One-pipe heating system Leningradka: schemes and principle of organization

Installation technology of the Leningradka system in a private house

What is Leningradka in heating, we figured it out, now it's the turn to talk about features of its installation. At the preparatory stage, holes are drilled in the walls for laying pipes, if they are planned to be hidden. At the same time, the pipeline must be insulated to protect against heat loss. If desired, you can not ditch the walls and make a visible wiring.

Selection of pipes and radiators

Polypropylene pipes are easy and quick to install, but are not suitable for buildings in northern latitudes.In such regions, only metal pipes are installed, because at high coolant temperatures, polypropylene can burst.

The diameter of the pipes is selected according to the number of batteries:

• for 4-5 radiators you will need a pipeline with a cross section of 25 mm, as well as a bypass with a diameter of 2 cm;
• for 6-8 batteries, a pipeline with a cross section of 3.2 cm and a bypass with a diameter of 2.5 cm are used.

You also need to correctly calculate the number of sections in the batteries, because at the inlet to the device the coolant has one temperature, and at the outlet it decreases by 20 degrees. After that, a slightly cooled liquid is mixed in the circuit with a heat carrier with a temperature of 70°C. That is why a liquid with a lower temperature enters the next radiator than the first one. With each passage of the heater, the temperature will drop lower and lower.

To compensate for heat loss, the number of sections in each subsequent radiator of the circuit is increased. Because of this, the heat transfer of the device increases. At the same time, it is taken into account that 100% of the power is laid on the first radiator, the second device requires 110% of the power, and the third - 120%. The required power of each subsequent radiator is increased by 10%.

Laying and installation

Heating wiring Leningradka in a private house implies the mandatory installation of bypasses. They are built into the main line with separate outlets.

It is important to accurately measure the distance between the taps. Permissible error no more than 0.2 cm

This will allow you to accurately install the radiator and corner taps with an American.

Tees are attached to the taps and one hole is left for installing the bypass. To install the second tee, measure the length between the axes of the branches. This takes into account the size after installing the bypass on this element.

When welding metal pipes, be sure to avoid internal flows

When connecting the bypass to the main, it is important to weld the end first that will allow easy installation of the other end, because there are situations when the soldering iron cannot be inserted between the tee and the pipe

Radiators are hung on combined couplings and corner valves. After that, a bypass is installed with taps, the length of which is measured separately. Excess sections are cut off and combined couplings are removed. Couplings are welded to the outlets.

Before the first start-up of the system, air is bled from it by means of Mayevsky cranes. When the start-up is completed, the system is balanced - the needle valves are adjusted and the temperature in the devices is equalized.

Installation technology of the Leningrad system in a private house

Now let's figure out how heating is done in a private house Leningradka. If you plan to carry out a hidden laying of pipelines, then you need to prepare the strobes in the walls in advance. To protect against heat loss, the pipeline must be insulated. If visible wiring is done, then the pipes do not need to be insulated.

Selection of radiators and pipelines

Heating wiring Leningradka in a private house can be made of steel or polypropylene pipes. The latter variety is quick and easy to install, but not suitable for northern latitudes. This is due to the fact that here the coolant is heated to a higher temperature, which can lead to pipe rupture. In the northern regions, only steel pipelines are used.

Depending on the number of heating devices, the diameter of the pipes is chosen:

• If the number of radiators does not exceed 5 pieces, then pipes with a diameter of 2.5 cm are sufficient. For a bypass, pipes with a cross section of 20 mm are taken.
• With a number of heaters within 6-8 pieces, pipelines with a cross section of 32 mm are used, and the bypass is made of elements with a diameter of 25 mm.

Since the temperature of the coolant at the inlet to the battery differs by 20 ° C from its temperature at the outlet, it is important to accurately calculate the number of sections. Then the water from the radiator mixes again with the coolant at a temperature of 70 ° C, but still one will be a few degrees cooler when it enters the next heater. Thus, with each passage of the battery, the temperature of the coolant decreases

Thus, with each passage of the battery, the temperature of the coolant decreases.

To compensate for the described heat losses, the number of sections in each next heating unit is increased in order to increase the heat transfer of the device. When calculating the first device, 100 percent of the power is laid. The second fixture needs 110% power, the third needs 120%, and so on. In other words, with each subsequent unit, the required power is increased by 10%.

Mounting technology

In the Leningrad system, all heating devices are installed on bypasses. That is, the installation of each battery in the line on special pipe bends. For correct installation, measure the distance between adjacent taps (the error is a maximum of 2 mm). Thanks to this, it will be easy to install American angle taps and batteries.

Tees are installed on the taps, and one open hole is left for mounting the bypass. To fix another tee, you need to measure the distance between the centers of the branches. Moreover, in the measurement process, it is necessary to take into account the dimensions after installing the bypass.

In the process of welding steel pipelines, they try to avoid sagging from the inside. During the installation of the bypass on the line, a more complex section is first welded, because sometimes it is almost impossible to start a soldering iron between the pipe and the tee.

Heating appliances are fixed on corner valves and combined type couplings. Then install the bypass. The length of its branches is measured separately. If necessary, cut off excess pieces, re-install the combined couplings.

Before the first start, you need to bleed the air from the system. To do this, open the Mayevsky taps on the radiators. After starting, the network is balanced. By adjusting the needle valves, the temperature in all heaters is equalized.

Heating "Leningradka" in a private house

Most often, this heating system is used in private homes, combining simplicity, affordability and quality, in which the existing shortcomings become insignificant.

Photo 1. Scheme of the heating system "Leningradka" with a solid fuel boiler and a circulation pump.

Peculiarities

It consists of the following:

1. The temperature of heating radiators is regulated in each individual room.
2. Since the batteries are connected in parallel with the pipe, any radiator can be turned off or completely dismantled, which will not affect the operation of the system.

Advantages

"Leningradka" has a number of advantages, for which it is chosen by the owners of private houses:

• Easy installation and restoration work in case of failure.
• Special skills are not required for installation: having understood, it is feasible for anyone.
• Pipes are laid anywhere, including under the floor.
• Available materials and equipment.
• Profitable operation.

Flaws

Despite its advantages, the system has several disadvantages:

• High pressure is required for maximum efficiency. For these purposes, a circulation pump is installed and the temperature of the coolant is increased.
• With a horizontal scheme, there are difficulties with connecting the second circuit (warm floor).
• With natural circulation, distant radiators give off less heat due to the cooling of the coolant, and the temperature at the inlet is much lower than at the outlet.
• Low efficiency with a long line length.

For efficiency and uniform distribution of the coolant, pipes of a larger diameter are used, and this spoils the appearance and leads to an increase in the cost of heating.

Which buildings are suitable for use

The main advantage of Leningradka is the simplicity and low cost of assembly. But this system also has one rather serious drawback. The last radiators in the chain in such a scheme heat up less than the first ones. After all, passing in a circle from battery to battery, hot water in the line begins to gradually cool down. Therefore, the Leningradka system is usually used for heating mainly only small buildings with a small number of rooms.

Sometimes such a system is still used in cottages on several floors. It is not prohibited to use it for such buildings by the regulations. After all, Leningradka was originally developed specifically for apartment buildings. However, in cottages, in order to balance the uneven heating temperature of the coolant, when using such a system, it is usually necessary to install radiators with a different number of sections.

Batteries can be included in such a scheme using different technologies.The most commonly used traditional bottom connection. But sometimes radiators in Leningradka crash into the highway in a diagonal way.

Heating "Leningradka" - open wiring diagram

The Leningradka open water heating scheme has an interesting feature - the consistent placement of all structural elements along the outer contour of the walls. The central node of such a one-pipe system is a heating boiler, which is connected to the first battery by means of a supply riser. Then, from the first radiator, hot water enters the next element and so on until it passes through all the heating units throughout the house. Having passed all the batteries, the cooled water returns through the return pipe to the boiler for reheating and everything repeats again, forming a closed cycle.

Due to the heating of water in the heating system, according to the laws of physics, it expands in volume. Therefore, to remove its excess in the circuit, an expansion tank is installed. At the same time, in an open heating system, such a structural element is connected to the air in the room through a special pipe. After the coolant cools down, it enters the system again from the expansion tank.

Very often, to increase the efficiency of heating, a single-pipe system is equipped with a circulation pump. which is installed in front of the boiler on the return pipe. Thanks to this addition, the heating rate of a private house, both one-story and two-story, increases significantly, since the coolant begins to circulate according to the forced principle.

To facilitate filling the heating system with water, a cold water supply pipeline is connected at the place where the return pipe passes through the locking mechanism and the cleaning filter. Also, at the lowest point of the system, a drain pipe with a tap at the end is mounted. Such a device allows, if necessary, to drain the entire coolant from the system.

In private housing construction, standard radiators with a lower connection diagram are usually used. In addition, each battery for removing air congestion is equipped with a Mayevsky crane. In addition, in private houses for "Leningrad" they often use a serial diagonal method of connecting batteries.

But, despite the popularity of such heating wiring diagrams, they have a common significant drawback - they do not provide for adjusting the heat transfer level of each individual battery. To solve this problem, there is a radically different way to connect radiators.

To improve the operation of the heating system by adjusting the heat of each radiator, parallel connection of all batteries to the riser is used. At the same time, each heating device is equipped with shut-off valves at the inlet and outlet pipes. Also, in a section of the riser parallel to the battery, which in such a situation acts as a bypass, a needle valve is mounted to adjust the intensity of the water flow through the heating battery. This was achieved thanks to the laws of physics, because when the locking mechanism is fully opened, the coolant will not flow up the battery, overcoming gravity. This leads to the fact that with an increase in the degree of opening of the valve, the temperature in the battery decreases.

Pros and cons

What is useful to know about Leningrad?

Advantages

• She is unfailing. Absolutely trouble free. The situation when the system stops due to airing is completely excluded.
• It allows independent adjustment of heating devices and their dismantling. At the same time, shutdown, throttling or the absence of one radiator does not affect the operation of the others.
• As already mentioned, it can work with forced and natural circulation.
• Starting the circuit is extremely simple, regardless of the presence of air in it. Since the pressure in the water supply or heating main significantly exceeds atmospheric pressure, when radiators are located above the filling, air will be forced out into their upper part.
• The circulation of the coolant will begin even with an air-filled system, and due to the thermal conductivity of the heating devices, they will be completely warmed up until the air is bled.

With air forced into the upper part of the battery, circulation will go through its lower collector.

Flaws

These include, perhaps, only the inevitable temperature spread between the first and last heaters in the circuit. To be precise, the spread will be noticeable at the radiator inlet: balancing a single-pipe heating system, if necessary, can even out heat transfer.

Single pipe heating system

A single-pipe heating system of the Leningradka type has a fairly simple device scheme. A supply line is laid from the heating boiler, to which the required number of radiators is connected in series.

After passing through all the heating elements, the heating pipe returns to the boiler. Thus, this scheme allows the coolant to circulate in a vicious circle, along the circuit.

The circulation of the coolant can be either forced or natural. In addition, the circuit can be a closed or open type heating system, this will depend on the source of coolant you have chosen.

To date, a single-pipe Leningradka scheme can be mounted taking into account the requirements of modern construction for private housing. At your request, the standard scheme can be supplemented with radiator regulators, ball valves, thermostatic valves, as well as balancing valves.

By installing these add-ons, you can qualitatively improve the heating system, making it more convenient for controlling the temperature regime:

• Firstly, you can reduce the temperature in those rooms that are rarely used or not used at all, while it is always recommended to leave the minimum value to maintain the room in good condition, or vice versa, increase the temperature in the children's room;
• Secondly, the improved system will allow lowering the temperature in a separate heater without affecting or lowering the temperature regime of the next one following it.

In addition, it is recommended to include a scheme of taps on bypasses for connecting heating radiators to the one-pipe system of Leningradka.

This will make it possible to repair or replace each heater independently of the others and without the need to shut down the entire system.

Installation of a horizontal single-pipe system

Installing a Leningradka horizontal heating system is quite simple, but it has its own characteristics that should be considered when planning a private house:

The line must be installed in the plane of the floor.

With a horizontal installation scheme, the system is laid either in the floor structure, or it is laid on top of it.

In the first option, you need to take care of reliable thermal insulation of the structure, otherwise you cannot avoid significant heat transfer.

When installing heating in the floor, the flooring is mounted directly under the Leningradka. When installing single pipe heating system on the floor, the installation scheme can be recycled during construction.

The supply line is installed at an angle in such a way as to create the necessary slope in the direction of movement of the coolant.

Heating radiators must be installed at the same level.

Before the start of the heating season, air bubbles are removed from the system using Mayevsky taps, which are installed on each radiator.

Features of installing a vertical system

The vertical connection scheme of the Leningradka system, as a rule, with forced circulation of the coolant.

This scheme has its advantages: all radiators heat up faster, even with small diameter pipes in the supply and return lines, however, this scheme requires a circulation pump.

If the pump was not provided, the circulation of the coolant is carried out by gravity, without the use of electricity.This suggests that water or antifreeze moves due to the laws of physics: the changed density of a liquid or water when heated or cooled provokes the movement of masses.

A gravity system requires the installation of large diameter pipes and the installation of a line at an appropriate slope.

Such a heating system does not always organically fit into the interior of the room, and there may also be a danger of not reaching the main line to the destination.

With a vertical pumpless system, the length of the Leningrad can not exceed 30 m.

Bypasses are also provided in the vertical system, allowing dismantling of individual elements without shutting down the entire system.

Advantages and disadvantages of the Leningradka heating scheme

The main advantages of the Leningradka heating system include:

• High economy. Pipes for the installation of such heating leave exactly several times less than any other;
• Ease of installation and fast turnaround time;
• Easy service.

In general, the Leningradka heating system is a budget option that is applicable in small areas.

The disadvantages of such a heating system are no less, and maybe even more, than the advantages.

Cons of the Leningradka heating system

Now, as for the minuses of Leningrad, and there are not so few of them. Well, firstly, the biggest drawback is that the latest radiators with this connection scheme always turn out to be cold.

Everything is very simple, because the system is single-pipe, and the first heaters from the boiler take the largest part of the heat. This problem can be solved by installing radiators with a large number of sections at the end of the series pipeline circuit.

The second problem when using the Leningradka system is the inability to connect underfloor heating, a heated towel rail, etc. Also, it becomes problematic to adjust the temperature of the radiators, some of them will heat up strongly, and some will remain cold.

Actually, let's sum up. Perhaps, for heating small country houses, such a heating system justifies itself, but not in the case of heating a cottage with several floors. Plus, given all the above disadvantages, it will be very difficult to improve and modernize something in heating.