The role of natural ventilation for indoor climate control in Austrian buildings.

The influence of air infiltration and window opening on the indoor air quality in Austrian residential buildings was investigated. During the heating season, air infiltration plays a major role in securing hygienic conditions of indoor air and acts as basic ventilation. Air tight windows in new or renovated buildings do not provide this basic ventilation and can give rise to poor indoor air quality unless acceptable fittings for permanent ventilation are provided. Window opening can not replace the effect of permanent ventilation but plays a role as comfort ventilation.