Thermal Comfort in Built Environment

A special issue of Buildings (ISSN 2075-5309). This special issue belongs to the section "Building Energy, Physics, Environment, and Systems".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 52586

Special Issue Editors


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Guest Editor
College of Landscape Architecture & Arts, Northwest A&F University, Yangling 712100, China
Interests: outdoor thermal comfort; built environment; bioclimatic design; landscape architecture; sustainable architecture; CFD
Special Issues, Collections and Topics in MDPI journals
School of Architecture, Tsinghua University, Beijing100084, China
Interests: green building; indoor environmental quality; building energy; post-occupancy evaluation; building performance analysis; big data; thermal comfort
Department of Architecture, School of Design, Shanghai Jiao Tong University, Shanghai, China
Interests: urban microclimate; occupant thermal comfort; occupant behavior; green building; COVID-19 transmission and infection; generative design
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Thermal comfort is a long-standing topic explored by many architectural scientists and landscape achitects, which involves comprehensive knowledge and understanding of environmental, social, psychological, and physiological factors. Although most solid thermal comfort problems have been well studied, there are still many new spaces worth exploring in the context of artificial intelligence (AI), human health, and carbon neutrality targets. For example, how can AI be used to achieve non-invasive monitoring of thermal comfort, instead of traditional questionnaires? How can reasonable thermal comfort control objectives be established and how can the current thermal strategies be adjusted to meet the goal of carbon neutrality? How should the thermal environment change with the dynamics of power supply and human demand conditions? These problems are all significant and need to be answered through new studies on thermal comfort.

Therefore, this Special Issue aims to encourage any new exploration on thermal comfort. Both original research papers and review papers are welcomed. Topics of interest include, but are not limited to:

  • New interpretation or improvement on thermal comfort model;
  • New sensing technologies on thermal comfort;
  • New thermal control strategy;
  • Thermal comfort and outdoor environment;
  • Thermal comfort and landscape design;
  • Thermal comfort and human health;
  • Thermal comfort and sleeping;
  • Thermal comfort for vulnerable populations (i.e., children, elderly, etc.);
  • Thermal comfort integrated with other environmental factors (i.e., IAQ, lighting, and acoustics);
  • Climate chamber experiment;
  • Field test or survey;
  • Simulation;
  • Case study.

Dr. Bo Hong
Dr. Yang Geng
Dr. Dayi Lai
Guest Editors

Manuscript Submission Information

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Keywords

  • indoor/outdoor thermal comfort
  • indoor environmental quality (IEQ)
  • sensing technology
  • thermal mechanism
  • thermal control strategy
  • dynamic responses
  • outdoor environment
  • bioclimatic design
  • children/elderly
  • occupant-centric design

Published Papers (22 papers)

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Research

20 pages, 4507 KiB  
Article
The Spatial Pattern and Mechanism of Thermal Environment in Urban Blocks from the Perspective of Green Space Fractal
by Yilu Gong, Xueming Li, He Liu and Yu Li
Buildings 2023, 13(3), 574; https://doi.org/10.3390/buildings13030574 - 21 Feb 2023
Cited by 1 | Viewed by 1254
Abstract
Land resources in cities are limited, and the cost of green space construction is high. Compared with increasing the amount of green space, maximizing the cooling effect of limited green space has important theoretical and practical significance. Green fractal is a new innovative [...] Read more.
Land resources in cities are limited, and the cost of green space construction is high. Compared with increasing the amount of green space, maximizing the cooling effect of limited green space has important theoretical and practical significance. Green fractal is a new innovative branch of urban fractal that uses a fractal index to quantify the green space structural index in studying the thermal environmental effect. Multi-source data, such as high-resolution remote sensing images, were used, and spatial regression models and inconsistency indices were applied to explore the spatial pattern of the urban thermal environment at the block scale, and the mechanism of green space fractal characteristics in terms of correlation and spatial heterogeneity, to assess the quality of green space development. This study shows the following: (1) In 2019, the land surface temperature in Dalian formed a spatial distribution structure of “high in the central region and low in the surrounding region” at the block scale, and the fractal indices of different green spaces show the spatial distribution structure of “dual-core” and “multi-core” spaces. (2) The driving direction and force of the fractal index of green space on the spatial pattern of land surface temperature differs. The influence of the green space structure index (grid and boundary dimensions) is greater than that of the quantity index (area and circumference), and the influence of the grid dimension is the most significant. (3) The spatial heterogeneity between the fractal index of block-scale green space and land surface temperature in Dalian is significant, showing a centralized and contiguous spatial pattern, with a trapezoidal structure decreasing from north to south. (4) The spatial adaptation between the fractal and thermal environments of green spaces can be evaluated using the inconsistency index. The development quality of green space can be divided into three types: advanced, relative coordination, and lagged green spaces. Finally, this study proposes specific suggestions for the development of block-scale green spaces and thermal environment management in Dalian City. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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16 pages, 2392 KiB  
Article
The Effect of Climate Factors on 400 Years of Traditional Chinese Residential Building Roof Design: A Study from Southwest China
by Qinghua Xu, Zhifan Ding, Hui Wang, Yuncai Wang and Lingfeng Mao
Buildings 2023, 13(2), 300; https://doi.org/10.3390/buildings13020300 - 19 Jan 2023
Viewed by 1527
Abstract
Indigenous people have used architecture over millennia to adapt to climatic factors and achieve stable and comfortable living. These adaptations can still inform the design of contemporary regional architecture. In order to explore the relationship between traditional dwellings and climatic factors, we examine [...] Read more.
Indigenous people have used architecture over millennia to adapt to climatic factors and achieve stable and comfortable living. These adaptations can still inform the design of contemporary regional architecture. In order to explore the relationship between traditional dwellings and climatic factors, we examine buildings in four provinces and cities in southwest China. A database was created using detailed data obtained from the literature on indicators of climatic factors (e.g., temperature, precipitation, temperature difference, wind speed, solar radiation) and architectural elements (e.g., roof slope and eave length). Thorough statistical analysis shows that (1) MPWM has the most significant correlation with the slope angle of traditional building roofs but is not recommended as a predictor in multivariate equations. (2) Temperature and wind speed were significant correlates of roof slope, and a multiple regression model dominated by AMT and AWS serves as a good predictor of roof slope. (3) Solar radiation was not correlated with roof slope but was the largest correlate of eaves length in traditional buildings. AMSR and AWS also dominantly affect eaves length in a regression relationship. These results serve not only as a reference to catalog the use of traditional passive technologies but can guide the design of green buildings. However, more research is needed to refine the use of passive technologies to adapt to climate change Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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21 pages, 14109 KiB  
Article
Evaluating the Effects of Different Improvement Strategies for the Outdoor Thermal Environment at a University Campus in the Summer: A Case Study in Northern China
by Lina Yang, Jiying Liu and Shengwei Zhu
Buildings 2022, 12(12), 2254; https://doi.org/10.3390/buildings12122254 - 17 Dec 2022
Cited by 2 | Viewed by 1545
Abstract
A lack of consideration of outdoor spaces of universities has resulted in lower outdoor thermal comfort in summer. This study investigates the thermal comfort of outdoor spaces of a university in summer and proposes the model’s accuracy and optimization strategies to improve the [...] Read more.
A lack of consideration of outdoor spaces of universities has resulted in lower outdoor thermal comfort in summer. This study investigates the thermal comfort of outdoor spaces of a university in summer and proposes the model’s accuracy and optimization strategies to improve the outdoor thermal environment, including vegetation greening, building morphology, and surface albedo. The ENVI-met program was used for the simulation. The measured data were utilized to verify the accuracy of the simulation model. The typical meteorological year data were applied as the inlet boundary condition of the optimized case. The simulation results show that vegetation greening has the most significant effect on improving the outdoor thermal environment. At a greening rate of 45%, the air temperature (Ta), mean radiant temperature (Tmrt), and physiological equivalent temperature (PET) in the study area were 3.2 °C, 14.4 °C, and 6.9 °C lower, respectively, than that in the base case. In areas shaded by building, the Ta, Tmrt, and PET were 2 °C, 8.7 °C, and 5.5 °C lower, respectively, than that in the base case. Increasing the height of buildings did not significantly improve thermal comfort when the height-to-width ratio (H/W) exceeded 1.0. Increasing the ground albedo from 0.2 (base case) to 0.6 can reduce the Ta by 1.44 °C but increase the Tmrt by 3.7 °C and the PET by 4.3 °C. These findings can be used by urban planners to develop sustainable cities and improve thermal comfort on university campuses. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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25 pages, 6582 KiB  
Article
Investigative Study on Adaptive Thermal Comfort in Office Buildings with Evaporative Cooling Systems (ECS) under Dry Hot Climate
by Yuang Guo and Yuxin Wang
Buildings 2022, 12(11), 1827; https://doi.org/10.3390/buildings12111827 - 31 Oct 2022
Cited by 2 | Viewed by 1751
Abstract
Evaporative cooling systems (ECS) in buildings, which are driven by cleaner and more sustainable energy, had been widely applied in recent years especially for the dry hot regions in summer. In this study, an investigation was conducted for office buildings by using ECS [...] Read more.
Evaporative cooling systems (ECS) in buildings, which are driven by cleaner and more sustainable energy, had been widely applied in recent years especially for the dry hot regions in summer. In this study, an investigation was conducted for office buildings by using ECS in Urumqi (China) from July to August 2021. Through subjective survey and objective measurements, 577 initial questionnaires and measured data were obtained. Outcomes showed that the indoor expectative temperature (Te) was received by 26.6 °C, 0.7 °C lower than neutral temperature (Tn). And the acceptable intervals for the 90% and 80% level were obtained at 27.1–28.9 °C and 26.4–30.3 °C, respectively. It appeared to possess a wider scope than that calculated by PMV algorithm, which further indicted that subjects have adapted to the local climate. Furthermore, the adjustment PMV models (ePMV, APMV) were found to have an effectively narrow gap comparing to the actual thermal sensation vote (TSV). The appropriate usage intervals of ePMV and APMV were quantified by Top < 27.6 °C/Top > 29.8 °C, 27.6 °C < Top < 29.8 °C, respectively. These findings may provide reference values for the revision of local energy-saving standard to some extent. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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26 pages, 17277 KiB  
Article
The Impacts of Urban Configurations on Outdoor Thermal Perceptions: Case Studies of Flat Bandar Tasik Selatan and Surya Magna in Kuala Lumpur
by Lin Yola, Timothy O. Adekunle and Olutobi G. Ayegbusi
Buildings 2022, 12(10), 1684; https://doi.org/10.3390/buildings12101684 - 13 Oct 2022
Cited by 2 | Viewed by 1603
Abstract
This study assesses the impacts of urban configurations on thermal perceptions in Flat Bandar Tasik Selatan (FBTS) and Surya Magna (SM) in Kuala Lumpur, Malaysia. It aims to understand the impacts of urban configurations on thermal perceptions in outdoor spaces. The study addresses [...] Read more.
This study assesses the impacts of urban configurations on thermal perceptions in Flat Bandar Tasik Selatan (FBTS) and Surya Magna (SM) in Kuala Lumpur, Malaysia. It aims to understand the impacts of urban configurations on thermal perceptions in outdoor spaces. The study addresses the following research questions: (1) Do urban configurations influence outdoor comfort? (2) Do urban configurations also have significant impacts on thermal perceptions? We mapped out the sites to understand their configurations. The research considered on-site measurements of the environmental conditions and carried out modelling and simulations (ENVI-met V3.1) of the sites. Mathematical models (Wet-Bulb Globe Temperature (WBGT), Universal Thermal Climate Index (UTCI), and Standard Effective Temperature (SET)) were used to determine the thermal indices and the impact of the urban configurations on outdoor comfort. The thermal indices varied from 25.44 to 34.75 °C. In terms of the main contribution of this work, the results show that in hot and humid climate regions, urban configurations plus other design variables (e.g., orientation towards the Sun’s path) and environmental parameters influence occupants’ comfort and perceptions. Our findings show that high solar radiation and the need for a better thermal environment in hot and humid climates are the contributing factors for developing alternative urban configurations. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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18 pages, 40880 KiB  
Article
Modelling Residential Outdoor Thermal Sensation in Hot Summer Cities: A Case Study in Chongqing, China
by Ying Liu, Yafeng Gao, Dachuan Shi, Chaoqun Zhuang, Zhang Lin and Zhongyu Hao
Buildings 2022, 12(10), 1564; https://doi.org/10.3390/buildings12101564 - 29 Sep 2022
Cited by 4 | Viewed by 1589
Abstract
Exposure to extreme heat is a significant public health problem and the primary cause of weather-related mortality, which can be anticipated by accurately predicting outdoor thermal sensation. Empirical models have shown better accuracy in predicting thermal sensation than the most frequently used theoretical [...] Read more.
Exposure to extreme heat is a significant public health problem and the primary cause of weather-related mortality, which can be anticipated by accurately predicting outdoor thermal sensation. Empirical models have shown better accuracy in predicting thermal sensation than the most frequently used theoretical thermal indices, which have ignored adaptability to local climate and resulted in underestimating or overestimating the neutral levels of residents. This study proposes a scheme to build an empirical model by considering the multiple linear regression of thermal sensation and microclimatic parameters during summer in Chongqing, China. Thermal environment parameters (air temperature, relative humidity, wind speed, and surface temperature) were recorded and analyzed, together with 375 questionnaire survey responses referring to different underlying surfaces. The results found that the proposed model predicted neutral sensations as warm and 19.4% of warm sensations as hot, indicating that local residents adapted to warm or even hot sensations. In addition, the empirical model could provide references for local pedestrians’ daytime path choices. Residents might feel more comfortable staying beside a pond from 8:00 to 11:00 or sheltering under trees from 08:00 to 14:00 and 17:00 to 19:00. Masonry offered a comfortable microclimate between 10:15 and 11:00, and residents on the lawns were comfortable from 17:30 to 19:00. However, asphalt should be equipped with cooling infrastructures in order to cool thermal sensation. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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13 pages, 2162 KiB  
Article
A Field Study of Outdoor Human Thermal Perception in Three Seasons in Shanghai, China
by Dongxue Wei, Zefeng Lian and Binyi Liu
Buildings 2022, 12(9), 1453; https://doi.org/10.3390/buildings12091453 - 16 Sep 2022
Cited by 3 | Viewed by 1542
Abstract
The locality of landscape design needs to obtain human thermal perception in different cities or regions. Previous studies in Shanghai have focused on a single season and ignored the seasonal characteristics of hot summers and cold winters. The objective of this research was [...] Read more.
The locality of landscape design needs to obtain human thermal perception in different cities or regions. Previous studies in Shanghai have focused on a single season and ignored the seasonal characteristics of hot summers and cold winters. The objective of this research was to examine the outdoor human thermal perception in three seasons—summer, autumn, and winter. For this purpose, a field survey was conducted in two urban squares in Shanghai, and during three seasons, an outdoor human thermal perception questionnaire survey was completed combined with micrometeorological measurements. In the questionnaire, the thermal sensation and thermal comfort of interviewees were evaluated through the 9-point scale and the 4-point break scale, respectively. Regression lines gave the possibility to calculate the neutral ranges and the comfort ranges. A neutral PET (physiological equivalent temperature) range of 13.0~28.6 °C and a comfort PET range of 14.2~32.6 °C were obtained for three seasons. In addition, the relationships between personal (gender and age of respondents) and microclimatic (air temperature, relative humidity, wind velocity, and solar radiation) factors on thermal sensation votes (TSV) and thermal comfort votes (TCV) were evaluated. The results of multiple regression analysis showed that the variables affecting TSV and TCV changed with the season. The findings of this research enhance our understanding of outdoor human thermal perception and can contribute to more friendly outdoor open space design in Shanghai. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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17 pages, 6561 KiB  
Article
Infrared-Fused Vision-Based Thermoregulation Performance Estimation for Personal Thermal Comfort-Driven HVAC System Controls
by Ali Ghahramani, Qian Xu, Syung Min, Andy Wang, Hui Zhang, Yingdong He, Alexander Merritt and Ronnen Levinson
Buildings 2022, 12(8), 1241; https://doi.org/10.3390/buildings12081241 - 15 Aug 2022
Cited by 13 | Viewed by 2044
Abstract
Thermal comfort is one of the primary factors influencing occupant health, well-being, and productivity in buildings. Existing thermal comfort systems require occupants to frequently communicate their comfort vote via a survey which is impractical as a long-term solution. Here, we present a novel [...] Read more.
Thermal comfort is one of the primary factors influencing occupant health, well-being, and productivity in buildings. Existing thermal comfort systems require occupants to frequently communicate their comfort vote via a survey which is impractical as a long-term solution. Here, we present a novel thermal infrared-fused computer vision sensing method to capture thermoregulation performance in a non-intrusive and non-invasive manner. In this method, we align thermal and visible images, detect facial segments (i.e., nose, eyes, face boundary), and accordingly read the temperatures from the appropriate coordinates in the thermal image. We focus on the human face since it is often clearly visible to cameras and is not merged into a hot background (unlike hands). We use a regularized Gaussian Mixture model to track the thermoregulation changes over time and apply a heuristic algorithm to extract hot and cold indices. We present a personalized and a generalized comfort modeling method, selected based on the availability of the occupant historical indices measurements in a neutral environment, and use the time-series of the hot and cold indices to define corrections to HVAC system operations in the form of setpoint constraints. To evaluate the efficacy of our proposed approach in responding to thermal stimuli, we designed a series of controlled experiments to simulate exposure to cold and hot environments. While applying personalized modeling showed an acceptable average accuracy of 91.3%, the generalized model’s average accuracy was only 65.2%. This shows the importance of having access to physiological records in modeling and assessing comfort. We also found that individual differences should be considered in selecting the cooling and heating rates when some knowledge of the occupant’s overall thermal preference is available. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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21 pages, 6832 KiB  
Article
Improvement Strategies for Microclimate and Thermal Comfort for Urban Squares: A Case of a Cold Climate Area in China
by Haiming Yu, Hiroatsu Fukuda, Mengyuan Zhou and Xuan Ma
Buildings 2022, 12(7), 944; https://doi.org/10.3390/buildings12070944 - 2 Jul 2022
Cited by 9 | Viewed by 2544
Abstract
Urban squares are an important part of a city’s overall spatial environment. However, many urban squares lack rational designs, causing the thermal environment to deteriorate. To ensure sustainable urban development, urban square microclimates should be improved. Given that, this study investigates the effects [...] Read more.
Urban squares are an important part of a city’s overall spatial environment. However, many urban squares lack rational designs, causing the thermal environment to deteriorate. To ensure sustainable urban development, urban square microclimates should be improved. Given that, this study investigates the effects of three coverages of three landscape elements of urban squares through modeling and simulation using the ENVI-met model validated by field measurements. The correlation between physiological equivalent temperature (PET) and different amounts of landscape elements is investigated using Spearman analysis. This study presents a case study of a typical urban square in a cold climate area. Design strategies in the area are proposed. The results show that the microclimate and thermal comfort of the urban square can be improved by expanding water bodies, modest increasing buildings and optimizing vegetation. Vegetation is the most important landscape element affecting thermal comfort in the urban square. The PET can be reduced by about 1.5 °C by increasing the vegetation cover from 40% to 70%. However, the degree of microclimate regulation by vegetation is disturbed by water bodies and buildings (|ρ| ≥ 0.5). Therefore, to achieve a more comfortable thermal environment, a combination of landscape elements should be considered. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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23 pages, 6423 KiB  
Article
The Influence of Transient Changes in Indoor and Outdoor Thermal Comfort on the Use of Outdoor Space by Older Adults in the Nursing Home
by Hua Zong, Jiao Wang, Ting Zhou, Jiarui Sun and Xuehong Chen
Buildings 2022, 12(7), 905; https://doi.org/10.3390/buildings12070905 - 26 Jun 2022
Cited by 8 | Viewed by 1868
Abstract
Recently, the requirements regarding the environment of nursing homes are high, because the elderly are a vulnerable group with limited adaptive capacity to respond to transient environmental change. This paper presents a field investigation on the influence of transient thermal comfort changes between [...] Read more.
Recently, the requirements regarding the environment of nursing homes are high, because the elderly are a vulnerable group with limited adaptive capacity to respond to transient environmental change. This paper presents a field investigation on the influence of transient thermal comfort changes between the indoor and outdoor spaces (i.e., air temperature (Ta), solar radiation (SR), relative humidity (RH), wind speed (WS), and the thermal comfort indices of Universal Thermal Index (UTCI)) on the willingness of the elderly to use outdoor spaces of the Wanxia nursing home of Chengdu City. Results indicated that, in summer, the mean UTCI values of indoor and corridor spaces corresponded to the level of moderate heat stress, while those of road and garden corresponded to the strong heat stress level. Road and garden spaces even showed moderate heat stress in spring. Approximately 28.93% (139) of the elderly living here used outdoor spaces every day. The morning period (from 9:00 a.m. to 10:00 a.m.) was the elderly’s favorited period for using outdoor spaces in seasons. The microclimatic transient differences between indoor and outdoor spaces ranged from 0.47 °C to 2.93 °C (|ΔTa|), from 86.09 W/m2 to 206.76 W/m2 (|ΔSR|), from 5.29% to 14.76% (ΔRH), from 0.01 m/s to 0.07 m/s (|ΔWS|), and from 0.25 °C to 2.25 °C (ΔUTCI). These big microclimate differences could cause enormous health risks for the elderly in the process of indoor and outdoor space conversion. The minimal transient change occurred between corridors and indoors. Pearson correlation analysis indicated ΔTa and ΔRH between indoor and outdoor spaces were the primary meteorological factors that influenced the elderly’s willing to use outdoor spaces. The elderly preferred to live in a constant Ta and RH environment. Only when the ΔTa and ΔRH are small enough to resemble a steady-state (ΔUTCI ≤ 0.5 °C), ΔWS and ΔSI could affect the elderly’s choice of using outdoor space. Optimal design strategies were put forward for reducing the transient differences between indoor and outdoor microclimates to inspire the elderly to use outdoor spaces safely, including improving outdoor canopy coverage and indoor mechanical ventilation. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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19 pages, 15035 KiB  
Article
Spatial Differences in Outdoor Thermal Comfort during the Transition Season in Cold Regions of China
by Fei Guo, Zuoxing Wang, Jing Dong, Hongchi Zhang, Xiaodong Lu, Stephen Siu Yu Lau and Yijia Miao
Buildings 2022, 12(6), 720; https://doi.org/10.3390/buildings12060720 - 26 May 2022
Cited by 14 | Viewed by 2536
Abstract
This study investigates the differences in outdoor thermal comfort in different spatial types over long-term observations during the transition season in a cold region. Using the Universal Thermal Climate Index (UTCI) as an evaluation index, subjective questionnaires and field surveys were conducted on [...] Read more.
This study investigates the differences in outdoor thermal comfort in different spatial types over long-term observations during the transition season in a cold region. Using the Universal Thermal Climate Index (UTCI) as an evaluation index, subjective questionnaires and field surveys were conducted on thermal comfort in three different typical outdoor environments (sunlight, tree shade and building shade) in Dalian (Northeast China). The results demonstrated the following: (1) Air temperature and mean radiant temperature were the dominant meteorological factors affecting outdoor thermal comfort in Dalian. (2) The main thermal sensation recorded in the transition season was “slightly cool”. Over time, the human thermal sensation experienced a gradual transition from “hot” to “cold”. (3) Compared with direct sunlight, the average UTCI decreased by 6.6 and 3.5 °C for building shade and tree shade environments, and the neutral UTCI in Dalian was found to be 18.8 °C. Subjects were most sensitive to the thermal environment in building shade, then in tree shade and the least in sunlight. (4) When UTCI ≥ 21.9 °C, the thermal acceptability rate in building shade remained the highest; when 10.2 °C ≤ UTCI < 21.9 °C, it was highest in tree shade; and when the UTCI < 10.2 °C, it was highest in sunlight. This study verifies the UTCI applicability in the transition season in cold regions and analyzes the spatial differences in human thermal comfort. These differences play a positive role in developing optimization strategies for outdoor thermal environments, improving environmental satisfaction and facilitating pedestrian outdoor activities. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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17 pages, 9853 KiB  
Article
Coupling CFD Simulation and Field Experiments in Summer to Prove Feng Shui Optimizes Courtyard Wind Environments: A Case Study of Prince Kung’s Mansion in Beijing
by Peiyan Guo, Chenyang Ding, Zipeng Guo, Tingfeng Liu and Taifeng Lyu
Buildings 2022, 12(5), 629; https://doi.org/10.3390/buildings12050629 - 9 May 2022
Cited by 10 | Viewed by 5321
Abstract
Feng shui in ancient China was harmonized with the natural environment. The layout of houses following feng shui is conducive to a comfortable wind environment. To explore the positive influence of feng shui on ventilation, this study takes Prince Kung’s Mansion, which has [...] Read more.
Feng shui in ancient China was harmonized with the natural environment. The layout of houses following feng shui is conducive to a comfortable wind environment. To explore the positive influence of feng shui on ventilation, this study takes Prince Kung’s Mansion, which has the characteristics of a feng shui layout, as the research object. In parallel, the study assumes a dissimilation layout that has lost the feng shui layout characteristics. Comparing the ventilation of courtyards in the summer for both the feng shui layout and the dissimilation layout through CFD simulation, the results were as follows: (1) the wind speed values in the summer, taken from 60 points in Prince Kung’s Mansion by way of CFD simulation and field experiments, were well coupled, which proves that PHOENICS is suitable for the courtyard wind environments simulation in this study. (2) The CFD simulation results show that the average wind speed and the comfortable wind speed zone ratio in the courtyards of the feng shui layout were higher than those of the dissimilation layout during the summer, and the courtyard wind speeds of the two layouts were linearly related. Therefore, the feng shui layout is more conducive to the comfort of courtyards’ wind environment than the dissimilation layout. (3) The front and rear wind pressure differences of the main houses in the feng shui layout can optimize the indoor ventilation better than those of dissimilation layout in the summer. (4) According to the evaluation criteria for the wind environment, the wind speed and wind pressure of the feng shui layout are superior to those of dissimilation layout in the summer. In summary, this study verifies that the layout of feng shui optimizes the courtyard wind environment in the summer, which embodies the ecological concept of the Chinese ancients in the layout of houses. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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20 pages, 8999 KiB  
Article
Low-Cost Thermohygrometers to Assess Thermal Comfort in the Built Environment: A Laboratory Evaluation of Their Measurement Performance
by Francesco Salamone, Giorgia Chinazzo, Ludovico Danza, Clayton Miller, Sergio Sibilio and Massimiliano Masullo
Buildings 2022, 12(5), 579; https://doi.org/10.3390/buildings12050579 - 29 Apr 2022
Cited by 8 | Viewed by 2401
Abstract
A thermohygrometer is an instrument that is able to measure relative humidity and air temperature, which are two of the fundamental parameters to estimate human thermal comfort. To date, the market offers small and low-cost solutions for this instrument, providing the opportunity to [...] Read more.
A thermohygrometer is an instrument that is able to measure relative humidity and air temperature, which are two of the fundamental parameters to estimate human thermal comfort. To date, the market offers small and low-cost solutions for this instrument, providing the opportunity to bring electronics closer to the end-user and contributing to the proliferation of a variety of applications and open-source projects. One of the most critical aspects of using low-cost instruments is their measurement reliability. This study aims to determine the measurement performance of seven low-cost thermohygrometers throughout a 10-fold repeatability test in a climatic chamber with air temperatures ranging from about −10 to +40 °C and relative humidity from approximately 0 to 90%. Compared with reference sensors, their measurements show good linear behavior with some exceptions. A sub-dataset of the data collected is then used to calculate two of the most used indoor (PMV) and outdoor (UTCI) comfort indexes to define discrepancies between the indexes calculated with the data from the reference sensors and the low-cost sensors. The results suggest that although six of the seven low-cost sensors have accuracy that meets the requirements of ISO 7726, in some cases, they do not provide acceptable comfort indicators if the values are taken as they are. The linear regression analysis suggests that it is possible to correct the output to reduce the difference between reference and low-cost sensors, enabling the use of low-cost sensors to assess indoor thermal comfort in terms of PMV and outdoor thermal stress in UTCI and encouraging a more conscious use for environmental and human-centric research. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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22 pages, 13138 KiB  
Article
Correlation Analysis of Thermal Comfort and Landscape Characteristics: A Case Study of the Coastal Greenway in Qingdao, China
by Yu Cong, Ruirui Zhu, Lei Yang, Xiaotong Zhang, Yibin Liu, Xi Meng and Weijun Gao
Buildings 2022, 12(5), 541; https://doi.org/10.3390/buildings12050541 - 24 Apr 2022
Cited by 5 | Viewed by 2582
Abstract
With the acceleration of urbanization throughout the world, climate problems related to climate change including urban heat islands and global warming have become challenges to urban human settlements. Numerous studies have shown that greenways are beneficial to urban climate improvement and can provide [...] Read more.
With the acceleration of urbanization throughout the world, climate problems related to climate change including urban heat islands and global warming have become challenges to urban human settlements. Numerous studies have shown that greenways are beneficial to urban climate improvement and can provide leisure places for people. Taking the coastal greenway in Qingdao as the research object, mobile measurements of the microclimate of the greenway were conducted in order to put forward an evaluation method for the research of outdoor thermal comfort. The results showed that different vegetation coverage affected the PET (physiologically equivalent temperature), UTCI (Universal Thermal Climate Index) as well as thermal comfort voting. We found no significant correlation between activities, age, gender, and thermal comfort voting. Air temperature sensation and solar radiation sensation were the primary factors affecting the thermal comfort voting of all sections. Otherwise, within some sections, wind sensation and humidity sensation were correlated with thermal sensation voting and thermal comfort voting, respectively. Both PET and UTCI were found to have a negative correlation with the vegetation coverage on both sides of the greenway. However, the vegetation coverage had positive correlation (R = 0.072) for thermal sensation and significant positive correlation (R = 0.077*) for thermal comfort. The paved area cover was found to have a positive correlation with PET and UTCI, while having a negative correlation with thermal sensation (R = −0.049) and thermal comfort (R = −0.041). This study can provide scientific recommendations for the planning and design of greenway landscapes to improve thermal comfort. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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14 pages, 3210 KiB  
Article
Outdoor Wind Comfort and Adaptation in a Cold Region
by Meng Zhen, Zilin Chen and Rui Zheng
Buildings 2022, 12(4), 476; https://doi.org/10.3390/buildings12040476 - 12 Apr 2022
Cited by 4 | Viewed by 1770
Abstract
The outdoor wind comfort is important for evaluations of the urban wind environment. The existing wind comfort criteria are based on the correlations between wind parameters, human activity levels, and wind comfort level categories. These criteria vary among different climates and regions, and [...] Read more.
The outdoor wind comfort is important for evaluations of the urban wind environment. The existing wind comfort criteria are based on the correlations between wind parameters, human activity levels, and wind comfort level categories. These criteria vary among different climates and regions, and they are influenced by meteorological parameters and human wind adaptation. In this study, an outdoor wind comfort questionnaire survey was conducted and meteorological measurements were collected in Xi’an, which is located in the cold region of China. The square and lake side were chosen as the test sites. The mean wind sensation vote (MWSV) and wind speed of neutral wind sensation were used as indexes to analyze the correlation between outdoor wind comfort and human wind adaptation. The results showed that the wind sensation level was generally moderate. At −1 < MWSV < 1, the fluctuations in the wind speed had little effect on the wind sensation, but when MWSV > 1 or MWSV < −1, the degree of discomfort increased as the absolute value of MWSV increased. When the wind speed exceeded 1 m/s, the amount of clothing insulation was greatly increased. The metabolic rate fluctuated between 1.5 met and 2 met. Expectations that the wind speed in the winter would be less than 1.05 m/s were greater than expectations that the wind speed would be more than 1.05 m/s in the summer, and people generally adapted to a low wind environment with wind speeds below 1 m/s. The acceptable wind ranges for more than 90% of participants at the square and lake side were (0 m/s, 2.02 m/s) and (0.01 m/s, 2.86 m/s). This study provides support for the revision of outdoor wind comfort standards and a methodological basis for outdoor wind comfort research at the same latitude throughout the world. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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18 pages, 5481 KiB  
Article
Climate Chamber Experiment Study on the Association of Turning off Air Conditioning with Human Thermal Sensation and Skin Temperature
by Yiwen Jian, Shuwei Liu, Mengmeng Bian, Zijia Liu and Shengjie Liu
Buildings 2022, 12(4), 472; https://doi.org/10.3390/buildings12040472 - 12 Apr 2022
Cited by 2 | Viewed by 1698
Abstract
To date, few attempts have been made to associate air conditioning behavior with environmental conditions and the occupants’ thermal sensations and physiological states simultaneously. In this study, a series of experiments were conducted in a climate chamber environment, representative of a typical intermittent [...] Read more.
To date, few attempts have been made to associate air conditioning behavior with environmental conditions and the occupants’ thermal sensations and physiological states simultaneously. In this study, a series of experiments were conducted in a climate chamber environment, representative of a typical intermittent air conditioning process in residences. For 29 participants, local skin temperatures, thermal sensation and the participants’ intention of turning off air conditioning were recorded continually. Skin temperature and thermal sensation were found to keep decreasing over time, which in turn triggered turning off air conditioning. It is also noted that participants reported different thermal sensations when they intended to turn off air conditioning. However, there was no statistically significant difference in skin temperature of exposed body parts such as foot and calf. Additionally, given the ambient set temperature, the probability of turning off air conditioning exponentially increased with the increasing air conditioning duration. Accordingly, from a physiological perspective, the occupants’ behavior of turning off air conditioning was largely dependent on the local skin temperature of exposed body parts. From an environmental perspective, air conditioning duration demonstrated influences on the air conditioner switch-off. The lower the ambient temperature or the longer the exposure to air conditioning environment, the stronger the intention of the participants to turn off air conditioning. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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16 pages, 5213 KiB  
Article
Quality Analysis on Indoor Thermal Comfort and Energy-Saving Improvement Strategy of Slate Dwellings, China
by Juan Xu, Wenting Yang, Ziliang Lu, Yan Wu, Chaoping Hou and Dan Liu
Buildings 2022, 12(4), 468; https://doi.org/10.3390/buildings12040468 - 11 Apr 2022
Cited by 2 | Viewed by 1866
Abstract
Slate dwellings are known as the “living fossil of primitive dwellings” in China. Energy-saving strategies are crucial to slate dwellings for sustainability as well as maintaining thermal comfort. In this research, a subjective satisfaction analysis on the indoor thermal environment in Daziliang village, [...] Read more.
Slate dwellings are known as the “living fossil of primitive dwellings” in China. Energy-saving strategies are crucial to slate dwellings for sustainability as well as maintaining thermal comfort. In this research, a subjective satisfaction analysis on the indoor thermal environment in Daziliang village, China, was conducted. It was found that neutral temperature is 20.92 °C in summer, 8.92 °C in winter, and the actual operating temperature in winter is too low to meet the 80% acceptable range. Therefore, a series of improvement strategies in winter were proposed. The results showed that adding external thermal insulation material—expanded polystyrene board with a thickness of 80 mm on the roof and outside walls—and sunspace depth of 1.5 m are better in terms of energy-saving effects. In addition, the slate dwelling’s daily energy-saving rate of the heating day is 44.26% lower than the original state through these strategies. The air temperature of Bedroom D in winter non-heating days increases by 3.82 °C after improvement and the mean radiant temperature increased by 2.54 °C. Our approach puts forward specific energy-saving improvement measures and provides feasible suggestions for the protection and development of slate dwellings in this area. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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16 pages, 3482 KiB  
Article
Spatiotemporal Impact of Urbanization on Urban Heat Island and Urban Thermal Field Variance Index of Tianjin City, China
by Nadeem Ullah, Muhammad Amir Siddique, Mengyue Ding, Sara Grigoryan, Tianlin Zhang and Yike Hu
Buildings 2022, 12(4), 399; https://doi.org/10.3390/buildings12040399 - 24 Mar 2022
Cited by 9 | Viewed by 2937
Abstract
The rapid infrastructure development in densely populated areas has had several negative impacts. Increases in urbanization have led to increased LST, and urban ecological systems have been negatively affected. Urban heat islands (UHIs) can be mitigated by understanding how current and future LST [...] Read more.
The rapid infrastructure development in densely populated areas has had several negative impacts. Increases in urbanization have led to increased LST, and urban ecological systems have been negatively affected. Urban heat islands (UHIs) can be mitigated by understanding how current and future LST phenomena are linked to changes in landscape composition and land use cover (LUC). This study investigated the multi-scale spatial analysis of LUC and LST in Tianjin using remote sensing and GIS data. We used Landsat data from 2005 to 2020 to examine the effects of LUC on LST in urban agglomeration. According to the Urban Thermal Field Variance Index (UTFVI), the city’s ecological evaluation was carried out. Results show that changes in LUC and other anthropogenic activities affect the spatial distribution of LST. For the study years (2004–2009), the estimated mean LST in Tianjin was 25.32 °C, 26.73 °C, 27.62 °C, and 27.93 °C. Between LST and urban areas with other infrastructures, and NDBI, significant positive correlation values were found about 0.53, 0.48, and 0.76 (p < 0.05), respectively. Temperatures would almost certainly increase by 3.87 °C to 7.26 °C as a result of decreased plant cover and increased settlements. These findings strongly imply a correlation between LST and the vegetation index. Between 2005 and 2020, the anticipated increase in LST of 3.39 °C is expected to harm urban environmental health. This study demonstrates how Tianjin and other cities can achieve ecological sustainability. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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19 pages, 46798 KiB  
Article
Architectural Simulations on Spatio-Temporal Changes of Settlement Outdoor Thermal Environment in Guanzhong Area, China
by Kai Xin, Jingyuan Zhao, Tianhui Wang, Weijun Gao and Qihui Zhang
Buildings 2022, 12(3), 345; https://doi.org/10.3390/buildings12030345 - 12 Mar 2022
Cited by 4 | Viewed by 2181
Abstract
This paper aims to provide data support for rural sustainable development through analyzing the spatio-temporal characteristics of the interactions of the outdoor thermal environment. The ordinary and representative rural settlements in the Guanzhong area were selected to analyze the dynamic process of the [...] Read more.
This paper aims to provide data support for rural sustainable development through analyzing the spatio-temporal characteristics of the interactions of the outdoor thermal environment. The ordinary and representative rural settlements in the Guanzhong area were selected to analyze the dynamic process of the rural thermal environment through field measurements and numerical simulations. RMSE (root mean square error) and MAPE (mean absolute percentage) were used to verify the numerical simulation model, and physiological equivalent temperature (PET) was used to evaluate the outdoor thermal environment. Results show that the ENVI-met model reliably predicts the thermal environment of a rural settlement, as the air temperature and relative humidity values range of the RMSE and MAPE were 0.85–1.79 and 2.04–5.11%, respectively. Moreover, the air temperature rose by 3.08% and relative humidity dropped by 4.42% from 2003 to 2018 as the amount of artificial surfaces increased by 35.4% and the PET index gradually increased by 27.43% at daytime and 34.03% at nighttime. Furthermore, trees could improve the outdoor thermal environment significantly, mainly because the average air temperature decreased by 3.6% and relative humidity increased by 8%, and the PET index decreased by 12.4% and 13.1%, respectively, for daytime and nighttime. This case study is representative of rural settlements in the Guanzhong plain, and thus is an appeal to rural planners to pay attention to the thermal environment issues caused by increased artificial underlay surfaces and to focus on trees in rural areas. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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18 pages, 7782 KiB  
Article
Landscape Efficiency Assessment of Urban Subway Station Entrance Based on Structural Equation Model: Case Study of Main Urban Area of Nanjing
by Zhe Li, Xiaoshan Lin, Xiao Han, Xinyi Lu and Hengyi Zhao
Buildings 2022, 12(3), 294; https://doi.org/10.3390/buildings12030294 - 3 Mar 2022
Cited by 7 | Viewed by 2730
Abstract
Public landscape efficiency is one of the research hotspots in contemporary landscape performance. The renewal of micro landscape space has positive effects on community vitality and the sustainable development of landscape resources. The subway station entrance is a typical representative of the miniature [...] Read more.
Public landscape efficiency is one of the research hotspots in contemporary landscape performance. The renewal of micro landscape space has positive effects on community vitality and the sustainable development of landscape resources. The subway station entrance is a typical representative of the miniature landscape environment. To improve the construction of subway station entrances, clear cognition on the landscape efficiency of subway station entrances and their impact indicators is necessary. For this purpose, a structural equation model with a parameter system was established to measure landscape efficiency. There are four latent variables (e.g., traffic capacity) and 10 observed variables (e.g., visual level) composed of an estimation model. Researchers selected 131 subway station entrances in the main urban area of Nanjing as survey samples. Various methods, including investigation, image recognition, and modelling analysis, were comprehensively used to analyse the landscape characteristics of the subway station entrances quantitatively. A calculation was conducted to obtain the correlation coefficient of latent variables and the explanatory degree of observed variables. The result shows that green space landscapes and traffic capacity impresses the landscape efficiency of subway station entrances. Furthermore, all these variables have complex correlations. The fluctuation of any latent variable may cause the decay or enhancement of related variables. Therefore, designers should have a comprehensive cognition of the landscape environment of subway station entrances to enable them to propose balanced design strategies under traffic, visibility, plants and facilities. This paper aims to help designers gain an in-depth understanding of the ideal landscape construction forms at subway station entrances and facilitate the high-quality development of the urban landscape environment. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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15 pages, 4762 KiB  
Article
Analyzing the Environment Characteristics of Heat Exposure Spaces from the Humanistic Perspective and Spatial Improvement Approaches in Central Beijing, China
by Xin Yang, Wenwen Gao, Qi Zhang, Sha Li, Fan Fu and Nana Li
Buildings 2022, 12(2), 138; https://doi.org/10.3390/buildings12020138 - 27 Jan 2022
Cited by 1 | Viewed by 2143
Abstract
Global warming, high temperatures, and heatwave weather are some of the factors affecting human settlement environment health. In high-temperature weather, human production and life are seriously threatened, as long-term exposure to high temperatures causes a variety of diseases, and children and elderly, who [...] Read more.
Global warming, high temperatures, and heatwave weather are some of the factors affecting human settlement environment health. In high-temperature weather, human production and life are seriously threatened, as long-term exposure to high temperatures causes a variety of diseases, and children and elderly, who have poor tolerance, require strengthened protection. From a human perspective, this study calculated the thermal duration distribution of high temperatures based on maximum temperature data in a central urban area of Beijing combined with the results of the sixth population census of Beijing, investigated the population distribution of individuals under 15 years old and over 65 years old, and analyzed the spatial distribution of a thermal exposure space in a central urban area of Beijing with the help of the ArcGIS platform. Based on 130 district districts, streets with high-risk heat exposure spaces in the central urban area of Beijing were reddened to determine the distribution of high-risk grades. Using the semantic segmentation method and a street view map, the high-risk thermal exposure space environment from the humanistic perspective was restored, and the typical characteristics were summarized and analyzed. Finally, the environmental characteristics of the high-risk thermal exposure space were analyzed from the humanistic perspective, and an improvement strategy for thermal exposure spaces was proposed based on the perspective of emotional relief. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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23 pages, 6804 KiB  
Article
Investigation of Indoor Asymmetric Thermal Radiation in Tibet Plateau: Case Study of a Typical Office Building
by Meilin Wang and Pengyuan Shen
Buildings 2022, 12(2), 129; https://doi.org/10.3390/buildings12020129 - 26 Jan 2022
Cited by 2 | Viewed by 2043
Abstract
The unique climate in cold plateaus leads to long and cold winters, which result in the characteristics and creation of an indoor thermal environment different from that of plain areas. However, there is a lack of detailed research on and evaluation of indoor [...] Read more.
The unique climate in cold plateaus leads to long and cold winters, which result in the characteristics and creation of an indoor thermal environment different from that of plain areas. However, there is a lack of detailed research on and evaluation of indoor temperature distributions. This study took an office building in Lhasa as an example to study the indoor non-uniform temperature distributions with radiator and solar radiation. The indoor and outdoor thermal environment parameters were tested. Next, a numerical model was established and verified. On a typical winter weather day, although the average indoor air temperature and radiation temperature in Lhasa are higher than those in Beijing (both are cold areas), the temperature in both is lower than comfortable levels. The indoor vertical air temperature differences are below 3 °C, with a 5% dissatisfaction most of the time. Solar radiation and radiators seriously affect the uniformity of the indoor thermal environment. The radiation asymmetry in Lhasa is significant, and the maximum radiation temperature asymmetry can reach 8.73 °C. In addition, the setting of north-facing windows should be avoided as far as possible in Tibetan areas. Suitable design and evaluation standards should pay attention to the obvious phenomenon of uneven indoor temperature distribution. Full article
(This article belongs to the Special Issue Thermal Comfort in Built Environment)
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