Natural Ventilation - A New Method Based on the Walton Model Applied to Cross-Ventilated Buildings having Two Large External Openings

摘要

In order to provide comfort in a low energy consumption building, it ispreferable to use natural ventilation rather than HVAC systems. To achievethis, engineers need tools that predict the heat and mass transfers between thebuilding's interior and exterior. This article presents a method implemented insome building software, and the results are compared to CFD. The results showthat the knowledge model is not sufficiently well-described to identify all thephysical phenomena and the relationships between them. A model is developedwhich introduces a new building-dependent coefficient allowing the use ofWalton's model, as extended by Roldan to large external openings, and whichbetter represents the turbulent phenomena near large external openings. Theformulation of the mass flow rates is inversed to identify modeling problems.It appears that the discharge coefficient is not the only or best parameter toobtain an indoor static pressure compatible with CFD results, or to calculatemore realistic mass flow rates.