The cross-sectional area of ​​the ventilation channel. Device of smoke and ventilation ducts

Maintaining the necessary parameters of the microclimate in the room is impossible without proper organization of air exchange. Ventilation ducts are designed to provide the necessary frequency of air replacement in the room, so their arrangement is planned at the design stage of the building. The most common and reliable material used for these purposes is brick.

Ventilation channels: the need for arrangement

Building structures are usually built in the walls (inside). In this case, the brick is laid in one row, if the wall does not exceed 38 cm in thickness, and in 2 rows - with a wall surface 64 cm thick. One of the ventilation elements - an exhaust pipe - should be formed with walls of 2.5 bricks. It is this size that makes it possible to maintain a constant temperature condition inside the mine, to protect the passing air from cooling.

For multi-storey buildings, inclined rather than orthogonal ventilation systems are characteristic. At the same time, the level of their branches reaches 1 m. The maximum deviation of the vertical shaft without deteriorating the ventilation performance is no more than 30 degrees.

Performing channel laying: technical features

The laying of brick ventilation ducts begins with the design work. For a private house at the initial stage of drafting the project it is impossible to deviate from the requirements set forth in SNiP 2.04.05-86.

• Construction of air ducts without an approved project is prohibited.
• It is impossible to combine smoke and ventilation bends.
• With a wall thickness of up to 380 mm, laying is single-row.
• If the wall thickness of 640 mm - laying in 2 rows.
• Before the start of erection, the outlines of the channel are drawn using a template, etc.

The dimensions of the ventilation shafts are calculated in such a way as to provide the necessary rate of air exchange in the room. The power of the heating system that heats the room is taken as the initial data:

• Channel size (cm): 14x14 - at a power of not more than 3.5 kW;
• 14x20 (cm) - 3.5 - 5.2 kW, respectively.

The type and parameters of the ventilation passages in the brickwork depend on the purpose of the building, but basically it is a square cross section of a vertical shaft (140x140mm), laid out in 2 bricks in the internal walls. You need to focus on the following parameters of a single brick: its length is 250 mm, width is 120 mm, height is 65 mm.

Attention! The exhaust channel together with the removed air takes out and heat. A small structural detail inside it - a bend in the form of a laid out brick ladder - will become an obstacle to the outflow of warm air masses.

In homes with stove heating ducts for air exchange are best placed parallel to the stove flue, close to it. Air heated from exhaust gases improves draft and efficiency of their work. If it is structurally difficult to do this, then the outlet arranged in the outer wall is insulated. This ensures good traction. For a constantly operated fireplace in the house, an autonomous vent should be provided. Through it, the smoke entering the room from the combustion of fuel is brought out into the street.

Brick for laying and notes on working with him

For brick walls, as a rule, full-bodied stone is used. It is possible to use hollow bricks, but with clay or mortar-filled voids.

Attention! Silicate brick for the formation of ventilation ducts is not used, because sudden changes in temperature provoke its destruction.

The brick is fixed in the canals with the same solution that was used for the construction of internal walls. In order for the batch to be of sufficient strength, in preparing the mortar it is necessary to observe the proportions:

• sand construction purified - 3 parts;
• m500 cement - 1 part.

Water is added in metered portions to a dry, previously prepared mixture with constant mixing. The consistency of the mixture should be such that when it is tilted at 45 degrees of capacity, it does not overflow.

The formation of the ventilation channel often requires the use of bricks of a non-standard size in cases of bandaging the seams, in places where the walls abut, etc. For their mechanical processing, use is made of:

• felling with a trowel or hammer;
• bulgarian;
• mechanism for cutting bricks.

In order to save, the battle is processed, the material with broken corners, chips, etc.

Algorithm for masonry ventilation duct

• Careful study of the drawing.
• Marking using the inventory folding template. If it is not, in the board with dimensions (mm): 140x2500x25, the openings are identical to those on the plan of the wall.
• The brick is laid strictly according to the level, for which buoys are used or a box with the dimensions of a channel knocked out of the boards. The straightness of surfaces, angles must be observed.
• If the air temperature is high and the brick is dry, it is necessary to moisten it with water to improve adhesion between the material and the solution.
• Formed 3 or 4 rows of masonry.
• Buoys are installed - bricks laid out on the level in the cross section of the channel. Protect it from debris during work, keep the specified shape of the hole.
• The buoy moves every 7 or 8 brick layings with a single or multiple ligation system.
• If there is a possibility of penetration into the premises, as well as nearby ventilation systems along with the supplied air from the combustion products of the fuel, then laying is best done using the “butt” method.
• Ensure compliance with the thickness of the seams.
• All them thoroughly repaired.

How much does a brickwork build

Despite the popularity of monolithic and frame housing construction, masonry from piece materials is still in demand during construction. Qualitatively do the work under the force of experienced craftsmen, with certain skills and knowledge. If it is planned to invite specialists to perform this type of work, then an estimate is compiled. It affects:

• the height of the building;
• floor space;
• geometric complexity of the channels;
• dressing with existing masonry;
• the need to finish sedimentary joints;
• type of material and its price, etc.

At the same time, the speed of the work does not depend on such characteristics of the brick as the strength mark, resistance to freezing, color preferences. Therefore, these parameters do not affect pricing.

Refined calculations take into account the real costs of working time for each type of work performed (man-hours). After conducting the timing of each construction operation, it determines the exact duration of it. Having these data, as well as the size of the average wage for a specific region, you can calculate the hourly rate according to the formula:

Р - tariff (rub.);

C - salary (average) (rubles / day);

V - the duration of work per day (hour).

Example

The team performs masonry, working 12 hours a day. With the indicator C = 900 p. / Day, the cost of work 1 hour will be: 900/12 = 75 rubles per hour.

It is also taken into account that the rate for laying, for example, of a hollow one-and-a-half brick will be much lower. This is argued by a higher speed of work. The number of pieces in a masonry unit in this case will also be less. All this explains why the prices for this type of services in different regions, at different sites differ.

Properly executed ventilation system in the house will help to maintain optimal microclimate parameters, contributes to the cleanliness of the air in it, prevents the formation of pollution in the channels and heat loss.

Comments:

• Performance standards and natural ventilation channels
• Channel parameters and ventilation calculation
• Example of calculation of ventilation

  - This is a system in which there is no forced driving force: a fan or other unit, and the flow of air occurs under the influence of pressure drops. The main components of the system are vertical ducts, starting in a ventilated room and ending above the roof level by at least 1 m. Their number is calculated and their location is determined at the structure design stage.

The temperature difference at the lower and upper point of the channel contributes to the fact that the air (in the house it is warmer than outside) rises. The main indicators that affect the thrust force are: the height and cross section of the channel.  In addition to them, the efficiency of the natural ventilation system is influenced by the thermal insulation of the shaft, turns, obstacles, narrowing in the tunnels, as well as the wind, and it can contribute to the reduction and reduction of it.

Such a system has a fairly simple arrangement and does not require significant costs during installation and during operation. It does not include mechanisms with electric drives, it works silently. But natural ventilation has drawbacks:

• work efficiency directly depends on atmospheric phenomena, therefore it is not optimally used for most of the year;
• performance can not be adjusted, the only thing that is subject to adjustment is air exchange, and then only downwards;
• in the cold season is the cause of significant heat loss;
• in the heat does not work (there is no temperature difference) and air exchange is possible only through the open air vents;
• in case of inefficient work, dampness and drafts may occur in the room.

Performance standards and natural ventilation channels

The best option for the location of channels is a niche in the wall of the building. When laying it should be remembered that the best traction will be with a flat and smooth surface of the ducts. To maintain the system, that is, cleaning, you need to design a built-in hatch with a door. To prevent debris and various sediments from appearing inside mines, a deflector is installed above them.

According to building codes, the minimum system performance should proceed from the following calculation: in those rooms where people are constantly present, a complete renewal of air should occur every hour. As for other premises, it should be removed:

• from the kitchen - not less than 60 m³ / hour when using an electric stove and not less than 90 m³ / hour when using gas;
• baths, toilet - at least 25 m³ / hour, if the bathroom is combined, then at least 50 m³ / hour.

When designing a cottage ventilation system, the most optimal is the model, which provides for laying a common exhaust pipe through all the rooms. But if there is no such possibility, then the ventilation passages are laid out from:

Table 1. The ventilation rate of ventilation.

• bathroom;
• kitchens;
• storage rooms - provided that her door opens into the living room. If it leads to the hall or kitchen, then only a supply channel can be equipped;
• boiler room;
• from rooms that are separated from rooms with ventilation by more than two doors;
• if the house is of several floors, then, starting from the second, if there are entrance doors from the stairs, the channels are also laid from the corridor, and in the absence from each room.

When calculating the number of channels, it is necessary to take into account how the floor on the first floor is equipped. If it is wooden and mounted on logs, then a separate course is provided for ventilation of air in the voids under such a floor.

In addition to determining the number of ducts, the calculation of the ventilation system includes determining the optimal cross-section of the channels.

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Channel parameters and ventilation calculation

When laying ducts can be used as rectangular blocks and pipes. In the first case, the minimum side size is 10 cm. In the second case, the smallest duct cross-sectional area is 0.016 m², which corresponds to a pipe diameter of 150 mm. A channel with such parameters can pass an air volume of 30 m³ / h, provided that the height of the pipe is more than 3 m (with a lower figure, natural ventilation is not provided).

Table 2. Ventilation channel performance.

In that case, if it is necessary to enhance the duct performance, then either the cross-sectional area of ​​the pipe expands or the channel length increases. The length is usually determined by local conditions - the number and height of floors, the presence of an attic. In order for the thrust force in each duct to be equal, the length of the ducts on the floor must be the same.

To determine what size is required to lay the ventilation channels, it is necessary to calculate the amount of air that must be removed. It is assumed that air enters the premises from the outside, then it spreads to rooms with exhaust shafts and through them is discharged.

The calculation is made by floor:

1. The smallest amount of air that must be received outside is determined - Q p, m³ / h, the value is found according to the table from SP 54.13330.2011 “Multi-residential residential buildings” (table 1);
2. According to the standards, the least amount of air that must be removed from the house is determined - Q in, m³ / hour. The parameters are listed in the section “Performance Standards and Natural Ventilation Channels”;
3. The obtained figures are compared. For the minimum performance - Q p, m³ / h - take the most of them;
4. For each floor is determined by the height of the channel. This parameter is set based on the size of the entire building;
5. According to the table (table 2), the number of standard channels is found, while their total performance should not be less than the minimum estimated;
6. The resulting number of channels is distributed between the rooms where air ducts must be mandatory.

For any home is important ventilation, which will not allow him to get into the stuffiness, unpleasant odors and dampness. One option to get rid of this is to provide ventilation ducts in the brick walls. With a hidden "hood" in the house will be a good microclimate.

The indispensable rules of the device

Exhaust ventilation channels are arranged when laying the walls of the house, inside them. If the wall has a thickness of 38 cm - in 1 row, if 64 cm - in 2 rows. Traditional section - 140x140 mm. Used the same solution as for laying the house. It is allowed to apply a solution of clay and sand.

Before you make the ventilation duct in a brick wall, you need to have a solid ceramic brick. You will need a template that is made with your own hands. This is a board (length, width, thickness — 2.5 mx 140 mm x 25 mm), in which cuts are made corresponding to the dimensions of the ventilation ducts and their location on the wall. We need inventory buoys - hollow boxes of boards. Their cross section is like that of a canal, the height should be 8-10 bricks. Masonry cleaning will be done with a mop, the “purity” check with a testing ball on a cord with a diameter of 100 mm.

The laying is done vertically. Must be moved away from the doorway as well as from the wall junctions not less than 380 mm. Located next to the channel and the chimney, they isolate each other with the help of heat-resistant materials and increase the walls of the channel.

Practical experience

The device of the ventilation duct is divided according to the following important points:

And if without masonry

Homemade ventilation duct in the brick walls is done with the use of pipes. But in this case it is also necessary that each room has its own air duct. One of the exits should be at a height of two meters above the foundation (possible and higher) inside the outer wall (it draws in air from the street). The second is on the roof (removes air from the house). All channels are reduced to it. The pipe should rise a meter above the roof. The inlets for the gratings are under the ceiling, not lower than 10 cm. They are closed with flaps that regulate the flow of air.

You can combine extracts from the sauna-kitchen, bathroom-toilet. All four can be combined in the attic. It is important that the joints have reliable seals. Information "in the bouquet" can only be done if the services are located on one side of the house. In the one-story house they can be mounted in the ceiling (go to the roof through the attic). In the attic of the pipe should be insulated.

For natural ventilation risers, the diameter of the pipes is 125 x 150 mm, forced - 100 x 125 mm. The choice of materials depends on what the owner likes and prices. May be made of polymers, galvanized, asbestos cement, concrete. When installing the pipe is lowered into the space between the walls and cement. Important tightness at the exit of the ventilation pipe on the roof. To do this, use the passage element of rubber or silicone. The air duct and the exhaust outlet are connected by a corrugated pipe.

How to make the pipes themselves

The ventilation channel in the brick wall is done with its own hands, even if it is thin. When the partition is half a brick thick, a tube of asbestos cement with a diameter of 120 mm (inside - 100) will “fit in”. The opening in this case should be 130 mm wide. Putting the pipe into it, it is strengthened with cement mortar.

In the absence of a pipe, it is done like this: two large half-waves of slate of the required size are fastened with wire. It is mounted on a brick bollard, which is laid out flush with the partition. But it can be done differently: on the sides of the partition in its upper part, lay a pair of bricks on the edge and install the structure. Under the ventilation grille below is cut a hole in the bottom, where it is attached. In the end - plaster. The part that turns out to be in the attic should be insulated with asbestos (foil is also suitable). On the roof it should be no closer than a meter from its highest point.

There are even more subtle openings - a quarter of a brick. In this case, the cabinet will be replaced by a construction that can be made from flat slate strips (width 20 cm). Inserted into the channel, ripped and tied with wire, and plaster.

Connection hood

In the kitchen, only the ventilation in the wall can be “missed”, especially if the kitchen is often cooked and is small. Rescues the hood, which removes unpleasant air from the kitchen. It is important to properly connect it to the ventilation duct. The distance to the ventilation chamber is desirable to be minimal. Otherwise, the hood effect will be reduced. Yes, and look long air ducts ugly.

For connection you need special air ducts and adapters. Connect the elements tightly. A number of rules are important for safety and efficient operation. When connecting the exhaust pipe, it should not block the entire ventilation duct: when it is not working, the main ventilation is working, from the air draft. To do this, you need to remember to put the grill over the exhaust tube inlet.

So that the hood does not disappoint, it is necessary that the air had no obstacles. That is why it is important that the length of the duct is shorter. And it's better to forget about turns. Quality smoothness will contribute to the smoothness of the pipe. Therefore, corrugated pipelines, which are preferred because of their flexibility, still delay the air flow. Well, if you can not do, you need to smooth turns. Dangerous: if a gas heating column is used in the kitchen, the hood cannot be led out into its smoke channel.

The most frequent mistakes

1. There is no ventilation channel in the kitchen, bathroom, bathrooms, storage rooms without windows.
2. Instead of the channel, a hole in the wall, closed by a grid, “acts”. It does not give traction, and therefore not effective.
3. The windows and doors are hermetically buried and there are no ventilators. In such conditions, ventilation does not work, as reported by unpleasant odors, condensation, mold.
4. "Brute force" with ventilation. Forced ventilation, if there is a special hood, for example, a fireplace, is not allowed.
5. There is no hood in the room with a fireplace. A working fireplace chimney is safe. But when the fireplace is ignited, smoke can enter the room, it is better to have a separate ventilation channel in it.
6. There is no hood in the room, which is separated from the other two doors. Their “overcoming” by the flow of air is sometimes completely impossible, as is effective ventilation.
7. Non-insulated channel. If the channels are in the outer walls, it is necessary to insulate, otherwise the thrust force is lost.
8. Gas pipes must not be installed in the wall. Do this only in penalties with screens that have holes for ventilation.
9. Deviation of the vertical channel may interfere with ventilation. Maximum 30 °. If the job is done, the only way out is to install an additional fan. Only not in the room where there is a fireplace!