Combining photovoltaic double-glazing curtain wall cooling and supply air reheating of an air-conditioning system: Energy-saving potential investigation

Abstract

To address the problems of PV facade overheating and air-conditioning cold-heat offset, this study proposed a novel PV double-glazing ventilated curtain wall system (PV-DVF) that combined PV cooling and dew-point air reheating. A case study was conducted based on an office building with a south-facing PV-DVF in Hefei, compared to one with a conventional PV double-glazing insulated curtain wall system (PV-DIF). This study mainly includes mathematical modeling and validation, performance prediction, and parametric analysis. During a typical summer week, the results reveal that the PV-DVF system achieved (1) a 4.64 °C drop in PV temperature and a 3.4 W (1.07 %) increase in power output, with 7.10 % electrical efficiency; (2) a 2083.22 W reduction in cooling energy consumption; (3) a 4431.81 W reduction in reheat energy; and (4) total electricity savings of 27.92 kWh/day. In the summer, the total electricity savings reached 1566.33 kWh, with an energy-saving ratio of 27.51 %. Furthermore, parametric study results show that properly increasing channel thickness and PV coverage ratio achieves better energy-efficient performance.