Assessment of the thermal and visual efficiency of solar shades

Solar shades are efficient architectural elements in order to reduce the thermal loads inside buildings. In one way, they can reduce significantly the energy needs of cooling systems. But in other way, they can decrease the visual comfort and increase the energy consumption of artificial lighting. Actually, the sizing of shading devices is mainly a thermal optimization process. The efficacy of solar shades must be assess taking into account both thermal and visual point of view. In this paper simple indices were proposed to compare the thermal and visual efficacy of different types of solar shadings in non-residential buildings. These indices can be derived from the results of numerical simulations that include thermal and daylighting analysis such as the EnergyPlus software. A typical office is studied in order to assess the efficacy of different types of solar protections. The use of the proposed indices made obvious the choice and the sizing of the most efficient solar shade for the case study. (C) 2011 Elsevier Ltd. All rights reserved.