[Radiance-general] Evalglare - Luminance or Illuminance

Wed Nov 10 00:54:10 PST 2010

Hi Andrew,

you can download now the pdf-file of my dissertation now here:

http://www.ise.fraunhofer.de/veroeffentlichungen/nach-jahrgaengen/2010/buecher-und-beitraege-zu-buechern/dayligth-glare-in-offices

The layout is in A5, the font may appear large if you print it on A4 or
letter size.
If you want a printed version, you can order it also in any on-line
bookshop.

Cheers,

Jan

Bissell, Andrew wrote:
>
> Thanks Jan, very much appreciate the quick response.  I look forward
> to reading your dissertation.
>
>  
>
> Regards
>
>  
>
> Andrew
>
> __________________________
> *Andrew Bissell*
>
> B.Eng(Hons) C.Eng MSLL MCIBSE MIET
> Associate Lighting Designer
>
> Cundall *Light4*
> Direct: 0161 200 1235
> Mobile: 07899 907 978
>
> Office: 0161 244 5660
>
> P Please consider the environment before printing this e-mail
>
>  
>
> *From:* radiance-general-bounces at radiance-online.org
> [mailto:radiance-general-bounces at radiance-online.org] *On Behalf Of
> *Jan Wienold
> *Sent:* 04 October 2010 17:23
> *To:* Radiance general discussion
> *Subject:* Re: [Radiance-general] Evalglare - Luminance or Illuminance
>
>  
>
> Hi Andrew,
>
> yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image.
> Internally it calculates the vertical illuminance as Greg mentioned
> before.
>
> A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).
>
> At the last building simulation conference, I suggested some "glare
> classes" based on user assessments, which may help to interpret the
> DGP values.
> (table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf
> ). Further details can be found also in my dissertation "Daylight
> Glare in Offices", which will be available in some days as pdf on our
> web-site.
>
>
> Cheers,
>
> Jan
>
>
> Greg Ward wrote:
>
> Hi Andrew,
>  
> You definitely want a luminance image -- using -i would give you wrong results.  Evalglare should add up luminances with the appropriate weighting to get vertical illuminance at the eye.
>  
> Cheers,
> -Greg
>  
>   
>
>     From: "Bissell, Andrew" <a.bissell at cundall.com> <mailto:a.bissell at cundall.com>
>
>     Date: October 2, 2010 1:07:53 PM PDT
>
>      
>
>     Sorry for what must be obvious questions.  I have just compiled evalglare for Linux and I have run a few test images albeit the images were very low res.  I have read various papers and posts on the net and seen the images referred to as luminance images and illuminance images.  So which is it?  Part of me says luminance as brightness is more relative to glare, on the other hand my understanding of DGP is that it measures illuminance at the eye.  Which led to me confusing myself over the type of image required.  Certainly if you try both, the results are different, however the images I am using are crude with just 1 bounce so that could easily explain the difference.
>
>      
>
>      
>
>      
>
>     Also I read the luxeuropa2005.pdf on the evaluation method etc.  However I was still at a loss as to what the DGP results really meant.  E.g. if the DGP result is 0.4756 what does that mean.  The document talked about levels below 0.2 not being reliable. 
>
>      
>
>      
>
>      
>
>     The other evalglare posts were useful wrt –vth and –vta, also the picture header.  Thank you.
>
>      
>
>      
>
>      
>
>     Regards
>
>      
>
>      
>
>      
>
>     Andrew
>
>      
>
>         
>
>  
> _______________________________________________
> Radiance-general mailing list
> Radiance-general at radiance-online.org <mailto:Radiance-general at radiance-online.org>
> http://www.radiance-online.org/mailman/listinfo/radiance-general
>   
>
>
>
>
> -- 
> Dipl.-Ing. Jan Wienold
> Project Manager
> Fraunhofer-Institut für Solare Energiesysteme
> Thermal Systems and Buildings, Lighting and Daylighting
> Heidenhofstr. 2, 79110 Freiburg, Germany
> Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
> jan.wienold at ise.fraunhofer.de <mailto:jan.wienold at ise.fraunhofer.de>
> http://www.ise.fraunhofer.de
>  
> In office: 
> Mo,Tue: 8:30-18:00
> We,Thu: 8:30-16:00
> Fr:  8:30-15:30
> ------------------------------------------------------------------------
> Cundall Johnston & Partners LLP is a limited liability partnership
> registered in England and Wales. Registered number OC300389.
> Registered office: Horsley House, Regent Centre, Gosforth, Newcastle
> upon Tyne, NE3 3LU
> Privilege and Confidentiality Notice: Use of this email and any
> attachments is subject to the terms on our Website at
> http://www.cundall.com/email.htm
> If you cannot access these terms, please email terms at cundall.com with
> SEND TERMS in the subject heading or telephone +44 (0191) 213 1515 and
> we will send you a copy.
> ------------------------------------------------------------------------
> This email message has been scanned for viruses by Mimecast. For more
> information please visit http://www.mimecast.com
> ------------------------------------------------------------------------

-- 
Dr.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
jan.wienold at ise.fraunhofer.de
http://www.ise.fraunhofer.de

In office: 
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr:  8:30-15:30

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://radiance-online.org/pipermail/radiance-general/attachments/20101110/b29ab64c/attachment.htm