Measurements of ventilation performance in a retrofitted conference room.

The ventilation system of a 60 seats conference room was retrofitted to improve indoor air quality. The old, mixing type installation was replaced by a displacement ventilation system. However, the building layout did not allow an optimum location of air inlets and outlets. It was therefore interesting to measure the actual performance of the new system. Using tracer gas techniques, the age of air was mapped within the room, and the ventilation effectiveness was measured in various configurations. The actual air flow rates were also measured in the ventilation system. Configurations were: empty room, room occupied by immobile, heated artificial bodies, and room with real occupancy. The air change efficiency was found unsatisfactory, and recommendations were given to improve it. The ventilation system was modified, the room was made more airtight, and measurements were performed again, which proved the efficiency of these modifications. The contribution presents the experimental planning, the results, and the practical conclusions, which can be deduced from this experiment.