Smart Composite Material for Advanced Building Fenestration to Enhance Energy Efficiency

Lead Research Organisation: University of Exeter
Department Name: Engineering

Abstract

Energy consumed by buildings for heating, cooling, and lighting needs, accounts for more than 40% CO2 emissions. However, while keeping the thermal and visual comfort, a substantial portion of energy is lost due to our inability to control the ingress and egress of energy through transparent building envelope - mainly windows and facades. The UK government's ambitious target of reaching zero emission by 2050 cannot be achieved without controlling ingress and egress of energy through buildings. By 2050, 85% of the existing building stock will still be in use which indicates that retrofitting of building envelope is indispensable. Among the other building envelope, windows and facades are the least energy efficient but are easily replaceable. Glazing technology plays an important role in determining a building's energy performance, required to perform multiple roles of regulating heat transfer by conduction convection, solar and long wave radiation between internal and external environments while maintaining comfortable daylight environments by allowing the transmittance of natural daylight; reducing the need for supplementary electric lighting. The windows and facades also play an important aesthetic function by providing occupants a visual link to the external environment and influencing the appearance of buildings. Thus, developing new smart glazing technology for windows and facades to modulate the incoming and outgoing heat into indoor space to reduce building energy load, while at the same time providing visual comfort, is crucial.

The proposed project aims to undertake an ambitious innovative research program of developing new technology to significantly reduce energy demand in the built environment at an acceptable cost. The goal will be achieved by reducing heat loss, controlling incoming solar radiation to maximise solar gain, minimise heat loss in winter and reverse it by flipping windows in summer while ensuring the best natural lighting conditions with no glare.

The overarching goal of energy efficacy and visual comfort will be achieved by smart composite material in which each elements of composite will bring a unique property and contribute to enhance energy efficiency of windows and facades. In winter, the TIA will absorb external IR radiations and transfer heat to PCM for storage, which will be released back to the building, the TIM in composite will forbid heat loss through longwave thermal radiation and the IR reflective coating will prevent heat loss by reflecting IR back to room. In summer, the orientation will be flipped around to reduce cooling load. In the flipped case, heat gain by IR will be prevented by IR reflective layer while the TCM will regulator the transparency to control the indoor temperature constant. The multi-fold smart composite developed in this research program. This will enable advanced glazing technology to achieve U-values down to 0.4 W/m2K1 while maintaining comfortable daylight environments and reduce annual energy consumption by 30-40% for buildings. The outcome of this research will enable us to create technological pathways towards achieving energy positive buildings in the UK.

Planned Impact

The societal and environmental impacts of energy efficient buildings using cost effective and sustainable approaches has received national and global exposure and cannot be overstated. Recently, the demand for high performance glazing technology for windows to reduce building energy load and enhance building energy efficiency had been enormously increased due to changes in the Building Regulations. The solution for both new constructions and existing building renovations can be found by developing dynamic and smart technology which is capable of automatically and continuously responding to changing energy and light transmission values to external environmental conditions and users' requirements.

This innovative project will combine multilevel modelling and experimental formulation approaches to overcome the fundamental challenge of current energy loss through transparent component building to enhance building energy performance. The innovative project aims to systematically develop advanced glazing facades providing U-values down to 0.4 W/m2K, maintaining comfortable daylight while reducing annual net energy consumption by 30-40% for commercial and residential buildings in the UK. The proposed project fits well with CREDS themes of Materials and Products, Building & Energy and Decarbonisation of Heat.

The project and its outcomes will impact on: Industry, society; the economy and knowledge.

Industry: The main commercial beneficiaries of the project's outcomes will be construction-related industries which includes building designers, glazing/materials manufacturers and installation companies. The direct beneficiaries of the project outcomes are the industries participating in this project: NSG -Pilkington group Limited and Yorkshire Photonics Technology. Being one of the largest glass manufacturers, NSG will be benefited by the outcome of the multi-fold smart glazing unit applied into building sector, through the development of low U value system. The direct benefits and impacts of these companies are given in their support letters.

Government policy makers: The multi-fold smart composite based glazing technology will reduce heating, cooling and lighting energy consumption which will ultimately lead to the reduction in greenhouse gas and other emissions associated with energy supply to buildings. To achieve governments greenhouse emissions reduction target by 2050, policy maker needs to address the challenge of building energy loss and the project outcome will contribute to emissions reduction target by reducing building energy load.

The impact on Society: People living in energy efficient buildings will benefit from reduced energy costs, improved conditions and comfort. Health and wellbeing of the occupants will also be enhanced from the improved internal environmental conditions.

Economy: The impact on economy will be through the design, production and commercial exploitation of new smart glazing system. This impact will be affected through partnership with UK industrial collaborators, such as the project partners on this project, namely: Yorkshire Photonic Technology and NSG -Pilkington group Limited.

Knowledge: The impact will be achieved through the significant advances made in the project in: (i) new Knowledge of computational simulation and methodology of PCM, TIM, TIA and TCM. (ii) new scientific discoveries, understandings and methodologies for composition-controlled composite, (iii) new understandings of materials and optoelectronic and thermal properties and (iv) new understanding of smart glazing technology. The impact on people will be through the technical expertise developed by the research team during the project, the training received in societal and ethical issues and the transferable skills developed in collaboration and engagement with other academics, industrial partners and general public.

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