Coaxial chimneys for gas boilers vaillant instruction. Choosing a two-channel coaxial chimney for a gas boiler, installation tips

23 May 2014 Alexei

The use of modern boiler equipment is impossible without a system for removing combustion products. It is necessary for the efficient operation of the 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 ideal solution there will be a coaxial chimney device. In this article, we will look at what this design is and how to install it.

Purpose and types of coaxial systems

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:

And stainless steel
Galvanized

Depending on the installation method, they are divided into:

Internal
External

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.

Installation rules

No matter how simple the design of the chimney is, its installation must be carried out in accordance with the requirements of regulatory documents. When installing coaxial chimneys, the following rules must be observed:

The outlet is made 1.5 m above the gas boiler and not lower than 1 m above ground level
If it is necessary to build up the pipe, its length should not exceed 3 m, while the use of sealants and other similar materials is prohibited.
Horizontal installation is carried out with an inclination angle of 3 degrees
Do not use more than 2 knees
Between the chimney and the nearest opening in the wall, a distance of 60 cm is allowed

Only by fulfilling all the requirements listed above can you be sure of quality work systems.

Benefits of using

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 latter factor contributes to the complete combustion of 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:

Wide choice of diameters
Ease of installation
Compact size

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.

Where does the installation start?

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.

Assembly without errors

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. The assembled structure is 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 can enter the room.

Installation of an external chimney

Installation of this design can be performed in two versions:

outdoor
internal

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 doing so, follow the rules fire safety. 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.

Checking the functionality of the design

After all the installation steps have been successfully completed, you need to check:

Reliability of fastening of the connecting parts of the chimney
The correct position of the flue pipe (it should be slightly inclined)
The absence of barriers at the exit point of the structure to the outside

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.

It is important

The coaxial exhaust gas exhaust system is a design that not only improves the characteristics of heating boilers, but also increases the efficiency of their work.

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.

The German company Vaillant, which specializes in the production of systems autonomous heating, has always been one step ahead of its competitors, offering consumers the latest technological solutions. She managed to achieve incredible success in a variety of niches in the market for household heating equipment, including in such a specific area as the production of exhaust gas systems.

Today, Vaillant, being one of the industry leaders, is actively developing the direction of coaxial chimneys - a new global trend. In this article, we will take a closer look at one of the latest developments of German engineers - the Vaillant 60x100 coaxial chimney, which is designed for units with a closed combustion chamber.

The design is made in the classic "pipe in pipe" format, which ensures efficient intake of fresh air and rapid removal of exhaust gases. The Vailant coaxial chimney provides complete isolation of the processes of air supply to the furnace and smoke removal. The installation of such a chimney not only helps to maintain the optimal level of humidity and oxygen in the room, but also increases the coefficient useful action boiler by a few percent.

The principle of operation of the Vaillant chimney, with all the perfection of the design, is quite simple. The pressurized burner, which is located in the boiler, exhausts the exhaust gases into the street through the inner pipe, and fresh air is sucked in from the combustion chamber through the outer pipe of a larger diameter.

This design is compact and easy to operate and install. The Vaillant smoke extraction system is no match for a traditional chimney. A coaxial pipe can be installed absolutely in any room, and quickly enough. To install a chimney in an apartment, you need to make a small hole in the wall for the unhindered removal of gases.

The versatility of the German coaxial chimney Vaillant is noted by many experts. It can be installed both on the right and on the left side of the boiler.

What is included in the installation kit? It includes:

Elbow 90 degrees with a flange for aggregation with a boiler and specially provided holes that make it possible to take a sample of combustion products;
750 mm section of the coaxial chimney;
Cuffs for decoration of the interwall passage;
Mounting kit for the installation of self-tapping screws, gaskets and clamps.

The Vaillant brand coaxial chimney is used for the horizontal removal of exhaust gases and the rapid flow of air into the combustion chamber. The total length of the structure is 1 meter.

Results

If you do not have the opportunity to equip a full-fledged exhaust system, this does not mean that your only choice is an electric water heating boiler. Today the installation of a gas or solid fuel boiler requiring additional installation of a gas exhaust system is possible in any room. In resolving this issue, the Vailant coaxial design, which has proven itself among European consumers, will help you.

Updated:

2016-08-15

It is no secret that one of the main components of comfort in the house is the warmth in it. A coaxial chimney will serve as a faithful assistant to solve the problem in private homes. This boiler fume extractor is an effective replacement for aging traditional chimneys.

The device of a coaxial chimney (hereinafter referred to as CD) involves a design of a pair of pipes arranged according to the principle of a nesting doll. The contours of the pipes are connected by jumpers. The design itself is designed to work with closed-type heat generators. An example of such is geyser. inner pipe the removal of combustion products is ensured, while the external one serves to supply air from the outside. This allows you to forget about the constant ventilation of the room. The price justifies the means, because boilers with CD, especially from the well-known company Baxi, are much more efficient than traditional ones, and at the same time their maximum length does not exceed 2 m in length. Most often, KD is taken out into the street through a hole in the wall. Much less common is a vertical coaxial chimney leading to the roof.

In addition, there are a number of problems that the installation of a coaxial chimney successfully resolves:

the compactness of the device allows you to save a lot of space;
an impressive selection of CD models for systems of various capacities, the price of which may surprise no less than their quality;
ecology and economy: due to the high efficiency, the system not only ensures complete combustion of fuel, but also reduces heat losses (due to heating the air entering through the outer pipe with hot smoke in the inner one);
the risk of ignition of surfaces in contact with the coaxial chimney is significantly reduced (due to constant cooling of the inner pipe);
after installing a coaxial chimney, additional ventilation of the room will not be required; the design eliminates the possibility of poisoning residents with carbon monoxide, whether it be systems from Baxi or from other manufacturers.

Where does the installation of coaxial chimneys begin?

Before installing a coaxial chimney, you first need to select the type of system - vertical or horizontal (including at an angle). The price here is about the same, but it should be noted that the latter option requires the installation of forced ventilation with the device. In addition, the horizontal section of the appliance must not exceed 3 m in length. A vertical AC is recommended if smoke will enter nearby nearby windows or into a narrow street. Always follow the diagram and instructions from the manufacturer (Baxi, Ochag, etc.) for a specific system, which describes in detail the installation rules.

For example, the ratio of the size of the boiler to the diameter of the outlet pipe matters, they must be equal in order to avoid overheating of the channel. And so that the combustion products come out unhindered, pipes, tees and elbows are fastened by a specialist. With your own hands, it is better not to perform the installation of a CD without having the experience of installing a coaxial chimney. Mounting a vertical CD is easier, the main thing is to stock up on brackets. The coaxial pipes themselves are connected into a system using a special transition node. At the joint site, clamps are used that securely fasten the elements.

Chimney outlet and finishing work

The price of success is the accuracy of installation. When removing the branch pipe from the side of the heating device, there should be a horizontal section of the CD. In this case, the level of the branch pipe must exceed the level of both the boiler and the street by 1.5 m or more so that the CD does not become contaminated. The angle of inclination of the outlet pipe is set from 3 degrees. So condensate will not fall back into the boiler. The opening of the branch pipe should be 60 cm or more from the window, and half the diameter of the pressure vessel from the gas pipes. In order to circle the device around an obstacle, you can use up to two differently inclined knees. The joint between the wall and the pipe must be insulated with non-combustible materials.

If the branch pipe is displayed vertically on the roof, fire safety requirements must be taken into account. Use fire-resistant insulation, insulating pipes and special protective covers for the flue duct. The pipe and the ceiling must be separated by an air gap. The outlet itself must be covered with a special apron that isolates the joint.

If the working CD is always cool, even when the geyser is working intensively, then the installation is done correctly. However, everything has its price: in cold climates, the device can freeze. As a rule, this happens when it is horizontal. In this case, you should contact the office of Baxi or another manufacturer supplying heating products to purchase special protection.

Conclusion

To feel the desired comfort in the house, sometimes it is enough to know what a coaxial chimney is and how it is installed. Literally in a few days, as if by magic, the home will be transformed, and life will become even more beautiful. The installation of a coaxial chimney is also done by one's own hands, however, if there are reasonable doubts about one's abilities, it is better to hire an experienced specialist.

Coaxial chimney - new technical solution, which replaced the standard chimneys. A feature and a big advantage of this device is that oxygen for combustion in the boiler furnace is taken from the street, and not from home.

Coaxial chimney designs

Chimneys are used for different types boilers:

B - chimneys for boilers with an open combustion chamber;
C - chimneys for boilers with a closed combustion chamber.

In high-rise buildings, you can find a variant of a collective chimney, to which individual boilers are connected. This chimney goes to the roof

Coaxial chimneys are mounted in two positions:

vertical;

horizontal.

Only the installation method differs, but the principle of operation of the chimney is the same. Like everyone else engineering systems It has both advantages and disadvantages. Let's consider them.

Advantages

Structurally, the chimney consists of two pipes, one plays the role of an outer shell, the other is an inner one. Through a pipe of smaller diameter, combustion products are discharged - exhaust gases. Air enters the combustion chamber of the boiler through the outer pipe to maintain combustion. This system provides a compact and aesthetic appearance, takes up little space. The system provides heating of the incoming outdoor air with exhaust gases - this increases the efficiency of the boiler.

Another important advantage of this system is its fire safety. When flue gases are removed, they are cooled by air that enters the combustion chamber of the heat unit, reducing the risk of fire to zero. Additional insulation of the chimney with flame-retardant materials is not required.

A similar chimney system can be installed on different types boilers:

on gas;
on liquid fuel;
on solid fuel.

Disadvantages of a coaxial chimney

Freezing. This is probably the main and most serious drawback when installing a horizontal chimney.

The first models of coaxial chimneys that appeared on the Russian market were not designed for such low operating temperatures - -15 - -30 ° С. They are designed for countries with milder climates. As a result - the possibility of freezing of the chimney and failure of the heat unit.

Although not all experts are so categorical. In their opinion, main reason freezing of the coaxial chimney is an incorrect thermal calculation. In this case, the efficiency of the boiler depends on the supply air temperature. In pursuit of increased efficiency, designers reduced the diameter of the exhaust pipe. In this case, the temperature of the flue gases drops below the dew point, which leads to an increase in the formed condensate inside the exhaust pipe and freezing. To reduce the effect of this factor, it is necessary to increase the flue gas temperature by increasing the pipe diameter. A properly selected coaxial chimney should not freeze over.

When installing a vertical coaxial chimney, we face the problem of collecting condensate. Since the problem is known to all manufacturers, models of coaxial chimneys designed for vertical installation are equipped with a condensate trap.

Rules for installing a coaxial chimney for a gas boiler

When installing a coaxial chimney yourself, you must read the manufacturer's instructions. Be sure to follow the rules for installing a coaxial chimney.

During installation, use only materials and components that have been tested by the state gas supervision; it is forbidden to make any changes to the configuration and design of the chimney.
During installation, it is forbidden to use materials not from the manufacturer of the chimney; the necessary additional components must be purchased only at service centers.
All parts of the chimney are firmly connected and tested for flue gas leakage.
The use of sealants and adhesives is prohibited.
It is forbidden to join pipes in the thickness of the wall; it is necessary to provide a junction outside it.
A horizontal coaxial chimney is installed (unless otherwise specified by the boiler manufacturer): for condensing boilers 2-3° towards the boiler, for classic 2-3° to the outside, to ensure condensate drain and prevent precipitation from entering the boiler.
The length of the coaxial chimney depends on the model of the boiler, the complexity of the chimney route and ranges from 1 to 7 m (the maximum length for a straight installation for a boiler with a turbine installed, with a power of more than 30 kW.).
It is forbidden to equip the exit of the coaxial chimney below ground level into the window pit of the basement.
Remember, for breakdowns and accidents during the operation of the chimney, the installer is responsible.

Coaxial chimney installation diagram

The exit of the coaxial chimney through the building envelope must comply with a number of rules and requirements. Since type C boilers have a closed combustion chamber, they can be installed in all types of premises. Regardless of the presence of windows of the ventilation system and the volume of the room itself, it is necessary to adhere to several norms. The photo shows the requirements for installing a coaxial chimney in different versions:

a - the minimum distance from the axis of the chimney to any opening element of the facade of the house;
b - minimum distance from the axis of the chimney to any air intake;
c - the minimum distance to the sidewalks (to reduce the distance, a grate with a deflector is installed, in this case the distance will be 0.15 m);
d - minimum distance from the ground;
e - minimum distance from the axis of the chimney to the wall at an angle of 90 ° with opening elements or air intake openings; (0.15 m in the presence of a deflector);
f - minimum distance from the axis of the chimney to the wall at an angle of 90° without opening elements;
g - minimum distance to green spaces;
h - minimum distance to the drainage system or vertical pipeline.

Choosing a coaxial chimney

When choosing a coaxial chimney, first of all, you need to pay attention to the recommendations of the boiler manufacturer. There were cases when the service center did not accept equipment for warranty through the installation of a coaxial chimney that was not recommended for this boiler.

A coaxial chimney must ensure not only the removal of flue gases, but also fully ensure the intake of oxygen from the street, so the reliability of its operation is very important. You should choose from proven foreign brands: Baxi, Vaillant, Navien, Ferroli, Ariston, Viessmann.

Coaxial chimney Baxi

Chimneys are made of stainless steel and high-strength polymeric materials. The standard kit includes a chimney pipe 1 meter long, a 90° elbow, a wind protection nozzle, and decorative rings. If you need an extension cord, please purchase it separately. It should be noted that for a chimney up to 1 m long, it is necessary to install a narrowing diaphragm on the boiler air duct. The procedure is carried out to compensate for draft, since the boiler fan is designed for the maximum length of the chimney (5m), and in the absence of a diaphragm, a large amount of air will enter the combustion chamber, which will lead to a decrease in the efficiency of the boiler. To protect against freezing, the coaxial pipe should protrude from the wall by the length of the tip, no more. If the length of the pipe is longer than necessary, the excess is cut off from the inside.

Photo of the main coaxial chimneys Baxi:

Chimney coaxial Vaillant

Vaillant completes boilers own production coaxial chimneys. Compliance with the dimensions of the nozzles is the key to the successful operation of the boiler. Also, Vaillent coaxial chimneys can be purchased for boilers from other manufacturers.

Navien coaxial chimney

Navien smoke exhaust systems from a Korean company have proven themselves well in the heating equipment market. Chimneys are produced for wall-mounted and floor-standing boilers with a power of up to 75 kW. The cost of Navien coaxial chimneys is slightly lower than its European competitors, while the quality of workmanship is not inferior to them.

Coziness and comfort in the house creates warmth. And in our time there are many ways to heat housing. In multi-storey buildings, heating is central, but the owners of private houses prefer various boilers that directly require a chimney. Through it, the smoke will go out into the street, and not into the living room. Standard pipes are being replaced by more advanced and compact ones.

The coaxial chimney is the latest system with increased level security. It is designed for many gas boilers. The baxi coaxial chimney is especially popular. Let's take a closer look at what a coaxial smoke exhaust system is, with its device, installation standards.

What is a coaxial chimney?

This question is asked by many owners of heating boilers. A coaxial chimney is a design that is assembled according to the “pipe in pipe” principle and is used in heaters, such as: gas boilers, convectors, radiators with buried combustion chambers. The uniqueness of such chimney channels is that this design is assembled from several parts that are inserted into each other and held due to the fact that there are specialized jumpers inside this device. They do not allow parts to touch and slide off.

The advantage of these models of chimney channels is that the cold air currents that are needed for draft penetrate through the outer pipe from the street, and not from the room. Also, coaxial-type chimney channels solve several of the most important issues in heating at once:

safety during the operation of the chimney is increased due to the flow of cold air through the outer pipe, which cools the inner one;
carries out the supply of oxygen, which is simply necessary for combustion and the output of burning;
the efficiency of heating devices increases due to the heating of cold air flows against a heated exhaust pipe;
good efficiency increases the degree of environmental friendliness of heat generators and improves afterburning of gas fuel;
the entire work process is carried out outside the room, which increases comfort in it when heated by a gas boiler;

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they reduce the consumption of combustible material and increase the efficiency of the heating system as a whole due to full combustion;
at low weight and affordable price they have high refractoriness and high quality steel. Especially these qualities are known for the coaxial chimney for the baxi gas boiler;
they have a special drain for condensate;
the risk of fire is reduced to zero, because due to constant circulation, the air temperature in the chimney is reduced to a safe temperature.

Equipment with such a chimney is ecological, as they do not allow the remnants of unburned particles to fly out into the street and enter the atmosphere.

Advice! They are great for houses, as they provide comfort and safety to the owners of even wooden houses due to their construction.

For the current situation in the field of heating, an urgent issue is the arrangement of the selected type of equipment. An important point is a chimney for a gas boiler in a private house or apartment. Today there are a number of products suitable for this purpose, so it is important not to make a mistake in choosing. To do this, you need to take into account specific conditions and comply with established requirements.

Types of coaxial chimneys

They are divided into two types: insulated and non-insulated. The first of them is most adapted to winter conditions and is successfully used throughout Russia.

They are divided into three types by installation:

vertical coaxial chimney. Can be used if it is not possible to bring the chimney through the wall;
horizontal coaxial chimney. It is installed when installing forced ventilation of the boiler. The maximum length of the horizontal section is limited. It should be no more than three meters, but still manufacturers set their own limits. Before designing a structure, it is necessary to study the characteristics of the device to be installed;
inclined coaxial chimney. The rarest installation option and only be used when the other two options cannot be used.

For each boiler, the direction of the chimney is individual.

Installation Requirements

The coaxial chimney, the installation requirements of which are indicated in the passport for each device, is individual, but there are also general ones. Among them:

To assembly work should be carefully prepared. First you need to choose the right section. It is necessary to carefully study the passport for the boiler and the instructions from the manufacturer, which should contain information about the required length of the chimney;

Advice! If it is not specified, then you should focus on the generally accepted framework. In the very the best options the length of the flue duct must be at least five meters.

in order for the draft in the chimney to be better, it should be installed slightly higher than the roof ridge;
they must be installed very carefully and carefully fastened. If the chimney duct is installed incorrectly, leakage or smoke may enter the heated room;
the outlet channel, with the correct installation of the chimney, must be larger in diameter than the outlet from the boiler;

Advice! Before installation, it is necessary to check the data with the technical passport for the chimney channel in the field - diameter. This will help avoid mistakes.

the heating device must be installed one and a half meters lower than the outlet pipe of the flue duct, while the pipe entry must have an angle of at least three degrees. This arrangement ensures unhindered condensate drainage.
The chimney inlet must be located at a height of at least a meter and a half from the floor. This will keep it from getting dirty.

Advice! If false chimney systems are being installed, its length should not exceed three meters. This will allow the smoke to freely enter the outside.

Required fasteners

The list of elements required for assembling a coaxial flue duct will depend on where the smoke outlet will be installed: from the side or from above. For the first case, a horizontal assembly of the structure will be required, in the second case, the withdrawal of the chimney channel will be much easier. To bring the outlet to a vertical position, brackets of various modifications and clamps for fixing the joints will be required.

Important! It is strictly forbidden to use sealant and homemade adapters for fastening, as this is unsafe and can lead to incorrect functioning of the system.

At right choice elements installation will not require much time, and the system will serve for a long time.

Features of Baxi chimneys for boilers

Baxi is one of the most famous companies in the production of heating systems. It manufactures chimneys from high quality polypropylene.

The coaxial chimney for the Baxi gas boiler has such characteristics as: reliability and lightness. They are manufactured by the manufacturer in two types of diameters: 100/60 mm and 125/80, while the size of the chimney protrusion is 350 mm. This type is suitable not only for the southern, but also for the northern regions of Russia. They prevent the formation of internal frost at low temperatures. temperature conditions. Baxi chimneys have an elongated head and protection design, which allows them to work without interruption at fifty degrees below zero Celsius.

Video: tips for installing a coaxial chimney

Coaxial chimneys are a new step in the creation of modern heating systems for private houses. They are environmentally friendly, safe and comfortable, and easy to install. When choosing, it should be borne in mind that some of them are not designed to work at low temperatures, so residents of the northern regions are best to pay attention to the heating system from Baxi. Providing heat at home with the advent of such a system will become easier.