Abstract | Windcatchers are widely utilized in building design as natural ventilation devices, providing fresh air supply and thermal comfort under suitable outdoor conditions. However, their performance is often constrained by environmental factors such as outdoor temperature, wind speed and direction. While passive heating, cooling, and heat recovery devices have been integrated into conventional windcatcher designs, the impact of changing wind directions, which can render the windcatcher ineffective, is often not considered. Addressing this gap, this research builds upon a novel dual-channel windcatcher system. This system employs a rotary wind scoop to ensure a consistent fresh air supply and stale air exhaust, irrespective of wind direction and facilitates the integration of passive/low-energy technologies. Using a validated numerical computational fluid dynamics (CFD) model, the design of the proposed system was enhanced, incorporating technologies such as an anti-short-circuit device and wing walls, wind scoop area, a larger wind scoop area, and a redesigned wind cowl, to increase the pressure differential between the inlet and outlet and reduce system friction. The modified windcatcher achieved a 28% improvement in ventilation rate and outperformed a conventional four-sided windcatcher of the same size by up to 58%. Furthermore, the full-scale simulations of the building and windcatcher of varying heights were conducted using an atmospheric boundary layer wind flow to better capture the true nature of the wind flow that the building will encounter in real-world conditions to provide a more realistic assessment of the windcatcher's performance. This research contributes to the development of more efficient windcatcher systems for further passive technology integrations, enhancing their viability as sustainable ventilation solutions. |
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