Zhineng He came to the University of Navarra four years ago thanks to a scholarship from the Chinese Government. He studied Engineering at the University of Yangzhou (China), did a Master's Degree in Engineering at the Dalian University of Technology (China) and did a research stay at the University of Kaiserslautern-Landau (Germany). After four years in Pamplona, he has just defended his doctoral thesis . During the research process she has had the support of her tutors, César Martín-Gómez and Amaia Zuazua-Ros, professors and researchers of the School.

In this interview he discusses his thesis , System modeling and control strategy of thermoelectric window frames:

What does your thesis consist of?

Thermoelectric window frames (TEWF) function as auxiliary components of enclosures to provide supplementary heating or cooling indoors. This thesis focuses on improving their thermal performance through the development and implementation of advanced control strategies. The strategies are formulated through a detailed analysis of the core topic control core topic parameters, using both numerical simulations and experimental validation.

What is the main motivation for using thermoelectric window frames in buildings?

Although thermoelectric applications in vertical enclosures, horizontal enclosures and air conditioning systems are relatively common, their use in windows is not widespread. However, windows are responsible for approximately 20% to 40% of energy consumption in buildings. This is largely due to heat gains from ambient heat transfer and solar radiation, which increase the thermal load on buildings and cause uneven indoor temperature distribution.

To address this problem, a thermoelectric system can be integrated into window frames, called thermoelectric window frames (TEWF). The adoption of TEWFs, combined with the integration of renewable energy in buildings, not only reduces carbon emissions, but also contributes significantly to sustainable development goals.

What advantages can this technology offer in terms of energy savings?

Control systems for TEWFs are based on accurate computational models using real data , occupant behavior and customized parameters. These control systems enable a more accurate, efficient and automated response to meet occupant thermal demands.

By exploring advanced control strategies, such asmachine learning andreinforcement learning, increasingly applied in building energy systems to anticipate and optimize performance under uncertainty.

Incorporating these methods will position TEWFs within the broader context of intelligent building controls and enable pathways to improve both energy efficiency and occupant well-being.

How does the system respond to different climatic conditions?

In this study, all experiments supporting the discussion and conclusions have been carried out under controlled laboratory conditions and in real outdoor environments. The ambient test temperatures range from 27 °C to 32 °C in summer and from 0 °C to 23 °C in winter. In addition, the experiments are conducted for relatively short periods of time. Consequently, the results have difficulty in fully representing the actual performance of TEWFs when applied within a particular climate zone.

What are the core topic factors that determine the efficiency of a thermoelectric system?

During the thesis we have reviewed the applications of thermoelectricity in buildings, collecting research related to factors, parameters, strategies or control methods for thermoelectric systems from 2000 to 2022. This thesis focuses on the core topic groups of factors and control methods for TE control systems.

In the control factors group , this work has defined thermal capacity, electrical power and operating voltage or current as indicators of the power of the Peltier cells and the issue of Peltier cells in operation. This is because the thermal capacity is influenced not only by the entrance voltage or current, but is also greatly affected by the issue of activated Peltier cells.

Zhineng He with his thesis supervisors, César Martín-Gómez and Amaia Zuazua-Ros.