Impact of photovoltaic energy-saving window on building heating load

Photovoltaic (PV) glazing contributes to energy conservation; however, its low transmittance increases building heating load, limiting its application in heating-dominated regions. This study aims to address this issue by proposing an innovative photovoltaic energy-saving window (PEW). The PEW combines the control of PV glazing and an insulated shutter, enhancing solar heat gain during the day and improving insulation at night, thereby reducing heating load. A numerical model was validated, and both single-factor and multi-factor analyses were used to examine key factors affecting heating load. Further simulations and on-site experiments quantified the heating load reduction achieved by the PEW with the proposed control mode. The main findings are as follows: 1) Key factors are negatively correlated with heating load, ranked by descending correlation: the number of clear glazing layers, insulated shutter thickness, number of PV glazing layers, and PV glazing transmittance. 2) The optimal window configuration reduced heating load by 17.93 % compared to the least efficient configuration. 3) Over the annual heating period, the proposed window achieved a 23.54 % reduction in heating load relative to double-pane clear glazing. This study introduces a novel window and control mode that mitigates the impact of the low transmittance of PV glazing and enhances thermal insulation performance. It offers valuable insights into the influence of key factors on building heating load. Additionally, it provides an effective solution for improving energy efficiency in buildings, especially in heating-dominated regions.