The impact of increasing urban surface albedo on outdoor summer thermal comfort within a university campus

Taleghani, M

Abstract

The impact of increasing urban surface albedo on outdoor thermal comfort was studied in two phases:

Firstly, the thermal conditions of three locations with different ground surface materials were compared. The study used CFD modelling followed by a measurement campaign to validate the control simulation. It was observed that the physiological equivalent temperature (PET as the outdoor thermal comfort index) in the campus park (covered with grass) was 11.0 °C lower than the parking lot (paved with concrete) at 16:00 CET.

As the next step, the albedo of the roofs and walls were increased from 0.2 (control) to 0.3, 0.4, 0.5 and 0.6. It was found that increasing the albedo made the open space of the courtyard uncomfortable due to the higher reflectivity of high-albedo materials. An increase of every 0.1 albedo of the surfaces led to 1.2 °C higher mean radiant temperature, and consequently, 0.8 °C higher PET. The study also showed that the increase of albedo radiated more sun to the ground surface. This increased average ground surface sensible heat flux (6.7 W/m2) and surface temperature (0.4 °C) during the day. This finding shows that the position and orientation of high albedo materials can significantly affect pedestrians' thermal comfort in urban open spaces.

Citation

Taleghani, M. (2018). The impact of increasing urban surface albedo on outdoor summer thermal comfort within a university campus. Urban Climate, 24, 175-184. https://doi.org/10.1016/j.uclim.2018.03.001

• Journal Article Type: Article
• Acceptance Date: Mar 10, 2018
• Online Publication Date: Mar 17, 2018
• Publication Date: Jun 1, 2018
• Deposit Date: Mar 19, 2018
• Publicly Available Date: Mar 17, 2019
• Journal: Urban Climate
• Print ISSN: 2212-0955
• Publisher: Elsevier
• Volume: 24
• Pages: 175-184
• DOI: https://doi.org/10.1016/j.uclim.2018.03.001
• Publisher URL: https://doi.org/10.1016/j.uclim.2018.03.001
• Related Public URLs: https://www.sciencedirect.com/journal/urban-climate