HI-85-40-2 -- An Automatic Multi-Tracer-Gas Method for Following Interzonal Air Movement ✓ Most Recent

A new method for measuring interzonal air movement, using up to four different tracer gases simultaneously, has been developed at the Polytechnic of Central London and tested in a solar air-heated experimental house in Peterborough, UK. This paper describes the method and its application in an investigation of the transfer of air between a passively heated conservatory and the main living space of the house.

Four perfluorocarbon tracer gases are injected, and samples of tracer gas in air are collected automatically using the principle of gas adsorption on a solid adsorbent. Samples of room air are taken simultaneously at up to five points in space and up to ten points in time, leading to a profile of gas concentration with time for each gas at each sampling position.

The tracers are retrieved from the adsorbent by thermal desorption and are separated and analyzed using a gas chromatograph. The injection system, sampling system, tracer retrieval, quantitative analysis, and data collection are all controlled by a microcomputer. Airflow rates are calculated using a new matrix method of analysis.

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