A qualitative ventilation model for prototype cavity structure

Creating a physical model structure that is able to simulate different ventilation scenarios is essential for improving the understanding of passive designs that are both sustainable and environmentally acceptable. The purpose of this investigation was to build a physical prototype model that could be heated from both the outside and inside to duplicate an occupied structure during the morning hours. This model was then used to provide information for two Computational Fluid Dynamic (CFD) models to firstly compare and then validate results obtained from experimental data. A sample of computational findings was initially presented in Chawynski et al. (2003). This paper presents the experimental sections used to validate numerical simulation in Chawynski et al. (2003) and incorporates findings from Chawynski (2004). The experimental component consisted of approximately 80% of the overall investigation. The findings enabled a better scientific understanding of how a structure’s thermal performance can be improved by mechanically forcing air (to simulate outside wind) inside to both lower and create an overall uniform internal air temperature distribution in a cavity enclosure. A chart-based model is proposed to qualitatively gauge the temperature inside a cavity enclosure for different ventilation scenarios.

► Improvement of structure’s thermal performance using outside wind.
► Carefully engineered structures can allow for passive ventilation.
► Developed a chart to qualitatively gauge the temperature inside a cavity enclosure.