Simulation models of an electric-driven smart window: energy and visual performances

In this paper, the “in situ” measurements acquired to characterize full-scale electric-driven glasses, able to switch from opaque to transparent state thanks to an electric field, were used to develop, calibrate and validate thermal and visual simulation models of these devices, by means of the simulation software TRNSYS. The validated simulation models were then used, in the same simulation software, to assess the ability of the electric-driven glasses, integrated in historical buildings, to control the indoor comfort conditions as well as to evaluate their ability for reducing cooling energy consumption. The analysis was conducted for an office located in an historical building, comparing the simulation results associated to the electric-driven window with those of a conventional double-glazing window, from energy and visual points of view. The energy and visual analyses were carried out considering two different switching strategies: i) Daylight strategy and ii) Thermal strategy.