In buildings with mechanical ventilation there are spaces with substantial pressure differences, which bring exfiltration, infiltration and transferred air between the rooms. For such buildings we have converted a multiple cell theory to a quadratic programming problem, and developed a computer programme, MCSPID for airflow identification. Today MCSPID is inpractical use to simultaneously determine flow rates for airsupply, exhaust air, transferred air, infiltration and exfiltration with a single tracer gas.
The use of computers for data acquisition and analysis in air exchange measurements with tracer gases has become state of the art for the researcher. However, for air exchange measurements in the field, reliable operation of the equipment and the proper reporting of the results are still points of concern. Here, the computer can assist the user in the correct handling of the tracer gas equipment, in dealing with unfavourable measurement conditions, and in the production of a readable report.