HB & HB+ Gridbased vs Annual Daylight Simulation

[evefarrugia]

Hi!

I set up a daylight simulation with two panels receiving indirect light from the ground.

I have set it up using the HB annual simulation, HB gridbased simulation, HB+ annual simulation and HB+ grid based simulation using the same geometry, test points, weather data and material data for a particular hour (HOY = 15).

Firstly, there is a large difference in results between the four different simulations.

And secondly, the HB+ Annual Daylight Simulation results in weird scattered results – with the same exact pattern forming in both the top and bottom panel. HB+ components have been updated.

Can anyone help? Perhaps there is something I am missing?
Results from HB simulation (Grid Based left Annual right)

Results from HBplus simulation (Grid Based left Annual right)

GH file attached.
HBDaylight_Comparison.gh (580.7 KB)
Thanks!!

[MDB]

Hi,

Does anyone know why there is this difference in irradiation levels between the 4 simulations? I know there are quite a few other threads that look at the differences between Radiance and Daysim, but the difference here is >15%, which I think quite big to just down to the calculation methodology. Any help would be much appreciated!

Thanks!