An attempt to increase the performance of a climatizing system using water from boreholes, in an old building”-SG2-07

Abstract

Abstract: This work is done with data obtained in the air conditioning system of the old building of the University of Évora, dating from the 16th century. In order to obtain an adequate temperature in the rooms covered with tiles of the 17th century, a system was built, that uses water obtained in four boreholes made for that purpose. The water coming from the boreholes is fed to a reservoir connected to a heat pump that heats the water in winter and cools it in summer, before distributing it through the building. The aim of our work is to optimize the conditions of transport of the water from the holes to the reservoir, in order to minimize temperature fluctuations. Mean air temperatures values in Évora are 30,2ºC during the day (sometimes we have 40ºC) and 16,3ºC during the night, in July and 13,6ºC during the day and 7,2ºC (sometimes we have 1 or 0ºC) during the night, in December. In an attempt to avoid the effects of such temperature changes, the pipes through which water circulates were buried to a depth of 20 cm. Nevertheless, there is still significant losses which will have an influence on system performance. The proposed model considers heat transfer through the pipes and the surrounding medium, taking into account the thermal properties of the different parameters under study.