus and mold. Fungus significantly reduces service life finishing materials, and can also affect load-bearing elements building structures. Microscopic spores released by mold into the air cause severe allergic diseases- dermatitis, asthma, chronic bronchitis.