The wind towers of Bastakiya: assessing the role of the towers in the whole house ventilation system using dynamic thermal modelling

Abstract

A thermal model of the complex wind environments in and around a traditional wind tower house in Bastakiya, Dubai, was constructed using Virtual Environment Software. The original house with its three wind towers was simulated and the potential to increase comfort in it using adaptive comfort criteria was explored with varying iterations of the wind tower design. The height of one tower was increased and reduced by 33%, and the cross-sectional area of a tower increased and reduced by 50%. This article presents the results of these simulations and the three key methodological conclusions reached. Firstly, that only by using the adaptive comfort model was it possible to understand how the buildings actually operated in terms of the comfort they provide for tradition populations in this historic building. Secondly, that the whole house behaves as a self-regulating thermal system in which the internal ventilation system operates around on modal shifts in each of the three towers from updraft to downdraft airflows. Thirdly that these modal shifts occur around thermal thresholds that are a direct result of the cross-sectional area and height of the towers and that by changing the dimensions of the towers these thresholds can be raised or lowered. Thus, the geometry of the towers themselves provides some control over the temperatures experienced in the home and its indoor comfort environment.

Keywords:

• Adaptive comfort
• middle eastern culture
• natural ventilation
• thermal modelling
• wind towers

Notes

Source: Coles and Jackson (2007).

Source: IES (VE) Suncast.

Source: Reference data obtained from Dubai International Airport.

Source: Coles and Jackson (2007).

Source: IESVE Vista Application.

Source: IESVE – Suncast application, site orientation.

Source: IES (VE) model viewer.