Single- and double-inlet PV curtain wall systems using novel heat recovery technique for PV cooling, fresh and supply air handling: Design and performance assessment

Abstract

Building integrated photovoltaic (BIPV) technology has emerged as a promising solution for serving electricity and heat demands in buildings. However, PV overheating causes reduced production, increased space cooling load, and stagnation damage. To address overheating and save energy in air conditioning, this study proposed novel single- and dual-inlet ventilation PV curtain wall systems (SVPV and DVPV). In summer, the building exhaust is introduced into the channel to strengthen PV cooling, while incoming fresh air is used to preheat dew-point air. In winter, warm exhaust within the channel decreases heat loss through the facade and then raises the fresh air intake temperature. Mathematical models were developed for the systems, and a comprehensive performance evaluation criterion (PEC) was defined. Economic analysis was conducted using simple payback (SP) and net present value (NPV) models. Additionally, the impact of ambient temperature and solar radiation on system performance was investigated. The case study demonstrates that SVPV and DVPV reduced annual energy consumption by 957.23 kWh (28.07%) and 910.97 kWh (26.72%), respectively, compared to a conventional non-ventilated system. SVPV slightly outperformed DVPV, with an average PEC of 0.556 and 0.544, respectively. This study provides valuable insights for operational strategies and future large-scale promotion of BIPV applications.