Bioclimatic design of open public spaces in the historic centre of Tirana, Albania

The aim of this paper is to study the urban micro-climatic conditions in the historic centre of Tirana in order to integrate the information in the rehabilitation of specific open spaces. The process included field measurements of the thermal characteristics in the examined area, bioclimatic design and use of passive cooling techniques (cool materials, green spaces, water, solar control & earth to air heat exchangers). Advanced simulation tools were used to evaluate and optimize the planed microclimatic modifications. CFD calculations with model PHOENICS have been applied for the simulation of the air flow and the temperature field at the concept design stage. The proposed design solutions included the increase of vegetation (planting of trees), the use of shading, as well as the use of cool materials with appropriate thermal and optical properties. In parallel, earth to air heat exchangers, are proposed to supply cool air during the summer period and preheat the ambient air during the winter. Simulations have shown that the use of the proposed bioclimatic measures can decrease the peak summer ambient temperatures up to 3 °C, while surface temperatures are decreased seriously. In parallel, the calculation of appropriate bioclimatic indices showed that the thermal comfort conditions were significantly improved with the application of interventions mainly because of the increase of shading as well as because of the use of construction materials with high emissivity and reflectivity values.