Temporal Evolution of the Potential of Passive Cooling Systems for Arid Areas

Abstract

The purpose of this paper is to investigate the impact of climatic variations on bioclimatic buildings within urban areas, especially in arid zones, and to investigate building bioclimatic variations in relation to their surroundings. This work presents the results of a three-year research project to determine variations in urban temperature and relative humidity in cities in arid areas and implications for bioclimatic design. A case study was conducted in San Juan, Argentina. Variations over 12 years (1993–2004) were recorded including daily maximum, minimum and medium temperature evolution in the core area, as well as variations of the amplitude during the warmest months (December, January and February). The findings show that the average temperature has increased, requiring an increase in building cooling requirements. Simultaneously the thermal amplitude has diminished, requiring a reduction in the potential of night cooling as a strategy to apply in the bioclimatic design of buildings. The average relative humidity has diminished, representing an advantage for passive evaporative cooling systems. These results may be considered for the bioclimatic design of buildings in other warm to hot urban areas in arid zones of increasing temperature and relative humidity. The results also show that climatic global change may be small, but the change in the urban climate is quite significant resulting in necessary modifications to the bioclimatic performance and therefore the bioclimatic design of buildings.