Passive downdraught evaporative cooling applied to an auditorium

The performance of a passive cooling system was evaluated as part of design works for the project of an auditorium. The passive cooling system uses the atmosphere as natural heat sink and incorporates a solar chimney together with an evaporative cooling tower. The natural ventilation is enhanced with the help of the solar chimney and fresh air is cooled down by passive downdraught evaporative cooling. The application of this system to the acclimatization of an auditorium was evaluated. A model was developed to this purpose, which allows to foresee the temperature and the relative humidity of the air in the auditorium. The evaluation of the performance of the passive cooling system was based on the number of cooling degree hours. The model was also used to evaluate the influence of the main parameters characterizing the solar chimney and the evaporative cooling tower upon the thermal environment within the auditorium fully occupied. The period under study was June to September and it comprised the diurnal period, from 6h 30m to 17h 30m (solar time).