Advanced building façade design for optimal delivery of end use energy demand

Lead Research Organisation: University of Nottingham
Department Name: Faculty of Engineering

Abstract

Buildings currently account for over 40% of the total UK energy consumption and a similar percentage of the UK CO2 emissions. The energy used in buildings is largely required for creating a thermally and visually comfortable environment for building occupants. Glazed façades play an important role in determining a building's energy performance and are called upon to perform a range of, sometimes conflicting, functions. They are required to i) regulate heat transfer to and from the external environment by solar and long wave radiation, conduction and convection ii) allow transmittance natural daylight to provide interior illumination, reducing the need for supplementary electric lighting and to provide an aesthetic function, both in terms of their influence on building appearance and providing occupants a visual link to the external environment. Improving fenestration energy performance can make a significant contribution to reducing building energy loads. It is reported that optimal glazing design could reduce residential building energy consumption by 10-50% in most climates, while for commercial, institutional and industrial buildings, a properly specified fenestration system could reduce lighting and air-conditioning costs by 10-40%.

We are going to carry out a holistic approach to develop advanced façades technologies to achieve building energy demand reduction goals. This compliments Centre for Research into Energy Demand Solutions (CREDS) objectives of energy demand within the 'building' & 'heat decarbonisation' theme of the centre. Low cost optical components will be designed and integrated into conventional double glazing, which will significantly increase the thermal resistance of the window, provide control of the solar heat gain, and enable windows to perform better than walls on a yearly basis in terms of their net energy balance. Building energy loads will be reduced significantly while providing comfortable daylight. The target is that when integrated in a typical commercial building the novel glazing façade system will provide comfortable annual daylight levels achieving over a 20% reduction in annual artificial lighting energy consumption, reduce space heating demand by over 30% in the heating season and cooling load by 20% in Summer. The integration in a façade system of active solar energy technologies with better performing windows may potentially lead commercial buildings to be a negative energy load on an annual basis.

Planned Impact

The principal commercial beneficiaries will be construction-related industries. In recent years there have been an increase in the demand for high performance glazing and façades, due to the increase demand for energy efficient buildings and changes in the Building Regulations. The proposed project aims to develop a range of advanced glazing façades, which can be effectively integrated into an existing building envelop component suitable for retrofit and new buildings. Prototypes of advanced glazing systems will be developed during the project and the performance data from a selection of test installations available for evaluation by companies. The project industry partners will be in a prime position to commercially exploit the output of the project. University of Nottingham, Loughborough University and University of Exeter all have dedicated business development teams, who will assist with commercial exploitation of the work. Throughout the project, an assessment will be made of the intellectual property arising and patents will be put in place where appropriate to facilitate commercial exploitation by the companies.

Building designers, glazing/materials manufacturers and installation companies also stand to benefit. The greater functionality and performance of advanced glazing will allow architects and building designers to explore new and more energy efficient design concepts. The reduction in weight and glazing bulk afforded by the advanced glazing in comparison to conventional glazing for a given level of performance level will make installation easier benefitting construction and glazing installation companies.
Building occupants and building owners will benefit from reduced energy costs, improved conditions and comfort and the reduced levels of building services required. The improved internal environmental conditions are likely to lead to improvements in health and economic productivity.

The fourth group of beneficiaries is likely to be government policy makers. A reduction in the energy consumption of buildings for heating, cooling and lighting will lead to an associated reduction in greenhouse gas and other emissions associated with their provision. Therefore, building energy use is a key issue that needs to be addressed by the government policies. A large scale deployment of the developed advanced glazing and innovative facade systems on a 5-10 year horizon would significantly contribute to the UK Government's ambition to achieve an 80% reduction in greenhouse emissions by 2050.

To deliver this impact, a number of workshops and dissemination events/exhibitions will be held during the project period (and the associated budget for the impact activities has been requested from the funder). The project consortium partners will also develop a long term (after the project is successfully completed) strategy to engage with academia, industry, policy makers and to further raise the awareness of the general public.

Publications

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Description A prototype of the proposed novel smart window system has been developed. The proposed system can enhance energy efficiency and an improved indoor luminous environment by integrating a Transparent Insulation Material (TIM) structure incorporating a Thermotropic material. This system automatically regulates the admittance of solar heat and natural light into the building by responding to a changing environment while taking advantage of the increased thermal resistance and scattered daylight of window integrated TIM.

A comprehensive building and daylighting simulation using EnergyPlus and RADIANCE was used to accurately predict the luminous and energy performance of applying the proposed smart window system on a typical south-facing office under selected climates (London, Stockholm, Rome and Singapore). Annual simulation results predict that, with a careful selection of the Thermotropic material properties, for simulated locations other than Singapore, the proposed Smart windows (TT PS-TIM windows) can provide 16.1-27.1% energy saving when compared with Double Glazing (DG). All the TT PS-TIM windows outperformed DG in term of daylight performance as quantified by UDI for all cities. Under the climate of London, the lowest solar absorptance with a transition temperature of 21 °C yields the lowest energy consumption. From the perspective of achieving highest availability of natural daylight, the system with the lowest translucent-state transmittance and lowest transition temperature (i.e. 19 °C) can provided the best levels of daylight performance. The system that leads to greatest predicted energy saving potential does not deliver good levels of useful illumination in the office for the climate of London. All of the tested TT PS-TIM window systems show good performance in Rome. The TT PS-TIM with translucent-state transmittance of 40% provides the greatest energy saving potential and simultaneously good levels (52-52.4%) of daylight availability if its transition temperature is in the range of 19-23 °C. The system with reflectance of 35% provides the best levels of daylight availability (61.1-62.3%) of all the tested specimens and simultaneously best energy saving potential when the transition temperature is 21 (20%) or 23 °C (20.8%). For the climate of Stockholm, most of the selected TT PS-TIM could not provide satisfactory daylight levels. Under the climate of Singapore, it can be seen that there is no significant difference of the energy and daylight performance between TT PS-TIM with a fixed optical property and varying switching temperature between 19 and 23 °C. This indicates that, the Thermotropic (TT) material is always in its translucent state, suggesting that a switching temperature between 19 and 23 °C is not suitable for a tropical climate. Finally, it can be concluded that different climates require different optimised designs of TT PS-TIM systems to achieve maximum energy savings and daylight comfort. For cities with extreme climate conditions (e.g. Stockholm and Singapore), the optimised design of a TT PS-TIM system will be investigated in detail in our future research.
Exploitation Route Industrial partners have been invited joining the current project meetings and also project advisory board to directly contribute to project development and provide guidance/suggestions for the proposed system development.
The project team is also discussing to work with industrial partners to host a workshop in advanced facade and energy reduction in built environment in July 2023.
Sectors Energy

URL https://www.nottingham.ac.uk/research/groups/low-carbon-energy-and-resources-technologies-research-group/research/projects/epsrc-funded-project.aspx
 
Description International partners - Turkey 
Organisation Gaziosmanpasa University
Country Turkey 
Sector Academic/University 
PI Contribution We have established new collaboration with Turkish partners, we made an application together through the RAEng Transforming Systems through Partnership scheme 20/21. The Ministry of Environment and Urbanization of Turkey considers the building sector as a priority area for all policies and programs dealing with increasing energy efficiency and combating climate change. One-third of the country's energy consumption of 105 million tonnes of oil equivalent is consumed by the building sector. With the increasing urbanisation (100,000 new buildings annually) and population this is expected to rise further (4.4% increase annually), and hence there is a need to employ energy efficiency measures in buildings. The country's dependence on the imported source of energy has reached alarming levels (75%). Space heating, air conditioning and lighting lead to half of all buildings' energy demand in Turkey, and are areas where the highest energy efficiency improvement potentials exits. The current National Energy Efficiency Strategy aims to upgrade 25% of the building stock to sustainable buildings and reduce energy intensity by 20% by 2023. One of the focus of the strategy and policy development are energy efficient glazing and lighting, which are not sufficiently addressed in the existing regulations such as Green Buildings Regulation and TS 825. With the collaboration, if successful, we will develop an advanced façade system which has the potential to provide comfortable annual daylight levels achieving over a 20% reduction in annual artificial lighting energy consumption, reduce heating demand by over 30% in the heating season and cooling demand by 20% in summer. This will help Turkey to achieve their target in building energy efficient and CO2 reduction target.
Collaborator Contribution Istanbul Teknik is a leading building material and civil engineering company in Turkey. It has a strong R&D team and is experienced with development and characterisations of various building façade systems. Istanbul Teknik will provide advice on the development of the proposed system and support both indoor and outdoor characterisations through providing testing facilities and building case study sites. This project is well fitted into Istanbul Teknik future business development plan in developing energy efficient building components. Istanbul Teknik will help to convert outputs of this research into a feasible commercial product. Its R&D section will support this project by using its product design, testing and development expertise at all stages of the project activities. Istanbul Teknik will also provide important dissemination opportunities through its network of non-academic contacts. The plan is for the collaboration between the partners to continues beyond the project lifetime and also evolve via various routes planned for after project finalisation. Future work between the partners includes further optimising the system design and testing the performance of the developed façade systems under diverse weather conditions in Turkey.
Impact We have made funding application through RAEng Transforming Systems Partnership scheme 20/21 and have been awarded funding.
Start Year 2020
 
Description National partner - Polysolar 
Organisation Polysolar
Country United Kingdom 
Sector Private 
PI Contribution Polysolar is a developer, designer and installer of architectural solar solutions who is based in Cambridge having developed a number of innovative transparent solar glass. Previously, Polysolar only focused on design the PV and PV window systems alone, and this is a lack of consideration of their impact on building performance. We have established a collaboration with Polysolar and provide suggestions on how their designed systems influence the building comfortable (e.g. daylight) and also energy performance and therefore, helping them to improve their future system design.
Collaborator Contribution Polysolar provides their developed PV window systems for us for our model validation and understanding the performance of commercial available PV window systems. They also provide guidance on how to develop advance window systems and provide potential sites for us to install our developed prototype system for long term monitoring.
Impact With the support from Polysolar, I have secured a new project "Siemens-EPSRC: Cloud-based solar forecasting for improved grid management" EP/W028581/1.
Start Year 2021
 
Description 16th CONFERENCE ON SUSTAINABLE DEVELOPMENT OF ENERGY WATER AND ENVIRONMENT SYSTEMS - SDEWES 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We have presented our findings from our project at the SDEWES conference and the audiences are very interested in our project and agrees that if it is sucessful, it will have potential to reduce building energy consumption and also maintain a comfortable indoor environment.
Year(s) Of Engagement Activity 2021
URL https://www.dubrovnik2021.sdewes.org
 
Description A presentation at ALTERNATIVE ENERGY SOURCES, MATERIALS AND TECHNOLOGIES (AESMT'22) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We made a presentation about the current outcome of our project at the AESMT'22. Over 100 professionals attended the conference online, good feedback were received and audiences have better understanding on how window/facade systems affect building comfortable and energy performance.
Year(s) Of Engagement Activity 2022
 
Description A talk or presentation - the 11th Solaris 2021 International Symposium on Solar Energy and Efficient Energy Usage 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We made a presentation about the current outcome of our project at the 11th Solaris 2021 conference. Over 100 professionals attended the conference online, good feedback were received and audiences have better understanding on how window/facade systems affect building comfortable and energy performance.
Year(s) Of Engagement Activity 2021
URL https://solaris2021.com/
 
Description AESMT'20 - Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We have presented our preliminary findings from our project at the AESMT conference and the audiences are very interested in our project and agrees that if it is sucessful, it will have potential to reduce building energy consumption and also maintain a comfortable indoor environment.
Year(s) Of Engagement Activity 2020
URL https://aesmt.lima-city.de/Home_AESMT_20.html
 
Description SHMat2020 conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Our findings in the materials development from the project has been presented at the SHMat2020 conference organised by Shanghai University, China.
Year(s) Of Engagement Activity 2020
 
Description the 13th International Conference on Applied Energy 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We have presented the performance of our prototype system from our project at the ICAE conference and the audiences are very interested in our project.
Year(s) Of Engagement Activity 2021
URL https://applied-energy.org/icae2021cfp