Optimizing Ventilation Performance of Rooftop Solar Chimneys: A Study on Design Parameters in Erbil City, Iraq

Abstract

The implementation of a solar chimney in buildings can enhance ventilation and create a comfortable indoor environment using renewable energy. A research study conducted in Erbil City, Iraq, utilized numerical modelling with MATLAB to investigate the impact of design parameters on the ventilation performance of rooftop solar chimneys throughout the year. The study focused on the relationship between solar energy availability and its conversion within the chimney, particularly considering inclination angles. Results demonstrated that the highest solar radiation occurred in June, while the lowest was observed in December. The angle at which the solar incident struck the chimney had a significant impact on the amount of solar energy captured at different times of day and in different seasons. During the summer, a 30-degree inclination angle maximized solar energy capture, whereas a 60-degree angle was best for the spring and fall. Interestingly, with a chimney angled vertically, wintertime energy conversion efficiency is at its maximum. The conversion of solar energy to thermal energy within the chimney was also impacted by the angle of inclination. A 60-degree inclination angle was found to be ideal for a 2 m² solar chimney arrangement in Erbil City. The amount of solar energy captured is greatly influenced by the angle at which sunlight strikes the chimney, which varies depending on the season and time of day. In the summer, a 30-degree tilt is ideal for capturing the most energy; in the spring and fall, a 60-degree slant works best. It's interesting to note that in the winter, a vertical chimney achieves the best energy conversion efficiency. The process by which solar energy is converted into thermal energy inside the chimney is also greatly influenced by this inclination angle. For example, a 60-degree angle was found to be the most efficient in a 2 m² solar chimney arrangement in Erbil City, producing a ventilation rate exceeding 3.75 air changes per hour (ACH) for a 27 m³ space. The study finds that these design factors can greatly improve the ventilation effectiveness of solar chimneys.