We do not imagine homes without heating. Our concept of comfort unconditionally includes a suitable temperature regime. There is no central heating in a private house, and each owner has a heating problem.

We welcome our regular reader and bring to his attention an article about chimneys for stoves - an absolutely necessary component of any heating system, whether it is a stove, a modern fireplace or a boiler with automatic fuel supply.

Chimney - a vertically located pipe that discharges hot flue gases of the fuel in the heating unit into the atmosphere to a height sufficient to create draft in the duct and disperse toxic combustion products away from windows and ventilation ducts.

Principle of operation

The principle of operation of chimneys is based on the phenomenon of expansion of hot gases, a decrease in their density and, accordingly, the rise of lighter gases upwards.

Flue gases rise upwards, a rarefaction is formed in the furnace and colder air is sucked in - a draft phenomenon occurs.

How is the chimney

The main part of any chimney is a vertical pipe structure. Structurally different from modern prefabricated counterparts from prefabricated modules.

A traditional brick chimney includes the following elements: a neck for connecting to a furnace, a riser with valves, a slope, an otter, a neck (at the point of passage through the roof), a headband, and sometimes a metal cap.

Homemade chimneys made of metal or asbestos cement include pipes, caps, adapters for connecting to the furnace, and insulation.

The most modern types of chimneys are ceramic and made of. The ceramic structure consists of an external expanded clay concrete frame, an internal prefabricated ceramic pipe, and a layer of insulation between them. The ceramic and sandwich structures themselves include the following blocks: straight, for collecting condensate, tees, cleaning modules, transition elements for connecting heating units. An integral part of a modern chimney is a deflector.

Types and designs

The design features of the chimney primarily depend on the material from which they are made.

According to the material of the chimneys are:

• brick;
• reinforced concrete (usually industrial);
• asbestos-cement;
• of steel;
• ceramic;
• three-layer metal - two layers of steel with mineral wool insulation between them.

By design, chimneys are:

• indigenous - the design has its own foundation;
• wall, built into the bearing walls of the building;
• mounted - light pipes are mounted on a vertically located outlet pipe of a boiler or fireplace (and a potbelly stove);
• often lightweight structures are simply suspended from the supporting structures of the building;
• coaxial - arranged according to the "pipe in pipe" principle. The most common example is the horizontal gas outlets of gas heating boilers. It is used in devices with a closed combustion chamber and provides maximum safety for residents. Save fuel consumption. Recently, vertical structures of the Shidel system have appeared, taking air for combustion on the roof of the house (just below the head).

Which is better to choose

The choice of a chimney largely depends on the parameters of the installed heating unit (design, temperature, type of fuel used), the degree of readiness of the house (we are modernizing an old house with a stove and a wall pipe, the house is only “in the project” or the supporting structures have already been mounted, or there is already a finish) ; heated volumes.

Features of various types of chimneys are shown in the table:

Table 1

It is not worth using flexible steel corrugation - they burn out very quickly.

Despite the price, it is worth choosing modern ceramic chimneys or "sandwich". If necessary, they can be mounted both in the finished house and outside the house, they are durable, easy to assemble, resistant to high temperatures, well insulated, and have a large assortment of ready-made factory elements.

If you want to use an old wall box from a conventional heating stove, you need to insert a stainless steel insert and insulate it. But perhaps you should choose a sandwich - less hassle.

Do it yourself or order

You can do it yourself some elements for the installation of single-layer pipes or lay out a brick structure (if you have the skills of a qualified bricklayer).

But the installation of prefabricated structures - this will help save a considerable amount from the family budget. You will have to pay a lot for the services of a qualified team - the amount is comparable to the cost of materials. There is a risk of running into unskilled workers.

When deciding whether to do the work yourself, you need to carefully analyze your capabilities:

• how accessible is the roof;
• Do you have friends or relatives who can help?
• do you have a fear of heights;
• What are your qualifications in performing repair work.

Building regulations

The arrangement of chimneys is determined by the provisions of SNiP 41-01-2003.

The design of the chimney must meet the following regulatory requirements:

• the minimum height must be at least 5,000 mm or grate;
• when located on a roof slope at a distance of less than 1.5 m to the ridge - the pipe must be 500 mm higher than the ridge;
• when located on a roof slope at a distance of 1.5-3 m to the ridge - the pipe must not be lower than the ridge;
• when located on a roof slope at a distance of more than 3 m to the ridge, the angle between the horizontal and the line passing through the ridge and the top of the pipe should be no more than 10 °;
• the head should rise above the flat roof to a height of at least 1,000 mm;

• the maximum length of each horizontal and inclined sections should not exceed 1000 mm, the total length of their projections on the horizontal should not exceed 2000 mm. In the presence of oblique and horizontal sections, it is necessary to lengthen the pipe by the length of the horizontal projections. For ceramics, the presence of horizontal sections is not allowed.

Fire safety requirements for chimneys

The distance from the surface of chimneys made of ceramic, insulated steel and asbestos-cement to combustible structures of the house must be at least 250 mm; for brick chimneys and sandwich pipe structures - at least 130 mm.

It is necessary to protect building structures made of combustible materials with cement or gypsum plaster over a grid of at least 25 mm thick.

If the roof covering can burn (roofing material, shingles, ondulin), or leaves and fluff can accumulate on it, a mesh spark arrestor should be installed on the head.

Remember that the quality of smoke removal depends on the life and health of your loved ones.

Traction force

Factors affecting traction force:

• pipe height;
• the state of the surface of the internal channel - the regularity of cleaning from soot, the roughness of the walls;
• the presence of inclined or horizontal sections. The presence of horizontal and inclined sections is undesirable, since the lengthening of the chimney is undesirable - the gases will cool, the draft will decrease up to tipping over;
• deflector installation;
• quality of insulation;
• air supply to the furnace.

Your safety depends on the traction force, therefore it is necessary to regularly check the presence of traction and take measures to clean the channel from soot, the pipe head from ice.

Making and installing a chimney with your own hands

What materials are better to make

The easiest to install are steel structures. Single-layer steel products require insulation and the manufacture of components - in general, work for pathological workaholics, and here we will not consider their installation.

Installing a chimney from a sandwich pipe is quite simple, the presence of a large number of various elements and components in stores allows you to assemble a device of any configuration.

Drawing and diagrams

Before starting work, determine the dimensions and draw a diagram or drawing - this will help to correctly calculate the required amount of materials and properly organize the work.

Size calculation

The height of the pipe is determined in accordance with the requirements of SNiP 41-01-2003, but should not be lower than 5 m from the grate. The diameter is taken equal to the diameter of the outlet of the heater.

Installation video

Watch our video - it will help you see all the intricacies of the assembly process.

Mounting Features

Installation starts from the stove or fireplace. The first starting element is mounted on the nozzle of the boiler or furnace. This element is not insulated for technological reasons (alt-free filler is melted and sintered into stone). All elements are designed in such a way that one of its ends has a smaller diameter and is inserted one into the other, as into a socket. One of the docking options is to slightly pull out the inner pipe, insert it into another inner pipe. Press down. Then lower the outer pipe with insulation along it, press it down. Fasten the connection with a crimp collar, tighten it with a bolt and nut. All joints must be sealed with sealant.

Then a tee is mounted, modules with a cleaning hatch and a condensate trap are mounted from below. There are designs for installing the lower part of the chimney on the floor.

Then mount the rest of the structure. After a meter, the sandwich is attached to the wall with special brackets. An element with a cleaning hatch should be installed on each floor and in the attic.

It is advisable to connect the elements of the chimney “through condensate” - the pipes are mounted in such a way that the upper one is inserted into the lower one and the condensate cannot seep through the joints, but flows down the walls into the trap.

An element with a gate is mounted under the ceiling.

The passage of the pipe in the ceiling is covered with a galvanized sheet and filled with insulation. The distance to the structures must be at least 130 mm.

The most difficult stage in the installation is the passage of the roof. Mark the hole in the right place on the roof. Make a hole in the roof. A roof sheet is attached from the inside, a roof cutting is installed on the roof. It is selected depending on the angle of the roof. The cutting edges lead under a sheet of roofing material.

If necessary, install extensions. Install deflector.

Common errors and installation problems

The most serious mistake is the lack of a condensate collector and elements with cleaning hatches.

In places where structures pass through ceilings, it is strictly forbidden to install joints of individual elements - leaking hot smoke can cause a fire.

A very significant mistake is the absence of a deflector or at least a cap over the chimney.

Snow and rain should not get inside the pipe - they increase the formation of condensate, ice can block the cross section of the pipe.

Maintenance and cleaning

Any chimney requires regular cleaning of soot. This will avoid fires, reduce traction. Cleaning should be done twice a year.

There are two cleaning methods - mechanical and chemical.

With a chemical fire, special agents are burned in the furnace. They burn at a very high temperature and accelerate the wear of the inner walls of the chimney, so it is better to use mechanical cleaning methods for a sandwich.

Icicles and ice from condensate can freeze on the head - they block the section of the box and reduce draft, which increases the risk of carbon monoxide poisoning for residents.

It is necessary to choose pipes in which the thickness of the outer metal layer is 1 mm (and not 0.5 mm). It is very easy to check - for a product with a thin wall, the wall bends if you squeeze it with your hands.

When installing sandwich structures, it is necessary to use a special sealant for high operating temperatures (automotive sealant with an operating temperature of 500 ° is not suitable).

If the pipe rises above the roof by more than one meter, it should be reinforced with stretch marks.

Although manufacturers today offer private homeowners a wide variety of heating boilers, nevertheless, many of them prefer to install stoves or fireplaces in the house, because thanks to them, minimal costs are required to heat the premises. Any heating equipment needs a 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, creates a chimney for the stove. It is an air channel through which the products of combustion come out. It can be an ordinary brick pipe or modular metal types, it is only important that it functions properly.

Basic structures

Outlet channels through which the utilization of air saturated with combustion products passes 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 furnaces.

• 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 main part of the generated heat is also carried away.
• Direct-current structures equipped with transverse jumpers. 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 a stove without a chimney in baths: the stones in them are heated by hot combustion products.

• With labyrinth. There are many varieties of such structures, but they all share common features. In particular, this applies to the rate of removal of gases. 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.

• Became a classic, Russian stove. The scheme of the chimney is bell-shaped. The incandescent gas rises up, cools down a little on the sloping arch of the hearth and descends to the channel. The disadvantage of such a system is that it warms 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 extraction, they are made of metal. They are used in gas heating systems. The fact is that the products of methane combustion are acidic compounds that destroy bricks with their aggressive effect.

Device Features

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

• It is preferable that the chimney pipes, say, for a bath, be a regular circle in cross section, that is, they have a cylindrical shape. Outgoing smoke with this configuration, in contrast to 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 match in cross section with the chimney channel. 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. The extensions of the pipes during docking should be directed upwards in order to prevent condensate and resins from flowing along their outer wall.

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

The correct chimney for sauna stoves is exclusively vertical. Nevertheless, it is allowed to lay the pipe at a slight slope, provided that the length of the inclined section is not 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 furnace and chimneys.

Height above roof

To determine the height of the discharge channel of industrial boilers, a special formula is used that describes its relationship with static draft, average temperature (K) in the pipe and the average outside air temperature in summer. If necessary, the value obtained from the calculation results is adjusted upwards, 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 taken out above their roofs.

Pipe area

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

• 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, then the thrust will deteriorate, and as a result, the system will work 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 construction of the flue 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 device for the exhaust system is considered to be a brick chimney for a metal furnace. The brick structure is assembled exactly according to the project, where the laying of each layer of the channel is specified 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 uninsulated:

• uninsulated ones are used exclusively for internal installation of furnaces and chimneys: they are installed in a special shaft;
• when installing a pipe from the 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 combustible materials. are based on the type of floor material and on the temperature of the pipe. It is great if the walls and ceiling near the place where the structure passes are finished with fireproof material. If this is not the case, then the heated parts are isolated from hazardous materials using metal sheets and a layer of non-combustible materials.

The part of the pipe that goes out must be securely fixed and protected from the wind. From above they are covered with deflectors 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 the chimney of the stove and fireplace

• Smoke exhaust ducts can also be located on external walls in the case when they are made of non-combustible material, and the heating device is located near the internal ones. At the same time, external thermal insulation is required, which will not allow condensation of moisture inside the pipe.
• Brick channels complement the pockets needed for cleaning. They are closed with a brick (laid on the edge) or a door is installed.
• For roofs made of combustible materials, it is necessary to provide a mesh spark arrester, which is installed along the upper part of the channel. If the latter is made of brick, then between it and combustible materials it is necessary to provide a gap of 13 cm, in the case of non-insulated ceramic - 25 cm, and for insulated - 13 cm.

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

• In the new building, the maximum length of all horizontal sections is more than 3 m, in the old building - up to 6 m. The pipe is installed with a slight slope in the direction of the heating unit. If two units work in the house, then they can be connected to a common outlet channel. They should be separated from each other at a distance of less than 75 cm.
• The outlet channel can have a maximum of three turns, the radius of curvature of which must exactly match the diameter of the pipe section.

The efficiency of heating stoves and other similar devices largely depends on the design chimney in the house.
Furnace chimney designed to remove volatile and gaseous products of combustion from the furnace and to create thrust 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 at a temperature of the exhaust gases over 100 degrees C, zinc began to evaporate into the room, and its fumes are harmful to health. That is why they used non-galvanized metal, covering it from 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 has served faithfully for decades.

Asbestos-cement chimney
Asbestos-cement pipes have been widely used since the middle of the last century. They were cheap, they were easy to manufacture, there was enough natural asbestos in the country. Moreover, such pipes could be used without any preliminary insulation for a variety of agricultural needs. That's just for the arrangement of chimneys, they were never intended.
At the time of land reclamation in rural areas, asbestos-cement pipes were not uncommon, and during the period of mass construction of private houses, they were already used as chimney pipes.
Many opponents of such an implementation immediately appeared - first of all, environmentalists who claimed that asbestos cement releases many bad compounds into the environment.
Although, according to scientists, the asphalt on the road is even more carcinogenic.
But, nevertheless, even the roofs of buildings today are covered with a variety of expensive roofing instead of cheap and durable asbestos.
All these fears and myths have little to do with asbestos-cement chimneys.
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 already put them, then just not at the stove itself - but as close as possible to the roof, where the smoke is already going a little chilled.
To prevent the danger of fragments flying 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 lingers on them.
But asbestos-cement pipes just never differed in smoothness, and soot accumulates on them very, very much. And it’s easy for her to catch fire - any stove-maker knows this.
Moreover, if soot ignites inside an asbestos-cement pipe, it can break from temperature. This is dangerous.
Even asbestos-cement pipes are severely destroyed by condensate. Condensate is an aggressive environment from 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 into itself, transferring all this to the structure in the form of unsightly spots with the same unpleasant odor.
So, if you decide to use an asbestos-cement pipe for the chimney, clean it as often as possible.
True, cleaning such pipes is difficult - it will not work to make revision windows in such pipes.

brick pipe

The construction of a brick chimney has a long history.
Such a pipe is laid out from red oven bricks simultaneously with the stove. A competent stove-maker knows exactly which brick to choose for the stove, even different inside and out, which brick is needed for the pipe inside the attic, and which one - from the outside of the chimney on the street.
The inside of the chimney should not be corroded by condensate, and the outside should not be washed away by rain and crack from temperature changes. Therefore, overheated, under-heated and raw bricks should be clearly distinguished.
A pipe made of this material needs periodic repairs. In addition, for do-it-yourself installation of a brick pipe, it is necessary 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 is placed on a separate foundation that is not connected with the house.
Brick chimneys and chimneys are also arranged inside the brickwork of the building wall.
Lay chimneys and chimneys with dressing, 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 solid red 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 done, the inner surface of the brick chimney is rough and it will still become covered with soot over time. In any uneven section of the chimney, soot accumulates more intensively.
The wall with the chimney channel inside is almost constantly wet from condensate.

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

Ceramic chimney

Ceramic chimneys are also a modular system of elements of complete factory readiness.
In the simplest cases, they are a conventional 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 warranty period of up to 30 years, and an expected service life of up to 100 years.
The inner surface of ceramics is covered with a special heat-resistant glaze, which makes it absolutely smooth.
This does not allow the formation of turbulent eddies, the flow of gases passes through a calm laminar flow. Soot does not linger on a smooth ceramic surface.
The chimney of such pipes is the most durable. He is not afraid of either prolonged intense heating, or chemical aggressive environments, or corrosion. Its inner surface is very smooth, soot or ash almost does not linger in it, and as a result, pipe maintenance is minimal.
And ceramics is 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 does not heat up at all. And this is a complete guarantee that your house will never fall into those sad statistics of houses that burn because of chimneys!
These elements have a significant total weight, so the ceramic chimney is installed on a separate foundation.
Brickwork requires considerable time, and the 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 a practically modular system of straight sections and fittings: adapters, bends, tees, umbrellas.
Such systems can either be embedded inside brick channels or mounted separately.
Stainless steel is heat-resistant and acid-resistant and condensate 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 surface without soot and a 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, and double-walled ones of two layers of metal and mineral (most often basalt) wool is laid 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 there is almost no condensation 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 buying, you need to carefully check the quality of steel, because there are many cases of pipe burns 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 indispensable if there is just a beam above the furnace and it remains only to go around it. For more, they do not yet have sufficient anti-corrosion or thermal insulation qualities.
It should be noted that metal chimneys are not made of stainless steel. For example, for sauna stoves, some manufacturers offer thick-walled low-alloy steel pipes.
And craftsmen, when constructing bath stoves, quite often use cast-iron chimneys from sewer pipes.

Concrete pipes for the chimney

The main advantage of such pipes is the cheapness of the material, durability, maintainability and lack of seams. And you can make the pipes themselves at home by using a sliding formwork.
The composition of the mixture is as follows: three parts of sand, water and one part of Portland cement M400. Concrete is quite hard. It is better to make pipes monolithic, and there will be very little soot.
The only drawback of such pipes is their heaviness. This can be corrected by using expanded clay 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 also light, but it does not absorb moisture at all, tolerates high temperatures and has good resistance to any physical influences.

Chimney cap
Many have seen at the end of the pipe something like an umbrella, fungus or cap. This part of the chimney is called the head, more modern terminology refers to this design as a spark arrestor, deflector.
The head of the chimney can perform either one or more functions - it protects against precipitation, extinguishes sparks flying out of 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 also have a complex design to protect against wind blowing and improve overall traction, the appearance in this case may have a different shape.

Chimney draft
There are special devices that measure the chimney draft in pascals (pressure difference in the sections of the chimney), although they are very expensive, so in most cases rather trivial methods are used to determine the draft:
- the traction force is set by the deflection of the sheet of paper (in most cases, toilet paper is the best fit);
- the direction of the draft is determined by the direction of the smoke from the lit cigarette.
Also, the sufficiency of traction can be determined visually:
- Smoke in the room - reverse draft;
- The flame is bright white, a hum in the chimney is possible - the draft is too strong;
- Flame with dark stripes, red - insufficient draft;
- The flame is golden yellow - draft is normal.
What determines the draft of the chimney:
- insufficient height will lead to a decrease in thrust, 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 shape of the section directly affects the aerodynamic characteristics of the chimney: in the case of a rectangular or square section, we get additional twists at the corners that prevent the overall flow, which is not observed in round counterparts.
- Placing the chimney mainly in the inner part 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 a constant good draft (even in frosty weather).

At the same time, the location of the chimney outside the building requires a longer heating and, as a result, will cause a decrease in draft.
- Too small dimensions of the cross-sectional area with the release of a large volume of combustion products will not create the necessary 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 pipe”. 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 closer to the roof ridge, but certain conditions must be observed here: if the pipe is at a distance of 1.5 meters from the ridge, then the head must rise at least half a meter. If the distance between the ridge and the head 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 roof ridge down. Incorrect positioning of the chimney in relation to the roof ridge can lead to a weakening of draft in certain wind directions.
- Chimney draft also depends on the smoothness of the chimney walls, the presence of sharp turns.
- The shape and dimensions of the pipe head also affect the thrust. When assembling and choosing an umbrella, there is a significant risk of “miscalculating” the dimensions and, as a result, getting a reverse thrust, for example, if the umbrella is too large and lowered too low. In the case of installing a factory stainless steel chimney umbrella, there will be no problems - all the necessary parameters have already been calculated by engineers
- Atmospheric phenomena, air pressure, temperature, humidity, presence of wind - all this, of course, affects the draft in the chimney.
We can manually adjust the draft with the help of a gate.
A gate is a damper, the intended use of which is designed not only to regulate the traction force, but also to protect the room from fire. One gate is installed in the chimney channel, the other, as a rule, is mounted either in the furnace itself or in its door. Thus, by varying their position, we can adjust the traction force, which is an important plus.
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 fold the stove and pipe correctly with their own hands, which is why in order to perform such work, you need certain knowledge and work 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.

Perhaps everyone knows what chimneys are and what they are for. Those who were more deeply interested in the arrangement of stoves and fireplaces understand how important the right choice of a smoke exhaust system in a house or bath is. This article is devoted to a description of what types of chimneys are their features, advantages and disadvantages.

This is one of the oldest types of chimneys, which is still very popular. They lay a brick chimney made of solid ceramic bricks. The smoke exhaust channel is located in the brickwork.

The advantages of brick chimneys include:

• resistance to mechanical stress;
• high heat capacity of the structure, allowing the heated chimney to give off heat for a long time;
• absolute fire safety subject to compliance with safety requirements.

Note: The disadvantages of brick chimneys are worthy of detailed coverage. Thanks to this, it will be possible to better appreciate the advantages that other types of chimneys have.

Disadvantages of brick chimneys

1. The rectangular section of the chimney is not a very good solution in terms of draft. In the corners, the flow rate of the flue gases is lower, which reduces the efficiency of removing combustion products from the furnaces.
2. Irregularities of the inner surface (protrusions and recesses) reduce the rate of passage of gases. Also, soot and condensate easily settle on such a surface. Combustion products of solid fuels or natural gas contain large amounts of sulfur oxides. An odorant is specially added to the gas, providing that very recognizable pungent smell. A feature of the odorant is the high content of sulfur. Sulfur oxides deposited on the walls of the chimney react with water (condensate), forming sulfurous (weak) and sulfuric (very caustic) acid. These acids are the cause of the destruction of bricks and mortar, reducing the strength of the structure.
3. The large mass of the brick chimney makes it necessary to build a separate foundation for it. Moreover, it is advisable to make the foundation for the stove and chimney before the construction of the building begins.
4. Complex and time-consuming installation of brick chimneys, which is incomparable with any other type. The work requires a highly skilled mason and takes several days.

Single-circuit modular steel chimneys

It is assembled from several elements. Most of the elements are a piece of steel pipe. However, the design also includes more complex elements - tees, equipped with glasses for collecting condensate.

The material for the chimney elements is acid-resistant heat-resistant stainless steel (stainless steel) with a wall thickness of 0.6-1 mm. Pipes manufactured according to these requirements have a long service life. In practice, different types of stainless steel and even galvanized steel are used. Galvanizing is the worst solution. The protective layer of zinc quickly burns out under the influence of temperature and the unprotected walls of the channel begin to collapse under the influence of water and acids.

Advantages of single-circuit steel chimneys:

• smooth inner surface that prevents the deposition of soot and condensate;
• round section, providing good traction and uniform gas flow rate;
• light weight;
• simplicity and low labor intensity of installation;
• sufficiently high resistance to corrosion;
• maintainability.

Disadvantages of single-circuit steel chimneys:

• high thermal conductivity leads to rapid cooling of gases and the formation of a large amount of condensate. Pipes require large indents at the points where the chimney passes through the wooden elements of buildings (ceiling, walls, roof).
• short service life of the chimney - no more than 15 years.

Steel sandwich chimneys

Dual-circuit sandwich chimneys - products from two steel pipes of different diameters, inserted one into the other. The space between the pipes is filled with non-combustible insulation. Thanks to the insulation, sandwich pipes have low thermal conductivity, which provides additional benefits:

• slow cooling of flue gases and high speed of their passage through the channel;
• minimal formation of condensate;
• the possibility of outdoor installation without output through the roof;
• simplified requirements for installation inside the building and output through the roof.

The disadvantage of this type of chimney is one - the price. They are noticeably more expensive than other types of steel chimneys.

Steel corrugated

This type of chimney is made of a flexible pipe made of steel tape. Such flexible chimneys are used for lining brick smoke channels of a curved shape. These types of chimneys are easy to install and maintain, but their service life is very limited.

Ceramic

This type of chimney appeared in Russia quite recently, but quickly became popular, despite the high price. The smooth surface of the ceramic chimney does not need frequent cleaning. Each element of the ceramic chimney includes:

• chimney made of special refractory ceramics;
• a heat-insulating layer of non-combustible material that ensures safe passage through walls and roofs;
• protective cover made of lightweight cellular concrete.

This type of chimney has collected all the advantages:

• smooth inner surface;
• round section and smooth, good traction;
• excellent thermal insulation and sealing;
• heat and fire resistance;
• ease of installation;
• durability.

The disadvantages of ceramic chimneys include only their high cost. They can be used to remove smoke from any stoves, fireplaces, boilers and columns.

Asbestos-cement

Asbestos-cement pipes are used in the construction of chimneys for heating devices, the flue gases of which have temperatures not exceeding 300 degrees. They are not suitable for conventional ovens. These limitations are caused by the unsatisfactory heat resistance of chrysotile cement.

Advantages of asbestos cement chimneys:

• light weight (if we take brick chimneys in comparison);
• round section;
• simple quick installation;
• very low price.

Price is the deciding factor here. This is the material that can be taken, as they say, "by the bottle."

Disadvantages of asbestos cement chimneys:

• low strength;
• poor heat resistance;
• lack of thermal insulation;
• the complexity of the device bends;
• unreliable connection with rubber couplings;
• porous wall structure;
• frequent cleaning of chimneys.

The last point deserves special attention - the ignition of soot in asbestos-cement chimneys is a serious problem. For safety reasons, regular cleaning of such chimneys is necessary. Therefore, the use of this type of chimney has significant limitations.

Polymer

Flexible chimneys made of polymeric materials are used for lining brick or concrete smoke channels. The polymer does not have high heat resistance, so this solution is used only for the removal of not very hot flue gases. Such requirements are met by gas water heaters and boilers with high efficiency. They cannot be used as a chimney for a stove.

Advantages of polymer chimneys:

• ease of installation;
• light weight and flexibility;
• low price.;
• long service life.

Disadvantages of polymer chimneys:

• poor resistance to high temperatures;
• lack of thermal insulation;
• low strength.

The chimney at first glance seems to be a simple design. In fact, this is a brick pillar with a channel inside for the output of combustion products. In practice, its dimensions and design determine whether the furnace will function at all, since it is the chimney that is responsible for the draft.

Material

The size of the chimney, no doubt, depends on the material from which it is made, and the latter is selected in accordance with the heater and the combustion temperature of the fuel.

A stove in a private house belongs to the category of solid fuel boilers - coal, firewood, which means that the chimney material must be ready for the action of flue gases at a temperature of 500–800 C and a short-term increase in heating to 1000 C. Only heat-resistant materials are suitable for this.

• Brick - refractory, of course. Withstands a constant temperature up to 900 C, heats up for a long time and gives off heat for a long time, which is an advantage for a chimney laid inside a building. Due to the same property, it is not suitable for low-efficiency and gas boilers.
• Stainless heat-resistant steel - you need to use a product from this category, despite the higher cost. Firstly, such a brand really withstands heating up to 800 C, and secondly, it is resistant to acids and condensate.
• Glass - made of refractory glass, it has excellent performance characteristics, but it is difficult to install and has a decent cost. This option is used for fireplaces.
• Ceramic - designed to operate at temperatures up to 1200 C, resistant to condensate, chemically inert. They would be the most popular option for a chimney in a private house, if not for the higher cost.

The choice of material is also influenced by the nature of the fuel. Brown coal, stone, wood of different breeds have different calorific value. In addition, it emits different amounts of soot, soot and acid anhydrides.

Section shape

The diameter of the chimney is a somewhat arbitrary value, since when building a brick oven, the default chimney is also made of brick. However, it is now more common to place a metal or ceramic pipe inside it to improve its performance.

However, such a decision should not be in a hurry, and here's why.

• Rectangular section provokes the formation of turbulence. The smoke rises in a spiral, part of it, once in the corners, slows down and forms a separate swirl. This worsens the draft, so for a boiler that needs good draft, this option is not rational.
• However, for wood-burning stoves and fireplaces in the home, the picture is different. Very good draft is not needed here, and even vice versa: during this additional time, the smoke gives off more heat and the room warms up better and faster. Thus, it is even possible to compensate for the insufficient number of smoke circulations.

For furnaces, a chimney with a square or rectangular section is considered optimal. And to improve its performance, various types of lining are used.

House chimney diameter

What diameter the chimney should be depends on the shape of the section and the power of the furnace. If finished industrial products are used, then, as a rule, special tables are attached to the instructions, which indicate the required cross-sectional area depending on the boiler power and its dimensions. If there is none, use the general recommendations. When installing a wood stove, where the strongest draft is not necessary, the calculations may be approximate.

• The inner diameter of the chimney determines the area of ​​the firebox. The length and width of the section must be proportional to the length and width of the firebox in the ratio 1:1.5. This also applies to the shape of the section, respectively.

• The cross-sectional area cannot be less than the blower area - this is a prerequisite.
• The power of the furnace, other things being equal, also affects the diameter. If the heat transfer of the device is less than 300 kcal / h, the cross-sectional dimensions must be at least 140 * 140 mm.
• What diameter of the chimney of a private house is needed also depends on the design of the heating chamber. If it is open - fireplaces and stoves with open fireplaces, then it is equipped mainly with round chimneys - good draft is extremely important here. In this case, the diameter is defined differently: as 1: 10 in relation to the area of ​​​​the furnace. In the photo - the device of the chimney.

It must be borne in mind that the inner and outer diameters of the stove chimney are different values. For a metal or ceramic chimney, both parameters are constant. A brick pipe is somewhat more complicated: when passing through the ceiling, it expands, but at the same time its internal dimensions must remain unchanged.