Daylight optimization in an office building through atrium improvements

Abstract: Daylighting has become a fundamental measure not only to decrease the electrical energy demand in buildings, but also to provide good indoor comfort for the occupants. Atria have been implemented in buildings since old times as a space to foster interaction and provide indoor comfort through ventilation and daylight. However, the implementation of this feature can be complex if good natural light levels are to be achieved, especially in tall buildings. Bearing that in mind, this thesis reviewed the studies that were developed in the field of daylighting in atria and proposed an investigation about the atrium parameters that affected the most the daylight conditions in a building project located in Gothenburg. In order to evaluate the current atrium and propose modifications that fit the architectural design, simulations were carried out in different programs. This evaluation concentrated in two main aspects of the building, which were the geometry and the wall reflectance values. Due to the size of the study case, the evaluation grid is located only along the atrium and the results are translated in area, so it is possible to draw a comparison between the different modifications proposed. Results showed that the geometrical volume alterations were the ones to increase the most the daylight quantity in the rooms along the atrium. Nonetheless, some of the modifications on the original project were followed by a floor area addition to compensate the losses brought by the alterations, therefore daylighting and property value were also analyzed. Lastly, a few options were investigated when it comes to the daylight quantity in each floor. Overall, the outcomes demonstrated that shifting the atrium characteristic from an enclosed one to a semi-enclosed can double the daylight quantity in the adjacent rooms.