Protection of non smoking persons against cigarette smoke by airflow.

The protection of non-smoking persons against cigarette smoke is a very popular subject. In Germany the ,pro' and , contra' of non-smoking regulations especially in public accessible areas like restaurants, train stations or in governmental buildings is discussed in a more and more controversial way. Especially the discussion about passive smoking and negative health effects through passive smoking lead to the demand of an effective protection of nonsmokers. But often even in ventilated rooms an effective protection of nonsmokers can not be reached, because the concept of the ventilation system and the airflow is not designed for this purpose. The aim of the study is to show that with a normal ventilation system an effective protection of nonsmokers can be reached if some rules are observed. In the first part of this study different airflows are compared with regard to their ability to prevent a smoke transportation from smoking areas to nonsmoking areas. The efficiency of the protection-effect of different airflow patterns (mixing flow, displacement flow) are discussed. In addition to the general description of the different airflow patterns the transportation of cigarette smoke as a contaminant is discussed in detail for mixing- and displacement flow. The second part of the study offers additional possibilities in combination to the airflow to prevent a smoke transportation into non-smoking areas.