| 1. |
- Lin, Li-Yen, et al.
(author)
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A laboratory validation study of comfort and limit temperatures of four sleeping bags defined according to EN 13537 (2002)
- 2013
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In: Applied Ergonomics. - : Elsevier BV. - 1872-9126 .- 0003-6870. ; 44:2, s. 321-326
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Journal article (peer-reviewed)abstract
- In this study, we validated comfort and limit temperatures of four sleeping bags with different levels of insulation defined according to EN 13537. Six male subjects and four female subjects underwent totally 20 two-hour exposures in four sleeping bags at four intended testing temperatures: 11.2, 3.8, 2.1 and -9.0 degrees C. The subjective perceptions and physiological responses of these subjects were reported and analyzed. It was found that the EN 13537 defined comfort temperature and limit temperature were underestimated for sleeping bags MA3, HAG and MAM. The predictions are so conservative that further revision may be required to meet the requirements of both manufacturers and consumers. In contrast, for the sleeping bag MAO with a low level of insulation, the limit temperature defined by EN 13537 was slightly overestimated. In addition, two individual case studies (-28.0 and -32.0 degrees C) demonstrated that low toe temperatures were widely observed among the male and female subjects, although the mean skin temperatures were almost within the thermoneutrality range (32.0-34.0 degrees C). It seems that the IREQ model (ISO 11079) overestimated both the comfort and limit temperatures of the sleeping bags. Finally, traditional sleeping bags may be required to be re-designed to provide consumers both whole body comfort as well as local thermal comfort at feet/toes or users need to be made aware of the higher need for their insulation. (C) 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.
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| 2. |
- Wang, Faming, et al.
(author)
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Effects of various protective clothing and thermal environments on heat strain of unacclimated men: The PHS (predicted heat strain) model revisited
- 2013
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In: Industrial Health. - 1880-8026. ; 51:3, s. 266-274
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Journal article (peer-reviewed)abstract
- Five protective garments were assessed on eight unacclimated male subjects at two WBGT temperatures: 19.0 and 24.5 °C. The thermophysiological responses and subjective sensations were reported. The PHS model (ISO7933) was used for predicting thermophysiological responses for each testing scenario. It was found that there were significant differences between clothing FIRE and other clothing on thermal sensation (p<0.05). Significant differences were found on skin humidity sensation between FIRE and L, HV or MIL (p<0.001). The RPE value in FIRE is significant different with L and HV (p<0.05). At 19.0 °C WBGT, the post-exercise mean skin temperatures increased by 0.59 and 1.29 °C in MIL and CLM. In contrast, mean skin temperatures in L, HV, MIL, CLM and FIRE at WBGT=24.5 oC increased by 1.7, 2.1, 2.1, 2.8 and 3.3 °C, respectively. The PHS model presented good performance on predicted mean skin temperatures in MIL and CLM at both two thermal environments. However, the skin temperature prediction with light clothing in high humidity (RH> 80%) was weak. For thick protective clothing, the prediction on rectal temperature was greatly conservative. It is thus concluded that the PHS model is inapplicable for high insulating clothing and measurements performed in high humidity environments.
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| 3. |
- Zhao, Mengmeng, et al.
(author)
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A Study on Local Cooling of Garments with Ventilation Fans and Openings Placed at Different Torso Sites
- 2013
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In: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141. ; 43:3, s. 232-237
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Journal article (peer-reviewed)abstract
- Abstract in UndeterminedThe aim of the study was to examine the various design features of ventilatedgarments on cooling performance. Five jackets with small ventilation units andclosable openings were designed. The ventilation units with a flow rate of 12 l/s wereplaced at five different torso sites. They were examined on a sweating thermalmanikin in four clothing opening conditions in a warm environment(Ta=Tmanikin=34 °C, RH=60 %, Va=0.4 m/s). Total torso cooling was increased by 137to 251 %, and clothing total dynamic evaporative resistance was decreased by 43 to69 %. Neither the ventilation location nor the opening design had a significantdifference on total torso cooling. The ventilation location had a significant differenceon localized intra-torso cooling, but not the opening design. When the ventilationunits were placed at the local zone where it was ventilated, that zone underwent thehighest cooling than other local zones. The study indicated that the ventilation unitsshould be placed at the region where it required the most evaporative cooling, e.g.along the spine area and the lower back. The openings could be adjusted (closed oropened) to make comfortable air pressure for the wearers but without makingsignificant difference on the whole torso cooling under this flow rate.
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| 4. |
- Zhao, Mengmeng, et al.
(author)
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The torso cooling of vests incorporated with phase change materials: a sweat evaporation perspective
- 2013
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In: Textile Research Journal. - : SAGE Publications. - 0040-5175 .- 1746-7748. ; 83:4, s. 418-425
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Journal article (peer-reviewed)abstract
- Cooling vests incorporated with phase change materials (PCMs) add extra insulation and restrict sweat evaporation. It is still unclear how much cooling benefit they can provide. The aim of this study was to investigate the torso cooling of the PCM vests in two hot environments: hot humid (HH, 34C, 75% relative humidity (RH)) and hot dry (HD, 34C, 37% RH). A pre-wetted torso fabric skin was used to simulate torso sweating on a thermal manikin. Three cooling vests incorporated with three melting temperatures (Tm) of PCMs were tested (Tm=21C, Tm=24C and Tm=28C). They were worn under a military ensemble (total thermal insulation 1.60 clo; evaporative resistance 0.0516 kPam2/W), respectively. In a HH environment all the three cooling vests provided effective torso cooling; in a HD environment the cooling benefit was negative. In both environmental conditions, the evaporative cooling was greatly restricted by the cooling vests. The study indicated that when wearing the protective clothing with the relatively low evaporative resistance and when sweat production was high, the cooling vests were effective in a HH environment, but not in a HD environment.
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