Presents a claimed simple and accurate technique for directly measuring the outdoor air delivery rates to building occupants. States two or three measurements of tracer concentrations are sufficient for calculation. Experimental results show that the calculated outdoor air change rates from the tracer gas experiments agreed well with the outdoor airflow rates measured independently by nozzles. Derives a relationship between the local outdoor air exchange rate and the mean age of air. Describes how the proposed technique makes it possible to simplify the measurement of the mean age of air and to correct experimental errors.

KEYWORDS: year 1996, Outdoor air, measuring, tracers, experiment, accuracy