Closed water heating. Closed heating in a private house. Filling the heating system: video

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The heating system is a whole complex of devices that are combined into a single circuit using a pipeline. The work of heating in this case consists in the constant movement of the coolant (as a rule, liquid). As the heat carrier heats up, it expands, and an expansion tank is used in a closed heating system to neutralize this phenomenon. These devices are divided into two types, and it depends on them whether the system will be closed or open. A closed heating system implies the presence of a tank that is not in contact with the environment, but in an open heating system, the tank interacts with air.

For the circulation of the coolant in closed heating systems, pumps are used that ensure the constant movement of liquid at a sufficient level. The use of pumps allows a closed system to work much more efficiently by varying the speed of movement of the coolant (read: "").

Forced circulation is also good because additional circuits with connected heating devices can be connected to such a system. Of course, such systems become volatile, since the pumps require electricity to operate, but this disadvantage is compensated for by the high efficiency of the entire structure.

The pumps in a closed heating system are mounted on the return pipe directly before the boiler. An expansion tank can be placed in the same place. A closed heating system has a number of advantages, which become obvious when compared with other types of heating systems: the installation of the system is carried out without much difficulty, since there is no need to maintain a constant slope. The pipeline does not require insulation, and the pipeline itself can be made thinner, which will affect not only its aesthetic qualities, but also the cost of the structure.

In a closed heating system, the coolant cannot evaporate, so you will have to monitor its level much less often. In addition, the use of circulation pumps provides accelerated heating of the premises, and if thermostats are installed in the circuit, it becomes possible to fine-tune the temperature regime throughout the house.

Elements of a closed-loop heating system

The circuit of a closed heating system contains a large number of elements:

boiler;
membrane expansion tank;
circulation pump;
heating devices;
pipes for laying the circuit, installing risers and connections;
fitting;
cranes;
filters;
fasteners.

The principle of operation of a closed heating system

In the boiler, the coolant is heated, after which it is carried through the heating devices through the pipeline. When the coolant fills the entire space of the circuit, an expansion tank is connected to work, containing the excess liquid. The membrane expansion tank consists of two cavities: excess coolant enters one of them, and the second part is filled with gas or air. Read also: "".

When installed in a closed heating system, pressure is created, which subsequently sets the pressure for the entire circuit. Heating the coolant provokes an increase in pressure in the system, and its excess, together with the pressure that has arisen, enters the tank, bending the membrane located in it. The further path of the coolant runs through the circulation pump, and the system continues to operate normally.

Features of the circuit of a closed heating system

In a closed heating system with forced circulation, there are several features:

The possibility of installing an expansion tank and a circulation pump next to the heating boiler, which reduces pipe costs and simplifies installation of the entire system.
The complete tightness of the tank leads to the fact that the coolant cannot evaporate from the system, and the pipeline itself is reliably protected from air ingress.
Install the expansion tank and pump on the return pipe. Operation of the pump is possible only when a liquid at a low temperature passes through it.
Compared to an open heating system, a closed one can be located in rooms of any size.

Pros and cons of a closed heating system

The scheme of a closed heating system, in which the movement of the coolant is carried out forcibly, has its advantages and disadvantages. There are fewer negative points, but in some cases they are decisive. There is a dependent and independent heating system, from which you need to choose a system that is optimal for your case.

Advantages of a closed heating system:

high efficiency;
inability to evaporate liquid;
use of pipes of reduced diameter;
increasing the service life of the boiler due to the temperature difference on the supply and return circuits;
reducing the corrosive effect on the pipeline;
the possibility of using antifreeze.

Disadvantages of a closed heating system:

dependence on electricity, especially in regions where power outages are not uncommon;
the need to install a more complex, roomy and expensive expansion tank.

Conversion of an open system to a closed one

A closed-loop heating system with natural circulation of the coolant is used quite rarely, but exclusively because of its characteristics. What features are we talking about, and how is the transition from one type of system to another carried out? When installing an open heating system, the thought of switching to a closed system does not come up often, but it is quite simple to do this - just install a membrane expansion tank, and the structure will immediately become closed.

Of course, it is always possible to design such a scheme, but it will have some disadvantages of the two types of systems. To ensure the natural movement of the coolant, the pipeline must be laid with a constant slope, which often leads to the appearance of air locks and significantly complicates the installation.

What are the advantages of this design? In this case, independence from electricity is the only plus, but its necessity can be questioned: as a rule, electricity is always available in most houses. The cost of the pump and the operating costs associated with its use are relatively low, so a classic closed circuit is still much better than an open circuit.

Heating system installation

Before the installation of the heating system, a project is drawn up, according to which all elements will be installed. In order for the selected scheme to justify itself, it is necessary to correctly select the devices that will work in the circuit, and it is worth starting with the choice of a heating boiler. When choosing a boiler, you need to build on the type of boiler, depending on the fuel used and its power.

In recent years, solid fuel boilers have become widespread, which practically do not require operating costs, but you can choose another option from among those on the market.

How is system capacity calculated? When carrying out averaged calculations, the ratio of 1 kW of power per 10 square meters of room is usually taken. Having chosen a suitable boiler, you can start calculating heating devices. The best option are radiators, the characteristics of which are individual, but there are usually few differences in them, so you can choose the right devices based on personal preferences. In addition to the boiler and heating devices, other elements will also be required, and the installation of the system must also be included in the calculations.

The approximate cost of the construction can range from 4,000 to 4,500 thousand dollars, but if you wish, you can find options that are cheaper or more expensive. It is important to remember that a too cheap design may not provide the house with the necessary amount of heat, and overly expensive options often do not meet the expectations.

Conclusion

What conclusions can be drawn from all of the above? A closed-loop heating system with forced circulation is quite reliable and durable, and such a structure will serve the house for many years. If necessary, you can use natural circulation in a closed circuit, but this option will create some inconveniences that could well be dispensed with.

An open heating system is the simplest and most non-volatile natural circulation system. Such a system is based on the laws of thermodynamics. At the outlet of the boiler, an increased pressure is created, then hot water passes through the pipes to an area with a lower pressure, losing temperature during its passage.

Then the cooled heat carrier returns back to the heating boiler, where it heats up again. There is a natural circulation of the coolant. The system operates exclusively on water, since the use of antifreeze for heating leads to their rapid evaporation.

In an open heat supply system, an expansion tank is required, since the heated water expands. The expansion tank is used to receive excess water during expansion and return it to the system when it cools down, as well as to remove water in case of an excessive volume. The tank is not completely sealed, therefore water evaporates as a result of which it is necessary to constantly renew its level. An open heating system does not use a pump. The system is pretty simple. Consists of pipes, steel expansion tank, radiators and boiler. Diesel, gas and solid fuel boilers are used, except for electric ones.

In an open heating system, water circulates slowly. Therefore, the pipes during operation must warm up gradually to avoid damaging them and boiling the coolant. This can lead to premature wear of the equipment. If heating is not used in winter, then the water from the system must be drained, in order to avoid freezing of the pipeline.

In order for the circulation of the coolant to be carried out at the required level, it is necessary to install the heating boiler in a lower place in the system, and in the highest place to install expansion tank, for example, in the attic. In winter, the expansion tank must be insulated. When installing the pipeline in an open heating system, it is required to use a minimum number of turns, shaped and connecting parts.

In a closed heating system, all elements of the system are sealed, there is no water evaporation. The circulation is carried out using a pump. The so-called system forced circulation the coolant includes pipes, a boiler, radiators, an expansion tank, a circulation pump.

In a closed heating system, when the temperature rises, the expansion tank valve opens and takes in the excess coolant. When the temperature drops the circulating pump pumps it back into the system. In this heating system, the pressure is maintained within predetermined limits. Thanks to this, coolant deaeration function.

For the stable operation of the closed heating system, an expansion tank made of high-strength metal is also used. This is a closed tank, consisting of two halves, sealed towards each other.

Inside there is a membrane (diaphragm) made of high-strength heat-resistant rubber. Also inside there is a small gas volume (can be nitrogen, which is pumped in at the manufacturing plant, or air, which accumulates in the system as needed). The membrane divides the tank into parts: one part - where excess water flows when the heating system is heated, in the other part there is nitrogen or air that does not come into direct contact with water. Thus, heating medium enters the expansion tank and penetrates the membrane. When the coolant cools down, the gas behind the membrane begins to push it back into the system.

Differences between open and closed heating systems

There are the following distinctive features of open and closed heating systems:

At the location of the expansion tank.In an open heating system, the tank is located at the highest point in the system, and in a closed system, the expansion tank can be installed anywhere, even next to the boiler.
The closed heating system is isolated from atmospheric currents, which prevents air from entering. it increases service life. By creating additional pressure in the upper nodes of the system, the possibility of air congestionin the radiators located at the top.
An open heating system uses pipes with a large diameter, which creates inconvenience, and the installation of pipes is carried out at an angle to ensure circulation. It is not always possible to hide thick-walled pipes. To ensure everyone hydraulics rules it is necessary to take into account the slopes of the flow distribution, the lifting height, turns, narrowing, connection to radiators.
In a closed heating system, pipes of a smaller diameter are used, which reduces the cost of construction.
Also in a closed heating system it is important install the pump correctly, to avoid noise.

Benefits of an open heating system

easy system maintenance;
the absence of a pump ensures silent operation;
uniform heating of the heated room;
quick start and stop of the system;
independence from power supply, if there is no electricity in the house, the system will be operational;
high reliability;
no special skills are required to install the system, first of all, the boiler is installed, the boiler power will depend on the heated area.

Disadvantages of an open heating system

the possibility of reducing the service life of the system when air enters, since heat transfer decreases, as a result of which corrosion appears, water circulation is disturbed, air plugs are formed;
air contained in an open heating system can cause cavitation, in which system elements located in the cavitation zone, such as fittings, pipe surfaces, are destroyed;
possibility of freezing coolant in the expansion tank;
slow heating systems after switching on;
is necessary constant level control coolant in the expansion tank to prevent evaporation;
inability to use antifreeze as a coolant;
bulky enough;
low efficiency.

Advantages of a closed heating system

easy installation;
there is no need to constantly monitor the level of the coolant;
possibility the use of antifreezewithout fear of defrosting the heating system;
by increasing or decreasing the amount of coolant supplied to the system, you can regulate temperature in room;
due to the lack of evaporation of water, the need to recharge it from external sources is reduced;
independent pressure regulation;
the system is economical and technological, has a longer service life;
the ability to connect additional heating sources to a closed heating system.

Disadvantages of a closed heating system

the main drawback is the dependence of the system on the availability constant power supply;
the pump requires electricity;
for emergency power supply, it is recommended to purchase a small generator;
if the tightness of the joints is broken, air may enter the system;
the dimensions of the expansion membrane tanks in closed rooms of a large area;
the tank is 60-30% filled with liquid, the smallest percentage of filling falls on large tanks, at large facilities tanks with an estimated volume of several thousand liters are used.
there is a problem with the placement of such tanks, special installations are used to maintain a certain pressure.

Everyone who is going to install a heating system chooses which system is easier and more reliable for him.

Open heating system thanks to ease of use, high reliability, used for optimal heating small rooms. These can be small one-story country houses, as well as country houses.

A closed heating system is more modern and more complex. It is used in multi-storey buildings and cottages.

Water heating in an individual residential building consists of a boiler and radiators connected by pipes. The water heats up in the boiler, moves through the pipes to the radiators, gives off heat in the radiators and enters the boiler again.

Central heating is arranged like autonomous. The difference is that a central boiler house or CHP plant heats many houses.

The terms "closed system" and "open system" are used to characterize autonomous heating and central heating, but differ in meaning:

In autonomous heating systems, open systems are called systems that communicate with the atmosphere through an expansion vessel. Systems that have no communication with the atmosphere are called closed.
In houses with central heating, an open system is called a system where hot water to the taps is supplied directly from the heating system. And closed, when the hot water entering the house heats the tap water in the heat exchanger.

Autonomous heating systems

The water, which is filled with the boiler, pipes and radiators, expands when heated. The pressure inside rises sharply. If you do not provide for the possibility of removing the additional volume of water, then the system will rupture. Compensation for changes in water volumes with temperature changes occurs in expansion vessels. As the temperature rises, excess water moves into the expansion vessel. As the temperature decreases, the system is replenished with water from the expansion vessel.

Open system permanently connected to the atmosphere through an open expansion vessel. The vessel is made in the form of a rectangular or round tank. The form does not matter. It is important that it has sufficient capacity to accommodate the additional volume of water resulting from the thermal expansion of the circulating water. The expansion vessel is located in the highest part of the heating system. The vessel is connected to the heating system by a pipe called a riser. The riser is attached to the bottom of the tank - to the bottom or side wall. A drain pipe is connected at the top of the expansion tank. It is discharged into the sewer or outside the building. A drain pipe is needed in case the tank is overfilled. It also provides a permanent connection of the tank and the heating system to the atmosphere. If the system is filled with water manually with buckets, the tank is additionally equipped with a lid or hatch. If the tank capacity is selected correctly, the water level in the tank is checked before turning on the heating. The water pressure in an "open system" is equal to atmospheric pressure and does not change when the temperature of the water that circulates in the system changes. A pressure build-up safety device is not required.
Closed system isolated from the atmosphere. The expansion vessel is sealed. The shape of the vessel is chosen so that it can withstand the greatest pressure with a minimum wall thickness. There is a rubber membrane inside the vessel that divides it into two parts. One part is filled with air, the other part is connected to the heating system. The expansion vessel can be installed anywhere in the system. As the water temperature rises, the excess enters the expansion vessel. Air or gas in the other half of the membrane is compressed. As the temperature drops, the pressure in the system decreases, water from the expansion vessel is forced out of the expansion vessel by the compressed air into the system. In a closed system, the pressure is higher than in an open system and constantly changes depending on the temperature of the circulating water. In addition, a closed system is necessarily equipped with a safety valve in case of a dangerous increase in pressure and an air release device.

District heating

Central heating water is heated in a central boiler room or CHP. This is where the compensation of the expansion of water with temperature changes takes place. Next, hot water is pumped into the heating network by a circulation pump. Houses are connected to the heating network with two pipelines - direct and reverse. Having entered the house through a direct pipeline, the water is divided in two directions - for heating and for hot water supply.

Open system... The water goes directly to hot water taps and is discharged into the sewer after use. An "open system" is simpler than a closed one, but in central boiler houses and CHP plants it is necessary to carry out additional water treatment - purification and air removal. For residents, this water is more expensive than tap water, and its quality is lower.
Closed system.The water passes through the boiler, giving off heat to heating tap water, connecting to the heating return water and returning to the heating network. The heated tap water flows to the hot water taps. A closed system, due to the use of heat exchangers, is more difficult than an open one, but tap water is not subjected to additional processing, but only heats up.

A hot water heating system, which uses a membrane expansion tank and the heat carrier does not in any way come into contact with atmospheric air, is considered closed and operates under pressure. This scheme is the most common at the moment, as it has many advantages. In this article we will analyze what a closed heating system of a private house is, its pros and cons, as well as service features.

What is a closed heating system?

An important feature of such a system is the absence of contact with the outside air and the presence of a slight overpressure. As a rule, the scheme works with artificial induction of the circulation of the coolant using a pump. This allows you not to worry about compliance with large slopes of the main lines, as well as accept smaller pipe diameters and lay them in the most convenient way.

As a rule, a gravitational heating system with natural circulation of the coolant is made with an open expansion vessel installed at the highest point. A closed system is traditionally supplied with a circulation pump, which increases its efficiency and reduces material consumption.

Due to their features, closed-type systems have a lot of advantages:

the coolant under pressure heats up faster;
the probability of airing the network of pipelines and radiators is very low;
the coolant is not saturated with oxygen and does not evaporate into the atmosphere, which is very important when filling the system with antifreeze;
installation of an expansion tank in a closed heating system is carried out on the return pipe near the boiler, which is very convenient in terms of maintenance;
there is no need to use large-diameter pipelines and lay them in plain sight, in this regard, a closed system with forced circulation is the best choice for a private house.

There is only one significant drawback - the dependence on the reliability of the power supply, a closed heating system without a pump powered by the mains will not work. Fortunately, circulating units for individual systems have low power consumption, and therefore, during a power outage, they will be able to operate from an uninterruptible power supply for a long time.

Some experts argue that a closed system with natural circulation will help solve the problem of power outages. Recall that in this case, the movement of the coolant occurs due to the difference in density and mass of hot and cooled water. The first, heating up in the boiler, as a lighter one, is displaced upward by a cooled coolant with a large mass coming from the radiators.

Despite the fact that the pressure in a closed heating system (1.5-2 bar) does not impede the gravitational movement of hot and cold water flows, its efficiency is highly questionable. The fact is that the difference in convective forces is already small, and here you still need to overcome the resistance of the tank membrane, which stretches when the water expands. In order not to get involved with these slippery moments, it is always better to install a pump on a closed system. If there is a need to mount a gravity circuit, then it must be made open.

Closed heating system diagram

In private housing construction, 2 types of schemes are traditionally used:

one-pipe;
two-pipe.

One-pipe, better known as "Leningrad", works satisfactorily in one- and two-story houses of a small area, when no more than 5 radiators are installed on each floor. The implementation of the scheme requires an accurate calculation of the pipe diameters and the number of battery sections, since the coolant cools down significantly after passing through each subsequent radiator. A one-pipe diagram of a closed-type heating system with top wiring also needs to comply with these requirements, which is shown in the figure below:

Note. Regardless of the type of circuit chosen, a closed system must contain a security group, sometimes it comes with a boiler. The group consists of a pressure gauge for pressure control, an air vent and a safety valve for emergency water discharge. The unit is installed on the supply pipe leaving the boiler, and without any shut-off valves.

The two-pipe scheme of a closed system is easier to calculate and install, it is famous for its popularity due to its good performance. After all, the coolant is delivered to all radiators at the same temperature, and when implementing a passing scheme, it also travels the same distance. An example of a two-pipe system is shown in the figure:

Some additions have a closed heating system with a solid fuel boiler. To avoid the formation of condensation in the furnace of the heat generator, the circuit is supplemented with a mixing unit with a three-way valve and a bypass line. The valve forces the water to circulate through the bypass until it heats up to the set temperature, and only then starts the coolant from the main into the boiler.

How to fill the system with coolant?

When the make-up connection is connected to the water supply network by means of a ball valve, it is quite simple to fill the closed-type heating system with a coolant. For this business, it makes sense to involve an assistant, especially if the house has several floors. One person operates the make-up tap, and the second is engaged in bleeding air from the batteries. The tap opens about a third so that the pressure is not strong.

A person in the boiler room monitors the pressure gauge readings, the feed of the closed heating system is closed when the pressure reaches 2 bar. Now the assistant, using Mayevsky's taps, bleeds air from the radiators, after which the pressure drops. The goal is to reach the design pressure by removing all air from the pipelines by gradually displacing it with tap water.

It is more difficult to pump the coolant into a closed system when there is no make-up from the water supply or an anti-freeze liquid needs to be filled. To do this, you will need a special manual or electric pump and a container for the coolant, from which it will be pumped into the system. First, you must open all the air taps on the radiators, and then fill the pipes through the drain fitting by connecting a pump with a check valve to it.

As the fluid is pumped, it is necessary to close the Mayevsky taps, from which the coolant will flow. Having pumped up the system to 1.5 bar, it is necessary to remove air, after which the pressure is brought to the working one. At the end, a test run of the boiler is carried out and the pressure is adjusted, and if necessary, air is vented.

Why does the pressure drop in a closed heating system?

There is only one reason why the pressure drops - the lack of tightness, that is, a leak. The question is to find it. A characteristic sign of a leak is a puddle in a certain place or a brown spot when the water has time to dry. In the search process, you should inspect the following nodes and elements:

pipe connections and fittings: it happens that cracks appear in the latter;
automatic air vents: a faulty element with a stuck float will leak water;
shut-off and control valves, safety valve;
expansion tank: a crack in the membrane will cause a drop in pressure, air in the system and frequent shutdowns of the boiler.

To eliminate the leak, you cannot do without partial or complete emptying of the pipelines. At the end of the work, you will have to pour water into the system again, create the necessary pressure and monitor the pressure gauge for several days.

Conclusion

A closed heating system has a lot of advantages, hence its popularity. If installation and commissioning is done correctly, then it does not require intervention in its work for a long time. Most of the malfunctions that occur can be safely eliminated by hand, as well as system maintenance. It is advisable to check the functionality of such items as air vents, valves and expansion tank annually.

The level of comfort in a home is determined by an efficient heating system. Correct 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 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 thermal 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 is required in it. The pressure allows water to circulate and increases the efficiency of the structure. When moving, the coolant overcomes frictional 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. Heated water has less mass, so it is displaced by heavier chilled water. This principle of operation is applied when constructing 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 movement along the contour. To increase the service life of the 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. Moreover, the design has the following advantages:

It is possible to heat houses with a large area, since there is no limitation on the length of the highway.
New schemes and modern types of heating are used.
Heat transfer increases.
There is no evaporation loss of the coolant.
The diameter of the pipes is reduced, which saves money on their purchase and installation.
The temperature difference decreases, which facilitates the operating conditions of the heating equipment and relieves the system.
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 allow achieving 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 designs include:

Installation of a closed circuit is fraught with certain difficulties.
The heat generator works continuously.

If a long break in the operation of the system is expected in the cold season, then the coolant must be drained. This disadvantage is eliminated by using non-freezing liquids as a heat carrier.

Closed heating system

Features of a closed heating system

A closed heating system has a number of features. You can mount it by creating a top or bottom routing. The first scheme differs in that the coolant moves to the attic, and the water is distributed along the risers to the heating devices. When using the second scheme, the coolant is supplied from the bottom of the basement, where the boiler equipment is located. It is immediately directed to the supply pipeline, and from it to the radiators. If in an open circuit the expansion tank is placed at a point with a maximum height, then in a closed one it can be assembled in the immediate vicinity of the boiler or in any other convenient place.

The installation of the system can provide for a one- or two-pipe method of connecting heating devices to the mains. The two-pipe connection is characterized by the presence of a riser that leads 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.

System wiring

The single-pipe scheme is simpler in execution, which has the following features:

After the release of heat, the water returns to the riser, which supplies and is transferred to the next heater. As a result of this, the heat carrier of different temperatures moves in it. This circumstance requires an increase in the heat exchange area to achieve the required temperature level.
The use is limited to structures of houses that have an attic space.
There is no phased launch option.

Equipment

When creating a one-pipe system, use:

flow-through scheme, in which there is a sequential movement of the coolant through the radiators. In this case, you cannot regulate the heat flow in the room;
circuit with closing sections. It is designed in such a way that a crane is installed in front of each radiator, with the help of which the heat flow is regulated.

Depending on the method of installing 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 single-storey buildings when all appliances are located at the same level and connected to a horizontal pipe. This design significantly reduces the need for materials, but during operation, air locks can occur.

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 a different length of the pipeline. The second option has the same circuit design and constant pressure level.

Heating circuit elements

The structural elements of a closed heating system include:

boiler;
pump equipment;
expansion tank;
heating devices.

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

Equipment adjustment, heating devices

Boiler equipment provides heating of the coolant to the required temperature. Solid or gaseous fuels are used more often, with gas being the cheapest and most readily available.

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

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

To extend the life of the reservoir, avoid significant pressure drops, especially during start-up.

The use of a circulating pump equipped with electronic regulation of work reduces energy consumption by 40%. Such equipment provides a low noise level and has a long service life. The main indicators when choosing a pump are: power, the period covered by the factory warranty, and the length 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 of the structural elements of the system, the type of boiler equipment, and the availability of automation.

The closed-type heating system circuit 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 are able to operate at pressures up to 10 atm at temperatures over 100 degrees Celsius. However, steel pipes are prone to corrosion, which reduces their service life.

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

With metal-plastic, you can work at temperatures up to 90 degrees Celsius. The assembly is simple and does not require complex tools. But the fittings are expensive. Such pipes are not allowed in central heating.

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

Conversion of an open system to a closed one

A closed-type heating system is rarely found, the circulation of the coolant of which occurs in a natural way: 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. This transformation occurs when the conventional expansion tank is removed and replaced with a structure equipped with a membrane.

The design and installation of such a system is not excluded from the outset. 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 becomes the cause of airing.

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

Heating system installation: step by step instructions

In the course of drawing up a project, you need to select a boiler and decide on how to create a 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 the work will be carried out.

The boiler is mounted on a site prepared in advance.

Places for placing heating devices and highway routes are marked.

A pipeline is laid that starts from the boiler and leads to the radiators.

Carry out the installation of all equipment.

The system is sealed and filled with a coolant.

A test run is carried out.