Thermal Environment In Summer Research Articles

Field Investigation on Adaptive Thermal Comfort in Rural Dwellings: A Case Study in Linyi (China) during Summer

A large number of people in China still live in rural villages. The indoor environment of these rural dwellings directly affects the quality of life of the occupants. Nevertheless, constrained by the quality of dwelling construction, rural buildings have poorer indoor environments and, at the same time, have a higher operating energy consumption. However, inadequate attention has been given to the summer thermal environment in cold regions. This work has been carried out around the thermal environment of rural residences in cold regions during summer. Field measurements, questionnaires, and data analysis were used in this study. We recorded the indoor and outdoor thermal environment parameters on a typical summer day in the Linyi rural area. Moreover, the subjective sensations and thermal adaptive behaviors of the participants were recorded in detail with a questionnaire. Linear regression showed that the neutral temperature for residents in summer was 27.52 °C, with acceptable temperatures ranging from 25.14 °C to 29.9 °C. Age and gender differences were found to affect the occupants’ sensation of thermal comfort and humidity, as well as their thermal adaptive behavior. In addition, a thermal adaptive model has been constructed in the study, which will further enrich the thermal adaptive investigation and provide a scientifically sound reference for the renovation and development of the local rural areas.

Simulating the 3D Distribution of Absorbed Shortwave Radiation in a Tree Crown: Comparison of Simplified and Monte Carlo Models

AbstractUrban trees are expected to alleviate severe thermal environments in summer. The absorbed shortwave radiation is a key variable to estimate the microclimatic effects of trees. In numerical simulation tools for the urban and built thermal environment, the difficulty lies in how to calculate the absorbed radiation in terms of accuracy and computational load. Here we investigated the difference between a radiative transfer model calculating scattering by the Monte Carlo method and a simpler model that accounts for scattering by modifying the optical depth. The calculations of absorbed radiation were performed under various conditions of leaf normal distribution and zenith angle of incident radiation, using tree models represented by voxels with different leaf area density values. For the photosynthetically active radiation, the relative difference between models was less than 10% for most cases. For the near‐infrared radiation, the difference was also small for a large canopy consisting of several trees. The difference was 30%–60% and 0%–20% for zenith angles of incident radiation of 0° and 60°, respectively, for small isolated trees with a crown height and width of less than 5 m, which was a significantly different condition from a uniform canopy. This large difference was related to the uniformity of the canopy and was explained by the transmittance from each voxel to the outside of the canopy. The present study enables us to evaluate the applicability of the simple model and correct the difference from the Monte Carlo model.

Influence of greenery configuration on summer thermal environment of outdoor recreational space in elderly care centers

Greenery can improve the outdoor thermal environment in elderly care centers during heat wave in summer. However, it lacks quantitative results and rules. This study investigated the summer outdoor thermal environment of four representative elderly care centers in Tianjin to establish the thermal demand of seniors. The different thermal effects of greenery types (GTs) were revealed in elderly care centers. To improve the quality of the outdoor recreational space, this study utilized numerical simulation to quantitatively establish the influence of tree-shrub coverage rate (TSCR) on the thermal comfort of seniors. The results showed that the thermal neutral physiologically equivalent temperature (PET) of elderly people was 27.0 °C in summer, and the thermal acceptance range of PET was 23.6–36.8 °C. Shrubs overall could significantly increase the tree's ability to improve the outdoor thermal environment. Furthermore, this study proposed different TSCR strategies. TSCR of the elderly care center should be greater than 31.5% to obtain great thermal acceptance for the elderly in summer; when the TSCR of the elderly care center could not reach 31.5% due to the reality, TSCR = 10.0% was the efficient strategy to improve outdoor thermal comfort. This research provided a scientific reference for the greenery configuration plan of elderly care centers in summer.

Experimental and numerical study on thermal performance of phase-change-material cool roofs in summer

Cool roofs can reduce building energy consumption and improve indoor and outdoor thermal environments. A phase change material cool roof (PCMC roof) was proposed in order to reduce roof heat gain in the indoor thermal environment in summer. Indoor thermal and energy environmental parameters in three full-size rooms (ordinary room, PCM room, and PCMC room) were tested from July to September 2022. The heat transfer characteristics and energy saving effect of roofs were investigated by combining experimental analysis with numerical analysis. Compared with the ordinary roof, the PCMC roof decreased external and internal roof surface real-time temperatures up to 30.0 °C and 6.4 °C respectively, and reduced the roof inner surface heat flux of 33.3%-66.7%. Compared with the relevant roof studies, the energy saving and cooling effects are more significant. Then, based on the mathematical model of roof heat transfer, the correlation analysis between seven different elements was carried out to evaluate the energy-saving effect of PCMC roof. This study investigates the PCMC roof from the aspects of roof heat transfer characteristics, influence on indoor thermal environment, energy saving evaluation, etc., which provides a more complete and valuable reference for advancing building roofs.

Comparison of the influences of different ventilation corridor forms on the thermal environment in Wuhan City in summer

The ventilation corridor is an essential element in urban planning and design to improve the climate and environment. In this paper, four forms of two ventilation corridors were set up in the southeast of Wuhan City based on its urban planning outline to quantitatively study the influences of different ventilation corridor forms on the urban thermal environment in summer. The urban micro-meteorological environment was simulated using the next-generation mesoscale Weather Research and Forecast (WRF) model coupled with an urban canopy model (UCM). Critical time-dependent meteorological values were extracted and plotted, including temperature and wind difference fields, average temperature at 2-m height, average wind speed at 10-m height, and surface energy flux. By conducting a comparative analysis of the quantitative results, the ventilation corridors in construction land are arranged at intervals in the upwind position of the city in summer, which can slightly adjust the thermal environment of the central area of the city, and have an effective regulation on the temperature of the corridors and surrounding areas during the daytime. Especially at 15:00 pm when the temperature is at its highest during the day, the temperature can be reduced by 0.8 °C. Compared to other corridors, the wind speed in and around the corridor is the strongest 11 h a day. Due to the internal arrangement of construction land, this corridor form is more advantageous in the urban land utilization. After considering comprehensively, the ventilation corridor form with construction land arranged at intervals is the preferred corridor form in the southeast of Wuhan. The experimental results can provide quantitative reference for the layout of ventilation corridors in hot inland cities located in central China.

Differences in the evolution of urban and rural surface thermal environment and their responses to urban renewal in Shanghai, China.

The rapid and extensive urbanization has profound impacts on urban thermal environment. It is of great significance to comprehensively understand how urbanization affects the evolution of urban thermal environment for urban ecological safety, environmental quality, and residents' health. Based on daily land surface temperature (LST) products of MODIS Aqua satellite in the summer of 2002-2020, we investigated the evolution of urban-rural differences in surface summer thermal environment in Shanghai during 2002-2020 and its response to urban spatial renewal. We used normalized land surface temperature (NLST) and urban heat island ratio index (URI) as the surface thermal environment measurement indicators, by combining vegetation index and impervious surface cove-rage, and used M-K trend analysis and interpretation analysis. The results showed that the linear growth rate of LST in Shanghai was 0.09 ℃·a-1 (2002-2020), and that URI showed a trend of first increasing (2002-2010) and then decreasing (2010-2020). The mean summer LST was generally in the order of urban core>suburban>rural. 1.6% of the areas showed a significant cooling trend, of which 54.0% were distributed in the urban core. 39.5% of the regions showed a significant warming trend, of which 77.6% were distributed in the suburban. In general, there were concentrated significant cooling areas in the highly urbanized urban areas, while there was a significant warming trend in the suburban. The transformation from urban expansion to urban renewal was the main reason for the emergence of concentrated and significant cooling areas in the urban. Nearly 20% of the urban area showed a signi-ficant increase of vegetation coverage. Urban renewal projects such as gathering vegetation or dispersing impervious surfaces in highly urbanized areas are important ways to effectively improve the urban residential thermal environment.

Optimization of Atrium Thermal Environment in Summer Based on DeST Platform

The indoor environment simulation and optimization of atrium buildings are a research hotspot in the field of architectural technology. This article presents linear atrium buildings as the research object, introduces DeST simulation technology into thermal environment analysis, and studies the dynamic conditions and typical day time, the atrium itself structure, the structure of the rooms around the atrium and the thermal environment of the atrium space and its adjacent rooms. In the research process, two modes of natural ventilation and air conditioning were considered, and the optimal atrium building structure parameters under different outdoor weather conditions were obtained. The research results show that in natural ventilation mode, the thermal comfort temperature is the best when the atrium’s aspect ratio is 1.71; when using the air-conditioning mode, the air conditioning load is the smallest when the atrium’s aspect ratio is 1.55. In summer, the thermal environment of the linear A-shaped atrium is better than the H-shaped atrium. When the atrium window hole position is about 0.9 ∼ 1.5 m, the thermal environment is comfortable and energy saving.

Evaluating summer thermal environment of temporary housing unit adapting the layout plan, “Kumamoto Type D”

AbstractIn Japan, natural disasters have historically caused massive damage, and the importance of emergency temporary housing is increasing. In this paper, the summer thermal environment at the Shirahata temporary housing site in Kousa Town was assessed. The site was constructed following the 2016 Kumamoto Earthquake. The site was improved by applying a design methodology called “Kumamoto Type D,” “D” stands for “Default & Design.” Field measurements and computational fluid dynamics simulations were conducted to investigate the influence of the building arrangement on the outdoor thermal environment for the Kumamoto Type D layout. The results indicated that the impact of wind was reduced using this layout. However, when the surface temperature in the parking lot and other areas increased, hot air could be transmitted to the site, even under reduced wind conditions.

Analysis of Thermal Environment of Waterfront Space in Summer in Mountain City: A case study in Chongqing, China

A crucial component of the urban ecology, waterfront space plays a key role in mitigating the urban heat island effect. However, waterfront spaces in mountain cities differ greatly from those in plain cities in terms of spatial form and environmental factors. Accordingly, it is urgent to study and improve the thermal environment of waterfront spaces in mountain cities. According to the spatial morphological characteristics and shading means of the waterfront space in Chongqing, a typical mountain city in China, the summer thermal environment of the waterfront space has been studied through field measurements. The outdoor thermal environment factors assessed include air temperature, relative humidity, wind speed, and mean radiation temperature. The results showed that the cooling effect was more significant at 1 m from the water's edge and decreased as the elevation increased. Air temperature and humidity showed a clear stratification characteristic with increasing elevation. At the same time, viaduct-shading was the most effective way of reducing heat stress, followed by the combined shading of sun sails with building-shading, while tree-shading was the least. This study offers basic data for further study and optimization of shading strategies for waterfront spaces in mountain communities.

Analysis of Heat and Moisture Transfer and Thermal Comfort in Green Logistics Storage Space

Regular logistics storage spaces suffer a very high temperature during summer. To build a green logistics storage space, it is truly necessary to optimize the thermal environment in summer. At present, there are few related studies on the energy consumption, thermal environment and human comfort of green logistics storage spaces. Therefore, this paper analyzes the heat and moisture transfer in and studies the impacts of the thermal environment of green logistics storage space. Based on the survey results, a coupled heat-moisture transfer model of green logistics storage space was constructed, which consists of three parts - the envelope structure, the hot and humid indoor environment, and the heating, ventilation and air conditioning (HVAC) system. Based on the idea of linear regression, a model was established to predict human body’s subjective thermal sensation in green logistics storage space. The experiment showed the analysis results of heat and moisture transfer and thermal comfort in green logistics storage space, and verified the effectiveness of the proposed model.

An innovative fan control strategy aimed at responding to human physiological characteristics for comfort sleeping

• Comfortable air speed interval of the fan under 6 operating conditions. • The trend of the skin temperature during sleep can be divided into 5 stages. • The dynamic air supply control strategy of fans can improve people's sleep quality. A comfortable sleeping environment can improve sleep quality. Electric fans are widely accepted as an effective method in South China to improve the thermal environment in summer when people are sleeping. To determine the proper fan control strategy under the all-night blowing mode, pre-sleep and during-sleep experiments were performed in a climate room. Under 6 operating conditions (28/30/32 °C, 50 %/80 % RH), subjective sensations (thermal sensation votes and sleep quality indexes) were recorded and objective physiological parameters (brain waves and skin temperature) were monitored. The results showed that the comfortable air speed interval before sleep was 0.15–1.44 m/s. The skin temperature showed a clear trend of first rising, then falling, stabilising, rising again, and finally rising with fluctuations throughout the night. Based on the characteristics of physiological parameters in different sleep periods, the sleeping time was divided into 5 stages to perform linear regression, and a dynamic air supply control strategy for fans that imitated the circadian rhythm of sleep was proposed. Compared with steady-state blowing, the sleep efficiency and proportion of deep sleep under this optimisation control strategy increased by 3.24 % and 3.59 %, respectively. This study provides a reference for fan control in a sleep environment.

Influence of tunnel ventilation on the indoor thermal environment of a poultry building in winter

Tunnel ventilation systems are widely used to create thermal environments for poultry buildings in China. However, existing research mainly focuses on the indoor thermal environment in summer and rarely considers the winter season. A field test was conducted in a layer breeder building in Handan City, China to systematically investigate the characteristics and problems of the thermal environment in winter. Forty-two measuring points were set to analyze the indoor air velocity and temperature distributions, and the nonuniformity coefficient and temperature humidity velocity index (THVI) were adopted as the evaluation indices. Furthermore, the exhaust fan layout of tunnel ventilation was explored to improve the indoor thermal environment using a validated computational fluid dynamics (CFD) method. The results show that (1) the indoor air velocity distribution is quite nonuniform with a nonuniformity coefficient of 0.74, the maximum difference of which is as large as 0.62 m/s; (2) the nonuniformity coefficient of indoor air temperature distribution is 0.16, and the maximum temperature difference is as large as 12.9°C; (3) the indoor THVI is below the appropriate range of 18–25, making the thermal comfort zone only 61.4%; (4) separately installing exhaust fans at the front and end walls with the symmetrical locations and sizes can improve the distribution uniformities of indoor air velocity and temperature by 22.0% and 88.3%, respectively. The experimental results and parametric optimization of tunnel ventilation in this study will be beneficial for designing an appropriate thermal environment for poultry buildings during winter. • The non-uniformity coefficient of air velocity in experimental poultry house is 0.74. • The maximum difference of air temperature in experimental poultry house is 12.9 °C. • The thermal comfort zone in experimental poultry house is only 61.4% of entire space. • Separately installing exhaust fans on front and end walls improves the environment.

Experimental and Numerical Analysis on Effect of Passive Cooling Methods on an Indoor Thermal Environment Having Floor-Level Windows

Natural ventilation is a common passive cooling method for improving air quality and thermal comfort; however, hot temperatures in summer and safety and privacy issues at night often result in its unideal performance. Therefore, we proposed the use of floor-level windows, mainly combined with microclimate improvement, to improve the indoor thermal environment by enhancing the cooling effect of natural ventilation during summer. Our study area was a house in Machida, Tokyo. We evaluated the effectiveness of our method in improving the indoor thermal environment in summer and performed a numerical simulation, while illustrating the detailed horizontal and vertical distribution of airflow in the house through the floor-level windows. The influence of different window types and opening angles of floor-level windows on ventilation and cooling was determined using the simulation. We found that: (a) natural ventilation-based passive cooling methods reduced semi-outdoor and indoor temperature and increased the humidity; (b) the airflow formed an indoor wind path; south-westerly inflow was from western floor-level windows and the skylight, and the outflow was from northern floor-level windows; and (c) the side hung windows (with an opening angle of 60°) were an ideal option to improve indoor airflow. However, there was no improvement in the passive cooling performance, due to the inflow of warmer outside air.

Quantifying the influence of 2D and 3D urban morphology on the thermal environment across climatic zones

Urban heat islands (UHIs) exert a substantially negative impact on human health and urban sustainability. The role of two-dimensional (2D) landscape patterns in UHIs are well documented; while the effects and contributions of three-dimensional (3D) urban structures remain unclear, especially across different climatic zones. Here we investigated the relationship between 2D/3D urban morphology and the urban thermal environment in summer and winter during the day and at night in 62 representative large cities across four major climate zones in China. First, we extracted the seasonal surface regional heat island intensity (SRHII) using the MODIS 8-Day land surface temperature product. Subsequently, we constructed 25 2D and five 3D urban features and explored their relative importance and respective roles in UHIs in different climatic contexts. Results show that: (1) significant differences (p < 0.05) exist in SRHII between various climate zones; cities with a humid subtropical climate experience temperatures approximately 2 °C higher during the day in summer compared to those with the other climate types. (2) 3D urban features can effectively improve the interpretation of urban features for SRHII, with an average optimization level of 21%. (3) Urban trees have a higher cooling effect than other green spaces, whereas tall buildings can also reduce the UHI effect. (4) On summer days, equal proportions of tree to building volume provide the greatest cooling effects. This study provides new insights into the effect of 3D urban characteristics on SRHII and has promising implications for climate resilience planning and heat-related risk management

Dominant Factors in the Temporal and Spatial Distribution of Precipitation Change in the Beijing–Tianjin–Hebei Urban Agglomeration

Urbanization has a significant influence on precipitation, but existing studies lack the spatial and temporal heterogeneity analysis of its impact on precipitation in urban areas at different levels. This study investigates the spatial heterogeneity of precipitation and the influencing factors on six dimensions in 156 urban areas in the Beijing–Tianjin–Hebei urban agglomeration from 2000 to 2018, utilizing a mixed-methods analytical approach. The results show that the change in the natural factor layer caused by urbanization was the most important factor, affecting urban precipitation variation in summer and over the whole year, accounting for 34.5% and 10.7%, respectively. However, the contribution of the urban thermal environment in summer cannot be ignored, and the change in the urban thermal environment caused by human activities in winter is an important influencing factor. When considering the optimal combination of factors, relative humidity was shown to be significant in the spatial variations in precipitation during summer, which contributed 26.2%, followed by human activity as indicated by night-time light intensity. Over the whole year, aerosol optical depth makes the substantial contribution of 21.8% to urban precipitation change. These results provide benchmarks for improving the adaptability of urban-environment change and urban planning in the context of urbanization.

Green Space Cooling Effect and Contribution to Mitigate Heat Island Effect of Surrounding Communities in Beijing Metropolitan Area.

With the rapid process of urbanization and global warming, many metropolises are vulnerable to high temperatures in summer, threatening the health of residents. However, green spaces can generate a cooling effect to mitigate the urban heat island effect in big cities. They can also help to improve the living quality and wellbeing of surrounding residents. In this paper, we utilized the radiative transfer equation algorithm, k-means clustering algorithm, big data crawling, and spatial analysis to quantify and map the spatial distribution, cooling capacity, and cooling contribution for surrounding communities of 1,157 green spaces within Beijing Fifth Ring Road, a typical metropolitan area. The findings showed that (1) the area proportion of the heat island in the study area is larger than that of the cooling island. Accounting for only about 30% area in the study area, the green spaces reduce the average land surface temperature by 1.32°C. (2) The spatial features of green space, such as area and shape complexity, have a significant influence on its cooling effect. (3) Four clusters of green spaces with specific spatial features and cooling capacity were identified. And there were differences among these clusters in green space cooling contribution for the surrounding communities. (4) The differences in green space cooling contribution also existed in different urban zones. Specifically, the middle zone performed significantly better than the inner and outer zones. (5) We furthered in finding that some green spaces with medium and high cooling contributions need to improve their cooling capacity soon, and some green spaces with low cooling contributions or no contributions have a good potential for constructing new communities in the future. Our study could help planners and government understand the current cooling condition of green spaces, to improve their cooling capacity, mitigate the urban heat island effect, and create a comfortable and healthy thermal environment in summer.

A numerical study on applying the movable PCM design to disaster‐relief prefabricated temporary houses used in different climate regions to improve indoor thermal environments in summer

Prefabricated temporary houses (PTHs) are extensively used for temporarily accommodation disaster victims. However, the thermal environment inside PTHs can be intolerable in summer. Previous related studies showed the success of applying a movable phase change material (PCM) design to PTHs for improving indoor thermal environments in Chengdu, China; it only represented the “warm temperate-fully humid-hot summer” climate. Since various natural disasters may occur around the world, it became necessary to study the effectiveness of applying the movable PCM design to PTHs installed in other climate regions globally. Therefore, following the previous experimental and numerical studies where only one climate condition was considered, in the current article, a numerical study is reported on applying the movable PCM design to PTHs in 12 selected cities in different climate regions to improve their indoor thermal environments in July. The results from the numerical study showed that, in all the 12 selected cities in July, after introducing the movable PCM design to the PTHs, both the maximum indoor air temperature, the monthly averaged air temperature inside the PTHs, the daily peak and daily average indoor air temperature on the hottest day were lowered. It was further demonstrated that on the hottest day in July, the difference between the daily peak air temperature values inside the disaster-relief PTH with and without incorporating the movable PCM design varied from 2.12°C to 5.34°C, and that between the daily air temperature values varied from 1.53°C to 3.56°C. In all the 12 selected cities, although applying the movable PCM design to disaster-relief PTHs in July was functional, it was more effective for the following seven cities, that is, Singapore, Miami, Bangkok, Chengdu, Damascus, Hanoi, and Urumqi (with Δ $$ \Delta $$ values being not less than 300°C·h and Δ ′ $$ \Delta^{\prime } $$ being not less than 46%), with six of the seven cities located in both tropical and temperate climate regions, based on the evaluating criteria proposed in this article.

Assessment of the Mechanisms of Summer Thermal Environment of Waterfront Space in China’s Cold Regions

Water is an essential part of the urban ecosystem and plays a vital role in alleviating urban heat island (UHI) problems. The contribution toward UHI mitigation made by bodies of water needs to be ascertained to establish waterfront thermal environment construction standards. In this study, the thermal environment of the waterfront space of Tianjin in the cold regions of China was the research object. Through a survey including 141 valid questionnaires and the field measurement of four typical waterfront spaces in Tianjin, the thermal demand characteristics of recreational use for the waterfront environment and the influence of water on microclimate are discussed, supplemented by results from low-altitude infrared remote sensing technology, which was mainly used to obtain a wider range of infrared thermal images with higher accuracy. To improve the urban heat island effect and the quality of the ecological environment, this paper used outdoor thermal environment simulation software to quantitatively analyze the thermal environmental impact of outdoor public activity spaces around the representative urban body of water and proposes the optimization scheme of the waterfront space’s thermal environment. The results show that, based on the factors of water itself, the most economical water width was 70–80 m, and the cooling effect intensity of water had an essential correlation with the distance between the measured site and the water center. In terms of the environmental factors around the water, when the green lawn of the waterfront space was 12 m and the water shore’s geometric form was S-shaped, this could improve the cooling effect of water significantly. Waterfront activity spaces should focus on thermal comfort on the east and south water shores. It is expected that this study could provide practical implications and useful guidance for the planning and design of urban waterfront space in China’s cold regions.

Coupling mechanism of water and greenery on summer thermal environment of waterfront space in China's cold regions

Water and greenery space is an essential part of the urban ecosystem and plays a vital role in alleviating the urban heat island effect. Water and greenery differently affect the urban microclimate. After coupling the two factors, the quantitative human thermal environmental experience analysis needs to be revealed. This study investigated the thermal environment of the waterfront space with the greenery of Tianjin in the cold regions of China. Different types of microscale water were analyzed to evaluate their thermal environment in summer using subjective and objective analysis and model simulation. We concluded the coupling mechanism of waterfront greenery and thermal evaluation standard. The results show that water and greenery's coupling effect peaked at 14:00 and waterfront at 4–8 m. Conversely, the cooling effect was more significant at 3–6 m from the water's edge, where the location was suitable for construction as verified by the optimization model. The prerequisite of coupling mechanism was suitable green coverage rate and vegetation type, based on the comprehensive analysis of four cases. The objective effects of different waterfront distances on the thermal comfort of Heat Index (HI) and the subjective evaluation of Universal Thermal Climate Index (UTCI) for people were quantified. This research provides a theoretical basis and data support for urban waterfront renewal in cold regions.

Environmental Effects from Pocket Park Design According to District Planning Patterns—Cases from Xi’an, China

Rapid urban expansion leads to the continuous deterioration of the urban thermal environment, which endangers the sustainable development of the city; meanwhile, countries all over the world are becoming increasingly interested in the mitigating effects of urban green spaces on heat islands. In this context, many studies show that pocket parks play an important role in optimizing the thermal environment of urban blocks, especially with the high-intensity development of urban blocks. Moreover, many cities in China have become mature, and it is difficult to open up large green areas. Therefore, to improve the urban thermal environment in summer, it is necessary to adapt to an efficient pocket-park design strategy in blocks. To consider the impact of block development intensity on the design strategy of pocket parks, three pocket parks in blocks with different floor-area ratios in the central area of Xi’an were selected as examples. This research compares the effects of tree density and green-space layout on the thermal environment in different floor-area ratio districts on a summer day using environmental simulation (ENVI-met). The results show that the design strategies of pocket parks in urban blocks with different development intensities are different. High tree density performs better from the perspective of improving the urban thermal environment. For the low and medium development intensity blocks, the effects of the open green space and closed green space are similar, while the open green space layout can significantly improve thermal comfort in high-intensity development blocks.