Ventilation performance evaluation using passively-generated carbon dioxide as a tracer gas.

Tracer gases are commonly used to evaluate the performance of ventilation systems. One way to reduce the time, complexity, and cost of such experiments is to use the carbon dioxide generated by occupants as a tracer gas. In this paper, a method for using the carbon dioxide generated by occupants as a tracer gas for determining the effective supply air flow rate to a zone or the relative air-change effectiveness of a zone is described. The approach is to make use of a model of the accumulation dynamics and a model of the way that occupants generate carbon dioxide.

CFD simulation as a tool for designing tracer gas measurements of ventilation performance.

A recently proposed tracer gas method - the homogeneous emission technique-which is suitable for measurement of ventilation air distribution in large enclosures is explained. It is discussed how a CFD-simulation of tracer gas distribution could be utilised to optimise the design of a tracer gas experiment in order to achieve the requested information at a minimum cost.