A solar chimney is a natural draft device, which uses solar radiation energy to build up stack pressure, thereby driving airflow through the chimney channel. By converting thermal energy into the kinetic energy of air movement, solar chimneys have a number of different applications such as ventilation, passive solar heating and cooling of buildings, solar-energy drying and power generation.
Solar chimneys with a uniform heat flux on a single wall were investigated experimentally for different chimney gaps, heat flux inputs and different chimney inclinations, covering a gap-to-height ratio from to 2:5. It is shown that by changing the chimney gap while maintaining all the other conditions, the airflow rate increases continuously with increasing chimney gap. Results also showed that the airflow rate reached a maximum at a chimney inclination angle of around 45° for a 200 mm gap and 1.5 m high chimney, which is about 45% higher than that for a vertical chimney under otherwise identical conditions. This is due to the relatively even airspeed inside the chimney, which significantly reduces the pressure loss at the chimney inlet and outlet compared to the corresponding vertical chimney. 34 refs.