[TRNSYS-users] negative radiation one 1 surface in type 56

[David BRADLEY]

Richard,
   The equation would probably work but I would try to hunt down the 
cause of the problem. When I have gotten this error, it is usually 
because I have messed something up about the orientation of the 
building; when I draw a building in Trnsys3D, I often draw it facing 
plan north (instead of true north) so I have to correct for that when I 
implement the building in the Studio. Look at the "turn" equation in the 
3D_building example for how this can be accomplished.

   A second possibility is a bad connection to Type56. Type56 takes 
total and beam radiation. If you give it a beam radiation and forget to 
connect the total radiation, Type56 will compute that there is a 
negative amount of diffuse radiation on the surface.

   The other possibility is that there is actually a problem in the 
weather reading / processing component. To check this, remove the 
building from your project and put an online plotter on the radiation 
outputs of the weather reader. Check and make sure that they never go 
negative. If they do, please send me that project so that we can get it 
fixed.

Kind regards,
  David


On 6/13/2012 06:56, Richard Thygesen wrote:
>
> Hi again.
>
> I guess it would be possible to solve this problem with an equation 
> which never sends any negative values to type 56. What do you think 
> about that?
>
> Does that only cure the symptoms but not the problem?
>
> Best regards
>
> *Richard Thygesen*
>
> *Från:*Richard Thygesen
> *Skickat:* den 13 juni 2012 12:53
> *Till:* TRNSYS-users at engr.wisc.edu
> *Ämne:* [TRNSYS-users] negative radiation one 1 surface in type 56
>
> Hi.
>
> I have gotten an error message in my simulation stating that one 
> surface in Type 56 have negative radiation.
>
> This happened when I changed the sky model for diffuse radiation from 
> Perez to Hay and Davies.
>
> Has anyone encountered this problem before? How can I solve this?
>
> I am using Trnsys version 17.
>
> Best regards
>
>
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
> https://mailman.cae.wisc.edu/listinfo/trnsys-users

-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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