Towards Pedestrian Microclimatic Comfort: A Rapid Predication Model for Street Winds and Pedestrian Thermal Sensation

Nano LIFE ◽  
2018 ◽  
Vol 08 (02) ◽  
pp. 1840006
Author(s):  
Jing Li ◽  
Mengnan Qi ◽  
Qiuhua Duan ◽  
Lei Huo ◽  
Julian Wang
Keyword(s):  
Wind Speed ◽  
Built Environment ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Goodness Of Fit ◽  
Comfort Level ◽  
Outdoor Thermal Comfort ◽  
Design Parameters ◽  
Rapid Urbanization ◽  
The Impact

Significant changes in the urban built environment have occurred due to rapid urbanization and increases in the urban population. Such alterations may produce environmental health-related issues such as urban heat stress, air pollution and traffic noise. This research undertook a field study to collect data including urban design parameters, micro-environmental factors and city climatic information. This work was conducted over a two-year period on three pedestrian streets located in high-density urban areas in Beijing. These areas were selected in order to study the influences of urban street canyon texture within a particular geometric layout, wind flow corridors and variations in air temperature on pedestrian microclimatic comfort. The results will facilitate the work of urban planners by providing them with information for use in improving outdoor thermal comfort through their designs. A total of 60[Formula: see text]485 samples were organized into training, validation and test sets. We confirmed our hypothesis that internal wind speed ([Formula: see text] is attributable mainly to the urban texture coefficient ([Formula: see text], air temperature ([Formula: see text] and leading-in wind speed ([Formula: see text]. The model was tested using the test data collected onsite, which demonstrated a very accurate goodness-of-fit; the model achieved an R-squared value of 0.82, which meant that [Formula: see text] as a dependent variable was 82% correlated to the three predictors as independent variables. With this computer simulation, urban planners can now predict and visualize the impact of changes on the built environment in terms of either the direction of solar radiation received or increases in wind speed, in return for the desired thermal comfort level for residents of the neighborhood.

scholarly journals User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation

2020 ◽  
Vol 12 (22) ◽  
pp. 9672
Author(s):  
Mamdooh Alwetaishi ◽  
Ashraf Balabel ◽  
Ahmed Abdelhafiz ◽  
Usama Issa ◽  
Ibrahim Sharaky ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
High Altitude ◽  
Air Temperature ◽  
Thermal Performance ◽  
Indoor Air ◽  
Computer Modelling ◽  
Evaporative Cooling ◽  
Comfort Level ◽  
Thermal Mass ◽  
The Impact

The study investigated the level of thermal comfort in historical buildings located at a relatively high altitude in the Arabian Desert of Saudi Arabia. The study focused on the impact of the use of thermal mass and orientation on the level of thermal performance at Shubra and Boqri Palaces. Qualitative and quantitative analyses were used in this study, including a questionnaire interview with architecture experts living at the relatively high altitude of Taif city, to obtain data and information from local experts. The computer software TAS EDSL was used along with on-site equipment, such as thermal imaging cameras and data loggers, to observe the physical conditions of the building in terms of its thermal performance. The study revealed that the experts’ age and years of experience were important aspects while collecting data from them during the survey. The use of thermal mass had a slight impact on the indoor air temperature as well as the energy consumption, but it helped in providing thermal comfort. Use of ventilation can improve thermal comfort level. Evaporative cooling technique has a considerable impact on reducing indoor air temperature with 4 °C drop, improving the thermal comfort sensation level. The novelty of this work is that, it links the outcomes of qualitative results of experts with field monitoring as well as computer modelling. This can contribute as method to accurately collect data in similar case studies.

scholarly journals Sensitivity Analysis of Passive Design Strategies for Residential Buildings in Cold Semi-Arid Climates

2020 ◽  
Vol 12 (3) ◽  
pp. 1091 ◽  
Author(s):  
Waqas Ahmed Mahar ◽  
Griet Verbeeck ◽  
Sigrid Reiter ◽  
Shady Attia
Keyword(s):  
Sensitivity Analysis ◽  
Thermal Comfort ◽  
Residential Buildings ◽  
Design Parameters ◽  
Rapid Urbanization ◽  
Design Recommendations ◽  
Adaptive Comfort ◽  
Passive Design ◽  
The Impact ◽  
Semi Arid

Buildings are significant drivers of greenhouse gas emissions and energy consumption. Improving the thermal comfort of occupants in free-running buildings and avoiding active and fossil fuel-based systems is the main challenge in many cities worldwide. However, the impacts of passive design measures on thermal comfort in cold semi-arid regions are seldom studied. With the rapid urbanization and the widespread use of personalised heating and cooling systems, there is a need to inform building designers and city authorities about passive design measures that can achieve nearly optimal conditions. Therefore, in this study, a global sensitivity analysis of the impact of passive design parameters on adaptive comfort in cold semi-arid climates was conducted. A representative residential building was simulated and calibrated in Quetta, Pakistan, to identify key design parameters for optimal thermal comfort. The results list and rank a set of passive design recommendations that can be used widely in similar climates. The results show that among the investigated 21 design variables, the insulation type of roof is the most influential design variable. Overall, the sensitivity analysis yielded new quantitative and qualitative knowledge about the passive design of buildings with personalised heating systems, but the used sensitivity analysis has some limitations. Finally, this study provides evidence-based and informed design recommendations that can serve architects and homeowners to integrate passive design measures at the earliest conceptual design phases in cold semi-arid climates.

scholarly journals On the Optimisation of Urban form Design, Energy Consumption and Outdoor Thermal Comfort Using a Parametric Workflow in a Hot Arid Zone

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4026
Author(s):  
Yasser Ibrahim ◽  
Tristan Kershaw ◽  
Paul Shepherd ◽  
David Coley
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Urban Form ◽  
Energy Use ◽  
Arid Zone ◽  
Morphological Characteristics ◽  
Outdoor Thermal Comfort ◽  
Design Parameters ◽  
Overall Performance ◽  
The Impact

The recent reports from the Intergovernmental Panel on Climate Change (IPCC) urge for the reconceptualization of our design of the urban built environments. However, current efforts to integrate urban environmental assessment into practice in Egypt are proving insufficient. This paper utilises the Ladybug tools simulation plugins to investigate the impact of changing the morphological characteristics of three-block typologies (scattered, linear and courtyard) and their associated parameters to understand their multidimensional relationship with environmental conditions, outdoor thermal comfort and energy use intensity. This study based in Cairo, Egypt, considers 3430 hypothetical geometrical configurations comprising of a variety of design parameters and indicators. The results show a strong correlation between the design parameters and the combined performance of thermal comfort and energy consumption (R2 = 0.84), with urban density having the strongest impact on both thermal comfort and energy use (R2 = 0.7 and 0.95, respectively). The design parameters exhibited a consistent impact on the different typologies, albeit with varying magnitude. Compact and medium-density urban forms are shown to elicit the best overall performance, especially for ordinal orientations (e.g., ~45°) across all typologies. Compact high-density scattered forms are favoured when considering thermal comfort, while courtyards outperform other typologies when considering energy efficiency and overall performance.

scholarly journals How to Improve the Liveability in Cities: The Effect of Urban Morphology and Greening on Outdoor Thermal Comfort

2021 ◽  
Vol 65 (2-4) ◽  
pp. 361-370
Author(s):  
Guglielmina Mutani ◽  
Valeria Todeschi ◽  
Simone Beltramino
Keyword(s):  
Built Environment ◽  
Thermal Comfort ◽  
Energy Savings ◽  
Green Roofs ◽  
Urban Morphology ◽  
Outdoor Thermal Comfort ◽  
Water Runoff ◽  
Physiological Equivalent Temperature ◽  
The Impact ◽  
The City

Extensive and intensive green roofs and vegetated walls should be used to improve the livability in cities, especially in densely built-up context, in order to optimize their contribution on energy savings and greenhouse gas emissions, improving thermal comfort conditions and ensuring a greater storm-water runoff. The aim of this study is to evaluate the effect of urban morphology and to quantify the impact of green surfaces and plants on outdoor thermal comfort conditions. The analysis was applied to six neighborhoods in the city of Turin, identified as typical districts with different building geometries, urban contexts and green presence. The outdoor thermal comfort conditions were assessed calculating a set of indicators, such as the predicted mean vote and the physiological equivalent temperature, with the support of ENVI-met tool. Retrofit scenarios were hypothesized, and outdoor thermal comfort conditions were investigated before and after the installation of green roofs and vegetated areas. The result allowed to understand how thermal comfort vary, considering the building geometry, urban morphology, and green areas in different zones of the city of Turin. By analyzing neighborhoods, it is possible to identify the optimal built environment that ensure better thermal comfort conditions. These models and tools could support urban planners in defining the best measures to improve the liveability and quality in the built environment considering local constraints and the real characteristics of the territory or in designing new neighborhoods.

scholarly journals Urban heat resilience at the time of global warming: evaluating the impact of the urban parks on outdoor thermal comfort

2020 ◽  
Author(s):  
Farshid Aram ◽  
Ebrahim Solgi ◽  
Ester Higueras García ◽  
Amir Mosavi
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Mental Image ◽  
Urban Parks ◽  
Cooling Effect ◽  
Outdoor Thermal Comfort ◽  
Heat Island ◽  
Physiological Equivalent Temperature ◽  
Urban Heat ◽  
The Impact

Abstract Background: In densely populated urban centers, increased air temperature due to urban heat island (UHI) effect can undermine the thermal comfort and health of citizens. Research has shown that large urban parks can mitigate the effect of UHIs and improve thermal comfort, especially in the warmer months of the year when temperature changes are more noticeable. This study investigated the cooling effect intensity (CEI) of the Retiro Park in the center of Madrid at three different distances from its southern edge and the impact of this cooling effect on thermal comfort from physiological and psychological perspectives. This investigation was performed by measuring microclimate data and conducting a survey simultaneously during the summer days. Results: The results showed that the CEI of the park varies with distance from its edge. Because of this effect, air temperature within the 130m and 280m distance of the park was respectively 1.6°C and 0.9°C lower than the temperature at the 520m distance (the nearest heat island). After examining the effect of the park in terms of Physiological Equivalent Temperature (PET), it was found that the PET at the 130m and 280m distance of the park was 9.3% and 5.4% less than the PET in the heat island domain. More than 81% of the respondents (in all three areas) had a mental image of the park as the place where they would experience the highest level of outdoor thermal comfort, and this rate was higher in the areas closer to the park. The analysis of citizens’ responses about perceived thermal comfort (PTC) showed that citizens in areas with higher CEI had perceived a higher degree of thermal comfort from the psychological perspective.Conclusion: This study demonstrates the significant role of large urban parks located in the core of the populated cities in providing thermal comfort for citizens from both physiological and psychological perspectives. Additionally, the results of this study demonstrated that among the environmental (natural and artificial) factors around the park (topography, urban structure, etc.), the aspect ratio has the greatest impact on thermal comfort.

scholarly journals Heat-Mitigation Strategies to Improve Pedestrian Thermal Comfort in Urban Environments: A Review

2020 ◽  
Vol 12 (23) ◽  
pp. 10000
Author(s):  
Nazanin Nasrollahi ◽  
Amir Ghosouri ◽  
Jamal Khodakarami ◽  
Mohammad Taleghani
Keyword(s):  
Thermal Comfort ◽  
Climatic Factors ◽  
Urban Environments ◽  
Mitigation Strategies ◽  
Comfort Level ◽  
Outdoor Thermal Comfort ◽  
Factors Affecting ◽  
Urban Forms ◽  
Radiant Temperature ◽  
The Impact

Thermal comfort is one of the main factors affecting pedestrian health, and improving thermal comfort enhances walkability. In this paper, the impact of various strategies on thermal-comfort improvement for pedestrians is thoroughly evaluated and compared. Review studies cover both fieldwork and simulation results. These strategies consist of shading (trees, buildings), the orientation and geometry of urban forms, vegetation, solar-reflective materials, and water bodies, which were investigated as the most effective ways to improve outdoor thermal comfort. Results showed that the most important climatic factors affecting outdoor thermal comfort are mean radiant temperature, wind speed, and wind direction in a microclimate. The best heat-mitigation strategy for improving thermal comfort was found to be vegetation and specifically trees because of their shading effect. The effect of height-to-width (H/W) ratio in canyons is another important factor. By increasing H/W ratio, the thermal-comfort level also increases. Deploying highly reflective materials in urban canyons is not recommended, as several studies showed that they could reflect solar radiation onto pedestrians. Results also showed that, in order to achieve a satisfactory level of thermal comfort, physiological and psychological factors should be considered together.

Evaluating the Impact of Solar Radiation on Outdoor Thermal Comfort by the Development and Validation of a Simple Urban Climatic Model

Solar Energy ◽  
2006 ◽  
Author(s):  
Yuemei Zhu ◽  
Jing Liu ◽  
Yang Yao ◽  
Zuiliang Ma ◽  
Aya Hagishima ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Outdoor Thermal Comfort ◽  
Outdoor Thermal Environment ◽  
Development And Validation ◽  
The Impact ◽  
Canopy Model

In this paper, in order to predict the outdoor thermal environment, a simple multi-layer canopy model coupled with calculation of outdoor thermal comfort was developed. SET* value was used to estimate the pedestrian level of thermal comfort in the outdoor thermal environment. Preliminary verification of this model using observational data on the outdoor thermal conditions showed good results. In addition, the results show that outdoor thermal comfort is significantly different with air temperature. Except for air temperature, both solar radiation and humidity play important roles on outdoor thermal comfort.

scholarly journals The impact of the cooling effect of urban parks on thermal comfort from the physiological and the psychological perspective

2020 ◽  
Author(s):  
Farshid Aram ◽  
Ebrahim Solgi ◽  
Ester Higueras García ◽  
Amir Mosavi
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Mental Image ◽  
Urban Parks ◽  
Cooling Effect ◽  
Outdoor Thermal Comfort ◽  
Heat Island ◽  
Psychological Perspective ◽  
Physiological Equivalent Temperature ◽  
The Impact

Abstract Background: In densely populated urban centers, increased air temperature due to urban heat island (UHI) effect can undermine the thermal comfort and health of citizens. Research has shown that large urban parks can mitigate the effect of UHIs and improve thermal comfort, especially in the warmer months of the year when temperature changes are more noticeable. This study investigated the cooling effect intensity (CEI) of the Retiro Park in the center of Madrid at three different distances from its southern edge and the impact of this cooling effect on thermal comfort from physiological and psychological perspectives. This investigation was performed by measuring microclimate data and conducting a survey simultaneously during the summer days. Results: The results showed that the CEI of the park varies with distance from its edge. Because of this effect, air temperature within the 130m and 280m distance of the park was respectively 1.6°C and 0.9°C lower than the temperature at the 520m distance (the nearest heat island). After examining the effect of the park in terms of Physiological Equivalent Temperature (PET), it was found that the PET at the 130m and 280m distance of the park was 9.3% and 5.4% less than the PET in the heat island domain. More than 81% of the respondents (in all three areas) had a mental image of the park as the place where they would experience the highest level of outdoor thermal comfort, and this rate was higher in the areas closer to the park. The analysis of citizens’ responses about perceived thermal comfort (PTC) showed that citizens in areas with higher CEI had perceived a higher degree of thermal comfort from the psychological perspective. Conclusion: This study demonstrates the significant role of large urban parks located in the core of the populated cities in providing thermal comfort for citizens from both physiological and psychological perspectives.

scholarly journals Urban heat resilience at the time of global warming: evaluating the impact of the urban parks on outdoor thermal comfort

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Farshid Aram ◽  
Ebrahim Solgi ◽  
Ester Higueras Garcia ◽  
Amir Mosavi
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Mental Image ◽  
Urban Parks ◽  
Cooling Effect ◽  
Outdoor Thermal Comfort ◽  
Heat Island ◽  
Physiological Equivalent Temperature ◽  
Urban Heat ◽  
The Impact

Abstract Background In densely populated urban centers, increased air temperature due to urban heat island (UHI) effect can undermine the thermal comfort and health of citizens. Research has shown that large urban parks can mitigate the effect of UHIs and improve thermal comfort, especially in the warmer months of the year when temperature changes are more noticeable. This study investigated the cooling effect intensity (CEI) of the Retiro Park in the center of Madrid at three different distances from its southern edge and the impact of this cooling effect on thermal comfort from physiological and psychological perspectives. This investigation was performed by measuring microclimate data and conducting a survey simultaneously during the summer days. Results The results showed that the CEI of the park varies with distance from its edge. Because of this effect, air temperature within the 130 m and 280 m distance of the park was, respectively, 1.6 °C and 0.9 °C lower than the temperature at the 520 m distance (the nearest heat island). After examining the effect of the park in terms of physiological equivalent temperature (PET), it was found that the PET at the 130 m and 280 m distance of the park was 9.3% and 5.4% less than the PET in the heat island domain. More than 81% of the respondents (in all three areas) had a mental image of the park as the place where they would experience the highest level of outdoor thermal comfort, and this rate was higher in the areas closer to the park. The analysis of citizens’ responses about perceived thermal comfort (PTC) showed that citizens in areas with higher CEI had perceived a higher degree of thermal comfort from the psychological perspective. Conclusion This study demonstrates the significant role of large urban parks located in the core of the populated cities in providing thermal comfort for citizens from both physiological and psychological perspectives. Additionally, the results of this study demonstrated that among the environmental (natural and artificial) factors around the park (topography, urban structure, etc.), the aspect ratio has the greatest impact on thermal comfort.

Implications of Building Material Choice on Outdoor Microclimate for Sustainable Built Environment

2015 ◽  
Vol 650 ◽  
pp. 82-90 ◽  
Author(s):  
D. Kannamma ◽  
A. Meenatchi Sundaram
Keyword(s):  
Thermal Comfort ◽  
Building Material ◽  
Building Materials ◽  
Climatic Factors ◽  
Outdoor Environment ◽  
Outdoor Thermal Comfort ◽  
Physical Factors ◽  
Physiological Equivalent Temperature ◽  
Material Choice ◽  
The Impact

The climatic conditions in a man-made urban environment may differ appreciably from those in the surrounding natural or rural environs.... each urban man-made buildings, roads, parking area, factories......creates around and above it a modified climate with which it interacts [1].Outdoor thermal comfort has gained importance in thermal comfort studies especially in tropical countries. In country like India, culturally the activities are spread both indoors and outdoors. Therefore the need for ambient outdoor environment gains importance. As there are many factors that contribute to outdoor thermal comfort (climatic factors and physical factors), this study aims in analyzing the impact of building material contribution, in an institutional courtyard. In order to understand the thermal contribution of various building materials and to suggest material choice to designers, ENVIMET is used for simulation purpose. The outdoor thermal comfort index employed in this study is PET (Physiological Equivalent Temperature), calibrated using RAYMAN.

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