Our service team updates your Ortovox or Pieps LVS device for you.
wind and weather protection layer (layers 3 and 4)
This layer is the outer and therefore the most weather-
affected layer of clothing according to the multi-
layer principle. Even within the products in this
layer there are various qualities. Depending upon
the sort of use, windproof and watertight materials
A. As for windproof clothing, we often find Windstopper
® from the company Gore or comparable
products such as Power Shield® from Malden Mills.
These materials are characterised by the fact that
they are up to 100 per cent windproof and thus
prevent rapid cooling of the body through disruption
to the warm air layer (wind chill effect). Other
positive features of windproof materials can be the
strong water-repellent effect (water-repellent but
not 100% watertight!) (= Softshell), the relatively
high breathability, the pleasant and often soft feel
and the flexibility of use.
B. Alongside this there is watertight clothing. An
item of clothing which is intended to be watertight,
must also of course be watertight at its seams. So all
seams are sealed on the inside with a seal strip. Basically,
when it comes to watertight materials, a distinction
must be drawn between “breathable” and
“non-breathable” materials (such as Raintec®).
It must be noted here that the term “breathable” is
in fact incorrect. It would be better to say: “moisture-
permeable”! Moisture-permeability relies on the
structure of membranes or layers. Moisture-permeable
membranes and layers have pores or are microporous.
These pores are so large that moisture can
escape, but not sufficiently large for water droplets
to penetrate from the outside.
In order to guarantee moisture-permeability, certain
prerequisites must be fulfilled. A higher temperature
must prevail inside the clothing than outside, because
higher pressure is necessary. It can also occur in
certain circumstances that a first-class GORE-TEX®
membrane does not “function” as it might (the
moist warm climate in the tropics is an example).
But even under optimum conditions, “breathability”
can be restricted. At present the highest levels
achieved are approximately 200 to 300 grams of
moisture per hour per square metre. With many activities,
however, more perspiration is produced: for
example when walking, cycling or skiing, sweat can
be produced at the rate of two litres an hour. In order
to maintain a pleasant climate even under those
circumstances, functional clothing and if necessary
functional intermediate layers are necessary.
Endeavours are currently being made to obtain a
uniform value for the moisture-permeability of a
material. The RET (Resistance to Evaporating Heat
Transfer) value ignores the resistance of a material
in manufactured clothing (not only the membranes)
to moisture penetration. There are various opportunities
to promote moisture-permeability, such as
underarm zips and pocket ventilation.