Assessment of visitors' thermal comfort based on physiologically equivalent temperature in open urban areas

Urban Climate ◽  
2019 ◽  
Vol 28 ◽  
pp. 100466
Author(s):  
Dusan Kicovic ◽  
Dragan Vuckovic ◽  
Dusan Markovic ◽  
Srdjan Jovic
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Physiologically Equivalent Temperature ◽  
Equivalent Temperature

scholarly journals Comparison of Thermal Comfort between Sapporo and Tokyo—The Case of the Olympics 2020

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 444
Author(s):  
Yuting Wu ◽  
Kathrin Graw ◽  
Andreas Matzarakis
Keyword(s):  
Heat Stress ◽  
Thermal Comfort ◽  
Olympic Games ◽  
Physiologically Equivalent Temperature ◽  
Precipitation Rate ◽  
Equivalent Temperature ◽  
Thermal Indices ◽  
Climate Conditions ◽  
Northern City ◽  
The Olympic Games

Weather and climate conditions can be decisive regarding travel plans or outdoor events, especially for sport events. The Olympic Games 2020, postponed to 2021, will take place in Tokyo at a time which is considered to be the hottest and most humid time of the year. However, a part of the athletic competitions is relocated to the northern city Sapporo. Therefore, it is important to quantify thermal comfort for different occasions and destinations and make the results accessible to visitors and sport attendees. The following analysis will quantify and compare thermal comfort and heat stress between Sapporo and Tokyo using thermal indices like the Physiologically Equivalent Temperature and the modified Physiologically Equivalent Temperature (PET and mPET). The results reveal different precipitation patterns for the cities. While a higher precipitation rate appears in Sapporo during winter, the precipitation rate is higher in Tokyo during summer. PET and mPET exhibit a greater probability of heat stress conditions in Tokyo during the Olympic Games, whereas Sapporo has more moderate values for the same period. The Climate-Tourism/Transfer-Information-Scheme (CTIS) integrates and simplifies climate information and makes them comprehensible for non-specialists. The CTIS of Tokyo illustrates lower suitable conditions for “Heat stress”, “Sunny days” and “Sultriness”. Transferring parts of the athletics competition to a northern city is thus more convenient for athletes, staff members and spectators. Hence, heat stress can be avoided and an acceptable outdoor stay is ensured. Overall, this quantification and comparison of the thermal conditions in Sapporo and Tokyo reveal limitations but also possibilities for the organizers of the Olympic Games. Furthermore it can be used to raise awareness for promoting or arranging countermeasures and heat mitigation at specific events and destinations, if necessary.

Assessment of bioclimatic comfort conditions based on Physiologically Equivalent Temperature (PET) using the RayMan Model in Iran

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohammad Daneshvar ◽  
Ali Bagherzadeh ◽  
Taghi Tavousi
Keyword(s):  
Thermal Comfort ◽  
Physiological Stress ◽  
Coastal Areas ◽  
Physiologically Equivalent Temperature ◽  
Annual Precipitation ◽  
Equivalent Temperature ◽  
The Caspian Sea ◽  
Bioclimatic Comfort ◽  
The Persian Gulf ◽  
Rayman Model

AbstractIn this study thermal comfort conditions are analyzed to determine possible thermal perceptions during different months in Iran through the Physiologically Equivalent Temperature (PET). The monthly PET values produced using the RayMan Model ranged from −7.6°C to 46.8°C. Over the winter months the thermal comfort condition (18–23°C) were concentrated in southern coastal areas along the Persian Gulf and Oman Sea. Most of the country experienced comfort conditions during the spring months, in particular in April, while during the summer months of July and August no thermal comfort conditions were observed. In November coastal areas of the Caspian Sea had the same physiological stress level of thermal comfort as April. The map produced showing mean annual PET conditions demonstrated the greatest spatial distribution of comfortable levels in the elevation range from 1000 to 2000 meter a.s.l., with annual temperatures of 12–20°C and annual precipitation of under 200 mm. The statistical relationship between PET conditions and each controlling parameter revealed a significant correlation in areas above 2000 meter, annual temperature over 20°C and annual precipitation of 200–400 mm with a correlation coefficient (R 2) of 0.91, 0.97 and 0.96, respectively.

URBAN FACADE GEOMETRY ON OUTDOOR COMFORT CONDITIONS: A REVIEW

2020 ◽  
Vol 4 (1) ◽  
pp. 45
Author(s):  
Elahe Mirabi ◽  
Nasrollahi Nazanin
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Natural Ventilation ◽  
Flow Behavior ◽  
Air Flow ◽  
Urban Geometry ◽  
Wide Range ◽  
Low Energy Buildings ◽  
Outdoor Comfort ◽  
Solar Access

<p>Designing urban facades is considered as a major factor influencing issues<br />such as natural ventilation of buildings and urban areas, radiations in the<br />urban canyon for designing low-energy buildings, cooling demand for<br />buildings in urban area, and thermal comfort in urban streets. However, so<br />far, most studies on urban topics have been focused on flat facades<br />without details of urban layouts. Hence, the effect of urban facades with<br />details such as the balcony and corbelling on thermal comfort conditions<br />and air flow behavior are discussed in this literature review. <strong>Aim</strong>: This<br />study was carried out to investigate the effective factors of urban facades,<br />including the effects of building configuration, geometry and urban<br />canyon’s orientation. <strong>Methodology and Results</strong>: According to the results,<br />the air flow behavior is affected by a wide range of factors such as wind<br />conditions, urban geometry and wind direction. Urban façade geometry<br />can change outdoor air flow pattern, thermal comfort and solar access.<br /><strong>Conclusion, significance and impact study</strong>: In particular, the geometry of<br />the facade, such as indentation and protrusion, has a significant effect on<br />the air flow and thermal behavior in urban facades and can enhance<br />outdoor comfort conditions. Also, Alternation in façade geometry can<br />affect pedestrians' comfort and buildings energy demands.</p>

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 Numerical simulation of urban thermal plume merging

2021 ◽  
Author(s):  
Shuojun Mei ◽  
Chao Yuan ◽  
Wenhui He ◽  
Tanya Talwar
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Urban Areas ◽  
Turbulence Models ◽  
Wave Radiation ◽  
Thermal Plume ◽  
Water Tank ◽  
Surface Cooling ◽  
Thermal Plumes ◽  
The Impact

&lt;p&gt;Densely packed urban buildings trap outgoing long-wave radiation, leading to reduced surface cooling and increased building surface temperature. In calm conditions, poor natural ventilation causes both thermal comfort and air quality issue. The buoyancy flow generated by heated urban surfaces is the main driving of the urban flow and pollutant dispersion. A 3D numerical modelling is conducted to investigate the thermal plumes merging and buoyancy-driven airflow in urban areas. The performances of four different turbulence models, i.e., two URANS (Unsteady Reynolds-averaged Navier&amp;#8211;Stokes equations) models and two LES (Large-Eddy Simulation) models are evaluated by comparing the velocity field with previous water tank measurements. Validation results show that all four turbulence models can capture the bending of thermal plumes toward the centre, and LES models provide a better prediction on the vertical velocity profiles, while both URANS models show underestimation. The plume merging mechanism is analysed with the high accuracy LES results. Both pressure difference and swaying motion caused by mean flow and turbulence are important for plume merging. The turbulence coherent structure of plume merging is analysed by a quadrant analysis, which shows ejection and sweep events could significantly change with the building density. A case study with complex urban geometry is conducted to show the impact of thermal plumes merging in the real high-density urban areas. The convergence airflow at the pedestrian level is estimated to 2 m/s under a surface-air temperature difference of 5 &amp;#176;C, which is comparable to wind-driven ventilation and beneficial to thermal comfort and air quality.&lt;/p&gt;

scholarly journals Thermal Comfort Simulation on Cik Ditiro Corridor

2019 ◽  
Vol 46 (1) ◽  
pp. 67-78
Author(s):  
Septian Eka Prayoga ◽  
Arif Kusumawanto
Keyword(s):  
Land Use ◽  
Thermal Comfort ◽  
Urban Areas ◽  
Rapid Development ◽  
Thermal Conditions ◽  
Simulation Method ◽  
Surface Material ◽  
Climate Variable ◽  
The City ◽  
Research Show

Surface materials that turn into hard surface material and lack of vegetations are some of the effects of rapid development that can affect the micro climate in urban areas. This happened on Cik Ditiro corridor in the city of Yogyakarta which had quite dense activities, this was marked by various functions of land use and human activities throughout the day. The method is simulation method that uses the EnviMET 4.0 software and the empirical measurements. This method is to simulate the value of each climate variable in existing conditions and ideal conditions. The results of this research show that the condition of the Cik Ditiro corridor still belongs to the heat which is uncomfortable thermal conditions. Recommendations result of this research is to make better thermal comfort on corridor. The result of this research to give recommendations in terms of improving better for thermal comfort.

scholarly journals The Temporal Variation of the Microclimate and Human Thermal Comfort in Urban Wetland Parks: A Case Study of Xixi National Wetland Park, China

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1322
Author(s):  
Zhiyong Zhang ◽  
Jianhua Dong ◽  
Qijiang He ◽  
Bing Ye
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Temporal Variations ◽  
Cold Season ◽  
Scientific Data ◽  
Cold Weather ◽  
Recreational Activities ◽  
Human Thermal Comfort ◽  
Island Effect ◽  
Urban Wetland

As an important part of the ecological infrastructure in urban areas, urban wetland parks have the significant ecological function of relieving the discomfort of people during their outdoor activities. In recent years, the specific structures and ecosystem services of urban wetland parks have been investigated from different perspectives. However, the microclimate and human thermal comfort (HTC) of urban wetland parks have rarely been discussed. In particular, the changing trends of HTC in different seasons and times have not been effectively presented. Accordingly, in this research, a monitoring platform was established in Xixi National Wetland Park, China, to continually monitor its microclimate in the long term. Via a comparison with a control site in the downtown area of Hangzhou, China, the temporal variations of the microclimate and HTC in the urban wetland park are quantified, and suggestions for clothing are also provided. The results of this study demonstrate that urban wetland parks can mitigate the heat island effect and dry island effect in summer. In addition, urban wetland parks can provide ecological services at midday during winter to mitigate the cold island effect. More importantly, urban wetland parks are found to exhibit their best performance in improving HTC during the daytime of the hot season and the midday period of the cold season. Finally, the findings of this study suggest that citizens should take protective measures and enjoy their activities in the morning, evening, or at night, not at midday in hot weather. Moreover, extra layers are suggested to be worn before going to urban wetland parks at night in cold weather, and recreational activities involving accommodation are not recommended. These findings provide not only basic scientific data for the assessment of the management and ecological health value of Xixi National Wetland Park and other urban wetland parks with subtropical monsoon climates, but also a reference for visitor timing and clothing suggestions for recreational activities.

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