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Dear
Hilde,
the
entries that you make in TRNBUILD for an internal shading are the following
where the bold parameters are the keywords
used in the bui file:
reflishade=the reflection towards a
window of the internal shading device - this is the material
property - the reflectivity of the opaque material
refloshade=the reflection
towards the zone (backside of the shading) - this is the material
property - the reflectivity of the opaque material
Ishade=(1-Transmission)= opaque part
of the window. Please not that your data set
includes transmission for one special position of the
device.
Ishade is an
input because the transmission changes depending on the position of
the shading device (closed/open).
CCISHADE=The part of the absorbed
radiation on the internal shading that is transferred directly to the air node
of the zone by convection.
RISHADE= additional heat resistance of
the internal shading device.
You
will find an example for the calculation on page 49 of
06-MultizoneBuilding.pdf in TRNSYS16.
TRNSYS
only needs the reflection of the opaque part = reflishade = (Reflection Coefficient of the
shading device)/(1-Transmission data)
(this is e. g the reflectivity of the
colour white or grey),
The
advantage is that the reflectivity of the opaque part doesn't change when
you open or close the shading.
Iref,z
and I?
We
will add that to the manual:
Iref,z ..... is the radiation coming from the zone due
to reflection on walls or different windows hitting the backside (refloshade) of the internal
shading
I ..... is the external radiation after the external
shading hitting window and then the front side (reflishade) of the internal
shading.
internal shading
factor.
Due to
the internal shading factor is
depending on the glazing, the resistances between the panes and towards the zone
which are it self
temperature depending, it can not be an input.
Since
TRNSYS16 the internal shading factor is an output of Balance 3 - solar
balance for a window .
This
balance was not possible with TRNSYS15 because you have to look only at the
solar radiation coming through the window
in
front of the internal shading. So for this balance in TRNSYS16 all radiation
from other windows or reflected by the zone (Iref,z) is
excluded.
best
regards
Torsten Welfoner
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