Scheme of a closed heating system in a private house. Closed heating system: diagrams and installation features of a closed system

In the last few years, a closed heating system has become increasingly popular. Heating equipment is becoming more and more expensive, and you want it to last longer. In systems closed type the possibility of free oxygen getting inside is practically excluded, which prolongs the life of the equipment.

Closed heating system - what is it

As you know, in any heating system of a private house there is an expansion tank. This is a container in which some coolant is removed. This tank is necessary to compensate for thermal expansion in various operating modes. By design, expansion tanks are open and closed, respectively, and heating systems are called open and closed.

In recent years, it is the closed heating circuit that has become increasingly popular. Firstly, it is automated and works without human intervention for a long time. Secondly, any type of coolant can be used in it, including antifreeze (it evaporates from open tanks). Thirdly, the pressure is maintained constant, which makes it possible to use any household appliances. There are a few more advantages that relate to wiring and operation:

• There is no direct contact of the coolant with air, therefore, there is no (or almost no) free oxygen, which is a powerful oxidizing agent. This means that the heating elements will not oxidize, which will increase their service life.
• An expansion tank of a closed type is placed anywhere, usually not far from the boiler (wall-mounted gas boilers come immediately with expansion tanks). An open tank should be in the attic, and these are additional pipes, as well as insulation measures so that heat does not “leak” through the roof.
• In a closed system, there are automatic air vents, so there is no airing.

In general, a closed heating system is considered more convenient. Its main drawback is energy dependence. The movement of the coolant is provided by a circulation pump (forced circulation), and it does not work without electricity. Natural circulation in closed systems can be organized, but it is difficult - flow control is required using the thickness of the pipes. This is a rather complicated calculation, because it is often believed that a closed heating system only works with a pump.

To reduce energy dependence and increase the reliability of heating, they install uninterruptible power supplies with batteries and / or small generators that will provide emergency power.

Components and their purpose

In general, a closed heating system consists of a certain set of elements:

• Boiler with safety group. There are two options here. First - a safety group is built into the boiler (gas wall boilers, pellet and some solid fuel gas generators). The second - there is no safety group in the boiler, then it is installed at the outlet in the supply pipeline.
• Pipes, radiators, convectors.
• Circulation pump. Provides the movement of the coolant. It is installed mainly on the return pipeline (here the temperature is lower and there is less possibility of overheating).
• Expansion tank. Compensates for changes in the volume of the coolant, maintaining a stable pressure.

Now more about each element.

Boiler - which one to choose

Since the closed heating system of a private house can work offline, it makes sense to install a heating boiler with automation. In this case, after setting the parameters, you do not need to return to this. All modes are supported without human intervention.

The most convenient gas boilers in this regard. They have the ability to connect a room thermostat. The temperature set on it is maintained with an accuracy of one degree. She fell by a degree, the boiler turned on, heating the house. As soon as the thermostat has tripped (temperature reached), the operation stops. Comfortable, convenient and economical.

In some models, it is possible to connect weather-dependent automation - these are external sensors. According to their testimony, the boiler adjusts the power of the burners. gas boilers in closed systems, heating is a good piece of equipment that can provide comfort. The only pity is that gas is not everywhere.

No less degree of automation can give electric boilers. In addition to traditional units on heating elements, induction and electrode ones appeared not so long ago. They are compact in size and low inertia. Many believe that they are more economical than boilers on heating elements. But even this kind of heating units can not be used everywhere, since power outages in winter time- a frequent occurrence in many regions of our country. And to provide electricity to the boiler power. 8-12 kW from the generator is a very difficult task.

Boilers for solid or liquid fuel are more versatile and independent in this regard. Important point: a separate room is required for the installation of a liquid fuel boiler - this is a requirement of the fire department. Solid fuel boilers can stand in the house, but this is inconvenient, since a lot of debris falls from the fuel during combustion.

Modern solid fuel boilers, although they remain intermittent equipment (they warm up during combustion, cool down when the bookmark burns out), they also have automation that allows you to maintain the set temperature in the system by adjusting the intensity of combustion. Although the degree of automation is not as high as that of gas or electric boilers, it is.

Boilers on pellets are not very common in our camp. In fact, this is also solid fuel, but boilers of this type operate continuously. Pellets are automatically fed into the firebox (until the stock in the burker is finished). At good quality fuel, ash cleaning is required once every few weeks, and all operating parameters are controlled by automation. Only its high price hinders the distribution of this equipment: the manufacturers are mainly European, and their prices are corresponding.

A little about the calculation of boiler power for closed-type heating systems. It is determined by general principle: per 10 sq. meters of area with normal insulation take 1 kW of boiler power. Only take "back to back" is not advised. Firstly, there are abnormally cold periods during which you may not have enough rated power. Secondly, work at the power limit leads to rapid wear of the equipment. Therefore, it is desirable to take the boiler power for the system with a margin of 30-50%.

Security group

A safety group is placed on the supply pipeline at the outlet of the boiler. It should control its operation and system parameters. It consists of a pressure gauge, an automatic air vent and a safety valve.

The manometer makes it possible to control the pressure in the system. According to the recommendations, it should be in the range of 1.5-3 bar (in one-story houses this is 1.5-2 Bar, in two-story - up to 3 Bar). In case of deviation from these parameters, appropriate measures must be taken. If the pressure has dropped below normal, it is necessary to check if there are any leaks, and then add a certain amount of coolant to the system. At high blood pressure everything is somewhat more complicated: it is necessary to check in what mode the boiler is operating, whether it has overheated the coolant. The operation of the circulation pump, the correct operation of the pressure gauge and the safety valve are also checked. It is he who should dump the excess coolant when the threshold pressure value is exceeded. A pipe / hose is connected to the free branch pipe of the safety valve, which is led into the sewer or drainage system. Here it is better to do it in such a way that it is possible to control whether the valve works - with frequent discharge of water, it is necessary to look for the causes and eliminate them.

The third element of the group is an automatic air vent. Through it, the air that has entered the system is removed. A very handy device that allows you to get rid of the problem air locks in system.

Security groups are sold assembled (pictured above), or you can buy all the devices separately and connect them using the same pipes that were used to wire the system.

Expansion tank for closed heating system

The expansion tank for is designed to compensate for changes in the volume of the coolant depending on temperature. In closed heating systems, this is a sealed container, divided by an elastic membrane into two parts. In the upper part there is air or an inert gas (in expensive models). While the coolant temperature is low, the tank remains empty, the membrane is straightened (picture on the right in the figure).

When heated, the coolant increases in volume, its excess rises into the tank, pushing the membrane and compressing the gas pumped into the upper part (in the picture on the left). On the pressure gauge, this is displayed as an increase in pressure and can serve as a signal to reduce the intensity of combustion. Some models have a relief valve that releases excess air/gas when a pressure threshold is reached.

As the coolant cools, the pressure in the upper part of the tank squeezes the coolant out of the tank into the system, the pressure gauge returns to normal. That's the whole principle of operation of the expansion tank of the membrane type. By the way, there are two types of membranes - dish-shaped and pear-shaped. The shape of the membrane does not affect the principle of operation.

Volume calculation

According to generally accepted standards, the volume of the expansion tank should be 10% of the total volume of the coolant. This means that you have to calculate how much water will fit in the pipes and radiators of your system (it is in the technical data of the radiators, but the volume of pipes can be calculated). 1/10 of this figure will be the volume of the required expansion tank. But this figure is valid only if the coolant is water. If an antifreeze liquid is used, the tank size is increased by 50% of the calculated volume.

Here is an example of calculating the volume of a membrane tank for a closed heating system:

• the volume of the heating system is 28 liters;
• expansion tank size for a system filled with water 2.8 liters;
• the size of the membrane tank for a system with antifreeze liquid is 2.8 + 0.5 * 2.8 = 4.2 liters.

When buying, choose the nearest larger volume. Do not take less - it is better to have a small supply.

What to look for when buying

The stores have red and blue tanks. Red tanks are suitable for heating. Blue ones are structurally the same, only they are intended for cold water and cannot tolerate high temperatures.

What else to pay attention to? There are two types of tanks - with a replaceable membrane (they are also called flanged) and with an irreplaceable one. The second option is cheaper, and significantly, but if the membrane is damaged, you will have to buy the whole thing. In flanged models, only the membrane is bought.

Place for installation of expansion tank of membrane type

Usually they put an expansion tank on the return pipe in front of the circulation pump (when viewed in the direction of the coolant). A tee is installed in the pipeline, a small piece of pipe is connected to one of its parts, and an expander is connected to it through the fittings. It is better to place it at some distance from the pump so that pressure drops are not created. An important point is that the piping section of the membrane tank must be straight.

After the tee put a ball valve. It is necessary to be able to remove the tank without draining the heat carrier. It is more convenient to connect the container itself with the help of an American (flare nut). This again facilitates assembly/dismantling.

Please note that some boilers have an expansion tank. If its volume is sufficient, the installation of a second one is not required.

Empty device weighs not so much, but filled with water has a solid mass. Therefore, it is necessary to provide a method of fixing on the wall or additional supports.

Circulation pump

The circulation pump ensures the operability of a closed heating system. Its power depends on many factors: the material and diameter of the pipes, the number and type of radiators, the presence of shut-off and thermostatic valves, the length of the pipes, the operating mode of the equipment, etc. In order not to go into the intricacies of calculating power, the circulation pump can be selected from the table. Choose the nearest greater value according to the heated area or the planned thermal power of the system, in the corresponding line in the first columns, find the required characteristics.

In the second column we find the power (how much coolant it is able to pump per hour), in the third - the pressure (system resistance) that it is able to overcome.

When choosing a circulation pump in a store, it is advisable not to save. The entire system depends on its performance. Therefore, it is better not to save and choose a trusted manufacturer. If you decide to buy unknown equipment, you need to somehow check it for noise levels. This indicator is especially critical if the heating unit is installed in a residential area.

Strapping scheme

As mentioned earlier, circulation pumps are installed mainly on the return pipeline. Previously, this requirement was mandatory, today it is only a wish. The materials that are used in the production can withstand temperatures up to 90 ° C, but it's still better not to risk it.

In systems that can also operate with natural circulation, it is necessary to provide during installation the possibility to remove or replace the pump without the need to drain the coolant, as well as to be able to work without a pump. To do this, a bypass is installed - a bypass through which the coolant can flow if necessary. The installation diagram of the circulation pump in this case is in the photo below.

In closed systems with forced circulation, a bypass is not needed - it is inoperative without a pump. But two ball valves on both sides and an inlet filter are needed. Ball valves make it possible, if necessary, to remove the device for maintenance, repair or replacement. The dirt filter prevents clogging. Sometimes, as an additional element of reliability, a check valve is also placed between the filter and the ball valve, which will prevent the coolant from moving in the opposite direction.

Scheme of connection (piping) of a circulation pump to a closed-type heating system

How to fill a closed heating system

At the lowest point of the system, as a rule, on the return pipeline, an additional tap is installed to supply / drain the system. In the simplest case, this is a tee installed in the pipeline, to which a ball valve is connected through a small section of the pipe.

In this case, when draining the system, it will be necessary to substitute some kind of container or connect a hose. When filling the coolant, a hand pump hose is connected to the ball valve. This simple device can be rented at plumbing stores.

There is a second option - when the coolant is simple tap water. In this case, the water supply is connected either to a special boiler inlet (in wall-mounted gas boilers), or to a ball valve similarly installed on the return. But in this case, another point is needed to drain the system. In a two-pipe system, this may be one of the last in the radiator branch, to the lower free entrance of which a drain ball valve is installed. Another option is shown in the following diagram. It shows a single-pipe closed-type heating system.

Scheme of a closed single-pipe heating system with a system power supply unit

The level of comfort in the house is determined by an efficient heating system. Proper selection of the design and arrangement of elements ensures the performance of the entire configuration. Previously, developers preferred an open system. True, a number of shortcomings have led to an increase in the popularity of a closed heating system.

Principle of operation

The operation of a closed heating system is based on the transfer of heat energy by a heated coolant through heating devices to the premises of the house. The temperature in them proportionally depends on the degree of heating of the coolant and its volume.

In order for the heating system to work, a certain pressure in it is necessary. The pressure allows water to circulate and increases the efficiency of the structure. When moving, the coolant overcomes friction resistance, so its value is determined by the diameter and length of the pipes, the number of fittings and bends.

You can create pressure in the heating system using the force of gravity. This is possible when there is a difference in the densities of the heated and cold liquids flowing in the supply and output pipelines. The heated water has less mass, so it is displaced by the heavier cooled water. This principle of operation is used in the design of an open type circuit.

Scheme

In a closed circuit, pressure is artificially created by installing a pump. Such a device creates a fluid pressure and provides a circular motion along the contour. To increase the service life of pumping equipment, the connection is made to the return line, in which the temperature is lower. The disadvantage of such a system is the dependence of its operation on the availability of electricity. In this case, the design has the following advantages:

1. It is possible to heat houses with a large area, since there is no restriction on the length of the highway.
2. New schemes are being used modern views heating.
3. The heat transfer increases.
4. There are no losses for the evaporation of the coolant.
5. The diameter of the pipes is reduced, which saves money on their purchase and installation.
6. Reduced temperature difference for easier working conditions heating equipment and unload the system.
7. The level of heat transfer is regulated individually for each heater.

Advantages and disadvantages

A closed heating system has several advantages:

• The characteristics of the coolant make it possible to achieve a high concentration and heat transfer of heat.
• Affordable cost of materials and the ability to use them effectively.
• Creation and maintenance of the required temperature regime.

The disadvantages of such structures include:

• Installation of a closed circuit is associated with certain difficulties.
• The heat generator operates continuously.

If a long break in the operation of the system is expected during the cold season, then it is necessary to drain the coolant. This drawback is eliminated when using non-freezing liquids as a coolant.

Features of a closed heating system

The closed heating system has a number of features. You can mount it by creating an upper or lower wiring. The first scheme is different in that the coolant moves to the attic, and the water is distributed through the risers in heating appliances. When using the second scheme, the coolant is supplied from below from the basement, where the boiler equipment is located. It immediately goes to the supply pipeline, and from it to the radiators. If in an open circuit the expansion tank is located at a point with a maximum height, then in a closed circuit it can be arranged in close proximity to the boiler or in any other convenient place.

Installation of the system may provide for a one- or two-pipe method of connecting heaters to the main. A two-pipe connection is characterized by the presence of a riser that discharges the cooled coolant into the boiler. Two methods are used to implement it:

Star. In this case, the pipelines that supply and drain water have branches that go individually to each battery.

Plume. The supply and return pipes are connected in series to the radiators.

The single-pipe scheme is more simple to implement, which has the following features:

• After the heat is released, the water returns to the riser, which supplies it and is transferred to the next heater. As a result of this, the coolant of different temperatures moves in it. This circumstance requires an increase in the heat exchange area in order to achieve the required temperature level.
• Application is limited to the construction of houses that have an attic.
• There is no possibility of a phased launch.

When creating a one-pipe system, use:

• flow scheme, in which there is a sequential movement of the coolant through the radiators. In this case, it is impossible to regulate the heat flow in the room;
• diagram with closing sections. It is designed in such a way that a tap is installed in front of each radiator, with the help of which the heat flow is regulated.

Depending on the installation method of the supply pipeline, a closed system can be:

Vertical. It is advisable to use it in multi-storey buildings. The radiators of all floors are connected to one vertical riser.

Horizontal. It is used in one-story buildings, when all appliances are located on the same level and connected to a horizontal pipe. This design significantly reduces the need for materials, but air pockets may occur during operation.

The movement of the coolant can be organized according to a dead-end scheme or with a passing movement of the coolant. The first option provides for several heating circuits, which have a different number of devices and different lengths of the pipeline. The second option has the same design of the circuits and a constant level of pressure.

Elements of the heating scheme

The structural elements of a closed heating system include:

• boiler;
• pump equipment;
• expansion tank;
• heating appliances.

The parts necessary to connect the structural elements and auxiliary equipment are also used.

Boiler equipment provides heating of the coolant to the required temperature. Most often, solid or gaseous fuels are used, and gas is the cheapest and most accessible.

The expansion tank affects the safe operation of the system, as it does not allow dangerous pressure in the pipeline. The main part is a membrane, to which the following requirements are imposed:

• ability to work at elevated temperatures;
• durability;
• compliance with sanitary and hygienic standards.

To increase the life of the tank, significant pressure drops should not be allowed, especially during start-up.

The use of a circulation pump equipped with electronic regulation of operation reduces energy consumption by 40%. Such equipment provides a reduced noise level and has a long service life. The main indicators when choosing a pump are: power, the period for which the factory warranty applies, and the duration of the period that does not require Maintenance. The volume of the circuit affects the choice of its power. In addition, the parameter depends on the characteristics structural elements systems, type of boiler equipment, availability of automation.

The contour of the heating system of a closed type consists of pipes, the material of which can be: steel, metal-plastic, reinforced polypropylene. Parameters influencing the choice of material: the ability to work at high temperatures and the ability to withstand a certain pressure.

Steel pipes are durable, as they can be operated at pressures up to 10 atm at temperatures over 100 degrees Celsius. However, steel pipes are prone to corrosion, which reduces the service life.

Reinforced polypropylene pipes are capable of operating at coolant temperatures up to 95 degrees Celsius. A special soldering iron is required for their installation.

It is possible to work with metal-plastic at temperatures up to 90 degrees Celsius. Assembly is simple and does not require complex tools. But the fittings are expensive. Such pipes should not be used in central heating.

Operating conditions determine the choice of heating devices. AT apartment buildings the water temperature reaches 120 degrees Celsius, and the pressure is 10 atm. At the same time, the quality level of the coolant is rather low. Such operating conditions necessitate the installation of cast iron batteries. In a private house, the conditions are less severe, so it is possible to install modern radiators with an improved design.

Converting an open system to a closed one

A closed-type heating system is rarely found, the coolant circulation of which occurs naturally: pumping equipment is excluded from this scheme.

This design is usually not included in the original plans. It is obtained by self-re-equipment of an open system. Such a transformation occurs when a conventional expansion tank is removed and replaced with a structure equipped with a membrane.

It is not excluded the design and installation of such a system initially. However, most of the advantages of a closed system cannot be achieved. The calculation of the diameters of all sections of the pipeline becomes much more complicated, and when laying it, a certain slope is observed, which causes airing.

The only advantage of such a re-equipment of the heating system is autonomy from the supply of electricity.

Installation of the heating system: step by step instructions

In the course of drafting the project, you need to select a boiler and decide on a method for creating coolant circulation.

Based on the parameters of the boiler equipment, they make calculations and choose the material and diameter of the pipes, they are determined with the type of heating devices and fittings. After that, a project is drawn up, in accordance with which work will be carried out.

The boiler is mounted on a site prepared in advance.

Mark out places for placing heating devices and highway routes.

A pipeline is laid, which originates from the boiler and leads to the radiators.

Perform installation of all equipment.

Seal and fill the system with coolant.

Perform a test run.

If a Vacation home designed not only for the periodic arrival of their owners during the summer season, but for a long or even permanent residence them in it, then you can’t do without a heating system. This issue is always carefully thought out even at the design stage of construction or reconstruction, and is taken into account when buying ready-made housing.

This question is extremely serious, requiring scrupulous consideration of all existing conditions: the periods of future operation of the building, the climatic zone of the area, the availability of power supply lines, utilities, building design features, the total estimated cost of implementing a particular project. And yet, most often, homeowners come to the conclusion that the best solution would be water system closed-type heating in a private house.

This publication will review basic principles closed system, its differences from the open one, existing advantages and disadvantages. Attention will be drawn to the main elements of such a system with recommendations for their selection, typical wiring diagrams for the heating network in the house are given.

Closed heating system in a private house - main features

A private house can be heated in different ways.

• For a long time, the main source of heat was one or more stoves (fireplaces), each of which heated one or another part of the building. The disadvantages of this approach are obvious - uneven heating, the need to carry out regular fireboxes, monitor the combustion process, etc.

Currently, this type of heating is used less and less, and as a rule - with the absolute impossibility or complete inexpediency of using another, more efficient system.

• Electric heating system using convectors or oil coolers- extremely expensive to operate due to the high price of electricity and its high consumption.

True, alternative methods appear, in the form of film infrared elements, but they have not yet gained wide popularity.

• Most of the owners of private houses still stop at water heating. This is verified efficient system, which, by the way, can operate on almost all energy sources - natural gas, liquid or solid fuel, electricity, which determines its complete versatility - the difference is only in the type of heating boiler. A well-calculated and properly installed water heating system ensures uniform distribution of heat throughout all rooms, and is easily adjustable.

Not so long ago, the main scheme for organizing water heating in a private house was open with the gravitational principle of moving the coolant through pipes and radiators. Compensation for the thermal expansion of water was due to the presence of a leaky one, which was installed at the highest point of the entire circuit of the heating system. causes constant evaporation of water, so there is a need for constant monitoring of its required level.

The movement of the coolant through the pipes is ensured in this case by the difference in the density of cold and heated water - the denser cold one, as it were, pushes the hot one forward. To facilitate this process, an artificial slope of the pipes is created along their entire length, otherwise the effect of hydrostatic pressure may occur.

It is quite possible to embed a circulation pump into an open system - this will dramatically increase its efficiency. In this case, a system of valves is provided so that it is possible to switch from forced circulation to natural and vice versa if necessary, for example, during power outages.

The closed-type system is arranged somewhat differently. Instead of an expansion tank, a sealed compensation tank of a membrane or balloon type is installed on the pipe. It absorbs all thermal fluctuations in the volume of the coolant, maintaining one pressure level in a closed system.

AT currently this the system is the most popular, as it has many significant advantages.

Advantages and disadvantages of a closed heating system

• First of all, there is no evaporation of the coolant. This gives one important advantage - you can use not only water, but also antifreeze in this capacity. Therefore, the possibility of freezing of the system during forced interruptions in its operation is eliminated, for example, if it is necessary to leave the house for a long time in winter.
• The compensation tank can be located almost anywhere in the system. Usually, a place is provided for it directly in the boiler room, in the immediate vicinity of the heater. This ensures the compactness of the system. An open-type expansion tank is often located at the highest point - in an unheated attic, which will require its mandatory thermal insulation. In a closed system, this problem does not exist.
• Forced circulation in a closed system provides heating of the premises much faster from the moment the boiler is started. No unnecessary losses of thermal energy in the area of ​​the expansion tank.
• The system is flexible - you can adjust the heating temperature in each specific room, selectively turn off some sections of the general circuit.
• There is no such significant difference in the temperature of the coolant at the inlet and outlet - and this significantly increases the period of trouble-free operation of the equipment.
• For heating distribution, pipes of a much smaller diameter can be used than in an open system with natural circulation without any loss in heating efficiency. And this is both a significant simplification of installation work, and significant savings in material resources.
• The system is sealed, and with proper filling and normal operation of the valve system, there should simply be no air in it. This will eliminate the appearance of air pockets in pipelines and radiators. In addition, the lack of access to oxygen contained in the air does not allow corrosion processes to actively develop.

• The system is highly versatile: in addition to conventional heating radiators, water “warm floors” or convectors hidden in the floor surface can be connected to it. A domestic water heating circuit is easily connected to such a heating system - through an indirect heating boiler.

The disadvantages of a closed heating system are few:

• The expansion tank must have a larger volume than with an open system - this is due to the peculiarity of its internal design.
• Requires installation the so-called "security group"– safety valve systems.
• The correct operation of a closed heating system with forced circulation depends on the continuity of the power supply. It is possible, of course, to provide, as with the open type, switching to natural circulation, but this will require a completely different arrangement of pipes, which can reduce a number of the main advantages of the system to zero (for example, the use of "warm floors" is completely excluded). In addition, the heating efficiency will also decrease sharply. Therefore, natural circulation, if it can be considered, is only as an “emergency”, but most often a closed system is planned and installed specifically for the use of a circulation pump.

The main elements of a closed heating system

So, the composition of the general closed-type heating system for a private house includes:

- heating device - boiler;

- circulation pump;

— system of distributing pipes for heat carrier transfer;

- Expansion compensation tank of sealed type;

- heating radiators installed in the premises of the house, or other heat transfer devices (“warm floors” or convectors);

— safety group — valve system and air vents;

- necessary shut-off valves;

- in some cases - additional automatic control and management devices that optimize the operation of the system.

Heating boiler

• by the most widespread are . If a gas main is connected to the house or there is a real opportunity to lay it, then most owners without an alternative prefer this particular method of heating the coolant.

Gas boilers are distinguished by high efficiency, ease of operation, reliability and cost-effectiveness in terms of paying for energy. Their disadvantage is the need to coordinate the installation project with the relevant organizations, since such a heating system has very special safety requirements.

The variety of gas boilers is very large - you can choose a floor or wall model, with one or two circuits, simple in device or saturated with electronics, requiring connection to a stationary chimney or equipped with a coaxial combustion products exhaust system.

• They are usually installed in those conditionswhen gas supply to the house is impossible for some reason. Such an installation will not require coordination - the main thing is that the requirements of electrical safety and compliance of the boiler power with the capabilities of the electrical network are observed. Such heaters are distinguished by compactness, simplicity and ease of adjustment.

Heating systems with electric boilers have a well-established reputation for being “uneconomical” due to the rather high cost of electricity. This is only partly true - modern electric heaters, thanks to new technologies for heating water, have a very high efficiency, and with reliable insulation at home should not burden the budget too much.

In addition to the well-known boilers with heating elements (which are really not very economical), modern developments are actively used.

For example, they are widely used in which heating is carried out by flowing alternating current directly through the coolant (although here you will need a specially selected chemical composition water in the system). By themselves, such boilers are inexpensive, but there are certain problems with adjustment.

Closed heating system in a private house

Features and Benefits

Heating systems differ in the configuration of the expansion tank - a special tank that compensates for the thermal expansion of the coolant. An open tank is installed in a gravity system - the liquid moves through the pipes without installing a circulation pump for heating. The movement of the coolant occurs due to the natural circulation of the medium, which changes density when heated and under the influence of gravity.

A feature of the closed system is the use of a closed-type expansion tank, which is a sealed container equipped with an elastic membrane inside. This ensures efficient operation under pressure and eliminates the contact of fluid with air.

With forced circulation

A closed-type heating system in a private house may include a circulation pump, which causes the coolant to actively move, warming up all heating devices or the underfloor heating circuit as much as possible.

A closed heating system with forced circulation has a number of advantages:

• heating of a liquid under pressure occurs faster;
• the risk of airing the pipeline and radiators is reduced;
• the evaporation of the coolant is prevented (which is especially important when using antifreeze), the penetration of oxygen into the liquid, which provokes corrosion metal elements systems;
• due to the installation of a membrane tank at the bottom next to the boiler, and not at the upper point of the circuit, as in open systems, installation and maintenance are simplified;
• the movement of liquid under low pressure simplifies the calculation and installation of the pipeline - unlike the gravity system, in this option there are no strict requirements for the angle of inclination of the pipes and pipes of smaller diameter can be used;
• no need for pipes large diameter and mount them open way to have access to any part of the system to eliminate air congestion.

The heating system of a private house with a circulation pump and a membrane expansion tank provides better space heating compared to gravity. But at the same time it has one significant drawback - energy dependence. The operation of the pump requires electricity, so this option is not suitable for buildings in remote areas with poor or no power supply.

with natural circulation

The gravitational heating system is non-volatile, and this is its advantage. Usually this is a heating system with a solid fuel boiler or stove, less often liquid fuel units are used.

Heating without a pump is suitable for a dwelling with a relatively small area, while it is important to correctly calculate the diameter of the pipes for each part of the system and design their installation scheme, observing the optimal angle of inclination of the pipeline links. It is necessary to reduce the risk of airing and ensure the effective movement of the coolant.

A circulation pump can be added to a closed heating system with natural circulation at any time, increasing its efficiency. This is best option for areas where there are problems with power supply. In this case, in the event of a temporary lack of electricity, the house will not be left without heat - a closed-type system in a private house will work as a gravitational one.

Note! The use of a membrane tank in a gravity system negatively affects its functioning, since the liquid in a closed heating system needs to overcome the resistance of the membrane in a sealed container. For gravity systems, an open tank is preferred, and a circulation pump is usually added to the circuit with a membrane expansion tank.

Scheme

The scheme of a closed heating system is single-pipe and two-pipe. The choice depends on the conditions of use and performance requirements.

A single-pipe circuit of a closed heating system is suitable for small buildings. It is allowed to install it in two-story house, and each floor should have no more than 5 radiators. The single-pipe scheme (Leningradka) has a significant drawback - the radiators are connected in series, and the farther the heating device is located from the boiler, the lower the temperature of the coolant that passes through it. Radiators closing the chain should be heating devices with an increased heat transfer area compared to the first ones.

The two-pipe scheme of a closed heating system is more efficient, since it allows the coolant of the same temperature to be delivered to all radiators. This option suitable for large houses, including several floors.

Mounting Features

Solid fuel units, double-circuit and single-circuit, are prone to the formation of condensate in the combustion chamber, which causes corrosion and damages the metal. In order to avoid this effect, a mixing unit is added to the piping scheme, which includes a three-way valve and a bypass. Thanks to the valve, the coolant circulates through the small circuit until it reaches the required temperature, after which access to the boiler for the coolant from the heating circuit is opened. Solid fuel boilers with a strapping of this type are safe in operation and serve as long as possible.

The closed-type heating system is designed to work offline and use temperature sensors to maintain a comfortable microclimate. This is taken into account when choosing the type of boiler - it is recommended to use an automated unit. Gas and electric boilers are equipped with automation, if a solid fuel boiler is connected to the heating system, it is better to choose a unit long burning, pyrolysis or pellet.

Security group

The coolant supply pipeline at the outlet of the boiler is equipped, which is responsible for controlling the operation of the heat generator. It includes a pressure gauge (measures pressure), an automatic air vent (for bleeding gases), a safety valve (discharges excess coolant at elevated pressure). The security group (GB) can be purchased ready-made or the corresponding devices purchased separately can be installed on the manifold.

Attention! It is forbidden to mount cut-off valves between the safety group and the boiler branch pipe.

Expansion tank

Heating of a closed type provides for the installation of a device to compensate for the increase in the volume of the heated coolant. A membrane expansion tank is a hermetic container with an elastic pear-shaped or dish-shaped internal partition. The heated coolant, having increased in volume, stretches the membrane and fills part of the reservoir. As the liquid cools, the volume of the liquid decreases, and the membrane tends to return to its previous shape, displacing the coolant from the container. Due to this, a certain level of pressure is maintained in the system.

The volume of the membrane tank is calculated specifically for each system. It must be at least 10% of the total volume of the coolant in the circuit (the capacity of the boiler, all heating devices and pipes), if we are talking about water, or from 15% if antifreeze is selected as the coolant.

Circulation pump

Water circulation is provided by a special pump, the choice of which takes into account the thermal power, the heated area, the length of the pipeline, the scheme autonomous system, pipe diameter and a number of other factors.

It is recommended to choose a wet-type circulation pump, where the coolant passes through the rotor - with such a device, the heating system makes much less noise during operation. Installation of the system involves the installation of a pump on the return pipeline.

If the system is designed for operation with natural and forced circulation, depending on the availability of power supply, it is necessary to provide a bypass through which the coolant will bypass the pump.

Priming system

It is important for home craftsmen who equip independent heating with their own hands to figure out in advance how to properly fill the heating system in a private house in order to prevent the formation of air congestion.

For the first start of heating in a private house, it is advisable to invite a specialist who will check the correctness of the scheme and the quality of the installation of the elements, and control the operation of the boiler. But in the future, after maintenance work, it will again be necessary to fill the heating system with a coolant, so you need to know how to do this without errors.

Note! Filling a closed-type heating system is recommended to be done with an assistant. One person will fill the circuit with water or antifreeze, and the second person will monitor the venting of air from the pipes.

Filling with water

At the top point of a properly installed heating system is located. Before filling the circuit with water, the valve must be fully opened so that the displaced air escapes through it.

The return pipeline is mounted at a slope and a drain valve is installed at the lowest point, which allows you to remove the coolant from the system. Nearby, just below the boiler unit, there should be a branch pipe with a check valve, which serves to fill the heating system.

A water pipe can be connected to the pipe, in this case, to fill the heating system with water, it is enough to turn the valve. In the absence of a stationary pipe, the pipe is connected to the water supply using flexible hose. Filling a closed heating system with water requires that the water be supplied at a pressure slightly higher than the design operating pressure.

The water supply to the system is completed when all heating devices and pipes are full - coolant begins to drain from the upper air valve. At the final stage of filling, close the upper air valve and open the Mayevsky taps on all batteries in turn to eliminate air bubbles. Water injection stops when all air is removed from the system and the pressure gauge on the safety group shows the calculated pressure (1.5 atm or more, depending on the characteristics of the boiler).

If a double-circuit boiler with a water make-up module is used in a closed heating system, the procedure involves connecting the filling hose to a special tap for pumping the coolant, which is part of the module.

If we are talking about a system with a gas boiler and a water circuit, it is important to know how to start the unit. The front cover is removed from the boiler to provide access to the boost circulation pump. After filling the system with your own hands and checking it for leaks, turn on the unit by setting the operating mode. From the booster circulation pump, which begins to gurgle, slightly unscrew the cover with a screwdriver so that air comes out and water begins to drip. Then the lid is screwed back and after 3-4 minutes the operation is repeated two or three times at short intervals. The unit will become quieter and the burner ignition will turn on. Check the pressure gauge and briefly open the supply valve to build up the correct pressure.

Filling with antifreeze

The use of antifreeze liquid as a coolant has its own characteristics. Let's figure out how to fill a closed-type heating system with antifreeze, given that it cannot be poured through an expansion tank or supplied from a water supply.

The system is populated as follows:

• Option 1. Anti-freeze fluid is pumped with a manual pressure test pump, which will provide the necessary pressure.
• Option 2. An electric pump is used, capable of pumping liquids with different densities.
• Option 3. Filling is carried out through a hose, the lower end of which is connected to the nozzle check valve, and the top one is raised above the top point of the system (to the attic, roof, second floor). Upon completion of work, the remaining coolant from the hose is drained into a substituted container.

System pressure and make-up

Stable working pressure is a guarantee effective work heating system. Let's figure out why the pressure in the heating system drops. This is due to a decrease in the volume of the coolant, which is caused by the inevitable leaks in the nodes and joints, the release of liquid from the air vents during the manual deaeration of radiators, etc.

An automatic make-up valve connected to the water supply will prevent the pressure from dropping below the required values. In small systems, a mechanical valve is mounted, but in this case, the consumer needs to regularly check the pressure gauge and add the required volume of coolant manually.

Conclusion . The ability to properly fill a closed-type heating system will allow you to properly prepare it for heating season and perform start-up after repair or maintenance work.

Widespread now open system heating has a number of serious disadvantages. One of them is direct contact with the atmosphere. As a result, a coolant flows through the pipes, in which there is air. Air bubbles can gradually cause corrosion of the metal elements of the heating system, as well as cause the “noise” of the coolant. All this can be avoided by just making a closed heating system of a private house.

The main feature of such systems (and what an open circuit does not have) is complete isolation from the influence of the environment. Closed heating system, which you can do with your own hands, includes the following elements:

• boiler;
• automatic air valve;
• thermostatic valve;
• heating radiators;
• expansion tank;
• balancing valve;
• ball valve;
• pump and filter;
• manometer;
• safety valve.

How does it work water heating closed type? If the temperature of the coolant rises, then excess liquid is squeezed into the expansion tank. When the temperature drops, the liquid returns to the system, i.e. pressure is maintained within a fairly narrow range.

For efficient circulation of the coolant, a pump is used (an open system may have natural circulation). True, there is also a minus here - in the absence of electricity supply, a closed system will not be able to function normally (lack of electricity for a country private house is a very urgent problem). But the advantages of using a “pump” more than compensate for the disadvantages - for both an apartment and a private house, installation of additional heating systems is possible. In particular, you can make a warm floor.

The circulation pump is installed on the return pipe ("return") in front of the heating boiler. An expansion tank is also mounted here. Such an arrangement of these important elements allows you to be uncritical about the diameter of the pipes used during installation and the observance of the slope, which open water heating must have.

As a result, less time and materials are spent on the installation of such a heating system (for example, it is no longer necessary to insulate the pipeline, since the expansion tank is installed next to the boiler). However, you should not "abuse" such advantages. This is especially true for the slope (it’s better to do it anyway) - if it is observed, the system will at least work in the event of a power outage, but it will still work, i.e. defrosting does not threaten her.

In the video below, you can see a detailed example of the organization of closed-type heating using solid fuel and electric boilers.

The closed heating system is isolated from air penetration. However, its operation does not provide 100% tightness: air can fill the pipes, for example, when adding a coolant to the system. In this case, it will accumulate at the top points. You can get rid of it by means of a Mayevsky crane or float diverters operating on an "automatic". The air already dissolved in the water is removed using special separators installed directly in the pipeline.

Good results in terms of saving heat gives the use of a thermostat. It turns on the main consumer of electricity (pump) only when the temperature in the room drops below a predetermined limit.

How to choose a boiler for closed heating

The scheme of closed heat supply of a private house provides for the use of any type of fuel. It can be gas (the most efficient and profitable option), electricity, diesel or solid fuel.

It is necessary to pay attention to the power of the boiler. The approximate value for an insulated room with ceilings up to 3 meters high is 1 kW per 10 "squares" of a private house.

The figure above is very, very approximate. It all depends on many factors: the material from which the building is built, the quality of the insulation, the presence (absence) of a heated attic or attic. The efficiency of heating is affected by the number of windows and how well they were installed. Therefore, a competent thermal calculation is required, which a qualified engineer can do.

The heating boiler can be single-circuit, double-circuit or with a boiler. As practice shows, in general country houses have a small area and, consequently, a small need for hot water. From this point of view the best choice there will be a double-circuit boiler (its installation is simple), capable of heating about 10 liters of water to + 30C in half an hour. A boiler with a storage boiler is more comfortable - it constantly “has” ready-made several tens of liters hot water– no permanent filling required.

Expansion tank for closed type heating

Most often, in the heating system of a private house, water plays the role of a coolant. As the temperature increases, the volume increases and the pressure increases. If a closed heat supply scheme is used, then the pressure can overcome a certain critical value and then the elements of the heating system will be destroyed.

To avoid such a development of events, the installation of a heating system for a private house involves the use of an expansion tank.

Features of the design of the tank of a closed type

Any tank of this type has two main parts: a body made of metal and an elastic membrane inside.

The scheme of its operation is quite simple - air is pumped into the upper half of the tank (in expensive modifications - inert gas), the lower part is filled with water from the pipeline.

When the coolant is heated, the pressure rises, while the membrane “bends”, condensing air or an inert gas. To prevent dangerous situations, there are safety valves. When the pipeline with water cools down, the air pressure on the membrane becomes stronger than the coolant pressure, and it fills the heating system. The expansion tank is installed next to the heating boiler. Membranes are of 2 types.

• Fixed - tightly fixed around the perimeter of the expander. Such devices can be found in the tanks of the heating system of a private house or a small enterprise.
  

  These membranes will last a long time if you follow the recommendations for use. In the event of a rupture, it is impossible to change such a membrane - you will have to change the entire tank;

• Replaceable - they are made in the form of rubber pears, balls that must be filled with water. The installation of such a membrane is carried out on the tank flange. If a rupture occurs, then you can replace the damaged membrane with a new one with your own hands, without involving specialists.

When planning a heating scheme, it is important to first of all calculate the power of the heating boiler, take into account the number of radiators and the length of the pipeline.

Careful planning and calculation of the water heating system, and the installation carried out in accordance with the obtained data, will help you achieve productive, economical and efficient heating.

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