On the time-dependant efficiency of building ventilation on the indoor air quality in a medium sized urban area in Greece.

From an air pollution study in a medium-sized, seaside town in Central Greece (Volos) it wasfound that some common air pollutants (CO, NO, NOx, SO,, 0,), whose emissions are connectedto activities and conditions that reveal some characteristics of periodicity on a daily,weekly or yearly basis (e.g.: production activities, meteorological conditions), are monitoredin the atmosphere in concentrations that reflect this periodicity. Additionally, characteristicsof periodicity can also be found in the concentrations of indoor gas pollutants whose emissionsare connected to some inhabitants' activities (e.g. : cooking) or are influenced by the microclimaticconditions in the building interior (e.g.: temperature, humidity). By processingthis data, by statistical methods, periods were identified during the day, week or year when itis feasible to predict that indoor or outdoor air is more contaminated and harmful and, accordingly,to appreciate the relative contribution of building ventilation to the formation of indoorair quality. Corresponding findings, especially those related to periodicity on a daily basis,are used for the judgement and corroboration of the measures that are taken for the protectionof indoor air quality during episodes of environmental air pollution and for the elaborationof proposals for the design of natural ventilation systems for the buildings in the area.