The most modern and most economical device for heating water is an induction water heater. Unlike analogues, it is completely environmentally friendly, does not dry out or burn out the air, and meets modern safety requirements. It can be used both as an instantaneous water heater and as a boiler for heating a room. The device is usually bought in a store, we offer an alternative - self-production. In the latter case, the device may not have such an attractive appearance, but it will cost much less.
Pros and cons of induction devices for heating water
The device has a rather simple design and does not require any special documents for use and installation. The induction water heater has a high degree of efficiency and optimum reliability for the user. When using it as a boiler for heating, you don't even need to install a pump, since water flows through the pipes due to convection (when heated, the liquid practically turns into steam).
Also, the device has a number of advantages, which distinguishes it among other types of water heaters. So, induction heater:
In induction heaters, water becomes hot due to the pipe through which it flows, and the latter is heated due to the induction current generated by the coil.
- much cheaper than their counterparts, such a device can be easily assembled on your own;
- completely silent (although the coil vibrates during operation, this vibration is not perceptible to humans);
- vibrates during operation, due to which dirt and scale does not stick to its walls, therefore it does not need cleaning;
- has a heat generator that can be easily made sealed due to the principle of operation: the coolant is inside the heating element and energy is transferred to the heater through an electromagnetic field, no contacts are needed; therefore, sealing gums, oil seals and other elements that can quickly deteriorate or leak are not needed;
- there is simply nothing to break in the heat generator, since the water is heated by an ordinary pipe, which is unable to deteriorate or burn out, unlike the heating element;
Do not forget that maintenance of an induction heater will be much cheaper than a boiler or gas boiler. The device has a minimum of parts that almost never fail.
Despite the huge number of advantages, an induction water heater also has a number of disadvantages:
- the first and most painful for the owners is the electricity bill; the device cannot be called economical, so you will have to pay a decent amount of times for its use;
- second - the device gets very hot and heats up not only itself, but also the surrounding space, therefore it is better not to touch the heat generator body during its operation;
- third - the device has an extremely high efficiency and heat transfer, therefore, when using it be sure to install a temperature sensor, otherwise the system may explode.
Diy induction water heater: diagram
The device is a transformer with two windings: primary and secondary. The first circuit converts electrical energy into eddy currents, thereby creating a directional induction field, which provides induction heating. On the secondary circuit, the converted energy is transferred to the coolant (in our case, it is water).
It is important to consider the type of material from which the winding is made. So, in household models, copper wire is most often used. This material is well suited for heating water in boilers.
In addition to the transformer, the device contains a generator and a pump (optional).
Diagram of a simple induction water heater. As you can see, the device has a fairly simple design and a small number of elements.
Heat generator assemblies and parts
The device includes:
- an alternator that increases the frequency of the current;
- an inductor that converts electricity into magnetic energy is a coil of copper wire;
- a heating element, most often a metal pipe plays its role.
Thanks to this design, power transmission is practically lossless. The efficiency reaches 98%.
Principle of operation
An induction water heater consists of a generator, a coil and a core, the latter is heated by electromagnetic energy
The device converts electrical energy into electromagnetic energy. The latter, in turn, acts on the core (pipe), which heats up and transfers thermal energy to the water. All these energies are converted by an inductor consisting of a coil and a core. The generator is used to increase the frequency of the current, since it is difficult to achieve high heating with the standard frequency of 50 Hz.
In factory models, the current frequency reaches 1 kHz.
Diy flow induction water heater
Before proceeding with the installation, you need to stock up on the necessary parts. So, the best option would be a high-frequency welding inverter, smoothly changing current range... Such a device will be the cheapest. A more expensive option would be a three-phase transformer, which is the AC power source for the water heater inductor. In this case, it is worth using a coil of 50-90 turns, and as a material, take copper wire with a diameter of 3 or more millimeters.
As a core, you can use both metal and polymer pipes together with a wire (used as a heating element). In the latter case, the thickness of the walls should not be less than 3 mm in order to easily withstand high temperatures.
To assemble the water heater, you will need: wire cutters, screwdrivers, a soldering iron and a welding machine if a metal pipe is used.
Installation of an induction water heater
Wrap copper wire about 90 turns around the pipe.
There are many options for assembling the device. We suggest trying to assemble the device according to the following scheme:
- Prepare your work area, materials and tools.
- Fix a small piece of plastic pipe (remember that the minimum wall thickness should be 3 mm).
- Trim the ends of the core to leave 10 cm of the lead wire for the taps.
- Mount the corner on the lower outlet. In the future, the return from the heating should be connected here (if the heater is used as a boiler).
- Lay the chopped wire tightly around the pipe. It is necessary to make at least 90 turns.
- Install a tee on the upper branch pipe through which hot water will come out.
- Fit the protective circuit of the device. It can be made from both polymer and metal.
- Connect copper wire to the terminals of the water heater, then fill the core with water.
- Check the functionality of the inductor.
Recommendations. It is better to install ball valves on all outputs for convenience and ease of dismantling the water heater in case of breakdown. But it is not necessary to fill the pipe with metal pieces, since this does not give the desired effect. Do not forget to leave a window in the housing to access the control panel of the welding machine.
Induction water heaters for heating
Heating circuit, where an induction boiler serves as a heat carrier heater.
Such a device has proven itself not only as an instantaneous water heater, but also as a boiler for heating. True, in this case, the welding machine as a generator will no longer work, you will have to use a transformer with two windings... The latter transforms the eddy currents arising on the primary winding into an electromagnetic field, which is created on the secondary circuit.
In the heating system, the coolant can be not only water, but also oil or antifreeze. That is, any liquid capable of conducting electrical current.
A boiler from an induction water heater must be equipped with two connections for hot and cold water. Cold water will flow from the bottom one, it must be mounted on the inlet section of the line, and a branch pipe must be placed on top that will supply hot water to the heating system. As a result, water is circulated naturally by convection without a pump.
What you need to know about safety
Do not forget that we are dealing with a source of increased danger - an electric heating device, therefore, when assembling and using it, some rules must be observed:
Be sure to use a separate electrical line to connect the induction boiler, and also equip it with a safety group.
- If water circulates in the boiler naturally, then be sure to equip it with a temperature sensor so that the device turns off automatically when it overheats.
- Do not plug a home-made water heater into an outlet, it is better to lay a separate line for this with an increased cable cross-section.
- All open sections of wires must be insulated to protect people from electric shock or burns.
- Never turn on the inductor if the pipe is not filled with water... Otherwise, the pipe will melt, and the device will close or it may even catch fire.
- The device must be mounted at a height of 80 cm from the floor, but so that about 30 cm remains to the ceiling. Also, do not install it in a residential area, since the electromagnetic field has a bad effect on human health.
- Do not forget to ground the inductor.
- Be sure to connect the device through the machine so that in the event of an accident, the latter disconnects the power from the water heater.
- A safety valve must be installed in the pipeline system, which will automatically reduce the pressure in the system.
Conclusion
An induction water heater has a high efficiency, it can act as a boiler for a heating system, self-assembly and installation is also allowed, and its use is not regulated by the law of the Russian Federation. But still, before using it, it is worth weighing the pros and cons. Despite its high efficiency, the device consumes a large amount of energy, is considered unsafe (especially homemade) and has a bad effect on human health. Therefore, we recommend installing the inductor in a private house or in the country.
An electric storage-type water heater, or, in a simple way, a boiler, has long and firmly entered our life, providing additional comfort and allowing you not to depend on communal hot water supply systems. This simple device automatically maintains the required water temperature, while having a certain supply of it. The devices produced by the industry have a variety of shapes, sizes and external designs. Despite the apparent differences, at their core, all water heaters have a similar design and a single operating principle. However, when making a choice between a particular model of a boiler, one should not only understand how it works, but also understand the features of the execution of some of its components.
In fact, any water heater of this type is a large thermos with a tubular electric heater (TEN) inside, so the design of all boilers has the following elements:
- external casing with parts that allow the device to be mounted on a wall or floor;
- internal tank;
- a heat-insulating layer between the inner container and the body;
- tubular electric heater;
- thermostat with the ability to adjust the heating temperature;
- safety valve;
- protective magnesium anode;
- control and indication circuit.
When choosing a boiler, one cannot fail to notice a big difference in price, even between different models of the same manufacturer. It is primarily due to the technology and material of manufacture of the internal tank, as well as the presence of an electronic control and display unit.
These parameters determine the convenience of using the device, as well as the duration of its service.
Frame
Cases of water heaters have both strictly cylindrical and oval and even rectangular shapes, various colors and design designs. Often a thermometer is attached to the outside of the housing to monitor the operation of the device, as well as regulators or control elements. The housings are made of steel sheet or plastic.
To install the boiler, there are fasteners in the housing structure, depending on the type of placement (wall or floor installation scheme). The space between the body of the water heater and the inner tank is filled with heat-insulating material - most often dense polyurethane plays its role.
Inner tank
The design of the internal tank of the boiler must comply with the criterion of increased corrosion resistance and at the same time withstand constant temperature changes, therefore, manufacturers pay a lot of attention to this element, developing new tank coatings and applying methods of its protection.
Steel tanks coated with glass enamel or glass porcelain
Such a coating is obtained by spraying a protective layer with its subsequent firing at a high temperature (up to 850 ° C). Glass enamel is not capable of oxidation, therefore it does not corrode at all. In addition, its smooth surface resists limescale build-up.
Paradoxically, the main disadvantage of such a coating stems from its advantage - the high hardness of the layer is low-plastic and over time, constant changes in water temperature lead to the formation of microcracks in its layer, which ultimately contribute to the destruction of the tank.
Manufacturers are constantly looking for new formulations for this type of coating. For example, the addition of titanium powder equalized the temperature coefficients of expansion of glass porcelain and steel, slightly improving the resistance of the layer to cracking. It is possible to slightly reduce the harmful effect of temperature exposure by setting the water temperature in the boiler to no higher than 70 ° C, although you still have to warm up the device as much as possible at least once a month in order to comply with sanitary rules. Another disadvantage of the glass-porcelain coating of the tank can be considered the increased weight of the boiler. Companies producing water heaters with tanks of this type give a guarantee for their products for no more than 3 years.
Titanium coated steel tanks
By spraying titanium powder onto the inside of the tank, excellent corrosion resistance is achieved. Moreover, this type of coating has high strength and mechanical resistance, having weak points only at the welding joints. The warranty for a device with such a tank is up to 10 years, which is a huge advantage, even if you take into account its rather high cost.
Stainless internal tanks
Such containers are devoid of the disadvantages of the two previous elements. Stainless steel, like titanium, is able to withstand the effects of impurities in the water, as well as corrosion. It is believed that stainless steel gives water a peculiar smell and taste that appear during its heating, but this is just speculation, absolutely not confirmed by scientific research. It is known that "stainless steel" does not enter into a chemical reaction with water. Manufacturers also give up to 10 years warranty for such tanks, but they are the most expensive ones. Tanks made of stainless steel, as well as those with titanium spraying, are more susceptible to scale formation than glass porcelain, but this does not detract from their merits in the least. The inner tank contains pipes for supplying cold water and removing hot water, as well as an electronic heating and protection unit.
Heating and protection unit
The elements responsible for heating water to a certain temperature, as well as protecting the metal of the inner tank from destruction, are installed on a metal flange, which is connected by means of a seal to the inner tank of the device.
Heating elements of various capacities are used to heat water. Depending on the heating principle, a distinction is made between:
- "Wet" heating elements, which are in direct contact with water, therefore inevitably become covered with scale, which must be periodically removed, otherwise the heating element will fail due to overheating;
- dry type heaters. Devoid of this drawback, since they are installed in a metal tube, which makes contact with the liquid. This scheme allows you to get rid of scale not only on the heater, but also on the tube covered with a layer of glass porcelain.
Some boiler models are equipped with several heaters. This design allows for stepwise regulation of heating, and also reduces the number of switching cycles for each of them (voltage surges during switching on of devices affect their durability).
Together with heating elements, a thermostat and a magnesium rod (anode) are installed on the flange. The thermostat is responsible for turning on the heating element when the water temperature drops below the set by the consumer. Thermoregulators of both mechanical type and electronic devices operating in conjunction with an electronic control unit are used. Often, the thermostat device includes a safety shutdown circuit for the heating element in the absence of water in the tank. The magnesium electrode is designed to reduce the exchange of ions of metal components inside the boiler, giving up its own particles in return. This scheme reduces the effect of leaching electrons from structural elements and they corrode to a much lesser extent. At the same time, the magnesium rod itself collapses rather quickly and requires periodic replacement (when thinning to 10 mm or reducing the length to 200 mm). The control and indication circuit provides additional convenience when using the water heater, having the functions of precise adjustment of the water temperature, switching on heating by time, maintaining a different degree of heating depending on the time of day.
The principle of operation of storage water heaters
The boiler operation scheme is based on the principle of separation of layers of water with different temperatures. As you know, warm layers of liquid are at the top. They are taken from the water heater through a hot water outlet pipe, the length of which allows the use of the upper, warmest layer. Cold water, on the other hand, enters the lower part of the tank, where the water heaters are installed. In addition, a divider is installed on the short inlet pipe, which prevents the liquid from flowing out and thereby facilitates mixing of warm and cold water.
The peculiarity of the warm liquid to rise up will not allow the use of a vertical design boiler, placing it parallel to the ground. You should pay close attention to this when choosing the type of device to suit your needs.
Heating of cold water is carried out by a heating element (one or more). A thermostat monitors its temperature. When the set temperature is reached, it opens the electric power supply circuit of the heater.
Good thermal insulation allows you to maintain the desired water temperature, spending a minimum of energy on its constant heating.
In the case of using several heaters, one heating element is used to maintain the temperature at a given level. The rest are switched on at a high flow rate, increasing the heating power many times over. This scheme increases the efficiency and reliability of the device.
The warm water taken from the top is constantly replaced by the newly heated liquid, which is supplied from the main. This is how the continuous heating process works. With a high flow rate, the temperature of the water leaving the boiler drops over time, therefore it is necessary to select the volume of the storage tank based on the amount of hot water draw-off.
A thermostat failure is possible, while the water can boil, as a result of which the pressure in the internal tank rises to a dangerous level. To prevent an accident, a safety valve is installed on the cold water supply pipe - when the maximum pressure is reached, it opens, thereby dumping part of the liquid into the supply line. The same valve is used to drain water from the device during maintenance work.
A detailed video on the boiler device is presented below:
Do not neglect the periodic preventive measures, which include cleaning the boiler from scale and rust. They will allow the device to work reliably and efficiently, as well as save you from unplanned expenses.
Today induction heating creates quite strong competition for gas and electric boilers. And on the heating equipment market, induction boilers are positioned as one of the most economical options. If such boilers began to appear in industry in the distant 80s, then already in the 90s they began to be used for domestic purposes.
Basic principles of work
The principle of operation of an induction boiler
Already from the name of induction heating, one can understand that the operation of such boilers is based on the principle of electromagnetic induction. And in order to understand exactly how the system works, it is enough to send a large current through a coil of thick wire. An electromagnetic field will surely appear around this device, and quite strong. And if you put any ferromagnet in it - that is, the metal that is attracted, then it will heat up - and quickly enough.
So, the simplest example of induction heating, that is, a heat source, is a coil that is wound around a dielectric pipe.
Inside it is necessary to place a core made of steel. The coil, which is connected to a source of electricity, will heat the metal rod. Now it remains to connect the device to the mains, where the heat carrier circulates, and such a primitive induction heating with its own hands will start working.
To briefly describe the principle of operation, then this requires only a few judgments. Electrical energy creates an electromagnetic field. The metal core is heated by electromagnetic waves. Excess heat from the rod goes to the coolant, heating it up.
The coolant in such systems can be not only ordinary water, but also ethylene glycol and oil. Due to the fact that the liquid is heated intensely, convection flows are obtained. The hot heat carrier goes up, and its power is already enough for a small circuit to work. If the line is long, then it is required to install a circulation pump.
Heating system with induction boiler
Debunking myths
Sometimes in stores selling equipment that carries out induction heating at home, you can hear simply unrealistic characteristics assigned to it. And, unfortunately, such properties are not always true. There are several main points to be aware of the truth about:
- The novelty of the principle. Many argue that these are innovative technologies that are based on the principles of physics. In reality, this is the case: the phenomenon of electromagnetic induction was discovered by Michael Faraday back in 1831. And since the twentieth century, the induction heating system has been used in full swing in industry to melt steel. As you can see, this is not a new technology, but just a well-known principle that has found application in modern times for household purposes.
Heating water in an induction boiler
- Profitability. A common statement is that an induction heater for heating uses 20-30% less energy than other electrical counterparts. In reality, everything is like this: any heating device converts 100 percent of the energy that it uses into heat - of course, if it does not do mechanical work. The efficiency may be lower. It all depends on how the heat is dissipated around the heating device. The time it takes for the heat carrier to heat up to the required temperature directly depends on how efficient the heating element is. Therefore, lofty speeches about revolutionary economy are only gimmicks. After all, the law of conservation of energy has not been canceled. To get 1 kW of heat, you need to spend at least 1 kW of electricity. In addition, some of the heat will be wasted just like that. For example, the coil itself heats up, since the resistance of the conductor is not zero.
The economic effect of using an induction boiler
- Durability. Another common statement is that heating with an induction hob will work for you for at least 25 years, and that this is the most durable option for heating with electricity. Mechanical wear of boilers of this type is impossible, since they have no moving parts. Copper winding has a large margin of safety, and if used with proper cooling, it will last a long time. In any case, the core will gradually collapse - since aggressive impurities can affect it, and constant heating-cooling will not impart strength. But let us note that even this process is very long. The control circuit contains several transistors. It is they who will determine the life of all equipment without failure. A 10-year warranty is usually given. Although there are cases when the equipment worked for 30 years. The conclusion from this is the following: induction water heaters for heating will work much longer than analogues - heating elements.
- Irreplaceable properties. Many people say that induction boilers retain their original characteristics for decades due to the fact that scale does not appear here. First of all, let's say that the effect of scale is slightly exaggerated. The lime layer does not have high heat-insulating properties, and in a closed system a lot of deposits will not appear. But the same cannot be said about the core - here scale is a frequent occurrence. So, heating with an induction hob is really not subject to limescale.
- Quiet work. In fact, if you study the reviews, you can say that any electric boiler will not make noise when water is heated, since there are no acoustic vibrations. The noise can only come from the pumps. So the judgment is correct.
- Compactness. Induction equipment can be installed in any room. This statement is true: this device is a piece of pipe that does not require special space.
Induction boiler
- Induction heating of water for heating is safe. If there is a leak of the heat carrier, then the electromagnetic field will not disappear automatically. The core will continue to heat up, unless the power supply is cut off, the case and mount will melt in a matter of seconds. That is why the installation should provide for the automatic shutdown of the induction boiler in such situations.
Hot water in an apartment or house has always been an integral part of comfort, without which a modern man cannot imagine his life. There are often cases when hot water in apartments is turned off, and in the private sector, the owner himself must take care of its availability. Water heaters can help in this matter. The device of a boiler for heating water can be very different, but the main distinctive feature it from flow heaters - the presence of an accumulation tank in which there is always a supply of heated, ready-to-use water.
Boiler device for heating water - photo
Modern storage water heaters can be of direct or indirect action. Direct fired boilers can be powered by electricity or natural gas. In indirect heating systems, heat exchange occurs from the home heating system or from other sources of thermal energy (for example, solar water heaters).
Consider various schemes for the device of modern boilers.
In such systems, the transfer of heat energy goes directly to the water heated for further domestic use. They can be electric or gas.
The layout, location, placement of inlet and outlet nozzles, control and automation system from manufacturer to manufacturer can vary significantly, but the basic diagram is the same. The figure shows its general simplified form:
Direct heating electric boiler - diagram
- The entire structure is assembled in a metal case (1), which has one or another external decorative design. There is a water tank (2) inside, and the space between it and the outer casing is filled with thermal insulation material (3), most often polyurethane foam.
- Cold water is supplied through the intake pipe (4), on which a check valve and a safety valve are installed, which is triggered when the pressure inside the boiler is exceeded. The supply pipe (10) is usually equipped with a mesh spray nozzle to avoid the formation of turbulent water flows.
- An alternating current is supplied to the heating element - heating element (9) through the power cord (5) The device must be equipped with a temperature control system and a thermostat that allows you to set the required water heating level and automatically turn off the power supply when the required temperature is reached.
- The branch pipe (6) is connected to the hot water supply system - through it, heated water through the pipe (8) from the upper part of the boiler goes to the consumption points. The required pressure is maintained by a constantly open supply of cold water - it refills the tank as it is consumed, and it always remains full.
- The air valve (7) serves to bleed air during the initial filling of the boiler with water - it prevents the formation of an air cushion.
To prevent galvanic corrosion in the water tank, an anode made of magnesium is placed in it. Its electrical potential is less than that of the tank body or the surface of the heating element, therefore, destructive corrosion processes will affect it. Periodically, as corrosion and overgrowing, the anode is replaced with a new one.
This scheme is simple, and is the most widespread among household boilers. These devices are generally inexpensive, which makes them popular with consumers. The main disadvantage is that the heating element works directly in heated running water, which leads to its rather rapid overgrowth with mineral deposits dissolved in it.
Direct fired gas boiler
The gas boiler is quite simple in its principle of operation and has the following general layout:
- A water tank is located in a metal case (most often made of stainless steel) with reliable thermal insulation.
- Cold water is supplied to the lower part of the tank through the branch pipe (1). In the upper part of the tank, a branch pipe is welded for the intake of heated water with its subsequent distribution to the points of consumption.
- The gas burner is located under the bottom of the tank (4), it is closed from water by a semicircular panel that plays the role of a heat exchanger.
- The second heat exchanger is a pipe for removing combustion products - it passes through a container with water. The gases are removed through a conventional chimney or a coaxial type system (depending on the boiler model - with an open or closed combustion chamber).
- The magnesium anode (5) is used to collect scale - it must be changed regularly as it gets overgrown.
- The boiler is necessarily equipped with an automatic control system - a thermostat (3) to monitor the temperature level, a valve to shut off the gas supply when the set water heating level is reached, a piezo ignition device - to automatically start gas burners when the liquid cools down as it flows.
A gas-fired boiler has a high performance, it is much more economical than an electric one. However, it also has significant drawbacks - it requires a mandatory chimney, and its installation is associated with the process of coordinating the project with the regulatory authorities of technical supervision. In addition, such direct heating boilers are much more expensive than electric ones.
Boilers for indirect heating
The main fundamental difference is heated for domestic needs ( so-called, sanitary) water does not have direct contact with electric or gas heating devices. Heat is transferred by connecting to the home heating system (or other sources of hot boiler water).
Such a boiler is most often installed in conjunction with a single-circuit heating boiler. This type of boiler can have a volume measured in tens or hundreds of liters, and which one to choose will depend on the number of households. Models are produced for floor-standing execution, or that are mounted to the wall horizontally or vertically on special brackets.
According to the organization of heat exchange, they can have a completely different layout:
Boiler with spiral heat exchanger
This boiler is structured as follows:
Indirect heating boiler with a heat exchanger - coil (photo in section)
- A volumetric tank for a sanitary bullock is placed inside the thermally insulated body. A heat exchanger (2) in the form of a coil is installed in its cavity.
- Through the nozzles 3 and 4, the heat carrier is circulated - hot service water received from a single-circuit boiler. Heat is transferred to sanitary water, which flows into the lower part of the tank through the inlet pipe (1).
- The heated sanitary water is discharged from the upper part of the tank through the pipe (5).
The coil in some models is located closer to the bottom of the tank, where cold water sinks, while in others it is evenly distributed throughout the tank, which allows you to quickly heat the entire volume of liquid.
Boilers are produced, the design of which includes two heat exchanger tubes. The heating agent heated by the boiler passes through one circuit, and through the second - from other possible heat sources, for example, from solar water heaters.
Tank-in-tank scheme
Another version of the indirect heating boiler does not have coils with a coolant inside, but is arranged somewhat differently. It consists of two containers, which are installed one into the other. Naturally, the tank, which is located inside, has a smaller volume - it is an accumulator of heated sanitary water.
Indirect heating according to the tank-in-tank principle
The diagram clearly shows the internal structure of this model.
- Through pipe 1, cold sanitary water is supplied to the internal tank.
- Branch pipes 2 and 4 are connected to the heating system - boiler hot water circulates through them.
- The inner tank (3) is made of stainless steel.
- Warmed water is taken through the branch pipe 5 for domestic consumption.
Positive qualities of indirect heating boilers:
- Good performance of the device if the heat exchanger has a sufficient area and the boiler is connected to a high power boiler.
- Energy saving and no load on the power grid.
- The coolant does not come into contact with sanitary water. Specially prepared water, which contains a minimum of salts, passes through the heat exchanger.
- The ability to switch the boiler to different energy sources, for example, in the winter time it can be powered by an optical boiler, and in the summer - from a solar battery.
However, there are also disadvantages:
- When water is heated in a boiler, the temperature in the heating system decreases.
- This is a rather expensive equipment compared to a direct heating boiler.
- The whole complex takes up a lot of space, i.e. it is better to allocate a separate room for him, which is not always possible.
You can familiarize yourself with the device of a boiler for heating indirect water in more detail by looking at the video material attached to the article:
Video - an overview of the capabilities of the indirect heating boiler
Combined action boilers
Boilers that combine both principles are a good option. They are connected to the heating circuit, but their design also implies the presence of their own heating element. For example, a diagram of the device of a heating boiler SMART by ACV:
- A steel outer tank (8) made of a sheet hoist with reliable polyurethane foam thermal insulation (3) is installed in an impact-resistant polypropylene casing (10). It is used to circulate water from the heating system supplied from the boiler through the pipes (11).
- Inside it is a stainless steel sanitary water tank (9). It provides for the inlet of water from the hot water supply (14) and its withdrawal to the points of consumption through the pipe (2).
- In the upper part there is a cover (7) with a manual air vent (1) - for the initial filling of the system.
- Inside the external tank there is a heating element with a capacity of 2 to 6 kW (5) - it will turn on at the command of the automatic controller if the thermostat (4) detects insufficient heating through the external heat exchange system. In the summer, when the heating system is turned off, the heating element will be the main source of heat energy.
- The control panel is equipped with the necessary adjustment devices - the temperature of heating of sanitary water, a timer for turning on the heating element (for example, for its use at a reduced night rate).
This boiler design is the most versatile and combines the positive qualities of all the systems mentioned above. Perhaps the only drawback of such a water heater is the rather high price.
When choosing a water heater, calculate the pros and cons of each option, looking at the characteristics of each of them. It is also important to pay attention to the size of the selected device and think over the place that it should take.
Indirect heating boilers are water heaters that allow you to ensure uninterrupted supply of hot water in a private household system. Such a water heater is a very good alternative to heating double-circuit boilers.
Indirect heating boilers must be purchased complete with single-circuit boilers, which means that this option of equipment takes up more space and its cost is higher than the prices of a standard double-circuit boiler. Nevertheless, an important advantage is the possibility of uninterrupted supply of a significant amount of hot water with constant temperature indicators.
Any method of heating running water by almost any system is accompanied by inadequate performance and inconsistent temperature of the supplied water. In this case, a well-developed water consumption schedule will be needed. The principle of operation of indirect heating boilers is somewhat different, which allows you to simultaneously use several points of use of hot water.
The principle of operation and the device of indirect heating water heaters
From a technical point of view, any indirect heating water heaters are standard heat exchangers capable of storing a certain amount of water at a given temperature. Hot water can be supplied at once through several points of water consumption. The simplest unit of this type is an insulated tank and has a coil, as well as four inputs and outputs:
- for the supply of hot heat carrier;
- for the return of the heat carrier;
- for cold water supply;
- for dispensing hot water.
Automation of work, as well as prevention of accidents and increasing the level of durability is carried out using additional elements:
- temperature sensor for water;
- circulation pump;
- safety valve;
- check valve;
- shut-off valves;
- cathodic protection against corrosive changes.
Heating equipment is connected in parallel with the heating wiring. The result of connecting to its own circuit is to ensure a sufficient flow rate of the coolant. Compliance with the connection diagram reduces the temperature spread in the heating system when the boiler is turned on.
Why and how to mount an indirect boiler (video)
Types of indirect heating boilers
There are practically no differences in the principle of operation of any models of indirect boilers. This type of water heating equipment mainly differs in the place of attachment:
- units for floor location;
- wall units.
The set of boiler equipment also allows you to classify water heating equipment into the following types:
- units with a spiral heat exchanger at the bottom;
- water heating devices with a pair of heat exchangers.
- Drazice OKC 160-NTR... It is immune to the quality characteristics of the heat carrier, and is made of high quality material that is not prone to corrosive changes. Not designed to operate at pressures above six atmospheres;
- Gorenje GV-120. A budget model for floor or wall mounting. It has a high-performance tubular heat exchanger. There is no possibility of top liner;
- Buderus Logalux L-135. The inside of the tank is covered with Duoclean heat-resistant glaze with high anti-corrosion properties. Designed for horizontal installation. The cost is quite high;
- Gorenje KGV 300-2 / BG. It is represented by a steel enamelled tank, with additional internal protection using a magnesium anode, a pair of tubular heat exchangers, a thermometer and overheating protection;
- VaillantVih CK-70. It features an attractive design, high build quality and good modern materials. The disadvantages include small volume and high cost;
- Protherm FE-200 BM. Floor-standing version in stainless steel with enamel finish. High-performance hot water heater with no possibility of connecting recirculation and heating element;
- Bosch SO 120-1. High-quality, compact and intelligent equipment designed for inlet pressures up to ten atmospheres. There is the possibility of a lower eyeliner. The unit is easy to install and maintain, but has only one outlet to the water.
It is important to remember that it is necessary to correctly determine the required volume, which will fully ensure the water supply. For a family of three to four people, a boiler with a volume of 100-150 liters is required.
How to connect an indirect boiler (video)
Heater connection diagram
As a rule, in a private household, an effective hydraulic system for installing hot water equipment is used.
Connection to the heating system
The piping and connection to the water supply system is carried out in accordance with the following rules:
- cold water is supplied to the bottom of the tank;
- hot water outlet is provided at the top of the tank;
- in the central part there is a recirculation point.
Three-way valve connection
The technology of such a connection is represented by a heating circuit and a heating circuit for hot water supply. The three-way valve ensures an even distribution of the heat carrier between these circuits.
Automatic control is carried out by means of a thermostat, which, when the water cools down, switches the valve, as a result of which water from the heating circuit enters the water heater circuit. When the required temperature values are reached, the thermostat switches the valve to the reverse position, and the heat carrier is redirected to the heating radiators.
Connecting a two-pump system
This option involves the movement of streams of heat carrier through different highways by means of a circulation pump. When connected in parallel, the operation of the pumping equipment is monitored by a temperature sensor.
Check valves are installed after the pumps. When the hot water supply line is turned on, the heating circuit is turned off. If a complex heating system is installed for two boilers, but the operation of heating and hot water supply will be uninterrupted.
Connection with hydraulic boom
The hydraulic distributor and the switch allow balancing the flow of the heating medium in multi-circuit systems with circulation pumps. The combined operation of the hydraulic manifold and the module helps to minimize pressure drops, but it is quite difficult to make such a connection on your own.
Recirculation connection
This option is relevant if there is a water towel dryer in the system. All consumers can be connected to such a recirculation loop, and hot water is constantly distilled in a circle using a pump. When recirculation is connected, the flow rate for heating the coolant increases.
Particular attention should be paid to the installation of additional units and elements., which should be represented by non-return and safety valves, as well as an automatic air vent and expansion tank. It is possible to install models that do not have an entrance to the recirculation circuit, connecting them using standard tees.
Possible errors when connecting equipment
Despite the fact that in most cases the independent installation and connection of indirect boilers does not cause difficulties, even a slight deviation from the installation technology can negatively affect the performance of the entire system. The main mistakes made when doing installation work with your own hands are as follows:
- wrong choice of place for the installation of a water heater. The indirect boiler should be located as close as possible to the heating boiler;
- improper connection of pumping equipment. The axial part of the engine must be located in a horizontal position, which will reduce the percentage of bearing wear;
- lack of control over the protection of pumping equipment. Prevent dirt and debris from entering the unit and systematically check the strainers.
Among other things, with a serial connection of the input and output of the heat carrier, it is possible to obtain the highest possible efficiency of the heating equipment. Optimum water heating and heating performance can be achieved if the heating medium enters the indirect heating boiler from the top and exits at the bottom.
How to connect a boiler (video)
Despite the relatively high cost and the need to allocate a sufficient amount of space for installation, indirect boilers are characterized by wide capabilities and have a large number of obvious advantages, thanks to which they have become very popular with domestic consumers.