Moisture accumulation in sleeping bags during extended periods of use is detrimental to thermal comfort of the sleeper, and in extreme cases may lead to sleep loss and hypothermia. As sub-zero temperatures were expected to affect vapour resistance of microporous membranes, the effect of using semipermeable and impermeable rain covers for sleeping bags on the accumulation of moisture in the bags during 6 days of use at − 7°C and 5 days at − 20°C were investigated. In addition, the routine of shaking off hoarfrost from the inside of the cover after the sleep period as a preventive measure for moisture accumulation was studied. Moisture accumulation (ranging from 92 to 800 grams) was found to be related to the vapour resistance of the materials used. The best semipermeable material gave the same moisture build-up as no cover at − 7°C, though build-up increased substantially at − 20°C. Shaking off the hoarfrost from the inside of the cover after each use was beneficial in preventing a high moisture build-up. It was concluded that semi-permeable cover materials reduce moisture accumulation in sleeping bags at moderate sub-zero temperatures, but in more extreme cold (− 20°C) the benefits are reduced in comparison to routinely shaking frost from impermeable covers. Compared to fixed impermeable covers, the benefits of all semi-permeable covers are large. For long-term use without drying facilities, the differences observed do favour the semi-permeable covers above impermeable ones, even when regularly removing the hoar frost from the inside in the latter.
Funding
The research was funded by the Netherlands Ministry of Defence.
History
School
Design
Published in
ERGONOMICS
Volume
47
Issue
13
Pages
1424 - 1431 (8)
Citation
HAVENITH, G., DEN HARTOG, E.A. and HEUS, R., 2004. Moisture accumulation in sleeping bags at-7 degrees C and-20 degrees C in relation to cover material and method of use. Ergonomics, 47 (13), pp. 1424 - 1431.
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Publication date
2004
Notes
This is an Accepted Manuscript of an article published by Taylor & Francis in Ergonomics in 2004, available online: http://wwww.tandfonline.com/10.1080/00140130410001704428