accommodation in country houses it is impossible without the arrangement of the heating system, and gas heating is considered the most economical. But for gas, as well as for another type of fuel, both the influx of oxygen and the removal of combustion products are necessary. AND the best system chimneys is recognized as coaxial: it can simultaneously cope with both the removal and the influx of the gases necessary for combustion.
Coaxial means internally combined, or in another way, one in the other. A coaxial chimney 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 to a closed combustion chamber, and remove the resulting carbon dioxide to the street.
Since this system needs not only an influx of oxygen, but also an autonomous removal of condensate and combustion products, it consists of several components:
What are the positive characteristics of a coaxial chimney system?
There are very few disadvantages of such a chimney system, these include high cost and low aesthetic perception: if installed in the basement, it can slightly reduce the harmony of the room.
The coaxial chimney system comes in horizontal and vertical types, each of which can be installed under certain conditions.
Vertical. For this system, it is necessary to equip a drain on the roof of the house, and a condensate collection tank is also very necessary, but usually all the necessary set of components is already included in the chimney supply.
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 equip a place for a chimney on the roof, and the collected condensate can be discharged 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.
The fire authorities require for the arrangement of the heating system the presence of a separate room, in which ventilation is carried out and there is everything necessary equipment. This leads to extra costs, you need to either rebuild an already finished house, or equip a separate chimney system.
But all this can be avoided if you purchase a gas boiler. closed type combustion and equip a special coaxial chimney system, which saves the owner of the house on the arrangement of a separate smoke outlet.
And only for these reasons, the 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 combustion is impossible to say.
The rules for mounting connections must be observed: they must end before the system exits the wall hole. The pipe itself must protrude from the wall by at least 20 cm, and a greater distance is allowed.
To ensure that the reverse thrust cannot be returned to the boiler, a special valve is equipped on it, which will prevent this phenomenon.
The connection of all parts of the chimney is carried out using clamps and, in some cases, insulation. Building foam can be used to achieve better sealing.
Tip: use as few vertical parts as possible: this way the efficiency of the chimney will be higher.
There are regulations self installation coaxial chimney:
If gas enclosed equipment is used to heat an apartment building, it may be necessary to extend the chimney system.
For installation you will need:
All additional extension parts must be purchased from the chimney system manufacturer's dealers, as parts from other brands may not be compatible with equipment already purchased.
The cost of a coaxial chimney largely depends on the configuration. For example, the basic kit may differ in cost depending on the diameter of the pipes. The most sought-after kit can cost from 4 thousand rubles to 13.5: which chimney pipes you need to purchase. Additional knees can cost from 1.5 to 3 thousand, a condensate collector - about 3 thousand.
If you want to buy a protective grill for the exit of the chimney, then its cost is about 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.
IN wooden house most often they began to use autonomous heating systems, consisting of many elements. Their composition may vary depending on which coolant is chosen or how it will be heated. It is worth noting that regardless of the material used for the furnace, the boiler must have a smoke exhaust system or, in other words, a chimney. The design can have a different configuration, features and even technical characteristics, however, among many, the coaxial chimney is recognized as the most popular.
A coaxial pipe for a gas boiler is not just a product, but one that has a lot of advantages, due to which it has become so popular. High efficiency is ensured by perfectly heated incoming air.
Compact dimensions are characteristic, since installation of 2 large pipes is not required, but one is enough.
The pipe does not require installation of additional ventilation. Environmental friendliness is extremely important for a person, since it is often possible to find heavy and cheap materials that can release toxic substances when heated.
Advantages:
A device such as a vertical coaxial smoke outlet is used for a heating system in which a gas boiler is installed, with closed camera combustion. The device for direct heating can be in the form of a gas boiler, convector or radiator. The installation of a double-circuit coaxial chimney should be carried out as correctly as possible so that the principle of operation is not violated. Each circuit is responsible for its specific task. The first is required to remove combustion products from the furnace cavity in the boiler. The second is intended for air flow into the cavity of the furnace, which ensures efficient combustion.
Our next article discusses in detail the criteria for choosing double-circuit boilers:.
It is precisely in order to have excellent draft and uniform combustion of gas that it is worth installing a coaxial chimney in a boiler with a closed combustion chamber, the length of which, according to the rules, does not exceed 2 m. Otherwise, turbulences may form on the pipe that prevent the exit of combustion products from the furnace.
In order to install a heating boiler with a closed combustion chamber, it is necessary to install an independent heating system, which can be used for individual construction, as well as in apartment building or industrial premises. If a decision is made to install a coaxial chimney, then certain rules and requirements will need to be observed so that the device is carried out as correctly and without missteps as possible.
Requirements:
It is strongly not advisable to install a coaxial chimney under the window opening, but if there is no other option, then there should be a distance of 1 m. To eliminate condensate, installation of a coaxial chimney and a slight slope of the pipe is required.
The coaxial boiler works, like everyone else, in order to heat the room, but why is it called that? Coaxial boilers got their name from the installation of coaxial chimneys.
Such a chimney performs the following functions:
The inner cavity is responsible for the removal of smoke. Air is also supplied to the combustion device or, in other words, the air mass is taken. Due to the air, the boiler functions along the cavity of the outer pipe.
The chimney for a coaxial boiler must be installed in accordance with provisions such as SNIP norms, carefully thought out, of high quality and working properly. A coaxial chimney differs from a vertical and traditional device in that it is not difficult to install it, and a number of special skills or training are not required, it is imperative to follow the instructions so that the installation technology is not violated. Only in this way can you be sure that the product works properly and the penetration of smoke into the room is categorically excluded.
Stages:
It is strictly forbidden to install a coaxial chimney with adhesive tape or sealant. The hole in the wall space must be laid with a special non-combustible insulation.
If forced ventilation is installed in the boiler, then it is required to install only that section of the chimney that is horizontal.
If there is a need to make a turn in the pipe, you can use a special swivel elbow, and a maximum of 2 elbows can be installed on 1 chimney. The installation of the pipeline on the wall surface is carried out using brackets, and so that they are necessarily present at each joint. At the end of the coaxial chimney, it is undesirable to install such additional elements as an umbrella, a deflector, and others.
Depending on the model of the coaxial boiler, the length of the chimney is selected, however, an extension is possible if this is allowed by technical specifications. On average, the length can be 3 m. A coaxial chimney has certain advantages, due to which its popularity is increasing almost every day.
The advantages are:
Unfortunately, there are also disadvantages of such products, but against the background of many advantages, they sometimes fade into the background. To carry out the installation, you need to coordinate the actions with the sanitary and epidemiological supervision. During operation of the chimney, toxic condensate is released, which is forbidden to be poured into the ground, and is a direct pollution environment. Disposal of such condensate must be carried out in a separate place. If you install a structure of this two-channel type in a house with many apartments, then there may be indignation from the residents. If there is no appropriate permission from the organization, then it will be necessary not only to remove the installation, but also to pay a fine. No matter how the condensate is isolated, it will be too large, and a minimal violation of the installation technology will lead to many problems.
The coaxial chimney is great option for installation on pipes for the removal of combustion products to a gas boiler, since, relative to other structures, it has a lot of positive aspects and a long service life. The most important thing is to purchase high-quality equipment and carry out the installation correctly.
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 installation classical system extracts of waste combustion products; for maintenance, it is enough to install a coaxial chimney.
The definition of "coaxial" - means coaxially, that is, it is such a chimney, which 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:
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.
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:
Installation of a heating boiler with a closed combustion chamber requires the installation of an independent heating system. Such a system can be used in individual construction, in city apartments or industrial premises.
In the event that 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:
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.
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 system arrangement, the condensate formed during the cooling of the exhaust gas will drain 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.
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. This is where trimming can help. inner pipe. 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.
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:
Attention! When installing a coaxial chimney, it is strictly forbidden to use adhesive tapes, as well as sealants.
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.
In conclusion, it should be noted that the coaxial chimney is becoming quite popular in rooms with autonomous system heating. Such chimneys are reliable, easy to install, have a long service life and are distinguished by modest price indicators.
We all know that performance heating systems, which use the principle of fuel combustion, is impossible without oxygen, which supports 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 of the owner in the work process.
This device looks more like a motorcycle exhaust pipe. In fact, this is a specially designed design, 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 through the space between the inner and outer tubes, the air necessary for fuel combustion enters the combustion chamber. A coaxial chimney for a gas boiler solves two main tasks at once: exhaust gases and air supply to the device.
Such chimneys are made of pipes round section, and the inner one is most often made of aluminum alloy, and the outer one is made of steel, 1 thick; 1.5 or 2 mm. The ratio of the inner and outer diameter for wall and floor heaters is 60 to 100 mm. For condensing boilers, chimneys are used, with a diameter ratio of 80 to 125 mm.
There are two types of coaxial chimneys: horizontal and vertical. The easiest to install, and accordingly, the most common smoke exhaust system of this type is a horizontal chimney. A vertical coaxial chimney is quite difficult to install and therefore is used if horizontal installation is not possible or if there is more than 4 m from the heater to the street wall.
As mentioned above, this type of smoke exhaust system is used only for gas equipment with a closed combustion chamber, namely:
The main advantages of such an air intake and smoke exhaust system are:
The most attractive for the use of chimneys of this type are apartment buildings, since the emission of carbon monoxide and fuel combustion products is not carried out into the ventilation shaft, but directly into the atmosphere.
Such chimneys also have disadvantages, namely: rather expensive insulation to prevent freezing of the chimney cap. The possibility of freezing of the pipe head is quite high. This happens because the temperature of the outgoing gases is too low and is not able to melt the ice formed during the exit of moist air. The consequences of icing can be quite serious: repairs to burners, combustion chambers and turbocharging.
As mentioned above, there are two main installation schemes for a coaxial chimney: vertical and horizontal. During installation, one 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 a set of "Safety Rules in the gas industry".
The total length of the coaxial chimney cannot exceed 4 m.
With vertical installation, the chimney passes through the ceiling and 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 equipment. To achieve the required length of the chimney, special extensions are used.
To ensure tightness during the passage of the chimney through the roof and protect it from precipitation, a device called a terminal is used.
When installing a vertical smoke exhaust system, one should be guided by the rules that regulate its height, depending on the location in relation to the ridge of the pitched roof. 
Most often, a vertical coaxial chimney is mounted in private homes. But there is another option for a vertical smoke exhaust system - a collective one, which is designed for apartment buildings. A common coaxial chimney in an apartment building makes the use of individual gas heating appliances completely safe.
The horizontal outlet of exhaust gases is most often used for wall-mounted heating equipment. The horizontal scheme implies the output of the chimney through the outer wall to the street.
During installation, the slope of the chimney of 2-3° should be taken into account to prevent condensate from entering the boiler.
Two types of fixtures are used to pass through the wall: 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.
Installing a coaxial chimney with your own hands is quite simple and anyone can do this job. House master with basic knowledge of using power tools. 
To perform the work, you will need a kit that includes: a pipe with a flange, a clamp, an adapter for connecting to a boiler unit and a coaxial elbow. If necessary, you should purchase a special extension of the coaxial chimney.
It should be noted that with each turn of the chimney by 90 ° decreases and maximum length coaxial chimney 0.5 m.
23 May 2014 
Alexey
The use of modern boiler equipment is impossible without a system for removing combustion products. It is necessary for effective work boiler using any type of fuel.
But the installation of a classic smoke channel is carried out in the process of building a house and is not possible in an already built building. In this case, the ideal solution would be a coaxial chimney. In this article, we will look at what this design is and how to install it.
Let's start with the name. The word coaxial is interpreted as a double channel. In constructive terms, such a chimney is a double-circuit. In it, a smaller pipe in diameter is located in a larger one. At the same time, they do not touch each other, but are connected into one whole with the help of special jumpers.
In general, this is a system that carries out the removal of combustion products and the supply of air from the street for the most complete combustion of fuel inside the boiler. About 90% of modern heating units are equipped with a closed combustion chamber, having a smoke exhaust pipe within 3 m in length.
When deciding to use a coaxial chimney, it is important to know that it is installed in a horizontal position. The output is through one of the outer walls.
The following are on the market:
Depending on the installation method, they are divided into:
Having decided to equip a coaxial chimney, the installation standards must be studied in advance, this will help to perform all the work correctly and guarantee trouble-free operation of the equipment in the future.
No matter how simple the design of the chimney is, its installation must be carried out in accordance with the requirements normative documents. When installing coaxial chimneys, the following rules must be observed:
Only by fulfilling all the above requirements can you be sure of the quality of the system.
Why do most consumers today choose these designs? The answer to this question can be its positive qualities. The main advantage of a coaxial chimney is the possibility of air intake from the outside.
This allows you to maintain a good indoor climate without additional investment in ventilation systems.
Another plus in favor of this design is the heating of the air during the intake process, which completely eliminates heat losses and significantly increases the efficiency of the boiler. The last factor contributes complete combustion gas, which makes the operation of the unit environmentally friendly.
Watch the video, the operation of the system:
Design features allow to avoid heating of the outer surface of the pipe. This makes it possible to minimize the risk of ignition of facing materials located at the junction of the pipe and the wall.
Add to this:
If we compare the capabilities of a conventional design and a coaxial one, we can once again be convinced of its superiority. The only drawback is the high cost and expensive maintenance.
Installing a coaxial chimney does not take much time if you make a plan of action. Make sure in advance that the equipment of the unit corresponds to that declared by the manufacturer and take care of purchasing the necessary tools.
The cross section of the chimney must correspond to the diameter of the boiler outlet pipe. You can determine this from your passport.
The first step in installing the chimney is to prepare the hole in the wall. Its diameter must correspond to the pipe that is brought out.
Then the chimney is connected to the outlet neck of the boiler, using a clamp to fix it. Assembled structure bolted on both sides. Next, proceed to the assembly of the chimney itself. Its parts are connected to each other with clamps, in order to ensure their reliability. On top of them put on decorative lining. Their function is to preserve the design of the room.
No matter how simple the installation and arrangement of a coaxial chimney may seem, certain knowledge is needed to complete it. After all, with incorrect calculations of the system for removing combustion products, smoke, carbon monoxide may enter the premises.
Installation of this design can be performed in two versions:
The first is used if the building has already been built. Before proceeding with the installation, determine the place for the location of the system and for the chimney inlet.
On the outer wall mark where the exit will be located. When performing it, fire safety rules should be followed. After the hole of the required diameter is ready, proceed to the installation of the chimney.
For this, all preliminary interior work: connecting the pipe to the boiler using a sectional single-circuit elbow and a double-circuit tee. The latter is necessary to secure the system in a vertical position. Next, the chimney is reinforced with brackets on the wall surface.
Installation internal system begins with the correct selection of the pipe diameter. Usually its diameter is indicated in the product passport. The main thing is that it matches in size with the outlet of the boiler.
The connection of the unit and the chimney is carried out using a tee. In this case, the links are fastened by a chain (the lower ones must go into the upper ones). This design allows the smoke to escape unhindered.
Double-circuit pipes are connected using a transition node. The joints are fastened using clamps.
If the branch pipe is located on the side of the boiler, then a horizontal assembly is made for the chimney outlet. When the exit is from above, the chimney is displayed in a vertical position using brackets.
After all the installation steps have been successfully completed, you need to check:
Just making sure correct installation equipment, the hole in the wall is covered with decorative overlays. Their fastening is carried out on building glue or liquid nails. It is recommended to foam the hole around the chimney, this will prevent cold air from entering the room and the accumulation of condensate.
The coaxial exhaust gas exhaust system is a design that not only improves the characteristics of heating boilers, but also increases their efficiency.
Its installation can be done independently, with the necessary skills and knowledge. If you are not confident in your own abilities, then it is better to entrust this work to professionals.
After all, competent installation of a condensate drain is only possible for a specialist. So it's not worth the risk.
