Strategies of cooling, ventilating, and shading for urban heat island mitigation
Urban Heat Island (UHI) refers to the heat captured by artificial materials, additional heat release from air conditioner usage, and insufficient ventilation occurring in the urban core area, especially at nighttime. Which has become an important global issues worthy of concerning. With the support of Ministry of Science and Technology (MOST), an interdisciplinary & international research team, led by Distinguished Professor Tzu-Ping Lin from Department of Architecture at National Cheng Kung University (NCKU), has been founded and installing intensive temperature/humidity monitoring networks among the streets in Taipei City, New Taipei City, Taichung City, Tainan City, and Kaohsiung City. By the analysis results of mapping high resolution urban thermal distribution, the extreme heat spots could be addressed, and the analysis could also be viewed as practical suggestions of scientific proof then taken into consideration during making policy process.
By long-term monitoring environmental data, not only indicating the tendency and the extreme heat spots location, it is also important to find out the causes and the possible solutions. Prof. Tzu-Ping Lin mentioned three key points in UHI mitigation of “cooling”, “ventilating”, and “shading”, and the aims of implementation would be “greener and less air conditioner usage”, “more wind accessible”, and “more shading for pedestrians” respectively. Those could help in creating thermal comfort condition for the residents, and effectively cool down the urban area.
The relevant research outcomes and results were provide to the corresponding local governments for making the assessments and strategies in UHI mitigation and adaptation, such as 1) putting “the ratio of wind accessibility” into formal requirements for future urban renewal projects, which has been well carried and accepted by the Urban Development Bureau of Taichung City Government, 2) helping to analyze the effectiveness in cooling and reducing carbon emission for Kaohsiung House Projects, and 3) providing suggestions to Tainan Bureau of Public Work for improving the building regulations regarding sustainable development and UHI mitigation and adaptation.
Nevertheless, the Thermal Comfort Range for sub-tropical/ tropical regions developed by Prof. Tzu-Ping Lin had been with hundreds cites and viewed as a representative standard. Which successfully broke the stereotype in measuring the thermal condition based on temperate climate regions, and indicated the fact that range for people in sub-tropical/ tropical regions in having thermal comfort would be 26oC - 30 oC in PET (physiological equivalent temperature), approximately 7 oC PET higher than the range measured at temperate climate regions. Meanwhile, Prof. Tzu-Ping Lin has initiated Heat Island Mitigation Alliance of Taiwan (HIMAT), and promoted the importance in UHI mitigation since 2019, and will keep supporting the university, government, and the public to work together in creating livable cities, and having better living quality in the near future. .
Prof. Tzu-Ping Lin
Department of Architecture, National Cheng Kung University, Taiwan