Page 22 - InnoRenew CoE International Conference 2021, Healthy and Sustainable Renovation with Renewable Materials
P. 22
pendence of virgin and recycled Scots pine heart- and sapwood VOC
emissions on indoor relative humidity conditions
Henrik Heräjärvi 1, Arttu Sivula 2, Anni Harju 3, Marko Hyttinen 2, Joona Lampela 4, Veikko
Möttönen 1, Pertti Pasanen 2
1. Natural Resources Institute Finland, Yliopistokatu 6B, FIN-80100 Joensuu, Finland, firstname.familyname@luke.fi
2. University of Eastern Finland, Department of Environmental Sciences, Yliopistonranta 1E, FIN-70100 Kuopio, Finland,
firstname.familyname@uef.fi
3. Natural Resources Institute Finland, Vipusenkatu 5, FIN-57200, Savonlinna, Finland, firstname.familyname@luke.fi
4. University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, FIN-80100 Joensuu, Finland,
firstname.familyname@uef.fi
Wood contains hundreds of different extractives, and some volatile organic compounds (VOCs) emit
already in room temperature. VOCs are important quality parameters of materials used indoors since
they may contribute to human health and surely contribute to well-being. Standard emission tests of
materials are carried out in a constant relative humidity (RH) of 50% and temperature (T) of +23 °C, thus not
accounting for the hygroscopic behaviour of wood. While the indoor T remains quite constant throughout
the year, the RH typically varies from approximately 15% (winter) to 80% (late summer) between the
seasons. Due to its hygroscopicity, the moisture content (MC) of wood follows the indoor air RH, reaching
<10% in the dry season and >15% in the humid season. Our hypotheses were that a) VOC emissions change
seasonally due to RH variations, and b) VOC emissions from recycled wood are lower than those from
virgin wood. The experiment was carried out comparing Scots pine wood that had been stored indoors
for 15 years (“recycled wood”) and recently sawn “virgin wood”; both heartwood and sapwood in both
groups. Emissions were recorded from a total of 20 specimens in RH conditions ranging from 20 to 80
per cent imitating the indoor air seasonal RH variations. Our results confirmed the hypotheses that indoor
air RH, as well as the storage history of the specimen, play a great role both in the total VOC emission
level and the composition of VOC’s emitted. The understanding created contributes to the development
of VOC test methods of hygroscopic materials. Information produced can be applied in the selection
and branding of wooden low-emission furnishing materials for allergy homes or other emission sensitive
spaces.
Keywords: emissions, indoor air, recycled wood, Scots pine, VOC
Acknowledgement
The authors gratefully acknowledge funding from the Ministry of the Environment of Finland under the
aid scheme for Growth and Development from Wood.
INNORENEW COE INTERNATIONAL CONFERENCE 2021
22
emissions on indoor relative humidity conditions
Henrik Heräjärvi 1, Arttu Sivula 2, Anni Harju 3, Marko Hyttinen 2, Joona Lampela 4, Veikko
Möttönen 1, Pertti Pasanen 2
1. Natural Resources Institute Finland, Yliopistokatu 6B, FIN-80100 Joensuu, Finland, firstname.familyname@luke.fi
2. University of Eastern Finland, Department of Environmental Sciences, Yliopistonranta 1E, FIN-70100 Kuopio, Finland,
firstname.familyname@uef.fi
3. Natural Resources Institute Finland, Vipusenkatu 5, FIN-57200, Savonlinna, Finland, firstname.familyname@luke.fi
4. University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, FIN-80100 Joensuu, Finland,
firstname.familyname@uef.fi
Wood contains hundreds of different extractives, and some volatile organic compounds (VOCs) emit
already in room temperature. VOCs are important quality parameters of materials used indoors since
they may contribute to human health and surely contribute to well-being. Standard emission tests of
materials are carried out in a constant relative humidity (RH) of 50% and temperature (T) of +23 °C, thus not
accounting for the hygroscopic behaviour of wood. While the indoor T remains quite constant throughout
the year, the RH typically varies from approximately 15% (winter) to 80% (late summer) between the
seasons. Due to its hygroscopicity, the moisture content (MC) of wood follows the indoor air RH, reaching
<10% in the dry season and >15% in the humid season. Our hypotheses were that a) VOC emissions change
seasonally due to RH variations, and b) VOC emissions from recycled wood are lower than those from
virgin wood. The experiment was carried out comparing Scots pine wood that had been stored indoors
for 15 years (“recycled wood”) and recently sawn “virgin wood”; both heartwood and sapwood in both
groups. Emissions were recorded from a total of 20 specimens in RH conditions ranging from 20 to 80
per cent imitating the indoor air seasonal RH variations. Our results confirmed the hypotheses that indoor
air RH, as well as the storage history of the specimen, play a great role both in the total VOC emission
level and the composition of VOC’s emitted. The understanding created contributes to the development
of VOC test methods of hygroscopic materials. Information produced can be applied in the selection
and branding of wooden low-emission furnishing materials for allergy homes or other emission sensitive
spaces.
Keywords: emissions, indoor air, recycled wood, Scots pine, VOC
Acknowledgement
The authors gratefully acknowledge funding from the Ministry of the Environment of Finland under the
aid scheme for Growth and Development from Wood.
INNORENEW COE INTERNATIONAL CONFERENCE 2021
22
