A bio-climatic approach to house design for semi-desert and hot climates (with special reference to Egypt)
The semi-desert and hot climate zones occupy one fifth of the Earth's surface. However, the design process for environmental control employs the same technical procedures as those of cold and temperate climates despite the differences in human response and the environmental factors in each zone. It is the thesis of this research to devise a bio-climatological approach to the design of building in these areas, with special reference to reidential units. Analysis of the housing problem in Egypt as a part of the global problem is considered. Both inside and outside the built environment metabolic rate, clothing, solar radiation, air temperature, air movement and humidity are the dominant parameters affecting human comfort. To assess the solar radiation contribution to the sensible effect of ambient air temperature, a computer program has been devised. A bioclimatic approach to the classification of cliniates is proposed, and analysis of the Egyptian climate and Cairo microclimates emphasizes the importance of ventilation for relieving thermal stress. A method of assessing ventilation performance in relation to human comfort during overheated periods has been proposed with emphasis on the importance of studying the aerodynamics of residential units comprising multi-cell spaces. A survey of historical precedent in house design in Egypt is aimed at defining the characteristics of both old and contemporary residential units, and how they responded to their micro-climates. As wind is the critical element determining the microclimates within Cairo and possibly other cities of similar climate, a programme for wind tunnel experiments was carried out to examine the parameters affecting air movement around and within buildings. A bioclimatic approach considering architectural design as a three phase process, ie analysis (feasibility studies), synthesis (spatial design) and appraisal (detail design), was considered. This included a procedure for optimization of ventilation systems. Conclusion and recommendations have been made for building forms, interior design, building regulations and new development design.