Emissions and treatment of VOCs emitted from wood-based construction materials: Impact on indoor air quality

Abstract

Concerns about insulation properties, bio-sourcing and recyclability of construction products promote the use of wood-based materials. Recent studies about indoor air quality in new constructions evidenced negative impacts of such material emissions on indoor air quality (IAQ). Efforts made on building air tightness to save energy promoted indoor pollutant confinement, encouraging the deployments of air treatment systems to improve IAQ. First, this study aims at characterizing wood-based material emissions in a real scale environment. Second, it aims at assessing the ability of widespread air treatment processes to address this specific IAQ problematic. Regarding emissions, a quantitative inventory of VOCs emitted by wood-based products is proposed. Terpenes and carbonyl VOCs (OVOCs) are the typical identified and quantified species. Concentration profiles of VOC and depletion rates are determined under environmental conditions. Then, the behaviors of two air treatment devices are addressed. It evidenced that the abatement of emitted VOCs not only depends on the chemical structure of the VOC but also on the conception of the device. Regarding terpenes, the devices induce noticeable but contrasted conversion rates. Moreover, possible sorption and transient secondary emissions of primary terpenes are evidenced. Regarding OVOCs, contrasted behaviors are observed between VOCs containing more than 4 carbon atoms compared to lighter ones. These behaviors still question the generation of lighter OVOCs as photocatalytic side-products, even in real scale environments. The proposed experimental approach gives a new insight and allows effective conclusions on sources and sinks of VOCs in a built environment.