How to choose a wall-mounted electric double-circuit boiler? What is a double-circuit electric boiler.

Winter time years implies heating system for residential premises. With absence centralized system heating, residents face the question of choosing a heat source. The simplest and the best option can be considered an electric boiler. It is especially relevant in the absence of a gas main near the house. Choosing a dual-circuit device, you will not only be able to adjust the required temperature regime indoors, but also provide for yourself hot water.

Specifications

Double-circuit electric boilers today are presented in a wide range, and each manufacturer invests in their basis design features. But they must all meet the following requirements:

working pressure - 3-6 atmospheres;
rated current - 35-40 A;
maximum power - 20 kW;
space for heating - 20-30 m²;
total weight within 10-20 kg.

Double-circuit electric boilers can operate both at single-phase and at three-phase voltage. This indicator depends on the power. If its value does not exceed 12 kW, then they can be operated with both types of mains power supply. If the load exceeds the indicated number, then the connection requires only three-phase voltage.

Design features

A distinctive feature of all heating boilers is the heating element. Depending on its type, the units are classified as follows:

electrode;
using heating elements;
induction.

There are also heating equipment according to the type of heat exchanger design. This design can be a built-in boiler or a flow system. Consider each category of boilers separately.

Electrode heating equipment

Heating is carried out by passing an electric current through the liquid. Electrodes can be used only if the coolant is water. Its heating occurs due to its own resistance, which occurs when a charge is emitted by the electrode.

Equipment based on this heating element is the safest for the home, because when water leaks, it turns off. The device reacts in the same way in case of a short circuit or an increase in temperature above normal.

The main requirement for operation is the constant circulation of water. Otherwise, the boiler will overheat and stop working.

Devices with heating elements

The principle of operation is to heat running water with the help of special elements - heating elements. The advantages of this type:

high degree of reliability;
compact overall dimensions;
automated control process;
natural circulation.

Such design features allow you to install the unit on the wall, and automated system- maintain the required temperature in the house. By turning it off and on required number heating elements can be regulated and electricity consumption.

The disadvantage of this type of double-circuit apparatus is the formation of scale. It increases power consumption by reducing heat transfer. But the advantages outweigh the disadvantages and make such units the most popular. They are easy to operate and have a low cost.

induction equipment

Heating is carried out by an inductor made of ferromagnetic alloys. It is located in a separate compartment and does not come into contact with the coolant. The water circulating around the perimeter is subjected to induction heating.

Compared with the options discussed above, this type of heating equipment has a higher cost, and also has large dimensions. These indicators are the main disadvantages, but there are also significant advantages:

leaks and breakages are excluded;
minimal scale formation;
operational safety.

Boilers with built-in boiler

Their installation is relevant when the house needs constant access to hot water. They have the following features:

in the absence of electrical power, there is always a supply of hot water;
no need for regular cleaning boiler;
hot water volume up to 60 liters.

The disadvantages of double-circuit boilers with a built-in boiler are big sizes and weight, as well as decent power consumption.

flow system

Installation is advisable in cases where the daily water consumption does not exceed 10-15 liters. The maximum temperature in such a system does not exceed 30 ° C, and the temperature of the water in it depends on the speed of its flow through the heat exchanger.

Giving preference to a two-circuit design, you can opt for any type. But an important role is played by indicators on which the cost of heating after the installation of an electric boiler will depend.

Calculation of heating costs

In order to get an approximate figure, you need to know the main indicators:

the total area of heated premises;
power consumption of the boiler;
number of months heating season- they depend on climatic conditions;
correction factors.

We will calculate for a house with an area of 60 m². To heat such a room, it is necessary heating unit with a power of 6 kW.

Let's define the daily equivalent of power consumption. For this, a correction factor is used. For a building with good insulation at full load it is 0.6. As a result, we get 0.6 × 6.0 = 3.6 kW.

Let's calculate the daily cost. It is determined by multiplying the power equivalent by the number of hours in a day. 3.6×24=86.4 kWh. If we take the average cost of electricity as an example, then it is 3.62 rubles / kWh. According to this parameter, the daily costs will be 313 rubles, and the monthly costs will be approximately 9000 rubles.

This is the maximum figure, it will correspond only to the indicators for the coldest 2-3 months. The rest of the time, the load indicator will drop to 0.3, and costs will be halved. The average value of the cost of heating will be 5700 rubles.

Despite the increased energy consumption, the choice of double-circuit heating equipment is associated with a number of advantages. It performs two important functions: supplying hot water and heating the house. Also, manufacturers provide the possibility of individual adjustment of the temperature and, accordingly, the cost of heat.

When a responsible decision is made to purchase an electric boiler for organizing the heating system of a residential building and supplying hot water, it should be taken into account that for optimal operation it will be necessary to ensure that a stable source of electricity is connected to the boiler.

Also plan a budget for the monthly costs of its maintenance.

Double-circuit electric boilers - pros and cons

If a modern residential facility cannot be connected to a standard heating and water supply system, then the solution is to purchase a high-quality double-circuit electric boiler.

When buying a boiler, each buyer considers the purchase in terms of an acceptable price, specifications products and economic feasibility his acquisitions.

Let's take a closer look at the main advantages of using a double-circuit electric boiler in order to approach its purchase consciously.

The main scope of production boilers are private residential buildings. It is there that the productivity of their work is especially evident. Installation requires only a work surface, which is located in close proximity to the source of electricity.

It is an electric boiler that is able to provide an uninterrupted supply of water in a house that is located in a remote area and cannot be connected to a gas main.

And yet the main advantage of the product is its compactness and affordable installation.

We must also not forget that a double-circuit boiler, which performs the function of a heating system, is based on environmentally friendly technology. The heating electric double-circuit boiler does not emit any harmful substances and does not use the air in the room.

For his practical application no need to worry about organizing a separate room, since the electrical appliance is comfortably placed in a small area, thereby saving space.

And a double-circuit electric wall-mounted boiler can generally find its place on any wall. Therefore, there is no need to think about the installation of chimneys, ventilation systems and the development of complex documentary projects!

In the aggregate of these signs, real financial savings can be traced, especially if you purchase an electric double-circuit boiler made in Germany!

An important factor is the indicator of electricity consumption, where double-circuit electric boilers from Germany simply have no equal! The appliance works absolutely silently and does not emit any hum and vibrations.

As for the maintenance of the electric boiler, practice shows the incredible durability and durability of the unit. The only node of the system that requires close attention from the owner is the reliable connection of the boiler to the electrical network.

In the event of sudden surges in the electrical network, the electric boiler is subjected to loads that can disrupt its operation.

Timely diagnostics of the equipment will help to quickly identify the problem and get rid of it without consequences. Since the electric boiler works without the use of an open fire, repair becomes a very feasible task.

How to calculate your heating costs before purchasing?

The calculation can be made on the basis of practical indicators, for example, to heat 10 square meters. m. of the premises, then the electricity consumption will be about 1 kW.

In addition, if the house is planned to install double-circuit boiler to ensure heating and hot water supply, additional power reserves will be required.

The average statistical indicators of water consumption comparable to the technical capabilities of the electric boiler will also help to make an optimal calculation.

Knowing the average data on the heating of water by an electric boiler, and counting all the consumption points of water in the house, it is possible to accurately calculate the required volumes of the boiler to provide hot water.

A double-circuit electric boiler is connected to a conventional electrical network. At the same time, the boiler is equipped with automation, thanks to which it first turns on the function of forcing the temperature into the coolant, and then goes into standby mode and only maintains a constant temperature.

Unlike apartment buildings residential buildings providing a private cottage with hot water has always been the concern of the homeowner himself. Now water heaters are being purchased and installed for this purpose. various types, including electrical ones. The latter are very popular because they are relatively inexpensive, reliable and easy to connect. But if you are planning to take electricity as an additional or main energy source for heating your home, then why not immediately purchase a double-circuit electric boiler? This will help you immediately solve the issue of heating water for household needs.

Device and principle of operation

In the modern market of heating equipment, two-circuit electric heating boilers of three types are offered:

with an additional flow heat exchanger;
with built-in storage boiler;
with the possibility of connection and joint piping with a remote boiler indirect heating.

In all heat generators with the possibility of supplying water for DHW heating carried out with the help of tubular electric heaters (TEHs). The heating elements are installed inside a closed container filled with a coolant. heating elements must be constantly immersed in water, so an automatic air vent is installed in the upper part of the tank. If the air is not released, then part of the heating element tube will no longer be washed by the coolant, as a result of which its tungsten coil will overheat and burn out in a short period of time.

For reference: ordinary tap water contains a certain amount of air, when heated in the container, it begins to accumulate in its upper part, forming an air gap. In industrial boilers, the heating system is filled with water that has undergone a procedure for removing air bubbles. It is difficult to perform it at the household level due to the high cost of equipment.

Electric boilers with a flow heat exchanger

Heat exchanger of a double-circuit boiler

In these units, hot water for hot water is heated from an already heated coolant through an additional heat exchanger. Here the principle of operation is as follows: in normal mode, heating elements heat the coolant to the required temperature, it moves along the main circuit using the built-in circulation pump.

As soon as the hot water valve opens in the house, the flow sensor detects this fact and transmits a pulse to the control unit. Then the coolant flow switches from the main circuit to the secondary circuit, giving a command to the electric drive two-way valve, which distributes flows. At the same time, the heating of the house ceases to be fed, since the heat generator runs on hot water.

Circulation pumps for heating

A heat exchanger is built into the secondary circuit, in which two flows move towards each other, exchanging heat. That is, the coolant intensively gives off heat to heat the running water. As soon as the tap closes, the reverse process occurs: the controller, at the signal of the sensor, gives a command to the electric drive of the two-way valve and it switches the flows back, the double-circuit electric boiler functions again in normal mode.

A heat generator of this type is advisable to use when there are 2 or 3 small consumers of hot water in the house, for example, a bathroom and a kitchen. Then the performance of the flow heat exchanger will be sufficient. In addition to this, electrical double-circuit boilers with flow heater also have other disadvantages:

The presence of temperature drops in hot water with the simultaneous use of two consumers.
Turning off the heating system during the operation of the DHW circuit begins to affect the microclimate when large rooms are heated, especially in non-insulated buildings.
The heater requires maintenance (flushing) because the internal surfaces over time, scale appears, preventing good heat transfer.

Boilers with storage boiler

Connection diagram for a flow and storage boiler

The disadvantages associated with a flow heater are absent in double-circuit electric boilers with a built-in storage tank for hot water. In this case, its consumption and the number of consumers depend on the capacity of this tank and the thermal power of the unit. Manufacturers offer wall-mounted and floor-standing versions of heat generators for home heating and hot water supply, the first ones have small capacity boilers (up to 100 liters), while in floor-standing units the tank capacity can reach 300 liters. This allows you to provide the necessary flow of hot water for all household needs when in large numbers people living in the house.

The principle by which an electric boiler works with a boiler resembles an electrical installation with a heat exchanger. The difference lies in the fact that the flow switching is carried out when the coolant in the system has reached the required temperature.

Double-circuit boilers Navien

In single-circuit units, when the required coolant temperature is reached, the control unit turns off the heating elements and turns them on after the water has cooled to the minimum lower threshold.

In the double-circuit apparatus, the heating elements continue to work, they only now heat the water in the storage tank. It turns out that the DHW system is always ready to work with a large flow of hot water. However, there are disadvantages here:

Electricity consumption is higher, since the heating elements constantly heat the water in the tank.
The overall dimensions of the heat generator are larger due to the presence of a tank.
The electronics are set to maintain the temperature in the rooms, and in the second place they heat the water in the tank. For this reason, on especially cold days, the temperature of the water in the boiler may drop, so it is important to initially choose the right unit for power.

Connecting an indirect heating boiler

Scheme of connecting an indirect boiler to an electric boiler

Many double-circuit electric boilers equipped with controllers that control not only the elements of the unit itself, but also external devices. These include a remote indirect heating boiler, the water in which is heated from the coolant circulating in the heating system. This process can be controlled by the electronic unit of the heat generator by controlling the electric drive of the three-way valve involved in the circuit in the following way:

Here, the electric boiler works according to the same algorithm as with the built-in storage tank. Until the coolant in the system reaches the maximum temperature, three-way valve at the command of the controller, it directs the flow to the radiators, and the rest of the time it switches to the boiler coil. Accordingly, the power of the electrical installation should be enough to provide heat for both systems.

In order to save electricity for domestic hot water, some controllers have the function of programming for the week ahead. The readiness of hot water can be "ordered" on certain time day, then the boiler will not heat it around the clock.

The disadvantages of such DHW systems a relatively high cost and the need to allocate a special room for heating equipment are considered.

Conclusion

Double-circuit electric heating installations can successfully replace a separate electric water heater, especially in cases where the consumption of hot water is small. If a large flow rate is required, then here there are options highlighted above. Therefore, buying a separate electric boiler is not always justified.

One of the ways to organize heating country house- use an electric double-circuit boiler for heating for this. In addition to heating the home, such devices are able to provide hot water.

Features of the device and operation

The core of almost any electric boiler is a heating element circuit. It consists of internal heating elements, to which automatic units are switched. With their help, the heat carrier is heated, transporting heat to the heating circuit. Electricity is supplied from single-phase and three-phase electrical networks. The efficiency of electric boilers is such that they almost completely convert electrical energy into thermal energy: the efficiency of devices approaches 99%.

Classical boilers are characterized by small dimensions, which avoids cluttering up the living space. However, in this case, the problem of the lack of hot water is not solved. As you know, only city apartments in high-rise buildings can boast of centralized hot water supply.

For residents country cottages the option remains with manual water heating or the use of an electric instantaneous and storage water heater. Double-circuit electric boilers for home heating are not much more complicated than their single-circuit counterparts. At the same time, they are able to heat water with an additional heat exchanger with a heating element.

This design consists of the following elements:

Two heating elements.
Expansion tank.
Safety group (sometimes replaced by a safety valve).
Circulation pump.

The supply heating circuit of the main heating element is switched on according to the set temperature indicators. At the same time, the heating element for the DHW circuit starts only after opening the hot water tap. As for other types of internal arrangement of double-circuit heating boilers, they have not taken root on the market. plumbing equipment due to imperfect design and a number of weak points. In one of these options, it is assumed that the water in the DHW circuit is heated from the heating circuit.

Electric double-circuit boilers for heating and water supply are divided into two groups according to the type of installation:

Wall.
Floor.

Floor-mounted models are more powerful: for this reason, they are used to heat large households. There is no need to worry about the loss of housing space, because. they take up little space, being compact. In a small dwelling, it is recommended to use miniature wall-mounted electric boilers for heating and hot water. Individual models of this type have good power, which is enough to heat large areas.

The novelty of the boiler equipment market is the so-called. "Energy-saving" double-circuit electric boilers for heating a private house. Their design contains alternative elements. These devices include electrode boilers of the "Scorpio" type. Thanks to the presence of automation, it becomes possible to quickly and inexpensively warm up housing. characteristic feature induction appliances is their safety and long service life.

Strengths and weaknesses of electric double-circuit boilers

Electric double-circuit boilers for the home are characterized by considerable convenience and practicality. Thanks to this, the hosts country houses Eliminate the need for hot water supply.

The advantages of the devices are as follows:

compactness. In terms of dimensions, electric double-circuit boilers are noticeably inferior to gas heaters.
No noise. The operation of the devices is not accompanied by hum and noise, which allows you to mount them in any room.
Environmental friendliness. During operation, there is no emission of harmful substances and carbon dioxide.
Installation speed. During installation, you have to fiddle with pipes and other components less.
Fire safety . There is no risk of gas leakage, fire or explosion.
Ease of maintenance. All that is required is to brush off the heat from the case from time to time.
Possibility of mounting anywhere. In this case, a special boiler room is not needed: the device can be installed in the kitchen, in the pantry or in the basement.
High efficiency(almost 99%).
Ability to use networks with a voltage of 220 V and 380 V. The decisive factor here is the power of the boiler used.

The disadvantages of double-circuit electric boilers for home heating usually include:

To connect a powerful device, you will need to lay an autonomous line. First of all, this applies to boilers with a power of more than 3 kW. The power supply of such a line is a common electrical panel.
Expensive compared to gas or solid fuel units.
high consumption electrical energy while turning on the spirit contours. It is for this reason that an autonomous power line is needed.
The high cost of electricity consumed. As you know, electricity cannot be called cheap.

The listed shortcomings are not critical, especially in situations where double-circuit electric boilers for heating are the only option for heating residential premises and organizing hot water supply. This primarily concerns regions where there is no gasification and stable supply of solid fuel.

The main criterion in the selection of a suitable electric boiler for heating and hot water supply is the area of heated premises. When calculating, they start from the fact that for every 10 m 2 of living space, 1 kW of thermal power is required. In addition, you should be aware of heat losses. As for the DHW circuit, it is recommended to purchase equipment with a capacity of approximately 10-14 l / min.

It is not easy to decide on the manufacturer, because. The market for boiler products is replete with high-quality appliances from different firms. This applies to both foreign and domestic brands. Boiler cost Russian production an order of magnitude lower, but the quality of individual models leaves much to be desired. At the same time, Western-made electric double-circuit boilers are reliable, so the money spent on their purchase is fully paid off. When considering options for electrode and heating element heaters, it is better to give preference to the latter: they are more reliable and undemanding to the quality of the coolant used.

Installation and strapping

There are no special requirements for where exactly to install an electric boiler for heating and hot water. For these purposes, both a separate room and a niche in the kitchen, corridor or basement can be used. At the same time, it is necessary to ensure natural ventilation device and protect it from direct moisture. The purchased floor model must be mounted on the floor. For wall models the proper quality of the wall fixing must be guaranteed.

The switching of the electrical part is carried out by wiring the required section: indications of these parameters are available in the accompanying documentation. For appliances with a power of more than 3 kW, a personal electrical line. RCDs are connected in close proximity to the boiler. To avoid defeat electric shock The device must be grounded without fail. Instructions on the organization of reliable grounding are contained in special literature. The main thing is not to use heating pipes and plumbing for these purposes.

To connect the boiler to the heating system, special skills are not needed. All that is needed is to connect the pipes and make sure the connections are tight. As for the purchase and installation of a circulation pump, the need for this usually does not arise. The fact is that such systems are usually initially equipped with pumping devices. This is also true for the expansion tank. If a security group does not exist, it is recommended that you install it. At the end of all installation activities, the coolant is poured into the system and a test run is performed. If there is no self-confidence, for the implementation installation work it is better to invite experts.

Not the cheapest to operate, but the most environmentally friendly, easy to install and maintain, a double-circuit heater.

The second circuit is designed to provide the house with hot water.

Advantages of electric over units using fuel:

environmental friendliness and compactness make it possible to place an electric double-circuit boiler () for heating a house in a residential area, a boiler room is optional;
no noise and vibration during operation;
the greatest opportunities for automation, the system requires virtually no user control;
low cost. Electric boilers comparable in price only with solid fuel, but much more convenient and easier to operate. Do not need fuel, do not spoil the air in the house.

Cons - the cost of electricity and dependence on it. Even urban networks (especially suburban ones) are subject to power surges.

Complete with the boiler, you have to buy a stabilizer, and outside the city and a generator - in case of a long-term power outage.

Features and principle of operation

An electric double-circuit boiler for heating and water supply functions due to a tubular element - a heating element.

Single-circuit ones are also electrode and induction, but in double-circuit their principle of operation cannot be realized.

The unit includes:

usually two heaters;
expansion tank;
automation, air vent (with strong airing of the heating system, the heating element may burn out), safety valve.

The boiler is equipped with a circulation pump.

The heating element itself is a metal tube, in the center of which a nichrome conductive thread passes, and the rest of the space is filled with a heat-conducting substance.

The element is built into the heat exchanger. When current is applied, the filament heats the tube, energy is transferred to the coolant. Circulation is carried out using a pump.

Each circuit is equipped with its own heating element, the circulation rings do not intersect. The temperature in the circuits is individually controlled. Controls the operation of the control unit. When the temperature in the room drops, the thermostat starts heating the water in heating circuit and a pump.

When the set temperature is reached, the operating units are switched off. In the event of a critical increase in pressure in the system, the safety valve is activated.

The emergency temperature switch responds to an increase in temperature above the norm. The heating element of the DHW circuit turns on at the moment the tap is opened. The distance between the boiler and the tap should be no more than 10 meters.

Types of double-circuit electric boilers

In individual buildings, in private apartments, in small offices, wall-mounted units () are popular, but there are also floor-mounted electric double-circuit boilers for heating a private house.

The power of floor models is high, 60 kW or more: such an acquisition is suitable for a large facility.

The double-circuit electric heating boiler can be connected to a three-phase and single-phase network. Units with a power of more than 12 kW are usually designed for three phases. Some models have two element connection schemes, for 380 and 220 volts. Switching is carried out by a manual toggle switch.

Boilers differ in DHW options:

flow heat exchanger. Switching from mode to DHW is carried out automatically when opening a hot tap using a two-way valve. Designed for a small number of water points (up to three);
boiler double-circuit electric boiler. The tank capacity for wall-mounted models is up to 100 liters, for floor models - up to 300. There are no temperature drops in such a system, but electricity consumption is higher, and the boiler itself is less compact;
the possibility of integrating an indirect heating boiler into the system. Switching modes is carried out by a three-way valve. The model includes all necessary elements strapping, incl. portable boiler. Automation allows you to set weekly settings for the DHW module. The cost of such a system is higher, more space is required for it.

Advantages and disadvantages of two circuits

The main plus of the two circuits is compactness. This is relevant when autonomous heating in apartments and small houses. In cramped conditions, one of the main limitations of the boiler (the remoteness of the points of water intake is undesirable) becomes irrelevant.

In some cases, a double-circuit electric boiler for an apartment is the only possible variant. In addition, the piping is much simpler than when using the boiler and heater separately. Fewer faucets and fittings - a small, but still savings. Simplified system design and installation.

The downside is the higher price. A single-circuit heating boiler and a hot water boiler in total cost almost half as much.

And this is not the only advantage of separate operation: although the circuits are autonomous, in the event of malfunctions, interpenetration of media occurs.

It is undesirable to use antifreeze as a coolant: it can get into drinking water or in the shower. At the same time, antifreeze is lost without a trace, its amount in the heating circuit has to be replenished.

Tanks for hot water supply in large families are often not enough, you have to install an additional one in addition to the built-in boiler. The DHW circuit imposes restrictions on the layout of the system: the boiler must be located as close as possible to the draw-off points, otherwise the water will cool down along the way.

A double-circuit electric heating boiler is more complicated than a single-circuit one - this means that it is more prone to breakdowns, and repairs are more expensive.

Cons of the heating element: scale accumulates on it; if the coolant leaks, the element may burn out. But an induction boiler can also burn out in the absence of water ().

Only the electrode apparatus () is deprived of this drawback, but it is not double-circuit. The coolant level is monitored by control devices: an accident is possible if they fail. The cost of heating elements boilers is lower than others.

Video about a double-circuit electric boiler.

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