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 disease-causing microbes. Violation or improper 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 device of ventilation ducts and chimneys, their inspection and maintenance is vital.

Brick chimney on the roof

The device and the difference between chimneys and ventilation ducts

Despite the similarity and 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 duct for removing combustion products from heating devices. Sometimes its walls serve as heat exchangers (in stoves, fireplaces). Coaxial chimneys (for turbo boilers) and supply ducts to fireplaces also provide fresh air to maintain combustion.

Chimneys made of stainless steel

The ventilation duct is designed exclusively for the exchange of air masses in the room. Strict fire safety requirements are not imposed on it; only stable operation at a certain bandwidth is required.

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

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

To prevent pollution, the ingress of birds and atmospheric precipitation, the channels are equipped with visors, caps, protective gratings. Deflectors are often used to increase traction.

Ventilation ducts with deflectors - installation

To determine the purpose and belonging of the 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 with a height of 50 mm with the top facing down and the apartment number (in high-rise buildings) is applied. This uses colors:

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

Checking and maintaining air ducts

The cost and procedure for checking chimneys and ventilation ducts are strictly regulated and may differ 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 gas services or organizations that control the operation of stove chimneys (almost always this is a structure under the Ministry of Emergencies). There you will also be prompted by the contacts of official specialized enterprises for checking, repairing and cleaning these devices.

Checking the ventilation duct from the premises

Who and when checks ventilation and chimneys

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

The initial check is carried out in the presence of the customer prior to connection and commissioning of the building or new equipment.

Subsequent checks are carried out:

before the start of the heating season;
for brick canals 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 at the onset of severe frosts, the heads of the outgoing canals are inspected once a month for icing and blockages.

In private single-family houses, repeated checks and cleaning of ventilation ducts and chimneys by the owner of the dwelling are allowed. To obtain permission to carry out 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. Any work, reconstruction or cleaning of these systems by tenants is not allowed.

Inspection of the condition of channels in an apartment building

Video: Inspection of chimneys and ventilation ducts

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

Documents to confirm the work performed

After carrying out any check, specialists 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 12/30/2011).

The following points must be defined in the chimney act.

Canal length, size and location.
The material from which the chimney is made.
Heating devices connection points.
Constrictions, transitions, others design featuresdisturbing normal operation.
Tightness and tightness of the structure.
The condition of the inner walls, the absence of blockages and blockages.
The presence and magnitude of thrust.
Condition of channel heads, cutting seams (for brick channels).
The height of the head above the ridge, the presence of obstacles for the normal operation of the chimney, nearby 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 gas contamination with carbon dioxide.

Completed certificate of technical condition in the Russian Federation

These documents can 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 devices; gas devices more than twenty years old, with missing or inoperative protective automatics), controlling 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, can be brought 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 illumination, technical video endoscopes with signal transmission to the base device and even industrial robots (at critical and complex objects) are used for these purposes. A thermal imager is used to determine leaking 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 against the ventilation grill, this is also a good indicator. But the most accurate values \u200b\u200bare obtained using a hydrometer - a device for measuring the speed of an air flow that looks like a child's toy with a propeller-wheel and a dial.

It is necessary to clean the chimney and ventilation ducts when clogged, poor draft, the presence of a layer of soot and dirt more than 2 mm.

In this case, both traditional scrapers, ruffs, weights are used, as well as specialized vacuum cleaners, which allow removing any deposits of not only vertical, but also horizontal sections of the passages.

Chimney cleaning at home

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

For self-cleaning in own home a special stiff brush with a detachable handle, the length of which can be changed during operation, is quite suitable. To facilitate the process, special chemicals are also used to loosen soot and deposits.

Ventilation and chimney device in apartment buildings

Ventilation ducts and chimneys in apartment buildings are diverse in design, methods of execution 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 intake is carried out through natural gaps and leaks of 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 recuperation (a recuperator is a device that transfers heat from the exhaust air to the supply air).

Modern ventilation apartment building

The most productive and stably working is the design in which ventilation ducts are removed from each apartment separately. This increases the stability of the system and prevents odors and gases from flowing to other apartments (for example, when one of the residents installs a high-power exhaust fan).

Ventilation system designs

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 an old building is the replacement of such elements by residents with modern, practically sealed, metal-plastic and steel structures... At the same time, air exchange sharply deteriorates, 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 of interior doors or equip them with breathable 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 life of loved ones and neighbors. Leave such work to professionals and just enjoy life in a cozy, warm house filled with fresh air.

Correct chimney installation - necessary condition for the normal functioning of a 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, due to 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: you 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 correct chimney

Fuel consumption, the amount of heat loss, fire safety and air quality in the heated room depend on how correctly the chimney functions. Therefore, its design and installation should 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 is a regular circle: this shape creates the least resistance to the outgoing smoke. The height and cross-section of the chimney is calculated in accordance with building codes, further this will be discussed in more detail.

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

The connection of the heating unit to the chimney pipe often has to be carried out when the diameters in the connection zone 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 extensions are directed upwards. This prevents condensation and resin from flowing along the outer wall of the pipe.

A brick chimney is erected according to the project: the order of masonry 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 gas systems must be fitted with a cleaning test.

Thermal insulation of the outer pipes is mandatory: this will not only eliminate condensation, but will contribute to the fastest warming up pipes.

When the channel passes through the ceilings, 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 vane or deflectors. An exception is gas equipment: in this case, the installation of a protective cap is a violation.

What is the wrong chimney

It is very difficult and expensive to correct the mistakes made during the construction of the chimney, and sometimes it is impossible at all 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 several years. You can also not use asbestos-cement pipes: when heated, they collapse. Plastic also cannot withstand high temperatures.
Errors in choosing the diameter of the pipe and calculating the height of the chimney threaten the lack of normal draft and low efficiency of the system.
Excessive loads on the base of the chimney can lead to its destruction.
Poor thermal insulation is the reason for the formation of condensation and ignition of nearby 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 of 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 of the pipe requires mandatory insulation, otherwise the formation of condensation 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) \u003d (∆p ⋅ Tp ⋅ Tn) / (3459 ⋅ (Tp - 1.1 ⋅ Tn))where ∆p (Pa) - static thrust, Tr - the average temperature in the middle of the pipe (in Kelvin), Tn - average outside air temperature. Pipe temperature (Tr) can be recognized 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. In this case, natural cooling is taken into account for each meter of the chimney: in a brick - 1 degree, in an insulated steel - 2 degrees, in a steel without insulation - 5 degrees. Outside temperature (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 corrected, but only upwards. The fact is that the house itself sometimes turns out to be higher than the obtained value of the chimney height. In this case, the rule is that:

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 so that it is not lower than the line drawn from the top of the house downward at an angle of 10 degrees.

Chimney height above the roof

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

But that's not all: if there is another, taller 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 the heat load of the burner according to the formula: S \u003d (K ⋅ Q) / (4.19 ⋅ √h)where TO - empirical coefficient, numerically equal to 0.02-0.03, and Q (kJ / h) - device performance indicated in the passport, h (m) - chimney height.

If it is easier to act, without formulas, then the following values \u200b\u200bshould be taken as a basis for the cross-section of the smoke exhaust duct made of bricks (the cross-section of the round ducts should be of exactly the same area):

for a unit with a capacity 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 consequence, to unstable operation of heating equipment. A smaller diameter threatens with poor removal of carbon monoxide and other combustion products and even the complete cessation of this process.

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

Some rules not mentioned previously that should be followed:

the use of a solid fuel stove requires mandatory compensation of exhaust ventilation using a supply ventilation;
chimney ducts can be located in the outer walls if they are built of non-combustible materials, but at the same time, external insulation should be provided to prevent condensation;
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 with a height of 1 m or more and a thickness of 12 cm are installed;
brick smoke channels should be built with pockets for cleaning, which are closed with bricks laid on an edge and covered with clay mortar (doors can be installed);
if necessary, deviations of pipes from the vertical by an angle of up to 30 ° and a section length of no more than 1 m are allowed, while the channel 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 roof parts made of combustible materials should be equal to or more than 130 mm, for ceramic uninsulated 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 duct for the removal of combustion products, if these devices are located no further than 750 mm from each other;
the cross-sectional area of \u200b\u200bthe chimney connected to the gas appliance should not be less than the cross-sectional area of \u200b\u200bthe gas outlet 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.

For connecting gas appliances to chimneys, connecting pipes made of galvanized or roofed steel with a thickness of 1 mm or more are suitable. You can also use flexible metal corrugated pipes that come with the equipment. In this case, 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 traction stabilizers and up to 0.15 m - for devices without stabilizers. The total length of horizontal sections in newly built houses should not be more than 3 m, for old buildings 6 m are allowed. A slight slope of the pipe towards the heating device must be observed.

The 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 the chimney through living quarters.

How to care for 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 dirt with a scraper and a stiff brush with a long folding handle: as you move deeper into the channel (work starts from the top), the length of the handle is increased.

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

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

Conclusion

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

Dmitry Portyanoy, rmnt.ru

Appendix G (mandatory)

DISCHARGE OF COMBUSTION PRODUCTS.

This appendix provides for the requirements that must be taken into account when designing smoke ducts from gas equipment and household heating and heating-cooking stoves. When designing chimneys 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 fuels, a verification calculation of the gas-air path must be performed.

The arrangement 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 device, 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 a device in the chimney cut to a height of at least 0.5 m.

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

Connection to the chimney of a batch heating furnace is allowed gas water heater, used for hot water supply, or other gas appliance that does not work continuously, with a sufficient chimney section, which should be determined by the calculation of the appliance. The connection of the flue pipe of the gas appliance to the chimney turns of the heating furnace is not allowed.

The cross-sectional area of \u200b\u200bthe chimney should not be less than the cross-sectional area of \u200b\u200bthe branch pipe of the gas appliance connected to the chimney. When connecting two devices, stoves, etc. to the chimney. the cross-section of the chimney should be determined taking into account their simultaneous operation. The design dimensions of the chimneys should be determined by calculation. Non-household gas appliances (restaurant stoves, cooking pots, etc.) may be connected to both separate and common chimneys. It is allowed to provide connecting chimneys common to several units. The introduction of combustion products into a common chimney for several devices should be provided at different levels or at the same level with the diffusion device according to Zh.Z. The cross-sectional area of \u200b\u200bchimneys and connecting pipes should be determined by calculation, based on the condition of the simultaneous operation of all devices 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 single-storey buildings. It is allowed to discharge the combustion products through steel chimneys. Flue duct designs can also be factory-made, supplied complete with gas equipment. When installing asbestos-cement and steel pipes outside the building or when passing through the attic of the building, they must be thermally insulated to prevent condensation. The design of the flue ducts in the outer walls and ducts attached to these walls must also ensure that the gases leaving them are 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. The slope of the chimneys from the vertical up to 30 ° with a deviation to the side up to 1 m is allowed, provided that the sectional area of \u200b\u200bthe inclined sections of the chimney is not less than the section of the vertical sections. For the removal of combustion products from restaurant stoves and other non-household gas appliances, it is allowed to provide for horizontal sections of chimneys with a total length of no more than 10 m. It is allowed to pass chimneys through ceilings, provided that the fire safety of combustible ceiling structures is ensured.

The connection of gas equipment to chimneys should be provided with 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 smoke outlet 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, it is allowed to reduce the length of the vertical section to 0.25 m, without draft stabilizers up to 0.15 m. The total length of horizontal sections of 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 chimney 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 place where the chimney is connected from the device to the chimney, a “pocket” device should be provided with a cross-section of at least the chimney cross-section and a depth of at least 25 cm, with a hatch for cleaning. Chimneys through unheated rooms should be covered with insulation if necessary. The laying of smoke pipes from appliances and stoves through living rooms is not allowed.

The distance from the connecting pipe to the ceiling or wall made of non-combustible materials is taken at least 5 cm, and from combustible and hardly combustible materials - at least 25 cm. It is allowed to reduce the distance from 25 to 10 cm, provided that combustible and hardly combustible structures are protected by roofing steel on an asbestos sheet thick not less than 3 mm. The thermal insulation should protrude 15 cm beyond the dimensions of the connecting pipe on each side.

Suspension and fastening of connecting pipes must exclude the possibility of their bending. The links of the connecting pipes must fit tightly, without gaps, into one another 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. The connecting pipes made of black sheet steel must be painted with a fire-resistant varnish.

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

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

Chimneys from gas appliances in buildings should be removed:

Above the boundary of the wind support zone, but not less than 0.5 m above the ridge of the roof when they are located (counting horizontally) not more than 1.5 m from the ridge of the roof;

- to the 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, when the pipes are located at a distance of more than 3 m from the roof ridge.

The zone of the chimney wind support is the space below the line drawn at an angle of 45 ° to the horizon from the highest points near the 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 performed together with ventilation ducts. At the same time, they must be divided along their entire height by sealed 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.

The removal of combustion products from gasified installations of industrial enterprises, boiler houses, public utilities is allowed to be provided through steel chimneys.

Discharge of combustion products into the atmosphere through outer wall a gasified room without a vertical channel from heating gas equipment with a sealed combustion chamber.

It is allowed to discharge combustion products into the atmosphere through the roof of the building into a vertical flue duct.

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:

- in 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;

Through the walls of the facades of buildings overlooking squares and streets that have historical, architectural and urban planning value, as well as located in the immediate vicinity of children's areas preschool institutions, schools and healthcare institutions;

- in buildings where 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 ducts on the outer wall of the building when exhausting combustion products from the heating equipment through the outer wall without a vertical duct should be placed in accordance with the manufacturer's instructions for installing gas equipment.

Safe use of furnace and gas equipment is possible only with timely removal of combustion products and continuous air exchange inside the premises. This and some other functions are performed by the chimneys of the of various kinds: from graceful decorations of country villas to giant monsters - indispensable attributes of industrial zones.

Natural draft principle

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 when the temperature difference between the street and the house. The higher the ventilation duct or chimney and the greater the temperature difference, the more intensively the chimney pulls. Therefore, natural ventilation works best on the ground 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 into the apartments from the ventilation.

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

Reasons for reduced thrust:

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

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 head 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 increases traction.

In ducts of large diameter, even with perfect observance of the rules for the safe operation of smoke and ventilation pipes the thrust is reduced, since the combustion products are cooled faster.

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

The draft in the chimneys during the operation of the boiler or stove is about 14 Pa. It is much lower in ventilation ducts. The opening of the vents in 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 area of \u200b\u200bthe wind back. This is the space below the line from the highest point of the nearest building to the horizon at a 45 degree angle.

Construction of ventilation pipes and chimneys

According to the rules for the operation of chimneys and ventilation pipes, they are arranged inside the house to maintain the temperature of the exhaust air. You can arrange ventilation and smoke ducts outside, then they need insulation.

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

Pocket device (holes) for cleaning the chimney

Openings for cleaning and a pocket with a depth of 25 cm are left at the base of the chimney. The openings are covered with doors and lined with brick installed on the edge. Laying is done on a clay solution. In asbestos-cement pipes, a leaf is left for cleaning.

The pocket is necessary so that when the masonry is destroyed, the fragments of brick do not block the entrance opening, falling slightly lower. All the garbage that gets into the chimney also accumulates in the pocket. If you do not provide for a pocket, debris will gradually reduce the cross section of the chimney and impair draft.

Unsuitable materials for the construction of smoke and ventilation ducts:

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

Although silicate brick and withstands high temperatures well, it is destroyed by carbon dioxide and wet vapors. If there are no other materials, SNiP requires a device in the ventilation and smoke channel inner lining made of red brick 13 cm thick.

Chimneys can be:

mounted (from asbestos-cement pipes inserted into each other);
solid (brick).

Packed pipes are distinguished by smooth inner walls, they are supported on fireplaces or stoves with powerful (no 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 disassembled 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 chimney walls are made of heat-resistant concrete.

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

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

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

Chimneys of gasified buildings

Ventilation and smoke ducts of gasified premises should rise above a 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 the gasified rooms must be equal to the height of the exhaust ducts.

Heating equipment is connected to the system of ventilation and smoke channels in the 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 existing buildings.

A slope towards the boiler from 0.01 is allowed. The pipes must be fixed firmly without the possibility of sagging. The pipe bends 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 from the walls of the channel.

If the pipe is made of sheet metal, it must be treated with a heat-resistant varnish.

The pipe is attached to the chimney, leaving a 25 cm pocket and a control hatch, just like in the construction of a chimney. If the device is not equipped with a draft stabilizer, a 15 mm perforated damper is required, through which the furnace is ventilated during the period of inactivity.

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

Chimney requirements

Chimney operation

The rules for the safe operation of smoke and ventilation pipes require periodic cleaning and inspection. Without cleaning, a long-term operating chimney becomes a potential source of fire or poisoning for residents. The need for cleaning ventilation and smoke channels is determined by routine 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 the draft decreases. But there is another danger: combustion products can ignite. Substances released by soot destroy pipe material and masonry joints. The tightness of the chimney decreases, the fuel does not burn completely, and the draft deteriorates.

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

If heating equipment is used every day, the frequency of checking and cleaning the ventilation and flue ducts is 8 weeks. If the stove is melted from time to time, the condition of the chimney must be monitored twice a year: in the fall before the start of the heating season and in spring.

Checking chimneys

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

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

Purpose of checking ventilation and flue ducts:

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

Progress of checking ventilation and smoke ducts:

To determine the blockages in the chimney from above, a load in the form of a sphere, weighing 3 kg and measuring up to 10 cm, is lowered into it. If the load passes unhindered, the channel is clean;
To determine the isolation and density of the 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 releases smoke abundantly when burning. The chimney outlet is tightly covered from above. If there is a smell of smoke in nearby rooms or channels, then the walls of the channel are not tight;
The cleanliness of the channel walls is inspected by lowering an electric light bulb up to 500 W power into the chimney. The density of the walls is determined at the same time. If there is light in the adjacent channels, then there are gaps.

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

mechanical;
chemical.

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

Dry cleaning is safer. In the firebox, a “chimney sweep log” is burned, which burns out soot on the walls of the chimney. The material is impregnated chemical compositiondecomposing soot and soot. But dry cleaning does not cope with thick deposits, therefore it is used as an auxiliary or preventive.

Industrial chimneys

The purpose of industrial chimneys and ventilation pipes is not only in the removal of combustion products, but also in maintaining combustion in boiler units. In the recent past, most industrial chimneys 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 be up to 60 meters.

According to the rules for the safe operation of chimney 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 inspections of ventilation and smoke channels are assigned.

They design chimneys and ventilation pipes for industry, taking into account each specific enterprise, since the task of the construction is always unique.

When designing, take into account environmental standards for the rate of dispersion of smoke and limit smoke concentrations.

Types of industrial chimneys:

Self-supporting metal... The cheapest, are made of metal with thermal insulation. Very heavy. Can be single-barreled or multi-barreled;
Self-supporting truss... They represent a truss column with heat-insulated gas ducts. 1 - 6 trunks are attached to one farm. The farm itself is made of rolled pipes;
Metal columns... One powerful "shell" in which 1 - 5 trunks are hidden. Maximum height 60 m, diameter up to 3.5 meters;
Stretching... Single-barrel metal pipe, which is attached with guy wires. Most often they are installed in industrial plants. 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 supporting 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 to 60 meters. There can be several gas outlet channels.

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

lightning rod;
protective lighting;
ladders and service platforms.

If a rectangular industrial chimney is installed, the correct aspect ratio is very important. The best is considered to be 1: 1.5 with the inner corners ground down.

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

And in the end, a video about dismantling industrial chimneys.

Dl i work normally 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 gas combustion into the atmosphere, there must be a certain thrust - a force that forces air to penetrate into the chimney, and the resulting combustion products move through 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 the best draft, the temperature of the flue gases must be high. The temperature of waste gases from water heaters is 180-200С. Due to the cooling of the ZhST and the suction of air in the weight stabilizer, the temperature drops. When using chimneys, condensation of vapors from flue gases must be excluded. Wetting the canal reduces the draft, leads to its destruction, in the winter season it can lead to freezing and blockage of the canal. The temperature at which condensation begins is called the dew point. For natural gas combustion products \u003d 60-65оС. Air suction in the weight stabilizer reduces the relative humidity of the exhaust gases, while the dew point also decreases to 40-50 degrees. To exclude condensation, the temperature of the flue gases at the outlet of the pipe head is usually taken to be 65 ° C. The thrust is reduced when the ambient humidity is high.

Purpose and arrangement of the chimney. Chimney requirements. Chimney operation

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

Chimney cross-section should be:

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 the outer walls, provided that the thickness of the outer wall of the chimney must be at least the thickness of the wall itself and at least 38 cm

Chimneys must be carried out vertically without ledges. A deviation from the vertical by an angle of no more than 30 degrees with a horizontal deviation of no more than 1 m is allowed. The deviation from the vertical is carried out by smooth drifts with a constant unchanging section. Chimney masonry must be tight. The inner surface of the masonry should be flat, smooth, without mortar sags. The chimney cross-section must be respected along its entire length.

In the lower part 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 should 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 the interfloor ceilings, fire-prevention cuts are arranged (thickening of the masonry). For combustible floors - not less than 38 cm. Fire-fighting cutting is performed from felt soaked in clay solution.

The distance from the ZhST to the non-combustible ceilings is at least 5 cm, to the wooden plastered (non-combustible) ceiling 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 pipe dimensions by 15 cm on each side.

The part of the chimney above the roof is called the “head”. The outer surface of the head is plastered cement mortar in a ratio of 1: 3, with a layer thickness of at least 4 cm. The upper part of the head "iron" - dry cement is rubbed into the solution in a ratio of 1: 1. After plastering, the heads are whitewashed and numbered.

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

Chimneys must have a certain height relative to the roof ridge

Location of chimneys relative to the roof ridge

If the head is located horizontally from the roof ridge no more than 1.5 m, its height should be 0.5 m higher than 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 a line drawn from the ridge to the horizon at an angle of 10 degrees.
The operation of chimneys is significantly affected by the wind support 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.
Conclusion (build-up) of the chimney above the wind support zone (the extended part is shown with a dotted line). With a certain direction of the wind, an increased pressure is created in the zone of the wind back. This causes a deterioration of the draft in the chimney until it stops and overturns. To eliminate this phenomenon, the chimney is built up above the backwater zone. Similar work is carried out according to the project.
In any case, for gable roofs, the head height must be at least 0.5 m relative to the roof. Head height for flat roofs must be at least 2 meters.
The chimneys provided for each of the device are called separate.
In existing residential buildings, no more than 2 devices are allowed to be connected 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 cut in the section of the channel, with a height of at least 75 see Such chimneys are called combined.

Requirements for chimneys:

should be tight;
a certain section;
permitted materials have been used;
must provide the necessary traction;
should not have blockages, blockages, blockages;
should not be in the area of \u200b\u200bthe wind support.

Checking chimneys for tightness is checked by burning strongly fuming materials in a pocket. The pipe outlet above the roof is closed. The appearance of smoke in adjacent ducts or rooms adjacent to the duct indicates that the duct 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 it into a channel on a strong cord of a 12 volt light bulb; 500 watts. View the checked and adjacent channels. The presence of light from a lamp in an adjacent channel indicates a leak. The place of leakage is determined by the length of the cord.

Iron connecting pipes

For the removal of combustion products from the gas appliance into the chimney, iron connecting pipes (ZhST) are made of roofing or galvanized steel with a thickness of at least 1.0 mm. Flexible corrugated metal pipes or standardized elements supplied with the equipment are allowed.
The diameter of the ZhST must not be less than the diameter of the device outlet. The links of the connecting pipes must fit tightly, without gaps, one into the other along the smoke path for at least 0.5 of the pipe diameter. In case of leaks, an asbestos cord and soaked asbestos are used.
The size of the vertical part of the ZhST should be at least 0.5 m.If the device has a traction interrupter, and the height of the room is 2.7 m, then it is allowed to reduce the size 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.With new construction - no more than 3 m.
No more than 3 angles of rotation with a bend radius of the bends not less than the diameter of the pipe itself are allowed. At the point where the ZhST enters the chimney, a conical insert is installed to prevent the ZhST from entering the chimney section, or a restrictive washer is installed.
The place where the ZhST 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 ZhST to hard-to-burn ceilings must be at least 25 cm.
ZhST are painted with fire-resistant varnishes (Kuzbass varnish, bronze paint, silver).

ZHST malfunctions:

incorrect assembly of links;
the section is narrowed;
the presence of a counterclone;
looseness in the links;
leakage at the point where the ZhST enters the chimney;
deviation of the ZhST from the vertical;
burnt links.

Chimney malfunctions in which gas appliances are disconnected from the gas supply:

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

Purpose and arrangement of ventilation ducts. Checking procedure and service. Checkout

Ventilation ducts are used 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, into basements through vents in the outer walls. In gasified rooms, unregulated grilles 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 plane of the ceiling to the top of the hole in the room with a height of not more than 4 m.

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

If 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, through the vertical exhaust shaft, air is thrown out.

For one apartment, exhaust ducts from the kitchen and bathroom, as well as the toilet and bathroom, are allowed to be shared. The thrust is checked with a sheet of thin paper, which should be pulled against the exhaust grille and held in this position. At the same time, in accordance with the standard "Ventilation systems for residential buildings" ZhNM-2004/02, the flow of outside air and its overflow from other rooms of the apartment must be ensured. If double-glazed windows are installed or glued window frames natural ventilation is monitored with ajar air intake devices.

It is forbidden to check the draft of the ventilation ducts with a 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 ducts, prefabricated ventilation ducts;
incorrect location of the head;
faulty finishing of mines outside or inside;
malfunction or absence of umbrellas or deflectors;
malfunction of ladders through boxes in the attic.

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