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D To remove combustion products inside the furnaces of heating devices, chimneys for a gas boiler in a private house of different designs from different materials are used. The standards SP 7.13130 ​​specify the requirements for cross-sections, heights, location of chimneys, safe diagrams of passage units through structures made of flammable materials.

Chimney from a gas boiler on the facade of the house

Requirements for chimneys and installation rules

Combustion products have high temperatures, so chimneys must fully comply with the standards of SP 7.13130. The use of factory products that have not passed the Russian Federation certification is not allowed.

The main provisions of the set of fire safety rules are:

• internal cross-section of the chimney - 14 x 14 cm - 14 x 27 cm depending on the thermal power of the boiler (3.5 - 7 kW, respectively) for concrete, brick, ceramic structures, the area of ​​round or asbestos-cement pipes must correspond to these dimensions;
• height – 5 m minimum from the firebox to the deflector;
• chimney thickness - 6 cm for heat-resistant concrete, 12 cm for ceramic brick, not standardized for asbestos cement, sandwich.

The height of the deflector (an umbrella structure that protects the pipe from rain and wind) relative to the ridge depends on the distance of the chimney from it:

• 0.5 m higher at a distance within 1.5 m;
• level with the ridge at a distance of 1.5 - 3 m;
• at the level of an imaginary line at an angle of 10 degrees relative to the horizontal, drawn from the ridge to the pipe, at a distance of more than 3 m from it.

When moving the chimney outside, elbows are allowed within 1 m from the axis of the main pipe to the side at an angle of less than 30 degrees relative to the vertical. The cuts should exceed the thickness of the floors with decorative ceiling cladding by 7 cm with an even distribution of this size from below/top.

The distances from the outer surfaces of structures to wooden elements of load-bearing structures (sheathing, rafters, beams, crossbars) must be greater than the specified dimensions, depending on the chimney material:

Attention! It is prohibited to combine chimneys with ventilation ducts without a special design. But you can run combustion products from two boilers into one pipe if necessary.

Chimney structures

When choosing a chimney or channel, you should focus on the best combination of construction budget, resource, and maintainability. Depending on the materials used, chimneys for a gas boiler in a private house are attached with clamps to the enclosing structures or rest on separate foundations.

In all vertical structures, a serious problem is the formation of condensation, which is released when hot gases come into contact with the cold walls of the pipes. In coaxial modifications, which are often located horizontally, this disadvantage is absent. In addition, it is enough to give the pipe a slight slope towards the ground so that possible condensation drains out of it without additional costs.

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Installation of a chimney for a gas boiler in a private house is carried out according to the general scheme for asbestos-cement, sandwich, and ceramic pipes. For coaxial aluminum and plastic pipes, a circuit is not needed in principle. When making masonry from blocks, modules, and bricks, standard masonry techniques are used.

Sandwich installation

Chimneys made of two pipes of different diameters, inserted into one another, with a heat insulator between them, are called sandwiches. The design allows you to reduce the external temperature of the walls (increased fire safety), eliminate the formation of condensation (useful for increasing the service life).

A sandwich chimney of a wall-mounted gas boiler is installed in a private house using two technologies:

• for condensate– the upper elbow is inserted into the socket of the lower one; when condensate drains in the interpipe space, its penetration into the channel and ignition are prevented;
• by the smoke– the upper pipe is put on the lower one, preventing the penetration of combustion products into the room.

Attention! Gas boilers have gases with low temperatures at the exit from the combustion chamber. Therefore, the “condensate” technology is used.

The chimney assembly technology looks like this:

• installing a damper on the boiler outlet pipe to adjust the cross-section of the chimney channel;
• installation of pipes until they are blocked by condensate;
• making a cutting from a steel box attached to the floor from below;
• cutting through the chimney, building up to the roof;

• fastening to the canopy sheathing - a plate with a conical pipe located at the desired angle to it, depending on the slope of the slopes;
• fixing the sandwich chimney pipe to the roof with a okapnik (a conical clamp of a complex profile), which decorates and seals the joint.

After that, it remains to install one of the elements at the mouth of the pipe:

• volper - deflector for increasing traction with a flat cover;
• weather vane - deflector to improve draft of the original design;

• fungus – conical nozzle for protection from precipitation.

These elements are made of stainless steel and fully correspond to the style of sandwich chimneys.

Stone and brickwork

Chimneys for a private house can be built into brickwork (only into a load-bearing internal wall) or made from blocks. Domestic manufacturers produce several types of chimney modules:

• concrete - used only in conjunction with ceramic pipes running inside them, the outer surface is square, the inner is round;

• ceramics - pressed into special molds, then fired in kilns, have the design of an internal pipe, an external square thin-walled box, connected by stiffening ribs.

The Ukrainian company Schiedel produces chimney blocks made of volcanic pumice. The modules are called Isokern and are a budget option for individual developers. The material is much lighter than concrete and ceramics, the only drawback is the rough inner surface and the lack of Russian certificates. Regional fire safety services accept structures made from this material in 50% of cases.

Brick chimneys are built into walls during the construction of enclosing structures. To lay the blocks, it is necessary to concrete a separate foundation. But, the pipes can be placed in any convenient place, there are no problems with the passage units, rafter systems, or floors.

Asbestos cement pipe

Aggressive advertising by manufacturers of sandwich chimneys cites the main disadvantage of asbestos - the lack of environmental safety. In fact, only safe raw materials and technologies are used in domestic production. According to reviews from craftsmen who install all types of modern chimneys, an asbestos-cement pipe has the following advantages:

• is self-supporting - no need to attach to walls;
• does not condense moisture - there are no leaks into the combustion chamber;
• resistant to combustion products - the resource is higher than that of concrete and brick;
• cheaper than ceramics - the cost is much lower.

Installation of an asbestos cement pipe is extremely simple:

• the first pipe is installed on the foundation, secured with racks or a frame;
• the chimney is increased to the required height, the pipes are connected with couplings;
• The top is covered with a deflector, and a hatch is made at the bottom to install the cleaning door.

The connection from the boiler is made with a steel elbow, which can be replaced if necessary.

Installation of coaxial structure

Unlike other chimney modifications, a coaxial pipe can only be used for closed combustion chambers. (supercharging) is a mandatory operating condition of the system. The design of a coaxial chimney is similar to a sandwich, but instead of insulation, there are jumpers between pipes of different diameters. The inner pipe is used to remove combustion products; the street air necessary for burning natural gas is sucked into the interpipe space.

Unlike conventional chimneys, the pipe does not need to be pulled vertically across all floors. Instead, a 90-degree outlet is put on the outlet pipe, a coaxial chimney is attached to it horizontally, and goes out through the nearest wall while maintaining fire safety distances:

• maximum length of horizontal part 3 m;
• minimum 0.2 m to the ceiling, floor, ground;
• more than 30 cm from the axis of the chimney to the wall surface;
• at least 60 cm from the mouth of the pipe to the opposite wall.

The coaxial structure can be installed vertically above the roof, horizontally through the wall, or connected to a smoke duct built into the brickwork of the wall.

conclusions

Thus, for closed combustion chambers, a coaxial chimney is preferable, saving the construction budget and the aesthetics of the roof, in which there will be no holes. The most reliable for open fireboxes are asbestos-cement pipes or sandwiches. The most discreet wiring is ensured by built-in smoke channels in brickwork, structures made of concrete, ceramic blocks or Isokern modules made of volcanic pumice.

Does a gas heating boiler need a chimney? Of course! Is it possible to build a chimney for a gas boiler with your own hands? Certainly! You just need to study the design features of the most common types of smoke exhaust structures, familiarize yourself with the key requirements for such systems and carry out everything in full accordance with the provisions of the manual.

Features of the chimney device

Regardless of the type of chimney chosen, it will include the following components:

Different materials can be used to make a chimney. Check out the features of the most common solutions and make your choice.

If we judge objectively, then a brick chimney is not even the last century, but the century before last. Such a smoke exhaust system has a complex design and requires serious time, labor and financial costs for arrangement.

In addition, a brick chimney will be inferior to its modern “brothers” in many significant indicators.

Chimney made of galvanized pipe

The sandwich-type design made of pipes is rightfully considered one of the most effective and successful options for smoke exhaust devices.

Today, manufacturers offer a huge range of such chimneys. Among their advantages, it is necessary, first of all, to note their resistance to aggressive external influences and various mechanical loads.

First step . We connect the adapter to the unit pipe.

Second step. We install the tee and revision.

Third step. We begin to build up the chimney.

If necessary, we carry out work using the so-called. knees Where the pipe crosses the floors, we use a special protective pipe.

Fourth step. We put a stainless steel sheet on the chimney. We cut out a hole in the sheet in advance, slightly larger than the pipes. Such a sheet should be located on both sides of each floor.

Fifth step. We strengthen the joints of the structure with clamps.

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:

1. 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.
2. 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.
3. Excessive loads on the base of the chimney can cause its destruction.
4. 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

One of the most important parts of a gas-fired heating system is a properly constructed chimney. It is no coincidence that gas service workers have strict but reasonable requirements for the chimneys of gas boilers. Not only the efficient operation of a gas boiler, but also the safety of the residents of the house depends on a properly installed system. When gas appliances operate, there is no visible smoke, as there is from appliances running on solid fuel, but this does not mean that there is no possibility of carbon monoxide accumulation. It is dangerous because it can negatively affect a person’s health without him noticing.

Owners of private houses must know how the smoke exhaust system is designed in the house where they live in order to operate it correctly. And those who are just planning to install a gas heating device should be aware in advance of which there are chimneys, and what way they are arranged to decide Which choose from them.

Types of chimney systems for gas boilers

Today, for heating systems with a gas boiler, several types of chimneys are most often used. You can build any of them yourself, but you will need a diagram for assembly and recommendations from a specialist. We will try to help you in this matter!

Brick chimney

Brick chimney

Brick pipes have been installed for a long time, even before the advent of pipes made from new materials. But even now, some house owners have not given up on their construction, although, to be honest, such a chimney is complex in design and labor-intensive to install. In addition, building a brick chimney takes a lot of time and is expensive. It should also be noted that the brick version is inferior in technical characteristics to more modern systems, since due to its shape and rough inner surface it is often overgrown with soot, which slows down the removal of fuel combustion waste. You don't want to hire a chimney sweep in a couple of years, do you?

Ceramic chimney

Ceramic chimney section

Such chimneys have a large number of positive qualities, which are especially evident in cases where the installation work will be carried out independently. The design is simple and reliable, easy to install, has a high degree of fire safety and, what is very important, is quite affordable. But, it should be noted that even with so many positive aspects, ceramic chimneys are not very popular.

Requirements for coaxial chimneys of gas boilers

The coaxial chimney is significantly different from all other designs in all respects.

Coaxial chimney connection diagram.

It has a neat, compact appearance and a different shape from other chimney pipes - it does not rise to the roof, but is discharged through the wall.

... and coaxial

Despite its small size, the chimney has high operating efficiency due to its structure and coating on the inner walls. Condensation does not appear inside it, which is very important for the operation of heating systems running on gas fuel.

Stainless steel sandwich chimney

This model is the most popular and in demand in recent years, as it has a number of undoubted advantages over other options. They have a large number of different transitions, tees and other parts made at different angles, which allows you to assemble structures of any complexity.

Chimneys made of stainless steel consist of three layers. The middle one is a heat-insulating one, which is made of mineral wool. This insulating layer can have different thicknesses - from five to ten centimeters. The choice of its thickness will depend on the location of the chimney pipe and the average winter temperatures of the region where the building is located. The correctly selected chimney pipe will determine whether condensate will collect in it, and therefore the proper operation of the entire system as a whole.

The stainless steel chimney has a perfectly flat inner surface, which allows the combustion products of the boiler to be easily removed. In addition, it has a mirrored outer surface, which contributes to the presentability of the overall appearance of the system.

Stainless steel chimney elements

Any chimney (except brick) neither installed, it will require additional elements, which are selected according to a pre-developed system assembly scheme. These include the following details:

• The connecting pipes that connect the pipe to the boiler are adapters.
• Pipes of various lengths.
• Pass-through pipes.
• An inspection tee with a fitting at the bottom through which condensate is removed.
• Cone-shaped tip.
• Bends.

Requirements for the efficiency and safety of a gas boiler chimney, SNiP standards

For the correct installation of the chimney structure, the requirements of SNiP 2.04.05-91 and DBN V.2.5-20-2001 have been developed, which must be taken into account to achieve complete safety during operation of the system. It should be noted that the health and life of the residents of the house, as well as the efficiency of the gas boiler, will depend on the implementation of all the prescribed rules.

Therefore, these rules must be taken seriously, since failure to comply with them will lead to troubles with the gas industry, and possibly to fines. And you still have to redo everything again according to established standards.

Requirements for the normal operation of chimneys of gas appliances include the following:

• Removal of condensate using a special moisture collector, which is installed at the bottom of the pipe.
• The chimney system must have good draft; it is the key to the efficiency of the device.
• To achieve good draft, when assembling the chimney, it is very important to ensure maximum tightness of the connection of the parts.
• The chimney must have a vertical shape without ledges. According to the rules, a slope of 30 degrees is allowed, so that the cross-sectional diameter will be maintained.
• The section of pipe connecting the gas boiler to the chimney system, the length of which must be at least half a meter, must have a vertical section.
• If room height is about three meters, the total length of the horizontal connecting sections should not be more room height.
• The distance between the chimney and the surfaces of walls or in passages, pipes through a wall made of flammable materials must be at least 20 centimeters, and those made of non-combustible materials - about five centimeters. In the walls or ceilings through which the chimney passes, non-combustible material, for example, mineral wool, is placed around the pipe.

• The head of the chimney pipe, having passed through the roof, should rise above it by at least half a meter. If the roof has a flat structure, then the head above it is raised to a height of one meter.

When installing a chimney system, it is prohibited:

• Installation of fungi and deflectors on the head of the gas boiler pipe, as they inhibit the removal of combustion products, so fumes can get inside the premises.
• Arrange more than 3 turns on the chimney flue pipes.
• Route the chimney pipe through any rooms where there is no ventilation system.
• Make chimney channels from materials with porous structures.
• Extend the chimney system through living spaces.

The entire structure is assembled according to the instructions and diagrams of the chimney system manufacturer, agreed upon with the regulatory organization.

Step-by-step installation of a gas boiler chimney

The installation of the chimney system is as follows:

• The passage of the pipe through the ceiling and roof is accurately marked - this process must be monitored repeatedly so as not to make mistakes.
• Next, holes are made according to the markings for the passage of the pipe.
• Mount transition adapter, which connects to the pipe located on the boiler.
• Then a tee with a compartment for collecting moisture is attached and secured with a special bracket.
• The next section of the chimney is joined. If necessary, an element called a “knee” is used.
• If the pipe will pass through the ceiling, a special passage pipe must be included in the chimney kit. The pipe passes through a metal sheet in which there is a hole slightly larger than the diameter of the pipe. The sheet is attached to the ceiling.
• For reliability, the joints of two pipe sections are fixed with clamps and tightened with bolts.
• The chimney is fixed to the wall with special brackets in increments of approximately two meters.
• The design is completed by a cone-shaped tip.
• The last step is to insulate the chimney pipe from flammable materials at the transitions.

It is impossible not to highlight the nuances of choosing and installing a chimney, depending on its location. It can be installed outside and fixed to the wall (wall-mounted), or run inside the building.

Internal chimney

• If heat must emanate from the chimney to all the rooms where it will pass, there is no need to choose a pipe with internal thermal insulation; it is insulated only from the outside.
• It should be taken into account that when the chimney passes inside the house, the risk of combustion products entering the rooms increases, and the fire hazard also increases. Therefore, it is very important to perfectly fit the individual parts and secure them securely with clamps.
• Installation will require a larger number of different additional elements, since the pipe will pass through at least one floor and roof.
• We should not forget that if in the future it is necessary to carry out repair work on such a chimney, this will become quite a problematic task.

External chimney

• The external version of the chimney requires correctly calculated thermal insulation.
• The advantage is the safety of this heating element.
• Installing an external chimney is much simpler than an internal one.
• If repairs are necessary, they can also be easily carried out under any existing conditions.

How to avoid condensation accumulation in the chimney of a gas boiler - video lesson

Any part of the heating system must be arranged as carefully as possible, and this should not be treated negligently. Therefore, if you do not have experience in this area, it is best to contact a specialist who knows his business, or a company that installs chimneys.

Correct operation of gas heating equipment largely depends on the system that removes combustion products. Before installing a chimney for a gas boiler in a private house, you need to have an idea of ​​the types of equipment, the principles of its operation and the regulatory documents according to which it is installed. Regardless of who will carry out the work, the choice of device and installation should be taken with full responsibility.

Installing a combustion product recovery system on a gas boiler contributes to the efficient functioning of the equipment and the entire heating system, safe and comfortable heating, as well as trouble-free operation of the boiler. Before buying a chimney for a gas boiler, it would be a good idea to get specialist advice about the existing options for chimneys and the feasibility of their use.

Types of smoke ducts for gas boilers:

• brick chimney - its construction is planned at the stage of building a house and a foundation is laid under it. A prerequisite is the smooth surface of the internal walls of the chimney. It should be noted that the structure must be resistant to acid, which is formed due to steam condensation. Otherwise, rapid destruction of the brick chimney pipe will occur. Used in combination with ceramic or steel liners. Brick chimneys for gas boilers are distinguished by their complex design, construction time and cost. In terms of technical indicators, they are in many ways inferior to the modern chimney systems that have emerged;

• stainless steel pipe design - this version of the chimney is highly resistant to chemical environments and mechanical damage. The system is made in the form of a sandwich structure: when a pipe with a smaller diameter is inserted into the outer pipe. Fire-resistant material - basalt wool - is placed in the free space between them. Manufacturers offer a wide selection of chimney models;
• coaxial chimney - the design is assembled according to the “pipe-in-pipe” principle: combustion air is taken in through one pipe, and combustion products are discharged through the other. Such a system has high technical characteristics that help improve the safety of all gas equipment and increase its efficiency. And due to the fact that the combustion cycle occurs outdoors, a boiler with a coaxial chimney is environmentally friendly equipment;
• chimney made of ceramic pipes - consists of ceramic blocks with thermal insulation, installed in a concrete frame. Such a smoke exhaust system is resistant to temperature fluctuations, waterproof, fireproof and has high mechanical strength. The main requirement for installation is high-quality joining of ceramic modules.

Which chimney pipe is best to use - everyone decides based on their specific situation. The main thing is to highlight the strengths and weaknesses of any option. Regardless of what type of chimney you choose, its design and installation must comply with SNiP 2.04.05-91 “Heating, ventilation and air conditioning.” After studying these standards, you can learn how to properly install a chimney on a gas boiler.

Chimney for a gas boiler in a private house: basic requirements of SNiP 2.04.05-91

Measures for installing a chimney for a gas boiler, from the design stage to the actual installation of the system, must comply with the requirements of the current regulatory framework, since improper installation and operation of gas equipment calls into question the safety of people using gas installations.

Main elements of the chimney design:

• flue - a channel leaving the boiler into the chimney pipe, connected by an adapter;
• chimney pipes;
• revision - attached to the bottom of the smoke exhaust shaft and serves to clean the channel from combustion products and remove excess moisture;
• fastening elements (brackets, clamps) - used for fastening to the wall;
• other components for the system device.

As a rule, the location of a gas boiler in a private house is planned on the ground floor in a separate room (boiler room). All elements of the heating system must be connected to each other strictly tightly. The basic rules for installing chimneys for gas boilers, regulating the technological order, are presented in regulations SNiP 2.04.05-91 and contain the following requirements:

• proper draft - ensures complete removal of exhaust gases;

• resistance to high temperatures;
• tightness of connecting points - all components along the entire length of the chimney exhaust system must fit tightly to each other;
• the pipe where it passes through the ceiling must be solid, without joints;
• condensate collector - the design of this element must ensure the collection and removal of liquid;
• if the structure has turns, inspection hatches are installed in these places to diagnose the condition of the chimney, clean it and drain condensate;
• the length of the pipe branch to the side should not exceed 1 m;
• the permissible number of turns on chimney pipes is possible - no more than 3;
• the height of the chimney pipe must exceed the height of the roof (at the highest point) to ensure good draft and prevent reverse draft;
• the distance between the chimney pipes and the surface, which is made of non-combustible materials, can be at least 5 cm, and if the surface material is flammable - at least 25 cm.

Helpful advice! Complete sealing of the chimney sections will not allow hot combustion products to escape the system.

The procedure for installing a chimney for a gas boiler in a private house

Depending on the stage at which it is planned to install a chimney for a gas boiler, the exhaust system can be internal or external (remote). In cottages under construction, where the use of gas boilers is envisaged, internal chimneys are used, the placement of which is taken into account in the design. In old houses, when switching to heating using a gas boiler, the chimney is vented outside.

You can compare the strengths and weaknesses of external and external chimneys by reading the table:

The installation of a chimney for an internal type gas boiler involves the construction of a foundation and a protective channel made of brick. Then safe operation will be ensured. Such systems are more efficient and the formation of condensate in them is minimal. In some cases, chimneys can be attached to the wall of the house behind which the boiler is installed.

The installation of an external chimney requires high-quality fastening and mandatory maximum insulation, since condensate in such structures is formed in larger quantities.

The main stages of installing a chimney for an internal gas boiler:

• marking places for making holes in the ceiling and roof of the house;
• arrangement of an opening for the chimney;
• connection of the boiler pipe with the gas duct;
• installation of revision, tee;

• extension of the chimney pipe;
• strengthening joints with clamps;
• fastening the structure with brackets;
• thermal insulation of the outer part.

Helpful advice! The location of the smoke exhaust system must be strictly vertical, without narrowing or widening the channel.

Chimneys for gas boilers made of stainless steel

Chimneys made of steel can have a single-walled or double-walled design. Single-layer exhaust pipes can be installed in heated rooms and used for lining brick chimneys. In three-layer systems, there is a heat-insulating layer between the two pipes, which makes it possible to use them for both internal and external installation.

Due to the fact that gas fuel contains sulfur impurities, when exhaust products are removed, its vapors have an aggressive effect, corroding the walls of the smoke exhaust channels. Therefore, in the production of stainless steel chimneys for gas boilers, heat-resistant and acid-resistant material AISI 316L is used. Its use greatly increases the service life of smoke exhaust systems.

One of the weak points of a stainless chimney pipe for a gas boiler is its not entirely aesthetic appearance. The benefits include:

• resistance to corrosion and aggressive chemical composition;
• light weight, no need for a foundation;
• non-flammability of the material - stainless steel does not melt even at a temperature of 500 ºС;
• modular design - factory production of a large number of tees, adapters and elbows allows you to integrate a chimney into any home;
• factory production of all elements of the steel chimney allows it to be assembled and removed at any convenient angle;
• absolutely smooth round inner surface - provides a minimum of obstacles to the exit of combustion products;
• possibility of installation in an already built house;
• Quite affordable price of a chimney for a gas boiler.

When installing an external chimney made of steel, there is a high probability of dew point formation: if the temperature outside is low, the exhaust vapors form condensation and a water plug is created. It clogs the channel, preventing products from escaping, and thereby blocks the combustion process. This can be avoided by placing the pipe in a brick-lined chimney duct. This technique will also solve the aesthetic side of the structure.

Another option to avoid the formation of a water plug is to use a sandwich structure of two pipes, one of which is protected by a layer of basalt wool. Such a remote chimney system no longer requires additional insulation. The diameter of the chimney for a gas boiler is selected so that it coincides with the cross-section of the equipment outlet.

Helpful advice! Stainless steel chimneys are easy to maintain, but it is necessary to have the system inspected by a specialist once every 3 years.

Rules for installing a chimney for a geyser

The key to safe operation of a gas water heater is a proper exhaust system. For the column, chimneys are used, which discharge combustion products into the smoke exhaust channel or directly into the atmosphere. The following types of pipes are used to remove exhaust gases:

• - easy to install, the flexibility of the material allows
  stretch it up to 2-3 m in length, and also lengthen it by connecting several sections of corrugation;
• aluminum pipe - easy to install, resistant to condensation, requires additional thermal insulation;
• coaxial chimneys - the price of such systems can be reduced due to the possibility of leading the pipe through the wall. This reduces material consumption and installation costs. The main advantage of such a chimney is that air from the room is not involved in the operation of all equipment.

Basic requirements for the installation of chimney pipes for geysers:

• operation of the devices is prohibited without a chimney securely fixed in it;
• the draft inside the chimney system must be constant;
• the pipe material must be non-flammable, resistant to corrosion, condensation and high temperatures;
• the outer section of the chimney must be vertical;
• the structure must be sealed to prevent carbon monoxide from entering the room;
• the exhaust pipe should be installed in an open place for quick troubleshooting if necessary;
• the chimney must be located at least 0.5 m above the roof level;
• It is strictly forbidden to use ventilation systems, the space between floors, or attics to remove combustion products.

How to check the draft in the chimney of a gas boiler

Draft is one of the main indicators of the proper functioning of the chimney. Its effectiveness depends on the following parameters:

• cross-section of the chimney pipe - heated gases are removed faster with a smaller cross-section, but if it is too small, there is a risk of combustion products entering the room. If the cross-section of the chimney is unreasonably large, a reverse draft effect may be created;

• accumulation of a large amount of soot on the walls of the barrel - due to this, the working cross-section is reduced, which leads to a decrease in the rate of carbon monoxide removal;
• a large number of turns in the system - any of the turns of the pipe inhibits the movement of exhaust gases;
• insufficient tightness of the chimney - the presence of small cracks and gaps allows cold air to penetrate into the system, which prevents the rapid removal of smoke;
• weather - high humidity and low atmospheric pressure can cause a decrease in traction.

You can check the state of traction using several methods. If diagnostics are carried out by professionals, they use an anemometer - a device for measuring the speed of gas movement. In everyday life they use the so-called folk methods:

• visual inspection - if there is smoke in the room, it means there is backdraft;
• using a thin sheet of paper - it is brought to the viewing window: the stronger the paper is attracted, the better the traction;
• candle flame - a lit candle is brought to the channel and the flame is blown out. The direction of smoke from an extinguished candle towards the chimney indicates good draft.

Important! The draft in gas boilers should be checked with the equipment turned off.

Depending on the reason why weak craving is observed, measures are taken to improve it. The channel is cleared of soot using a special device consisting of a brush, a sinker and a rope. The device is lowered into the canal and, with progressive movements, it is cleaned along its entire length. To achieve complete sealing of a brick chimney, it is necessary to eliminate all cracks formed as a result of the destruction of the masonry.

Coaxial chimney for a gas boiler: installation rules, advantages, installation

The main advantage of installing a coaxial chimney for a gas boiler is that such a chimney not only removes exhaust gases outside, but also provides the combustion chamber with air from the street. Thanks to this, the room does not require additional ventilation, and the air in the house remains capable of maintaining the health and performance of the people there. Equipment with such removal of combustion products is called a gas boiler without a chimney.

Design of a coaxial chimney

The design of a coaxial chimney is based on two pipes of different diameters, one of which is located inside the other. The inner pipe is designed to remove waste substances outside. Through the outer pipe, or rather, through the space between the inner and outer pipes, air is taken in from the outside, which is used for gas combustion. Thus, the chimney copes with several functions at once:

• increasing the degree of safety of the chimney - the incoming air from the street heats up, and the exiting combustion products cool down;
• increasing boiler performance - the efficiency of the equipment increases due to the fact that the air enters the combustion chamber already heated;
• maximum gas combustion - due to the fact that the boiler efficiency increases, complete combustion of fuel is achieved;
• environmental friendliness of the heating system - the entire operating cycle of gas equipment takes place outside, which ensures comfortable and safe heating.

To make a chimney, round pipes are used: the outer pipe with a diameter of 100 mm is made of steel 1-2 mm thick, the inner one is made of aluminum alloy. The diameter of the latter is 60 mm. Pipes with this ratio of diameters are used in coaxial chimneys for wall-mounted gas boilers and floor-standing devices with a closed combustion chamber. To avoid pipes coming into contact with each other, jumpers are installed along their entire length.

According to the installation method, coaxial type chimneys can be horizontal or vertical. The horizontal option is more popular due to its simple installation. In cases where it is technically impossible to install the system horizontally or the distance from the boiler to the outer wall exceeds 4 m, they resort to installing a vertical coaxial chimney. It is worth noting that its installation is more complicated.

Advantages of coaxial chimney systems

Coaxial chimneys are used for various gas equipment in which the combustion chamber has a closed structure. These are floor- and wall-mounted gas boilers, gas flow-through heaters (columns), convectors and other devices.

It is worth noting the main advantages of using coaxial chimneys over other types of gas exhaust systems:

• natural heat exchange - heating of the incoming air and cooling of the exhaust gases occurs due to the design of the pipe, which, in turn, prevents the wall from getting too hot;
• increasing the productivity of the gas equipment itself;
• compactness - the chimney is carefully installed and does not take up much space, which allows it to be used not only in private cottages, but also in high-rise apartments;

• operational safety - there is no lack of oxygen in the air of the room where the boiler is installed, since contact of the air from the room with the substances being eliminated is completely eliminated;
• ease of installation - allows you to reduce the cost of installing a coaxial chimney.

Helpful advice! If you purchased a wall-mounted gas boiler for autonomous heating of an apartment, using a coaxial chimney for it is the safest, since combustion products are not removed into the ventilation duct, but directly into the atmosphere.

Requirements for installing a coaxial chimney

As with any gas equipment, the installation of coaxial chimneys is subject to specific requirements SNiP 2.04.05–91, section 3 “Heating”; 2.04.08–87, as well as regulations regulated by the “Safety Rules in the Gas Industry”. They can be different depending on the installation method of the coaxial chimney: horizontal or vertical.

For any type of installation, there is a general requirement for the maximum length of a coaxial chimney for a gas boiler: it cannot exceed 4 m. When it is necessary to install a chimney system over a considerable distance, special coaxial models with dimensional standards are used.

When passing a vertical coaxial chimney for a gas boiler through the ceiling and roof, an adapter is used, the design of which is provided by the manufacturer specifically for this system. This also applies to coaxial chimney extensions when it is necessary to install a system of the required length. Tightness in places where pipes pass through the ceiling is ensured by a special head - a terminal. It also prevents precipitation from entering the system.

The horizontal method of installing a coaxial chimney is used, as a rule, for wall-mounted gas equipment. To avoid condensation, it is necessary to maintain a downward slope of the chimney from the boiler of 3 to 5%. There are standards for the location of smoke ducts for a chimney in the outer wall. So, if the hole is supposed to be in the wall next to the window, the distance to the window should not be less than 0.5 m, if above the window - not less than 0.25 m.

Many manufacturers of gas equipment also include a pipe for removing combustion products. If you bought a coaxial chimney for a gas boiler along with the equipment, you need to check that the kit includes a horizontal part of the pipe (usually about 1 m long), an outlet, a terminal (head), a set of sealing gaskets, and a membrane. If, when installing a pipe through a wall, it is necessary to bypass any protrusions or fittings, use elbows and bends.

Helpful advice! It is necessary to provide protection for all outputs and inputs on the coaxial chimney from foreign objects.

Coaxial chimney for a gas boiler in a private house: how to make it yourself

Before installing a coaxial chimney with your own hands, you must read the instructions for the design and operation of the purchased gas equipment. Due to the specific design of the coaxial pipe, the installation of a chimney for a wall-mounted gas boiler must be done with extreme caution. Avoid dents or other damage to the pipes that could lead to depressurization of the system.

To perform installation work, you will need the following system elements:

• pipe with flange;
• crimp clamps;
• coaxial elbow;
• adapter for connecting to the boiler;
• extension cord with sealing cuffs (if required);
• decorative overlays.

According to the requirements for chimney installation, a hole of the required diameter is made in the outer wall. If there is a window opening in the wall, it is necessary to place the hole at a distance no closer than 0.5 m from the window. When connecting a chimney to a gas boiler, first connect the adapter, and then all the links assembled into a single structure.

The pipe is led out through a hole in the wall, maintaining a slope from the boiler. If you need to connect the chimney to the wall, the structure is fixed with clamps. The gaps between the wall hole and the inserted pipe are filled with foam or sealed with mineral wool. After this, these places are covered with decorative rings.

Do-it-yourself brick chimney installation

The brick chimney design is an exclusively vertical channel with a square or rectangular cross-section. To lay a brick chimney, solid ceramic bricks are used, which are laid on mortar. The outer section of the channel is laid out with ordinary brick, corresponding in style to house construction, which can be seen in numerous photos of brick chimneys. If the house is lined with stone or plastered, you can decorate the chimney in the same way.

Brick chimneys for gas boilers: installation requirements

Before laying a brick chimney for a boiler, it is necessary to build a foundation, the height of which must be at least 0.3 m. The dimensions of the base around the perimeter must protrude beyond the contour of the channel itself by at least 0.15 m. If the chimney is located in part of the external wall, its foundation should be level with its base. Laying a brick chimney with your own hands (video instructions confirm this) begins at the stage of building the walls of the house.

Requirements for brick chimneys:

• the smoke channel must be vertical, without ledges, narrowed or widened areas;
• the thickness of the brick pipe for the chimney is taken taking into account the exclusion of freezing;
• the minimum permissible cross-section of smoke exhaust ducts is 14 x 14 cm, which corresponds to the size of half a brick, taking into account the seam;
• the size of a brick chimney, the height of which is less than 5 m, should be increased to a channel cross-section of 14 x 20 cm;
• the chimney is constructed in the walls between heated rooms, which will prevent it from cooling and reducing draft;
• tightness - the brick chimney is laid with ligation so that the vertical seam of the previous row overlaps with the brick of the next one;
• the inner surface of the channel must be smooth;

Helpful advice! To achieve a flat and smooth inner surface of the channel, use special templates when building a brick chimney with your own hands.

• the distance between adjacent smoke exhaust ducts should not be less than 5 average outer diameters of the pipe;

• if ventilation ducts are located near the chimney, their height should be equal to the height of the chimneys.

To reduce construction costs, you should place as many channels as possible in a common chimney. In this case, adjacent chimney and ventilation ducts will heat each other, which will generally improve the functioning of the chimney.

Preparation of mortar for laying a brick chimney

The composition of the mortar for laying a brick chimney is selected taking into account which section of the pipe is being laid: external or internal. To construct the external channel, the same mortar is used as for laying load-bearing walls of house construction. It is prepared from cement, sand, water and can harden in air and water. The mixture is prepared in such a volume that it can be used within an hour, as it sets quickly.

To ensure that the mixture does not deteriorate under the influence of an aggressive environment, it is recommended to add special additives to it that increase its plasticity, strength and acid resistance. Thanks to these additives, you can improve the quality of the masonry itself, increase the speed of construction and the durability of the work performed.

The preparation of a solution for a brick chimney running inside a house is based on the use of fireclay and fireclay in its composition in a 1: 1 ratio. Such mixtures cope well with high temperatures, they are durable and do not emit harmful substances. To give the clay mixture strength, you can add table salt to its composition (about 120-150 g per bucket).

Helpful advice! The strength of the chimney mortar can be enhanced by adding Portland cement in a proportion of 1 kg per bucket.

When laying a brick chimney with your own hands, you can purchase ready-made mixtures that are heat-resistant and acid-resistant. Preparing the solution yourself can reduce the cost of building a chimney.

It is quite possible to build a brick chimney with your own hands - the video below will help you familiarize yourself in detail with the stages of constructing the structure, taking into account all the basic requirements.

The feasibility of using a brick chimney for a gas boiler

Taking into account the advantages and disadvantages of brick chimneys, it is possible to draw conclusions regarding their use in combination with gas boilers. Their advantages include:

• the likelihood of using an existing chimney duct, which reduces chimney costs;
• possibility of operation in conjunction with gas equipment with an open combustion chamber;
• reasonable cost of materials for construction and finishing of the structure.

The durability of brick channels is observed only when they are used for fireplaces or stoves. If they are used for gas boilers, due to the low temperature of the combustion products, condensation will form on the channel walls, and harsh operating conditions in an aggressive environment will lead to the gradual destruction of the brickwork and deterioration in performance.

In addition, the requirements for such chimneys are more stringent:

• impeccable masonry - if the skills are not enough, you will need to invite a qualified mason to do the work, which will cost a lot of money. Prices for work: rough brick masonry from 6,000 rubles per 1 m³, facing masonry - 2,500 rubles. for 1 m²;

• inability to perform a complex channel configuration (if you need to bypass, for example, a beam in a ceiling);
• the use of the old channel should be carried out using sleeves;
• the need for thermal insulation.

The disadvantages of such a system include a decrease in traction while the brick is warming up. Thus, the correct chimney for a gas boiler will be a brick channel together with a steel or ceramic liner. The photo of brick chimneys shows that liners are installed during the process of laying the channel. In this case, it is necessary to leave a gap between the liner pipe and the brick surface. This is necessary so that the pipe can move inside the channel.

Chimneys for gas boilers: prices for different types of pipes

When planning your budget when purchasing chimney pipes, you should take into account the length and diameter of the channel, the presence and number of turns, as well as the material from which the pipes are made. There are no fundamental differences in the design and cost of chimneys for floor-standing gas boilers and wall-mounted appliances. A stainless steel chimney will cost more than a brick chimney, but a steel pipe is easier to install, which makes its installation costs quite affordable.

You can buy a chimney for a gas boiler at specialized sales points and in online stores that sell these products. A large assortment of fittings, shaped parts, tees, adapters, plugs and other necessary structural parts is also offered for sale. Given the convenient sorting of products by category and model, you can quickly find and order the product you need.

The cost of 1 m of a single-circuit stainless steel pipe with diameters of 100, 110, 115, 120 mm is 650 rubles, the same pipe with a diameter of 140-150 mm will cost 750 rubles. The price of an elbow with a rotation angle of 90° made of stainless steel for a pipe with a diameter of 110-120 mm is 550 rubles. with a metal thickness of 0.6 mm. You can purchase 1 m of stainless steel sandwich pipe with a diameter of 140-230 mm for 1,900 rubles.

Helpful advice! You can save on purchasing high-quality and durable chimney pipes if you place an order during the discount period.

The price of a coaxial chimney for a gas boiler with a diameter of 60-100 mm and a length of 1 m, sold in a horizontal set, is 3,500 rubles. The purchase of a coaxial chimney from Baxi, a global manufacturer of modern heating systems, will cost 4,200 rubles. A complete chimney kit for a wall-mounted gas boiler includes a 75 cm long pipe with a diameter of 60-100 mm, a 90° bend and a tip. All products are guaranteed.

Proper installation of any household appliance is the key to its safe and long-term operation. Especially when it comes to gas equipment. Installation of a combustion product removal system for gas boilers requires preliminary engineering calculations and qualified implementation.