Attached chimney. Chimney: basic rules for design and installation. What is important to know about the construction of a chimney to a boiler

September 23, 2014 Alexei

Any building, be it a wooden house or a brick cottage, needs a heating system. In the past, rooms were heated by stoves that burned coal or wood.

Today, homeowners often prefer gas boilers or furnaces running on fuel oil or diesel fuel. Each heating system, regardless of type, is equipped with a chimney.

In traditional Russian wooden huts, the stove was usually located in the center of the structure, and the smoke exhaust ducts were made of bricks or stone. They were coated with clay on the outside. Today, as in past times, the chimney device still remains relevant. This is explained by the fact that all currently known heating sources, excluding electric ones, require effective removal of gases and smoke generated by burning fuel.

Correct arrangement of chimneys and differences in types

Proper arrangement of the heating system also involves the precise installation of pipes that serve to remove combustion products to the outside. The chimney in a residential private house must be installed in accordance with the developed design documentation.

According to all construction rules in wooden house there should be three chimneys. According to equipment standards heating systems In addition to the chimney, it is necessary to provide ventilation pipe and gas outlet.

Watch the video, types of chimney systems:

The ventilation channel is very important for organizing the removal of polluted air from the kitchen, toilet and bathroom. The products of fuel combustion in fireplaces or stoves escape through a chimney installed in a wooden house. A gas outlet is necessary when the building has a gas boiler.

Installation in a wooden house

His correct installation based on what heating device will be used in the house. To remove smoke from a conventional stove or fireplace that burns solid fuel, a device will be quite sufficient brick chimney. It may look like a traditional mine. Moreover, if smoke channel turned out to be spacious, then in this case you can also install an iron pipe inside it.

To remove combustion products produced during the operation of a gas boiler, the installation of a chimney in a wooden house is carried out according to a different scheme. This also applies to equipment using diesel fuel. The point is that the gases escaping into the atmosphere are conditioned on the inner walls of the pipe. The resulting moisture comes into contact with the smoke escaping through the channel and turns into aggressive nitric acid, which gradually destroys the integrity of the walls, which will ultimately lead to the chimney in a wooden house being completely or partially destroyed.

Of course, when organizing the removal of gases from heating devices operating on solid fuel, this problem is not so relevant. For other equipment, for example, liquid fuel and gas furnaces, this point is very important, since the gases released during their operation have a lower temperature.

In this situation, a smoke exhaust device for boiler equipment in a house made of timber or wood is made in the form of an ordinary shaft with a ceramic or stainless steel pipe located inside it, as well as a durable polymer. A popular solution to this problem was the installation of a smoke exhaust duct with bright name"sandwich". Let's try to briefly consider what it is and how it differs from ordinary pipes.

Sandwich chimney device

For a wooden building this system is ideal option. Such a chimney consists of two pipes of different diameters located one inside the other. A heat insulator is placed between their walls. Such a chimney installed in a wooden house differs from a traditional brick one in a lot of advantages.

Watch the video about the sandwich pipe:

Roof structure made of wooden materials, even with good drying, over time it seems to play a little. Displacements invisible to the eye and seemingly insignificant can lead to the destruction of a brick chimney, even the hardest one. But thanks to the sandwich design features, these threats are not scary.

And it is not surprising that the chimney in a wooden private house is increasingly being made in exactly this way. All its many advantages include the excellent fire safety of the pipe compared to a brick pipe.

Coaxial chimney in a country house

For operation gas appliances For heating, ordinary chimneys are suitable. In these cases, architects propose using a coaxial system for removing combustion products in wooden houses. It allows you to simultaneously remove gases fresh air, which is used to support the combustion effect. This system is used in boilers with a closed combustion chamber.

It is characteristic that the installation of a coaxial chimney is possible both vertically and horizontally through the wall. If there is a need to install just such a smoke exhaust duct, then it must be laid along the shortcut from the boiler to the roof or wall.

To prevent debris from getting into the pipe, which can lead to problems with the gas outlet, you should provide reliable protection its outer part. All structural elements must be firmly connected to each other, and the joints must be carefully taped to prevent gas leakage.

The design of this type of chimney involves fixing the pipe with a fastening perforated metal tape. To ensure that condensate does not accumulate on the walls and can drain from the pipe, it is installed with a slight slope.

Aspects of Proper Installation

For normal operation heating equipment it is necessary not only to remove fuel combustion products from it, but also to provide the draft necessary for combustion. To do this, a reaction must be observed in the chimney caused by the temperature difference between the exhaust gas and the outside air.

We watch the video, the rules for arranging a brick chimney:

In this regard, installing a chimney in a private wooden house requires compliance with certain rules and knowledge of small but important nuances. That is why, in past times and today, those stove makers who know how to properly install a chimney are respected. They protected their achievements and nuances in their work from strangers and did not dedicate them to them. Nowadays, information on how to properly install a chimney in a wooden or brick house are no longer a secret and are available to any interested person. Therefore, creating an effectively working smoke exhaust structure is now within the power of many, but it is still better to entrust it to specialists.

The main condition that must be adhered to when constructing a chimney is the correct placement exactly vertically. The maximum permissible deviation is one meter from the vertical axis, which passes through the firebox and the roof of the house. The use of a pipe less than 5 meters in height is strictly prohibited.

Device correct chimney must be carried out in compliance with certain rules. In particular, it is necessary to adhere to a certain height of the pipe protruding above the roof of the building. For example, if there is a modern wooden house flat roof it should rise above the ceiling by more than half a meter. If the building structure has a ridge, then the chimney installed in a private house should also be 50 centimeters above its level and located at some distance from this building element.

How to pass wooden floors

Installing a chimney in a wooden house requires compliance with all rules fire safety. They are given special attention when passing through wooden floors. Such places must be protected with sheet steel and thermal insulation.

Currently, it is possible to install a ceiling passage unit in such cases. Made in the form of a sleeve or box, it is mounted to perform certain tasks.

The main ones:

• Preventing pipe bending
• Protection wooden structures from excessive heat and fire

In places where the polyurethane foam comes into contact with the ceiling, non-flammable thermal insulation materials. The installation of a chimney with a passage unit is carried out while maintaining a certain gap between it and the pipe.

We watch the video review and make a passage through the wooden floors:

A hole of the required size is made in the wooden ceiling, in which the polyurethane foam is installed. A chimney pipe is pulled through it. At the final stage, the edges of the edges of the box are tightly closed with a plate of fire-resistant material.

How to equip the system

Pipe installation in wooden building carried out taking into account fire safety standards. To prevent a possible fire, the construction and installation of a chimney made of any material, but most often stainless steel, in the wall requires reinforced insulation.

1. Non-flammability
2. Increased strength during operation
3. Use as a coating for all types of finishing materials

All this ensures the popularity of foam concrete construction work oh, when a chimney is installed in a wooden private house. In such buildings it is necessary to install separate systems for each firebox separately.

Chimney maintenance

In order for a chimney installed in a wooden house to work properly and efficiently, it must be regularly inspected to check the tightness of the structure at the joints. At least once every six months, soot must be removed from the inner walls of the pipe. A chimney in a private house will perform its functions well if the state of its draft is constantly monitored.

All this work should definitely be carried out in the case where the chimney for a long time was not used for its intended purpose.

If a leak is detected, this deficiency must be corrected immediately. If a chimney located in a wooden house is partially destroyed, a mandatory overhaul should be carried out.

The traditional brick chimney for a gas boiler is quite in demand, despite many existing shortcomings and low thermal characteristics. Despite the apparent simplicity of the design, during the construction of a brick channel, it is extremely important to adhere to the existing standards set out in SNiP. Operational safety and operational efficiency depend on compliance with the requirements. gas equipment.

Is a brick chimney allowed or not with a gas boiler?

The laying of the channel must be carried out by a qualified mason. It is better to avoid installing a chimney for a brick gas boiler with your own hands, without special construction skills. As practice shows, only an experienced stove maker can take into account all the nuances associated with the calculation and subsequent installation of the structure.

Chimney requirements for a brick gas boiler

From time to time, new requirements for a brick chimney for a gas boiler appear. Even before construction begins, find out about existing standards at the Gas Service. Up-to-date information will avoid unnecessary costs and facilitate the commissioning of the structure.

Mono-brick chimneys for gas boilers

During construction, the following conditions are observed:

The disadvantage of a brick smoke exhaust system is its short service life and high requirements for the quality of the masonry. It is difficult to lay out a chimney correctly yourself, so it is better to use the services of a qualified mason.

Combined brick smoke removal systems for gas boilers

When choosing combined systems, you need to pay attention to technical specifications cores, which ultimately determine the performance characteristics of the chimney.

Chimneys made of brick and stainless steel

Before commissioning, old brick chimneys must be lined for use with gas boiler equipment.

Combination of brick and ceramic pipes

A free-standing brick chimney with an internal ceramic pipe for connecting a gas boiler is used as an alternative.

Problems with a brick chimney with a ceramic core are extremely rare. The design is distinguished by a long service life and resistance of the ceramic walls of the pipe to burnout. Given that correct installation, the chimney will last at least 50 years.

Chimney made of asbestos-cement pipe lined with brick

• Excessive production of condensate– an asbestos-cement pipe, even inside a brick, cools quickly, which leads to large volumes of condensation. As a result, the chimney often becomes damp and the structure collapses.
• Low aerodynamic characteristics– asbestos pipe cannot be used for condensing boilers and gas equipment with a closed combustion chamber.

In terms of its thermal and aerodynamic properties, as well as the ratio of cost and durability, the leading position is occupied by a brick chimney shaft with a stainless pipe inside.

How to make a chimney pipe for a gas boiler from brick

It is important to prevent the accelerated formation of condensation and provide for the possibility of regular maintenance of the smoke exhaust system.

What kind of brick is used to make a chimney for a gas boiler?

For the smoke exhaust system not Any will do ceramic brick, but only of a certain brand. Moreover, for the manufacture of the outer and inner parts, material with different markings is used.

• Fire resistance - the material is assigned class “A” or “B”. The first is intended for heating up to 1400°C, the second 1350°C.
• Strength - for masonry you need a brick of grade M 250 or M 200. High density leads to an increase in heating time, therefore, use construction material those marked M300 and higher are not recommended.
• Frost resistance– the chimney is made from solid ceramic bricks with durability factor F300.

The chimney can be made from facing bricks, but the material, which can withstand frost, does not tolerate heating/cooling well. After several heating seasons, the surface begins to crack and crumble. If condensation occurs, facing material loses strength.

It is correct to make a brick chimney for a gas boiler in a private house, from solid brick, class “A” or “B”, with strength M 250 and frost resistance F300.

What masonry mixture is used during construction

If there is no financial opportunity to purchase a ready-made adhesive composition, the mixture is made independently.

• Clay mortar– is heat-resistant, used for the construction of structures located in the house. Clay gets wet when exposed to water, so the mixture is not suitable for the outer parts of the chimney.
• Cement composition- use cement mortar necessary for parts of the chimney located outside the building. To increase strength and give the solution acid-resistant characteristics, special additives are added to the finished mixture. The same solution is used in the manufacture of the chimney foundation.

IN ready-made composition The solutions contain all the necessary additives and plasticizers, which allows you to make a perfectly even seam without leaving voids. The only drawback is the high cost of masonry.

How to insulate a brick chimney

The technology for insulating an external brick chimney is as follows:

• First you need to repair the brick pipe. Damaged areas are replaced. Sagging from the masonry mortar is removed, the pipe is primed.
• To level the pipe and remove cracks and chips that have appeared, you will need to plaster brick surface. Work is carried out on lighthouses. The solution is allowed to dry. It is prohibited to heat the chimney during this period.
• The brick pipe is thermally insulated - the insulation thickness is 5-10 cm for external cladding, mounted on a special adhesive composition, after which the slabs are fixed with anchors. A reinforcing mesh is pulled over the top, embedding it in a layer of glue.
• Finishing is in progress.

To insulate a brick pipe in an unheated attic, use mineral wool. The material costs approximately half as much, and in the absence of precipitation, it performs well as a thermal insulator.

Chimney installation above the roof

• When passing through slabs or roof covering, observe fire breaks. SNiP 01/41/2003 states that from an uninsulated chimney to combustible structures there must be at least 38 cm. For insulated pipes, the gaps are reduced to 5 cm. The space is filled with basalt insulation.
• For penetration, a special box is made, installed under the roofing.
• The chimney head is insulated basalt slabs, covered with ceramic tiles on top or faced with facade plaster.
• The height of the pipe is calculated depending on the distance from the ridge. Exists general recommendation so that the brickwork in a private house is higher than the top level of the roof. In some cases, in accordance with this instruction, it will be necessary to rebuild the existing brick chimney to install a modern gas boiler.
• The pipe head is covered with a deflector to increase traction force.

Connecting a gas boiler to an existing brick chimney is carried out only if the pipe is of sufficient height and after mandatory lining of the system.

How to prevent condensation and methods for removing moisture

Repair of a brick chimney pipe from a gas boiler

• A defect discovered during regular inspection of the masonry.
• Re-equipment of the smoke exhaust system, allowing the use of conventional brick stove chimneys for modern gas boilers.

Why does the brick on a gas chimney collapse?

Is it necessary to line a brick chimney and with what?

Additional sealing of chimneys in brick walls for individual gas boilers is required only if ducts intended for ventilation are used.

How to clean a brick pipe with gas heating

Alternatively, you can call a specialist to clean it. The work will cost on average from 600 to 3000 rubles. The time taken is 3-6 hours, depending on the degree of contamination.

Advantages and disadvantages of connecting a gas boiler to a brick chimney

1. Low cost with the possibility of using an existing pipe.
2. Possibility of connecting a gas boiler with open camera combustion to a brick chimney.
3. Availability of construction and finishing materials.

1. Short service life.
2. High demands on the quality of masonry and the qualifications of the worker carrying out construction work.
3. The need for insulation.
4. Lots of restrictions - do gas chimney in an external brick wall, it is prohibited to use an old duct without liner, to connect the system to condensing boilers and equipment with a closed combustion chamber.

One of the main components in the heating system is the smoke exhaust channel. The installation of a chimney in a private house is quite complex and important process, since not only the proper functioning of the heating device, but also the health of the residents of the house depends on proper operation.

Installation of a boiler chimney in a private house

The functions of the chimney are to remove harmful products that are released during the combustion of fuel along with smoke, so it is impossible to allow at least part of these substances to leak into the room.

Another, no less important, factor in the arrangement of a chimney is its fire safety. It is necessary to ensure its correct passage through the floors and roof, and also to isolate it from walls built of flammable materials. By following all the rules when constructing this heating communication, you can achieve its excellent performance on long years, of course, carrying out annual preventive maintenance.

Everything must be done in such a way as not to get further problems with regulatory organizations, and also to feel completely safe, and for this it is worth studying the mandatory norms and regulations for the design and operation of chimneys of heating devices. This is especially true for brick stoves and fireplaces.

• The oven must have its own foundation. This condition is important because this structure should not depend on other foundations of the house. In the event of shrinkage or other unforeseen movements of the soil, the distortion of the general foundation may lead to a violation of the masonry of not only the stove, but also the chimney. The appearance of seemingly minor and unnoticeable cracks can pose a serious threat to the health of residents.
• The blower hole must be at a height of at least ten centimeters from the floor, as it must provide a sufficient flow of oxygen, thereby ensuring normal combustion of fuel and draft in the chimney.
• For fire safety purposes, the stove must be located at least 25 centimeters from the building walls made of flammable materials. A the best option The walls will also be insulated with heat-resistant materials.
• When constructing the internal structure of the stove, where the chimney with smoke exhaust channels actually begins, it is necessary to strictly follow the layout of the rows. Blocking at least one of the channel openings can threaten the house with smoke with all the ensuing consequences.
• The stove body itself should be 35-40 centimeters below the ceiling. Next comes the chimney pipe.
• It is very important to arrange the correct cutting of the chimney passage through attic floor. Brick protrusions should have steps seven centimeters high before entering the ceiling and after exiting the groove in the attic.
• If the attic floor is insulated with flammable insulation materials, it is necessary to lay them on top sand layer at least five to seven centimeters.
• When fireproofing in the attic, the distance from the inner wall of the chimney to combustible materials must be at least 50 cm. For this purpose, the chimney skirt is laid out, which is located directly in the attic floor.
• The wall thickness of a brick chimney pipe should be 12–15 centimeters.
• If the pipe comes out on the roof on at a distance of more than three meters from the ridge horizontally, its height should be no more than 10 degrees along the slope from the horizon. If the pipe is located at a shorter distance, it should rise above the ridge by at least half a meter.
• These rules are provided by fire safety services and must be strictly observed.

Chimney for metal stoves and boilers

Chimneys for cast iron stoves are simpler in structure and come in two types:

• The first of them, shown in the figure, is more complicated than the second in execution, since it passes inside the building through all the ceilings. The procedures for arranging it in the roof and waterproofing the seams around the pipe will be especially labor-intensive.

But the advantage of this chimney is that it retains more heat in the rooms and that it can also heat the second floor or attic through which the pipe will pass.

• The second option for the chimney metal furnace is a structure that runs almost entirely along the street. Only part of it remains inside the house, which is fixed horizontally. This is a branch section from the heating device, which can be straight or in the form of a so-called elbow. It exits through the wall onto the street and enters a vertical chimney that rises parallel to the wall. Such a device is safer, and the pipe will not take up excess space in the room. Its arrangement will not cause trouble with waterproofing on the roof and its passage through the ceilings.

But when making such a design, the pipe for it must be selected with a thicker thermal insulation layer, which can reach a thickness of up to 10 cm. Without such insulation, the smoke in the pipe will quickly cool down, the draft will decrease, and condensation may also form, which is extremely undesirable for the stove .

Parts for metal chimney

If earlier in order to make a decent chimney you had to tinker a lot or spend a considerable amount on ordering a tinsmith, today manufacturers of ventilation and heating systems produce ready-made parts of various configurations.

Such chimneys are available in different diameters, heights and insulation thicknesses. In addition, other accessories necessary for installing a smoke exhaust system on the wall and protecting it from moisture getting inside are also sold. Sample list parts intended for this purpose:

• Pipes of different lengths, equipped with special locking grooves for fastening them to other structural parts.
• Metal corner transitions made at different angles.
• Crimp clamps in various sizes.
• Mounting brackets
• Floor, wall and ceiling stands and pipe passages.
• Tees also made at different angles.
• Deflectors, fungi, spark arresters and thermal fungi.
• Connecting elbows with the required angle range.
• Other small parts required for chimney installation.

Important components in the chimney device

It is very important to correctly design the most complex components of the chimney - its passages through the attic, interfloor covering, roof, and also through the wall if the main pipe runs entirely along the street.

Interfloor and attic floors

The most difficult thing is to correctly route pipes through ceilings, walls, and roofs.

The chimney passage in the ceiling, made of wood, is framed with special pipes that isolate it from flammable materials to prevent them from igniting. The pipe has a larger diameter than the pipe, so when they are connected, a gap is formed, which also helps protect against overheating.

Chimney passage through the ceiling

There should be a distance between the chimney and the ceiling in which it is necessary to place foil or asbestos non-combustible material, the thickness of which should be at least 7-9 cm. The foil insulator is laid with foil inside.

The pipe is solid. Place of passage through wooden ceiling covered with a metal flange

It is important to remember that at the point of passage in the ceiling, the pipe cannot have joints, but must be continuous.

The same thing - on the floor

If there is a pipe passage in the room top floor, then you should arrange a casing around it, with holes for ventilation, through which hot air will enter the premises. They are usually drilled out from the top and bottom of the casing. Such protection is needed in order to avoid accidentally getting burned on a very hot pipe while firing the stove.

On the ceiling and floor of the second floor, where the pipe passes through the ceilings, metal parts of the flange pipe remain, which cover the flammable materials of the floor and ceiling.

Passage through the wall

The passage of the chimney pipe through the wall is designed in the same way as through the ceiling, using special pipes placed on the chimney, which will help isolate flammable materials from high temperatures. Also, the section of the pipe that will be located in the wall is wrapped in a heat-resistant material with a thickness of at least 7-10 cm.

Roof passage

The most difficult place is the pipe penetration through the roof. He demands special attention in work, since the safety of the sheathing and insulation from external moisture, as well as the general fire safety of the house, will depend on it.

To do this, waterproofing is installed around the outside of the pipe using special tape or “penetrations” on the flange, which are fixed with adhesive-sealant and screwed on top with self-tapping screws.

Particular attention to thermal insulation of the roof structure

To prevent overheating of the sheathing, the pipe must be wrapped in heat-resistant material, and with inside roof pass through a metal panel.

The final stage of chimney installation is to install an umbrella on top of it, which will protect against dirt and water getting inside.

Conditions for normal operation

The design should:

• effectively remove gaseous waste from fuel combustion;
• be safe and comfortable for home;
• have good traction;
• withstand high temperatures;
• be protected from moisture and condensation;
• be resistant to external aggressive environments.

Chimneys can have a square or cylindrical shape, the latter is considered optimal, since it is less susceptible to the accumulation of soot and soot.

Other parameters that are also indicated by building codes:

• alloy steel parts made for the installation of chimneys are distinguished by anti-corrosion qualities and are thick in in 0.5 cm;
• the diameter of the pipe should be the same size as the furnace pipe or be slightly larger;
• chimney arranged for brick oven, is equipped with pockets located at the bottom smoke exhaust ducts and have a depth of 20-25 centimeters. Doors are installed on them, through which soot deposits are removed;
• a metal chimney cannot have more than 3 turns;
• turning radius metal chimney cannot be larger than the diameter of the pipe;
• the pipe must have a height of at least five meters.

All these conditions will help create normal draft in the chimney and effective removal of combustion products hazardous to health.

A short video tutorial on installing a chimney in a private house

It must be remembered that the choice of a chimney does not depend on its external data, but on the stove on which it will be installed, as well as on the fuel used and other heating parameters. Therefore, before purchasing or constructing a chimney, you must consult a specialist.

And one more warning - for some inexperienced builders, the abundance of requirements for arranging stove heating and chimneys, in particular, may seem like unnecessary “nitpicking”, which can, if desired,

The question is almost Hamletian, but requires detailed consideration. Using the example of practical experience, the article describes the solution to this problem when installing a boiler room in your home. Paradoxical as it may seem, the article can be useful both to those who are planning and can afford to buy a chimney, and to those who plan to make a chimney with their own hands.

For the former, the article will be useful in that the information provided in it will allow you to correctly formulate an order for the manufacture of a chimney, and when installing a chimney, at least make sure that there are no “blunders” on the part of the contractors.

Those who plan to make a chimney with their own hands will find in the article useful information in terms of practical implementation of work.

In order not to waste time on theory, of which there is plenty on the Internet, I will note only the main thing. The influence of the chimney on safety is such that the correctness of its operation will be checked by the Fire Inspection authorities with the issuance of a written certificate, without which you simply will not be connected to the gas networks.

Choosing the design of a chimney in a house

Depending on the installation location of the boiler and the characteristics of the room, there are two possible various options chimney installations: external chimney or internal chimney. The figure below shows a simplified diagram of the design of an attached external modular chimney.

The main structural elements of an external attached modular chimney:

• Transition (connecting flue) from boiler to chimney (2)
• Load-bearing wall bracket (3) and revision installed in the lower part of the chimney
• Sections (segments) of prefabricated modular chimney (4)

When installing a chimney inside a building, additional work will be required related to the need to install a support (foundation) for the chimney, a protective casing for the chimney (usually a shaft lined with bricks), and install grooves for the passage of the chimney through the attic floor and roof.

A comparative description of the main properties of chimneys is presented in Table No. 1 below:

Conclusion: If possible, preference should be given to installing an external chimney.

Buy a chimney or make a chimney yourself?

If you decide to use an attached external chimney, there are two options: order a factory-made modular chimney and installation in a specialized organization, or make a chimney yourself.

A comparative description of the main properties of chimneys is presented in table No. 2 below:

Note: If the technical possibility exists, and the financial component is not a problem, then the easiest option is to order a chimney and its installation from a specialized organization.

What are the arguments of those who make a chimney with their own hands?

• Firstly, of course the price. The further you are from megacities, the higher it is.
• Secondly, the possibilities of using a modular chimney in some cases are very limited, and without carrying out additional work impossible. But more on this later.

If you decide to make an attached chimney yourself, then when considering the design and materials used, you must consider the following.

Selection of basic parameters, constructive solutions and materials for installing an attached chimney.

a) The internal cross-sectional area of ​​the chimney (along its entire length) must not be less than the internal area of ​​the chimney of the boiler itself. That is, the boiler must be available before work begins.
b) The optimal shape of the internal cross-section of the chimney (from the point of view of smoke removal) is a circle. Great importance also has smoothness inner surface chimney.
c) When gas is burned, chemically aggressive components are released as a result of combustion in the form of vapors and condensate. Therefore, the material for use in the chimney must be gas-tight and inert to chemical influences.
d) The temperature of the exhaust gases for boilers is low, at least usually it does not exceed 150 C for Russian boilers (and even less for imported ones). Therefore, the material used for the chimney must stably withstand the temperature with some margin, for example, about 250 - 300 C. This will be quite enough for reliable operation chimney.

Thus, general solutions for installing a homemade chimney in a house are as follows:

From the point of view of the stated requirements, it was decided to use an asbestos-cement pipe as a chimney.

Note The boiler passport specifies the possibility of using an ASB pipe with a diameter of 150 mm as a chimney. According to calculations, the internal cross-sectional area of ​​such a pipe is slightly smaller than that of the boiler, but a slight deviation in the cross-sectional size, within (± 5)%, can be compensated by increasing (decreasing) the total height of the pipe.

For the connecting flue between the boiler and the chimney, I decided to use a homemade design.

I decided to install the pipe and insulate the chimney by analogy with a modular chimney, i.e., perform an easier installation.

Transition device for the chimney.

The main difficulty in self-production The attached chimney is a transition device (connecting flue) from the boiler to the chimney itself. This is due to the need to perform welding and turning work. Therefore, we will consider this issue in more detail. There are certain requirements for the transition device between the boiler and the chimney; I will note the main ones.

The length of the horizontal section should not exceed 2 m (for a chimney with natural draft).

On the horizontal section it is necessary to provide a device for it.

The presence of a horizontal section must be compensated by increasing the total height of the chimney compared to the calculated or recommended one.

Connections between the boiler, passage and chimney must be sealed and gas-tight.

A steel sheet 3 mm thick was used to make the chimney. When choosing a material, proceed from the fact that saving on the thickness of the material is not rational, since the transition structure in the wall opening will be quite difficult to replace or repair. Since the boiler chimney outlet has rectangular shape size 202x96 mm, and the chimney itself is round, it was necessary to think about the transition.

The photo below shows the main stages of work.

Cutting blanks.

The design of a homemade transition is shown in the photo below.

The rectangular horizontal section of the channel (1) is intended for direct connection of the boiler to the structure. It is important to note the following here.

The transition should fit fairly freely onto the boiler chimney, with a gap around the perimeter of (5-10) mm and a depth of at least (4-5) cm. This is necessary so that when installing the boiler there is room for maneuver (unfold, move a little etc.). The gap between the walls can subsequently be easily eliminated using twisted asbestos cord (to obtain the required thickness) and a special oven sealant.

Rectangular inclined channel (2) of the transition, designed for passage in the wall. The length of the channel depends on the thickness of the load-bearing wall, plus the overlap. It is important to note the following here.

• When inflating, you need to take into account the amount of reserve for finishing works and the necessary margin (distance from the wall) for insulating the chimney itself. In my case, with a load-bearing wall thickness of 55 cm, the length of the inclined channel was about 90 cm.
• The rectangular channel is made at an angle, for better outlet smoke into the chimney. The bottom line is that if possible, it is better to exclude horizontal straight sections in the chimney.

Cleaning the transition is easily done from the boiler side through the screw (upper) door.

Supporting element for installing a chimney pipe (3).

Made from scraps metal pipe with a diameter of 219 mm, plugs are welded at both ends of the pipe, in which holes are machined to the size of a pipe with a diameter of 159 mm.

The upper glass (3) is made of a pipe with a diameter of 159 mm.

Designed for direct installation of the base of the ASB pipe; a groove is machined inside the pipe for this purpose, according to the dimensions of the ASB pipe.

The lower glass is also made from pipe 159, but of greater height (4)

Designed for inspection device. The photo below shows arrows. A flange is attached to the bottom of the glass with two bolts through a gasket, which ensures the tightness of the chimney in the operating position and the possibility of cleaning (draining condensate) when servicing the chimney.

What you need to consider when performing construction work.

The photo below shows the main points of the stages of construction work. The photo on the left shows that when laying the foundation for the boiler room, a platform was provided for the future chimney, taking into account the planned installation location of the boiler in the boiler room.

The photo on the right shows that when laying the walls, an opening was left in the wall for installing a transition in the wall structure. The photo on the right shows a “try-on” installation of the chimney when laying a wall.

It should be noted: if the wall is made of non-flammable material, as in the photo, then there will be no problems during installation. If the wall material is flammable, it is necessary to provide for cutting of non-combustible material in the wall, otherwise firefighters will not allow the chimney to be used. Despite the stated characteristics of modular chimneys, when laying them through building construction, cutting from non-combustible materials is also mandatory for them.

As noted earlier, the transition was installed in the wall opening during construction work. The space in the wall opening between the transition and brickwork can be sealed with expanded clay concrete screed. As the walls are laid, it is necessary to lay in brick wall metal fittings for subsequent fastening of the pipe with clamps to the wall.

The height of the chimney must be at least 5 meters. This parameter depends on many factors: the location of the pipe in relation to the ridge of the roof of the house, structural features, and the presence of other obstacles. For convenience, the figure below shows the main dimensions and ratios that must be maintained when installing a chimney in your home.

In our case, taking into account that the internal cross-section of the ASB pipe is smaller than the cross-section of the boiler chimney, the presence of an inclined section of the chimney, as well as relative position pipes and the ridge of the house, the height of the chimney was 7 meters. That is, it was necessary to buy two ASB pipes with DN = 150 mm and a length of 4 m. In addition, to securely fix the pipe in the upper part of the building, it was necessary to make an additional brick structure.

The general view of the chimney is shown in the photo below.

The photo on the right shows Bottom part chimney structure, which protects the thermal insulation of a homemade chimney transition. The design ensures unhindered inspection of the chimney due to the fact that flat slate It is fastened with only one M10 bolt in the upper part, in the lower part it is simply inserted into the corner embedded in the structure during laying.

Chimney insulation.

Next important point What you need to pay attention to is the insulation of the chimney structure. This must be done without fail, otherwise the draft will deteriorate due to the rapid cooling of the exhaust smoke. The service life of the chimney is also reduced due to the formation of condensation and its effect on the chimney structure. In addition, more frequent chimney maintenance is required (draining the same condensate), etc.

It is necessary to insulate the chimney as carefully as building structures. Taking into account the peculiarities of condensation formation, insulation of the chimney must be done to a height of at least 6 m (building height). The photo below shows the main stages of chimney insulation. Thermal insulation must be protected from external adverse influences.

An important practical criterion for the quality of chimney insulation is the absence of condensation during operation.

Some findings and conclusions

About the difficult choice of chimney pipe.

There is information circulating on the Internet about the unsuitability of ASB pipes for chimney installations and the impeccable quality of modern modular chimneys (made of stainless steel, glass, ceramics, etc.). Therefore, I would like to draw the readers’ attention to the following. In terms of its parameters, taking into account all the factors when using it as a chimney for boilers running on gas, the ASB pipe is no worse, and in some respects it even surpasses modern analogues.

It is really dangerous to use an ASB pipe if the boiler runs on solid fuel (coal, wood).

The temperature of the exhaust smoke can reach 250-400 degrees, and if the soot that is formed when burning solid fuel ignites, the ASB pipe will fail. But since the temperature during soot combustion reaches more than 1000 C, most modular chimneys will also become unusable.

The main advantage of modular chimneys is manufacturability, dimensional accuracy in their manufacture and the ability to manufacture various complex parts of transitions, tees, bends, a certain versatility, etc., which is convenient primarily for suppliers and installation organizations.

She allows in short time(a day or two) with the help of a small team (3-4 people) of average qualification, without using expensive equipment, install a chimney on site and earn very good money as a result. This is the main advantage of modular chimneys.

"Horror stories" about condensation.

This is another reason why modular chimneys are better.

• Yes, if we are talking about installing a chimney for a boiler room with a capacity of approximately 100-150 kilowatts or more.
• Indeed, such a problem is possible there. But if we take into account that in most private buildings the power of heating boilers does not exceed (30-50) kW, and sometimes even less, and the chimney insulation is done efficiently, then problems with condensation practically do not arise at all.
• An important point from the point of view of condensate formation is the operating mode of the boiler. In imported boilers (unlike boilers Russian production) the “start-stop” operating mode is usually used (economical mode in terms of gas consumption). Therefore, when the boiler is turned off, the cooling of the chimney of a modular chimney made, for example, from stainless steel will occur more intensively than, for example, from an ASB pipe. It is logical to assume that the probability of condensation formation for a modular chimney is even higher than when using an insulated ASB pipe (taking into account its properties and parameters). Example from personal experience: Russian-made boiler, most time (50-60 percent) it works on an ignition wick (wick power is about 2.5 kW). This is enough to maintain the temperature in the house (except severe frosts), and maintaining a constant temperature in the chimney. There was never any condensation. Total consumption gas, taking into account the boiler (16 kW), gas water heater (19 kW) and gas 4-burner stove is about 2100 cubic meters. m for seven months of the heating period (from October 1 to May 1). The area of ​​the residential building is about 100 m2 (8.5×12.5) m. Region of residence - middle lane Russia.

There are two main connection devices in the chimney: “smoke” and “condensate”. How are they different and what assembly scheme should be used to avoid problems in the future?

Assembly "by smoke"

Assembly "by condensate"

How to install pipes and assemble a chimney

Condensation and its effects

Liquid appears when fuel is burned. It usually contains hydrocarbons, sulfur, oxygen and potassium substances. During the combustion process, when oxygen combines with hydrogen, water vapor is actively synthesized, which in itself is a corrosion agent. In addition, a lot of water is contained in the fuel itself. For example, anthracite gives 3% of smoke steam, firewood - 30%.

When is it correct to assemble a chimney “by condensate”, and when “by smoke”?

It is especially important to correctly assemble the “condensate” for:

• Chimneys of gas boilers. They have abundant formation of water precipitation due to the low temperature and high saturation of flue gases with steam.
• Stoves and fireplaces with a chimney installed outside the house. In such a chimney in winter, flue gases cool faster and more strongly compared to a chimney that goes inside the house. Therefore, more condensation forms.
• Any firebox with smoldering combustion.