Norms from snip. Installation of smoke and ventilation ducts Maintenance of ventilation ducts and chimneys

Chimney and ventilation ducts ensure the operation of heating devices and ventilation. They maintain a normal microclimate in the house, reduce the concentration of dust and pathogenic microbes. Violation or incorrect operation of such channels leads to damage to interior items from high humidity and even death of residents from poisoning. carbon monoxide or fire. Knowledge of the arrangement of ventilation ducts and chimneys, their inspection and maintenance is vital.

Brick chimney on the roof

The device and difference between chimneys and ventilation ducts

Despite the similarity and the possibility of an identical device, ventilation and chimney ducts differ in purpose and requirements for them. It is strictly forbidden to use channels for other purposes and change them!

A chimney is an air channel for removing combustion products from heating appliances. Sometimes its walls serve as heat exchangers (in furnaces, fireplaces). Coaxial chimneys (for turbocharged boilers) and supply channels to fireplaces also provide fresh air to support combustion.

Stainless steel chimneys

The ventilation duct is designed exclusively for the exchange of air masses in the room. It does not have strict fire safety requirements, it only requires stable operation at a certain throughput.

Previously, almost all ventilation and chimney ducts were made of brick. Now the range of materials is much larger:

asbestos-cement and fiberglass pipes (unpopular due to low environmental friendliness);
concrete (such channels are laid during the casting of monolithic houses);
stainless molybdenum steel (used more often for gas appliances that emit a large amount of steam and aggressive acids during operation);
ceramic pipes (the most suitable material).

To prevent pollution, ingress of birds and precipitation, the channels are equipped with visors, caps, protective grilles. Often use deflectors that enhance traction.

Ventilation ducts with deflectors - installation

To determine the purpose and ownership of channels, they are marked in accordance with the requirements of SNiP. On each channel at a height of 700-800 mm from the floor (in the attic) or 200-300 mm above the roof (with a combined roof), a triangle 50 mm high with the top facing down and the apartment number (in high-rise buildings) is applied. The colors used are:

black - for solid fuel heaters;
red - for gas combustion products;
blue along the contour - ventilation.

Inspection and maintenance of air channels

The cost and procedure for checking chimneys and ventilation ducts are strictly regulated and may vary depending on the region and the requirements of regulatory authorities.

The average price of this service is 50-1500 rubles, more detailed information can be found in the gas services or organizations that control the operation of stove chimneys (almost always this is a structure under the Ministry of Emergencies). The contacts of official specialized enterprises for checking, repairing and cleaning these devices will also be prompted there.

Checking the ventilation duct from the room

Who and when checks ventilation and chimneys

A specialized organization that has the appropriate license, equipment and trained specialists has the right to inspect ventilation ducts and chimneys. In this case, the customer (and payer) of the inspection for multi-apartment buildings is a representative of an enterprise that operates the housing stock or provides housing and communal services, and for a private (single-apartment) house - its owner.

The initial inspection is carried out in the presence of the customer before the connection and commissioning of the building or new equipment.

Subsequent checks are carried out:

before the start of the heating season;
for brick channels at least once every three months;
for channels made of other materials (steel, asbestos-cement and others) - at least once a year;
after each repair or reconstruction of chimneys and ventilation ducts.

Clogged ventilation duct

Besides, in winter time and in the event of severe frosts, the heads of the outgoing channels are necessarily examined once a month for icing and blockage.

In private single-family houses, repeated inspections and cleaning of ventilation ducts and chimneys are allowed by the owner of the dwelling. To obtain a permit for the production of this type of work, he must undergo training in a specialized organization, followed by a knowledge test.

Checking ventilation ducts and chimneys in an apartment building is carried out only by specialists. No work, modification or cleaning of these systems by tenants is permitted.

Inspection of the condition of channels in an apartment building

Video: Inspection of chimneys and ventilation ducts

Important! If violations and shortcomings are detected, the operation of exhaust devices is prohibited until the defects are completely eliminated!

Documents to confirm the work performed

Specialists after carrying out any check are obliged to write out a special act with a hologram in two copies, certified by a seal. After signing, one copy of the act remains with the customer. The form of the form is regulated by the relevant regulations (in Russia, for example, according to Government Decree No. 1225 of December 30, 2011).

The following points must be defined in the act on the chimney.

The length of the channel, its size and location.
The material from which the chimney is made.
Connection points for heaters.
Constrictions, transitions, others design features disrupting normal operation.
Tightness and tightness of the structure.
The condition of the internal walls, the absence of blockages and blockages.
The presence and magnitude of traction.
Condition of channel heads, cutting seams (for brick channels).
The height of the head above the ridge, the presence of obstacles to the normal operation of the chimney, closely standing high-rise buildings.
The presence and condition of caps, protective grilles and other devices.
At the request of the customer, a laboratory analysis of the air can be carried out for carbon dioxide contamination.

Completed act of technical condition in the Russian Federation

These documents may be requested by authorized representatives of the Ministry of Emergency Situations, gas service, housing inspection and others.

In the absence of acts on chimneys and ventilation ducts (as well as other violations: improper operation of heating appliances; gas devices more than twenty years ago, with missing or non-working protective automation), regulatory organizations have the right to issue an order to prohibit the operation of housing, cut off gas supply lines.

Important! Violators in accordance with the law may be subject to administrative and even criminal liability!

Inspection and cleaning equipment

Previously, the inspection of chimneys and ventilation ducts was carried out visually or with the help of a lantern and a mirror. Now digital cameras with infrared or LED backlight, technical video endoscopes with signal transmission to the basic device and even industrial robots (at critical and complex facilities). A thermal imager is used to determine leaky and thinned sections of chimneys.

Robots for checking and cleaning ventilation ducts

Inspection of chimneys and ventilation ducts is necessary in case of deterioration or complete absence of draft. Its presence can be checked by drawing the flame of a match or candle into the chimney. If a standard A4 sheet does not fall when leaning it against ventilation grill, is also a good indicator. But the most accurate values are obtained using a hydrometer - a device for measuring the speed of air flow, outwardly resembling a children's toy with a spinner-propeller and a dial.

It is necessary to clean the chimney and ventilation ducts in case of clogging, poor draft, the presence of a layer of soot and pollution of more than 2 mm.

At the same time, both traditional scrapers, ruffs, weights, and specialized vacuum cleaners are used, which allow removing any deposits of not only vertical, but also horizontal sections of passages.

House chimney cleaning

According to existing standards, the channel is conditionally considered clean if a weight with a diameter of 100 mm passes freely through it to the bottom of the device, where there is an inspection hatch. Blockages and blockages are broken through with this weight or a special chimney-cleaning projectile attached to a strong rope. If it is impossible to break through the blockage, its location is determined and the outer wall of the channel is opened.

For self-cleaning own house a special hard brush with a detachable handle is quite suitable, the length of which can be changed during operation. To facilitate the process, special chemicals loosening soot and deposits.

Device for ventilation and chimneys of apartment buildings

Ventilation ducts and chimneys in apartment buildings are diverse in design, execution methods and, ultimately, comfort and safety for residents.

Types of ventilation and smoke exhaust systems

The most common natural, supply and exhaust type of ventilation and chimneys. At the same time, through satellite channels, air or combustion products from the premises enter the common channel (or a collector in the attic), and then into the atmosphere. Air is taken in through natural gaps and leaks in windows and doors.

A more advanced and efficient solution is forced ventilation using exhaust and blower fans. There are hybrid projects combined with a supply and exhaust system, options with air recovery (a heat exchanger is a device that transfers heat from the exhaust air to the intake air).

Modern ventilation apartment building

The most productive and stable working is the design, in which the ventilation ducts from each apartment are taken out separately. This increases the stability of the system and prevents the flow of odors and gases into other apartments (for example, when one of the tenants installs a high-power exhaust fan).

Ventilation system design schemes

Features and nuances of service

Maintenance of smoke and ventilation ducts in apartment buildings is practically not required due to the thoughtfulness of the systems and the characteristics laid down with a margin. According to Soviet SNiPs through window and door blocks up to 80% of air exchange was carried out. Therefore, the main problem for high-rise buildings of old construction is the replacement of such elements by residents with modern, practically airtight, metal-plastic and steel structures. At the same time, air exchange deteriorates sharply, dampness and fungus appear.

This problem is solved either by constant ventilation or by installing special supply valves.

They are mounted under the window above. heating devices for heating the air coming from the street. It is also recommended to leave gaps at the bottom interior doors or equip them with air-permeable grilles.

Supply valve in the apartment

Checking, repairing and cleaning ventilation ducts and chimneys is a troublesome and responsible business. Therefore, it is better not to risk the health and lives of loved ones and neighbors. Leave such work to professionals and just enjoy life in a cozy, warm home filled with fresh air.

Proper chimney installation necessary condition for the normal functioning of the fireplace, stove or boiler. This article indicates the basic installation rules and calculation principles used in the design and installation of chimneys.

The desire to build a house on their own arises, as a rule, because of the need to save material resources, because the services of specialized enterprises are not cheap. However, the construction of a chimney requires a special approach: one cannot do without the use of special knowledge in this matter. Therefore, let us recall the basic rules for creating effective smoke exhaust systems and the importance of observing them.

Chimney installation rules: what should be the right chimney

Fuel consumption, the amount of heat energy loss, fire safety and air quality in the heated room depend on how well the chimney functions. Therefore, its design and installation must be carried out in accordance with SNiP "Heating, ventilation and air conditioning", DBN V.2.5-20-2001 Appendix G "Removal of combustion products" and other regulatory documents. Let's talk about how a properly designed and installed chimney should be - these are the basic rules for its creation.

The material from which it is made has a great influence on the characteristics of the channel for the removal of combustion products. In new buildings, as a rule, pipes made of acid-resistant stainless steel containing molybdenum are installed. But for stoves and fireplaces that run on wood and coal, ceramic bricks are also quite suitable.

It is preferable that the cross-section of the chimney be a regular circle: this shape creates the least resistance to the outgoing smoke. The height and cross section of the chimney are calculated in accordance with building codes, which will be discussed in more detail later.

The correct approach to the horizontal sections of the channel is important: they should not be longer than 1 m, otherwise soot will be deposited and the draft will weaken.

The connection of the heating unit to the chimney pipe often has to be carried out if the diameters in the connection area do not match. To solve the problem, a reduction adapter is used. All joints are carefully sealed.

Docking of pipes is carried out in such a way that their expansions are directed upwards. Due to this, condensate and resins will not be able to flow along the outer wall of the pipe.

A brick chimney is erected according to the project: the laying order must be prescribed for each layer. In this case, one should strive to obtain an inner surface with a minimum of roughness and achieve complete tightness.

An old brick chimney can be used with a new gas boiler only after the sleeve has been completed: an acid-resistant steel pipe is inserted into the middle of the channel, leaving a small gap.

Most flue systems should be provided with revisions for cleaning.

Thermal insulation of external pipes is mandatory: this will not only get rid of condensate, but will contribute to the fastest warm-up pipes.

When the channel passes through the floors, it is necessary to take measures to isolate the heated parts from combustible materials.

The outer part of the pipe is securely fixed and protected from the wind. The upper part is closed from atmospheric precipitation with weather vanes or deflectors. An exception is gas equipment: in this case, the installation of a protective cap is a violation.

What is the wrong chimney

Correcting the mistakes made during the construction of the chimney is very difficult and expensive, and sometimes even impossible without dismantling the old system. Here are examples of the most common mistakes and their consequences:

The use of materials not intended for the construction of chimneys. So, for gas boilers, the use of bricks is unacceptable: the acid contained in the combustion products will destroy it within a few years. It is also impossible to use asbestos-cement pipes: when heated, they collapse. Plastic also does not withstand high temperatures.
Errors in choosing the diameter of the pipe and calculating the height of the chimney threaten the absence of normal draft and low system efficiency.
Excessive loads on the base of the chimney can cause its destruction.
Poor thermal insulation is the cause of condensation and ignition of closely spaced materials.

Chimney height: depending on the angle of the roof and the distance to the ridge

Ceramic bricks, previously used for the construction of chimneys, are increasingly being replaced by systems made from other materials. The most commonly used steel pipes: uninsulated and insulated. In this case, the option without insulation can only be used for internal installation- in a specially constructed mine. outdoor installation pipes require mandatory insulation, otherwise the formation of condensate on the internal surfaces is inevitable.

In order to determine the height of the chimney for an industrially manufactured boiler, you should use the formula: h(m) = (∆p ⋅ Tp ⋅ Tn) / (3459 ⋅ (Tp - 1.1 ⋅ Tn)), Where ∆p(Pa) - static thrust, Tr- average temperature in the middle of the pipe (in Kelvin), Tn is the average outside air temperature. The temperature in the pipe (Tr) can be found on the basis of measurements at the outlet of the boiler and is indicated by the manufacturer in the technical passport of the heating equipment. This takes into account natural cooling for each meter of the chimney: in brick - 1 degree, in insulated steel - 2 degrees, in steel without insulation - 5 degrees. Temperature outside (Tn) should be summer: at this time, the thrust will always be weaker than in winter.

However, the results of calculating the height of the chimney in some cases need to be adjusted, but only upwards. The fact is that the house itself is sometimes higher than the obtained value of the height of the chimney. In this case, the following rule applies:

the chimney, located at a distance of up to 1.5 m from the ridge, must be at least 0.5 m higher than it;
if it is located within 1.5-3.0 m from the ridge, then its top should not be lower than the ridge;
at large distances from the chimney outlet to the ridge, the height of the pipe is chosen such that it is not lower than the line drawn from the top of the house down at an angle of 10 degrees.

Chimney height above roof

For solid fuel and gas boilers, the height of the chimney must be at least 5 m: usually, manufacturers indicate this parameter in the accompanying documentation. It should be remembered that a high pipe should be fixed additionally - with the help of stretch marks.

But that's not all: if there is another, higher building next to the house, then the chimney must be brought out above the roof of the neighboring building.

Cross-sectional area

The value of this parameter can be calculated by knowing the height of the chimney h(m) and heat load of the burner according to the formula: S = (K ⋅ Q) / (4.19 ⋅ √h), Where TO is an empirical coefficient numerically equal to 0.02-0.03, and Q(kJ / h) - the performance of the device indicated in the passport, h(m) is the height of the chimney.

If it is simpler to act, without formulas, then the following values \u200b\u200bfor the cross section of the smoke channel made of bricks should be taken as a basis (the cross section of round channels should be exactly the same area):

for a unit with a power of up to 3.5 kW - 140 × 140 mm;
for power from 3.5 to 5.2 kW - 140 × 200 mm;
for power from 5.2 to 7.2 kW - 140 × 270 mm.

A significant excess of the calculated value leads to a deterioration in traction and, as a result, to unstable operation of the heating equipment. A smaller diameter threatens with poor removal of carbon monoxide and other combustion products, and even with a complete cessation of this process.

Additional requirements for chimneys for stoves, fireplaces, solid fuel, gas boilers and gas water heaters

Some rules, not mentioned earlier, that should be observed:

the use of a solid fuel stove requires mandatory compensation exhaust ventilation with the help of the supply;
chimney ducts can be located in the outer walls if they are built from non-combustible materials, but it should be provided with insulation from the outside to prevent the formation of condensate;
for each stove (if they are located on different floors) separate pipe, but it is allowed to use one pipe for two stoves located on the same floor: at the joints of the pipes, cuts are installed with a height of 1 m or more and a thickness of 12 cm;
smoke channels made of bricks should be built with cleaning pockets, which are closed with bricks laid on edge and smeared with clay mortar (doors can be installed);
if necessary, pipe deviations from the vertical at an angle of up to 30 ° and a section length of not more than 1 m are allowed, while the channel cross section must be the same;
if the roof is made of combustible materials, a mesh spark arrester is installed in the upper part of the chimney;
between chimneys made of brick or heat-resistant concrete and roofing parts made of combustible materials should be equal to or more than 130 mm, for ceramic non-insulated pipes - 250 mm, for them with insulation - 130 mm;
the top of the chimney for the fireplace is protected with a weather vane or fungus;
two devices operating on gas may be connected to a common channel for the removal of combustion products, if these devices are located no further than 750 mm from each other;
the cross-sectional area of the chimney connected to the gas appliance should not be less than the cross-sectional area of the gas outlet pipe of the appliance itself, while the upper part of the pipe is not covered with a visor.

Information from regulatory documents establishing the rules for the design and installation of chimneys

Frost-resistant clay bricks are suitable for laying chimneys. It is strictly forbidden to build channels from cinder-concrete and other similar materials.

To connect gas appliances to chimneys, connecting pipes made of galvanized or roofing steel with a thickness of 1 mm or more are suitable. You can also use flexible corrugated metal pipes that are supplied with the equipment. At the same time, it is important that the connecting pipe has a vertical section, the length of which from the lower level of the branch pipe to the axis of the horizontal section of the channel should not be less than 0.5 m. If the ceiling height is less than 2.7 m, this distance may be halved - for equipment equipped with draft stabilizers and up to 0.15 m - for devices without stabilizers. The total length of horizontal sections in new buildings should not be more than 3 m, for old buildings 6 m is allowed. A slight slope of the pipe towards the heating device must be observed.

Flue ducts should not have more than three turns, while the radius of curvature should be equal to the diameter of the pipe. It is forbidden to lay a chimney through residential premises.

How to take care of your chimney

If the thickness of deposits on the inner surface of the pipe exceeds 2 mm, it is time to start cleaning. You can get rid of dense contaminants with a scraper and a stiff brush with a long folding handle: as you move deeper into the canal (work starts from above), the length of the handle is increased.

The furnace hole must be closed from below: this will prevent soot from entering the room. In addition, it is advisable to cover the furniture with a film, lock the doors and windows. During operation, you can use chemical detergents, for example, "miracle logs", which emit a special non-toxic gas during combustion, from which soot lags behind the surface of the pipe.

There are also effective folk remedies. For example, it is sometimes recommended to heat the stove with aspen wood: in this case, a high flame is formed, which burns deposits on the walls of the pipe. But this should be done carefully: a large amount of soot can cause a fire. You can also burn potato skins: the steam that is generated is effective tool against soot deposits.

Conclusion

The requirements set forth in the article are binding. Otherwise, the chimney will be inefficient and even dangerous. This information will serve as a useful reminder for those who already have some experience with chimneys. For those who do not own it, the material of the article should convince of the need for a serious attitude to the details of the process of creating a chimney. Do not overestimate your capabilities: in order to avoid annoying mistakes, you should seek the help of professionals.

Dmitry Portyanoy, rmnt.ru

Annex G (mandatory)

REMOVAL OF COMBUSTION PRODUCTS.

This annex provides for the requirements that must be taken into account when designing smoke ducts from gas equipment and domestic heating and heating and cooking stoves. When designing smoke channels from gas-using installations of industrial buildings and boiler rooms, one should be guided by the requirements of technological design standards and SNiP II-35. When converting existing boilers, industrial furnaces and other installations from solid and liquid to gas fuel, a verification calculation of the gas-air path must be performed.

The device of smoke and ventilation ducts must comply with the requirements of SNiP 2.04.05.

The removal of combustion products from household gas appliances, stoves and other household gas equipment, the design of which provides for the removal of combustion products into the chimney, should be provided from each appliance, unit or stove through a separate chimney. IN existing buildings it is allowed to provide for the connection to one chimney of no more than two water heaters or heating stoves located on the same or different floors of the building, provided that combustion products are introduced into the chimney at different levels, not closer than 0.5 m from one another, or at the same level with the device in chimney cut to a height of at least 0.5 m.

Chimneys from gas equipment should be placed in internal walls buildings or provide attached channels to these walls. In existing buildings, it is allowed to use existing chimneys made of non-combustible materials in the outer walls or to provide them with attached chimneys.

It is allowed to connect to the chimney of a heating furnace of periodic operation gas water heater used for hot water supply, or another gas appliance that does not operate continuously, with a sufficient cross-section of the chimney, which should be determined by the calculation of the appliance. It is not allowed to connect the flue pipe of a gas appliance to the chimney turns of a heating furnace.

The cross-sectional area of the chimney must not be less area section of the pipe of the gas appliance connected to the chimney. When connecting two appliances, stoves, etc. to the chimney the cross section of the chimney should be determined taking into account their simultaneous operation. The structural dimensions of the chimneys must be determined by calculation. Non-domestic gas appliances (restaurant stoves, cooking pots, etc.) can be connected to both separate and common chimneys. It is allowed to provide connecting flue pipes common to several units. The introduction of combustion products into a common chimney for several appliances should be provided at different levels or at the same level with the device of cuts in accordance with Zh.Z. The cross-sectional area of chimneys and connecting pipes must be determined by calculation, based on the condition of simultaneous operation of all appliances connected to the chimney.

Chimneys should be made of frost-resistant bricks (Mrz 125), clay bricks, heat-resistant concrete for multi-storey buildings and asbestos-cement pipes for one-story buildings. It is allowed to provide for the removal of combustion products through steel chimneys. Smoke duct designs can also be factory-made, supplied complete with gas equipment. When installing asbestos-cement and steel pipes outside the building or when they pass through the attic of the building, they must be thermally insulated to prevent condensation. The design of smoke channels in the outer walls and the channels attached to these walls must also ensure that the temperature of the gases at their outlet is above the dew point. It is forbidden to make channels from slag concrete and other loose or porous materials.

Chimneys must be vertical, without ledges. It is allowed to slope chimneys from the vertical up to 30 ° with a deviation to the side up to 1 m, while ensuring that the cross-sectional area of the inclined sections of the chimney is not less than the section of the vertical sections. To remove combustion products from restaurant stoves and other non-domestic gas appliances, it is allowed to provide horizontal sections of chimneys with a total length of not more than 10 m. It is allowed to pass chimneys through ceilings, provided that fire safety of combustible ceiling structures is ensured.

Connection of gas equipment to chimneys should be provided by connecting pipes made of roofing or galvanized steel with a thickness of at least 1.0 mm, flexible metal corrugated pipes or unified elements supplied with the equipment. The connecting flue pipe connecting the gas appliance to the chimney must have a vertical section. The length of the vertical section of the connecting pipe, counting from the bottom of the flue pipe of the gas appliance to the axis of the horizontal section of the pipe, must be at least 0.5 m. In rooms up to 2.7 m high, for devices with draft stabilizers, the length of the vertical section can be reduced to m, without draft stabilizers up to 0.15 m. The total length of the horizontal sections of the connecting pipes in new houses should be no more than 3 m, in existing houses - no more than 6 m. The slope of the pipe should be at least 0.01 towards the gas appliance. On flue pipes it is allowed to provide no more than three turns with a radius of curvature not less than the diameter of the pipe. Below the point of connection of the flue pipe from the appliance to the chimney, a “pocket” with a cross section of at least the cross section of the chimney and a depth of at least 25 cm, with a hatch for cleaning, should be provided. Flue pipes leading through unheated rooms should be covered with insulation if necessary. Laying of flue pipes from appliances and stoves through living rooms is not allowed.

The distance from the connecting pipe to the ceiling or wall of non-combustible materials is taken at least 5 cm, and from combustible and slow-burning materials - at least 25 cm. not less than 3 mm. Thermal insulation should protrude beyond the dimensions of the connecting pipe by 15 cm on each side.

Suspension and fastening of connecting pipes must exclude the possibility of their deflection. The links of the connecting pipes must be tightly, without gaps, pushed one into the other along the flue gases by at least half the diameter of the pipe. The connecting pipe must be tightly connected to the flue duct. Its end should not protrude beyond the channel wall, for which limiting devices (washer or corrugation) are used.

The connecting pipes of restaurant stoves and cooking kettles must be covered with thermal insulation. Connecting pipes made of black sheet steel must be painted with fire-retardant varnish.

When connecting appliances with draft stabilizers to the chimney, the installation of dampers is not allowed. When several appliances are connected to a common chimney: restaurant stoves, boilers and other gas appliances that do not have draft stabilizers, dampers (flaps) with a hole with a diameter of at least 15 mm must be provided on the chimney pipes from the appliances.

Gates installed on chimneys from boilers must have holes with a diameter of at least 50 mm.

Chimneys from gas appliances in buildings must be removed:

Above the border of the wind backwater zone, but not less than 0.5 m above the roof ridge when they are located (counting horizontally) no further than 1.5 m from the roof ridge;

- level with the roof ridge, if they are at a distance of up to 3 m from the roof ridge;

Not lower than a straight line drawn from the ridge down at an angle of 10 ° to the horizon, with pipes located at a distance of more than 3 m from the roof ridge.

The zone of wind backwater of the chimney is the space below the line drawn at an angle of 45 ° to the horizon from the highest points near the located structures and trees. In all cases, the height of the pipe above the adjacent part of the roof must be at least 0.5 m, and for houses with a combined roof (flat roof) - at least 2.0 m. Installation of umbrellas and other nozzles on chimneys is not allowed.

Chimneys in the walls are allowed to be carried out together with ventilation ducts. At the same time, they must be separated along the entire height by hermetic partitions made of wall material, at least 120 mm thick. The height of the exhaust ventilation ducts located next to the chimneys should be taken equal to the height of the chimneys.

It is allowed to provide for the removal of combustion products from gasified installations of industrial enterprises, boiler houses, and household enterprises through steel chimneys.

It is allowed to exhaust combustion products into the atmosphere through outer wall gasified premises without a vertical channel from gas heating equipment with a sealed combustion chamber.

It is allowed to provide for the removal of combustion products into the atmosphere through the roof of the building into a vertical smoke channel.

The length of the horizontal section of the smoke channel from heating equipment with a sealed combustion chamber when exiting through the outer wall is taken to be no more than 3 m.

It is forbidden to provide for the exit of the smoke channel through the outer wall:

- entrances (arches), covered passages;

- in closed balconies, loggias, bay windows;

In buildings that are historical or architectural monuments, without the permission of the department under whose protection they are located;

Through the walls of the facades of buildings overlooking squares and streets of historical, architectural and urban planning value, as well as located in close proximity to children's areas preschool institutions, schools and health care facilities;

- in buildings in which the installation of gas appliances is prohibited by the requirements of DBN V.2.2-9, SNiP 2.08.01, SNiP 2.04.05.

The openings of the smoke channels on the outer wall of the building, when the combustion products are removed from the heating equipment through the outer wall without a vertical channel, should be placed in accordance with the manufacturer's instructions for installing gas equipment.

The safe use of furnace and gas equipment is possible only with the timely removal of combustion products and continuous indoor air exchange. This and some other functions are performed by the chimneys of the different kind: from elegant decorations of country villas to giant monsters - indispensable attributes of industrial zones.

The principle of natural traction

The outflow of gas combustion products from boilers, columns and furnaces is carried out through ventilation and chimneys by means of natural draft. Traction is provided with a temperature difference in the street and in the house. The higher the ventilation duct or chimney and the greater the temperature difference, the more intensely the chimney draws. Therefore, natural ventilation works best on the first floors of multi-storey buildings and in the cold season.

The temperature of the combustion products above the working stove is about 200 degrees. The air temperature in the ventilation and chimneys is not more than 25 degrees and therefore the draft is very weak. In summer, when the temperature outside is higher than indoors, the draft can “tip over”, that is, air is sucked from the ventilation into the apartments.

To a large extent, the effective operation of the system depends on the frequency of inspections of smoke and ventilation ducts.

Reasons for reduced traction:

contamination of the inner walls of the channels;
roughness, narrowing of the walls;
increase in the diameter of the channel;
air suction.

A significant part of the energy of the air moving through the channel is spent on resistance to friction against the walls, when turning and reducing the diameter of the channel. The pressure loss indicator depends on the laying of the smoke or ventilation duct, its length and condition. In the presence of protrusions, build-up of dust and roughness, the resistance increases. Therefore, timely inspection and cleaning of ventilation and smoke ducts enhances traction.

In channels of large diameter, even with perfect observance of the rules for the safe operation of smoke and ventilation pipes draft is reduced, as the combustion products cool faster.

When air leaks in the channel, the thrust also drops, since the air temperature in the channel decreases, and its volume increases. Therefore, all hatches for pipe maintenance must be kept closed.

The draft in the chimneys during the operation of the boiler or furnace is about 14 Pa. In ventilation ducts, it is much lower. The opening of the windows in the apartments, the direction and strength of the wind, and even the location of neighboring houses affect the draft. Ventilation and chimneys should not be located in the zone of wind backwater. This is the space below the line from the highest point of the nearest building to the horizon at an angle of 45 degrees.

Design of ventilation pipes and chimneys

According to the rules for the operation of chimneys and ventilation pipes, they are equipped inside the house to maintain the temperature of the exhaust air. It is possible to arrange ventilation and smoke ducts outside, then they need to be insulated.

The laying of ventilation and smoke ducts consists of clay bricks or heat-resistant concrete (asbestos cement). Thickness brickwork from 12 cm, the concrete wall of the ventilation or smoke duct - more than 6 cm. The SNiP states that ventilation and smoke ducts are arranged only vertically, without transitions and horizontal sections.

Pocket device (hole) for cleaning the chimney

Cleaning holes and a pocket 25 cm deep are left at the base of the chimney. The holes are covered with doors and lined with bricks installed on the edge. Masonry is carried out on a solution of clay. In asbestos-cement pipes, a sheet is left for cleaning.

The pocket is necessary so that when the masonry is destroyed, the brick fragments do not block the inlet, falling a little lower. All debris that enters the chimney accumulates in the pocket. If a pocket is not provided, the debris will gradually reduce the cross section of the chimney and worsen the draft.

Unsuitable materials for the construction of smoke and ventilation ducts:

slag concrete;
silicate, perforated, slotted brick;
coarse materials.

Although silicate brick and resists high temperatures well, it is destroyed by carbonic acid and moist vapours. If no other materials are available, SNiP requires a device in the ventilation and smoke duct interior cladding red brick 13 cm thick.

Chimneys can be:

mounted (from asbestos-cement pipes inserted into each other);
solid (made of bricks).

Attached pipes are distinguished by smooth inner walls; they are supported on fireplaces or stoves with powerful (not thinner than 1/2 brick) walls. If the pipe is heavy, a reinforced concrete slab is installed on the ceiling of the furnace and the pipe is already attached to it.

Asbestos-cement packed pipes are much lighter than brick ones, they do not need to be dismantled during overhaul, they are quickly installed.

A brick chimney requires a special foundation, which is laid to a depth exceeding the depth of soil freezing.

When erecting low-rise buildings, prefabricated chimneys are used, which are built into the wall or form a riser. The walls of the chimneys are made of heat-resistant concrete.

In places where the chimney passes through the roof, it is necessary to leave a hole with a width of 13 cm or more. The connection between the chimney and the roof is covered with a stainless metal apron.

The chimney can have an inclination of up to 30 degrees with an offset of no more than 100 cm to the side. Such sections must be of the same section, equal to the section of vertical sections with smooth walls.

Brick chimney heads are covered with 20 cm plaster to protect against precipitation. Deflectors and umbrellas are not installed on chimneys.

Chimneys of gasified buildings

Ventilation and smoke ducts of gasified premises should rise above the flat roof by 50 cm or more. On pitched roof 50 cm or more above the rib or to the height of the rib with a distance from the rib to the chimney of 1.5 - 3 meters.

The height of the chimneys of gasified premises should be equal to the height of the exhaust ducts.

Heating equipment is connected to the system of ventilation and smoke ducts in a gasified room through metal adapters. The length of the vertical adapter should be from 50 cm. If the height of the room is less than 2 m 70 cm and draft stabilization is used, the vertical adapter can be shortened to 25 cm. The total length of the horizontal adapters can be up to 3 m in new buildings or up to 6 m in already functioning buildings.

A slope towards the boiler is allowed from 0.01. Pipes must be fixed rigidly without the possibility of sagging. The pipe elbows are inserted into each other along the smoke path and overlap by 1/2 of the chimney diameter.

The metal adapter is tightly attached to the chimney, without protruding beyond the walls of the channel.

If the pipe is made of a metal sheet, it is necessary to treat it with a heat-resistant varnish.

The pipe is attached to the chimney, leaving a pocket of 25 cm and a hatch for control, as well as in the construction of a stove chimney. If the appliance is not equipped with a draft stabilizer, a damper with a perforation of 15 mm is required, through which the oven is ventilated during the idle period.

When retrofitting old chimneys from stoves for gas equipment, poor draft is often observed. Furnaces are heated for a longer time and the temperature of the combustion products is much higher than during the operation of a gas boiler, therefore, air discharge from gas combustion is not enough.

Chimney Requirements

Operation of chimneys

Rules for the safe operation of chimneys and ventilation pipes require periodic cleaning and inspection. Without cleaning, a long-term chimney becomes a potential source of fire or poisoning for residents. The need to clean the ventilation and smoke ducts is determined by scheduled inspections.

A chimney made of bricks or made of asbestos-cement pipes loses its appearance after a while and works worse. Soot and soot accumulate on the inner walls, the chimney clearance decreases and draft decreases. But there is another danger: combustion products can ignite. Substances released by soot destroy the pipe material and masonry seams. The tightness of the chimney decreases, the fuel does not burn completely, the draft worsens.

Only periodic checks of smoke and ventilation ducts will help to avoid dangerous situations.

If the heating equipment is used every day, the frequency of checking and cleaning the ventilation and smoke ducts is 8 weeks. If the stove is fired from time to time, it is necessary to control the condition of the chimney twice a year: in the fall before the start of the heating season and in the spring.

Checking chimneys

Inspection of smoke and ventilation ducts is carried out in the following cases:

when converting furnaces to gas fuel;
when connected to the chimneys of gas boilers;
if necessary, diagnose the condition of the chimney and poor draft.

The purpose of checking ventilation and smoke ducts:

compliance of the masonry materials of the smoke or ventilation duct and the device with the requirements of SNiP;
the presence of contaminants;
the presence of traction;
the density of the walls of the chimney;
the condition and presence of partitions separating the adjacent structures of the building;
the condition of the cap and its location relative to the roof, buildings and trees.

The course of checking ventilation and smoke ducts:

To determine blockages in the chimney, a load in the form of a sphere, weighing 3 kg and up to 10 cm in size, is lowered into it from above. If the load passes unhindered, the channel is clean;
To determine the isolation and density of channels, the smoke method is used. A burning tow soaked in gasoline or a bundle of straw is put into the window for cleaning, which, when burning, emits abundant smoke. From above, the outlet of the chimney is tightly covered. If there is a smell of smoke in nearby rooms or channels, then the walls of the channel are not dense;
The cleanliness of the walls of the channel is examined by lowering an electric light bulb up to 500 W with a power of up to 500 W into the chimney. At the same time, the density of the walls is also determined. If there is light in the adjacent channels, then there are gaps.

Based on the results of checking the ventilation and smoke ducts, cleaning is carried out. She may be:

mechanical;
chemical.

Mechanical cleaning is carried out with brushes and brushes made of metal wire. Under the weight of the load, they descend on cables into the chimney and scrape off all deposits from the walls. Some pipes (for example, ceramic) are difficult to clean - they can crack.

Dry cleaning is safer. A “chimney sweep log” is burned in the furnace, which burns out the soot on the walls of the chimney. The material is impregnated chemical composition decomposing soot and soot. But dry cleaning does not cope with thick deposits, so it is used as an auxiliary or preventive.

Industrial chimneys

The purpose of industrial chimneys and ventilation pipes is not only to remove combustion products, but also to maintain combustion in boiler units. In the recent past, most industrial smoke and ventilation pipes were made of brickwork. Today, it is increasingly being replaced by metal pipes with thermal insulation. The height of the structure can reach 60 meters.

According to the rules for the safe operation of chimneys and ventilation pipes, they need periodic cleaning. Prevention is carried out at the end of the heating season. And in order to exclude accidents, scheduled checks of ventilation and smoke ducts are scheduled.

Smoke and ventilation pipes for industry are designed taking into account each specific enterprise, since the task of construction is always unique.

When designing, environmental standards for the rate of dispersal of smoke and maximum concentrations of smoke are taken into account.

Types of industrial chimneys:

Metal self-supporting. The cheapest are made of metal with thermal insulation. Very heavy. Can be single-barreled or multi-barreled;
Truss self-supporting. They are a truss column with heat-insulated gas ducts. 1 - 6 trunks are attached to one farm. The farm itself is made of pipe;
metal columns. One powerful "shell" in which 1 - 5 trunks are hidden. Maximum height 60 m, diameter up to 3.5 meters;
Stretch marks. A single-barreled metal pipe, which is fastened with braces. Most often installed in industrial enterprises. Produced by rolling. Such a pipe will last no more than 15 years, even if all the rules for the operation of ventilation and chimneys are observed;
facade. The most economical option, does not need a foundation and load-bearing structure. It is attached to the facade, often this type of pipe is used in attached or built-in boiler houses.

The diameter of the pipes can be from 0.2 to 1.5 meters, and the height is 8 - 60 meters. There may be several gas outlets.

Depending on the conditions, industrial chimneys can be equipped with:

lightning rod;
protective lighting;
stairs and service platforms.

If a rectangular industrial flue chimney is installed, the correct aspect ratio is very important. The best is 1:1.5 with ground off internal corners.

The rules for the operation of chimneys and ventilation pipes require their installation only on special self-supporting foundations.

And at the end, a video on how industrial chimneys are dismantled.

Dl I have a normal job gas appliances require a constant supply of clean air, which is provided by natural supply and exhaust ventilation.

The removal of combustion products from gas appliances is provided through the chimney.

To remove the products of combustion of gas into the atmosphere, there must be a certain thrust - a force that causes air to enter the chimney, and the resulting combustion products move along the chimney and dissipate into the atmosphere.

The draft depends on the temperature difference between the smoke and air, the height of the chimney and a number of other factors.

To ensure better traction, the temperature of the exhaust gases must be high. The temperature of exhaust gases from water heaters is 180-200С. Due to the cooling of the LST and the suction of air in the draft stabilizer, the temperature drops. During the operation of chimneys, condensation of vapors from flue gases must be excluded. Wetting of the channel reduces traction, leads to its destruction, in the winter season it can lead to freezing and blockage of the channel. The temperature at which condensation begins is called the dew point. For natural gas combustion products = 60-65оС. Air leakage in the draft stabilizer reduces the relative humidity of the exhaust gases, while also reducing the dew point to 40-50 degrees. To avoid condensation, the temperature of the flue gases at the outlet of the pipe head is usually assumed to be 65°C. Draft decreases at high ambient humidity.

Appointment and arrangement of the chimney. Chimney requirements. Operation of chimneys

Chimneys are arranged in the internal capital walls. They are made of red burnt brick of the 1st grade, from asbestos-cement, pottery pipes and heat-resistant concrete blocks.

The cross section of the chimneys must be:

From red brick - 130 x 130mm, 130 x 250mm,
From pipe materials - with a diameter of 100 (150) mm, but in all cases not less than the diameter of the outlet pipe of the device. It is allowed to lay chimneys in external walls, provided that the thickness of the outer wall of the chimney must be not less than the thickness of the wall itself and not less than 38 cm

Chimneys must be vertical without ledges. Deviation from the vertical is allowed by an angle of not more than 30 degrees with a horizontal deviation of not more than 1 m. Deviation from the vertical is performed by smooth withdrawals with a constant unchanging cross section. The laying of chimneys must be dense. The inner surface of the masonry must be flat, smooth, without sagging mortar. The cross section of the chimney must be respected along its entire length.

At the bottom of the chimney, a pocket with a hatch and a lid is arranged, which serves to clean the chimney from soot debris, etc.

The depth of the pocket must be at least 25 cm, counting from the bottom of the iron connecting pipe at the point of entry into the chimney.

At the intersection of the chimney with interfloor ceilings, fire-prevention cuttings are arranged (thickening of the masonry). For combustible ceilings - at least 38 cm. Fire cutting is performed from felt soaked in a clay solution.

The distance from the ZST to fireproof ceilings is at least 5 cm, to wooden plastered (combustible) ceilings and walls - at least 25 cm. A decrease from 25 to 10 cm is allowed when the wall or ceiling is upholstered with roofing steel on an asbestos sheet 3 mm thick. The insulation should extend beyond the dimensions of the pipe by 15 cm on each side.

The part of the chimney located above the roof is called the "head". The outer surface of the head is plastered cement mortar in a ratio of 1:3, a layer thickness of at least 4 cm. After plastering, the heads are whitened and numbered.

It is allowed to provide wind protection devices on the channels.

Chimneys must have a certain height relative to the roof ridge

The location of the chimneys relative to the roof ridge

If the cap is located horizontally from the roof ridge no more than 1.5 m, its height should be 0.5 m above the roof ridge. If the head is located at a distance of 1.5 to 3 meters relative to the ridge, its height corresponds to the level of the roof ridge. If the head is located further than 3 m from the roof ridge, its height should not be lower than the line drawn from the ridge to the horizon line at an angle of 10 degrees.
The operation of chimneys is significantly affected by the wind backwater zone - the space below the line drawn at an angle of 45 degrees from the top of the building, a structure located closer than 15 meters from the house with chimney heads.
The output (build-up) of the chimney above the zone of wind backwater (the extended part is shown by a dotted line). At a certain wind direction, increased pressure is created in the wind backwater zone. This causes the draft in the chimney to deteriorate until it stops and overturns. To eliminate this phenomenon, the chimney is built up above the backwater zone. Similar work is carried out under the project.
In any case, for gable roofs, the height of the head should be at least 0.5 m relative to the roof. Head height for flat roofs must be at least 2 meters.
Chimneys provided from each appliance are called separate.
In existing residential buildings, it is allowed to connect no more than 2 devices to one chimney, provided that the cross section of the chimneys allows their simultaneous operation and the introduction of combustion products into it on different floors or at the same level, with a device in the cross section of the channel, a height of at least 75 see Such chimneys are called combined.

Requirements for chimneys:

must be tight;
a certain section;
permitted materials are used;
must provide the necessary traction;
should not have blockages, blockages, blockages;
should not be located in the area of wind backwater.

Checking chimneys for density is checked by burning strongly smoking materials in a pocket. The outlet of the pipe above the roof is closed. The appearance of smoke in adjacent canals or rooms adjoining the canal indicates that the canal is not isolated or dense. The cleanliness of the internal cavity of the chimney and the density of the channels in small houses can be checked by lowering into the channel on a durable cord of a 12 volt electric lamp; 500 W. View the tested and adjacent channels. The presence of light from a lamp in an adjacent channel indicates leakage. The location of the leak is determined by the length of the cord.

Iron connecting pipes

To remove combustion products from a gas appliance into the chimney, iron connecting pipes (ZHT) are made of roofing or galvanized steel with a thickness of at least 1.0 mm. Flexible corrugated metal pipes or unified elements supplied with the equipment are allowed.
The diameter of the ZHST must not be less than the diameter of the outlet pipe of the device. The links of the connecting pipes must be tightly, without gaps, pushed one into the other along the smoke path by at least 0.5 pipe diameter. For leaks, an asbestos cord and soaked asbestos are used.
The value of the vertical part of the ZHST should be at least 0.5 m. If the design of the device provides for a draft breaker, and the height of the room is 2.7 m, then it is allowed to reduce the value of the vertical section to 0.25 m. The total length of the horizontal sections of the ZHST in existing residential houses should not exceed 6 m. For new construction - no more than 3 m.
No more than 3 angles of rotation are allowed with a radius of bending of the elbows not less than the diameter of the pipe itself. A conical insert is installed at the point where the LST enters the chimney, preventing the LST from entering the chimney section, or a restrictive washer is installed.
The place where the LST enters the chimney is sealed. Suspension and fastening of pipes must exclude their deflection. The slope of the connecting pipe must be at least 0.01 (1 cm per 1 m) towards the device.
The distance from the ZHS to the fire-retardant ceilings must be at least 25 cm.
ZhST are painted with fire-resistant varnishes (Kuzbass varnish, bronze paint, silver paint).

ZhST malfunctions:

incorrect assembly of links;
narrowed section;
the presence of a counter slope;
looseness in the links;
leaks at the point of entry of the ZHST into the chimney;
deviation of the ZHST from the vertical;
burnt links.

Malfunctions of chimneys, in which gas appliances are disconnected from the gas supply:

obstruction, blockage, blockage of the channel section;
destruction of the brickwork of the chimney;
the head of the chimney is located in the zone of wind backwater;
violation of the terms of service of the chimney;
narrowed section of the chimney;
lack or insufficient depth of the pocket;
lack of draft in the chimney.

Purpose and arrangement of ventilation ducts. Inspection procedure and maintenance. Registration of the check

Ventilation ducts serve to provide natural supply and exhaust ventilation of rooms where gas appliances and gas pipelines are located, and must provide 3-fold air exchange within an hour. Unorganized air flow into apartments is carried out through windows, vents, balcony doors, to the basement through the vents in the outer walls. In gasified premises, unregulated gratings with a constant cross section are installed.

The ventilation system in a gasified house consists of:

ventilation grill;
a small horizontal section of the ventilation duct;
vertical ventilation duct.

Exhaust grilles should be placed:

under the ceiling, no closer than 2 m from the floor to the bottom of the hole;
not lower than 0.1 m from the ceiling plane to the top of the opening in the room with a height of not more than 4 m.

Ventilation ducts of buildings with a height of less than 5 floors are made individually. These channels provide fire safety ventilation system and fully meet sanitary and hygienic requirements.

When the number of floors is 5 or more than 5, it is allowed to combine individual vertical exhaust ducts into a prefabricated ventilation duct, which is located in the attic, and from there the air is thrown out through the vertical exhaust shaft.

For one apartment, exhaust ducts from the kitchen and bathroom, as well as the toilet and bathroom, are allowed to be shared. The draft is checked with a sheet of thin paper, which should be attracted to the exhaust grill and held in this position. At the same time, in accordance with the standard "Ventilation systems for residential buildings" ZhNM-2004/02, the inflow of outside air and its flow from other premises of the apartment must be ensured. If double-glazed windows are installed or sealed window frames control of the operation of natural ventilation is carried out with ajar supply devices.

It is forbidden to check the draft of the ventilation ducts with fire.

Methods and techniques for cleaning vertical channels are similar for chimneys.

The main malfunctions of ventilation systems are low draft or its complete absence, which can be caused by:

clogging of channels with debris;
leakage of vertical channels, prefabricated ventilation ducts;
incorrect location of the head;
malfunction of the finish of the mines outside or inside;
malfunction or absence of umbrellas or deflectors;
malfunction of the ladders through the boxes in the attic.

The most serious malfunctions that can lead to poisoning of people, fires should be eliminated immediately.