Can urban heat be mitigated in a single urban street? Monitoring, strategies, and performance results from a real scale redevelopment project

• Published in: Solar energy 2021-03, Vol.216, p.564-588
• Main Authors: Bartesaghi-Koc, Carlos, Haddad, Shamila, Pignatta, Gloria, Paolini, Riccardo, Prasad, Deo, Santamouris, Mattheos
• Format: Article
• Language: English
• Subjects: Canyons; Control equipment; Coolers; Cooling; Environmental quality; Evaporative cooling; Meteorological data; Overheating; Redevelopment; Shading; Shading devices; Solar energy; Thermal comfort; Wind speed
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2020.12.043

[Display omitted] •A holistic assessment of the cooling capacity of novel and typical mitigation strategies is provided.•The best scenario combining multiple mitigation solutions can decrease Ta and Ts by 3.3°C and 30.9°C.•Daytime radiative cooling applied to shading provide a maximum Ta and Ts decrease of 1.6°C and 24.2°C.•Reflective pavements added to greenery, can additionally reduce Ta and Ts by 0.2°C and 3.6°C.•Increased wind speeds have a positive impact on greenery, shading, radiative and reflective solutions and negative on spray systems. Urban overheating affects the health and wellbeing of communities, the environmental quality, and the economic performance of cities. This study demonstrates that outdoor thermal comfort can be improved in a single street by decreasing ambient (Ta) and surface (Ts) temperatures by implementing innovative and traditional heat mitigation strategies. Ten scenarios were modelled in ENVI-met and evaluated based on detailed in-situ and airborne-based meteorological data collected along Phillip Street (Parramatta) in Sydney, Australia. The best-performing scenario combining reflective materials, increased greenery, spray systems, and traditional shading provides a very significant reduction of Ta and Ts of up to 3.3 °C and 30.9 °C, respectively. On its own, radiative cooling materials applied on shading devices offer a comparable incanyon cooling capacity with maximum Ta and Ts decrease of up to 1.6 °C and 24.2 °C. Similar results are obtained by applying traditional solar control devices, which reduce peak Ta by 1.3 °C and Ts by 21.8 °C. When reflective pavements are accompanied by an increment in greenery, peak Ta and Ts are additionally reduced by 0.2 °C and 3.6 °C, respectively. When applied individually, an increase in evaporative cooling and greenery shows a strong local effect with a maximum in-canyon Ta decrease of 2.7 °C and 0.5 °C, respectively. Results show increased wind speeds have a positive impact on greenery, shading, radiative and reflective technologies and an unfavourable effect on spray systems. Future research should concentrate on examining the cooling potential of radiative coolers in different proportions and arrangements and quantifying the contributions and interactions between different strategies when applied simultaneously.