Requirements for installing a chimney for a gas boiler. Basic requirements for a chimney for a gas boiler: norms and rules How to make a chimney for a gas boiler

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

The desire to build a house on your own arises, as a rule, from 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: this matter cannot be done without the use of special knowledge. Therefore, let us recall the basic rules for creating effective smoke exhaust systems and the importance of observing them.

Chimney installation rules: what should a proper chimney be like?

Fuel consumption, the amount of thermal energy loss, fire safety and air quality in the heated room depend on how well the chimney functions. Therefore, its design and installation must be carried out in accordance with SNiP “Heating, ventilation and air conditioning”, DBN V.2.5-20-2001 Appendix G “Discharge of combustion products” and other regulatory documents. Let's talk about what a properly designed and installed chimney should be like - here 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 removing combustion products. In new buildings, as a rule, pipes made of stainless, acid-resistant steel containing molybdenum are installed. But for stoves and fireplaces that burn wood and coal, ceramic bricks are also quite suitable.

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

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

Connecting a heating unit to a chimney pipe often has to be done when the diameters in the connection area do not match. To solve the problem, use a reduction adapter. All joints are carefully sealed.

The pipes are joined in such a way that their extensions are directed upward. This will prevent condensate and resins from flowing down the outer wall of the pipe.

A brick chimney is erected according to a project: the order of masonry must be prescribed for each layer. In this case, one should strive to obtain an internal 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 liner has been completed: an acid-resistant steel pipe is inserted into the middle of the channel, leaving a small gap.

Most smoke exhaust systems must be equipped with inspections for cleaning.

Thermal insulation of external pipes is mandatory: this will not only get rid of condensation, but will help to quickly warm up the pipe.

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

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

What is an irregular chimney?

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

The use of materials not intended for the construction of chimneys. Thus, the use of brick is unacceptable for gas boilers: the acid contained in combustion products will destroy it within several years. Asbestos-cement pipes should also not be used: when heated, they are destroyed. Plastic also cannot withstand high temperatures.
Errors in choosing the pipe diameter and calculating the height of the chimney can result in a lack of normal draft and low system efficiency.
Excessive loads on the base of the chimney can cause its destruction.
Weak thermal insulation is the cause of condensation and fire 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 chimney pipes, are increasingly being replaced by systems made from other materials. The most commonly used steel pipes are bare and insulated. In this case, the option without insulation can only be used for internal installation - in a specially constructed shaft. External installation of the pipe requires mandatory insulation, otherwise condensation will inevitably form on the internal surfaces.

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

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

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

Chimney height above roof

For solid fuel and gas boilers, the chimney height must be at least 5 m: usually, manufacturers indicate this parameter in the accompanying documentation. It should be remembered that the tall pipe should be secured 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 installed higher than 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 thermal load of the burner according to the formula: S = (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 you act more simply, without formulas, then you should take as a basis the following values for the cross-section of a smoke exhaust duct made of brick (the cross-section of round ducts should be exactly the same area):

for a unit with a power of up to 3.5 kW - 140x140 mm;
for power from 3.5 to 5.2 kW - 140x200 mm;
for power from 5.2 to 7.2 kW - 140x270 mm.

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

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

Some rules not mentioned earlier that should be followed:

the use of a solid fuel stove requires mandatory compensation of exhaust ventilation with the help of supply ventilation;
chimney ducts can be located in external walls if they are built from non-combustible materials, but insulation from the outside should be provided to prevent the formation of condensation;
for each stove (if they are located on different floors) a separate pipe is provided, but it is allowed to use one pipe for two stoves located on the same floor: at the junctions of the pipes, cuts with a height of 1 m or more and a thickness of 12 cm are installed;
smoke ducts made of bricks should be constructed with pockets for cleaning, which are closed with bricks laid on edge and covered with clay mortar (doors can be installed);
if necessary, deviations of pipes from the vertical are allowed at an angle of up to 30° and the length of the section is not more than 1 m, while the cross-section of the channel must be the same;
if the roof is made of flammable 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 built from combustible materials, there should be equal to or more than 130 mm, for uninsulated ceramic 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 appliances operating on gas may be connected to a common duct for removing combustion products if these appliances are located no further than 750 mm from each other;
The cross-sectional area of the chimney connected to the gas appliance should not be less than the cross-sectional area of the gas outlet pipe of the appliance itself, and the upper part of the pipe is not covered with a canopy.

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 prohibited to build channels from slag concrete and other similar materials.

For connecting gas appliances to chimneys, connecting pipes made of galvanized or roofing steel with a thickness of 1 mm or more are suitable. You can also use flexible corrugated metal pipes that 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 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 can be reduced by half - 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 is allowed. It is necessary to maintain a slight slope of the pipe towards the heating device.

Smoke exhaust ducts should not have more than three turns, and the radius of curvature should be equal to the diameter of the pipe. It is prohibited to route the chimney through residential premises.

How to care for a chimney

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

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 film and lock doors and windows. During operation, you can use chemical detergents, for example, “miracle logs”, which during combustion emit a special non-toxic gas, from which carbon deposits lag behind the surface of the pipe.

There are also effective folk remedies. For example, it is sometimes recommended to heat the stove with aspen wood: this creates a high flame that burns deposits on the walls of the pipe. But this should be done carefully: a large amount of soot can cause a fire. You can also burn potato peels: the steam that is generated is an effective remedy for 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 working with chimneys. For those who do not know it, the material in the article should convince them of the need to take the details of the chimney creation process seriously. Don’t overestimate your capabilities: to avoid annoying mistakes, you should seek help from professionals.

Dmitry Portyanoy, rmnt.ru

When installing gas boilers, it is necessary to strictly follow the standards. Also, strictly according to the standards, it is necessary to install a chimney for a gas boiler. Although the temperature of the flue gases is low and has no color, it will cause no less harm, but more - because leaks are poorly detected. Therefore, you must immediately do everything diligently, paying special attention to the tightness of the joints.

Requirements for chimneys for gas boilers

All requirements for smoke ducts are specified in regulatory documents - SNiP 2.04.05-91 and DBN V.2.5-20-2001. Their implementation is mandatory. To summarize, everything can be reduced to several points:

These are the basic requirements. They must be followed. They provide the required degree of security. After all, the fact that the exhaust of a gas boiler is colorless does not mean that it is harmless. Therefore, maximum attention must be paid to all aspects of ensuring safety.

Boiler designs and methods of installing chimneys

There are two types of burners for gas boilers:

It is clear that the choice of chimney type primarily depends on the type of combustion chamber. In one case it should be a coaxial pipe, in the other - a regular one. But besides this, there are many more design nuances.

What material

A chimney for a gas boiler in a private house can be made from different materials. The main requirement is resistance to chemically aggressive substances and the inability to pass gases. Traditionally, several materials are used. Let's talk about the advantages and disadvantages and assembly features of each of them in more detail.

Brick chimney

Today this is no longer the most popular type of chimney. It turns out to be heavy and requires a foundation at high altitudes. In addition, laying a brick chimney takes a lot of time.

However, this type of chimney has a number of negative qualities. The first is in its internal walls are not smooth, which contributes to the accumulation of soot and impairs traction. Second - to Irpich is hygroscopic. Therefore, the condensate flowing down the walls is absorbed, which contributes to rapid destruction.

To solve these problems, a smooth pipe of suitable diameter is inserted inside the brick chimney. This is usually a stainless steel or asbestos pipe. When building such a combined chimney, attention must be paid to the following things:

The joints of the liner pipe must be made airtight. If these are ordinary or sandwich pipes made of stainless steel, everything happens as standard - we collect the chimney using condensate. If the liner is made of asbestos-cement pipes, you will have to take care of the tightness of the joints. Moreover, covering the joint with cement is not an option. Such a connection is not sealed in any way - condensation will be absorbed. We will have to come up with sealed clamps and use hydrophobic (water-repellent) compounds. Moreover, they must also be chemically resistant. As an option, you can consider coating the joints with heat-resistant sealants with an operating temperature of about 200°C.
To ensure that condensation forms as little as possible, it is better to insulate the pipes (even inside a brick casing). To do this, it is advisable to use insulation that is not afraid of getting wet.
A condensate collector must be attached to the liner pipe below. Access to it must be free.

If you make a chimney for a gas boiler according to these rules, then even with abundant condensation it will be easy to deal with.

Stainless steel - single wall pipes and sandwich

Modern gas boilers are designed so that the temperature of the flue gases at the outlet is not very high. Therefore, condensation always forms. With good draft, most of it flies into the pipe; with good insulation, the remaining part evaporates. So it turns out that liquid is not always present in the condensate collector. But condensate itself is formed when the gas boiler is running all the time. Sometimes in larger quantities, sometimes in smaller quantities. In this regard, the requirements for stainless steel for a chimney are high: it must withstand prolonged contact with caustic substances. These requirements are mainly met by food grade stainless steel. Yes, it costs a lot, but only it will serve for years.

Now let’s talk about whether to make a chimney for a gas boiler from a single-wall pipe or from sandwich pipes. In order for condensation to form in minimal quantities, it is desirable that the chimney does not cool down. That is, it needs to be insulated. And although the sandwich chimney has a lining made of insulation, when laying it externally (on the street) it is also better to insulate it - it will last longer, the draft will be better. But in this option, less insulation will be required - one layer, whereas a regular pipe may have to be wrapped in two or even three layers. So the costs of installing a chimney from a single-wall stainless pipe and sandwiches will be comparable. It’s just that in the first case you will have to use more insulation, and in the second less.

If we talk about reliability, then sandwich chimneys are more reliable, if only because they consist of two layers of metal. By the way, if you are insulating the chimney, the outer pipes can be made of galvanized steel - they do not come into contact with condensate, the temperatures are low, and the appearance is not important, since everything will be wrapped in insulation.

Ceramic chimneys

Ceramic chimneys are good for everyone: they are durable, reliable, and tolerate contact with aggressive substances well. But they have two significant drawbacks. First, they are expensive. Secondly, they have a lot of weight, so when installing a high chimney they require a foundation. And this is an additional expense to the already considerable amount. But the service life of such a chimney is calculated in decades.

Asbestos cement pipes

This was once the most popular type of material in the construction of chimneys for a gas boiler in a private house. The material, of course, is porous, has rough walls, and its cross-section is not ideal (not round, but rather oval). But this is perhaps the cheapest option.

When using asbestos-cement pipes for the chimney of a gas boiler, you must:

Make it as straight as possible, trying to make the joints even.
Seal the joints. As has already been said, simply covering it with cement is not an option. A tight connection is required. Several solutions to the problem are the use of hydrophobic additives in the mortar, coating the dried cement mortar with sealant, and the use of sealed clamps.
To reduce the amount of condensate, make the pipe high and insulate it well.

In general, nothing new, all the same rules as for the materials described above, but the hassle of joints is added. So, as a result, the price of a chimney made from asbestos pipes is almost the same as that made from stainless steel.

For boilers with an open combustion chamber

For gas boilers with an atmospheric burner, a smoke channel is required that provides good draft - the removal of combustion products occurs due to the movement of air through the pipe. Therefore, it is made as straight as possible, preferably with smooth walls. There are two versions:

Which option is better? An external chimney is easier to implement - with an outlet through the wall. It is only important to pass through the wall correctly (maintain a fire gap if the walls are flammable). But this option requires good insulation and high-quality fastening to the walls. And even under such conditions there is usually a lot of condensation. Therefore, the installation of a tee and a condensate collector at the outlet is mandatory.

In the case of a chimney outlet through the roof, there are at least two difficult points - passage through the first floor ceiling and through the roof. In these places, special passage units are installed. They provide the proper degree of fire safety.

Features of metal pipe assembly

If sandwich pipes or single-wall metal pipes are used, then the external chimney for a gas boiler is collected “by condensate”. That is, inserting the upper pipe inside the lower one. This is possible due to the presence of a corrugated edge on one side.

When assembling a chimney inside a building, the structure is assembled “according to the smoke.” In this case, it is more important that gases do not enter the room. Therefore, they unfold the pipes so that the upper element fits onto the already installed one.

There is a third option - to assemble two circuits in different ways: the external one for smoke, the internal one for condensate. For such an assembly, it is imperative to use sandwiches, since they are the only ones with two circuits. This is the best option, since the protection is complete, but the assembly is complicated.

Smoke pipes in the shaft (box)

To prevent communications from spoiling the interior, they are often “packed” into a shaft - a specially constructed box. Inside there are, as a rule, a chimney (or chimneys, if several devices are working), ventilation ducts, and there may be risers for water supply, heating, and sewerage. In any case, it is better to cover the chimney pipe with thermal insulation. If insulation can still not be used in a heated room, then in the attic (especially if it is cold), insulation must be mandatory. Use basalt wool with an operating temperature of at least 300°C.

Insulation will have a positive effect on the temperature inside the chimneys, which will increase draft and reduce the amount of condensate. But do not forget that we are talking specifically about gas boilers, and their combustion products have a low temperature.

For closed combustion chambers

A coaxial chimney looks like a pipe within a pipe. The structure is delivered ready-made and can be assembled quickly and without problems. You only need to know the diameter of the outlet pipe and the parameters - height, length.

The design of a coaxial chimney is the simplest. The pipe rises above the boiler and rotates 90°. From it to the ceiling there should be at least 20 cm. Then it is carried out through a hole in the wall, from the outside it should end at least 30 cm from the wall.

Coaxial chimney installation for a gas boiler - distances and standards

The height relative to the ground level is also standardized - the pipe outlet must be at least 20 cm above the ground, and the distance to the nearest wall - from the end of the pipe to the wall must be at least 60 cm.

The chimney pipes that we see from the street, rising above the roof of the house, are only a small part of the entire complex structure, which is responsible for processing combustion products and removing smoke from the room. It does not matter what fuel you use for heating equipment; in any case, it must be equipped with a special system for the release of combustion products. It is very important to have an idea about the structure of the chimney system in your home, since this knowledge will help you use the gas boiler correctly and competently.

Must be designed in accordance with the requirements of SNiP II 35, and SNiP No. 2.04.05 “Design of smoke and ventilation ducts”.

It is worth remembering that everyone must have a SEPARATE disposal of processed combustion products from gas boilers, stoves, and other gas household appliances!!!

Chimney for gas boilers according to SNiP

In all buildings, it is allowed to connect no more than two heating furnaces or water heaters to one smoke duct, which are located on the same or possibly different floors of the house. But in this case, a distance of half a meter from each other must be maintained - at different levels of the floors of the house, or at the same level - a cut of 0.5 meters high.

Compliance with the cross-section of the chimney duct is also an important point at the design stage of the chimney itself. The circumference of the chimney pipe must be no smaller than the circumference of the gas boiler pipe. The cross-section of the chimney when connecting two devices to it must be calculated taking into account their simultaneous operation.

If you decide to install a brick chimney, then you should adhere to DBN-V.2.5-20-2001-“Gas supply” and use: frost-resistant brick (Mrz125) or clay brick, as well as heat-resistant concrete in high-rise buildings, and asbestos pipes in small buildings . It is known that today gas boilers have high efficiency - even perhaps 95%. At the same time, the temperature of the processed combustion products at the outlet is very low, resulting in the formation of a lot of condensate. In turn, the resulting condensate, or rather its chemical composition, destroys the brick chimney. Based on the above, a brick chimney must be lined/lined.

When a single-layer pipe made of stainless, acid-resistant steel is installed in a brick chimney, the process is called. Thanks to this method of installing a chimney, the process of heating the chimney duct occurs much faster in relation to the condensate temperature. When gas is burned, harmful condensate and an acidic environment are formed, and this chimney design helps protect against their negative effects.

If your chimney duct has non-standard dimensions or may simply be crooked for some reason, then you can resort to lining the duct, i.e. use a flexible hose.

The best shape for any chimney duct is a cylinder shape. In second place is the oval shape of the pipe, then the square shape. Because Since combustion products and smoke produced by a gas boiler rise up into the chimney in a spiral, it is better to use a cylindrical pipe. If you use a square-shaped pipe, then dirt will accumulate in the corners of the pipe and the quality of traction will deteriorate.

Requirements for chimneys according to SNIP

The chimney for a gas boiler, according to SNiP, must be vertical. The slope of the chimney is allowed by 30 degrees and with a side deviation of 1 m, while it is necessary to observe the cross-sectional area of the inclined sections of the chimney (it must be no less than the cross-section of the vertical sections).

The part of the pipe that connects the gas boiler to the chimney must be fixed only vertically. The length of this part of the pipe should be more than half a meter (if you count from the bottom of the smoke exhaust pipe of the gas boiler to the horizontal section of the axis).

In new houses, the total length (total) of the horizontal connecting parts of the chimney pipe should be no more than 3 m, and in existing houses - no more than 6 m.

To the gas side. device, the pipe inclination should be 0.01 degrees, no less.

No more than 3 turns on chimney pipes are allowed, and the bend itself must have a radius of curvature no less than the diameter of the pipe.

Below the connection point of the pipe from the gas boiler to the chimney there should be a condensate collector and inspection.

The distance from the connecting section of the pipe to the ceiling (or wall) made of non-combustible material is allowed to be no less than 5 cm. When using flammable materials - no less than 25 cm. It is possible to reduce the distance from 25 to 10 cm, but only with the use of protection (steel + asbestos, at least 3 mm thick). Thermal insulation must extend beyond the dimensions of the connection. pipes 15cm on each side.

The possibility of sagging fastenings of connecting pipes and suspension must be excluded. Each link of the chimney connecting pipes must be tightly connected to each other, without gaps. The links must fit into one another in the direction of the flue gases - no less than ½ (half) of the smoke diameter. pipes. It is also necessary to install a tight connecting pipe to the smoke duct. To ensure that the end of the pipe does not protrude beyond the channel wall, limiters are used - a corrugation or a washer.

If you connect several devices at once that do not have draft stabilizers to a common chimney, then the chimney pipes must have dampers (their opening diameter is at least 15 mm).

In the dampers that are installed on chimneys there is gas. boilers, the holes must be at least 50mm (in diameter).

The free and complete release of waste combustion products into the surrounding atmosphere is important.

Each heating device must have its own separate chimney.

In order to clean exhaust gases, recesses with a depth of 250 mm must be placed in the chimney channels.

SNiP provides the following parameters for the height of the chimney for a gas boiler:

The height of the chimney pipes of a gas boiler relative to the roofs should be:

- not less than 500 mm above the roof ridge or parapet - if the pipes are located at a distance of up to 1.5 m from this ridge, parapet;

- not lower than the ridge/parapet - if the chimney is located at a distance of 1.5-3 m from the parapet/ridge;

- not below the border, which is drawn from the ridge down at a 10° angle to the horizon - when placing a chimney from the ridge of the roof or parapet, more than 3 m;

- at least 1200mm above a flat roof.

In any case, the height of the chimney above the touching part of the roof (adjacent) should be no less than half a meter, and for buildings where the roof is combined (flat) no less than 2 m.

Installation on chimneys for gas water heaters/boilers, umbrellas and other nozzles is not permissible (the only exception would be CONE, since it is considered a transition from a thermal pipe to a single-wall pipe).

Chimneys in the walls and ventilation ducts are allowed to be combined. But it is necessary to maintain their separation along the entire height with special fences, the thickness of which must be at least 120 mm. The height of exhaust ventilation ducts located close to chimneys must be taken equal to the height of the chimneys themselves.

The removal of waste combustion products is permitted from: industrial enterprises that use gas appliances, as well as from boiler houses, housing and communal services. It is permitted: the release of combustion products into the atmosphere through the external walls of gasified premises without a vertical channel from heating and gas equipment with a sealed combustion chamber. Let us allow the combustion product to be removed through the roof of the building into a vertical smoke channel.

The length of the horizontal section of the smoke duct from the heating device with a sealed combustion chamber when it passes through the external walls is taken to be no more than 3 m.

Basic rules for installing a chimney

The installation of a gas boiler should only be carried out when all the rules for installing a chimney are observed.
It is necessary to ensure the correct selection of chimney parameters, on which the further operation of the gas boiler depends.
It is important that all installation work is carried out by highly qualified workers, while observing all fire safety rules.
All manufacturer's recommendations must be followed.
It is necessary to choose the diameter of the chimney duct the same diameter as the device itself or perhaps a little larger.
The air flow in the chimney duct should have a speed of 10-25 meters per second (NPB-98).

Forbidden:

Make channels from loose, porous, slag concrete and other materials;
Lay smoke exhaust pipes from stoves/appliances through living rooms;
Install a damper when connecting devices with draft stabilizers to the chimney itself;
Install the smoke duct outlet through the external walls:

— in entrances, covered passages, arches;

- closed balconies, bay windows, loggias;

- in monument buildings, without permission from the special department that protects them;

— through the walls of buildings facing streets/squares that have urban, historical and architectural value;

- in buildings in which the installation of gas appliances is prohibited in accordance with DBN No. V.2.2-9, SNiP No. 2.08.01, SNiP No. 2.04.05.

Openings of smoke ducts on the outer wall of buildings when combustion products exit from the heating device through the outer wall without vertical. channel, should be placed in accordance with the manufacturer’s instructions, but at a distance not less than those indicated in the following table:
Chimney pipes must be checked at least twice during the heating season and must be performed by highly qualified workers. They should also conduct an inspection of the chimneys themselves.

A chimney for a gas boiler according to SNiP will always work efficiently and, most importantly, taking into account all legal standards!

To ensure a pleasant life in a cottage in winter, eliminating the occurrence of dangerous situations, it is necessary to develop and install a competent heating system. Of all types, gas is the most economical. However, when selecting and installing equipment of this type, it is necessary to strictly adhere to the existing set of rules. Then your stay will be not only comfortable and cost-effective, but also safe. At the same time, it is important to correctly install a chimney for a gas boiler in a private house, because the required heat transfer of the boiler largely depends on its throughput, tightness and safety.

Read in the article:

Chimney for a gas boiler in a private house: purpose, features
When designing heat supply for houses and cottages, you need to wisely choose chimneys for boilers that remove hot air containing harmful substances. The task is important, therefore the following requirements are put forward to such elements of the system:
Ensuring sufficient traction.

The main thing is to correctly position and select the diameter of the chimney for the gas boiler.
Elimination of deformation and damage under the influence of high temperature of the transported medium.

The temperature is quite high, so the chimney pipe for a gas boiler must be made of heat-resistant material.
There should be no change in the properties of the material due to chemical exposure.
Suitable shape.

Nowadays, round pipes are more common, since less soot lingers on their walls.

Basic requirements for installing a chimney in a private house
If you install a chimney in a cottage yourself, study and strictly adhere to the rules described in the following regulatory documents:
SNIP 40-01-2003.
SNIP 42-01-2002.

At the same time, the most important points that must be taken into account when installing a chimney are: correct calculation of the smoke removal system, that is, the height and diameter of the chimney for a gas boiler; selection of pipe material; frequency of service work (cleaning and routine repairs).

In addition, the fire safety regulations clearly define the requirements for the chimney of a gas boiler. Of course, every year they change somewhat, but general provisions can be highlighted:
The room in which the gas boiler is located must be sufficiently ventilated, that is, an exhaust ventilation device (mechanical or natural) is necessary. In this case, the chimney is strictly prohibited from being led into an exhaust shaft. Combustion products from several boilers can be discharged into one chimney; the main thing is that the room must be of sufficient volume (height - at least 2 meters, area - 7.5 meters per boiler), and the chimney is strictly prohibited from being blocked by any gratings.
Equipment located in different boiler rooms cannot be combined into one chimney. If it is located in the same room, such a device is allowed with two reservations: the boilers must be connected to a chimney located at a distance of more than 100 cm in height from each other; installation of a cutting device is required.
It is necessary to comply with fire safety standards when crossing a partition that is susceptible to fire. That is, when crossing wooden partitions, it is necessary to install fireproof cuts. In addition, you need to leave a small distance between the pipeline and flammable materials (for example, insulation) of at least 5 centimeters. Sandwich pipes are excellent for this purpose and do not require additional work in this case. The load-bearing combustible structures must be more than 100 cm from the pipe. This condition is fulfilled by horizontally tapping the channel. The main thing is not to make such a section too long, otherwise the system may not work correctly.
It is necessary to comply with fire safety requirements for the construction of combustible floors. Beams and walls located near the chimney must be treated with special fire-retardant solutions, the fire resistance of which is at least 120 minutes.

To pass through the roof of the building, a special passage must be installed. In the case of ceramic and sandwich pipes, this is quite simple; the necessary element is included in the standard line of materials.
The maximum length of all horizontal sections should be no more than 3 meters.
When installing a steel chimney, it is necessary to insulate it, and it is also prohibited to install it with breaks or leaky connections inside the building.

Related article:
As part of this review, we will try to sort it out. How to choose the best option and set priorities for ordinary users, what models exist, how to properly carry out installation on your own.
Features of chimney installation in a private house: calculation of diameter and height, choice of insulating material
How to make a chimney correctly so that it works correctly and for a long time? When installing an exhaust pipe for a gas heating boiler, it is necessary not only to adhere to fire safety rules, but also to make the correct calculations of the height and diameter of the pipe. Since the quality of traction, and therefore the safety of removal of combustion products, depends on these parameters.
If you are not confident in your own abilities, you should entrust this calculation to professionals. However, SNIP contains rules, after carefully studying them, you can calculate the length and diameter of the pipe for a gas boiler yourself.
To ensure the necessary draft, it is necessary to install a chimney of at least 5-7 meters.
The height of the part of the pipe protruding above the roof depends on the distance from the ridge of the building.

It is necessary to take into account the speed and direction of the wind at the point where the pipe exits on the roof, since in some cases it is possible to blow combustion products almost vertically downwards, which will lead to noticeable inconvenience.

Interesting! Some modern gas boilers are equipped with a draft sensor. If it often shows an error, the height of the pipe is not selected correctly, and it is necessary to increase it or move the chimney.

Rules regarding chimney diameter:
In most cases, the diameter of the chimney pipe should be equal to the size of the boiler outlet. However, if a very high duct is required, the diameter may need to be increased to prevent unnecessary resistance.

Under no circumstances should the channel be narrowed. For example, if the outlet from the boiler is 200 mm, then the pipe must be at least 200 mm.

Important! Ventilation of the boiler room is necessary to prevent the accumulation of gases in the room when the device is turned off. The main thing is to choose the right cross-section of the exhaust duct.
Another important point when installing a gas pipe is its insulation. This must be done to prevent condensation from forming and pouring into the boiler. The main purpose of the insulation is to retain the outside cold, so that when warm air moves inside the pipe, the walls heat up as quickly as possible, and the air does not cool to the “dew point”. You can insulate flues for gas boilers using one of the following methods:
Screwing and securing basalt wool onto the pipe using clamps.
Covering the surface of the chimney with basalt shells is the best option, as they have the best thermal insulation properties.
A brick chimney is usually insulated with cardboard or basalt mats, since in this case this option is the simplest. After installation, the mats are covered with an even layer of plaster.

Choosing a chimney for a gas boiler: materials
If you decide to install a chimney for a gas boiler yourself, first of all you need to choose the material from which it will be made.
Each of the options listed below has its own advantages and disadvantages. Therefore, usually only one of the types is ideal for a particular case:
Coaxial.

Made from stainless steel.

Brick.

From asbestos-cement pipes.

So that you can correctly choose what to make a chimney from in a private house, we will analyze each type separately.
Features of coaxial chimneys for gas boilers
A coaxial chimney is one of the types of metal or plastic pipes. It is made in the form of a structure of two pipes of different sizes (the smaller one is inserted into the larger one), and there are jumpers along the entire length that prevent them from touching, in order to achieve maximum efficiency. You can buy a coaxial chimney for a gas boiler at any specialized store, but its cost is quite high, so it is used only in extreme cases.

The principle of air movement through such a pipe is somewhat different from the standard version. The supply air enters the firebox not from the room, but through the outer contour of the pipe, while combustion products are released through the inner contour. Thanks to this device, coaxial chimneys have the following advantages:
The overall heat loss of the building is reduced, because in this case the air to maintain the combustion of the firebox does not come from the room, but is heated by the air removed (recovery principle).
The possibility of a fire in places where the pipe comes into contact with the building structure is reduced due to the isolation of the hot pipe.
High efficiency, due to which a minimum amount of pollution enters the atmosphere.
In this case, only closed-type cameras are used, which are the safest. In addition, the size of such a device is much smaller, which allows you to arrange a boiler room of a minimum area.
This option also has disadvantages:
High price of coaxial chimneys for gas boilers.
Limitation on the length of pipes located horizontally (maximum 2 meters).
Interesting! Such pipes are usually used when using gas boilers without a chimney. Since their installation is the only way to remove heated air without installing a complex chimney system.

Stainless steel chimney: features, advantages and disadvantages
The use of simple stainless steel chimneys for gas boilers is a rather rare case. Since they are susceptible to corrosion, they heat up quickly, which means they are a fire hazard. The only option is to use acid- and heat-resistant metal pipes. They are slightly more expensive, but more reliable and durable. In addition, their thickness does not exceed 0.5-0.6 mm, due to which a chimney made of this material is quite lightweight and can therefore be attached directly to the walls of the building.
The main thing when installing a galvanized chimney is to securely secure the pipe outside the building using an additional supporting structure. If this is not done, a strong gust of wind may simply blow it away.

Advantages of galvanized pipes:
Aesthetically attractive appearance.
Smoothness of the inner surface, due to which less soot settles on it (compared to a brick chimney).
Installation can be done both inside and outside the building. The main thing here is high-quality insulation of the channel.
There is no need to build a foundation for the channel (due to its low weight).
Brick chimney
The most common and reliable way to remove hot air is to install a brick chimney for a gas boiler. The main thing is to correctly calculate its size and location at the building design stage. If a mistake is made and the system does not work correctly, it will be almost impossible to make changes to the design.

Advantages of brick structures:
Price.
With proper calculation, the costs of installing this type of chimney will be minimal in comparison with other types.
Heat accumulation ability.
Fire resistance.
Brick does not burn, so even if a fire occurs, the fire will not spread throughout the building.
Durability.
Flaws:
Heavy weight.
Soot settling on the channel walls due to the roughness of the inner surface.
Lack of resistance to acidic environments.
Structural destruction due to strong temperature changes.
Chimney made of asbestos-cement pipes
Installing a chimney for a gas boiler from asbestos-cement pipes is not very easy to install, but is an inexpensive option. These non-metallic pipes are connected to the boiler using standard fittings. In this case, it is necessary to install a condensate collector in the lower part, and a roof umbrella in the upper part to prevent flooding of the pipe during rain. Such air ducts are installed on special supports made of brick or metal. The main thing is to correctly calculate the load to avoid collapse of the structure.

Most often, a separate chimney of this type is provided for each boiler. The main thing is to insulate the pipelines well so as not to get burned, and to mount the condensate collector in the right place.
How to properly make a chimney for a gas boiler in a private house with your own hands?
Before installing a chimney for a gas boiler, you need to correctly calculate its dimensions and height. Installation must be carried out strictly following the proposed plan. Otherwise, backdraft or rapid destruction of the structure may occur. In addition, it is necessary to decide on the material and location of the structure. After all, the need for insulation and installation features depend on these parameters.
Installation of metal pipes occurs according to the plan below:
Preparatory stage.

Includes purchasing the necessary materials and applying markings to the floors of the building in the places where the chimney will pass.
Drilling holes for pipes
Connecting the boiler to the chimney using an adapter.
Extending the pipe to the required length.
Installation of passages through ceilings.
Strengthening joints with clamps and self-tapping screws.
Attaching the pipe to the walls of the building using clamps (step – 2 meters).
Installation of a roof umbrella.

Chimney insulation.

If the installation is carried out correctly, repairs to the chimney for a gas boiler will need to be carried out after a very long period of time. Therefore, if you are not confident in your abilities, entrust this work to professionals.
Upon completion of installation, the question arises: how to check the draft in the chimney of a gas boiler, and is everything arranged correctly? Indeed, if there is insufficient draft, not only the formation of condensation can occur, but also the flow of gas into the house or the burner extinguishing.
You can check traction in the following ways:
Using an anemometer.
Holding a piece of paper up to the chimney.

If the draft is insufficient, it is necessary to suspend the operation of the equipment and not turn it on until the errors in the installation of the chimney from the gas boiler are eliminated.

Price table for chimneys for gas boilers
You can buy a chimney for a gas boiler at any specialized store. In this case, the price mainly depends on the pipe material and the number of fittings. Below is a table of average prices for different types of chimneys.
Conclusion
Errors when choosing and installing a chimney for a gas boiler in a private house can lead to an emergency. Therefore, if you are not confident in your calculations, contact a professional.
Type Diameter, mm Length, m Average cost, rub.

Coaxial 100 0,75 3200

Stainless steel 120 1 550

From asbestos cement pipe

Type	Diameter, mm	Length, m	Average cost, rub.
Coaxial	100	0,75	3200
Stainless steel	120	1	550
From asbestos cement pipe

To ensure normal, uninterrupted operation of the boiler, timely cleaning of the chimney and gas channels is necessary. Moreover, the frequency of maintenance is regulated by regulatory documents - snips for chimneys for gas boilers.

According to SNIP, the chimney and ventilation ducts must be checked and cleaned:

Before the start of the heating season - chimneys in which boilers and heating devices operate seasonally.
At least once a quarter - combined and brick chimneys.
At least 1 time a year - asbestos-cement chimneys and ducts, pottery, made of heat-resistant concrete.

The initial inspection of gas boiler chimneys should cover the following points::

correct use of materials is carried out in accordance with the requirements of DBN V.2.5–20;
presence of clogged channels;
checking partitions that serve as protection for combustible structures;
How separated are the ventilation and smoke ducts;
how serviceable and correctly positioned the head is;
checking the presence of normal draft, this parameter depends on the correctness of the construction, in particular, the height and cross-section of the pipe has an influence (see).

Check again ventilation and chimneys for blockages, their separation and density, the draft is checked:

Inspections for the first time and after repairs of ventilation and chimneys are carried out by specialists. organization with the participation of the operating organization. The results obtained are included in the act.
If the ventilation ducts and chimneys of gas boilers are recognized as unusable and not subject to operation, the inspector is obliged to warn the owner in writing about the dangers of using gas appliances.
Chimney SNIP in private houses allows owners to clean ventilation ducts and chimneys if they have a document confirming that they have undergone training.
Before starting repairs of ventilation passages and chimneys of gas boilers, the operating organization, which is the owner of the apartment building, is obliged to warn residents about the start of work. After completion of the repair, all chimneys and ventilation ducts should be checked.

Requirements for premises when placing gas appliances in them

SNiP 01/31/2003- about multi-apartment residential buildings;

SNiP 41-01-2003- everything about air conditioning, ventilation and heating is explained;

SNiP 42-01-2002- instructions on gas distribution systems;

SP 31-106-2002- will talk about the creation of the project and the construction of single-family houses used for living;

SP 42-101-2003- on the construction and design of gas distribution systems from pipes of various inlets.

What the letter of the law says:

The room in which the gas water heater will be placed and the chimney of the gas boiler will be provided for the removal of combustible products must meet certain requirements; not only the area, but also the height of the ceilings is regulated. So, the ceiling height should be no less 2 meters. The volume of areas is no less 7.5 m³ to install one device, and no less 13.5 m³ for two units.
The room must also be equipped with a ventilation duct. A grate or passage between the floor and the door should be provided at the bottom of the door or wall, where the open cross-section should be no less 0.02 m².
Attention: It is unacceptable to exhaust smoke into the ventilation duct. It is prohibited to install ventilation grilles on smoke ducts.
In rooms with a standard hood, it is necessary to compensate for the removed air by penetrating it from outside the room, as well as by replacing it from the remaining areas of this apartment.
Attention: When installing airtight windows in a room, the speaker may turn off due to inconsistent air supply. This is due to the automation of the column itself.
In the bathroom and utility rooms, doors should open outward.
The installation of sockets and switches in the bathroom is strictly prohibited.

Requirements for chimneys

General rules

Depending on the conditions of use, chimneys may have different designs. Its uninterrupted operation and efficiency depend on the quality of the chimney and its material.

Their installation is carried out in accordance with the requirements set out in DBN V.2.5-20-2001 and SNiP 2.04.05–91.

Improper design and use, improper connection to thermal equipment may lead to improper operation and accident.

This manual describes the principles of operation and installation of chimneys, sets out fire safety requirements, which are reflected in the documentation.

SNiP 41-01-2003— “Air conditioning, ventilation, heating”;
NPB 252–98- “Heat generating devices that operate on different types of fuel. Test Methodology";
GOST 9817–95- “Household appliances that run on various types of fuel. Technical conditions";
VDPO- “Rules for production work, repair of smoke ducts and furnaces.”

SNIP chimneys must comply in full. After commissioning of the chimney, a chimney inspection report is issued.

Installation rules read:

The rules for installing chimneys say that placing smoke ducts is allowed inside walls made of non-combustible materials. If there are no such walls, it is required to use crown and cap pipes (clause 3.69.SNiP-91).

Sections of the chimney passing through unheated rooms and on the outside of the building must be thermally insulated so that condensation of thermal vapor and flue gas does not occur in the inside of the chimney (4.2.16.VDPO).

According to the requirements of VDPO and SNiP-91, the following chimney options are allowed:

With modular chimney systems it is prohibited:
1. Melting with flammable liquids.
2. Melting with wood larger than the size of the firebox itself.
3. Drying clothes, shoes and other items on chimney parts.
4. Removing soot by burning.
5. It is prohibited to operate the unit using a method not specified in the manual.
6. Pouring water onto the fire in the firebox.
7. Use chlorine for its compounds.

Chimneys must be inspected by a qualified specialist at least twice during the heating season. To ensure the operation of the heating unit, chimneys should be inspected, and this should be done by specialists.

When two boilers are connected to the chimney, the cross-section of the pipe is determined by their joint operation DBN V.2.5-20-2001 (Appendix G, Clause No. 6). The dimensions of chimneys are determined by calculation, which is indicated in the technical documentation.
Gas appliances for non-domestic purposes (digesters, restaurant equipment) are allowed to be connected to common chimneys.
Installation of smoke exhaust pipes with an exit through one is allowed, but an additional calculation of the pipe cross-section must be made.
The release of exhaust gases for several devices is allowed. The calculation must be made at different levels, according to DBN V.2.5-20-2001 (Appendix G, Clause No. 3).
The cross-section and height of the chimney is determined taking into account the operation of all devices simultaneously, DBN V.2.5-20-2001.

Chimneys made in accordance with SNIP work efficiently and do not contradict legal standards.

Pipe connections

Installation requires welding. Quality control of welding work is regulated in SNiP 3.05. 03.85 5.

Gas water heaters and other gas appliances must be connected to the chimney using pipes that are made using roofing steel.
The length of the connected pipes should not exceed 3 meters in new buildings and more 6 meters in existing ones.
The slope of the pipe in relation to the device must be at least 0,01.
On smoke exhaust pipes, no more than 3 bends are allowed, the radius should not be less than the diameter of the pipe.
The connection of the pipes must be tight; the entry of one pipe into the other must be at least half the diameter of the pipe.
If the pipes are made of black iron, they require painting with fire-resistant varnish.

Attention: If the above requirements are violated, water heaters must be disconnected from the gas supply.