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Re: [TRNSYS-users] solar absorptance of walls
Wirich,
If you are using Trnsys17 then there is almost certainly an automatic
connection of solar radiation between the weather data reader and the
building because in TRNBuild the default selection is that those
connections will be made for you.
I would guess that the difference lies in how you have treated the
floor of your zone. If you created a BOUNDARY wall for your floor then
Type56 is expecting you will provide a temperature on the back side of
the floor (i.e. the interface between the floor and the soil). If you
did not make a connection to the boundary temperature Type56 input then
it is probably set to a constant value of 0 C, which would keep your
zone temperature quite low throughout the year.
Regards,
David
On 8/28/2014 03:30, FREPPEL Wirich wrote:
Hello everyone,
I'm running some tests in order to compare TRNSYS to another software,
which is Energy+.
My model is simple, a 3 meters long cube, with the same composition
for all the faces, without windows.
What I did in first place, was to create a new multizone project using
an idf file created from sketch up. Then I runned the simulation in
order to observe the evolution of the air temperature inside the box.
Comparing it to Energy+ results, I noticed that in summer, the
temperature is far below those of Energy+. So I looked at the
connections in simulation studio to see if there was a problem on the
solar radiation on the walls, and I noticed that initially, there are
not any connection which give the solar radiation on the walls.
My conclusion is that to take account of the solar radiation on walls,
we have to link it by ourself at the beginning, is it right or did I
miss something?.
Furthermore, in the "wall type manager", there's a tab called "Solar
Absorptance of wall". When I change the value, nothing change
regarding the temperature inside the box. So when is this value used
exactly?
Thank you in advance.
King regards
--
***************************
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@tess-inc.com
http://www.tess-inc.com
http://www.trnsys.com