Swimming pool modeling issue

Everything concerning the adequate application of WUFI in the USA and Canada depending on local conditions e.g. architecture, building codes, standardization, laws et cetera.
Michael Hurd
WUFI User
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Joined: Thu Oct 19, 2006 5:27 am -1100

Re: Swimming pool modeling issue

Post by Michael Hurd » Tue Apr 04, 2017 8:30 am -1100

Good to know, perhaps it was something I unwittingly did differently.
Respectfully,

Michael Hurd

veitner
WUFI SupportTeam IBP
WUFI SupportTeam IBP
Posts: 129
Joined: Tue Mar 08, 2005 11:14 pm -1100

Re: Swimming pool modeling issue

Post by veitner » Tue Apr 04, 2017 11:36 pm -1100

Michael Hurd wrote:I know it is coming from the pool area because both the concrete inner layer, mid layer and the insulation all are gaining moisture over time, there isn't enough moisture in one of those products to elevate the moisture in all 3. The concrete certainly cannot add moisture to itself. Additionally, since the mid layer of the concrete basically is locked down for moisture flow, it cannot be coming from the outer layer of the concrete or outdoors since the mid concrete layer is locked down. Those are my thoughts.
To verify the moisture is coming from the pool area you could modify the permeance (additional sd-value) of the inner surface. Did you watch the results using Animation1D? It might be helpful to switch from R.H. to vapour pressure inside Animation1D (Edit/Properties/Moisture/Humidity) to fully understand whats going on.

Best regards
Veit Eitner

Michael Hurd
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WUFI User
Posts: 92
Joined: Thu Oct 19, 2006 5:27 am -1100

Re: Swimming pool modeling issue

Post by Michael Hurd » Wed Apr 05, 2017 3:29 am -1100

inserting a low perm layer (.01 perms) on the surface does help but does not solve the issue. I switched the animation to vapor pressure but I'm not really sure what to look for/how to read what the pressure is doing.
Respectfully,

Michael Hurd

Michael Hurd
WUFI User
WUFI User
Posts: 92
Joined: Thu Oct 19, 2006 5:27 am -1100

Re: Swimming pool modeling issue

Post by Michael Hurd » Wed Apr 05, 2017 4:36 am -1100

I switched the film to the vapor pressure mode and the predominant drive into the layers that are gaining moisture seems to be from the inside of the wall. In the animation, does the length of the arrow show magnitude of the drive or the depth in the actual material(s)? Does the arrow have to fully cross a layer for the vapor drive to be going through a material and into the next layer?
Respectfully,

Michael Hurd

veitner
WUFI SupportTeam IBP
WUFI SupportTeam IBP
Posts: 129
Joined: Tue Mar 08, 2005 11:14 pm -1100

Re: Swimming pool modeling issue

Post by veitner » Wed Apr 05, 2017 6:34 am -1100

Michael Hurd wrote:I switched the film to the vapor pressure mode and the predominant drive into the layers that are gaining moisture seems to be from the inside of the wall. In the animation, does the length of the arrow show magnitude of the drive or the depth in the actual material(s)? Does the arrow have to fully cross a layer for the vapor drive to be going through a material and into the next layer?
The length of the arrow is scaled to it's maximum - either global or per time step (configurable on tab "/edit/properties/moisture/water_content"). Hovering the mouse over (stop film at desired time step) opens a hint-window showing its actual magnitude.
Michael Hurd wrote:I'm not really sure what to look for/how to read what the pressure is doing.
Diffusive driving potential is the Vapour Pressure - which could be written as a function of R.H. and Temperature (R.H.=vp/vpsat(T) -> vp=R.H.*vpsat(T)).

Because of the "convenient" ambient tempurature at the inner side (the pool area) the vapour pressure gradient will force the diffusive flow towards the inside during a significant period of the year. Just a guess :)

Best regards
Veit Eitner

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