Interpretation and error analysis of multi-tracer gas measurements to determine air movement in a house.

Although infiltration of outside air across the envelope of a building has been considered of prime interest in relation to energy conservation and indoor air quality, it also important to understand the way in which air moves between zones within a building. A knowledge of the air movement pattern enables the transfer of pollutants or heat to be determined. In order to achieve this, a number of experimental methods have recently been developed, using either single or multiple tracer gases. (See, for instance, references 1,2,6,7,9) . It is important in any method to assess the confidence which can be placed in the resulting flow rates. This paper discusses methods for analysing and evaluating errors arising from measurements made using three tracer gases. The test data presented are taken from a programme of measurements to determine the infiltration rates and air interchange between three zones of a mehanically ventilated experimental house. The full programme is designed to investigate the effect of operating the mechanical ventilation system and the use of internal doors, as well as meteorological factors.