Maximum length of coaxial and separate chimneys. Installation and installation of a coaxial chimney - proper assembly Do-it-yourself coaxial pipe

- lower efficiency.

A significant part of the heat goes through the chimney to the street along with the products of combustion. It will not be possible to completely eliminate this drawback, but it is possible to reduce heat loss. An effective solution to the problem is a coaxial chimney for a gas boiler.

What is a coaxial chimney for a gas boiler, what is its structure and principle of operation?

The coaxial pipe to the gas boiler is double. Two hollow cylinders with different sections placed one inside the other. The distance between the walls of the pipes is several centimeters. The inner cavity is designed for exhaust, the outer one is for taking air from the street, which is necessary for the operation of the burner.

Thus, the air enters the burner already heated - it is heated from the cylinder wall with hot smoke (). Additional energy is not spent on heating the air. At the same time, the "cold" outer cylinder cools the inner "hot" cylinder - reducing the fire hazard of the structure. The output of the channel is made through the wall next to the boiler.

The installation of a coaxial pipe for a gas boiler requires additional steps to optimize the system:

the vertical coaxial chimney for a gas boiler has a large length of the street section and cools down a lot. Such pipes need to be insulated. There are designs with three channels instead of two, the outer one is filled with a heat insulator - basalt wool;
draft is improved due to the built-in fan;
the system is equipped with a condensate collector, anti-icing nozzles.

Coaxial chimneys for gas boilers can be used as individual and collective (). The former serve boilers in a private house or apartment. The latter are planned at the design stage of an apartment building. In both cases, a careful calculation of the thermal efficiency of the system and strict adherence to the installation rules in accordance with SNiP are necessary.

Installation options

The rules for installing a coaxial chimney for a gas boiler recommend connecting to the following types of units:

condensing boilers;
turbocharged with a closed firebox;
parapet boilers and convectors.

In some cases, coaxial chimneys for stainless steel boilers can be mounted on units with atmospheric burners. The possibility of installation does not depend on the number of circuits.

Floor-standing boilers with a coaxial chimney can have a power of not more than 40 kilowatts (). At higher power, the chimney does not provide sufficient draft, the formation of condensate increases, and ice forms on the outer section.

When choosing a flue system, the brand of the boiler manufacturer should be taken into account. For example, Buderus, Viessmann, Baxi equipment has non-standard pipes, chimneys from the same companies will be required.

Varieties of chimneys

According to the material of manufacture, chimneys are divided into aluminum, plastic, stainless steel. In Russia, plastic and stainless steel are popular.

A gas boiler with a coaxial plastic chimney is usually condensing. The pipe is two-channel, made of heat-resistant plastic. The smoke temperature is up to 205 degrees. Such chimneys are inexpensive, lightweight, and easy to install. Minus - not enough high durability.

Connection to non-condensing boilers is not recommended, as their temperatures are higher. Conventional chimneys cannot be connected to condensing chimneys.

Stainless steel can withstand temperatures up to 550 degrees, it is durable and acid-resistant. These pipes are insulated and non-insulated. When installing coaxial chimneys for two-channel gas boilers, thermal insulation is required. The first type has improved aerodynamics, can be used as a collective in an apartment building, can be connected to boilers with an atmospheric burner. Durability - from 30 years.

The scheme of a vertical coaxial chimney for a gas boiler implies an output along the front wall to the roof. In other cases, the pipe is led through the outer wall and ends there.

SNiP requirements

Project documentation is drawn up in accordance with the rules 60.13330.2012 SP. The installation of coaxial pipes is regulated by the Code of Rules dated 02.04.05-91 and 02.04.08-87.

The document indicates the standard distances from the chimney to doors, windows, nearby buildings, and installation restrictions:

pipe head on the facade - at least 2 meters from the ground;
a hole for the outlet of the pipe in a brick wall - 1 centimeter more than the cross section of the chimney;
in wood - by 5 cm. It is necessary to create a non-combustible layer (basalt wool or refractory mounting foam);
distance from windows and doors in a multi-storey building - from 50 cm;
from the window directly above the pipe - from 1 m;
from windows and doors of neighboring houses - at least one and a half meters;
in the first approximation, there should be no obstacles from the outlet - walls, trees, pillars;
when installing collective chimneys, it is not allowed to combine boilers with forced and natural draft into a common system.

A pipe can be passed through an adjacent non-residential room if the horizontal section is not more than 3 meters. In the presence of forced draft - up to 5. The pipe is placed at an angle to the boiler.

With a steam trap, the outlet can be turned towards the ground to keep rain out. Condensate must not drain to the ground. To reduce its quantity, the pipe is insulated. For the disposal of condensate from collective chimneys, a sanction from the Sanitary and Epidemiological Supervision Authority is required.

Before the start of the heating season and at the end, preventive maintenance is obligatory: removal of condensate, checking the integrity of the pipes and the tightness of the joints.

Installation Features

The horizontal chimney must protrude at least 30 cm from the wall. When the pipe is diverted 1 meter from the turbocharged boiler, a special unit is installed to compensate for insufficient length - a narrowing diaphragm.

This is necessary to limit the amount of air entering the furnace. The maximum length of the coaxial chimney for a turbocharged gas boiler is 5 meters. The slope of the horizontal section to the boiler is 3 degrees. When installing a tee with a condensate trap, an inclination to the other side is permissible.

When designing, it should be taken into account that the complex geometry of the chimney makes it difficult to remove combustion products. The dimensions of the coaxial chimney for a gas boiler must be calculated so that the length of the horizontal part is within 3 meters with a maximum of two elbows. The exit must be located at least 0.6 m from the window. The distance between the chimney and the gas supply pipe is more than half the diameter of the chimney.

The coaxial chimney for a floor-standing gas boiler must be at least a meter high - the distance from the boiler nozzle to the outlet. It is not allowed to pass the pipe through the wall directly. For a wall model, this distance can be 50 cm (). If it is necessary to build up the pipe, a coupling with sealing rubber gaskets is used; silicone sealants cannot be used.

A vertical pipe can be installed in two ways - cascade (this is how collective chimneys are connected) and individual. With individual connection, the maximum length of the vertical part is 7 meters (for a house with 1 or 2 floors).

In houses made of aerated concrete blocks, a vertical chimney is carried out inside the house so as not to create an additional load on the facade wall. In a brick house, both external and internal installation is possible. Thermal insulation is carried out with any method.

Connect the system to the boiler through a special factory-made adapter. The use of home-made stainless steel pipes for this purpose is a violation of the installation rules. Next to the adapter is a tee with a condensate collector. On this device, an inspection hatch is made for cleaning the channel. Next, the pipe is lifted and passed through the wall.

To protect the external system from the formation of frost, use a special nozzle. To prevent wind blowing and, as a result, reverse thrust, a wind-shelter diaphragm is installed.

Video about what a coaxial chimney is.

Do-it-yourself installation of a coaxial chimney of a gas boiler is often done to optimize the functioning of the heating system. If it does not work on electricity, then without fail it requires smoke removal. Previously, standard chimneys were used for this, but today more advanced devices have appeared.

What is a coaxial chimney

Construction involves placing one object inside another. Such a chimney is made in the form of a double-circuit product. As a building material, pipes of different diameters are used. Such "structures" are divided into several types:

External and internal. Devices are divided into these categories depending on the location. The first variety is placed outside the building and is fixed with special brackets directly to the facade. A distinctive feature of the appearance is the convenience during installation and use. Internal types of chimneys are mounted in shafts prepared in advance. This variety is quite difficult to mount and maintain, moreover, strict adherence to safety regulations is required.
Uninsulated and insulated. The second option is useful in the cold season, when the channel responsible for the entry of air masses into the system freezes with a high degree of probability. This leads to a reduction in the supply of oxygen to the combustion chamber, which reduces the efficiency of the heating equipment. Insulated systems are able to ensure the functioning of the boiler even at extremely low temperatures. This variety differs from a conventional chimney by the presence of an additional pipe, and the system is a nested element. The space is filled with any type of insulation.
Collective and individual. The second variety is used when it comes to servicing one boiler. It is a simple design without branches. When it is required to ensure the removal of combustion products generated during the operation of several heating units, a collective type of chimney is used. It is a mine system with several branches.

Each of the described varieties has its own characteristics and scope. Before installing one or another type, it is recommended to study in detail all the information about them.

Accessories for a coaxial chimney can be purchased from specialized stores

Device and principle of operation

The design of such a device allows you to perform several functions, that is, to provide a stable supply of oxygen to “stimulate” the flame in the furnace and remove smoke. The device includes several modules, which include:

Straight pipes. They are used to build the main building.
Decorative overlays, which are flanges that cover the places where the chimney shaft passes through building structures.
Tees that become part of the system if combustion products need to be removed from several heating units at once.
Seals (they are devices that ensure complete tightness of the housing at the points of passage through the wall).
Connecting devices. They are 90° and 45° bends or couplings.
Reinforcing elements, which include clamps, as well as brackets.
Devices designed to remove condensate. This structural element is located on vertical sections, equipped with a water-type shutter that does not allow air pressure to decrease.
Adapters. They are needed to connect the flue system to the boiler.
Accessories equipped with a special hole. Such a "viewing window" is needed to diagnose and remove contaminants from the chimney.
Nozzles. They are needed for the timely removal of smoky masses, air intake from the street.

The operation consists in the external intake of air masses from the street through an external channel. While moving through the pipeline, the air is heated due to contact with the channel inside a special shaft for the "transportation" of smoky masses. Heated oxygen enters the furnace, which increases the efficiency, reduces the consumption of gas fuel during the operation of the boiler.

It is important! The channel outside plays the role of a cooling device that lowers the temperature on the surface of the pipeline. Due to this, a chimney of this kind can be mounted in a private (made of wood) building without taking serious measures to ensure safety (fire).

As mentioned above, the internal channel provides "transportation" of smoky masses. It is often equipped with special insulation, which makes it possible to increase traction in vertical structures. This variety has three channels, one of them is designed to be filled with basalt-based insulation. To ensure the smooth operation of a home-made chimney, it is required to make calculations in advance and perform the installation with high quality, taking into account the structural features.

Chimney installation diagram

Advantages and disadvantages

The main advantage of the coaxial chimney is that the air masses used in the operation of the boiler are not taken from the room, but from the open air. This eliminates the need to make a powerful ventilation system, moreover, even a small room is suitable for use as a boiler room in such a situation.

In addition to the described features, the positive aspects of such a device include:

High installation speed. The design of the chimney cannot be called complicated, so the installation can be done independently (it is not necessary to involve specialists and pay for their services).
The possibility of using for the removal of combustion products from the boiler room of an apartment building.
The ability to use to increase the efficiency of almost any type of heating equipment.
A good indicator of traction, which is observed if the installation work is done with high quality.

Thanks to the listed positive aspects, the coaxial chimney is popular among a large number of people. In addition to the advantages, two-channel chimneys have a number of disadvantages.

These include:

The need to coordinate the installation with the sanitary and epidemiological supervision service. This is due to the fact that during operation a lot of toxic condensate is emitted. Pouring this substance on the ground is strictly prohibited, and disposal is carried out in specially designated areas. However, if you use this type of chimney in a private house, then all claims will be reduced to the individual wishes of its owners. But when installing collective-type systems, obtaining permission from the service mentioned above is a prerequisite.
The need to organize pipe insulation from coaxial condensate. Even small mistakes made during installation will lead to icing of the outlet, which will cause a decrease in thrust.

Despite the shortcomings described, chimney systems of this kind are often installed both in private houses, cottages or cottages, and in multi-apartment buildings. However, the installation procedure must be treated with maximum responsibility and attention. This will help you avoid unnecessary expenses in the future.

Moreover, installation errors can lead to deformation of the chimney communications during operation. Some problems can be solved by specialists, but if problems are ignored for a long time, it may be necessary to purchase a new system and install it.

The diagram clearly shows how a coaxial chimney works.

Do-it-yourself installation of a coaxial chimney of a gas boiler

There is nothing complicated in the installation algorithm, however, there are features that have a tangible impact on the functioning of the system in the future. Before purchasing a finished chimney system, you need to carefully study the diameter of the pipeline that will be connected to the boiler.

It is important! An important role in the installation and further operation is played by the requirements of SNiP. Their observance is a prerequisite, since neglect of such rules can lead not only to problems with sanitary and epidemiological supervision, but also to accidents.

Regulatory requirements SNiP

The rules for installing chimneys for a gas boiler, as well as the relevant standards established by the state, are detailed in SNiP 2.04.08-87 and 2.04.05-91. Drawing up individual projects, calculation procedures and installation are carried out in accordance with them. Violation of these rules will lead to the failure of the gas service and make legal installation impossible. SNiP is regulated by:

Placement of the chimney on the facade. The head should be at least two meters from the ground. The size of the hole in the wall should be 1 cm larger than the diameter of the chimney for a brick wall and 5 cm for a wooden wall.
Maintenance. It should be carried out at the beginning and end of the heating season. It is required to remove condensate and check the joints for leaks.
Application of similar systems in MKD. The structure should be mounted at least half a meter from door and window openings. There must be at least 1 m to the window above the pipe.
Installation. The chimney pipe must be at least 30 cm from the wall. If we are talking about turbocharged boilers - from 1 m. A narrowing diaphragm must be installed without fail, which is required to limit the flow of air into the closed combustion chamber.
Fire safety standards. The minimum gap between the chimney pipe and the wooden wall should be 5 cm. This is due to the fact that during operation the outer surface is practically not subject to heat. Non-combustible materials must be placed between the wall and the pipeline. The best option is basalt insulation. The chimney pipe must be at least 1.5 m from the windows and doors of neighboring houses. There should not be poles, trees or other objects in this gap. It is forbidden to use a standard chimney to discharge combustion products (only coaxial varieties).
Restrictions on output through the facade. The ban on the flow of condensate to the ground must be observed without fail. Therefore, the pipeline must be installed at an angle to the boiler. If the design includes a special device designed to drain condensate, then the slope of the outlet pipe to the ground is allowed (in order to drain rainwater). If we are talking about the use of a collective type of chimney, then the disposal of condensate should be agreed with the sanitary and epidemiological supervision service.
Features of each type of chimney system. It can be horizontal or vertical. It is strictly forbidden to connect to the same network of chimneys with forced and natural type of removal of combustion products.
Features of laying a horizontal section. It is allowed to lay through an adjacent room that is not intended for human habitation, if the length of the pipeline section that will pass through it does not exceed 3 m. If we are talking about a turbocharged system with forced removal of combustion products, then it is allowed to increase the pipe section passing through the non-residential premises , up to 5 m.

The described safety requirements may change over time, therefore, before starting installation work, it is necessary to obtain expert advice.

Requirements of sanitary norms and rules for distances between objects

We make the installation

If you want to independently install the chimney of the internal variety, then all actions are performed in the following sequence:

Check that the dimensions of the boiler nozzle and flue pipe match.
Prepare a hole through which the pipeline will be brought out. Its diameter must be made slightly larger than the same parameter of the pipeline.
Connect the appropriate element of the flue system to the gas boiler nozzle.
Fix the connection with bolts and clamps.
Consistently assemble the entire chimney system. Each element is installed in its “own” place, after which it is fixed with clamps (they increase the level of connection reliability).
Install overlays that perform decorative functions over the fasteners. They will help maintain the aesthetic appearance of the structure.
Take the chimney pipe outside.
Ensure joint tightness.
Put on a casing with protective properties on the pipe. This will help to increase the level of safety of the occurrence of uncontrolled fire.

After completing the described installation process, it is required to check the tightness of the joints, cover them with a special apron.

If we are talking about an external chimney system, then the installation procedure has its own characteristics. When it is required to install such a chimney, it is necessary to adhere to the following algorithm:

Determine the exit point and mark its location on the wall of the building.
Make a hole at the mark. The diameter must match the cross section of the pipe.
Connect the chimney to the heater. This requires the use of a double-circuit elbow and a special tee. It is needed to ensure the stability of the finished structure in a vertical position.
Fix the "structure" to the wall with brackets.
Seal the section of the chimney exit from the wall and continue to collect it to the desired height.
Fasten the structure to the outer wall using clamps.

To ensure a reliable connection of double-circuit pipes, it is required to use transitional nodes.

Transition nodes connecting double-circuit pipes are important design elements of the device

Features of horizontal and vertical mounting

If we are talking about a horizontal installation option, then this procedure must be carried out taking into account the technical features of the building. The following parameters must be calculated in advance:

Pipe height. The distance from the outlet pipe to the hole in the wall must be less than 1 m. The direct outlet of the pipe from the outlet pipe to the street is not allowed.
Number of rotary couplings (less than three).
The maximum length of the horizontal section. Should not exceed 3 - 5 m.

An increase in condensate production is a feature of the operation of the chimney system in the cold season. Excess moisture loss is due to harsh operating conditions.

When it is required to install a vertical chimney, it must be remembered that this procedure can be carried out in two ways:

Cascading. It involves connecting several heating units to one pipe at once. A similar scheme is quite often used in MKD.
Individual. The maximum length of the vertical elements is 7 m. This allows installation in a two-story private house.

Chimney installation options in a private house

If we are talking about a brick building, then the chimney system can be installed both inside and outside. However, effective thermal insulation is required in any case. This will avoid unpleasant consequences, which are likely to occur during intensive operation of the boiler, if the insulation is neglected.

Video: options for connecting a coaxial chimney to gas boilers

Installing a chimney is a procedure that can be performed by any tenant of a private or multi-apartment building who has basic skills and knowledge in the relevant field. If these are completely absent, then contacting specialists in the installation of such systems is the best solution. This approach will help to avoid unnecessary costs, as well as problems with certain services associated with errors that are made during installation, and their consequences, which manifest themselves during heavy use.

When installing heating boilers (except for electric boilers), it is necessary to take care of proper smoke removal and oxygen supply, necessary to maintain the combustion of the coolant. A coaxial chimney for a gas boiler can be installed together with heating boilers with a closed combustion chamber. Often the necessary equipment is initially included in the boiler itself.

Heating boilers with a closed combustion chamber can be installed in any room, they do not require the installation of a classic system for extracting waste combustion products, it is enough to install a coaxial chimney for maintenance.

The definition of "coaxial" - means coaxially, that is, it is such a chimney that consists of two component pipes, located one in the other and brought out into the street. This is a single double-circuit design of two pipes of different diameters. Inside the pipes do not come into contact with each other, thanks to special jumpers, which give the pipeline increased rigidity.

This design combines two independent channels used for specific purposes:

The pipe of small diameter is intended for removal of products of combustion of fuel;
A larger diameter pipe serves to take air into the combustion chamber.

Thus, it turns out that the smoke is removed from the boiler, and the air enters the boiler without connecting with each other. . The advantage of such a system is that it is securely closed and the internal air of the room does not mix with the air and smoke inside the coaxial (coaxial) chimney.

Basically, horizontal coaxial chimneys are installed, although in rare cases vertical structures can also be found.

Special Benefits

When considering the main positive qualities of coaxial chimneys, it should be noted once again that such a design may not be connected to all types of heating boilers. For the highest quality operation of such a chimney, it should be borne in mind that it must be installed with heating boilers with a closed combustion chamber on forced draft. It is the built-in fan that allows the entire smoke exhaust system to work extremely efficiently. Such boilers can be both floor-standing and wall-mounted.

The most important advantage in favor of a coaxial chimney is the simplicity of the system and the installation of the heater in any required place.

Consider in detail all the undeniable advantages:

Horizontal chimney. There is no need to pierce the roof to remove combustion products. The pipe is brought out through the wall or window closest to the boiler.
The coaxial chimney system is not connected to the indoor air. During the operation of the boiler, oxygen in the room is not burned out, and carbon monoxide gases do not enter the interior of the rooms, as is the case with the operation of conventional gas boilers.
The air taken from the street enters the combustion chamber heated. This is possible due to the fact that it passes between the outer pipe and the inner one, through which hot, exhausted smoke is discharged outside. This allows you to increase the efficiency of the heating boiler.
The coaxial chimney is easy to install, the work does not require special knowledge and major redevelopment to equip the chimney. Thanks to such smoke removal, it is possible to install a heating boiler even in an apartment.
The coaxial chimney has an excellent degree of protection against possible fire. This is achieved by cooling the entire system with cool outdoor air, which enters through the channel between the pipes.
For such a chimney there is no need to arrange a separate equipped boiler room. Any of the boilers - wall or floor, can be installed in a convenient place chosen: in the kitchen, in the basement, in the annex, in the pantry.

Important installation requirements

Installation of a heating boiler with a closed combustion chamber requires the installation of an autonomous heating system. Such a system can be used in individual construction, in city apartments or industrial premises.

If a decision is made to use a coaxial chimney, certain rules and regulations for safety and installation should be followed. They will allow you to carry out the chimney as correctly and reliably as possible and protect the room from exhaust gases.

Rules for installing a coaxial chimney:

The maximum length of the vertical outlet pipe of the coaxial chimney should be around 3 meters. Sometimes longer chimneys are found. For example, it is possible to connect coaxial chimneys 4-5 meters long to Ferolli boilers (floor-mounted).
The outlet of the pipe to the street is carried out horizontally through the wall, near which the boiler is located in the room. The length of the horizontal section is not more than 1 meter.
In the case of forced draft installation with fans, there is no need for a vertical section of the system.
The chimney outlet is located at a height of two or more meters above the ground and at least 1.5 m relative to the location of the boiler (above it).
The chimney outlet should be at a distance of half a meter from any window (side or top), door or ventilation grill.
The outlet of the coaxial chimney pipe under the window is not recommended. But if necessary, the location of the window above the chimney should be more than 1 meter.
To drain condensate, when installing a coaxial chimney, it is necessary to provide a certain slope of the pipe.

It should be noted here that the debate about the necessity and correctness of setting the pipe slope is a topic that is quite controversially interpreted and vigorously discussed on many construction forums and sites. At first glance, such a simple matter, it requires an intelligent approach and careful clarification of all the nuances. The main dispute arises over the side of the slope of the chimney. It is necessary to understand this issue in detail and note some of the nuances of installing a horizontal coaxial chimney.

Chimney slope

There are two different opinions about where the chimney slope should be installed.

In the first case, some experts are inclined to believe that it is best to make a slope from the boiler towards the street. This is quite logical, since with such a design of the system, the condensate formed during the cooling of the exhaust gas will flow out by gravity. This will prevent condensate from entering the boiler. But such a system can fully work only when there are no severe frosts on the street.

Otherwise, the condensate, not having time to drain through the pipe, simply freezes at the outlet. The resulting icicles interfere with the normal intake of air into the combustion chamber. Also, condensate can freeze not only at the outlet of a smaller pipe, but also inside the annular space of the chimney.

Here, condensate is formed due to the fact that the internal moist air, heated from a small channel, settles on a cold outer pipe. In the case when the slope is made towards the street, the condensate freezes before it leaves the pipe. Ice forms inside, the chimney ceases to function properly.

It is because of the constant freezing and ice formation during severe frosts that leading manufacturers of heating boilers recommend installing coaxial boilers with a slope towards the boiler. The issue of condensate getting into the furnace is solved very simply. To prevent this, a condensate collector is additionally installed.

Is there any point in warming

It should immediately be noted that the insulation of such a chimney does not solve the problem of freezing condensate. At first glance, it seems that you can simply insulate the outer pipe well, but even so, the prerequisites for the formation of ice inside the chimney remain. Cutting (shortening) the inner tube can help here. Naturally, all these measures are necessary only if the chimney slopes towards the street.

Attention! The instructions for the coaxial chimney indicate the maximum allowable pipe sizes. These parameters must be strictly observed - they are inextricably linked with fire safety requirements.

Installation

A coaxial chimney, unlike vertical traditional chimneys, is easy to install and does not require special skills, knowledge and devices. You must follow the instructions, be careful and adhere to safety standards. It should be noted that almost always a coaxial chimney is installed together with a heating boiler.

Installation steps:

At the first stage, a place in the room under the boiler is determined. The floor boiler is installed on a small foot, wall models are fixed on the outer wall.
The outlet of the chimney is marked on the same wall near which the boiler is located, at a height of more than 1.5 m above it. The diameter of the hole in the wall should be slightly larger than the outer dimension of the pipe.
A special connecting element is installed through which the heating boiler is connected to the chimney. All turns and joints of pipes are fixed with fixing clamps.

Attention! When installing a coaxial chimney, it is strictly forbidden to use adhesive tapes, as well as sealants.

The hole in the wall, that is, the place where the pipe passes, must be laid with non-combustible insulation.
If forced ventilation is used in the boiler, then only a horizontal section of the chimney pipe is installed.

Attention! If it is necessary to turn the pipe, a swivel elbow is used. No more than two bends should be mounted on the entire chimney.

The pipeline is attached to the wall with brackets: one for each joint.
At the end (head) of the coaxial chimney, additional elements should not be installed: umbrellas, deflectors, etc.

In conclusion, it should be noted that the coaxial chimney is becoming quite popular in rooms with an autonomous heating system. Such chimneys are reliable, easy to install, have a long service life and are distinguished by modest price indicators.

Warmth is one of the components of comfort and coziness in the house. Today, there are many ways in which you can heat your home. For multi-apartment buildings, the solution lies in district heating, while owners of private houses have to install boiler equipment.

Such devices that work with fire necessarily require the presence of a smoke exhaust device. And if ordinary pipes were used before, today they have been replaced by a more perfect solution. An increasing number of homeowners are resorting to the installation of coaxial chimneys, which are efficient.

Coaxial pipe device

The coaxial pipe provides for the presence of two nodes, one of which is inserted into the other. The design has two contours, which have different diameters and are arranged according to the principle of Russian nesting dolls. Inside there is a jumper, which excludes the contact of parts.

Such a device is mounted in a heat generator, which has a closed combustion chamber, it should include a gas boiler. The coaxial pipe has such a device that the inner pipe is used to bring the products of combustion to the street, while the more impressive diameter pipe, which is located outside, is used to supply the oxygen necessary to ensure combustion.

A standard coaxial type chimney has a special device, it allows you to solve problems, one of which guarantees the combustion process, the other ensures the flow of air. The length of the device does not exceed 2 m. Typically, such structures are located horizontally, and are brought out through the wall. Sometimes there is a coaxial pipe that exits through the roof and ceiling.

Problem solving

The design of the described chimney allows it to work on a principle that differs from the usual one. The oxygen required for combustion enters the equipment from the outside. This eliminates the need for a constant supply of air into the room by ventilation, which is traditional for conventional smoke ducts. Among other things, several more problems that are characteristic of traditional chimneys are quite successfully solved, among them:

reduction of heat losses;
reducing the risk of fire;
high efficiency;
the course of the combustion process in a closed chamber;
saving space;
the possibility of choosing a chimney from a wide range.

More about the advantages of a chimney for gas boiler equipment

The coaxial pipe allows you to reduce heat losses due to the fact that the air entering from the outside is heated from the outgoing internal hot pipe, as a result of which it is possible to achieve a higher efficiency. The risk of fire is minimized, especially in areas that come into contact with the exhaust duct and flammable surfaces, because the inner pipe is cooled to a safe temperature when it gives off heat to the one located outside.

Such chimneys for gas boilers ensure complete combustion of fuel, and unburned particles are not thrown out and do not pollute the atmosphere. Equipment equipped with a coaxial chimney is environmentally friendly. Due to the fact that processes such as combustion, exhaust gases and oxygen supply occur in a closed chamber, the operation of the equipment becomes safer for humans, combustion products that could pose a health hazard no longer enter the room. This also indicates that the device of the ventilation system is not required.

Chimneys for gas boilers are quite compact in size, this additionally saves space. Having visited the store, you can find such designs that are presented in a wide range, certain models are used for systems of different capacities.

Installation Requirements

To date, there are two ways in which a coaxial chimney can be installed:

vertical;
horizontal.

The flue duct will have a direction that is determined by each boiler individually. It is important to consider that horizontal structures are intended exclusively for those devices that have forced ventilation. If you look at the sanitary norms and rules, you can find out that the horizontal section must have a limited length, its maximum value does not exceed 3 m. But some manufacturers set other restrictions for their products. Therefore, before designing structures, it is necessary to familiarize yourself with the characteristics of the device.

Pipe orientation and connection

The coaxial gas pipe is located vertically if it is not possible to equip the channel outlet through the wall. This case applies to small street widths or close windows. The coaxial chimney can also be oriented obliquely.

Installation work should begin after you can choose the right device. If we take into account the installation standards for the internal chimney, then the diameter of the outlet should not be larger than the diameter of the outlet channel. This moment should be controlled by referring to the data of the chimney passport, where you can find its diameter.

Coaxial pipes for gas boilers are connected to the equipment using a pipe, tee or elbow. Each subsequent element must be fixed to the previous one in such a way that no obstacles are created for the removal of combustion products.

Work methodology

The list of elements that will be required for installation will depend on where the outlet pipe is located - at the top or on the side. In the first case, the chimney is much easier to remove. For the second option, you need to use a horizontal structure, which is displayed using modifications and brackets in a vertical position.

To install the pipe, you need to use a transition node. Clamps are fixed to other elements in a rigid way. Using an adapter or homemade extension cords, winding with tape and applying sealant is unacceptable, because these options will not only be unsafe, but also unreliable.

When installing the chimney, it is important to remember that the outlet pipe must be at least 1.5 m higher than the heater. The pipe outlets must have an angle of 3 °, which will ensure the unhindered exit of condensate. The coaxial chimney is best placed 1.5 m above the roof surface, otherwise it may become clogged.

If it is supposed to equip a rather complex system, then the total length should be 3 m. The installation of a coaxial pipe should not involve the presence of more than 2 elbows. From the nearest windows to the outlet pipe, a distance of 60 cm should be provided, as for the distance to the gas supply pipes, this parameter should be 1/2 of the diameter of the outer pipe. Fragments of the structure should fit as tightly as possible to each other; if obstacles are to be surrounded by a chimney, then a special elbow with different angles of inclination should be used. You can use two such nodes at once.

Arrangement of a responsible area

The roof area is considered the most critical area, here work must be carried out taking into account fire safety. For this, insulating pipes are used, as well as non-combustible insulation. An air gap must be left between the pipe and the ceiling. The flue duct must not come into contact with objects; protective covers are used for this.

If the chimney is discharged through the roof, then this assembly must be sealed by protecting it with an apron, which should cover the junction. When the output is through a wall, non-combustible materials must be used. The coaxial chimney must always remain cold, this feature is one of the main ones.

Chimney freezing

Quite often, the owners of boiler equipment wonder why the coaxial pipe freezes. In this case, the boiler room may even stop functioning. In order to avoid such a nuisance, it is important when connecting the boiler to try not to ignore the manufacturer's advice. It is necessary to observe the length of the pipe, its location and slope. The presence of a fan will free the chamber from combustion products, it will provide rarefaction, which is necessary for sucking in new air.

Coaxial kits also differ in the material of manufacture, as well as in design, so some of them may freeze while others function normally. If the vertical coaxial pipe is frozen, then the problem can be partially solved by removing the plugs that are located at the top of the boiler. Flue gases in this case will go outside, and air will begin to flow from the room.

The plug should be reinstalled once the ice has melted. After all, the boiler will not be able to work in this mode all the time. Failure of the unit is inevitable if airborne particles such as kitchen dust and soot enter the equipment. When icing does not happen so often, this method is quite possible to use, but with regular freezing, you should purchase an "anti-ice" kit.

Conclusion

Coaxial pipe 60/100 can be purchased by you for 1500 rubles. It is an active design that is able to improve the environmental performance of the boiler and its fire-fighting properties, while increasing the efficiency of operation. You can do the installation yourself, but if you doubt your abilities, then it is better to entrust the installation to professionals.

Various elements can be used in modern heating devices. Their composition depends on the type of heat carriers and the method of heating. A mandatory component of such installations is a chimney, which is responsible for removing smoke and other products of combustion from the room. Let's see what it is - a coaxial chimney for a gas boiler and what are its advantages. With proper installation, such a design not only eliminates burning and smoke, but also provides fresh air.

It looks like a design for the removal of combustion products

The design of a coaxial chimney for a gas boiler is not so complicated. It consists of two pipes of different diameters, which are installed in each other. In this case, a gap of several centimeters is left between the walls.

Such chimneys are of two types:

collective structures are produced only in industrial conditions and are assembled only at the stage of construction work. The device assumes the presence of heat-insulating components;
individual options are used in everyday life and can only be connected to one heating unit.

The coaxial installation works like this: air is taken from the street through the external line, then it moves through the pipes and heats up. The air is supplied to the furnace already warmed up, which allows to reduce the gas consumption. Smoke is removed from the inside through the channel. Certain devices have a heating system. In order for the chimney structure to work correctly, high-quality assembly should be carried out. This turns on the security nodes.

For units with closed chambers, chimneys are suitable, the length of which is not more than two meters. This will prevent swirling from occurring.

Useful information! The coaxial version can be installed even in a wooden building, as it is perfectly protected from fires.

Related article:

Do you know why this technique is so good? In this review, we will consider all the advantages and disadvantages, as well as the secrets of choosing this type of boiler.

Location of the coaxial chimney system

Most often, the installation of a coaxial chimney is carried out using a direct passage through the wall. In some cases, the passage of the device through the roof or through the ceiling is used. The best location for such a design is horizontal. If the heater is located in a hard-to-reach place, then the air duct is removed using vertical sections.

Such lines are ideal for parapet equipment and convectors. A coaxial type system with a burner can be used. Steel chimneys are suitable for double-circuit and single-circuit units. In the production of pipes, stainless steel, aluminum or plastic are used.

For your information! When selecting pipes for gas equipment, it must be borne in mind that only designs made by the same manufacturer as the main units are suitable for individual heaters.

Related article:

In the article, we will consider the design features of the design, average prices, customer reviews and the secrets of choosing the right type of boilers. .

The composition of the coaxial pipe to the gas boiler

A coaxial chimney for a gas boiler contains the following elements:

straight pipes were used to form a chimney;
a rotary element or a tee is used as connecting parts. With their help, direct parts of the device are mounted to the boiler;
a special area for maintenance work;
capacity for accumulation of condensate;
the upper part of the structure, used to protect the circuits of the installation.

The unit is made of acid-resistant stainless steel, which can withstand significant temperature rises. Chimneys are:

pipes without insulation have a simple device. Such a structure must be additionally insulated in order to reduce the resulting condensate;
pipes with insulation are used for vertical structures. Insulated lines have excellent aerodynamic characteristics.

Important information! Many boiler manufacturers advise mounting coaxial equipment with a slope towards the heating unit.

Why do you need a coaxial installation?

The most important advantage of a floor-standing gas boiler with a coaxial chimney is that the flow of fresh air allows you to maintain the combustion process. When mounting such a device, you will not have problems with excessive dryness in the room. In addition, you do not have to ventilate the rooms often.

The air passing through the circuit of the installation warms up, thereby improving the combustion process. This contributes to greater equipment efficiency. Due to the constant air supply, the gas in the combustion chamber is completely burned, which increases the efficiency of the system. The coaxial line does not have as high a surface temperature as a traditional chimney.

For your information! You can choose a coaxial type chimney for each heating structure. There are pipes of various diameters and from various types of material. Such a device can easily be installed even by an untrained specialist.

Coaxial chimney: installation requirements and installation

Some rules for installing a coaxial chimney will help you build a high-quality heating system. Of particular importance is the step-by-step instruction:

make sure all the elements are in the right places. In addition to the set of pipes, there must be connecting parts and various heaters;
before installation, you need to mark up, calculate all the channels of the chimney and make all the necessary holes;
installation of the heating unit and the chimney is carried out simultaneously;
the exit is located one and a half meters above the combustion chamber;
the chimney line is fixed to the outlet pipe with a clamp and a pair of bolts;
the design is assembled according to a special project;
installation knees are fastened with clamps;
a slight slope is created on the outgoing section of the chimney.

The device of the chimney through the wall does not require special devices and skills. This design is relevant for buildings with an autonomous heating system.

Such chimney elements are easy to install and also have a long service life. Under the influence of low temperature values, some sections of the chimney structure may freeze, which affects the efficiency of the entire system. Warming will help to avoid such situations. In this case, it is important to take into account the features of a specific device when the pipe is in the pipe. An effective solution would be to reduce the cross section of the chimney installation. You can try making the inner tube shorter. This will prevent icing of the condensate. The installation of separate steel pipes is practiced. In this case, one will take in air, and the second will remove combustion products.

In the table you can see the prices for individual models.

Image	Models	price, rub.
	Ferroli Ø 60/100 (010012X0 / KIT12X0)	1750
	Kiturami 125	4300
	De Dietrich DY 908 DN 60/100 mm (800 m)	4100
	Set universal 60*100 (PL) 750	3200
	Buderus 60/100 - length 810 m	2900
	Navien set	3100

The decision to install a coaxial chimney will give good results. And useful recommendations and the use of instructions will help to install such a structure on your own, without the involvement of specialists.

Coaxial chimney for a parapet gas boiler (video)

You may also be interested in:

Do-it-yourself instructions and drawings of solid fuel boilers for long burning