Potential of PV Façade for Supplementary Lighting in Winter

AbstractModern office and public buildings have to meet the requirement of zero-emission buildings through high insulation and integration of renewable energy sources on the own premises. The presented paper is devoted to exploring a BIPV facade potential as a source of electricity for supplementary lighting in an office room during winter. Analysis was carried out, for a typical office room with window centrally located in the facade, using simulation tool ESP-r for energy performance and Daysim for daylight luminance distribution calculation. Results indicate that electrical energy generated by BIPV cover supplementary lighting only in the room with south oriented façade

The effect of wall thickness and window position on efficient daylight utilisation in building interiors

This paper presents a numerical analysis of the daylighting of exemplary office interiors. Simulation results were obtained using a radiance model. The following indexes: UDI, DF, DA, DSP were calculated and analysed for different solutions of building façade. The construction differs in the total thickness of the wall. Two cases were considered: 25 cm and 50 cm opaque sections. Additionally, window magnitude changes from 0.36 m2 to 1.44 m2, with different shapes and locations relative to the centre of the wall. The idea of the work was to find out the architectural solution of the transparent element (geometry and magnitude) taking into account two criteria: decreasing solar heat gains; increasing the daylight utilisation factor. The results are presented in the form of a diagram of daylight distribution as well as average values of visual comfort indexes. The highest values of each indicator (DF, DA and DSP) were obtained for a centrally placed window 1.44 m2. However, the results of useful daylight index UDI depend on the assumed range and it is not easy to identify a relationship between window size and daylight efficiency

Providing an interior daylight environment through the use of light pipes

The paper presents the effect of using additional daylight illumination of building interiors using tubular skylight systems. Interior illuminance distribution was analysed using a combination of two daylight sources – window and skylight pipes. The results were obtained for cloudy weather conditions. Final remarks concern the effectiveness of supplementary daylighting of interiors using different configurations of light pipes