CFD Analysis of Different Ventilation Strategies for a Room with a Heated Wall

Abstract

Solar chimneys can help to reduce solar heat gain on a building envelope and to enhance natural ventilation. In this work, we proposed three configurations of two solar chimneys combined with a heated wall for the natural ventilation of a room: (I) the chimneys are connected serially, (II) the chimneys are parallel and exhaust air at two separate outlets, and (III) the chimneys are parallel, but the outlets are combined. The airflow rate achieved with each configuration was predicted with a Computational Fluid Dynamics model. The results show the effects of the heat flux in each channel and the geometries of the channels. Configuration (II) shows the highest flow rate. Particularly, the proposed configurations enhance the flow rate significantly and up to 40% when compared to the typical setup with a single channel solar chimney. The findings offer a novel design option for building façades for reducing solar heat gain and enhancing natural ventilation.

Evaluating the Performance of a Combined Vertical Wall–Horizontal Roof Solar Chimney for the Natural Ventilation of Buildings

“…• Turbulence terms of u ′ i u ′ j and T ′ u ′ j were computed with the RNG k − ϵ model, which has been utilized intensively in the literature [8,20,26].…”

“…In this study, the performance of a combined vertical wall-horizontal roof solar chimney was investigated, particularly considering the effects of the reverse flow at the outlet, flow resistance at the bend connecting the vertical and horizontal sections, and the location of the heat source, as previous studies have demonstrated the crucial roles of these factors. A reverse flow at the outlet of a vertical solar chimney has been found to lessen the induced flow rate significantly [12,[21][22][23][24], but its effects were not reported in Nguyen et al [20]. Zamora and Kaiser [25] and Nguyen and Wells [6] claimed that the bend resistance was even enhanced when its downstream recirculation zone merged with the reverse flow.…”

“…However, as the heat source was applied on only the horizontal channel, the effects of the heat source in the vertical inlet section were not considered. Nguyen et al [20] reported the ventilation performance of two vertical wall solar chimneys connected to a horizontal outlet. Although the heat source was also distributed in the horizontal section, their analysis was only on the vertical parts.…”

“…Details of the above settings can be found in our previous works [6,7,20] 2.2. Computational Domain, Mesh, and Boundary Conditions Figure 1 depicts the main dimensions of the solar chimney, the computational domain, and the mesh structure.…”

Solar Chimney Performance Driven Air Ventilation Promotion: An Investigation of Various Configuration Parameters

“…In Maysan, a SC at any angle of inclination on the horizontal bottom suction opening offered the best thermal results. Ling LS, Rahman MM, Chu CM, Misaran MSB, and Tamiri FM [76] examined the area related to the inlet and outlet of a SC, which varied depending on the inclination angle and space between the inner and outer walls from 0.0224 m 2 to 0.6 m 2 and 0.1 m 2 to 0.14 m 2 , respectively. The area ratio between the inlet and outlet provides an essential parameter, according to the CFD results, and the inlet opening area should be at least twice as large as the outlet opening area.…”