Abstract In this paper, an analysis of three-dimensional transient thermal transfer is presented to evaluate the performance of a photovoltaic thermal module with an optimize structural design, incorporating direct use of an aluminum collector as the substrate. The effect of cross-sectional geometries and ratios of size and spacing was considered to optimize the performance of a photovoltaic-thermal (PVT) module. The temperature, velocity and pressure distributions were demonstrated in a steady state model using a finite element method. Simulation results indicated the temperature of the PVT module was increased by the solar irradiation incident with the panel, yet overall decreased by an increased flow velocity. In this study, we examine seven types of media used as the medium to cool the PVT module, where water was preferred, due to its higher specific heat capacity. Further, for multiple interconnected PVT modules, connecting method in parallel and series resulted in pressure drop for the PVT module. In addition, the simulations were compared to experimental data providing validation of the estimated operating temperature in agreement with simulation results, and the outcomes will provide an indication for preferred assembly of PVT modules for application in building integration and future product design.