Thermal neutral temperature in moderate climate zones: a case study of Kunming region

Abstract

While extensive thermal comfort research exists for severe cold and hot-humid climates, studies focusing on moderate climate zones remain scarce and fragmented. To address this gap, this study synthesizes one of the most temporally extensive and typologically comprehensive field investigations (2006–2022) in such zones, with a primary focus on Kunming. By analyzing 7 289 subjective questionnaires across diverse building types (residential, office, educational, healthcare), this study quantifies the seasonal thermal neutral temperatures, revealing a mean of 23.3 ℃ in summer (range: 21.6–25.0 ℃) and 18.1 ℃ in winter (range: 15.6–21.4 ℃). A key finding is the significant disparity between the winter neutral temperature and the measured average indoor temperature (14.5 ℃), highlighting a critical comfort deficit during colder months. Furthermore, this study pioneers the explicit inclusion of vulnerable groups and explores synergies between comfort attainment and energy efficiency. Based on these findings, we propose actionable indoor temperature setpoints of 23.0–25.0 ℃ for summer and 17.0–19.0 ℃ for winter, alongside tailored architectural design strategies. This study provides a robust, data-driven foundation for refining building standards and optimizing energy-efficient design in understudied moderate climate zones.

Keywords

Moderate climate zone / Thermal comfort / Thermal neutral temperature / Architectural design optimization / Individual thermal adaptation measures

References

[1] Gao, Y. (2013). Southern Indoor Temperature Survey: Government Buildings at 20°C, Homes at 5°C (Photo). CCTV. http://news.cntv.cn/2013/01/08/ARTI1357602461187969.shtml

[2] Yan, H. (2015). How Can the South "Shelter All the Poor from the Cold"? People’s Daily. http://opinion.people.com.cn/n/2015/1128/c159301-27865956.html

[3] Ministry of Housing and Urban-Rural Development of the People's Republic of China. (2016). Thermal design code for civil building (GB 50176-2016). China Architecture & Building Press.

[4] Yang, L. (2003). Climatic analysis techniques and architectural design strategies for bio-climatic design [Unpublished doctoral dissertation]. Xi’an University of Architecture and Technology.

[5] Zhihao W, Jinxin L, Tong Li, et al. . The Requirement and Regional Adaptability Strategies of Building Heating in Temperate Zone [J]. Refrigeration and Air Conditioning (Sichuan), 2021, 35(4): 6

[6] ASHRAE. (1992). Thermal environmental for human occupancy (ASHRAE Standard 55-1992). ASHRAE.

[7] Yang, D. (2018). Research on indoor thermal environment and human thermal comfort in residential building of temperate area in winter [Unpublished master’s thesis]. Kunming University of Science and Technology.

[8] Khan SA, Hussain F, Khushnood RA, et al. . Feasibility Study of Expanded Clay Aggregate Lightweight Concrete for Nonstructural Applications. Advances in Civil Engineering, 2024, 119

[9] Raza UM, Butt F, Ahmad F, et al. . Seismic safety assessment of buildings and perceptions of earthquake risk among communities in Mingora, Swat, Pakistan [J]. Innovative Infrastructure Solutions, 2025, 10(4): 124

[10] Ahmad F, Qureshi IM, Rawat S, et al. . E-waste in concrete construction: Recycling, applications, and impact on mechanical, durability, and thermal properties—a review [J]. Innovative Infrastructure Solutions, 2025, 10(6): 246

[11] Wang, W. (2010). Study on indoor thermal environment and human thermal comfort of no air-conditioning in typical moderate area [Unpublished master’s thesis]. Kunming University of Science and Technology.

[12] Yang, L., Yang, Q., & Wang, L. (2010). Research on adaptive thermal comfort model for temperate area. International Conference on Building Environment Science and Technology.

[13] Yan, H. (2013). Study on adaptive thermal comfort on the basis of regions and climates of China [Unpublished doctoral dissertation]. Xi’an University of Architecture and Technology.

[14] Zhang, G. (2022). Study on the influence of fresh air system on indoor air quality and thermal comfort in mild area [Unpublished master’s thesis]. Kunming University of Science and Technology.

[15] Li Y. Research of the role of thermal sensation in modifying thermal comfort modeling in mild climate regions. Bulletin of Science and Technology Bulletin of Science and Technology. Bulletin of Science and Technology, 2024, 08: 45-50

[16] Meng Y, Mu Di, Cao B, Zhu Y. Evaluation of Actual Thermal Environment in Free-running Office Building in Mild Zone. Building Energy Efficiency, 2020, 06: 27-32+45

[17] Deng, T. (2018). The research on indoor environment and ventilation of urban residential buildings in temperate climate zone: a case study of Kunming [Unpublished master’s thesis]. Tianjin University.

[18] Zhou, L. (2018). Study on energy consumption index of passive low energy consumption residential buildings in mild areas--taking Kunming as an example [Unpublished master’s thesis]. Kunming University of Science and Technology.

[19] Zhang, S. (2022). Research on natural ventilation in general ward of Kunming community hospital [Unpublished master’s thesis]. Kunming University of Science and Technology.

[20] Liu, Q. (2022). Study on optimization of university dormitory plane shape based on thermal comfort in mild area [Unpublished master’s thesis]. Kunming University of Science and Technology.

[21] Zhang F. Study on modified modeling of thermal comfort for living in mild climate area in low-latitude plateau of China. Energy Engineering, 2023, 03: 81-88+96

[22] Duan, M. L. (2017). Relationship between human thermal comfort and indoor thermal environment parameters in various regions of China. Building Science, (06), 115-122.https://doi.org/10.1016/j.proeng.2017.09.913

[23] Duan ML, Sun X, Li X, Wang Z, Zhai Z. Relationship between Human Thermal Comfort and Indoor Thermal Environment Parameters in Various Regions of China (Sequel). Building Science, 2018, 12: 114-120

[24] Zhaojun W, Haoran N, Jing R, et al. . Human thermal adaptation in severe cold area (1): Field study in residential buildings [J]. HVAC, 2015, 45(11): 73-79

[25] Wang W, Luo H, Gao Y, Li B, Wang Y. Residential building thermal environment test and thermal comfort investigation in Kunming area in summer. HVAC, 2011, 06: 93-95+46

[26] Zhao, Y. (2021). Research on optimization design method of building envelope based on energy-saving and comfort [Unpublished doctoral dissertation]. Sichuan University.

[27] Long, G. (2020). Research on energy-saving reconstruction design of buildings in Kunming University of Science and Technology based on thermal comfort [Unpublished master’s thesis]. Kunming University of Science and Technology.

[28] Li, Y. (2022). Numerical simulation of solar radiant floor heating room in temperate area. Industrial Safety and Environmental Protection, (03). https://doi.org/10.3969/j.issn.1001-425X.2022.03.025

[29] Ma, T., & Lian, Z. (2017). Thermal comfort evaluation of Chinese elderly. Refrigeration and Air Conditioning (Sichuan), (04).

[30] Zhou, H., Yu, W., & Wei, S. (2025). Variability in thermal comfort and behavior of elderly individuals with different levels of frailty in residential buildings during winter. Building and Environment, 267.https://doi.org/10.1016/j.buildenv.2024.112290

[31] Kang, Q. (2023). Research on indoor thermal comfort of preschool children in hot-humid areas [Unpublished master’s thesis]. South China University of Technology.

[32] Xu, Y. (2019). Study on the factors influencing thermal comfort and learning performance of primary and secondary school students in summer [Unpublished master’s thesis]. Xi’an University of Architecture and Technology.

[33] Nasir A, Butt F, Ahmad F. Enhanced mechanical and axial resilience of recycled plastic aggregate concrete reinforced with silica fume and fibers [J]. Innovative Infrastructure Solutions, 2024, 10(1): 4

Funding

the Key R&D Program of Yunnan Province(202303AC100005)

RIGHTS & PERMISSIONS

The Author(s)