Direct heating stations with instantaneous domestic hot water preparation are used in single-family houses, where pressure and temperature conditions allow direct connections, but the most common use is in the multi-family buildings with decentralized heating and DHW installations.
An indirect substation is used when district heating network conditions, such as pressure and temperature, do not allow direct connection. When a substation is connected indirectly, a heat exchanger provides energy-efficient heat transfer. It also ensures that the primary network supply side and the secondary building installation side remain safely separated.