Control of Daylight and Natural Ventilation in Traditional Architecture of Ghadames, Libya

Housing energy consumption accounts for almost 36% of total primary energy use in Libya of which cooling and lighting are the main source of demand. This study reviews passive control methods employed in traditional dwellings of Ghadames that highly contribute to enhance indoor thermal and visual comfort. Designing for natural ventilation and daylighting in harsh environment poses a greater challenge to building designers. Twenty one traditional dwellings were surveyed to assess building designs and performance in terms of daylight and natural ventilation interoperability. The study conducted field surveys comprising measurements of indoor/outdoor temperatures while concurrently investigating inhabitants’ thermal feeling through both direct semi-structured interviews and questionnaire. In addition, drawings were made to demonstrate the design elements and techniques used to minimize extreme outdoor temperatures and best make use of daylight. Findings indicate that skylight openings play an important role in promoting day and night ventilation. The opening’s position and size have to be carefully studied to prevent excessive direct solar heat gains and induce air movement across internal spaces. The field surveys showed that occupants were thermally satisfied in naturally ventilated dwellings having considered that fixed ceiling fan is used at late afternoon when indoor temperature starts to rise gradually. Also the use of light color roofs and walls is recommended which is approved to enhance interior lighting and increase the outdoor albedo ratio. Embedding passive design measures in traditional dwellings can be very effective and cheap in reducing the cooling and lighting demand; the impact on future housing development is also discussed.