[Radiance-general] Modelling glass lamellas in Radiance.

[Jacob Birck Laustsen]

I'm a relatively new user of Radiance and using it from within IESve
(the IES virtual environment program suite), which means there are
certain limitation for the input to the program. I'm currently working
on a research project on glass lamellas for daylight directing and solar
shading purposes at the technical university of Denmark. 

Here's the question:
What is the best way to model the glass blinds in Radiance? 
The glass that I'll be using for the project has the following
characteristics:

Visual properties		
Ext. Reflectance, LR [%]	31	
Int. Reflectance, LR [%]	31	
Transmittance, LT [%]	59	
RA-index	97.3	
		
Solar properties		
Solar reflectance [%]	32	
Direct solar transmittance [%]	40	
Solar Absorption [%]	20/8	
g-vl/solar factor	0.48	

I have been trying to use the material types "trans" and "dielectrica",
in order to benefit from the angular dependent properties of the glass,
I would prefer to use a matrial type which includes the refraction
index.  
Here comes my dilemma:
The material type "glass": in IESve the type does not include the
refraction index which means that the only input is the transmissivity
of the glass. 
The "trans" material type: same problem but at least I'm able to define
the reflectance of the glazing. 	
The "dielectrica" material type: IESve only allows me to enter values
between 1 and 2 for the refraction index which in this case have no
significant effect.
I'm sure that the best thing I could do is to model the whole thing over
again in the "original" Radiance - but as I have a short deadline, I
prefer to get it done in IESve!

Hope someone out there is able to help me out on this one!

Kind Regards 

Jacob B Laustsen, DTU, Denmark 	

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://radiance-online.org/pipermail/radiance-general/attachments/20070105/351cc1a2/attachment.html