Chimneys for a gas boiler in a private house: how to choose and install? Chimney for a gas boiler: design features and requirements for gas boilers Calculation of chimneys for gas boilers in an apartment building

The arrangement of the exit path for carbon monoxide from the boiler must be carried out in accordance with established requirements and standards. There are dimensional and other restrictions for the chimney so that the outflow of smoke from the gas boiler is carried out safely for human health.

Each individual heating system has its own special requirements for organizing a combustion product removal system. For gas heating equipment, the main thing is to design the chimney in such a way as to ensure the best possible draft.

Gas boiler with chimney and air intake pipe

Ill-proper chimney system equipment can lead to the penetration of carbon monoxide into a living space - this, in turn, poses a serious danger to human health and life.

Requirements for the material for the manufacture of chimneys

The following requirements apply to the material used for the manufacture of pipes intended for the removal of flue gases:

resistance to high temperatures;
high anti-corrosion qualities;
chemical inertness.

Exhaust pipe

Inside, on the walls of the smoke exhaust pipes, due to constant temperature changes, condensate constantly forms, which contains a high content of sulfuric acid. Therefore, it is extremely important that the material used to make the chimney does not react chemically with acids and also has excellent corrosion resistance. When purchasing, you should also separately specify that the thickness of the inner layer is at least 0.05 cm.

Advice. To reduce the amount of condensate released inside the pipe, the chimney should be insulated.

Metal, ceramic or coaxial chimney?

In a private house, chimney pipes for gas-fired boilers can be metal, ceramic or coaxial. The preferred type of flue pipe material that is suitable for use with a particular boiler is usually indicated by the manufacturer in the technical documentation.

Chimney device

The most common option is a metal chimney that can withstand an operating temperature of 800 degrees. Typically, the pipes of such chimney structures are made of stainless steel; ferrous metal coated with zinc can also be used as a manufacturing material.

In general, the standard design consists of several components: the inner layer of the chimney is made of stainless steel, on top of which there is a layer of heat-resistant basalt wool and a thin iron casing. Among the advantages of metal chimneys are high resistance to mechanical damage, as well as increased reliability and a universal, presentable appearance.

Ceramic chimney pipe

Ceramics, which can withstand up to 1200 degrees, are in slightly less demand among consumers. The structure also consists of three layers: a ceramic component, a layer of insulation and a hard shell of expanded clay concrete. Chimneys made from this material are distinguished by their simplicity and reliability, ease of installation, as well as high fire safety.

The coaxial chimney is valued for its presentable appearance and fairly high performance characteristics. In general, this type of construction has a somewhat specific shape, due to which it has an important advantage - condensation does not form on its internal walls. This property is very important for gas equipment, so when choosing a suitable material you should consider purchasing a coaxial chimney.

Diagram: coaxial chimney device

Attention! Brick pipes are suitable for solid fuel, not gas equipment. Therefore, for gas boilers, an old brick chimney must be converted by inserting a liner made of metal, followed by insulation.

Basic standards

Section size and shape

When calculating the cross-sectional area of a chimney pipe, the dimensions of the pipe installed on a particular gas boiler are taken into account - the chimney ultimately must be no smaller in size. Two boilers can be connected to the chimney pipe, but only on the condition that their inputs will be located at different levels and at a distance of 0.5 m relative to each other.

In this case, the cross-sectional area of the pipe is calculated as the total power of both heaters, multiplied by 5.5. For example, provided that the power of one according to the passport is 1 kW, and the other is 1.4, the cross-sectional area of the common pipe will be (1 + 1.4) x 5.5 = 13.2 cm square.

Installation of a chimney system for a gas boiler

The cross-sectional shape can be in the form of a rectangle or a circle. The smoke flow moves in a spiral inside the chimney pipe and, encountering corners, loses its speed, therefore the round shape is more preferable, allowing for high-quality draft.

Pipe location

The chimney must be installed in a vertical position. The permissible deviation is no more than 30 degrees or up to 1 meter in any direction. At the point of connection to the chimney pipe of the gas unit, a vertical section must be installed, and the height of the section must be at least 0.5 m.

Correctly installed chimney for a gas boiler

Ideally, there should be no bends and all kinds of roundings on the chimney pipe at all, but up to 3 such outlets are allowed. It is allowed to slope horizontal pipes exclusively in the direction where the boiler is located, with a slope angle of up to 0.01 degrees.

Number of probes

It is allowed not to install headers if they impede the exit of flue gases. Under each of the probes, which are located on the tip, you cannot place more than 1 pipe, that is, all individual pipes must have their own “fungi”. The headband must have a cone shape.

Rules for the installation of chimney pipes intended for gas units

During the installation process, you must adhere to a number of established rules:

installation is always carried out in the direction from bottom to top;
the structure is attached strictly vertically;
pipes in height should not reach more than 5 m;
the slightest deflections of pipes are excluded;
all joints, transitions and curves must be carefully sealed using heat-resistant sealant;
along the path of smoke movement there should not be more than 3 horizontal transitions more than 1 meter long;
the head should be located above the wind pressure zone.

Chimney outlet options

Another important requirement for a chimney structure is the mandatory fastening of the pipe to the adjacent wall. Ideally even sections of the pipe are fastened in sections of 150 cm, while its individual parts are fixed to each other without exception. To enhance the overall reliability of the structure, all connections of the elements are fastened together with metal clamps.

SNiP requirements

Regardless of the type of construction, all chimneys for gas boilers must be manufactured and installed in accordance with SNiP 2.04.05-91 and DBN V.2.5-20-2001. Strict adherence to all requirements guarantees safe operation of the heating system. If the standards set out in these documents are violated, problems will arise that will need to be resolved directly with the gas industry.

Proper chimney installation

The main points of the regulatory documents:

good traction must be organized;
the design of the condensate collector must be carefully thought out so that excess moisture does not accumulate on the walls of the chimneys;
It is not permitted to install fungi, deflectors, etc. on the chimney head, since they inhibit the process of removing combustion products;
When carrying out installation work, special attention must be paid to the tight fit of all individual structural parts at the connection points;
A mandatory requirement is to maintain complete tightness at the joints and joints.

Conclusion

The installation of chimney pipes is a responsible process. If installation errors are made, the system may fail, causing serious harm to health and even a threat to human life. Also, if the requirements and standards are not met, more frequent cleaning of the pipe will be required, since large quantities of ash will settle on its walls.

Connected gas boiler

Therefore, during the installation process, especially when it comes to a complex chimney system, it is recommended to involve qualified specialists who will draw up a separate project, as well as carry out all the necessary calculations and ensure the uninterrupted functioning of gas equipment.

Connecting a gas boiler: video

Chimney for a gas boiler: photo

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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.

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:

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

The aggressive advertising of 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, asbestos-cement pipes have 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 secretive wiring is provided by built-in smoke channels in brickwork, structures made of concrete, ceramic blocks or Isokern modules made of volcanic pumice.

Installing a chimney pipe, it is very important to calculate the correct chimney diameter, this issue needs to be given special attention when designing an autonomous heating system. Often the chimney pipe is selected based on approximate parameters. Many people believe that it would be better to make the cross-sectional diameter of the chimney larger, but this is not at all the case. In order for the heating system to function optimally, it is necessary to accurately calculate the diameter of the chimney.

Initial parameters for calculating the chimney pipe.

To calculate the chimney, you can use the chimney calculator.

The characteristics of the future chimney are directly influenced by certain parameters, of which the most important are:

1. Type of heating device. The organization of a gas exhaust system is in most cases necessary for solid fuel boilers and furnaces. The volume of the combustion chamber is taken into account, as well as the area of the opening of the chamber for air entering the firebox - the ash pan. Often calculations are made for homemade boilers that run on diesel fuel or gas.

2. The total length of the chimney and its configuration. The most optimal design is considered to be 5 meters long and with a straight line. Additional vortex zones that negatively affect traction are created by each turning angle.

3. Geometry of the chimney section. The ideal option is a cylindrical chimney design. But this shape is very difficult to achieve for brickwork. The rectangular (square) cross-section of the chimney is less efficient, but it will also require less labor.

Approximate and accurate calculation of the chimney diameter.

Accurate calculations are based on a complex mathematical platform. To calculate the chimney diameter, you need to know its main characteristics, as well as the characteristics of the fuel and heating device. For example, you can take the calculation of a standard pipe with a round cross-section without rotating units, connected to a stove and burning wood. The following calculation input parameters are taken:

gas temperature at the entrance to the pipe t- 150°C;
the average speed of gas passage along the entire length is 2 m/s;
burning rate of wood (fuel) with one stack B = 10 kg/hour.

Following these data, you can proceed directly to the calculations. First you need to find out the volume of exhaust gases, it is determined by the formula:

Where V is the volume of air required to maintain the combustion process at a speed of 10 kg/hour. It is equal to 10 m³/kg.

Substituting this value we get the result:

Then we substitute this value into the formula according to which chimney diameter is calculated:

To make such a calculation, you need to know exactly all the parameters in the future gas exhaust system. This scheme is very rarely used in practice, especially in the case of organizing a household autonomous heating system. Determine the diameter of the chimney it is possible in other ways.

For example, based on the dimensions of the combustion chamber. Since the amount of fuel burned depends on its size, the volume of incoming gases also depends on it. If there is an open firebox and a chimney with a round cross-section, then the ratio is taken to be 1:10. That is, when the size of the combustion chamber is 50*40 cm, then the optimal chimney diameter will be 18 cm.

When constructing a brick chimney structure, the ratio is 1:1.5. Chimney system diameter in this case it must be larger than the size of the blower. The square cross-section will be no less than 140*140 mm (this is due to the turbulence created in the brick pipe).

Swedish method for calculating chimney diameter.

In the examples described above, the height of the gas exhaust system is not taken into account. For it, the ratio of the area of the combustion chamber to the cross-section of the pipe is used, taking into account its height. The pipe value is determined according to the graph:

Where f is the chimney area, and F is the firebox area.

However, this method is more applicable to fireplace systems, since the volume of air for the firebox is not taken into account.

You can choose different methods for calculating chimney diameter, but when installing complex heating systems, an optimally accurate design is important, especially for low-temperature long-burning heating devices.

From the article you will learn how to install a chimney for a gas boiler in a private house, about external and internal chimneys, about chimney elements, about coaxial chimneys, about the features of a condensing gas boiler that does not use conventional chimneys, about brick chimneys and about the correct installation of a chimney .

Why do many people choose gas heating these days? Yes, because it is the cheapest type of fuel.

Once you have decided on the choice of a gas boiler, you should also think about removing the “waste” gas from the room. What should a chimney be like for a gas boiler? The Fire Inspectorate has very high requirements for these structures, so approach the work consciously and with full responsibility.

Selecting the overall dimensions of the chimney

The gas boiler chosen for heating a private house must be available to you, only after that you can select the correct chimney for the gas boiler and calculate its dimensions (see).

The height of the chimney depending on its location relative to the ridge of the house

Attention. If there are extensions above the house or it is planned to build them in the near future, then it is necessary to build a pipe that extends beyond the adjacent building.

Variations with chimney length

By selecting the required diameter and length for the chimney pipe and calculating its usable area, it may turn out that this same area will be less than the internal area of the gas boiler. If you change the pipe diameter to the next one (all pipes are produced in standard diameters), then with the same length you will get an excess chimney area and, accordingly, an excess consumption of material.

What can be done in this situation? Increase the length using a smaller pipe diameter. The table shows the minimum pipe heights. They can be increased, but not decreased.

After calculating the overall dimensions of the chimney pipe and purchasing the necessary building materials, you can begin installation.

Installation of chimneys for gas boilers

Immediately before starting work, you should determine the location of the chimney. There are 2 accommodation options:

When choosing the location of the chimney, you should understand:

location inside a private house will provide the structure with the most “comfortable” operating conditions;
the location behind the walls of a private house requires the presence of insulation to prevent the chimney from freezing; in this case, it is advantageous to use a sandwich pipe (the sandwich pipe has a multi-layer device, in the center of the sandwich pipe there is a layer of insulation).

Of course, the choice of location of the chimney for a gas boiler is yours. Check out the table below to help you make your choice.

Comparative characteristics of a chimney inside and outside a private house.

How to make a chimney for a boiler?

Installing a chimney for a gas boiler in a private house is not very easy.

Let's look at the basic principles of installing a chimney for a gas boiler.

It is necessary to correctly assemble all pipe elements.
In places where the smoke exhaust structure passes through the ceilings or walls of a private house, it is necessary to install special passage elements.
Insulation of all surfaces in contact with flammable materials.

Chimney elements of a floor-standing gas boiler:

adapter from the gas boiler pipe to the chimney pipe;
tee with inspection (at the bottom there is a fitting designed to remove condensate);
main fastenings - bracket and wall clamp;
bends, they are used at a distance of no more 2 m from the beginning of the chimney, otherwise it becomes possible to reduce the boiler draft;
feedthrough pipe;
telescopic pipes;
special tip having a conical shape

Please note that the tip for chimneys that remove “exhaust” gas must have a conical shape. It is strictly forbidden to install ordinary deflectors and umbrellas. It is allowed not to install the tip at all.

Requirements for the chimney of a floor-standing gas boiler:

the slope of some sections of the chimney is allowed no more than 30°;
maximum branch to the side - 1 m;
the smoke exhaust duct device should not have ledges or narrowing of the cross section;
the maximum number of elbows that a structure can include is 3, the radius of curvature must be greater than the diameter of the pipe;
at turning points it is necessary to install a hatch for cleaning and eliminating condensation;
one side of a rectangular chimney should not be 2 times larger (smaller) than the other, i.e. the shape should not be elongated;
At the bottom of the chimney, an inspection and drip device is required;
Deflection of chimney elements is not allowed;
the pipe links are placed on top of each other by at least half the diameter of the pipe;
Any gaps between pipe joints are not allowed;
in places where the ceilings (roofs) pass, the pipe should not have joints;
all elements must be very tightly connected to each other;
the slope of the pipe towards the gas boiler must be at least 0.01°;
Roughness in the chimney is not allowed, the inner surface of the chimney elements must be perfectly smooth;
horizontal sections can have a total length 3 m in buildings under construction and no more 6 m in built;
Below the connection point of the tee, a so-called “pocket” with a length of at least 25 cm with a hatch (this will provide access to the pipe and the ability to clean it);
distance from the pipe to the structure (walls and ceiling) for flammable materials - 25 cm, non-flammable - 5 cm;
if the pipe passes through unheated areas of the structure, thermal insulation or installation of a sandwich pipe must be provided;
when removing “exhaust” gases from utility appliances, dampers (gates) should be provided;
it is necessary to bring the gate control to an accessible place with fixation of the “open” and “closed” positions;
If the device has a traction stabilizer, then dampers are not needed.

How to properly build a chimney for a gas boiler outside the house?

We attach a passage element to the pipe coming from the floor-standing gas boiler, which will pass through the wall of a private house.
After the opening is ready, we take the chimney out. The sandwich pipe section and the hole in the wall must be insulated.
We attach the tee with revision, put on the plug.
We extend the sandwich pipe by attaching links, attach it to the wall of the house with brackets, in increments of at least 2 m .
Having reached the estimated height of the chimney, we attach a cone-shaped tip.
We reinforce all sandwich pipe joints with clamps, which must be tightened with bolts or wire.
It is advisable to paint the pipe with heat-resistant paint, which will protect the material from corrosion.

If you do not want to use sandwich pipes as a building material for the chimney, then do not forget about the thermal insulation of the structure.

Installation of chimneys for boilers in the house

Let's start with the preparatory work:

We mark the holes for the chimney in the ceilings and roof.
Be sure to check the marked marks several times with the dimensions of the passage pipe. Cut out the required opening for the pipe.

Let's start installing the pipe:

A pipe comes from the boiler. We connect the adapter to it.
Next, we attach the tee and revision (for cleaning the pipes), attach the steel sheet and install the main bracket.
We extend the pipe, if necessary, use the so-called elbows.
When passing through ceilings, we use a special pipe.
We put a galvanized steel sheet on the pipe with a hole slightly larger than the diameter of the pipe. We attach the sheet to the ceiling on both sides.
We reinforce all joints with clamps secured with wire or bolts.
The chimney is secured using wall clamps (each 2 m) and brackets (each 4 m).
We complete the design with a special cone-shaped tip, which will protect the chimney from precipitation and wind blowing.

Insulation of chimney elements

All contacting parts of the chimney and flammable structure must be insulated. To do this, the passage pipe must be covered on all sides with a foil-coated basalt mat with fire-resistant mastic. Mineral wool insulation can be laid around the perimeter of the opening in the ceiling.

Upon completion of installation work, be sure to check the tightness of all seams in the structure. Make an ordinary soap solution and apply it to all chimney seams. If, after connecting a gas boiler to the chimney, you see bubbles, this indicates a leak.

Brick chimney for gas boilers

A chimney can be built not only from steel (certain grades), but also from brick. Or rather, the chimney will be located in brickwork, i.e. the chimney pipe can be metal, asbestos or ceramic. Visually, it will seem that the chimney is made of brick.

Why is it undesirable to build a chimney made of brick?

The fact is that brick is a fairly porous material that does not hold heat well enough. When gas burns, water vapor with various impurities is formed, which, in fact, must be removed from the room, and the construction of a brick chimney will contribute to the formation of condensation.

Chimney for condensing boilers

In general, the chimney of a condensing boiler differs little from the chimney of a conventional boiler, but there are some peculiarities. The chimney of a condensing boiler must be made of acid-resistant materials to protect against corrosion.

It is important that the chimney of the condensing boiler is located with a slope towards the heating unit. It is necessary that the condensate flows back, but that precipitation does not enter the unit. Raindrops can damage the condensing boiler.

Chimney for wall-mounted gas boilers

The most optimal building material for a wall-mounted chimney is double-circuit pipes.

A coaxial chimney consists of 2 pipes, which are inserted one into the other (see). Such a chimney resembles sandwich-type pipes, but without insulation between the pipes. This ensures the removal of “exhaust” gas and the flow of fresh air through the gap between the pipes.

Installation of such a chimney is quite simple. We attach a flow pipe to the pipe from the boiler and take the pipe outside. The distance from the chimney to the ground must be at least 2 m. When placing the chimney under a window, at least 1 m from the window to the ground level.

Gas boilers without chimneys

Gas boilers without a chimney are the last word in technical progress in this direction. The operation of the system as a whole differs from a conventional gas boiler. Let's not go deeper into this issue. The best thing about this system is that there is no need for a traditional chimney.

In any heating system it is necessary to remove combustion products outside the room. The difference is in the chimneys. In the new system, the chimney can be made of PVC pipes (the temperature of the “exhaust” gases is relatively low) with any number of turns; it no longer has to be strictly vertical.

The boiler operating temperature can be any. The unit runs on both natural and liquefied gas. In case of any problem it turns off automatically.

The information you have gathered will help you when installing a chimney with your own hands. If you want to use the services of professionals, then you will be savvy in the topic of chimneys for gas boilers. This will allow you to independently carry out supervision of the work being carried out.

The pipes of flue gas boilers must be designed with the utmost seriousness. Even the fact that they have less harmful emissions than smoke and wood ones does not make them easy to install. The danger lies in the possibility of fuel leakage. This can lead to disastrous results.

Requirements for chimneys for gas boilers

When designing, it is necessary to take into account all the standards prescribed in special documents regulating the installation of a chimney for a gas boiler. Be sure to follow the following recommendations:

The diameter of the chimney cannot be less than the outlet opening. If the outlet has a diameter of 100 mm, then throughout the entire structure this number should not decrease, only increase.
The maximum tilt angle of the structure should not exceed 30 degrees. A completely vertical pipe is considered ideal. If you cannot do without a slope, then the length of the curved section should be less than the height of the room with the boiler.
There should be no curves in the entire structure.
The entire structure must be covered with hermetically sealed thermal insulation.
All joints and connections must not allow gases and fine suspended matter to pass through.
The lower part of the structure must be equipped with outlets for accumulated condensate. It is formed due to the large temperature difference between the exhaust gases and the environment.
The minimum height to which the pipe must rise above the roof ridge is 0.5 m.
It is advisable to install protection at the end of the pipe from precipitation and clogging. A metal umbrella is suitable as a barrier.

Only the last item from the list is not mandatory. However, it will allow you to use the structure with greater comfort, reducing the likelihood of breakdown.

Without fulfilling the remaining points, it is necessary to legitimize the design and construction. In addition, all requirements are aimed at reducing the risk of accidents such as exhaust gas poisoning, fuel leaks and explosions.

Constructions

According to the method of fuel combustion, there are two types of burners: with an open and closed combustion chamber.

In boilers with an open combustion chamber, the burner is not insulated. It uses oxygen sucked from the atmosphere for combustion. The second name for such structures is atmospheric. The disadvantage of such designs is the need to install a chimney with high draft.

In closed combustion chambers, the oxidizer is supplied through a special system. It creates the movement of gases using a pump or temperature difference.

Thanks to this, there is no need for a good chimney. But their design is more complex. Usually, in such boilers they try to route the pipe into the side wall. This allows you to save on chimney construction and use heat more efficiently. They are also called coaxial chimneys for gas boilers.

The type of boiler determines the design parameters of the chimney for a private boiler in a private house.

Brick

It is found more often than other materials. It provides good thermal conductivity and durability. However, every day it is used less and less. This is due to the complexity of construction and the cost of the material.

If a house with a boiler has more than one floor, the chimney structure will be too massive and a foundation will be required.

Brickwork has two disadvantages:

The surface has a lot of unevenness, which causes a lot of soot to accumulate on it. Over time, such structures require cleaning.
Moisture coming from the atmosphere and resulting moisture greatly wears out the structure over time.

Installation Features

Before making a chimney for a brick boiler, it is advisable to familiarize yourself with the latest innovations. One of them is a metal sleeve. It allows you to reduce the amount of ash settling on the surface.

When adding a sleeve, consider the following:

The joints between the parts must be hermetically sealed. Sandwich pipes are ideal for this.
To reduce the amount of condensation, which has a detrimental effect on all components of the installation, you need to insulate the walls of the chimney.
To prevent the accumulation of moisture, you need to provide a container for its accumulation, from which it will be easy to remove.

Conclusion

The chimney allows combustion products to be removed. If errors are made in the calculations, living spaces will begin to fill with toxic gases. Certification of the finished pipe is mandatory.

Before construction, it is advisable to contact a specialist who can assess the possibility of breakdowns. On the Internet you can find various drawings and photos of chimneys for gas boilers.