THERMAL PERFORMANCES OF A SOLAR CHIMNEY WITH THERMAL STORAGE IN A RESIDENTIAL BUILDING

Among the solutions adopted in order to reduce the use of fossil fuels in the cooling of buildings, turning to natural ventilation with outdoor air takes on great importance, when it is found to be of a temperature that is lower than the indoor temperature. A solar chimney placed at the summit of a pitched roof, formed by a black coloured opaque wall with southern exposure and by three glazed surfaces, capable of accumulating incident solar energy increasing the temperature of the wall, permits the activation of natural ventilation by means of the aspiration of moderate temperature outdoor air, which will cool the building, in particular at night, with a limited, yet continuous air flow rate. The building taken into consideration is situated in the Mediterranean area, where the energy requirement for cooling is comparable with that required for winter heating. An opportune control strategy will either activate the chimney, or not, according to the necessity of the environment to be controlled. Performances of the building equipped with a solar chimney were determined by means of the Energyplus simulation code, varying some parameters such as the section, the height and the storage capacity of the chimney wall. Once the best configuration was identified, seasonal energy evaluations were carried out in both the presence and absence of a conditioning plant in order to evaluate the benefits deriving from the presence of the solar chimney.