Coaxial chimney requirements. Coaxial chimney - requirements for installation and use

Modern gas boilers- this is reliable equipment that can provide us not only with heat in the house, but also with hot water supply. But for them proper operation and high performance, it is necessary to install a special chimney. It must perform two main functions at once: supplying oxygen to the burner and discharging it outside the room. For this, a coaxial pipe is used. Let's talk about what it is and what its features are.

General information

We will not talk about any design features heat generators. It is enough to understand that for them efficient work a chimney is required. The situation here is the same as with the most ordinary wood stove. Of course, the coaxial pipe for the boiler has a completely different design, and its installation is carried out with its own nuances, which will be discussed below. So, the key feature of such a chimney is that it works on the “pipe-in-pipe” principle. It turns out that we have two pipes: one smaller, and the second larger diameter(external and internal). One of them supplies oxygen to the combustion chamber, and the other removes combustion products into environment. A very effective solution, especially considering that such a pipe takes up very little space and is installed in one day.

About the advantages of the system

The coaxial gas pipe has a number of significant advantages, thanks to which it has earned such popularity. Firstly, this is the localization of the combustion process, which is carried out by an isolated supply and exhaust of air and, accordingly, combustion products. As a result, there is no mixing of oxygen and gas mixtures. Consequently, the productivity of the equipment increases.

Another plus is that as the air enters the boiler, it heats up. This is achieved due to the fact that the pipe through which it enters is heated by waste combustion products. Overall very effective, especially in the cold season. Of course, one cannot ignore the fact that the “pipe-in-pipe” chimney design itself has smaller dimensions compared to a separate installation. At the same time, the number of fasteners is reduced, and the complexity of installation is significantly reduced.

A little about the disadvantages of the system

Of course, there is no ideal system that would not have shortcomings. In our case, although there are disadvantages, some of them can be dealt with simply because they are insignificant, while others will have to be tolerated.

The main disadvantage of such structures is that their cost is ultimately 20-40% higher than the installation of separate systems. Another problem is the concentric arrangement of hot and cold air pipes. You have probably noticed icing on such pipes more than once. It is formed due to the accumulation of condensate and its freezing during sub-zero temperature. You can combat this by installing additional drainage and insulation. But all this will increase the price even more.

Well, the last drawback is the limited length of the coaxial pipe. This is approximately 4-5 meters. Therefore, if your boiler is not installed near a window or it is not possible to remove the coaxial pipe for some reason, this option is not suitable for you.

About the regulatory framework

It is necessary to understand that you cannot just take and install such a chimney, since the installation of a coaxial pipe is carried out taking into account existing requirements and standards. For example, there is a clear rule that states that chimneys can only be installed through the roof. But that doesn't concern individual heating, where it is possible to install horizontal coaxial chimneys. In general, horizontal systems for exhausting combustion products and supplying air can only be installed in private houses, and for multi-storey buildings provided vertical structures, which should rise 1.5 meters above the roof of the building.

System classification

All modern coaxial chimneys are divided into internal and external. First in residential buildings are practically not used. Such structures are installed in special shafts or old chimneys. But they must comply. In addition, installation of such systems is often very difficult, as is maintenance.

External coaxial chimneys do not have such disadvantages. By the way, they are also usually classified according to their insulation. So, there are insulated and non-insulated. In regions where the air temperature does not fall below -10 degrees Celsius, chimneys do not need to be additionally insulated. In other cases, there is a risk of partial or complete freezing of pipes. In addition, there are individual and collective chimneys. The first ones are designed to serve one gas boiler, and the second - for an entire multi-story building.

Structural composition and material of the chimney

The coaxial system is modular and consists of a large number of assembled elements. This includes an adapter for a gas boiler, straight sections of pipe, connecting elements, such as couplings and tees, and much more. True, such components as a coaxial pipe extension, decorative overlays, may not be supplied in the kit - you need to purchase them yourself if necessary. But the mounting hardware and sealing gaskets that ensure the strength and tightness of the system must be included in the kit. When installing such a system, it is advisable to use jumpers. They are necessary for fixation inner pipe relative to the outside.

As for the materials from which the coaxial pipe is made, most often it is galvanized and can easily withstand high temperatures and does not corrode for a long time. In some cases, it is advisable to use heat-resistant plastic or aluminum. Often, for the consumer, it makes no difference what material the pipe is made of; the main thing is to carry out the correct installation.

Features of chimney selection

In most cases, a coaxial pipe is supplied together with heating equipment, that is, with a gas boiler. That is why almost all manufacturers of heat generators produce and similar type chimneys. The equipment installation instructions contain a clause that indicates the maximum permissible length of the chimney. This value must not be exceeded under any circumstances. Otherwise, the efficiency of the equipment is significantly reduced. If the chimney operates on natural draft, that is, the boiler does not have a fan, then a parameter such as the minimum pipe length is entered. If you install a chimney that is shorter in length, there will be no draft and combustion products will remain in your apartment or house. The diameter of the pipeline is written as 100/140, where the first value is the diameter of the inner pipe, and the second, respectively, the outer one.

Do-it-yourself installation of a coaxial pipe

The first thing you should remember is to have no more than 2 bends in your chimney. When will you install horizontal system, place the pipe with an inclination of at least 3 degrees. This is necessary so that the condensate drains on its own. If the coaxial pipe ultimately connects to a common chimney, then the angle must be changed in the opposite direction with a slope towards the boiler.

The most critical stage of work is drilling a hole in the wall. This must be done using diamond equipment. But it is advisable to carry out such work if the house is being renovated, since there will be quite a lot of noise and dirt. After the hole is ready, it is necessary to lay the pipe, insulate it, and seal it. In general, there is nothing complicated here. The main thing is that the chimney at the bends is well sealed. Also don't forget about minimum slope, which is necessary for the drainage of condensate.

System installation rules

A vertical coaxial pipe is much easier to install than a horizontal system. But it is not always possible to bring the chimney to the roof. So, if you want the coaxial pipe to be installed correctly, you need to follow a few simple requirements.

Thus, the system cannot be installed below ground level. If the distance from the outlet to the ground is less than 1.8 meters, then a deflector grill is installed to protect the pipe from dirt. If there are strong winds in your region, then it is quite possible that the boiler will go out and not work at full capacity; this problem can be completely and completely solved. Of course, it is advisable to trust similar works specialists who installed heating equipment, but if this is not possible, then by observing these requirements, you can cope on your own.

Conclusion

We talked about what a coaxial pipe is. As you can see, this is a very efficient and practical chimney in terms of performance and space saving. It is quickly installed and serviced, which is without a doubt important point. If necessary, you can install a coaxial pipe extension, which will slightly increase the total length of the chimney. Special attention Pay attention to insulation, as such systems often freeze completely. There is nothing good about this. Moreover, this happens in the most severe frosts. Although the problem is solved quickly, it is still better that it does not exist. Now you can decide for yourself whether to use such a system or not. All the best!

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 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 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 a regular traditional pipe. His European quality combined with an excellent price.

The principle of operation of a coaxial chimney

The smoke exhauster built into the boiler system allows external pipe intake air from the outside simultaneously with the removal of flue gases internally. 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, so the inner pipe 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, installation standards and fire safety including. One more the most important condition Its reliable operation is ensured by 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 duct on the facade of the house is placed according to the installation instructions gas equipment from the manufacturer, but subject to 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 smoke channel placed 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
Ariston chimneys made in Italy are 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 contribute to increase in efficiency corresponding Protherm boilers. In addition to them, the company also offers extensions for chimneys, adapters designed for separate smoke removal, and more.

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. Its special design prevents the pipe from freezing in winter.

Everyone knows that performance heating systems, which uses the principle of fuel combustion, is impossible without oxygen to support combustion and proper removal of exhaust gases. Today, to create autonomous heating systems, various gas equipment is in great demand. It is compact and safe, easy to use, perfectly automated and does not require constant intervention by the owner in the work process.

Design and purpose of a coaxial chimney

This device looks more like a motorcycle exhaust pipe. In fact, this is a specially designed structure, a pipe in a pipe with different diameters, which are inserted one inside the other and rigidly fixed to each other. Combustion products are removed through the inner tube, and the air necessary for combustion of the fuel enters the combustion chamber through the space between the inner and outer tubes. A coaxial chimney for a gas boiler solves two main problems at once: removing exhaust gases and supplying air to the device.

Such chimneys are made from pipes round section, and the internal one is most often made from aluminum alloy, and the outer one is made of steel, thickness 1; 1.5 or 2 mm. The ratio of internal and external diameters for wall and floor heating devices is 60 to 100 mm. For condensing boilers, chimneys with a diameter ratio of 80 to 125 mm are used.

There are two types of coaxial chimneys: horizontal and vertical. The easiest to install, and therefore the most common smoke exhaust system of this type, is a horizontal chimney. A vertical coaxial chimney is quite difficult to install and is therefore used if horizontal installation not possible or from the heating device to street wall more than 4 m.

Advantages and disadvantages

As mentioned above, this type of smoke exhaust system is used only for gas equipment with closed camera combustion, namely:

• Dual-circuit heating boilers wall and floor installation with a closed combustion chamber.
• Gas hot water heaters.
• Generators and convectors.

The main advantages of such an air intake and smoke removal system are:

• Safety. In such a chimney exhaust system, heat exchange occurs between street air and exhaust gases, resulting in a decrease in the temperature of combustion products.
• Heating air coming from the street by contacting it through the pipe wall significantly increases the efficiency of the boiler.
• The coaxial chimney takes in outside air, not from the room, so there is no vacuum created, which prevents normal operation boiler and natural circulation indoor air.
• Easy installation and a large number of accessories.
• Significant savings in internal space.
• Oxygen from the room is not used.

The most attractive for using chimneys of this type are apartment buildings, since the emissions carbon monoxide and fuel combustion products are produced not into the ventilation shaft, but directly into the atmosphere.

Such chimneys also have disadvantages, namely: rather expensive insulation to prevent freezing of the chimney head. The possibility of freezing of the pipe head is quite high. This happens because the temperature of the exhaust gases is too low and is not able to melt the ice formed during the exit. humid air. The consequences of icing can be quite serious: repair of burners, combustion chambers and turbocharging.

Installation diagrams and installation requirements

As mentioned above, there are two main schemes for installing a coaxial chimney: vertical and horizontal. When installing, you should adhere to certain rules installation of a coaxial chimney, regulated by SNiP 2.04.08–87; SNiP 2.04.05–91.3, as well as the set of “Safety Rules in the Gas Industry”.

The total length of the coaxial chimney cannot be more than 4 m. If a larger length of the smoke exhaust system is required, then a larger coaxial chimney should be used.

At vertical installation, the chimney passes through ceiling and the roof. In order to install the system in a vertical position, a special adapter is used.

It should be noted that such an adapter is not a universal device and each manufacturer produces this device strictly for its own equipment. To achieve the required length of the chimney, special extensions are used.

To ensure tightness when the chimney passes through the roof and protect it from precipitation, a device called a terminal is used.

When installing vertical system smoke exhaust should be guided by the rules that regulate its height, depending on its location in relation to the ridge of the pitched roof.

Most often, a vertical coaxial chimney is installed in private houses. But there is another option for a vertical smoke exhaust system - collective, which is designed for apartment buildings. General coaxial chimney in apartment building makes the use of individual gas heating appliances completely safe.

Horizontal exhaust gas outlet is most often used for wall mounting heating equipment. Horizontal scheme implies the exhaust of the chimney through outer wall outside.

During installation, you should take into account the slope of the chimney of 2-3° to prevent condensate from entering the boiler unit.

To pass through the wall, two types of devices are used: basic or horizontal. The only difference between these kits is the connection adapter to heating device. If, when passing through a wall, it is necessary to go around a beam, reinforcement, etc., then special bends and elbows are used.

Self-installation

Installing a coaxial chimney with your own hands is quite simple and anyone can do this work House master with basic skills in using power tools.

To complete the work, you will need a kit that includes: a pipe with a flange, a clamp, an adapter for connecting to the boiler unit and a coaxial elbow. If necessary, you should purchase a special coaxial chimney extension.

1. Make a hole in the outer wall at the required location. It should be noted that the chimney outlet should not be located closer than 0.6 m to the window.
2. Connect the adapter to the boiler.
3. Connect the chimney directly to it using a crimp clamp. If you need to bring the structure to the wall, then use a knee. Secure everything with crimp clamps.
4. Exit the pipe through the hole, providing a slope towards the exit of 2-3 °.
5. Seal the cracks polyurethane foam or mineral wool.
6. Cover the pipe exit with a decorative cover.

It should be noted that with each turn of the chimney by 90°, the maximum length coaxial chimney by 0.5 m.

– lower efficiency.

A significant portion of the heat escapes through the chimney to the street along with combustion products. It will not be possible to completely eliminate this drawback, but it is possible to reduce heat loss. Effective solution problems - coaxial chimney for a gas boiler.

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

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

Thus, the air enters the burner already heated - it is heated from the wall of the cylinder with hot smoke (). No additional energy is spent on heating the air. At the same time, the “cold” outer cylinder cools the internal “hot” one - reducing the fire hazard of the structure. The channel outlet is made through the wall next to the boiler.

Installing a coaxial pipe for a gas boiler requires additional steps to optimize the system:

• vertical coaxial chimney for a gas boiler has longer length street segment and cools down greatly. Such pipes require insulation. There are designs with three channels instead of two, the outer one is filled with a heat insulator - basalt wool;
• draft is improved due to the built-in fan;
• The system is equipped with a condensate collector and anti-icing nozzles.

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

Installation options

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

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

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

Floor-standing boilers with a coaxial chimney can have a power of no more than 40 kilowatts (). With higher power, the chimney does not provide sufficient draft, the formation of condensation increases, and ice forms in the external area.

When choosing a smoke exhaust system, you should take into account the brand of the boiler manufacturer. For example, Buderus, Viessmann, Baxi equipment has non-standard pipes and will require chimneys from the same companies.

Types of chimneys

Based on the material they are made of, chimneys are divided into aluminum, plastic, and stainless steel. Plastic and stainless steel are popular in Russia.

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

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

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

The design of a vertical coaxial chimney for a gas boiler involves an outlet along the facade wall to the roof. In other cases, the pipe is routed through an outside wall and ends there.

SNiP requirements

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

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

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

A pipe can be laid through an adjacent non-residential room if the horizontal section is no more than 3 meters. In the presence of forced draft - up to 5. The pipe is placed at an angle to the boiler.

If you have a condensate drain, the outlet pipe can be turned towards the ground to prevent rain from getting inside. Condensation should not drain to the ground. To reduce its amount, the pipe is insulated. To dispose of condensate from collective chimneys, a sanction from the Sanitary and Epidemiological Supervision Authority is required.

Before the beginning heating season and upon completion, preventive maintenance is required: removing condensate, checking the integrity of pipes and the tightness of joints.

Installation Features

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

This is necessary to limit the amount of air entering the firebox. The maximum length of a coaxial chimney for a turbocharged gas boiler is 5 meters. The inclination of the horizontal section to the boiler is 3 degrees. When installing a tee with a condensate collector, it is permissible to tilt it in the other direction.

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

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

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

In houses made of aerated concrete blocks, the vertical chimney is installed inside the house so as not to create additional load on the façade wall. IN brick house Both external and internal installation is possible. Thermal insulation is performed using any method.

The system should be connected to the boiler using a special factory-made adapter. The use of homemade stainless steel pipes for this purpose is a violation of installation rules. A tee with a condensate collector is installed next to the adapter. An inspection hatch is made on this device to clean the channel. Next, the pipe is lifted and passed through the wall.

To protect external system from the formation of ice, use a special nozzle. To prevent wind blowing and, as a consequence, reverse draft, a windproof diaphragm is installed.

Video about what a coaxial chimney is.

The onset of winter always poses a question of necessity proper organization heating systems.

Everyone needs to warm up, no one wants to live in cold apartment and freeze. Gas boilers heat rooms most efficiently. They heat up quickly, hold the temperature well, and the cost of operating such equipment will probably be affordable for everyone.

Let's not forget about the functionality of boilers. A good unit is capable of not only heating the room itself, its power is also enough to heat water for domestic needs. But here another question comes to the fore - how to remove combustion products from the boiler to the outside of the building and do this as efficiently as possible? Now you'll find out.

Contents of the article

Problems with standard chimneys

A gas boiler has many advantages compared to the same electrical appliances. But there are also disadvantages. The disadvantages primarily relate to the removal of combustion products from the boiler.

Be that as it may, electricity does not leave waste behind, but after the operation of a gas boiler, a large amount of carbon dioxide and carbon monoxide is formed, which must be removed in a timely manner.

To eliminate carbon waste they use. Chimneys are different. Meet the usual steel pipes, ceramic, brick pipes etc. Their installation and features depend on the specific variety, type of house, location of outlet and many other things.

However, conventional chimneys also have their disadvantages. They are quickly forgotten, and the draft inside the boiler decreases. If cleaning is not done in a timely manner, the problem only gets worse.

The chimney may become clogged, completely blocking the operation of the gas boiler. As a result, it either will not function or will emit combustion products inside the room, which is also, of course, unacceptable.

Plus, an ordinary chimney, although an effective thing, has its design flaws. For example, the smoke exit and air supply go through the same pipe. In most cases there is no problem here, but there are exceptions.

For example, if the chimney is even slightly clogged, then the flow of incoming air will greatly decrease, which will immediately affect the draft inside the gas boiler, and this will accordingly reduce its efficiency. You will have to burn more fuel to get the same result. Not the most pleasant action, is it?

Product Description

However, such situations can be circumvented. Modern technology has long learned to create truly effective designs, freed from the problems of the past.

A coaxial pipe is just one of these structures. A coaxial pipe is a pipe that consists of two main parts. Two shells that function in pairs.

The inner shell of the pipe has a smaller diameter. Its standard size is approximately 60 mm. A pipe with a diameter of 60 mm is considered the basic one, but other, larger samples are also found.

Pipes smaller than 60 mm are not suitable for coaxial chimneys; their cross-section is too small to sufficient quantity remove smoke and combustion products outside.

Also, when interacting with a pipe less than 60 mm in diameter, the chance of it becoming clogged with sediment increases greatly, although it is significantly reduced for coaxial products compared to conventional chimneys.

The second pipe will be larger. Its diameter is approximately 100 mm, provided that the inner one has a diameter of 60 mm. That is, the size ratio is at the level of 1 to 1.5.

The task of a pipe with a diameter of 100 mm is to organize constant influx fresh air to the boiler. It also drains condensate, which accumulates on the outer walls of the inner pipe. It is worth understanding that a 100/60 mm pipe is only one of the options, and there are a great many of them.

The pipes are attached to each other using clamps and various types of supports. Due to their design, they do not touch each other, which is very important.

Actually, such a solution is called coaxial because of the two-axis structural mechanism embedded inside.

Advantages and disadvantages

The use of coaxial pipes together with the design of gas boilers gives an amazing result. This design has more than enough advantages.

Let's list the main ones:

• increasing the efficiency of heating equipment;
• safe and continuous drainage carbon monoxide, reducing the likelihood of clogging the chimney pipe with reverse draft;
• constant condensate removal and fresh air supply through insulated pipe with a diameter of 100 mm or more;
• reducing the likelihood of breakdowns;
• simple and at the same time very efficient design(installation is carried out according to a pre-designed scheme).

As you can see, this solution provides a lot of positive results. The efficiency of a gas boiler increases due to several factors. Primarily due to the constant and continuous flow of air through an external pipe with a diameter of 100 mm.

Condensation also accumulates in it; it does not have access to the insides of the smaller part of the chimney with a diameter of 60 mm. This brings up another important advantage.

Cleaning coaxial chimneys is greatly simplified in terms of the application of physical effort, since condensate with oxidation inside often causes the formation of solid deposits on its walls.

At the same time, the condensate dries out on its own, due to the same reverse draft. Moreover, this process occurs quickly, without unnecessary costs.

Accordingly, thoughtful design has a positive effect on all aspects of the heating equipment.

Do you have coaxial structures flaws? Of course have. All equipment without exception has them.

Main disadvantages:

• increased price;
• pipes are strictly typed and standardized, developers customize them for specific tasks, which complicates the modification process;
• more difficult to do on your own;
• installation involves following safety measures and special requirements that cannot always be met.

Installation of equipment

As we noted above, the installation and installation of coaxial pipes for a gas boiler differs from what we are used to seeing. The special design of coaxial outlets adds requirements that seriously complicate installation.

Now you need to think not only about how to lay the pipe along the simplest scheme. And this is not so easy, especially if the withdrawal is supposed to be organized from an apartment in an apartment building.

It is also necessary to comply with all requirements, ignoring which is fraught with serious complications in the future.

Primary requirements

Before we consider the entire installation from start to finish, let’s turn to these same requirements. They are very important and for good reason.

Basic requirements for the installation of coaxial pipes with dimensions of 100/60 mm:

• the pipe is installed so that it is suspended with a slope of approximately 3 degrees;
• The outlet of a coaxial chimney cannot be installed closer than 1.5 meters from the ground and 0.6 meters from the window;
• Installation of all components (and the coaxial chimney is completely collapsible) is carried out only using. No initiative, otherwise there will be trouble;
• If the pipe needs to be lengthened or further stretched, we use sealants and mastics for coaxial leads. It is better to buy them from manufacturers; they often provide their customers not only with direct products, but also with all the materials necessary to service them.

All these requirements must be strictly observed. This is especially true for points that are responsible for the direct location of pipes.

Installation at an angle of 3 degrees is necessary for safe and continuous removal of condensate from the pipe. If the angle is broken, condensation will flow slowly and stop drying, and this is fraught with serious problems.

Installation process

Let's look at the installation of a pipe using the example of installation under a Baxi boiler. In fact, you can choose any boiler; they almost always have an identical design.

As a working coaxial chimney, we will take the most common option in our area, a 100/60 mm pipe. Where 100 mm is the diameter of the outer pipe for generating draft, and 60 mm is the diameter of the inner pipe that directly removes combustion products.

Stages of work:

1. We are preparing all the equipment.
2. We are planning the route for laying the pipes.
3. We drill holes in the structures that interfere with us. We select the diameter according to the outer chimney pipe, adding another 10 mm to it for fasteners. If our pipe has a diameter of 100 mm, then the hole must be drilled with a diameter of 110-115 mm.
4. We connect the base to the output from the boiler. Most often, this pin is located on its top panel.
5. We install the first part of the pipe, secure it with fittings.
6. We continue to lay the coaxial chimney in compliance with all requirements.
7. We seal pipe joints.
8. We test the operation of the system.

As you can see, there is nothing complicated in this process.

Installation of a coaxial chimney (video)

Try to fasten all parts of the pipes as best as possible. The better the quality of the joints, the less problems will appear in the future.

If necessary, add fittings to the structure, but only where they are really needed. For every three meters of pipe, a maximum of 3 fittings or two elbows are allowed. But this is a boundary line mark. It is advisable to reduce their number to a minimum.

Make sure that the axes of the outer and inner pipes are parallel to each other and never move. Displacement, of course, can happen, but only over time. During the installation process, everything must be perfect.