Comparison of Ventilation with Moist and Dry Air in the Room Connecting to a Solar Chimney
This research aimed to investigate the ventilation rate of solar chimneys installed under dry and humid conditions. Building models for dry air and moist air were constructed in the Computational Fluid Dynamics, ANSYS Fluent 14.0 for numerical calculation of air flow rate and air temperature within the model. This study considered time-dependent turbulent flow and results when the system approaches steady state at 3 minutes. The hot air in the solar chimney was generated by a-constant heat flux of 60 W/m2 in the chimney external wall. The dry-air models applied the Boussinesq’s approximation. The species transport model was used to simulate the moisture content in the moist air. The simulation results showed that temperature of the moist air model was closer to the experiment than the dry air. The ventilation with dry air was lower than that with the moist air due to the reverse flow at the window. This research confirmed the optimum solar chimney ratio of 14: 1, similar to previous researches. In addition, the size of the opening between the building and the chimney highly affected the ventilation of the solar chimney. The best ventilation occurred in the chimney with inlet and outlet, as large as the width of the air space of the chimney.