Performance Evaluation of Solar Chimneys in the Tropics

Abstract

On hot days, pilot study shows the solar chimney?s operability with a 17oC temperature difference; solar chimney air temperature of 47oC and speed of 1.9m/s. There is one to two hours positive interior air temperature time lag with a speed of 0.49m/s. The hypothesis is modified: an interior subjected to solar chimney ventilation under strong tropical solar irradiance with no ambient air speed, the interior air temperature and speed depends on the solar chimney?s stack height, depth, width and inlet position. Parameterizations show that the length to hydraulic diameter ratio should be greater than 15 while the stack height to width ratio should be less than 7. The solar chimney?s inlet position has limited influence. To optimize the solar chimney, first maximizes its width. Secondly, maximizes its stack height while taking into account the two ratios. Lastly, its depth is calculated by allocating the required interior air speed.