Abstract
In this work, unsteady contaminant concentrations in enclosures have been analysed by using a sequential box model. The enclosure is divided into two cells for which a nondimensional analysis is introduced to find the unsteady contaminant concentrations in each cell. The dimensionless concentrations have been obtained in terms of input parameters which can be controlled. An analytical solution for the system of equations has been obtained. The results show that the input parameters which account for the air exchange across the boundary between the cells have a major effect on contaminant concentrations of the cells. As these parameters approach low values, one of the cells will not receive any contaminant and the other will have well mixed conditions; however, as they increase, both cells approach the same contaminant and the whole enclosure will be well mixed.
This work also represents a fundamental approach to obtain the contaminant concentration in an enclosure for different types of contaminant emission rates.