What pipes are needed for the solid fuel boiler

Chimney for a solid fuel boiler

Immediately after the installation of solid fuel boilers should begin creating a system for the emission of gas and smoke. To perform this work, you can entrust the hired masters, but it will cost money. Self-installation will not only save money, but also to fully understand the chimney structure, which is useful for its future use and maintenance.

To order or make a chimney for the solid fuel boiler with their own hands. which is more profitable?

The answer to this question is not as obvious as it seems. By design, solid fuel boilers are similar to conventional stoves. And it may seem that the device chimney for it. a simple task. It is not necessary to succumb to this misconception. For qualitative removal of products of combustion a well thought-out, solid and reliable construction is necessary. Ignoring these rules is inadmissible, because the lives of people living in the room depend on it. Leaky material joints or design flaws lead to harmful carbon monoxide getting in.

Therefore, in the absence of skills stove installation is more reasonable to entrust such a responsible work to a professional. If you have experience and confidence in your own abilities, you can carry out the installation with your own hands. However, the calculation of chimneys for solid fuel boilers is better to order in the profile organization.

The device chimney

Regardless of the material used for installation, all flues for solid fuel boilers are structurally similar. The chimney system consists of the same functional components:

  • Chimney. Cylindrical or rectangular section through which the combustion products are removed from the boiler. Must be made of durable and heat-resistant material.
  • Condensate collector. From physics course, everyone remembers that the heated air in contact with the cold surface forms on it condensate. small accumulations of moisture. To prevent water droplets from dripping into the boiler, the chimney must be equipped with a means for their removal from the system. Condensate collector is equipped in its lower part, which is not in direct contact with the boiler, and is connected through a tee.
  • Shiber. a damper to stop the air flow into the system from the boiler. The flue gas venting is necessary for economical operation. to prevent the escape of warm air into the outside environment after the stoking of the boiler.

This is a typical flue diagram. When working with specific materials, it may have slight differences and additions. For example, steel chimneys are equipped with a compensator of linear deformation. It is responsible for the tightness and reliability of the system, because the constant cycles of heating and cooling leads to loosening of the chimney. This reduces the tightness of components.

pipes, solid, fuel, boiler

Installation rules

  • Fire safety should be the most important guideline for the construction of the chimney for solid fuel boilers. Distance from the chimney walls to other surfaces must be at least 38 cm. When building an internal chimney you must be extremely careful to insulate the places where it passes through the ceiling.
  • The walls must not be less than 10 cm, including the insulation.
  • The height directly affects the efficiency of gas extraction and the strength of the draught in the chimney system. It is necessary that the top point of the chimney is at least one meter away from the roof.
  • The exact calculation of the internal cross-sectional area. It is necessary that this value remains constant throughout the chimney to avoid lowering the efficiency.
  • The maximum length of horizontal sections in the system is 1 m.
  • The design must have a condensate collector and doors for maintenance.

How to calculate the diameter of the chimney for a solid fuel boiler

The correct chimney for the solid fuel boiler with their own hands How to make a chimney for solid fuel boilers with their own hands. Chimney types for solid fuel boilers. Chimney design and installation features.

How to provide a reliable chimney draught

As mentioned above, a good and stable draught is the main requirement for any chimney system. Draught arises from the temperature difference. hot air from the burning boiler rises up. carrying along the gases produced during combustion.

Other important factors affecting the intensity of draft are the pressure difference in the furnace and in the atmosphere, temperature differences in the flue gases, wind force and direction, uneven combustion of fuel and other.

Temperature in boilers, working on wood, after giving out heat in the heating circuit can vary from 100 to 350 degrees, and with some high-calorie fuels can reach higher values. The temperature rises sharply when the boiler is fired up, and stabilizes in the transition to standard operation. All these factors have a direct influence on the draught.

Diagram of relationships between the type of heater, the temperature in the chimney and the material of its manufacture

In the diagram below you can see approximate temperature values at the outlet of different types of radiators, the corresponding degree of danger or vulnerability of different chimney systems, recommended materials for installation of chimney pipes.

In addition, you must consider the design of the chimney. its length and size of the cross-section of the pipe, the number of bends and knee turns, as well as the degree of smoothness of the inner surface.

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Optimal for good draught is a straight chimney with a circular cross-section

If the chimney is straight, without turns and narrowed to the outlet, the draft in it will be the highest, as the hot air rises up on the principle of the spiral. creates additional turbulence in the flow.

If you do not take into account all of the above parameters, the removal of combustion waste will meet on the way obstacles in the form of irregularities in the walls and curves. This can lead to mixing of air and gases that have different temperatures, which often leads to the opposite effect, sending smoke into the room. Therefore, when building a chimney is necessary to reduce or completely eliminate the device and the bends.

Chimney types

There are two types of chimneys. for gas and solid fuel boilers. Regardless of the type and shape of the chimney, its most important indicator is the draft. It affects the speed of movement of combustion products. There is a draft due to the difference in temperature and pressure between the street and the house. As practice shows, the draft in the flat chimneys that do not have any bends, much better.

Chimneys are of different types

Pay attention! The length of the chimney also affects the draught. Products of combustion in straight sections of the chimney are gaining speed, due to which the flow of smoke increases.

The chimney length affects the draught

For solid fuel boilers

Several factors can indicate the quality of the draft in the chimney for solid fuel boilers. These include:

When buying a chimney you need to pay attention to the thermal resistance of the product. During combustion, the temperature of the gases is high enough, so the material from which the chimney is made, must be able to withstand such temperature fluctuations without any problem. For the manufacture of chimneys can be used different materials, such as steel, ceramic or special fire brick.

The chimney selected must be heat-resistant

The product of refractory bricks can withstand temperatures up to 800 degrees, while retaining all its characteristics. That is why bricks are often used for interior cladding. But this material also has disadvantages. For example, during prolonged heating condensate appears on the brick, which over time leads to damage to the chimney.

Horizontal and vertical placement

Steel is the second most popular material for chimneys. Stainless steel or black steel is used, but black steel products are not durable. They are unstable to various irritants. If we talk about stainless steel, then such products are not exposed to external irritants, so they serve much longer. Such performance is achieved by the special chemical composition of the material.

For gas boilers

These chimneys must be high quality and safe. It is worth noting that chimneys for gas boilers have one problem. the emergence of condensation. Condensation is usually due to improper installation of the chimney or the ingress of cool air. As in the case of solid fuel boilers, chimneys for gas boilers are made of different materials. The variety of products creates additional problems when choosing, so it is important to familiarize yourself with the main types of chimneys designed for gas boilers.

Chimney for a gas boiler

Table. Variety of chimneys for gas boilers.

Name, photoDescription
Made of stainless steel Products made of this metal are easy to install. In addition, stainless steel is quite resistant to irritants acid nature. Durability of chimneys made of stainless steel, much longer than products made of conventional steel.
Enameled The inner surface of the products is not exposed to soot accumulation, so the enameled chimneys are well suited for gas boilers.
Sandwich chimney A variety of chimneys, mainly used for homes without a brick shaft. Among all the advantages of the sandwich is the inability of the chimney to accumulate moisture. This is important, especially for buildings made of timber.
Coaxial Coaxial chimneys are used in those cases where the constant circulation of air in the building can not be provided. The product itself is two pipes of different sizes inserted into each other. The chimney ensures the complete combustion of the fuel in the boiler.

The main types of chimney assemblies

Please note! Install a closing flat valve on the chimney for gas boilers is strictly prohibited. Therefore, such chimneys have a conical shape in the upper part.

To each his place

If the house is installed several heat generating devices, each device requires installation of a separate chimney, or their connection should be made through a common compensating collector. Its parameters are calculated depending on the power of the units to be connected.

Every chimney has its place

No need to connect the flue pipe to the ventilation system. Install the flue pipe should be so that its output was above the ventilation pipe, as well as placed at a certain distance from the windows. at least 400 mm.

Types and designs

There are several varieties of chimneys for gas boilers:

  • Brick chimney (both as an independent system and with an internal insert made of stainless or galvanized pipe);
  • Single metal (made of galvanized or stainless steel sheet); (ducts made of two metal pipes inserted one into the other, with insulation put between them);
  • Coaxial (smaller diameter pipe inserted into a larger pipe, with no insulation padding);
  • Ceramic (made of special ceramic blocks);
  • Asbestos-cement.

All designs are schematically presented in the figures in the section “Drawings and diagrams”.

You can install the chimney both indoors and outdoors.

Common installation mistakes and problems

The most common mistake is not insulating a single layer pipe. Inside the house it can cause combustion of flammable structures and objects and burns people. Outdoors, lack of insulation causes many very unpleasant consequences:

  • Combustible gases cool down very quickly, the draft decreases, and combustion products or even carbon monoxide can enter the room and cause poisoning. In case of frost, there can even be a reverse draught, a very dangerous phenomenon;
  • A very large amount of condensate settles on the walls, which leads to rapid failure of the chimney.

Do not install the chimney without the deflector or at least a cap. the snow and rain must not get into the hatchway and the channel.

It is necessary to provide the access to the boiler with the necessary amount of air. a special window must be permanently open in the boiler room.

Chimney must be straight. In extreme cases, allowed sloping and horizontal sections of length not exceeding 1000 mm each and the total length of their projections to the horizontal no more than 2000 mm. The angle of inclination not more than 30 ° from the vertical (allowed 45 °).

The length of the chimney is increased by the sum of the lengths of projections to the horizontal.

If the chimney passes in the same place with the ventilation ducts, it must be higher than the other channels, the vent ducts must be covered with a cap below the head of the gas pipe. This protects against the possible ingress of combustion products into the room.

What is the best chimney for a solid fuel boiler

The pipe for the solid fuel boiler must be heat resistant. The combustion temperature ranges from 200⁰ wood to 600⁰ coal. In some cases, the air entering the chimney is heated to 1000 ⁰ and the outlet channel must withstand.

These requirements are met by materials:

Each of them has its own positive sides and disadvantages.

The design of the chimney of solid fuel boilers must meet the following characteristics:

  • Provide a good draught;
  • Have a design that is easy to dismantle and maintain;
  • Resist corrosion;
  • Have smooth inner walls;
  • To be well insulated from the cold;
  • fireproof;
  • Have an aesthetically pleasing appearance.

Build a chimney with your own hands or a hired team of professionals for a long time. The design is expensive and difficult to repair. Therefore, the operating life should be long, measured in decades.

brick chimney

The output channel made of brick for solid fuel boilers is constructed according to the classical scheme, as chimneys of fireplaces have been erected for centuries. A dome is installed over the combustion chamber, collecting hot air in a single stream. In modern equipment, this is the dispersed section immediately behind the outlet pipe from the body. Stove masonry chimney made of brick provides several channels to divert gas with bends. It fits a solid fuel boiler, but requires for maintenance in each “” to create access to clean it of soot and debris. It is advisable to use a brick chimney when it is left after the dismantling of the furnace and a solid fuel boiler is simply connected to it. Then the flue duct is hermetically connected to the outlet of the combustion chamber.

  • withstands high temperatures without destruction;
  • is fireproof;
  • has a damper;
  • laid out of thermal insulation material;
  • beautiful aesthetic appearance.

Furnace chimneys are equipped with dampers that allow you to regulate the draft, increasing to a maximum the area of the exhaust duct at ignition and then reduce it, reducing the activity of combustion and heat output outside. It is convenient when using firewood in the combustion chamber.

In the long burning process, the diameter of the exhaust port is calculated based on the capacity of the boiler. The cross-sectional area of the hole along the entire length of the pipe must be the same. The damper will be an obstacle to the uniform movement of air.

Installation of a chimney for solid fuel equipment made of brick is complicated, with many disadvantages when compared to modern designs and materials:

  • Complex chimney layout, laying bricks in layers;
  • Time-consuming and complex technology;
  • Requires the creation of a supporting foundation;
  • a lot of debris;
  • it takes a long time for the cement mortar to harden;
  • The work is performed only in the summertime;
  • The rectangular shape of the exhaust duct;
  • high heat capacity;
  • rough walls.

The amateur does not know how to properly make a chimney from bricks. It is necessary to hire a stove operator with extensive experience. When moving upward, the flow of hot air spirals. The corners create an obstacle to this process. They inhibit the gases and accumulate soot.

Additionally, fine particles of combustion products settle on the rough walls of the. The brick is an insulating material. The dew point is displaced from the inner surface of the outlet duct into the masonry. But it takes a lot of heat to heat and dry the pipe itself.

pipes, solid, fuel, boiler

The hot stream cools down quickly, especially at the beginning of the ignition and combustion process. Occurrence of reverse draught when the cooled air does not go out, but falls down. Made of brick construction has a complex chimney arrangement of solid fuel boilers.

  • foundation;
  • pipe riser;
  • The opening in the places of overlapping;
  • the otter in the place of the passage through the roof;
  • The neck above the roof;
  • header.

All elements are made by masonry brick to expand the structure from the outside, narrowing of the outer dimensions while maintaining the same size hole inside. To avoid ignition of adjacent materials roofing and interfloor ceilings, it is necessary to do insulation, filling the gap with foam with low thermal conductivity.

Sandwich chimney

Install the flue of solid fuel boilers is more practical with sandwich pipes and fittings designed for them. In a private home exhaust structure can be placed inside the building and outside.

The pipeline is assembled from the individual elements that comprise it:

On one side of the pipe parts have an expansion of 1. 2 mm without thermal insulation between them. The vertical pipeline section is assembled like lego, the pipe elements are inserted into each other.

Over time in the joints strength and tightness can be destroyed. Installing the exhaust pipe, use for hardening clamps. In the wall to fix the structure are hammered spikes, and the sandwich construction is firmly fixed.

The advantages of such a design for the removal of smoke from the solid fuel boiler:

Of the disadvantages can be noted only the high cost of pipes and fittings, and a short life. about 15 years. Sandwich pipe installation is made on the dew, this is when the moisture flows down freely, without meeting obstacles in the form of protruding ends. The size of the hole is matched to the pipe coming out of the boiler.

Steel

Installation of a solid fuel boiler with steel construction looks beautiful. Pipes and fittings are made of stainless steel with a perfectly smooth inner surface. The design is characterized by a mirror shine.

But such a system does not work well if you do not make insulation, especially the elements that are outside. Positive qualities of the steel flue duct:

No insulation and high heat output of steel can be used as an additional heating element inside the house. In this case, the chimney length is determined by experimenting with the maximum intensity of draught.

Types and details

Modern ceramic chimneys are superior to the obsolete brick masonry, but are also able to withstand extremely high temperatures (sometimes up to 1200 ° C). Simply put, they can be installed on any powerful solid fuel boilers. Three-layer construction provides full compliance with the requirements for the chimney:

The smooth inner surface of the duct does not create obstacles in the way of the outgoing flow.

Insulating layer allows to get rid of the problem of condensation.

The outer claydite concrete shell partly performs the function of thermal insulation, but mainly provides sections with mechanical strength.

But the ability of ceramics to absorb moisture through the outer pores cannot be attributed to the advantages. But the problem is solved by the organization of ventilation for the outer walls of the chimney. So, the only disadvantages are labor-intensive assembly and high price. But if the heating solid fuel boiler works on coal, these systems can not be avoided.

The most popular today are steel chimneys. And they clearly win on those parameters where ceramics were not up to the mark. But their metal walls have a good heat transfer capacity, so they must be insulated from the enclosing structures and the cold air. Plus the life of steel in such aggressive conditions is short.

Thermal insulation of the single-circuit chimney do themselves, but it is easier to buy ready-made sandwich pipes. By their design, they are remotely reminiscent of the already discussed ceramic. Branch is insulated with basalt wool, the outer shell can be galvanized or enamelled steel. But the inner tube is only made of corrosion-resistant metal.

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First of all, when selecting a chimney to take into account the fuel that operates the solid fuel apparatus. It is all about the temperature of the outgoing gases:

  • Wood. when burning in the furnace of a solid fuel boiler produces 300 ° C.
  • Coal. about 500-700 ° C (depending on the brand).
  • Pellets. only 120-250 ° C.
  • Sawdust and pellets. short term 220-240 ° C.

The low output temperature is also found in pyrolytic boilers, since their operation scheme is based on taking away heat energy from the products of combustion still in the furnace. So under the gas generator equipment can take the chimney from stainless steel. Wood units normally work with ferrous metal, and for coal only ceramics are suitable. But even here you need to look at the marking. the number after the letter designation “T” will show at what temperature is allowed to use pipes. However, this is only general advice. the recommended type of chimney is indicated in the passport of the solid fuel boiler.

In addition to thermal resistance, corrosion resistance must be taken into account. Most of the discussed chimneys have the right properties, but the pipes of ferrous metal in this regard are in last place. Therefore, it is desirable to buy a rolled product with the maximum possible wall thickness, regardless of cost. The stainless steel alloys are better, but before you buy a chimney, ask about the used brand of steel.

With their task well copes AISI 321 (analogue of 12X18H10T) and 316L (it 03X17H14M3). By the way, it is on the Russian marking of stainless steel alloys is easier to determine which chimney is better to choose for a solid fuel boiler. The percentage of chromium (second digit after the letter X) must be equal to or greater than 17%. This means that the metal is resistant to corrosion, even under the influence of aggressive flue gases in the chimney.

Chimney for a solid fuel boiler

The chimney. is one of the most important elements of the autonomous home heating system, without which it can not function properly and safely. It can be made of metal or ceramic pipes, or made of brick. Its main purpose is to divert gaseous waste products of fuel combustion from the boiler, and prevent their penetration into the premises of the house.

The smoke flue for the solid fuel boiler must be highly efficient and reliable. because the efficient operation of the heater itself depends on it, and therefore. room temperature. To ensure that the process of extracting gases passed normally, you need a good draft, which determines the effectiveness of the chimney system.

For the right choice of chimney for a particular boiler you need to study the technical characteristics of the system, which will help to learn about its performance and quality.

Since the entire design of the chimney primarily aimed at achieving a good draft, this property is the first thing to consider.

How to provide a reliable chimney draught

As mentioned above, good and stable draught is the main requirement for any chimney system. The draught arises from the temperature difference. hot air from the burning boiler rises upwards. carrying away with it the gases formed during combustion.

Other important factors affecting the intensity of draft are the pressure difference in the furnace and in the atmosphere, temperature differences in the flue gases, wind force and direction, uneven combustion of fuel and other.

The temperature in wood boilers, after giving out heat to the heating circuit may vary from 100 to 350 degrees, and with some high-calorie fuels can reach higher values. The temperature rises sharply when the boiler is fired up, and stabilizes in the transition to standard operation. All these factors directly affect the strength of the draught.

Diagram of relationship between the type of heater, the temperature in the chimney and the material of its manufacture

The chart below shows approximate temperature values at the outlet of different types of heaters, the corresponding degree of danger or vulnerability of different chimney systems, recommended materials for installation of chimney pipes.

In addition, you need to consider the design of the chimney. its length and size of the cross-section of the pipe, the number of bends and knee bends, as well as the degree of smoothness of the inner surface.

Optimal for good draught is a straight chimney with a circular cross-section

How to install a boiler stove

If the chimney is straight, has no turns and narrowed to the outlet, the draft in it will be the highest, as the hot air rises up by the principle of the spiral. creates additional turbulence of the flow.

If all the above parameters are not taken into account, the exhaust of combustion wastes will meet on the way obstacles in the form of irregularities of walls and curves. This can lead to mixing of air and gases having different temperatures, which often leads to the opposite effect, directing the smoke into the room. Therefore it is necessary to reduce or completely eliminate elbows and bends when building the chimney.

Rules for the effective operation of the chimney

For the safe and effective operation of the chimney system, which is designed to create a comfortable atmosphere in the house, it is necessary to adhere to certain requirements for this design. These can include:

  • Ensuring a stable draught, as already mentioned above.
  • Resistance of chimney materials to high temperatures.
  • Protection against the penetration of moisture and the emergence of condensation.
  • Resistance to aggressive influences of the environment and gases emanating from the channel.

Building regulations specify the following requirements for chimneys:

  • The chimney must be at least 5 meters high.
  • If metal parts are used for this element of the heating system, they must be made of stainless steel, with a thickness of at least 0.5 mm.
  • Diameter of the metal flue must match the size of the metal boiler spigot or slightly exceed it.
  • Metal chimney should not have more than three turns or bends, and their radius should not be less than the diameter of the chimney.
  • Brick chimney is more complicated in its construction, and consists of several chimney ducts. At the bottom of each of them there should be a chamber or for the collection of soot deposits. Each chamber is equipped with a door, which allows you to clean the channels when the draft in the chimney is reduced.

All these requirements contribute to rarefaction of flue gases, creating a good draft and as a consequence the effective operation of the boiler.

Chimney designs

Since the smoke best comes out on a spiral trajectory, the optimal shape for the chimney would be round or oval cross-section, which will provide the most efficient removal of gases. In selecting a square or rectangular cross-sectional area, as is usually the case with brick chimneys, the draft is significantly reduced, the corners created unnecessary whirls of air and smoke can even go in the opposite direction. In addition, on the inner surfaces of such a pipe much more soot deposits are collected.

pipes, solid, fuel, boiler

For each individual building and heating boiler selected for individual parameters, but the principle of construction is the same, the purpose of which is to create a good draft.

  • Straight pipe, coming out through the attic floor and roof, has a simpler structure and is much more efficient in operation, because when heated, it gives the heat to the rooms through which it passes. Straight pipe is good to install in a two-storey house, because the heat coming from it will additionally warm the room on the second floor.
  • Chimney coming out through the wall and fixed to it from the outside, has advantages. it does not clutter the premises and is completely safe for the occupants of the house, because if there is a leak and drained gases from the boiler, they will not fall into the living space.
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