The performance analysis on a multifunctional photovoltaic driven air heating, cooling and purification building roof

Thermal catalytic oxidation technology is an advanced method for indoor air purification. Photovoltaic panels can achieve daytime heating and nighttime radiative cooling due to their high solar spectral absorptivity and high atmospheric window emissivity. Therefore, this study integrated photovoltaic technology with thermal catalytic purification technology and proposed a multifunctional photovoltaic driven air heating, cooling and purification building roof. We designed and constructed an experimental platform to evaluate the comprehensive performance of system. A coupled electrical, thermal and mass transfer model of the proposed roof system was established and validated. Based on the model, the energy-saving potential of the system was assessed across 34 provincial capital cities in China. The main conclusions are as follows: (1) Under one-day operation during heating season, the system achieved an average electrical efficiency of 17.5 %, an average thermal efficiency of 37.1 % and produced a total of 30.03 m3 of clean air. (2) The effective daytime heat collection of the photovoltaic panel increased the system's average purification efficiency by 19.8 %. (3) When applied in China, the system generated 1091–3903 kW of electricity annually, produced 8889–16894 m3/m2 of clean air annually, and achieved an annual cooling gain of 4049–27073 Wh/m2 and thermal gain of 1897–24717 Wh/m2.