Osborn Associates Ltd required a detailed assessment of "Assessment and Optimisation of the Cooling Systems for a Large Data Centre in London" in 2024. The work brought together computational fluid dynamics (CFD) and the project information supplied for this data-centre engineering application. The central objective was to connect local flow, thermal, transport or process behaviour with system-level performance, risk and design decisions that the client could implement.

The main aim of this project was to run a series of CFD simulations for the external plant room at Global Switch London East building and construction, following the replacement of an air-cooled chiller bank in the Northeast (NE) Quadrant with a new set of water-cooled chillers and corresponding hybrid coolers. In this project, all the individual components on the roof of the building and construction were modelled and different wind conditions and heat loading scenarios were modelled based on the ASHRAE guidelines to ensure compliance. Also, different mitigation techniques were also considered and modelled to ensure the new cooling system is capable of providing the cooling required under the worst-case scenario. This was an extremely complex problem given the size of the building and construction and the equipment but was a success and the final design was approved and implemented by the client.

The methodology centred on a large external CFD and heat-transfer model of the data-centre roof and its cooling plant. The representation retained hybrid coolers, dry-air coolers, chillers, screens, buildings and exhaust sources that influence wind shelter, plume dispersion and warm-air recirculation. Boundary and operating conditions covered the relevant wind directions and speeds, heat-rejection loads, ambient temperatures and worst-case operating combinations guided by the applicable design criteria, with material, fluid and equipment properties assigned from the available design information. Resolution was concentrated in regions where steep velocity, thermal, concentration or phase gradients were expected, while the overall model remained efficient enough to compare several credible configurations. This balance allowed system-level performance to be linked to the local mechanisms responsible for it.

The assessment compared rain screens, equipment layout, physical mitigation and operational fan or control responses. Performance was judged using cooler intake temperature, airflow, hot-air re-ingestion, plume interaction, local recirculation, thermal margin and the duration or likelihood of adverse conditions. Results were reviewed through quantitative summaries and engineering visualisations, such as contours, vectors, streamlines, sections and time histories, selected to suit the physics. Important assumptions and operating uncertainties were considered so that the recommendations relied on repeatable comparative trends rather than a single nominal case.

For Osborn Associates Ltd, the principal value was assurance that the rooftop plant and control philosophy could maintain resilient cooling performance with proportionate mitigation. The final evidence linked each recommendation to the relevant model or process output, making it suitable for internal design reviews, supplier or contractor discussions and, where applicable, planning, safety or regulatory dialogue. The work also created a reusable baseline that can be updated as geometry, operating data or test results become available, reducing the cost and risk of later design iterations.