I’ve done something similar and it worked.
Another approach is to run two Simulation, one with a reflectance set very low on the PV.
And then compare those.
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Thank you for your response! Could you please elaborate? do you mean one with little reflectance and another with the actual PV reflectance and then compare both?
When I set the -ab to 0 the irradiance results just do not make sense. So I believe that the workflow will be lower reflectance with -ab 1 and higher reflectance with -ab 2?
Thanks
Hi.
I would not change -ab to do this, as you will loose a lot of energy from bounces.
just run one with -ab over 3 with the correct reflection, and another with a very low reflection. And then compare those.
This should give you a sensible answer, if i understand what you are working on correctly.
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We usually rely Veiling Luminance where I work. you could use the 500 cd/m2 as an upper threshold.
My issue is mainly that we cannot run annually for the VL. it only works for DGP which is as you know already, suitable for indoor only.
I have been looking for the same thing for long. I use the Veiling luminance as a metric to identify glare in a PIT. However, since this cannot be processed annually, I do a raytracing study, and I add set the receptor (viewer i.e., window, or vehicle driver…) as part of the context to include it in the calculations. Then after a loooong annual run, depending on how big is the reflecting surface (e.g., facade), I pick the vectors that reaches the receptors (which could be too 100s of vectors), and I find the time and date when it occours. in the end I select few times to test VL using PIT.
It is such a long and painful process, and each assessment I seed to do alot.
I am soory I can not share an example due to company policy. but hopefully you could benifit from this methodology.
And feel free to share if any better way…
Hi Chris, thanks for your efforts here.
Apparently am not the only one nagging for a more advanced external glare components.
Since running Grid Based Veiling Luminance study similar to the DGP seems not easy to do atm. Could we improve the Raytracing component as this will help identify the times were we could test PIT?
My main issues with the RT component are:
1- 3 issues with Raytracing;
1- we cannot set up a receptor (a final receptor where reflected light is reaching). This would eleminate thouthands of unneccessary rays and make the results more readable.
2- The script draws vectors on the reflecting surface even if there is a burier blocking the ray. in other words, if the ray is directed toward the reflecting surface, and there is a building in the way (added to the context), the component is still going to drop the ray and will bounce of the context. The problem here is that we end up with endless number of rays which are not even reaching the reflecting surface.
3- if a new component can simply identify the times when the reflection reaches the receptor.
4- a limitation I struggle with is the 1 hour interval in the Sunpath, which misses thouthands of minutes in such study which could be critical, as glare may occour in between the 1 hour interval.
And a minor request if you could add on/off toggle to the component. usually if runnung annual rays, it freezes for days.
Pardon me, last question, can we run such studies using pollination?
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