Module Overview
This module teaches engineers how cities overheat, how the urban microclimate is simulated, and how the same validated model can both expose a problem and evaluate a solution. It opens with the fundamentals -what the Urban Heat Island (UHI) is, the physical drivers behind it, the self-reinforcing cycle in which air conditioning makes cities hotter, and how impact can be assessed where people actually stand (pedestrian level) using a comfort index (UTCI). It then introduces the coupled atmosphere–canyon–building modeling stack, validated for Beirut. Two contrasting case studies follow. In the first - a problem to diagnose - an energy-saving cooling upgrade (desiccant/MOF dehumidification) is shown to dump extra waste heat into the street, quantifying how much hotter it makes the city and which material is least harmful. In the second - a mitigation to deploy - daytime radiative-cooling roofs are evaluated as a passive way to shed heat to the sky, benchmarked against conventional cool roofs. The unifying lesson: judge any cooling technology by its city-scale microclimate impact, not just its building-level energy.
Learning Outcomes
By the end of
this module, participants will be able to:
1. Explain the Urban Heat Island effect and its physical drivers (anthropogenic heat, solar absorption/storage, reduced sky-view factor, lost evapotranspiration, and weakened convective cooling).
1. Explain the Urban Heat Island effect and its physical drivers (anthropogenic heat, solar absorption/storage, reduced sky-view factor, lost evapotranspiration, and weakened convective cooling).
2. Describe how the urban microclimate is simulated using a coupled atmosphere–canyon–building model, and why a city cannot be experimented on directly.
3. Assess how an energy-saving HVAC upgrade can intensify the UHI, and interpret waste-heat and pedestrian-temperature results to compare materials.
4. Evaluate radiative-cooling roofs as a passive mitigation, including the physics of the atmospheric transparency window and an honest comparison to cool roofs.
5. Interpret pedestrian-level air temperature and UTCI results, and apply the principle of judging a technology's city-scale impact rather than its building-level energy alone.
