Master’s thesis from Politecnico di Milano awarded at the 2025 DHC Student Awards.
In September, during the 2025 DHC Student Awards held as part of the IEA DHC Conference in Genk, Belgium, Sajedeh Roustaei was awarded in the Bachelor’s & Master’s students category for her master’s thesis in Building Engineering. The thesis, titled “Data-driven approach for diagnosing inefficiencies and optimizing district heating networks,” was conducted at the Department of Energy of Politecnico di Milano under the supervision of Dr. Alice Denarie, who served as her advisor, and Dr. Giulia Spirito, who was co-advisor.
Roustaei is now a PhD student in the STEN – Science and Technology for Energy and the Environment program, but the recognition pertains to the research she carried out during her master’s studies.
An innovative contribution to improving the efficiency of district heating networks.
The thesis addresses one of the most complex challenges in managing district heating networks: reducing the return temperature, a crucial parameter for the overall efficiency of the system. Lowering return temperatures improves network performance, but identifying the causes of high temperatures and implementing targeted interventions is particularly difficult in large-scale systems.
The work proposes a scalable, data-driven framework to support operators in diagnosing and optimizing substations. Using time-series clustering techniques, substations are grouped based on their temperature profiles; a structured ranking method then evaluates the contribution of each substation to network inefficiencies. User-side data analysis allowed the identification of the main causes of high return temperatures and the proposal of targeted interventions, with particularly promising results: the average return temperature could be reduced from 62°C to approximately 56°C.
In addition to analyzing problematic substations, the research examines user consumption behaviors, identifying nine load profiles and developing a method for imputing missing data, useful for improving the planning of district heating networks.
