DIY boiler for a brick oven for a country house

Despite global progress in the field of gasification, in some settlements there is no main fuel supply. As an alternative, you can build a brick stove with a water heating boiler with your own hands. This will reduce the cost of heating the building and solve the problem of lack of hot water supply.

A brick stove with a water heating boiler will reduce heating costs.

Types of stoves with built-in boiler

The design can be made of metal or brick with different placement of the heater, with a boiler for heating water for washing, if we are talking about a bathhouse. The dimensions are not limited: the choice of parameters is determined taking into account the dimensions of the room, the building materials, as well as the local climate.

It is necessary to consider the design features of two types of furnaces with heating boilers:

The boiler is built into the chimney. This model has a long service life, the walls of the stove completely receive heat from the firebox, and the heat transfer rates are unchanged. Disadvantage: you cannot heat a large area.
The boiler is located directly in the firebox. You can heat a large area of the room. It is possible to use different types of heat exchanger. Disadvantages: metal parts come into direct contact with fire, resulting in destruction. Due to the low temperature of the heat exchanger, condensation is generated, which later causes a lot of soot to stick to the surface, resulting in a decrease in efficiency.

Installing a coil on a pipe

This is an excellent and fairly simple way to increase the efficiency of the stove. Flue gases heat the pipe to extremely high temperatures. The outer coil, like the inner one, helps reduce the temperature and somewhat cool the outer surfaces of the chimney. An external water heat exchanger is especially often installed on metal chimneys. This is an excellent auxiliary device for heating small spaces.

This heat exchanger has two pipes. The top one is connected to a pipe going to the storage tank, the bottom one is connected to the heating circuit. It is easy to make such a structure, as well as attach it to a pipe.

Use copper pipe or ready-made modules.

Masonry and brick

The principle of brick laying

Stove makers have enjoyed well-deserved respect since ancient times. Masters of their craft create stoves with a heating boiler, which always have good “draft” and an evenly heated surface.

There are several general rules that all specialists follow without exception:

Combustion chambers are made of fire-resistant materials. Open fire can easily damage ordinary brick and even stone.
You shouldn’t skimp on materials by laying quarter-brick walls. This reduces the reliability and stability of the entire structure.
It is necessary to carefully monitor the tightness of the seams. Any gap will subsequently allow carbon monoxide to pass through, which is dangerous for the lives of the inhabitants of the house.

Sometimes home owners resort to a little trick by setting up separate chambers for heating and cooking in the summer. This is a completely justified solution that allows you to save fuel in the warm season.

Fuel

The following types of raw materials can be used:

Coal (brown, stone, reach temperatures of 1500 degrees);
Logs (the most accessible, with a long shelf life and low cost);
Fuel briquettes (they are convenient to store, burn for a long time and evenly).

By the way. Which resource to choose depends on personal preferences. This parameter does not affect the furnace design.

Laying the boiler and installing a horizontal heat exchanger in it

A do-it-yourself heat exchanger using any of the options is installed in a brick boiler. The latter is laid according to the same principle as a brick oven.

The dimensions of a solid fuel boiler must be proportional to the volume of the premises that must be heated by it. The values available in the article are given based on a house with an area of 90-100 square meters. m. with 6 cast iron radiators and a distribution of 2 pipes (25-50 mm).

The choice and design of the boiler piping should be based on many factors:

How many circuits are there in the system?
How complex is the system?
Is there any other equipment available?

The entire boiler must stand on a solid reinforced concrete foundation.
The size of the foundation is selected based on the dimensions of the furnace. When laying a solid fuel boiler, the heat exchanger must be positioned so that the outlet pipe is the highest point. The height difference must be at least 10 mm. This is necessary to ensure that a plug of air does not form in the boiler while filling with water. This slope will also improve fluid circulation. Brickwork is done with your own hands, following the rules for bandaging the seams. The pipes should be approximately 2-3 cm lower than the brick wall itself. To prevent a decrease in efficiency, it is necessary to have a removable cast-iron plate on top of the boiler for easier cleaning. The smoke is discharged into a separate or main pipe. The pipe can be brick or metal.

Preparatory activities

Organizing stove heating involves preparing drawings, choosing a suitable location for pipes and radiators, as well as competent calculation of power. Next, a register is made or purchased and the structure with a built-in heat exchanger is laid.

Calculation of power and dimensions

The efficiency of a heat exchanger is determined by the materials from which it is made. Cast iron products of the MS-110-300 and MS90-300 series have a power of 0.14–0.16 kW/sq. m for the rib. Taking into account such figures, it is possible to predict the number of sections for heating each circuit. For 10 sq. m of area you need at least 1 kW. For a building of 60 sq. m. requires a register with a power of 5.5 kW.

The efficiency of a heat exchanger is affected by the materials from which it is made.

The dimensions of the furnace system are 1020x1160x2380 mm. The heat exchanger has dimensions of 750x500x350 mm.

Required materials and tools

To assemble the stove you need to prepare:

A sufficient amount of fireclay and solid bricks with fire-resistant properties.
Furnace and blower doors.
Grate.
Steel corners and strips.
Valves for ovens and cooking chambers.
Pre-furnace sheet.

The tools you will need are a basic stove set and containers for mixing the solution.

Radiator assembly

Assembling radiators is a simple process, because it completely repeats the process of disassembling them. The sections are connected by nipples that have left and right threads on both sides. This way, the sections at the top and bottom will be pulled tightly against each other when the nipple is turned. When the gap becomes 2 cm wide, you should wind the asbestos-impregnated cord and only then tighten the nipples completely.

When the entire structure is assembled, you should wait for the drying oil to dry, and then check the joints for leaks. that is, supply water under high pressure to the radiator. This will ensure the subsequent use of the radiator and there will be no leaks.

The return and coolant supply pipes must be connected diagonally to the radiators. Holes that remain open must be closed with plugs. It is better to take inch pipes. On one side of the radiator there will be a right-hand thread, so there will be no difficulties with connection. On the opposite side, use a coupling with a squeegee and a nipple.

Advantages

Economical. The services of a stove maker will cost much less than the purchase of modern devices, their maintenance and installation. The stove can be made from mortar and bricks that were left over after building the house. Repair and operation of such devices does not require large investments.
Design variability. A modern master can build a stove of any shape and size. It can be decorated with exquisite designer decor and painted in various colors. There are designs that combine a fireplace and stove.
High degree of maintainability. Over many years of operation, this equipment requires only minor cosmetic repairs. This is much faster, cheaper and easier than taking an expensive unit for service.
Possibility of regulation of combustion intensity in the firebox.
An atmosphere of comfort, which is characteristic only of Russian ancient huts with stoves.
The intensity and speed of air heating is determined by the position of the dampers.

What dimensions should the chimney have?

Chimney placement options.

The draft in the chimney channel will occur due to differences in the height of the inlet and outlet, as well as due to temperature differences. To ensure continuous operation of any heating device, you will need to make a strong draft

Before starting masonry, it is important to decide what type of heating device will be used, what dimensions it has and how many channels it is planned to make

The number of channels can be determined taking into account the power of the heating device, fuel and the special requirements of the device manufacturer.

If the diameter of the chimney channel significantly exceeds the calculated value, the draft in such a channel will greatly decrease. As a result, there will be frequent interruptions in the functioning of a gas boiler or other heating device. If the channel diameter is smaller, this may impede the removal of combustion products. It is for this reason that in most cases the operation of boilers stops.

To make brick channels, you will need to use ceramic brick grade M50-75. You can also use concrete blocks that have channels with a square cross-section.

If you plan to use ceramic bricks to make a chimney, then you should know that its minimum cross-section is 14x14 cm. If you plan to purchase material with a round cross-section, then the permissible diameter is 15 cm or more.

In a brick chimney whose height is less than 5 m, the dimensions of the channels must be increased to 14x20 cm or 18 cm in diameter. Such structures should be made in the walls between rooms that are planned to be heated. In this way, it will be possible to create a certain protection of supporting structures from cooling, which in most cases leads to a weakening of traction.

It is necessary to try to group the chimney channels so that in the device that will be installed above the roof, their number is maximum. In this way, it will be possible to reduce the cost of manufacturing work and significantly improve the performance of the chimney device.

Laying a brick oven with a water boiler

Diagram of a solid fuel boiler.

Laying a brick oven with a water boiler is carried out in the following sequence:

The foundation is poured under the furnace location.
While the foundation is drying, mix a solution of clay and sand in a ratio of 1:2. Depending on the fat content of the clay, this proportion can be changed. Before preparing the mixture, the clay is soaked in water for 10-12 hours (large lumps of clay must be kneaded with your hands). Before starting masonry, sand and clay are thoroughly mixed.
Waterproofing is laid on the dried foundation - usually roofing material the size of the future furnace.
A layer of mortar is applied over the waterproofing, the first layer of brick is leveled and laid. It should be noted that it is better to use beautiful brick for the outer layer; it will look more aesthetically pleasing. The inner layers can be formed from defective or broken bricks.
Each layer of brick is carefully covered with mortar.
At the required height, a compartment for ash and the firebox itself are made.
A sheet of metal is placed in the ash compartment to make it convenient to remove ash residues in the future. The blower door is installed here.
Behind the firebox, in front of the chimney, a water boiler is installed. Brick ledges with metal corners are built for it. A level must be used to prevent air pockets from forming. A door for loading fuel is fixed in the firebox itself.
A metal plate is placed on top of the boiler, a chimney and a cleaning system are formed. It would be useful to make a separate door for cleaning the boiler from carbon deposits.
A metal sheet is fixed to the floor in front of the firebox in order to comply with fire safety regulations.

Boiler design diagram.

When you first light up a finished stove, you must ensure that the system is in good working order and that there are no leaks. The room must be ventilated, as often during the first heating there are unpleasant odors of burning industrial lubricants and heating clay. It is carried out for at least an hour with the maximum possible amount of fuel.

A brick stove with a homemade boiler is one of the best ways to heat small country houses, which will allow you to enjoy the warmth on cold winter evenings and save your budget.

Cast iron radiators as a boiler

You can build old radiators into a brick stove, and they will serve as a boiler. Cast iron built-in water heating elements have their own characteristics, for example, cast iron does not react very well to open fire. Nevertheless, this method is used quite widely. You can use the M-140 radiator, which can easily be found at demolition sites of five-story buildings. If you weld a dozen sections, you will get a heater with an area of 3 sq.m and 18 liters of capacity. A flat boiler with the same characteristics would require a lot of space. Such boilers can heat large areas.

Before the radiators are welded together, they must be disassembled, cleaned of dirt and thoroughly rinsed with a hot 6% hydrochloric acid solution. Then rinse again with water. Then change the cardboard spacers located between the sections, as they will simply burn out. Instead, use asbestos cord impregnated with graphite powder and natural drying oil.

The radiator elements should be assembled in a certain sequence. Screw nipples with their right and left threads into the sections to be connected, then wind an impregnated asbestos cord around them and tighten both nipples with a wrench, making sure that there is no misalignment of the sections. After connecting two sections, you can attach a third, then compress the radiator to check the quality of the assembly. Now you can install the risers.

You can position the cold water inlet and hot water outlet diagonally. The other two holes can be plugged to allow water to circulate through the entire volume. The radiator must be mounted in the smoke duct located behind the firebox. This will help avoid contact of cast iron with open fire: the boiler will be heated by hot gases.

You can increase the natural circulation of water in such furnaces by running a return line pipe through its foundation and the space under the floor, which will increase the temperature difference between the return and hot lines. The battery in the furnace is installed with a slight slope to allow air to escape and enter the system. For cleaning, you can build an additional door into the smoke channel itself.

Principles of heating operation

Heating based on a stove with a water circuit works on the principle of heat exchange. In the furnace firebox, hot air heats the water in the circuit. It rises up the pipe and is sent to the heating system. When the coolant enters the radiators (batteries), it gives off its thermal energy, and the cooled liquid flows back into the furnace circuit. This ensures a closed cycle of the system.

There are 2 main types of this heating:

Gravity system. In accordance with physical laws, heated water rises and rushes into the heating circuit on its own, making room for the already cooled liquid. Such a system can function well with a small number of radiators and a short total pipeline length.
Compulsory system. In radiators and as it moves through pipes, the water flow experiences significant resistance, which slows it down. In branched and fairly long systems, the own pressure is often insufficient, and therefore it is necessary to ensure forced movement of the coolant. To do this, an electric pump is installed (most often in the return pipe).

Design features of the furnace

A furnace for water heating differs from a conventional one in that a water circuit (heat exchanger) is built into it. It contains 2 pipes: at the top - for supplying hot water to the system, at the bottom - for connecting the return pipe with cooled liquid. The furnace's design must ensure heating of the coolant passing through the pipes.

The efficiency of the furnace is ensured by the correct choice of circuit design and its location, taking into account the following features:

Design. A furnace heat exchanger can be made of sheet metal in the form of containers (boilers), round or profile metal pipes, complex metal structures (for example, a heating battery).
Material. The water circuit is made only of metal. Cast iron is ideal for strength and corrosion resistance, but it is difficult to process. The most commonly used steel pipes or sheets. You cannot use copper in the furnace firebox, because... its melting point is less than 1100ºС, and short-term heating in a wood-burning oven is possible up to 1200ºС.
Dimensions. The volume and length of the circuit must provide hot water to the entire heating system, taking into account its gradual cooling in each radiator. It is quite difficult to accurately calculate the dimensions of the heat exchanger, and therefore this process is entrusted to specialists. You can estimate the size based on the required power of the heating system. Practice shows that sufficient heating power is 1.1-1.3 kW for every 10 m² of room area with standard ceilings (height 2.7-2.8 m). The heat exchanger, on average, delivers 6-8 kW of energy from each 1 m² of area.

The location of the circuit in the furnace is also important:

The most efficient heating of the coolant is ensured by placing the circuit directly in the combustion chamber. This option is installed during the construction of a new furnace or major reconstruction with complete disassembly.
To increase the durability of the heat exchanger, it can be separated from the firebox by a thin partition with good thermal conductivity. In this case, direct contact with an open flame is eliminated, and the requirements for the exchanger material are reduced. In this case, more thermal energy will be required for heating.
The significant thermal energy of the exhaust smoke can be harnessed. Installing a circuit in the chimney system eliminates the need to reduce the useful volume of the combustion chamber.

Various types of stoves are used for water heating. In private homes, brick stoves with a built-in water circuit are popular. In small houses, you can use long-burning pyrolysis stoves. Nowadays, you can simply install a purchased, ready-made furnace with a water circuit.

Boiler installation

When implementing plans to create a combined heating system, it is important to pay attention to some features. Water-heated brick stoves have many options, each of which differs in material, type of main element and other nuances. Ignoring technical and construction requirements will certainly lead to the rejection of the entire work

Ignoring technical and construction requirements will certainly lead to the rejection of the entire work.

The boiler must fit completely into the firebox. However, in practice there are incidental situations when part of the heat exchanger is located outside the stove. This is unacceptable, because the main task of the unit is to heat the coolant. The boiler is made in the shape of a “P” from pipes or sheet iron. All its elements are hollow and are designed to remove heat.

The preferred option is from pipes. It has a larger convection area and allows the flame to reach the cooking surface to cook food. In addition, attention is required:

Dimensions. It would seem that a massive product is needed that can heat a lot of water and provide heat to a decent-sized structure. But that's not true. The boiler itself is made of very modest dimensions - 75 * 50 * 30 cm (length, width, height). The convection surface of such a device is enough to heat a house up to 200 square meters. Installing a pump for forced circulation of coolant increases productivity by up to 50%. Boiler. Its shape is designed in such a way that the heated surface area is as large as possible

It is very important to install it in the center of the combustion center. This is the only way to achieve high efficiency of water heating. Peculiarities

A small gap must be left between the walls of the furnace and the surface of the boiler. The optimal distance is considered to be 5 millimeters. It is quite sufficient to level the free movement of the metal during thermal expansion.

The heat supply and outlet lines are carried out in strict accordance with the laws of physics. It is known from school that hot flows tend to go upward, while cold flows are always directed downward. Therefore, the pipe supplying hot water to the house is always adjacent to the boiler at the top point, and the channel with the “return” is at the lowest point. This arrangement eliminates the accumulation of hot steam, which poses a serious threat to the integrity of the system.

Do you need electricity?

The system can be implemented in two versions:

Free circulation when heating occurs by gravity;
Forced way.

In the latter case, a pump and a battery will be required (provide uninterrupted power supply). At first glance, this is convenient: after all, stability is maintained. You can heat not only the first floor, but also other floors.

However, such components significantly increase the cost of stove heating; the design itself acquires impressive dimensions.

Flat-plate heat exchanger

A popular option, which is used both for stoves in the bathhouse and for the home. They are the simplest to manufacture, the surface is easy to clean from soot accumulations, installation is possible both vertically and horizontally, and the efficiency is relatively high.

A flat boiler can have a high volume, so you can take hot water for washing directly from the heating system. An expansion tank with an increased linear size is installed, into which water constantly flows after the level drops below critical. This option is quite convenient and helps solve several problems at once, but there is also a condition - the room temperature in winter should not drop to minus.

Key disadvantage: a sharp decrease in heat transfer from the furnace walls. This type of heat exchanger is made in the shape of the letter “P” and is installed around the perimeter of the firebox, bypassing the door. As a result, it turns out that the temperature of the external walls is quite low, as a result, warming up the room takes much longer. This is critical only if the stove is installed in a bathhouse; for residential buildings, where the stove is constantly heated, increasing the warm-up time by several hours does not play any role.

Thus, when choosing a flat boiler, think about how you can increase the heating rate. One option is to enlarge the heater and place it directly above the firebox. Second option: using a metal chimney for heating, increasing its length.

Safety regulations

The main rule is not to close the oven view ahead of time. Kuznetsov’s boiler works on the principle of a gas view - cold gases do not mix with hot ones, so the stove does not cool down much. If you close the view ahead of time, carbon monoxide may enter the room, causing poisoning.

The boiler is especially afraid of overheating - the boiling coolant will rupture the heat exchanger. Therefore, in severe frosts, if the power is not enough, resort to additional heating of the room with electric heaters.

When installing a water pump in the heating system, operating efficiency increases.

When firing, some parts of the stove become very hot. Keep small children away from doors and do not let teenagers heat the house.

While burning, keep the door either closed or slightly open, as escaping embers can cause a fire.

An “apron” made of ceramic tiles or a sheet of iron is installed in front of the stove.

Soot is removed twice during the heating season. Its accumulation in the chimney can lead to a fire.

A brick stove is an excellent option for heating a home. The rules for safe use are simple and intuitive.

Simple rules for an efficient heat exchanger

The operating principle of stove heating.

If the house has a ready-made brick stove, then organizing water heating with your own hands is a fairly simple task. To do this, it is enough to place a homemade boiler in the firebox in the form of a coil or any other shape. The main thing to consider is:

The height difference between the fluid outlet from the heat exchanger and its inlet;
It is necessary to ensure the maximum possible surface area;
The heat exchanger should not interfere with the loading and combustion of fuel.

If you are building a stove with your own hands, then the boiler for a brick stove can be made as efficient as possible. To do this, several important conditions must be met:

Combustion products must leave the chimney as cold as possible;
Greater heat transfer of furnace gases inside the furnace increases its efficiency;
It is best to place the heat exchanger in the chimney rather than in the firebox.

These rules may seem somewhat strange, because logically, the heat exchanger should be heated best by the open flame of the firebox. However, it is necessary to take into account other processes occurring in the furnace. From a physics point of view, flames are burning fuel particles. And if we take heat away from these particles, then they will not burn completely, which will reduce the usefulness of the stove.

Diagram of connecting the boiler to the heating system.

In addition, for better heating, the coolant must move towards the heat flow. Only in this way is the temperature difference between different parts of the coolant maintained, increasing the heating efficiency and ensuring better circulation within the system.

Another advantage of this arrangement of the heating tank is that less condensation forms on it, which contributes to the absence of corrosion.

Choosing the best option

It will be difficult to install a massive brick stove in an already built house. In this case, water heating is best organized on the basis of a metal potbelly stove, which can be placed on a reinforced wooden floor without pouring the foundation.

However, if it is possible to make the foundation as it should be, then preference should be given to a more reliable brick stove structure.

The water circuit around the house for a wood-burning stove is best made from thick steel pipes and with natural circulation of coolant

Installing a circulation pump and/or accumulator in the heating circuit in question is a waste of money and zero additional benefit. They will only complicate the installation of the system. And if the lights go out, these devices will create problems. Whereas the heating option without them will continue to calmly heat the house if there are problems in the electrical network.

Laying a furnace with a boiler

If you decide to delve deeper into the topic, you may decide to install a Kuznetsov bell furnace, the operating principle of which is the free flow of gases, which does not require additional external energy. The drawings are available on the Internet. Here we will talk about a simpler design. So, first you need to pour a foundation, the depth of which is 50-70 cm. Sand should be poured onto the base in a layer of 10-15 cm, crushed stone, gravel or construction waste should be laid on top, and a space of 25-30 cm should be kept for pouring cement. It is best to prepare the solution for the foundation without using sand, replacing it with screenings, the ratio will be approximately 1:6. Roofing felt should be laid under and on top of the screed for waterproofing.

Then you should make a solution of clay + sand in a ratio of 1: 2.5, however, the proportions may vary depending on the level of fat content of the material

It is important not to leave lumps, and therefore the clay should be soaked in the evening. If the mixture slides off the trowel, leaving small streaks on it, then the concentration is appropriate

Before starting masonry, it is necessary to lay out roofing felt over the area of the poured foundation and cover it with mortar. The first row is laid out with a pallet completely made of bricks, where the furnace will then be laid. Then the first row of the furnace contour is laid out, then the next, etc. During laying you will need order.

Now the firebox, ash compartment and ash pit are made. The doors are secured using galvanized wire or a strip of galvanized sheet. It is necessary to trim the brick above the doors using a grinder, but it is best to make one of them with a wedge, so that the masonry will not crack. Make protrusions for the boiler on the brick in advance, which can also be cut with a grinder. Do not forget that the instructions require level installation, and therefore you should use a level. Then the firebox and the rear part of the structure are installed, where the chimney with cleaning is located. The pipe should protrude at least 50 cm above the roof.

You can make your own stoves for heating your home without being a pro in this matter. They are versatile and have a high heat transfer coefficient. The big advantage is their autonomy, since they do not depend on external energy sources. Such boilers can have any size depending on the area of the heated room.

Peculiarities

Today, heating boilers have sufficient power to heat rooms for various purposes. They are economical. Their continuous operation time is almost the entire heating season.

These devices can operate on wood, coal, pellets (wood waste compressed and processed into granules), briquettes, peat, and wood gas.

Boiler types

Depending on the type of solid fuel, they are divided into the following types:

wood-burning (heated not only with wood, but also with pellets);
universal (they use different types of fuel and their combinations for work);
gas generator boilers (they have increased efficiency and operate on wood and wood gas).

Models of the latter type are more convenient to use, since soot does not accumulate inside them, and a minimum of ash remains.

There are models of long-burning boilers, dependent on the electrical energy carrier and independent.

Such heating equipment operates on the principle of top combustion (the hearth burns from top to bottom). The combustion chamber, located at the top of the structure, is filled with fuel. The fan forces air through the duct, and the heat generated by combustion is sent to the heat exchanger. The volume of the combustion chamber is about 500 dm3, so such a heating device can operate without interruption for several days.

Advantages

Long-burning designs are heating devices that are very popular among the population. This is explained by their many advantages: not only the use of various types of fuel, but also their long combustion time, as well as the simplicity and environmental safety of their use.

A boiler of this type in its modern variation is a design equipped with automation and a fan to increase the pressure in the system. With a small amount of fuel consumed, such devices can maintain the temperature in large rooms.

The big disadvantage of the design is the high cost, more than 1000 USD. e.

Water boiler made of cast iron radiators

M-140 radiators are suitable for this type of boiler. They are quite easy to find, since large quantities of them are sent to scrap when radiators are replaced with more modern ones or old buildings are demolished. Each section of such a radiator has a capacity of 1.5 liters, and their area is 0.254 square. That is, if you combine 12 sections, the volume of the heat exchanger will be 18 liters, and the area will be 3 square meters. Such a boiler has a capacity of up to 100 square meters. So it’s quite enough for a residential building.

In order to use the radiator, you need to modify it a little. Initially, you should remove the cardboard gaskets located between the sections with your own hands. The best replacement for them would be an asbestos cord, which must be impregnated with drying oil with the addition of graphite. Thus, the gaskets will be protected from burning through at high temperatures.

In addition, before starting assembly, the sections should be washed from the inside using a 6% solution of hydrochloric acid, and then washed with water. This will clean the pipes from dirt and rust that has accumulated there during operation.

Heating registers

Before installing stove heating, it is worth deciding on the type of heating water circuit, also called a register, heat exchanger, coil or water jacket. Most often it is a rectangular flat container or several tubes connected together.

But before connecting the heating to the stove, two pipes must be welded to the register. The first serves to draw hot coolant from the furnace, and the second supplies cooled water back to the heat exchanger.

The size of the heat exchanger can be determined by the level of heat loss in a particular house. So, if 10 kW of thermal energy is required, the heat exchanger area should be 1 m2. It is worth considering that the oven does not work all day, but for about 1.5-3 hours, depending on the outside temperature. This time should be enough to warm up the water in the heat accumulator. Consequently, to calculate the register area, the daily consumption of thermal energy in the house is determined.

So, with heat loss at home of 12 kW/hour, daily consumption will be 288 kW of energy. Let's assume that the oven operates 3 hours a day. It turns out that every hour 288÷3=96 kW of energy should be released. Then the area of the heating register will be 96÷10=9.6 m2. The shape of the heat exchanger in this case is not important, the main thing is that the surface area is no less than the obtained data.

When using antifreeze as a coolant, you can further increase the volume of the heat accumulator, since water and antifreeze have different heat capacities.

If the buffer tank is additionally insulated, the heat will be retained in it further, and the efficiency of stove heating will increase.

Heat exchanger construction

Installation diagram of the heat exchanger and storage tank.

You can easily build an effective boiler with your own hands. If it is made in the form of a tank, then high-quality steel is required, which can withstand thermal loads and corrosion due to the coolant. In addition, the manufacturing material must have high thermal conductivity to increase the efficiency of the system.

The thickness of the tank walls should be within 4-5 mm, which ensures its strength while simultaneously heating quickly. There are no standard sizes for such a heat exchanger; it all depends on the configuration of the existing or planned furnace. The main thing is that the height of the tank is at least 500 mm for better circulation.

If the heat exchanger is a coil or another circuit of pipes, then there are also some nuances. Pipes for the manufacture of such structures must be thick-walled and have no seams. If it is difficult to find a seamless pipe, then it is necessary to weld the existing seams to prevent possible coolant leakage.

The inlet pipe is best located at the top of the structure, and the return pipe is located in any convenient place. The pipes are not butt welded, but with chamfers to avoid unwelded areas that will leak in the future. The minimum distance between the knees of the structure is 5-6 cm, so that the heating of each knee is maximum. Before placing such a boiler directly into the oven, it is necessary to fill it with water and check for leaks, which are promptly eliminated.

When placing the boiler directly into the furnace, you should adhere to the level, but minor deviations are allowed.

How to choose a project? Order

First of all, decide on the conditions in which the furnace with a water circuit will operate.
If this is integration into an existing OS, it is important to ensure interchangeability in the operation of existing communications. For the independent option, it is important to determine the area that the system will heat

For 100 square meters of a one-story house, a conventional stove is quite enough.

Another thing is if the area, number of rooms and floors is larger

Finally, it is important to understand whether the OS will be used all year round or only in cold weather. If people live in a house in the summer, and in winter it is idle, then after cold weather and frosts the system will require restoration work, which will entail additional costs

Photo 4. An example of the order of a brick kiln with a water circuit: the initial stages of construction from 1 to 20 are depicted.

What materials will be needed

For the furnace itself: concrete, mortar, refractory and red clay bricks, valves, fire door, grate, ash pan.

For the manufacture of a heat exchanger: metal pipes with a diameter of up to 50 mm or steel sheets 3 mm thick and a rectangular profile 60x40 mm.

For the manufacture of outlet and supply lines of the furnace: metal pipes. For distribution of hot water throughout the house: polypropylene pipes and radiators.

Required Tools

For laying the furnace, making a heat exchanger, installing communications and heating devices you will need:

building level;
roulette;
Master OK;
bucket;
pliers;
electric drill;
welding inverter;
wrench;
screwdriver.

Other tools may also be required, since the laying of a furnace with a water circuit and the wiring in each case are carried out taking into account individual conditions.

Preparing the site

A furnace with a water circuit is located in a fireproof area that is waterproofed.

This area of the room should be well ventilated and access to the oven should always be open. Then make sure that the place for the stove is level and its walls rise up at a right angle.

It is important that the roof allows the pipe to be brought outside without obstacles. Then check how strong the foundation under the future structure is

After all, a stove is a heavy structure that requires a prepared base. The approximate weight of the stove is calculated by equating 1 cubic meter to 1350 kg. If a suitable location is identified, it is cleared and prepared for the construction process.

Attention! To achieve maximum effect, a stove with a water circuit is positioned so that it heats as much space as possible. This will reduce heat loss and reduce the cost of its production.

Building a stove with a water heating boiler with your own hands

Construction begins with the foundation. Its lower part is filled with concrete, and its upper part is laid out with bricks. Then the laying begins. The first row is laid out dry, and then - on the solution. In this case, the masonry is made from the walls to the middle.

During the laying process, a heat exchanger is installed in the firebox, and the pipes coming from it are distributed throughout the body right up to the point of entry/exit of communications. When external communications are installed, water is released into the circuit and the system is tested for leaks. If the test is successful, the furnace with a water circuit is considered ready for operation.

Difficulties during construction and commissioning

The main challenge when building hot water furnaces is their integration into the existing building layout. You have to look for a convenient place in it, and then adapt it to the operating conditions of the furnace.

If you put the design of the system into perspective at the design stage of the building, you will be able to calculate all the nuances and make the efficiency of the heating system as high as possible.

It is better to test the elements of the water circuit (heat exchanger, pipes for hot water outlet and return inlet) immediately after manufacture and before installation.

If everything is already built and installed, and the heat exchanger suddenly leaks, you will have to dismantle the masonry and disconnect the communications in order to eliminate the detected defect.

Another problem when building a system can arise from pressure. The liquid moves through the water circuit under its own pressure. But it is not always enough for the coolant to reach remote areas of the room. Then an electric pump comes to the rescue to distribute heat evenly throughout all areas of the building.

Brick chimney construction

Brick chimney laying diagram.

Laying should begin with the mounting tube. It should be laid out in compliance with the brick dressing. After this, a cutting (fluff) is formed. It needs to be laid out from 5 bricks. The channel will have dimensions of 270x140 mm. The external dimensions of the cutting are 450x590 mm. This can be achieved by inserting brick halves. To maintain the dimensions of the channel, you will need to insert brick plates inside. In this case, the channel will not change.

The next row will have dimensions of 650x510 mm. Brick plates 6 cm thick are mounted inside. At this stage, the cutting will begin to take its shape. In the next row, the external dimensions will be 710x570 mm. Inside you will need to install material 9-10 cm thick.

After this, the fluff ends. In the next row, be sure to observe the dressing. If you need to make a cut of greater height, you can install another row; the dressing should be done under the bottom row.

To allow the riser to exit outside, you will need to prepare a hole in the roof. Next, the riser should be routed through the roof. The rest of the work is done on the roof.

At the next stage, the riser is laid out. You need to carefully monitor the dressing of the brickwork. The riser must be placed several rows above the roof. After this, the otter lays out. The internal plates are selected so that the channel does not expand.

After this you will need to form the neck and head. The actions will be the same as in the case of erecting a cutting.

Benefits from combining the two systems

A traditional stove-heater consists of a combustion chamber, grates, ash pan and channels for smoke removal. All the attributes of a familiar Russian stove are known to every village resident. Modern boiler furnaces are practically no different visually.

But they have different characteristics:

An ordinary rural stove can produce a little more than 6500 kcal of heat in one hour of full operation. This energy is enough to create a comfortable microclimate in a small house. For example, this heating method is suitable for a summer house.
If you install a water boiler, its productivity will be 2.5 times greater. Naturally, the area of the heated room will also increase proportionally. The amount of fuel burned is the same. And savings are achieved through improved heat extraction. That is, less warm gases are released into the atmosphere.
Next, a very important nuance becomes clear. If you combine convection (oven) and water (boiler) heating systems, the efficiency increases multiple. The point is that when both systems are running, their performance is additive. In other words, a tandem of two heating methods produces about 21,000 kcal per hour of operation. This is quite enough to heat about 300 square meters of living space.
The positive aspect of this method of heat supply is the availability of energy resources. In most cases, firewood or a combination of wood and coal is used. The cost of these types of fuel is low, and acquiring them is not particularly difficult.
The oven does not need to be lit all the time. Fuel is added 2 times a day. A comfortable microclimate is created in the house, regardless of the temperature outside the window.
If the efficiency of a traditional stove did not even reach 50%, then the combined option reaches 85%. And for wood heating this is almost an ideal indicator.
The price of materials is low. The cost is usually determined by installation work.

Circuit

The pipeline consists of a supply from the furnace and a return to it. In the room farthest from the stove, both branches are connected. In other rooms they run in two lines along the outer walls.

On a note! This option is cheaper than a system with radiators and is easier to install.

Rules you need to know when building a chimney

Diagram of a brick chimney.

The structure for solid fuel boilers is made together with the walls of a private house. These elements are constructed according to a single principle, and it does not matter whether the channels will be used as ventilation or smoke. You will definitely need to build a foundation for the chimney. The base structure can be made of brick or concrete.

In all cases, a foundation project is prepared. During the design process, it must be taken into account that its height must be at least 30 cm, and its width must be such that the base structure extends beyond the border of the chimney device by 15 cm or more. If the chimney is made as an element of the external wall, then you need to know that the lower part of the chimney base must be placed at the lower level of the wall base.

During the construction of chimney structures, special attention should be paid to the quality of tightness. To make a durable brick chimney, you will need to follow the rules

The material should be laid so that the seams overlap the elements of the next row. In most cases, the same mixture is used as for the construction of load-bearing walls of the structure.

In the process of making a chimney for a solid fuel boiler, it must be taken into account that its internal base must be smooth.

Therefore, when performing construction work, you need to use a template. The walls between the elements must be at least half a brick thick. For ventilation elements, the thickness of the partition should be 2 times less.

At the end you will need to make a header. The extreme parts of the element must protrude beyond the structure by 10 cm or more. The outlets of the ventilation ducts must be created under the head; in most cases, 2 walls are used, which are placed opposite each other. This placement method will prevent air from being blown in.

Covering instructions

Step-by-step instructions on how to line an iron stove with bricks in a bathhouse or house are as follows:

First, a cord protruding as a level is pulled. As it is laid, it is raised higher;
Then the first and second layers are laid out, which are coated with the solution. The width of the seams between layers should be up to seven millimeters, and horizontal ones up to ten. It is very important that the first row is executed perfectly, since it is fundamental for the others.
Next, small ventilation gaps are created, and the masonry continues according to the pattern previously selected for the formation of the stove;
By the third row, excess mortar is removed using a rubber hammer or trowel;
The masonry continues to the level of the slab or to the ceiling, covering the chimney.

At the time of laying, it is important to understand that when the master reaches the ash pit and firebox, it is necessary to correctly position the window with hinges. When installing near doors, you need to check the ease of operation.

Note! The laid wall should not prevent the doors from opening freely. It is also necessary to make several holes near the chimney responsible for ventilation.