≡× MENU

• Interior
• Windows
• Walls
• Projects
• Buildings

Extension of a coaxial chimney for a gas boiler. Coaxial chimney for a wall-mounted gas boiler. Coaxial chimney Navien

Accommodation in country houses impossible without installing a heating system, and it is considered the most economical gas heating. But gas, like any other type of fuel, requires an influx of oxygen and removal of combustion products. AND the best system For chimneys, coaxial is recognized: it can simultaneously cope with both the exhaust and the influx of gases necessary for combustion.

What are coaxial chimneys

Coaxial means internally combined, or in other words, one within the other. Coaxial chimney It is a structure of two pipes, which are reinforced with jumpers that do not allow them to come into contact with each other. This arrangement of the chimney system is best suited for gas heating boilers, but it can also be used in other heating systems where the combustion chamber does not have open access.

A coaxial chimney can simultaneously supply air into a closed combustion chamber and remove the resulting carbon dioxide to the street.

Device

Since this system requires not only an influx of oxygen, but also an autonomous removal of condensate and combustion products, it consists of several components:

• Double straight pipe for carbon dioxide removal;
• A small container to collect the resulting condensate: under no circumstances should it enter the combustion boiler;
• The connecting triple structure is used to assemble all the parts;
• An elbow bent at 90 0, intended for turning the chimney pipe;
• Cleaning systems: with its help, repair or maintenance work is carried out;
• Tip - it is designed to protect the system from precipitation.

Pros and cons

What are the positive characteristics of a coaxial chimney system?

• The air required for combustion is taken from the street, which does not create a stuffy environment;
• Minimal heat loss, since air is supplied through an external pipeline, and it is heated by the internal structure;
• Meets all environmental requirements: gas boiler a large percentage of useful action, and all fuel burns completely, so virtually no components harmful to nature and humans are emitted into the atmosphere;
• Meets all requirements fire safety: both pipes compensate for heating and cooling, and therefore even if they come into contact with flammable objects, fire cannot occur;
• The compact design allows installation in any, even small, room;
• Installation does not involve violating the integrity of the roof of the house.

There are very few disadvantages of such a chimney exhaust system, these include high cost and low aesthetic perception: if you install it in the basement, it can slightly reduce the harmony of the room.

Species

The coaxial chimney system can be horizontal or vertical view, each of them can be installed under certain conditions.

Vertical. For this system, it is necessary to install a drain on the roof of the house, and a container for collecting condensate is also very necessary, but usually the entire necessary set of components is already included in the delivery of the chimney.

Horizontal. This is the most popular coaxial chimney system because its installation is very simple: you need a hole in the wall and that's it. In addition, there is no need to arrange a place for a chimney on the roof, and the collected condensate can be drained directly, that is, there is no need to equip an additional container: it simply flows down the pipe to the street if the pipe is installed with a slight slope.

Placement of coaxial chimney systems

1. Experts recommend determining the location of the chimney system only after installing the gas combustion boiler itself.
2. Place the pipes away from the windows and doorways at a distance of at least 50 cm. To ensure best traction the first component pipe must be at least 1 meter long. It is secured to the boiler outlet on the pipe with a metal clamp.
3. If the boiler is equipped with a natural exhaust, then the chimney elbow must be installed above this structure. If a fan is installed, installation can be carried out at any height.
4. Then you need to arrange a hole for the pipes to exit to the street; if the house is made of wood, then you will need to install a thermal insulation layer: this will prevent a possible fire in the wood.
5. So that the condensate formed can escape through drainage system to the street, the pipes are installed with a downward slope.

Installation

For the installation of a heating system, fire inspection authorities require the presence of a separate room in which ventilation is carried out and there is everything necessary equipment. This leads to unnecessary costs, you either need to rebuild it already ready house, or install a separate chimney system.

But all this can be avoided if you purchase a gas boiler closed type combustion and arrange a special coaxial system chimney, which saves the home owner money on arranging a separate smoke exhaust.

And only for these reasons, installation of the boiler is allowed in any suitable room, even where there is no ventilation system: in the attic, in the kitchen, in the basement of the house. About boilers with open type It is impossible to say this about combustion.

The rules for installing connections must be observed: they must end before the system exits the wall opening. The pipe itself must protrude from the wall by at least 20 cm; a greater distance is allowed.

To ensure no return reverse thrust into the boiler, a special valve is installed on it that will prevent this phenomenon.

All parts of the chimney are connected using clamps and, in some cases, insulation. To achieve better sealing, you can use construction foam.

Tip: use as few vertical parts as possible: this will make the chimney more efficient.

There are regulatory rules self-installation coaxial chimney:

• To install the system, it is recommended to use only kit parts;
• Do not use self-made parts, but purchase missing parts only from service centers manufacturer;
• After installing the chimney system, it must be tested for leaks;
• Joining joints should be done in free space, not in wall space.

Step by step instructions

1. First, determine the location of the gas boiler;
2. Installation gas equipment carried out simultaneously with the installation of a coaxial chimney system;
3. The chimney itself should be located 1.5 meters above the gas boiler itself;
4. Fulfill the fire safety requirement: position the chimney pipes so that there is at least 50 cm between the window, ventilation hole and door;
5. Make a hole for the pipe outlet in the wall in accordance with the diameter;
6. Connect the pipes to the boiler outlet with a metal clamp. Do not forget about the slope to the ground to discharge condensate;
7. After installing the pipe, the hole is sealed;
8. You can try the system in test mode.

How to extend a coaxial chimney for a gas boiler

If closed gas equipment is used to heat an apartment building, it may be necessary to extend the chimney system.

For installation you will need:

• Propylene elbows;
• Additional chimney pipe no more than 5 meters long;
• Adapting device for hermetic connection;
• Overlays for attaching to an external wall;
• Flanges and clamps.

All additional parts for extension must be purchased from dealers of the chimney system manufacturer, since parts from other brands may be incompatible with equipment already purchased.

Estimated cost

The cost of a coaxial chimney largely depends on the configuration. For example, a basic kit may vary in cost depending on the diameter of the pipes. The most popular kit can cost from 4 thousand rubles to 13.5: Which chimney pipes do you need to purchase. Additional elbows can cost from 1.5 to 3 thousand, a condensate collector - about 3 thousand.

If you want to buy a protective grille for the chimney outlet, its cost is approximately 3 thousand rubles.

As can be seen from our review, the coaxial chimney system is a new word in the construction of chimneys; it is completely autonomous and easy to use.

Everyone knows that performance heating systems, which uses the principle of fuel combustion, is impossible without oxygen to support combustion and proper removal of exhaust gases. Today, to create autonomous heating systems, various gas equipment is in great demand. It is compact and safe, easy to use, perfectly automated and does not require constant intervention by the owner in the work process.

Design and purpose of a coaxial chimney

This device looks more like a motorcycle exhaust pipe. In fact, this is a specially designed structure, a pipe in a pipe with different diameters, which are inserted one inside the other and rigidly fixed to each other. Combustion products are removed through the inner tube, and the air necessary for combustion of the fuel enters the combustion chamber through the space between the inner and outer tubes. A coaxial chimney for a gas boiler solves two main problems at once: removing exhaust gases and supplying air to the device.

Such chimneys are made from pipes round section, and the inner one is most often made of aluminum alloy, and the outer one is made of steel, thickness 1; 1.5 or 2 mm. The ratio of internal and external diameters for wall and floor heating devices is 60 to 100 mm. For condensing boilers, chimneys with a diameter ratio of 80 to 125 mm are used.

There are two types of coaxial chimneys: horizontal and vertical. The easiest to install, and therefore the most common smoke exhaust system of this type, is a horizontal chimney. A vertical coaxial chimney is quite difficult to install and is therefore used if horizontal installation is not possible or heating device more than 4 m to the street wall.

Advantages and disadvantages

As mentioned above, this type of smoke exhaust system is used only for gas equipment with a closed combustion chamber, namely:

• Double-circuit heating boilers for wall and floor installation with a closed combustion chamber.
• Gas hot water heaters.
• Generators and convectors.

The main advantages of such an air intake and smoke removal system are:

• Safety. In such a chimney exhaust system, heat exchange occurs between street air and exhaust gases, resulting in a decrease in the temperature of combustion products.
• Heating air coming from the street by contacting it through the pipe wall significantly increases the efficiency of the boiler.
• The coaxial chimney draws in outside air and not from the room, which prevents the creation of a vacuum that interferes with the normal operation of the boiler and natural circulation indoor air.
• Easy installation and a large number of accessories.
• Significant savings in internal space.
• Oxygen from the room is not used.

The most attractive for using chimneys of this type are apartment buildings, since carbon monoxide and fuel combustion products are released not into the ventilation shaft, but directly into the atmosphere.

Such chimneys also have disadvantages, namely: rather expensive insulation to prevent freezing of the chimney head. The possibility of freezing of the pipe head is quite high. This happens because the temperature of the exhaust gases is too low and is not able to melt the ice formed during the exit. humid air. The consequences of icing can be quite serious: repair of burners, combustion chambers and turbocharging.

Installation diagrams and installation requirements

As mentioned above, there are two main schemes for installing a coaxial chimney: vertical and horizontal. During installation, you should adhere to certain rules for installing a coaxial chimney, regulated by SNiP 2.04.08–87; SNiP 2.04.05–91.3, as well as the set of “Safety Rules in the Gas Industry”.

The total length of the coaxial chimney cannot be more than 4 m. If a larger length of the smoke exhaust system is required, then a larger coaxial chimney should be used.

At vertical installation, the chimney passes through ceiling and the roof. In order to install the system in a vertical position, a special adapter is used.

It should be noted that such an adapter is not a universal device and each manufacturer produces this device strictly for its own equipment. To achieve required length special extension cords are used for the chimney.

To ensure tightness when the chimney passes through the roof and protect it from precipitation, a device called a terminal is used.

When installing vertical system smoke exhaust should be guided by the rules that regulate its height, depending on its location in relation to the ridge of the pitched roof.

Most often, a vertical coaxial chimney is installed in private houses. But there is another option for a vertical smoke exhaust system - a collective one, which is intended for apartment buildings. General coaxial chimney in apartment building makes the use of individual gas heating appliances completely safe.

Horizontal exhaust gas outlets are most often used for wall-mounted heating equipment. The horizontal scheme involves the exit of the chimney through the outer wall to the street.

During installation, you should take into account the slope of the chimney of 2-3° to prevent condensate from entering the boiler unit.

To pass through the wall, two types of devices are used: basic or horizontal. The only difference between these kits is the adapter for connecting to heating device. If, when passing through a wall, it is necessary to go around a beam, reinforcement, etc., then special bends and elbows are used.

Self-installation

Installing a coaxial chimney with your own hands is quite simple and anyone can do this work home handyman with basic skills in using power tools.

To complete the work, you will need a kit that includes: a pipe with a flange, a clamp, an adapter for connecting to the boiler unit and a coaxial elbow. If necessary, you should purchase a special coaxial chimney extension.

1. Make a hole in the required place external wall. It should be noted that the chimney outlet should not be located closer than 0.6 m to the window.
2. Connect the adapter to the boiler.
3. Connect the chimney directly to it using a crimp clamp. If you need to bring the structure to the wall, then use a knee. Secure everything with crimp clamps.
4. Exit the pipe through the hole, providing a slope towards the exit of 2-3 °.
5. Seal the cracks polyurethane foam or mineral wool.
6. Cover the pipe exit with a decorative cover.

It should be noted that with each turn of the chimney by 90°, the maximum length coaxial chimney by 0.5 m.

Content

1. Design and principle of operation
2. Advantages of coaxial chimneys
3. Installation and connection to a gas boiler

Introduction

The main feature of gas boilers with a closed combustion chamber is that they use for combustion outside air. They also need a chimney to release combustion products into the atmosphere. Both of these functions are combined in a unique device - a coaxial chimney for a gas boiler.

In this article we will talk about the design, operating principle and advantages of coaxial chimneys, the requirements and regulations governing their installation in private houses and apartments, as well as what you should pay attention to when doing the installation yourself.

Design and principle of operation

Wall-mounted and floor-standing gas boilers are divided into two large groups: with open and closed combustion chamber. The first ones use air from the room to work. That is why there must be good ventilation in the place where such a boiler is installed. To remove gases, traditional chimneys made of material suitable for working with aggressive environments are used.

Boilers with a closed combustion chamber are completely isolated from the room. Air is supplied to them from the outside, and flue gases are also discharged there. A coaxial chimney is designed to perform both of these functions simultaneously. What is its structure?

Photo 1: Coaxial chimney installation

The term coaxial in technical markings means two-wire. An analogue of the veins in the chimney is made by two pipes different diameters, inserted one into the other. To hold the inner pipe in the center of the outer pipe, they are connected to each other by special spacers. In addition to performing their main function, they also give the structure additional rigidity.

The operating principle of a coaxial chimney is very simple. Along the inner pipe environment Gas combustion products are removed, and at the same time, the air necessary for combustion enters the gas boiler through the external pipe.

Most often together with gas boilers horizontal coaxial chimneys of short length are used. They come out right through the wall country house or ordinary apartment. Also found vertical design, which is mounted in the usual way through holes in the ceilings and roof.

Photo 2: Coaxial chimney kit with anti-icing

To combat glaciation horizontal installation, a special design is often used. Its peculiarity is that the pipe for removing combustion products protrudes from the air intake pipe to a considerable distance. Air intake holes are located only in the lower part of the outer pipe, which prevents precipitation from entering inside.

The most common are coaxial chimneys 60/100 with an internal pipe with a diameter of 60 mm and an external pipe with a diameter of 100 mm. Models with such parameters are produced by many manufacturers, such as: Baxi, Vaillant, Buderus, Bosch, Viessmann, Ariston, Ferroli, Electrolux.

Return to contents

Advantages of coaxial chimneys

Despite its simplicity, the advantages of a coaxial chimney are quite significant. In addition to the obvious advantages of this design, there are a number of advantages that do not immediately come to mind. Let's look at them all in order:

Photo 3: Vaillant 60/100 coaxial chimney system

• The combustion chamber is completely isolated, so the boiler does not burn out the air in the room. The entry of carbon monoxide into the living space is also excluded. For this reason, installing a heating device does not require the organization of a special boiler room, such as for example. It can be installed even in a room in an ordinary apartment in a typical multi-storey building.
• Passing from the outside to the inside, the air is heated by flue gases flowing through the adjacent channel in the opposite direction. Thanks to this, the efficiency of the gas boiler increases.
• The outer walls of the chimney have a safe temperature, thanks to the cooling of the central channel by the flow of outside air directed into the system. This increases the fire safety of the system in contact with elements of the building’s cladding and floors.
• Installation of a coaxial chimney is very simple. For installation, you do not need to involve expensive specialists and carry out serious redevelopment with large-scale construction work. All work can be done by the owner with his own hands.

Despite the apparent simplicity of connecting a gas boiler to a coaxial chimney, during installation some requirements must be met, which are in many ways similar to the rules for installing chimneys with. The safety and efficiency of the entire system depends on their implementation.

Return to contents

Installation and connection to a gas boiler

As we have already found out, a coaxial chimney can be installed both vertically and horizontally. It is much easier to build a horizontal chimney, however, due to poor natural traction It is only suitable for models equipped with exhaust fans.

Work on installation of gas chimneys is regulated regulatory documents SNiP SP 42-101-2003. We will list the basic rules and points that should be taken into account when installing coaxial chimneys. Let's start with horizontal structures:

1. When purchasing a coaxial chimney kit, you should make a choice based on its cross-section. It should not be smaller than the outlet pipe of the gas boiler.
2. According to the regulated rules for installing chimneys, the length of the horizontal section should be no more than 3 m. Some manufacturers recommend longer lengths for their models, relying on increased power exhaust fans.
3. The installation of a coaxial chimney should be carried out at an inclination of 3° per meter of pipe away from the boiler. This is done in order to set the direction for the drainage of the resulting condensate.
4. When planning a place for a hole in the wall, it should be taken into account that there should be a distance of 0.5-1 m from the boiler outlet to the wall. This is done in order to avoid icing of the chimney inside the room when low temperatures in winter.
5. When installing a gas boiler near windows, it should be taken into account that the distance from the outer pipe of the coaxial chimney to the nearest window must be at least 0.5 m. It is strongly not recommended to place the pipe under the window. If there is no other possibility, then it should be at least 1 m below the window level. The distance to the gas supply pipe should be at least half the diameter of the coaxial chimney.
6. To avoid contamination, the external pipe must exit at a distance of at least 2 meters from the ground surface.
7. If the coaxial chimney is located under a canopy or balcony, then it must have a certain length of the protruding part. How to determine it is shown in the following figure:

Photo 4: Rules for installing a coaxial chimney under a canopy

A vertical coaxial chimney is installed if for some reason it is impossible to install a horizontal one. Installation of this design is more complex and is subject to the same requirements as for installation chimney for a solid fuel heater such as . We list the main points that are worth paying attention to:

1. When assembling chimney elbows for a gas boiler, each upper elbow should be inserted inside the previous one and connected with clamps. If this rule is violated, condensate will penetrate through the joints and flow down the outer walls of the chimney.
2. To collect condensate, ease of cleaning and maintenance, a tee is required to be installed at the bottom of the structure.
3. Particular attention should be paid to the section of the coaxial chimney located on the roof. How this part of the chimney should be built is clearly shown in the following figure:

Photo 5: Requirements for installing a coaxial chimney on the roof

Attention: Due to the risk of icing, the installation of protective caps (deflectors) on gas chimney pipes is prohibited.

To see more clearly how to properly install a coaxial chimney, see the following video:

The advantages of such a chimney

Installation features

Any person wants his home to be warm. After all, it depends on this comfortable accommodation the whole family. Those who don't have central heating, must take care of it themselves. In addition to installing the boiler and other components, the issue with the chimney has to be resolved. Without it, smoke from fuel combustion would go straight into the room. Previously, ordinary pipes were used for this. However, over time, the coaxial chimney was invented. What kind of device is this? What is its advantage? These issues deserve special attention.

What is a coaxial chimney?

Coaxial means one object in another. The chimney was so named because it also has one pipe built into another. Inside they do not touch each other, but are connected by a jumper. This device is intended for gas boilers, convectors, radiators, and other devices with a closed combustion chamber. The coaxial chimney has 2 tasks:

1. provides a constant supply of air for gas combustion in the chamber,
2. removes fuel combustion products.

coaxial chimney design

The principle of its operation is easy to understand. Air enters through the outer pipe, and out through the inner pipe harmful substances. Usually this structure is about 2 m, and it consists of the following parts:

• straight pipes - they form the channel of the chimney system itself;
• collection for condensate - since water vapor accumulates in the pipe, it is necessary to prevent it from entering the boiler;
• tee - used when connecting to the boiler;
• knee bent 90% - this part helps make turns in the chimney;
• cleaning – allows for routine maintenance;
• tip – protects from precipitation and wind.

This is the design of a standard chimney, but if its orientation is horizontal, then more often the composition will be as follows:

• straight pipes,
• bent knee,
• side tip.

3 types of steel are used for the manufacture of coaxial chimneys:

1. stainless,
2. acid-resistant,
3. galvanized.

In addition to these options, there are also combined designs where parts from different steel. Due to the fact that the device is made from quality material, it is not subject to destruction. These are the main points you should know when choosing a coaxial chimney.
But for it to work well, you should take the acquisition of equipment seriously. Before purchasing you will have to consider some points:

• do detailed plan highways with exact dimensions,
• what type of fuel,
• outside temperature,
• isolation of the room,
• boiler performance may affect the choice of pipe,
• product quality,
• wall thickness.

Taking all this into account, you will be able to select the pipes suitable diameter, length and so on.

The advantages of such a chimney

There are many arguments in favor of using a coaxial chimney.

• One of the most important advantages is that the oxygen necessary for gas combustion is taken from the street. Conventional boilers are fed with air from the room, so it becomes stuffy.
• Heat loss is also reduced. This happens due to the fact that fresh air enters through the outer pipe, which is heated by the inner one. Therefore, this air is also warm. This design significantly reduces heat loss from the heating main.
• Environmentally friendly process. Due to the fact that such a process has high efficiency, the gas in the boiler burns completely. Because of this, there are no emissions that harm the atmosphere and humans.
• Prevents fire. Just like outer pipe heats up, the inside cools down. Therefore, if flammable objects come into contact with the chimney, there will not be a high temperature for ignition.
• People won't have to breathe smoke or carbon monoxide. Everyone hates when there is a strong smell of stove smoke in the house. This negatively affects the human body. But, since this chimney supplies the oxygen necessary for combustion, all processes take place in a closed chamber. This means that nothing gets into the room, and there is no need to breathe smoke or install an exhaust hood.
• Large assortment. The choice of this equipment is very wide. Therefore, you can choose it for a system of any power.
• Compactness. Coaxial chimneys have small sizes, due to which they do not take up much space from the area of ​​the room.
• Installation. Installation of this design is very easy.

So, from the points listed above you can see how convenient it is to use a coaxial chimney.

Installation features

Speaking about the installation of this equipment, you should remember that there are 2 options - vertical and horizontal.

1. A vertical pipe outlet is used if it is not possible to mount it in the wall.
2. Horizontal installation is carried out provided that the boiler has forced ventilation. According to the rules, maximum length, horizontal installed chimney, should be no more than 3 m. But, before installing it, it is better to read the instructions from the manufacturer.

standard and coaxial chimney

Next, it is worth considering the basic principles of installing this device.

• First you need to choose a place for the boiler and pipe. They should be installed at the same time. In relation to the boiler, the chimney should be 1–1.5 m higher. If there is a need, the pipe can be extended up to 3 m in height. And in relation to the ground, the structure is raised by 2 m. Also, you need to maintain a distance of at least 0.5 m from the windows, ventilation holes and doors. Windows located above the chimney should be at a distance of 1 m from each other. No obstacles, such as walls, should be closer than 1.5 m.
• The next step is to verify your purchase. Make sure that all parts of the device are in place. Otherwise, in the middle of the installation process, you will have to run to the store to get the missing element.
• Now you can begin the work itself. First, a hole is drilled in the wall. Its diameter is measured along the chimney.
• The pipe is inserted into the hole and then connected to the boiler using a clamp. When assembling all parts of the chimney, it is necessary to maintain an angle with respect to the ground. This is done so that the condensate drains behind the building and not into the boiler.
• The hole made is sealed with foam around the chimney.
• For an aesthetic appearance, various attachments are placed on the joints. They can be attached with liquid nails or construction adhesive.
• If the pipe is brought out through the roof, then it is important to use insulating pipes and non-combustible insulation. Also, do not forget to leave an air gap between the ceiling and the chimney. The hole through which the pipe is routed should be carefully sealed.
• The last step will be a test run of the system.

It is very important to adhere to safety precautions when installing a chimney. Since the pipes can be sharp, it is safer to work with gloves. Connections can only be strengthened and sealed fireproof materials. By following these installation and safety instructions, you will be able to create a quality smoke outlet.

However, there is a problem that you can still encounter - freezing of the chimney. If you ignore this possibility, freezing can lead to breakdown of the heating unit. On at the moment experts believe that the problem lies in the wrong thermotechnical calculation. Since the efficiency heating apparatus depends on how heated the supply air is, the designers reduced the diameter of the pipe for the exit of the combustion product. This increased their efficiency. However, precisely because of this, more condensation appears in the inner pipe, which subsequently freezes. To avoid this problem, it is recommended to select the correct pipe diameter and length.

Gas boilers with coaxial chimney

Seeing the advantages of such a chimney, many want to use it. However, for this you need to choose the right boiler, because to use a coaxial chimney, you need closed chamber combustion in the boiler. Gas-powered devices are suitable for this. But is it worth purchasing them? How are they different from conventional boilers?

exit of a coaxial chimney from the wall of the house

Nowadays, such equipment is in great demand. What is the advantage of a gas boiler with a closed combustion chamber?

• Today, in order to install a boiler, safety precautions require a specially designated place. It must be properly equipped and have supply ventilation. If the house does not have such a room, then it is necessary to either make external chimney, or remodel the house. Both of these options are unprofitable from a financial point of view. Therefore, the solution to this problem will be a boiler with a closed combustion chamber and a coaxial chimney. Thus, it can be emphasized that this equipment will significantly save money.
• You can install such a boiler anywhere in the house, regardless of ventilation. The only important condition is the distance from the window. Therefore, such a room could be an attic, a kitchen, ground floor and so on. This cannot be said about many boilers.
• Chimney installation. This is another argument in favor of a gas boiler with a closed combustion chamber. To install a coaxial chimney for it, you do not need to have special skills, but just follow the instructions.
• Another advantage of such a device is its high efficiency. This point is very important from the point of view of fuel economy. As already written above, hot air, coming out of the inner pipe, heats cold air, which is directed to the boiler through an external pipe. Thanks to this, energy is not wasted on heating the air entering the device. All heat energy is used for coolant.
• This process is worth considering with reverse side. Outer pipe, taking heat from the internal one, cools it. This way, all equipment does not reach dangerous temperatures that could cause a fire. Other boilers with a chimney do not have such fire ratings.
• Due to high efficiency, gas equipment also has high environmental characteristics. After all, if all the gas inside is burned due to the constant presence of oxygen in the chamber, it means that harmful substances are not released into the atmosphere.
• Residents' safety. This is another clear advantage. Since the combustion chamber is closed, neither gas nor smoke enters the room. In addition, the possibility of fire is eliminated.

It is not surprising that today this equipment is in great demand on the market.

Conclusion

What conclusion can be drawn from the above information? The coaxial chimney is very practical and useful invention. Unlike the usual one, it performs 2 functions simultaneously - removing combustion products and introducing air necessary for combustion into the chamber. Among the listed advantages, we can particularly highlight high efficiency, safety for people and the atmosphere, and ease of installation. This is what every person expects from a heating system today. In addition, this chimney is compatible with the most popular type of gas boiler.

Any heating equipment: stove or heating boiler, fireplace or even simple geyser connects general feature: they need to utilize air that is saturated with combustion products. This is not only a guarantee of comfort, but also safety. Failure to comply with chimney installation standards can even lead to dire consequences - carbon monoxide poisoning.

The latest solution for modern technologies heating is a coaxial chimney. It allows you to significantly reduce the volume of the chimney; moreover, during operation, air from the room is not used at all, which is undoubtedly an important advantage. This type of chimney is suitable for boilers with a built-in smoke exhauster (forced draft). It is much shorter and more compact than a regular traditional pipe. His European quality combined with an excellent price.

The principle of operation of a coaxial chimney

The smoke exhauster built into the boiler system allows air to be taken in from the outside through the external pipe simultaneously with removal through the internal pipe. flue gases. Since air draft is practically guaranteed, the outer pipe has a small diameter and length corresponding to the installation layout. Exhaust air containing an admixture of combustion products is discharged from the boiler through an internal pipe. It is also shorter than the traditional one, and thus the boiler does not take up much space. The coaxial chimney is made from modern reliable acid-resistant materials, therefore inner tube does not react with harmful impurities, that is, it is not subject to destruction.

The structure of such a smoke exhaust is such that when exhausting, flue gases do not enter the air channel. All this must be taken into account when designing a coaxial chimney, including installation and fire safety standards. One more the most important condition its reliable operation is the tightness of the external connection air channel and pipe.

SNiP for installation

Heating systems operating on gas fuel, are somewhat different from coal and wood stoves. Therefore, if a coaxial chimney is installed, the installation standards are also different.

In the case of chimneys of this type, combustion products can be discharged into the atmosphere through external wall premises. In this case, in particular, there is no need to construct a vertical channel from the system through which combustion products will be forcibly removed. In this case, the opening of the smoke channel on the facade of the house is placed according to the instructions for installing gas equipment from the manufacturer, but taking into account the following conditions:

• at a distance of at least 2 meters from the ground level;
• minimum distance to doors, windows and open ventilation grilles(holes) horizontally should be 0.5 meters;
• the minimum distance to the top edge of doors, windows and open ventilation grilles (openings) should also be 0.5 meters;
• the vertical distance from the windows located above the smoke duct opening is from 1 meter;
• in the area of ​​1.5 meters from the coaxial pipe there should be no obstacles, say, walls, pillars, etc.

The chimney pipe, if there is no condensate collector, must be installed at an angle to the ground, preventing condensate from flowing back. Optimal slope is 6–12°.

• If smoke channel placed under a balcony, canopy or roof eaves of a house, then it must extend beyond the circle with radius R. It is equal to the width of the part of the building protruding above the chimney.
• The smoke duct should not go through the external wall into passages (arches), underground passages, tunnels, etc.

When exiting through a wall, the length of the horizontal section of the channel is taken to be no more than 3 meters. However, manufacturing plants have different interpretations on this issue. For example, according to the instructions, the Ferroli coaxial chimney has a maximum permissible pipe length of 4 m (60/100) or 5 m (80/125), and the Navien coaxial chimney is 3 m. From all this we can conclude that, first of all, even before At the beginning of design, it is necessary to carefully study the instructions for the gas equipment that is supposed to be installed, since for different boilers some of the basic parameters may not be the same.
(below are the SNIP documents and installation rules for chimneys of some manufacturers)

Coaxial chimneys from the best manufacturers are the key to reliability and quality

Coaxial chimney Ariston
Ariston chimneys made in Italy are suitable for most modern boilers. They also come with sealing gaskets and wall trims.

Coaxial chimney Baxi
The chimney in its design should have a length of up to 5 m. If it is directed towards the street, it is given a slope at the rate of 1 cm for each meter of its length. For Russian climate conditions, insulated options with the following changes made to the design are more suitable:

• head lengthened
• the design of the air intake duct is especially protected,
• made of composite material.

Such a system makes it possible to prevent icing of the chimney and cause the boiler to stop in emergency mode, if the temperature outside drops to -50 C.

Coaxial chimney Proterm
These products are very easy to install and contribute to increase in efficiency corresponding Protherm boilers. In addition to them, the company also offers extensions for chimneys, adapters designed for separate smoke removal and more.

Coaxial chimney Vaillant
This company is considered one of the leaders in the European market. Its products are in great demand in recent years. When choosing a chimney, it is especially important that its cross-section matches the cross-section of the Vaillant boiler pipe. When installing, it is necessary to ensure a distance between the chimney and flammable structural elements at least 100 mm.

Viessmann coaxial chimney
In addition to the coaxial bend (diameter 60/100, 90°), the kit usually includes: coaxial pipe, equipped with a tip (diameter 60/100, length 0.75 m) and wall linings. Its special design prevents the pipe from freezing in winter.