Evaluation of the Buoyancy-Induced Natural Ventilation Performance of PVC Tube-Type Solar Chimneys: Numerical Study and Experimental Validation

The present research evaluates the natural ventilation potential of Polyvinyl chloride (PVC) tube-type solar chimneys. Some recent studies have considered the idea of using non-glazed PVC pipes as an inexpensive solution for the natural ventilation of buildings. However, an accurate estimation of the ventilation potential of these types of chimneys has not yet been provided. The present research uses numerical simulation to study the buoyancy-induced flow in PVC tube-type solar chimneys with heights 1–3 m and diameters of 90, 110, 125, and 160 mm under solar irradiance of 300–800  \(\text{W}/{\text{m}}^{2}\) $\text{W}/{\text{m}}^2$ . Results indicated that the flow rate increases linearly as the chimney diameter grows from 90 to 160 mm. The induced airflow rate is between 5.7 and 8.7  \({\text{m}}^{3}/\text{h}\) ${\text{m}}^3/\text{h}$ for a chimney with a height of 1 m. PVC tube-type solar chimneys with heights of 2, 3 m and a diameter of 160 mm under an average solar heat flux of 550  \(\text{W}/{\text{m}}^{2}\) $\text{W}/{\text{m}}^2$ could provide the maximum required ventilation rate of 4.7 and 7.7 m² of the floor area of an office building, respectively. On average, each unit length of the PVC tube-type solar chimney can supply the required air of 2–2.5 m² of the floor area of an office building. Due to the limited ventilation capability, these chimneys can only be used as an auxiliary ventilation system. Tube-type chimneys with a height-to-diameter ratio of less than 16 is not recommended due to the significant adverse flow reversal effects.