Numerical Estimation of the Thermal Response of Thermal Protective Clothing-Air Gap-Human Skin Micro-system

Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.

Clothing Thermal Insulation for Typical Seasonal Clothing of Infant with Infant Thermal Manikin

Infants are less thermally adapted to their environment and can be considered as needing protective measures against thermal environments. It is not ethical to conduct subject experiments on infants. Thermal insulation in clothing is an essential control coefficient for the evaluation of the thermal environment of an infant. A thermal manikin can be used as an alternative method for carrying out experiments and to control the thermal manikin based on heat balance. The purpose of this study was to clarify the thermal insulation of infants’ clothing. An infant thermal manikin was used to clarify the thermal insulation (Icl) of typical summer, mid-season, and winter clothing combinations for infants. The thermal insulation of typical seasonal clothing combinations was 0.30 clo for summer clothing, 0.57 clo for mid-season clothing and 1.02 clo for winter clothing. It was clarified that it is essential to consider clothing conditions by taking into account differences in posture and to define the clothing thermal insulation (Icl) when designing and evaluating thermal environments. When designing and evaluating an infant’s thermal environment, it is essential to investigate using data from infants.

Influence of Stroller upon Thermal Insulation of Infant

In outdoor spaces, infants in strollers are significantly affected by thermal radiation from the ground surface due to their proximity to it. Infants are at increased risk of heat stroke while riding in a stroller. Infants are less thermally adapted to their environment and can consequently be considered to need protective measures against thermal environments. In order to treat strollers as clothing, in the present study, experiments were conducted to clarify the thermal environment of an infant riding in a stroller. Using an infant thermal manikin, the clothing area factor fcl and the clothing thermal insulation Icl of the stroller were determined. The stroller clothing area factor fcl was 3.21 and the stroller clothing thermal insulation Icl was 0.47 clo. Therefore, it can be inferred that strollers have a pronounced effect on the body heat balance between an infant and their environment.

Wearing Comfort of Women's Pantyhose in Winter

The wearing comfort of clothing has been frequently investigated,but there are few researches on the wearing comfort of pantyhose. This study first carried out a questionnaire survey on female consumers to know about their preference and demand on pantyhose. Then thermal manikin test and subject wearing trials were performed to evaluate the commonly used pantyhose. It was found that female consumers felt cold on the legs when wearing pantyhose which puts forward more requirements on pantyhose for its ability to keep warm. The thinner and more permeable the pantyhose,the thermal insulation was smaller. And the thicker the pantyhose,the pressure it caused to the body was higher. Sample 1# brought the highest prickle sensation, and prickle sensation was increased with the movement of the body. Samples 2# and 3# caused the highest and lowest thermal sensation,which was in line with their thermal insulation.

Predicting the clothing insulation through machine learning algorithms:A comparative analysis and a practical approach

Since indoor clothing insulation is a key element in thermal comfort models,the aim of the present study is proposing an approach for predicting it,which could assist the occupants of a building in terms of recommendations regarding their ensemble.For that,a systematic analysis of input variables is exposed,and 13 regression and 12 classification machine learning algorithms were developed and compared.The results are based on data from 3352 questionnaires and 21 input variables from a field study in mixed-mode office buildings in Spain.Outdoor temperature at 6 a.m.,indoor air temperature,indoor relative humidity,comfort temperature and gender were the most relevant features for predicting clothing insulation.When comparing machine learning algorithms,decision tree-based algorithms with Boosting techniques achieved the best performance.The proposed model provides an efficient method for forecasting the clothing insulation level and its application would entail optimising thermal comfort and energy efficiency.

Exploring the effects of mask wearing on outdoor thermal comfort at different walking speeds—A thermal manikin-based experiment

Face masks’wearing for a long duration brings thermal discomfort,especially in hot climate cities.The face masks’thermal insulation and its effect on outdoor thermal comfort have been rarely investigated.In this study,five types of face masks and their thermal insulations have been tested by using a thermal manikin in the climate chamber.Experimental results are assessed by using physiological equivalent temperature(PET)and standard effective temperature(SET^(*))for thermal comfort with masks at three walking speeds both in summer and winter.Slight differences in thermal insulation are observed among the different masks,the values of PET and SET^(*)rise with increasing mask thermal insulation,and they are generally higher in summer than in winter.Moreover,the variation of SET*is more obvious than PET with same masks at different walking speeds.And the differences of SET^(*)with and without masks appear to rise significantly for fast walking.Results further indicate that the individuals’physical discomfort caused by wearing masks cannot simply be assumed as an additional effect of the clothing thermal insulation.The findings enrich the clothing thermal insulation database,explore the differences in thermal indices if the face mask is used,and provide advice on heat mitigation with masks outdoors.