The impact of urban microclimate on indoor-outdoor air exchange
Over 40% of the UK population spend their working lives carrying out knowledge work in offices enclosed spaces in the built environment. While these buildings must meet basic environmental and
safety standards, building codes are primarily defined around the performance of the physical
infrastructure rather than the performance of the occupant. Indeed, the energy agenda has recently
focused on making these work environments as air tight and thus as energy efficient as possible,
leading at times to overheated, stuffy conditions. But what if this energy efficiency is costing our
well-being, and thus our performance and capacity to contribute to environmental, economic and
social sustainability? There is a clear need to be able to quantify the impact of indoor air on human
performance and determine what is optimal for quality performance as well as energy efficiency.
Buildings do not exist in isolation, and in turn contribute to significant urban microclimatic effects
such as the Urban Heat Island (UHI). As the neighbourhood around a building becomes more builtup, a good design can “turn bad” (e.g. cross-ventilation strategies in high-rise buildings fail if flow is
impeded by new buildings). Natural ventilation of buildings is seen as a sustainable solution, but can
be impeded by the UHI due to a reduction in cold air purging overnight. The flow of air and heat
around a building is strongly affected by the presence of other buildings nearby. This PhD project will
investigate to what degree indoor-outdoor air exchange is determined by the local urban
microclimate. The physical and dynamical processes acting at the building surface and around
openings such as windows are far from fully understood and not yet well modelled.
LHS: the figure shows the “steady state” wind-flow around a multi-storey building, causing
pressure differences across the building envelope, leading to ingress of air (thanks to C. Noakes).
RHS: previous Reading work - in situ monitoring of oxides of nitrogen, NOx, in a central London
building, allows infiltration rate to be calculated for different external weather conditions.
The student will work closely with other members of the interdisciplinary Refresh project team
(Refresh: Remodelling Building Design Sustainability from a Human Centered Approach). This 5-year
EPSRC funded project brings together expertise in Urban Meteorology (Prof Janet Barlow, University
of Reading), Human Computer Interaction (Prof mc schraefel, University of Southampton) and
Building Ventilation (Dr Cath Noakes, University of Leeds. The overall project will measure the
“dynamic” airflow changes in and around a building and relate them to human performance in that
building. By combining these measures with numerical and physical model simulations, the project
aims to create new models of building environments that take human well-being into account. These
models will help us to design new kinds of environmental interaction tools that allow energy
efficiency targets to be met without compromising productivity.
Student profile and funding particulars: This project will suit someone with a strong grounding in
applied physics/maths, engineering, or other physical or environmental science. Initiative, creativity,
experimental ability and willingness to work across disciplines are bonuses! This PhD project is
funded by a University of Reading studentship and is open to UK students and other EU students.