Reducing Wind-Induced Heat Loss Through Multilayer Clothing Systems by Means of a Bypass Layer

This paper concerns multilayer clothing systems whose outermost layers consist of a somewhat permeable exterior sheath and a layer of light insulating batting. Wind-tunnel tests show that the wind-induced heat loss through such systems can be greatly reduced by introducing a layer with low resistance to airflow between the sheath and the underlying batting layer. The low resistance layer acts as a bypass, allowing air that has penetrated the somewhat permeable sheath to flow downstream with little or no penetra tion of the batting layer. The results have been correlated into a form suitable for guiding of design decisions.