Influence of the type of solar protection on thermal and light performance in classrooms

Abstract

Solar protections are often designed as passive strategies in buildings, both for thermal and lighting performance. In this sense, the importance of the balance between these two parameters could be crucial in the early stages of design. The purpose of this research is to compare the variation solar protection strategies (glazing with solar protection, and the length of overhangs) have on energy and lighting, using as reference, the value defined by the Modified Solar Factor (MSF), used in some countries like Spain and Chile, to restrict solar contributions. Simulations were carried out to understand the potential of solar protections with the same MSF and the implications on thermal and lighting performance. The case study is a classroom located in Talca, in central-southern Chile, with a climate of marked seasons, including cold winters and hot summers. The results showed that the use of solar protection strategies with the same and similar MSF values do not provide comparable energy performance. Specifically, the differences in energy consumption are 0.62 kWh (East (E) - MSF 0.14) for heating, in cooling 42.28 kWh (Northeast (NE) - MSF 0.47), in lighting 5.30 kWh (Northwest (NW) - MSF 0.11), and 39.77 kWh in the total consumption (Northeast (NE) - MSF 0.47). According to the results obtained, suitable solar protection requires evaluating different alternatives that allow balancing both performances, while attaining significant energy savings.