Dear Davide,
The amount of solar radiation received by each part of the building is important, especially if you have windows.
In your case, you should first define in your TRNBuild file a different orientation for each shaded portion of the building, because the incident radiation is not the same as the building’s non-shaded portions.
Then, in your TRNSYS studio file you can use either type 34 or type 67 to define the solar masks. With your specific problem, type 34 really seems appropriate because you can model adjacent walls simply by putting their dimensions in the type’s parameters. However, if you use the type 34, remember to use the anisotropic sky model (sky model number 1 – defined in type 109 if you use this type) because this is the sky model type 34 computes the radiation with.
Regards,
Héloïse Pelen
ETAMINE
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De : davide disco [mailto:chester_83@hotmail.it]
Envoyé : mardi 1 mars 2011 11:37
À : trnsys-users@cae.wisc.edu
Objet : [TRNSYS-users] shadings
Dear all,
I have some doubts about shading.
Looking at the attached (that is a plant of the thermal zone subject of my study), you can see that there are portions of wall (indicated by letters) that, depending on the sun direction (e.g. north or north-west in my case), cause a shadow zone on the walls indicated by numbers.
In consequence of this, walls indicated by numbers shouldn't have the same amount of solar radiation incident on their outside surface. Am I wrong if I think so?
Is this shading important for the calculation of the incoming and outgoing heat from each wall and for the calculation of heat and cooling demands?
In this case,maybe I should indicate separately every portion of wall indicated by numbers and letters so that I can take into account these shadings by an appropriate value of geosurf for each portion of wall or can I alternatively take into account these shadings in some other way?
For example, can I use types 34, 64 or 67 for my purpose?
Thanks in advance for any help.
Best regards,
Davide.