LEED Option 1 DA Threshold

Hi all,

I’ve been enjoying testing the LEED Option 1 Pollination recipe! If I’m right, the DA threshold is 300 lx, but I was wondering whether it’s possible to set it at 200 lx (for WELL L01 you need sDA200/40%). Is there any way to set this threshold manually?

I’ve tried taking the “results” and inputting these data into the regular LB 1.7.0 DaylightMetrics component, however I get different results (even leaving the default threshold at 300 lx).

They only give the same results when the shade transmittance = 1, suggesting that what comes out of “results” is the regular illuminance data without the 2% rule applied, whereas what comes out of “DA” includes the 2% rule. Is that right?

In summary, is it possible to manually set the DA threshold, and, more broadly, is it possible to output the raw .ill files with the 2% rule applied so that I can see the blinds’ effect on other metrics (cDA, UDI etc)???



Hi @jroberts,

Thanks for the questions!

That is correct.

Both of these are possible.

DA (and other) thresholds
We can add a thresholds recipe input similar to the one in annual-daylight, so you can customize the following:

  • Illuminance threshold for daylight autonomy (default: 300)
  • Illuminance threshold for annual sunlight exposure (default: 1000)
  • Max occupied hours above threshold for annual sunlight exposure (default: 250)
  • Target (percentage of) time for spatial daylight autonomy (default: 50)

The only reason why I would be hesitant to expose this as a recipe input, is that as soon as you change any of the values you are no longer calculating LEED Daylight Option 1, and we do not want users to mistakenly think that they can achieve credits by changing the default values.

One way to counter this could be to simply hard code the credits to be 0 if any of these thresholds are not the default value. @mostapha, what do you think about this?

Results with 2%
The illuminance arrays with the 2% rule are created in full for each grid during the post-processing, so it is just a matter of writing the NumPy arrays to a secondary results folder. I imagine we can add a new flavor of the recipe with a full tag which will also output the modified results folder.

Hi @mikkel,

I see what you mean about LEED confusion… maybe you could hard code the requirements for IES LM-83-12 and leave the other parameters as customisable. Just an idea, but then you might have to change the name of the recipe component haha :smiley:

In any case, it would be great to see these options in the future.

Thank you!