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Advantages and disadvantages of a single-pipe heating system. Two-pipe water heating system: varieties and installation

Among the countless wiring options heating systems the most common scheme is two-pipe system heating with lower wiring and forced circulation of the coolant. It can be assembled independently, provided that it is designed and calculated correctly. But not every homeowner understands these issues, and even if it is decided to hire specialists for design and installation, their work must be checked. This is possible only if you figure out what a two-pipe heating system of a private house is and how to install it correctly. Our article is just to help such homeowners.

Types of two-pipe heating systems

Our topic is entirely devoted to these systems, since they have a number of advantages over single-pipe ones. It makes no sense to list them all, it is worth noting only the main thing: a two-pipe system works in such a way that a coolant of almost the same temperature enters all radiators.

The word "almost" means that there are exceptions to this rule, these are circuits assembled from steel, copper and stainless corrugated pipes that are not covered with a heat-insulating layer.

The fact is that the heating system of a private house, made by hand from non-insulated metal pipes, will give off heat to the premises not only through radiators. The metal has a high thermal conductivity, so the coolant flowing in such a line will cool slightly as it moves away from the boiler. Although the temperature drop compared to single-pipe wiring is insignificant, it still needs to be taken into account.

Note. Many supporters of single-pipe schemes such as Leningradka say that they are cheaper, since the material will take half as much. But at the same time, they forget about the drop in water temperature, as a result of which it is necessary to increase the capacity of the radiators, that is, add sections. These are additional funds, and considerable ones.

According to the orientation of the risers in space, vertical and horizontal types of systems are distinguished, and they can have an upper, lower and combined wiring. At vertical pattern the building has one or more risers, powered by a heat source located in the basement or first floor. Radiators are connected directly to vertical risers, as shown in the figure:

This is a circuit with a lower wiring, since the main pipelines supply the coolant to the risers from below. The vertical system with top filling implies their laying from above, in the combined version, only the supply horizontal collector runs under the ceiling, and the return one - from below. Usually, the lines laid from above are placed in the attic space, and in its absence, under the ceiling of the last floor. Which is not very good in terms of aesthetics.

Horizontal systems

This is a closed two-pipe system in which horizontal branches are laid instead of vertical risers, and a certain number of heating devices are connected to them. As in the previous case, branches can have top, bottom and combined wiring, only now this happens within the same floor, as shown in the diagrams:

As can be seen in the figure, the system top wiring requires laying pipes under the ceiling of the premises or in the attic and will fit into the interior with difficulty, not to mention the consumption of materials. For these reasons, the scheme is used infrequently, for example, for heating basements or when the boiler room is located on the roof of a building. But if the circulation pump is correctly selected and the system is set up, then it is better to let it go down from the roof boiler pipe, any homeowner will agree with this.

Combined wiring is indispensable when you need to install a two-pipe gravity system, where the coolant moves naturally due to convection. Such schemes are still relevant in areas with unreliable power supply and in houses of small area and number of storeys. Its disadvantages are that many pipes of large diameter pass through all the rooms, it is very difficult to hide them. Plus the high material consumption of the project.

And finally, a horizontal system with a lower wiring. It is no coincidence that it is the most popular, because the scheme combines a lot of advantages and has almost no drawbacks. The connections to the radiators are short, the pipes can always be hidden behind a decorative screen or cast into a floor screed. At the same time, the consumption of materials is acceptable, and from the point of view of work efficiency, it is difficult to find a better option. Especially when a more advanced associated system is used, as shown in the diagram below:

Its main advantage is that the water in the supply and return pipes runs the same distance and flows in the same direction. Therefore, hydraulically, this is the most stable and reliable scheme, provided that all calculations are carried out correctly and installation features are taken into account. By the way, the nuances of systems with a passing movement of the coolant lie in the complexity of the arrangement of ring circuits. Pipes often need to cross doorways and other obstacles, which can increase the cost of the project.

Output. For a private house, the best option is a two-pipe horizontal heating system with a lower wiring, but only in conjunction with artificial circulation of the coolant. If it is required to ensure non-volatile operation of thermal equipment and networks, then it is recommended to take one of the combined gravity systems - horizontal or vertical. The latter will be appropriate in a house with two floors.

Forced circulation heating system

So, the wiring diagram is selected, further actions the following:

  • draw it in the form of a sketch, or even better - a three-dimensional model (axonometry);
  • calculate and select pipe diameters in all branches and sections;
  • pick up all the necessary elements of a two-pipe system: batteries, pump, expansion tank, filter, fittings and other parts of the boiler and radiator piping;
  • purchase equipment and materials, perform installation work;
  • test, balance (if necessary) and put the system into operation.

On the sketch in the form of an axonometric view, it is necessary to draw lines, arrange radiators and valves, put down elevation marks, taking the surface of the first floor screed as a reference point. Subsequently, after completing the calculation, it will be necessary to put down the dimensions and sections of the pipes on the drawing. An example of how a two-pipe system with forced circulation is installed is shown in the drawing:

Important. The finished sketch will allow you to better understand all the nuances of the future system, up to the number and types of fittings made of polypropylene, metal-plastic or other material. It is especially convenient when a house plan is attached to a three-dimensional image.

Selection of pipe diameter

This calculation consists in determining the flow rate of the coolant from the thermal power necessary for heating the room, and from it the diameter of the pipes for a two-pipe heating system. In simple words, the flow section of the pipe should be enough to deliver the right amount of heat to each room, along with hot water.

Note. By default, it is assumed that the calculation of the heat losses of the building has already been completed and the amount of heat for all rooms is known.

To carry out the selection of the diameter of the pipes, they begin from the very end of the system, from the last battery. First, the coolant flow rate for heating this room is calculated according to the formula:

G = 3600Q/(c∆t), where:

  • G - desired flow hot water per room, kg/h;
  • Q - the amount of heat for heating this room, kW;
  • c is the heat capacity of water, taken as 4.187 kJ/kg ºС;
  • Δt - the calculated temperature difference in the supply and return manifolds, usually take 20 ºС.

For example, 3 kW of heat is needed to heat a room. Then the flow rate of the coolant will be equal to:

3600 x 3 / 4.187 x 20 = 129 kg / h, in volume it will be 0.127 m3 / h.

To balance a two-pipe water heating system initially, it is necessary to choose the diameter as accurately as possible. Based on the volumetric flow, we find the flow area using the formula:

S=GV/3600v, where:

  • S - area cross section pipes, m2;
  • GV is the volumetric flow rate of the coolant, m3/h;
  • v is the water flow velocity, taken in the range from 0.3 to 0.7 m/s.

Note. If the heating system one-story house- gravitational, then the minimum speed should be taken - 0.3 m / s.

In our example, let's take a speed of 0.5 m / s, find the cross section and, using the formula for the area of ​​​​a circle - the diameter, it will be equal to 0.1 m. The polypropylene pipe closest in assortment has inner size 15 mm, and put it on the drawing. By the way, connecting radiators to a two-pipe system is usually carried out with just such a pipe - 15 mm. Next, go to the next room, count and summarize with the previous result, and so on until the boiler itself.

Connecting radiators to a two-pipe system

Installed batteries are connected to the lines during installation, correct connection heating radiators with a two-pipe system - it is lateral or diagonal. Everything existing methods shown in the picture:

What temperature balance does the bottom connection of the radiator to a two-pipe system lead to is well illustrated by the figures:

Batteries used in a vertical circuit usually have a side connection (method No. 3). In horizontal systems, it is most preferable diagonal pattern connection (method No. 1), due to this, the maximum heat transfer of the heater is achieved, which is shown below in the image:

Balancing

The meaning of this operation is to balance all branches of the system and regulate the flow of water in each of them. To do this, each branch must be correctly connected to the mains, that is, special balancing valves must be installed on the sidebar. Also, control valves or thermostatic valves are installed on the connections to all radiators.

It is not so easy to carry out precise balancing with your own hands, you need to have the appropriate instruments (at least a pressure gauge to measure the pressure drop across the balance valve) and perform pressure loss calculations. If none of this is present, then after testing it is necessary to fill the system, bleed air and turn on the boiler. Further, the balancing of the two-pipe system is done by touch, according to the degree of heating of all batteries. Appliances located near the heat generator must be “pressed” so that more heat goes to the distant ones. The same is true for entire branches of the system.

Conclusion

It is noteworthy that it is much easier to install a two-pipe heating system than to develop it, calculate it, and then balance it. So this stage you can go through on your own, and it is advisable to coordinate all the rest with specialists.

The heating system of a private house is an obligatory and integral part of housing in the Russian Federation, the territory of which is located mainly in cold climate zone. Regardless of the type of heat generator (gas, electric, solid and liquid fuel boilers), heat sources (radiators, registers or batteries) are installed in the house, and the two-pipe heating system is by far the most popular and preferred due to its efficiency and high efficiency. Although the single-pipe circuit is simpler and cheaper to install, it is less efficient, since it does not have the ability to regulate heat transfer in each room and for each heating device, whether it be a battery, a radiator or a home-made pipe register.

Varieties of double-circuit wiring of the coolant

The main advantage that a two-pipe heating scheme provides is a very high heat transfer efficiency, so even double the cost of pipes, in comparison with a single-pipe network, is justified many times over. What explains this? The pipes in this scheme are used with a small diameter - the main source of heat is the radiator - and due to significant savings on materials, it turns out to cut the estimate. You also need to purchase much less fittings, valves and other fittings. The entire assembly of the system is easily done by hand.

Equipment in a private house of two-pipe heating is warmth, coziness, comfort and quality of the heating method used. The arrangement itself according to the two-pipe scheme is the supply of two pipes to each radiator: one is supplied with a hot coolant, the other is discharged. The supply is connected to all radiators in parallel, and a shut-off valve is cut in front of each heat source to regulate heat exchange, carry out preventive maintenance or repair the system without a general shutdown.

For the installation of piping in a two-pipe scheme, you will need to purchase the following materials:

  1. heating boiler, expansion tank and a circulation pump (if it is not already installed in the boiler);
  2. Heating radiators or batteries, safety valve, manometer;
  3. Cleaning reagents, fittings (quantity and functionality is determined based on the project or scheme), air outlet devices (Maevsky taps, valves);
  4. Metal-plastic or PVC pipes.

And these tools:

  1. Impact type electric drill and screwdriver;
  2. Apparatus for welding and electrodes with a diameter of 3-4 mm;
  3. Keys - adjustable and gas, as well as a tape measure and a hammer;
  4. Plumb and spirit level.

A significant and fundamental difference between heating schemes in the vertical and horizontal planes lies in their wiring. Pipes enclose all batteries in one system, but according to different schemes.

Heating with wiring on top - varieties

Top-mounted home heating systems connect all radiators to a vertical riser that supplies heated coolant to the system. This is a reliable system in operation, since plugs from the air cannot appear in it, but installation and wiring are more expensive than a single-pipe circuit. Such a heating scheme is optimal for a low-rise building or cottage, since each floor can be connected to the boiler with a separate branch.

A two-pipe horizontal connection is relevant for a one-story house. Heat sources are connected to horizontally separated pipes, the connection risers of which are usually mounted in hallways, halls or corridors.

Such a two-pipe heating system, the scheme of which is assembled according to a horizontal type, can have radial (collector) and serial types of radiator connection. With radiant wiring, the coolant is supplied separately to the radiators, and there is no need to regulate the heat supply in each individual heater, since the heat is distributed evenly throughout the system through pipes and batteries. The beam wiring scheme is effective in a one-story building.

The serial wiring solution is based on the total number of pipes, and if there are not many, then this type of connection can also be implemented. With horizontal wiring along the walls, it is difficult to ensure the original intentions of the designer - a large number of pipes will ruin everything. The only solution is to hide all the wiring under the floor or in the walls at the design stage of the house and heating.

There are secrets in the installation and wiring of a two-pipe heating system according to the horizontal type of heating:

  1. This is a long and labor-intensive process;
  2. It is recommended to connect and adjust the entire circuit for each room before the onset of frost;
  3. The correct calculation is heat in the house. Therefore, if you are not sure of your capabilities, contact a specialized company.

The principle of operation of a two-pipe vertical system, according to which the heating of the house is organized, is based on the parallel connection of heating points (batteries or radiators). In such a scheme, the presence of an expansion tank is mandatory, as well as piping along the upper circuit. The hot coolant from the boiler rises through each pipe, falling into all points of the system. The expansion tank is mounted at the top of the heating circuit.

When organizing vertical double-circuit heating, the hot coolant rises under pressure, and then is distributed from top to bottom over heat sources. In the return line, which is laid lower than Bottom part heating batteries, already cold coolant is supplied. Such a scheme promotes the movement of air through the pipes into the expansion tank and its automatic removal.

Bottom wiring diagram

When installing a horizontal system, pipes are bred around the premises in compliance with a certain slope - 5-10 mm per 1 meter of pipe. The cooled coolant from the radiators on the return line enters the pipeline and into the boiler. The difference between this scheme is two main pipelines: one for supplying the coolant, the second for the return supply to the boiler. Hence the common name of the scheme - two-pipe.

The water in the system is replenished either through a connected water supply, or manually - through the neck of the expansion tank. If it is possible to connect water from the water supply, then it is better to connect it to the return pipe so that cold and heated water mix immediately.

The operation of such a scheme differs from the wiring along the top in that the coolant supply pipe cuts into the wiring from below, next to the return pipe, and the heated water and the boiler moves through the pipes and radiators from the bottom up - through the return pipes and radiators back to the boiler. If air locks form in the system, then the air is bled using special valves embedded in each heating device.

A two-circuit system with a lower wiring can have one, two or more circuits, and can also be implemented using the organization of an associated or dead-end circuit. In their homes, the owners rarely use these schemes because of their high cost - air vents are required for each heating device. Also, heating systems made according to these schemes are equipped with a special expansion tank through which the air in the system circulates along with the coolant. Due to this feature of the scheme, it is necessary to bleed the accumulating air masses at least once every 5-7 days. But there is also a big advantage - heating, organized according to such a scheme, can be started even before the construction of the house is completed.

difference dual circuit from a scheme with one circuit is contained in the name itself - when a two-pipe heating system is operating, two pipes are connected to each heater, and the hot coolant is supplied to the radiators through the upper heating pipe, and through the lower one it is discharged to the boiler already cooled down. The scheme for heating a private house in a two-circuit system consists of the following components, parts and elements:

  1. heating boiler;
  2. Balance;
  3. Radiators, registers or radiators;
  4. Shut-off valve and expansion tank;
  5. Cleaning filter;
  6. Pressure gauge and water pump;
  7. Valve.

The expansion vessel is mounted in the highest level of the heating circuit. If water is supplied to the house from an external source and is supplied to the pipeline under some pressure, then the expansion tank can be combined with a supply water supply tank. It is also necessary to observe the slope in the return water supply pipe and the supply - it should be no more than 10 mm per 2 meters of pipe length - too small a slope will not ensure proper movement of the coolant, and the radiators will warm up for a long time. Also, a small slope will contribute to the creation of air congestion. But if the slope is more than acceptable, then the air will also remain in the system, not having time to get to the outlet points.

If an autonomous double-circuit heating circuit is organized in the house with wiring along the upper circuit, then its installation itself can be carried out using different design solutions, depending on where, how and at what height the expansion tank is mounted. The best option can be considered if the expansion tank is located in a heated room, and it will be possible to freely approach it. The upper pipe of the horizontal circuit should run as high as possible - preferably under the ceiling, but in such a way that the expansion tank can also be mounted in the house, and not in the attic.

Most high efficiency a scheme with two circuits can only be if the supply pipe is as long as possible. Even with different sizes of pipes and other elements of the system, the efficiency and efficiency of the system will always be high, since the upper connection point of the heat carrier supply pipe is located at the beginning of the heating main.

Also, the efficiency of the system can be significantly increased by including in the circuit circulation pump. A standard pump with a power of 65-110 watts consumes little electricity, and even with non-stop operation it does not need additional maintenance or preventive maintenance. The presence of a circulation pump increases the speed of movement of the coolant, which means heating the premises. But the installation of heating in a two-pipe scheme with an upper circuit makes the inclusion of a pump in the circuit superfluous and optional.

The heating system is divided into two types: one-pipe and two-pipe. Obviously, it is most advantageous to install a more efficient one that will not only cope with its functions, but will also serve you for more than one year. In order not to remain "out of the blue" and not make a mistake with the choice of the heating system.

You need to properly understand which of the heating systems is best for you and why.

Thus, you will know which system is better from a technical point of view and how to choose it, taking into account your budget.

High water pressure ensures a natural cycle, and antifreeze makes the system more economical.

Disadvantages of a single pipe system - a very complex thermal and hydraulic calculation of the network, since, having made a mistake in the calculations of devices, it is very difficult to eliminate it.

Also, this is a very high hydrodynamic resistance and an involuntary number of heating devices on one line.

The flow of the coolant goes immediately to everything and is not subject to separate adjustment.

In addition, very high heat losses.

In order to be able to regulate the operation of individual devices connected to one riser, bypasses (closing sections) are connected to the network - this is a jumper in the form of a piece of pipe connected by a direct and return radiator pipes, with taps and valves.

To be able to control the temperature of each individually, the bypass allows you to connect automatic thermostats to the radiator.

In addition, it also makes it possible, in the event of a breakdown, to replace or repair individual devices without turning off the entire heating system.

Single-pipe heating is divided into vertical and horizontal:

  • vertical - this is the connection of all batteries in series from top to bottom.
  • horizontal - this is a serial connection of all heating devices on all floors.

Due to the accumulation of air in batteries and pipes, so-called traffic jams occur, which is a disadvantage of both systems.

Installation of a one-pipe system

Connection is made according to the scheme, using valves for airing radiators, which block the valves and plugs.

Crimping system - after which the coolant is poured into the battery and the system adjustment is directly adjusted.

Two-pipe heating system

The advantage of a two-pipe heating system - this is the installation of automatic thermostats, which gives you the full ability to adjust the temperature in individual rooms.

This also includes the independence of the operation of the circuit devices, which is provided by a special collector system.


The difference between a two-pipe and a one-pipe system is that you can connect the first extra batteries already after connecting the main ones, as well as the possibility of extending in vertical and horizontal directions.

Unlike a single-pipe, here you can also easily correct permissible errors.

The disadvantages of this system are minimal if you have enough material resources and have the opportunity to call the master.

Installation of a heating system with lower horizontal piping


This system allows you to locate the open tank in a convenient warm place. Also, it is possible to combine expansion and supply tanks allow you to use hot water directly from the heating system itself.

In systems with forced circulation, to reduce pipe consumption, the discharge and supply risers are located at the level of the first.


According to statistics, over 70% of all residential buildings are heated by water heating. One of its varieties is a two-pipe heating system - this publication is devoted to it.

The article discusses the advantages and disadvantages, diagrams, drawings and recommendations for installing a two-pipe wiring with your own hands.

Article content

Differences between a two-pipe heating system and a one-pipe

Any heating system is a closed circuit through which the coolant circulates. However, unlike a single-pipe network, where water flows to all radiators in turn through the same pipe, a two-pipe system involves dividing the wiring into two lines - supply and return.

The two-pipe heating system of a private house, in comparison with a single-pipe configuration, has the following advantages:



  1. Minimal coolant losses. In a single-pipe system, the radiators are alternately connected to the supply line, as a result of which, passing through the battery, the coolant loses temperature and enters the next radiator partially cooled. With two-pipe configuration, each of the batteries is connected to the supply pipe by a separate outlet. You get the opportunity to install on each of the radiators, which will allow you to regulate the temperature in different rooms at home independently.
  2. Low hydraulic losses. When arranging a system with forced circulation (necessary in large buildings), a two-pipe system requires the installation of a less efficient circulation pump, which allows good savings.
  3. Versatility. A two-pipe heating system can be used in a multi-apartment, one or two-story building.
  4. Maintainability. Shutoff valves can be installed on each branch of the supply pipeline, which makes it possible to cut off the coolant supply and repair damaged pipes or radiators without stopping the entire system.

Among the disadvantages of this configuration, we note a twofold increase in the length of the pipes used, however, this does not threaten a cardinal increase in financial costs, since the diameter of the pipes and fittings used is smaller than in the arrangement of a single-pipe system.

Classification of two-pipe heating

The two-pipe heating system of a private house, depending on the spatial arrangement, is classified into vertical and horizontal. More common is the horizontal configuration, which involves connecting radiators on a floor of a building to a single riser, while in vertical systems, radiators from different floors are connected to a riser.

The use of vertical systems is justified in a two-story building. Although this configuration is more expensive to set up due to the need to use more pipes, with vertical risers, the possibility of air locks inside the radiators is excluded, which increases the reliability of the system as a whole.

Also, a two-pipe heating system is classified according to the direction of movement of the coolant, according to which it can be direct-flow or dead-end. In dead-end systems, the liquid circulates in different directions through the return and supply pipes, while in direct-flow systems, their movement coincides.


Depending on the method of transportation of the coolant, the systems are divided into:

  • with natural circulation;
  • with forced circulation.

Heating with natural circulation can be used in one-story buildings with area up to 150 squares. It does not provide for the installation of additional pumps - the coolant moves due to its own density. characteristic feature systems with natural circulation is the laying of pipes at an angle to the horizontal plane. Their advantage is independence from the availability of electricity, the disadvantage is the inability to adjust the rate of water supply.

In a two-story building, a two-pipe heating system is always carried out with forced circulation. In terms of efficiency, this configuration is more efficient, since you get the opportunity to control the flow and speed of the coolant using a circulation pump, which is installed on the supply pipe leaving the boiler. In heating with forced circulation, pipes of relatively small diameters (up to 20 mm) are used, which are laid without a slope.

Which heating network layout to choose?


Depending on the location of the supply pipeline, two-pipe heating is classified into two varieties - with upper and lower wiring.

The scheme of a two-pipe heating system with an upper wiring involves installation expansion tank and distribution line in highest point heating circuit, above the radiators. Such laying cannot be done in a one-story building with a flat roof, since communications will require an insulated attic or a specially designated room on the second floor of a two-story house to accommodate communications.

A two-pipe heating system with a lower wiring differs from the upper one in that the distributing pipeline in it is located in the basement or in an underground niche, under the radiators. The extreme heating circuit is a return pipe, which is installed 20-30 cm lower than the supply line.

This is a more complex configuration that requires the connection of an upper air pipe, through which excess air will be removed from the radiators. With absence basement additional problems may arise due to the need to install the boiler below the level of the radiators.

Both the lower and upper circuits of a two-pipe heating system can be performed in a horizontal or vertical configuration. However, vertical networks, as a rule, are carried out with a lower wiring. With this installation, there is no need to install a powerful pump for forced circulation, because due to the difference between the temperatures in the return and supply pipes, strong drop pressure, which increases the speed of the coolant. If, due to the peculiarities of the layout of the building, such laying is impossible, a highway with an upper wiring is equipped.

We make a two-pipe system with our own hands (video)

The choice of pipe diameter and the rules for installing a two-pipe network

When installing two-pipe heating, it is extremely important to choose the correct diameter of the pipes, otherwise you can get uneven heating of radiators remote from the boiler. For most boilers for domestic use, the diameter of the supply and return pipes is 25 or 32 mm, which is suitable for a two-pipe configuration. If you have a boiler with 20 mm nozzles, it is better to stop at a single-pipe heating system.

The dimensional grid of polymer pipes on the market consists of diameters of 16, 20, 25 and 32 mm. Do-it-yourself installation of the system is necessary, taking into account the key rule: the first section of the distributing pipe must match the diameter of the boiler nozzles, and each subsequent pipe section after the branch tee to the radiator is one size smaller.

In practice, it looks like this - a diameter of 32 mm comes out of the boiler, a radiator is connected to it through a tee with a pipe of 16 mm, then after the tee the diameter of the supply line decreases to 25 mm, at the next outlet to the radiator of the 16 mm line after the tee the diameter decreases to 20 mm etc. If the number of radiators is greater than the pipe sizes, it is necessary to divide the supply line into two arms.

When installing the system with your own hands, follow these recommendations:

  • the supply and return lines must be parallel to each other;
  • each outlet to the radiator must be equipped with a shut-off valve;
  • distribution tank, if installed in attic when installing a network with an upper wiring, it is necessary to insulate;
  • fastening pipes on the walls should be placed in increments of no more than 60 cm.

When equipping a system with forced circulation, it is important to choose the right power for the circulation pump. The specific choice is made based on the size of the building:

  • for houses with an area of ​​​​up to 250 m 2, a pump with a capacity of 3.5 m 3 / h and a pressure of 0.4 MPa is sufficient;
  • 250-350 m 2 - power from 4.5 m3 / h, head 0.6 MPa;
  • over 350 m 2 - power from 11 m 3 / hour, pressure from 0.8 MPa.

Despite the fact that do-it-yourself two-pipe heating is more difficult to install than a single-pipe network, such a system, due to its high reliability and efficiency, fully justifies itself during operation.


Today, several heating systems are known. Conventionally, they are divided into two types: one-pipe and two-pipe. To determine the best system heating, it is required to understand well the principle of their work. With this, it will be easy to make the choice of the most suitable heating system, taking into account all the positive and negative qualities. except specifications when choosing, you must also take into account your financial capabilities. And yet, is a single-pipe or two-pipe heating system better and more efficient?

Here are all the details that are installed in each system. The most important are:


Positive and negative properties of a one-pipe system

It consists of one horizontal collector and several heating batteries connected to the collector by two connections. Part of the coolant moving through the main pipe enters the radiator. Here, heat is released, the room is heated and the liquid returns back to the collector. The next battery gets liquid, the temperature of which is slightly lower. This continues until the last radiator is filled with coolant.

Main hallmark single-pipe system is the absence of two pipelines: return and supply. This is the main advantage.

No need to run two lines. It will take much less pipes, and installation will be simpler. No need to break through the walls and make additional fastenings. It would seem that the cost of such a scheme is much lower. Unfortunately, this does not always happen.

Modern fittings allow for automatic adjustment of the heat transfer of each individual battery. To do this, it is necessary to install special thermostats with a large flow area.

However, they will not help to get rid of the main drawback associated with the cooling of the coolant after it enters the next battery. Because of this, the heat transfer of the radiator included in the common circuit is reduced. To keep warm, it is necessary to increase the battery power by increasing additional sections. Such work increases the cost of the heating system.

If you make the connection of the device and the line from pipes of the same diameter, the flow will be divided into two parts. But this is unacceptable, since the coolant will begin to cool quickly when it enters the first radiator. In order for the battery to be filled with at least a third of the coolant flow, it is necessary to increase the size of the common collector by about 2 times.

And if the collector is installed in a large two-story house, whose area exceeds 100 m2? For the normal passage of the coolant, pipes with a diameter of 32 mm must be laid around the entire circle. To mount such a system, you will need a large financial investment.

To create water circulation in a private one-story house, it is necessary to provide a one-pipe heating system with an accelerating vertical collector, the height of which should exceed 2 meters. It is installed after the boiler. There is only one exception, this is a pumping system equipped with a wall-mounted boiler that is hung at the right height. The pump and all additional elements also lead to an increase in the cost of single-pipe heating.

Individual construction and single-pipe heating

The installation of such heating, which has a single main riser in a one-story building, eliminates the serious drawback of this scheme, uneven heating. If something like this is done in a multi-storey building, heating upper floors will be noticeably stronger than the heating of the lower floors. As a result, an unpleasant situation will arise: it is very hot upstairs, and cold downstairs. Private cottage usually has 2 floors, so the installation of such a heating scheme will evenly heat the entire house. Nowhere will it be cold.

Two-pipe heating system

The operation of such a system has some differences from the above scheme. The coolant moves along the riser, getting into each device through the outlet pipes. Then it returns to the main pipeline through the return pipe, and from there it is transported to the heating boiler.

To ensure the operability of such a scheme, two pipes are supplied to the radiator: through one, the main supply of the coolant is carried out, and through the other it returns to the common line. That is why they began to call it two-pipe.

Pipes are installed around the entire perimeter of the heated building. Radiators are installed between pipes to dampen pressure surges and form hydraulic jumpers. Such work creates additional difficulties, but they can be reduced by creating the correct circuit.

Two-pipe systems are divided into types:


Main advantages

What are the benefits of such systems? The installation of such a heating system makes it possible to achieve uniform heating of each battery. The temperature in the building will be the same on all floors.

If you attach a special thermostat to the radiator, you can adjust the desired temperature in the building yourself. These devices do not have any effect on the heat dissipation of the battery.

Two-pipe piping makes it possible to maintain the pressure value during the movement of the coolant. It does not require an additional high capacity hydraulic pump. The circulation of water occurs due to the gravitational force, in other words, by gravity. In case of poor pressure, you can use pumping unit low power that does not require special maintenance and is quite economical.

If you use shut-off equipment, various valves and bypasses, you will be able to mount such systems in which it becomes possible to repair only one radiator without turning off the heating of the whole house.

Another advantage of the two-pipe piping is the possibility of using any direction of hot water.

The principle of operation of the passing circuit

In this case, the movement of water along the return and main pipes occurs along the same path. With a dead-end scheme - in different directions. When the water in the system has a favorable direction, and the radiators have the same power, excellent hydraulic balancing is obtained. This eliminates the use of battery valves for presetting.

With different power of radiators, it becomes necessary to calculate the heat loss of each individual radiator. To normalize the operation of heating devices, it will be necessary to install thermostatic valves. This is difficult to do on your own without specific knowledge.

Hydraulic gravity flow is used during the installation of a long pipeline. In short systems, a dead-end circulation scheme of the coolant is created.

How is a two-pipe system serviced?

In order for the service to be of high quality and professional, it is necessary to perform a whole range of operations:

  • adjustment;
  • balancing;
  • setting.

Special pipes are used to adjust and balance the system. They are installed at the very top of the system and at its lowest point. The air is discharged after opening the upper pipe, and the lower outlet is used to drain the water.

Excess air accumulated in the batteries is bled off with the help of special taps.

To adjust the pressure of the system, a special container is installed. Air is pumped into it with a conventional pump.

Using special regulators that help reduce the water pressure in a particular radiator, a two-pipe heating system is configured. After the pressure is redistributed, the temperature in all radiators is equalized.

How to make a double pipe from a single pipe

Since the main difference between these systems is the decoupling of threads, it is quite simple to perform such an alteration. It is necessary to lay another pipeline parallel to the existing highway. Its diameter should be one size smaller. Near the last device, the end of the old collector is cut off and tightly closed. The remaining section is connected in front of the boiler directly to the new pipeline.

A passing scheme of water circulation is formed. The outgoing coolant must be sent through a new pipeline. To this end, the inlet pipes of all radiators must be reconnected. That is, disconnect from the old collector and connect to the new one, according to the diagram:

The conversion process can cause additional difficulties. For example, there will be no place for laying a second highway, or it is very difficult to break through the ceiling.

That is why, before you do such a reconstruction, you need to think through all the details. future work. It may be possible to adjust the one-pipe system without making any alterations.