Energy performance assessment of advanced glazed façades in office buildings

The adoption of glazed façades in commercial building is becoming more and more widespread. The main limits of conventional transparent façades related to energy efficiency and IEQ aspects have been overcome developing a new generation of transparent building envelope components called Advanced Integrated Façades This paper evaluates if the thermal behaviour of this kind of technologies can be correctly assessed by means of conventional performance parameters. Data from experimental campaigns on a reflective double glazed unit and on a Climate Façade under actual operating conditions have been used to estimate the correspondent equivalent U-value and g-value. Subsequently, these parameters have been employed to calculate the energy balance of the same glazed façades. The validation of the parameters is then carried out through the comparison between experimental and simulated specific total hourly heat flux and specific total daily energy. The result shows that it is still acceptable to use conventional performance parameters for “simple” glazing technology (e.g. reflective double glazing unit). On the contrary, the adoption of such parameters in case of more advanced façade technologies leads to considerable inaccuracies and makes the predictions based on these metrics not reliable.