Microclimate Simulation Research Articles

A Study on the Summer Microclimate Environment of Public Space and Pedestrian Commercial Streets in Regions with Hot Summers and Cold Winters

Pedestrian commercial streets are an important part of a city. However, the open outdoor street is easily affected by the external climate, and a poor microclimate environment can indirectly affect the volume of visitors to the commercial street. This paper takes pedestrian commercial streets in regions with hot summers and cold winters as the research object in order to obtain reasonable prototypes of street space. Adopting the experimental method of controlling variables, microclimate simulation analysis is conducted on different street flow lines, various locations of open space, and the different greening arrangements of typical street spaces. This paper also proposes design strategies for improving the microclimate environment, such as reserving ventilation passages in the dominant wind direction, setting up air buffer areas to increase the “wind storage” effect, building an open space in the upwind direction to increase the “wind absorption” effect, preventing planar greening space from hindering airflow in streets with poor ventilation, and establishing planar green space in the upwind direction to increase the coverage of the cooling effect of plants. In this paper, comfort in the outdoor microclimate comfort is taken into consideration in commercial street design, aiming to achieve the revitalization of commercial streets through “micro renovation” and provide some reference for the future design of commercial streets.

Evaluating the impact of sky view factor and building shadow ratio on air temperature in different residential and commercial building scenarios: A case study of Beijing, China

The urban building morphology is one of the most important effects of urban thermal environment (UTE). The sky view factor (SVF) is a crucial structure index of buildings and it combines height and density attributes. These attributes have impacts on the air temperature(Tair). However, there are few studies on the association between SVF and Tair across block scales. In this paper, we designed ten scenarios according to the characteristics of Beijing's commercial and residential buildings. Furthermore, we used ENVI-met, a microclimate simulation model, to simulate the Tair in designed scenarios and evaluate the impact of SVF on the Tair of each component. A number of significant observations were noted based on the experimental results: (1) from 10:00 to 17:00, there is a positive correlation between SVF and Tair; from 18:00 to 9:00 the next day, there is a negative correlation between SVF and Tair (2) the relationship between building shadow ratio (BSR) and Tair is not a single negative correlation: at sunrise, BSR is the maximum in a day, but the cooling effect of BSR on Tair is not obvious because of the weak solar radiation. In addition, the arrangement of building directions has a great influence on the relationship between BSR and Tair (3) for the same building scenario, BSR decreases with the increase of SVF (4) the synergistic effect of SVF and BSR on Tair in the daytime can be divided into two periods, the separation time points are 7:00 and 14:00. This study can provide instructions for urban design in optimizing building layout and mitigating the urban heat impact on human health.

Quantitative Evaluation of the Effects of Heat Island on Building Energy Simulation: A Case Study in Wuhan, China

The climate data used for dynamic energy simulation of buildings located in urban regions are usually collected in meteorological stations situated in rural areas, which do not accurately represent the urban microclimate (e.g., urban heat island effect), and this might affect the simulation accuracy. This paper aims at quantitatively evaluating the effects of heat island on a high-rise building’s energy performance based on the microclimate simulation tool ENVI-met and the building energy simulation tool COMFIE. However, the computation of microclimate models is time consuming; it is not possible to simulate every day of a year in a reasonable time. This paper proposes a method that generates hourly “site-specific climate data” to avoid long microclimate simulation times. A coupling method of ENVI-met and COMFIE was developed for more precise building energy simulation, accounting for the heat island effect. It was applied to a high-rise building in Wuhan, China. The results showed that the yearly average urban heat island effect intensity at the height of 3 m was estimated to be 0.55 °C and decreased with height. Compared to the simulation considering the outdoor temperature variation with the height and orientation, using the original climate data collected in rural areas led to an overestimation of the heating load by around 5.8% and an underestimation of the cooling load by around 8.7%. Compared to the weather file at the height of 3 m near the north facade neglecting the temperature variation along the height, the heating load was overestimated by 8.2% and the cooling load was underestimated by 10.8%. The methods proposed in this paper can be used for the more precise application of urban building energy simulation.

Improving the Climate Resilience of Urban Road Networks: A Simulation of Microclimate and Air Quality Interventions in a Typology of Streets in Thessaloniki Historic Centre

The improvement of the urban microclimate in the densely-built central areas of Mediterranean cities should be a key objective of integrated urban and transport planning and design in accordance with the UN Sustainable Development Goals on energy, sustainable cities, and climate action. The urban climate of cities in warm regions, already burdened by the urban heat island effect, is expected to worsen further due to the global climate crisis. This study investigates the performance of common environmental street design strategies on microclimate, thermal comfort, and air quality under extreme heat conditions in the Mediterranean city of Thessaloniki, Greece. A typology of streets was selected using criteria such as road functional classification and orientation, land uses, building height/street width ratio, the sky view factor, and the continuity/discontinuity of buildings. A conservative scenario (use of cool/photocatalytic and porous materials for sidewalks, lighter pavements, additional tree planting, installations of green roofs) and a radical scenario (pedestrianization and total traffic prohibition) of environmental design interventions were simulated using the ENVI-met 5.1 software. The research findings demonstrated that the car-free interventions combined with the use of environmentally friendly materials in the public realm could significantly reduce the heat island effect and mitigate gaseous pollutants. The perceived air temperature (Physiological Equivalent Temperature—PET index) can decrease by up to 15 °C in well-shaded locations and near building corners, while nitrogen oxides can be reduced by up to 87% when considering a more radical pedestrianization scenario. The standardization of environmental interventions following a typology of urban streets could support planners and decision-makers in detecting the appropriate solutions for improving the urban microclimate.

Experimental study on the influence of virtual tourism spatial situation on the tourists' temperature comfort in the context of metaverse.

The Metaverse is a new application of the internet and social form which integrates a myriad of new technologies. It can not only create a parallel space that is closely connected to the real world while highly independent, but also bring the immersive experience of virtual scenarios without delay. The virtual tourism space situations that integrate realistic visual, audio, and temperature sensations can restore the real tourism environment to the greatest extent, and improve tourists' perception and satisfaction with the experience. The purpose of this experimental lab study is to examine the effects of the virtual tourism audio-visual conditions and environmental temperature on tourists' thermal sensation and temperature comfort. VR equipment and microclimate simulation technology was applied in a 3 × 2 × 2 experimental design (n = 180), simulating the virtual tourism scenarios. Electrocardiogram devices were also employed to assess participants' physiological indicators. Study results suggest that: (1) Virtual tourism spatial situations (environmental temperature and audio-visual conditions) significantly affect participants' thermal sensation and part of the physiological indicators; (2) Virtual tourism spatial situations (environmental temperature and audio-visual conditions) significantly affect participants' temperature comfort; and (3) Physiological responses (indicators) mediate the effect from tourism spatial situations to temperature comfort. The study mainly contributes to the literature about virtual tourism experience and spatial situations under the concept of the Metaverse, as well as provides theoretical and managerial implications for the development of "immersive" virtual tourism scenarios.

Climate-resilient and resource-conserving architecture through renewable building materials and microclimate improvement

Due to climate change, together with the need to reduce the ecological footprint and the future resource shortages, a climate-resilient and resource-conserving architecture must be reinforced. Dealing with the issue of resources not only affects the materialisation of the building, but also the handling of resources on the building site. The interactions between the environment (sun, wind, precipitation), buildings, sealing, plants and people form a complex system in which small changes in few factors can influence the situation on a large scale. In this context, topics such as microclimate improvement around built infrastructure through greening and rainwater management, will gain in importance. The correct assessment of measures for a sustainable and resilient building is extremely complex and time-consuming and requires extensive, multi-layered know-how and experience. This paper analyses the project “House of Learning“ (MAGK Architekten) and its immediate surroundings and focuses on its climate resilience and neutrality, proposing improvement measures based on the interaction of blue and green infrastructure and the building. The potential favourable conditions are evaluated through microclimate simulations and planning principles implying an integral approach which includes landscape gardeners, building planners and constructors, as well as decision-makers.

Investigation of the thermal environment in schoolyards under Mediterranean conditions. Contribution to bioclimatic conditions improvement with the application of mild interventions – The case study of a school within the urban environment

This study aimed to examine the thermal environment in schoolyards under Mediterranean conditions, and the impact of two interventions on the amelioration on the bioclimatic conditions.The investigation was performed for three schools in Athens, Greece, through microclimatic simulations by ENVI-met, for a typical day in June, and was evaluated based on the air and surface temperature values. The bioclimatic index Physiological Equivalent Temperature (PET) was applied to evaluate the thermal comfort conditions.By that, the school under the most adverse thermal conditions was selected for the application of two interventions, which increased the greenery by 25% (Proposal 1) and 50% (Proposal 2). The surface coating material “safety floor slabs”, was selected to replace the others in both proposals.Through microclimatic simulations, the following results were obtained: “Proposal 1” caused a 2.3°C reduction in surface temperature, and a 4% reduction in PET values. ‘Proposal 2’ caused an 8.1°C reduction in surface temperature, and an 11% reduction in PET values. The cooling effect of ‘Proposal 2’ was double compared to ‘Proposal 1’, achieving a maximum air temperature reduction by up to 0.8°C. The cooling effect produced was limited to the areas affected by tree shade, leaving the unshaded areas almost unaffected.

녹지 조성 시나리오에 따른 도시 열환경 개선 효과 분석†

To alleviate the urban heat island phenomenon, this study aims to quantitatively analyze the effects of neighborhood green spaces on the improvement of the thermal environment based on detailed scenarios of five types of green spaces, including parks, pocket parks, parking lot greening, roadside planting, and rooftop-wall greening. The ENVI-met 4.4.6v model, a microclimate simulation program, was used to analyze the effects of green spaces. As a result, it was found that the air temperature decreased as the planting density of the park increased, but the thermal comfort index PET, which is the degree of heat sensation felt by humans, was not directly proportional to temperature. The establishment of a pocket park reduced air temperature up to a radius of 56m, while the range of temperature reduction increased by about 12.5% when three additional pocket parks were established at 250m intervals. Unlike the air temperature, PET was only affected in the vicinity of the planted area, so there was no significant difference in the thermal comfort of the surrounding environment due to the construction of pocket parks. Changing the surface pavement from asphalt to lawn blocks and implementing rooftop or wall greening did not directly act as solar shading but positively affected air temperature reduction; PET showed no significant difference. Roadside planting showed a higher air temperature reduction effect as the planting interval was narrower, but PET was not directly proportional to tree density. In the case of shrub planting under trees, it did not significantly affect the air temperature reduction but positively affected the improvement of thermal comfort. This study can outline strategies for constructing neighborhood green spaces to solve the urban heat island phenomena and establish detailed strategies for efficient thermal environment improvements.

Study on the Green Space Patterns and Microclimate Simulation in Typical Urban Blocks in Central China

This study attempted to classify blocks in the second ring road of Changsha, a central city of urban agglomeration in central China, according to their green space patterns, and to explore the influence of green spaces in different blocks on the surrounding microclimate. Researchers divided the blocks into five types: green space enclosed by buildings type, green space parallel with buildings type, green space centralized in buildings type, green space interspersed in the block type, and green space dispersed in the block type. Thermal comfort conditions in the different blocks were studied by ENVI-met simulations and using the thermal comfort indicators physiological equivalent temperature (PET), predicted mean vote (PMV), and standard effective temperature (SET). Because the green space was more evenly distributed in the block of green space parallel type and green space interspersed type, the overall fluctuation of the thermal comfort value of all areas of the whole block was small, with more areas having a value close to the median value of the thermal comfort value of the block. In the green enclosed blocks, thermal comfort was better within the green space in the area enclosed in the middle when the surrounding buildings were lower. The green areas in the green space enclosure type significantly improved the thermal comfort around the buildings, and the thermal comfort in the areas decreased rapidly as the distance between the green areas and the buildings increased. The green space dispersion type was found more in older blocks that were not well planned and had poor thermal comfort in the areas. On the premise that the green space area in the different high-rise blocks was equal, if only the thermal comfort of the green space coverage area was considered, in the summer, the green space parallel type was the best (|ΔPET| = 7.96, |ΔPMV| = 1.22). In the winter, the green space centralized type was the best (|ΔPET| = 11.26, |ΔSET| = 10.88). On the premise of equal green space area in the different multilayer blocks, if only the thermal comfort of green space coverage area was considered, in the summer, the green space parallel type was the best (|ΔPET| = 8.89, |ΔPMV| = 1.49). In the winter, the green space centralized type (|ΔPET| = 11.04, |ΔSET| = 10.64) was the best. This shows that different greening patterns have different advantages and disadvantages in different seasons and different situations.

The effects of shading devices on outdoor thermal and visual comfort in Southern China during summer

Shading effectively alleviates heat stress caused by heatwaves and urban heat islands. Artificial shading is a viable alternative to urban greenery when tree planting is impracticable. While tree shade has been studied extensively, the effects of shading devices on the microclimate and illuminance are not well understood. To examine the influence of shading devices on outdoor thermal and visual comfort, we conducted on-site meteorological observations and surveys (n = 1272) on a university campus in Guangzhou during the summer of 2018. In ENVI-met simulations, various shading device properties were compared, including materials, transparency, and size. Simulation results indicate that shading devices reduced mean radiant temperature, Physiological Equivalent Temperature (PET), and Universal Thermal Climate Index (UTCI) up to 24.8 °C, 12.0 °C and 5.9 °C, respectively. However, there was a negligible reduction in air temperature and wind speed. Opaque materials and glass covers with 10% transparency decreased illuminance by 73%–83% and 65%–75%, respectively. Moreover, the size threshold for optimal cooling effects differs in locations with different sky view factors and tree shade. Our survey reveals that reducing the illuminance by > 90,000 lux and sun sensation vote from +2.5 to +1 can lower the thermal sensation vote by up to one vote. As shading devices decrease illuminance and thermal indices, the cross-modal effect between visual and thermal comfort would need to be considered in optimizing the design of shading devices. Further observation and numerical simulation of outdoor microclimate and illuminance are necessary to validate this cross-modal effect in other climatic regions.

Machine learning-based evaluation of dynamic thermal-tempering performance and thermal diversity for 107 Cambridge courtyards

The dynamic thermal conditions profoundly impact on the quality of physical, cultural, and social experiences in courtyard spaces. This research aims to identify the microclimatic dissimilarities between courtyards in terms of tempering seasonal–diurnal thermal extremes and enriching ground-level thermal textures. The methodology included field measurements in summer-2021 and winter-2022 in Cambridge, UK; microclimatic simulations of 107 courtyards in ENVI-met and model validations; and machine learning-driven clustering using Super Organising Maps (SuperSOM). The results indicate that the diurnal thermal range of the spatial-UTCI mean in summer (DTR(M)<24∘C) is double that in winter (DTR(M)<12∘C); meanwhile the maximum spatial-UTCI deviation is three times as significant (δ>3∘Cat 7:00 BST versus δ>1∘Cat 12:00 GMT). SuperSOM analysis was performed using K-means and hierarchical agglomerative clustering to partition all courtyards into seven subclusters on its graph-lattice structure. Clusters Km_I, Hac_I, and Hac_IV feature a positive synergy between the thermal-tempering and thermal-enriching potentials. In contrast, the other four clusters exhibit conflicting scenarios during the day and night across the two seasons analysed. These data-driven outcomes enabled us to optimise spatial and landscape strategies for designing and retrofitting courtyard microclimates, contributing to the current discussions on climate-responsive and sensation-inclusive design in historical urban contexts.

Evaluation of a novel WRF/PALM-4U coupling scheme incorporating a roughness-corrected surface layer representation

In this study we conduct realistic urban microclimate simulations using a multiscale approach that couples the PALM-4U microscale model to the WRF mesoscale model. The coupling is achieved by a one-way forcing of the initial and boundary conditions of the microscale model with data interpolated from the mesoscale model. To improve upon similar studies, our approach applies the roughness-corrected Monin–Obukhov similarity theory to fill the gap in the mesoscale results between the first model level and the ground. To assess the improvements of the coupled approach, we compare it to the standalone mesoscale simulation as well as to DWD measurements. Furthermore, the impact of the mesoscale model setup is investigated by comparing different inner domain grid sizes, coupling time steps, and urban parameterizations in an urban district of Berlin for a total of six different mesoscale setups. The comparison of the WRF mesoscale and PALM-4U microscale results indicate that the microscale results, in most cases, follow the mesoscale forcing and hence the microscale accuracy depends on the mesoscale setup. A comparison of simulations to measurements shows that the PALM-4U results tend to have a better agreement with measured data than the WRF results, in most but not all cases. It is also found that one mesoscale forcing setup may lead to better temperature accuracy of PALM-4U results while another one leads to better wind accuracy of PALM-4U results. However, the best overall results for temperature, mixing ratio and wind speed are achieved when forcing PALM-4U by the WRF multi-layer urban canopy model setup. Finally, decreasing the coupling time step from 1 h to 10 min or refining the WRF horizontal grid from 2 km down to 0.4 km do not lead to a significant improvement of PALM-4U simulation results. In all of the investigated cases, the PALM-4U results were sufficiently close to measurements to validate the coupled model approach.

EVALUATING THE PERFORMANCE OF HIGH LEVEL-OF-DETAIL TREE MODELS IN MICROCLIMATE SIMULATION

Abstract. Present urbanization influences urban morphology by the increasing number of dense buildings and infrastructure, which effects climate change. Microclimate simulations including urban vegetation help in mitigating climate change. Most of existing microclimate simulations simplify trees and thereby may introduce some erroneous estimates. Tree models of high levels of detail (LOD) can provide a more accurate measure. Technology advances make it possible to reconstruct detailed tree models, which can be further used in microclimate simulations. However, the few studies presenting detailed tree models focus predominantly on the reconstruction process and omit the microclimate simulations. The objective of this study is to investigate high LOD tree models in microclimate simulation to estimate the potential gain in accuracy. This study focuses on voxel-based tree models and microclimate simulations using computer fluid dynamics software. A series of microclimate simulations are completed in two scenarios, which are single tree and a set of trees with buildings. Based on the simulation results, the advantages of detailed voxel tree models are demonstrated. Final discussion elaborates on the needed and preferred levels of detail for tree models.

Building Energy Simulation Model Application to Greenhouse Microclimate, Covering Material and Thermal Blanket Modelling: A Review

This review documents the present knowledge and knowledge gap in applying building energy simulation (BES) dynamic models to greenhouses. The focus of this review is to compile the literature on the BES dynamic model of greenhouse microclimate, covering materials, energy requirements and thermal blankets using the Transient System Simulation version 18 (TRNSYS 18) software. Fifty-two journal articles, mostly Science Citation Index (SCI) and Scopus index journals, on BES development and simulation of greenhouse microclimate, greenhouse energy requirement, covering materials and thermal blankets were reviewed. These researchers sought to optimise greenhouse crop production. The main features of the TRNSYS 18 software for BES development are outlined; each research consulted for this review successfully developed, simulated and validated its BES. However, none of these developed models included the vapour pressure deficit (VPD) as a greenhouse microclimate factor, an essential climate parameter. In conclusion, this study demonstrates that applying a BES developed using TRNSYS has excellent potential to optimise greenhouse crop production and help adapt appropriate climate control strategies and energy-saving techniques. However, it is recommended to include VPD in future BES model development.

Identifying urban morphological archetypes for microclimate studies using a clustering approach

Urban morphology relates to the form, structure, physical characteristics, and arrangement of buildings affecting the urban microclimate. As the morphological characteristics vary across the city, small units such as urban blocks are analysed for microclimate estimation. However, microclimatic analysis of all the blocks in a city is computationally challenging and time-consuming. Therefore, it is vital to identify representative blocks in a city to obtain a general overview of the microclimate. Urban morphological archetypes are the representative units of a homogenous group of blocks based on morphological parameters. Here, we propose a systematic approach for identifying urban morphological archetypes suited for microclimatic analysis. Specifically, we employ a well-defined, PCA-based k-means clustering approach supported by validation using external criterion analysis. We use urban morphological parameters based on form, shape, arrangement, and variations within a block in Liege, Belgium. We use the cubic clustering criterion and pseudo F statistic to identify nine distinct homogenous clusters. Then, we propose a validation approach in the absence of existing typologies using ANOVA analysis on the external criterion of land surface temperature, a proxy for measuring microclimate. The validation suggests that the clusters are significantly different, indicating successful clustering. We also compare our classification to the existing local climate zone (LCZ) classification. We identify relevant sub-classes within the broader LCZ classes essential for capturing microclimatic variation. Finally, the study provides realistic archetypes for performing microclimatic simulations at a city scale. The proposed approach can be effectively applied to other cities for urban microclimate studies.

Detailed Mapping and Modeling of Urban Vegetation: What Are the Benefits for Microclimatic Simulations with Town Energy Balance (TEB) at Neighborhood Scale?

Abstract Cities develop a specific climate related to their morphology and the materials that constitute them. The addition of vegetation in urban areas induces cooling and shading effects that can modify local climate and thermal comfort conditions. The Town Energy Balance (TEB) urban canopy model offers several configurations for a more or less fine-tuned consideration of natural covers and associated physical processes in the urban environment. This study aims to evaluate the sensitivity of TEB to the representation of vegetation and the resolution of the chosen databases in the simulation of microclimatic variables, at the scale of a heterogeneous urban neighborhood located in Toulouse, France. First, the effect of the improved description of the vegetation input to the model is highlighted by comparing the results obtained with a readily available national database and then with a very-high-resolution satellite-derived vegetation database. Second, the two vegetation parameterizations, with or without explicit tree stratum, that are available in the TEB model are evaluated and compared. Measurements carried out on specific routes and stop points in a neighborhood of Toulouse allowed microclimatic variables to be evaluated. Results show that refining the vegetation database can somehow improve the modeling of air temperature. As a result of enhancing the vegetation description in the model, that is, physical processes associated with the presence of trees in urban canyons, the air temperature, but also the wind and the thermal comfort index, are better simulated. These results are encouraging for the use of TEB as a decision support tool for urban planning purposes.

Simulation Tools for the Architectural Design of Middle-Density Housing Estates

Temperatures in every Mediterranean city are increasing due to the effects of climate change, with a consequent increase in extreme events. A previous study of French holiday housing designed during the glorious 1930s allowed us to characterize the environmental performance of four additive morphologies. Starting from in situ measurements during a typical summer day and numerical simulations, the goal of this study is to analyze the influence of two calculation methods used in microclimate simulations on the architectural design process. The results are interpreted through the mean radiant temperature and the Physiological Equivalent Temperature, hour by hour in one day, at six different places in a public lane. This work allows us to explore the use of simulation tools for the development of middle-density housing estates to improve outdoor thermal comfort in summertime.

Planning scenarios and microclimatic effects: The case of high-density riverside residential districts in Seoul, South Korea

Water bodies, such as rivers, ponds, and lakes, act as natural landscape resources to improve the urban microclimate. However, the cooling effects of water bodies may be lessened as a result of poorly planned buildings along the waterfront due to the “wall effect.” This research aimed to investigate the microclimate impacts of the following three strategies typically used in waterfront development: 1) building height restriction, 2) ventilation corridors, and 3) stepped building height variation. To compare the microclimate change after applying each strategy, we calculated the air temperature, wind speed, mean radiant temperature, and thermal comfort using the numerical simulation with microclimate simulation software, ENVI-met. The results showed that each strategy led to different microclimate patterns. The restriction on building height had a negative impact on the microclimate, increasing the physiological equivalent temperature by up to 1.34 °C. In contrast, the ventilation corridor provided a moderate cooling effect during the afternoon. Lastly, the stepped building height variation strategy did not have an effect on thermal comfort. The results suggest that the microclimate-related strategies for waterfront development did not always contribute to the improvement of thermal comfort; thus, additional heat-mitigation solutions are needed.

A numerical study of cool and green roof strategies on indoor energy saving and outdoor cooling impact at pedestrian level in a hot arid climate

Green and cool roofs retrofit technologies, aim to mitigate the urban heat island effect and cooling energy demands from buildings. This study reports on parametric energy modelling of energy saving loads and indoor air temperature, as well as microclimate modelling of outdoor air temperature. The work adds new knowledge by evaluating roof retrofit technologies at the building and neighbourhood scale, and the results should guide strategic decisions for building envelope retrofitting. The simulations respectively predicted a 10% and 7.5% reduction in the cooling load for cool and green roofs versus a conventional roof. In summer, the indoor air temperature was similar for these roofs, but in winter the cool roof's indoor air temperature was 0.5°C lower than the green. In the microclimate simulation, average roof surface temperatures were 31.5°C (cool) and 31.3°C (green), versus 40.2°C (conventional); the air temperature difference was −0.8°C (cool) and −0.6°C (green) against the conventional roof.

A microclimate model for plant transpiration effects

In the context of global warming, microclimate improvement is one of several important strategies for alleviating environmental problems such as urban heat islands, and plants are indispensable components of these strategies. The urban microclimate has thus become a pertinent research topic, and simulating the effects of plant transpiration in microclimate models has received increasing attention. Using the principles of fluid dynamics combined with the assistance of FLUENT software, this study constructed an urban microclimate simulation model that includes the effect of canopy transpiration in an attempt to obtain relatively accurate parameter values for future urban microclimate studies. Our model demonstrated the effect of plant transpiration on the mass-heat exchange of the plant, and the effect of solar radiation, wind speed, and humidity on the transpiration rate. The results showed the importance of plant canopy transpiration for microclimate simulation parameters, and our model also accurately simulated the mass-heat exchange of the microclimate as well as the resulting airflow. This study thus provides a more accurate method for microclimate optimization.