Ventilation measurements in large buildings.

Compares and contrasts different methods of ventilation measurement in large buildings. Conventional methods of using tracer gas to measure ventilation rates in large volumes are cumbersome and expensive. These constant concentration and decay measurements require artificial mixing, complex monitoring equipment and large installation costs. By using discrete injection and sampling units, long term samples of tracer gas be collected with the minimum of capital and installation costs. Samples collected represent the mean local equilibrium tracer gas concentrations. Finds the method to be auseful measure of ventilation rate but increasing problems are found with increase of measured volume requiring greater attention to thorough mixing of the atmosphere and injection sample bag positioning.