An Experimental Facility for the on Site Characterization of Smart Windows

A "smart window" is a transparent element that enhances the interaction between the inner and outer environment and can be considered as the most promising type of window in terms of energy saving and visual comfort. Differently from standard windows, smart windows allow for the reduction of heat losses together with the control of solar radiation. In order to increase the diffusion of this emerging technology, its on-site assessment and characterization upon varying internal and external conditions is necessary. In order to evaluate the performances of different types of smart windows, an experimental station was set up; the facility consists of a "spinning" structure placed on a turntable that can vary the orientation of the walls and window. Three of the four walls as well as the window can be easily removed and changed with the aim of characterizing different types of walls and windows. For a complete assessment of the tested windows, the experimental station is equipped with several sensors. The outdoor sensors measure the external climatic conditions, whereas the sensors installed inside collect data on daylighting distributions. The main purpose of this paper is to describe the set-up of the experimental station and present the results of preliminary experimental tests performed on smart windows with the aim of validating the measurement procedures.