Conference article

In this study using two low-energy systems to enhance passive cooling and natural ventilation in a solar room have been compared. First system consists of a Solar Chimney (SC) and an Evaporative Cooling Cavity (ECC) and the second one includes a Solar Chimney (SC) and an Earth-to-Air Heat exchanger (EAHE). To determine the heat and mass transfer characteristics of the systems; a mathematical model based on conservation equations of mass and energy has been developed and solved by an iterative method. The findings show that when the cooling demand of the room is 116W and the relative humidity is lower than 50%; the SCECC system can make acceptable indoor air conditioning even at ambient 40oC; with weak solar intensity of 200 W/m2. It is also found that; the proposed system can provide thermal comfort conditions even during the night with zero solar radiation. The results about SC-EAHE system show that when the ambient temperature and cooling demand are high (1500W); proper configurations could provide good indoor condition even at poor solar intensity of 100 W/m2 and high ambient air temperature of 50oC. Comparative survey shows the SC-EAHE system is the best choice for buildings with poor insulation at day time; but SC-ECC system is better for night ventilation and cooling purposes especially in arid climates.

Comparative survey; Passive cooling; SC-EAHE; SC-ECC