Natural Ventilation in 18 Belgian Apartments: Final Results of Longterm Monitoring.

In the framework of a CEC demonstration project on humidity controlled ventilation, detailed measurements are carried out in 18 apartments in Namur, Belgium.The paper gives a brief description of the building, of the airtightness of the apartments and of the ventilation provisions. The largest part of the paper deals with the major outcomes of the study. This includes the following issues: air flow rates: on the average, dependency of wind and temperature difference; indoor air quality indicators: CO2 and water vapour; behaviour of the humidity controlled system; energy losses due to theventilation. Finally, some conclusions about the ventilation performances and of the monitoring programme are given. The demonstration project showed very well the influence of the building characteristics on the performances of the ventilation system.