Performance analysis of a passive cooling system equipped with a new designed solar chimney and a water spraying system in an underground channel

A large portion of electricity use in the residential and commercial sectors is for space conditioning. Reducing the energy use for space conditioning is also important in order to develop energy-efficient buildings. Therefore, this paper dealt mainly with analyzing the performance of a new passive solar cooling system in air conditioning of a room under arid climate by means of computational fluid dynamics (CFD) method. The passive cooling system consisted of a solar chimney with four tilted absorbers, faced symmetrically towards south-north direction, and a wet underground channel. The cooling effect of the wet underground channel was replicated using water spraying system (WSS) model. The results revealed that the new design of the solar chimney could create a desirable natural air conditioning in the room during the daytime without risk of temperature stratification in the occupancy zone. Applying WSS in the room air intakes satisfied the thermal comfort requirements by decreasing the average indoor temperature around 7-13 degrees C. Furthermore, it improved the temperature effectiveness of the passive solar system by, at least, 80% implying a uniform diffusion of supply air in the zone of occupancy.