The inclusion of a central court or atrium within a building is a popular design due to its aesthetic, open appearance. The greater penetration of natural light aids in the reduction in use of artificial lighting during the day. Care must be taken to balance the solar heat gain against the daylight penetration. This balance is critical for the reduction of the electrical energy load of the building, whilst maintaining a high level of comfort for the occupants. In the tropics modifications to atrium building designs are necessary to diminish high elevation direct solar heat gain. Traditionally, shading the window apertures or lowering the transmission through the glazing was used. These solutions limit the view and reduce the light level. The use of angular selective glazing upon atria allows the rejection of high elevation direct sunlight whilst redirecting and therefore improving low elevation skylight penetration. Tilted angular selective glazing used upon adjoining spaces to atria help vertical light in the atrium well to be redirected horizontally deep into the space. These effects reduce overheating which would normally restrict the use of atria in warmer environments as well as improve illumination penetration into adjoining spaces. The research showed that under clear sky conditions the modified glazing gave a lower temperature in the middle of the day within the atrium well. A more even distribution of illuminance across the course of the day was found and a higher level of illuminance was achieved within the well and its adjoining spaces under clear skies. These effects were simulated using computer algorithms. The algorithms were verified by field data collected from the QUT Daylighting Research Test Building located at the Brisbane Airport Bureau of Meteorology site where two simultaneously monitored model (1:10 scale) atriums were studied for several months.

Proefschr. Rijksuniversiteit Groningen. / Met lit. opg.-Met bibl.-Met samenvatting in het Nederlands.

Proefschrift Erasmus Universiteit Rotterdam. / Thesis Erasmus University Rotterdam. Met lit. opg. - Met samenvatting in het Nederlands. With bibliogr., with a summary in Dutch.

Proefschrift Universiteit Maastricht. / Met lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met een samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Among the different environmental functions atria perform, this research has focused only on daylighting. The thesis has been presented in two parts. The first part provides the background information, the extent of daylighting research in atria, objective and scope of the research. The environmental role of atria has also been discussed. The second part deals with the research procedure, the description of the scale model used for the study, the conditions under which the study have been conducted, and finally, the conclusions of the study. The effects of changing the reflectivity of the wall and floor surfaces of the atria well on the illumination in the adjacent spaces to atria have been studied. The objective of the thesis was to establish the relative contributions of the changes in the surface reflectance of the wall and the effects of variations in the area of the openings in the wall facade on lighting in the adjacent occupied spaces. The importance of the floor reflectivity in lighting the spaces adjacent to the atria was also determined. Quantitative analysis of daylighting in atria has been conducted using physical scale models under natural overcast skies using daylight factor and well index to normalize the results. Although the thesis has concentrated on daylighting, in reality there are other functions, both social and environmental, that atria are required to perform, and where appropriate, these functions have been acknowledged. It has been established by this research, that the atria well and the spaces adjacent to it are affected by changes in the area of openings in the form of windows in the wall facades of the well. Small variations in higher reflective surfaces on the wall facade produce greater differences in the daylight factors as compared to similar differences in surfaces with lower reflectances. Using high surface reflectance on the floor of the atria well will enhance illumination in the lower levels of the atria. As the area of the (high) reflective surfaces along the edges of the floor is increased, the illumination in the side spaces in the lower levels also increases. The area of floor reflectivity needed for increasing the illumination levels in the side spaces is dependent on the area of openings on the walls at the lower levels. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg.