Influence of the roofs ending on the building ventilations

There are many works in which various aspects associated with natural or forced ventilation in buildings are studied. Currently, and due to the growing importance that energy efficiency (and the control of CO2 emissions) is acquiring in buildings, these studies are mainly focused on obtaining relations between one or other type of ventilation and the energy consumption of the building [1 -3]. The authors are trying to find more efficient ventilation methodologies as well as adapting existing ones in order to reduce energy losses either by thermal conditioning or by the need to use electric lighting. Some authors focus their work on comparing the use and comfort of natural and mechanical ventilation, and their influence on the indoor air quality of buildings [4-6]. Some of them analyze, even, the noise produced by mechanical ventilation. Logically, these studies are conditioned by the climatology of the place where they are carried out and by the season of the year. The results show that in the seasons and hot climates, natural ventilation prevails and in the cold or rainy seasons and cold climates the preference for mechanical ventilation prevails. There are also studies about the influence on health of ventilation in buildings [7] and even works has been done to detect pollution agents inside buildings [8], by using sensors for the detection of various gases (electronic noses) . The results of these studies usually obtain optimal ventilation conditions that are radically opposed to energy efficiency studies.