One-pipe heating system (definition)

One-pipe heating system — is a type of heating system that uses a single pipe to circulate the coolant through the heating devices. In this system, the hot coolant enters through one pipe and then returns through the same pipe after passing through radiators or other heating elements.

One-pipe heating system: main aspects

1. Principle of operation:
   • Submission and return: The hot coolant is supplied through one pipe to the radiators, where it gives off some of the heat, and then returns back to the boiler through the same pipe.
   • Distribution: In radiators, the coolant gives off heat and cools down before returning to the system. This means that the coolant temperature decreases as it moves through the system.
2. Advantages:
   • Simplicity of design: Fewer pipes simplify installation and reduce material costs.
   • Saving space: A one-pipe system requires fewer pipes and space to accommodate them.
3. Flaws:
   • Uneven heating: The temperature of the coolant decreases as it moves through the system, which can lead to less efficient heating of radiators located far from the boiler.
   • Limited adjustment options: Since all radiators are connected in series, it is difficult to regulate the temperature in individual radiators. Thermostatic radiator valves and balancing devices are often used to improve regulation.
   • Dependence on subsequent devices: If one radiator is blocked or requires servicing, this may affect the heating of the other radiators in the system.
4. Types of one-pipe systems:
   • Top connection system: Water is supplied from above, and the coolant passes through all the radiators as it moves downwards.
   • Bottom connection system: Water is supplied from below and returned upwards, which can improve circulation and uniformity of heating in some cases. A single-pipe heating system improves the movement of the coolant in systems with insufficient pressure.
5. Installation and equipment:
   • Pipes: One pipe passes through all the radiators and returns back to the boiler.
   • Regulating elements: Although temperature control in individual radiators may be limited, the system can be fitted with thermostatic valves and other devices to improve control.
   • Air vents: Installed to remove air from the system, which helps maintain its efficiency and reliability.

Application:

Single pipe heating system are often used in older buildings or in systems where it is important to minimize the amount of piping and installation costs. They can be effective in small or homogeneous rooms where complex temperature control is not required.