Improving the Microclimate in a Dense Urban Area Using Experimental and Theoretical Techniques – The Case of Marousi, Athens

An urban heat island results in higher urban temperatures than the surrounding area and is considered as the most documented phenomenon of climate change. This increase in urban temperature has a serious impact on the energy consumption for cooling and also contributes to higher urban pollution levels. Athens suffers from high summer temperatures that affect the quality of life of citizens. In response to the problem, a major rehabilitation plan was designed and applied, based on the use of advanced mitigation techniques. The present paper reports the results of a major urban climatic rehabilitation in the Marousi area, in Athens. This project is currently under construction. Detailed monitoring techniques have been applied and the main climatic problems have been identified. Using accurate simulation techniques the specific climatic environment under peak summer conditions was computed. Based on the results of experimental and theoretical analysis a detailed rehabilitation plan was designed using advanced mitigation and passive cooling techniques. The design involves the use of cool materials for pavements and streets, earth to air heat exchangers, solar control devices, photovoltaic panels and extensive use of green spaces and water. The climatic impact of the proposed design was evaluated and estimated to reduce ambient urban temperatures by up to 3.4 K under peak summer climatic conditions. At the same time, an important decrease of the surface temperature was calculated, resulting in a very significant improvement of thermal comfort conditions. The results of the present analysis are valid inside the climatic boundaries of the whole study.