Cooling the Cities
Solar Energy and Urban Cooling Technologies
Volume 103, May 2014, Pages 682-703
Cooling Cities: A Review of Reflective and Green Roof Technologies to Combat Heat Islands and Enhance Urban Comfort
Author: M. Santamouris, Group Building Environmental Research, Physics Department, University of Athens, Athens, Greece.
Published: Available online 30 July 2012
Highlights:
- Heat Islands: The phenomenon is well-documented.
- Mitigation Technologies: Various solutions have been proposed.
- Reflective and Green Roofs: These are key methods for increasing urban albedo and reducing heat.
- State-of-the-Art Review: A comprehensive overview of these technologies is provided.
Highlights
► Heat island is a very well documented phenomenon.
► Several Mitigation Technologies have been proposed.
► The increase of the albedo in cities and green roofs are among the more important ones.
► The state of the art of both mitigation technologies is presented.
Abstract
Urban temperatures are rising due to the heat island effect and climate change, exacerbating energy issues, reducing comfort, endangering vulnerable populations, and worsening pollution. In response, several mitigation strategies have been developed. Among the most promising are increasing the city’s albedo (reflectivity) and implementing green roofs. This paper presents a comprehensive review of these technologies. The analysis includes both simulation studies and experimental data.
Key Findings:
- Albedo Increase: A global increase in city albedo by 0.1 can reduce average ambient temperatures by 0.3 K and peak temperatures by 0.9 K.
- Cool Roofs: A 0.1 increase in roof albedo can lower average urban temperatures by 0.1 to 0.33 K.
- Green Roofs: City-wide green roofs can reduce average ambient temperatures by 0.3 to 3 K.
The paper synthesizes the conditions under which these technologies perform best, providing clear boundaries and guidelines for their application.
For further details, please refer to the original article or explore more on reflective and green roof technologies.
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