The Summer Thermal Environment and Human Comfort of Shaded Outdoor and Semi-Outdoor Spaces to Living in the Urban Area of Chiang Mai City
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Abstract
Outdoor and semi-outdoor spaces are important to sustainable cities because they accommodate leisure and activities of citizens, and contributing to urban livability and vitality. In the urban context of climate environments especially in summer, public spaces that provide a pleasurable thermal comfort experience for citizens effectively improve the quality of urban living. Consequently, in this paper, a quantitative field study was applied to investigate outdoor and semi-outdoor thermal comfort conditions in hot and humid tropical climate of Chiang Mai, Thailand. Thermal conditions of both spaces were evaluated based upon the measurement of major climatic parameters, while the thermal perception and thermal acceptability of subjects was captured simultaneously using a questionnaire survey. Meanwhile, the Physiologically Equivalent Temperature (PET) thermal comfort index was utilized to assess the thermal comfort conditions of selected spaces. The measurement period was conducted during the daytime from 8 am to 4 pm on April within the year 2557 BE, which is the most representative a hottest month of summer in Chiang Mai city.
A total of 296 questionnaires were collected in the outdoor (72.3%) and semi-outdoor (27.7%) urban spaces during the survey, which was carried out on days with suitable weather and avoid rainy days. The majority of the respondents (99.8%) stayed under trees or buildings shaded conditions. The thermal neutrality was derived by solving the simple linear equations for a mean sensation vote of zero, which are determined by analyzing the relationship between the Mean Thermal Sensation Vote (MTSV) and PET values. The results found that, the neutral sensation PET temperatures (MTSV=0) of outdoor and semi-outdoor spaces were 27.1 °C and 28.5 °C PET, respectively. And the acceptable thermal conditions ranges were 31.0-23.1°C PET and 32.0-22.4°C PET, respectively. Compared with the thermal acceptable range between both spaces was found that the thermal acceptable range in different spaces have different thermal requirements in summer, even if they are feeling comfort.
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References
ASHRAE. (1992). ANSI/ASHRAE Standard 55-1992. Thermal environmental conditions for human occupancy. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Inc, Atlanta.
ASHRAE 55. (2010). Thermal environmental conditions for human occupancy. ASHRAE, Atlanta, GA.
Atthajariyakul, S. (2007). Thermal comfort for air-conditioning in Thailand. KKU Engineering Journal, 34 (2), 141 –150.
Auttarat, S., Srivanit, M. & Poonsukcharoen, N. (2014). A study on urban planning concepts to create a body of knowledge for the reduction of urban heat Island guideline in Chiang Mai urban area. Chiang Mai University, Goodwork Media.
Blazejczyk, K., Epstein, Y., Jendritzky, G., Staiger, H. & Tinz, B. (2012). Comparison of UTCI to selected thermal indices. International Journal of Biometeorology, 56, 515–535.
Bruse, M. (2011). ENVI-met model homepage. Retrieve from http://www.envi-met.com.
Charoentrakulpeeti, W. (2014). Physical characteristics and ventilation pattern in Uthai Thani city. Journal of Architecture/Planning Research and Studies, 11(2), 99-112.
Chen, L. & Ng, E. (2012). Outdoor thermal comfort and outdoor activities: A review of research in the past decade. Cities, 29, 118–125.
Iamtrakul, P., Nusook, T. & Ubolchay, P. (2014). Impact of urban heat Island on daily life of people in Bangkok metropolitant region (BMR). Journal of Architecture/Planning Research and Studies, 11(2), 53-72.
ISO 7726. (1998). Ergonomics of the thermal environment – Instruments for measuring physical quantities. International Organization for Standardization, Geneva.
Johansson, E., Thorsson, S., Emmanuel, R. & Krüger, E. (2014). Instruments and methods in outdoor thermal comfort studies – The need for standardization. Urban Climate, 10(2), 346-366.
Lindberg, F., Holmer, B. & Thorsson, S. (2008). SOLWEIG 1.0 – modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings. International Journal of Biometeorology, 52, 697–713.
Matzarakis, A., Rutz, F. & Mayer, H. (2010). Modelling radiation fluxes in simple and complex environments: Basics of the RayMan model. International Journal of Biometeorology, 54(2), 131–139.
Mayer, H. & Höppe, P. (1987). Thermal comfort of man in different urban environments. Theoretical and Applied Climatology, 38, 43–49.
McMichael, A. J., Wilkinson, P., Kovats, R. S., Pattenden, S., Hajat, S., Armstrong, B., Vajanapoom, N., Niciu, E. M., Mahomed, H., Kingkeow, C., Kosnik, M., O’Neill, M. S., Romieu, I., Ramirez-Aguilar, M., Barreto, M. L., Gouveia, N. & Nikiforov, B. (2008). International study of temperature, heat and urban mortality: the ‘ISOTHURM’ project. International Journal of Epidemiology, 37(5), 1121-1131.
Ng, E. & Cheng, V. (2012). Urban human thermal comfort in hot and humid Hong Kong. Energy and Buildings, 55, 51–65.
Santamouris, M., Cartalis, C., Synnefa, A. & Kolokotsa, D. (2015). On the impact of urban heat island and global warming on the power demand and electricity consumption of buildings—A review. Energy and Buildings, 98, 119–124.
Srivanit, M., Hokao, K. & Iamtrakul, P. (2014). Classifying thermal climate zones to support urban environmental planning and management in the Bangkok metropolitan area. Journal of Architectural/Planning Research and Studies, 11(1), 73-92.
Thorsson, S., Lindberg, F., Eliasson, I. & Holmer, B. (2007). Different methods for estimating the mean radiant temperature in an outdoor urban setting. International Journal of Climatology, 27, 1893–1983.
Vanno, S. (2012). Bangkok’s green infrastructure. Journal of Architectural/Planning Research and Studies, 9(2), 1-13.
VDI 3787. (2008). Part 2, Environmental meteorology – Methods for the human biometeorological evaluation of climate and air quality for urban and regional planning at regional level; Part I: Climate. Beuth Verlag, Berlin.
WHO. (1995). Physical status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. WHO Technical Report Series 854. Geneva: World Health Organization.
World Health Organization, Regional Office for the Western Pacific [WPRO]. (2000). International Association for the Study of Obesity, International Obesity Task Force. The Asia-Pacific Perspective: Redefining obesity and its treatment; Health Communications Australia Pty Ltd: Sydney, Australia.
Yang, W., Wong, N. H. & Jusuf, S. K. (2013). Thermal comfort in outdoor urban spaces in Singapore. Building and Environment, 59, 426-435.