Delivering low carbon buildings using cellulose materials Pete - - PowerPoint PPT Presentation

Delivering low carbon buildings using cellulose materials

Pete Walker University of Bath

Opportunities for natural materials in modern construction

• Reduced GHG emissions

Lower embodied carbon (stored carbon) Improved building performance

• Resource efficiency

Renewable supply Reduced waste

• Healthier buildings
• New agricultural markets

Traditional natural materials

• Craft based
• Weather dependent:

seasonal construction

• Labour intensive
• Slow
• Expensive
• Concerns for inferior durability
• Concerns for poor structural resilience
• Unregulated supply chain
• Lack of certification, regulations, standards

Market development: barriers for natural materials

• Certification (lack of)
• Cost
• Financing
• Perceptions of poor performance
• Supply chain
• Warranty (lack of)

Products not Materials

Prefabricated Straw Bale Insulated Panels: ModCell

• Main components:
• Timber framed panels
• Straw bale infill
• Lime:sand render
• Manufactured off-site in temporary flying

factories

• Panels’ designed to be dismantled, reused and

recycled

Manufacture

Construction

Environmental Performance Testing

Air ¡permeability: ¡0.86 ¡m3/hr ¡m2 ¡@ ¡50Pa ¡ ¡

Environmental Performance Testing

Co-heating test:

• 36 kWh/m2 per annum
• Represents around

70% savings on current UK stock average

Environmental Performance Testing

Prefabricated ¡hemp-­‑lime ¡panels ¡

Wall 1: comprises 300 mm Mineral Wool insulation U = 0.15 W/m2K Wall 2: comprises 300 mm Hemp- Lime U = 0.30 W/m2K

Hemp-lime insulation performance

Time to reach steady-state, ts-s

2 4 6 8 10 12 14 16 18 20 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Temperature, oC Normalised distance through wall

Steady-state Figure 1 -Temperature change in 300 mm HL wall after sudden temperature drop

2 4 6 8 10 12 14 16 18 20 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Temperature, oC Normalised distance through wall

Steady-state Mineral Wool 24 hours Figure 1 -Temperature change in 300 mm HL wall after sudden temperature drop Figure 1 -Temperature change in 300 mm HL wall after sudden temperature drop

2 4 6 8 10 12 14 16 18 20 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Temperature, oC Normalised distance through wall

144 hours Steady-state Mineral Wool 24 hours Figure 1 -Temperature change in 300 mm HL wall after sudden temperature drop

2 4 6 8 10 12 14 16 18 20 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Temperature, oC Normalised distance through wall

144 hours 240 hours Steady-state Mineral Wool 24 hours Figure 1 -Temperature change in 300 mm HL wall after sudden temperature drop

2 4 6 8 10 12 14 16 18 20 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Temperature, oC Normalised distance through wall

144 hours 240 hours 264 hours Steady-state Mineral Wool 24 hours Figure 1 -Temperature change in 300 mm HL wall after sudden temperature drop

2 4 6 8 10 12 14 16 18 20 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Temperature, oC Normalised distance through wall

144 hours 240 hours 264 hours 312 hours Steady-state Mineral Wool 24 hours

Product certification

• Performance requirements:

– Structural safety – Environmental performance – Durability

• Quality assurance

– Materials and components – Manufacturing process – Installation

Spot the difference…

Unintended consequences of airtight buildings

Studies have confirmed that airtight buildings with low air exchange rates lead to deterioration in indoor environmental quality for occupants.* Several factors affect a healthy indoor environment, including:

• Volatile Organic Compounds (VOCs)
• Radon
• Fibres
• Particulate matters
• Moisture and humidity
• Rotting and microbiological/mould growth

*Yu, Chuck W. F.; Kim, Jeong Tai: Low-Carbon Housings and Indoor Air Quality. In: Indoor and Built Environment, 21(1), 2012, pp. 5 - 15

ECO-SEE project

Eco-innovative, Safe and Energy Efficient wall panels and materials for a healthier indoor environment The ECO-SEE project aims to develop new eco- materials and components for the purpose of creating both healthier and more energy efficient buildings.

Partners

University ¡of ¡Bath ¡ UK ¡ Acciona ¡ Spain ¡ University ¡of ¡Aveiro ¡ Portugal ¡ Bangor ¡University ¡ UK ¡ BCB ¡ France ¡ BRE ¡ UK ¡ Claytec ¡ Germany ¡ Environment ¡Park ¡ Italy ¡ Fraunhofer ¡IBP ¡ Germany ¡ Greenovate! ¡Europe ¡ Belgium ¡ IIT ¡Delhi ¡ India ¡ Kronospan ¡ UK ¡ Nesocell ¡ Italy ¡ Skanska ¡ UK ¡ Tecnalia ¡ Spain ¡ Wood ¡Technology ¡InsRtute ¡ Poland ¡

VOC capture

• Reaction between

formaldehyde and proteins.

• Reduce the VOCs

and formaldehyde levels in indoor air by the sequestration and chemisorption of VOCs. Biocomposites ¡Centre, ¡Bangor ¡University ¡

Conclusions

• Development of prefabricated panels undertaken to

address practical concerns for straw bale and hemp-lime construction.

• Successful development of panels has provided
• pportunity for addressing much wider barriers to market

acceptance caused by lack of certification and warranty.

• Wall panels using bio-based materials, including wood

based panels and insulation products, aim to contribute to improved indoor environmental quality, and occupant well-being, through Moisture buffering and VOC capture.

Acknowledgements

– Dr Katharine Wall – Dr Andy Shea – Neil Price – Dr Dan Maskell – Dr Mike Lawrence – Dr Chris Gross – Sophie Hayward – Will Beazley – Dr Andrew Thomson – White Design Associates – ModCell Ltd – Integral Engineering Design – Lime Technology – Ian Pritchett – TSB UK – Carbon Connections UK – EACI Eco-Innovation – EU (FP7)

Thank you