Estimating Terrestrial Radiation for Human Thermal Comfort in Outdoor Urban Space

Cities inadvertently create warmer and drier urban climate conditions than their surrounding areas through urbanization that replaces natural surfaces with impervious materials. These changes cause heat-related health problems and many studies suggest microclimatic urban design (MUD) as an approach to address these problems. In MUD-related research, although terrestrial radiation plays an important role in human thermal comfort and previous studies use thermal comfort models to identify human heat stress, few studies have addressed the effect of terrestrial radiation. This study develops the ground ratio factor (GRF) model to estimate the different terrestrial radiation according to different ground conditions. Three types of ground materials (asphalt, concrete, and grass) were considered in the model, and field studies were conducted in humid subtropical climate (Cfa) zone during the hot season (13 July to 19 September 2020). The model was validated by comparing the predicated terrestrial radiation (PTR) from the model with the actual terrestrial radiation (ATR). The results showed that there is a statistically significant strong correlation between PTR and ATR. The model can contribute to MUD strategies by updating existing human energy budget models, which can lead to the measurement of more accurate human thermal comfort for mitigating thermal environments.

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Empirical Model of Human Thermal Comfort in Subtropical Climates: A First Approach to the Brazilian Subtropical Index (BSI)

Atmosphere ◽

10.3390/atmos9100391 ◽

2018 ◽

Vol 9 (10) ◽

pp. 391 ◽

Cited By ~ 4

Author(s):

João Gobo ◽

Marlon Faria ◽

Emerson Galvani ◽

Fabio Goncalves ◽

Leonardo Monteiro

Keyword(s):

Thermal Comfort ◽

Empirical Model ◽

Thermal Sensation ◽

Meteorological Data ◽

Well Being ◽

Global Solar Radiation ◽

Coefficient Of Determination ◽

Subtropical Climate ◽

Human Thermal Comfort ◽

The City

The bioclimatic well-being of individuals is associated with the environmental characteristics of where they live. Knowing the relationships between local and regional climatic variables as well as the physical characteristics of a given region and their implications on thermal comfort is important for identifying aspects of thermal sensation in the population. The aim of this study is to develop an empirical model of human thermal comfort based on subjective and individual environmental patterns observed in the city of Santa Maria, located in the state of Rio Grande do Sul, Brazil (Subtropical climate). Meteorological data were collected by means of an automatic meteorological station installed in the city center, which contained sensors measuring global solar radiation, air temperature, globe temperature (via a grey globe thermometer), relative humidity and wind speed and direction. A total of 1720 people were also interviewed using a questionnaire adapted from the model recommended by ISO 10551. Linear regressions were performed to obtain the predictive model. The observed results proposed a new empirical model for subtropical climate, the Brazilian Subtropical Index (BSI), which was verified to be more than 79% accurate, with a coefficient of determination of 0.926 and an adjusted R2 value of 0.924.

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15 year re-analysis of the urban climate of Amsterdam using WRF

10.5194/egusphere-egu2020-11560 ◽

2020 ◽

Author(s):

Sytse Koopmans ◽

Gert-Jan Steeneveld ◽

Ronald van Haren ◽

Albert Holtslag

Keyword(s):

Data Assimilation ◽

The Netherlands ◽

Thermal Comfort ◽

Prediction Models ◽

Weather Prediction ◽

Urban Climate ◽

Urban Canopy ◽

Human Thermal Comfort ◽

Weather Observations ◽

Simulated Precipitation

15 year re-analysis of the urban climate of Amsterdam using WRF &#160;Sytse Koopmans1 ([email protected]), Gert-Jan Steeneveld1, Ronald van Haren2, Albert A.M. Holtslag1.&#160;1 Wageningen University and Research, the Netherlands:2 Netherlands eScience Center, the Netherlands:&#160;&#160;Ongoing world-wide climate change and urbanization illustrate the need to understand urban hydrometeorology and its implications for human thermal comfort and water management. Numerical weather prediction models can assist to understand these issues, as they progress increasingly towards finer scales. With high model resolutions (grid spacing of 100m), effective representation of cities becomes crucial. The complex structures of cities, configuration of buildings, streets and scattered vegetation, require a different modelling approach than the homogeneous rural surroundings. The current urban canopy-layer schemes account for these city specific characteristics, but differ substantially amongst each other due to uncertainty in land use parameters and incomplete physical understanding. Therefore, the hindcasting of the urban environment needs improvement.In this study, we improve the WRF (Weather Research and Forecasting) mesoscale model performance by incorporating observations of a variety of sources using data assimilation (WRF-3DVAR) and nudging techniques on a resolution up to 167 meter. Data assimilation aims to accurately describe the most probable atmospheric state by steering the model fields in the direction of the observations. Specific to urban boundary layers, a novel approach has been developed to nudge modelled urban canyon temperatures with quality controlled urban weather observations. Adjusting the urban fabric accordingly is crucial, because of the large heat storage within urban canopies. The road and wall layers of the urban canopy are adjusted depending on the bulk heat transfer coefficient and urban geometry. Other data assimilation sources consists of WMO synoptic weather observations and volume radar data.The results of the 15-year climatological urban re-analysis are here presented and it is subdivided in three key questions. First, we attempt to answer how large the trends are in human thermal comfort over the 15 year period. Second, we investigate if there are seasonality&#8217;s detected in maximum urban heat island intensities. Earlier found hysteresis-like curves were reproduced to a large extent for for pedestrian level air temperatures. Lastly, we analyse trends in extreme precipitation using simulated precipitation data on one second interval.

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Impact of urbanization level on the interactions of urban area, the urban climate, and human thermal comfort

Applied Geography ◽

10.1016/j.apgeog.2016.12.007 ◽

2017 ◽

Vol 79 ◽

pp. 50-72 ◽

Cited By ~ 29

Author(s):

Kenobi Isima Morris ◽

Andy Chan ◽

Kwami Justina Kwami Morris ◽

Maggie C.G. Ooi ◽

Muhammad Y. Oozeer ◽

...

Keyword(s):

Thermal Comfort ◽

Urban Area ◽

Urban Climate ◽

Urbanization Level ◽

Human Thermal Comfort ◽

Impact Of Urbanization

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ANÁLISE DO CONFORTO TÉRMICO HUMANO NO MUNICÍPIO DE ARAPIRACA – ALAGOAS, UTILIZANDO SOFTWARE MATLAB (ANALYSIS OF THE HUMAN THERMAL COMFORT THE CITY OF ARAPIRACA - ALAGOAS USING SOFTWARE MATLAB)

Revista Brasileira de Geografia Física ◽

10.26848/rbgf.v7.5.p939-948 ◽

2015 ◽

Vol 7 (5) ◽

pp. 939

Author(s):

Juliete Baraúna dos Santos

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Effective Temperature ◽

Rainy Season ◽

Prolonged Exposure ◽

Urban Climate ◽

Heat Stroke ◽

Human Thermal Comfort ◽

Discomfort Index ◽

The City

Foram obtidas medidas das variáveis meteorológicas temperatura do ar, umidade relativa do ar e velocidade do vento através da estação automática instalada em Arapiraca com a finalidade de monitorar as condições de tempo no município em diferentes períodos (época chuvosa e seca). Sendo utilizado o índice de desconforto (ID), o índice de desconforto de Kawamura (IDK), índice da temperatura efetiva (TE) e o índice de temperatura efetiva em função do vento (TEV). Os valores mais elevados dos índices que foram registrados para o período chuvoso, foram do índice id com aproximadamente 2,5 °C acima dos valores observados da temperatura do ar (em média 26,5 °C), caracterizando crescente desconforto para os indivíduos locais. Para o período seco não houve registros de grandes variações entre os respectivos índices. E assim como no período chuvoso, os valores mais elevados no período seco foram do índice id, indicando nesse período também forte desconforto. Os valores obtidos estiveram condizentes com a literatura, sendo a sensação térmica mais preponderante durante o inverno. E, de acordo com as variações, em todo período de estudo (05 de maio de 2008 a 05 de maio de 2011) a população foi submetida aos alertas de atenção e muito cuidado, situação esta que pôde provocar fadiga ou cãibras, esgotamento e insolação nos casos de exposição prolongada e atividade física. A B S T R A C T Measurements of meteorological variables air temperature, relative humidity and wind speed by automatic station installed in Arapiraca in order to monitor the weather conditions in the city in different periods (dry and rainy season) were obtained. Being used the discomfort index (ID), the discomfort index of Kawamura (IDK), index of effective temperature (TE) and the index of effective temperature as a function of wind (TEv). Higher index values that were recorded for the rainy season, the index id were approximately 2.5 ° C above the observed values of air temperature (average 26.5 ° C), indicating increasing discomfort for local individuals . For the dry period there were no reports of large variations between the respective indices. And just as the rainy season, the highest values in the dry season were the index id, indicating that period also strong discomfort. The values obtained were consistent with the literature, the most predominant wind chill during the winter. And, according to the variations in the study period (May 5, 2008 to 05 maio 2011) the population was subjected to warnings of attention and care, a situation that could cause fatigue or cramps, exhaustion and heat stroke in cases of prolonged exposure and physical activity. Key-Words: Urban climate. Thermal comfort Human. Bioclimatic

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Long-term impact of rapid urbanization on urban climate and human thermal comfort in hot-arid environment

Building and Environment ◽

10.1016/j.buildenv.2018.06.007 ◽

2018 ◽

Vol 142 ◽

pp. 83-100 ◽

Cited By ~ 11

Author(s):

Shereif H. Mahmoud ◽

Thian Yew Gan

Keyword(s):

Thermal Comfort ◽

Urban Climate ◽

Arid Environment ◽

Rapid Urbanization ◽

Human Thermal Comfort ◽

Long Term Impact

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Indoor thermal comfort conditions in summer under subtropical climate conditions

International Journal of Sustainable Energy ◽

10.1080/14786451.2019.1701472 ◽

2019 ◽

Vol 39 (4) ◽

pp. 396-411

Author(s):

Kyriakos S. Xystouris ◽

Paris A. Fokaides ◽

Panagiota Antoniadou ◽

Agis M. Papadopoulos

Keyword(s):

Thermal Comfort ◽

Subtropical Climate ◽

Climate Conditions ◽

Indoor Thermal Comfort

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Calculating human thermal comfort and thermal stress in the PALM model system 6.0

Geoscientific Model Development ◽

10.5194/gmd-13-3055-2020 ◽

2020 ◽

Vol 13 (7) ◽

pp. 3055-3065 ◽

Cited By ~ 2

Author(s):

Dominik Fröhlich ◽

Andreas Matzarakis

Keyword(s):

Thermal Comfort ◽

City Planning ◽

Urban Climate ◽

Climate Index ◽

Mean Radiant Temperature ◽

Thermal Indices ◽

Large Eddy Simulation Model ◽

Human Thermal Comfort ◽

Model Based ◽

Radiant Temperature

Abstract. In the frame of the project “MOSAIK – Model-based city planning and application in climate change”, a German-wide research project within the call “Urban Climate Under Change” ([UC]2) funded by the German Federal Ministry of Education and Research (BMBF), a biometeorology module was implemented into the Parallelized Large-Eddy Simulation Model (PALM) system. The new biometeorology module is comprised of methods for the calculation of UV-exposure quantities, a human–biometeorologically weighted mean radiant temperature (Tmrt), as well as for the estimation of human thermal comfort or stress. The latter is achieved through the implementation of the three widely used thermal indices: perceived temperature (PT), Universal Thermal Climate Index (UTCI), as well as physiologically equivalent temperature (PET). Comparison calculations were performed for the PT, UTCI and PET indices based on the SkyHelios model and showing PALM calculates higher values in general. This is mostly due to a higher radiational gain leading to higher values of mean radiant temperature. For a more direct comparison, the PT, PET and UTCI indices were calculated by the biometeorology module, as well as the programs provided by the attachment to Verein Deutscher Ingenieure (VDI) guideline 3787, as well as by the RayMan model based on the very same input dataset. Results show deviations below the relevant precision of 0.1 K for PET and UTCI and some deviations of up to 2.683 K for PT caused by repeated unfavorable rounding in very rare cases (0.027 %).

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Field studies on human thermal comfort — An overview

Building and Environment ◽

10.1016/j.buildenv.2013.02.015 ◽

2013 ◽

Vol 64 ◽

pp. 94-106 ◽

Cited By ~ 159

Author(s):

Asit Kumar Mishra ◽

Maddali Ramgopal

Keyword(s):

Thermal Comfort ◽

Field Studies ◽

Human Thermal Comfort

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Effect of Landscape Microclimates on Thermal Comfort and Physiological Wellbeing

Sustainability ◽

10.3390/su11195387 ◽

2019 ◽

Vol 11 (19) ◽

pp. 5387 ◽

Cited By ~ 2

Author(s):

Binyi Liu ◽

Zefeng Lian ◽

Robert D. Brown

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Thermal Comfort ◽

Skin Temperature ◽

Skin Conductance ◽

Thermal Sensation ◽

Global Climate ◽

Evidence Base ◽

Climate Conditions ◽

Human Thermal Comfort

Global climate change and intensifying heat islands have reduced human thermal comfort and health in urban outdoor environments. However, there has been little research that has focused on how microclimates affect human thermal comfort, both psychologically and physiologically. We investigated the effect of a range of landscape microclimates on human thermal comfort and health using questionnaires and physiological measurements, including skin temperature, skin conductance, and heart rate variability, and compared the results with the effect of prevailing climate conditions in open spaces. We observed that in landscape microclimates, thermal sensation votes significantly decreased from 1.18 ± 0.66 (warm–hot) to 0.23 ± 0.61 (neutral–slightly warm), and thermal comfort increased from 1.18 ± 0.66 (uncomfortable–neutral) to 0.23 ± 0.61 (neutral–comfortable). In the landscape microclimates, skin temperature and skin conductance decreased 0.3 ± 0.8 °C and 0.6 ± 1.0 μs, respectively, while in the control, these two parameters increased by 0.5 ± 0.9 °C and 0.2 ± 0.7 μs, respectively. Further, in landscape microclimates, subject heart rate variability increased significantly. These results suggest landscape microclimates improve human thermal comfort and health, both psychologically and physiologically. These findings can provide an evidence base that will assist urban planners in designing urban environments for the health and wellbeing of residents.

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Solar assisted cooling rule in indoor air quality

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v10i4.pp3948-3956 ◽

2020 ◽

Vol 10 (4) ◽

pp. 3948

Author(s):

Ali M. Baniyounes ◽

Yazeed Y. Ghadi

Keyword(s):

Air Quality ◽

Thermal Comfort ◽

Indoor Air Quality ◽

Indoor Air ◽

Air Conditioning ◽

Cooling System ◽

Internal Heat ◽

Subtropical Climate ◽

Mould Growth ◽

Human Thermal Comfort

Indoor air quality as always is the centre of attention for researchers, architect developers and public health officials. As every-one know. The human exposure to a variety of indoor pollutants and the high cost of energy are the motivation for these kinds of studies. Fungus and mould growth has always been a problem in subtropical climate areas due to the high temperature and high humidity. Generally in institutional buildings, most of the internal heat load is generated by human body and thermal comfort is achieved with extensive usage of recycled air and air conditioning. The main considerations in any air conditioning system economisers are based on the usage of recycled air and air ventilation. The current practice in an institutional building cooling system under subtropical climate is to curb the mould issue by overcooling large recirculation airflow to remove the moisture content from the air, which is considered as an expensive practice. The use of a solar desiccant cooling system to reduce moisture from the air and to improve indoor air quality is found to be economical, environmental friendly and readily achievable in the tropics. This technology is the future alternative to the conventional vapour compression cooling system to maintain human thermal comfort conditions and enhance indoor air quality. Solar desiccant cooling systems are also environmentally friendly and energy efficient. This paper presents review on a solar desiccant cooling system and its effect on indoor air quality. It first introduces the issue of air moisture, mould growth and indoor air quality and then the development and application of thermally activated desiccant cooling technologies.

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