Natural Ventilation Through Windows in a Classroom (CFD Analysis Cross-Ventilation of Asymmetric Openings: Impact of Wind Direction and Louvers Design)

Natural ventilation is one of the most effective parts of sustainability. In fact, it can improve thermal comfort to expand the comfort zone area. Designing an optimum natural ventilation system is not so simple; however, it has a long-lasting effect on human health and economic benefit. There are many different items that have a significant impact on air movement rate in a façade such as an angle and geometry of louvers, building orientation and wind direction. Therefore, the geometry of louvers and wind direction can have a considerable influence on the cross-ventilation flow. Many studies on natural ventilation have been released in the past; however, a review of the literature shows that most of them just considered the angle and direction of louvers. The purpose of this research is finding the efficient wind direction in Lubbock and optimum geometry for a design of a louvered window to improve natural ventilation in a classroom.

This paper shows the Computational Fluid Dynamic (CFD) simulation to analyze natural ventilation flow with five different geometry of louvers and five different wind directions as well, in a generic isolated room. To make the study valid, the geometry and dimension of the wind tunnel is the base for this simulation. The louvers operate in a circular motion about a central pivot and all louvers are at 30°. Wind direction based on results generated from wind direction simulation is 15° toward the north-west to simulate louver models. The results show that aerodynamic geometry has the best impact to improve air movement through the louvers. This design would increase the air velocity from 80 in/s in model without louver to 120 in/s in model with louver. Furthermore, it would conduct air to the upper side of the room. This result would be beneficial for designers and the construction industry to design and produce high-performance façades in the future.