Daylighting design for energy saving in a building global energy simulation context

A key factor to substantially reduce the energy consumption for electric lighting consists in a more widespread exploitation of daylight, associated with the use of the most energy efficient lighting technologies, including LEDs or electric lighting controls. At the same time daylight harvesting in indoor spaces can influence the global energy performance of a building also in terms of heating and cooling loads. For this reason, it’s always necessary to account for the balance between daylighting benefits and energy requirements. Furthermore the increasing awareness of the potential benefits of daylight has resulted in an increased need for objective information and data on the impact that different design solutions, in terms of architectural features, can have on the daylighting condition and energy demand of a space. Within this frame the research activity has been focusing on three main aspects: − Analyzing limits and potentials of the current daylighting design practice and proposing synthetic information and tools to be used by the design team during the earliest design stage to predict the daylight condition within a space. − Analyzing the effect of a proper daylighting design approach on energy requirements for electric lighting, associating with the use of efficient lighting technologies and control systems. − Assessing the influence of energy demand for electric lighting on the global energy performance. The methodology that was adopted relies on dynamic simulations carried out with Daysim and EnergyPlus used in synergy to perform a parametric study to assess the indoor daylighting conditions and the energy performance of rooms with different architectural features. Within the first phase the database of results of the lighting analysis was used to assess the sensitivity of new metrics which have been proposed by the scientific community as predictors of the dynamic variation of daylight. Furthermore it was analyzed how indoor daylight can be influenced by room’s architectural features. Than the energy demand for electric lighting for all simulated case studies have been analyzed so as to examine the influence of a proper daylighting design in presence of different lighting control systems. Finally results related to the amount of daylight available in a space were compared with annual energy demand for lighting, heating and cooling to highlight the influence of a proper daylighting design on the global energy performance.