WUFI

Hi Roger, One way would be to use a regular OSB board from the database and add a 1mm thick membrane to it, the 1 perm vapor retarder from the database would work. Then you need to adjust the perm-inch value (or mue value in case you are a metric guy) of the membrane to reflect the correct vapor per...

Hello Toby, you can access all moisture fluxes over time at all points where layers connect. Typically, salt increases the liquid transport coefficients due to a higher fluidity. It also decreases the vapor transport coefficient due to a reduction of the pore volume. Both phenomena you can measure, ...

I am not aware of any. European claddings certainly differ to North Americans' and probably do also differ within Europe country by country

That number comes originally from brick veneer studies where rain intrusion in terms of water leakage performance according to ASTM C1601 and ASTM C1715 (See Note 6 in there) has been tested.
In lack of any information for other claddings, SSPC 160 decided to make this the default number.

I am pretty sure that the first layer is the surface condition. Fraunhofer IBP experts may confirm that.

OK, I didn't know it was WUFI 2D. Right mouse click on the graph should give you the export option. You just need to create temperature and R.H. graphs at the desired positions

WUFI main menu pull-down tab "Outputs"|"ASC-Export"
Or Quick Graph right mouse click on the graph

Of course it is; pull-down menu ASC-Export

1. Of course this is possible set liquid transport coefficient to zero and fill in a my value for your material
2. If you mean "Vapor Transport Coefficient" then the my value = sd value [m] / Thickness [m]. The sd value is roughly 200 ng/smPa / 1823 ng/sm2Pa =0.11m.

Yes this is really possible by our experience. I am also pretty sure no one in our support team can explain exactly under which circumstances it happens. Regarding the "old air", yes we know this too, The old air is more forgiving due to higher moisture buffering (numerically spoken the hi...

1. I think you mixed up US perm, Metric Perm, and ng/sm2Pa
2. I am not sure what you want to do.
3. Not sure what you want to do. If you are designing a roof, Georgia Pacific will likely say to you this is not a roofing board

Michael, I am not sure what you mean with "material with nearly identical brightness" The material properties in WUFI do not have a brightness, because solar absorption happen only at exterior surfaces, therefore the solar absorptivity is to be found at the surface transfer dialog. There i...

No I cannot confirm your hypothesis, the color (or to be more specific the brightness) should be a good indicator for the solar absorptivity. A change of the solar absorptivity by 0.01 should not have a big impact on the results. In case it does there might be some numerical problems, i.e. at least ...

i. Sorry I have overseen your cloud index input data. In case the the hourly input will be used and the constant value (0.66) will be ignored

ii. Not sure, I think I went through a bunch of climate files back in 2007 or so and figured that 0.66 is reasonable number.

Hello JohannBjorn 1. If I do not have the data for counterradiation, does WUFI approximate values from my weather data to calculate its effect? Yes using a annual constant cloud index which you can change in your inputs 2. Should I be using explicit radiation balance in general if I am not simulatin...