Prediction of natural ventilation in buildings with large openings

Abstract

This paper first presents a consistent pressure-based formulation for natural ventilation of single-zone and multi-zone buildings with multiple openings. Pressure-based multi-zone formulation is made easier to implement by introducing an auxiliary concept of external pressure, which allows all the formulas to be presented in an integrated form. Multi-zone situations considered include vertically interconnected zones, and horizontally interconnected zones with same heights and different heights. The formulation includes the combined effect of wind, thermal buoyancy and mechanical ventilation, and it can be used for both external and internal large openings. A simple and easy implementation method was then presented. Single-zone and multi-zone analytical solutions are revisited or developed by the pressure-based formulations and used for the validation of the implementation method. A CFD method is also used to cross-check the implementation method in a single-zone building with very large external openings. A reasonable agreement has been found between the results predicted by the pressure-based formulation and those predicted by the analytical solutions and CFD methods.