For more than a century air quality standards have been based on the Pettenkofer Theory, which regards the human being as the decisive source of air pollution in residential and community building. Regrettably these standards have not prevented many buildings from having serious air quality problems. Presented here is a new philosophy of ventilation, which takes into account pollution sources other than human contiminants and tobacco smoke, e. g. construction materials, furniture, and utilities. Use is made of the new quantities for measuring perceived air quality, the olf and the decipol.

The studies described in the present paper have been developed by the teams involved in the French National Research Programm "ARC Convection Naturelle dans l'Habitat" coordinated by CNRS-PIRSEM (Inte disciplinary Research Programm on Energy and Materials, National Scientific Reseach Center) and suported by AFME (French Agency for Energy Management). After a short description of the experimental facilities of each laboratory, we give some significant results on high Rayleigh number natural convection in rooms.