scholarly journals Investigating the Behaviour of Human Thermal Indices under Divergent Atmospheric Conditions: A Sensitivity Analysis Approach

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 580 ◽  
Author(s):  
Ioannis Charalampopoulos ◽  
Andre Santos Nouri
Keyword(s):  
Energy Balance ◽  
Thermal Comfort ◽  
Thermal Conditions ◽  
Radiation Condition ◽  
Additive Models ◽  
Balance Model ◽  
Climate Index ◽  
Atmospheric Conditions ◽  
Thermal Indices ◽  
Human Thermal Comfort

This paper aims to analyse and conclude about the behaviour of the most commonly used human thermal comfort indices under a variety of atmospheric conditions in order to provide further information about their appropriateness. Utilising Generalized Additive Models (GAMs), this article examines the indices’ sensitivity when exposed to diverse classified atmospheric conditions. Concentrated upon analysing commonly used human thermal indices, two Statistical/Algebraic indices (Thermohygrometric Index (THI) and HUMIDEX (HUM)), and four Energy Balance Model indices (Physiologically Equivalent Temperature (PET), modified PET (mPET), Universal Thermal Climate Index (UTCI), and Perceived Temperature (PT)) were selected. The results of the study are twofold, the identification of (1) index sensitivity to parameters’ variation, and change rates, resultant of different atmospheric conditions; and, (2) the overall pertinence of each of the indices for local thermal comfort evaluation. The results indicate that the thermohygrometric indices cannot follow and present the thermal conditions’ variations. On the other hand, UTCI is very sensitive under low radiation condition, and PET/mPET present higher sensitivity when the weather is dominated by high radiation and air temperature. PT index provides the lower sensitive among the human energy balance indices, but this is adequately sensitive to describe the thermal comfort environment.

A Human Energy Balance Model With Clothing Effects for Estimating Human Thermal Comfort

2010 ◽  
Author(s):  
Atsumasa Yoshida ◽  
Yasuhiro Shimazaki ◽  
Shinichi Kinoshita ◽  
Ryota Suzuki
Keyword(s):  
Heat Transfer ◽  
Energy Balance ◽  
Thermal Comfort ◽  
Human Body ◽  
Thermal Load ◽  
Thermal Environment ◽  
Energy Balance Model ◽  
Balance Model ◽  
Comfort Index ◽  
Human Thermal Comfort

There is an increased world attention on environmental issues with the global trend of environmental degradation. Especially thermal environment was highly concerned as human safety. We have been focused on creation of amenity environment with energy-saving way. This study is uncommonly dealing with human feeling for human thermal comfort, that is to say quantification of environment has been done. The feeling of comfort is mixed sense and can be totally easier to improve compared with straightforward way, and this may lead to energy and cost saving way of improvement. Moreover, this is human-oriented and can reflect humans’ wishes. Since thermal comfort index is useful tool for understanding the present state and evaluating the impact of countermeasures, effectiveness of human thermal load which is thermal comfort index based on energy balance of human body was examined. The human thermal comfort around the human body in outdoor is influenced by six dominant factors; air temperature, humidity, solar radiation, wind speed, metabolism and clothing. The difference between indoor and outdoor is expressed mainly as non-uniform and unsteady. Therefore, the unsteady responses of each dominant factors were examined and clarified human thermal load is quite good estimation of human thermal comfort. In steady state and even in unsteady state, thermal comfort can be obtained by using human thermal load on the whole. The reason is human thermal load consider the amount of physiology and also weather parameters. In the process of creating energy balance model of human, clothing material was deeply considered. For establishing better thermal environment, clothing material is of great use, because clothing material has an impact on thermal exchange between exterior environment and human body and more easy way to improve in 6 factors. The traditional treatment of clothing in human science was only resistance of heat transfer and this was not enough for all clothing effects. In daily life, effect of humidity exists and moisture property is required. Moreover color of material has impact on energy balance in clothing material. In order to show a way of better thermal environment, the heat and the moisture transfer coefficients on clothing material, radiative properties, and additional properties such as convection heat transfer coefficient were measured, and energy flow of clothing material was totally investigated. Finally, the effects of clothing material for human thermal comfort were predicted and this energy balance human model has become much better model.

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

2020 ◽  
Vol 13 (7) ◽  
pp. 3055-3065 ◽  
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 %).

Transient Human Thermal Comfort Response in Convective and Radiative Environments

2008 ◽  
Author(s):  
Mohamad Al-Othmani ◽  
Nesreen Ghaddar ◽  
Kamel Ghali
Keyword(s):  
Thermal Comfort ◽  
Thermal Conditions ◽  
Activity Level ◽  
Convective Heating ◽  
Convective System ◽  
Clothing Insulation ◽  
Indoor Space ◽  
Human Thermal Comfort ◽  
Walking Activity ◽  
Local Thermal Comfort

In this work, human transient thermal responses and comfort are studied in non-uniform radiant heating and convective heating environments. The focus was on a change from walking activity of human in outdoor cold environment at high clothing insulation to warm indoor environment at sedentary activity level associated with lower clothing insulation. A transient multi-segmented bioheat model sensitive to radiant asymmetry is used to compare how fast the human body approaches steady state thermal conditions in both radiative and convective warm environments. A space thermal model is integrated with the bioheat model to predict the transient changes in skin and core temperature of a person subject to change in metabolic rate and clothing insulation when entering conditioned indoor space. It was found that overall thermal comfort and neutrality were reached in 6.2 minutes in the radiative environment compared to 9.24 minutes in convective environment. The local thermal comfort of various body segments differed in their response to the convective system where it took more than 19 minutes for extremities to reach local comfort unlike the radiative system where thermal comfort was attained within 7 minutes.

scholarly journals Future Changes in Human-Biometeorological Index Classes in Three Regions of Luxembourg, Western-Central Europe

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hanna Leona Lokys ◽  
Jürgen Junk ◽  
Andreas Krein
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Stress ◽  
Thermal Comfort ◽  
Central Europe ◽  
Spatial Resolution ◽  
Climate Index ◽  
Human Thermal Comfort ◽  
Air Temperatures ◽  
The Impact

Projected climate change will cause increasing air temperatures affecting human thermal comfort. In the highly populated areas of Western-Central Europe a large population will be exposed to these changes. In particular Luxembourg—with its dense population and the large cross-border commuter flows—is vulnerable to changing thermal stress. Based on climate change projections we assessed the impact of climate change on human thermal comfort over the next century using two common human-biometeorological indices, the Physiological Equivalent Temperature and the Universal Thermal Climate Index. To account for uncertainties, we used a multimodel ensemble of 12 transient simulations (1971–2098) with a spatial resolution of 25 km. In addition, the regional differences were analysed by a single regional climate model run with a spatial resolution of 1.3 km. For the future, trends in air temperature, vapour pressure, and both human-biometeorological indices could be determined. Cold stress levels will decrease significantly in the near future up to 2050, while the increase in heat stress turns statistically significant in the far future up to 2100. This results in a temporarily reduced overall thermal stress level but further increasing air temperatures will shift the thermal comfort towards heat stress.

scholarly journals Application of wearable EEG sensors for indoor thermal comfort measurements

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 214
Author(s):  
Silvia Angela Mansi ◽  
Ilaria Pigliautile ◽  
Camillo Porcaro ◽  
Anna Laura Pisello ◽  
Marco Arnesano
Keyword(s):  
Thermal Comfort ◽  
Brain Activity ◽  
Low Cost ◽  
Wearable Sensors ◽  
Real Life ◽  
Thermal Conditions ◽  
Ambient Temperatures ◽  
Human Thermal Comfort ◽  
Power Spectral ◽  
Wearable Eeg

Multidomain comfort theories have been demonstrated to interpret human thermal comfort in buildings by employing human-centered physiological measurements coupled with environmental sensing techniques. Thermal comfort has been correlated with brain activity through electroencephalographic (EEG) measurements. However, the application of low-cost wearable EEG sensors for measuring thermal comfort has not been thoroughly investigated. Wearable EEG devices provide several advantages in terms of reduced intrusiveness and application in real-life contexts. However, they are prone to measurement uncertainties. This study presents results from the application of an EEG wearable device to investigate changes in the EEG frequency domain at different indoor temperatures. Twenty-three participants were enrolled, and the EEG signals were recorded at three ambient temperatures: cold (16 °C), neutral (24 °C), and warm (31 °C). Then, the analysis of brain Power Spectral Densities (PSDs) was performed, to investigate features correlated with thermal sensations. Statistically significant differences of several EEG features, measured on both frontal and temporal electrodes, were found between the three thermal conditions. Results bring to the conclusion that wearable sensors could be used for EEG acquisition applied to thermal comfort measurement, but only after a dedicated signal processing to remove the uncertainty due to artifacts.

scholarly journals Thermal Comfort Assessment and Heat-Related Illnesses among Sellers in Periodic Local Markets: A Case Study in Hot and Dry Climate of Iran

2021 ◽  
Author(s):  
Hoda Rahimifard ◽  
Hamidreza Heidari ◽  
Abolfazl Mohamadbeigi ◽  
Ahmad Soltanzadeh ◽  
Mohsen Mahdinia ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Environmental Parameters ◽  
Thermal Conditions ◽  
Tympanic Temperature ◽  
Thermal Indices ◽  
Local Conditions ◽  
Environmental Indices ◽  
Local Markets ◽  
Hot Climate ◽  
Globe Temperature

Background:This study aims to evaluate the thermal conditions of periodic local markets and determine the thermal comfort and sensation of sellers, as well as the prevalence of heat-related diseases in the hot and dry climate of Iran. Methods:In this study, thermal comfort and sensation of 330 sellers from periodic markets in Qom city, a dry and hot climate in Iran, were evaluated. Measurements were performed for 15 days, from July 16 to August 1. To assess environmental thermal condition, wet bulb globe temperature (WBGT) index and discomfort index (DI) were determined, and participants' tympanic temperature was determined to consistency assessment with thermal indices. Finally, the effects of environmental, personal, and working conditions on the prevalence of heat-related diseases among sellers were determined. Results:The environmental indices, including DI and WBGT index, had the most association with heat-related illnesses and tympanic temperature (P<0.05). The sellers perceived the environmental conditions as warm to hot after 1:00 pm. Besides, they expressed an uncomfortable or very uncomfortable situation after 12:00 pm. The findings showed that environmental parameters play a more important role in the prevalence of heat-related diseases and heat strain than individual and occupational factors. Conclusion:The sellers may be at risk of heat stress in outdoor markets in nearly half of the workday in the summer months. Therefore, it is very important that these people receive the necessary training in the prevention of heat illness in order to take appropriate protective measures in accordance with local conditions.

scholarly journals Impact of biometeorological conditions and air pollution on influenza-like illnesses incidence in Warsaw

2021 ◽  
Author(s):  
Katarzyna Lindner-Cendrowska ◽  
Peter Bröde
Keyword(s):  
Generalized Additive Models ◽  
Age Groups ◽  
Health Resources ◽  
Additive Models ◽  
Temperate Climate ◽  
Climate Index ◽  
Climate Change Scenarios ◽  
Atmospheric Conditions ◽  
Thermal Climate ◽  
Pm2.5 And Pm10

AbstractIn order to assess the influence of atmospheric conditions and particulate matter (PM) on the seasonally varying incidence of influenza-like illnesses (ILI) in the capital of Poland—Warsaw, we analysed time series of ILI reported for the about 1.75 million residents in total and for different age groups in 288 approximately weekly periods, covering 6 years 2013–2018. Using Poisson regression, we predicted ILI by the Universal Thermal Climate Index (UTCI) as biometeorological indicator, and by PM2.5 and PM10, respectively, as air quality measures accounting for lagged effects spanning up to 3 weeks. Excess ILI incidence after adjusting for seasonal and annual trends was calculated by fitting generalized additive models. ILI morbidity increased with rising PM concentrations, for both PM2.5 and PM10, and with cooler atmospheric conditions as indicated by decreasing UTCI. While the PM effect focused on the actual reporting period, the atmospheric influence exhibited a more evenly distributed lagged effect pattern over the considered 3-week period. Though ILI incidence adjusted for population size significantly declined with age, age did not significantly modify the effect sizes of both PM and UTCI. These findings contribute to better understanding environmental conditionings of influenza seasonality in a temperate climate. This will be beneficial to forecasting future dynamics of ILI and to planning clinical and public health resources under climate change scenarios.

scholarly journals Thermal Indices Influence on Occupants’ Window Opening Behaviours: A Case of Ibadan and Ogbomoso, Oyo State, Nigeria

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Abdulrasaq Kunle Ayinla ◽  
Ilelabayo Ismail Adebisi ◽  
Olubunmi Adedayo Olaoye ◽  
Emmanuel Oloruntoba Aina
Keyword(s):  
Thermal Stress ◽  
Thermal Comfort ◽  
Thermal Conditions ◽  
Climatic Data ◽  
Indoor Climate ◽  
Thermal Indices ◽  
Chi Square ◽  
Air Conditioners ◽  
Window Opening ◽  
Chi Square Analysis

Window opening operations are considered as one of the significant way of regulating indoor climate and maintaining thermal comfort in buildings, even when alternative active devices such as fans and air conditioners are available. This study investigates responses of occupants of the traditional core areas of Ibadan and Ogbomoso to thermal comfort conditions (thermal stress) through window opening behaviours. Climatic data of the two cities were subjected to Evans scale to predict their day and night thermal stress and questionnaires were administered to know how occupants respond to changing thermal conditions through window opening behaviours. Descriptive and inferential statistics were used in analysing the data.The study found the morning periods to be the most comfortable, the afternoon periods offer the most hot discomfort condition and cold discomfort is mostly experienced in the evening periods in both cities. Findings revealed that majority of occupants in both cities prefer to keep their windows opened in the morning and afternoon periods and an increase was observed in the numbers of occupants who prefer to keep their windows closed in the evening periods. This is an indication that building occupants in both cities actively respond to thermal stress using window opening operations. Results obtained from chi square analysis concluded that there is a significant relationship between occupants’ window opening behaviour and thermal conditions at different periods of the day in both cities. Recommendations were given on how to improve on window opening systems in the future.

scholarly journals The Role of Shade in Persian Garden, The Study of Thermal Comfort Conditions in Jahannama and Delgosha gardens

2019 ◽  
Author(s):  
Hassan Taghvaei Seyed ◽  
Mansoureh Tahbaz ◽  
Samaneh Mottaghi Pishe
Keyword(s):  
Thermal Comfort ◽  
Landscape Architecture ◽  
Open Space ◽  
Thermal Conditions ◽  
Structural Features ◽  
Climate Index ◽  
Urban Landscapes ◽  
Local Climate ◽  
The City

Since the advent of modern methods and new constructional approaches in architecture and landscape architecture, traditional architecture techniques which were based on utilizing natural energies have been completely set aside. In this case, the art of Iranian gardening has a great deal of valuable achievements and experiences which need to be reconsidered. Owing to its special geographic situation, the city of Shiraz includes a number of globally well-known gardens such as Eram, Jahannama, and Delgosha garden. As long as Persian gardens are considered as important parts of open and green spaces and urban landscapes in cities, the main purpose of this paper is the study of their structural features along with the role they play in improving environmental quality and comfort conditions. From this point of view in Landscape architecture, a quantitative-qualitative study was performed for the first time based on two distinct samples of Persian garden, Jahannama and Delgosha, to evaluate the thermal conditions of the garden's microclimate compared with the local climate and surrounding urban environment in extreme summer heat as well as intense winter cold. In this research, the latest assessment index of the open space thermal condition named the universal thermal climate index (UTCI) has been employed to evaluate the obtained data on January 24th and 25th of 2013 and July 31th and August 4th of 2014. Field data has been collected by mobile weather forecast facilities capable of recording temperature, humidity, wind, air pressure, and radiation temperature on the pre-set grid in both gardens. Final results obtained by extracting data from meteorological stations and the achieved data indicated that the structural features of the samples can highly mitigate the microclimate condition against local climate as well as short-term and long-term climate of the city. So, the main achievement of the present study is determining the role of Persian garden in improving the quality of microclimate and local climate as well as investigating the role of garden's components in enhancing thermal comfort conditions inside it.

Sign in / Sign up

Export Citation Format

Share Document