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

Author(s):  
Atsumasa Yoshida ◽  
Yasuhiro Shimazaki ◽  
Shinichi Kinoshita ◽  
Ryota Suzuki

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.

Author(s):  
П. О. Яганов ◽  
І. В. Редько

Modeling the hyperspace of system states by the method of regression analysis, mathematical analysis of regression equations that model the thermal comfort index, optimization of thermal comfort by determining the coordinates of the projection of the vector image of thermal comfort onto a state hyperplane and solving an equation with many variables. Development of methods and models for a formal description of the space of states of human thermal comfort. The use of the method of regression analysis as a tool for modeling the state of thermal comfort in multidimensional hyperspace of system states is investigated. The procedure for calculating the PMV thermal comfort index and the formation of control commands for ACS of the thermal environment have been simplified. It is proved that a linear and quasilinear model of the state surface of the TC system within the selected TC intervals with sufficient accuracy for practical use calculates the PMV thermal comfort index. The regression analysis method is developed and extended to the class of thermal comfort systems. For the first time, a formal model of the space of states of thermal comfort is represented by linear and quasilinear polynomials. The state model of a complex multifactor system for providing thermal comfort for a person is represented by regression polynomials in a linear and quasilinear form, which greatly simplifies the calculation of the PMV index, classification of the state of thermal comfort, the search for optimal operating modes and command formation for actuators that are part of the ACS of the TC.


2014 ◽  
Vol 14 (23) ◽  
pp. 3344-3348 ◽  
Author(s):  
Kiam Beng Yeo ◽  
Cheah Meng Ong ◽  
Kenneth Tze Kin Te

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 580 ◽  
Author(s):  
Ioannis Charalampopoulos ◽  
Andre Santos Nouri

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.


2014 ◽  
Vol 522-524 ◽  
pp. 1707-1712 ◽  
Author(s):  
Qing Long Peng ◽  
Zhao Hui Qi ◽  
Xia Gan ◽  
Chao Li

How to use numerical simulation method to analyze human body heat transfer and human thermal comfort is introduced in this paper systematically. Under the same working conditions, numerical simulation of human body heat transfer has been finished based on three thermal boundary conditions, and then the results are compared. The results show that the third thermal boundary condition is better than the first and the second one, which have some problems in simulation and are not good at reflecting the fact on thermal comfort of human body. The third thermal boundary condition which is made to adapt the surrounding flow field automatically can get a more accurate result on calculating the heat transfer of different parts on human body and reflect hot or cool feeling preferably, which proves that the method put forward in this article to research the human body comfort is feasible.


1990 ◽  
Vol 36 (123) ◽  
pp. 217-221 ◽  
Author(s):  
Roger J. Braithwaite ◽  
Ole B. Olesen

AbstractDaily ice ablation on two outlet glaciers from the Greenland ice sheet, Nordbogletscher (1979–83) and Qamanârssûp sermia (1980–86), is related to air temperature by a linear regression equation. Analysis of this ablation-temperature equation with the help of a simple energy-balance model shows that sensible-heat flux has the greatest temperature response and accounts for about one-half of the temperature response of ablation. Net radiation accounts for about one-quarter of the temperature response of ablation, and latent-heat flux and errors account for the remainder. The temperature response of sensible-heat flux at QQamanârssûp sermia is greater than at Nordbogletscher mainly due to higher average wind speeds. The association of high winds with high temperatures during Föhn events further increases sensible-heat flux. The energy-balance model shows that ablation from a snow surface is only about half that from an ice surface at the same air temperature.


2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Akansha Patel ◽  
Ajanta Goswami ◽  
Jaydeo K. Dharpure ◽  
Meloth Thamban ◽  
Parmanand Sharma ◽  
...  

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