Microclimate profile and contribution of air conditioning to local heat island effects at the Aristotle University of Thessaloniki main campus

The Aristotle University of Thessaloniki (AUTh) main campus is characterized mainly by its building volume, the energy fluxes serving campus needs and resulting from campus operations, and the local climatic conditions. In an effort to investigate the effects of the existence and operation of the AUTh main campus to the local climate of the Greater Thessaloniki Area (GTA), we applied a heat island effect related methodology to identify its subareas that belong to specific urban climate zones. This identification was supported by meteorological observations that identified specific characteristics of the urban heat island effect within the campus. As a next step, we investigated the influence of the air conditioning (AC) operation in AUTh to the local climate. For doing so we firstly estimated the actual AC cooling power installed in the campus. Then we employed the cooling degree days method to identify the overall AC operational profile during the summer period. On this basis, we calculated the total volume of heated air produced by the external AC units in the campus. Overall, we were able to identify three climate zones within the AUTh campus, and to estimate that local heat production from AC can affect urban climate. These findings are among the first to quantify the impact of specific urban structures and operations (AUTh campus) to the local climate in the GTA. The results of our study can be used for planning interventions at the urban web aiming at levering the burden of campus operation to the microclimate of the city center. The method used in our paper can be applied to wider urban areas in order to identify microclimate profiles and local heat island effects.