Determination of single-sided ventilation rates in multistory buildings: Evaluation of methods

• On-site measurement is conducted to verify the existing empirical models.
• Previous empirical models are not applicable to multistory buildings.
• CFD method is suitable for predicting ventilation rate in multistory buildings.
• Ventilation characteristics are different between rooms in a multistory building.
• A larger incident k profile leads to a decrease of ventilation rate to leeward rooms.

This study aims to evaluate the performance of different methods in determining single-sided ventilation rates in multistory buildings. The study is motivated by the fact that the methods established from very simple physical models, such as a single-room building, have been applied directly to multistory buildings. On-site measurement in a multistory building was conducted to verify the applicability of existing empirical models. A computational fluid dynamics (CFD) simulation was performed to (a) examine the integration method and the tracer gas decay method and (b) investigate the ventilation characteristics of a multistory building and how these differ from the ventilation characteristics of a single-room building. The empirical models are not applicable to multistory buildings as they cannot account for the difference in ventilation rate between different rooms in the same building. This study finds that the CFD method is particularly suitable for the determination of ventilation rates in multistory buildings despite the fact that the methods reproduced by CFD simulation are compromised by the accuracy of the velocity and turbulence fields generated by the selected numerical model. Finally, a parametric study shows that an increase in the incident k profile leads to a significant decrease in ventilation rate to the leeward rooms.