Development of a multi-tracer gas technique for observing air movement in buildings.

A method for following air movement within buildings, which uses several different tracer gases simultaneously, has been developed. The method consists of the following sequence of operations: 1 up to 4 tracer gases are released at various points within the building, 2 the mixture of gases is sampled at any number of positions in the building as a function of time since the release, 3 the samples are chemically analyzed to produce curves showing the concentrations of each gas stepping through time and space, 4 the variations in gas concentrations are used to evaluate air movement through the space. Specific experiments to illustrate such air movement have been carried out and these are summarized.