Field measurements and simulation of energy, lighting and comfort performance of retrofit of windows by means of film coatings

Windows may represent a very important element for determining comfort condi-tions and energy efficiency in a building. This problem is quite important on both histor-ical buildings, where usually glazing elements present poor performance in terms of en-ergy, and new buildings, where very often the use of wide surfaces leads to excessive heat and light especially in summer season. The study was based on a comprehensive three year assessment of an existing 9 storey building located in Padova, with over 1000 m2 glazed surface area. The field test campaign includes 450 days of consecutive monitoring of environmental conditions and investigation of the buildings energy consumption over the three years. A key method used to assess the impact of the installed solar control film was the development of sophisticated computer simulations for energy use and lighting conditions as well as economic benefits, CO2 emissions reduction, thermal comfort, and visual comfort. These were calibrated based on data collected from the monitoring phase and from measured local weather conditions. Detailed calibration was vital to ensure simulations properly represented the behaviour of the building before and after film was applied. In addition to the quantitative analysis techniques used, occupant surveys were undertaken to identify the perceived impact of the film on the building occupants.