The potential for climate change mitigation in sustainable building design using nanotechnology Geoffrey Mitchell
Introduction
New plastics
Carbon emissions from energy use in buildings account for up to half of carbon emissions; of which half comes from housing; Much of housing design is conservative and makes limited use of new materials; Use of plastics in construction is limited and largely restricted to passive components; Considerable scope for new designs and new materials;
Terms such as biomimetic and intelligent design abound and there is a huge variation of plastic materials with different functions including plastic electronics, shape changing, light responsive; These active functions are in addition to being lightweight, easily fabricated, low cost; What is the scope for an integrated approach which incorporates new functionality in to a building design ?
Energy harvesting
Buildings and Energy Climate
Building Envelope
Building Equipmen t
Operation & Maintenance
Occupant Behaviour
Occupant Behaviour
Data from Department of Communities and Local Government UK
Buildings and Plastics
Harnessing solar energy has no impact on the climate other than slightly changing the proportion of radiation reflect back in to the atmosphere; Growth in polymer/organic based solar cells; Use of flexible plastic substrate may ease integration in to building design; Drive for low cost Photoactive polymers change shape upon variation of the light intensity - use to reorient solar energy devices to maximise efficiency; Micro-capillary films offer a new approach for collectors - key is processing; Cost effective solutions emerging for capturing motional energy;
Energy Storage
Phase change materials absorb heat during the day and release it at night, eliminating the need for airconditioning. Plastics provide high performance phase change materials as well as encapulsants; The key is the cost and how to package this in to building materials – effective input and output of the energy and controlling the trigger temperatures
Light, Air and Ventilation .
High proportion of housing is mature; Already a high proportion of retrofit using plastics; Windows, doors, bathrooms, kitchens; New build for housing is conservative as shown in the pie-chart for use of plastics in buildings; New build for non-residential buildings highly innovative World-wide many houses needed;
Plastics with photosensitive nano particles control the light spectrum in a building using the light itself; Air quality an early problem in predicted climate change, use polymer nano membranes for energy; recovery in ventilation systems; Use energy to humidify or dehumidify air, filter out harmful contaminants , Use environmental stimulated actuators; The key is the cost.
Conclusions
Plastics offer a rich range of opportunities; The maximum value will come from an integrated design in which there is incorporation in to the building; Development requires an understanding at the outset of the constraints of the end-use; Plastics offer promise of low cost.
www. cdr-sp.ipleiria.pt