How to install a coaxial chimney. Coaxial chimneys for gas boilers: what is it? Structural composition and material of the chimney

In society on this moment there was an opinion that safe and stable operation in the bathhouse depends solely on how correct the installation of the coaxial chimney is and where it goes outside. The truth is actually great importance has the output of waste harmful to the human body through a special coaxial chimney. Coaxial - "together along the axis." Its main advantage is that for the operation of the boiler, the air is not taken from the boiler room of the bath, but from the outside. Such a chimney differs from others in that it performs two very important functions at once. Firstly, it brings out flue gases. Secondly, it supplies oxygen to the boiler, which is necessary for its operation. Its structure is somewhat similar to a sandwich - "a pipe in a pipe", but through the external one it enters cold air, and through inner tube only hot products of combustion rise.

And the “burning out” of oxygen in the room is also bad because in such a situation the oven door is smoked, the fuel does not burn out completely, and a lot of soot collects in the chimney. Do you want to get rid of all this? Then let's figure it out together how to independently install a coaxial chimney in a bath.

Advantages of coaxial chimneys

Here's why such chimneys are good:

• Enough high efficiency, thanks to the strongly heated incoming air.
• Compactness - instead of two large pipes in volume, only one is obtained.
• No need for additional ventilation.
• Very high environmental friendliness.
• Safe for the human body air in the boiler room. In this case, the boiler takes already “its own” oxygen, specially supplied.
• Decrease in the price of diverting systems.
• A solution to a known problem with chimney condensate.
• Significant reduction in fuel costs for the bath.

Another advantage of a coaxial chimney: the incoming cold air perfectly keeps the walls from too much overheating.

But what certainly may not please is the risk of freezing of a pipe of too small diameter. This happens due to the fact that when leaving the chimney, the temperature of the flue gases is already very low - after all, it simultaneously heats the inner pipe. Therefore, the formation of condensate for coaxial chimneys is the norm. But only at a street temperature of about -15 degrees, which for Russian Federation quite normal, the pipe is able to freeze with all the sad consequences.

There is even an opinion that coaxial chimneys are absolutely not suitable for cold Russian winters - they were originally designed for latitudes southern countries. Therefore, they freeze. But some experts believe that such freezing is just the result of improper design of such a chimney, and nothing more. Nevertheless, the result is the same: burners, turbocharging and a galvanized chamber break quite quickly due to icing and freezing, and it is very expensive to repair them.

Nevertheless, as a rule, models are frosted over, in which, in pursuit of too high efficiency, the temperature flue gases comes close to the dew point. For this, the diameter of the coaxial chimney is reduced to a minimum. For various southern continents, this practically does not change anything, although in the cold Russian winter, with its not at all the lowest temperature of -15 ° C, the chimney freezes up almost to the stop of the boiler. Manufacturers generally answer this question like this: “We have not tested the system at these temperatures.” Thus, it is worth remembering that the narrower the coaxial chimney pipe, the less suitable it is for winter. Take note of this.

Coaxial chimneys, among other things, do not tolerate power outages and power surges quite well.

Which chimney to buy for a bath

There is no universal chimney for a bath. It is selected depending on the fuel used, the isolation of the boiler room, the power of the boiler, as well as the thickness of the walls. However, the arrangement of coaxial chimneys for various stoves is identical.

The pipes of coaxial boilers are usually made of plastic or aluminum. Both of them are of good quality. Only when buying, you should pay attention: inside such a chimney there are special jumpers that prevent two different pipes from touching.

But it is not advisable to design a coaxial chimney on your own. Although its design seems quite simple, however, any mistake can subsequently cost quite a lot. The literacy of its design in the Russian Federation is determined by special standards and laws. Understanding them is not easy at all. It is much better to buy a ready-made and high-quality chimney for the steam room with all the necessary certificates.

There are horizontal and vertical (for low-temperature mounted boilers) coaxial chimneys. This is what you need to take into account when buying them.

Such a chimney is installed in all gas boilers, and which have closed combustion chambers.

So, here's what you will certainly need to install a coaxial chimney:

• knee;
• flange;
• flue pipe;
• crimp collar
• boiler adapter;

It is necessary to install such a chimney at the smallest distance from the wall to the boiler, and all materials and objects that are too afraid must be completely removed from this zone. high temperature. It is also important to accurately determine the point at which the pipe will be led out into the street - it is desirable that it be approximately one and a half meters higher than the outlet of the chimney from the boiler. The hole should be made with a diameter of 110-125 mm - absolutely exactly along the pipe. Thus, the requirements for the location of such a chimney are much less stringent than for a conventional one.

Coaxial chimney through log walls baths are best carried out through a sleeve from a special asbestos-cement pipe, then clogged asbestos cord around the chimney - fireproof and quite practical. If for some reason the boiler is located far from the wall, then in this case it is necessary to increase the length of the chimney - the maximum is 3 meters. To do this, additionally purchase connecting elbows, and then stretch the places where the coaxial chimney is built up with a crimping clamp.

After installing the chimney, you need to close the hole in the wall with a decorative overlay exactly to the diameter of the pipe. Use liquid nails or construction adhesive for this. The hole from the street, as a rule, is foamed so that air does not enter the boiler room from the outside and does not create any condensate or drafts.

It is also worth saying that the coaxial chimney does not have to pass through the wall at all - today the schemes of various collective chimneys are quite successfully implemented.

Fire safety requirements for coaxial chimneys

Installation standards for a coaxial chimney:

• Half a meter horizontally to all open ventilation holes, doors and windows.
• One meter vertically to the windows, in case the chimney exits under them.
• Half a meter vertically to the windows, in case the chimney exits above them.
• Two meters from the ground level - regardless of whether someone walks on it or not.

And the last: when under the coaxial chimney is gas pipe, then the distance between them should be at least 20 cm. And the distance from the corner of the building in this case is no longer regulated - as you can, mount it.

The main advantage of a coaxial chimney is considered by most to be the absence of the need to equip auxiliary ventilation in the boiler room, but experienced stove-makers are absolutely sure that it is necessary. Such ventilation, at least, will definitely not be superfluous.

Coaxial - this word means the presence of one object in another. The coaxial chimney for wall-mounted gas boilers is built according to the "pipe in pipe" system. . The chimney is double circuit design, in which a pipe with a smaller diameter is located in a pipe with a larger cross section. Inside the pipes are interconnected only with the help of jumpers that do not allow them to come into contact.

Coaxial chimneys are used for heat generators with closed combustion chambers. Such heat generators can be not only gas boilers, but also convectors, radiators and others.

The coaxial chimney for a gas boiler performs 2 functions at once: it removes the products of combustion to the outside and provides an influx of fresh air, which is necessary to maintain the process of gas combustion in the chamber.

As a rule, for boilers that have a closed combustion chamber, the length of the chimney does not exceed two meters. It is worth noting that often the chimney is laid simply through the wall to the street. Very rarely, but you can find a vertical coaxial chimney brought out into the street through the ceiling and roof.

Advice! When installing a coaxial chimney, you should try to ensure that the pipes have only a horizontal orientation.

If the place in the wall where the chimney is supposed to be brought out is located next to the window, then it is better to bring the chimney out just above the roof. In this case, you will definitely have to collect a vertical section of the chimney.

The standard set of coaxial chimney for wall-mounted boilers contains the following components:

• straight pipes;
• tee;
• cleaning;
• condensate collector;
• upper tip of the chimney;
• knee (turning angle is 90 °).

Straight pipes are a direct chimney shaper. The elbow is intended for connection between the horizontal part of the chimney and the vertical part, as well as for connecting the horizontal chimney with a gas boiler.

If the chimney has only a horizontal orientation, then the kit includes the following items:

• a set of straight pipes;
• knee (turn angle 90°);
• side chimney cap.

At the moment, the industry offers coaxial chimneys for gas boilers in the following range:

• chimneys made of stainless acid-resistant steel;
• chimneys for gas boilers made of stainless steel;
• coaxial chimneys for gas boilers made of galvanized steel.

In addition, it is worth considering that there are chimneys that have various combinations, that is, the outer and inner pipes can be made of different steel.

Advantages of coaxial chimneys

The first and main advantage of coaxial chimneys is that the air to support the combustion process is taken not from the room, but from outside. A conventional stove takes oxygen from the room where it is installed, so it often has to be ventilated to get rid of the lack of fresh air.

The principle of operation of the coaxial chimney is slightly different (see). The combustion product enters the inner pipe, but fresh air flows through the outer pipe.

This design solves several problems at once, which are typical for conventional heating appliances and chimneys:

• The air that enters from the outside comes already hot, since it is heated by the inner pipe due to the passage of highly heated combustion products through it. This greatly reduces heat loss, and as a consequence, increases the coefficient useful action all heating system.
• The higher efficiency leads to natural gas burned completely. This contributes to the fact that particles of unburned fuel are not emitted into the atmosphere, this increases the environmental friendliness of the boiler.
• Equally important is the fact that the inner pipe, transferring part of its heat to the outer one, becomes not so hot. This is reduces the risk of fire at the point of contact between the pipe and flammable parts of the room (wallpaper, wood paneling and others).
• All heating processes, from the moment of receipt clean air and until the moment of removal of combustion products, they occur in a closed space - the combustion chamber. This is makes it more comfortable for the person, since there is no need to take care of additional ventilation of the room, into which smoke and carbon monoxide, that is, maximum security is ensured;
• The presence of a large range of pipe sizes - both external and internal, contributes to the fact that it is possible to choose a coaxial chimney for a gas boiler of any power.
• Small size, which is largely saves indoor space.

The advantages include the most simple installation. If a lot of difficulties arise during the installation of a conventional chimney pipe, then the installation of a coaxial chimney can be done independently. You can also talk about the relative ease of operation and maintenance of such a heating system.

Installation of coaxial chimneys

All the advantages that distinguish a coaxial chimney for a gas boiler, including safety and environmental friendliness, can be reduced to zero. This situation occurs when an incorrect installation of the coaxial chimney was performed.

Advice! Before you start installing a coaxial chimney, you should make sure that all necessary elements the chimney itself, as well as tools and other materials.

In order to carry out the installation of the chimney, it is required:

• coaxial pipe or several pipes;
• flue pipe;
• connecting adapter;
• lining on the walls - 2 pieces;
• flange for pads;
• connecting clamp;
• pipe tip.

The chimney is attached to the pipe heating installation and goes outside the room. If there are any obstructions, it is best to remove them before removing the chimney. In addition, if possible, flammable substances and objects should be removed from the pipe at a safe distance.

In any case, the installation begins with the choice of location. It is easier to do this when you have already decided on the choice of a place for installation for the boiler itself. It is better to mount gas boilers with a coaxial chimney together. The best option will be if the distance from the chimney to the boiler is approx. 1–1.5 m. If necessary, the length of the chimney can be increased, but so that there are no more than 2 elbows in total, but maximum length is equal to 3m.

Hole smoke channel should be placed in compliance with certain rules:

• distance from the ground - at least 2 meters;
• minimum distance from the door and windows - at least 50 cm

Further, as already noted, you need to remove everything superfluous from the chosen place to a safe distance. After that, you can begin installation by proceeding with drilling a hole desired diameter, which can vary from 11 before 12.5 cm.

Next, the pipe is connected to the outlet neck of the heating installation using a clamp, which is clamped with bolts on both sides. After that, the installation of the chimney of the required configuration is carried out. All connections are made with clamps. The chimney leaving the room should have a slight slope so that moisture (condensate) can easily be removed by itself.

After the chimney is installed, decorative overlays are installed, which perform only an aesthetic function.

Insulation of coaxial chimneys

Sometimes there is such a problem that coaxial chimneys for gas boilers freeze.

A simple solution seems to be just warming it (see). However, this does not help. It is for this reason that the insulation of coaxial chimneys is not practiced. The only way out of this situation is to reduce the size of the chimney itself.

If the tip freezes due to the fact that condensate enters the air intake pipe from the pipe with combustion products, then the length of the inner pipe must be reduced relative to the outer one.

by the most the best option there will be an option to install 2 separate pipes, the insulation of which has a much greater effect than the insulation of a coaxial chimney.

One of the most effective means for heating the house is a heating system connected to a gas boiler. Boilers using gas as fuel warm up quickly enough, support well temperature regime and inexpensive to operate. In addition, a good gas boiler often also provides water heating, which is very convenient and profitable.

An important component of the heating system, which allows the boiler to work, is a pipe that removes combustion products into the atmosphere. The removal of combustion products can be carried out by coaxial pipes for gas boilers, which will be discussed in this article.

Problems of conventional chimneys

As mentioned above, one of the main problems that arise when using gas heating equipment, is the removal of combustion products from the system. This is a serious drawback, and most other heat sources are not of this quality - and here you have to take care to remove carbon dioxide and carbon monoxide.

To remove these substances, chimneys are used, which may have different design and be created from different materials- metal, ceramics, bricks and many others. The installation and characteristics of the chimney directly depend on its purpose, design features and other parameters.

All chimneys that fit this description, in addition to advantages, have a lot of disadvantages. First, it is worth noting the problem associated with the removal and supply of air through one pipe - sometimes this leads to a deterioration in the system. However, this problem looks insignificant compared to the next one.

Secondly, any chimney eventually becomes clogged, as a result of which the draft in the boiler becomes much worse. If you leave a clogged chimney for a geyser in an apartment without attention, then at some point it will clog completely, and the heating system will stop working. In addition to stopping the heating, a clogged chimney also threatens that the products of gas combustion will enter the living room - and this should not be allowed in any case.

Installing a coaxial pipe gas boiler as a solution

The problems described above are quite unpleasant, but technology does not stand still, and the construction industry is no exception - coaxial pipes began to be used as chimneys. A coaxial pipe is a structure that includes two pipes, one of which is outside and the second, respectively, inside.

The inner tube has a smaller diameter - the standard value is usually around 60 mm. However, sometimes selected larger diameter coaxial pipe for gas boiler. It will not work to use a pipe with a diameter of less than 60 mm as a chimney - such a cross section is not enough for the efficient removal of combustion products. In addition, the small diameter of the chimney often causes complete clogging with various deposits, even taking into account the low susceptibility of the coaxial pipe to such a factor.

The outer pipe has a larger diameter - the average value for a 60 mm inner pipe is 100 mm. simple calculations allow us to say that the dimensions of the pipes are related in a ratio of 1: 1.5. A pipe with a diameter of 100 mm provides continuous air supply to the boiler. In addition, the outer shell is necessary to drain the condensate that is released on the inner pipe.

Regardless of the chosen sizes of coaxial pipes (and their configuration may differ significantly from standard values), the installation of a coaxial pipe of a double-circuit gas boiler is carried out using clamps and special fasteners. During installation, it is necessary to ensure that there is no direct contact between the two pipes - in fact, the coaxial nature of the design implies the presence of a two-axis mechanism.

Advantages and disadvantages of such a solution

Coaxial pipes in combination with gas heating equipment provide quality work the entire system. This is largely due to the positive qualities inherent in the type of chimneys in question.

The main advantages of coaxial pipes are as follows:

• Significant increase in the efficiency of the heating system;
• Safe and constant removal of combustion products;
• Good protection of the structure from clogging;
• Condensate is removed from the system through a safe circuit, and air enters the system through a separate pipe;
• Low probability of malfunction;
• Simplicity of a design at high efficiency.

All these advantages together greatly increase System efficiency generally. For example, a constant supply of fresh air through an external pipe provides the system with the oxygen necessary for combustion. The condensate is also retained on the outer pipe and gradually dries out, so inner part system is protected.

The condensation aspect is very important - most of internal damage he provokes the system. As a result of the release of condensate and the accompanying oxidation processes, solid deposits appear on the surface of the pipe, which subsequently need to be cleaned. The use of a coaxial pipe with its special characteristics makes it possible to significantly simplify the cleaning of the structure.

However, coaxial pipes have several disadvantages, including:

• High cost of materials;
• The standardization of pipes does not allow the creation of an individual configuration design;
• Installation of a coaxial chimney is very difficult to do on your own;
• During installation, it is necessary to comply with a number of safety requirements, which is far from always possible to do.

Requirements for the installation of coaxial pipes

To realize everything positive traits coaxial chimney, the following requirements must be observed:

1. The slope of the pipe from the axis should be about 3 degrees. This requirement will allow the system to independently drain condensate from the pipe. Otherwise, the removal of moisture will be too slow, as a result of which the system will become clogged and will not be able to perform its functions.
2. The outlet of the pipe should be located at a height of 1.5 meters from the ground and at a distance of 0.6 m from the nearest window.
3. During installation individual elements construction, it is necessary to use fittings, avoiding various artisanal methods of connecting pipes. In addition, it is undesirable to bend the pipe more than three times - an excessive number of turns reduces the strength of the structure.
4. The length of the coaxial pipe for a gas boiler can only be increased with the help of special sealants or mastics purchased from pipe manufacturers. Inappropriate materials can cause damage to the integrity of the chimney.

Installation of a coaxial pipe of a gas boiler, carried out in compliance with these requirements, will allow you to assemble a reliable and high-quality design.

Installation of a coaxial pipe

The installation of a coaxial pipe for a gas boiler belongs to the category of complex processes - the design is not simple, and the requirements for it are quite serious. In addition, you need to think in advance about how to install the pipe according to the simplest possible scheme, so as not to complicate an already problematic installation.

The process of installing pipes for different boilers is practically the same. For example, you can take a standard chimney, which includes pipes with a diameter of 100 and 60 mm (outer and inner pipes, respectively).

The installation algorithm for coaxial pipes is as follows:

1. First you need to prepare all the equipment and design the future design.
2. In all ceilings and obstacles through which the pipe will pass, it is necessary to drill holes, the size of which should be 10 mm larger than the diameter of the outer pipe. A 10mm tolerance is required to install fasteners.
3. The base is connected to the outlet of the boiler. For most boilers, the outlet is on the top, so there should be no problems.
4. Next, the lower part of the pipe is installed. Its fixation is carried out with the help of clamps and fittings.
5. After installing the first segment, you can proceed with the installation of the remaining elements of the coaxial chimney.
6. Pipe joints must be treated with sealant or similar material.
7. Final stage- checking the system for operability, for which you need to conduct a trial run.

It is necessary to connect the pipes tightly and with high quality - its operation depends on how well the sections of the chimney are connected. The outer and inner pipes must be located on the same vertical axis and strictly parallel to each other - any contacts are not allowed. As practice shows, a small displacement occurs during operation, but it is insignificant and does not affect the performance of the system.

The number of fittings and elbows is best kept to a minimum. According to the requirements, 3 fittings or 2 elbows can be installed on a three-meter pipe section, but this is the maximum allowable number - the less various connections, the more reliable the design will be.

Conclusion

Installing a coaxial pipe for a gas boiler is quite complicated, but in the future it pays off with the efficiency of the heating equipment. When designing and installing, it is necessary to take into account all the nuances and approach the work with all care in order to create the most reliable and high-quality design.

Coaxial chimneys for wall-mounted gas boilers in recent times have wide application for modern heating equipment. This is perfect solution for a private house in the absence of a chimney in it, as well as for apartment buildings having a common riser for smoke removal.

Simplicity of design and aesthetic appearance do coaxial chimney indispensable for correct operation gas wall-mounted double-circuit or single-circuit boiler. Let's take a closer look at its features, principle of operation, requirements for installation and installation of this design.

Coaxial chimney for a gas boiler: what is it and where is it used

Coaxial chimney is used for heating with forced draft. The boiler itself must be turbocharged, i.e. have a built-in fan for ejection of combustion products. The very concept of "coaxial" means coaxial, i.e. chimney "pipe in pipe". Air flows into the boiler through the outer pipe, and exhaust gases into the atmosphere through the inner pipe.

The diameter of these chimneys is usually 60/100. Its inner tube is 60 mm, and the outer tube is 100 mm. For condensing boilers chimney diameter: 80/125 mm. The material of execution is steel, painted with heat-resistant enamel white color. We are watching standard equipment according to the photo scheme.

There is also such a thing as an insulated coaxial chimney. This is the same coaxial chimney, only outer pipe It's made of plastic, not metal. Or the second option: when the inner pipe is slightly longer than the outer one. This is done specifically so that condensation does not form on the outer pipe. This type of chimney is a little more expensive, but not much.

A coaxial chimney can be made up of several elements:

– coaxial pipes (extensions) of different lengths from 0.25 m to 2 meters;

- coaxial knee (corner) at 90 or 45 degrees;

- coaxial tee;

- a pipe tip, sometimes an umbrella;

- clamps and gaskets.

Manufacturers of coaxial chimneys for gas boilers

When buying a wall-mounted gas boiler, you will be offered to immediately buy a coaxial pipe for it. In a normal, standard situation, a coaxial kit is sold for horizontal system smoke extractor, which includes: a 90 degree elbow, a 750 mm extension with a street end, a crimp collar, gaskets and decorative inserts.

If you have a slightly different case, then all other parts and elements can be purchased separately. These elements are universal for almost any manufacturer of wall-mounted gas boilers.

The first element is an exception; it is either the first elbow or the first pipe from the boiler. The fact is that each manufacturer of boilers has its own characteristics of the seat. This applies to branded (native) coaxial chimneys.

But there are times when pipes are not available for a certain brand of boiler or they are very expensive. For example, a branded coaxial kit for a German boiler costs about 70 euros. In such cases, you can consider buying its counterpart.

Analogues of manufacturers of coaxial chimneys

These kits are universal seats, and holes for mounting the starting elbow (outlet) coincide with most manufacturers of gas boilers on the Russian market.

Coaxial chimney "Royal Thermo"

Another manufacturer on the market of coaxial pipes and elements for them is the company " Grosseto».
Their chimneys are universal and suitable for boilers of the brands Ariston, Vaillant, Wolf, Baxi, Ferroli, as well as Korean and Korea Star.

The main advantage of universal analogues of coaxial chimneys is their low price. It differs from branded kits by two or even three times.

Installation and installation requirements for a coaxial (coaxial) chimney

The coaxial chimney can be installed in three versions:

— horizontally with an output to the street;

- horizontally with an output to the shaft ( apartment heating);

- vertically with an output to an existing chimney.

The most common way to output a coaxial chimney is the horizontal variant with an output to the street.

Coaxial chimney to the wall

1 - coaxial pipe with a tip;

2 - knee coaxial;

4 - coaxial pipe (extension);

For correct installation coaxial chimney there are a number of requirements

1. The total length of the chimney should not exceed 4 meters.

2. Only two turns are allowed, no more than two knees.

3. The minimum distance from the pipe to the ceiling and walls made of non-combustible material should be 0.5 meters.

4. The horizontal section of the pipe should be made with a slight downward slope towards the street.

These must be done so that the resulting condensate does not flow into the boiler, but goes outside.

Separate chimney systems for gas boilers

Another popular way to remove combustion products from turbocharged gas wall-mounted boilers is a separate smoke exhaust system. What is it?

There are cases when, for one reason or another, it is impossible to remove a coaxial chimney. For this, a system was developed, consisting of two separate pipes: one for the emission of gases, the other for air suction into the boiler. See installation diagram.

Separate chimney for the boiler

As a rule, the diameter of such pipes is 80 mm. Execution material — steel. In some cases, the air suction pipe is replaced with a flexible aluminum corrugation, which stretches up to 3 meters.

In order to install a separate chimney on a gas boiler, you need to buy a special adapter - a channel separator. It is installed on top of the mounted boiler and converts the pipe-in-pipe outlet into a separate one, on which the pipes are then mounted.

Some manufacturers, for example, the same Navien, took care of consumers in advance, and produce wall-mounted gas boilers with already installed system for separate pipes. This is a purely Korean version of the boilers, designated under the article "K". A boiler with such a system will have the name "Navien Deluxe-24 K", where 24 is its power in kW.

Installation of a boiler with a separate chimney system

Pipes can be displayed in 3 versions:

- both pipes in one wall;

both pipes in different walls;

- one pipe into the wall, the second - into the existing chimney.

Which of the methods of smoke removal is suitable for your home should be decided by the design organization. According to specifications, they make up individual project for every home.

It prescribes the design of the gas boiler (floor, wall), its maximum power, as well as which pipes should be installed: separate or you need to buy a coaxial chimney for a gas boiler.

The only thing they can't decide for you is the brand of the boiler. No one can force you to buy a model from a certain manufacturer. Here, the choice is yours alone. Let's watch the video.

When installing any heating boiler (with the exception of an electric one), it is necessary to take care of the smoke exhaust system and the supply of oxygen, which is necessary to maintain the combustion process of the fuel. Boilers with a combustion chamber closed type can be installed in any room. Wherein classical scheme extracts of combustion products are completely useless. A coaxial chimney is enough. In this article, we will consider all the rules for installing a coaxial chimney for a gas boiler.

Design

The meaning of the word “coaxial” itself means “coaxial”. These are two tubes inserted one into the other and brought out. From the inside, the pipes do not contact each other due to the system of jumpers.

The reason for this is the different purpose of the tubes:

• Small - designed to divert products formed during the combustion of fuel.
• A large one is needed to supply air, and therefore oxygen, to the combustion chamber.

In doing so, it turns out that Fresh air and combustion products do not mix with each other. Such a system is reliably isolated, and the air from the room does not mix with the gases in the chimney.

Important! The most common coaxial designs horizontal, although, in principle, it is possible to equip a vertical chimney.

Advantages

The main advantage of this design is its versatility. It can be used for all types of heating boilers. Maximum effective work is the installation of coaxial chimneys for gas boilers with closed camera combustion and forced draft. The boiler itself can be wall or floor type.

Here are some more benefits:

• Location is horizontal. There is no need to punch a hole in the roof. It is enough to bring the pipe out the window or make a hole in the wall closest to the boiler.
• The flue system is isolated and not connected to the air in the room. There is no risk of carbon monoxide penetration into the room.
• The air that enters from the street comes to the combustion chamber already heated, due to the fact that it comes into contact with a hot chimney. This improves the efficiency of the boiler.
• Ease of installation of a coaxial chimney. Work on its arrangement does not require special skills and special knowledge.
• Security. The coaxial gas duct is reliably protected from the risk of fire, since the system is cooled by relatively cold air from the street.
• No need for equipment a separate room boiler room. Any place convenient for you - kitchen, hallway, annex or basement suitable for boiler installation.

Rules for installing a coaxial chimney for a gas boiler

If the arrangement of a coaxial smoke exhaust system is planned, it is necessary to adhere to the installation and safety rules. This will avoid even the smallest risks associated with the ingress of exhaust gases into the room:

• The maximum length of the outlet vertical tube in a coaxial chimney is 3 m. Sometimes you can find chimneys of a greater (up to 5 m) length. For example, this applies to the installation of a coaxial pipe of a double-circuit gas boiler Ferroli floor standing type.
• The pipe is brought to the street horizontally. In this case, the maximum length of the horizontal section is 1 m.
• When installing forced fan draft, there is no need to equip a vertical section.
• The height of the gas flue outlet above the ground is from 2 m, and relative to the boiler unit, the excess value is from 1.5 m.
• The minimum distance of the chimney pipe outlet from any window or door opening, as well as ventilation grilles is 0.5 m.
• It is undesirable to equip the outlet of the coaxial flue pipe under the window. But if you cannot do without it, the minimum distance between the chimney outlet and the window is 1.0 m.
• A slight inclination of the pipe ensures the removal of condensate.

Chimney slope

There is no consensus on this issue:

• The most common recommendation is to slope the pipes “away from the boiler”. In general, this is quite logical. The condensate formed during the operation of the boiler flows out, and does not enter the boiler. However, such a system works flawlessly until the onset of severe frosts. In winter colds, the condensate flowing down simply freezes, sometimes even inside the pipe. All this worsens the air intake for the fuel chamber.
• You still have to make a decision to make the slope of the pipe towards the boiler. To solve the problem of condensate entering the boiler, an additional condensate collector is installed.

Do you insulate the chimney?

The fact is that the insulation of the gas flue pipes does not solve the problem. The condensate still freezes. This problem can be more effectively solved by shortening the inner tube a little. Naturally, this is true if the pipes are tilted away from the boiler.

Mounting order

Unlike the usual vertical chimney, the coaxial system does not require any professional skills during installation. But at the same time, you must strictly follow the instructions. This is the only way to achieve complete security.

Installation of a coaxial chimney for a gas boiler is performed according to the following algorithm:

• Determined with the location of the boiler. wall models located on the outer walls, floor - on a small elevation.

Important! Exceeding the outlet on the wall above the boiler, in accordance with the rules, is 1.5 m or more. The diameter of the hole in the wall should be slightly larger than the diameter of the outer pipe.

• Install a special element for connecting the chimney to the boiler. All joints and turns are fastened with clamps. Under no circumstances should sealants or adhesive tapes be used.

Important! The number of swivel elbows for the entire system should not exceed 2.