[TRNSYS-users] Removing Weather data from a 3D building project

[David BRADLEY]

Arnaud,
   With the release of TRNSYS 17.1, a new feature was added to prevent 
users from having to manually connect a weather file to a building. 
However, you can switch off that feature, which allows you to give your 
building whatever values you want as inputs (whether they are constant 
or time varying). When you open your *.b17 file in TRNBuild, look at the 
"orientations" list in the project window. The radiation falling on 
various surfaces will be set to either "internal" or "-". Double click 
on an orientation name and you can switch back and forth between 
"Internal" and "External by another component." If you change all of 
your orientations to have externally calculated radiation then you will 
be able to set constant values for the inputs simply by entering input 
initial values for Type56 and not connecting the inputs up from any 
other component.
Regards,
  David


On 3/14/2013 04:13, Arnaud Candaele wrote:
> Hi,
>
> I'm new to TRNSYS, and I'd like to create steady weather conditions to 
> test a building.
> I created a building using Google Sktechup, then started a new "3d 
> building project". Now, I'd like to force steady oustide conditions, 
> so that I can make a first analyze of my building.
> My question is : how can I do that ? It seems that the building model 
> impose that I use a weather file. So I see 2 options : 1) I create a 
> "steady" weather file that I then use in my project, but this doesn't 
> seem that easy to do (or does such a weather file already exist ? I 
> didn't find one..), or 2) I try to modify my project so that my 
> building receives steady conditions instead of time varying conditions 
> from the weather file. I tried to do that, and I could almost do it. I 
> used "equations" modules to impose constant conditions for TAMB, 
> TGROUND, and so on.. it works. But then, when I monitor the 
> temperature in a room, it is not completely flat. I don't understand 
> why, because there is no gain/heating in any room, and all inputs to 
> the building are constant, except for "AZEN" which is related to solar 
> position. This parameter, I can't impose constant because TRNSYS tells 
> me it HAS to be connected to the weather file.. So, that's the only 
> thing actually varying, so I guess this is the reason why I don't get 
> steady temperature in my monitored room.
>
> In other words : how can I "disconnect" solar calculations from my 
> project ?
> Or even a more generic question : how can I impose steady outside 
> conditions on my building, knowing that I created my project from a 3D 
> building from Google Sketchup... ?
> I mean, it seems to me like a quite simple problem, but the solution 
> seems quite complicated...
>
> Thank you for your help,
>
> Arnaud.
>
>
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> TRNSYS-users at cae.wisc.edu
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-- 
***************************
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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