Developments in a multi-tracer gas system and measurements using portable SF6 equipment.

In this paper we describe the development of a multi-tracer gas system for measuring interzonal air movement in buildings. The system consists of simple and stand-alone gas injectors and sampling units. The injectors are capable of releasing up to four perfluorocarbon tracer gases in different parts of a building. Following tracer gas injection and mixing, small samples of air are collected using automatic sampling units. Each unit consists of a 16-position valve and a group of removable stainless steel tubes packed with solid absorbent.

Measurement of seasonal air flow rates in an unoccupied single family house.

For more than four years air infiltration measurements have been made on two nearly identical side-by-side test houses in Gaithersburg, Maryland, USA. This testing of the complete seasonal weather influence on air infiltration has, in the past two years, included constant concentration tracer gas measurements (CCTG). These multizone air infiltration measurements have added further detail on the response of air infiltration into the house to weather changes and the variation of air infiltration between different house locations.