Impact of Providing Shade on Outdoor Thermal Comfort during Hot Season: a Case Study of a University Campus in Cold Semi-arid Climate

Talebsafa, Shahrzad; Taheri Shahraeini, Masoud; Yang, Xiaoshan; Rabiei, Mohammadreza

doi:10.22044/rera.2022.12254.1169

Document Type : Original Article

Authors

¹ Faculty of Architectural Engineering and Urbanism, Shahrood University of Technology, Shahrood, Iran.

² Faculty of Architectural Engineering and Urbanism. Shahrood University of Technology, Shahrood, Iran

³ College of Architecture, Nanjing Tech University, Nanjing, China

⁴ Faculty of Mathematical Sciences, Shahrood University of Technology, Shahrood, Iran

https://doi.org/10.22044/rera.2022.12254.1169

Abstract

Thermal comfort is one of the most important factors affecting the quality of outdoor space. This work investigates the effect of shade on outdoor thermal comfort during the hot season. For this purpose, meteorological measurement and questionnaire surveys are conducted simultaneously at four points of the university campus in the cold semi-arid climate of Shahrood, Iran. Then the ENVI-met V4 is validated and implemented to examine the impact of different shading scenarios on outdoor thermal comfort. The neutral physiological equivalent temperature (PET) and the upper boundary of the PET comfort range are obtained at 21.9 °C and 26.9 °C, respectively. The results demonstrate that the plant shade creates the most acceptable thermal environment. Also shading cause a significant reduction in the PET value and thermal stress, while increasing the comfort levels and the comfort hours during the sunny days. Furthermore, the simulation results indicate that creating shade in the open space by trees contribute to lower level of mean radiant temperature up to 24.79 °C and up to 13.7 °C for PET. Moreover, a maximum mitigation effect of an architectural shade is obtained at 32.6 °C for mean radiant temperature and 17 °C for PET. The highest reduction of PET (17.2 °C) is achieved by the combination of trees and the architectural shade. The outcomes of this research work provide useful design recommendations to improve outdoor thermal comfort.

Keywords

20.1001.1.2717252.2023.4.2.6.7

References

[1] L. Chen, E. Ng, (2012) Outdoor thermal comfort and outdoor activities: A review of research in the past decade, Cities, 29, pp 118–125.

[2] R. A. Nasir, S. S. Ahmad, A. Z. Ahmed, (2013) Physical Activity and Human Comfort Correlation in an Urban Park in Hot and Humid Conditions, Procedia - Social and Behavioral Sciences, 105, pp 598 – 609.

[3] J. Niu, J. Liu, T.-c. Lee, Z. J. Lin, C. Mak, K.-T. Tse, B.-s. Tang, K. C. S. Kwok, (2015) A new method to assess spatial variations of outdoor thermal comfort: Onsite monitoring results and implications for precinct planning, Building and Environment, 91, pp 263-270.

[4] F. Canan, I. Golasi, V. Ciancio, M. Coppi, F. Salata, (2019) Outdoor thermal comfort conditions during summer in a cold semi-arid climate. A transversal field survey in Central Anatolia (Turkey), Building and Environment, 148, pp 212-224.

[5] E. Erell, D. Pearlmutter, T. Williamson, (2011) Urban Microclimate, Designing the Spaces Between Buildings, Earthscan, UK and USA.

[6] Y. Dzyuban, D. M. Hondula, J. K. Vanos, A. Middel, P. J. Coseo, E. R. Kuras, C. L. Redman, (2022) Evidence of alliesthesia during a neighborhood thermal walk in a hot and dry city, Science of the Total Environment, 834.

[7] K. Liu, Z. Lian, X. Dai, D. Lai, (2022) Comparing the effects of sun and wind on outdoor thermal comfort: A case study based on longitudinal subject tests in cold climate region, Science of The Total Environment, 825.

[8] F. Rossi, M. Cardinali, A. D. Giuseppe, B. Castellani, A. Nicolini, (2022) Outdoor thermal comfort improvement with advanced solar awnings: Subjective and objective survey, Building and Environment, 215.

[9] A. Chatzidimitriou, S. Yannas, (2017) Street canyon design and improvement potential for urban open spaces; the influence of canyon aspect ratio and orientation on microclimate and outdoor comfort, Sustainable Cities and Society, 33, pp 85–101.

[10] S. Bouketta, Y. Bouchahm, (2020) Numerical evaluation of urban geometry's control of wind movements in outdoor spaces during winter period. Case of Mediterranean climate, Renewable Energy, 146, pp 1062-1069.

[11] F. Salata, I. Golasi, D. Petitti, E. d. L. Vollaro, M. Coppi, A. d. L. Vollaro, (2017) Relating microclimate, human thermal comfort and health duringheat waves: An analysis of heat island mitigation strategies through a case study in an urban outdoor environment, Sustainable Cities and Society, 30.

[12] H. Lee, H. Mayer, L. Chen, (2016) Contribution of trees and grasslands to the mitigation of human heat stress in a residential district of Freiburg, Southwest Germany, Landscape and Urban Planning, 148, pp 37–50.

[13] Y. Wang, H. Akbari, (2016) The effects of street tree planting on Urban Heat Island mitigation in Montreal, Sustainable Cities and Society, 27, pp 122-128.

[14] E. Jamei, P. Rajagopalan, (2017) Urban development and pedestrian thermal comfort in Melbourne, Solar Energy, 144, pp 681–698.

[15] I. McRae, F. Freedman, A. Rivera, X. Li, J. Dou, I. Cruz, C. Ren, I. Dronova, H. Fraker, R. Bornstein, (2020) Integration of the WUDAPT, WRF, and ENVI-met models to simulate extreme daytime temperature mitigation strategies in San Jose, California, Building and Environment, 184.

[16] Z. Tan, K. K.-L. Lau, E. Ng, (2016) Urban tree design approaches for mitigating daytime urban heat island effects in a high-density urban environment, Energy and Buildings, 114, pp 265-274.

[17] X. Yang, L. Zhao, M. Bruse, Q. Meng, (2013) Evaluation of a microclimate model for predicting the thermal behavior of different ground surfaces, Building and Environment, 60, pp 93-104.

[18] A. S. H. Abdallah, S. W. Hussein, M. Nayel, (2020) The Impact of outdoor shading strategies on Student thermal comfort in Open Spaces Between Education Building, Sustainable Cities and Society, 58.

[19] ZhengTan, A. Wang, T. E. Morakinyo, E. H. K. Yung, E. H. W. Chan, (2022) Assessing the mitigation performance of building setback from street and the combination with roadside tree planting, Building and Environment, 212.

[20] E. S. Darbani, D. M. Parapari, J. Boland, E. Sharifi, (2021) Impacts of urban form and urban heat island on the outdoor thermal comfort: a pilot study on Mashhad, International Journal of Biometeorology, 65, pp 1101–1117.

[21] F. Salata, I. Golasi, R. d. L. Vollaro, A. d. L. Vollaro, (2016) Outdoor thermal comfort in the Mediterranean area. A transversal study in Rome, Italy, Building and Environment, 96, pp 46-61.

[22] A. Middel, N. Selover, B. Hagen, N. Chhetri, (2016) Impact of shade on outdoor thermal comfort—a seasonal field study in Tempe, Arizona, International Journal of Biometeorology, 60, pp 1849–1861.

[23] R. Sharafkhani, N. Khanjani, B. Bakhtiari, Y. Jahani, J. S. Tabrizif, (2018) Physiological Equivalent Temperature Index and mortality in Tabriz (The northwest of Iran), Journal of Thermal Biology, 71, pp 195-201.

[24] A. Matzarakis, H. Mayer, (1996) Another kind of environmental stress: thermal stress, WHO newsletter, 18, pp 7-10.

[25] H. Farajzadeh, A. Matzarakis, (2012) Evaluation of thermal comfort conditions in Ourmieh Lake, Iran, Theoretical and Applied Climatology, 107, pp pages451–459.

[26] B. Biqaraz, R. Fayaz, G. H. Naeeni, (2019) A comparison of outdoor thermal comfort in historical and contemporary urban fabrics of Lar City, Urban Climate, 27, pp 212–226.

[27] S. Teshnehdel, H. Akbari, E. D. Giuseppe, R. D. Brown, (2020) Effect of tree cover and tree species on microclimate and pedestrian comfort in a residential district in Iran, Building and Environment, 178.

[28] Semnan Meteorology Organization, Available from: http://www.semnanweather.ir.

[29] World Weather & Climate Information, Available from: https://weather-and-climate.com.

[30] ISO, (1998) International Standard 7726, Ergonomics of the thermal environment-Instruments for measuring physical quantities, International Standard Organization, Geneva.

[31] ASHRAE, (2013) ASHRAE Standard 55-2013,Thermal Environmental Conditions for Human Occupancy.

[32] G. Havenith, (2004) Thermal conditions measurement, CRC Press, Florida.

[33] P. K. Cheung, C. Y. Jim, (2019) Improved assessment of outdoor thermal comfort: 1-hour acceptable temperature range, Building and Environment, 151, pp 303-317.

[34] D. Lai, D. Guo, Y. Hou, C. Lin, Q. Chen, (2014) Studies of Outdoor Thermal Comfort in Northern China, Building and Environment, 77, pp 110-118.

[35] M. Nikolopoulou, S. Lykoudis, (2006) Thermal comfort in outdoor urban spaces: Analysis across different European countries, Building and Environment, 41, pp 1455–1470.

[36] L. Chen, Y. Wen, L. Zhang, W.-N. Xiang, (2015) Studies of thermal comfort and space use in an urban park square in cool and cold seasons in Shanghai, Building and Environment, 94, pp 644-653.

[37] J. Spagnolo, R. d. Dear, (2003) A eld study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia, Building and Environment, 38, pp 721–738.

[38] S. Oliveira, H. Andrade, (2007) An initial assessment of the bioclimatic comfort in an outdoor public space in Lisbon, International Journal of Biometeorology, 52, pp 69–84.

[39] T. Stathopoulos, H. Wu, J. Zacharias, (2004) Outdoor human comfort in an urban climate, Building and Environment, 39, pp 297–305.

[40] K. Pantavou, S. Lykoudis, M. Nikolopoulou, I. X. Tsiros, (2018) Thermal sensation and climate: a comparison of UTCI and PET thresholds in different climates, International Journal of Biometeorology, 62, pp 1695–1708.

[41] T.-P. Lin, A. Matzarakis, R.-L. Hwang, (2010) Shading effect on long-term outdoor thermal comfort, Building and Environment, 45, pp 213–221.

[42] S. Coccolo, J. Kämpf, J.-L. Scartezzini, D. Pearlmutter, (2016) Outdoor human comfort and thermal stress: A comprehensive review on models and standards, Urban Climate, 18, pp 33–57.

[43] A. Matzarakis, H. Mayer, M. G. Iziomon, (1999) Applications of a universal thermal index: physiological equivalent temperature, International Journal of Biometeorology, 43, pp 73-84.

[44] ISO, (2005) International standard 7730, Ergonomics of the thermal environment - Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria, International Standard Organization, Geneva.

[45] N. Nazarian, T. Sin, L. Norford, (2018) Numerical modeling of outdoor thermal comfort in 3D, Urban Climate, 26, pp 212–230.

[46] C. K. C. Lam, H. Lee, S.-R. Yang, S. Park, (2021) A review on the significance and perspective of the numerical simulations of outdoor thermal environment, Sustainable Cities and Society, 71.

[47] D. Lai, W. Liu, T. Gan, K. Liu, Q. Chen, (2019) A review of mitigating strategies to improve the thermal environment and thermal comfort in urban outdoor spaces, Science of the Total Environment, 661, pp 337–353.

[48] N. Kántor, (2016) Differences between the evaluation of thermal environment in shaded and sunny position, Hungarian Geographical Bulletin, 65, pp 139-153.

[49] K. Li, Y. Zhang, L. Zhao, (2016) Outdoor thermal comfort and activities in the urban residential community in a humid subtropical area of China, Energy and Buildings, 133, pp 498-511.

[50] T.-P. Lin, A. Matzarakis, (2008) Tourism climate and thermal comfort in Sun Moon Lake, Taiwan, International Journal of Biometeorology, 52(4), pp 281-290.

[51] T.-P. Lin, (2009) Thermal perception, adaptation and attendance in a public square in hot and humid regions, Building and Environment, 44, pp 2017-2026.

[52] A. H. A. Mahmoud, (2011) Analysis of the microclimatic and human comfort conditions in an urban park in hot and arid regions, Building and Environment, 46, pp 2641-2656.

[53] E. Jamei, P. Rajagopalan, M. Seyedmahmoudian, Y. Jamei, (2016) Review on the impact of urban geometry and pedestrian level greening on outdoor thermal comfort, Renewable and Sustainable Energy Reviews, 54, pp 1002–1017.

[54] A. Lai, M. Maing, E. Ng, (2017) Observational studies of mean radiant temperature across different outdoor spaces under shaded conditions in densely built environment, Building and Environment, 114, pp 397-409.

[55] M. Xu, B. Hong, R. Jiang, L. An, T. Zhang, (2019) Outdoor thermal comfort of shaded spaces in an urban park in the cold region of China, Building and Environment, 155, 408–420.

[56] A. Ghaffarianhoseini, U. Berardi, A. Ghaffarianhoseini, K. Al-Obaidi, (2019) Analyzing the thermal comfort conditions of outdoor spaces in a university campus in Kuala Lumpur, Malaysia, Science of the Total Environment, 666, pp 1327-1345.

[57] S. Watanabe, K. Nagano, J. Ishii, T. Horikoshi, (2014) Evaluation of outdoor thermal comfort in sunlight, building shade, and pergola shade during summer in a humid subtropical region, Building and Environment, 82, pp 556-565.

Renewable Energy Research and Applications

Impact of Providing Shade on Outdoor Thermal Comfort during Hot Season: a Case Study of a University Campus in Cold Semi-arid Climate

References

References

Volume 4, Issue 2
July 2023
Pages 209-224

Impact of Providing Shade on Outdoor Thermal Comfort during Hot Season: a Case Study of a University Campus in Cold Semi-arid Climate

References

References

Volume 4, Issue 2July 2023Pages 209-224

Volume 4, Issue 2
July 2023
Pages 209-224