Towards an integrated method to assess effects of lift-up design on outdoor thermal comfort in Hong Kong

Abstract City residents wish to have pleasant experience in outdoor space, which are often impeded by thermally uncomfortable conditions, particularly in hot and humid summer. Lift-up design can provide comfortable microclimate in summer but the effects of lift-up design on thermal comfort in a built-up environment have not been systematically studied. This paper aims to investigate the effects of lift-up design on outdoor thermal comfort comprehensively, as well as the effects on pedestrian level wind environment. The thermal comfort assessments are carried out by using a proposed integrated method, which combines wind tunnel tests and on-site monitoring to calculate Physiologically Equivalent Temperature (PET) values. The Hong Kong Polytechnic University (HKPolyU) campus is selected as study area. The investigation mainly focuses on summer and winter seasons. Four typical days in a year were chosen to carry out on-site monitoring for obtaining environmental parameters. This study demonstrates that the proposed integrated method can be used to predict outdoor thermal comfort. Results also show that lift-up design can effectively improve pedestrian level wind environment and thermal comfort. Moreover, lift-up design can provide a comfortable microclimate in summer while not cause strong cold stress in winter. These findings provide solid evidence bases to city planners and architects of available options for creating pleasant outdoor microclimate in precinct planning.

[1]  Kenny C. S Kwok,et al.  Effects of lift-up design on pedestrian level wind comfort in different building configurations under three wind directions , 2017 .

[2]  Tzu-Ping Lin,et al.  Thermal perceptions, general adaptation methods and occupant's idea about the trade-off between thermal comfort and energy saving in hot–humid regions , 2009 .

[3]  Kenny C. S Kwok,et al.  Adopting ‘lift-up’ building design to improve the surrounding pedestrian-level wind environment , 2017, Building and Environment.

[4]  Jan Gehl,et al.  Life Between Buildings: Using Public Space , 2003 .

[5]  G. Mihalakakou,et al.  On the use of bioclimatic architecture principles in order to improve thermal comfort conditions in outdoor spaces , 2007 .

[6]  V. Cheng,et al.  Urban human thermal comfort in hot and humid Hong Kong , 2012 .

[7]  Kenny C. S Kwok,et al.  A new method to assess spatial variations of outdoor thermal comfort: Onsite monitoring results and implications for precinct planning , 2015 .

[8]  K. Steemers,et al.  Thermal comfort and psychological adaptation as a guide for designing urban spaces , 2003 .

[9]  Standard Ashrae Thermal Environmental Conditions for Human Occupancy , 1992 .

[10]  Helmut Mayer,et al.  Human thermal comfort in summer within an urban street canyon in Central Europe , 2008 .

[11]  Madhavi Indraganti,et al.  Effect of age, gender, economic group and tenure on thermal comfort: A field study in residential buildings in hot and dry climate with seasonal variations , 2010 .

[12]  H. Mayer,et al.  Applications of a universal thermal index: physiological equivalent temperature , 1999, International journal of biometeorology.

[13]  A. K. Mishra,et al.  Field studies on human thermal comfort — An overview , 2013 .

[14]  Jianlei Niu,et al.  Combining measured thermal parameters and simulated wind velocity to predict outdoor thermal comfort , 2016 .

[15]  M. Santamouris,et al.  Outdoor thermal sensation of pedestrians in a Mediterranean climate and a comparison with UTCI , 2013 .

[16]  Tzu-Ping Lin,et al.  Tourism climate and thermal comfort in Sun Moon Lake, Taiwan , 2008, International journal of biometeorology.

[17]  Elias Salleh,et al.  Thermal comfort conditions of shaded outdoor spaces in hot and humid climate of Malaysia , 2012 .

[18]  Erik Johansson,et al.  The influence of urban design on outdoor thermal comfort in the hot, humid city of Colombo, Sri Lanka , 2006, International journal of biometeorology.

[19]  Koen Steemers,et al.  Thermal comfort in outdoor urban spaces: understanding the human parameter , 2001 .

[20]  H. Mayer,et al.  Thermal comfort of man in different urban environments , 1987 .

[21]  Richard de Dear,et al.  A field study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia , 2003 .

[22]  S. Kato,et al.  Study on outdoor thermal environment of apartment block in Shenzhen, China with coupled simulation of convection, radiation and conduction , 2004 .

[23]  E. Ng Policies and technical guidelines for urban planning of high-density cities – air ventilation assessment (AVA) of Hong Kong , 2008, Building and Environment.

[24]  Fazia Ali-Toudert,et al.  Effects of asymmetry, galleries, overhanging façades and vegetation on thermal comfort in urban street canyons , 2007 .

[25]  Attila Kovács,et al.  Seasonal differences in the subjective assessment of outdoor thermal conditions and the impact of analysis techniques on the obtained results , 2016, International Journal of Biometeorology.

[26]  Tzu-Ping Lin,et al.  Thermal perception, adaptation and attendance in a public square in hot and humid regions , 2009 .

[27]  Baruch Givoni,et al.  Outdoor comfort research issues , 2003 .

[28]  Kenny C. S Kwok,et al.  Effects of building lift-up design on the wind environment for pedestrians , 2017 .

[29]  Sung H. Hong,et al.  A field study of thermal comfort in low-income dwellings in England before and after energy efficient refurbishment , 2009 .

[30]  Bje Bert Blocken,et al.  Pedestrian-level wind conditions around buildings: Review of wind-tunnel and CFD techniques and their accuracy for wind comfort assessment , 2016 .

[31]  Eddy Willemsen,et al.  Design for wind comfort in The Netherlands: Procedures, criteria and open research issues , 2007 .

[32]  Mats Sandberg,et al.  Wind conditions and ventilation in high-rise long street models , 2010 .

[33]  B. Givoni,et al.  Urban design factors influencing heat island intensity in high-rise high-density environments of Hong Kong , 2007 .

[34]  A. Mochida,et al.  Wind tunnel tests on the relationship between building density and pedestrian-level wind velocity: Development of guidelines for realizing acceptable wind environment in residential neighborhoods , 2008 .

[35]  Q. Ouyang,et al.  Field study of human thermal comfort and thermal adaptability during the summer and winter in Beijing , 2011 .

[36]  H. Mayer,et al.  Modelling radiation fluxes in simple and complex environments—application of the RayMan model , 2007, International journal of biometeorology.

[37]  Jack E. Cermak,et al.  Wind-tunnel development and trends in applications to civil engineering , 2003 .

[38]  P. Höppe,et al.  The physiological equivalent temperature – a universal index for the biometeorological assessment of the thermal environment , 1999, International journal of biometeorology.

[39]  Tzu-Ping Lin,et al.  Shading effect on long-term outdoor thermal comfort , 2010 .

[40]  Tsz-cheung Lee,et al.  Temperature trends in Hong Kong from a seasonal perspective , 2012 .

[41]  Kenny C. S Kwok,et al.  Wind tunnel study of pedestrian level wind environment around tall buildings: Effects of building dimensions, separation and podium , 2012 .

[42]  Joseph Andrew Clarke,et al.  Using results from field surveys to predict the effect of open windows on thermal comfort and energy use in buildings , 2007 .

[43]  Ryozo Ooka,et al.  Study on optimum design method for pleasant outdoor thermal environment using genetic algorithms (GA) and coupled simulation of convection, radiation and conduction , 2008 .

[44]  Tsz-cheung Lee,et al.  Projection of extreme temperatures in Hong Kong in the 21st century , 2011 .

[45]  Cheuk Ming Mak,et al.  CFD simulation of flow and dispersion around an isolated building: Effect of inhomogeneous ABL and near-wall treatment , 2013 .