Inclination and drainage

Everything concerning hygrothermal Sources & Sinks within the assembly
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WUFI User
WUFI User
WUFI User
Posts: 6
Joined: Tue Mar 12, 2013 8:48 am -1100

Inclination and drainage

Post by WUFI User » Wed Mar 13, 2013 10:43 pm -1100

Hello!

In reality water will not stay on the surface of a flat roof, because of its inclination. How can this movement/reduction of moisture be taken account of?
Is there any possibility to take account of inclination in flat roofs? As far as i know, gravity is not available in WUFI. Would it be ok, to reduce the rain load on the outside-surface?

I am also trying to use several drainages. How can they reduce the amount of water in the layers up to the outside surface. Is air change in the drainage any good? Or should i again reduce the rain load?

I hope this was mor or less clear and i'm looking forward to your answer.

Best regards,
Martin

Christian Bludau
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Re: Inclination and drainage

Post by Christian Bludau » Wed Mar 13, 2013 10:58 pm -1100

Hello Martin,

i do not understand your problem. If you calculate a surface with rain, the given amount of water can be uptaken by the surface only at the timestep, where the rain occurs. The next timestep the amount is different. So in your case of the roof the water will not stay on the roof. If you have a material on the surface without transport coefficients, no water sucking will suck in even if you have rain.
BTW: If you consider the roofing felt by using a sd-value on the outer surface, you have to switch of the rain, as the sd-value has no influence on the rain.

For drainage you can try to use the moisture source, as it also can work as a sink. The problem with this is to find out the amount of drainage....

Christian

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Re: Inclination and drainage

Post by WUFI User » Thu Mar 14, 2013 1:00 am -1100

Hi!

Thanks for the tip on the drainage!

Is there any other possibility, besides evaporation and the sucking material, to get rid of the amount of rain per timestep? I reality water will float to the sink quite fast, and therefor it won't be available for sucking, right?!

Best regards,
Martin

Christian Bludau
WUFI SupportTeam IBP
WUFI SupportTeam IBP
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Joined: Tue Jul 04, 2006 10:08 pm -1100
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Re: Inclination and drainage

Post by Christian Bludau » Thu Mar 14, 2013 2:38 am -1100

Hello Martin,

yes, you can edit the percentage of water which is available for suction on the surface. Go to the surface coefficients. In WUFI Pro it is called adhering fraction of rain and in WUFI 2D it is called rain reduction factor (thats an failure as it is the same as adhering fraction of rain). If you set the value to 0, the rain from the climate file is ignored.

Christian

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