[TRNSYS-users] Combining shading masks and overhangs (type 68 and type 34)

[Diego A. Arias]

Dear Amelie:

You can find a discussion about how to use type68 and type 34 to model 
far-away objects and overhang shading in the mailing list archive. 
(https://www.cae.wisc.edu/pipermail/trnsys-users/2005/000680.html).  
Here is a review from this discussion.

The order of the components should be:
- Type68(horizontal)  -->  Type34 --> Building
- Type68(vertical)     -->

This means that you need two Type68 components for each Type34.  As you 
described in your email, this is because the inputs to Type34 and the 
outputs for Type68 are not the same for only one instance of Type68.

One of the Type68 (the one that I called Type68(horizontal)) should be 
used to calculate the total shaded radiation by far-away objects on the 
horizontal.   The other Type68, which I called Type68(vertical), is used 
to calculate the shaded beam radiation on the vertical surface. 
With these two outputs from the two Type68's you have the right inputs 
for Type34.

As you can see, it is a little bit complicated.  That is why we have 
created a new version of Type68 that will be available in the next 
TRNSYS release, before the end of this year.  This new version of Type68 
calculates internally the total shaded  radiation on the horizontal in 
addition to the specific surface that you need.
Best regards,

Diego


Amelie Mariller wrote:

>  
>  
> Hello,
> 1. we try to use for the same orientation shading mask with type 68 
> and overhang or wingwall (type 34).
> Which one should come first after radiation processing? :
> -in type 34, the horizontal diffuse and total radiations are inputs, 
> so is the beam radiation on surface.  
> -upstream component mode equals 1 signifies the view factor is already 
> taken into account for the diffuse radiation with type 68  .
> how can it  take into account the view factor for shaded diffuse 
> radiation on horizontal since this is not an  output of type 68 ,.... 
> but still an input of type 34. I assume it can't neither be through 
> the shaded beam on surface...
>  
> Furthermore, we encountered inconsistent results using type 34 after 
> type 68 : more sun on the window than with type 34 only. Using type 68 
> after type 34 seems to give more consistent results but we are still 
> not sure they are correct since it is not the right order. Could you 
> give an explanation of this problem?  
>  
> 2. Else, another problem :
> when the .bui file and the .tpf file are located in the same folder, 
> we sometimes get an error message. Changing the location of the bui 
> file in another folder solves the problem... has anybody ever 
> encountered this bug?
>  
> Thanks in advance for any explanation (especially for the first point!)
>
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