Optimization of global energy consumption of buildings based on photothermal coupling effect of exterior windows in Qinghai-Tibet plateau

Due to cold winter and abundant solar energy, passive solar houses have significant energy-saving potential and application prospect in Qinghai-Tibet plateau. For passive solar houses, exterior windows can affect lighting energy consumption through natural lighting, which in turn affects the indoor thermal environment. Meanwhile, solar radiation and heat transfer by temperature difference can also influence heating and cooling energy consumption through exterior windows. To explore the effect of exterior windows on the overall energy consumption, it is necessary to conduct specialized research from the perspective of the photothermal coupling effect of exterior windows. Thus, a global energy consumption calculation method (GECM) is proposed in this paper to evaluate the impact of exterior windows on building energy consumption. In GECM, the correlation of daylight factor has been established, and main exterior window design factors affecting the global energy consumption have been investigated, including window to wall ratio (WWR), window orientation and window type on. A residential building is selected as a case study and results show that reasonably selecting window type and designing WWR can effectively reduce the global energy consumption, which provides a theoretical basis and technical support for the optimization design of exterior windows in Qinghai-Tibet plateau region. •A global energy consumption calculation method (GECM) is proposed for buildings in Qinghai-Tibet plateau.•The GECM takes into account the photothermal coupling effect of exterior windows.•The correlation of daylight factor is established based on experiments and simulations.•Main exterior window design factors affecting global energy consumption are investigated.