Chimney for gas boiler. Standards, requirements, features and experience of FORUMHOUSE participants

The installation of any heating device or structure operating on solid, liquid or gaseous fuel, a stove, fireplace or boiler, will require the mandatory installation of a waste combustion product removal system.

Stainless steel chimney

Not so long ago there was no particular alternative - it was necessary to erect a brick structure or resort to the use of asbestos-cement pipes, which have many more disadvantages than advantages. Currently, the situation has changed dramatically - a stainless steel chimney shows excellent versatility.

In skillful hands, a set of stainless steel parts turns into a universal tool, making it possible to quickly install a chimney system that fully meets all the requirements of current standards and safety requirements. In addition, the overall cost of installing a chimney, even with the seemingly expensive components, will always be more attractive than other options. With a competent approach and knowledge of the basic principles of installation, assembling such a system is a completely feasible task for any home owner.

Varieties

begins with choosing the type of pipe that is optimally suited for specific conditions. The following varieties are available for sale:

Single-circuit

The so-called mono pipes consist of a single layer of alloy steel alloy, the layer thickness of which is about 0.5 mm, and the operating temperature is 500 degrees.

The scope of application of such pipes is limited; their installation is possible only indoors, since due to the lack of an insulating layer, a single-circuit chimney freezes in winter, allowing condensation and soot to settle on the internal walls.

Single-circuit chimney pipes made of alloy steel

Sandwich pipes

In construction terminology, they are also known as thermal systems, two- or three-layer pipes with insulation laid between layers of steel. The operating temperature of a double-circuit steel alloy chimney pipe is up to 850 degrees.

For thermal insulation of such a chimney, insulation based on mineral wool, in particular, basalt fiber, is used. They protect sandwich pipes from condensation and also retain heat inside, reducing fuel consumption.

Sandwich pipe for chimney

For most regions of Russia, professional builders recommend the use of double-circuit sandwich pipes. They are indispensable if the project plans for external installation with an exit through the wall.

However, remember that stainless steel is installed after the chimney exits to the street, and not immediately to the inlet pipe of the heating device.

Principle of operation

The principle of operation of the chimney is based on the natural draft force that occurs in the circuit due to temperature differences. The heated air becomes light and naturally rushes upward.

Fresh cool air coming from outside not only replaces exhaust gases, but also supports the operation of the system as a whole, because oxygenated air masses support the physics of combustion.

Installation of a stainless steel chimney

The parts for assembling a stainless chimney are very diverse, so the channel configuration can be any without harming the draft force and the working process in the stove. Quite often, a corrugated pipe and several elbows become an element of the chimney, helping to avoid a global reconstruction of the walls.

Instructions for assembling the smoke channel

A stainless steel chimney is installed as follows:

1. A design sketch is created on paper, which reflects the expected configuration of the smoke channel. Then the walls are marked, indicating exactly where the pipe will be attached. Based on the results of this work, the length of the structure is determined and all parts are found, including rotating elements for connecting pipe sections. At the same time, do not forget about the fragment of the chimney that goes onto the roof of the house. It should rise slightly above the level of the roof ridge.
2. Before assembling the chimney, the pipe joints are lubricated with a sealing compound. A special tool will make the articulation of parts more reliable.
3. Moving from bottom to top, one chimney section is connected to another. The elements are joined to each other so that the upper section is inserted into the lower section using a special latch. In the absence of this device, one element is inserted into the other by approximately one-half the size of the outer diameter.
4. Clamps are attached at all joints of elements. The manufactured structure is fixed on the external or interior wall of the house every 1.5 or 2 meters. Elements passing through the wall and inspection sections of the pipe must be secured. The smoke duct is fixed to additional brackets in the areas where the tees and elbows are located.

Video: connecting chimney elements

Rules for installing stainless pipes

Installation of the structure should be carried out according to the following rules:

• horizontal elements and elbows cannot be installed in places where they will be in close contact with electrical wires and gas pipes;
• chimney elements must not be connected where the structure passes through the wall;
• pipe fragments located horizontally cannot be made long (the permissible limit is 1 m);
• The direction of the chimney can be changed no more than three times;
• the diameter of the selected stainless steel pipe cannot be less than the size of the pipe coming from the furnace of the stove or fireplace;
• when running a smoke duct through the wall, ceiling and roof around an uninsulated stainless steel pipe, it is customary to leave at least a meter of free space;
• the height of the smoke channel must be more than 5 meters, otherwise the products of fuel combustion will be poorly drawn out;
• It is customary to pass a stainless steel pipe through non-flammable roofing material, creating a clearance of 13–15 cm;
• a stainless steel chimney installed outdoors or in a cold building must be covered with thermal insulation materials;
• at the point where the smoke duct exits through a roof made of flammable materials, it is necessary to install a device that extinguishes sparks.

Important principles for installing a chimney

If you want to make your chimney work efficiently, you should listen to some recommendations. In many respects they relate to the use of corrugated pipes. It can be installed both inside and outside the house, but the best place to place such a product is considered to be the transition from the stove pipe to the main channel.

The advice of the experts does not ignore the shape of the hole for the pipe. It is better to make it rectangular or elliptical. The hole in the roof should be located where the smoke duct can pass centrally between the ceiling beams and the roof support structure.

Most often, a rectangular hole is created for the chimney pipe, since it is easier to cut and seal.

Installation of a stainless steel chimney requires mandatory waterproofing of the structure.

This is important, because the upper section of the pipe, not protected from dampness, can cause moisture to leak onto the attic floor

Video: installation of a chimney from a sandwich pipe

The smoke exhaust channel, made of stainless steel pipes, copes well with the functions assigned to it. The installation of this structure will seem simple, like an easy mathematical problem, if you know the intricacies of the process and take into account the advice of the experts.

How to clean?

Any device requires good treatment and care, the same goes for a stainless steel chimney.

It is in order to be able to clean the device that a small door or so-called glass is installed in its lower part. This element can be removed and the inner surface of the pipes can be cleaned. Read an overview of the types of chimneys for a fireplace.

Dirt in a system is the formation of a space with a high level of roughness, and this has a direct impact on the functionality of the device and the operation of the entire system.

An ash pan is also specially installed for comfortable maintenance of a stainless steel chimney. Solid combustion elements will collect in it.

The picture shows the installation of a stainless steel chimney.

Types of chimneys

Based on the components used, these devices can be divided into the following:

• single;
• multilayer.

The materials used for their manufacture are particularly durable and highly resistant to acid condensate. A clean surface helps to completely remove moisture and soot from the smoke duct.

Single pipe structures are very often used. Such technical solutions are used to adapt old chimneys to new heating equipment. Pipes for them are made square, oval or round. Austenitic stainless steel is used for their production. Enameled pipes are also produced, but they are not widely used because they are sensitive to mechanical stress.

Single chimney needs additional protection

When installing a single chimney, you should be guided by the fire safety rule, which requires a distance to the nearest wall made of flammable materials of at least 1 m.

Double-layer structures have their advantages. The thermal insulation layer between the walls of such a chimney reduces the cooling of the inner pipe, resulting in less condensation. The inner pipe is made of high-quality steel, since condensate has an acidic reaction and other materials, including galvanized steel, will not be able to work for a long time in such conditions.

The double-layer chimney is already insulated

Such chimneys are placed at a distance of at least 20 cm from walls made of flammable materials. If this cannot be avoided, then the wall is sheathed with metal with a backing. It is made from fire-resistant material, for example, asbestos sheet.

According to the installation method, chimneys are:

1. Internal. This design can rise vertically from the furnace through the internal ceilings and roofing pie. Its main disadvantage is that condensate flows directly into the firebox, increasing its concentration in the flue gases. The result may be an unpleasant pungent odor in the room and accelerated wear and tear of the chimney.
2. External. With this design, the chimney is diverted from the stove horizontally through the wall. For this, two elbows are used, which can have a rotation angle of 30, 45, 60 or 90 degrees. In this case, the outer one looks like a tee, and at the bottom there is a container for collecting condensate. The vertical part of the chimney is installed parallel to the wall, the pipe is attached to it using brackets and clamps.

Components

It is impossible to assemble a chimney without using fittings. They are intended for:

• performing contours of engineering systems;
• changes in pipeline direction;
• switching to another diameter;
• traction adjustments;
• condensate collection;
• protecting the upper end from precipitation, leaves, debris and nesting birds.

Additional elements for assembling a chimney from pipes must be used

Using these structural elements, you can assemble a chimney of any configuration with your own hands. The permissible length of horizontal sections is no more than 1 m, otherwise the traction will be greatly weakened.

Advantages and disadvantages

Stainless steel chimney ducts are characterized by a number of advantages:

• adaptability to any heating concept;
• strength of steel body;
• light weight and, as a result, no need to build a separate foundation;
• long service period (up to 30 years);
• high heat resistance coefficient. They are able to withstand temperatures up to 900⁰C;
• resistance to destruction and vibration;
• resistance to temperature changes, moisture and acid condensate formed inside the circuit;
• immunity to corrosion;
• operational safety;
• ease of installation and minimal time spent on installation work;
• the ability to give the smoke circuit the desired configuration;
• ease of maintenance and repair work;
• acceptable price.

Among the disadvantages it should be noted:

• the need for thermal insulation measures (relevant only for single-wall chimneys);
• visually unsightly design and, as an option, additional finishing in the form of erecting a decorative box. Although the natural specularity of stainless steel can easily be used in the design of any room.
• non-solidity of the structure when using poor-quality or unsuitable sealant leads to depressurization of the circuit under the influence of high temperatures.

Types of metal structures

Components for chimney installation are available in two types:

• single-walled,
• three-layer sandwiches.

Single-wall metal pipes are made from galvanized steel or stainless steel. A chimney made of single-layer steel has one significant disadvantage - heat exchange with the external environment. As a result of this thermal interaction, a single-layer chimney is susceptible to condensation and is a fire hazard.

Most often, single-circuit pipes are used:

• for smoke exhaust equipment in outbuildings where heat loss is not of fundamental importance;
• to construct the internal part of the chimney, if it is planned to be used as an additional heat source;
• as a smoke channel during the construction of a combined chimney.

Sandwich chimneys are ready-made sections for assembly, consisting of two circuits: an inner pipe and an outer casing, the space between them is filled with mineral wool.

Possible combinations of materials:

Double-circuit pipes are more expensive than single-circuit pipes, but the chimney assembled from them is self-sufficient and does not require either insulation or additional protection.

Chimney installation - the best ideas for building metal and stone options (75 photos)

The very name chimney implies that we are talking more about country-type houses. The category of such structures includes dachas, cottages and other buildings where there is no central heating. To make a house warm you have to use other methods of generating heat.

The most well-known options are home stoves and fireplaces. They are built according to strict rules, and one of the most important rules characterizes the installation of a smoke exhaust device. In other words, building a chimney.

Advice from professionals

When installing a chimney, you should take the advice of experts to make the ideal unit for the smoke to escape. The tube that comes from the outside collects condensate. If you perform the smoke procedure, condensation can leak into the cartridges. The insulation cannot be wetted; in this situation, the tubes will be poorly insulated, and the outer sleeve can cause a fire when the wall structures heat up. In addition, freezing of liquids can cause holes to form in the tubes, and the acid inside the condensate substance causes the liner to burn out from the inside. The leakage of smoke in open spaces is not dangerous; it can be eliminated if you additionally lubricate the joint parts with sealant.

It is not recommended to reduce the diameter of the chimney opening; this may cause a stop or decrease in draft. The chimney duct must be cleaned of soot twice a year, and the head part of ice, snow or condensate frozen on it. Sandwich pipes do not require additional insulation, except for the section of passage through the partition or wall. For this purpose, it is better to use fire-resistant insulation and eliminate the use of glass wool. The area where the pipe runs through the wall must be insulated using ceramic or basalt wool, asbestos or foamed vermiculite. The use of asbestos does not cause problems; at the final stage, the product will not begin to generate dust or release hazardous substances.

When working with wooden walls, you must remember the danger of fire, so installing chimneys in such buildings is much more difficult when compared with brick ones. When the chimney is routed through a wooden wall, the distance from the pipe to the wall must be strictly observed; it should not be thicker than 260 mm. Additionally, you need to take care of the thermal insulation part and treat the walls with fire retardants. When installing a chimney in such a structure, you will need to insulate the surfaces of the walls near the monopipe and the outlet pipe from the heat generator. Such insulation is created using combustible materials, such as tiles, plaster, stone or metal sheets.

https://youtube.com/watch?v=SrXoY-IEbs0

What is it and what is it for?

A chimney is a system of pipes, connecting fittings, fastenings and structural protection elements.

In any heating circuit with a stove or boiler in the form of a heater, including those running on gas, this system performs 2 main functions:

1. Discharge of combustion products into the atmosphere.
2. Ensuring the supply of fresh air for complete combustion of fuel.

If the chimney does not cope well with at least one of its tasks, that same dangerous carbon monoxide will inevitably enter the human body.

With proper design, the chimney facilitates the operation of the boiler, increases its efficiency, provides a comfortable microclimate in the room and safety for the residents of the house.

Installation of stainless steel pipes

A single-wall chimney pipe can be installed either indoors with further lining with heat-resistant and fire-resistant material, or in an existing brick chimney (chimney liner).

Provided that double-walled stainless steel chimney pipes with sandwich thermal insulation are used, installation can be carried out both inside and outside the room. . This type of chimney pipes is reliable and durable (fire safety, corrosion resistance, etc.). Due to its increased fire resistance, stainless chimney pipes are usually installed in bathhouses and wooden houses.

Installation of single-wall stainless steel pipes

One of the easiest ways to install chimney pipes is to “chimney liner” (see Chimney repair). The stainless steel pipe for the chimney is lowered into the existing brick chimney, after which it must be connected to the pipe of the heating unit - this is done to avoid condensation on the brickwork, which is formed from the chimney gases.

A chimney without a pipe absorbs condensate, resulting in the destruction of the chimney.

https://youtube.com/watch?v=6JGzRnrPgyE

Installation of double-walled pipe with thermal insulation

Installing a chimney pipe with thermal insulation is considered more difficult. A chimney pipe made of stainless steel “sandwich” is a double pipe of a larger and smaller diameter, which is inserted into one another. The layer between the pipes is made of fire-resistant material - basalt.

Double wall pipe with thermal insulation

When installing pipes with thermal insulation, some nuances should be taken into account:

When joining “sandwich” pipes, it is important that inside the “sandwich” the upper pipe fits into the lower one, and outside the “sandwich” the lower pipe fits into the upper one (fitted). Not all manufacturers take this into account, so before installation you need to take this point into account and, if necessary, pull out the inner pipe, turn it over and insert it back.

When joining, it is advisable to use a heat-resistant sealant.

The joints of the outer sandwich pipe must be secured with self-tapping screws. Incorrect installation of a double-walled pipe with thermal insulation can lead to the appearance of stains and streaks on the outer sandwich pipe.

Improper installation of a double-wall pipe with thermal insulation can lead to stains and streaks on the outer sandwich pipe.

Options for the location of chimney pipes

Installation of pipes starts from the bottom (from the heating system upwards). Before installing the chimney pipe, it is necessary to prepare a passage between the ceiling. A special adapter pipe can be purchased at the store. It is needed to insulate the ceiling from overheating.

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Prepared adapter pipe

The inside of the adapter pipe must also be protected from heat. This is done using foil mats made of basalt fiber.

Then you can begin installing the pipes. The stainless steel pipe for the chimney is installed in such a way as to avoid joints in the transition pipe.

For ventilation and cooling, it is necessary to provide clearance between the via and the pipe. Next, you need to check the level and secure the protective elements of the adapter.

The pipe also needs to be additionally secured to the wall. This can be done using brackets, which should be installed every 2 m.

To clean the smoke duct, it is necessary to provide a removable part or door, which is located at the bottom of the chimney.

The chimney is cleaned twice per heating season.

Main advantages

Chimneys made from asbestos-cement pipes were in demand due to their low cost, despite their low practicality. Brick structures are still actively used today, including due to their solid and impressive appearance, but they are increasingly being modernized with the help of stainless steel inlays. The list of advantages of a chimney made of stainless steel includes:

• Light weight. The chimney does not require a foundation, which reduces the cost and speeds up installation work.
• Corrosion resistance. Stainless steel is resistant to acids contained in smoke condensate and dangerous for brick and asbestos cement.
• Resistance to temperature changes. The metal can withstand cooling to low temperatures on frosty days and heating by flue gases up to 800 degrees Celsius or more.
• Effective chimney removal. Good traction is facilitated by the round cross-section of the pipe.
• Low maintenance. There is practically no soot deposited on the internal walls of the chimney channel (unlike rough walls made of brick or asbestos cement), so it rarely needs cleaning.
• Easy installation. The configuration of standard elements allows for quick assembly of pipes of any length.
• Maintainability. The modular system allows, if necessary, to change only the element that has failed, which reduces the cost of operating the smoke exhaust system.
• Long service life (subject to the correct selection of manufacturing materials and proper installation).
• Versatility. A stainless steel chimney is suitable for any type of heating unit.
• Freedom of installation. It is not necessary to mount a strictly vertical structure; inclined elements and turns are allowed, which simplifies the search for a convenient place to install a boiler, fireplace or stove. A pipe with internal insulation can be installed outside the building - in this case there will be no need to install passage units through the floors and roof.
• Affordable price.

Chimney components

Materials and tools for making a chimney

Before you start purchasing parts, fasteners and tools to perform this work, you need to decide on the design of the device and complete a preliminary design, an integral part of which is a material list, which lists all the necessary parts. By adding the cost of materials to this list, you will receive a cost estimate.

Before construction, it is recommended to sketch the chimney

Installation of the device is carried out from the bottom up, that is, from the stove to the top, for which you will need:

• a transition device made of fittings from the furnace to the pipe; depending on the design, a branch may be required;
• multilayer pipe;
• gate;
• fireproof material for the passage through the ceiling;
• plates made of galvanized sheet, approximately 500x500 mm in size - to close the passage;
• materials for insulating the intersection of the roofing pie, for example, a probe for protection from the outside;
• chimney head;
• clamps for fixing connections at the rate of 1 pc. for each;
• brackets for attaching chimneys to walls (depending on its design);
• collection for draining condensate;
• high-temperature sealant for sealing joints;
• steel pipes at the rate of 1 pc. per meter of chimney;
• stainless steel wire for guy wires;
• screws, nails.

The list of tools is small and may look like this:

• drill with drill bits for concrete and wood;
• jigsaw;
• screwdriver or wrench for installing fasteners;
• plastic inserts (dowels) for attaching brackets;
• hammer.

Depending on the design of the chimney, other tools may be needed; this will become clear when drawing up a preliminary design.

Frequent errors and problems during installation

• Incorrect configuration. Unjustified deviation from verticality, sharp bends and excessive horizontal lines reduce the traction force in the circuit.
• Insufficient or excessive shaft height also reduces the efficiency of the chimney.
• If the pipe head enters the wind pressure zone, it provokes a backdraft effect.

• The use of stainless steel of insufficient strength leads to its rapid wear and threatens to burn out the steel.

Location rules

Location on the roof
When designing the installation of such combustion product removal systems, take into account the standards provided for by technical standards:

• The roof duct outlet, located on a flat roof or 1.5 m from the ridge, must have a height of at least 0.5 m.
• The chimney, located at a distance of 1.5–3 m from the ridge, reaches its level.
• The edge of the pipe, located at a distance of more than 3 m from the ridge, is flush with a line 10° from the horizon of the ridge line.
• The minimum height of the chimney is 5 m, the maximum length of the horizontal section is 1 m.
• The thickness of the channel walls for solid fuel boilers is 1 mm, devices on
• liquid fuel - 0.8 mm, for gas appliances 0.5–0.6 mm is sufficient.
• The joints of the structure do not fall on the floor.
• The passage through the roof of the sandwich pipe has a gap of 13 cm, through the ceiling - 20 cm.
• The permissible number of turns of smoke exhaust channels is 3. The diameter of the pipe is not less than that of the outlet pipe.

Chimney pipe diameters

Each type of product under consideration has two diameters: external and internal. The selection of products by size must be carried out taking into account the equipment used. The lower the boiler power, the smaller the diameter of the flue is needed for its installation.

In the table below you can see the main sizes of stainless steel pipes for a chimney.

Sandwich pipe size chart for chimney. D—pipe diameter, H—segment length

It is important that the internal size of the flue is equal to the cross-section of the boiler outlet pipe. It is the inner surface of the starting tube that receives the main impact from the exhaust gases. Therefore, it must match the diameter of the outlet pipe. The main parameters of heating units are specified in the requirements of SNiP.

The dimensions of chimney pipes can be as follows:

• fittings - tee angle: 135, 90, 45 degrees, bend: 90 and 45 degrees;
• thermal insulation size - from forty to sixty millimeters;
• length of the pipe product - from 0.5 to 1 meter;
• steel thickness of the inner pipe (sandwich) - from 1 to 0.5 millimeters;
• outer diameter - from two hundred to four hundred and thirty millimeters;
• internal section - 200, 150, 120, 115, 110 millimeters (there are options up to 300 mm).

There are many additional components that facilitate the installation of a flue structure.

There is a wide variety on sale:

• braces, clamps and brackets;
• support platforms and protective aprons;
• head, plugs and weathervane caps;
• roofing seals;
• decorative overlays for passage units;
• compensators necessary to regulate changes in the linear dimensions of sandwich structures when changing temperature conditions;
• inspection tees designed to remove contaminants.

The presence of a large assortment of additional components can greatly reduce the cost of erected structures. Sandwich chimneys are easy to assemble. Their installation can be carried out independently, without the involvement of specialists.

Installation features

When installing a chimney, it is recommended to follow a number of rules.

The basic rule is that all objects surrounding the pipe should heat up by no more than 50 °C. Steel ones tend to heat up, so when installing them it is recommended to lay an additional layer of thermal insulation. This problem can be solved using ready-made sandwich systems.

The chimney must be located at a safe distance from electrical wiring, gas pipes and trees.

Where the pipe passes through walls or roofing, there should be a thick layer of heat-resistant sealant between it and the appropriate material. The same sealant is laid between the pipes at their joints.

When connecting, they are guided by one more rule: one pipe must enter another at a distance that is equal to the radius of the outer section of the pipes.

When assembling the structure, it is worth considering that the chimney should not have any narrowing areas, otherwise the aerodynamics of the pipe will suffer.

Horizontal sections should not be longer than 100cm.

An inspection window is installed at the bottom of the chimney - a removable nozzle. The upper part ends with a head with a spark arrester and a cone.

Connecting and checking traction

Connection to the gas pipeline can only be carried out by a specialist. To do this, apply to the local gas service (waiting period 30 days)

IMPORTANT! Installation of a chimney for a gas boiler is carried out in accordance with SNiP (building regulations) and basic fire safety requirements.

Any equipment that operates on a hazardous energy carrier, such as gas, must be installed in compliance with all rules.

First of all, they carry out all engineering and technical calculations, draw up documentation, and then obtain permission from the gas service. And only after that they implement the project - on their own or with the involvement of specialists.

Disadvantages of a steel chimney

In addition to the advantages, steel pipes have a number of disadvantages. Their main disadvantage is the rapid absorption of heat. Steel heats up quickly, so they need to be insulated. If this is not done, the pipe may heat the materials it comes into contact with and cause a fire. In addition, when it gets hot, it loses its ability to extinguish sparks that occur in the chimney.

Another disadvantage of steel pipes is the large formation of condensate. This feature of the material can vary in severity depending on the coating and type of structure. The least condensate falls on straight pipes without horizontal outlets.

Which one is better to choose?

When choosing a smoke exhaust duct, you need to focus on the optimal combination of budget, gas boiler power, type of fuel combustion chamber and general design features of the building.

The installation of an external chimney saves internal space and is safer for the residents of the house, but such systems are susceptible to environmental influences, so their service life is shorter.

Types of chimneys depending on the type of gas combustion chamber:

• Open chamber boilers

Floor-standing gas boilers are often made with an open firebox. Such devices require a chimney that provides consistently good draft. Brick, ceramic, single and sandwich pipe chimneys are suitable. But it should be remembered that a brick chimney is hygroscopic and difficult to install, while a ceramic chimney is very heavy.

• Boilers with a closed combustion chamber

In this case, most craftsmen recommend installing a coaxial chimney, or a system of sandwich pipes, tees and fittings.

Features of operation

Metal chimneys, having a lot of undoubted advantages, require increased attention both during assembly and during operation:

1. They should not be located near other utilities, such as electrical wiring or plumbing.
2. Before starting installation work, the internal longitudinal seams of the pipes must be coated with a special sealant, since they are subject to temperature changes, which gradually weakens the joining edges.
3. When cleaning stainless steel pipes, it is better not to use traditional metal balls with a wire “hedgehog”. Their influence deteriorates the mirror inner surface, making it difficult to drain condensate into the storage tanks. It is better to choose a brush made of synthetic materials.

Material selection

To make stainless steel pipes for chimneys, various grades of steel are used. The service life of the product and its resistance to burnout when soot ignites in the pipe depend on the choice. The higher the quality of the steel, the more expensive it is. Be sure to take into account the frequency of operation of the chimney - the requirements for the chimneys of boiler units that operate around the clock during the heating season are higher than for the pipes of sauna stoves that are fired from time to time.

Selection of stainless steel material
In private housing construction, stainless steel pipes of grades 409, 430, 439 are predominantly used. With periodic operation (weekly heating of a sauna stove with wood), such a system will last about ten years. On boilers in load mode 24 hours a day, the average service life will be 2–3 years. To extend the service life of the chimney system, it is recommended to install it from 3XX stainless steel.

Features of transition of sandwich pipes in floors

In size, such a structure must exceed the thickness of the ceiling by at least 70 mm. It is these parameters that make it possible to ensure high-quality protection of the ceiling from fire.

In this case, you need to pay special attention to the quality of the box fastening

It is important that the pipe mounted in the box does not have joints. Before directly installing the dividing box with your own hands, you need to correctly mark it

It is possible to make a hole in the ceiling only if the dimensions of the box are known and the pipe in it is correctly located.

After the box with the pipe is installed, it is properly insulated. For this purpose, it is better to use basalt mats with a foil base. The hole made in the ceiling is also subject to insulation. For this purpose, mineral wool or other heat-insulating material that is not subject to fire is used.

Stabilizer draft limiter in the chimney

The valve is a limiter, a draft stabilizer in the chimney.
The opening force of the valve is regulated by moving the weight below. to install an automatic limiter or draft stabilizer in the chimney . A draft limiter is a valve that is installed in the chimney. During draft surges, the valve opens under the influence of a pressure difference and lets cold air from outside into the pipe. The intake of cold air reduces the draft in the pipe. Automatic draft limitation stabilizes the boiler operating mode.

Three options for installing a draft stabilizer valve in the chimney

The valve must be placed in the same room as the boiler. On sale you can find valves for different chimney designs. Home craftsmen come up with designs and make them themselves.

Features of installing a sandwich pipe on the roof

To bring the sandwich chimney above the roof level, a special link is used, called “roof cutting” by stove makers. Such a structural element should be selected based on the slope of the roof structure. Only taking into account this parameter, all work on the removal of the chimney above the roof will take place without any problems. Doing such work yourself consists of the following steps:

1. Using a marker, mark the inside of the roof.
2. A hole is installed in the roof structure that matches the diameter and thickness of the sandwich pipe.
3. For insulation, a sheet of galvanized metal is fixed to the roof structure, in which
4. a hole is cut in advance for the chimney pipe, through which it will come out.
5. A groove is mounted on top, on top of which a sandwich pipe is assembled, the length of which must correspond to the calculated parameters.
6. At the finishing stage, the edge of the sandwich chimney is protected from precipitation by an umbrella-shaped tip.

As you can see, self-installation of a sandwich chimney is not as simple as it might seem at first glance. But if you familiarize yourself with all the materials and videos, all the work on installing sandwich pipes can be done independently.

However, before deciding on experiments of this kind, you need to sensibly assess all your capabilities, and if you are not confident in them, then it is better to entrust all the work to professionals.

Homemade pass-through unit

Internal installation of a stainless steel chimney is more demanding for the master: the main difficulty lies in one device - the ceiling-passage assembly, which guarantees the necessary clearance, as well as high-quality waterproofing. You can make a similar detail yourself. This is a box that has a hole in the center for a pipe. The height of its walls is equal to the thickness of the ceiling (wall, roof).

1. First, the necessary hole is made in the structure, then the edges are further strengthened. Two blank plates are cut out of a metal sheet (usually from the same stainless steel), the sides of which are 50 mm longer than those of the prepared hole, the height is equal to its height.
2. These “extra” 500 mm are bent at a right angle. The elements are secured on both sides of the hole made with self-tapping screws. Another pair is made in the same way; they are placed overlapping with the first. Then they make a bottom in which a hole is cut for the chimney. It is laid on plates.
3. The free space is filled with basalt wool or expanded clay. The box is covered from below and above with decorative plates.

Choosing a chimney for a gas boiler

When choosing a chimney for a gas boiler, it is necessary to take into account some features of the device and the parameters of the boiler's exhaust gases, and also take into account the severity of the winter climate. Otherwise, the owner of the house will get into trouble. Here are some “surprises” that may await the homeowner.

The temperature of the flue gases of a gas boiler usually does not exceed 200 °C. In addition, most of the time the boiler operates at reduced power, which further reduces the temperature of the flue gases.

A steel chimney placed outside, on the facade of the house, often does not warm up well. As a result, the condensate on the walls of the chimney flows down into the condensate collector and freezes there. Condensate drainage is blocked by ice. Condensate accumulates, its level rises, and water from the chimney begins to flow into the combustion chamber of the boiler.

For a chimney located outside, it is necessary to arrange heating for the condensate collection area .

Another popular smoke removal scheme for a gas boiler with a fan looks like this: exhaust gases are removed through a vertical chimney channel, and for air flow, a horizontal pipe is laid and discharged along the shortest route through the wall of the house, to the facade. When the boiler burner is not working, due to the presence of natural draft in the chimney, cold air from the street is sucked through a short air intake pipe into the combustion chamber of the boiler. The internal parts of the boiler freeze up and damage the smoke control system. The water in the heat exchanger freezes and destroys it.

Read about the problems of working in a harsh climate with coaxial chimneys of gas boilers in this article above.

Schematic diagram of a two-channel smoke removal system for a gas boiler with forced circulation of exhaust gases

In harsh climates, for a gas boiler with forced gas removal, a two-channel smoke removal circuit works most reliably. One vertical duct serves as a chimney, and the other vertical duct serves as an air intake. To stabilize the air flow and eliminate natural draft through the boiler, the chimney channel in the lowest part is connected to the air intake channel by a jumper - a bypass.