Visual and energy performance of glazed office buildings in Mediterranean climate

The present study is aimed at analyzing to which extent the type of window glazings affects the energy performance and the indoor comfort of buildings in Mediterranean climate. An office building located in Bari, southern Italy, was assumed as a case study due to its largely transparent envelope. Different glazings were applied to the building: a reflective window, a solar control window with low-E properties and an electrochromic window. The proposed solutions were compared with the existing windows, supposed to be ordinary clear double glazings. Thermal simulations, daylight analysis and economic evaluations were carried out to obtain an all-comprehensive view of the issue, involving energy parameters and comfort indicators. Reports pointed out that on an annual basis the main cost is entailed by cooling needs. The electrochromic window reduces the annual electricity demand for air conditioning by 17%, but its installation costs were found to be not sustainable with reference to the envelope life span. The low-E solar control window succeeds in ensuring the best thermal comfort indoors and in reducing the cost of air-conditioning by nearly 15%, as well as performing slightly better than the reflective glass in terms of electricity demand for lighting.