Energy assessment of a sliding window integrated with PV cell and multiple PCMs

Windows often serve as a thermal weak point between a room's interior and the outside world. As such, we are exploring a new design for a sliding window that integrates both multiple phase change materials (PCMs) and photovoltaic (PV) cells. During the day, the PV cells produce electricity, which can be used in the building during the night. The sliding mechanism introduces several innovative features: use the PV-PCM glass unit (as the external sliding layer) or a standard glass unit (the internal sliding component). The PV-PCM window also can be used as a sliding light shutter or curtain. The PV cell in the proposed design is operated in the closed and open case due to the sliding design. We compared the thermal performance of a single PCM type (either RT-35or RT-27) with a combination of multiple PCMs (RT-35-RT27). Further, we evaluated various thickness combinations of the multi-PCM configuration (RT-35-RT27), including 2.5mm–7.5mm, 5 mm–5 mm, and 7.5 mm–2.5 mm, to identify the best-performing setup. Over the course of a day, the multi-PCM setup (RT-35-RT27) maintains a consistently lower average interior wall temperature than using a single PCM. Among the configurations tested, the 5 mm–5 mm multi-PCM setup (RT-35-RT27) emerged as the most effective, displaying steadier results than the other variations. Compared to a standard single glass pane, the proposed PV-PCM window reduced the highest interior wall temperature by up to 46 % when employing multiple PCMs. As a result, we advocate for the adoption of this innovative sliding window in future building designs.