Eddy3D: A toolkit for decoupled outdoor thermal comfort simulations in urban areas

2021 ◽  
pp. 108639
Author(s):  
Patrick Kastner ◽  
Timur Dogan
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Outdoor Thermal Comfort

scholarly journals Biomimicry-Based Strategies for Urban Heat Island Mitigation: A Numerical Case Study under Tropical Climate

Biomimetics ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 48
Author(s):  
Kevin Araque ◽  
Paola Palacios ◽  
Dafni Mora ◽  
Miguel Chen Austin
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Urban Areas ◽  
Outdoor Thermal Comfort ◽  
Base Case ◽  
Heat Island ◽  
Urban Heat ◽  
Historical Heritage ◽  
Pet Index ◽  
Radiant Temperature

In recent years, demographic growth has caused cities to expand their urban areas, increasing the risk of overheating, creating insurmountable microclimatic conditions within the urban area, which is why studies have been carried out on the urban heat island effect (UHI) and its mitigation. Therefore, this research aims to evaluate the cooling potential in the application of strategies based on biomimicry for the microclimate in a historical heritage city of Panama. For this, three case studies (base case, case 1, and case 2) of outdoor thermal comfort were evaluated, in which the Envi-met software was used to emulate and evaluate the thermal performance of these strategies during March (highest temperature month) and October (rainier month). The strategies used were extracted from the contrast of zebra skin, human skin, evaporative cooling, and ant skin. The results showed a reduction of 2.8 °C in the air temperature at 11:00, the radiant temperature decreased by 2.2 °C, and the PET index managed to reduce the thermal comfort indicator among its categories. The importance of thinking based on biomimicry in sustainable strategies is concluded; although significant changes were obtained, high risks of discomfort persist due to the layout and proximity of the building.

scholarly journals Spatially Resolved Analysis of Urban Thermal Environments Based on a Three-Dimensional Sampling Algorithm and UAV-Based Radiometric Measurements

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4847
Author(s):  
Daniel Rüdisser ◽  
Tobias Weiss ◽  
Lukas Unger
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Global Radiation ◽  
Three Dimensional ◽  
Evaluation Process ◽  
Outdoor Thermal Comfort ◽  
Wave Radiation ◽  
Imaging Data ◽  
Three Dimensional Model ◽  
Spatially Resolved

A new method and workflow to assess outdoor thermal comfort and thermal stress in urban areas is developed. The new methodology is applied to a case of an urban quarter in the city of Graz. The method recognises the significance of detailed and accurate spatially resolved determination of mean radiant temperatures taking into account all relevant radiative components, comprising thermal radiation, as well as global radiation. The method relies on radiometric imaging data that are mapped onto a three-dimensional model. The image data are acquired by means of drones (UAVs) equipped with multispectral and thermographic cameras to capture short- and long-wave radiation. Pre-existing city models and a Monte Carlo raytracing algorithm to perform anisotropic sampling based on a 3D model with human topology are used to determine local radiation temperatures with high spatial resolution. Along with spot measurements carried out on the ground simultaneously, the spatially resolved and three-dimensionally determined mean radiation temperatures are used to calculate thermal comfort indicator maps using UTCI and PMV calculation. Additional ground measurements are further used to validate the detection, as well as the entire evaluation process.

scholarly journals Sky View Factors from Synthetic Fisheye Photos for Thermal Comfort Routing—A Case Study in Phoenix, Arizona

2017 ◽  
Vol 2 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Ariane Middel ◽  
Jonas Lukasczyk ◽  
Ross Maciejewski
Keyword(s):  
Thermal Comfort ◽  
Urban Form ◽  
Urban Areas ◽  
Meteorological Data ◽  
Routing Algorithm ◽  
Google Earth ◽  
Urban Environments ◽  
Tree Planting ◽  
Outdoor Thermal Comfort ◽  
View Factor

The Sky View Factor (SVF) is a dimension-reduced representation of urban form and one of the major variables in radiation models that estimate outdoor thermal comfort. Common ways of retrieving SVFs in urban environments include capturing fisheye photographs or creating a digital 3D city or elevation model of the environment. Such techniques have previously been limited due to a lack of imagery or lack of full scale detailed models of urban areas. We developed a web based tool that automatically generates synthetic hemispherical fisheye views from Google Earth at arbitrary spatial resolution and calculates the corresponding SVFs through equiangular projection. SVF results were validated using Google Maps Street View and compared to results from other SVF calculation tools. We generated 5-meter resolution SVF maps for two neighborhoods in Phoenix, Arizona to illustrate fine-scale variations of intra-urban horizon limitations due to urban form and vegetation. To demonstrate the utility of our synthetic fisheye approach for heat stress applications, we automated a radiation model to generate outdoor thermal comfort maps for Arizona State University’s Tempe campus for a hot summer day using synthetic fisheye photos and on-site meteorological data. Model output was tested against mobile transect measurements of the six-directional radiant flux density. Based on the thermal comfort maps, we implemented a pedestrian routing algorithm that is optimized for distance and thermal comfort preferences. Our synthetic fisheye approach can help planners assess urban design and tree planting strategies to maximize thermal comfort outcomes and can support heat hazard mitigation in urban areas.

The Benefits of Tree Shade and Turf on Globe and Surface Temperatures in an Urban Tropical Environment

2020 ◽  
Vol 46 (3) ◽  
pp. 228-244
Author(s):  
Lai Fern Ow ◽  
Subhadip Ghosh ◽  
Mohamed Lokman Mohd Yusof
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Mitigation Strategies ◽  
Urban Heat Islands ◽  
Outdoor Thermal Comfort ◽  
Mitigation Measures ◽  
Heat Islands ◽  
Ambient Temperatures ◽  
Surface Temperatures ◽  
Island State

The process of urbanisation increases temperature and alters the thermal comfort in cities. Urban heat islands (UHIs) result in the rise of ambient temperatures. For example, in the densely populated island state of Singapore, the UHI intensity was some 4.5 °C. Such elevation in heat can negatively impact outdoor thermal comfort and may give rise to serious health problems. The present study investigated the benefits of trees and turf as mitigation strategies for urban areas. Short- and long-term observations were made for surface and globe temperatures over smaller plots of vegetation and hard surfaces involving tree shade and full sun. Similar observations were investigated over a larger extent of vegetation across concrete, asphalt, and turf within an urban park setting. The presence of turf and shade from trees greatly affected surface temperatures, and the effect was most pronounced when both were present. The presence of turf reduced surface temperatures by up to 10 °C, while tree shade led to a 12 °C reduction. Globe temperatures showed that the presence of turf and shading reduced temperatures between 5 and 10 °C. These results suggest that turf and trees can effectively cool surfaces and improve outdoor thermal comfort. The results of this study can be applied to urban planning of greenery and can be used as a reference for other tropical cities with similar climates that are also working to develop mitigation measures to improve the liveability of their cities.

Numerical Study of Thermal Comfort with the Effects of Canopy Transparency

2014 ◽  
Vol 919-921 ◽  
pp. 1677-1680
Author(s):  
Choul Woong Kwon ◽  
Sung Woo Shin
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Thermal Environment ◽  
Numerical Study ◽  
Complex Surface ◽  
Outdoor Thermal Comfort ◽  
Thermal Indices ◽  
Physiological Equivalent Temperature ◽  
Thermal Index ◽  
Radiation Fluxes

Several complex thermal indices (e.g. PMV and PET) were developed in the last decades to describe the quantify the thermal environment of humans and the energy fluxes between body and environment. Compared to open spaces the complex surface structure of urban areas creates an environment with special microclimatic characteristics, which have a dominant effect on the energy balance of the human body. In this study, outdoor thermal comfort conditions are examined through numerical model with different transparency ratios in canopy. The intensity of radiation fluxes is dependent on several factors, such as orientation, size and transparency of canopy. Special emphasis is given to the human-biometeorological assessment of the microclimate of building element (canopy) through the application of the thermal index PET (Physiological Equivalent Temperature). The analysis is carried out by the utilization of Ecotect and RayMan software.

scholarly journals Outdoor Thermal Comfort of Urban Park—A Case Study

2020 ◽  
Vol 12 (5) ◽  
pp. 1961 ◽  
Author(s):  
Lili Zhang ◽  
Dong Wei ◽  
Yuyao Hou ◽  
Junfei Du ◽  
Zu’an Liu ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Thermal Sensation ◽  
Urban Parks ◽  
Living Environment ◽  
Outdoor Thermal Comfort ◽  
Climate Index ◽  
Urban Residents ◽  
Physiological Equivalent Temperature ◽  
Different Types

Urban parks are an important component of urban public green space and a public place where a large number of urban residents choose to conduct outdoor activities. An important factor attracting people to visit and stay in urban parks is its outdoor thermal comfort, which is also an important criterion for evaluating the liability of the urban environment. In this study, through field meteorological monitoring and a questionnaire survey, outdoor thermal comfort of different types of landscape space in urban parks in Chengdu, China was studied in winter and summer. Result indicated that (1) different types of landscape spaces have different thermal comforts, (2) air temperature is the most important factor affecting outdoor thermal comfort; (3) because the thermal sensation judgment of outdoor thermal comfort research in Chengdu area, an ASHRAE seven-sites scale can be used; (4) the neutral temperature ranges of Physiological Equivalent Temperature (PET) and Universal Thermal Climate Index (UTCI) in Chengdu in winter and summer were obtained through research; (5) and UTCI is the best index for evaluating outdoor thermal comfort in Chengdu. These findings provide theoretical benchmarks and technical references for urban planners and landscape designers to optimize outdoor thermal comfort in urban areas to establish a more comfortable and healthy living environment for urban residents.

scholarly journals Behavioural Perspectives of Outdoor Thermal Comfort in Urban Areas: A Critical Review

Atmosphere ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 51 ◽  
Author(s):  
Mohamed H. Elnabawi ◽  
Neveen Hamza
Keyword(s):  
Thermal Comfort ◽  
Urban Space ◽  
Urban Areas ◽  
Thermal Characteristics ◽  
Local Economy ◽  
Urban Spaces ◽  
Outdoor Thermal Comfort ◽  
Extensive Literature ◽  
Adaptive Thermal Comfort ◽  
Comprehensive Framework

The thermal characteristics of outdoor urban spaces and the street networks connecting them are vital to the assessment of the liveability and sustainability of cities. When urban spaces are thermally comfortable, city dwellers spend more time outdoors. This has several benefits for human health and wellbeing, also reducing indoor energy consumption and contributing to local economy. Studies on outdoor thermal comfort have highlighted the need to develop interdisciplinary frameworks that integrate physical, physiological, psychological, and social parameters to assist urban planners and designers in design decisions. In this paper, an extensive literature review of outdoor thermal comfort studies over the past decade was undertaken, including both rational and adaptive thermal comfort approaches, from the contextualize the behaviour perspectives related to the use of urban space. Consequently, the paper suggests a comprehensive framework for evaluating the relationship between the quantitative and qualitative parameters linking the microclimatic environment with subjective thermal assessment and social behaviour. The framework aims to contribute to the development of exclusive thermal comfort standards for outdoor urban settings.

scholarly journals Sustainable Urban Greening and Cooling Strategies for Thermal Comfort at Pedestrian Level

2021 ◽  
Vol 13 (6) ◽  
pp. 3138
Author(s):  
Maurizio Detommaso ◽  
Antonio Gagliano ◽  
Luigi Marletta ◽  
Francesco Nocera
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Fluid Dynamic ◽  
Green Roofs ◽  
Outdoor Thermal Comfort ◽  
Balance Model ◽  
Urban Greening ◽  
Cfd Model ◽  
Urban Microclimate ◽  
Urban Warming

The increase of the urban warming phenomenon all over the world is gaining increasing attention from scientists as well as planners and policymakers due to its adverse effects on energy consumption, health, wellbeing, and air pollution. The protection of urban areas from the outdoor warming phenomenon is one of the challenges that policy and governments have to tackle as soon as possible and in the best possible way. Among the urban heat island mitigation techniques, cool materials and urban greening are identified as the most effective solutions in reducing the urban warming phenomenon. The effects produced by the adoption of cool materials and urban forestation on the urban microclimate were investigated through a computational fluid-dynamic (CFD) model. The CFD model was calibrated and validated thanks to experimental surveys within the Catania University campus area. The urban microclimate thermal comfort analysis and assessment were carried out with the Klima–Michel Model (KMM) and Munich Energy Balance Model for Individuals (MEMI). In particular, three scenarios were performed: cool, low, and high levels of urban greening. The cool scenario, although it produces air temperature at around 1.00 °C, determines the worst condition of outdoor thermal comfort, especially at the pedestrian level. On the contrary, a high level of urban greening, obtained by the extensive green roofs together with an urban forestation, guarantees the wellbeing of pedestrians, showing more convenient values of PMV and PET.

scholarly journals Assessment of Outdoor Thermal Comfort in Serbia’s Urban Environments during Different Seasons

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1084
Author(s):  
Milica Lukić ◽  
Dejan Filipović ◽  
Milica Pecelj ◽  
Ljiljana Crnogorac ◽  
Bogdan Lukić ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Urban Environments ◽  
Outdoor Thermal Comfort ◽  
Strong Impact ◽  
Data Set ◽  
Different Seasons ◽  
Novi Sad

The urban microclimate is gradually changing due to climate change, extreme weather conditions, urbanization, and the heat island effect. In such an altered environment, outdoor thermal comfort can have a strong impact on public health and quality of life in urban areas. In this study, three main urban areas in Serbia were selected: Belgrade (Central Serbia), Novi Sad (Northern Serbia), and Niš (Southern Serbia). The focus was on the temporal assessment of OTC, using the UTCI over a period of 20 years (1999–2018) during different seasons. The main aim is the general estimation of the OTC of Belgrade, Novi Sad, and Niš, in order to gain better insight into the bioclimatic condition, current trends and anomalies that have occurred. The analysis was conducted based on an hourly (7 h, 14 h, and 21 h CET) and “day by day” meteorological data set. Findings show the presence of a growing trend in seasonal UTCI anomalies, especially during summer and spring. In addition, there is a notable increase in the number of days above the defined UTCI thresholds for each season. Average annual UTCIs values also show a positive, rising trend, ranging from 0.50 °C to 1.33 °C. The most significant deviations from the average UTCI values, both seasonal and annual, were recorded in 2000, 2007, 2012, 2015, 2017, and 2018.

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