The flow temperature refers to the temperature of the water in the supply (flow) pipe in a heating system or separate part of a heating system. If a heating system is directly connected to the district heating system its flow temperature is set by the district heating provider.
In an indirect heating system water is mixed or sent through a heat exchanger before being distributed through the pipe system, i.e. the supply temperature is regulated, for example in relation to outside temperature. The automatic control is set according to a defined heating curve that matches the specifications of the system. However, the flow temperature for the heating system cannot exceed the district heating water temperature.
When choosing the supply temperature to a building’s heating system, the following should be taken into consideration:
- Maintaining a comfortable temperature
- Limiting energy consumption used for heating
- Achieving lowest possible district heating return temperature