It must not be confused with fresh air . The outside air can be improved by two measures for the ventilation and air conditioning technology: On the one hand, this is the choice of the intake location in the building where the outside air is least polluted (solar radiation, car exhaust, exhaust air outlet ...), and on the other hand, cleaning the outside air. The outside air was classified on the basis of the World Health Organization (WHO) , as there were no national or European specifications at the time (2007). In 2008, the European Parliament passed the Directive on Air Quality and Clean Air for Europe .
The outside air is divided into three categories:
- Category ODA -1 : The guidelines of the WHO are complied with, i.e. outside air may only be occasionally contaminated with dust ( pollen )
- Category ODA -2 : The guidelines of the WHO are max. exceeded by a factor of 1.5, ie outside air with a high concentration of dust or fine dust and / or gaseous impurities
- Category ODA -3 : The WHO specifications are exceeded by a factor of 1.5, ie outside air with a very high concentration of gaseous impurities, dust and / or fine dust.
Gaseous pollutants such as carbon monoxide , carbon dioxide , sulfur oxide , nitrogen oxide and volatile organic compounds ( VOC ), pollution from liquid aerosols (oil mist, vapor from recooling systems, etc.) or pollution from biological particles also have an impact on the outside air quality. However, ozone is not relevant in the assessment because it is extremely reactive and therefore its concentration in the room decreases very quickly.
The large cities of London, Madrid and Stuttgart, for example, were classified in the ODA-2 category in 2007.
- DIN EN 13779 ventilation of non-residential buildings (e.g. offices)
- DIN 1946-6 - ventilation of residential buildings
- Recknagel-Sprenger-Schramek: Pocket book for heating + air conditioning. , 73rd edition. Oldenbourg Industrieverlag Munich 2007, ISBN 3-8356-3104-7
- Directive 2008/50 / EC of the European Parliament and of the Council of May 21, 2008 on ambient air quality and cleaner air for Europe (PDF)