Passive Solar-driven Cooling Systems

Night cooling is mainly provided by means of natural ventilation driven by a solar chimney in order to increase night time ventilation rates. During the day the sun heats up the black-painted upper-part of the chimney situated on the building roof, which creates an updraft of air in the chimney. Airflow between the solar chimney and the building zones is controlled by motorized dampers which are closed during the day. At night, the dampers open to let the updraft of air create a naturally circulating cooling air flow by extracting the warm air from the zones and renew it with cooler outside air. At the Almeria building, the solar chimney-driven natural ventilation is limited to the office zones, where the highest heat gains are observed.

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Fig. 1. Solar collector of one of the solar chimneys.