Diffusion resistance factor

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Raymond
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Joined: Mon May 10, 2010 10:17 pm -1100

Diffusion resistance factor

Post by Raymond »

Help Basic material data / Diffusion resistance factor
Please note that even if you do not explicitly use a moisture-dependent ?-value, WUFI will treat it as
moisture-dependent for moisture contents above free saturation wf. WUFI will reduce it in proportion to
the moisture excess over wf, until it reaches ?=0 at wmax. This reflects - in a first approximation - the
fact that at very high moisture contents even the larger capillaries become clogged with water and can't
contribute to vapor transport any more.
Question :
when a material is full of water we consider that the capillaries become clogged with water and thus there isn't any vapor transport.
Or the diffusion resistance factor is defined to represent how much the diffusion resistance of the material is higher than that of stagnant air.
Thus ?=material diffusion resistance/air diffusion resistance

I don't understand why ? is'nt infinite when W=Wmax instead of being equal to 0.

Please could you explain me.
Thanking you by advance.
Greetings.
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