Paper Conference

Proceedings of BSO Conference 2020: Fifth Conference of IBPSA-England


Improvement of the Ladybug-tools microclimate workflow: A verification study

Yasser Ibrahim, Tristan Kershaw, Paul Shepherd

Abstract: Over the past two decades, there has been a marked increase in the consideration of outdoor thermal comfort by urban planners. Several researchers have developed their own models for a better understanding of the human energy exchange with their surrounding environment. Among those models developed is the Ladybug-tools microclimate model, the plugins of Grasshopper3D. These parametric design tools are acknowledged for being time and resource efficient. In this paper, modifications to the Python source code, in terms of ground reflectivity, radiative heat transfer coefficient, projected area factor and reflected radiation were made to improve the accuracy of the model. The modified model’s accuracy is verified against the validated software, ENVI-met V.4.4.4. A hypothetical simple urban geometry was simulated within each model. The analyses of the thermal performance are presented for two different locations, representing hot arid and temperate climates, namely Cairo, Egypt, and London, UK, for extreme summer and winter conditions. Results are presented in terms of the Mean Radiant Temperature (MRT) and the Universal Thermal Climate Index (UTCI). Results show a good level of conformity between the models particularly in terms of the UTCI, 𝑅² = 0.98. This study aims to present a more precise modelling methodology for the outdoor microclimate. The modified model allows for a better parameterisation of the outdoor environment and can be considered as rigorous for modelling the outdoor conditions as fully integrated engines, albeit in a significantly less time, allowing parametric optimisation of urban geometries to become a viable proposition.
Pages: 88 - 95