Measurement-based control strategies for thermal comfort and regulation in low-temperature district heating networks

Low-temperature district heating networks represent a key pathway for decarbonising urban heating by enabling the integration of zero-carbon energy sources, including renewables and waste heat. These networks support energy-efficient heat delivery, large-scale seasonalstorage (e.g. geothermal) and improved performance of heat pumps, solar panels and combined heat and power systems. Despite thesebenefits, significant challenges remain, such as designing networks to minimise heat losses and pumping energy consumption whilereliably meeting heat demand. Ensuring compatibility of temperature levels with existing buildings, which are often designed for hightemperature heat sources, is also a major concern.
This study investigates measurement-based control strategies to ensure thermal comfort under both design and operational conditions.Specifically, it evaluates the use of simple return temperature control strategies based on measured data, adjusting pump speeds inresponse to the return temperature of the most critical consumer. The aim is to investigate strategies that replicate practical approachesused in the implementation of district heating networks. By coupling dynamic models of key system components - including thermalstorage, networks, pumps, control and building envelopes - the study provides a complete picture of the system dynamics that the controlsystem has to deal with.
The novelty of this approach lies in the integration of system dynamics with the resulting indoor temperatures of the connected buildings,providing a comprehensive strategy to optimise both thermal comfort and operational efficiency, while addressing the challenges posed bythe existing building infrastructure, its specific requirements and occupancy. Field measurements from two existing buildings and theirassociated thermal networks validate the proposed models and methods.