Single-sided ventilation: a comparison of the measured air change rates with tracer gas and with the heat balance approach.

In the frame of the European PASCOOL project, several experiments regarding single sided ventilation were carried out at BBRI in the outdoor PASSYS test cel. The test room of 30 m³ has a vertical window of about 1 m². During a first measurement period, an open cold box, which allows one to control the vertical wind speed, was placed in front of this window. During a second measurement period, the window was directly exposed to "real wind". The air change rates were evaluated by using two different methods: a tracer gas technique and the heat balance approach. The heat balance approach is very attractive in this test cell because the heat flow through the cell envelope can be accurately determined thanks to the Pseudo- Adiabatic-ShellL The tracer gas measurement is made diflicult because a clear air flow pattern appears and accordingly, the concentration in the room is not homogenous. An error analysis has been applied on both methods. The agreement between both methods is very good and the heat balance approach proved to be more accurate than the tracer gas technique. A correlation model was derived from the first measurement period.