9.4. Evaluation of energetic performance

In order to evaluate the total energetic performance of the single window element, two specific locations with very different irradiance profiles were selected as examples: Hamburg in Germany and Sevilla in Spain. Further, two orientations (south and west) and two different shading states were considered: unshaded and fully shaded with slats in a static horizontal position (0°). EPW files (Lawrie et al., 2019) representing typical meteorological years can be imported directly. Data of climate.OneBuilding.org (Crawley et al., 2022) was used to model the local climate for the chosen locations. The reference years DEU_HH_Hamburg-Fuhlsbuttel_101470_TRY2010_03_Jahr and ESP_AN_Sevilla.083900_TMYx were used to reflect the climate of Hamburg and Sevilla. For the sake of comparability and simplicity, a constant indoor temperature of 22 °C was assumed for the entire year. The annual simulation runs were processed with 1-minute time steps. The total calculation time for the whole year was less than one second on a single CPU. The simulation model’s high performance is ideal for carrying out parametric studies or control-strategy optimisations efficiently.

Figure 152 shows the results of the simulation runs displayed as biweekly average values for the total power values transmitted through the window. Due to the high insulation effect of the triple glazing, all simulation cases show positive annual totals. However, a significant seasonal variation can be seen. While the west-oriented window in Hamburg shows total energy losses between November and March, the south-facing window in Sevilla clearly shows the highest total gains, with minima occurring in the summer months. The significantly different seasonal pattern results from the lower latitude and clearer sky conditions compared to Hamburg. The strong angular dependence of shading-, projection- and reflection-effects result in remarkably low solar gains for the unshaded south-oriented window in Sevilla during the spring and summer months.