ACL - Emmanuel Bozonnet

Articles

• [hal-05017503] A methodology to bridge urban shade guidelines with climate metrics

  2 avril, par ano.nymous@ccsd.cnrs.fr.invalid (Simon Martinez), Simon Martinez
  Urban overheating poses significant challenges to public comfort and health, particularly in pedestrian areas. While urban climate studies offer detailed maps of thermal discomfort and heat stress, urban planning often relies on simplified guidelines, creating a gap between research and practice. This study introduces a methodology to bridge this gap by developing a spatially aggregated dissatisfaction indicator, PPD*^, based on the Universal Thermal Climate Index (UTCI) and incorporating a minimum spatial requirement for shade derived from existing cities' shading policies. The novel indicator separately accounts for thermal discomfort in both shaded and sunlit pedestrian areas. A simulated case study in a neighborhood in La Rochelle, France, evaluates six tree planting scenarios, with canopy cover ranging from 0% to 80%. Results indicate that a 20% canopy cover is a practical threshold for mitigating discomfort in moderate and warm climates. This methodology can also be extended to assess additional cooling strategies, such as evaporative systems, and provides valuable insights for optimizing cost-effective and sustainable urban adaptation measures.

• [hal-04950835] Specific metrics for direct adiabatic cooling of industrial buildings and climate adaptation

  17 février, par ano.nymous@ccsd.cnrs.fr.invalid (Antoine Breteau), Antoine Breteau
  This paper presents an analysis of the performance of a direct evaporative cooling system incorporated into an industrial building, evaluated in various climates and weather conditions. This system is a simple and economical cooling solution widely used in industrial buildings that combines ventilation and water evaporation cooling. We characterized the system operation through the development of a coupled numerical model of the system and a typical industrial building, in a Mediterranean climate, in the mid-term horizon of 2050. A comparison without any system showed a 74 % reduction in degree-hours of thermal discomfort. Analysis of the building operation shows a predominance of nighttime free cooling, while the adiabatic operates during the occupancy hours. We compared the performance in four different locations, taking into account future weather and heatwaves. The system performed better in hot and dry climates if we consider only the thermal discomfort based on degreehours, with a 48 % reduction in Abu Dhabi, compared to 41 % in Singapore. However, we observed very different tendencies with water consumption and cooling efficiency: with a cooling efficiency ratio to water use of 22.46 °Ch/m³ in the equatorial climate, which is almost double that obtained in the dry and arid climate. Arid climates were the most appropriate in terms of energy consumption. In Abu Dhabi, the performance (0.24 °Ch/kWh) was 13 % higher than in an equatorial climate such as Singapore. The results also show that the system performs better under future weather conditions for all the locations studied. Under future conditions, the cooling gain per unit of water consumed rose to 1.48 °Ch/m³ , while the thermal escalation factor decreased by 0.054 points. These results highlight the ability of the system to effectively reduce thermal discomfort, while revealing trade-offs between thermal efficiency, energy consumption and use of water resources. This analysis underlines the relevance of the system to current and future climate challenges.