Loughborough University
Leicestershire, UK
LE11 3TU
+44 (0)1509 263171
Loughborough University

Loughborough University Institutional Repository

Please use this identifier to cite or link to this item: https://dspace.lboro.ac.uk/2134/9745

Title: A simple theoretical model of heat and moisture transport in multi-layer garments in cool ambient air
Authors: Wissler, Eugene H.
Havenith, George
Keywords: Protective garments
Sweat evaporation
Condensation
Cooling efficiency
Issue Date: 2009
Publisher: © Springer
Citation: WISSLER, E.H. and HAVENITH, G., 2009. A simple theoretical model of heat and moisture transport in multi-layer garments in cool ambient air. European Journal of Applied Physiology , 105 (5), pp. 797 - 808
Abstract: Overall resistances for heat and vapor transport in a multilayer garment depend on the properties of individual layers and the thickness of any air space between layers. Under uncomplicated, steady-state conditions, thermal and mass fluxes are uniform within the garment, and the rate of transport is simply computed as the overall temperature or water concentration difference divided by the appropriate resistance. However, that simple computation is not valid under cool ambient conditions when the vapor permeability of the garment is low, and condensation occurs within the garment. Several recent studies have measured heat and vapor transport when condensation occurs within the garment (Richards et al. in Report on Project ThermProject, Contract No. G6RD-CT-2002-00846, 2002; Havenith et al. in J Appl Physiol 104:142-149, 2008). In addition to measuring cooling rates for ensembles when the skin was either wet or dry, both studies employed a flat-plate apparatus to measure resistances of individual layers. Those data provide information required to define the properties of an ensemble in terms of its individual layers. We have extended the work of previous investigators by developing a rather simple technique for analyzing heat and water vapor transport when condensation occurs within a garment. Computed results agree well with experimental results reported by Richards et al. (Report on Project ThermProject, Contract No. G6RD-CT-2002-00846, 2002) and Havenith et al. (J Appl Physiol 104:142-149, 2008). We discuss application of the method to human subjects for whom the rate of sweat secretion, instead of the partial pressure of water on the skin, is specified. Analysis of a more complicated five-layer system studied by Yoo and Kim (Text Res J 78:189-197, 2008) required an iterative computation based on principles defined in this paper.
Description: This article was published in the European Journal of Applied Physiology [© Springer] and the definitive version is available at: http://dx.doi.org/10.1007/s00421-008-0966-5
Version: Accepted for publication
DOI: 10.1007/s00421-008-0966-5
URI: https://dspace.lboro.ac.uk/2134/9745
Publisher Link: http://dx.doi.org/10.1007/s00421-008-0966-5
ISSN: 1439-6319
Appears in Collections:Published Articles (Design School)

Files associated with this item:

File Description SizeFormat
2009 Wissler Havenith Heat transfer manuscript.pdf425.68 kBAdobe PDFView/Open

 

SFX Query

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.