Natural Ventilation Design of Community Hall


The Community Hall is located on the sloped mountain, wind from downhill to uphill. This is prevailing wind direction using for ventilation design and assessment.


The goal of natural ventilation is to create cross ventilation. The design is started with openable window at the both side of building. One side of window is opened in 「as-catching」 wind direction. Other side window is opened 「as-following」 wind direction. Ventilation in this case is created at the double side of building. Fresh air can be flowed into building from 「as-catching」 windows and exhausted from 「as-following」 window.


This conceptual design can be checked in wind tunnel. The scaled model of Community Hall is created, with smoke injection, the fluid flow can be seen by LASER assisted flow visualization.


In the first experiment, the flow is separated at the middle of building inlet direction, and passing through both sides of the building. The wind guiding panel is installed to redirect the air flow into open window.


Flow visualization can provide you an instant result. The performance of wind guide panel is not very good, it just creates an air passage in between the panel and window.


You can modify the design in wind tunnel, for example changing the panel position, add more panels.



From now on, with three panels installed, it improves the performance of redirecting air flow into window. The ventilation design jumps into assessment of cross ventilation. You will notice the flow inside the room in a slow speed – smoke circulation in room after end of smoke injection.


With LASER assisted flow visualization, you can see air exhausted out at the openable window. It is called ventilation short-circuiting which degraded the cross ventilation performance. The most common form of ventilation short circuiting occurs when more than one type of exhaust vent system is installed.



The panel is attached in the wind frontward direction and close one of the exhausted window. Air are pushed into building in one side of openable windows and are exhausted at the opposite side of the openable window. Cross ventilation occurs in this case, the performance of ventilation is improved.


With properly designed experiment, you can visualize many experimental flow result very quickly. To evaluate another wind direction, for example perpendicular to prevailing wind direction, you can rotate the scaled model in wind tunnel and check the result.


Cross ventilation occurs in perpendicular to prevailing wind direction. The ventilation design is accepted here.


You can make a further advancement. An innovative ideas can be checked immediately, for example additional wing panels, aerofoil shaped tower. Wind tunnel is valuable tools for fluid design.





Should you have any questions, please contact us at 3586 1826.