Airflow in ducts: Measurement by perfluorocarbon (PFT) tracer

This paper describes the development of a tracer-gas system for measuring airflow in ducts. The fast-response system is capable of sampling different types of gases including a perfluorocarbon tracer (PFT) which was used for this study. The PFT, which is a liquid at room temperature, was injected into the duct using a thermostatically controlled heating block. Tracer gas samples were collected using stainless steel tubes packed with adsorbent. The samples were stored for subsequent analysis in the laboratory using a thermal desorber and gas monitor. Airflow in ducts was tested in the laboratory and field using the sampling and injection units.