Len: Die Seite wurde neu angelegt: = Rain Reduction Factor =
The r.r.f. takes into account that some of the rain water hitting an inclined surface splashes off on impact and is therefore not availab...

2008-08-19T11:49:51Z

Die Seite wurde neu angelegt: = Rain Reduction Factor = The r.r.f. takes into account that some of the rain water hitting an inclined surface splashes off on impact and is therefore not availab...

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= Rain Reduction Factor =


The r.r.f. takes into account that some of the rain water hitting an inclined surface
splashes off on impact and is therefore not available for
[[Details:LiquidTransportCoefficients | capillary suction]].


WUFI [[1D:Dialog_Orientation | calculates the rain load]] on the component from
the data in the
[[1D:Dialog_Climate | climate file]] and multiplies it by the r.r.f. The
resulting rain quantity is offered to the component for capillary suction. (The
component may imbibe the offered quantity or less, but not more).


The r.r.f. depends on the roughness, orientation and inclination of the surface,
and on the nature of the precipitation (rain, snow...).


With horizontal surfaces, the r.r.f. is usually one, since the scattered drops fall
back to the surface.


With vertical surfaces, it is nearly zero for snow and hail, for other conditions it
must be estimated. A value of 0.7 might be a good starting point.


Since most component surfaces - with the exception of unrendered masonry and natural
stone facades - only have a moderate water absorption, they cannot imbibe all the offered
water anyway. In these cases, an exact knowledge of the rain quantity is not essential
(whereas the duration of the rain is still important) and estimates for the r.r.f.
and the position-specific [[1D:Dialog_Orientation | driving rain coefficients]]
may be sufficient.


WUFI automatically determines the r.r.f. from the inclination and the construction type;
a user-defined value may be employed as well.


The rain reduction factor is entered in the
[[1D:Dialog_SurfaceTransferCoefficients | dialog "Surface Transfer
Coefficients"]].

Details:RainReductionFactor - Versionsgeschichte

Len: Die Seite wurde neu angelegt: = Rain Reduction Factor = The r.r.f. takes into account that some of the rain water hitting an inclined surface splashes off on impact and is therefore not availab...

Len: Die Seite wurde neu angelegt: = Rain Reduction Factor =
The r.r.f. takes into account that some of the rain water hitting an inclined surface splashes off on impact and is therefore not availab...