The impact of users’ behaviour on solar gains in residential buildings

Abstract

Regulations governing the relevant procedures for the energy certification of buildings in Serbia do not consider the impact of users’ behaviour on the level of heat loss or gain. In the case of solar heat gains, the gains are calculated both through transparent, as well as through non-transparent thermal envelope positions. Solar gains through transparent parts - windows and balcony doors are dominant, and depend on thermal properties of windows, orientation, shadings. In this regard, the regulation stipulates that all transparent (and semi-transparent) surfaces in the residential areas, other than those oriented to the north, northeast and northwest, must have non-transparent protection from direct solar radiation in the summer period. Shading elements can be permanent and movable, and their shading effect is defined by the standard EN 13790. Users express different attitude towards the possibilities of solar gains provided through the glazed parts. This is mainly determined by the dynamics of moving (lifting) the shadings, which depends on their presence and, to a large extent, on the heating system (with the assumption that in buildings connected to the district heating system and the lump sum of heat consumption per m2, users are not motivated to contribute actively to the heat gains). The paper analyses the ratio of lifted / lowered (outer) shadings at different times of the day in the winter period on several examples of collective housing in Belgrade, with the aim of establishing the effective calculated area of the window for solar gains. The comparison of the obtained results with the parameters of the reduction due to sun protection equipment defined by the standard EN 13790, aims to establish and promote the design values that are realistic for use in the energy certification procedure of residential buildings.