Colibri simulation with double glazing


I have some issues regarding daylight simulation for a zone within another glazed zone (see picture below).

I am testing different light transmittance for each glazing and running it through colibri. The results are listed below.

As you see the daylight factor does not change for the inner zone glazing. But when i run it without Colibri the value is different. Why does this happen? (539.4 KB)

Thanks in advance, hope someone can help :slight_smile:

Best regards
Tobias Kristiansen

Hi @TK,

Apparently, you need to show more decimals:

Thank you for your reply @MingboPeng,

There is a much greater difference in the results between the different glazings when I run the simulations separately. Does Colibri have any particular settings witch change the results when simulating several parameters?

Hi @TK,

I am not sure what you meant by “greater difference”, how big? could you show screenshots?.
I don’t think this has anything to do with Colibri.
Did you try to run the same simulation twice manually? You will get slightly difference result numbers, which is the nature of daylight simulations.

Thank you again @MingboPeng ,

I did an simulation with T_glazing 0.6% and T_facade 0.6%:

And another with T_glazing 0.7% and T_facade 0.6%:

And last one with T_glazing 0.8% and T_facade 0.6%:

As you see the average daylightfactor varies from 1,43 % to 2,67%. While the colibri simulation only goes from 1,43667% to 1,4352% (almost static), in addition the daylightfactor decreases while the glazing transmittance value increases, wich don’t make sense, since more light is transmitted through the glass.

Thanks again, best regards


What are your input Radiance parameters for recipe. Can it be just because the parameters are two low and the result can randomly change each time?

I think I know why, you have two materials with the exact same name, they are overriding each other.

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You are absolutely right @MingboPeng. I did not notice. I did new simulations and it is working now. Thank you so much!

Thank you also @mostapha for engaging in the conversation.

This looks more correct.

Thanks again for the help.

Best regards
Tobias Kristiansen