The potential for natural ventilation as a viable passive cooling strategy in hot developing countries

Natural ventilation offers opportunities for reducing cooling energy-demand at low-cost in developing countries with limited resources. In this paper the natural day- and night-time ventilation potential for cooling in hot-arid and hot-humid Mediterranean climates is characterised against the key weather and building parameters affecting its performance. In particular, the study seeks to quantify the limits of outdoor environmental conditions under which natural ventilation is an effective strategy for achieving thermal comfort. Furthermore, the study explores the effects of certain building characteristics that enhance the performance of natural ventilation such as ventilation rates and thermal mass. This is achieved by short-term environmental monitoring and dynamic energy modelling of selected naturally ventilated domestic buildings in Lebanon and Jordan. The summer monitoring regime compared external and internal temperatures, relative humidity and air velocity in free-running 'well-designed' buildings in order to identify the external environmental limits for effective day- and nighttime ventilation. Computer modelling of the monitored buildings was undertaken using IES VE to determine the design parameters affecting the performance of natural ventilation. Initial results show that computer modeling overestimate ventilation rates through windows with Venetian shutters.