Use of a single tracer gas for measurement of ventilation rates in a large enclosure.

This paper describes a preliminary investigation of the validity of a means of calculating the ventilation rate of a large enclosure from experimental data. It was assumed that the air in the enclosure is not perfectly mixed. The measurement method selected was tracer gas concentration decay. Thecalculation of ventilation rate was performed by "least squares" fitting of a model to the observed tracer gas concentrations. Simulations of tracer gas concentration decay measurements were performed with varying initial distribution of tracer gas. The ventilation rate was then calculated from the simulated concentration data. Conclusions are drawn concerning the accuracy of such calculations and general strategy for measuring ventilation rates using tracer gases.