Assessment of the Effects of Using Wood Stoves on Indoor Air Quality in Two Types of Norwegian Houses

Abstract

This study aims to assess the effects of using wood stoves on indoor air quality (IAQ) regarding fine PM, ultrafine PM, CO2 and relative humidity in Norwegian residential houses. Measurements were performed in an old natural ventilated house and a new mechanical ventilated house. Three locations for PM measurements were selected: close to the stove opening, in the middle of the room and at the supply air inlet, with original installed stoves typical for the buildings’ time of construction. Each measurement lasted 3 h, which includes monitoring of the background concentration, the light up process, the burning and the refill processes. The results show peaks of fine and ultrafine PM emissions during the light up and refill phases, connected to opening of the wood stove door. The ultrafine PM peaks were higher and occurred more frequently than the fine PM ones, indicating that not only the opening of the wood stove door caused these PM peaks. Significant differences were found between the two houses regarding the relative distribution between fine PM and ultrafine PM. Peak concentrations of ultrafine PM took longer time to fall back towards background levels compared to the fine PM concentrations. No clear correlations were found between the load of the stove and PM emissions, and further research is required to assess why. Yet the situation was not alarming as the 24 h mean PM2.5 concentration in both houses was below the WHO guideline. CO2 emissions in both houses were on average always at a healthy level.