The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
Ingvar Holmér - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature difference between Manikin and wet fabric skin Surfaces on clothing evaporative resistance: how much error is there?
International journal of biometeorology, 2011Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:Clothing evaporative resistance is one of the inherent factors that impede heat exchange by sweating evaporation. It is widely used as a basic input in physiological heat strain models. Previous studies showed a large variability in clothing evaporative resistance both at intra-laboratory and inter-laboratory testing. The errors in evaporative resistance may cause severe problems in the determination of heat stress level of the wearers. In this paper, the effect of temperature difference between the Manikin nude Surface and wet textile skin Surface on clothing evaporative resistance was investigated by both theoretical analysis and thermal Manikin measurements. It was found that the temperature difference between the skin Surface and the Manikin nude Surface could lead to an error of up to 35.9% in evaporative resistance of the boundary air layer. Similarly, this temperature difference could also introduce an error of up to 23.7% in the real clothing total evaporative resistance (Ret_real < 0.1287 kPa m2/W). Finally, it is evident that one major error in the calculation of evaporative resistance comes from the use of the Manikin Surface temperature instead of the wet textile fabric skin temperature.
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Development and validity of a universal empirical equation to predict skin Surface temperature on thermal Manikins
Journal of Thermal Biology, 2010Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:Clothing evaporative resistance is an important input in thermal comfort models. Thermal Manikin tests give the most accurate and reliable evaporative resistance values for clothing. The calculation methods of clothing evaporative resistance require the sweating skin Surface temperature (i.e., options 1 and 2). However, prevailing calculation methods of clothing evaporative resistance (i.e., options 3 and 4) are based on the controlled nude Manikin Surface temperature due to the sensory measurement difficulty. In order to overcome the difficulty of attaching temperature sensors to the wet skin Surface and to enhance the calculation accuracy on evaporative resistance, we conducted an intensive skin study on a thermal Manikin ‘Tore’. The relationship among the nude Manikin Surface temperature, the total heat loss and the wet skin Surface temperature in three ambient conditions was investigated. A universal empirical equation to predict the wet skin Surface temperature of a sweating thermal Manikin was developed and validated on the Manikin dressed in six different clothing ensembles. The skin Surface temperature prediction equation in an ambient temperature range between 25.0 and 34.0 °C is Tsk=34.0–0.0132HL. It is demonstrated that the universal empirical equation is a good alternative to predicting the wet skin Surface temperature and facilitates calculating the evaporative resistance of permeable clothing ensembles. Further studies on the validation of the empirical equation on different thermal Manikins are needed however.
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effect of different fabric skin combinations on predicted sweating skin temperature of a thermal Manikin
Proceedings Of The Second International Conference On Advanced Textile Materials & Manufacturing Technology; pp 184-186 (2010), 2010Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:In this study, a knit cotton fabric skin and a Gore-tex skin were used to simulate two sweating methods. The Gore-tex skin was put on top of the pre-wetted knit cotton skin on a dry heated thermal Manikin 'Tore' to simulate senseless sweating, similar to thermal Manikins 'Coppelius' and 'Walter'. Another simulation involved the pre-wetted fabric skin covered on top of the Gore-tex skin in order to simulate sensible sweating. This type of sweating simulation can be widely found on many thermal Manikins worldwide, e.g. 'Newton'. Two empirical equations to predict the wet skin Surface temperature were developed based on the mean Manikin Surface temperature, mean fabric skin Surface temperature and the total heat loss. The prediction equations for the senseless sweating and sensible sweating on the thermal Manikin 'Tore' were T-sk=34.05-0.0193HL and T-sk=34.63-0.0178HL, respectively. It was found that the Gore-tex skin limits moisture evaporation and the predicted fabric skin temperature was greater than that in the G+C skin combination. Further study should validate those two empirical equations, however. (Less)
Faming Wang - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature difference between Manikin and wet fabric skin Surfaces on clothing evaporative resistance: how much error is there?
International journal of biometeorology, 2011Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:Clothing evaporative resistance is one of the inherent factors that impede heat exchange by sweating evaporation. It is widely used as a basic input in physiological heat strain models. Previous studies showed a large variability in clothing evaporative resistance both at intra-laboratory and inter-laboratory testing. The errors in evaporative resistance may cause severe problems in the determination of heat stress level of the wearers. In this paper, the effect of temperature difference between the Manikin nude Surface and wet textile skin Surface on clothing evaporative resistance was investigated by both theoretical analysis and thermal Manikin measurements. It was found that the temperature difference between the skin Surface and the Manikin nude Surface could lead to an error of up to 35.9% in evaporative resistance of the boundary air layer. Similarly, this temperature difference could also introduce an error of up to 23.7% in the real clothing total evaporative resistance (Ret_real < 0.1287 kPa m2/W). Finally, it is evident that one major error in the calculation of evaporative resistance comes from the use of the Manikin Surface temperature instead of the wet textile fabric skin temperature.
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Development and validity of a universal empirical equation to predict skin Surface temperature on thermal Manikins
Journal of Thermal Biology, 2010Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:Clothing evaporative resistance is an important input in thermal comfort models. Thermal Manikin tests give the most accurate and reliable evaporative resistance values for clothing. The calculation methods of clothing evaporative resistance require the sweating skin Surface temperature (i.e., options 1 and 2). However, prevailing calculation methods of clothing evaporative resistance (i.e., options 3 and 4) are based on the controlled nude Manikin Surface temperature due to the sensory measurement difficulty. In order to overcome the difficulty of attaching temperature sensors to the wet skin Surface and to enhance the calculation accuracy on evaporative resistance, we conducted an intensive skin study on a thermal Manikin ‘Tore’. The relationship among the nude Manikin Surface temperature, the total heat loss and the wet skin Surface temperature in three ambient conditions was investigated. A universal empirical equation to predict the wet skin Surface temperature of a sweating thermal Manikin was developed and validated on the Manikin dressed in six different clothing ensembles. The skin Surface temperature prediction equation in an ambient temperature range between 25.0 and 34.0 °C is Tsk=34.0–0.0132HL. It is demonstrated that the universal empirical equation is a good alternative to predicting the wet skin Surface temperature and facilitates calculating the evaporative resistance of permeable clothing ensembles. Further studies on the validation of the empirical equation on different thermal Manikins are needed however.
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effect of different fabric skin combinations on predicted sweating skin temperature of a thermal Manikin
Proceedings Of The Second International Conference On Advanced Textile Materials & Manufacturing Technology; pp 184-186 (2010), 2010Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:In this study, a knit cotton fabric skin and a Gore-tex skin were used to simulate two sweating methods. The Gore-tex skin was put on top of the pre-wetted knit cotton skin on a dry heated thermal Manikin 'Tore' to simulate senseless sweating, similar to thermal Manikins 'Coppelius' and 'Walter'. Another simulation involved the pre-wetted fabric skin covered on top of the Gore-tex skin in order to simulate sensible sweating. This type of sweating simulation can be widely found on many thermal Manikins worldwide, e.g. 'Newton'. Two empirical equations to predict the wet skin Surface temperature were developed based on the mean Manikin Surface temperature, mean fabric skin Surface temperature and the total heat loss. The prediction equations for the senseless sweating and sensible sweating on the thermal Manikin 'Tore' were T-sk=34.05-0.0193HL and T-sk=34.63-0.0178HL, respectively. It was found that the Gore-tex skin limits moisture evaporation and the predicted fabric skin temperature was greater than that in the G+C skin combination. Further study should validate those two empirical equations, however. (Less)
Kalev Kuklane - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature difference between Manikin and wet fabric skin Surfaces on clothing evaporative resistance: how much error is there?
International journal of biometeorology, 2011Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:Clothing evaporative resistance is one of the inherent factors that impede heat exchange by sweating evaporation. It is widely used as a basic input in physiological heat strain models. Previous studies showed a large variability in clothing evaporative resistance both at intra-laboratory and inter-laboratory testing. The errors in evaporative resistance may cause severe problems in the determination of heat stress level of the wearers. In this paper, the effect of temperature difference between the Manikin nude Surface and wet textile skin Surface on clothing evaporative resistance was investigated by both theoretical analysis and thermal Manikin measurements. It was found that the temperature difference between the skin Surface and the Manikin nude Surface could lead to an error of up to 35.9% in evaporative resistance of the boundary air layer. Similarly, this temperature difference could also introduce an error of up to 23.7% in the real clothing total evaporative resistance (Ret_real < 0.1287 kPa m2/W). Finally, it is evident that one major error in the calculation of evaporative resistance comes from the use of the Manikin Surface temperature instead of the wet textile fabric skin temperature.
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Development and validity of a universal empirical equation to predict skin Surface temperature on thermal Manikins
Journal of Thermal Biology, 2010Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:Clothing evaporative resistance is an important input in thermal comfort models. Thermal Manikin tests give the most accurate and reliable evaporative resistance values for clothing. The calculation methods of clothing evaporative resistance require the sweating skin Surface temperature (i.e., options 1 and 2). However, prevailing calculation methods of clothing evaporative resistance (i.e., options 3 and 4) are based on the controlled nude Manikin Surface temperature due to the sensory measurement difficulty. In order to overcome the difficulty of attaching temperature sensors to the wet skin Surface and to enhance the calculation accuracy on evaporative resistance, we conducted an intensive skin study on a thermal Manikin ‘Tore’. The relationship among the nude Manikin Surface temperature, the total heat loss and the wet skin Surface temperature in three ambient conditions was investigated. A universal empirical equation to predict the wet skin Surface temperature of a sweating thermal Manikin was developed and validated on the Manikin dressed in six different clothing ensembles. The skin Surface temperature prediction equation in an ambient temperature range between 25.0 and 34.0 °C is Tsk=34.0–0.0132HL. It is demonstrated that the universal empirical equation is a good alternative to predicting the wet skin Surface temperature and facilitates calculating the evaporative resistance of permeable clothing ensembles. Further studies on the validation of the empirical equation on different thermal Manikins are needed however.
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effect of different fabric skin combinations on predicted sweating skin temperature of a thermal Manikin
Proceedings Of The Second International Conference On Advanced Textile Materials & Manufacturing Technology; pp 184-186 (2010), 2010Co-Authors: Faming Wang, Kalev Kuklane, Ingvar HolmérAbstract:In this study, a knit cotton fabric skin and a Gore-tex skin were used to simulate two sweating methods. The Gore-tex skin was put on top of the pre-wetted knit cotton skin on a dry heated thermal Manikin 'Tore' to simulate senseless sweating, similar to thermal Manikins 'Coppelius' and 'Walter'. Another simulation involved the pre-wetted fabric skin covered on top of the Gore-tex skin in order to simulate sensible sweating. This type of sweating simulation can be widely found on many thermal Manikins worldwide, e.g. 'Newton'. Two empirical equations to predict the wet skin Surface temperature were developed based on the mean Manikin Surface temperature, mean fabric skin Surface temperature and the total heat loss. The prediction equations for the senseless sweating and sensible sweating on the thermal Manikin 'Tore' were T-sk=34.05-0.0193HL and T-sk=34.63-0.0178HL, respectively. It was found that the Gore-tex skin limits moisture evaporation and the predicted fabric skin temperature was greater than that in the G+C skin combination. Further study should validate those two empirical equations, however. (Less)
A. Makris - One of the best experts on this subject based on the ideXlab platform.
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Effect of thermal Manikin Surface temperature on the performance of personal cooling systems.
European Journal of Applied Physiology, 2004Co-Authors: F.-x. Jetté, J.-p. Dionne, J. Rose, A. MakrisAbstract:Thermal Manikin experiments were carried out to investigate the effect of Manikin Surface temperature on the performance of a personal cooling system (PCS), more specifically, a liquid circulating garment (LCG). Three Manikin temperatures were tested using a dry thermal Manikin torso: 38, 34, and 30°C. Mean environmental temperature during experiments was 23.5±1°C. Results show that more heat was extracted from the thermal Manikin by the PCS as the Manikin Surface temperature was increased. This is due to the larger difference in temperature between the Manikin and the chilled fluid flowing in the PCS when the Manikin temperature is high. Finally, it was demonstrated that if insulating garments that reduce heat losses to the environment were worn over the PCS, the PCS efficiency increased.
Holmér Ingvar - One of the best experts on this subject based on the ideXlab platform.
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Effect of Different Fabric Skin Combinations on Predicted Sweating Skin Temperature of a Thermal Manikin
'Zhejiang University Press', 2010Co-Authors: Wang Faming, Kuklane Kalev, Gao Chuansi, Holmér IngvarAbstract:In this study, a knit cotton fabric skin and a Gore-tex skin were used to simulate two sweating methods. The Gore-tex skin was put on top of the pre-wetted knit cotton skin on a dry heated thermal Manikin 'Tore' to simulate senseless sweating, similar to thermal Manikins 'Coppelius' and 'Walter'. Another simulation involved the pre-wetted fabric skin covered on top of the Gore-tex skin in order to simulate sensible sweating. This type of sweating simulation can be widely found on many thermal Manikins worldwide, e.g. 'Newton'. Two empirical equations to predict the wet skin Surface temperature were developed based on the mean Manikin Surface temperature, mean fabric skin Surface temperature and the total heat loss. The prediction equations for the senseless sweating and sensible sweating on the thermal Manikin 'Tore' were T-sk=34.05-0.0193HL and T-sk=34.63-0.0178HL, respectively. It was found that the Gore-tex skin limits moisture evaporation and the predicted fabric skin temperature was greater than that in the G+C skin combination. Further study should validate those two empirical equations, however
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Development of Empirical Equations to Predict Sweating Skin Surface Temperature for Thermal Manikins in Warm Environments.
2010Co-Authors: Wang Faming, Kuklane Kalev, Gao Chuansi, Holmér IngvarAbstract:Clothing evaporative resistance is one of the most important parameters for clothing comfort. The clothing evaporation resistance can be measured on a sweating guarded hotplate, a sweating thermal Manikin or a human subject. The sweating thermal Manikin gives the most accurate value on evaporative resistance of the whole garment ensemble compared to the other two methods. The determination of clothing evaporative resistance on a thermal Manikin requires sweating simulation. This can be achieved by either a pre-wetted fabric skin on top of the Manikin (TORE), or a waterproof but permeable Gore-tex skin filled with water inside. The addition of a fabric skin can introduce a temperature difference between the Manikin Surface and the sweating skin Surface. However, calculations on clothing evaporative resistance have often been based on the thermal Manikin Surface temperature. A previous study showed that the temperature differences can cause an error up to 35.9 % on the clothing evaporative resistance. In order to reduce such an error, an empirical equation to predict the skin Surface temperature might be helpful. In this study, a cotton knit fabric skin and a Gore-tex skin were used to simulate two types of sweating. The cotton fabric skin was rinsed with tap water and centrifuged in a washing machine for 4 seconds to ensure no water drip. A Gore-tex skin was put on top of the pre-wetted cotton skin on a dry heated thermal Manikin ‘Tore’ in order to simulate senseless sweating, similar to thermal Manikins ‘Coppelius’ and ‘Walter’. Another simulation involved the pre-wetted fabric skin covered on top of the Gore-tex skin in order to simulate sensible sweating. This type of sweating simulation can be widely found on many thermal Manikins worldwide, e.g. ‘Newton’. Six temperature sensors (Sensirion Inc, Switzerland) were attached on six sites of the skin outer Surface by white thread rings to record the skin Surface temperature. Twelve skin tests for each skin combination were performed at three different ambient temperatures: 34, 25 and 20 oC. Two empirical equations to predict the skin Surface temperature were developed based on the mean Manikin Surface temperature, mean fabric skin Surface temperature and the total heat loss. The prediction equations for the senseless sweating and sensible sweating on the thermal Manikin ‘Tore’ were Tsk=34.0-0.0146HL and Tsk=34.0-0.0190HL, respectively. Further study should validate these two empirical equations, however