Heating system V Lately becomes not only a necessary condition living in a private house, but also a way to provide comfort and savings Money owners of living space in multi-apartment buildings. The increased demand for heating devices has become the reason for the development of more powerful and efficient models. Modern equipment places increased demands on the safety of connection and removal of combustion waste through chimney ducts. For this reason, a coaxial chimney has come into use for gas boiler, the device of which is fundamentally different from the usual one.

Device and functions

A coaxial chimney is a smoke removal channel, the design of which consists of two pipes different diameters, inserted one into the other. Internal surfaces pipes do not touch each other, between the contours there is air gap. A coaxial chimney is assembled from additional elements: straight pipes, bends, tees, condensate collectors. It performs two main functions:

Important! This device is designed on the principle of dividing the function of the chimney. This allows for increased productivity and efficiency. Fuel combustion products, the temperature of which is quite high, heat the external circuit. And the outer pipe through which it passes atmospheric air, in turn cools the internal one. Thanks to this design, the temperature in the chimney is equalized, which prevents condensation and reduces the risk of fire.

Advantages

The coaxial chimney is considered more advanced and effective way removal of combustion products from the furnace of the heating device. Elements for assembly are often supplied with the equipment. Most manufacturers recommend installing their products with chimneys of this type, as they have the following advantages:

Important! The coaxial chimney is suitable exclusively for gas boilers with a closed firebox and forced draft, operated by a small fan built inside the pipe. The design of a smoke removal system of this type must include a condensate collector and an inspection through which the pipe is cleaned.

Installation safety requirements

According to statistics from the Ministry of Emergency Situations and manufacturers, coaxial smoke exhaust ducts are considered safer and more efficient. However, when installing them, certain requirements must be observed:

Note! Professional builders arguing about the effectiveness of using coaxial chimneys on the territory middle zone Russia and more northern regions, claiming that they were developed for use at temperatures down to -15 degrees. Where in winter most of the time the temperature drops below this mark, they freeze. Manufacturers explain the problems by incorrectly calculating the diameter of the outer and inner pipes and the length of the chimney.

Installation

Unlike traditional methods of smoke removal, a coaxial type chimney is simply installed. To complete the installation, you must strictly follow the gas equipment manufacturer's instructions and requirements. fire safety. Experienced craftsmen We advise you to pay attention to the following points:

Video instruction

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

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

The principle of operation of a coaxial chimney

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

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

SNiP for installation

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

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

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

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

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

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

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

Coaxial chimney Ariston
Chimneys Ariston Italian made Suitable for most modern boilers. They also come with sealing gaskets and wall trims.

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

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

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

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

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

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

IN modern devices heating can be used various elements. Their composition depends on the type of coolant and heating method. A mandatory component of such installations is a chimney, which is responsible for removing smoke and other combustion products from the room. Let's figure out what it is - a coaxial chimney for a gas boiler and what its advantages are. When installed correctly, such a design not only eliminates burning and smoke, but also provides a flow of fresh air.

This is what the design for removing combustion products looks like

Design coaxial chimney for a gas boiler is not so difficult. It consists of two pipes various diameters, which are installed into each other. In this case, a gap of several centimeters is left between the walls.

There are two types of similar chimneys:

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

Works coaxial installation like this: air is taken from the street through an external pipeline, then it moves through pipes and heats up. The air is supplied to the firebox already heated, which reduces gas consumption. Smoke is removed from the inside through a channel. Certain devices have an insulation system. In order for the chimney structure to work correctly, high-quality assembly must be carried out. This turns on the security nodes.

For units with chambers closed type chimneys with a length of no more than two meters are suitable. This will prevent swirls from appearing.

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

Related article:

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

Location of the coaxial chimney system

Most often, a coaxial chimney is installed using direct passage through the wall. In some cases, the device is passed through the roof or through ceilings. The best location for such a design is horizontal. If the heater is in hard to reach place, then the air duct is routed using vertical sections.

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

For your information! When selecting pipes for gas equipment, it must be taken into account that only designs manufactured by the same manufacturer as the main units are suitable for individual heating devices.

Related article:

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

Composition of a coaxial pipe to a gas boiler

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

• straight pipes were used to form the chimney;
• A rotating element or tee is used as connecting parts. With their help, straight parts of the device are mounted to the boiler;
• special area for performing maintenance work;
• container for condensate accumulation;
• the upper part of the structure used to protect the installation contours.

The unit is manufactured from acid-resistant stainless steel, which can withstand significant temperature increases. Chimneys are like this:

• pipes without insulation have a simple structure. Such a structure must be additionally insulated to reduce condensation;
• pipes with insulation are used for vertical structures. Insulated lines have excellent aerodynamic characteristics.

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

Why do you need a coaxial installation?

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

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

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

Coaxial chimney: installation requirements and installation

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

• make sure all elements are in place. In addition to the set of pipes, there must be connecting parts and various insulation materials;
• before installation, you need to mark, calculate all the chimney channels and make all the necessary holes;
• installation heating unit and chimney is produced simultaneously;
• the exit is located one and a half meters above the combustion chamber;
• the chimney line is fixed to the outlet pipe using a clamp and a pair of bolts;
• the structure is assembled according to a special project;
• the installation elbows are secured using clamps;
• a slight slope is created on the exit section of the chimney.

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

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

In the table you can see prices for individual models.

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

The decision to install a coaxial chimney will give good results. A useful recommendations and using the instructions will help you install such a structure yourself, without the involvement of specialists.

Coaxial chimney for a parapet gas boiler (video)

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Instructions and drawings of solid fuel boilers long burning with your own hands

When installing heating equipment there is a need to organize the removal of gases burned during operation. Coaxial chimneys for boilers are the best option systems for removing combustion products. What are the advantages of using a coaxial type chimney exhaust device and what are the features of its installation?

The device has a two-channel circulating system, through which air masses are simultaneously supplied to the boiler and fuel combustion products are removed. A chimney of this type is usually used for turbocharged or condensing heating devices with natural or forced removal of burned gases.

The operating principle of a coaxial chimney is quite simple:

• combustion products pass through the inner pipe, heating it;
• the air that enters through the external channel is heated by contact with the exhaust outlet that removes combustion products;
• Warm air masses enter the fuel chamber, promoting complete combustion of the fuel;
• the cold air flow passing through the external channel prevents the system from overheating.

As a result of this process, the efficiency of the heating system increases significantly and the fire safety of the entire device increases. The presence of a device for collecting condensate protects against moisture entering the boiler, and the tip mounted on top of the system protects against precipitation from entering the channels.

When installing coaxial type chimneys for a gas boiler, the following parameters are taken into account:

• heating unit power;
• level of thermal insulation in the room;
• average monthly air temperature outside the building;
• type of fuel used;
• general boiler performance.

Such factors are taken into account when selecting the size of pipes for installing a chimney.

Types of coaxial smoke exhaust pipes

Installation of chimney ducts is carried out in two ways - vertically and horizontally. In the first, the pipe is passed through the roof, and in the second, the outlet is made through a window opening or wall. Most often, horizontal installation of the device is used.

The technical characteristics of a coaxial chimney and its service life largely depend on the material from which the pipes are made.

Aluminum

The material is quite light. Its main advantage is resistance to temperature changes and good anti-corrosion characteristics.

Due to the inability to withstand high temperatures aluminum is used quite rarely in a coaxial chimney system. It is mainly used in combined version with plastic.

Stainless steel

Stainless steel pipes are the most popular. They do not deform under the influence of sudden temperature changes and can withstand heating up to 550 degrees. The material is highly resistant to aggressive substances and can be used as a smoke exhaust system for 30 years.

Two types of stainless steel pipes are used for the coaxial system for exhausting combustible gases:

1. Insulated. Mainly used for installing vertical chimneys. Such a pipe greatly improves the aerodynamic qualities of the device and is installed during the construction of the building.
2. Not insulated. It is used for both domestic and industrial coaxial type chimney structures. Differs in service life

The disadvantages of using uninsulated pipes include high vapor condensation.

Plastic

Chimneys made of heat-resistant plastic are used for condensing gas boilers. In addition to being light in weight and able to withstand heating up to 205 degrees, the material has a relatively low cost.

Plastic coaxial pipes are easy to install. But still, unlike stainless steel products, the duration of their use is short. Such chimneys are used exclusively in gas exhaust systems with low temperature conditions.

When selecting pipes, you should pay attention to the manufacturer’s recommendations for the type of heating device.

Technical requirements for installing coaxial pipe

Installation of a flue coaxial system for gas heating devices with a closed combustion chamber is carried out in accordance with regulatory documentation. If you deviate from the required standards, the gas service does not give permission to operate the boiler.

According to the rules established by SNiP, the following technical requirements are prescribed for coaxial chimneys:

1. Coaxial smoke exhaust structures can be placed in vertical and horizontal positions. Their installation, regardless of the type of installation, is carried out after approval of the provided project by the gas service.
2. It is not allowed to connect heating units with different types withdrawals – forced and natural.
3. The placement of the chimney pipe on the facade should not be below the level of 2 meters. The diameter of the hole for the chimney outlet in the wall must be made 1 centimeter larger than the pipe. For houses made of wood, it is recommended to increase the opening by 5 centimeters and protect it with non-combustible materials.
4. In multi-storey buildings, the distance from the pipe to the window opening located above it should be maintained at least 1 meter. If the doors and windows are on the same level as the smoke exhaust system, then a distance of 50 centimeters is maintained.
5. The outlet of the coaxial pipe should be located above top point heat generator at 1.5 meters.
6. A distance of more than half the diameter of the outer pipe is maintained from the gas pipeline to the chimney.

When the chimney is brought outside the building, the joints should not be in the wall. All structural parts must completely match each other in diameter. Chimneys for thermal systems with a capacity of no more than 30 kilowatts are allowed to be exhausted through the walls. Under no circumstances should smoke escape through the connections of the combustion product exhaust device.

To avoid problems with the assembly of parts and the tightness of the entire structure, it is recommended to purchase a complete chimney device from one manufacturer.

Installation additional equipment To gas appliances heating is carried out exclusively by specialists in this field. Also, every year a full maintenance of the system is carried out - checking connections for leaks, removing condensate accumulations, and inspecting the integrity of the structure.

Installation options for coaxial chimneys

Coaxial type boiler smoke removal systems are quite safe to use, provided correct installation. The length of the horizontal elements of the chimney must be more than 1 meter, and the pipe itself must be more than 5 meters. The height of the device itself at the outlet is set below the roof ridge. The size of the pipes is calculated so that there are no joints in the wall opening.

Installation of chimneys is carried out in two ways - external and internal. Each option has its own installation features.

Outdoor Unit Installation

This method is used for finished buildings that have not yet been heated. Initially, the location of the chimney is marked on the wall of the room. The installation of the device itself is quite simple:

• a hole is made in the wall to remove the pipe;
• areas with low heat resistance are insulated with basalt insulation;
• a pipe is inserted into the prepared opening;
• using a single-circuit chimney pipe outlet of 90 degrees and a double-circuit tee, the device is connected to the heating unit;
• the elbow is used as a connecting element, and the tee with a removable slope for vertical fixation of the structure;
• the connected system is attached to the wall with brackets.

After this, the entire structure is assembled. All parts are fastened with clamps. The section of the opening for the chimney outlet is sealed, and the pipe is protected with a special casing. The joints of the opening are covered with an apron.

Installation of internal chimney

Before installing the combustion exhaust system, the compatibility of the diameters of the outlet pipe of the heating unit and the smoke exhaust is checked. The size of the tube at the boiler outlet should be no larger than the volume of the gas outlet pipe.

Installation is carried out in the following sequence:

1. A connecting elbow and a tee are attached to a special chimney pipe on the boiler. For dual-circuit units, an adapter unit is also installed. All joints are fixed using clamps.
2. An opening is made in the wall to lead the chimney pipe outside.
3. If the chimney pipe is located on the side of the boiler, then after installing the transition elements, a horizontal chimney structure is assembled. In this case, the hole for leading the pipes to the street is located from the fastenings to heating device at a distance of 1.5 meters.
4. So that the condensate flows randomly down the channel into a special collection tank, outer pipe secured at a slight slope.
5. The upper location of the outlet pipe on the boiler greatly facilitates the installation of the chimney structure. Vertical assembly carried out using special brackets. An air gap is left at the exit from the chimney roof and material with non-combustible properties is laid. The joints are covered with an apron.

After assembling the structure, the tightness of all joints is carefully checked.

Pros and cons of coaxial smoke removal systems

Coaxial type chimneys for boilers have many advantages:

1. Productivity increase heating system. Due to the heated air masses coming from the street to the firebox, the fuel is completely burned, which, thanks to the air masses, is not spent on heating the boiler. Therefore, the efficiency of coaxial devices is significantly higher than that of simple chimneys.
2. Safety of use. Air, penetrating from the street into the channels, does not allow the system that removes gases to heat up too much, thereby increasing the fire safety of the entire structure. The hole in the wall through which the chimney is discharged may not be additionally insulated.
3. Universal application. Coaxial devices for exhausting combustion gases can be used for turbocharged units operating on any type of fuel.

One disadvantage of such chimney systems is the possibility of ice formation on the pipes when low temperatures air. This occurs due to the presence of condensate in the channels. It is formed due to the fact that the temperature of the exhaust combustion products falls below the dew point level.

Coaxial chimneys are much more productive than conventional smoke exhaust devices. They are easy to use, safe, practical and installation of the system is completely simple. The relatively high price of the product is fully justified by the effectiveness of its application.

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Due to the growing demand for small-sized heating units gas installations there was a need to develop new constructive solutions for removal of combustion products. The coaxial pipe became such a system.

The products are used primarily for gas boilers. The pipe allows:

• reduce the length (footage) of the chimney duct, eliminating interruptions in draft;
• remove combustion products through the outer wall of the home.

The use of coaxial systems is indicated in smoke exhaust for heat generators with closed and open combustion chambers. The following devices can be such generators:

• gas boilers;
• convectors;
• radiators, etc.

Advantages and disadvantages of coaxial pipes

Coaxial gas pipes have a number of advantages among analogues. The products not only provide safe work heat generator, but also eliminates the burning of oxygen in the room, since the dual-circuit system simultaneously removes combustion products and provides a passage for fresh air from outside.

Target product benefits:

1. High performance indicators: Fresh air, arriving at the burners, heats up significantly as it passes through the inner pipe. This results in minimizing energy consumption and increasing efficiency levels.
2. When installing a chimney, a hole with a small diameter is required: 200-250 mm. The small size of the systems is also an indicator of space saving.
3. An increased percentage of efficiency results in complete combustion natural gas. This characterizes the environmental friendliness of the installation, since external environment no unburnt fuel particles enter.
4. No heating until critical temperatures outer surface- the inner pipe transfers heat to the outer one, which as a result reduces the possibility of ignition of contacting surfaces.
5. When installing a boiler with a coaxial chimney, the issue of re-equipping the room is simplified (instead of several pipes - one).
6. Parts for installations are manufactured in various diameters. That is, for boilers with different power ratings, there are various designs coaxial pipes.

Main disadvantages:

1. The disadvantages of coaxial systems include the inability to remove smoke through ventilation ducts. Especially in apartment buildings. That is, the pipes are led exclusively through a hole in the wall directly to the street.
2. The exceptions are complex systems, manufactured on a collective basis using an industrial method. The peculiarity of the designs is that individual chimneys are connected into one common (central) one. But the installation of such a system must be carried out during the construction of the facility; in other circumstances, the efficiency of the installation decreases.
3. Another disadvantage is ignoring the boiler performance. If the device has a power of no more than 23 kW, then the volume of heated water per minute is about 9 liters. Moreover, after turning on the taps, the heating temperature immediately decreases.

Different manufacturers, relying on the listed design features, produce systems with different performance characteristics. This is how coaxial heat generators of European and Korean brands are distinguished.

Korean chimneys

Korean-made gas installations are more in demand, as they are most adapted to changes in gas pressure.

Advantages:

• combination of indicators: high quality at an affordable price;
• easy to use;
• protection sensors are built-in and number 12 (in European systems, the elements require separate installation);
• The tubular heat exchanger is durable and resistant to corrosion;
• installation of systems is possible at residential and industrial sites;
• have high efficiency indicators.

The disadvantage of Korean installations is the difficulty of repair. If any spare parts fail, they cannot be replaced with analogues from other manufacturers. Only “native” parts.

Nevien boilers have the most positive reviews. Especially the Atmo systems series. The advantages include:

• resistance to pressure and voltage changes;
• manufacturing of the body and individual parts from stainless steel;
• Russified control and control panel;
• stability in operation at low water pressure.

European coaxial systems

Baxi is the leader among European companies. The company provides savings and flow units in 70 countries of the world.

Features of Baxi brand boilers are:

• smoke removal by natural traction(due to an open combustion chamber);
• resistance to changes in electricity, water and gas pressure;
• corrosion protection is due to the enameled coating of the tank and stainless steel parts;
• possibility of working on liquefied gas (reconfiguration);
• has the ability to turn off the gas when blockages in the chimney are detected, controls the presence of a flame in the burner;
• has the ability to connect to multiple water collection points, parallel connection, etc.

An important advantage of European systems is the ability to replace parts from different manufacturers.

Design of a coaxial chimney

The mechanism of the device performs two functions at once (dual-circuit) and assumes several types of direction:

• horizontal (best);
• vertical.

Gas boiler kit

The coaxial chimney kit includes various parts that differ in the characteristics of the manufacturers and the type of direction. But it is customary to define the following elements in the standard set:

• set of straight pipes (inlet/smoke exhaust);
• connecting clamp;
• coaxial elbow (with an angle of 900);
• adapter for pipe connection;
• flange and wall trim (decorative).

Additional elements of the coaxial system:

• tee;
• decorative trim for the outer wall;
• cleaning;
• tip protecting against gusts of wind;
• collection for condensate;
• coaxial chimney extension.

Coaxial pipe material

The main raw material in the manufacture of coaxial pipes is steel. Distinctive feature The following grades of material are considered:

1. Pipes with zinc coating: are characterized by minimal cost and have a limited (short) service life.
2. Stainless steel products with acid resistant coating: are optimal solution For of this chimney, since combustion products contain aggressive chemical components.
3. Pipes from stainless steels without coatings.

Scheme. How does a coaxial chimney work?

The mechanism of the coaxial chimney consists of a dual-circuit system that simultaneously separates two gas flows:

• using a fan, fresh air from outside is supplied to the combustion chamber to maintain the combustion process;
• Smoke is also released into the atmosphere by means of a fan.

A pipe of smaller diameter is considered the central channel for combustion products; accordingly, atmospheric air enters between the gaps. The same distance between products is maintained along the entire line (main), which is fixed with jumpers.

Dimensions of coaxial pipe for a gas boiler

Define different formats of coaxial pipes. But the main criterion is to identify the size of the tip of the product:

• 60/100 mm (for all types of installations);
• 80/125 mm (for certain types).

Extension pipes and connecting elements are made taking into account the above parameters.

Requirements for installing a coaxial chimney

Before starting installation, choosing a location is a priority. The structure must be installed together with the boiler.

Please consider these parameters:

• the distance from the chimney to the ground must be at least 1 m (preferably 1.5);
• you can lengthen the chimney using no more than two elbows, so that the footage is equal to 3 m;
• the diameter of the hole in the wall varies: 11-12.5 cm;
• the pipe is installed at an angle of three degrees to remove condensate;
• exit hole - at least 0.6 m from the window.

Preparation for installation

Safety precautions should also be taken into account:

1. Avoid contact with other objects.
2. Remove or protect flammable parts and substances from the pipe area.
3. Take into account the thermal insulation of the walls.

Installation of a vertical coaxial system

Installing the chimney vertically or at an angle is used if it is not possible to lead the pipes directly through the wall or the required distance is not maintained:

1. Afterwards the chimney is assembled. The connecting elements are clamps.
2. Mount decorative elements.

Installation of horizontal coaxial pipe

Installation of the unit in the horizontal direction is used if there is a circulation system in the boiler:

1. The coaxial pipe is connected to the outlet (neck) of the boiler. The connecting element is a clamp.
2. The fastening area is fixed with bolts on both sides.
3. Assemble the chimney. The connecting elements are clamps and swivel elbows.
4. During the process, the slope of the product is observed.
5. Install decorative trims.

Insulation of coaxial pipe

There is a problem with freezing of the coaxial pipe. But the solution to the problem does not include conventional insulation, because the chimney is exposed to high temperatures.

To eliminate the problem, simply shorten the length of the chimney. If the outlet on the pipe side freezes, it is also reduced. But on this moment Manufacturers have provided chimneys that prevent freezing of the ring parts of the pipe. This is due to the materials used in the manufacturing process, as well as technical characteristics.

Yulia Petrichenko, expert

Coaxial pipes are safe and effective method removal of combustion products. The chimney allows you to install a wall-mounted or floor-mounted heat generator, which eliminates the need to re-equip the room without large financial costs. Environmental friendliness and high efficiency indicators have been noted by various experts.