What would be the best way to simulate a roof, considering that it is in the shade all day long, all year long (no absorptivity in the short-wave radiation, cloud rate =1...) ?
Thank you for your answer
Roof in the shade all year long
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Christian Bludau
- WUFI SupportTeam IBP
- Posts: 1161
- Joined: Tue Jul 04, 2006 10:08 pm -1100
- Location: IBP Holzkirchen, the home of WUFI
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Re: Roof in the shade all year long
Hallo François,
that depends on the kind of shading. If the surface is shaded by trees or buildings with some distance to the roof the worst case should be to set the absorptivity to zero and leave the emissivity at 0.9.
If it is covered by solar panels please se this post:
http://www.wufi-forum.com/viewtopic.php?p=2790#p2790:
If it is a north pitched roof, it is enough to just enter the inclination and orientation, the radiation will be calculated by WUFI.
Simplified you can also set the roof as north wall (inclination 90°, orientation North), but then you have to switch off the rain otherwise the amount will be calculated as well related to a north wall.
In all cases you have to use the explicit radiation balance. You do not have to change the cloud index, that is used to calculate the values of the atmospheric counter radiation if not given in the climate file.
Christian
that depends on the kind of shading. If the surface is shaded by trees or buildings with some distance to the roof the worst case should be to set the absorptivity to zero and leave the emissivity at 0.9.
If it is covered by solar panels please se this post:
http://www.wufi-forum.com/viewtopic.php?p=2790#p2790:
If it is a north pitched roof, it is enough to just enter the inclination and orientation, the radiation will be calculated by WUFI.
Simplified you can also set the roof as north wall (inclination 90°, orientation North), but then you have to switch off the rain otherwise the amount will be calculated as well related to a north wall.
In all cases you have to use the explicit radiation balance. You do not have to change the cloud index, that is used to calculate the values of the atmospheric counter radiation if not given in the climate file.
Christian
Re: Roof in the shade all year long
Hi, I am working on the same kind of issue. French regulations are not kind with solar panels which have to be 'integrated' in the roof.
Unfortunately, the link you provided does not work Christian. Could you possibly repost it?
Unfortunately my roof model is not ok with 0 absorptivity so any indication as to how to set up the radiation balance in this case would be greatly appreciated.
Thanks,
.Nico.
Unfortunately, the link you provided does not work Christian. Could you possibly repost it?
Unfortunately my roof model is not ok with 0 absorptivity so any indication as to how to set up the radiation balance in this case would be greatly appreciated.
Thanks,
.Nico.
-
Christian Bludau
- WUFI SupportTeam IBP
- Posts: 1161
- Joined: Tue Jul 04, 2006 10:08 pm -1100
- Location: IBP Holzkirchen, the home of WUFI
- Contact:
Re: Roof in the shade all year long
Sorry for that. Corrected it. Here is the working one:
http://www.wufi-forum.com/viewtopic.php?p=2790#p2790
http://www.wufi-forum.com/viewtopic.php?p=2790#p2790