IEA Task 21: Daylight in buildings

Background: In many national and international research programs, daylight is being recognized as an important source for potential energy savings, due to the fact that energy for artificial lighting represents a major part of the overall energy consumption in non-domestic buildings and electric lighting often increases the cooling load of commercial and institutional buildings. Daylighting techniques and technologies have also been given high priority in the Strategic Plan of the International Energy Agency Solar Heating and Cooling Program, and therefore it was decided to start the Task 21: daylight in Buildings. Task description: The main objective of the Task is to promote daylight-conscious building design with the aim of realising energy savings and visual comfort and amenity value of the building. The means to reach the objective will be: - To provide an IEA guidance for the integration of fenestration and daylighting systems in combination with strategies for control of electric lighting. - To provide a set of efficient, user-friendly daylighting design tools. - An IEA report documenting pertinent case studies in buildings. The task will focus on daylighting of new and existing buildings with a high aggregate electricity saving potential such as offices, schools, institutional and commercial buildings. The application of daylight systems will be considered under different climates when analyzing the impact on the overall energy balance and power demand by measurements, calculations, and computer simulations. Assessment will include a careful evaluation of visual and termal comfort and user satisfaction of the daylighting systems and control strategies examined. The work has been organized in the following four subtasks: Subtask A: Performance evaluation of daylighting systems. Subtask B: Daylight responsive control of electric lighting. Subtask C: Improvement and integration of daylight design tools. Subtask D: Case of study buildings