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

Abstract

The ?in-situ? measurements acquired to characterize full-scale electric-driven glasses, able to dynamically switch from opaque to transparent state, were used to develop, calibrate and validate thermal and visual simulation models of these devices. The validated models were then used, in the simulation software TRNSYS, to assess the ability of these dynamic glasses to control the indoor conditions and reduce cooling load.

The analysis was conducted for an office in a historical building, comparing the simulation results associated with the electric-driven glasses with those of the conventional double-glazing ones, from energy and visual points of view. Two different switching strategies were considered: i) Daylight strategy and ii) Thermal strategy. The use of electric-driven glasses allows from the thermal point of view to reduce about 12.5% of the cooling load, while from a visual point of view, to reach the highest values of Useful Daylight Illuminance, if controlled following the Daylight strategy.