The Use of Solar Shading in a Nearly Zero-Energy Neighbourhood

Ghent University, Faculty of Engineering and Architecture, Research group Building Physics, 9000 Ghent, Belgium

^* Corresponding author: silke.verbruggen@ugent.be

Abstract

The use of solar shading can have an important influence on the internal heat gains, especially in zero-energy buildings. However, the research in literature is almost uniquely focused on offices, while information on the use of solar shading in residential dwellings is lacking. Therefore, the solar shading behaviour of occupants of a nearly zero-energy social housing neighbourhood in Belgium is analysed. Data are gathered by solar shading logging with a building monitoring system, logbooks and cross-sectional surveys. In general, the solar shades were not often adjusted, with many of the solar shades either always opened or always closed. Clear seasonal influences were observed; however, the temperature and solar irradiance did not reveal a significant relationship with the use of the solar shading. This relationship could be biased by the fact that some of the occupants use the solar shades not to prevent solar heat gains but to darken the room in the evening (blinds). Since the shades are not often adjusted and are thus in the same position for a long time, the use is independent of the prevailing weather conditions. The position of the solar shades seems to be more influenced by the personal preference of the occupant than by external factors. Additional simulations, carried out with Modelica, showed that when the full capacity of the solar shades is used, the overheating can be decreased up to 29% in south oriented rooms. The possible negative impact on the heating demands can be neglected. This shows the necessity to correctly model the solar shading behaviour in residential buildings, especially in nearly zero-energy buildings, for which the cooling demands are increasingly important.