- Classification of hot water heating systems
- Open and closed heating systems
- Which is better: one-pipe or two-pipe structure?
- Horizontal and vertical routing
- Radiator connection types
Water heating is the most common heating option for a private house. The location of the main structural elements determines the type of system and the features of its operation. The competent choice of the piping layout is the key to the efficiency of heating and the comfort of residents.
Classification of hot water heating systems
Hot water heating systems are complex engineering systems with many varieties. Water or special-purpose aqueous solutions act as a coolant in them. Depending on the configuration of the systems, they can be classified according to the following parameters:
- by the way of circulation of the coolant;
- by the presence of contact with atmospheric air;
- according to the power supply scheme of devices;
- by location of main pipelines.
Open-type natural circulation heating circuit. 1 – boiler; 2 – expansion tank; 3 radiator; 4 – the hot outlet of the boiler heat exchanger goes strictly vertically to the expansion tank; 5 – main supply pipe; 6 – riser; 7 – main return pipe; 8 – ball valve; 9 – drain with a ball valve for dumping the coolant
The first way to organize the movement of the coolant through the system is natural circulation. This option allows you to ensure the operability of heating without reference to the availability of electricity. The circulation is carried out by gravitational forces. The liquid heated in the boiler rises due to a decrease in density, enters the radiators, gives off heat and returns to the boiler.
Closed-type forced circulation heating circuit. 1 – boiler; 2 – air vent; 3 – manometer; 4 – safety valve (numbers 2, 3, 4 make up a safety group); 5 – expansion tank; 6 – radiator; 7 – coarse filter; 8 – drain; 9 – circulation pump; 10 – ball valve
The second way is forced circulation. The coolant is moved using a pump installed on the return pipeline and located either in front of the boiler inlet or in the boiler itself.
Open and closed heating systems
Natural circulation hot water heating systems are always open systems. They provide for an open expansion tank at the top of the system. It is often located in the attic..
Expansion tank of open type with access of atmospheric air to the coolant
Forced circulation heating systems are usually closed, i.e. completely sealed. Expansion tanks are made in the form of barrels with membranes inside and are located next to the boiler or inside it.
Diaphragm sealed expansion vessel
Which is better: one-pipe or two-pipe structure?
The devices are powered according to a one-pipe or two-pipe scheme. In the first case, the heating devices are connected in series, and in the second in parallel. The fundamental difference lies in the presence of two types of pipelines in a two-pipe system: for supplying the coolant to the radiators and for returning to the boiler.
1 – one-pipe serial connection of radiators without bypass; 2 – one-pipe connection with bypass; 3 – two-pipe connection with supply and return pipes laying around the building perimeter; 4 – collector “beam” switching circuit
Single-pipe systems only work well in small houses with 6 to 10 radiators per branch. In other cases, they are ineffective due to the uneven distribution of the coolant temperature at the inlet to the radiators.
Two-pipe systems are more versatile and provide more opportunities for thermal regulation. With the help of thermostatic valves, you can adjust the comfortable heat transfer of each radiator without affecting the operation of the rest.
Horizontal and vertical routing
According to the location of the main pipelines, several types of pipelines are distinguished. First of all, this is the division into horizontal and vertical.
The figure shows a single pipe system with vertical wiring. Different types of connection of devices are shown on different risers.
The diagram below shows a typical configuration of a two-pipe system with vertical wiring..
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
The simplest one-pipe system with horizontal wiring implies the sequential passage of the coolant through all devices within one floor.
Collector circuit: 1 – boiler; 2 – expansion tank; 3 – feed manifold; 4 – heating radiators; 5 – return manifold; 6 – pump
A two-pipe horizontal system can have perimeter or beam (collector) wiring. In the first case, pipes are laid along the perimeter of the room, gradually feeding all devices, in the second, each heating device has a separate connection.
Radial distribution pipes are laid in the floor screed by the shortest paths to each radiator. Moreover, their configuration resembles rays emanating from one source – a distribution manifold. This was the reason for the appearance of the corresponding name.
Collectors in modern interiors of private houses are often neatly hidden in special cabinets, which allows you to preserve the aesthetics of the room and hide the elements of setting and regulating the system.
Radiator connection types
The heating device connection diagram is selected based on the selected structure of the heating system, ease of installation and maintenance, as well as interior features.
1 – Two-pipe wiring. 2 – One-pipe wiring
The figure shows the main options for connecting radiators, typical for vertical systems.
A – lateral connection; B – diagonal; B – bottom connection
An analysis of the circuits that are most often found in horizontal systems shows that the type of connection of radiators has a significant effect on the efficiency of heat transfer. Before giving preference to a more convenient installation option, you should think carefully about whether you are ready to sacrifice some of the precious heat.
As can be seen from all of the above, the choice of a water heating scheme for a private house is associated with the need for a thorough analysis of many options. In addition to the described main varieties, there is an even more detailed classification. Consulting a qualified specialist will help you quickly navigate in all the diversity, take into account the existing nuances and achieve the best results.