- Systems differing in the way of circulation
- Gravity flow system
- Forced system
- Various connection schemes for pressure heating systems
- One-pipe system (“Leningradka”)
- Two-pipe collector (beam) heating wiring diagram
- Two-pipe shoulder (dead-end) system
- Two-pipe passing system (Tichelman loop)
- Connection to the underfloor heating system
We have prepared for you an overview of the main heating schemes for private houses, comparative characteristics, advantages and disadvantages of each system. Consider the gravitational and forced systems for moving the coolant, one-pipe and two-pipe wiring diagrams, embedding warm floors in the heating system.
Heating system schemes are very diverse. Moreover, the choice of one of them should be made based on the design and size of the house, the number of heating elements, depending on the power supply.
Systems differing in the way of circulation
In a system with natural circulation, the movement of the coolant is based on the action of gravity, therefore they are also called gravitational or gravity. The density of hot water is lower, and it rises, displaced by cold water that enters the boiler, is heated and the cycle repeats. Forced circulation – in systems using injection equipment.
Gravity flow system
The gravity system does not come out cheaper, as developers expect. On the contrary, as a rule, it costs 2, or even 3 times more than the forced one. This arrangement requires larger pipes. For its operation, slopes are necessary, and for the boiler to stand below the radiators, that is, installation in a pit or basement is required. And even with normal system operation on the second floor, the batteries are always hotter than on the first. To balance this bias, measures are required that make the system much more expensive:
- bypass device (additional material and welding);
- balancing cranes on the second floor.
For a building with three floors, this system is poorly suited. The movement of the coolant is “lazy”, as the masters say. For a two-story house, it works when the second floor is full, the same as the first, plus there is an attic. An expansion tank is installed in the attic, to which the main riser, preferably strictly vertical, is supplied from the boiler installed in a deep pit or in the basement. If in some places it is necessary to bend the riser, this impairs the work of gravity.
From the main riser, horizontal pipelines (sun beds) are laid with a slope, from which the risers descend, going into the return line, which returns to the boiler.
Gravity heating: 1 – boiler; 2 – expansion tank; 3 – feed slope; 4 – radiators; 5 – return slope
Gravity systems are good in buildings like a Russian hut and in one-story modern cottages. Although the cost of the system will be more expensive, but it does not depend on the availability of power supplies.
When the house is attic, the installation of an expansion tank causes a problem with placement – it has to be mounted directly in the living space. If the house does not live permanently, then the coolant is not water, but an anti-freeze liquid, the vapors of which will fall directly into the living area. To avoid this, you can take the tank out to the roof, which will lead to additional expenses, or it is necessary to close the top of the tank tightly and lead the gas outlet pipe from the lid outside the living space.
The forced circulation system is distinguished by the presence of pumping equipment, and is now very widespread. Among the disadvantages of the method, it is possible to note the dependence on power supply, which is solved by purchasing a generator for autonomous power supply when the network is disconnected. Of the advantages, it should be noted that it is more adjustable, reliable and the possibility, in some cases, to save money on organizing heating.
Pump connection: 1 – boiler; 2 – filter; 3 – circulation pump; 4 – taps
Various connection schemes for pressure heating systems
There are several connection schemes for forced circulation systems. Consider the advantages, disadvantages and recommendations of the masters for choosing a scheme for various structures and systems.
One-pipe system (“Leningradka”)
The so-called Leningradka is difficult to calculate and difficult to execute.
One-pipe pressure heating system: 1 – boiler; 2 – security group; 3 – radiators; 4 – needle valve; 5 – expansion tank; 6 – drain; 7 – water supply; 8 – filter; 9 – pump; 10 – ball valves
With such a system, the filling of the radiator decreases, which reduces the speed of movement of the medium in the battery and increases the temperature difference to 20 ° C (the water has time to cool down strongly). With sequential installation of radiators in a one-pipe circuit, a large temperature difference of the coolant is observed between the first and all subsequent radiators. If there are 10 or more batteries in the system, then water cooled to 40–45 ° С enters the outermost one. To compensate for the lack of heat dissipation, all radiators, except for the first, must have a large heat transfer area. That is, if we accept the first radiator as a standard of 100% power, then the area of the subsequent ones should be larger by 10%, 15%, 20%, etc., to compensate for the cooling of the coolant. It is difficult to predict and calculate the required area without experience in performing such work, and leading, ultimately, to an increase in the cost of the system.
In the classic “Leningradka”, the radiators are connected from the main pipe O 40 mm bypass O 16 mm. In this case, the coolant after the radiator returns to the line. A big mistake is not connecting the radiators in transit, but directly from the radiator to the radiator. This is the cheapest way to assemble a piping system: short lengths of pipes and fittings, 2 pieces per battery. However, with such a system, half of the radiators are barely warm and do not provide sufficient heat transfer. Reason: there is no mixing of the coolant after the radiator with the main pipeline. Way out: increasing the (significant) area of the radiators and installing a powerful pump.
Masters recommend using a one-pipe system if there are no more than 5 radiators in the circuit.
Two-pipe collector (beam) heating wiring diagram
It is a comb, from which two pipes extend to each radiator. It is advisable to install the comb at an equidistant distance from all radiators, in the center of the house. Otherwise, with a significant difference in the length of the pipes to the batteries, an imbalance of the system will occur. This will require balancing (adjustment) with cranes, which is quite difficult to accomplish. In addition, in this case, the pump of the system must be of greater power in order to compensate for the increased resistance of the balancing valves on the radiators..
Collector circuit: 1 – boiler; 2 – expansion tank; 3 – feed manifold; 4 – heating radiators; 5 – return manifold; 6 – pump
The second disadvantage of the collector system is the large number of pipes.
The third drawback: pipes are not laid along the walls, but across the premises.
The advantages of the scheme:
- lack of connections in the floor;
- all pipes of the same diameter, most often 16 mm;
- the connection diagram is the simplest of all.
Two-pipe shoulder (dead-end) system
If the house is small (no more than two floors, with a total area of up to 200 m2), it makes no sense to build a ride. The coolant will reach each radiator. It is highly desirable to think over and install the boiler in such a way that the “shoulders” – separate heating branches, are approximately the same in length and have approximately the same heat transfer power. At the same time, up to the tees dividing the flow into two arms, pipes with O 26 mm are sufficient, after the tees – O 20 mm, and on the main line to the last radiator in the row and branches to each radiator – O 16 mm. Tees are selected corresponding to the diameters of the pipes to be connected. Such a change in diameters is a balancing of the system, which does not require adjustment of each radiator separately..
Difference in connection of dead-end and passing schemes
Additional advantages of the system:
- minimum number of pipes;
- laying pipes around the perimeter of the premises.
Connections “sewn” into the floor must be made of cross-linked polyethylene or metal-plastic (metal-polymer pipes). Proven, reliable design.
Two-pipe passing system (Tichelman loop)
This is a system that does not have to be adjusted after installation. This is achieved due to the fact that all radiators are in the same hydraulic conditions: the sum of the lengths of all pipes (supply + return) to each radiator is the same.
Connection diagram of one heating loop: single-level (at the same static height), with radiators of equal power, is very simple and reliable. The supply line (except for the supply to the last radiator) is made of pipes Ø 26 mm, the return pipeline (except for the outlet from the first battery) is also made of pipes Ø 26 mm. The rest of the pipes are Ø 16 mm. The system also includes:
- balancing cranes, if the batteries differ in power among themselves;
- ball valves if the batteries are the same.
The Tichelman loop is somewhat more expensive than the collector and dead-end systems. It is advisable to design such a system if the number of radiators exceeds 10 pcs. For a smaller number, you can choose a dead-end system, but subject to the possibility of a balanced division of “shoulders”.
When choosing this scheme, you need to pay attention to the possibility of laying pipes around the perimeter of the house, so as not to cross the doorways. Otherwise, the pipe will have to be turned 180 °, lead it back along the heating system. Thus, in some areas, not two pipes will be laid side by side, but three. This system is sometimes called a “three-pipe”. In this case, the ride becomes unnecessarily expensive, cumbersome and it is worth considering other heating schemes, for example, to divide into several “shoulders” of a dead-end system.
Connection to the underfloor heating system
Most often, underfloor heating is an addition to the main heating system, but sometimes they are the only heaters. If the heat generator for underfloor heating and radiators is one and the same boiler, then the piping on the floor is best done on the return line, on a cooled coolant. If the underfloor heating system is powered from a separate heat generator, set the temperature according to the recommendations for the selected underfloor heating.
The connection of this system goes through a manifold, which consists of two parts. The first one is equipped with valve regulating inserts, the other part is equipped with rotameters – that is, heat carrier flow meters. Rotameters are produced in two types: with installation on the supply and on the return. Masters advise: if during installation you forgot which rotameter you bought, orient yourself in the direction of flow – the fluid supply should always go “under the seat”, opening the valve, not closing it..
Connecting underfloor heating on the return: 1 – ball valves; 2 – check valve; 3 – three-way mixer; 4 – circulation pump; 5 – bypass valve; 6 – collector; 7 – to the boiler
When planning a heating system in your home, you need to weigh the pros and cons of each scheme in relation to the design of the house itself.