1. Summary of D1.1 ISOBIO _ 6 Month Meeting at University of Bath
-Commercially available bio-based insulation materials and requirements of industrial partners
Yunhong Jiang, Mike Lawrence, University of Bath
01/07/2015

2. Introduction
Background: The objective of the ISOBIO project is to develop bio-based insulation panels and renders, by combining existing technologies to produce a range of new, low embodied energy, low embodied carbon, hygrothermally efficient materials for use either as a building envelope or for retrofitting to existing buildings in order to improve their energy efficiency.
Objective: full scientific characterization of the hygrothermal, sorption and VOC capture performance of selected bio-based materials to provide the basis for creation of new products, resulting in improved insulation properties and at least 30% reduction in embodied energy and CO2.
D1.1 in WP1: to summarize the commercially available bio-based insulation materials and identify the requirements of the industrial partners.

3. Approach
Commercial availability of different bio-aggregates from each partner
Technical requirements
Economic constraints
Available products listed in Appendices 1 & 2
Identification of potential new products

4. Review of materials with potential development
Categories
composition: (cellulose, cork, wood fibre, hemp, flax, strawbale and sheepwools),
form: (batts, blankets, loosefill, spray foam, and panels),
functional mode: (conductive, radiative, convective) and more.
231 products summarized from 66 different companies
Batt/blanket bio-based insulation
Fibre/particle boards bio-based insulation
Loose-fill bio-based insulation

5. Review on Batt/blanket bio-based insulation
Cellulose Insulation:
Sheep’s wool insulation:
Property
Typical value
Density
kg/m3
Thermal conductivity
0.039 W/m.K
Specific heat capacity
J/kg.K
Property
Typical value
Density
kg/m3
Thermal conductivity
W/m.K
Specific heat capacity
1600 – 1800 J/kg.K
Material
Density (kg/m3)
Thermal conductivity (W/m.K)
95% natural wool fibre, 5% combination recycled adhesive binder 19
0.039
75% British wool, 15% recycled polyester, 10% polyester binder 18 31
0.035
85% British wool, 15% binder fibre 23
0.038
Sheep fibres, recycled plastic bottles
Pure new sheep's wool, Thorlan IW, Rubber 22
0.037
Pure new sheep's wool, Thorlan IW 14
0.042
85% Sheep wool 15% polyester
13.5
0.04
100% Sheep wool
Hemp insulation:
Property
Typical value
Density
kg/m3
Thermal conductivity
W/m.K
Specific heat capacity
1370 – 2300 J/kg.K
Wood fibre Insulation:
Property
Typical value
Density
kg/m3
Thermal conductivity
W/m.K
Specific heat capacity
2100 – 2800 J/kg.K
Flax Insulation:
Property
Typical value
Density
kg/m3
Thermal conductivity
W/m.K
Specific heat capacity
1200 – 2350 J/kg.K

6. Review on Fibre/particle boards bio-based insulation
Fibre board bio-based insulation consists of either wood/hemp fibres, hemp shiv or straw and is primarily used for external wall with vapour permeable and water repellent protection. It is also used when there is a need for insulaton that can withstand high temperatures.
These products come in a range of thicknesses from 4 mm to 240 mm. Standard fibre board bio-based insulation have a thermal conductivity between and 0.41 W/mK and a specific heat capacity from 1100 to 2100 J/kg.K. The densities of fibre board bio-based insulation materials range from 55 to 1150 kg/m3.
Most of manufacturers are located in France and Germany. See Appendix 1 for an overview of these characteristics.
Table 2 lists fibre boards made from hemp fibre, wood fibre, hemp shiv, cork granules and strawbales with their general performance.
Category
Density
(kg/m3)
Thermal conductivity (W/m.K)
Specific Heat Capacity (J/kg.K)
Fire Performance
Compression strength (kPa)
Wood fibres
55-875
Euro Class E/F
40-200
Hemp shiv
2100
B S1 d0/M1 —
Hemp fibres
Straw bales
85-470
2000
Euro Class E
Cork granules
20-300

7. Review on Loose-fill bio-based insulation
This is made from a variety of granular or lightweight materials such as cork granules, mineral wool or cellulose fibre.
Loose-fill insulations are well suited for places where it is difficult to install other types of insulation, such as irregularly shaped areas, around obstructions (such as plumbing stacks), and in hard-to-reach places.
There are five primary types of loose-fill bio-based insulation, inculding cellulose, cork granules, wood fibre, hemp fibre and hemp shiv (as shown in Figure ).
Category
Density
(kg/m3)
Thermal conductivity (W/m.K)
Specific Heat Capacity (J/kg.K)
Fire Performance
Cellulose
25-65
Euro Class E/F
Wood fibres
20-230
2100
Euro Class E
Hemp shiv
110
0.05 —
Hemp fibres
700
0.06
1700
Cork granules
60-570

8. Summary of Characteristics in different forms
Density
Application
Thermal
Conductivity
Specific heat capacity
Hygric
Vapour resistivity
Loose Fill
25 to 750 kg/m3
well suited for places where it is difficult to install other types of insulation, such as irregularly shaped areas, around obstructions (such as plumbing stacks), and in hard-to-reach places.
0.037 and 0.17 W/m.K
1000 to 2150 J/kg.K
1 to 5 MN.s/g.m
Mat
13.5 to 60 kg/m3
suited to standard spacing of wall studs, attic trusses or rafters, and floor joists.
0.035 to W/m.K
1200 to 2350 J/kg.K
1 to 10 MN.s/g.m
Boards
55 to 1150 kg/m3
used for external wall with vapour permeable and water repellent protection. It is also used when there is a need for insulaton that can withstand high temperatures
0.037 and 0.41 W/m.K
1100 to 2100 J/kg.K
2 to 13 MN.s/g.m
Except Pavafloor 5.4 (60 MN.s/g.m)

9. Summary of exploitation opportunities
Loose fill
Additives for plasters and renders (CLAYTEC and BCB)
Raw material for bio-concrete (CAVAC)
Loose fill insulation (CAVAC)
Batt/Blanket – transformation of fibres (CAVAC)
Fibre / Particle boards – transformation of aggregates (STRAMIT, CAVAC, other manufacturer?)

10. Manufacturer considerations on the bio-based insulation products
Applications
Installation: Quick, Easy, Low cost and flexible installation
Recyclability
Economic constraints
Industrial locations
Physical:
Format
Density
Width & Dimensions
Porosity
Particle Size Distribution
Chemical
Material composition
Recycled content
Mechanical
Compression Strength
Flexural Strength
Tensile Strength
Bending Strength
Shear Strength
Modulus of elasticity
Shrinkage
Surface resilience
Thermal
Specific Heat Capacity
Thermal conductivity (λ)
Thermal transmittance coefficient (U-value)
Thermal resistance (R)
Hygric
Vapour permeability
Vapour diffusion resistance factor
Moisture Buffer Value
Water absorption coefficient
Isotherms of absorption/desorption
Acoustic
Sound absorption coefficient
Sound reduction index
Fire performance
Fire and Heat resistance
Ignition point
Durability
Durability rating
Solubility
Effect of moisture
Microbiological
Viability of materials on category 2 pathogens
Mould, fungal, bacterial degradation
Moth resistance/Mice infestation/mould resistance
Indoor Air Quality (IAQ)
VOC emission rate
Dynamic vapour sorption (DVS)
Embodied CO2/energy in manufacture
ODP*(Ozone depletion potential)
GWP* (Global warming potential)
GHG emissions

11. Conclusion Appendix 1 summarises available insulation materials
Industrial partners have been asked to identify opportunities for improvement
The advantages and disadvantages have been compared and analyzed
According to the feedback of questionnaire and data in Appendix 1, the commercially available bio-based insulation products and the requirements of industrial partners have been reported.
Based on the performance characteristics of available products, surveys from industrial partners and our experiences, finely chopped material, such as straw, hemp or other readily available materials, has been choosen to improve the insulation properties through the porous structure of bio-based aggregates and use of binder with low thermal conductivity (compared with those of mineral binders) and to improve the quality control by industrialising the manufacturing process which will enable certification and standardisation.
The key approach and advances have been summed up in the discussion section.