scholarly journals Optimizing Street Canyon Orientation for Rajarhat Newtown, Kolkata, India

2017 ◽  
Vol 21 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Bhaskar De ◽  
Mahua Mukherjee
Keyword(s):  
Air Temperature ◽  
Orientation Angle ◽  
Anthropogenic Heat ◽  
Outdoor Thermal Comfort ◽  
Wave Radiation ◽  
Humid Climate ◽  
Street Canyons ◽  
Physiological Equivalent Temperature ◽  
Urban Geometry ◽  
Radiant Temperature

Abstract Air temperature in urban street canyons is increased due to the morphed urban geometry, increased surface area, decreased long wave radiation and evapo-transpiration, different thermo-physical properties of surface materials and anthropogenic heat which results in thermal discomfort. Outdoor thermal stress can be mitigated substantially by properly orienting the canyons. It is crucial for the urban planners and designers to orient street canyons optimally considering variable local climatic context. It is important especially for cities in warm humid climatic context as these cities receive higher insolation with higher relative humidity and low level macro wind flow. This paper examines influence of canyon orientation on outdoor thermal comfort and proposes the optimum canyon orientation for the Rajarhat Newtown, Kolkata – a city in warm humid climate zone. Different scenarios are generated with different orientations. Change in air temperature, wind speed, Mean Radiant Temperature (MRT) and Physiological Equivalent Temperature (PET) of different scenarios are compared to find out the optimum orientation by parametric simulation in ENVI_met. Analysing the simulation results it is observed that orientation angle between 30°–60° to north performs the best for the study area of the Rajarhat Newtown. The findings of this research will be helpful for the planners to orient the street canyons optimally for future development and extension of the Rajarhat Newtown, Kolkata.

scholarly journals Assessing The Thermal Comfort Conditions In Open Spaces: A Transversal Field Survey On The University Campus In India

2021 ◽  
Vol 8 (3) ◽  
pp. 77-92
Author(s):  
Pardeep Kumar ◽  
Amit Sharma
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Arid Regions ◽  
Thermal Sensation ◽  
Probit Analysis ◽  
Outdoor Thermal Comfort ◽  
Cold Weather ◽  
Open Spaces ◽  
Physiological Equivalent Temperature ◽  
Preferred Temperature

Outdoor thermal comfort (OTC) promotes the usage frequency of public places, recreational activities, and people's wellbeing. Despite the increased interest in OTC research in the past decade, less attention has been paid to OTC research in cold weather, especially in arid regions. The present study investigates the OTC conditions in open spaces at the campus area in the arid region. The study was conducted by using subjective surveys(questionnaire) and onsite monitoring (microclimate parameters). The study was conducted at the Deenbandhu Chhotu Ram University of Science and Technology, Murthal, Haryana-India campus during the cold season of 2019. The timings of surveys were between 9:00 and 17:00 hours. The authors processed the 185 valid questionnaire responses of the respondents to analyze OTC conditions. Only 8.6% of the respondents marked their perceived sensation "Neutral." Regression analysis was applied between respondents' thermal sensations and microclimate parameters to develop the empirical thermal sensation model. The air temperature was the most dominant parameter affecting the sensations of the respondents. The empirical model indicated that by increasing air temperature, relative humidity, and solar radiation, the thermal sensations also increased while wind speed had an opposite effect. Physiological equivalent temperature (PET) was applied for assessing the OTC conditions; the neutral PET range was found to be 18.42-25.37°C with a neutral temperature of 21.89°C. The preferred temperature was 21.99 °C by applying Probit analysis. The study's findings could provide valuable information in designing and planning outdoor spaces for educational institutions in India's arid regions

scholarly journals The most problematic variable in the course of human-biometeorological comfort assessment — the mean radiant temperature

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Noémi Kántor ◽  
János Unger
Keyword(s):  
Thermal Comfort ◽  
Short Wave ◽  
Urban Environments ◽  
Outdoor Thermal Comfort ◽  
Radiation Environment ◽  
Wave Radiation ◽  
Mean Radiant Temperature ◽  
Radiation Fluxes ◽  
The Mean ◽  
Radiant Temperature

AbstractThis paper gives a review on the topic of the mean radiant temperature Tmrt, the most important parameter influencing outdoor thermal comfort during sunny conditions. Tmrt summarizes all short wave and long wave radiation fluxes reaching the human body, which can be very complex (variable in spatial and also in temporal manner) in urban settings. Thermal comfort researchers and urban planners need easy and sound methodological approaches to assess Tmrt. After the basics of the Tmrt calculation some of the methods suitable for obtaining Tmrt also in urban environments will be presented.. Two of the discussed methods are based on instruments which measure the radiation fluxes integral (globe thermometer, pyranometer-pyrgeometer combination), and three of the methods are based on modelling the radiation environment with PC software (RayMan, ENVI-met and SOLWEIG).

scholarly journals O desconforto térmico estival em Lisboa - uma abordagem bioclimática

Finisterra ◽  
2012 ◽  
Vol 33 (66) ◽  
Author(s):  
Henrique Andrade
Keyword(s):  
Air Temperature ◽  
Mean Radiant Temperature ◽  
Wind Regime ◽  
Physiological Equivalent Temperature ◽  
Northerly Wind ◽  
Thermal Discomfort ◽  
Daily Data ◽  
Human Energy ◽  
Hot Days ◽  
Radiant Temperature

THE SUMMER THERMAL STRESS IN LISBOA; A BIOCLIMATIC APPROACH. The summer frequency of hot days was studied, in Lisboa/Portela, with daily data from the period 1981/97. We used the Physiological Equivalent Temperature, an index of thermal confort based on the human energy balance, and calculated with air temperature, vapour pressure, wind speed and mean radiant temperature. It was assumed that mean radiant temperature was equal to air temperature, which is acceptable in the shade. The days were classifiend in two groups: hot days and very hot days, according to the thresholds of PET of 29ºC and 35ºC; 10% of the days had warm stress, with a maximum of frequency in July and a great interanual variability. The relation between the thermal discomfort and the wind regime was analysed. Most of the unconfortable days had breeze conditions, with the wind blowing from the East (from the estuary) during the morning; in the afternoon, the barometric gradient between the Ocean and the Iberian Peninsula increases, the breeze is replaced by a week northerly wind. The frequent occurence of strong northerly winds in summer is an important factor of reduction of the warm stress in Lisbon

scholarly journals Building Configuration of Low-Cost Apartments in Bandung—Its Contribution to the Microclimate and Outdoor Thermal Comfort

Buildings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 123 ◽  
Author(s):  
Beta Paramita ◽  
Hiroatsu Fukuda ◽  
Rendy Perdana Khidmat ◽  
Andreas Matzarakis
Keyword(s):  
Thermal Comfort ◽  
Open Space ◽  
Low Cost ◽  
Human Perception ◽  
Ground Cover ◽  
Outdoor Thermal Comfort ◽  
Humid Climate ◽  
Hot Humid Climate ◽  
Radiant Temperature ◽  
Building Form

This paper aims to find the microclimate aspect within the building form and configuration of five low-cost apartments (henceforth rusun) in Bandung, Indonesia. There are parallel, square, and interspersed plots investigated with specific discussion on the microclimate aspects that gain human perception of outdoor thermal comfort. The microclimate prognostic model, i.e., ENVI-met, was used to determine the mean radiant temperature (Tmrt), which was then used to describe the living quality of outdoor thermal comfort, i.e., PET (physiologically equivalent temperature) in a hot-humid climate context. A parallel plot with building orientation toward north-south was found as the most beneficial building form and configuration. Somehow, the parallel plot toward the west-east orientation did not provide similar performance. Nevertheless, the square plot provided uncomfortable perception as there was an absence of building shade within the wide open space and ground cover to absorb the insolation. The interspersed plot can be considered for the building configuration because it generates more wind among other plots. The building form and configuration of rusun with passive design seems to not be able to achieve outdoor thermal comfort. The highest PET value of Model D with the square plot had PET = 41 °C (hot) while the lowest PET in Model A with the parallel plot (N-S) had PET = 34.2 °C (slightly warm).

scholarly journals Correlative Impact of Shading Strategies and Configurations Design on Pedestrian-Level Thermal Comfort in Traditional Shophouse Neighbourhoods, Southern China

2019 ◽  
Vol 11 (5) ◽  
pp. 1355 ◽  
Author(s):  
Shi Yin ◽  
Werner Lang ◽  
Yiqiang Xiao ◽  
Zhao Xu
Keyword(s):  
Thermal Stress ◽  
Thermal Comfort ◽  
Southern China ◽  
Simulation Models ◽  
Outdoor Thermal Comfort ◽  
Humid Climate ◽  
Physiological Equivalent Temperature ◽  
Axis Orientation ◽  
Covered Area ◽  
The Impact

Traditional shophouse neighbourhoods (TSNs) in southern China respond well to the local hot and humid climate through proper street configurations and the integration of different shading strategies. Investigating the impact of shading strategies and configurations in TSNs on outdoor thermal comfort is valuable for guiding current urban design. Three street canyons in a TSN of Guangzhou with different shading strategies were selected as basic cases for microclimatic measurement in the summer season, i.e., alleys, streets with arcade for pedestrians, and streets with high-density greenery. After validating their simulation models in ENVI-met, five groups of parametric simulations were generated by varying the canyon aspect ratio (CHW), the canyon axis orientation, arcade proportion (AHW), and the tree-covered area (TCA). Using the physiological equivalent temperature (PET) to assess the above results, the correlative impact of different variations on pedestrian’s thermal comfort and their corresponding favourable ranges are summarized. The findings suggest that: (a) only in alleys and arcade streets, the pedestrian-level thermal comfort was significantly influenced by canyon axis orientation. (b) The thermal stress for pedestrians increased dramatically when the CHW was lower than 1.5 in alleys and 0.78 in boulevards (in TCA = 89%), while the CHW higher than 1 indicated a remarkable reduction on the PET for pedestrians in arcades. (c) The pedestrians started losing the protection from shading strategy to thermal stress when the AHW was higher than 1.33 (in canyon with CHW = 1) or the TCA was lower than 33% (in canyon with CHW = 0.78).

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 Application and performance of Kestrel sensors for assessing thermal comfort in outdoor built environments

2021 ◽  
Author(s):  
Lisette Klok ◽  
Erica Caverzam Barbosa ◽  
Luc van Zandbrink ◽  
Jeroen Kluck
Keyword(s):  
Decision Making ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Urban Spaces ◽  
Outdoor Thermal Comfort ◽  
Simple Type ◽  
Built Environments ◽  
The Sun ◽  
Physiological Equivalent Temperature ◽  
Air Temperatures

<p>In face of climate change and urbanization, the need for thermally comfortable outdoor urban spaces is increasing. In the design of the thermally comfortable urban spaces and decision making about interventions that enhance thermal comfort, scientists and professionals that work for cities use meteorological measurements and models. These measurements can be done by professional and accurate meteorological sensors, but also by simpler mobile instruments such as the easy-to-use Kestrel weather meters. In using these simple type of sensors, it is important to know what the performance of these sensors is for outdoor thermal comfort assessments and how they can be used by scientists and professionals in decision making about urban designs that enhance thermal comfort.</p><p>To answer these questions, we carried out three experiments in the summer of 2020 in Amsterdam, in which we tested the 11 Kestrel 5400 heat stress sensors and assessed the performance of this equipment for thermal comfort studies. We concluded that Kestrel sensors can be used very well for assessing differences in air temperature and PET (Physiological Equivalent Temperature) between outdoor built environments. For both air temperature and PET, the RMSE between the 11 Kestrel sensors was 0.5 °C maximum when measuring the same conditions. However, Kestrel sensors that were placed in the sun without a wind vane mounted to the equipment showed large radiation errors. In this case, temperature differences up to 3.4 °C were observed compared to Kestrels that were shaded. The effect of a higher air temperature on the PET calculation is, however, surprisingly small. A sensitivity analysis showed that an increase of 3 °C in the air temperature results in a maximal PET reduction of 0.5 °C. We concluded that Kestrel sensors can very well be used for assessing differences between air temperatures and PET between two locations and assessing the thermal effects of urban designs, but care should be taken when air temperature measurements are carried out in the sun. We always recommend using the wind vanes to deviate from high radiant input orientations for the temperature sensor, and placing the stations next to each other at the beginning and at the end of the measurements to check whether the stations actually measure the same values. Any differences can be corrected afterwards.</p>

scholarly journals Integrated Weather Effects on Cycling Shares, Frequencies, and Durations in Rotterdam, the Netherlands

2014 ◽  
Vol 6 (4) ◽  
pp. 468-481 ◽  
Author(s):  
Lars Böcker ◽  
Sofia Thorsson
Keyword(s):  
Wind Speed ◽  
The Netherlands ◽  
Air Temperature ◽  
Panel Study ◽  
Thermal Conditions ◽  
Meteorological Variables ◽  
Mean Radiant Temperature ◽  
Physiological Equivalent Temperature ◽  
Transport Modes ◽  
Radiant Temperature

Abstract With the increasing societal interest in climate change, health, accessibility, and liveability and subsequent policy aims to promote active transport modes over car usage, many scholars have investigated the relationship between weather and cycling. Existing studies, however, hardly address the effects of weather on cycling durations and often lack assessments of the combined effects of different meteorological variables and potential nonlinearity of these effects. Drawing on travel diary data from a panel study of 945 Greater Rotterdam respondents (the Netherlands), this paper investigates and compares the effects of different meteorological variables, singly as well as combined, on cycling frequencies, cycling durations, and the exchange between cycling and other transport modes. Results show linear negative effects of precipitation sum and wind speed and nonlinear bell-shaped effects of thermal variables on cycling and opposite effects on car usage. Out of three thermal variables investigated, mean radiant temperature (radiant heat exchange between humans and the environment) and physiological equivalent temperature (an index combining the effects of air temperature, mean radiant temperature, air humidity, and wind speed) better explain cycling behavior than just air temperature. Optimum thermal conditions for cycling were found on days with maximum air temperatures around 24°C, mean radiant temperatures around 52°C, and physiological equivalent temperatures around 30°C. Policy and planning implications are highlighted that could reduce cyclists’ exposures to disadvantageous weather conditions such as heat, precipitation, and wind, at present and in a potentially changing climate.

scholarly journals The Effect of Street Orientation on Outdoor Thermal Comfort in a Cold Mountainous Climate

2021 ◽  
Author(s):  
Narges Delpak ◽  
Hassan Sajadzadeh ◽  
Saide Hasanpourfard ◽  
Farshid Aram
Keyword(s):  
Thermal Comfort ◽  
Urban Spaces ◽  
Outdoor Thermal Comfort ◽  
Mean Radiant Temperature ◽  
Direct Sunlight ◽  
Physiological Equivalent Temperature ◽  
The North ◽  
Radiant Temperature ◽  
Climatic Characteristics ◽  
New Settlements

Lack of due attention to the orientation of streets and establishment of urban blocks without regard for climatic characteristics and conditions of the environment have an adverse effect on thermal comfort in open urban spaces. Construction of new settlements without taking into account climatic requirements undermines thermal comfort for pedestrians and other users, especially in cold regions. Considering the coldness of the region under study and the significance of the orientation of streets in absorbing radiation and providing heat to outdoor urban spaces, this study investigates the effect of the orientation of streets on microclimatic comfort in one of the residential towns of Hamadan City in Iran. For this purpose, microclimate simulation was performed using ENVI-met software. A residential block with four different orientations (the most common orientations of its surrounding buildings) were simulated in the coldest day of winter and the hottest day of summer. The results suggest that streets have different thermal behavior in different orientations. Orientation affects mean radiant temperature (Tmrt), the duration of exposure to direct sunlight, wind speed, and physiological equivalent temperature (PET), which are all important factors in thermal comfort. Based on these findings, north-south streets in Hamedan receive more radiant temperature during winter compared to other simulated orientations and provide more desirable thermal comfort. The average PET value on a winter day at a point on the north-south passage was 4.5-8 °C warmer than other orientations. In summer, streets with intercardinal orientations (i.e., northeast-southwest and northwest-southeast) provided the lowest PET (about 2 °C cooler than other orientations) and better thermal comfort

Public Housing in Bandung an Assessment and Approaches through Urban Physics

2014 ◽  
Vol 935 ◽  
pp. 273-276 ◽  
Author(s):  
Beta Paramita ◽  
Hiroatsu Fukuda
Keyword(s):  
Thermal Comfort ◽  
Public Housing ◽  
Urban Form ◽  
High Density ◽  
Outdoor Thermal Comfort ◽  
Humid Climate ◽  
Urban Forms ◽  
Hot Humid Climate ◽  
Radiant Temperature

High density of population and vertical buildings seems to be the only aspect fit to the concept for city in the developing country. The vertical housings then become a matter of necessity in high density area, in which the building groups themselves significantly contribute to microclimate at urban scales. This study is going to give descriptions of outdoor thermal comfort of public housing in Bandung by means its correlation between urban forms and mean radiant temperature. A number of simulations have used ENVI-met to reveal a better urban form which addresses the role of urban physics in the study of outdoor thermal comfort in a hot humid climate area.

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