Dr Sukumar Natarajan


Senior Lecturer (Associate Professor)
in the Environmental Design of Buildings
Director EPSRC CDT dCarb | Blog
Deputy Director EDEn
Department of Architecture and Civil Engineering
University of Bath, UK
ORCID | Google Scholar
Recent publications:
Completed Projects
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Completed Projects

This page provides a short description for completed projects. To find out more, click on the project's title to be taken to it's own web-page, if it is still alive. Wherever possible and sensible, project value shown is non-FEC, i.e. the actual cost to the funder which is 80% of its true value.

Funder Engineering and Physical Sciences Research Council (EPSRC)

Value £0.8M

It is well known that climate change will have a significant impact on UK building design and energy use. It is also known within the building science and architectural communities that the current weather files used for thermal modelling of buildings only represent average weather rather than heat waves or cold snaps. As was shown by the 14,000 deaths in Paris during the 2003 heat wave, this is a highly serious issue and there is the need to ensure future buildings are designed to deal with future weather, or extremes of current weather.

In addition, the current weather files used by the construction industry and building scientists divide the UK into only 14 regions, with, for example, the whole of the South West peninsular (including up-land areas) being assigned the coastal Plymouth weather file. It is known that this can easily lead to a 200% error in the estimation of annual energy demand. The scale of this error is such that it renders many of the dynamic simulations carried out by engineers questionable. This is unfortunate when simulation is used within the framework of the building regulations, but it is fatal when trying to use simulation to estimate how resilient a pre-existing building is, or the danger its vulnerable occupants might be in.

The aim of this project will be to see if a method can be devised that is capable of creating local weather from 2015 to 2080 covering the whole UK at a resolution of 5km, and to include within this files that represent various excursions from the mean: e.g. heat waves and cold snaps.

Summary of Work Packages

WP 1

We will use a method already published by the team together with the UKCP09 weather generator to produce current and future typical weather at a resolution of approximately 5km.

WP 2

The work in the previous work package will initially require the creation of thousands of years of weather per site. Within these initial years will reside a large number of weather events of interest to the building scientist or engineer. These files will be used in computer models of 1200 differing architectures and building uses to identify what are the key drivers of weather variable coincidence that defines the likelihood of building system failure or thermal issues for occupants.

WP 3

Having characterised which events best describe the stresses on a building, its occupants and systems in WP2. Event years (i.e. times series of weather data variables on a one hour time step that represent atypical hot, dry, cold and wet periods) will be created for the whole UK.

WP 4

Having generated the event years, and simulations from the 1200 buildings, the two will be recombined to produce the first map of UK resilience to a changing climate. Although others have looked at the regional resilience of the built environment using average weather years, the concern is not about the response of building and occupants to such average time series, but to more extreme events.

WP 5

Given the large number of files proposed, guidance will need to be given on which to use in practice, and how this might be expressed in the building regulations and other documentation. We plan to use case studies as the main guidance tool. This will add greatly to their intellectual validity within the target audience of practicing engineers. In total, we expect the guidance to be tested on >100 real building projects

WP 6

All weather files produced by the project will be publicly available for a minimum of 10 years. A series of road shows will be undertaken at the end of the project. At these events the results of the project will be presented to a large number of users. The idea will be to introduce the whole UK built environment community to the idea of designing resilient buildings aided by the weather data produced by the project. A short film will also be produced for those that cannot attend and for an international audience.


Funder Engineering and Physical Sciences Research Council (EPSRC)

Value £1.5M

The UK is committed to an 80% reduction in human-created greenhouse gas emissions. As well as financial incentives, carbon reduction will require an increase in "energy literacy", i.e. it will require members of the public to better understand the energy, carbon and financial implications of their behaviours and habits. The ENLITEN project aims to reduce carbon emissions from energy use within buildings by understanding and influencing occupants' habits and behaviours around energy use.

Significantly reducing energy use within buildings through internal physical controls, such as automatically closing windows, is difficult economically. For example, equipping windows with sensors and motors would cost in the region of £100 per window. Reducing energy use within buildings through external policy controls, such as enforcing times when appliances can and cannot be run, is difficult socially and politically. For example, when California tried to impose a state-wide reduction of 1F in air-conditioning temperature settings, there was public outrage and resistance. Hence, an approach that has more chance - economically, socially and politically - of achieving significant energy reductions is to persuade building occupants to change their energy consuming behaviours.

There have been many studies of the effect on energy demand of providing building occupants with information on their energy use, founded on the hope that such information will encourage them to reduce their use. The results vary widely, suggesting anything from 0% to 20% reductions. Where reductions are achieved through occupants' behavioural changes, they are often not sustained in the longer term. To achieve significant sustained reductions in energy use by building occupants, we need to avoid simply presenting more information - an approach that has failed in other domains - and focus on providing information that has an effect which lasts beyond any temporary interventions or campaigns.

This may be achieved by encouraging changes to sustainable behaviours that are sustained in the longer term, maximising the savings by each individual while minimising the burden of behavioural change required, and maximising the number of individuals making changes. In order to achieve these goals, we will specifically target long term sustained effects by focusing on changes to the habitual behaviours of building occupants and not just short-term responses to interventions. We will develop an innovative smart system that provides information, recommendations and rewards personalised to each household and associated with novel behaviour-driven energy tariffs. We will maximise accessibility and potential uptake of the system by making the equipment cheap, easily deployable and minimally disruptive to the building fabric.

The system will be based on a whole building energy model that, uniquely, integrates a thermal model of the building, a model of occupants' habits and requirements and a disaggregated model of energy use in the building. We will use data from a minimal sensor set to develop a unique auto-generated thermal model of the building, and a disaggregated model of energy use. We will use a range of automated and human data collection and analyses to develop an understanding and model of occupants' energy- related attitudes, behaviours and habits. We will bring these models together to inform an interactive in-building tool to help occupants identify and break poor energy habits, form better ones and reduce energy demand and carbon emissions. While fostering changes in the habits of the occupants, we will relate these changes to the broader social and economic context, examining the trade-offs between the value and costs of behavioural change, quantified in terms of reductions in energy cost and carbon footprint for individuals and the energy supply chain. This analysis will allow us to develop novel tariff-based incentives that reward desired behavioural changes.


Funder Engineering and Physical Sciences Research Council (EPSRC)

Value £50k

EPSRC funded 22 projects over two calls in 2010 and 2012 to investigate `Transforming Energy Demand through Digital Innovation' (TEDDI) as a means to find how and how people use energy in homes and what can be done reduce energy consumption. As a result a lot of data is being collected at different levels of detail in a variety of housing up and down the UK, but the mode, detail and quantity are largely defined by the needs of each individual project. At the same time, the research councils (RCUK) are defining guidelines for what happens to data generated by projects they fund, for which universities are then defining policies and finally researchers are then taking concrete actions to store, preserve and document data for future reference.

The problem at this current time is that there is relatively little awareness, limited experience and only emerging practice of how to incorporate data management into much of (physical) science research. This is in stark contrast to established procedures for data formats and sharing in the biosciences, stemming from international collaboration on the Human Genome Project, and in the social sciences, where data from national surveys, including census data, have been centrally archived for many years. Consequently, current solutions adopted by (Build)TEDDI projects may be able to meet a minimal interpretation of the requirements, but not effectively deliver the desired data legacy, such as (for example) the means to execute trans-project queries, or being able to cite the results of such queries for the sake of reproducibility.

Aims and Objectives

The challenges described above, which we address in DM4(B)T in the microcosm of the TEDDI projects, are tackled in three ways:

  1. Raising awareness with those who are responsible for data management (principal investigators),

  2. Developing a framework to guide the process of making the choices for how to go about implementing data management and

  3. Demonstrating example tools that will enable researchers to bring together and re-analyse data from different projects more easily,

which together will help researchers (i) to satisfy funding and institutional guidelines for data management, (ii) begin the process of forming a data management culture in science research and (iii) create a substantial case study in science data management which can inform the three primary stakeholders (researchers, institutions and research councils) across a range of issues (see Recommendations below).

Key activities and outputs

  1. Workshops (i) to gather information about current practice, (ii) present data management problems and outline analysis and solutions and (iii) to disseminate knowledge of tools and (new) practices to support effective data management.

  2. Tools and techniques: to allow researchers to harness both the variety and volume of data being collected specifically within the (Build)TEDDI projects. The tools will be made available open-source for access by other researchers to expand and adapt.

  3. Recommendations: these will take the form of an online report to identify routes to facilitate a sustainable data legacy (management, curation and citation) for projects in the science and engineering domain.

Applications and Benefits

  1. (Build)TEDDI projects will benefit directly from the above activities and outputs to meet institutional and research council requirements.

  2. Other researchers will benefit from being able to access (Build)TEDDI data.

  3. The outputs will benefit the wider research community in science and engineering through the provision of an easy-to-adopt (and adapt) data management methodology.


SimPod

Funder EPSRC Institutional Grant

Value £120k

For many years it has been known that there is a performance gap between modelled and monitored energy use. This arises from model outputs not reflecting reality; be it occupant behaviour, construction practice, or the physics of some materials. There is also evidence that it is not just physical parameters that are the cause. Recent work indicates that there may also be a calculation gap in how researchers and design engineers model a building's energy performance. This project is in response to an urgent drive to reduce differences and improve energy use prediction. SIMPod will provide a highly controlled test facility that will allow researchers to:

  • verify thermal models and codes
  • to test new technologies (e.g. phase change materials)
  • field test new materials and controls
  • to validate new ways of modelling
  • allow building performance modellers to test remotely via the internet

COincident Probabilistic climate change weather data for a Sustainable built Environment (COPSE)

Funder Engineering and Physical Sciences Research Council (EPSRC)

Value £112k (Bath)

This project will develop sound methods for future climate change data for building designers to use for new buildings and refurbishments that could last to the end of this century. The principal application output will be a draft Technical Memorandum (TM) for the Chartered Institution of Building Services Engineers, CIBSE, suitable for practising designers. This will be supported by extensive case studies to validate the new weather data design methodology and be used in research tasks described later. 'Story lines' relevant to different scenarios for the climate and built environment will be developed as well as risk levels in building design to enable designers to use the weather data with confidence. The TM will provide CIBSE with a consistent methodology for the selection and use of future data for its new Design Guide, a fundamental document used by designers of buildings and their services and a supporting document for the Government's Building Regulations. The basis for this project will be the UK Climate Impacts Programme (UKCIP) future scenarios to be published in 2008 (UKCIP08) from which may be derived probabilities of different weather outcomes over this century. Academic outputs will include an extensive assessment of the carbon reduction potential of active and passive systems and designs for new and refurbished buildings. They will utilise case studies with PC simulation of the building and systems, employing the new probabilistic weather data. These assessments will provide designers and policy makers with guidelines to help reduce the growth in greenhouse gases (GHGs) from buildings, which at present contribute about 50% of the UK emissions. Other academic outputs will provide the theoretical basis underlying the proposed consistent PC-based and manual design methodology with coincident, probabilistic future weather data parameters such as solar radiation, air temperature, wind speed and direction. It is known that solar radiation and air temperature have peak values at different times and on different days but current design methods do necessarily separate them so that over-design often occurs. A related academic output will be a theory underpinning the selection of the proposed new Design Reference Year (DRY) which will facilitate building design (including passive and active heating and cooling systems and comfort assessment) with simulation on a PC. The DRY will replace the currently unsatisfactory Design Summer Year. Solar radiation data, not covered in detail in the HadRM3 and UKCIP02 models, will be developed to satisfy designers' requirements. Likewise wind data (crucial to include since wind drives natural ventilation) although the confidence level will be lower. Rainfall duration and quantity are also important in the building design process because of drainage and rain penetration damage and designers' requirements will again be reviewed.'Urban heat island' effects (urban areas are often hotter than the nearby rural areas), briefly mentioned in the present Guide, will be incorporated in the new data, developing on SCORCHIO work to provide more realistic urban weather data. Local modification or downscaling will also be applied to generate data for other sites in the UK. This will enable the new Guide to cover more than the current 14 sites for which data were developed by Manchester for CIBSE.To ensure that the new, probabilistic outputs will be useful to professionals, and to reflect best practice in design, there will be strong stakeholder involvement through the formation of a Stakeholders Group, including Corresponding Members, which will include CIBSE, architects and software houses and housebuilders. Policy interests will be reached via the Department for Communities and Local Government, and DEFRA and their contractors, such as BRE. There will be links to the Manchester-led EPSRC SCORCHIO urban heat island and climate change project, UKCIP and the Tyndall Centre.

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