ABSTRACT
In the last decade, the world has begun making a shift to sustainable and environmentally friendly alternatives of power one of which is daylighting. The most common method of harnessing daylighting is through windows openings. Daylighting was observed in several studies to improve student performance and health in lecture rooms.With increasing cost of electricity and epileptic state of electricity in Nigeria, it has become a necessity to harness daylighting in lecture rooms but with the advantages of daylight follows the problems of inadequate placements of apertures, which brings about overheating, underlighting, overlighting and glare. This is due to varying intensity of daylighting from place to place, that is most evident at openings to the east and west side of a building suffer from drastic changes of light quality through the day, heat gains and require versatile solutions to harness which makes openings to the north and south as the best choices for harnessing daylighting.However, there are no researches under adequate methodologies that identify the optimum head height of openingsalong the north and south orientation, without shading devices for lecture rooms in the Tropical Wet and Dry Climate of Nigeria.The aim of this research is to determine the optimum head height of openingsalong the north and south orientation without shading devices, based on the quality and quantity of daylight in alecture room while minimizing the probability for glare and therefore develop models which can be employed in the design of lecture rooms in the Tropical Wet and Dry Climate of Nigeria. The methodology for this research climate based daylight modelling due to its prediction of various radiant or luminous quantities (e.g. irradiance, illuminance, radiance and luminance) using sun and sky conditions that are derived from standard meteorological datasets. Case studies were selected from the Faculty of environmental design, Ahmadu Bello University Zaria, which consists of; the Department of Architecture, Department of Building, Department of Urban and Regional Planning, Department of Quantity Surveying viii and the Department of Geomatics. They were used for validation studies and evaluation of current daylighting design practices in University lecture rooms. Prototype lectures rooms were created and simulated using ecotect, radiance and Daysim. Results showed that the quantity and quality of daylighting for both north and south orientations were affected by a change in head height of openings. The study concludes that for maximized daylighting of lecture rooms in the wet and dry tropic region of Nigeria, window openings to the south should have a window head height of 2400mm and window openings to the north should have a window head height of 2700mm. For areas of further research, evaluation for the impact of window head height of thermal comfort can be performed. In addition, this research was conducted for lecture rooms in tropical wet and dry region of Nigeria only so further research can conducted on the other climate regions such as the tropical wet region and the semi-arid regions of Nigeria.