Wood is more than meets the eye!

Transcription

1 Wood is more than meets the eye! Mark Hughes Aalto University Puupäivä 30 th November 2017

2 Globally, more than 30% of materials are used in building construction Over 1/3 of primary energy used in buildings Huge impact! Huge potential to have an impact!!

3 Why wood? 1. The substitution of carbon-intensive materials 2. The carbon storage effect of wood products 3. Energy-efficiency benefits from the material

4 Why wood? 1. The substitution of carbon-intensive materials 2. The carbon storage effect of wood products 3. Energy-efficiency benefits from the material

5 Why wood? 1. The substitution of carbon-intensive materials 2. The carbon storage effect of wood products 3. Energy-efficiency benefits from the material

6 Carbon storage of wood? In 2015, the global production of sawnwood and wood-based panels was about 850 million cubic metres 1 Every tonne of wood stores about 1.75 tonnes carbon dioxide 950 m Roughly equivalent to 750 million tonnes of CO 2 ( 1 FAOSTAT-Forestry database)

7 Wood and energy-efficiency

8 What is the potential for impact? Therefore small changes big energy savings!

9 A fresh look at a traditional material? Can we use the inherent properties of wood more effectively to improve the energyefficiency of buildings?

10 We spend most of the day in indoors! Materials in our interiors count!

11 Active and functional wooden surfaces Material-moisture interaction Material-human interaction Image: Segato, Sundin, Quirarte, Noodapera

12 Approach Wood has under-exploited physical properties that can potentially help to passively mediate a living environment But, it is not simply a technological challenge, it is also about people! Important to look holistically at how the use of wood, in conjunction with the occupant, can lower energy consumption in buildings

13

14 (

15

16

17 Indoor environment materials people

18 Know your wood!

19 Material properties, energyefficiency, comfort and health? (Source: Simonson, C. J., Salonvaara, M. & Ojanen, T., Improving Indoor Climate and Comfort with Wooden Structures, VTT Publications 431, Technical Research Centre of Finland, Espoo 2001)

20 Moisture is a natural part of wood

21 Measuring the moisture buffering ability of wood MBVpractical= m/s. RH m moisture exchange S open surface area RH change in relative humidity Calculations and measurements were done in accordance with NORDTEST method

22 Moisture buffering value MBV Practical Moisture Buffer Value classes (Nordtest method, p. 38)

23 (Source: Simonson, C. J., Salonvaara, M. & Ojanen, T., Improving Indoor Climate and Comfort with Wooden Structures, VTT Publications 431, Technical Research Centre of Finland, Espoo 2001)

24 Measuring the moisture buffering ability of wood MBVpractical= m/s. RH m moisture exchange S open surface area RH change in relative humidity Calculations and measurements were done in accordance with NORDTEST method How do different species buffer relative humidity? Is the buffering ability anisotropic?

25 Moisture buffering of wooden surfaces Softwood: Douglas fir, larch, pine and spruce Hardwood: ash, birch, black alder, elm, maple and oak All species tested: MBV classes moderate or good

26 Wood is a versatile material Grain direction makes a difference: Transverse surface: MBV is excellent Sapwood and heartwood: Heartwood: MBV limited/moderate Sapwood: MBV good

27 What about coatings?

28 Typical coatings inhibit the interaction between wood and the indoor environment

29 Know your wood and coating Student projects: Integrated Interior Wooden Surfaces course

30 Warming and cooling with wood

31

32 Heat of sorption RH 95% RH 1% Dry wood Heat of adsorption Wet wood Heat of desorption

33 Measuring surface temperature changes in wood due to sorption

34 Experimental

35 Thermal images

36

37 Surface temperature rise due to heat of adsorption Bone dry wood 90% RH Tangential surface Transverse surface Dupleix, A., Van Nguyen, T., Vahtikari, K. et al. Wood Sci Technol (2017).

38 Modelling with WUFI

39 Heat of sorption Distinct species and anisotropic effects in moisture buffering Heat of adsorption results in anisotropic temperature rises of around 1,5 o C on the radial and tangential surfaces and 3,5 o C on the transverse surface Further work is ongoing to understand the phenomenon better and to assess how this might affect the energy-efficiency of buildings

40 Coworkers and collaborators Monika Österberg, Alina Lozhechnikova, Nina Forsman Xiaoshu Lu-Tervola, Tuula Noponen Marketta Kyttä, Shiv Bhatta Pekka Heikkinen, Yrsa Cronhjort, Tomi-Samuel Tulamo Katja Vahtikari, Anna Dupleix, Kaarlo Nieminen, Katja Kortelainen, Tien Van Nguyen, Riikka-Liisa Toikka, Vincent Roehl Niko Meri, Aarni Aspi, Heikki Lappalainen

41 Thanks to: Aalto Energy Efficiency Program: Wood Life project WoodWisdom.net: Wood2New project Contact: Mark Hughes Department of Bioproducts and Biosystems Aalto University, School of Chemical Engineering PO Box 16400, FI Aalto Tel: mark.hughes@aalto.fi

42 Further information about the Wood Life project