Simulations of energy efficient windows in a historical building located in mid-Sweden

Abstract: Amorphous silicon photovoltaic windows intend to not only improve thethermal bridge that windows represent but also to collect energy from theradiation incident on the windows themselves. This kind of windows can beapplied anywhere, however to maximize the benefit these can bring it isrecommended for sun-oriented façades. This research aims to investigate theimpacts that this type of windows can have on the energy performance andthermal comfort of a three-story historical stone building in the cold climateof Sweden using the simulation software IDA ICE. The model used for thesimulations had previously been developed and tested in other researches thatinvolved this same building. This research shows that the yearly energyconsumption for the townhall can be reduced down to 280000 kWh,representing a reduction of 5000 kWh compared to the base model, if theHigh transparency windows are applied, representing a reduction of 1,7%.The use of any of the four proposed windows has shown to increase thepercentage of best comfort hours by at least 5% and lowers the percentage ofunacceptable comfort hours at least by a 10%, even having cases with 0 hoursat this comfort level. The upper level of the South façade would be able toprovide the building with 800 kWh yearly, being the level with the highestenergy collection due to having more windows. Approximately every windowcould collect around 90 kWh yearly, which represents 20% of what a solarpanel of the same area correctly oriented could obtain in the same period oftime. Thus, the amorphous silicon photovoltaic windows do not seem to bethe best change despite offering a very promising thermal comfort. Theeconomical viability of this project is what prevents it from being feasiblesince the energy saving/obtaining characteristics are not of great magnitude.