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Artemi,
I just realized that the shading only applies to
windows, not an entire facade. Also, I thought this problem through a little
more and have a different suggestion. I must not have had enough coffee last
time...
If I understand what you're trying to do, it's actually
pretty simple. In TrnBuild, select your roof surface. Set the category as a
BOUNDARY. This kind of wall has no radiation on it (only EXTERNAL walls do), and
then you can select the boundary temp as user defined, then set up the input
from your special component. As far as I know, you cannot tell trnsys that the
surface temp of the roof or wall is anything in particular, but you can
tell it that the air outside of it is a certain temperature. It's not a perfect
solution but it might suffice.
The issue of negative radiations is solved by equations
that are put between type 109 and type 56. These check to see if the value is
<0, and if so, send only 0 to type 56, and not the negative value. I'm not
sure why such a check is not built into type 109 already, but whatcha gonna
do. Some example deck files include these equations I think, but
if you start from scratch you need to know to put them in yourself.
They look like this: output=max(input, 0). Thus if the input is <0, the
output is 0, otherwise the output is the input.
The parameter is "locked" due to the way trnsys studio
is set up to handle different variations of the same type (109-user, 109-tmy,
etc). If you open your deck file in Notepad (or any other text editor), you
can see the 'real' code of the file. Find type 109, and you'll see how the
parameters are set up. Just change the value for the first parameter and you
should be all set. Save it and reopen in Simulation
Studio.
I hope this helps,
-Cramer
From: Artemi Spanaki [mailto:spanakiart@hotmail.com] Sent: Wednesday, January 21, 2009 6:24 AM To: trnsys-users@engr.wisc.edu; techsupport@tess-inc.com; Cramer Silkworth Subject: Further questions about weather data file and new component
(This mail is sent to Matt
Duffy,
Cramer Silkworth
and TRNSYS Users List) Dear Matt
Duffy, Cramer
Silkworth and TRNSYS
users. Thank you for your important advises.
Your ideas about dealing with my additional
component through the building’s roof are quite helpful. I would like to ask the
way to do it. How can I define the inside
of the wall, such as the drywall, and then connect that to my
component? How can
I define that as a
boundary wall with an input temperature (from my roof component)? The TRNBuild
software has very limited options to do the above. I do have created the roof
temperature as an output of my new component and input of type 56, but I am not
sure that the software “understands” that this is the roof temperature on the
ceiling of the building? From the other
hand, Cramer Silkworth advises to block solar
radiation to the roof by saying that it's 100% shaded, or override the usual
horizontal radiation input and set it equal to zero. Additionally I can say that
the temperature "outside" this particular surface is equal to an input. Through
which software can I apply these opltions? As far as it
concerns the weather data reading and processing, when I transform a component
as type 109-user in order to make it similar to the options of one of TRNSYS
examples that is similar to my problem I get errors (negative radiation in one
or more orientation). If I copy the components (type 109) from the example and
paste it to my project I don’t get these errors. The problem is that I cannot
change the parameter 1 of type 109 to 2 because it is locked.
Best regards, Artemi Spanaki Get news, entertainment and everything you care about at Live.com. Check it out!
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