AW: [TRNSYS-users] internal shading Type56

[Matthias Rudolph]

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
 
 
 
 

	-----Ursprüngliche Nachricht-----
	Von: trnsys-users-bounces at engr.wisc.edu [mailto:trnsys-users-bounces at engr.wisc.edu] Im Auftrag von Hilde Breesch
	Gesendet: Dienstag, 11. Januar 2005 13:34
	An: TRNSYS users
	Betreff: [TRNSYS-users] internal shading Type56
	
	
	Dear Trnsys users,
	 
	I have some problems to implement in Trnsys Type 56 with Prebid/Trnbuild an internal shading device with known data of transmission, reflection and absorption coefficients. I also have calculated the g-value of the whole system (glass + shading). I don't understand how these data correspond to the input data in Prebid/Trnbuild:
	- internal shading factor: I have estimated this by 1 - (g glass + sunblinds)/(g glass)
	- reflection coefficient of internal device: is this the real reflection coefficient of the sunblinds of corresponds this to REFLISHADE (as explained in the manual of Prebid/Trnbuild)
	 
	I also don't understand the equation 4.8.8.1.44 in the Trnsys15 manual or (44) in Trnsys16 - Trnbuild manual that explains the irradiation that is transmitted trough a window with an internal shading. Some parameters in this equation aren't explained. Where e.g. can you give a value to the 'solar transmittance of all window panes'? What is the difference between Iref,z and I?
	 
	best regards,
	 
	Hilde Breesch
	PhD student Buildings & Climatic Control
	Department of Architecture & Urban Planning
	Ghent University
	J. Plateaustraat 22, B-9000 GENT
	tel. +32 9 264 78 61  fax. +32 9 264 41 85
	e-mail: Hilde.Breesch at UGent.be
	http://allserv.ugent.be/~hbreesch/research
	

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