Performance and optimization of a BIPV/T solar air collector for building fenestration applications

The different elements of the building envelope such as facades, roof and windows play a central role in its thermal behaviour, and new technologies that integrate their architectural functions with energy generation are emerging. A prototype of a building-integrated photovoltaic/thermal (BIPV/T) air collector was built, which is intended to perform the functions of thermal and electrical generation, light transmission and shading control. In this work, the prototype was tested under different conditions to investigate its thermal and electrical performances. The results showed a maximum temperature rise (from bottom to top) of 31 °C and average thermal and electrical efficiencies of 31% and 7%, respectively. The experimental data were used to build a two-dimensional model in COMSOL Multiphysics, in order to assist in the optimization of the various system components for the design of the next prototype. Simulations were performed on the glazing system to optimize the thermal output, through the use of coatings and additional glass panels. Different configurations were analyzed, and it was found that a 3-pane system with low-e coatings applied to the inside surfaces represents the best cost-effective solution, which results in a 64.7 °C air temperature output and a 40% increase in temperature rise over the existing prototype.