Characterizing indoor air quality, thermal environment and window opening in natural-ventilated Norwegian bedrooms: An extensive field study

Abstract

To generalize research on indoor air quality (IAQ) in bedrooms, the objective of this article is to characterize IAQ for the cold climate of Norway. The relationship between ventilation, indoor thermal environment and IAQ is revealed. 58 natural-ventilated bedrooms with different levels of renovation were investigated using detailed measurements during the heating season. Compared to other studies in Nordic climate, a larger fraction of the occupants used extensive window openings. A larger fraction of the bedrooms showed low CO2 concentrations. Only few other studies also measured TVOC concentrations. Its average value was well correlated with CO2. However, TVOC concentration is characterized by more peaks. Low CO2 concentrations were found with extensive window openings. Nonetheless, extensive window openings did not systematically lead to low CO2 concentrations, for instance the influence of curtains is shown. It is confirmed that the door opening can lead to relatively low CO2 concentrations when the window is closed. The highest CO2 concentrations are found with the window and door closed. The study confirms relatively low temperatures in bedrooms. Nevertheless, no clear correlation between the indoor temperature and the fraction of time with the window opened was observed. For instance, the lowest bedroom temperatures were obtained using window opening, but also with the window closed. Finally, the results suggest that it is possible to achieve a high IAQ with window ventilation when this is a deliberate strategy (if no filtering of the fresh air is needed), also in renovated buildings where the envelope airtightness has been improved.