Predicting wind-induced indoor air motion, occupant comfort, and cooling loads in naturally ventilated buildings

In many warm climate regions, wind-driven natural ventilation can be used to improve human thermal comfort and reduce cooling energy use in buildings. In addition to offsetting solar and internal gains, and cooling down the structure of the building itself, wind-induced natural ventilation also has the potential to cool building occupants directly by increasing indoor air movement. To design effective naturally ventilated buildings, evaluation tools are needed to assess the performance of each aspect of natural ventilation. In the past, due to the lack of simple and reliable methods to predict wind-induced indoor air motion, such evaluation tools have been difficult to develop. The primary goal of this dissertation was to develop a design tool for the evaluation of the performance of naturally ventilated buildings using wind-induced indoor air motion for occupant cooling. The development of this tool was divided into two phases. First, an empirical model for the prediction of wind-induced indoor air motion in naturally ventilated buildings was developed. Second, a procedure coupling the empirical prediction method to a human comfort model and a building energy simulation program was formulated.; The model was based on correlations developed from a large set of experimental pressure and velocity data collected from architectural models in a boundary layer wind tunnel. To develop this model, the approach used was to assess how, and to what extent, the information required for evaluation (indoor velocities and turbulence intensities) could be derived from knowledge already available to the designer (external surface pressure distributions measured on sealed models and simple building design variables). To do this, a large number of architectural configurations were investigated. These were selected to cover a wide range of possible building-airflow interactions, and included building orientation, upwind obstructions, building shape, external building projections, interior partitions, window size, and window location.; The evaluation tool was used to assess the impact of wind-induced indoor air motion on thermal comfort and energy consumption in naturally ventilated buildings for a number of case studies. The results indicated that, under certain conditions, improved thermal comfort and reduced cooling loads can be obtained.