Light wind conditions are important in the assessment of risks from releases of hazardous gases, in the assessment of urban air quality, and also in the determination of ventilation requirements for buildings. Although very light winds would often prese

Airflow and thermal stratifications solutions in a single-zone building with buoyancy-driven ventilation are derived. Two new 'empty air-filling box' models are developed, and it is shown that the fully-mixed model overpredicts the clean zone height an

The paper presents the results of a study into the effects of unsteady wind pressures on the mean flow rates in certain types of purpose-designed naturally ventilated buildings. The study used non dimensional parameters and the results should therefore cover a wide range of conditions and should be of general application. It is concluded that unsteady) effects are restricted to a relatively narrow band of conditions. These conditions have been quantified in terms of non dimensional parameters.

This short article aims to inform modellers and model users about efficient sensitivity analysis methods. Also presented is a tool under development aimed at simplifying the application of sensitivity methods. Such techniques are essential to add confid

Discusses two completed annexes of the IEA Energy Conservation in Buildings and Community Systems Programme, Multi-zone air flow modelling, and Energy efficient ventilation of large enclosures. For the former, it considers the tasks, the algorithm, the user interface, numerical reliability, evaluating potential user difficulties, comparing numerical predictions with experimental data, outcome and conclusions. For the latter, considers background and objectives, the tasks, the design principles guide, analysis and prediction techniques, case studies and outcome and results.