The present paper reports on tracer gas measurements performed in five large buildings during normal operating conditions. In all buildings air was supplied through ceiling diffusers and returned through a ceiling plenum. The measurements were taken during summer with the systems in cooling mode, i.e. the supply temperature was lower than the room temperature. The global air change effectiveness and the occupied zone average air change effectiveness were calculated based on the age-of-air concept.
This paper deals with the problem of the weather influence on ventilation rate for naturally ventilated buildings with purpose provided openings and vertical shafts. Hitherto, it has not been possible to predict the ventilation rate or to extrapolate it for other weather conditions than the measured ones, without performing a heavy calculation exercise by means of running a computer program. In the paper a prediction as well as an extrapolation procedure is outlined . The procedures are based on generalised output data from a single zone infiltration and ventilation model (AIDA).
The methods available for the measurement of air infiltration and air movement in large industrial halls are restricted by the size of the building and the nature of the operations which take place within it. Single tracer decay measurements are the easiest to perform and this paper examines the possibility of extracting useful information from them. Using a multi-zone representation of the building volume, the properties of tracer decay curves are considered, and the ease of extraction infiltration and air flow data examined by means of simulations.