In this short article I explain what a heating system with circulating pump is, how it works and what its advantages and disadvantages are. The most important feature of a heating system with circulating pump is the use of a pump to transport water in the heating system. An alternative heating system is gravity heating.
Table of Contents
Heating system with circulating pump
In a heating system with circulating pump, the heating water is forced to circulate in a heating circuit with the help of a circulation pump. The circulation pump can be installed in the flow pipe (FP) or in the return pipe (RP). However, it has become generally accepted to install the pump in the flow pipe. If you can’t imagine a circulating pump, you will find a modern circulation pump in Fig. 1.
Function of heating system with circulating pump
For the function of this type of heating system, the heating water is transported by using a pump. In the first step, it is heated in the heating source and then pumped into the heating circuit by the circulation pump.
It flows via the flow to the radiators and returns via the return to the heating source. As long as the pump is in operation, there is a permanent circulation and thus a circulation of the heating water in the heating circuit (see sketch of the diagram of a heating system with circulating pump).
Advantages and disadvantages
Advantages of a circulating pump
In contrast to a gravity heating system, the heating system with circulating pump has several advantages, for example, radiators can be placed further away from the heat generator or can be located below the heat generator. This means that with a heating system with circulating pump, the heat generator can be installed anywhere in the building, for example in the attic.
Further advantages of a heating system with circulating pump are smaller pipe cross-sections and thus lower pipe costs. As a result, there are fewer line losses, less heating water is required, and thus the heating times of the heating water are also shorter.
However, one thing is mandatory: when installing a heating system with circulating pump, hydraulic balancing is necessary to ensure proper operation of the system.
Tip: Here you find more information about hydraulic balancing.
All the advantages are listed here once again:
- Small nominal diameters of the pipelines and thus lower piping costs
- Lower water volumes and thus faster heating of the heating water
- Inert system and good controllability
- Arrangement of the radiators is arbitrary
- Arrangement of the heat generator is arbitrary
Disadvantages of heating system with circulating pump
A major disadvantage of this type of heating system is the necessary power supply for the circulating pump. However, this disadvantage plays a minor role in Europe.
For this reason, I see the biggest disadvantage as being the mandatory performance of hydraulic balancing, which, however, is usually forgotten, neglected or not even considered in existing buildings, for example when converting from gravity to heating system with circulating pump.
A lack of hydraulic balancing leads to flow noise in the heating network, unintentional short circuits, so that areas of the building are overheated or undersupplied, and suboptimal flow behavior of the heating water.
Here once again listed all the disadvantages:
- Electricity connection for the circulating pumps is mandatory
- If hydraulic balancing has not been done, there will be problems in the heating network
- Flow noise in the heating network as well as pump noise
- With stage-controlled circulating pumps, the share of the total power consumption is relatively high (can amount up to 5% of the total consumption) – see article “7 reasons for replacing the heating pump”.
Due to the advantages mentioned above, today’s hot water heating systems are almost exclusively planned as heating system with circulating pump and gravity heating systems are converted to systems with circulating pump. Only in remote areas without power supply the use of a gravity heating system is still reasonable.
I hope this article helps you to understand a heating system with circulating pump a bit better. If you have any questions I’m looking forward to see your comments
Best regards! Martin
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