Re: [TRNSYS-users] Pergola as Shading mask

[David Bradley <bradley@tess-inc.com>]

Murielle,

> Then, I'm trying two different strategies:
>
> 1-      I'm trying the simulation when using only "Fraction of solar 
> shading" as output from the calculation module, going to a new 
> variable in my BUI file, used in "external shading factor" for the 
> window shaded by a pergola.
>
> 2-      I'm also trying to use IT, Beam radiation and angle of 
> incidence as output from the calculation module, to a new 
> orientation I defined in my BUI file.

I would suggest the second strategy. In TRNBuild, the external (and 
internal) shading factors are assumed to treat both beam and diffuse 
radiation exactly the same. If you give a value of 0.5 then you will 
shade half of the diffuse radiation and half of the beam radiation. 
Often times with shading devices, however, the beam radiation is 
completely shaded while the diffuse radiation is only partially 
reduced. Your second strategy will allow the pergola to affect the 
beam and diffuse radiation independently.

> Last question: when using 2 type 34, one after the other, do I have 
> to put "upstream component mode" of the second Type 34 on "1" ?

I am not sure why you decided to use two Type34s. A single instance 
of Type34 can be used to model any combination of two wingwalls and 
one overhang on a given facade. There are some situations where it is 
a good idea to cascade two instances of Type34 and I think that in 
this case, you would want to set the upstream component mode to 1 as 
you have done.
Kind regards,
 David


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