Microclimate and building energy in the built environment : a study of planning high-rise building groups at a city-block scale in China

In the past two decades, most regions of China have gone into the process of rapid urbanisation. In response to the enormous pressure due to the booming economy and fast growth in urban population, large-scale high-rise building group appeared and dominated the civil construction industry. However,...

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Bibliographic Details
Main Author: Deng, Xi
Published: Cardiff University 2018
Online Access:https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.768080
Description
Summary:In the past two decades, most regions of China have gone into the process of rapid urbanisation. In response to the enormous pressure due to the booming economy and fast growth in urban population, large-scale high-rise building group appeared and dominated the civil construction industry. However, these city-block scale estate projects have been criticised for the low-level thermal comfort in poorly designed indoor/outdoor spaces, and for its high energy consumption. Chengdu, a megacity in China, has been chosen as the research subject in consideration of its high urbanisation speed with a large number of estate projects at city-block scale and the deteriorating urban built environment. This study investigates the impact of multi-design variables on microclimates and the building energy performance of large-scale buildings through the application of GIS mapping and modelling. The relevant tools used in this study are ArcMap, ENVI-met, and SketchUp integrated with HTB2 and Virvil Plug-in. The study makes contributions to the research on microclimate and building energy consumption in four aspects. Firstly, it fills the gap in the outdoor thermal comfort and building energy consumption study at city-block scale in China by building up a theoretical framework of planning and design the high-rise building group in China. Secondly, design guidelines are established to improve both the microclimate performance and the building energy performance. Thirdly, a new approach to observe the local temperature of multi-scale subjects in a long-time period is concluded, which provides a new option of a method to analysis microclimate conditions for building scale research. Lastly, this study offers implications to relevant stakeholders for understanding the evaluation of low-carbon development at city-block scale. There are four phases in this study. In the first phase, document analysis is used to review the existing literature for discovering the research gaps, selecting potential measurements and technical tools, understanding the background and development history of the research subject. The second phase is the observation on microclimate condition. At this stage, on-site local urban heat island intensity is obtained by mapping the derived MODIS satellite data. In the third phase, multi-stage computational simulations will be used to calculate the microclimate performance and building energy performance accordingly. The former provides the predicted local meteorological data to be compared with data obtained from MODIS satellite, as well as the local air temperature of the target project sites for the adjusted simulation of the later which quantify the impact of variation in outdoor temperature. In the last phase, quantitative analysis and discussion are carried out for the results. Therefore, design guidelines of design strategy for mitigating building energy demand and optimising outdoor thermal comfort at city-block scale are concluded.