Safe chimneys for stoves. Chimney for a stove: design features and basic installation rules

Choosing the right chimney

For a heating system to function efficiently and safely, the chimney must be properly designed. In addition, you need to take a responsible approach to choosing the material from which it will be made.

There are several types of chimneys.

Types of chimneys depending on material

The main advantage of such a chimney is its low cost. However, there are many more disadvantages here:

fire hazard;
heavy weight;
lack of corrosion resistance;
increased condensation formation.

It follows that this type of chimney is the worst option.

Asbestos is a fairly inexpensive material with good corrosion resistance. However, this option also has its disadvantages:

fire hazard;
increased formation of condensation;
the material is very unstable to temperature changes - due to strong differences, the asbestos pipe may burst;
the presence of asbestos in a house can lead to the development of cancer in people living in this house.

You shouldn’t skimp on your health and safety, which is why asbestos chimneys are used less and less.

3. Brick chimney

The advantages of such chimneys include:

beautiful aesthetic appearance;
high fire resistance;
additional heat transfer.

Among the disadvantages are:

the need to build a foundation for the furnace;
fire hazard (due to improper installation or operation);
the chimney design is not very stable;
brick may crack over time;
If installed or used incorrectly, condensation will form;
high cost of material.

A brick chimney is a fairly good option, but the expensive material and the need to build a foundation are not suitable for everyone.

4. Ceramic chimney.

Such chimneys have several “advantages”:

durability;
resistance to high temperatures (up to 1200°C);
allow the use of all types of fuel.

However, ceramic chimneys also have disadvantages:

the most expensive material;
If installed and used incorrectly, ceramic chimneys become a fire hazard;
a chimney of this type can only have a vertical design;
if the building “leads”, then the structure becomes unstable;
the need to build a foundation.

5. Stainless steel chimney.

Such chimneys have a number of advantages:

beautiful aesthetic appearance;
minimum condensation when installed correctly;
ease of installation;
allow you to install chimneys of any design;
cheaper than brick;
durability;
high fire safety;
there is no need to build a foundation.

The disadvantages of stainless steel chimneys include:

high fire hazard if installed or used incorrectly;
You cannot continuously burn coal, otherwise the chimney will burn out.

Of all the options, stainless steel chimneys are the best option, with an optimal price/quality ratio.

Choosing a chimney depending on the heating unit.

1. Wood burning fireplace

This heating device is one of the hottest. At the average operating mode of a wood-burning fireplace, smoke with a temperature of about 300-500oC will be formed at the outlet. And if an open flame gets into the chimney, the temperature of the gases in it can reach 800°C.

In this case, the fireplace chimney must withstand regular and long-term exposure to temperatures of 500 ° C and short-term exposure to temperatures of about 800-900 ° C. It is also necessary to protect flammable materials in the home from fire.

In addition, the fireplace chimney must be in harmony with the fireplace and the surrounding interior in which it is located. Chimneys made of ceramics in a stainless or concrete shell are most suitable for these requirements.

As another option, you can consider a sandwich chimney made of stainless steel. Here you should pay special attention to the material and thickness of the inner pipe. The material can be austenitic steels with a thickness of 0.5...0.6 mm or ferritic steels with a thickness of at least 1 mm. It is important that the insulation between the inner and outer pipes is of high quality and can withstand high temperatures and does not sinter over time.

Wood burning fireplaces can be viewed

2. Wood-burning sauna stove

In this case, the specificity of the chimney corresponds to the chimney for a wood-burning fireplace. But there is still a difference. In a bathhouse, the design of the pipe does not matter, but its compact location in the steam room is extremely important. The most common finishing material in a bathhouse is wood, so the chimney in a bathhouse must ensure high safety.

The most suitable chimney option for a wood-burning sauna stove is a ceramic pipe lined with concrete. The chimney can be tiled with salt or natural stone tiles to give it not only a beautiful appearance, but also healing properties.

If a ceramic chimney does not suit you, then you should opt for stainless steel. And again, it is important to choose a chimney with high-quality thermal insulation between the inner and outer pipes.

You can see the wood-burning saunas

3. Wood heating stove

The best option would be a stainless steel pipe with an insulation thickness of 30 – 50 mm. If the stove has a “long burning” (smoldering) mode, then it is better to choose a chimney made of austenitic (acid-resistant) steel.

4. Solid fuel, pellet or gas boiler

All modern boilers have very high efficiency: more than 90%. Because of this, the temperature of the gases at the outlet is extremely low. Therefore, there are no requirements for the heat resistance of the chimney. Another factor is important here: the absence of condensation along the entire length of the chimney (or its minimum amount).

The hotter the air, the more moisture it can hold. And when the temperature drops, excess moisture is displaced in the form of condensation. This is exactly the process that occurs in the chimney: as hot gas moves through it, its temperature decreases. If it is -20°C outside and the chimney is laid on the outside of the house, then the temperature decrease occurs very intensively. As a result, moisture is released abundantly on the walls of the chimney. During the combustion of diesel fuel or gas, the nitrogen, carbon and sulfur they contain react with water and form concentrated acids: nitric, carbon and sulfuric. If the chimney is made of materials that can absorb moisture - for example, brick or fireclay, then under the influence of aggressive acids it will quickly deteriorate and may ultimately fail.

Therefore, for boilers it is necessary to use chimneys that are highly resistant to aggressive acids and moisture. It can be ceramics or austenitic (acid-resistant) stainless steel.

Correct chimney

When choosing a chimney, the most important thing to understand is that you cannot choose it based on price alone. Of course, the cost of the chimney is of no small importance, but not the main one.

In order to decide on the choice of chimney, you need to consider the following factors:

heating type used;
type of fuel for the chimney;
type of heating unit used;
proposed chimney installation diagram;
calculation of the operating intensity of the heating system;
assessment of your own knowledge and skills in chimney installation.

There are a number of standards and recommendations for the design of chimneys to ensure constant stable draft. If the smoke channel is not made correctly, then at best the draft will be very weak, and the stove, fireplace or boiler will not be able to fully operate. The worst option in this case is “draft tipping,” that is, exhaust gases escaping into the building and not out. This phenomenon is very dangerous, since it will release toxic combustion products, and this poses a danger to human life.

Safety requirements

When constructing chimneys, the most important condition is strict compliance with fire safety regulations. The main attention should be paid to the passage of pipes through the roof and ceilings. You also need to operate fireplaces and stoves correctly - they should not be overloaded with firewood.

One of the most common types of fire is the so-called “chimney” fire. About 26% of fires in the private sector are caused by improper installation or operation of chimneys and furnaces. Nowadays there are very few people who can install a chimney efficiently, and many cottages and country houses are being built. It is extremely important that the installation of the chimney is carried out by professional installers who are licensed by the Ministry of Emergency Situations and have good skills.

The efficiency of heating stoves and other similar devices largely depends on the design chimney in the house.
Stove chimney pipe designed to remove volatile and gaseous combustion products from the firebox and create draft to ensure the combustion process.
Until relatively recently, all chimney pipes were made either from brick, or from asbestos-cement pipes, or from black non-galvanized metal.
The thing is that when the temperature of the exhaust gases exceeded 100 degrees C, zinc began to evaporate into the room, and its fumes are harmful to health. That’s why they used non-galvanized metal, covering it on the outside with beautiful silver.
Today, chimneys are built from a variety of materials, and each of them has its own pros and cons. So let's try to figure out which pipe to choose for the chimney of your house so that it serves faithfully for decades.

Asbestos cement chimney pipe
Asbestos-cement pipes have been widely used since the middle of the last century. They were cheap, easy to produce, and there was plenty of natural asbestos in the country. Moreover, such pipes could be used without any preliminary insulation for a wide variety of agricultural needs. But they were never intended for arranging chimneys.
During the times of reclamation in rural areas, asbestos-cement pipes were not uncommon, and during the period of mass construction of private houses, they came into use as chimney pipes.
Many opponents of this implementation immediately appeared - first of all, environmentalists who argued that asbestos cement releases many bad compounds into the environment.
Although, according to scientists, asphalt on the road is even more carcinogenic.
But, nevertheless, even the roofs of buildings today are covered with a variety of expensive roofings instead of cheap and durable asbestos.
All these fears and myths have little to do with chimneys made from asbestos-cement pipes.
And at the same time, they are not at all safe - this material was never designed for high temperatures, and can burst already at 300 degrees C. Therefore, if you place them, then not at the stove itself - but as close to the roof as possible, where The smoke is already a little cooled.
To prevent the danger of flying fragments and accidental fire (God forbid) in the hot part of the pipe, as well as in uncontrolled places (attic), it is better to wrap the asbestos-cement pipe with a sheet iron bandage.

There is also another point. Soot forms in any chimney, but the smoother its walls, the less soot is retained on them.
But asbestos-cement pipes have never been smooth, and a lot of soot accumulates on them. And it’s easy for it to catch fire – any stove maker knows this.
Moreover, if the soot catches fire inside an asbestos-cement pipe, it can burst due to temperature. Is it dangerous.
Asbestos-cement pipes are also severely damaged by condensation. Condensate is an aggressive medium consisting of a mixture of combustion oxides and a very small amount of moisture.
Moreover, the oxides contain a good percentage of hydrochloric acid, which even destroys bricks, but asbestos also absorbs it, transferring all this to the building in the form of unsightly stains with the same unpleasant odor.
This means that if you decide to use an asbestos-cement pipe for your chimney, clean it as often as possible.
True, cleaning such pipes is difficult - inspection windows cannot be made in such pipes.

Brick pipe

The construction of a brick chimney has a long history.
Such a pipe is laid out of red stove brick at the same time as the stove. A competent stove maker knows exactly which brick to choose for the stove, even different ones inside and outside, which brick is needed for the chimney inside the attic, and which one is needed for the outside of the chimney on the street.
The inside of the chimney should not be corroded by condensation, and the outside should not be washed away by rain or crack due to temperature changes. Therefore, overheated, underheated and wet bricks should be clearly distinguished.
A pipe made of this material requires periodic repair. In addition, to install a brick pipe with your own hands, you need to use a special solution that is resistant to the combustion process, but at the same time is plastic and heat-resistant.
Since the weight of a brick pipe is very significant, the entire stove-pipe structure is usually one piece and placed on a separate foundation not connected to the house.
Brick chimneys and chimneys are also installed inside the brickwork of the building wall.
Place chimneys and chimneys with bandages on lime or cement-lime mortar inside the house, and above the roof on cement mortar.
According to SNiP, wall channels are made of high quality red solid brick, with a seam no thicker than 10 mm. The inner surface of the channel is not plastered.
However, no matter how well such brickwork is made, the inner surface of a brick chimney is rough and it will still become covered with soot over time. In any uneven area of the chimney, soot accumulates more intensely.
The wall with the chimney duct inside is almost constantly wet from condensation.

Aggressive acidic condensate destroys the brickwork, the brick crumbles and sometimes even collapses inside the channel and narrows its cross-section.
To significantly increase the service life of the chimney, it is necessary to periodically clean it at least once every six months.
The internal cross-section of a brick chimney has a rectangular cross-section, so when gases move in the corners, turbulence occurs, reducing draft.
Therefore, an asbestos-cement or steel pipe is sometimes placed in the internal channel.
The main disadvantages of a brick pipe are weight, size, difficulty of repair and replacement.
But the aesthetics, fire safety and durability of brick chimneys exceed any of their shortcomings.

Ceramic stove pipe

Ceramic chimneys are also a modular system of fully prefabricated elements.
In the simplest cases, they are a regular ceramic pipe, but it is considered more appropriate to use sandwich structures that provide safe operating conditions.
Heat-resistant ceramics are acid-resistant and durable.
Some manufacturers claim a guaranteed service life of up to 30 years, and an expected service life of up to 100 years.
The inner surface of the ceramic is coated with a special heat-resistant glaze, which makes it absolutely smooth.
This prevents the formation of turbulent vortices, the gas flow passes in a calm laminar flow. Soot does not stick to the smooth ceramic surface.
The chimney of such pipes is the most durable. It is not afraid of prolonged intense heating, chemical aggressive environments, or corrosion. Its inner surface is very smooth, almost no soot or ash lingers in it, and as a result, maintenance of the pipes is minimal.
Ceramics is also an excellent heat-absorbing material, and in combination with the expanded clay concrete box in which it is hidden, the outer surface of the chimney ultimately does not heat up at all. And this is a complete guarantee that your house will never fall into that sad statistics of houses that burn due to chimneys!
These elements have a significant total weight, so the ceramic chimney pipe is installed on a separate foundation.
Carrying out brickwork requires considerable time, and installation of a chimney with a ceramic pipe can be carried out in a short time.
Ceramic pipes are expensive and practical.

Metal chimney
Metal chimneys are almost always made of stainless steel. They are an almost modular system of straight sections and shaped elements: adapters, elbows, tees, umbrellas.
Such systems can either be embedded inside brick channels or mounted separately.
The stainless steel used is heat-resistant and acid-resistant and condensation cannot corrode it.
Stainless steel is the most suitable material in terms of overheating, soot and getting wet. This material can even heat up to 500 degrees C – and it will not melt yet.
Soot does not accumulate on the smooth inner surface of the chimney.
Thus, due to the smooth, soot-free surface and stable cross-section, stable aerodynamic characteristics of the passage of exhaust gases are ensured.
Single-walled metal chimneys consist of one layer of stainless steel, while double-walled ones consist of two layers of metal with mineral (most often basalt) wool placed between them.
These are sandwich systems. In this case, the outer surface heats up minimally, heat is retained perfectly throughout the entire chimney, and therefore condensation almost does not form on the inner surface.

Sandwich pipes are very technologically advanced and have been used quite often lately, especially for baths. The only thing is that when purchasing, you need to carefully check the quality of the steel, because there are many cases of pipes burning through and fires for this reason.
Sometimes, during repair or restoration work, a metal pipe is placed inside brick channels. This is called a "sleeve".
The low weight allows these chimneys to be installed without a special foundation.

There are also corrugated pipes. They are used exclusively to create turns and bends in the chimney, but almost never as the main pipe. But they are irreplaceable if there is a beam just above the stove and all that remains is to go around it. For more, they do not yet have sufficient anti-corrosion or thermal insulation qualities.
It should be noted that there are metal chimneys that are not made of stainless steel. For example, for sauna stoves, some manufacturers offer thick-walled pipes made of low-alloy steel.
And when constructing sauna stoves, craftsmen quite often use cast iron chimneys from sewer pipes.

Concrete chimney pipes

The main advantage of such pipes is the low cost of the material, durability, maintainability and lack of seams. And you can make the pipes themselves at home using sliding formwork.
The composition of the mixture is as follows: three parts sand, water and one part Portland cement M400. The concrete turns out to be quite hard. It is better to make the pipes monolithic, and there will be very little soot.
The only drawback of such pipes is their heaviness. This can be corrected if expanded clay is used in the composition.

Vermiculite pipes
Vermiculite pipes are a new wave of popularity in the construction market. Condensation does not form inside such pipes at all, and therefore they very rarely need to be cleaned.
In its composition, vermiculite is close to aerated concrete, and is just as light, but it does not absorb moisture at all, tolerates high temperatures well and has good resistance to any physical influences.

Chimney pipe head
Many people saw something like an umbrella, a mushroom or a hat at the end of the pipe. This part of the chimney is called the head; more modern terminology refers to this structure as a spark arrester or deflector.
The head of the chimney can perform one or more functions - it protects from precipitation, extinguishes sparks flying from the chimney, improves the draft of the stove, and sometimes it is a very beautiful decoration.
The head of the chimney can be structurally simple - in the form of an umbrella, or it can have a complex design to protect against wind blowing and improve overall draft; the appearance in this case can have a different shape.

Chimney draft
There are special devices that measure chimney draft in pascals (the difference in pressure in sections of the chimney), although they are very expensive, so in most cases, rather trivial methods are used to determine draft:
- the traction force is determined by the deflection of a sheet of paper (in most cases, toilet paper is ideal);
- the direction of draft is determined by the direction of the smoke from a lit cigarette.
The sufficiency of traction can also be determined visually:
- Smoke in the room - reverse draft;
- The flame is bright white, there may be a roar in the chimney - the draft is too strong;
- Flame with dark stripes, red – insufficient draft;
- The flame is golden yellow – the draft is normal.
What does chimney draft depend on:
- insufficient height will lead to a decrease in traction, and in the case of excess, then, on the contrary, to an excessive increase. If you are not going to carry out an accurate physical and mathematical calculation, you should focus on a length of at least 4.5 meters.
- The cross-sectional shape directly affects the aerodynamic characteristics of the chimney: for example, in the case of a rectangular or square cross-section, we get additional turbulence in the corners that impede the overall flow, which is not observed in round analogues.
- Placing the chimney mainly in the interior of the building will allow you not only to increase the heating capacity of the entire heating system, but will also make it possible to maintain constant good draft (even in frosty times).

At the same time, placing the chimney outside the building requires it to warm up for a longer time and, as a result, will cause a decrease in draft.
- Too small cross-sectional area sizes when releasing a large volume of combustion products will not create the required thrust. This rule is exactly the opposite: too large a cross-sectional area with small volumes of combustion products will lead to the fact that all the heat will “fly out into the chimney”. Installing chimney pipes of different diameters in different sections of the chimney will not only lead to unpredictable draft behavior, but will also allow the formation of soot and other deposits.

- It is best to place the chimney pipe close to the ridge of the roof, but here certain conditions must be observed: if the pipe is located at a distance of 1.5 meters from the ridge, then the head should rise at least half a meter. If the distance between the ridge and the cap is in the range from 1.5 to 3 meters, then we place the chimney flush with the ridge. When the distance exceeds 3 meters, in this case the head should be located on a line drawn at an angle of 10 degrees from the ridge of the roof downwards. Incorrect location of the chimney in relation to the ridge of the roof can lead to weakening of draft in a certain wind direction.
- The chimney draft also depends on the smoothness of the chimney walls and the presence of sharp turns.
- The shape and dimensions of the pipe head also affect the draft. When assembling and choosing an umbrella, there is a significant danger of “miscalculating” the dimensions and, as a result, getting backdraft, for example, if the umbrella is too large and lowered too low. If you install a factory stainless steel chimney hood, no problems will arise - all the necessary parameters have already been calculated by engineers
- Atmospheric phenomena, air pressure, temperature, humidity, the presence of wind - all this naturally affects the draft in the chimney.
We can adjust the draft manually using a gate.
A damper is a damper, the intended use of which is intended not only to regulate the traction force, but also to protect the room from fire. One damper is installed in the chimney duct, the other, as a rule, is mounted either in the stove itself or in its door. Thus, by varying their position, we can adjust the traction force, which is an important advantage.
A good stove and chimney are the key to warmth and comfort in the house, because with its help you can easily heat even a very large house.
However, not everyone can correctly assemble a stove and pipe with their own hands, which is why in order to do such work, you must have certain knowledge and experience. Laying a chimney with your own hands is not at all difficult, you just need to have all the necessary materials and follow the instructions.

Although manufacturers today offer private homeowners a wide variety of heating boilers, many of them still prefer to install stoves or fireplaces in the house, since thanks to them, heating the premises requires minimal costs. Any heating equipment requires reliable removal of combustion products. That is why during its construction it is necessary to pay special attention to both aesthetic characteristics and operational characteristics.

The required level of draft, which provides the most comfortable and safe conditions for being in a particular room, is created by the chimney for the stove. It is an air channel through which combustion products exit. It can be a regular brick pipe or modular metal types, the only important thing is that it functions properly.

Basic designs

Exhaust channels through which air saturated with combustion products is disposed of are necessary not only for stoves, but also for fireplaces or heating boilers or gas water heaters.

We list the main types of chimneys for stoves.

Direct current. This is one of the first systems through which combustion products were removed. They have a significant drawback - due to the non-stop removal of gases to the outside, the bulk of the generated heat is also carried away.
Direct flow structures equipped with crossbars. These small additions allow some of the heat to be retained. When heated, the jumpers transfer heat to the walls of the heating unit. The same design is typical for stoves without a chimney in bathhouses: the stones in them are heated by the hot combustion products.

With a "labyrinth". There are many varieties of such designs, but they all have common features. In particular, this concerns the rate of gas removal. It is quite low, since the exhaust gases are passed through a tortuous channel. In the process, the device itself warms up in parallel and ensures maximum heat transfer.

A now classic Russian stove. The chimney diagram is bell-shaped. The hot gas rises up, cools slightly on the inclined arch of the hearth and descends to the channel. The disadvantage of such a system is that it heats up unevenly. For example, in the lower part of the hearth it does not warm up at all, since the heat mainly goes to the roof.
Modular. Unlike the classic brick version of smoke removal, they are made of metal. They are used in gas-fired heating systems. The fact is that the products of methane combustion are acidic compounds that destroy bricks with their aggressive effects.

Device Features

The efficiency of brick, metal, flexible chimneys for stoves and others depends on several factors, for example, material and dimensions, cross-section, height.

It is preferable that the chimney pipes, say, for a bathhouse, have a regular circle in cross section, that is, they have a cylindrical shape. The escaping smoke with this configuration, unlike the angular one, does not encounter obstacles in its path and is discharged with the least resistance. In addition, a minimum of soot accumulates on the walls of the outlet pipe.
The outlet of the heating device must coincide in cross-section with the smoke exhaust duct. If the width of the latter in the connection area turns out to be greater, which occurs quite often, then a special reducing adapter is installed, which must be carefully sealed at the junction. When joining, the expansion of the pipes should be directed upward to prevent condensate and resins from flowing out along their outer wall.

The horizontal part of the channel structure requires special attention. Warm smoke, as you know, moves vertically upward, so moisture condenses especially actively in these areas and a thick layer of soot is deposited. To compensate for such undesirable consequences and improve traction, it is necessary, firstly, to strictly limit the length of these sections: they must be less than 1 m in length, and, secondly, to provide condensate receivers and inspection doors there.

The correct chimney for sauna stoves is exclusively vertical. However, it is permissible to lay the pipe at a slight slope, provided that the length of the inclined section is no more than 2 m.

Main stages of calculation

The calculation of the chimney is carried out taking into account such parameters as the power of the connected heating device, shape and others. The optimal height and diameter of the section are calculated based on the SNiP of the stove and chimneys.

Height above roof

To determine the height of the outlet channel of industrial boilers, a special formula is used that describes its relationship with static draft, the average temperature (K) in the pipe and the average outside air temperature in the summer. If necessary, the value obtained from the calculation results is adjusted upward, taking into account the following rule:

When calculating the height, the height of neighboring buildings is also taken into account: in the case of higher ones, the channel is installed above their roofs.

Pipe cross-sectional area

In practice, they usually do without special calculations, based on the following cross-sectional values, depending on the power of the unit:

less than 3500 W - 14 ×14 cm;
3500–5200 W - 14×20 cm;
5200–7200 W - 14×27 cm.

The cross-sectional area of the cylindrical channel is assumed to be the same.

If the cross-section is significantly larger than the calculated value, the traction will deteriorate and, as a result, the system will operate unstably. A smaller cross-section leads to poor removal of combustion products, up to the complete cessation of this process.

Material

The choice of material for the design of the smoke exhaust system is based on the type of fuel used for heating. For example, MDS ceramic pipes are best suited for gas equipment, while brick pipes can quickly collapse.

The classic version of the exhaust system is a brick chimney for a metal stove. The brick structure is assembled exactly according to the design, where the laying of each layer of the channel is prescribed separately. In this case, it is necessary to obtain a minimally rough surface from the inside and ensure complete tightness.

Today, stainless steel is most often used. In the design, steel pipes can be: insulated and non-insulated:

non-insulated ones are used exclusively for internal installation of stoves and chimneys: they are installed in a special shaft;
When installing a pipe outside, it must be insulated to prevent moisture condensation inside the pipe.

Safety

For safety reasons, the chimney must be properly insulated, especially if the duct passes through ceilings in the immediate vicinity of flammable materials. based on the type of floor material and pipe temperature. It would be great if the walls and ceiling close to where the structure passes are finished with fireproof material. If this is not the case, then the heated parts are insulated from hazardous materials using sheets of metal and a layer of non-combustible materials.

The part of the pipe going outside must be securely fixed and protected from the wind. They are covered with deflectors on top to protect them from precipitation. Gas boilers are an exception in this matter: the protective cap on the chimney pipe in this case is a violation.

Some information from SNiP used when installing a stove and fireplace chimney

Smoke exhaust ducts can also be located on external walls if they are made of non-combustible material, and the heating device is located near the internal ones. In this case, external thermal insulation is required, which will prevent moisture from condensing inside the pipe.
The brick channels are complemented by pockets necessary for cleaning. They are covered with bricks (layed on edge) or a door is installed.
For roofs made of flammable materials, it is necessary to provide a mesh spark arrester, which is installed along the top of the channel. If the latter is made of brick, then between it and flammable hazardous materials it is necessary to provide a gap of 13 cm, in the case of non-insulated ceramics - 25 cm, and for insulated ones - 13 cm.

Installation of stoves and fireplaces using gas fuel has its own characteristics. The connection is made using flexible metal pipes included in the equipment set. A prerequisite is the presence of a vertical section in the system, and the distance between the horizontal axis and the line of the lower level of the pipe must be at least 50 cm. This distance can be reduced, for example, if the ceiling height is less than 270 cm
doubled if the heating unit is equipped with a draft stabilizer;
up to 15 cm if there is no stabilizer.

In a new building, the maximum length of all horizontal sections is more than 3 m, in an old building - up to 6 m. The pipe is installed with a slight slope in the direction of the heating unit. If there are two units operating in the house, then they can be connected to a common outlet channel. They should be spaced less than 75 cm apart from each other.

For dense dirt, use a scraper or a stiff brush equipped with a folding handle of sufficient length.
When cleaning, soot can get inside the room, so before starting cleaning it is necessary to close the combustion hole from below, and it is advisable to cover upholstered furniture.
The deposit of carbon deposits can be significantly alleviated if you use chemical cleaning agents such as “miracle log” during the cleaning process.
You can also use folk remedies to remove soot. For example, burning potato peels is quite effective.

How to assemble stoves with vertical chimneys: video

It is not surprising, but in the age of cheap electricity, countless amounts of gas in the depths of the vast country, a huge number of households, dachas and bathhouses continue to be heated with wood. Almost every rural home owner uses a stove.

What is a stove without a chimney? The article is dedicated to them. Stove pipes and chimneys are a mandatory attribute of a heater stove in a bathhouse, a Russian stove in a house, or a long-burning stove in a country house. Just as there is a huge variety of furnaces, so solutions for removing combustion products can be varied. Interestingly, in Rus', pipes on stoves appeared relatively recently. Before this, huts were heated “black” and this is due to the state collecting a tax “from the chimney”.

Brick chimneys and chimneys

Traditionally, the most common were stove pipes and chimneys made of brick. They are placed on brick ovens. They are durable and fireproof. It is necessary to follow a few simple rules during installation and use. The brick one is made from red stove bricks. Closer to the head it can be replaced with a regular red ceramic one. The higher the smoke rises up the chimney, the colder it becomes. The requirements for the thermal conductivity of the material are becoming less stringent. But you still need to follow a number of rules:

1. When crossing ceilings, especially those made of flammable material, it is necessary to make a so-called “fluff” on the chimney - a thickening that has increased thermal insulation due to increased wall thickness.

2. When crossing the roof, it is necessary to make a fireproof cut. This can be clearly seen in the drawing below. The thickness of the chimney wall should be at least 120 millimeters - this is the width of the red brick. If you decide to make a brick chimney yourself, then the figure shows the order of laying out the “fluff”.

Keep in mind that the inside needs to be made as smooth as possible. When laying out each row, carefully cover the inter-row seams. The smoother the surface, the less soot will be deposited on it.

If you use a brick chimney for a fireplace, the inside of the chimney must be made of fireclay bricks, since the temperature of the gases from the combustion of the fireplace is much higher than the gases coming out of a conventional stove.

Stainless steel sandwich stove pipes and chimneys

The next most common are stove pipes and chimneys made of stainless steel. They are durable and easy to install. The sandwich is the most popular. A chimney made from sandwich pipes has its own characteristics. The most commonly used are sandwiches with a thermal insulation thickness of 50 millimeters. They are found with insulation thickness of 100 millimeters, but this is rather exotic for private housing construction. A thermal insulation thickness of 50 millimeters is enough to protect open areas passing through the attic space. The main rule is that the distance from the walls to the pipe should be at least 50 centimeters. Where it is not possible to maintain these dimensions, it is recommended to lay an additional layer of non-combustible thermal insulation along the wall and cover it with a glass-magnesium sheet or a sheet of iron (stainless steel).

Despite the fact that the pipe itself already has a layer of thermal insulation, when crossing the floors it is necessary to make additional heat and fireproof insulation.

Its width must be at least 30 centimeters. When crossing a wall, it is advisable to even increase it a little. The passage box can be filled with expanded clay, filled with clay, or compacted tightly with non-flammable insulation. An incorrectly executed passage through a ceiling or wall can cause a fire, so it is necessary to take the manufacture and installation of these chimney components very responsibly.

When installing chimneys from sandwich pipes, one should take into account the peculiarity of using a heat generator - a furnace. The chimney can be installed “through smoke” or “through condensate.”

The first connection option is more suitable for a stove that is heated daily, when the chimney does not cool down between firings - most of it passes through warm rooms. Using the oven in this mode does not lead to the release of large amounts of condensate and its accumulation.

The second type - “by condensate” is preferable to use in case of rare heating or with a chimney passing along the external wall of the building. A condensate trap must be installed.

Since the mass of the pipe can be quite large, when installed on the external wall of a building, the base must be additionally reinforced with a supporting structure, a version of which can be seen in the above photograph. The pipes must be secured to the wall using special brackets. It must be taken into account that each knee must be secured with at least one bracket. The maximum distance between brackets is 2 meters 20 centimeters.

The part that rises above the roof must be secured with at least three guy wires. A pipe standing on a roof higher than one meter is subject to significant wind loads, and in winter also snow loads. This factor should be taken into account when designing from a sandwich.

A very important point: all connections must be visible and accessible for inspection. Under no circumstances should a connection be allowed inside a ceiling or wall.

Let us mention an important factor - the first pipe from the stove must be without thermal insulation. The smoke coming directly from the furnace is still very hot and therefore there is a possibility of burning the insulating material. A pipe without thermal insulation sharply lowers the temperature of the smoke, plus it is an additional element for heating the room. To protect against burns, an additional mesh is often placed on it.

Sandwich stove pipes and chimneys are practical, easy to install and fairly easy to clean. We do not recommend that you use galvanized sandwich pipes; they quickly burn out and do not last long. If you need quality, choose stainless steel.

When touching on this issue, one cannot ignore asbestos cement pipes. In Soviet times, these were used to make irrigation systems for fields, and enterprising collective farmers used them as chimneys. In fact, they are not intended to be used in this capacity. At temperatures above 200 degrees they crack. Therefore, use for stoves with direct smoke flow is strictly prohibited.

An asbestos-cement pipe can be used as the final element of a brick-on-stone stove. It has a rough surface, which facilitates the deposition of soot. A large amount of soot in the chimney not only prevents smoke from escaping, but is also explosive.

When using any pipe, it must be positioned correctly on the roof. Incorrect placement results in the chimney being blown out by the wind and precipitation entering it. An umbrella or a similar structure can save you from precipitation. The correct location is shown in the figure:

Cleaning of chimneys and chimneys

Cleaning from soot and soot is a mandatory part of operation. The rougher the surface of the chimney, the more soot is deposited on the walls. We have already written that soot not only makes it difficult for smoke to escape, but is a rather dangerous factor, as it can explode when the temperature rises and lead to a rupture of the chimney. Stainless steel sandwiches are least susceptible to soot deposition. But, unfortunately, these chimneys have another problem - condensation. Therefore, they must be equipped with condensate collectors, periodically cleaning them from water and tar.

Brick asbestos-cement chimneys are cleaned with a metal brush with a weight tied to it from below. To clean, you need to go up to the roof. Carefully lowering the tool down and lifting it up, clean off all the soot from the walls. The soot will fall down, where it is removed through the cleaning door.

Burning aspen wood gives a good cleansing effect. The combustion temperature is significantly higher than the combustion of other firewood. When aspen burns, the soot in the chimney burns out. It is better to do this periodically, not allowing a large amount of precipitation to accumulate. The procedure will produce an effect once a month, and not at the end of the season. You can add aspen during normal heating of the stove.

A preventive measure against clogging and large formation of soot deposits is the main rule of the stoker - do not burn garbage, especially plastic, in the stove.

Chimneys and chimneys - price

The price range for different types of chimneys is large. A good stove brick costs about 25 - 30 rubles apiece. The higher the chimney, the more bricks. The cost of the chimney is also increasing.

An asbestos-cement pipe 4 meters long, with a diameter of 120 millimeters in construction stores costs about 800 - 1000 rubles.

A sandwich pipe 1 meter long costs from 1,200 rubles. It all depends on the grade of stainless steel, the quality of the insulation, and the method of joining the steel sheets.

Our advice is not to skimp on the cost of chimneys. It must be remembered that a high-quality chimney is a guarantee of health and safety.

This article will help you decide on the choice of a metal chimney for your stove. Choose the best option for specific conditions and budget.

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Material selection

The material plays a huge role; the service life of the chimney, its ability to withstand various aggressive chemical compounds, reliability and strength depend on it. A steel chimney for a stove is made from three main materials: stainless steel, galvanized and ferrous metal. Now let's look at each material in detail.

Stainless steel

Made from heat-resistant and acid-resistant stainless steel. A good chimney should have a thickness of 0.8 - 1 mm; a thinner one will not last so long.

Characteristics:

Able to withstand temperatures of more than 600 degrees, and have a long service life.
They are not afraid of many substances, and work calmly with constant contact with nitric acid, sulfuric acid, creosote and other substances that are part of the combustion products of coal and firewood.
They can be either single-walled or double-walled, with thermal insulation between the pipes. Such a chimney is safe and can be installed in any buildings: residential buildings, baths, saunas, technical buildings, etc.

Cink Steel

It is a budget option for construction. The thickness of the pipes ranges from 0.3 to 01 mm. It is made of steel coated with a layer of zinc, thanks to zinc it has good characteristics of resistance to alkalis and acid combustion products.

They are installed in the same way as stainless steel pipes. They are used less frequently as a material for stove chimneys, as they have a shorter service life and are less reliable in terms of their design and metal thickness. To extend the service life of galvanized pipes, they need to be insulated, this will reduce the formation of destructive condensate.

Black steel chimney

They are now very rarely made from black steel, due to the fact that they have a short service life. Such a chimney is justified only when the budget is very limited. They are made from boiler or ordinary steel, the thickness of the pipes ranges from 0.6 to 2 mm.

More often they are installed on small sauna stoves or in country houses, the use of which will be periodic. Can be used for stoves in greenhouses and outbuildings. With severe overheating, a lot of scale forms inside the pipe, which blocks the flow of the pipe.

Types by design

The iron chimney for the stove can be divided into two types according to its design: single-walled and double-walled. Now let's take a closer look at each of them:

Single wall

Based on the name, they have only one wall. These are installed mainly in the finished chimney duct of the stove, and serve as a sleeve. Also used in outbuildings, garages, etc. such a chimney. They can be made from stainless steel, galvanized steel, or ordinary iron.

They are more fire hazardous, and therefore are used in those areas of the chimney where the risk of fire is reduced. The cost of such pipes is two times lower than double-walled ones.)