Simulation of the ventilation and energy performance of a PV-integrated breathing window

Abstract

A photovoltaic (PV) integrated double skin breathing window was proposed, which adopts double-layer structure, and four operable openings at the upper and lower part of both inside and outside of the window. Different combination of open and close of the operable openings represent different working mode. The outside glazing is equipped with photovoltaic, which can absorb solar energy to heat the window surface to induce airflow for ventilation and generate electricity to drive the openings actuator open and close. Therefore more efficient use of solar energy is achieved. A CFD model was built to optimize the size of the window, including size of glazing, size of opening and thickness of the air flow path. Six different working modes were designed and simulated during both daytime and night time of typical summer, winter, spring equinox and fall equinox day in Shanghai to evaluate ventilation and thermal performance of the window under cooling, heating and transitional season. Ventilation air flow rate, air temperature increase/decrease through window, total ventilation air heat gain/loss as well as thermal conductivity of the entire window is optimized by changing glazing size, opening size and airflow path. It shows great potential of the window to ventilate building and save energy.