The one-pipe type water heating system is used to heat private and municipal houses and apartments. It is chosen by homeowners looking to install a circuit that does not require a large investment. This is a more profitable option compared to other types of wiring, for example, collector or two-pipe. When choosing such a system, it is useful to familiarize yourself in advance with the principle of its operation, the advantages and disadvantages, device options and connection methods.
Principle of operation
Each water system operates on the principle of heat exchange between the coolant circulating along the circuit and the air contained in the heated room. The water supply to the batteries is carried out depending on the layout of the room where they are installed. Water is supplied using loungers in a horizontal main-type pipeline or vertical risers. The types of wiring of the system are implemented taking into account the way in which the heat carrier passes along the circuit, and are divided into two types:
- gravitational, when the coolant moves by gravity;
- forced circulation.
For the stable operation of any system, it is necessary that the diameter of the distributing pipe exceeds the size of the radiator connections. This rule does not apply to top-flow risers in which the heat medium flows downward by gravity.
The difference between one-pipe and two-pipe systems
A single-pipe heating system operates with units connected by a single pipe. The coolant in it must be supplied sequentially to each device. In a two-pipe scheme, there are two pipes intended for supply and backflow, in which case the coolant goes to the batteries through the pipe and goes to the heating boiler using the return outlet. The main difference between single-pipe wiring is that the radiators are connected to a single distribution line.
Pros and cons of a one-pipe system
A single-pipe heating system for any apartment or private house warms up faster when compared to a two-pipe one. Subject to the installation rules, the system will be well balanced, the rooms will be heated evenly. This scheme is chosen for its aesthetic appearance, since only a single pipe is needed for routing. In addition to the main advantages when wiring a one-pipe type, you can connect the tap to the battery, which will allow you to remove it without having to turn off the entire heating system. It is advisable to install a scheme of this type in small private houses, this is a more economical option in contrast to the two-pipe method.
Of the minuses of the scheme with a single pipe, difficulties are noted with adjusting the temperature regime in the premises. For this purpose, you need to use polypropylene thermal valves or radiator regulators. In addition to regulation, it is necessary to create strong pressure and install powerful pumps with tanks for expansion at the maximum point of the circuit. If the house is two-story, the heat carrier must come from above.In large houses, it is sometimes necessary to increase the number of sections in the batteries, due to which they have to increase their length and spend additional energy on placement.
Installation methods
Single-pipe heating in a private house can be open or closed, vertical or horizontal, with lower or upper wiring, natural or artificial circulation of the coolant.
Natural and forced circulation systems
The natural circulation system is considered the most common. Previously, one-pipe standard heating of this type was installed in all one-story buildings, including those with stove heating. Its plan includes an expansion tank under the ceiling that receives water from a boiler. Then it flows by gravity into gas or automatic radiators through pipes.
Now in most multi-storey and private houses, automatic boilers with built-in circulation pumps are installed.
If you need to install a boiler with complex automation, the pump is installed for it separately to avoid overheating when the fuel flares up to extreme temperatures. Forced circulation schemes make it possible to implement projects of increased complexity, they are often used for the installation and connection of underfloor heating. Forced circulation is relevant for multi-storey buildings or houses with attic structures.
Open or closed heating system
In widespread open systems, the water level inside the tank rises after overheating and decreases as it cools. They are supplemented with tanks with branch pipes for venting excess steam and atmospheric pressure. Automated devices operating on gas, pellets or fuel oil are complemented by compact expansion vessels that compensate for the minimum expansion of pressure.
Since the pressure itself will depend on the temperature, in the absence of malfunctions, the boiler turns off on its own, the pressure in it drops. If the boiler runs on peat fuel, coal or wood, the combustion process in it cannot be stopped quickly, which can provoke overheating of the water.
An open or closed system design must necessarily include an expansion tank, a polypropylene pump, a valve for steam release and a circuit for automatic water make-up. For solid fuel boilers, closed systems are more often used.
Horizontal and vertical layout
The choice of an option for a single-pipe single-circuit design depends entirely on the type of building, the number of floors in the building and other factors. For small houses, horizontal piping of the required diameter is considered ideal. In buildings with an area of more than 60 sq.m. and with more than three rooms, it is recommended to use a horizontal scheme when it comes to a building with one floor, and a vertical one for a two-story building. In the second case, the wiring is installed on the second floor, then stretched from the upper to the lower, then supplied to the boiler.
The vertical circuit in a one-pipe system for heating is mainly used in multi-storey buildings, where water goes to the attic or to the upper floor and pours down through separate risers, after which it passes through the radiators. This scheme is called Leningrad.
With a horizontal connection, the pipes are located horizontally, and the heating devices are connected one after another. This method is relevant for one-story buildings, since it is much less complicated.
Options for connecting the radiator to the highway
Various options and schemes are used to connect batteries to the line.The efficiency of supplying the thermal medium depends on the method, therefore it is so important to choose the most suitable one.
Diagonal
Diagonal connection is considered the most effective; manufacturers use this scheme when testing appliances for heating. Other options give off heat worse. Also, the diagonal method is quite versatile, which makes it possible to use it both in one-pipe and two-pipe schemes.
Lateral
Compared with the diagonal, with a side connection, the heating efficiency will be slightly lower, by about 2%, if the battery has no more than 10 sections. If the radiator has a long length, its far edges will not completely warm up or will remain cold. To eliminate the problem, flow extenders are installed in panel batteries - special tubes that bring the heat carrier to the middle. Similar devices can be placed in batteries made of aluminum or metal alloys to improve heat output.
Lower
The bottom or saddle connection is considered the least effective, with heat losses reaching 12-14%. Moreover, this option is the most aesthetic, since the pipes are laid on the floor or under it. The heat loss problem is solved by purchasing more powerful batteries to raise the temperature in the room.
Perfectly matched wiring eliminates heat loss and helps prevent unnecessary fuel consumption. A single-pipe heating system for a private house or multi-storey building is a profitable and affordable option for those who want to save money and provide the premises with heat.
