Mean radiant temperature modeling in HB[+]


I am trying to collect information on the way mean radiant temperature is modeled by Ladybug (new version). I know that the new tools rely on radiance for the view factor calculation and solar reflections. However, it is not clear to me which one is the underlying formulation: has it changed from previous versions? I have found some older references with a formulation based on ERF (solar part) + a formulation considering the view factors and surface temperatures (but not emissivity values) of surrounding elements for longwave radiation. Is there an updated description of the formulation?

Are reflections of shortwave radiation calculated for the diffuse solar radiation also? (I noticed that in the HB UTCI Comfort Map component refers to “direct sun”). Moreover, the calculation includes multiple reflections of shortwave radiation, right? I noticed it is possible to change the “ambient bounce” in Radiance parameters, which is set to 2 by default, so I guess it does – I just need confirmation.

The emissivity of the surrounding surfaces is taken into account for the longwave radiation exchanges in the new model?

Thank you in advance