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.
