Lawrence Berkeley National Laboratory
Effects of window size in daylighting and energy performance in buildings
- Author(s): Melendo, JMA
- La Roche, P
- et al.
Published Web Locationhttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.720.8329&rep=rep1&type=pdf
The design of buildings is a complex process in which decisions are taken during the design stage that critically affect the habitability and energy performance. In this sense, large window areas allow more daylight into a space, but they may also allow excessive heat gains or losses which increase the air-conditioning cooling or heating load, and the energy consumption. For a correct selection of window size it is advisable to consider the combined effect of daylight and temperature. In this paper a typical office space in Los Angeles, 4 × 4 × 3 m. high (13.12×13.12×9.84 ft.) was used as a base case to analyze this question and provide guidelines on appropriate glazing ratios in the façade. To determine this ratio the daylight availability and energy consumption are identified as the major criteria and an energy analysis software HEED (Develop by the Energy Design Tools Group of UCLA and CTG Irving Energetics. California) has been used together with a daylighting computer software based on configuration factors. The results can serve as reference for similar spaces and show that a suitable design of fenestration, in which it considers the combined effect of illumination and temperature, could significantly reduce peak cooling load and energy consumption of HVAC, while maintaining good thermal and illuminance indoor conditions.