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Indoor Air Quality: The Influence of Neighbourhood Microclimates and Indoor-Outdoor Exchange

PGR-P-674

Key facts

Type of research degree
PhD
Application deadline
Friday 17 April 2020
Project start date
Thursday 1 October 2020
Country eligibility
UK and EU
Funding
Competition funded
Source of funding
Research council
Supervisors
Professor Catherine Noakes and Professor Alison Tomlin
Additional supervisors
Dr. Amirul Khan
Schools
School of Chemical and Process Engineering, School of Civil Engineering
<h2 class="heading hide-accessible">Summary</h2>

Short term high exposures to air pollution are shown to exacerbate conditions such as asthma and COPD, increase risks of heart attacks and stroke, and influence respiratory infections. During the day people move through a variety of indoor and outdoor spaces and experience differing levels of exposure to a range of pollutants. Urban populations spend a large part of their time indoors. This means that a limited number of spatially fixed outdoor measurements, as well as mean values predicted from operational models, are not a good measure of people&rsquo;s actual exposure to pollution. A growing number of studies show that indoor air pollution is also important and influenced by indoor sources such as cooking, smoking, damp, cleaning products and heating appliances. However to date very few studies consider the interface between indoor and outdoor environments and the exchange of pollutants. This exchange is influenced not only by the time-varying external environment (levels of pollution, air flows, temperature), but also by the building design and performance as well as ventilation strategies. Optimised building design and ventilation that takes into account the neighbourhood microclimate will play an important factor in terms of reducing people&rsquo;s exposure to pollution within the indoor environment. Project details Through a combination of computational modelling, experimental and fieldwork measurements, the project aims to improve the understanding of the dynamic indoor-outdoor exchange of air and pollutants within urban environments. The modelling strategy will adopt a multi-scale approach with semi-empirical models used at the city scale providing boundary conditions for coupling with an unsteady large-eddy simulation (LES), based on the Lattice Boltzmann method (LBM) for a neighbourhood aware unsteady airflow and dispersion model to be used at the street to building scale. Case study scenarios will include buildings situated on streets with high traffic flows as well as suburban buildings within areas of significant domestic solid fuel burning (e.g. from wood stoves). A range of ventilation options will be explored for each case study model to explore optimal ventilation strategies and opportunities for mitigating indoor air pollution. Model validation will be supported via measurements taken in the environmental research chamber within the School of Civil Engineering at Leeds as well as using suitable field locations. The project supervisory team are currently developing collaborative projects with researchers at Shanghai Jiao Tong University and there may be scope for the student to interact with the SJTU team.

<h2 class="heading hide-accessible">Full description</h2>

<h4>Aim</h4> <p>To improve the understanding of how factors such as building design, ventilation and heating strategies influence indoor air quality and the indoor-outdoor exchange of air pollution under varying external atmospheric conditions.</p> <h4>Background</h4> <p>There are an increasing number of studies which find causal links between air pollution within cities and adverse health outcomes. Through a network of pollution sensors we have a good picture of how trends in external urban air pollution have changed in response to changing emission sources and climate patterns. Urban populations however, spend a large part of their time indoors, either at home, or at school or university, within the workplace etc. The Royal College of Paediatrics and Child Health reports that children in the UK spend on average just 68 minutes a day outside. During the day people move through a variety of indoor and outdoor spaces and experience differing levels of exposure to a range of pollutants. Short term high exposures are shown to exacerbate conditions such as asthma and COPD, increase risks of heart attacks and stroke, and influence respiratory infections. However, a limited number of spatially fixed outdoor measurements, as well as mean values predicted from operational models, are not a good measure of people&rsquo;s actual exposure to pollution. Local turbulent flow patterns coupled with emissions from traffic, industrial sources, domestic combustion and regional and long-range pollutant transport all contribute to the fluctuating urban outdoor pollutant concentrations. There are a growing number of studies showing that indoor air pollution is also important and influenced by indoor sources such as cooking, smoking, damp, cleaning products and heating appliances. However to date very few studies consider the interface between indoor and outdoor environments and the exchange of pollutants. This exchange is influenced not only by the time-varying (unsteady) external environment (levels of pollution, air flows, temperature), but also by the building design and performance as well as any ventilation strategies being used within the building. An airtight building (such as an energy efficient passive house) may limit the ingress of outdoor air pollutants, but may lead to a build-up of CO<span class="subscript_text">2</span> and other pollutants from indoor sources within the indoor space. Ventilation may be required in order to control indoor sources, but depending on the ventilation strategy may lead to the ingress of external pollutants such as fine particulates or NO<span class="subscript_text">2</span>. Differing ventilation strategies may be required for different building types and locations and designing such systems effectively depends on understanding the indoor-outdoor exchange of air. Optimised building design and ventilation that takes into account the neighbourhood microclimate will play an important factor in terms of reducing people&rsquo;s exposure to pollution within the indoor environment.</p> <h4>Project details</h4> <p>Through a combination of computational modelling, experimental and fieldwork measurements, the project aims to improve the understanding of the dynamic indoor-outdoor exchange of air and pollutants within urban environments.</p> <ul> <li>Cities influence air flows at multiple scales and the modelling strategy to be developed in the project will adopt a multi-scale approach. Semi-empirical models will be used at the city scale providing boundary conditions for coupling with an unsteady large-eddy simulation (LES), based on the Lattice Boltzmann method (LBM) for a neighbourhood aware unsteady airflow and dispersion model to be used at the street to building scale.</li> <li>Case study scenarios will be developed in order to assess different potential exposure situations. These will include buildings situated on streets with high traffic flows as well as suburban buildings within areas of significant domestic solid fuel burning (e.g. from wood stoves).</li> <li>A range of ventilation options will be explored for each case study model to explore optimal ventilation strategies and opportunities for mitigating indoor air pollution such as sensor-controlled ventilation, and filtration techniques.</li> <li>The influence of outdoor air flows (flow patterns, recirculation behaviour and levels of turbulence) will be explored.</li> <li>Model validation will be supported via measurements taken in the environmental research chamber within the School of Civil Engineering at Leeds as well as using suitable field locations.</li> </ul> <h4>International collaboration opportunities</h4> <p>The project supervisory team are currently developing collaborative projects with researchers at Shanghai Jiao Tong University and there may be scope for the student to interact with the SJTU team.</p>

<h2 class="heading">How to apply</h2>

<p>Formal applications for research degree study should be made online through the&nbsp;<a href="https://eps.leeds.ac.uk/chemical-engineering-research-degrees/doc/apply">University&#39;s website</a>. Please state clearly in the research information section&nbsp;that the research degree you wish to be considered for is &ldquo;Indoor Air Quality: The Influence of Neighbourhood Microclimates and Indoor-Outdoor Exchange&rdquo; as well as <a href="https://eps.leeds.ac.uk/chemical-engineering/staff/122/professor-alison-tomlin">Professor Alison Tomlin</a> as your proposed supervisor.</p> <p>If English is not your first language, you must provide evidence that you meet the University&#39;s minimum English language requirements (below).</p> <p><em>We welcome applications from all suitably-qualified candidates, but UK black and minority ethnic (BME) researchers are currently under-represented in our Postgraduate Research community, and we would therefore particularly encourage applications from UK BME candidates. All scholarships will be awarded on the basis of merit.</em></p>

<h2 class="heading heading--sm">Entry requirements</h2>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

<h2 class="heading heading--sm">English language requirements</h2>

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid.

<h2 class="heading">Funding on offer</h2>

<p><strong>UK/EU</strong> &ndash;&nbsp;Engineering &amp; Physical Sciences Research Council Studentship&nbsp;for 3.5 years. A full standard studentship consists of academic fees (&pound;4,600 in Session 2020/21), together with a maintenance grant (&pound;15,009 in Session 2019/20) paid at standard Research Council rates. UK applicants will be eligible for a full award paying tuition fees and maintenance. European Union applicants will be eligible for an award paying tuition fees only, except in exceptional circumstances, or where residency has been established for more than 3 years prior to the start of the course.&nbsp;&nbsp;Funding is awarded on a competitive basis.</p>

<h2 class="heading">Contact details</h2>

<p>For further information regarding the application procedure, please contact Doctoral College Admissions:<br /> e: <a href="mailto:phd@engineering.leeds.ac.uk">phd@engineering.leeds.ac.uk</a>, t: +44 (0)113 343 5057.</p> <p>For further information regarding the project, please contact:<br /> Professor Alison Tomlin, e: <a href="mailto:h.e.wang@leeds.ac.uk">A.S.Tomlin@leeds.ac.uk</a><br /> Professor Cath Noakes, e: <a href="mailto:h.e.wang@leeds.ac.uk">C.J.Noakes@leeds.ac.uk</a><br /> Dr Amirul Khan, e: <a href="mailto:A.Khan@leeds.ac.uk">A.Khan@leeds.ac.uk</a></p>


<h3 class="heading heading--sm">Linked funding opportunities</h3>