3D thermal bridges

All about the Software WUFI Plus
Post Reply
Fuadbaba
WUFI User
WUFI User
Posts: 3
Joined: Thu Nov 05, 2015 6:02 am -1100

3D thermal bridges

Post by Fuadbaba » Thu Nov 05, 2015 6:09 am -1100

Please I want to know the meaning and the difference between the "Terminologies" in the "Boundary conditions" list in 3D object , such as:
* Climate: this term has Rs = 0.04 m2.K/W for out side(which is reasonable) but the short wave and long wave is 0 (which is not reasonable)
* while, West Azimuth 270 inclination 90: this term has Rs = 0.13 m2.K/W for outside (which is not reasonable) but the short wave and long wave is 0.4 , 0.9 (which is reasonable) and the same values for North, East and South.
* zone1 South... etc
When and where can we use each one?

Thanks

mpazold
WUFI SupportTeam IBP
WUFI SupportTeam IBP
Posts: 177
Joined: Wed Jul 11, 2012 11:21 pm -1100

Re: 3D thermal bridges

Post by mpazold » Sun Nov 08, 2015 10:31 pm -1100

If you choose "climate" as boundary conditions, the 3D-Object doesn't know about the orientation of the object surfaces, so the solar radiation is not regarded in this case.
You have to choose the boundary conditions from a component (the outer side condition of this component) for the object, then the same solar radiation is used for the 3D-object. This is why absorbtion an emission is not zero for "component xzy" boundary conditions but for the "climate" condition.

Of cause, we will check Rsi, if you choose the component. meanwhile you may can deactivate "use component settings" and input the heat transfer resistance uesr defined.

stevebe
WUFI User
WUFI User
Posts: 1
Joined: Sun Nov 11, 2018 1:25 pm -1100

Re: 3D thermal bridges

Post by stevebe » Sun Jan 20, 2019 4:34 pm -1100

It appears that for 3D objects, the component boundary conditions do not include any shading calculation.

The component boundary condition includes the exterior temperature, and includes the solar radiation determined by orientation and absorptivity, but the shading of the component is not taking into consideration for calculation of the solar radiation.


Is there any way to include the appropriate shading or solar radiation as the part of the component boundary conditions for 3D objects in WUFI Plus?

mpazold
WUFI SupportTeam IBP
WUFI SupportTeam IBP
Posts: 177
Joined: Wed Jul 11, 2012 11:21 pm -1100

Re: 3D thermal bridges

Post by mpazold » Fri Mar 15, 2019 12:28 am -1100

For a constant shading factor, you can regard the shading with the absorptivity factor.

for a hourly dependend shading factor, the workaround is not simple done. You have to do a first simulation, to get teh solar shaded radiation (W/m²) on a component, then you can set this, and temperature and relative humidity as external measured data file for the coponent. and use this as optional climate for the boundray conditions, for the 3D-Object.

Post Reply