Green Star specifies that for daylighting simulations:
…the project team must demonstrate that the software is based on the Radiance simulation engine, and that it uses the statistical sky, the daylight coefficients and Perez All Weather Sky model, or the annual CIE sky simulation algorithms.
Can someone please tell me if the following definition fulfils the above (or how to find out whether this is the case)?
Hi @MaxMarschall, the answer is yes but I’m not sure! Mainly because I don’t know what they mean by including all these types in one statement! The results can vary based on which one of these sky types you will be using. Do they have any place that they are more specific about which one to be used for what?
it uses the statistical sky, the daylight coefficients and Perez All Weather Sky model, or the annual CIE sky simulation algorithms.
@sarith, any thoughts on this?
Thanks @mostapha,
This is the whole section for reference:
It seems a bit clumsily worded, but there is an “or” in that list so I’m assuming any one of those need to apply…I’m fairly confident that we are in the clear. Also because Green Star allows several methods to assess daylighting, of which the dynamic simulation approach is the most granular (others including simple hand calculations and markups in plans etc.).
Yes to all of the above!
Both HB-Legacy and HB[+] employ Radiance as the back-end calculation engines. HB[+] uses Radiance directly and HB-Legacy uses Daysim. The core binaries in Daysim are “inherited” from Radiance and the sky model it uses is the Perez Sky Model.
PS: “Statistical sky” is a fancy way of saying that the luminance mapping of the sky model is derived parametrically from weather-based data. In the case of the Perez Sky Model these are location data like longitude, latitude, time and radiation (direct-normal radiation and diffuse-horizontal radiation).
