Stove chimneys (smoke circuits). Movement of flue gases in a stove, smoke circulation designs How to build a stove with horizontal chimneys

Good day, dear reader!

In today's article we will learn how to save money. Moreover, taking into account the price of heating raw materials, the funds are quite considerable.

A horizontal chimney will help with this. Installing it instead of the usual vertical pipe will save us thousands of rubles.

So, make yourself comfortable, let's begin.

Horizontal chimneys are sections of the chimney parallel to the floor, in one form or another passing between the stove and the exit to the roof. Performed in three types:

In the form of a branch from the main one. The maximum length of the “lying” part is 1 m;
Fully, with minimum height vertical pipe sections. Exited to the street through a hole in the wall of the house;
Snake (only in brick version).

Square work surface the horizontal chimney is many times larger than that of a conventional one.

In what cases is installation necessary?

The boiler or furnace should be connected to an outlet located far away. There are situations when, for certain reasons, it is impossible to install a vertical pipe in a room. In these cases, it is taken outside the room and connected to the stove using the above-mentioned pipeline;
The stove (boiler) has a low heat transfer rate, it is less than what is required for the heated area, and cannot cope with providing heat for the entire room. Here the horizontal section of the pipe acts as a kind of battery;
If the heat source is not connected to coolants. This is especially true for a stone (brick) stove, which transfers heat inside the room due to the cooling of the masonry. In this case, the use of multi-turn chimneys (snakes) is most justified.

What is the difference from a coaxial chimney

Conclusion

A horizontal chimney is a complex design, but its difficulty is justified by the reduction in heating costs.

Ergonomics are an extremely important factor for a comfortable existence. And it’s better to make some efforts once than to overpay for energy for years.

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By such a chimney we need to understand a section that can pass at some point between the stove, boiler and the direct exit to the roof. There is also a full-fledged horizontal chimney, in which there are a minimum of vertical channels.

With a horizontal chimney there are many nuances during construction; you need to take into account not only the length, as you know, it is limited to certain limits for each channel. You need to take into account the level of inclination, the degree at which the pipe will lie. These are features that must be adhered to to ensure the normal functioning of the oven.

Please note under what conditions the need to install a “lying” pipe arises:

A classic case when it is necessary to connect a boiler to a channel located at a distance. This could happen, for example, when the stove is inside and the outlet is outside. Then the segments pass through the walls.
When you need to improve the heat transfer characteristics of the furnace. To do this, they create a so-called “snake” so that the smoke does not just escape in a straight line, but overcomes a winding path, thereby transferring a larger percentage of thermal energy to the house.

Requirements for horizontal chimneys

General requirements can be identified:

Dimensions maximum length no more than 3 meters.
The width of the pipes should not change throughout the entire channel.
The slope must be left at least 1 cm for each meter segment.
The internal walls should only have smooth surfaces and corners.
A maximum of three turns is allowed.

Verticality is not always justified

The vertical channel is not always optimal, especially when it comes to boilers, the dimensions do not exceed the classic dimensions and the heating area is not large. In this case, additional “benefit” from the removed hot air is required. That is why long sections of horizontal position are designed. In addition, for some types of boilers, such as gas boilers with a closed operating mode, a standing chimney is, in principle, superfluous. The configuration itself requires horizontal section, that is, the image. The principle of its operation is clear.

Swirls - methods for solving the problem

The only one the right decision in terms of combating turbulence from the furnace to the pipes and vice versa, it is considered smoothing corner connections. That is, watch the angle at which your joints are located. There should be no sharp turns, otherwise reverse flows will always form, thereby worsening traction.

Swirls inside the chimney

This applies not only to “lying” pipes; standing channels often encounter similar problems. Considering that metal corrugation and stainless steel are often used to construct horizontal channels, be careful when choosing the diameter. It should not be small; pipes with a small cross-section form almost a 90-degree angle at turns.

Scheme of gas movement.

Unlike vertical chimneys, the “snake” has a larger heated area and is capable of giving off more heat. These are the so-called multi-turn ones, and can even exceed the length of the classic vertical “riser”. Provided that the same volume of fuel is used, the heat transfer from horizontal ones is much higher. It is also necessary to take into account the peculiarities; they require very good traction, perhaps even of a forced nature.

If you come across the phrase “horizontal chimney,” you should understand it correctly. The entire structure, from the firebox in the stove to the outlet in the pipe on the roof, is a chimney-smoke pipe. And since the difference in height between the firebox and the chimney on the roof is several meters, it is obvious that “horizontal chimney” is the name of the part of the structure located somewhere between the firebox and on the roof.

The horizontal section appears in the following cases:

When it is necessary to connect the furnace to a vertical pipe located at a distance. A typical case is that the stove or fireplace is located in the house, and the chimney is located outside. A horizontal pipe from a stove or fireplace passes through the wall and connects to a vertical pipe from the outside, forming horizontal part of the chimney.
When the goal is to increase the heat output of the furnace by using the heat of the furnace gases. In this case, the combustion products do not simply fly out, but travel a winding path in a specially designed chimney. Since the surface accompanying such a path is much larger than in a vertical chimney connecting the firebox and the pipe on the roof, it is significantly more heat transfer from the stove.

How to make a “snake” correctly

The benefit of increasing heat results in a significant complication of the design and labor-intensive manufacturing of a horizontal chimney, which is identical in appearance to the “coil” pipe present in almost every bathroom in the world. apartment buildings. Each change in direction in such a snake is called a “turn”, and the chimney itself, if there are several such changes in direction, is called multi-turn.

Since the horizontal section leads to poor traction, it is not recommended to make this section more than one meter long. There are also other additional requirements:

Along the entire length square cross section multi-circuit chimney must be the same.
Transitions from horizontal sections to vertical sections should be rounded.
The inner surface should be as wide as possible smooth and even.

The listed requirements are aimed at obtaining maximum draft in a multi-turn chimney.

In such a chimney it is possible by increasing the temperature of the furnace gases in it. As a result, the characteristics of the stove as a whole will improve, especially the burning time of the wood. In this case, the chimney will be used as chamber for afterburning furnace gases. To do this, a separate shut-off tube should be installed in the lowest horizontal part, closer to the firebox, the other end of which should be located just below the furnace vent door. Air will flow through the tube, and the stove gas will effectively burn out in the chimney.

Read also: Installing a chimney on the roof

How to effectively remove clogs

But in addition to problems with deteriorating traction, another most unpleasant problem is added. Such winding chimneys are difficult to clean from accumulated ash. Therefore, you cannot use coniferous wood in the stove, which leads to rapid clogging of the chimney. In order to gain access for cleaning, the following are installed at the turning points:

special metal doors;
removed bricks.

But the listed traditional solutions for cleaning the chimney are very labor-intensive and cause contamination of the room. Today you can solve the cleaning problem differently. A smoke exhauster should be installed on the roof, on the chimney and used in the stove firebox chemical agent to remove soot. If you regularly produce in this way cleaning, the house will always be warm and clean.

The oven is rude and the source of a fair amount of confusion. The fact is that “rude” or “rude” is not an established term. In Western and, partly, in South Slavic languages, rude is either simply a house heating and cooking stove, or a wood-burning stove for summer kitchen for 150-200 bricks. Well, according to acc. When searching on the Russian Internet, Dutch, Swedish, bathhouse (!), bell-type (!!) stoves, etc. appear. You can even find statements that say that there was once an outstanding stove designer, Grub.

In fact, a stove with a rough, or simply rough, is a compact heating and cooking stove with a heating panel, separate from the stove according to the heat cycle, but combined technologically, i.e. they are built together (see also below). Hence the conclusion that there cannot be a bell housing - heating shields for stoves are always ducted. A do-it-yourself rough oven is easier to build than a channel furnace of equal thermal power with a single thermal cycle, requires less materials and weighs less. However, its thermal efficiency (analogous to the efficiency for furnaces) is lower. Therefore, rude buildings are built in seasonally inhabited premises or small houses with good thermal insulation, where some excess fuel consumption in absolute and monetary terms does not impact the budget.

Note: a heating and cooking unit made of brick for 12 kW of heat requires up to 1200 bricks; the same power without a hob – 1200-1350, – 1800-2000, – 2500-3500 bricks.

Varieties

A do-it-yourself stove can be built with a shield built into the body (structure) of the stove, and then in appearance it is indistinguishable from the stove, pos. 1 in Fig. The slab grinder is compact, least material-intensive, lightest, and requires a minimum amount of additional construction work, but her thermal power limited to 10-12 kW, and then with great strain. Therefore, rough slabs are installed mostly in seasonal dachas (spring-autumn) with occasional trips there in winter, hunting lodges, etc. An important advantage of a rough slab is that it can be built without a foundation directly on the floor, if it load bearing capacity not less than 500 kgf/sq. m.

A rough structure with an attached shield (item 2) is structurally more complex and heavier, although a simplified foundation (see below) is also suitable for it, but its thermal power is potentially greater. A wood-burning grub with an attached shield can develop up to 16-18 kW; on coal - up to 20-22 kW. Current circuit flue gases in rough form with a shield is given in pos. 3; This is how the popular Galanka stove was built. However, you need to know that there is no point in building a furnace with more than 3 revolutions: such a furnace with a single cycle will be simpler and cheaper. In addition, during construction it will be necessary to pay special attention to some of the features of rough stoves, the consideration of which is devoted to a significant part of the article.

Note: wood burning can also be done with a stove bench, see below. It is not advisable to heat such a stove with coal; the stove will overheat.

Why is it rude - rude

Visually, a rough stove can be distinguished from a stove with a later added shield due to the integrity of the structure (item 4), but in essence they are one and the same. The calculation of a heat-efficient furnace is very complex and requires quite deep knowledge of heating engineering, and the development of a furnace design based on its results also requires a solid practical experience. It is much easier to design and build a grub because its combustion (fire) part and the shield are calculated separately and then “molded” together according to the pairing rules building structures taking into account the requirements of heating engineering. Naturally, the thermal efficiency of the resulting device will be lower, because the interaction of the thermal cycles of the fire part and the shield is not taken into account, and it is by taking it into account that it is possible to increase the efficiency of a single cycle furnace. That's why, If you live in an area with a harsh climate, a rude stove may only make sense for you as a seasonal stove for temporary use.

Firebox, shield and chimney

The main differences from a solid fuel stove are a more powerful firebox and the absence of a pass (smoke tooth) in the firebox. The tooth traps hot gases under hob, which in a summer stove allows you to reduce fuel consumption for cooking. In the rough it is not needed, because excess heat will be used for heating.

A rough stove should have a more powerful firebox because the shield provides additional resistance to the flow of flue gases. A chimney with increased draft will not help here: the gases in the shield will immediately expand and cool. Their thermal energy will turn into a mechanical one, which will successfully fly out into the pipe. Figuratively speaking, a firebox with a chimney in a stove with a shield works on the push-pull principle, and “push” here is the firebox more power. This explains the special requirements for the firebox and stove fittings, see below.

Shields

Depending on the purpose of the rough heating panels, they are made different types. Diagrams of heating panels for furnaces are shown in Fig. below; The fuel part is shown conditionally everywhere.

Sequential stroke with short vertical channels. The least material-intensive and easiest to build. The resistance to gas flow is greatest. The compactness and thermal efficiency of the stove are average. The most commonly used scheme;
Sequential stroke with horizontal channels. The dimensions and weight of the oven are the same as before. case, but building a shield with horizontal channels is much more difficult. Gas flow resistance approx. 1.5 times less. As a result, the thermal efficiency of the furnace is higher. It is possible to install a bed, i.e. the upper channel does not heat up much;
Sequential stroke with long vertical channels. Thermal efficiency is the same as that of a shield with horizontal channels, the technological complexity is the same as that of a shield with short vertical channels. Occupies smallest area, but requires a lot of materials and good foundation(see below) due to the high specific pressure on the support. The best option for brownie heating stove for 2-3 rooms, see below;
Parallel move. Highest thermal efficiency, lowest weight per unit of thermal power. The occupied area and technological complexity are the greatest. Can be used with a reduced power firebox. Optimal for adding to an existing slab without altering it.

Note: There are also shields of a series-parallel circuit or chessboard. The most complex, but also the lightest, have the least resistance to the flow of gases. Only possible variant for rough in a house with a heated attic, see below.

Special requirements

We repeat: the advantages are simple - compactness and the ability to build in an existing house without major construction work. But it is not so easy to place a more powerful firebox in a furnace structure of generally the same dimensions; from excessive heat load it will quickly become unusable. If special requirements are not met:

Furnace foundation.
Masonry mortars.
Methods of laying the structure of the furnace.
The choice and methods of installing stove fittings.

Foundation

The design of the foundation for the rough is shown in Fig. Crushed stone cushion without sand bedding before pouring it is leveled to the horizon. Pouring mortar M150 – cement M300 and sand 1:2. The gap between the rubble foundation and the flooring is 30-40 mm. Don't forget to support the cut joists! Leaving their ends hanging is a common but serious mistake. The dimensions of the foundation in plan should protrude onto the contour of the furnace by at least 100-150 mm.

Note: the brick bed on the foundation under the furnace is laid out with bandaging in the rows and between the rows in the same way as the first 2 rows of masonry for the furnace structure, see below.

Solutions

To fold the rough, 3 types of solutions are used, see fig. below. The bed on the foundation and the chimney are laid out on lime mortar as combining sufficient heat and moisture resistance, but the rubble needs to be laid only on completely moisture-resistant cement-sand mortar. Sand on clay mortar It is highly advisable to take mountain or ravine, with rough grains. Ordinary clay - purchased from the oven, guaranteed fat content and, most importantly, purity. Self-excavated clay, brought to the required fat content with sand, is of little use for coarse masonry.

Masonry

For rough masonry, stove bricks and, if the order (see below) is provided for, fireclay bricks are used; red worker fit highest quality– light red color (fully annealed), without burn marks, distortion and swelling. Dry molded brick is absolutely unsuitable. The masonry of the structure is roughly carried out following the trail. rules:

If you are an inexperienced stove maker, each row of masonry is first laid out dry; detected defects in cutting/chipping bricks are eliminated.
Before laying on the mortar, each brick is soaked until the release of air bubbles stops. You can’t dump all the bricks into a barrel indiscriminately!
A 5 mm layer of mortar is applied to the bed and the base of the brick being laid.
The brick being laid is laid with a smooth movement, slightly tilted, and moved towards the previous one so that there are no air bubbles left in the seam.
The brick is pressed until the seam comes together to 3 mm; You can't knock!
Between fireclay and ordinary masonry, the initial seam is 8-10 mm; after pressing – 6 mm.
The seam between bricks and metal embedded parts (see below) is 10 mm.
Excess mortar squeezed out of the seam is removed with a trowel (trowel).
The recesses in the seams found after removing the excess mortar are filled with the mortar by pressing without lateral movements, but not by mashing!

Those who prefer to learn visually can watch a video tutorial on laying heating and cooking stoves below:

Video: laying a heating and cooking stove

Accessories

Fittings and grates for roughing require cast iron; doors and latches - with an installation skirt and holes in it for diagonal wire whiskers. Welded steel or cast iron fittings with eyes for straight lugs (laid along the corresponding furnace wall) in in this case unsuitable. However, install the doors/latches as in Fig. on the right, in the rough it is impossible; This is not according to stove rules at all. For a Dutch country house with 2.5 bricks in plan, which is heated once or twice a season, it may be fine, but not for a rough one.

It is necessary, firstly, to crimp the mustache (galvanized wire 2-3 mm) with a twist so that it does not move. Press lightly at first, place it at the desired angle (from the far end of the mustache to inside masonry must remain at least 12 mm). Then tighten carefully and shake the door/latch slightly. Didn't leave? Good. Then, secondly, you need to tightly wrap the skirt with asbestos cord (or basalt fiber), and only now put it in place. You can also watch the following videos about installing accessories into the oven.

Video: installing the oven door

Video: grates and stove

Design examples

The figure below shows the order of a simple rough wood for a seasonal dacha or temporarily inhabited house. A special feature is the minimal use of fireclay bricks (highlighted by textured filling), which, generally speaking, is difficult to do without in rough wood, and a niche above the hob. In cold weather, it speeds up cooking, and, if it is already warm enough outside, it prevents the stove from overheating the room while cooking.

On the trail. rice. – the arrangement of a single-burner coarse stove is also compact and light, but more complicated, with combined system channels. This is an option more suitable for a hunting lodge or a summer cottage where weekends are spent in winter.

Next in Fig. – arrangement of the house heating and cooking system with switching to winter and summer operation (two-way). This stove is quite complex, but quite economical both in winter and summer. Option for a permanently inhabited cottage or one-room house.

On the trail. rice. – order and drawings of a heating stove (firebox door can be glass) for a house of 2-3 rooms. In a 2-room apartment, this rug is placed in a wall, and in a 3-room apartment, the front faces the living room and the rear opens into 2 rooms adjacent to it; the partition between them is located on the back side (back) of the stove. Agree, 650 bricks for a heating stove for a 3-room house is not much.

Now - in Fig. Below is a rough diagram and order of the stove bench: a cooking area in the kitchen/hallway with a bathroom; bed - in the living room. This is already quite complex design for an experienced stove maker. For heating in warm weather, the bed is covered with a feather bed, etc., so that the room does not overheat, but then the windows in the kitchen/hallway will have to be kept wide open, because... switching to summer speed is not provided.

And finally - rough, so to speak, aerobatics, see fig. below: for a house with a heated attic, where an additional panel with staggered channels is located (in the inset below on the right). This stove can also be a fireplace stove if the firebox door is made of glass. It is 2-way; ZLH in the drawings is a summer valve.

About chimneys

The chimney for rough must meet all the rules fire safety. Here it is only necessary to note that best chimney for coarse - sandwich, because it also does not require additional capital construction work.

Finally

If this is your first oven (which is quite possible), do not rush to build, model it on the table first. Suddenly you have a little extra money - you can buy a set for modeling stoves with layout diagrams and plastic bricks to scale, they sell these. No – bricks can also be cut to scale from foam plastic. Then it is convenient to imitate masonry seams using strips of thick paper or thin cardboard, depending on the selected scale.

The most a large number of heat goes into the pipe when vertical design chimney. You can make a heating unit more energy efficient using a horizontal smoke exhaust duct. In the stove it must simultaneously rise upward, which is why the horizontal chimney is a snake. The upper walls of its horizontal sections heat up most strongly, and the vertical parts have a small height. Thus, this design leads to good heating of the walls and significantly increases the heat transfer of the stove or fireplace.

More information about horizontal chimney

A horizontal channel has a surface area several times larger than a straight vertical channel. Gases tend to rise upward, thanks to natural draft, but to do this they have to travel a long way: constantly turn left, right, and go through horizontal sections. That is why this design is called multi-turn. It settles only in brick chimneys stoves and fireplaces.

The work must be carried out by an experienced stove-maker, as turns, roundings, and tucks must be positioned correctly. It is these structural elements that create areas of high resistance due to the fact that gases change direction. It should be remembered that these places sharply reduce traction, so turning the corners of the brick into curves is very important. To do this, they are chipped at the laying stage, and it is better to clean them to a smooth oval surface grinder.

Standard design parameters

When laying the stove and smoke exhaust ducts, you should observe design parameters. For example, a horizontal section of a chimney must have specific size section, which is not advisable to change at your own discretion. The cross-section of the passages depends on the design and power of the heating unit, with values selected from the following standards:

260x260 mm (size brick x brick),
260x130 mm (brick x half brick),
130x130 (half brick x half brick).

Why can’t you take other parameters of the chimney channels? A cross-section larger than normal leads to a slowdown in the movement of gases; because of this, it will be necessary to increase the size of the firebox and the entire furnace. Also, the slow movement of gases leads to the fact that they cool down in the chimney. As a result, its walls do not heat up enough, and the heat transfer of the unit decreases.

As a result, condensation appears on the walls of the chimney. It contains acid, which destroys the masonry over time. In addition, condensation is moisture, and soot will begin to stick to it. The walls of the chimney become clogged, the diameter decreases and, ultimately, the draft decreases, which leads to the release of gases into the room.

The cross-section of smoke exhaust passages below normal leads to overheating of the chimney and the appearance of cracks in the masonry. The temperature of the gases rises to 300ºC with a maximum rate of 140ºC. Overheating will not increase the furnace's energy efficiency or heat the room any more. However, over time it can lead to destruction and the need to relay the pipe.

No less important has the length of each horizontal channel. The speed and temperature of the gases leaving the furnace also depends on it. Standard in chimney 8 bricks wide, the length of the channel is made into 3 masonry units. Wherein according to standards it should not exceed 0.5 m.

Requirements for cleaning horizontal channels

It should be noted that stoves with a horizontal chimney require regular and more frequent cleaning than other designs. To do this, cleaning doors are made in its side wall. Their number corresponds to the number of channels, since each door is located opposite one of them. Thus, this design is different the largest number cleaning As standard, there are 4 horizontal channels and 4 cleaning doors.

However, it should be understood that this number is not mandatory, since it depends on the parameters, dimensions of the stove and chimney. An alternative to cleanout doors are knockout bricks. It is believed that they retain heat better and increase the efficiency of the chimney. Also, the same structure of materials will lead to uniform heating of the surface. Metal doors have a different heating temperature than bricks. This leads to a temperature difference and a weakening of traction.

Features of masonry

It is important that the thickness of the seams does not exceed 5 mm. It is better if the stove maker can maintain a thickness of no more than 3 mm. Increasing the parameter leads to a decrease internal dimensions pipes. During work, the horizontalness of the masonry is constantly monitored building level. A rubber hammer is used to knock down the brick. It is forbidden to knock bricks from top to bottom.

Overlapping the horizontal channel is done in the following sequence:

One side of the channel should be higher by one brick laying. This will ensure that it is positioned in a bed on the side with a lower height and end-to-end with the opposite side.
The prepared brick is laid on the lower wall so that its butt side is flush with the opposite wall. This is a brick fitting, which is mandatory.
Then the mortar is placed in an even layer on the bonded side of the brick and on the lower wall of the channel. The brick is pressed, and the mixture that comes out of the seams is immediately removed.
It should be remembered that the last brick must have rounded and polished corners with bottom side. It is better to process them directly during laying, and if this is done in advance, you should calculate exact amount such bricks. The next channel is arranged in the opposite direction.

Requirements for horizontal chimneys

The corners inside the channel lead to turbulence of gases, and soot settles on its walls. Chimneys of this design are characterized by the highest degree of soot formation, so their internal surface should be as smooth as possible. The channel cross-section should not change throughout its entire length. For masonry, only refractory bricks and mortar are used, the characteristics of which correspond to the following parameters:

gas-tight structure,
maintaining tightness,
resistance to condensate and its acids.

The horizontal part of the chimney is installed in heating and cooking stoves, in which the design provides for the presence drying chamber. It is its location above the horizontal channels that ensures optimal conditions for drying. Also this type chimneys are fundamental in the design of drying ovens. It should be noted that heating units of this design are rarely installed, since the work is considered complex and requires experience. The weight of such stoves is the largest compared to other options.