[TRNSYS-users] Type 34: Non-ortoghonal overhang shading

[Jochen Doell]

Dear TRNSYS users,

I have a problem with the correct use of type 34.
How are different angles of the overhang shading device (e.g. a balcony 
= horizontal, a marquee = slope downwards) taken into acoount?

The info on parameter 4 "Overhead projection" says "The length of the 
overhead projection; measured in the plane of the overhead projection." 
What exactly does that mean?
A) The absolute length of the shading device (this would mean the angle 
is ignored because the absolute length does not change with the angle)
B) The projected length of the shading device on the plane orthogonal to 
the receiver plane (error because a shading device with "slope upwards" 
would have the same length like one with a "slope downwards")
C) The projected length on the receiver plane (error, because horizontal 
shading devices would have no effect)

The picture in the mathematical reference suggests option A...

Has anyone a hint on that?

Best regards,
Jochen
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Dipl.-Ing. (FH) Jochen Döll
Dept. Thermal Systems and Buildings

Fraunhofer-Institut für Solare Energiesysteme ISE
Heidenhofstrasse 2, 79110 Freiburg, Germany

Phone:	+49 (761) 4588-5468
Fax:	+49 (761) 4588-9000
Mail:	jochen.doell at ise.fraunhofer.de
Web:	www.ise.fraunhofer.de
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