Designing the Malqaf for summer cooling in low-rise housing, an experimental study

The malqaf or windcatcher is Egyptian vernacular archetypal device that traps the wind into the building. For centuries, the malqaf has been used as a viable solution to ensure natural ventilation. However, for the last 50 years, Egyptian practice has failed in combining traditional architectural devices into new techniques that could lead to sustainable and energy aware buildings. In Egypt, more than half of the urban peak load of energy consumption in the mean time is used to satisfy air conditioning demands alone. Therefore, the objective of the research is to develop a viable passive alternative to active cooling by exploring the potentials and design parameters of windcatchers as solution for passive cooling and natural ventilation during the summer season for low-rise housing. Experimental wind tunnel and smoke visualisation testing were conducted to compare the air flow in a scale model room with and without windcatcher on top of the roof with different orientations. The final result shows that the performance of the windcatcher depends greatly on the position, orientation and size of the inlet and outlet opening in relation to the wall ratio. The study developed a comparative matrix for examined parameters to support architects with the basic principles for windcatchers design.