Copper tube heat exchanger. Do-it-yourself furnace boiler or heat exchanger for a furnace. Heat exchange devices of the "pipe in pipe" type

When the house has a stove, then you should not rush to disassemble it. Indeed, by installing a heat exchanger in it, it is possible to modernize the equipment and make the heating system more advanced. How to make a heat exchanger, and even with your own hands for, it will be interesting to know for all homeowners who still use stove heating.

Functional features of heat exchangers

Before you begin to manufacture a heat exchanger, you should understand the nature of its function in the heating system. The principle of operation of this device is implemented in devices, gas and solid fuel. The heat exchanger is a structure of curved pipes that are placed inside the heating equipment and heated by an energy source.

A coolant passes through the pipes of the heat exchanger, for example, water, which is heated and sent to, cooled water from the batteries enters in its place and heats up again. Thus, it happens. Gases can be used as a heat carrier, then a heat exchanger will work as a heating element. However, in residential buildings such a device is used extremely rarely.

By installing a heat exchanger in the oven, you can get a complete system.

Material selection

It should be noted right away that at home it is almost impossible to create a heat exchanger like at a factory. However, homemade design in terms of functionality will not be inferior to the one created at the enterprise.

You can give any shape to the structure, but the most popular options are a system made of several metal pipes in the form of a lattice or plates. Due to the fact that the combustion temperature is quite high, especially when coal is used as a fuel, special attention should be paid to the choice of material, as well as the level of quality of the welds. In addition, the type of metal plays an important role, since each has its own thermal conductivity. If we take a copper pipe, then it will be 7 times higher than the coefficient of thermal conductivity than a similar pipe made of steel. With an identical diameter and volume of heat transferred, 3.5 meters is sufficient copper pipe, with the same parameters, steel will need 27 meters.

Copper heating elements are the most expensive, but effective. If it is not possible to spend money on the purchase of such materials, you can purchase steel pipes, but their diameter must be at least 3.5 centimeters.

For reference! In the event that coal is used as fuel, then the most rational option will install a heat exchanger made of cast iron. It is the most durable and heat-resistant metal. In addition, old cast iron batteries can be used as a heating element.

Power calculation

It is very difficult to make an ideal one without knowing the power of the heat exchanger. When calculating this indicator, the following parameters should be taken into account:

pipe diameter;
heater length;
thermal conductivity of the metal used;
the maximum combustion temperature of the fuel;
fluid circulation rate.

If it is problematic to establish these initial values, you can use the average calculation, based on the fact that to obtain a power of 1 kW, you need a meter of pipe with a radius of at least 2.5 centimeters.

Construction and installation

The heating element can be made in the form of a register - a lattice of smoothly welded pipes. This is the most common design. However, it can be simplified by making it in the form of a tank, in the form of a cylinder or a rectangle. The main condition is a sufficient area for the process of fluid exchange.

When manufacturing a heating element, the following rules must be observed:

To prevent water from boiling, the internal volume of the pipes must be at least 50 mm.
The metal should not burn through, so its recommended thickness is at least 3 mm.
When heated, the metal has the ability to expand, this moment should be taken into account by providing for the distance between the walls of the furnace and the heating element.

The installation process of the heating element consists of a few simple steps:

lay a heat exchanger on the bottom of the furnace furnace tank;
provide holes for pipes in the furnace.

Benefits of a heat exchanger

The heating element in the heating system installed in the furnace has its advantages. Among the main advantages are the following:

Ease of manufacture and installation.
Appears in the house combined heating, which makes it possible to heat large areas, and not just locally one room.
Possibility to use different types fuel. For example, boilers are focused only on a specific type, and a stove can be fired with any solid energy carriers.
The stove gives the interior a special charm and comfort, and thanks to the new function, it will bring even more benefits.

Despite the obvious advantages, it should be noted that in comparison with factory-made boilers, the efficiency will be lower, in addition, there is no automatic control of the heating medium heating temperature. At the same time, not everyone can afford the cost of factory boilers, but making a heating system with their own hands using a home-made heating element is within the power of everyone.

For heating residential buildings, there is a wide range of heat generators that differ in design and types of fuel. If the building is located far from large settlements or is used periodically, the best option will be the installation of a furnace heating system.

The stove heat exchanger used in this design will ensure uniform heating of the entire house, as well as provide required amount hot water.

Application specifics

Standard stove heating implies an uneven distribution of thermal energy - the farther from the source, the colder. After connecting the radiators and pouring water, the furnaces act as analogues of solid fuel boilers, providing heating of the coolant, smoke channels and walls. Such a system during the furnace will allow heat to be transferred from the coil to the radiators, and after the fuel is extinguished, it will use the energy of the heated walls of the furnace.

When installing a heat exchanger, it should be taken into account that its installation will reduce the useful volume of the fuel compartment and fuel will have to be added much more often. The correct design of the water circuit and its relationship with the dimensions of the heating chamber will help eliminate this problem. A good alternative would be a long-burning stove.

There are some nuances in such an upgrade of the heating system. The energy that is released during the combustion of firewood will begin to heat the heat exchange unit and the working fluid placed in it, but the furnace walls will not change their temperature.

The upper part of the body with smoke channels will be heated. If the building is used as a temporary residence, the oven will not turn on regularly and may cause the liquid inside the pipes to freeze. In order to prevent accidents, it is recommended to replace water with antifreeze.

Advantages

Installing a water circuit in the furnace heating system allows you to increase the efficiency of fuel consumption.

The energy of the burnt coolant is spent on heating the body, smoke channels and walls, and also provides a high temperature for the water circulating through the pipes.

For property owners, this method provides additional benefits:

ease of manufacture (brick ovens are often installed in residential buildings, and for high-quality energy distribution it is enough to make a home-made heat exchanger by connecting it to the heating system of the building);
combined heating due to warm air from the furnace and hot water from batteries;
a variety of fuel types (most boilers for heating use only one type of energy carrier, which can be expensive and inefficient, and a brick oven heat exchanger works with any solid fuel);
nice appearance(design country house often takes place in the national style, but the installation of heat exchange units does not violate the traditional look of the Russian stove).

Design features

If the owner of the building has experience in laying bricks or kiln works, installation can be done by hand. Before connecting the water heating system, you will also need to make a heat exchange unit.

Despite the fact that the construction market offers a large selection of prefabricated structures, self-production is more profitable. A self-made installation allows you to take into account all the parameters of this particular furnace, its placement and dimensions of the fuel compartment.

Pipe heat exchanger

The device of a furnace heating system with a water circuit involves the installation of a heat exchanger in the fuel compartment of the furnace and the connection of pipes to it for supplying the working fluid. For heating and cooking stoves and stoves, coils welded from pipes and placed in metal containers are well suited. Their manufacture requires professionalism, and cleaning from combustion products is quite laborious, but the sinuous surface will provide fast heating.

The 50 mm U-shaped pipes used in the construction can be replaced with segments profile pipes 40x60 mm. This will simplify welding work and greatly facilitate installation. If the oven is not used for cooking, additional small diameter tubes are welded to the top of the heat exchanger. A do-it-yourself design will give off much more heat.

Devices of this type are used in ovens designed exclusively for space heating. For their manufacture, you will need sheet metal half a centimeter thick, sections of rectangular pipes 40x60 mm, as well as round tubes of the same diameter for supplying water to the working surface. The dimensions of the heat exchangers depend on the dimensions of the furnace compartments for fuel.

A similar heating system can be used for a heating and cooking stove or a simple stove. To do this, the structure must be mounted so that the heated gases from the fuel chamber move towards the upper shelf of the register, flow around it and enter the smoke channels.

An alternative option would be to manufacture a heat exchanger without a top shelf, the sides of which will be connected to round or rectangular pipes.

Installation of a heating device

Heat exchangers for brick ovens can be made by hand from metal 2.5 mm thick. The basis of the design will be two containers - a cylindrical upper and a rectangular lower one, interconnected by pipes. The conjugation of the seams should occur with a minimum gap, and the diameter of the pipes should be calculated based on the dimensions of the furnace and the area of \u200b\u200bthe heated room. After checking the accuracy of the calculations and re-measuring the workpieces, the parts are connected by welding.

The strength of the finished structure is determined after welding the bottom pipe, pouring water and connecting the outlets to the radiator tanks. When the installation is completed, it is necessary to fill the system with compressed air, controlling the pressure with a pressure gauge. Well-sealed seams will not leak. In case of detection of leaks or other defects, the water is drained and the problem areas are sealed. An important parameter during installation will be the total length of the pipes - the smaller it is, the better the space will be heated.

Nuances of installation and operation

During the installation of thermal units and their commissioning, it is necessary to follow the installation technology and avoid emergency situations. The high temperature in the heating chamber makes high demands on the quality of the metal, the rationality of the heat exchange unit and the quality of welding. knowledge of several simple rules will help ensure long-term and reliable operation of the furnace heating system.

The load-bearing contours of the heat exchangers must not be fixed to the walls with fixed connections. The temperature to which the pipes are heated causes the metal to expand, which can lead to a change in their dimensions.

Copper will be a good material for furnace heating pipes. The use of this metal will provide high thermal conductivity of the structure and ease of manufacture of the coil due to plasticity.

The cross section of the pipelines must be at least an inch. At smaller values, the circuit will become inertial, and the fluid flow in it will seriously slow down. The growth of heat losses in the heating mains will lead to a decrease in the efficiency - the room will become colder with the same fuel consumption.

It is not always and not everywhere advisable to gasify a house, plot, bathhouse and other objects. In some cases it is simply impossible, sometimes expensive. Only the need for heat and hot water does not disappear anywhere. Therefore, conditions sometimes dictate alternative solutions to gas to provide heat at home.

What is a furnace heat exchanger

There are a lot of heat generators for sale, as well as a lot of fuels for them. Stove heating still remains one of the most popular and affordable alternatives to gasification. But even if there is gas within reach of the site, it is not always rational to spend money on connection, since the premises can be used periodically, and a rather large amount must be paid for gas right away. In a word, the stove is one of the most available options, besides, it allows not only to heat the room locally, but in the presence of a heat exchanger, to carry out efficient and uniform heating of the room, plus to meet the needs of residents in hot water.

The operation of the heat exchanger is based on the properties of the liquid to expand when heated. The principle is extremely simple, as simple and circuit diagram devices. The furnace heats the coil, which is connected to a tank with a heat carrier and heating radiators. Most often, antifreezes, non-freezing liquids, and less often water, act as a coolant. Thus, when heating the furnace, we heat the water in the coil heat exchanger, from there the water enters the heating circuit, and after that, having given off heat to the room, it passes into the expansion tank, from which it again enters the furnace heat exchanger.

Types of heat exchangers

Structurally, the heat exchanger can be made in two versions:

External heat exchanger.

The external heat exchanger receives heat from the chimney structure. It is located directly in the part of the chimney and heats up from the gases released during combustion. External heat exchangers are very easy to operate, they practically do not require additional equipment and, when cleaning or repairing, they can be easily dismantled, restored, and put back into place without making structural changes to the furnace device.

The integrated heat exchanger is located directly above the combustion chamber and is structurally simpler external device. Installing it is quite easy, only during operation it may require repair or stonecrop from scale, and it will be quite difficult to get to it. In principle, this largely depends on the design of the furnace itself, but, whatever one may say, the built-in heat exchanger is more difficult to repair than the external one, although it is structurally simpler.

Stove fireplace with heat exchanger

Such designs, as a rule, do not provide for water heating, so the hydraulic circuit remains closed. These designs are called non-volatile. The expansion tank is mounted directly in the body, and structurally they are made according to the principle of any heating boiler. The heat carrier in such a fireplace stove is not only water, but also non-freezing antifreeze liquids.

The structure of such a multifunctional fireplace includes:

a reservoir with a heat carrier placed above the firebox of a fireplace stove;
hydraulic system through which the coolant circulates;
heating radiator or other heating devices distributed throughout the room.

For sauna stove with a heat exchanger, it is typical not only to use it for space heating, but also for heating water. By the same principle, a heat exchanger for a stove with your own hands can be assembled for a summer residence, a small cottage. The design will not pull the heating and hot water supply of a large house, but for a bathhouse and a summer residence - just right.

The oven with a heat exchanger is also quite simple. The heat exchanger itself in the form of a coil is located directly in the furnace furnace. At the inlet to the heat exchanger, a valve must be installed to drain the water from the system. An expansion tank is installed separately from the furnace, which communicates with the heat exchanger with inch pipes. The expansion tank has a separate outlet for hot water, which can be shut off with a tap. Thus, it is possible to discharge water into a shower for a bath or into a hot water circuit for a summer residence. And if the dimensions and volumes of the furnace and tank allow, then it is possible to combine the heating of water for heating and the heating of water for selection.

Materials and designs of the heat exchanger

There can be a lot of design solutions for heat exchangers. It all depends on what material and what pipes are at hand, what possibilities exist for manufacturing the device. You can take any ready-made design and mount it in the furnace, so, of course, the easiest way. Suitable for this:

heating radiators;
collectors;
automotive radiators;
old steel heated towel rails;
metal tanks of various designs.

The list can be long. It is enough just to go into the barn and look for something suitable, or just buy an old collector or battery.

The only limitation will be only the section of the pipe. It must be at least one inch, otherwise, there will be slow circulation, and as a result, reduced efficiency. It will not be difficult to assemble a heat exchanger for a furnace with your own hands, and the effect of it will make you think about whether gasification is needed at all suburban area or baths.

The main element of any of the heating systems is a special device - a heat exchanger for heating a house, in which heat is transferred from a heat generator to a coolant. On modern market a large number of different heating boilers are presented, but all their diversity does not limit the imagination of home craftsmen regarding the independent manufacture of such devices. In our article, readers will be asked to find out why a heat exchanger is needed in the heating system, how to do it yourself and how to connect it.

The function of the heat exchanger in the heating system

In domestic air heating systems, surface heating system heat exchangers are most commonly used, where heat energy is transferred through the surfaces of the metal walls of the device.

The principle of heating through a heat exchanger is most fully implemented in the design of gas, solid fuel or electric boilers. Water circulates through pipes bent in the form of a coil, installed inside the heating unit, and is heated from the temperature of the burning fuel. The heated coolant goes into the pipeline of the heating system, and cooled water from the radiators enters the heat exchanger to replace it.

Until now, in many individual houses, the stove remains the traditional source of heat. It is good for heating a small hut, however, in a multi-room cottage, it thermal power insufficient. Therefore, in a private house, a heat exchanger in the heating system is needed in order to turn the stove into a full-fledged water-heating boiler. The size and shape of a home-made heat exchanger for heating must fit into the dimensions of the fuel chamber of the furnace. Pipelines and radiators can be connected to this device, and then the heating of the house will become more efficient.

Types of heat exchangers

Water heat exchangers for heating are more practical. This is due to the fact that water transfers heat energy much better than air. However, air heat exchanger for heating also finds application. In addition to water and air, a heat exchanger is also used on the chimney for heating, which is installed not inside, but outside.

All heating devices produced by the industry are equipped with heat exchangers, the design of which is most adapted for efficient heating of water.

In the factory, heat exchangers are made of copper. The pipe is a coil, across the bends of which there are many plates that provide a large heat exchange area.

It is almost impossible to build a home-made heat exchanger for heating at home, so that it is exactly like a factory one. Therefore, you will have to choose a simpler option.

System device

The principle of operation of a home-made heat exchanger is that the stove transfers energy to it from the combustion of wood or coal, and the heated water circulates through pipes to all rooms. This method of heating allows the inhabitants of the house to enjoy a uniform distribution of heat. In addition, all rooms warm up much faster, and fuel costs are reduced.

There are two ways to improve the stove heating of a private house:

build a furnace "from scratch" for a specific size of the heat exchanger;
install a home-made heat exchanger made according to the size of the furnace in the existing furnace.

Having made a heat exchanger for heating with his own hands, the homeowner can be sure that his stove with a water circuit will work no worse than a real solid fuel boiler. The only difference will be that at the stove, the location of the inlet of the heat exchanger will turn out to be slightly higher above the floor than for factory boilers. This is a rather significant difference, which can affect the rate of natural circulation of the coolant.

The connection of the heat exchanger to the heating system must be done in such a way that the cold water supply pipe (return) is located as low as possible.

Just like in a conventional heating system, an expansion tank must be installed at the top of the pipelines. It will compensate for the change in the volume of heated water and release air bubbles from the system. If heating through a heat exchanger with natural circulation is insufficient to heat a large cottage, a circulation pump will have to be installed in the system.

To connect a home-made heat exchanger for heating, 2 fittings are used: one from the bottom (cold water inlet), the other from above (hot water outlet). When installing the heat exchanger, it is necessary to ensure the necessary slope of the pipes, as required by the scheme.

Advantages of heating with a heat exchanger

If you understand why a heat exchanger is needed in a heating system, you can notice several clear advantages:

Ease of manufacture . If a stove already exists in the house, then you will only have to spend money on making a home-made heat exchanger and installing a heating system.
Combined heating. In addition to heating the house from the surface of the stove, a water heating system will be added.
Variety of fuels. It is possible to heat the stove with any solid energy carriers, in contrast to boilers focused only on a certain type of fuel.
Beautiful appearance. Preserving the traditional look of the Russian stove can be useful when creating an interior in the national style.

Among the disadvantages of heating through a heat exchanger are: lower efficiency compared to factory boilers and the lack of automatic control over the intensity of heating of the coolant.

How to make a homemade heat exchanger

The shape of a do-it-yourself heat exchanger for heating can be different. The most common option is a register of several steel or copper pipes, but plate-type samples are also used.

The temperature in the combustion zone is very high, especially when coal is burning. Therefore, increased requirements are placed on the metal from which the elements of the heat exchanger will be made, the rationality of its design and the quality of the welds.

Materials for manufacturing

The task of water heat exchangers for heating is to ensure optimal heat transfer, and the degree of thermal conductivity of the metal is important in this process. For example, a steel pipe conducts heat 7 times less than a copper pipe. Therefore, with the same pipe diameter, to transfer the same amount of heat, 25 meters of steel pipe will be needed instead of 3.5 meters of copper.

Copper heat exchangers are the most economical to operate, but also expensive. Heat exchangers made of steel pipes with a diameter of at least 32 mm are considered more affordable for self-production.

If it is supposed to heat the stove with coal, it is better to install a cast iron heat exchanger. This metal is stronger, and the walls of the device will not burn through for a long time.

Heat exchanger power calculation

It is quite difficult to calculate in advance the power of a heat exchanger for a heating system. To do this, too many factors must be taken into account: the diameter of the pipes, the length of the coil, the thermal conductivity of the metal, the combustion temperature of the fuel, the circulation rate of the coolant, etc. The real ability of the heat exchanger to cope with its functions will become clear only after the start of operation of the heating system.

When calculating, you can be guided that 1 meter of a pipe with a diameter of 50 mm, which serves as a heat exchanger, will give 1 kW of thermal power.

You can take for example any well-known boiler model and, in accordance with its parameters, make your own home-made heat exchanger.

Design features

A heat exchanger for water heating at home, welded from smooth-walled pipes, is called a register. It looks like a kind of "grid", and this is the most popular form of homemade heat exchanger. In addition to this design, they make more simple devices in the form of a rectangular or cylindrical tank. The main thing is that the surface area for heat exchange is as large as possible.

When making a heat exchanger with your own hands, several conditions must be observed:

the width of the internal voids in the heat exchanger must be at least 5 mm, otherwise the water in it may boil;
the wall thickness of the pipes must be at least 3 mm so that the metal does not burn through;
a gap of 10–15 mm between the heat exchanger and the walls of the furnace should compensate for the expansion of the metal during heating.

Mounting Features

The easiest way is to install the heat exchanger simultaneously with the construction of the furnace. If you install it in an old furnace, you will have to disassemble part of its brickwork.

Procedure:

A tubular heat exchanger is installed directly into the cavity of the furnace on the prepared foundation of the furnace.
With further laying of rows of bricks, space is left for the inlet and outlet pipes of the device.
After the completion of the laying of the furnace, the heat exchanger is connected to the heating system, the system is filled with water and a test furnace is fired.

The video material invites you to familiarize yourself with useful tips By self-manufacturing heat exchanger:

So far, we have only talked about heat exchangers in a hot water heating system. Let's look at other areas of their application.

air heating

If you characterize the air heating system, we can say that it has more minuses than pluses. Air heat exchangers for heating are not very common in the private residential sector; they have not yet become familiar.

The advantage of this system is the ability to combine heating with forced ventilation. However, possible errors in its design and installation can reduce the benefits to a minimum. Fan noise can be heard in the air ducts, and there is a temperature imbalance in the rooms.

Heat exchangers for air heating there are direct heating as well as indirect heating. In the first of them, gas or diesel fuel burns directly in the heat exchanger itself. Other models use an intermediate coolant.

Chimney heat exchanger

In dachas and in the baths of the "craftsmen" you can see a home-made water or air heat exchanger installed on the chimney small oven. It turns out very profitable: the heat does not go away with the smoke, and part of it serves to heat the water.

By installing a heat exchanger on the chimney for heating, you can get a fairly large amount of hot water. Of course, this is not enough to heat the whole house, but it is enough to put one or two radiators in the dressing room. You can use the heat exchanger on the chimney both for heating and for quickly heating water in the bath.

Such a device can be very simple to manufacture. You can take a segment as a basis big pipe with a diameter of 500–700 mm, or weld a stainless steel tank. In the center of the structure there will be a vertical pipe corresponding to the diameter of the chimney, and two pipes must be welded on top and bottom.

Giving their temperature to the heat exchanger, the combustion products leaving the furnace cool down quickly. Because of this, draft in the chimney decreases and the combustion of fuel slows down somewhat.

Making a heat exchanger for heating with your own hands can be a way to arrange a full-fledged home in the house. water heating without purchasing expensive equipment.

Each of us has come across this household appliance at least once in a lifetime. For example, one of the varieties of heat exchangers are towel warmers, radiators and batteries familiar to us. The main task of the heat exchanger is the heating of water due to natural circulation in the conditions of an external tank or heating circuit.

Description of the heat exchanger

The construction market sells many electric thermal energy generators powered by different fuels. However, it is sometimes more practical to use traditional ovens. For example, in cases where the house is located in remote rural areas where there are problems with the supply of electricity or gas. It is acceptable to place the stove in country houses. But in order for the stove not only to be able to heat the house, but also to provide you hot water, the right option will install a heat exchanger.

The heat exchanger is a small metal tank, with a volume of 3 to 5 liters, with built-in pipes. The device heats the incoming cold water and sends it to the radiators and to a removable tank with a capacity of up to 100 liters, which is additionally attached to the heat exchanger. The system of operation is provided in such a way that when the stove is heated, the adjacent room is also provided with hot water, and in the case when the bath is not in use, the water is automatically drained from the system. The tank does not come into direct contact with the fire, and its installation is carried out in the gap between the furnace furnace and the convector. The furnace is melted when the system is assembled and filled with water.

There are basically 2 types of heat exchangers: internal and external:

The internal heat exchanger is located directly inside the oven. Easy to install, but in a brick stove, getting to it is more difficult. With a metal oven, this is easier to do.
External - looks like a chimney module and is a pipe hidden inside a sealed container. This pipe removes heat from the furnace. This design is easy to repair and maintain.

Any type of heat exchanger for a sauna stove must be filled with water, and in some cases with antifreeze. The liquid in them is supplied from a hinged tank. By circulating it in a natural way, the system works. Sometimes an electric pump is used for circulation. However, experts recommend using the method of natural movement of water in the system, plus it is better if the total length of the pipes does not exceed 3 meters and the thickness is not less than 2.5 cm.

The heat exchanger area is determined based on the total area of the bath room. As a rule, for heating a standard room with an area of 2 sq.m. consumes approximately 5 kW of electricity. In many ways, this indicator also depends on the strength of the fuel burning in the furnace, on the location of the boiler itself, and even when the furnace process stops, the boiler power is rapidly reduced. The calculation of the surface area of the heat exchanger for the furnace must be done with a margin, in order to organize a system capable of maintaining the required temperature in the bath.

The principle of operation of the heat exchanger

After the furnace is kindled, the water in the heat exchanger will heat up. As the temperature rises, the liquid slowly moves up the pipe. From the bottom pipe cold water enters the heat exchanger, heats up and moves back to the tank.

It is strictly forbidden to start the device “dry”, otherwise it will lose the sealant and begin to leak. Avoid use in the steam room plastic pipes as they emit toxic fumes when heated.

A separate type of heat exchangers for the furnace is applicable for a bath as a chimney element. The heat consumption from fuel combustion in such devices is more rational. The main thermal energy that goes to heat the steam room, the heat exchanger built into the stove, absorbs from the furnace furnace. But a samovar-type device (that is, on a pipe) uses the heat of a chimney to heat water. As a result, its efficiency is high.

To understand how the device works, imagine a hot water bottle submerged in cold water. The bottle is cooled, and the water, on the contrary, is heated. The heat exchanger works on the same principle.

In simple words, this is a rolled-up pipe section with two outlets laid in a barrel, which heats or cools the liquid. Annealed copper pipe is suitable as a pipe. It simply bends and the threaded futor is easily attached to it.

A do-it-yourself heat exchanger for a furnace can be made according to the principle of a water jacket, when heat is exchanged between containers nested in each other. But this type of device is very difficult for a non-specialist in this matter to manufacture.

As parts for the heat exchanger, an old heated towel rail or radiator (maybe even an automobile one), a coil, a register, a manifold or a metal tank can also be suitable. Used gas water heaters are also suitable for this. The choice of materials for the manufacture of the device depends on the duties assigned to it in the future.

The most durable material for a heat exchanger is food grade stainless steel. It is able to withstand high temperatures, while its characteristics remain the same. Zinc, for example, evaporates at 200 ° C, and at more high temperature, becomes hazardous to health due to its fumes. Therefore, heat exchangers with galvanized profiles must be under your supervision.

The design of heat exchangers involves their manufacture both from sheet steel and from pipes. The latter, in turn, have a large heating area. A heat exchanger made of pipes is most often used in plates, they are placed under hob. And in heating furnaces it is advisable to install devices made of sheet steel, with a thickness of 3 to 5 mm. Their length is individual and depends on the dimensions of the fuel compartment of the furnace.

What are the benefits of heat exchangers:

Thanks to the use of a heat exchanger, the hot water tank can be installed away from the stove.
The device provides rapid heating of the liquid and the entire system.
The heat exchanger can be used not only for working in a sauna stove, but also in other heating and heating equipment.
It is easy to mount and dismantle the device.
Provided that the welds of the heat exchanger are strong and tight, it is able to work for a long time and reliably.
The heat exchanger forms steam, heats water, air in two or three rooms.
Easy maintenance of the device.
High efficiency.
Can be installed in any bath.
The compact sizes allow to save the place considerably.
High power of the device and its fast heating.
Deformations during heating are excluded.

Do-it-yourself heat exchanger for a sauna stove

The design of home-made heat exchangers for brick ovens is varied. The most acceptable, inexpensive and high-quality option is a stainless steel system.

Below is an elementary diagram of a heat exchanger for a brick oven.

Manufacturing technology:

Use sheet metal with a thickness of 2 mm or more as the basis of the device.
Make 2 tanks from metal: 1 - upper cylindrical shape, 2 - rectangular. Dimensions are calculated individually, depending on the size of your bath room.
Connect the tanks together with pipes.
Weld the bottom pipe by welding and fill the heat exchanger with water. Connect the outlet to the main container.
Fill the system with compressed air and check the tightness of the seams.
Try to make the length of the pipes as short as possible. This is necessary so that large flows of thermal energy are quickly transferred to the coolant.
Before mounting the device in a common system, on the outlet and then on the inlet pipe, mount the threads.
Make all seams as tight as possible, without visible gaps.
If you do not provide a pump in your device, then the water circulation system should be carried out in this way: cold water from the tank rises through the pipe to the furnace, and hot water returns to the tank. In this case, install the pipes in compliance with the angle of inclination from 2 to 5 degrees.
To heat adjacent rooms, insulate the tank.
The weak point of the heat exchanger is the susceptibility to corrosion upon contact with moisture. Synthetic metal processing agents are not suitable in this case, as they have low thermal conductivity. It is better to initially use more durable copper or steel pipes for the manufacture of the system.

Heat exchanger operation

According to the advice of the masters, heat exchangers for wood stove should not be very large, with a power that corresponds to the power of the furnace. A removable tank should be selected of medium size so that during the time the firebox takes place, the water in it has time to heat up. In a large tank, the heating process will stretch for a long time. Do not pour water into a hot brick oven with a heat exchanger, or do it with great care. As a thread seal for connecting pipes to a heat exchanger, use high-quality and heat-resistant materials.

If you do not plan to use the pump in your system, then the pipes should be arranged as follows: water from the removable tank should drain by gravity through the pipe into the furnace and heat exchanger, and from there it should rise into the tank in a hot state. The system will work exactly like this if you place the pipes at an angle.

When making a heat exchanger for a furnace with your own hands, choose heat-resistant materials; high-quality steel is ideal for this.

Do-it-yourself heat exchanger for a potbelly stove

At home, making a heat exchanger for a chimney is not difficult, first you need to stock up on tools:

2 sheets of metal - 35x35 cm;
8 parts of the pipe (diameter - 3.2 cm, length - 30 cm);
pipe (length - 30 cm, diameter - 5.7 cm);
jigsaw for metal;
marker for marks;
welding machine;
20 liter steel bucket.