scholarly journals Intraurban Temperature Variations: Urban Morphologies of the Densification Process of Copacabana Neighborhood, Brazil

Climate ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 65 ◽  
Author(s):  
Gisele S. Barbosa ◽  
Patricia R. C. Drach ◽  
Oscar D. Corbella
Keyword(s):  
Thermal Sensation ◽  
Morphological Changes ◽  
Urban Morphology ◽  
View Factor ◽  
Physiological Equivalent Temperature ◽  
Urban Models ◽  
Thermal Climate ◽  
Outdoor Comfort ◽  
City Model ◽  
The Tropics

The idea of compact cities is attracting enthusiasts, and some have proposed sustainable options for its implementation. This concept is based on planning for higher density cities with efficient connectivity in their structures. Because climatic characteristics are one of the basic factors to consider when planning a town, the models imported from different climates of Brazil must be intensely scrutinized and analyzed for their adequacy and effectiveness. Previous studies have revealed the inadequacy of the compact city model for tropical countries. In this study, the Copacabana neighborhood in Rio de Janeiro, a city that is currently compact, was assessed using computational tools (ENVI-met) to observe the intraurban temperature dynamics and sky view factor (SVF) alterations at three time-points’ unit occupation history: 1930, 1950, and 2018. To determine the effects of morphological changes on thermal sensation, two outdoor comfort indexes were calculated: the physiological equivalent temperature (PET) and the universal thermal climate (UTCI). From the obtained results, the relationship between urban morphology, air temperature, and thermal comfort indicates that the debate about urban models will be heightened, particularly with regard to the concept of compact cities in the formation of new cities and neighborhoods in the tropics.

scholarly journals In-situ Measurement of Pedestrian Outdoor Thermal Comfort in Universities Campus of Malaysia

2019 ◽  
Author(s):  
Nurnida Elmira Othman ◽  
Sheikh Ahmad Zaki ◽  
Nurul Huda Ahmad ◽  
Azli Razak
Keyword(s):  
Thermal Comfort ◽  
Field Measurement ◽  
Thermal Sensation ◽  
Outdoor Thermal Comfort ◽  
View Factor ◽  
Thermal Preference ◽  
Equivalent Temperature ◽  
Physiological Equivalent Temperature ◽  
Sky View Factor

The present study is intended to evaluate an outdoor thermal comfort at two universities campus in Malaysia. Field measurement and questionnaire survey were conducted simultaneously to assess the microclimatic condition and pedestrian thermal sensation. A total of 3033 samples were collected at seven different sky view factor (SVF) values that range from 0.2 to 0.9. The physiological equivalent temperature (PET) was estimated to evaluate outdoor thermal comfort. It was observed that at a highly shaded area (SVF < 0.35) the respondent’s thermal sensation vote (TSV) are neutral (> 25%), acceptable for thermal acceptance vote (TAV) (> 50%) and no change (> 50%) for thermal preference vote (TPV). For moderate shaded (0.35 ≤ SVF ≤ 0.70) TSV was voted as hot (> 25%), acceptable for TAV (40%), and prefer slightly cooler for TPV (>50%). For less shaded area (0.70 < SVF ≤ 1), TSV was voted as hot and very hot (> 25%), acceptable for TAV (>40%) and prefer slightly cooler for TPV (> 40%). Moreover, the PET value increases simultaneously with the increase of SVF. Results thus suggest that at any given activities such as sitting, walking, and standing also caused effects slightly on the way people thermally perceive it during the on-campus daytime.

scholarly journals Development and initial tests of an urban comfort monitoring system

2021 ◽  
Vol 2042 (1) ◽  
pp. 012051
Author(s):  
Giacomo Chiesa ◽  
Luo Yingjun ◽  
Sheng Yuxuan ◽  
Wang Guoxin ◽  
Zhang Bolun
Keyword(s):  
Thermal Sensation ◽  
Low Cost ◽  
Outdoor Thermal Comfort ◽  
Climate Index ◽  
Thermal Climate ◽  
Outdoor Comfort ◽  
Early Testing ◽  
Cost Measurement ◽  
Radiant Temperature ◽  
Comfort Indices

Abstract The paper presents a newly developed low-cost measurement system for outdoor comfort monitoring. The solution is based on IoT (Internet of Things) technologies and is cloud-connected. The system is able to collect physical environment data, and includes a movable GPS monitoring station as well as the subjective thermal sensation of pedestrians via a devoted app. The cloud interface promptly elaborates the received data to calculate outdoor thermal comfort indices such as UTCI (Universal Thermal Climate Index), MRT (mean radiant temperature), and ET (effective temperature). The system is conceived for supporting both fixed and traveling measurements, and to support correlation studies between monitored environmental variables and personal comfort sensations to promote the local adaptation of comfort indices. Results from early testing are also reported.

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 Evaluation of Outdoor Thermal Sensation and Outdoor Energy Efficiency of a Commercial Pedestrianized Zone

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1324 ◽  
Author(s):  
Xuan Ma ◽  
Hiroatsu Fukuda ◽  
Dian Zhou ◽  
Mengying Wang
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Open Space ◽  
Thermal Sensation ◽  
Heat Island ◽  
Physiological Equivalent Temperature ◽  
Winter Climate ◽  
Coverage Ratio ◽  
Urban Heat ◽  
The Relationship

The growth of the scale of cities intensifies urban heat island (UHI) by obstructing the wind and building more radiation at pedestrian level, thus leading to an energy consumption. Commercial pedestrianized-zones cannot only become symbols of cities but also an important factor increasing local economic income. This study conducts on-site measurement and numerical simulation to evaluate the cooling energy efficiency of different parameters (building, vegetation, pavement material) in Fo Shan city, which locates in hot-summer and warm-winter climate region of China. Also, calculations are done to evaluate the index physiological equivalent temperature (PET) for understanding thermal sensation at a pedestrian level (1.5 m). To evaluate different impacts of this zone renewal on the environment and choose the most energy-saving method, it is easy for us to utilize the linear regression for understanding the relationship between coverage ratio of trees (TCR) and thermal comfort in canyon space, which shows that ∆PET = 0.1703 × TCR + 0.2444 with a most important R2 value of 0.9836, for TCR increases from 12.5% to 22%. In open space, also increasing coverage ratio of trees (TCR) can effectively improve humans’ thermal comfort, which shows that ∆PET = 0.2644 × TCR + 0.3955 with a most important R2 value of 0.8892.

Outdoor thermal comfort in a tropical coastal tourist resort in Haikou, China

2019 ◽  
Vol 29 (5) ◽  
pp. 730-745 ◽  
Author(s):  
Chunjing Shang ◽  
Xinyu Huang ◽  
Yufeng Zhang ◽  
Maoquan Chen
Keyword(s):  
Solar Radiation ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Outdoor Thermal Comfort ◽  
Survey Period ◽  
Physiological Equivalent Temperature ◽  
Local Climate ◽  
Acceptable Range ◽  
Tropical Areas ◽  
Autumn And Winter

Considering the importance of thermal comfort in decision-making in tourism, a transverse study involving micrometeorological measurements and questionnaires was performed at a popular coastal destination during the seasons of spring, autumn and winter. We examined the thermal sensation and thermal acceptability using the physiological equivalent temperature (PET). The results indicate that tourists’ thermal sensations varied with the season and the neutral PETs were 19.2°C, 23.8°C and 23.3°C in winter, spring and autumn. The 90% acceptable ranges of the PET affected by the local climate were 19.6–29.5°C during the entire three-season survey period, 21.4–27.1°C in the spring, 19.2–32°C in the autumn and more than 15.9°C in the winter. The analysis of microclimate parameters that affect thermal comfort in three seasons reveals that people expected weaker solar radiation, stronger wind and lower humidity with the air temperature rising, and vice versa. The acceptable range of wind speed was 0.6–2.5 m/s in winter, 0.6–3.5 m/s in spring and autumn. The acceptable range of solar radiation was 0–150 W/m2 in autumn and 0–250 W/m2 in winter. These findings contribute to the better designs for coastal facilities and the thermal comfort of tropical areas.

scholarly journals Thermal Sensation in Courtyards: Potentialities as a Passive Strategy in Tropical Climates

2020 ◽  
Vol 12 (15) ◽  
pp. 6135 ◽  
Author(s):  
Ivan Julio Apolonio Callejas ◽  
Luciane Cleonice Durante ◽  
Eduardo Diz-Mellado ◽  
Carmen Galán-Marín
Keyword(s):  
Climate Change ◽  
Urban Areas ◽  
Thermal Sensation ◽  
Thermal Response ◽  
Tropical Climate ◽  
Design Strategies ◽  
Physiological Equivalent Temperature ◽  
Synoptic Conditions ◽  
The Impact ◽  
Passive Strategy

Climate change will bring changes to our living conditions, particularly in urban areas. Climate-responsive design strategies through courtyards can help to moderate temperatures and reduce the thermal stress of its occupants. Thermal response inside courtyard is affected not only by its morphological composition but also by subjective factors. Thus, standardized thermal scales may not reflect the stress of the occupants. This study investigated the impact on thermal attenuation provided by a courtyard located in a tropical climate under extreme cold and hot synoptic conditions by means of local thermal sensation scales. Microclimatic variables were monitored, simultaneously with the application of a thermal comfort questionnaire, by using weather stations installed outside and inside the courtyard. The Modified Physiological Equivalent Temperature Index (mPET) was utilized to predict the heat stress. Calibration was conducted using linear regression to attribute particular thermal sensation votes to correspondent mPET values. It was found that thermal sensation can be affected by factors such as psychological, behavioral, and physiological. The courtyard’s form provides a passive cooling effect, stabilizing interior thermal sensation, with attenuation peaks of 6.4 °C on a cold day and 5.0 °C on a hot day. Courtyards are an alternative passive strategy to improve thermal ambience in tropical climate, counterbalancing climate change.

scholarly journals Mediterranean Morphologies in Hot Summer Conditions: Learning from France’s “Glorious Thirty” Holiday Housing

2020 ◽  
Vol 5 (1) ◽  
pp. 19-34
Author(s):  
Marjan Sansen ◽  
◽  
Andrés Martínez ◽  
Philippe Devillers
Keyword(s):  
Case Studies ◽  
Environmental Performance ◽  
Urban Areas ◽  
Urban Morphology ◽  
Coastal Development ◽  
City Centre ◽  
View Factor ◽  
Individual Housing ◽  
Mediterranean Regions ◽  
The One

Climate change and rising temperatures lead to air-conditioning proliferation in summertime in Mediterranean regions. This study links urban morphology to microclimate. It claims that we can learn from holiday housing morphologies designed with an additive approach during the “Glorious Thirty” (1946-75) French coastal development. It is based on a morphological analysis of four case studies, with on the one hand re-drawing and site visiting, on the other hand assessment of environmental performance through key parameters: Absolute Rugosity, Compactness Ratio, Building Density, Mineralization, Sky View Factor (SVF) and H/W Ratio. Compared to literature reference values of a traditional courtyard morphology, the case studies are less compact and with lower H/W Ratio (higher SVF), but they are less mineral than an historical medieval city centre. This research contributes to the search for semi-collective alternatives (for example additive morphologies) to individual housing in peri-urban areas, with a high environmental performance in summertime.

scholarly journals Microclimate Environmental Assessment and Impact of Mountain City Pedestrian Streets in Summer

2020 ◽  
Vol 172 ◽  
pp. 11001
Author(s):  
Ke Xiong ◽  
Zhenjing Yang ◽  
Canhua Cheng
Keyword(s):  
Thermal Comfort ◽  
Environmental Assessment ◽  
Thermal Environment ◽  
Climate Index ◽  
View Factor ◽  
City Street ◽  
Thermal Climate ◽  
The One ◽  
Microclimate Environment ◽  
Important Form

In mountainous cities, walking is an important form of transportation. The microclimate environment of pedestrian streets in summer affects the comfort of pedestrians, especially in hot summer cities. Besides, there are many height differences in mountainous city pedestrian streets, while existing researches of the thermal environment were mainly aimed at plain cities. We used typology to analyze different spatial patterns and tested microclimate of five kinds of streets in the Shanchengxiang of Chongqing. Then the universal thermal climate index (UTCI) was used to evaluate the thermal comfort of different spatial spaces. Firstly, the thermal environment of the mountain city street in summer is extremely uncomfortable and needs to be improved. Secondly, the sky view factor (SVF) has a great impact on the street thermal environment. Among all kinds of streets, the one-sided open B-N (SVF = 0.474) has the worst thermal environment, with an average UTCI of 44.7℃. However, the two-sided enclosed B2-B2 (SVF = 0.052) represents a better thermal environment, with an average UTCI of 35.5℃. The R2 value of 0.88 reflects that the linear correlation between UTCI and SVF is larger than that of H/W, whose R2 value is mere 0.04. Finally, different interfaces and enclosure forms have a great impact on space thermal comfort. This study quantifies the parameters that influence the design of pedestrian streets in mountain cities from the perspective of outdoor microclimate environmental assessment and provide a reference for the sustainable design of regional streets.

Effects of temperature, air movement and initial metabolic rate on thermal sensation during transient state in the tropics

2019 ◽  
Vol 155 ◽  
pp. 70-82 ◽  
Author(s):  
Kuniaki Mihara ◽  
Chandra Sekhar ◽  
Kwok Wai Tham ◽  
Yuichi Takemasa ◽  
Bertrand Lasternas
Keyword(s):  
Metabolic Rate ◽  
Thermal Sensation ◽  
Transient State ◽  
Air Movement ◽  
Effects Of Temperature ◽  
The Tropics

A tropical field study on outdoor bioclimatic comfort of people with different thermal histories

2020 ◽  
pp. 1420326X2095123
Author(s):  
Chunjing Shang ◽  
Yanxi Chen ◽  
Jianhong Cai ◽  
Zhongjun Zhang
Keyword(s):  
Thermal Comfort ◽  
Field Study ◽  
Thermal History ◽  
Environmental Changes ◽  
Thermal Sensation ◽  
Physiological Equivalent Temperature ◽  
Cold Regions ◽  
Bioclimatic Comfort ◽  
Thermal Histories

Several studies reported that the long-term thermal history of the human body affects its thermal comfort and preferences. We conducted a tropical field study in Sanya city, China; 1512 questionnaires were collected from tourists. The tourists had five thermal histories associated with five different climate regions (cold, severely cold, hot summer, cold winter, hot summer and warm winter and temperate regions). Our results showed that the human body's long-term thermal history had distinct influences on their thermal sensation, thermal comfort and preferences at their destination. Greater difference in a subject's thermal history from that of the tourist destination showed greater difference in the bioclimatic comfort and thermal preference. The neutral physiological equivalent temperature (nPET) of tourists with thermal histories in the severely cold and cold regions was 25.6°C and 25.9°C, respectively. The nPET was 1.4°C and 1.7°C higher than that of the temperate regions, respectively. The relationship between thermal acceptability vote and thermal comfort vote showed that the tourists with thermal histories in the severely cold and cold regions were more sensitive to environmental changes than those with histories from the other regions.

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