[esp-r] Re: Proposed development of window shading models

Tue Mar 20 08:58:15 GMT 2007

Hi Achim,

to clarify the names "cut-off"-angle and "profile"-angle: 

1) The so called cut-off angle is the slope angle of the blinds,
which is as open as possible - but avoids DIRECT sun bean transmission.
As the sun elevantion varies with daytime, the cut-off-angle is NOT
a constant angle, but also varying with daytime (see attachment) .... 

As only 100 kB are allowed in the ESP-r email list, a second mail with
definition of "profile angle" will follow ....

> -----Original Message-----
> From: Geissler Achim [mailto:Achim.Geissler at josef-gartner.ch]
> Sent: Tuesday, March 20, 2007 9:44 AM
> To: Pueltz, Gunter; esp-r at lists.strath.ac.uk
> Cc: Bart Lomanowski
> Subject: RE: [esp-r] Re: Proposed development of window shading models
> 
> 
> Hi Gunter,
> good point on azimuth angle (if it was not already being 
> focused on). However, what WIS actually models in regard to 
> angle dependany is not so clear to me.
> 	- cut off by Venetian type blinds is definitely modelled.
> 	- other than that, comparison calculations seem to 
> imply that all the angle dependant results are simply 
> calculated by the Fresnel equation.
> 	- The paper on "new model" for Venetian type blinds: 
> The blinds considered are, of course, relatively special 
> cases. It would be interesting to see differences for more 
> "standard" types of Venetian blinds. Additionally, I do not 
> understand why "0°" and "cut-off" gives the same discrepancy. 
> Anyway, for typical control scenarios "blind down and closed 
> if sun", I assume the simple models do O.K. for most cases.
> Enhancing the model capabilities of ESP-r in this regard is 
> very interesting for us, in any case! However, an interesting 
> question (at least here in Europe) will be: How do results / 
> performance parameters gained with enhanced models fit in 
> with the EPBD-oriented planning / calculation tools (for 
> Germany e.g. DIN 18599)?
> 
> Mit freundlichen Grüssen / Best regards
>  
> Achim Geissler
> 
> > -----Original Message-----
> > From: esp-r-bounces at lists.strath.ac.uk [mailto:esp-r-
> > bounces at lists.strath.ac.uk] On Behalf Of Pueltz, Gunter
> > Sent: Tuesday, March 20, 2007 8:30 AM
> > To: esp-r at lists.strath.ac.uk
> > Cc: 'Bart Lomanowski'
> > Subject: [esp-r] Re: Proposed development of window shading models
> > 
> > Bart,
> > 
> > a short info concerning transmission and absorption of each 
> layer of a
> > tmc:
> > 
> > The European software "Advanced Window Information System (WIS)",
> > Version 3.0.1, des Window Energy Data Network (WinDat), coordinated
> > by TNO Building and Construction Research (TNO Bouw), Department:
> > Sustainable Energy and Buildings (DEG), The Netherlands (details
> > see http://windat.ucd.ie/wis/html/index.html)
> > 
> > is able to calculate both the overall transmission as well as the
> > absorption
> > in each layer of a facade WITH venetian blinds as a function of sun
> > altitude
> > angle (this is the "profile angle" you suggested). The WIS 
> software is
> > similar
> > to the WINDOW-software from LBNL, but also treats venetian blinds.
> > Therefore you should use the software WIS for the enhanced 
> window model in
> > ESP-r ...
> > An interface between WIS and ESP-r would be a great help 
> for ESP-users !!
> > 
> > But also WIS shows a crued defect: It is NOT able to take 
> the azimuth
> > angle
> > of
> > the sun into account. A recent work from Mr. Kuhn, 
> Fraunhofer-Institute of
> > solar
> > energy systems in Freiburg, Germany, has shown, that this 
> defect may yield
> > -
> > at critical
> > sun angles - to an underestimation of solar heat gain of appr.
> > 100% !!!!!!!
> > Therefore it would be the best - for my opinion -, if the 
> new enhanced
> > facade model
> > (glazing AND blinds) takes into account ALL relevant angles:
> > - the slope angle of the blinds
> > - the sun heigt angle (or the profile angle)
> > - the sun azimuth angle
> > Concerning this topic, Mr. Kuhn has developed a new, 
> enhanced algorithm (I
> > assume
> > based on raytracing), which considers all these angles. Please see
> > 
> > 1) Tilmann E Kuhn, Solar Control: A general evaluation 
> method for facades
> > with venetian blinds or other solar control systems, Energy and
> > Buildings, 38 (2006), 648-660.
> > 
> > 2) Tilmann E Kuhn, Solar Control: Comparison of two new 
> systems with the
> > state-of-the-art on the basis of a new general evaluation method for
> > facades with venetian blinds or other solar control 
> systems, Energy and
> > Buildings, 38 (2006), 661-672.
> > 
> > You can also find more information about this new algorithm at the
> > IBPSA-Germany
> > website at http://129.187.44.165/konferenz/paper/2006/108.pdf
> > 
> > I propose that you contact Mr. Kuhn directly, because he 
> has already told
> > his
> > willingness to support or even participate the code 
> enhancement of ESP-r.
> > His contact data are following:
> > 
> > Dipl.-Phys. Tilmann E. Kuhn
> > Head of Group Solar Facades and Durability Analysis
> > Dept. Thermal Systems and Buildings
> > Fraunhofer Institut für Solare Energiesysteme ISE
> > Heidenhofstr. 2, 79110 Freiburg, Germany
> > Phone: +49 (0) 761/ 4588-5297  Fax: +49 (0)761/ 4588-9297
> > tilmann.kuhn at ise.fraunhofer.de
> > http://www.ise.fraunhofer.de
> > 
> > As a stupid ESP user I would appreciate it greatly if all 
> experts for
> > facade
> > modelling
> > cooperate for the enhancement of facade modelling in ESP-r  ....
> > 
> > Regards,
> > Gunter
> > 
> > --
> > Dr. Gunter Pültz
> > 
> > Müller-BBM GmbH
> > Robert-Koch-Straße 11
> > 82152 Planegg
> > Telefon +49(89)85602-336
> > Telefax +49(89)85602-111
> > http://www.MuellerBBM.de
> > 
> > HRB München 86143
> > Geschäftsführer: Bernd Grözinger, Dr. Edwin Schorer, 
> Norbert Suritsch
> > 
> > 
> > 
> > 
> > 
> > > -----Original Message-----
> > > From: esp-r-bounces at lists.strath.ac.uk
> > > [mailto:esp-r-bounces at lists.strath.ac.uk]On Behalf Of 
> Bart Lomanowski
> > > Sent: Monday, March 19, 2007 3:45 PM
> > > To: esp-r at lists.strath.ac.uk
> > > Subject: [esp-r] Re: Proposed development of window shading models
> > >
> > >
> > >
> > > Thanks for all the feedback, I appreciate the interest this
> > > subject has
> > > generated.
> > >
> > > I've attached some ppt slides outlining in more detail our
> > > model capabilities,
> > > the ESP-r development proposal in broad strokes, and some
> > > implementation issues
> > > for discussion. What I am most interested in is the
> > > capabilities of other
> > > ongoing developments (e.g., SHOCC) and the expected
> > > interactions of these
> > > facilities with transparent constructions. Ideally I would
> > > like to retain
> > > generality with respect to the window shading 
> developments to ensure
> > > functionality with other windows related projects. I hope a
> > > brief discussion
> > > will be possible at the Developer's conference to shed some
> > > light on this.
> > >
> > > Thanks,
> > >
> > > Bart Lomanowski
> > > University of Waterloo
> > >
> > >
> > >
> > >
> > >
> > 
> > _______________________________________________
> > esp-r mailing list
> > esp-r at lists.strath.ac.uk
> > http://lists.strath.ac.uk/mailman/listinfo/esp-r
> 

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