The Experts below are selected from a list of 102957 Experts worldwide ranked by ideXlab platform
Andreas Matzarakis - One of the best experts on this subject based on the ideXlab platform.
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Concepts and New Implements for Modified Physiologically Equivalent Temperature
Atmosphere, 2020Co-Authors: Yung-chang Chen, Wei-nai Chen, Charles C.-k. Chou, Andreas MatzarakisAbstract:Different kinds of thermal indices have been applied in several decades as essential tools to investigate thermal perception, environmentally thermal conditions, occupant thermal risk, public health, tourist attractiveness, and urban climate. Physiologically Equivalent Temperature (PET) has been proved as a relatively wide applicable thermal indicator above other thermal indices. However, the current practical PET performs a slight variation influenced by changing the humidity and clothing insulation. The improvement of the PET has potentiality for further multi-application as a general and consistent standard to estimate thermal perception and tolerance for different studies. To achieve the above purpose, modified physiologically Equivalent Temperature (mPET) is proposed as an appropriate indicator according to the new structure and requirements of the thermally environmental ergonomics. The modifications to formulate the mPET are considerably interpreted in the principle of the heat transfer inside body, thermo-physiological model, clothing model, and human-environmental interaction in this study. Specifically, the mPET-model has adopted a semi-steady-state approach to calculate an Equivalent Temperature refer to an indoor condition as the mPET. Finally, the sensitivity test of the biometeorological variables and clothing impact proves that the mPET has better performance on the humidity and clothing insulation than the original PET.
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The potential of a modified physiologically Equivalent Temperature (mPET) based on local thermal comfort perception in hot and humid regions
Theoretical and Applied Climatology, 2019Co-Authors: Shing-ru Yang, Yung-chang Chen, Andreas MatzarakisAbstract:Physiologically Equivalent Temperature (PET) is a thermal index that is widely used in the field of human biometeorology and urban bioclimate. However, it has several limitations, including its poor ability to predict thermo-physiological parameters and its weak response to both clothing insulation and humid conditions. A modified PET (mPET) was therefore developed to address these shortcomings. To determine whether the application of mPET in hot-humid regions is more appropriate than the PET, an analysis of a thermal comfort survey database, containing 2071 questionnaires collected from participants in hot-humid Taiwan, was conducted. The results indicate that the thermal comfort range is similar (26–30 °C) when the mPET and PET are applied as thermal indices to the database. The sensitivity test for vapor pressure and clothing insulation also show that the mPET responds well to the behavior and perceptions of local people in a subtropical climate.
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modified physiologically Equivalent Temperature basics and applications for western european climate
Theoretical and Applied Climatology, 2018Co-Authors: Andreas Matzarakis, Yung-chang ChenAbstract:A new thermal index, the modified physiologically Equivalent Temperature (mPET) has been developed for universal application in different climate zones. The mPET has been improved against the weaknesses of the original physiologically Equivalent Temperature (PET) by enhancing evaluation of the humidity and clothing variability. The principles of mPET and differences between original PET and mPET are introduced and discussed in this study. Furthermore, this study has also evidenced the usability of mPET with climatic data in Freiburg, which is located in Western Europe. Comparisons of PET, mPET, and Universal Thermal Climate Index (UTCI) have shown that mPET gives a more realistic estimation of human thermal sensation than the other two thermal indices (PET, UTCI) for the thermal conditions in Freiburg. Additionally, a comparison of physiological parameters between mPET model and PET model (Munich Energy Balance Model for Individual, namely MEMI) is proposed. The core Temperatures and skin Temperatures of PET model vary more violently to a low Temperature during cold stress than the mPET model. It can be regarded as that the mPET model gives a more realistic core Temperature and mean skin Temperature than the PET model. Statistical regression analysis of mPET based on the air Temperature, mean radiant Temperature, vapor pressure, and wind speed has been carried out. The R square (0.995) has shown a well co-relationship between human biometeorological factors and mPET. The regression coefficient of each factor represents the influence of the each factor on changing mPET (i.e., ±1 °C of T a = ± 0.54 °C of mPET). The first-order regression has been considered predicting a more realistic estimation of mPET at Freiburg during 2003 than the other higher order regression model, because the predicted mPET from the first-order regression has less difference from mPET calculated from measurement data. Statistic tests recognize that mPET can effectively evaluate the influences of all human biometeorological factors on thermal environments. Moreover, a first-order regression function can also predict the thermal evaluations of the mPET by using human biometeorological factors in Freiburg.
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Confronting potential future augmentations of the physiologically Equivalent Temperature through public space design: The case of Rossio, Lisbon
Sustainable Cities and Society, 2018Co-Authors: A. Santos Nouri, António Lopes, J. Pedro Costa, Andreas MatzarakisAbstract:Abstract When considering cities such as Lisbon, which due to their Koppen Geiger classification of ‘Csa’, witness hot and dry summers, the translation of local bottom-up knowhow upon climatic guidelines has been a topic of considerable dissemination over recent years. Depicting upon a concrete case study located in Lisbon’s historical quarter, the results from a previous bioclimatic study undertaken by the authors were taken further in order to consider how worst-case-scenarios of climate change (A1FI/RCP8.5) could potentially impact the existing human thermal environment within the square. In addition to considering its existing layout, public space design interventions were also examined within different thermal/temporal scenarios through the use the Physiologically Equivalent Temperature (PET) and PET(Load) indices. The results of the study revealed that within a climatic worse-case-scenario, and without any adaptive measures to address Physiological Stress (PS) levels, the majority of the square presented potential PS thresholds ranging between ‘Extreme Heat Stress Lv.3/4′, with PET values exceeding that of 51 °C and 56 °C. On the other hand, and particularly in regions prone to high levels of solar radiation, the thermal amelioration effects of the proposed public space design interventions presented reductions of PET values up to 16.6 °C.
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A comprehensive analysis of physiologically Equivalent Temperature changes of Iranian selected stations for the last half century
Theoretical and Applied Climatology, 2018Co-Authors: Gholamreza Roshan, Robabe Yousefi, Attila Kovács, Andreas MatzarakisAbstract:As a preliminary and major step for land use planning of the coming years, the study of variability of the past decades’ climatic conditions with comprehensive indicators is of high importance. Given the fact that one of the affected areas by climatic change includes variability of thermal comfort, this study uses the physiologically Equivalent Temperature (PET) to identify and evaluate bioclimatic conditions of 40 meteorological stations in Iran. In this study, PET changes for the period of 1960 to 2010 are analyzed, with the use of Mann-Kendall non-parametric test and Pearson parametric method. The study focuses particularly on the diversity in spatio-temporal distribution of Iran’s bioclimatic conditions. The findings show that the mean frequency percentage of days with comfort is 12.9 % according to the total number of selected stations. The maximum and minimum frequency percentage with values of 17.4 and 10.3 belong to Kerman and Chabahar stations, respectively. The findings of long-term trend analysis for the period of 1960–2010 show that 55 % of the stations have significant increasing trend in terms of thermal comfort class based on the Pearson method, while it is 40 % based on Mann-Kendall test. The results indicate that the highest frequency of days with thermal comfort in the southern coasts of Iran relates to the end of autumn and winter, nevertheless, such ideal conditions for the coastal cities of Caspian Sea and even central stations of Iran relate to mid-spring and mid-autumn. Late summer and early autumn along with late spring can be identified as the most ideal times in the west and northwest part of Iran. In addition, the most important inhibiting factors of thermal comfort prove to be different across the regions of Iran. For instance, in the southern coasts, warm to very hot bioclimatic events and in the west and northwest regions, cold to very cold conditions turn out to be the most important inhibiting factors. When considering the variations across the studied period, an increase in the frequency of thermal comfort condition is observed in almost half of the stations. Moreover, based on Pearson and Mann-Kendall methods, the trend of changes in monthly averages of PET has decreased in most stations and months, which can lead to different consequences in each month and station. Thus, it is expected that due to PET changes in recent decades and to the intensified global warming conditions, Iran’s bioclimatic conditions change in a way that transfers the days with comfort to early spring and late autumn.
Yung-chang Chen - One of the best experts on this subject based on the ideXlab platform.
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Concepts and New Implements for Modified Physiologically Equivalent Temperature
Atmosphere, 2020Co-Authors: Yung-chang Chen, Wei-nai Chen, Charles C.-k. Chou, Andreas MatzarakisAbstract:Different kinds of thermal indices have been applied in several decades as essential tools to investigate thermal perception, environmentally thermal conditions, occupant thermal risk, public health, tourist attractiveness, and urban climate. Physiologically Equivalent Temperature (PET) has been proved as a relatively wide applicable thermal indicator above other thermal indices. However, the current practical PET performs a slight variation influenced by changing the humidity and clothing insulation. The improvement of the PET has potentiality for further multi-application as a general and consistent standard to estimate thermal perception and tolerance for different studies. To achieve the above purpose, modified physiologically Equivalent Temperature (mPET) is proposed as an appropriate indicator according to the new structure and requirements of the thermally environmental ergonomics. The modifications to formulate the mPET are considerably interpreted in the principle of the heat transfer inside body, thermo-physiological model, clothing model, and human-environmental interaction in this study. Specifically, the mPET-model has adopted a semi-steady-state approach to calculate an Equivalent Temperature refer to an indoor condition as the mPET. Finally, the sensitivity test of the biometeorological variables and clothing impact proves that the mPET has better performance on the humidity and clothing insulation than the original PET.
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The potential of a modified physiologically Equivalent Temperature (mPET) based on local thermal comfort perception in hot and humid regions
Theoretical and Applied Climatology, 2019Co-Authors: Shing-ru Yang, Yung-chang Chen, Andreas MatzarakisAbstract:Physiologically Equivalent Temperature (PET) is a thermal index that is widely used in the field of human biometeorology and urban bioclimate. However, it has several limitations, including its poor ability to predict thermo-physiological parameters and its weak response to both clothing insulation and humid conditions. A modified PET (mPET) was therefore developed to address these shortcomings. To determine whether the application of mPET in hot-humid regions is more appropriate than the PET, an analysis of a thermal comfort survey database, containing 2071 questionnaires collected from participants in hot-humid Taiwan, was conducted. The results indicate that the thermal comfort range is similar (26–30 °C) when the mPET and PET are applied as thermal indices to the database. The sensitivity test for vapor pressure and clothing insulation also show that the mPET responds well to the behavior and perceptions of local people in a subtropical climate.
-
modified physiologically Equivalent Temperature basics and applications for western european climate
Theoretical and Applied Climatology, 2018Co-Authors: Andreas Matzarakis, Yung-chang ChenAbstract:A new thermal index, the modified physiologically Equivalent Temperature (mPET) has been developed for universal application in different climate zones. The mPET has been improved against the weaknesses of the original physiologically Equivalent Temperature (PET) by enhancing evaluation of the humidity and clothing variability. The principles of mPET and differences between original PET and mPET are introduced and discussed in this study. Furthermore, this study has also evidenced the usability of mPET with climatic data in Freiburg, which is located in Western Europe. Comparisons of PET, mPET, and Universal Thermal Climate Index (UTCI) have shown that mPET gives a more realistic estimation of human thermal sensation than the other two thermal indices (PET, UTCI) for the thermal conditions in Freiburg. Additionally, a comparison of physiological parameters between mPET model and PET model (Munich Energy Balance Model for Individual, namely MEMI) is proposed. The core Temperatures and skin Temperatures of PET model vary more violently to a low Temperature during cold stress than the mPET model. It can be regarded as that the mPET model gives a more realistic core Temperature and mean skin Temperature than the PET model. Statistical regression analysis of mPET based on the air Temperature, mean radiant Temperature, vapor pressure, and wind speed has been carried out. The R square (0.995) has shown a well co-relationship between human biometeorological factors and mPET. The regression coefficient of each factor represents the influence of the each factor on changing mPET (i.e., ±1 °C of T a = ± 0.54 °C of mPET). The first-order regression has been considered predicting a more realistic estimation of mPET at Freiburg during 2003 than the other higher order regression model, because the predicted mPET from the first-order regression has less difference from mPET calculated from measurement data. Statistic tests recognize that mPET can effectively evaluate the influences of all human biometeorological factors on thermal environments. Moreover, a first-order regression function can also predict the thermal evaluations of the mPET by using human biometeorological factors in Freiburg.
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Modified physiologically Equivalent Temperature—basics and applications for western European climate
Theoretical and Applied Climatology, 2017Co-Authors: Yung-chang Chen, Andreas MatzarakisAbstract:A new thermal index, the modified physiologically Equivalent Temperature (mPET) has been developed for universal application in different climate zones. The mPET has been improved against the weaknesses of the original physiologically Equivalent Temperature (PET) by enhancing evaluation of the humidity and clothing variability. The principles of mPET and differences between original PET and mPET are introduced and discussed in this study. Furthermore, this study has also evidenced the usability of mPET with climatic data in Freiburg, which is located in Western Europe. Comparisons of PET, mPET, and Universal Thermal Climate Index (UTCI) have shown that mPET gives a more realistic estimation of human thermal sensation than the other two thermal indices (PET, UTCI) for the thermal conditions in Freiburg. Additionally, a comparison of physiological parameters between mPET model and PET model (Munich Energy Balance Model for Individual, namely MEMI) is proposed. The core Temperatures and skin Temperatures of PET model vary more violently to a low Temperature during cold stress than the mPET model. It can be regarded as that the mPET model gives a more realistic core Temperature and mean skin Temperature than the PET model. Statistical regression analysis of mPET based on the air Temperature, mean radiant Temperature, vapor pressure, and wind speed has been carried out. The R square (0.995) has shown a well co-relationship between human biometeorological factors and mPET. The regression coefficient of each factor represents the influence of the each factor on changing mPET (i.e., ±1 °C of T a = ± 0.54 °C of mPET). The first-order regression has been considered predicting a more realistic estimation of mPET at Freiburg during 2003 than the other higher order regression model, because the predicted mPET from the first-order regression has less difference from mPET calculated from measurement data. Statistic tests recognize that mPET can effectively evaluate the influences of all human biometeorological factors on thermal environments. Moreover, a first-order regression function can also predict the thermal evaluations of the mPET by using human biometeorological factors in Freiburg.
Xiaodong He - One of the best experts on this subject based on the ideXlab platform.
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influence of sky view factor on outdoor thermal environment and physiological Equivalent Temperature
International Journal of Biometeorology, 2015Co-Authors: Xiaodong He, Shiguang Miao, Shuanghe Shen, Ju Li, Benzhi Zhang, Ziyue Zhang, Xiujie ChenAbstract:Sky view factor (SVF), which is an indicator of urban canyon geometry, affects the surface energy balance, local air circulation, and outdoor thermal comfort. This study focused on a continuous and long-term meteorological observation system to investigate the effects of SVF on outdoor thermal conditions and physiological Equivalent Temperature (PET) in the central business district (CBD) of Beijing (which is located within Chaoyang District), specifically addressed current knowledge gaps for SVF-PET relationships in cities with typical continental/microthermal climates. An urban sub-domain scale model and the RayMan model were used to diagnose wind fields and to calculate SVF and long-term PET, respectively. Analytical results show that the extent of shading contributes to variations in thermal perception distribution. Highly shaded areas (SVF 0.5), and vice versa. Because Beijing has a monsoon-influenced humid continental climate with hot summers and long, cold, windy, and dry winters, a design project that ideally provides moderate shading should be planned to balance hot discomfort in summer and cold discomfort in winter, which effectively prolongs the comfort periods in outdoor spaces throughout the entire year. This research indicate that climate zone characteristics, urban environmental conditions, and thermal comfort requirements of residents must be accounted for in local-scale scientific planning and design, i.e., for urban canyon streets and residential estates.
Xiujie Chen - One of the best experts on this subject based on the ideXlab platform.
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influence of sky view factor on outdoor thermal environment and physiological Equivalent Temperature
International Journal of Biometeorology, 2015Co-Authors: Xiaodong He, Shiguang Miao, Shuanghe Shen, Ju Li, Benzhi Zhang, Ziyue Zhang, Xiujie ChenAbstract:Sky view factor (SVF), which is an indicator of urban canyon geometry, affects the surface energy balance, local air circulation, and outdoor thermal comfort. This study focused on a continuous and long-term meteorological observation system to investigate the effects of SVF on outdoor thermal conditions and physiological Equivalent Temperature (PET) in the central business district (CBD) of Beijing (which is located within Chaoyang District), specifically addressed current knowledge gaps for SVF-PET relationships in cities with typical continental/microthermal climates. An urban sub-domain scale model and the RayMan model were used to diagnose wind fields and to calculate SVF and long-term PET, respectively. Analytical results show that the extent of shading contributes to variations in thermal perception distribution. Highly shaded areas (SVF 0.5), and vice versa. Because Beijing has a monsoon-influenced humid continental climate with hot summers and long, cold, windy, and dry winters, a design project that ideally provides moderate shading should be planned to balance hot discomfort in summer and cold discomfort in winter, which effectively prolongs the comfort periods in outdoor spaces throughout the entire year. This research indicate that climate zone characteristics, urban environmental conditions, and thermal comfort requirements of residents must be accounted for in local-scale scientific planning and design, i.e., for urban canyon streets and residential estates.
Shiguang Miao - One of the best experts on this subject based on the ideXlab platform.
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influence of sky view factor on outdoor thermal environment and physiological Equivalent Temperature
International Journal of Biometeorology, 2015Co-Authors: Xiaodong He, Shiguang Miao, Shuanghe Shen, Ju Li, Benzhi Zhang, Ziyue Zhang, Xiujie ChenAbstract:Sky view factor (SVF), which is an indicator of urban canyon geometry, affects the surface energy balance, local air circulation, and outdoor thermal comfort. This study focused on a continuous and long-term meteorological observation system to investigate the effects of SVF on outdoor thermal conditions and physiological Equivalent Temperature (PET) in the central business district (CBD) of Beijing (which is located within Chaoyang District), specifically addressed current knowledge gaps for SVF-PET relationships in cities with typical continental/microthermal climates. An urban sub-domain scale model and the RayMan model were used to diagnose wind fields and to calculate SVF and long-term PET, respectively. Analytical results show that the extent of shading contributes to variations in thermal perception distribution. Highly shaded areas (SVF 0.5), and vice versa. Because Beijing has a monsoon-influenced humid continental climate with hot summers and long, cold, windy, and dry winters, a design project that ideally provides moderate shading should be planned to balance hot discomfort in summer and cold discomfort in winter, which effectively prolongs the comfort periods in outdoor spaces throughout the entire year. This research indicate that climate zone characteristics, urban environmental conditions, and thermal comfort requirements of residents must be accounted for in local-scale scientific planning and design, i.e., for urban canyon streets and residential estates.