Have you thought about arranging water heating in the house? It is not surprising, because the one-pipe heating system of a private house can be traditional and completely non-volatile or, conversely, very modern and fully automatic.
But you still have doubts about the reliability of this option - you don’t know which scheme to choose and which “pitfalls” await you? We will help clarify these issues - the article discusses the layout of a single-pipe system, the pros and cons, awaiting the owner of a house with a similar heating system.
The material of the article is equipped with detailed diagrams and visual photos depicting individual elements used in the assembly of heating. In addition, a video was selected with an analysis of the nuances of installing a single-pipe system with warm floors.
The principle of operation of water heating
In low-rise construction, the simplest, reliable and economical design with one highway has gained the most popularity. The one-pipe system remains the most popular way of organizing individual heat supply. It functions due to the continuous circulation of the heat transfer fluid.
Moving through pipes from a source of thermal energy (boiler) to heating elements and vice versa, he gives up his thermal energy and heats the building.
The coolant may be air, steam, water or antifreeze, which is used in houses of periodic residence. The most common water heating schemes.
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The weighty advantages of single-pipe options for the construction of heating systems is the minimum number of pipes, which determines the economic and aesthetic attractiveness of the scheme
When using metal-plastic and plastic pipes, the aesthetic indicators of single-tube schemes are increased, because contour gasket can be hidden in structures or under the finish
In gravity heating systems, characterized by the natural movement of the coolant, single-pipe circuits are constructed exclusively with the upper wiring
In the circuits with the upper wiring, the supply pipe is located above the devices, the coolant flows sequentially from one to another and cools down along the way. To distribute the coolant more evenly, a bypass is installed in front of the radiators, partially cutting off the supply of heated water
By a similar principle, vertical contours of forced heating systems are constructed, along which the movement of heated water is stimulated by a circulation pump
In the direction of movement of heated and cooled water in the system, they are divided into associated and dead ends. In dead ends, the heated and cooled coolant moves in different directions, in passing - in one
In single-pipe heating circuits with lower wiring, the inlet and outlet pipes are connected from below
In systems with horizontal wiring, there is always a circulation pump, without which the movement of the coolant will be too difficult. Mechanical or automatic air vents are installed to remove excess air.
Aesthetic advantages of a one-pipe heating system
Concealed laying of a single pipe heating circuit
Single pipe heating gravity type
Improved one-pipe circuit with closing section
Vertical heating schemes
Dead end single pipe heating system
Single pipe bottom heating option
Arrangement of horizontal wiring systems
Traditional heating is based on the phenomena and laws of physics - the thermal expansion of water, convection and gravity. When heated from the boiler, the coolant expands and creates pressure in the pipeline.
In addition, it becomes less dense and, accordingly, light. Pushed from below by heavier and denser cold water, it rises upward, so the pipeline leaving the boiler is always directed upward.
Under the influence of the created pressure, convection and gravity forces, the water goes to the radiators, heats them, and it cools itself.
Thus, the coolant gives off thermal energy, heating the room. Water returns to the boiler already cold, and the cycle begins anew.
Modern equipment that provides heat to the house can be very compact. To install it, you do not even need to allocate a special room
The heating system with natural circulation is also called gravity and gravity. To ensure the movement of fluid, it is necessary to observe the slope of the horizontal branches of the pipeline, which should be equal to 2 - 3 mm per linear meter.
When heated, the volume of the coolant increases, creating hydraulic pressure in the line. However, since water is not compressed, even a slight excess will lead to the destruction of heating structures.
Therefore, in any heating system, a compensating device is installed - an expansion tank.
In a gravitational heating system, the boiler is mounted at the lowest point of the line, and the expansion tank at the highest. All pipelines are made downhill so that the liquid coolant can gravity move from one element of the system to another
The difference between single-pipe and double-pipe systems
Water heating systems are divided into two main types - one-pipe and two-pipe. The differences between these schemes lies in the method of connecting the heat transfer batteries to the line.
The single-pipe heating main is a closed ring circuit. The pipeline is laid from the heating unit, radiators are connected to it in series, and lead back to the boiler.
Heating with one main is simply mounted and does not have a large number of components, therefore, it allows to significantly save on installation.
Single-pipe heating circuits with natural coolant movement are arranged only with the upper wiring. A characteristic feature - in the schemes there are risers of the supply line, but there are no risers for return
The movement of the coolant of two-pipe heating is carried out along two highways. The first serves to deliver hot coolant from the heating device to the heat transfer circuits, the second - to drain the cooled water to the boiler.
The heating batteries are connected in parallel - the heated liquid enters each of them directly from the supply circuit, therefore it has almost the same temperature.
In the radiator, the coolant gives off energy and when it cools, it goes into the discharge circuit - the "return". Such a scheme requires a double number of fittings, pipes and fittings, but it allows you to arrange complex branched structures and reduce heating costs due to the individual adjustment of radiators.
The two-pipe system effectively heats large areas and multi-story buildings. In low-rise (1-2 floors) houses with an area of less than 150 m², it is more expedient to arrange a one-pipe heat supply both from an aesthetic and economic point of view.
The two-pipe radiator connection scheme is not widespread in the individual heat supply device of private houses, since it is more difficult to assemble and maintain. In addition, doubled the number of pipes looks unaesthetic
Single-pipe heating device options
Elements of any heating system:
- heat source - boiler (solid fuel, electric, gas boiler;)
- heat transfer devices - radiators, contours of underfloor heating;
- coolant circulation device - special booster section of the highway, water pump;
- device that compensates for excess coolant pressure in the line - expansion tank open type or closed type;
- pipes, fittings and related plumbing fittings.
Depending on the type of devices used, the heat supply scheme will also depend.
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Solid fuel unit for heating
Autonomous electric boiler
Gas floor boiler
Wall-mounted boiler for cottages and apartments
Natural and forced circulation systems
The circulation of the coolant in the heating system can be carried out naturally - under the influence of physical phenomena, or forced - by means of a circulation pump.
In the first case, the heating movement in the system is spontaneous and is called natural, in the second - forced or artificial.
With a focus on design features, single-tube heating schemes are divided into two types. The first is an outdated but simple flow diagram, the second is an advanced bypass circuit
To ensure fluid motion in the gravitational system, an acceleration section is necessary. This is a vertical pipe outgoing from the boiler, along which the heated coolant rises.
At the upper point, the pipeline smoothly turns down, so the water rushes along the highway with acceleration.
For the heating circuit with the upper wiring, as well as for two-story houses, this section is the supply pipe, since it rises to a sufficient level.
For heating a one-story building with a lower horizontal wiring, an accelerating collector is arranged, the height of which should not be less than 1.5 m from the level of the first radiator.
The booster section is a device that provides circulation of the coolant in a gravity heating system. The pipe bore diameter of this section of the trunk should be larger than its main part.
For example, with a trunk pipe diameter of 25-32 mm, a pipe with a diameter of 40 mm is selected for the booster manifold.
The upper point of the booster manifold is arranged in a convenient place near the boiler. Lower the manifold pipe in such a way as to ensure a sufficient height difference between the lower branch of the booster manifold and the lower point of the pipeline to maintain a constant slope of the pipeline
The main advantages of the gravitational system are its complete non-volatility (in combination with a solid fuel boiler), simplicity and the absence of complex devices.
The disadvantages are quite a lot:
- To minimize flow resistance, pipe diameters should be large enough.
- Each built-in device and device interferes with the movement of the liquid, therefore in the system there is a minimum number of stop valves. This creates difficulties during repair, as it requires a complete shutdown of the system and drain of the coolant from the main.
- For reliable operation, the gravitational system must be carefully calculated and balanced, choosing the optimal pipe diameters and the number of sections of radiators. Extreme radiators in the system must be larger than those into which the coolant enters after exiting the boiler.
Installing a circulation pump in the system neutralizes almost all of its shortcomings. The device gives the coolant an additional impulse, allowing it to overcome the hydraulic resistance of the pipeline elements.
Forced single-pipe heating schemes are implemented in private homes most often.
Thanks to the modernization of the flow system by installing bypasses, the coolant with the operating temperature almost simultaneously arrives at all devices
The pump can be mounted anywhere in the line. But it is worth considering that hot water reduces its service life by acting on rubber parts (gaskets and seals).
Therefore, it is more advisable to install the unit on the return pipe, where the cooled coolant circulates. Before it, they must include a coarse filter in order to prevent possible contaminants from entering.
It is advisable to connect all devices and devices of heating systems through shut-off valves and bypasses.
Such an installation will allow repair and maintenance of individual elements without the need to stop the entire system and completely drain the water.
Bypass can be unregulated and adjustable. In the first case, it is a simple pipe connecting the supply and outlet pipes. In the second - it is equipped with shutoff three-way valves
Advantages of a forced circulation heating system:
- You can implement more complex and branched circuits, increase the length of the contours;
- There is no need for increased pipe diameters - the pump creates a pressure in the line that is sufficient for movement and uniform distribution of fluid;
- The circulation is carried out at a given speed and does not depend on the degree of heating of the coolant and the presence of the acceleration section;
- It is not necessary to observe the inclination angles when laying the pipeline, as coolant movement is stimulated by the pump.
In addition, it is possible to install control devices on each radiator and maintain optimal heating mode, reducing energy and heating costs.
There are only three drawbacks of single-pipe forced heating:
- dependence on power supply;
- noise - some buzz that produces a working pump;
- cost - higher in comparison with the gravitational scheme the cost of the device.
It is quite simple to neutralize them. The energy dependence is solved by installing an autonomous electric generator or by the possibility of switching the system to a mode with natural circulation.
To make the pump work almost inaudible, it is enough to mount it in a non-residential premise - a bathroom, a toilet, a boiler room.
At the upper points of the line, especially with forced heating with a closed expansion tank, it is necessary to provide for the possibility of bleeding the air released from the water. For radiators, these are automatic air vents or Mayevsky taps, for a pipeline - an air separator
Open or closed heating system?
To avoid excessive increase in hydraulic pressure in the system and its jumps, an expansion tank is installed. It takes the excess water during expansion, and then returns it to the main line when cooling, restoring the balance of the system.
There are two fundamentally different designs that determine the appearance of the entire system.
An open expansion tank is a partially or completely open tank, which is connected to the main at its highest point, immediately after the boiler.
To prevent overflow of liquid over the edges at a certain level, a drain is provided, through which excess water will drain into the sewer or into the street.
In one-story houses, the compensating capacity is often displayed in the attic - in this case, it must be insulated.
In order not to constantly monitor the level of the coolant, a water pipe is brought to the expansion tank and a simple float valve is installed
A heating system with such a compensating device is called open. It is used in the arrangement of non-volatile or combined heat supply.
It assumes direct contact of the hot heat carrier with air, as a result of which it naturally evaporates and is saturated with oxygen.
Based on this, an open heat supply scheme is characterized by the following disadvantages:
- When installing the pipeline of gravitational systems, it is imperative that the slopes are observed - in this case, the air released in the system will be bleed into the tank and atmosphere.
- It is necessary to regularly monitor and replenish the volume of water in the tank in time, preventing its excessive evaporation.
- You can not use antifreeze as a coolant, since toxic substances are released during its evaporation.
Oxygen contained in the circulating liquid causes corrosion damage in the steel parts of the radiators, reducing their service life.
However, it has pluses:
- There is no need for constant monitoring of pressure in the line;
- Even with small leaks, the system will regularly heat the house, as long as there is a sufficient amount of liquid in the main;
- You can even replenish the coolant in the system with a bucket - just pour the expansion tank into the water to the required level.
The closed expansion tank is a solid sealed housing, the internal volume of which is divided into two parts by the membrane. One cavity is filled with air, the second is connected to the highway.
When heated, the coolant, increasing in volume, pushes the membrane towards the air chamber, which plays the role of a damper. As the water cools, the hydraulic pressure decreases and the compressed air balances the system, squeezing the excess water back into the pipeline.
All closed tanks are equipped with an air valve. In emergency mode, when the pressure in the air chamber exceeds the permissible limit, it vents gas and protects the device from destruction
A system with a membrane expansion tank is called closed. This is a completely air-tight closed hydraulic line.
Compensating capacity can be built in anywhere in the system, however, most often it is installed on the return pipe near the boiler - to increase ease of maintenance.
A closed heating system is characterized by a slight overpressure. Therefore, the security group becomes an essential element of the highway.
The assembly consists of an air vent, a pressure gauge and a safety valve for dumping the coolant in emergency mode. It is mounted with shut-off valves on the supply pipe for the possibility of shutdown in case of repair.
If there is a rise in the pipeline, then it is placed at its upper point.
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Functionality of the device
Component Location
Efficient single pipe system
When designing heating, many factors are taken into account - the availability of stable power supply and a separate room for equipment (boiler room, boiler room), the number of floors and layout, the aesthetics of the future design, etc.
In each case, the location of the equipment and how to connect it will differ.
For a very small room - a country house - the simplest self-flowing scheme for sequentially connecting batteries directly into the main pipeline will become most effective.
When installing two or three radiators, it is not necessary to install a large number of shutoff valves - in this case, it is easier to drain the water from the system if necessary.
In buildings with a larger area, the heat supply system is a complex, sometimes branched, structure. In this case, forced heating according to the Leningradka scheme with diagonal connection of heat-transferring batteries and adjustable bypasses becomes the best option.
This scheme guarantees maximum heating of the radiator area and the ability to adjust and adjust the operating mode. To disconnect any of the elements of the system, it is not necessary to drain water from the entire line
Ways to connect the radiator to the highway
Heat dissipation of radiators depends on how they are connected to the line.
There are three main types of connection:
- Diagonal;
- Lateral;
- Lower.
Consider the features of each of these methods in more detail.
Diagonal or Cross Connection
Diagonal, or cross, connection is most effective. The maximum heating of the battery over the area is achieved, and there is practically no heat loss.
According to this scheme, the supply pipe is led to the upper pipe of the radiator, and the discharge pipe is connected to the lower pipe located on the opposite side of the device. For devices with a large number of sections, only the diagonal type of connection is used.
Lateral or one-way connection
Lateral, or one-way, connection allows to achieve uniform heating of all sections of the device.
For connection, the supply and outlet pipelines are let down on one side. Most often, such a connection is used with a heating device with an upper wiring.
The heat dissipation of heating with lateral connection of radiators, with a top-down flow is equal to 97%. With the reverse movement of the coolant - from the bottom up - this figure is 78%
Lower radiator to pipe connection
The bottom connection is not the most efficient heating scheme. However, it is arranged quite often, especially when the main pipeline is hidden under the floor.
The inlet and outlet pipes are led to the lower pipes located on different sides of the radiator.
The heat transfer rate for the lower connection of radiators is 88%
Advantages and disadvantages of a single pipe system
Single-pipe heating has gained wide popularity in the field of private construction.
The main reasons are the relatively low cost of the structure and the ability to mount it on its own, without the involvement of specialists.
But a one-pipe heating system has other advantages:
- Hydraulic stability - the heat transfer of other elements of the system does not change when individual circuits are disconnected, radiators are replaced, or sections are built up;
- The device of the line costs a minimum number of pipes;
- It is characterized by low inertia and warm-up time due to less than in the two-pipe, the amount of coolant in the main;
- It looks aesthetically pleasing and does not spoil the interior of the room, especially if the main pipe is hidden;
- The installation of valves of the latest generation - for example, automatic and manual temperature regulators - allows you to fine-tune the operation mode of the entire structure, as well as its individual elements;
- Simple and reliable design;
- Simple installation, maintenance and operation.
When connecting control and monitoring devices to the heating system, it can be transferred to a fully automatic mode of operation.
Integration with the Smart Home system is possible - in this case, programs of optimal heating modes can be set depending on the time of day, season and other decisive factors.
The single-pipe heating line can be completely hidden by the finish. Such a device not only does not spoil the appearance of the room, but also becomes its detail - an item of interior
The main disadvantage of single-tube heat supply is the imbalance in the heating of heat-releasing batteries along the length of the line.
The coolant cools as it moves along the circuit. Because of this, radiators installed far from the boiler heat up less than closely located ones. Therefore, it is recommended to install slowly cooling cast-iron appliances.
Installing a circulation pump allows the coolant to heat the heating circuits more evenly, however, with a sufficient length of the pipeline, its substantial cooling is observed.
Reduce the negative effect of this phenomenon in two ways:
- In radiators remote from the boiler, the number of sections is increased. This increases their heat-conducting area and the amount of heat transferred, allowing the rooms to be heated evenly.
- They draw up a project with a rational arrangement of heat-releasing devices in rooms - the most powerful are installed in children's rooms, bedrooms, and “cold” (northern, corner) rooms. As the coolant cools down, the living room and kitchen go, they end up with non-residential and utility rooms.
Such measures minimize the disadvantages of a single-pipe system, especially for one- and two-story buildings with an area of up to 150 m². For such houses, single-pipe heating is the most profitable.
Not only radiators, but also the contours of underfloor heating are connected to the single-pipe heating line. The video shows how to carry out such an installation.
Single pipe heating is a simple and reliable system. However, for effective heating, it is necessary to carefully select its individual elements. To do this, it is advisable to seek the advice of a specialist, where they will help you perform an estimated calculation.
Do you disagree with the schemes given in our article? Or do you have practical experience in arranging one-pipe heating in a private house? Your experience will be useful to our readers. Feel free to share your knowledge in the comments below.