All existing heating systems can be divided into two groups:

• single-pipe;
• two-pipe.

To answer the question: which heating system is better, one-pipe or two-pipe, it is necessary to understand on what principle each of them works.

This will clearly indicate the advantages and disadvantages of each of them, and will also help to make the most optimal choice, both technically and from the point of view necessary funds To understand, a single-pipe or two-pipe heating system is more suitable.

Videos about the types of heating systems can be easily found on the World Wide Web.

Advantages of a single-pipe heating system

• fewer materials and tools;
• hydrodynamic stability;
• less labor intensive design and installation;
• no special infrastructure requirements.

But with all these advantages we can say with full confidence that a single-pipe system is far from the most best scheme, according to which heating can be realized. Still main reason Why the single-pipe system has become widespread in our country is an undeniable saving of material.

Single-pipe heating system: operating principle

Such a system has one riser (main pipe). Through it, heated water (or any other coolant) rises to the upper floors of the building (if it is a multi-story building).

All heating devices (units for heat transfer - batteries or radiators) are connected in series to the downward line.

Modernization of single-pipe heating systems

A technical solution has been developed that makes it possible to regulate the operation of each individual heating device.

It consists of connecting special closing sections (bypasses), which make it possible to integrate radiator automatic thermostats into heating systems. What other benefits are possible when installing bypasses? We'll talk about this in more detail later.

The main advantage of this modernization is that in this case it becomes possible to regulate the heating temperature of each battery or radiator. In addition, you can completely shut off the coolant supply to the device.

Thanks to this, such a heating device can be repaired or replaced without shutting down the entire system.

The bypass is a bypass pipe equipped with valves or taps. At correct connection such fittings to the system, it will allow you to redirect the flow of water along the riser, bypassing the heating device being repaired or replaced.

It is not difficult to understand that the task of installing such devices into a system with your own hands is hardly possible to solve, even if there is a detailed instructions. In this case, it is impossible to do without the participation of a specialist.

A heating system with one main riser must be equipped with heating devices that have improved reliability characteristics. Any devices in a single-pipe system must withstand increased pressure and high temperature.

Vertical and horizontal riser diagram

According to the implementation scheme itself, single-stack heating comes in two types:

• vertical;
• horizontal.

If heating appliances are connected from the top floor to the bottom, this is a vertical riser. If the batteries are connected in series to each other throughout all rooms of a building floor, this is a horizontal riser.

Disadvantages of a single-pipe heating system

• complexity of thermal and hydraulic calculation networks;
• difficulty in eliminating errors in the calculations of heating devices;
• interdependence of the operating characteristics of all devices on the network;
• increased hydrodynamic resistance;
• limiting the number of heating devices on one riser;
• inability to regulate batteries and radiators with regulators (pictured below)

Important!
If you connect more than ten heating devices (for example, eleven) to a vertical riser, then on the first radiator in the network the water temperature will be about 105 ° C, and on the last one - 45 ° C.

Single-stack heating in individual construction

If heating with one main riser is installed in a one-story building, then it will be possible to get rid of at least one significant drawback of such a scheme - uneven heating.

If such heating is implemented in a multi-story building, then the upper floors will be heated much more intensely than the lower floors. This will lead to a situation where it is cold on the first floors of the house, and hot on the upper floors.

A private house (mansion, cottage) is rarely more than two or three floors high. Therefore, installing heating, the scheme of which was described above, does not threaten that the temperature on the upper floors will be much higher than on the lower floors.

Two-pipe heating system: advantages and disadvantages

Advantages of a two-pipe manifold system

• It becomes possible to install automatic thermostats for radiators or radiators. In this case, such devices are provided at the system design stage;
• Pipes according to this scheme are routed throughout the premises through a special collector system. If one of the elements in the system fails or begins to operate unstably, this does not in any way affect the operation of the remaining devices in the circuit;
• In other words, with a two-pipe system, the elements of the thermal circuit have parallel connection in contrast to sequential - with single-pipe.

The main disadvantages of a two-pipe heating system

• heating becomes more complex according to the connection diagram;
• the price of the project requires more funds;
• installation of the circuit is more labor-intensive.

Where are two-pipe heating systems used:

• in individual housing construction;
• in so-called “elite” housing projects;
• high-rise buildings (with overhead wiring)

Important!
When designing buildings with more than 9-10 storeys, it is better to use either a single-pipe system with horizontal floor-to-floor wiring, or a two-pipe system with upper vertical wiring.
This will ensure better circulation.

Advantages of two-pipe collector heating

• reduced hydrodynamic resistance;
• possibility of independent temperature control in each room.

Before starting, the collector heating system requires careful pre-setting. For correct installation, installation and operation of a two-pipe system requires the availability of appropriate infrastructure.

Options for wiring diagrams of a two-pipe system

Upper wiring

A system with top wiring is suitable for natural circulation (without the use of pumps) (). It has lower hydrodynamic resistance. In this case, the upper supply main pipe is partially cooled. Due to this, additional coolant circulation pressure is generated.

Bottom wiring

In a system with bottom wiring, both the supply and discharge pipes are located nearby.

There are such modifications of the lower wiring:

So, is the heating system one-pipe or two-pipe? In each case it is necessary to have preliminary calculations and project (see), on the basis of which they will be selected as heating devices, and the main pipes themselves (see). The final decision is yours.

Today, several heating systems are known. Conventionally, they are divided into two types: single-pipe and double-pipe. To determine better system heating systems, you need to have a good understanding of how they work. With this you can easily make the choice of the most suitable heating system taking into account all the positive and negative qualities. Except technical characteristics when selecting, you must also take into account your financial opportunities. And yet, is a single-pipe or two-pipe heating system better and more efficient?

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

Positive and negative properties of a single-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 transferred, the room is heated and the liquid is returned back to the collector. The next battery receives liquid whose temperature 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.

There is no need to lay two highways. It will take a lot less pipes, and installation will be simpler. No need to break through walls and do 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 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 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 overall chain decreases. To retain heat, it is necessary to increase the battery power by adding additional sections. This type of work increases the cost of the heating system.

If you make the connection of the device and the main 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 approximately 2 times.

What if the collector is installed in a large two-story house with an area exceeding 100 m2? For normal coolant passage, pipes with a diameter of 32 mm must be laid throughout the circle. To install such a system, large financial investments will be required.

To create water circulation in a private one-story house, you need to equip the single-pipe heating system with an accelerating vertical collector, the height of which must exceed 2 meters. It is installed after the boiler. There is only one exception, which is a pumping system equipped wall-mounted boiler, which is suspended on required height. Pump and everything additional elements also lead to higher prices for single-pipe heating.

Individual construction and single-pipe heating

Installation of such heating, which has a single main riser in one-story building, eliminates the serious drawback of this circuit, uneven heating. If something similar is done in a multi-story building, the heating of the upper floors will be noticeably greater than the heating of the lower floors. As a result, an unpleasant situation will arise: it is very hot above, and cold below. Private cottage usually has 2 floors, so installing such a heating scheme will allow you to evenly heat the entire house. It won't be cold anywhere.

Two-pipe heating system

The operation of such a system differs somewhat from the scheme described above. The coolant moves along the riser, entering each device through outlet pipes. Then by return pipe returns to the main pipeline, and from there it is transported to the heating boiler.

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

The installation of pipes is carried out along the entire perimeter of the heated building. Radiators are installed between pipes to dampen pressure surges and form hydraulic bridges. Such work creates additional difficulties, but they can be reduced by creating the right diagram.

Two-pipe systems are divided into types:

Main advantages

What positive qualities have such systems? 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 it yourself desired temperature in a buiding. These devices do not have any effect on the heat transfer of the battery.

The two-pipe piping makes it possible to maintain the pressure value when the coolant moves. It does not require the installation of an additional high-power hydraulic pump. Water circulation occurs due to gravitational force, in other words, by gravity. If the pressure is poor, you can use pumping unit low power, which does not require special maintenance and is quite economical.

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

Another advantage of two-pipe piping is the ability to use any direction of hot water.

Operating principle of the passing circuit

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

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

Hydraulic gravity flow is used when installing a long pipeline. In short systems, a dead-end coolant circulation pattern is created.

How is a two-pipe system maintained?

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

• adjustment;
• balancing;
• setting.

To adjust and balance the system, special pipes are used. 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 released using special taps.

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

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

How can you make a two-pipe from a single pipe?

Since the main difference between these systems is the separation of streams, this modification is quite simple. It is necessary to lay another pipeline parallel to the existing main. Its diameter should be one size smaller. Next to 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.

Formed passing scheme water circulation. The exiting coolant must be directed through a new pipeline. For this purpose, the supply 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 remodeling process can present additional challenges. For example, there will be no space to lay a second highway, or it will be very difficult to break through the ceiling.

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

The water heating system can be single-pipe or double-pipe. The two-pipe system is called so because two pipes are required for operation - one from the boiler supplies hot coolant to the radiators, the other removes coolant from the heating elements and supplies it back to the boiler. With such a system, boilers of any type can operate on any fuel. Both forced and natural circulation can be implemented. Two-pipe systems are installed in both one-story and two- or multi-story buildings.

Advantages and disadvantages

The main disadvantage of this method of organizing heating follows from the method of organizing the circulation of the coolant: double the number of pipes compared to the main competitor - a single-pipe system. Despite this situation, the costs of purchasing materials are slightly higher, and all due to the fact that with a 2-pipe system, smaller diameters of pipes and, accordingly, fittings are used, and they cost much less. So the resulting material costs are higher, but not significantly. What there really is is more work, and accordingly it takes twice as much time.

This disadvantage is compensated by the fact that a thermostatic head can be installed on each radiator, with the help of which the system is easily balanced in automatic mode, which cannot be done in a single-pipe system. On such a device you set the desired coolant temperature and it is maintained constantly with a small error (the exact value of the error depends on the brand). In a single-pipe system, it is possible to regulate the temperature of each radiator individually, but this requires a bypass with a needle or three-way valve, which complicates and increases the cost of the system, negating the gains in cash for the purchase of materials and time for installation.

Another disadvantage of the two-pipe system is the impossibility of repairing radiators without stopping the system. This is inconvenient and this property can be circumvented by placing it near each heating device on the supply and return Ball Valves. By blocking them, you can remove and repair the radiator or heated towel rail. The system will function indefinitely.

But this type of heating organization has an important advantage: unlike a single-pipe system, in a system with two lines for each heating element water arrives at the same temperature - directly from the boiler. Although it tends to take the path of least resistance and will not extend beyond the first radiator, installing thermostatic heads or valves to regulate the flow intensity solves the problem.

There is another advantage - lower pressure losses and easier implementation of gravity heating or the use of lower power pumps for systems with forced circulation.

Classification of 2 pipe systems

Heating systems of any type are divided into open and closed. In closed ones, a membrane-type expansion tank is installed, which makes it possible for the system to operate at high blood pressure. This system makes it possible to use not only water as a coolant, but also compositions based on ethylene glycol, which have reduced temperature freezing (up to -40 o C) and are also called antifreeze. For normal operation of equipment in heating systems, special compounds developed for these purposes must be used, and not general purpose, and especially not automobile ones. The same applies to the additives and additives used: only specialized ones. It is especially important to adhere to this rule when using expensive modern boilers with automatic control– repairs in case of malfunctions will not be covered by warranty, even if the breakdown is not directly related to the coolant.

IN open system V top point built-in expansion tank open type. A pipe is usually connected to it to remove air from the system, and a pipeline is also installed to drain excess water in the system. Sometimes from expansion tank can take away warm water For economic needs, but in this case it is necessary to make the system recharge automatic, and also not to use additives.

Vertical and horizontal two-pipe system

There are two types of organization of a two-pipe system - vertical and horizontal. Vertical is used most often in multi-storey buildings. It requires more pipes, but the ability to connect radiators on each floor is easily realized. The main advantage of such a system is the automatic release of air (it tends upward and exits there or through expansion tank or through the drain valve).

The horizontal two-pipe system is used more often in single-story or, at most, two-story houses. To bleed air from the system, Mayevsky valves are installed on the radiators.

Two-pipe horizontal diagram heating of a two-story private house (click on the picture to enlarge)

Upper and lower wiring

Based on the method of supply distribution, a system with top and bottom supply is distinguished. With top wiring, the pipe goes under the ceiling, and from there the supply pipes go down to the radiators. The return runs along the floor. This method is good because you can easily create a system with natural circulation - the height difference creates a flow of sufficient force to ensure good speed circulation, it is only necessary to maintain a slope with a sufficient angle. But such a system is becoming less and less popular due to aesthetic reasons. Although, if at the top under the hanging or suspended ceiling, then only the pipes to the devices will remain visible, and they, in fact, can be monolid into the wall. Upper and lower wiring are also used in vertical two-pipe systems. The difference is demonstrated in the figure.

With bottom wiring, the supply pipe goes lower, but higher than the return pipe. The supply tube can be located in a basement or semi-basement (the return is even lower), between the rough and finished floors, etc. You can supply/discharge coolant to radiators by passing pipes through holes in the floor. With this arrangement, the connection is the most hidden and aesthetically pleasing. But here you need to select the location of the boiler: its position relative to the radiators does not matter - the pump will “push through”, but in systems with natural circulation, the radiators must be located above the level of the boiler, for which the boiler is buried.

Two-pipe system heating of a two-story private house is illustrated in the video. It has two wings, the temperature in each of which is regulated by valves, the lower type of wiring. The system is forced circulation, so the boiler hangs on the wall.

Dead-end and associated two-pipe systems

A dead-end system is a system in which the coolant supply and return flows are multidirectional. There is a system with passing traffic. It is also called the Tichelman loop/scheme. The latter option is easier to balance and configure, especially with long networks. If a system with a parallel flow of coolant has radiators with the same number of sections, it is automatically balanced, while in a dead-end circuit it will be necessary to install a thermostatic valve or needle valve on each radiator.

Even if radiators and valves/valves of different numbers of sections are installed with the Tichelman scheme, the chance of balancing such a scheme is much higher than a dead-end one, especially if it is quite long.

To balance a two-pipe system with multidirectional coolant movement, the valve on the first radiator must be screwed on very tightly. And a situation may arise in which it needs to be closed so much that the coolant will not flow there. It turns out then you need to choose: the first battery in the network will not heat, or the last one, because in this case it will not be possible to equalize the heat transfer.

Heating systems on two wings

And yet, more often they use a system with a dead-end circuit. And all because the return line is longer and it is more difficult to assemble. If your heating circuit is not very large, it is quite possible to adjust the heat transfer on each radiator and with a dead-end connection. If the circuit turns out to be large, and you don’t want to make a Tichelman loop, you can divide one large heating circuit into two smaller wings. There is a condition - for this there must be a technical possibility of such a network construction. In this case, in each circuit after separation it is necessary to install valves that will regulate the intensity of the coolant flow in each of the circuits. Without such valves, balancing the system is either very difficult or impossible.

Different types of coolant circulation are demonstrated in the video, and it also gives useful tips on installation and selection of equipment for heating systems.

Connecting heating radiators with a two-pipe system

In a two-pipe system, any of the methods of connecting radiators is implemented: diagonal (cross), one-sided and bottom. Most the best option — diagonal connection. In this case, the heat transfer from the heating device can be in the region of 95-98% of the rated thermal power of the device.

Despite different meanings heat loss for each type of connection, they are all used, just in different situations. The bottom connection, although the most unproductive, is more common if the pipes are laid under the floor. In this case it is easiest to implement. Possible with hidden gasket connect radiators using other schemes, but then either large sections of pipes remain visible, or they will need to be hidden in the wall.

Lateral connection is practiced if necessary when the number of sections is no more than 15. In this case, there is almost no heat loss, but when the number of radiator sections is more than 15, a diagonal connection is required, otherwise circulation and heat transfer will be insufficient.

Results

Despite the fact that more materials are used to organize two-pipe circuits, they are becoming more popular due to more reliable circuit. In addition, such a system is easier to compensate.

Almost all heating systems currently available in any buildings and structures can be classified into one of the two classes mentioned in the title of this article.

The question of whether a single-pipe or two-pipe heating system is better can only be answered by carefully understanding the advantages and disadvantages of each of the options considered.

Characteristics of a single-pipe home heating system

Which heating system is more efficient, one-pipe or two-pipe? It is impossible to answer this question unambiguously.

Single-pipe CO has all the basic elements inherent in any heating system. The main ones are:

• A heating boiler that runs on any type of fuel that is most available at the location of the heated building. This can be a gas boiler, solid fuel boiler or designed to operate on liquid fuel. The type of fuel used by the boiler does not have any effect on the heating circuit;
• Pipes through which the coolant circulates;
• Shut-off equipment for various purposes (valves, gate valves);
• Heating appliances and thermometers;
• Valves for bleeding air. Placed on radiators (Maevsky taps) and at the top point of the CO;
• Drain tap (at the lowest point of CO);
• Expansion tank of open or closed type.

Advantages of using single pipe systems

The difference between a one-pipe heating system and a two-pipe one is that the first is by far the simplest and in an effective way heating buildings up to 150 m2.

Installation of a circulation pump and use of modern technical solutions make it possible to guarantee the required temperature parameters in heated rooms. Therefore, answering the question of whether to choose a single-pipe or two-pipe heating system, among the undeniable advantages of the first system it should be noted:

Versatility of installation. Such a system can be installed in a building of any configuration, and a closed loop guarantees the movement of the coolant along the entire perimeter of the heated premises.
Unlike two-pipe, single-pipe CO can be installed in such a way that heating of the premises begins from the coldest side of the building (north), regardless of where the boiler is installed, or from the most important rooms (children's room, bedroom, etc.).

Installation of the system requires a minimum number of pipes and shut-off and control equipment, complete installation CO is completed in much less time than CO with two pipes. All this allows you to get serious savings in funds allocated for construction work.

The system allows the installation of pipes directly on the floor or under it, which allows you to implement any design solutions in the premises.

The scheme provides for serial and parallel connection of heating devices, which makes it possible to control and regulate the temperature in them;

If certain installation requirements are met, the system can be made in a non-volatile version. In the event that the pump stops due to a power failure, the coolant supply line is switched to a parallel branch. In this case, CO, from the version with forced circulation (PC), switches to natural circulation (EC).

Disadvantages inherent in the specified CO option

Two-pipe or one-pipe heating system for a private house? When assessing the pros and cons, it should be taken into account that the main disadvantage of single-pipe CO is the fact that the heating devices are connected in series. And this, during operation, eliminates the possibility of effectively adjusting the temperature in one of them, without it affecting the remaining radiators.

The factor influencing the choice of whether a two-pipe or one-pipe heating system for a private house will be installed at your facility; do not forget about the disadvantage of the latter, such as increased pressure in the system compared to the two-pipe option. This can be achieved by increasing the power of the circulation pump installed in the system, which entails an increase in operating costs and increases the likelihood of leaks, and also requires more frequent addition of coolant to the system.

The system requires vertical filling. And this automatically determines the location of the expansion tank attic space and, accordingly, solving the issue of its insulation.

If similar system mounted in two-story building, then another problem arises. The temperature of the water entering the first floor may differ by almost 50% from that initially supplied to the second floor. To avoid this, it is necessary to install additional jumpers on each floor, and the number of sections of heating devices on the first floor should significantly exceed that installed on the second.

Which heating system is more efficient, one-pipe or two-pipe? We have already considered the first one. Let's look at the second one.

Such a system a priori implies the presence of two pipelines located around the perimeter of the heated room. Radiators are inserted between them, which dampen pressure drops and create hydraulic jumpers. However, the problems created by this can be leveled out due to the correct configuration of the CO.

• Two-pipe systems can be vertical and horizontal, depending on the location of the supply and return (parallel to the ceilings or perpendicular to them). However, it should be understood that mounted in apartment buildings the circuit is essentially a horizontal two-pipe CO.

  A two-pipe vertical one will be obtained in the case when the radiators are installed not in the gaps of the risers (as in the case described above), but between the supply and return.

• Associated and dead-end SOs. The first type includes systems in which hot water, passing through the radiator, moves in the same direction along the return line. If after the heating device the direction of movement of the coolant changes, the system is classified as a dead end.

  The required option is selected taking into account the presence of CO pipes on the line doorways, which are quite difficult to bypass, it is easier to return the water in the direction in which it came.

• With bottom and top filling.
• With natural (EC) and forced (PC) circulation.

Advantages and disadvantages of the system

Schemes of one-pipe and two-pipe heating systems are compared according to their inherent advantages and disadvantages. The advantages of the second system are:

1. The supply of coolant to all heating devices at the same temperature, which allows you to set your own required temperature for a specific room;
2. Lower pressure losses in the lines, which allows the use of a lower power pump (saving operating costs);
3. The system allows installation in buildings of any size and number of floors;
4. Availability shut-off valves allows you to perform preventive maintenance and repairs without stopping the entire CO.

Let's compare what you need to choose - a single-pipe heating system, the so-called Leningradka, or a two-pipe one. Which one is cheaper to create and which one is better in terms of performance.

What are the opinions, what do the experts say?

The single-pipe heating system has been used quite widely, it is efficient and many of its owners will say that in their opinion it works either well or satisfactorily. At the same time, upon first consideration, two-pipe systems look clearly more expensive, because two conductors are used instead of one. This, according to some, increases prices not only in terms of materials, but also during installation and clutters up the space.

But experts are more likely to point out that a two-pipe heating system for a private home is cheaper and works better, and you need to choose it. Why is that?

Serious disadvantages of a single-pipe heating system - temperature difference

In a one-pipe heating system, where all radiators are connected in series, the latter will be colder than the previous ones. But how much will the temperature decrease? And how will this affect comfort?

The temperature drop will depend on the amount of liquid passing through the ring main pipeline. The larger the diameter of the pipe and the higher the speed in it, the less will be the influence of each radiator. By increasing these parameters, we can achieve, for example, that on five batteries the temperature drop will be no more than 10%. But this is in theory.

In practice, we are limited by the reasonableness of the costs for pipe diameters and their tees, as well as the choice of pump - choose the right low-power one circulation pump, and set it to first speed so that it consumes no more than 30 W of electricity.

In this case, in “Leningrad without madness,” we use a main pipe with a diameter of 26 mm for metal-plastic, or 32 mm (outer) for polypropylene, to connect four radiators in a ring. The radiator connections are 16 mm (20 mm polypropylene).

Then the power drop on each radiator will be about 7%. At the same time, the temperature will drop by about 4 degrees, and these are not the worst indicators.

Therefore, if the 1st radiator is 60 degrees, then at the entrance to the 4th we will already get +48 degrees C. In principle, the functionality of this circuit is maintained up to 4 heaters per ring. But 5 pcs. It can no longer be recommended - there is a significant loss of power and an increase in the costs of compensating for it by increasing the radiator itself.

And 8 pieces - etc. - completely ineffective temperature schemes that cannot provide comfort, since the temperature drop on a ring with an acceptable diameter and pump power (without creating water noise) will be completely critical - up to 32 - 36 degrees.

How to prevent the temperature from decreasing in Leningrad

• There is an opinion that you can install thermal heads on radiators, raise the temperature in the boiler and thus hope that the last radiator in a row of 8 pieces will someday heat up. In fact, this is completely wrong, if only for the reason that you have to wait - when it is already hot in the first room, then in the last there is still a glacier.
  It is also not correct to operate the boiler in mode elevated temperature, when it should often turn off - heated the rooms, turned off, then warmed up again...

• Another option to equalize the temperature in single-pipe radiators is to install additional balancing valves on the first radiators in order to turn them off and send more liquid to the last ones. The result is an expensive and difficult to customize system.
• Now the option recommended by experts is to increase the power of the radiators from what is required by calculation. The increase should be proportional to the cooling of the water. For 8 the battery is almost 100%. Expensive and cumbersome, but the heating power of rooms and the air temperature in them can be equalized.

Which is cheaper and more profitable - single-pipe or double-pipe?

A single-pipe not only entails setup difficulties, but it is also more expensive - only due to the increased diameter of the pipeline and its fittings.

Let's calculate how much materials will cost for a typical heating scheme small house approximately 110 sq. m., - the first floor is 60 sq. m., approximately 6x10 m, and the attic is 50 sq. m., 5x10 m. There are 4 units installed on each floor. radiators. A reasonable minimum pipe diameter for is 26 mm.

For a two-pipe scheme, 20 mm is suitable for both shoulders and risers, with such a small number of radiators. And we connect the second battery at the dead end already 16 mm.

Placing radiators around the perimeter of the house, 4 pcs. per floor, we get the following:

For a single-pipe we will need the following pipe lengths and diameters:

• 26 mm – 70 m.
• 16 mm – 5 m.
• Tees 26 mm – 18 pcs.

For a two-pipe we need

• 20 mm – 42 m
• 16 mm – 50 m
• Tees 20 mm – 14 pcs.

Then the difference in price only for a branded metal-plastic pipeline is about $200 - installation of a single-pipe will be more expensive. And if we add even a small increase in the power of the latest radiators (as recommended), then it’s already $250.
True, if you use cheap polypropylene the difference in price will be small, but still Leningradka will be much more expensive than a modern heating system with supply and return.

Unacceptable but cheap scheme

What if you turn on the radiators according to the circuit without a ring pipe, but simply by connecting them in series? After all, then the price is minimum. But the cooling of the coolant will be very significant, and include more than 3 pieces. batteries are not worth it according to this scheme.

The maximum number of radiators is 4 pieces, but at the same time the power of the latter drops by 35 - 40%.
Those. This scheme is also viable; it can be useful with 3 radiators in a ring. And with 4, there is a significant cost to increase its size and power, so it won’t be any cheaper.

Conventional dead-end two-pipe circuit, what are the advantages

The usual two-pipe dead-end circuit allows you to place 4 radiators in an arm, without balancing valves, and the temperature drop will be a maximum of 5% on the last radiator, which cannot even be detected without instruments. If you place 5 batteries, then without balancing with taps, the power output on the latter will drop to 15%, which is also acceptable.

The diameters of the pipes are as follows.

• A 26 mm line extends from the boiler, then in the shoulders to the penultimate radiator - 20 mm, and to the last radiator - 16 mm.
• Radiators are connected 16 mm.
• For polypropylene, the outer diameters are 32, 25, 20 mm, respectively.

As indicated, the cost of creating such a system is minimal; balancing is not required even between arms, if the dead ends are approximately equal in power and pipe length.

Where and when is single-pipe heating used?

Mono-tubes were previously widely used in centralized systems, where they laid steel pipes large diameter, and the pump was no joke. The systems are still in use and new ones are being designed, mainly based on industrial enterprises, where there are kilometers of pipes, and then the system becomes more profitable.

Also, the risers of high-rise buildings are the same heating systems with one pipe, where a central pump provides high pressure. But as soon as the temperature or pressure drops, which is not uncommon (due to lack of energy, in some places the valves are screwed on specially), the radiators on the 5th floor of the Khrushchev building become not at all comfortable, although on the 2nd it is still somehow acceptable, oh what the residents of such houses themselves can tell. This is a pronounced disadvantage of a single-pipe heating system.

As we see, it is possible to use Leningrad, it has the right to life, but only in very small systems, if for some reason only one pipeline needs to be laid, although in general it will cost more. The main choice should be a heating system with all radiators connected using two pipes.