Moisture in clothing and its transient influence on human thermal responses through clothing microenvironment in cold environments in winter

Abstract

Air humidity produces conditions of varying moisture contents in clothing, which affects the heat and moisture transfer between human body, clothing and environment, as well as the wearers' comfort. This study was designed to evaluate the moisture effects in clothing in cold environments. A series of wearing experiments were conducted in a climate chamber, simulating transient moisture absorption and desorption in experimental clothes. Totally 20 subjects were involved in three temperature levels (16 o C/20 o C/24 o C) and two relative humidity levels (15% RH/85% RH) during winter, with physiological measurement and subjective evaluation. The results showed that moisture in clothing under 85% RH significantly reduced subject mean skin temperatures(MST) and increased the local blood flow, due to enhanced heat loss by 2 vapour evaporation. The initial skin wettedness was approximately 0.7 at 85% RH and stabilised at 0.33 after 90min exposure. The skin heat loss (Qskin) at 85% RH was almost twice as high as that at 15% RH under the same temperature conditions, owing to larger sensible and evaporative heat loss caused by moist clothing. The inner clothing effective temperature Teff was proposed to relate to TSV that the TSV increased by 1.12 units with an increase of 1 o C of Teff, which quantified the coupled effects of air temperature and humidity in clothing microenvironment on human thermal comfort. The findings address the negative effect of clothing absorbing a large amount of moisture, which should be considered for indoor heating temperature designs in coldhumid environments.

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“…Therefore, more attention should be paid to high-temperature environments of nucleic acid sampling personnel, and it is necessary to study and analyze the thermal comfort of sampling personnel. suffer other effects after being covered [6,7], which can seriously affect their working efficiency and their health and increase the risk of heat stress [8][9][10][11]. Therefore, more attention should be paid to high-temperature environments of nucleic acid sampling personnel, and it is necessary to study and analyze the thermal comfort of sampling personnel.…”

Evaluation and modification of the weighting formulas for mean skin temperature of human body in winter conditions

“…This conclusion is drawn mainly according to the finding in our previous study [67] that the relative humidity has no significant effect on the skin temperature 30 in the range of 15%-85% in most winter conditions. The reasons for that could be the opposite effect of the increased (or decreased) vapor pressure in air and the increased (or decreased) moisture in heavy clothing on body surface heat transfer at the same time [68].…”

The predicted heat strain model considering wet and dynamic thermal insulation for thermal protective clothing: Modification and validation analysis

“…25 –27 Du et al. 28 also showed that the effect of water content on human mean skin temperature was significant ( p < 0.05) in a cold-humidity climate ( T a 16–24°C, relative humidity (RH) 15–85%). These studies indicate the great necessity of improving the accuracy of the physical properties considering moisture in thermal response prediction models.…”

“…Takanokura et al 24 have demonstrated that the moisture inside clothing can cause a variation of 0.3 units in the predicted vote for thermal sensation. [25][26][27] Du et al 28 also showed that the effect of water content on human mean skin temperature was significant (p < 0.05) in a cold-humidity climate (T a 16-24 C, relative humidity (RH) 15-85%). These studies indicate the great necessity of improving the accuracy of the physical properties considering moisture in thermal response prediction models.…”