Better ventilation for buildings: From idealised models to real-world influences

We spend around 90% of our time indoors in buildings which account for around 30% of our energy consumption. Ventilation is a crucial element of any building design and impacts significantly both on energy consumption and the health, comfort and well-being of building users. This PhD will contribute to the better ventilation of modern buildings.

Much fundamental work has been done to characterise and understand the fluid dynamics of these ventilating flows in idealised building geometries with prescribed heat sources, particularly in a steady state. However, real buildings are far more complex. Architects and engineers consistently design and construct buildings that challenge and excite the way we live, feel and work in our urban environments. Our collaborators, Foster + Partners, have over 40 years’ experience in this field, and are world leaders in delivering integrated architectural design.

The precise geometries experienced by ventilating air flows within buildings are dependent on numerous factors, from architectural form to internal layout and use. This is particularly pertinent to situations in which building occupants have control over the indoor environment and are able to change furniture layout, or open and close windows and doors, for example. How these changes affect the ventilating flows and just how to reflect these changes within the management of a given ventilation strategy is still unclear. This PhD will combine the academic expertise at Imperial with the world-leading practice and application of Foster + Partners to enable prediction of the changes from well-known idealised cases that occur in real buildings.

Guided by the understanding evidenced in the literature the candidate will utilise experiments and computational fluid dynamics to inform the development of methods capable of suitably characterising these effects within low-order models of the building and the ventilating flow. The candidate will exploit world-class laboratory facilities available at Imperial, cutting-edge open-source code developed there, and the unique facilities that are offered at Foster + Partners global headquarters (just down the road from Imperial!). For example, during the PhD the candidate might seek to classify a number of standard model rooms, for each assessing the ranges in real complex geometries that can be appropriately represented by them. Alternatively, they might examine how quickly the flow returns to the steady-state solution when people move within and doors open/close. In each case the candidate will consider how the occupancy experience (thermal comfort and air quality) might vary. An improved understanding of the scope and limitations of the models examined will be applied to our continued advancement of sustainable and healthy building design practice.