scholarly journals Comparison of correction factor for both dynamic total thermal insulation and evaporative resistance between ISO 7933 and ISO 9920

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Satoru Ueno
Keyword(s):  
Thermal Insulation ◽  
Correction Factor ◽  
Evaporative Resistance

scholarly journals Thermal and Wet Comfort of Fabrics Based on Fractal Dimension of Silicone Coating

2018 ◽  
Vol 13 (1) ◽  
pp. 155892501801300
Author(s):  
Yunlong Shi ◽  
Liang Wang ◽  
Wenhuan Zhang ◽  
Xiaoming Qian
Keyword(s):  
Fractal Dimension ◽  
Thermal Insulation ◽  
Coating Layer ◽  
Fractal Theory ◽  
Barrier Effect ◽  
Evaporative Resistance ◽  
Silicone Coating ◽  
Self Similar ◽  
Warmth Retention ◽  
Coated Fabrics

In this paper, thermal and wet comforts of silicone coated windbreaker shell jacket fabrics were studied. Both thermal insulation and evaporative resistance of fabric increased with an increase in coating area due to the barrier effect of the silicone coating layer. Moreover, the coated fabrics with self-similar structures showed different thermal insulation and evaporative resistance under the same total coating area. Fractal theory was used to explain this phenomenon. Optimal thermal-wet comfort properties were obtained when the fractal dimension (D=1.599) was close to the Golden Mean (1.618). When the fractal dimension of coating was lower than 1.599, fabric warmth retention was not high enough. In contrast, fabric evaporative resistance was beyond the value at which people would feel comfortable when the fractal dimension was greater than 1.599.

scholarly journals Inter-laboratory proficiency tests in measuring thermal insulation and evaporative resistance of clothing using the Newton-type thermal manikin

2016 ◽  
Vol 88 (4) ◽  
pp. 453-466 ◽  
Author(s):  
Magdalena Młynarczyk ◽  
George Havenith ◽  
Jean Léonard ◽  
Rui Martins ◽  
Simon Hodder
Keyword(s):  
Heat Exchange ◽  
Thermal Insulation ◽  
Thermal Environment ◽  
Reference Value ◽  
Thermal Manikin ◽  
Proficiency Tests ◽  
Evaporative Resistance ◽  
Vapor Transfer ◽  
Important Barrier ◽  
Wet Heat

Clothing acts as an important barrier for heat and vapor transfer between the human body and the environment. Parameters that could describe that transfer include, inter alia, thermal insulation (the so-called dry heat exchange) and evaporative resistance (the so-called wet heat exchange). Once the above-mentioned parameters are determined, it is possible to consciously adapt clothing ensembles to the existing thermal environment in the workplace. In order to validate the mentioned method of thermal insulation and evaporative resistance measurements, proficiency tests (PTs) were organized. The main goal of the PT was to compare thermal insulation and evaporative resistance for one set of clothing using the Newton-type thermal manikin. In total, four laboratories participated in the PT study. The reference value of the thermal insulation ( It) and evaporative resistance ( Ret) were calculated as the mean of all the results. The assessment criteria included permissible errors for thermal insulation and evaporative resistance measurements, which were 4% and 10%, respectively. Calculations included, inter alia, z-scores and indicators, such as the inter-laboratory coefficient of variation or the reproducibility limit. The results contribute to the worldwide discussion on standardized studies of evaporative resistance of clothing.

scholarly journals Characteristics of Specialised Firefighter Clothing Used in Poland – the Thermal Parameters

2020 ◽  
Vol 28 (1(139)) ◽  
pp. 65-70
Author(s):  
Magdalena Młynarczyk
Keyword(s):  
Thermal Insulation ◽  
Protective Clothing ◽  
Thermal Parameters ◽  
Thermal Manikin ◽  
Test Results ◽  
Evaporative Resistance ◽  
Different Types ◽  
Local Thermal Insulation ◽  
Materials Used ◽  
The Impact

This paper describes the characteristic thermal parameters of firefighters’ personal protective clothing (FFPPC) used in Poland. The total thermal insulation and evaporative resistance of three different types of FFPPC were measured and used on a thermal manikin. Next, the results were compared. Based on the analyses and calculations of the test results, it was shown that FFPPC provides a barrier to the heat exchange between the user and the surrounding environment. Differences in the local thermal insulation can be triggered not only by the material used but they can also be attributable to clothes fitted on the manikin. The biggest differences can be noted on the segments forming part of the manikin’s trunk. No difference was found in the evaporative resistance between the clothes tested. In order to examine further the impact of the materials used on thermal parameters of protective clothing, it is necessary to carry out an analysis of the impact of individual layers.

scholarly journals A thermal foot manikin as a tool for footwear evaluation and development

2020 ◽  
pp. 175433712095222
Author(s):  
Anna Maria West ◽  
Florian Oberst ◽  
James Tarrier ◽  
Christian Heyde ◽  
Heiko Schlarb ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Thermal Sensation ◽  
Rest Period ◽  
Absolute Humidity ◽  
Evaporative Resistance ◽  
Subjective Evaluations ◽  
Highly Sensitive ◽  
Running Shoes ◽  
Actual Use ◽  
The Relationship

This study investigated the relationship between thermal perceptions during human wear trials and thermal foot manikin measurements of heat and vapour resistance for five running shoes varying in material and construction. Measurements of thermal/evaporative resistance were performed using a 12-zone sweating thermal-foot manikin. Eleven males performed running trials on five occasions, wearing shoes of same design, differing in materials and construction, to achieve a range of heat/vapour resistances and air permeabilities. Trials in 20°C/60% RH consisted of three phases: 15 min rest, 40 min running, 15 min recovery. In-shoe temperature/humidity were measured at two sites on the left foot. Thermal sensation/wetness perception/thermal comfort were provided for the left foot and four foot regions. Variations in shoe material and construction resulted in differences in thermal and evaporative resistance. These differences were reflected in in-shoe temperature and in-shoe absolute humidity assessed during wear trials. At the end of the rest period, thermal sensation was strongly related to thermal insulation ( r2 = 0.69, p<0.001). During exercise however, thermal sensation, wetness perception and thermal discomfort were related to both thermal insulation and evaporative resistance. Thermal foot manikins provide a sensitive, effective evaluation of footwear thermal properties, which are also reflective of changes to in-shoe parameters during actual use. This discriminate power may be enhanced using higher, more realistic air-speeds during testing, as well as simulating foot movement. While thermal foot manikins are highly sensitive to design features/attributes of footwear (e.g. ventilation openings, air-permeabilities and coatings), subjective evaluations of footwear do not seem to have the same sensitivity and discriminative power.

Comparison of clothing thermal comfort properties measured on female and male sweating manikins

2016 ◽  
Vol 87 (18) ◽  
pp. 2214-2223 ◽  
Author(s):  
Chao Sun ◽  
Jintu Fan
Keyword(s):  
Thermal Comfort ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Female Body ◽  
Body Shape ◽  
The Body ◽  
Thermal Manikin ◽  
Unit Surface Area ◽  
Evaporative Resistance ◽  
Evaporative Water

Thermal manikins simulating human body’s thermal regulatory system are essential tools for understanding the heat exchange between human body and the environment and also for evaluating the thermal comfort of clothing and near environment. However, most existing thermal manikins adopt a male’s body shape and no sweating female thermal manikin has been reported so far. Furthermore, it is unclear how body shape (viz. male vs female) affects the heat loss and perspiration from the body. We report on a novel female sweating thermal manikin “Wenda”. Thermal properties of the nude body and clothing ensembles measured on “Wenda” are compared with those measured on the male manikin “Walter”. It was found that, although the more curvaceous female body reduces the thermal insulation of the nude manikin, it increases the apparent evaporative resistance at the same time. This may be due to the fact that the more curvaceous female body increases the surface still air layer to add resistance to heat loss by conduction and evaporative water loss by diffusion, and significantly increases the percentage of effective radiative area and the resultant radiative heat loss per unit surface area. It was further shown that clothing thermal insulation and apparent evaporative resistance measured on Wenda are typically 0 ∼ 11% higher than those measured on the male sweating fabric manikin-Walter, probably due to the greater clothing microclimate volume on the female manikin resulting from the looser fitting of the garments on the smaller female body and the more curvaceous surface of the female body.

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