Water heating system can be called the most common option among the rest. According to statistics, more than 2/3 of buildings are heated precisely by this technique. But the concept of a “water-based heating system” is quite general. It can include many varieties. Among them, a two-pipe system should be distinguished, which is popular and practical.
Principle of operation
Schemes of two-pipe heating systems will be considered in the article below. However, before starting installation work, you should familiarize yourself with the basic principles of the functioning of such heating structures. The system is a closed loop, through which coolant circulates through radiators from the heater and back. As a distinctive feature of this structure is the presence of two pipeline branches. The coolant is distributed along the first, while the chilled water is diverted from the radiator along the other, and the liquid then returns to the boiler.
The main advantages of a two-pipe system
The schemes of two-pipe heating systems are more complicated in design and expensive to implement, however, they are becoming more and more popular, as they have a number of advantages, among which we can single out that each radiator receives water with the same temperature. In each room, you can set a certain level of heating by means of a thermostat, which is installed if desired on each battery. Regulation will not affect the heat transfer of heating appliances in other rooms.
Area of use
Pressure losses are not so large compared to alternative systems, which allows the use of a not so powerful and economical circulation pump. The system can be installed in any building, whether it is multi-story, multi-apartment or single-story. Thanks to the shutoff valves that are installed on the supply pipelines, the replacement of the radiator or repair can be realized without stopping the system.
Extra features
The schemes of two-pipe heating systems have one drawback, which is considered very relative. During the construction, a double length of the pipeline will be used, which leads to the acquisition of a double number of pipes. But this should not be considered a negative characteristic for the reason that pipes of small diameter are used during installation, the standard sizes of fasteners, valves, joints and fittings are also not too large. For this reason, the amount that will be necessary to equip the described system will not be much higher, in particular this is true when comparing with the installation of a single-pipe system. But the advantages in the first case are much greater.
Schemes of two-pipe systems
Installation of heating of a two-pipe type may involve the use of one of two schemes, among which one can distinguish between closed and open. As a division criterion, the type of expansion tank that is used in the construction is used. With an open circuit, an open expansion tank is installed at the highest point of the structure, which allows the coolant to evaporate. In this case, the internal pressure of the system is relatively low. If you will be installing a classic two-pipe type heating, then the work requires the installation of an expansion tank, which has a membrane type. It causes fluid to circulate under forced pressure. The absence of evaporation makes it possible to use not only water as a coolant, but also solutions based on glycols, which are more practical. As for the closed scheme, it is recognized as more environmentally friendly and safe.
Piping Classification
If you will be installing a two-pipe heating system made of polypropylene, then you may prefer a vertical system that differs by connecting radiators to a vertically located riser. This method can be considered optimal for arranging heating in a multi-storey building, since at the same time each floor can be connected to the riser separately. The main advantage here is the absence of air jams during operation. However, it should be noted that the cost of the arrangement will be slightly higher compared to other options.
Horizontal layout
Connecting a two-pipe heating system can also be implemented according to a horizontal scheme. This solution is mainly used for single-story buildings, which have an impressive area. Installation involves connecting heating devices to a pipeline that will be oriented horizontally. At the same time, experts recommend placing risers and wiring in the stairwell or in the corridor. To eliminate air jams on the battery, a Mayevsky crane can be installed .
Classification by the arrangement of wiring
Two-pipe wiring of the heating system may suggest its lower or upper location. In the first case, the hot pipeline is located in the lower part of the building, this can include a basement, an underground space or a basement. The return line should be located even lower. To ensure circulation of the coolant, the boiler must be deepened so that all radiators are above it. During installation work, an upper air line must be included in the circuit, which will be used to divert excess air from the network. Schemes of two-pipe heating systems can also include upper wiring. In this case, the distributing line should be arranged along the top of the building, the expansion tank is installed at the highest point of the circuit. As a rule, the pipeline is laid in the attic, and if we are talking about a building with a flat roof, then this design is unacceptable.
Installation and connection
If you are considering a one-pipe and two-pipe heating system, then, quite possibly, the second variety will be selected, due to a more impressive number of advantages of this scheme. Before you begin installation, you need to familiarize yourself with the sequence of work. To begin with, wall mounted gas heating boilers are installed, which may have a different location. As the most suitable option for the location of this equipment, a separate small room is considered, which is equipped with a well-equipped ventilation system. All kinds of combustion products will be collected here. The floor and walls should be lined with special-purpose refractory materials , while the boiler itself should be positioned away from the wall. It should be in an easily accessible place.
After the calculation of the heating system has been completed, you can begin work. At the second stage, the circulation pump and the distribution manifold are installed , which is true if these components are provided for by the circuit. The master brings the pipeline, and the line should pass from the boiler equipment to the battery locations. In order to draw the structure through the wall, you need to make a small hole, which is then sealed with cement. All connections must be made in accordance with the material that underlies the pipes.
If you will be equipped with a two-pipe heating system at home, then the next step is to connect the radiators. Each device has a heating circuit, which assumes the presence of two pipes, namely the lower and upper. In the first case, we are talking about a variant in which the cooled coolant will be transported along the bottom, while hot will be transported along the top. Batteries must be installed under the windows using special brackets. 12 cm should be retreated from the floor, and the distance from the wall should vary from 2 to 5 centimeters. At the outlet and inlet, regulating and locking fittings, temperature sensors should be installed, with which you can adjust the temperature. After a two-pipe two-story heating system has been installed, it is necessary to pressure test the equipment.
Features of installation work
If the natural circulation of the coolant is used for heating a private house, then it is necessary to install the boiler below the pipe wiring and in those places where the radiators are located. After the wall-mounted gas heating boilers are installed, it is necessary to make a connection with the expansion tank, which is located in the attic. From the side wall of the tank from the lowest point drops the pipe intended for the collector. If there is a circulation pump in the heating system, then the collector can be placed anywhere slightly above the floor. If there is natural circulation, then it is strengthened below the expansion tank. It is important to assemble the return pipes in a single circuit, which is interfaced with heating boiler equipment. If a circulation pump is used in the heating system, then it must be positioned so that its connection is made to the return circuit. This is due to the fact that the pumps have all kinds of gaskets and cuffs, which are made of rubber. High temperatures are completely contraindicated for them. In the expansion tank, you need to weld another pipe, which is installed in the highest place. It is a drain, sewage surpluses coming from the coolant will drain through it.
Cost of materials
If you will be equipped with a two-pipe heating system, then initially you need to calculate the cost of all materials. Thus, for a house with an area of 70 square meters, you will have to purchase 6 radiators, as well as a wall-mounted double-circuit boiler, whose power is 11 kW. The pipes used will be made of polypropylene, and the cost of heating along with materials and work will be 75,000 rubles.
If we are talking about a more impressive area, which is limited to 100 square meters, then you will need already 8 radiators and a double-circuit wall-mounted boiler with a capacity of 24 kW. With a two-pipe wiring, the cost of materials and work will be equal to 100,000 rubles. For an area that is limited to 130 square meters, 12 batteries, a 24 kW double-circuit boiler, and polypropylene pipes will be needed. If we supplement the system with a warm floor, then the price will be equal to 185,000 rubles.
For a house with an area of 180 square meters, you will need 16 radiators, a wall-mounted single-circuit boiler with a capacity of 28 kW, as well as pipes for two-pipe wiring. The entire system, together with material and installation services, will cost 250,000 rubles. The most impressive houses, which are limited to 342 square meters, require the purchase of 28 radiators, an outdoor boiler with a capacity of 50 kW, as well as pipes. At the same time, the work and the purchase of material will cost 540,000 rubles.
Conclusion
Despite such an impressive cost of the services of specialists in the installation of a two-pipe heating system and materials, it is still worthwhile to turn to professionals who will install and competently launch the entire heating system at home.