Forum discussion
Hi everyone,
We're actually working on a project in France. Lighting system suppliers only give us the Photometric curv in cd/klm and no in cd/m². The EN 12464 defines luminance with UGR (Unified Glare Rating). Do you know if this indicator can be used ? Which thresholds do we have to take ?
I know that WELL Building Standard have an equivalency with an UGR < 19 for its luminance credit.
Thank you in advance,
Best regards
Marius
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Dionisio Franca
DirectorWoonerf Inc.
30 thumbs up
November 13, 2017 - 6:07 am
Hi Marius,
UGR seems like a good metric. You will probably have to apply for equivalency or for a alternative adherence path in order to be sure you can use UGR instead of cd/m2.
Pedro Julio Silva Perez
MrDINPRO SA
December 6, 2017 - 6:58 pm
Hi everyone,
I've evaluated some ligthing fixtures whit the Software Visual photometric Tool: https://www.usgbc.org/resources/visual-photometric-tool
This software rate the ligting fixtures from the IES phtometric file. This tool rate the ligthing fixtures for the BUG rating metod and also estimate the cd/m2 for diferents angles. May it be the information required to support the A Strategy?
This is a sample output PDF file from the software: https://www.dropbox.com/s/qawv0pnrvy03xh5/HBLED-LD5-24SE-N-UNV-L850-ED2-...
The software show a AVERAGE LUMINANCE (CD/M2) table. I Think whit this information you may meet the requierement. Actually I'm whit the same trouble
Kera Lagios
High Performance SpecialistEHDD
16 thumbs up
December 6, 2017 - 8:26 pm
Hello Pedro,
Yes, the table you highlighted shows the information required you need to use for the credit (although, in your example, the values in exceed the allowable levels).
Best,
Kera
Alberto Barbera
June 29, 2021 - 7:39 am
Dear Kera,
Does this equivalency between UGR<19 and <2500Cd/sqm is feasible, as per your experience, for the interior lighting quality credit, strategy A?
Best regards,
Alberto
Glenn Heinmiller
PrincipalLam Partners
100 thumbs up
June 29, 2021 - 11:16 am
Alberto,
Here are a few pieces of information that might be helpful.
1. The 2500 cd/m2 limit in the v4 version of the interior lighting credit is pretty much impossible to meet. It is a mistake in the credit that was never fixed.
2. You might want to consider using the v 4.1 version of the credit (you can use either version). In the 4.1 version the limit is 7000 cd/m2 max between 45 and 90 degrees.
3. There is no "equivalency" between UGR and cd/m2.
4. The UGR <19 option for glare control in the v4.1 version of the credit requires UGR computer modeling of the designed space (using AGI or Dialux). You cannot use manufacturer-supplied fixture based UGR ratings using the tabular method
Alberto Barbera
June 30, 2021 - 3:05 am
Dear Glenn,
Thank you very much for your reply. This requirement was driving us absolutely mad.
Best regards,
Alberto